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TABLE OF CONTENTS
INDEX TO FINANCIAL STATEMENTS
ANNEX A TABLE OF CONTENTS

As filed with the United States Securities and Exchange Commission on December 26, 2017February 12, 2018

Registration No. 333-221734

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

Amendment No. 17
to
FORM S-4
REGISTRATION STATEMENT
UNDER
THE SECURITIES ACT OF 1933

Avista Healthcare Public Acquisition Corp.
(Exact Name of Registrant as Specified in its Charter)

65 East 55th Street
18th Floor
New York, New York
(212) 593-6900
(Address, including zip code, and telephone number, including area code, of Registrant's principal executive offices)

Ben Silbert
General Counsel and Secretary
Avista Healthcare Public Acquisition Corp.
65 East 55th Street
18th Floor
New York, NY 10022
Telephone: (212) 593-6900
Facsimile: (212) 593-6901
(Name, address, including zip code, and telephone number, including area code, of agent for service)

Approximate date of commencement of proposed sale of the securities to the public: As soon as practicable after this Registration Statement is declared effective and all other conditions to
the business combination described in the enclosed Proxy Statement/Prospectus have been satisfied or waived.

          If the securities being registered on this Form are being offered in connection with the formation of a holding company and there is compliance with General Instruction G, check the following box:    o

          If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering:    o

          If this Form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering:    o

          Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See the definitions of "large accelerated filer", "accelerated filer", "smaller reporting company" and "emerging growth company" in Rule 12b-2 of the Exchange Act.

          If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act . o

          If applicable, place an X in the box to designate the appropriate rule provision relied upon in conducting this transaction:

          The Registrant hereby amends this Registration Statement on such date or dates as may be necessary to delay its effective date until the Registrant shall file a further amendment which specifically states that this Registration Statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933 or until the Registration Statement shall become effective on such date as the United States Securities and Exchange Commission, acting pursuant to said Section 8(a), may determine.

*

The Registrant intends, subject to shareholder approval, to effect a domestication under Section 388 of the Delaware General Corporation Law, pursuant to which the Registrant's state of incorporation shall be Delaware.

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The information in this preliminary proxy statement/prospectus is not complete and may be changed. The registrant may not sell the securities described herein until the registration statement filed with the United States Securities and Exchange Commission is declared effective. This preliminary proxy statement/prospectus is not an offer to sell these securities and it is not soliciting an offer to buy these securities in any jurisdiction where the offer or sale is not permitted.

PRELIMINARY PROXY STATEMENT/PROSPECTUS—SUBJECT TO COMPLETION, DATED DECEMBER 26, 2017FEBRUARY 12, 2018

PROXY STATEMENT/PROSPECTUS FOR ANNUAL GENERAL MEETING OF AVISTA HEALTHCARE PUBLIC ACQUISITION CORP.

PROSPECTUS FOR
31,000,000 UNITS
(EACH UNIT COMPRISING ONE SHARESHARES OF CLASS A COMMON STOCK AND
ONE WARRANT TO PURCHASE ONE-HALF OF ONE SHARE OF CLASS A COMMON STOCK); 31,000,000 SHARES OF CLASS A COMMON STOCK; AND 31,000,000 WARRANTS TO PURCHASE ONE-HALF OF ONE SHARE OF CLASS A COMMON STOCK

        The board of directors (the "AHPAC Board") of Avista Healthcare Public Acquisition Corp., a Cayman Islands exempted corporation ("AHPAC"), has unanimously approved the domestication of AHPAC as a Delaware corporation in accordance with Section 388 of the Delaware General Corporation Law and the Cayman Islands Companies Law (2016 Revision) (the "domestication"), the merger of a subsidiary of AHPAC with and into Envigo International Holdings, Inc., a Delaware corporation ("Envigo"), with Envigo surviving the merger as a wholly owned direct subsidiary of AHPAC (the "first merger"), the merger of Envigo with and into a subsidiary of AHPAC, with the subsidiary of AHPAC surviving the merger as a wholly owned direct subsidiary of AHPAC (the "second merger") and the other transactions contemplated by the Transaction Agreement, dated as of August 21, 2017, by and among AHPAC, certain of AHPAC's subsidiaries, Envigo and Jermyn Street Associates LLC, solely in its capacity as shareholder representative (in such capacity, the "Shareholder Representative"), as amended on November 22, 2017, December 22, 2017, January 21, 2018 and February 9, 2018 a copy of which is attached to this proxy statement/prospectus asAnnex A. After the domestication, AHPAC will change its name to "Envigo International Holdings, Inc.". We refer to AHPAC following the effectiveness of the domestication as "ENVG".

        Upon effectiveness of the domestication, ENVG's issued and outstanding share capital will consist of: (i) shares of Class A common stock, par value $0.0001 per share ("ENVG Class A common stock") issued in exchange for outstanding Class A ordinary shares, par value $0.0001 per share, of AHPAC ("AHPAC Class A ordinary shares"), (ii) warrants to purchase one-half of one share of ENVG Class A common stock ("ENVG public warrants") issued in exchange for outstanding warrants to purchase one-half of one share of AHPAC Class A ordinary shares and (iii) shares of Class B common stock, par value $0.0001 per share ( "ENVG Class B common stock") issued in exchange for outstanding Class B ordinary shares, par value $0.0001 per share, of AHPAC ("AHPAC Class B ordinary shares").

        The AHPAC units, AHPAC Class A ordinary shares and warrants to purchase AHPAC Class A ordinary shares are currently listed on the NASDAQ Capital Market ("NASDAQ") under the symbols "AHPAU", "AHPA" and "AHPAW", respectively. AHPAC has applied to continue the listing of the ENVG Class A common stock and ENVG public warrants, to be effective upon the consummation of the business combination, on NASDAQ under the proposed symbols "ENVG" and "ENVGW", respectively.

        This proxy statement/prospectus provides you with detailed information about the mergers and other matters to be considered at the annual general meeting. We encourage you to carefully read this entire document and the documents incorporated herein by reference. You should also carefully consider the risk factors described in "Risk Factors" beginning on page [37]37 of this proxy statement/prospectus.

        Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of the transactions described in this proxy statement/prospectus, passed upon the fairness of the Transaction Agreement or the transactions contemplated thereby, or passed upon the adequacy or accuracy of this proxy statement/prospectus. Any representation to the contrary is a criminal offense.

        This proxy statement/prospectus is dated [    ·    ], 2017,2018, and is first being mailed to AHPAC's shareholders on or about [    ·    ], 2017.2018.

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PRELIMINARY PROXY STATEMENT/PROSPECTUS—SUBJECT TO COMPLETION, DATED DECEMBER 26, 2017FEBRUARY 12, 2018

AVISTA HEALTHCARE PUBLIC ACQUISITION CORP.
A Cayman Islands Exempted Company
(Company Number 306402)
65 East 55th Street
18th Floor
New York, NY 10022

Dear Avista Healthcare Public Acquisition Corp. Shareholders:

            You are cordially invited to attend the annual general meeting of Avista Healthcare Public Acquisition Corp., a Cayman Islands exempted company ("AHPAC"), on [    ·    ] at [    ·    ] Eastern Time at the offices of Weil, Gotshal & Manges LLP, located at 767 Fifth Avenue, New York, NY 10153. This proxy statement/prospectus is dated [    ·    ] and is first being mailed to shareholders of AHPAC on or about [    ·    ].

            At the annual general meeting, which we refer to as the "general meeting", AHPAC shareholders will be asked to consider and vote upon a proposal, which is referred to herein as the "Business Combination Proposal" or "Proposal No. 1", to approve and adopt the Transaction Agreement, dated August 21, 2017, as amended on November 22, 2017, December 22, 2017, January 21, 2018 and February 9, 2018 (as it may be further amended from time to time, the "Transaction Agreement"), by and among AHPAC, Avista Healthcare Merger Sub, Inc., a wholly-owned subsidiary of AHPAC ("AHPAC Merger Sub"), Avista Healthcare NewCo, LLC, a wholly-owned subsidiary of AHPAC ("AHPAC NewCo"), Envigo International Holdings, Inc. ("Envigo") and Jermyn Street Associates LLC, solely in its capacity as shareholder representative, a copy of which is attached to the accompanying proxy statement/prospectus asAnnex A, and the transactions contemplated thereby. The Transaction Agreement provides for, among other things, an integrated transaction consisting of the merger of AHPAC Merger Sub with and into Envigo, with Envigo surviving the merger (the "first merger"), and then immediately thereafter, the merger of Envigo with and into AHPAC NewCo, with AHPAC NewCo surviving the merger (the "second merger," and together with the first merger, the "mergers").

            As a condition to consummating the mergers pursuant to the terms of the Transaction Agreement, the board of directors of AHPAC (the "AHPAC Board") has unanimously approved a change of AHPAC's jurisdiction of incorporation by deregistering as an exempted company in the Cayman Islands and continuing and domesticating as a corporation incorporated under the laws of the State of Delaware, which we refer to as the "domestication", and together with the mergers, the "business combination." To effect the domestication, AHPAC will file a notice of de-registration with the Cayman Islands Registrar of Companies, together with the necessary accompanying documents, and file a certificate of incorporation and a certificate of corporate domestication with the Secretary of State of the State of Delaware, under which AHPAC will be domesticated and continue as a Delaware corporation. After the domestication, AHPAC will change its name to "Envigo International Holdings, Inc." We refer to AHPAC following effectiveness of the domestication as "ENVG." On the effective date of the domestication, each currently issued and outstanding Class A ordinary share, par value $0.0001 per share, of AHPAC, which we refer to as "AHPAC Class A ordinary shares", will be exchanged, on a one-for-one basis, for a share of Class A common stock, par value $0.0001 per share, of ENVG, which we refer to as "ENVG Class A common stock". Similarly, each currently issued and outstanding Class B ordinary share, par value $0.0001 per share, of AHPAC, which we refer to as "AHPAC Class B ordinary shares", will be exchanged, on a one-for-one basis, for a share of Class B common stock, par value $0.0001 per share, of ENVG, which we refer to as "ENVG Class B common stock". In addition, all outstanding warrants to acquire AHPAC Class A ordinary shares will be exchanged for warrants to acquire a corresponding number of shares of ENVG Class A common stock on the same terms as in effect immediately prior to the effective time of the domestication. No other changes will be made to the terms of any outstanding warrants to acquire AHPAC Class A ordinary shares as a result of the domestication. See the section entitled "Proposal No. 2—The Domestication Proposal."

            You will also be asked to consider and vote upon (i) nine separate proposals to approve material differences between AHPAC's existing amended and restated memorandum and articles of association and the proposed new certificate of incorporation of ENVG following the domestication, which we refer to as the "Charter Proposals", (ii) a proposal to elect seven directors to ENVG's board of directors for staggered terms, which we refer to as the "Director Election Proposal" or "Proposal No. 12", (iii) a proposal to approve and adopt the Envigo International Holdings, Inc. 2017 Omnibus2018 Equity Incentive Plan and the material terms thereunder, which we refer to as the "Management Incentive Plan Proposal" or "Proposal No. 13", (iv) a proposal to approve for purposes of complying with applicable provisions of NASDAQ Listing Rule 5635, the issuance of more than 20% of AHPAC's issued and outstanding ordinary shares (or issued and outstanding common stock following the domestication) to the Selling Equityholders in connection with the business combination and to participants in the equity financing (if any), that may be deemed a change of control, which we refer to as the "NASDAQ Proposal" or "Proposal No. 14.", and (v) a proposal to approve the adjournment of the general meeting to a later date or dates, if necessary, to permit further solicitation and vote of proxies in the event that there are insufficient votes for the approval of one or more proposals at the general meeting, which we refer to as the "Adjournment Proposal" or "Proposal No. 15." The transactions contemplated by the Transaction Agreement will be consummated only if the Business Combination Proposal, the Domestication Proposal the Charter Proposals and the NASDAQ Proposal are approved at the general meeting. Each of these proposals is conditioned upon approval of these proposals, other than the Adjournment Proposal which is not conditioned upon the approval of any other proposal.

            Subject to the terms of the Transaction Agreement and customary adjustments set forth therein, the aggregate purchase price payable to the holders of equity interests in Envigo immediately prior to the effective time of the first merger, which are collectively referred to as the "Selling Equityholders", in connection with the business combination and related transactions is expected to be approximately (a) $428.88$322.44 million (the "purchase price"), subject to adjustment as described in the following sentence, in cash and shares of ENVG Class A common stock, (b) 4.10 million warrants to purchase one-half of one share of ENVG Class A common stock and (c) amounts payable to the Selling Equityholders under the Tax Receivable Agreement substantially in the form attached to the accompanying proxy statement/prospectus asAnnex D (the "Tax Receivable Agreement"). The purchase price will be reduced by, among other things, the aggregate amount of transaction expenses incurred by Envigo in connection with the negotiation and consummation of the business combination plus the cost of the 4.10 million warrants being purchased from Avista Acquisition Corp., an affiliate of AHPAC (the "sponsor"), for distribution to the Selling Equityholders.combination. It is anticipated that this adjustment will result in a deduction toreduction of the purchase price ofby approximately $38.5$42.3 million (including non-cash expenses in the amount of $8.3$7.8 million). The cash component of the purchase price is subject to an aggregate limit on cash consideration of $100 million (which amount may be increased or reduced as described in the Transaction Agreement). The cash and stock consideration to be paid to the Selling Equityholders will be funded with approximately 39.8728.80 million newly issued shares of ENVG Class A common stock, which amount will be reduced to the extent certain Selling Equityholders elect to receive $10.00 in cash in lieu of each share of ENVG Class A common stock such Selling Equityholder would otherwise be entitled to receive, subject to an aggregate limit on cash consideration of $100 million (which amount may be increased or reduced as described in the Transaction Agreement), and the aforementioned cash.

            At the closing of the business combination, ENVG will enter into the Tax Receivable Agreement with Envigo Holdings, Inc. and the shareholder representative on behalf of the Selling Equityholders that are entitled to receive merger consideration in connection with the business combination. The Tax Receivable Agreement will generally provide for the future payments by ENVG to the Selling Equityholders of 85% of the U.S. federal, state, local and U.K. cash tax savings deemed realized (see "AHPAC's Management's Discussion and Analysis of Financial Condition and Results of Operations—Liquidity and Capital Resources—Tax Receivable Agreement" in the accompanying proxy statement/prospectus) by ENVG and its subsidiaries in post-closing taxable periods as a result of the utilization of net operating losses available to be carried forward as of the consummation of the transactions contemplated by the Transaction Agreement and the imputed interest deductions arising from payments under the Tax Receivable Agreement. Although the amount and timing of any payments under the Tax Receivable Agreement will vary depending on a number of factors, including the amount and timing of ENVG's income, AHPAC expects that the payments ENVG may make thereunder could be substantial. Under certain circumstances, ENVG's obligations under the Tax Receivable Agreement may be accelerated as specified therein.

            Additionally, at the closing of the business combination, AHPAC, the sponsor, certain directors of AHPAC and the Selling Equityholders that receive ENVG common stock (such directors and Selling Equityholders, and the sponsor, collectively being the "restricted stockholders") will enter into an Amended and Restated Registration Rights Agreement substantially in the form attached to the accompanying proxy statement/prospectus as Annex D, in respect of the shares of ENVG common stock and ENVG warrants issued to the restricted stockholders in connection with the business combination, providing for, among other things, customary registration rights, including demand and piggy-back rights, subject to cut-back provisions. See the section titled "The Transaction Agreement—Related Agreements—Amended and Restated Registration Rights Agreement" in the accompanying proxy statement/prospectus for more information.

            Each of these proposals is more fully described in the accompanying proxy statement/prospectus, which each shareholder is encouraged to review carefully.

            In connection with AHPAC's initial public offering (the "IPO"), the initial shareholders agreed to vote all their AHPAC Class B ordinary shares and any AHPAC Class A ordinary shares purchased during or after the IPO in favor of the business combination. Currently, the initial shareholders own approximately 20% of AHPAC's issued and outstanding ordinary shares, including all of the AHPAC Class B ordinary shares.

            Pursuant to AHPAC's existing amended and restated memorandum and articles of association, a holder of AHPAC's public shares ("public shares") may request that AHPAC redeem all or a portion of such shareholder's public shares (which will become shares of ENVG Class A common stock following the domestication) for cash if the business combination is consummated. Holders of units of AHPAC (the "AHPAC units") must elect to separate the underlying public shares and warrants ("public warrants") prior to exercising redemption rights with respect to the public shares. If holders hold their AHPAC units in an account at a brokerage firm or bank, holders must notify their broker or bank that they elect to separate the AHPAC units into the underlying public shares and public warrants, or if a holder holds units registered in its own name, the holder must contact the transfer agent directly and instruct it to do so.Public shareholders may elect to redeem their public shares even if they vote "for" the Business Combination Proposal. If the business combination is not consummated, such public shares will not be redeemed for cash. If a public shareholder properly exercises its right to redeem its public shares and timely delivers its shares to the transfer agent, and the

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business combination is consummated, AHPAC will redeem each public share for a per-share price, payable in cash, equal to the aggregate amount then on deposit

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in the trust account established in connection with the IPO (the "trust account"), calculated as of two business days prior to the consummation of the business combination, including interest, divided by the number of then issued and outstanding public shares. For illustrative purposes, as of NovemberJanuary 17, 2017,2018, this would have amounted to approximately $10.07$10.08 per public share. If a public shareholder exercises its redemption rights, then it will be exchanging its redeemed public shares for cash and will no longer own such shares. Holders of public warrants do not have redemption rights in connection with the business combination. See the section entitled "Annual General Meeting of AHPAC Shareholders—Redemption Rights" in the accompanying proxy statement/prospectus for a detailed description of the procedures to be followed if you wish to redeem your public shares for cash.

            Notwithstanding the foregoing, a holder of public shares, together with any affiliate of such public shareholder or any other person with whom such public shareholder is acting in concert or as a "group" (as defined in Section 13(d)(3) of the Securities Exchange Act of 1934, as amended), will be restricted from redeeming its public shares with respect to more than an aggregate of 15% of the public shares. Accordingly, if a public shareholder, alone or acting in concert or as a group, seeks to redeem more than 15% of the public shares, then any such shares in excess of that 15% limit would not be redeemed for cash.

We are providing the accompanying proxy statement/prospectus and accompanying proxy card to AHPAC's shareholders in connection with the solicitation of proxies to be voted at the general meeting and at any adjournments or postponements of the general meeting. Information about the general meeting, the business combination and other related business to be considered by AHPAC's shareholders at the general meeting is included in the accompanying proxy statement/prospectus.Whether or not you plan to attend the general meeting, we urge all of AHPAC's shareholders to read the accompanying proxy statement/prospectus, including the Annexes and the accompanying financial statements of AHPAC and Envigo, carefully and in their entirety. In particular, we urge you to read carefully the section entitled "Risk Factors" beginning on page [37]37 of the accompanying proxy statement/prospectus.

            After careful consideration, the AHPAC Board has unanimously approved the business combination and unanimously recommends that shareholders vote "FOR" adoption of the Transaction Agreement and approval of the transactions contemplated thereby, including the business combination, and "FOR" all other proposals presented to AHPAC's shareholders in the accompanying proxy statement/prospectus. When you consider the AHPAC Board's recommendation of these proposals, you should keep in mind that AHPAC's directors and officers have interests in the business combination that may conflict with your interests as a shareholder. Please see the section entitled "The Business Combination—Interests of Certain Persons in the Business Combination" in the accompanying proxy statement/prospectus for additional information.

            The approval of each of the Domestication Proposal and the Charter Proposals requires the affirmative vote of holders of two-thirds of the ordinary shares represented in person or by proxy and entitled to vote thereon at the general meeting. The Business Combination Proposal requires the affirmative vote of a majority of the ordinary shares represented in person or by proxy and entitled to vote thereon at the general meeting. The approval of each of the Director Election Proposal, the Management Incentive Plan Proposal, the NASDAQ Proposal and the Adjournment Proposal requires the affirmative vote of holders of a majority of the ordinary shares represented in person or by proxy and entitled to vote thereon at the general meeting.

            AHPAC may enter into equity financing in connection with the proposed business combination through a private placement offered to a limited number of accredited investors (as defined by Rule 501 of Regulation D) pursuant to Section 4(a)(2) of the Securities Act of 1933, as amended (the "equity financing"). The purpose of the equity financing includes raising additional funds, up to a maximum of $75 million, to fund the business combination and related transactions. The Transaction Agreement provides that any such equity financing be on terms reasonably satisfactory to Envigo. Any additional equity issuances, including in connection with the equity financing, may result in dilution of the relative ownership interest of the non-redeeming public shareholders. As the amount of any such equity issuances is not currently known, AHPAC cannot provide exact figures as to percentage ownership that may result therefrom.

            The Transaction Agreement provides that Envigo's obligation to consummate the business combination is conditioned on there being at least $260$220 million of available funds, collectively from the trust account and proceeds from the equity financing (if any), after giving effect to redemptions of public shares. This condition to closing is for the sole benefit of Envigo and may be waived only by Envigo. If as a result of redemptions of public shares by public shareholders the condition is not met, and the condition is also not waived by Envigo, then Envigo may terminate the Transaction Agreement and the proposed business combination may not be consummated. In addition, in no event will AHPAC redeem public shares in an amount that would cause its net tangible assets (as determined in accordance with Rule 3a51-1(g)(1) of the Exchange Act) to be less than $5,000,001.

            The initial shareholders have agreed to waive their redemption rights with respect to the Class B ordinary shares and with respect to any public shares they may hold in connection with the consummation of the business combination. The AHPAC Class B ordinary shares will be excluded from the pro rata calculation used to determine the per-share redemption price. Currently, the initial shareholders own approximately 20% of AHPAC's issued and outstanding ordinary shares, including all of the AHPAC Class B ordinary shares.

            The initial shareholders also have agreed to waive their rights to any adjustment to the ratio in which the AHPAC Class B ordinary shares will automatically convert into a number of shares of ENVG Class A common stock one business day following the consummation of the business combination. As a result, each share of ENVG Class B common stock will automatically convert into one share of ENVG Class A common stock one business day following the consummation of the business combination.

            Your vote is very important.    Whether or not you plan to attend the general meeting, please vote as soon as possible by following the instructions in the accompanying proxy statement/prospectus to make sure that your shares are represented at the general meeting. If you hold your shares in "street name" through a bank, broker or other nominee, you will need to follow the instructions provided to you by your bank, broker or other nominee to ensure that your shares are represented and voted at the general meeting. The transactions contemplated by the Transaction Agreement will be consummated only if the Business Combination Proposal, the Domestication Proposal, the Charter Proposals and the NASDAQ Proposal are approved at the general meeting. Each of the Business Combination Proposal, the Domestication Proposal, the Charter Proposals and the NASDAQ Proposal are cross-conditioned on the approval of each other. Each other proposal is conditioned on the approval of the Business Combination Proposal, the Domestication Proposal, the Charter Proposals and the NASDAQ Proposal, other than the Adjournment Proposal, which is not conditioned on the approval of any other proposal set forth in the accompanying proxy statement/prospectus.

            If you sign, date and return your proxy card without indicating how you wish to vote, your proxy will be voted FOR each of the proposals presented at the general meeting. If you fail to return your proxy card or fail to instruct your bank, broker or other nominee how to vote, and do not attend the general meeting in person, the effect will be, among other things, that your shares will not be counted for purposes of determining whether a quorum is present at the general meeting. If you are a shareholder of record and you attend the general meeting and wish to vote in person, you may withdraw your proxy and vote in person.

TO EXERCISE YOUR REDEMPTION RIGHTS, YOU MUST DEMAND IN WRITING THAT YOUR PUBLIC SHARES ARE REDEEMED FOR A PRO RATA PORTION OF THE FUNDS HELD IN THE TRUST ACCOUNT AND TENDER YOUR SHARES TO AHPAC'S TRANSFER AGENT AT LEAST TWO BUSINESS DAYS PRIOR TO THE VOTE AT THE GENERAL MEETING. YOU MAY TENDER YOUR SHARES BY EITHER DELIVERING YOUR SHARE CERTIFICATE TO THE TRANSFER AGENT OR BY DELIVERING YOUR SHARES ELECTRONICALLY USING DEPOSITORY TRUST COMPANY'S DWAC (DEPOSIT WITHDRAWAL AT CUSTODIAN) SYSTEM. IF THE BUSINESS COMBINATION IS NOT COMPLETED, THEN THESE SHARES WILL NOT BE REDEEMED FOR CASH. IF YOU HOLD THE SHARES IN STREET NAME, YOU WILL NEED TO INSTRUCT THE ACCOUNT EXECUTIVE AT YOUR BANK OR BROKER TO WITHDRAW THE SHARES FROM YOUR ACCOUNT IN ORDER TO EXERCISE YOUR REDEMPTION RIGHTS.

            On behalf of the AHPAC Board, I would like to thank you for your support and look forward to the successful completion of the business combination.

            NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE SECURITIES REGULATORY AGENCY HAS APPROVED OR DISAPPROVED THE TRANSACTIONS DESCRIBED IN THE ACCOMPANYING PROXY STATEMENT/PROSPECTUS, PASSED UPON THE MERITS OR FAIRNESS OF THE BUSINESS COMBINATION OR RELATED TRANSACTIONS OR PASSED UPON THE ADEQUACY OR ACCURACY OF THE DISCLOSURE IN THE ACCOMPANYING PROXY STATEMENT/PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY CONSTITUTES A CRIMINAL OFFENSE.

            The accompanying proxy statement/prospectus is dated [    ·    ] and is first being mailed to shareholders on or about [    ·    ].

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PRELIMINARY PROXY STATEMENT/PROSPECTUS—SUBJECT TO COMPLETION, DATED DECEMBER 26, 2017FEBRUARY 12, 2018

AVISTA HEALTHCARE PUBLIC ACQUISITION CORP.
A Cayman Islands Exempted Company
(Company Number 306402)
65 East 55th Street
18th Floor
New York, NY 10022

NOTICE OF ANNUAL GENERAL MEETING
TO BE HELD ON [    ·    ]], 2018

TO THE SHAREHOLDERS OF AVISTA HEALTHCARE PUBLIC ACQUISITION CORP.:

        NOTICE IS HEREBY GIVEN that an annual general meeting of Avista Healthcare Public Acquisition Corp., a Cayman Islands exempted company ("AHPAC"), will be held on [    ·    ]], 2018 at [    ·    ] Eastern Time at the offices of Weil, Gotshal & Manges LLP, located at 767 Fifth Avenue, New York, NY 10153 (the "general meeting"). You are cordially invited to attend the general meeting to conduct the following items of business:

1.

Proposal No. 1—The Business Combination Proposal—To consider and vote upon a proposal to approve and adopt the Transaction Agreement, dated August 21, 2017, as amended on November 22, 2017, December 22, 2017, January 21, 2018 and February 9, 2018 (as it may be further amended from time to time, the "Transaction Agreement"), by and among AHPAC, Avista Healthcare Merger Sub, Inc., AHPAC's direct wholly-owned subsidiary ("AHPAC Merger Sub"), Avista Healthcare NewCo, LLC, AHPAC's direct wholly-owned subsidiary ("AHPAC NewCo"), Envigo International Holdings, Inc., a Delaware corporation ("Envigo") and Jermyn Street Associates LLC, solely in its capacity as shareholder representative (in such capacity, the "Shareholder Representative"), a copy of which is attached to the accompanying proxy statement/prospectus asAnnex A, and the transactions contemplated thereby, including an integrated transaction consisting of the merger of AHPAC Merger Sub with and into Envigo, with Envigo surviving the merger (the "first merger"), and then immediately thereafter, the merger of Envigo with and into AHPAC NewCo, with AHPAC NewCo surviving the merger (the "second merger," and together with the first merger, the "mergers"), which we refer to as the "Business Combination Proposal";



2.

Proposal No. 2—The Domestication Proposal—To consider and vote upon a proposal to approve by special resolution, assuming the Business Combination Proposal is approved and adopted, the change of AHPAC's jurisdiction of incorporation by deregistering as an exempted company in the Cayman Islands and continuing and domesticating as a corporation incorporated under the laws of the State of Delaware (the "domestication," and together with the mergers, the "business combination"), which we refer to as the "Domestication Proposal";


The Charter Proposals—To consider and vote upon nine separate proposals to approve by special resolution, assuming the Business Combination Proposal and the Domestication Proposal are approved and adopted, the following material differences between AHPAC's existing amended and restated memorandum and articles of association and the proposed new certificate of incorporation and bylaws of AHPAC (which will be renamed "Envigo International Holdings, Inc." after consummation of the domestication and referred to herein as "ENVG" following the domestication) the "proposed certificate" and the "proposed bylaws", respectively.

3.

Proposal No. 3—To consider and vote upon an amendment to AHPAC's existing organizational documents to authorize the classification of the Board of Directors of ENVG into three classes of directors, which shall consist of, as nearly as may be possible, one-third of the total number of directors on the Board of Directors of ENVG, which will initially be seven (7) and then as may be set by the Board of Directors of ENVG from time to time;

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4.

Proposal No. 4—To consider and vote upon an amendment to AHPAC's existing organizational documents to authorize that directors may only be removed for cause;

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5.

Proposal No. 5—To consider and vote upon an amendment to AHPAC's existing organizational documents to authorize that only the Board of Directors of ENVG, chairperson of the board of directors or chief executive officer may call a meeting of stockholders;



6.

Proposal No. 6—To consider and vote upon an amendment to AHPAC's existing organizational documents to authorize removal of the ability of stockholders to take action by written consent in lieu of a meeting;



7.

Proposal No. 7—To consider and vote upon an amendment to AHPAC's existing organizational documents to require the affirmative vote of holders of a majority of the voting power of ENVG's then issued and outstanding shares of stock entitled to vote thereon to amend the proposed certificate;



8.

Proposal No. 8—To consider and vote upon an amendment to AHPAC's existing organizational documents to authorize the adoption of Delaware as the exclusive forum for certain stockholder litigation;



9.

Proposal No. 9—To consider and vote upon an amendment to AHPAC's existing organizational documents to authorize ENVG to permit the sponsor, Jermyn Street Associates, LLC and Savanna Holdings LLC and their respective affiliates (the "ENVG Sponsors") to engage in competitive businesses and renounce certain corporate opportunities offered to the ENVG Sponsors or any of their managers, officers, directors, agents, stockholders, members, partners, affiliates and subsidiaries (other than ENVG and its subsidiaries) that are not expressly offered to them in their capacities as directors or officers of ENVG;



10.

Proposal No. 10—To consider and vote upon an amendment to AHPAC's existing organizational documents to approve the authorized number of shares of ENVG common stock contained in the proposed certificate; and



11.

Proposal No. 11—To consider and vote upon an amendment to AHPAC's existing organizational documents to authorize other changes to the organizational documents resulting from the domestication and business combination, including changing the post-business combination corporate name from "Avista Healthcare Public Acquisition Corp." to "Envigo International Holdings, Inc." and removing certain provisions relating to our status as a blank-check company that will no longer apply upon consummation of the business combination.


Proposals No. 3-11 are collectively referred to as the "Charter Proposals";

12.

Proposal No. 12—The Director Election Proposal—To consider and vote upon a proposal to elect seven directors to serve staggered terms on ENVG's Board of Directors until the 2019, 2020 and 2021 annual meeting of shareholders, respectively, and until their respective successors are duly elected and qualified, which we refer to as the "Director Election Proposal";



13.

Proposal No. 13—The Management Incentive Plan Proposal—To consider and vote on a proposal to approve and adopt, assuming the Charter Proposals, the Domestication Proposal and the Business Combination Proposal are all approved and adopted, the Envigo International Holdings, Inc. 2017 Omnibus2018 Equity Incentive Plan (the "2017 Omnibus"2018 Equity Incentive Plan") and the material terms thereunder, which we refer to as the "Management Incentive Plan Proposal". A copy of the 2017 Omnibus2018 Equity Incentive Plan is attached to the accompanying proxy statement/prospectus asAnnex G;



14.

Proposal No. 14—The NASDAQ Proposal—To consider and vote upon a proposal to approve, assuming the Charter Proposals, the Domestication Proposal and the Business Combination Proposal are all approved and adopted, for purposes of complying with applicable provisions

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of NASDAQ Listing Rule 5635, the issuance of more than 20% of AHPAC's issued and outstanding ordinary shares (or issued and outstanding common stock following the domestication) to the Selling Equityholders in connection with the business combination and

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to participants in the equity financing (if any), that may be deemed a change of control, which we refer to as the "NASDAQ Proposal"; and

15.

Proposal No. 15—Adjournment Proposal—To consider and vote upon a proposal to approve the adjournment of the general meeting to a later date or dates, if necessary, to permit further solicitation and vote of proxies in the event that there are insufficient votes for, or otherwise in connection with, the approval of one or more proposals to be submitted for shareholder approval at the general meeting, which we refer to as the "Adjournment Proposal."

        The above matters are more fully described in the accompanying proxy statement/prospectus, which also includes asAnnex A a copy of the Transaction Agreement.We urge you to read carefully the accompanying proxy statement/prospectus in its entirety, including the Annexes and accompanying financial statements of AHPAC and Envigo.

        The record date for the general meeting is [    ·    ].January 16, 2018. Only shareholders of record at the close of business on that date may vote at the general meeting or any adjournment thereof.

        We are providing the accompanying proxy statement/prospectus and accompanying proxy card to AHPAC's shareholders in connection with the solicitation of proxies to be voted at the general meeting and at any adjournments or postponements of the general meeting. Information about the general meeting, the business combination and other related business to be considered by AHPAC's shareholders at the general meeting is included in this proxy statement/prospectus.Whether or not you plan to attend the general meeting, we urge all of AHPAC's shareholders to read the accompanying proxy statement/prospectus, including the Annexes and the accompanying financial statements of AHPAC and Envigo, carefully and in their entirety.

        IN PARTICULAR, WE URGE YOU TO READ CAREFULLY THE SECTION ENTITLED "RISK FACTORS" BEGINNING ON PAGE [37]37 OF THE ACCOMPANYING PROXY STATEMENT/PROSPECTUS.

        After careful consideration, the AHPAC Board has unanimously approved the business combination and unanimously recommends that shareholders vote "FOR" adoption of the Transaction Agreement and approval of the transactions contemplated thereby, including the business combination, and "FOR" all other proposals presented to AHPAC's shareholders in the accompanying proxy statement/prospectus. When you consider the AHPAC Board's recommendation of these proposals, you should keep in mind that AHPAC's directors and officers have interests in the business combination that may conflict with your interests as a shareholder. Please see the section entitled "The Business Combination—Interests of Certain Persons in the Business Combination" for additional information.

        On the effective date of the domestication, each currently issued and outstanding Class A ordinary share, par value $0.0001 per share, of AHPAC, which we refer to as "AHPAC Class A ordinary shares", will be exchanged, on a one-for-one basis, into a share of Class A common stock, par value $0.0001 per share, of ENVG, which we refer to as "ENVG Class A common stock". Similarly, each currently issued and outstanding Class B ordinary share, par value $0.0001 per share, of AHPAC, which we refer to as "AHPAC Class B ordinary shares", will be exchanged, on a one-for-one basis, into a share of Class B common stock, par value $0.0001 per share, of ENVG, which we refer to as "ENVG Class B common stock". In addition, all outstanding warrants to acquire AHPAC Class A ordinary shares will be exchanged for warrants to acquire a corresponding number of shares of ENVG Class A common stock on the same terms as in effect immediately prior to the effective time of the domestication. No other changes will be made to the terms of any outstanding warrants to acquire AHPAC Class A ordinary shares as a result of the domestication. See the section entitled "Proposal No. 2—The Domestication Proposal."

        As a result of the business combination, AHPAC will acquire Envigo. Subject to the terms of the Transaction Agreement and customary adjustments set forth therein, the aggregate purchase price

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payable to the Selling Equityholders in connection with the business combination and related transactions is expected to be approximately (a) $428.88$322.44 million, in cash and shares of ENVG Class A common stock, subject to certain adjustments, (b) 4.10 million warrants to purchase one-half of one

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share of ENVG Class A common stock and (c) amounts payable to the Selling Equityholders under the Tax Receivable Agreement. The cash component of the purchase price is limited to $100 million, subject to certain adjustments. A copy of the Transaction Agreement is attached to the accompanying proxy statement/prospectus asAnnex A.

        In connection with AHPAC's initial public offering (the "IPO"), the initial shareholders agreed to vote all AHPAC Class B ordinary shares and any AHPAC Class A ordinary shares purchased during or after the IPO in favor of the business combination. Currently, the initial shareholders own approximately 20% of AHPAC's issued and outstanding ordinary shares, including all of the AHPAC Class B ordinary shares.

        Pursuant to AHPAC's existing amended and restated memorandum and articles of association, a holder of AHPAC's public shares ("public shares") may request that AHPAC redeem all or a portion of such shareholder's public shares (which will become shares of ENVG Class A common stock in the domestication) for cash if the business combination is consummated. For the purposes of Article 49.3 of AHPAC's amended and restated memorandum and articles of association and the Cayman Islands Companies Law (2016 Revision), the exercise of redemption rights shall be treated as an election to have such public shares repurchased for cash and references in the accompanying proxy statement/prospectus shall be interpreted accordingly. You will be entitled to receive cash for any public shares to be redeemed only if you:

(i)

(a) hold public shares or (b) hold public shares through units and you elect to separate your units into the underlying public shares and warrants prior to exercising your redemption rights with respect to the public shares;



(ii)

prior to [5:5:00 p.m.], Eastern Time, on [    ·    ], 2017,2018, submit a written request to Continental Stock Transfer & Trust Company, AHPAC's transfer agent (the "transfer agent"), that AHPAC redeem your public shares for cash; and



(iii)

deliver your public shares to the transfer agent, physically or electronically through Depository Trust Company ("DTC").

        Holders of AHPAC units must elect to separate the underlying public shares and warrants ("public warrants") prior to exercising redemption rights with respect to the public shares. If holders hold their AHPAC units in an account at a brokerage firm or bank, holders must notify their broker or bank that they elect to separate the AHPAC units into the underlying public shares and public warrants, or if a holder holds AHPAC units registered in its own name, the holder must contact the transfer agent directly and instruct it to do so.Public shareholders may elect to redeem their public shares even if they vote "for" the Business Combination Proposal. If the business combination is not consummated, the public shares will not be redeemed for cash. If a public shareholder properly exercises its right to redeem its public shares and timely delivers its shares to the transfer agent, AHPAC will redeem each public share for a per-share price, payable in cash, equal to the aggregate amount then on deposit in the trust account established in connection with the IPO (the "trust account"), calculated as of two business days prior to the consummation of the business combination, including interest, divided by the number of then issued and outstanding public shares. For illustrative purposes, as of NovemberJanuary 17, 2017,2018, this would have amounted to approximately $10.07$10.08 per public share. If a public shareholder exercises its redemption rights, then it will be exchanging its redeemed public shares for cash and will no longer own such shares. See the section entitled "Annual General Meeting of AHPAC Shareholders—Redemption Rights" in the accompanying proxy statement/prospectus for a detailed description of the procedures to be followed if you wish to redeem your public shares for cash.

        Notwithstanding the foregoing, a holder of public shares, together with any affiliate of such public shareholder or any other person with whom such public shareholder is acting in concert or as a "group" (as defined in Section 13(d)(3) of the Securities Exchange Act of 1934, as amended), will be

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restricted from redeeming its public shares with respect to more than an aggregate of 15% of the public shares. Accordingly, if a public shareholder, alone or acting in concert or as a group, seeks to

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redeem more than 15% of the public shares, then any such shares in excess of that 15% limit would not be redeemed for cash.

        AHPAC may enter into equity financing in connection with the proposed business combination through a private placement offered to a limited number of accredited investors (as defined by Rule 501 of Regulation D) pursuant to Section 4(a)(2) of the Securities Act of 1933, as amended (the "equity financing"). The purpose of the equity financing includes raising additional funds, up to a maximum of $75 million to fund the business combination and related transactions. Pursuant to the terms of the Transaction Agreement, AHPAC must use its commercially reasonable efforts to obtain such equity financing prior to the consummation of the business combination, on terms reasonably acceptable to Envigo.

        The Transaction Agreement provides that Envigo's obligation to consummate the business combination is conditioned on there being at least $260$220 million of available funds from the trust account and proceeds from the equity financing (if any), after giving effect to redemptions of public shares. This condition to closing is for the sole benefit of Envigo and may be waived only by Envigo. If, as a result of redemptions of public shares by public shareholders, the condition is not met or waived by Envigo, then the Transaction Agreement may terminate and the proposed business combination may not be consummated. As of [    ·    ], 2017January 17, 2018 there was approximately $[    ·    ]$312,497,921 in the Trust Account. Each redemption of shares will decrease the amount in the Trust Account. In no event will AHPAC redeem public shares in an amount that would cause its net tangible assets (as determined in accordance with Rule 3a51-1(g)(1) of the Exchange Act) to be less than $5,000,001. Holders of public warrants do not have redemption rights in connection with the business combination.

        The initial shareholders have agreed to waive their redemption rights with respect to AHPAC Class B ordinary shares, and with respect to any public shares they may hold in connection with the consummation of the business combination. The AHPAC Class B ordinary shares will be excluded from the pro rata calculation used to determine the per-share redemption price.

        The initial shareholders also have agreed to waive any adjustment to the ratio in which the AHPAC Class B ordinary shares will automatically convert into a number of shares of ENVG Class A common stock one business day following the consummation of the business combination. As a result, each share of ENVG Class B common stock will automatically convert into one share of ENVG Class A common stock one business day following the consummation of the business combination.

        The approval of each of the Domestication Proposal and the Charter Proposals requires the affirmative vote of two-thirds of the ordinary shares represented in person or by proxy and entitled to vote thereon at the general meeting. The Business Combination Proposal requires the affirmative vote of a majority of the ordinary shares represented in person or by proxy and entitled to vote thereon at the general meeting. The approval of each of the Director Election Proposal, the Management Incentive Plan Proposal, the NASDAQ Proposal and the Adjournment Proposal requires the affirmative vote of holders of a majority of the ordinary shares represented in person or by proxy and entitled to vote thereon at the general meeting.

        Your vote is very important.    Whether or not you plan to attend the general meeting, please vote as soon as possible by following the instructions in this proxy statement/prospectus to make sure that your shares are represented at the general meeting. If you hold your shares in "street name" through a bank, broker or other nominee, you will need to follow the instructions provided to you by your bank, broker or other nominee to ensure that your shares are represented and voted at the general meeting. The transactions contemplated by the Transaction Agreement will be consummated only if the Business Combination Proposal, the Domestication Proposal and the Charter Proposals are approved at the general meeting. Each of the Business Combination Proposal, the Domestication Proposal, the Charter Proposals and the NASDAQ Proposal are cross-conditioned on the approval of each other. Each other proposal is conditioned on the approval of the Business Combination Proposal, the Domestication Proposal, the Charter Proposals and the NASDAQ Proposal, other than the

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Adjournment Proposal, which is not conditioned on the approval of any other proposal set forth in this proxy statement/prospectus.

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        If you sign, date and return your proxy card without indicating how you wish to vote, your proxy will be voted FOR each of the proposals presented at the general meeting. If you fail to return your proxy card or fail to instruct your bank, broker or other nominee how to vote, and do not attend the general meeting in person, the effect will be that your shares will not be counted for purposes of determining whether a quorum is present at the general meeting. If you are a shareholder of record and you attend the general meeting and wish to vote in person, you may withdraw your proxy and vote in person.

        Your attention is directed to the proxy statement/prospectus accompanying this notice (including the annexes thereto) for a more complete description of the proposed business combination and related transactions and each of the proposals. We encourage you to read the accompanying proxy statement/prospectus carefully. If you have any questions or need assistance voting your ordinary shares, please contact MacKenzie Partners, AHPAC's proxy solicitor, by calling 1-800-322-2885 (toll free), or 1-212-929-5500 (call collect), or by emailing proxy@mackenziepartners.com.

        Thank you for your participation. We look forward to your continued support.

		By Order of the AHPAC Board,
		Thompson Dean Executive Chairman of the AHPAC Board

TO EXERCISE YOUR REDEMPTION RIGHTS, YOU MUST DEMAND IN WRITING THAT YOUR PUBLIC SHARES ARE REDEEMED FOR A PRO RATA PORTION OF THE FUNDS HELD IN THE TRUST ACCOUNT AND TENDER YOUR SHARES TO AHPAC'S TRANSFER AGENT AT LEAST TWO BUSINESS DAYS PRIOR TO THE VOTE AT SUCH MEETING. YOU MAY TENDER YOUR SHARES BY EITHER DELIVERING YOUR SHARE CERTIFICATE TO THE TRANSFER AGENT OR BY DELIVERING YOUR SHARES ELECTRONICALLY USING DEPOSITORY TRUST COMPANY'S DWAC (DEPOSIT WITHDRAWAL AT CUSTODIAN) SYSTEM. IF THE BUSINESS COMBINATION IS NOT COMPLETED, THEN THESE SHARES WILL NOT BE REDEEMED FOR CASH. IF YOU HOLD THE SHARES IN STREET NAME, YOU WILL NEED TO INSTRUCT THE ACCOUNT EXECUTIVE AT YOUR BANK OR BROKER TO WITHDRAW THE SHARES FROM YOUR ACCOUNT IN ORDER TO EXERCISE YOUR REDEMPTION RIGHTS.

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FREQUENTLY USED TERMS			1
QUESTIONS AND ANSWERS ABOUT THE PROPOSALS FOR SHAREHOLDERS			6
SUMMARY TERM SHEET			17
SUMMARY OF THE PROXY STATEMENT/PROSPECTUS			21
RISK FACTORS			37
Risks Related to Envigo and its business			37
Risks Related to AHPAC and the Business Combination			5152
Risks Related to the Redemption			6970
ANNUAL GENERAL MEETING OF AHPAC SHAREHOLDERS			7273
THE BUSINESS COMBINATION			8283
General			8283
Structure of the Business Combination			8283
Consideration to Selling Equityholders in the Business Combination			8384
Conditions to Closing of the Business Combination			8586
Conditions to Each Party's Obligations			8586
Conditions to AHPAC's Obligations			8586
Conditions to Envigo's Obligations			8687
Related Agreements			8687
Background of the business combination			8687
The AHPAC Board's Reasons for the Approval of the Business Combination			9293
Satisfaction of 80% Test			9496
Certain Envigo Projected Financial Information			9596
Interests of Certain Persons in the Business Combination			9697
Potential Purchases of Public Shares			9698
Total AHPAC Shares to be Issued in the Business Combination			9798
Sources and Uses for the Business Combination			9799
Board of Directors of AHPAC Following the Business Combination			9899
AHPAC Certificate of Incorporation			9899
Name; Headquarters			98100
Redemption Rights			98100
Appraisal Rights			99101
Accounting Treatment			99101
MATERIAL TAX CONSIDERATIONS			101102
Material U.S. Federal Income Tax Considerations			101102
U.S. Holders			102103
Consequences of the Domestication—F Reorganization.			102103
Redemption of AHPAC Class A Ordinary Shares			104105
Passive Foreign Investment Company Rules			106107
Taxation of Distributions on ENVG Common Stock			109
Gain or Loss on Sale, Taxable Exchange or Other Taxable Disposition of ENVG Stock and Warrants			109110
Exercise or Lapse of a Warrant			109110
Possible Constructive Distributions			110111
Non-U.S. Holders			110111
Dividends			111
Gain on Sale, Taxable Exchange or Other Taxable Disposition of ENVG Stock and Warrants			111112
Information Reporting and Backup Withholding			112
Foreign Account Tax Compliance Act			112113
Material Cayman Islands Tax Considerations			113

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Cayman Islands Taxation			113
Under Existing Cayman Islands Laws			113114
THE TRANSACTION AGREEMENT AND RELATED AGREEMENTS			114115
The Transaction Agreement			114115
General Description of the Transaction Agreement			114115
Consideration to Selling Equityholders in the Business Combination			116117
Material Adverse Effect			118119
Closing and Effective Time of the business combinationBusiness Combination			118119
Conditions to Closing of the Business Combination			119120
Representations and Warranties			120121
Covenants of the Parties			120121
Survival of Representations and Warranties; Indemnification			125126
Termination			125126
Amendments			126127
Related Agreements			126127
Amended and Restated Registration Rights Agreement			126127
Tax Receivable Agreement			127128
Parent Sponsor Letter Agreement			128129
Financing Arrangements			129
REGULATORY APPROVALS RELATED TO THE BUSINESS COMBINATION			129132
Regulatory Matters			129132
SELECTED HISTORICAL FINANCIAL INFORMATION OF AHPAC			130133
ENVIGO SELECTED CONSOLIDATED HISTORICAL FINANCIAL AND OTHER INFORMATION			131134
SELECTED UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL INFORMATION			133137
UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL INFORMATION.			135139
CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS			152156
COMPARATIVE SHARE INFORMATION			153158
INFORMATION ABOUT AHPAC			155161
AHPAC'S MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS			169172
INFORMATION ABOUT ENVIGO			175178
NON-GAAP FINANCIAL MEASURES			188191
INDUSTRY AND MARKET DATA TERMINOLOGY			191194
ENVIGO MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS			192195
ENVIGO MANAGEMENT			204212
EXECUTIVE COMPENSATION			213
MANAGEMENT AFTER THE BUSINESS COMBINATION			208216
DESCRIPTION OF SECURITIES			216224
COMPARISON OF CORPORATE GOVERNANCE AND SHAREHOLDER RIGHTS			228236
CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS			230238
AHPAC's Related Party Transactions			230238
Envigo Related Party Transactions			231239
Policies and Procedures for Related Party Transactions			232240
BENEFICIAL OWNERSHIP OF SECURITIES			234242
PRICE RANGE OF SECURITIES AND DIVIDENDS			236244
PROPOSAL NO. 1—THE BUSINESS COMBINATION PROPOSAL APPROVAL OF THE BUSINESS COMBINATION			237245
PROPOSAL NO. 2—THE DOMESTICATION PROPOSAL APPROVAL OF DOMESTICATION FROM THE CAYMAN ISLANDS TO DELAWARE			238246
THE CHARTER PROPOSALS APPROVAL OF PROPOSAL NOS. 3 through 11—THE CHARTER PROPOSALS			240248

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PROPOSAL NO. 12—THE DIRECTOR ELECTION PROPOSAL ELECTION OF NOMINEES TO THE BOARD OF DIRECTORS			248256
PROPOSAL NO. 13—THE MANAGEMENT INCENTIVE PLAN PROPOSAL APPROVAL AND ADOPTION OF THE 2017 OMNIBUS INCENTIVE PLAN			249257
PROPOSAL NO. 14—THE NASDAQ PROPOSAL APPROVAL OF THE ISSUANCE OF MORE THAN 20% OF THE COMPANY'S ISSUED AND OUTSTANDING COMMON STOCK IN CONNECTION WITH THE BUSINESS COMBINATION AND THE EQUITY FINANCING			257263
PROPOSAL NO. 15—THE ADJOURNMENT PROPOSAL			259265
INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM			260266
APPRAISAL RIGHTS			260266
HOUSEHOLDING INFORMATION			260266
TRANSFER AGENT AND REGISTRAR			260266
SUBMISSION OF SHAREHOLDER PROPOSALS			261267
FUTURE SHAREHOLDER PROPOSALS			261267
WHERE YOU CAN FIND MORE INFORMATION			261267
Index to Consolidated Financial Information			F-1
Annex A—Transaction Agreement
Annex B—Proposed Certificate of Incorporation
Annex C—Proposed Bylaws
Annex D—Form of Tax Receivable Agreement
Annex E—Form of Amended and Restated Registration Rights Agreement
Annex F—Parent Sponsor Letter Agreement
Annex G—2017 Omnibus2018 Equity Incentive Plan

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EXPLANATORY NOTE


        All financial information relating to Envigo for the year ended December 31, 2014 in this proxy statement/prospectus is for Envigo Holdings, Inc. ("BPAL"), a direct wholly-owned subsidiary of Envigo International Holdings, Inc. For the year ended December 31, 2014 and as of December 31, 2014, Envigo International Holdings, Inc. had no material assets or liabilities other than its equity interest in Envigo Holdings, Inc. and conducted no trading operations.


FREQUENTLY USED TERMS


        In this proxy statement/prospectus:

        "AHPAC," "we," "us," "company," or "our company" means Avista Healthcare Public Acquisition Corp., a Cayman Islands exempted company, except in the sections entitled "Information About Envigo" and "Envigo Management's Discussion and Analysis of Financial Condition and Results of Operations," where, in each case, "we," "us," "company," or "our company" means Envigo (as defined below); the term "ENVG" refers to AHPAC as it will continue to exist under the DGCL following effectiveness of the domestication.

        "AHPAC Board" means the board of directors of AHPAC.

        "AHPAC Class A ordinary share" means the Class A ordinary shares, par value $0.0001 per share, of AHPAC.

        "AHPAC Class B ordinary share" means the Class B ordinary shares, par value $0.0001 per share, of AHPAC.

        "AHPAC ordinary shares" means AHPAC Class A ordinary shares and AHPAC Class B ordinary shares.

        "AHPAC Shareholder Approval" means the affirmative vote (in person or by proxy) of the holders of a majority or a two-thirds majority (as applicable) of the issued and outstanding ordinary shares entitled to vote in favor of the Business Combination Proposal, the Domestication Proposal, the NASDAQ Proposal, the Charter Proposals, the Director Election Proposal, the NASDAQ Proposal, the Management Incentive Plan Proposal and the Adjournment Proposal.

        "Alternative Transaction" means any sale of any material assets of Envigo or its subsidiaries or any of the outstanding equity interests in Envigo or its subsidiaries, or any conversion, consolidation, liquidation, dissolution or similar transaction involving Envigo or its subsidiaries, other than with AHPAC and its Representatives.

        "Amended and Restated Registration Rights Agreement" means that certain Amended and Restated Registration Rights Agreement, substantially in the form attached hereto asAnnex E, to be entered into at the closing of the business combination, by and among AHPAC, the sponsor, and the restricted stockholders.

        "Avista" means Avista Capital Holdings, L.P., a Delaware limited partnership, and its affiliates; and

        "business combination" means the transactions contemplated by the Transaction Agreement, including: (i) the domestication, (ii) the merger of a subsidiary of AHPAC with and into Envigo, with Envigo surviving the merger as a wholly owned direct subsidiary of AHPAC and (iii) the merger of Envigo immediately thereafter with and into a subsidiary of AHPAC, with the subsidiary of AHPAC surviving the merger as a wholly owned direct subsidiary of AHPAC.

        "business day" means a day, other than Saturday, Sunday or such other day on which commercial banks in New York, New York are authorized or required by applicable laws to close.




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        "Class B Holders" means the sponsor and the initial shareholders, solely in their capacity as holders of Class B ordinary shares.

        "closing" means the closing of the transactions contemplated by the Transaction Agreement.

        "closing date" means the date on which the closing of the transactions contemplated by the Transaction Agreement occurs.

        "Code" means the Internal Revenue Code of 1986, as amended.




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        "DGCL" means the General Corporation Law of the State of Delaware.

        "domestication" means the intended deregistration of AHPAC as an exempted company in the Cayman Islands under the Cayman Islands Companies Law (2016 Revision), and domestication as a corporation incorporated under the laws of the State of Delaware under Section 388 of the Delaware General Corporation Law, pursuant to which AHPAC's jurisdiction of incorporation will be changed from the Cayman Islands to the State of Delaware.

        "Employee Benefit Plan" means any material "employee benefit plan" within the meaning of Section 3(3) of the Employee Retirement Income Security Act of 1974, as amended.

        "ENVG Class A common stock" means the Class A common stock, par value $0.0001 per share, of ENVG.

        "ENVG Class B common stock" means the Class B common stock, par value $0.0001 per share, of ENVG.

        "ENVG common stock" means the ENVG Class A common stock and the ENVG Class B common stock.

        "ENVG Sponsors" means the sponsor, Jermyn Street Associates LLC and Savanna Holdings LLC and their respective affiliates.

        "Envigo" means Envigo International Holdings, Inc. and its subsidiaries.

        "Envigo Board" means the board of directors of Envigo.

        "Envigo Common Stock" means Envigo's Class A common stock, par value $0.01 per share and Envigo's Class B common stock, par value $0.01 per share.

        "Envigo Option" means an option to purchase shares of Envigo Common Stock.

        "Envigo SAR" means each Envigo stock appreciation right awarded under the Lion Holdings, Inc. 2010 Omnibus Incentive Plan.

        "Envigo Series A Warrant" means a warrant to purchase one share of Envigo Class A Common Stock.

        "Envigo Series B Warrant" means a warrant to purchase one share of Envigo's Class B Common Stock, par value $0.01 per share.

        "equity financing" means equity financing through a private placement of equity securities in AHPAC with a limited number of accredited investors (as defined by Rule 501 of Regulation D) pursuant to Section 4(a)(2) of the Securities Act, for gross proceeds to AHPAC in an aggregate amount of approximately $75 million.

        "Exchange Act" means the Securities Exchange Act of 1934, as amended.

        "excluded shares" means each share of Envigo Common Stock that is owned by AHPAC, Merger Sub, NewCo or Envigo (as treasury stock or otherwise), or any of their respective direct or indirect wholly owned subsidiaries.




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        "first merger" means the merger of AHPAC Merger Sub with and into Envigo, with Envigo surviving the merger.

        "first merger effective time" means the time specified in the certificate of merger with respect to the First Merger.

        "founder shares" means AHPAC Class B ordinary shares initially purchased by the sponsor and certain other accredited investors.




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        "fully diluted total shares of Envigo" means the fully diluted total shares of Envigo (accounting for SARs and shares underlying warrants and options).

        "GAAP" means generally accepted accounting principles in the United States.

        "general meeting" means the general meeting of AHPAC that is the subject of this proxy statement/prospectus.

        "governmental entity" means any court, governmental, regulatory or administrative agency or commission or other governmental authority or instrumentality, domestic, foreign or supranational (including, without limitation, the European Commission and the European Medicines Agency), or other body having governmental or quasi-governmental or adjudicatory powers or any (public or private) arbitrator or arbitral body.

        "HSR Act" means the Hart-Scott-Rodino Antitrust Improvements Act of 1976.

        "initial shareholders" means holders of founder shares prior to the IPO.

        "Law" means, in any applicable jurisdiction, any applicable statute or law (including common law), ordinance, rule, treaty, code, directive or regulation and any decree, injunction, judgment, order, ruling, assessment, writ or other legal requirement, in any such case, of any applicable governmental entity.

        "IPO" means AHPAC's initial public offering, consummated on October 14, 2016, through the sale of 31,000,000 public units (including 1,000,000 units sold pursuant to the underwriters' partial exercise of their over-allotment option) at $10.00 per unit.

        "memorandum and articles of association" means AHPAC's amended and restated memorandum and articles of association in effect prior to the closing of the business combination.

        "NASDAQ" means the National Association of Securities Dealers Automated Quotations Capital Market.

        "Parent Sponsor Letter Agreement" means that certain letter agreement by and between AHPAC and the Class B Holders.Holders as amended from time to time.

        "Per Share Cash Consideration" means an amount in cash equal to the quotient obtained by dividing (x) $390,133,441,$283,686,737, subject to certain adjustments by (y) the fully diluted total shares of Envigo plus (b) an amount in cash equal to the product of (x) $10.00 multiplied by (y) the quotient obtained by dividing (A) 3,875,000 by (B) the fully diluted total shares of Envigo.

        "Per Share Merger Value" means an amount in cash equal to the quotient obtained by dividing (x) $390,133,441,$283,686,737, subject to certain adjustments by (y) the fully diluted total shares of Envigo.

        "Per Share Stock Consideration" means a number of newly issued shares of ENVG Class A common stock equal to the quotient obtained by dividing (x) the Per Share Merger Value by (y) $10.00.

        "Per Share Total Cash Consideration" means an amount in cash equal to the total obtained by adding (a) the Per Share Cash Consideration, (b) a number of warrants to purchase one-half of one share of ENVG Class A common stock, where two warrants must be exercised for one whole share of ENVG Class A common stock at a price of $11.50 per share, equal to the quotient obtained by




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dividing (x) 4,100,000 by (y) the fully diluted total shares of Envigo, and (c) such holder's pro rata share of certain payments under the Tax Receivable Agreement, subject to the terms and conditions set forth therein.

        "Per Share Total Stock Consideration" means the total obtained by adding (a) the Per Share Stock Consideration, (b) a number of shares of ENVG Class A common stock equal to the quotient obtained by dividing (x) 3,875,000 by (y) the fully diluted total shares of Envigo, (c) a number of warrants to purchase one-half of one share of Class A common stock where two warrants must be exercised for




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one whole share of ENVG Class A common stock at a price of $11.50 per share equal to the quotient obtained by dividing (x) 4,100,000 by (y) the fully diluted total shares of Envigo, and (d) such holder's pro rata share of certain payments under the Tax Receivable Agreement.

        "private placement warrants" means the warrants issued to the initial shareholders in a private placement simultaneously with the closing of the IPO.

        "proposed certificate of incorporation" or "proposed certificate" means the proposed certificate of incorporation of ENVG, a form of which is attached hereto asAnnex B, which will become AHPAC's certificate of incorporation subject to the approval of the Charter Proposals, assuming the consummation of the domestication and business combination.

        "proposed bylaws" means the proposed bylaws of ENVG, a form of which is attached hereto asAnnex C, which will become AHPAC's bylaws subject to the approval of the Charter Proposals, assuming the consummation of the domestication and business combination.

        "public shareholders" means the holders of AHPAC public shares.

        "public shares" means AHPAC Class A ordinary shares sold as part of the units in the IPO.

        "public units" or "AHPAC units" means one AHPAC Class A ordinary share and one redeemable public warrant of AHPAC, whereby each public warrant entitles the holder thereof to purchase one-half of one AHPAC Class A ordinary share, where two warrants must be exercised for one whole Class A share at an exercise price of $11.50 per AHPAC Class A ordinary share, sold in the IPO.

        "public warrants" means the warrants included in the units issued in AHPAC's IPO, where two warrants must be exercised for one whole share of ENVG Class A common stock in accordance with the terms of the warrant agreements governing the warrants.

        "Related Agreements" means the Tax Receivable Agreement and the Amended and Restated Registration Rights Agreement.

        "representatives" means a Person's officers, directors, employees, accountants, consultants, agents, legal counsel, and other representatives.

        "restricted stockholders" means, collectively, the sponsor, certain directors of AHPAC (as set forth in the Amended and Restated Registration Rights Agreement) and the Selling Equityholders that receive ENVG common stock in the business combination.

        "second merger" means the merger of Envigo with and into AHPAC NewCo, with AHPAC NewCo surviving the merger.

        "second merger effective time" means the time specified in the certificate of merger with respect to the Second Merger.

        "SEC" means the United States Securities and Exchange Commission.

        "Securities Act" means the Securities Act of 1933, as amended.

        "Selling Equityholders" means, collectively, the holders of equity interests (including shares, warrants, SARs and options) in Envigo immediately prior to the effective time of the first merger.




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        "Shareholder Representative" or "shareholder representative" means Jermyn Street Associates LLC.

        "sponsor" means Avista Acquisition Corp., a Cayman Islands exempted company and an affiliate of Avista Capital Holdings, L.P., a Delaware limited partnership.

        "Tax Receivable Agreement" means that certain Tax Receivable Agreement to be entered into at the closing of the business combination by and among ENVG, Envigo Holdings, Inc. and the shareholder




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representative on behalf of the Selling Equityholders entitled to receive merger consideration pursuant to the Transaction Agreement.

        "Transaction Agreement" means that certain Transaction Agreement, dated August 21, 2017, as amended on November 22, 2017, and on December 22, 2017, January 21, 2018 and February 9, 2018 (as it may be further amended from time to time), by and among AHPAC, AHPAC Merger Sub, AHPAC NewCo, Envigo and the shareholder representative, a copy of which is attached to this proxy statement/prospectus asAnnex A.

        "transfer agent" means Continental Stock Transfer & Trust Company.

        "trust account" means the trust account of AHPAC that holds the proceeds from the IPO.




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QUESTIONS AND ANSWERS ABOUT THE PROPOSALS FOR SHAREHOLDERS


        The questions and answers below highlight only selected information from this document and only briefly address some commonly asked questions about the proposals to be presented at the general meeting, including with respect to the proposed business combination. The following questions and answers do not include all the information that is important to AHPAC's shareholders. We urge shareholders to read carefully this entire proxy statement/prospectus, including the Annexes and the other documents referred to herein, to fully understand the proposed business combination and the voting procedures for the general meeting, which will be held on[    ·    ] at[    ·    ] Eastern Time at the offices of Weil, Gotshal & Manges, LLP located at 767 Fifth Avenue, New York, New York, 10153.

Q:

Why am I receiving this proxy statement/prospectus?



A:

AHPAC's shareholders are being asked to consider and vote upon, among other proposals, a proposal to approve and adopt the Transaction Agreement and approve the transactions contemplated thereby, including the business combination. As a result of the business combination, AHPAC will acquire Envigo. Subject to the terms of the Transaction Agreement and customary adjustments set forth therein, the aggregate purchase price payable to the holders of equity interests (including shares, warrants, SARs and options) in Envigo immediately prior to the effective time of the first merger (the "Selling Equityholders") in connection with the business combination and related transactions is expected to be approximately (a) $428.88$322.44 million (the "purchase price"), subject to adjustment as described in the following sentence, in cash and shares of ENVG Class A common stock, (b) 4.10 million warrants to purchase one-half of one share of ENVG Class A common stock and (c) amounts payable to the Selling Equityholders under the Tax Receivable Agreement. The purchase price will be reduced by, among other things, the aggregate amount of transaction expenses incurred by Envigo in connection with the negotiation and consummation of the business combination plus the cost of the 4.10 million warrants being purchased from the sponsor for distribution to the Selling Equityholders.combination. It is anticipated that this adjustment will result in a deduction to the purchase price of approximately $38.5$42.3 million (including non-cash expenses in the amount of $8.3$7.8 million). The cash component of the purchase price is subject to an aggregate limit on cash consideration of $100 million (which amount may be increased or reduced as described in the Transaction Agreement). A copy of the Transaction Agreement, including each amendment thereto through the date hereof is attached to this proxy statement/prospectus asAnnex A.

This proxy statement/prospectus and its Annexes contain important information about the proposed business combination and the other matters to be acted upon at the general meeting. You should read this proxy statement/prospectus and its Annexes carefully and in their entirety.

Your vote is important. You are encouraged to submit your proxy as soon as possible after carefully reviewing this proxy statement/prospectus and its Annexes.

Q:

When and where is the general meeting?



A:

The general meeting will be held on [    ·    ] at [    ·    ] Eastern Time at the offices of Weil, Gotshal & Manges, LLP located at 767 Fifth Avenue, New York, New York, 10153.



Q:

What are the specific proposals on which I am being asked to vote at the general meeting?



A:

AHPAC's shareholders are being asked to approve the following proposals:



1.

Proposal No. 1—The Business Combination Proposal—To consider and vote upon a proposal to approve and adopt the Transaction Agreement, and the transactions contemplated thereby, which we refer to as the "Business Combination Proposal";




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2.

Proposal No. 2—The Domestication Proposal—To consider and vote upon a proposal to approve by special resolution, assuming the Business Combination Proposal is approved and adopted, the domestication, which we refer to as the "Domestication Proposal";


The Charter Proposals—To consider and vote upon nine separate proposals to approve by special resolution, assuming the Business Combination Proposal and the Domestication Proposal are approved and adopted, the following material differences between AHPAC's current amended and restated memorandum and articles of association and the proposed certificate and proposed bylaws.

3.

Proposal No. 3—To consider and vote upon an amendment to AHPAC's existing organizational documents to authorize the classification of the Board into three classes of directors, which shall consist of, as nearly as may be possible, one-third of the total number of directors on the Board, which will initially be seven (7) and then as may be set by the Board from time to time;



4.

Proposal No. 4—To consider and vote upon an amendment to AHPAC's existing organizational documents to authorize that directors may only be removed for cause;



5.

Proposal No. 5—To consider and vote upon an amendment to AHPAC's existing organizational documents to authorize that only the Board, chairperson of the Board or chief executive offer may call a meeting of stockholders;



6.

Proposal No. 6—To consider and vote upon an amendment to AHPAC's existing organizational documents to authorize removal of the ability of stockholders to take action by written consent in lieu of a meeting;



7.

Proposal No. 7—To consider and vote upon an amendment to AHPAC's existing organizational documents to require the affirmative vote of holders of a majority of the voting power of ENVG's then issued and outstanding shares of stock entitled to amend the proposed certificate;



8.

Proposal No. 8—To consider and vote upon an amendment to AHPAC's existing organizational documents to authorize the adoption of Delaware as the exclusive forum for certain stockholder litigation;



9.

Proposal No. 9—To consider and vote upon an amendment to AHPAC's existing organizational documents to authorize ENVG to permit the ENVG Sponsors to engage in competitive businesses and renounce certain corporate opportunities offered to the ENVG Sponsors or any of their managers, officers, directors, agents, stockholders, members, partners, affiliates and subsidiaries (other than ENVG and its subsidiaries) that are not expressly offered to them in their capacities as directors or officers of ENVG;



10.

Proposal No. 10—To consider and vote upon an amendment to AHPAC's existing organizational documents to approve the authorized number of shares of ENVG common stock contained in the proposed certificate; and



11.

Proposal No. 11—To consider and vote upon an amendment to AHPAC's existing organizational documents to authorize other changes to the Organizational Documents resulting from the domestication and business combination, including changing the post-business combination corporate name from "Avista Healthcare Public Acquisition Corp." to "Envigo International Holdings, Inc." and removing certain provisions relating to our status as a blank-check company that will no longer apply upon consummation of the business combination.


We refer to Proposals No. 3-11 collectively as the "Charter Proposals";




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12.

Proposal No. 12—The Director Election Proposal—To consider and vote upon a proposal to elect seven directors to serve staggered terms on ENVG's Board of Directors until the 2019, 2020 and 2021 annual meeting of shareholders, respectively, and until their respective successors are duly elected and qualified, which we refer to as the "Director Election Proposal";



13.

Proposal No. 13—The Management Incentive Plan Proposal—To consider and vote on a proposal to approve and adopt, assuming the Charter Proposals, the Domestication Proposal and the Business Combination Proposal are all approved and adopted, the 2017 Omnibus2018 Equity Incentive Plan and the material terms thereunder, which we refer to as the "Management Incentive Plan Proposal". A copy of the 2017 Omnibus2018 Equity Incentive Plan is attached to the accompanying proxy statement/prospectus as Annex G;



14.

Proposal No. 14—The NASDAQ Proposal—To consider and vote upon a proposal to approve, assuming the Charter Proposals, the Domestication Proposal and the Business Combination Proposal are all approved and adopted, for purposes of complying with applicable provisions of NASDAQ Listing Rule 5635, the issuance of more than 20% of AHPAC's issued and outstanding ordinary shares (or issued and outstanding common stock following the domestication) to the Selling Equityholders in connection with the business combination and to participants in the equity financing (if any), which we refer to as the "NASDAQ Proposal"; and



15.

Proposal No. 15—Adjournment Proposal—To consider and vote upon a proposal to approve the adjournment of the general meeting to a later date or dates, if necessary, to permit further solicitation and vote of proxies in the event that there are insufficient votes for, or otherwise in connection with, the approval of one or more proposals to be submitted for shareholder approval at the general meeting, which we refer to as the "Adjournment Proposal."



Q:

Why is AHPAC providing shareholders with the opportunity to vote on the business combination?



A:

Under AHPAC's existing amended and restated memorandum and articles of association, AHPAC must provide all holders of public shares with the opportunity to have their public shares redeemed upon the consummation of AHPAC's initial business combination either in conjunction with a tender offer or in conjunction with a shareholder vote. For business and other reasons, AHPAC has elected to provide AHPAC's shareholders with the opportunity to have their public shares redeemed in connection with a shareholder vote rather than a tender offer. Therefore, we are seeking to obtain the approval of AHPAC's shareholders of the Business Combination Proposal in order to allow public shareholders to effectuate redemptions of their public shares in connection with the closing of the business combination. Additionally, approval of the Transaction Agreement and the business combination are required under AHPAC's amended and restated memorandum and articles of association, and such approval is a condition to the consummation of the business combination under the Transaction Agreement.



Q:

When is the business combination expected to be completed?



A:

The consummation of the business combination is expected to take place on or prior to the third business day following the satisfaction or waiver of the conditions set forth in the Transaction Agreement and described below in the subsection entitled "The Transaction Agreement—Conditions to Closing of the Business Combination." The closing is expected to occur in the first quarter of 2018. The Transaction Agreement may be terminated by AHPAC or Envigo if the consummation of the business combination has not occurred by March 31, 2018.

For a description of the conditions to the completion of the business combination, see the section entitled "The Transaction Agreement—Conditions to Closing of the Business Combination."




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Q:

Following the business combination, will AHPAC's securities continue to trade on a stock exchange?



A:

Yes. Our publicly traded ordinary shares, units and warrants are currently listed on the NASDAQ Capital Market under the symbols "AHPA," "AHPAU" and "AHPAW," respectively. We intend to apply to continue the listing of our publicly traded ENVG common stock and warrants on NASDAQ under the symbols "ENVG" and "ENVGW," respectively, upon the closing of the business combination. As a result, our publicly traded units may separate into the component securities upon consummation of the business combination and, as a result, may no longer trade as a separate security.



Q:

What happens if I sell my AHPAC Class A ordinary shares before the general meeting?



A:

The record date for the general meeting is earlier than the date that the business combination is expected to be completed. If you transfer your AHPAC Class A ordinary shares after the record date, but before the general meeting, unless the transferee obtains from you a proxy to vote those shares, you will retain your right to vote at the general meeting. However, you will not be able to seek redemption of the AHPAC Class A ordinary shares because you will no longer be able to deliver them for redemption upon consummation of the business combination. If you transfer your AHPAC Class A ordinary shares prior to the record date, you will have no right to vote those shares at the general meeting or redeem those shares for a pro rata portion of the proceeds held in the trust account.



Q:

What vote is required to approve the proposals presented at the general meeting?



A:

The approval of each of the Domestication Proposal and the Charter Proposals requires the affirmative vote of holders of two-thirds of the ordinary shares represented in person or by proxy and entitled to vote thereon at the general meeting. Accordingly, if an AHPAC shareholder fails to vote by proxy or to vote in person at the general meeting, their shares will not be counted in connection with the determination of whether a valid quorum is established, however, if a valid quorum is otherwise established, such failure to vote will have no effect on the outcome of any vote on the Domestication Proposal or any of the Charter Proposals. Abstentions will be counted in connection with the determination of whether a valid quorum is established and will have the same effect as a vote "AGAINST" the Domestication Proposal and the Charter Proposals.

The approval of the Business Combination Proposal requires the affirmative vote of holders of a majority of the ordinary shares represented in person or by proxy and entitled to vote thereon at the general meeting. Accordingly, if an AHPAC shareholder fails to vote by proxy or to vote in person at the general meeting, their shares will not be counted in connection with the determination of whether a valid quorum is established, however, if a valid quorum is otherwise established, such failure to vote will have no effect on the outcome of any vote on the Business Combination Proposal. Abstentions will be counted in connection with the determination of whether a valid quorum is established and will have the same effect as a vote"AGAINST" the Business Combination Proposal. The initial shareholders have agreed to vote their founder shares and any public shares they may hold in favor of the business combination. Currently, the initial shareholders own approximately 20% of AHPAC's issued and outstanding ordinary shares, including all of the founder shares.

The approval of each of the Director Election Proposal, the Management Incentive Plan Proposal, the NASDAQ Proposal and the Adjournment Proposal requires the affirmative vote of holders of a majority of the ordinary shares represented in person or by proxy and entitled to vote thereon at the general meeting. Accordingly, if an AHPAC shareholder fails to vote by proxy or to vote in person at the general meeting, their shares will not be counted in connection with the




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determination of whether a valid quorum is established, however, if a valid quorum is otherwise established, such failure to vote will have no effect on the outcome of any vote on the NASDAQ Proposal, the Director Election Proposal or the Adjournment Proposal. Abstentions will be counted in connection with the determination of whether a valid quorum is established and will have the same effect as a vote"AGAINST" the NASDAQ Proposal, the Director Election Proposal and the Adjournment Proposal.

Q:

How many votes do I have at the general meeting?



A:

AHPAC's shareholders are entitled to one vote on each proposal presented at the general meeting for each ordinary share held of record as of [    ·    ], 2017,January 16, 2018, the record date for the general meeting. As of the close of business on the record date, there were [    ·    ]38,750,000 outstanding ordinary shares.



Q:

What constitutes a quorum at the general meeting?



A:

A majority of the issued and outstanding AHPAC ordinary shares entitled to vote as of the record date at the general meeting must be present, in person or represented by proxy, at the general meeting to constitute a quorum and in order to conduct business at the general meeting. Abstentions will be counted as present for the purpose of determining a quorum. The initial shareholders, who currently own approximately 20% of AHPAC's issued and outstanding ordinary shares, will count towards this quorum. In the absence of a quorum, the chairman of the general meeting has power to adjourn the general meeting. As of the record date for the general meeting, [    ·    ]19,375,001 shares of AHPAC ordinary shares would be required to achieve a quorum.

At the general meeting, we will count a properly executed proxy marked "ABSTAIN" with respect to a particular proposal as present for purposes of determining whether a quorum is present.

Q:

How will the sponsor, directors and officers vote?



A:

In connection with the IPO, the initial shareholders agreed to vote their founder shares and any public shares purchased during or after the IPO in favor of the business combination. None of the sponsor, directors or officers has purchased any shares of AHPAC ordinary shares during or after the IPO and, as of the date of this proxy statement/prospectus, neither we nor the sponsor, directors or officers have entered into agreements, and are not currently in negotiations, to purchase shares prior to the consummation of the business combination.



Q:

What happens if I vote against the Business Combination Proposal?



A:

If you vote against the Business Combination Proposal but the Business Combination Proposal still obtains the affirmative vote of a majority of the ordinary shares represented in person or by proxy and entitled to vote thereon at the general meeting, then the Business Combination Proposal will be approved and, assuming the approval of the Domestication Proposal, the NASDAQ Proposal and the Charter Proposals and the satisfaction or waiver of the other conditions to closing, the business combination will be consummated in accordance with the terms of the Transaction Agreement.

If you vote against the Business Combination Proposal and the Business Combination Proposal does not obtain the affirmative vote of a majority of the ordinary shares represented in person or by proxy and entitled to vote thereon at the general meeting, then the Business Combination Proposal will fail and we will not consummate the business combination. If AHPAC does not consummate the business combination, we may continue to try to complete a business combination with a different target business until October 14, 2018. If AHPAC fails to complete an initial




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business combination by October 14, 2018, then AHPAC will be required to dissolve and liquidate the trust account by returning the then-remaining funds in such account to public shareholders.




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Q:

Do I have redemption rights?



A:

If you are a public shareholder and you properly exercise your right to redeem your public shares and timely deliver your shares to the transfer agent, AHPAC will redeem each public share for a per-share price, payable in cash, equal to the aggregate amount then on deposit in the trust account, calculated as of two business days prior to the consummation of the business combination, including interest, less income taxes payable, divided by the number of then issued and outstanding public shares;provided that AHPAC will not redeem any public shares to the extent that such redemption would result in AHPAC having net tangible assets (as determined in accordance with Rule 3a51-1(g)(1) of the Exchange Act) of less than $5,000,001. The initial shareholders have agreed to waive their redemption rights with respect to their founder shares and with respect to any public shares they may hold in connection with the consummation of the business combination. The founder shares will be excluded from the pro rata calculation used to determine the per-share redemption price. For illustrative purposes, based on the fair value of marketable securities held in the trust account of approximately $312,092,295$312,497,921 as of NovemberJanuary 17, 2017,2018, the estimated per share redemption price would have been approximately $10.07.$10.08. Additionally, shares properly tendered for redemption will only be redeemed if the business combination is consummated; otherwise holders of such shares will only be entitled to a pro rata portion of the trust account (including interest but net of franchise and income taxes payable) in connection with the liquidation of the trust account, unless we complete an alternative business combination prior to October 14, 2018.



Q:

Can AHPAC's initial shareholders redeem their founder shares in connection with consummation of the business combination?



A:

No. The initial shareholders have agreed to waive their redemption rights with respect to their founder shares and any public shares they may hold in connection with the consummation of the business combination.



Q:

Is there a limit on the number of shares that may be redeemed?



A:

Yes. A public shareholder, together with any affiliate of such shareholder or any other person with whom such shareholder is acting in concert or as a "group" (as defined under Section 13 of the Exchange Act), is restricted from seeking redemption rights with respect to more than an aggregate of 15% of the shares sold in the IPO. Accordingly, all shares in excess of 15% owned by a holder will not be redeemed for cash. On the other hand, a public shareholder who holds less than 15% of the public AHPAC Class A ordinary shares may redeem all of the public shares held by such shareholder for cash.

In no event is your ability to vote all of your shares (including those shares held by you in excess of 15% of the shares sold in the IPO) for or against the business combination restricted.

There is no specified maximum redemption threshold under AHPAC's existing amended and restated memorandum and articles of association, other than the aforementioned 15% threshold. Each redemption of AHPAC Class A ordinary shares by public shareholders will reduce the amount in the trust account. The Transaction Agreement provides that Envigo's obligation to consummate the business combination is conditioned on there being at least $260$220 million of available funds from the trust account and proceeds from the equity financing (if any), after giving effect to redemptions of public shares. This condition to closing in the Transaction Agreement is for the sole benefit of Envigo and may be waived only by Envigo. If, as a result of redemptions of public shares by public shareholders, these conditions are not met (or waived), then Envigo may




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elect not to consummate the business combination. In addition, in no event will AHPAC redeem public shares in an amount that would cause its net tangible assets (as determined in accordance




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with Rule 3a51-1(g)(1) of the Exchange Act) to be less than $5,000,001. Holders of public warrants do not have redemption rights in connection with the business combination.

Q:

Will my vote affect my ability to exercise redemption rights?



A:

No. You may exercise your redemption rights whether you vote your ordinary shares for or against, or whether you abstain from voting on the Business Combination Proposal or any other proposal described by this proxy statement/prospectus. As a result, the Transaction Agreement can be approved by shareholders who will redeem their shares and no longer remain shareholders, leaving shareholders who choose not to redeem their shares holding shares in a company with a potentially less-liquid trading market, fewer shareholders, potentially less cash and the potential inability to meet the listing standards of NASDAQ.



Q:

How do I exercise my redemption rights?



A:

Pursuant to AHPAC's existing amended and restated memorandum and articles of association, a holder of AHPAC's public shares may request that AHPAC redeem all or a portion of such shareholder's public shares (which will become shares of ENVG Class A common stock in the domestication) for cash if the business combination is consummated. For the purposes of Article 49.3 of AHPAC's amended and restated memorandum and articles of association and the Cayman Islands Companies Law (2016 Revision), the exercise of redemption rights shall be treated as an election to have such public shares redeemed for cash and references in this proxy statement/prospectus shall be interpreted accordingly. You will be entitled to receive cash for any public shares to be redeemed only if you:



(i)

(a) hold public shares or (b) hold public shares through units and you elect to separate your units into the underlying public shares and warrants prior to exercising your redemption rights with respect to the public shares;



(ii)

prior to [5:5:00 p.m.], Eastern Time, on [    ·    ], 2017,2018, submit a written request to Continental Stock Transfer & Trust Company, AHPAC's transfer agent (the "transfer agent"), that AHPAC redeem your public shares for cash; and



(iii)

timely deliver your public shares to the transfer agent, physically or electronically through Depository Trust Company ("DTC").

To complete the written request, you must (i) check the box on the enclosed proxy card to elect redemption, (ii) check the box on the enclosed proxy card marked "Shareholder Certification" and (iii) if you hold public units, separate the underlying public shares and public warrants. You must submit the written request that we redeem your public shares for cash and tender your shares physically or electronically and submit a request in writing that we redeem your public shares for cash to the transfer agent, at the following address:

Continental Stock Transfer & Trust Company
1 State Street- 30th Floor
New York, NY 10004
Attn: Mark Zimkind
Email: mzimkind@continentalstock.com

Please check the box on the enclosed proxy card marked "Shareholder Certification" if you are not acting in concert or as a "group" (as defined in Section 13d-3 of the Exchange Act) with any other shareholder with respect to ordinary shares. Notwithstanding the foregoing, a holder of the public shares, together with any affiliate of his or any other person with whom he is acting in concert or




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as a "group" (as defined in Section 13d-3 of the Exchange Act) will be restricted from seeking redemption rights with respect to more than 15% of the AHPAC Class A ordinary shares included




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in the units sold in the IPO, which we refer to as the "15% threshold." Accordingly, all public shares in excess of the 15% threshold beneficially owned by a public shareholder or group will not be redeemed for cash.

Shareholders seeking to exercise their redemption rights and opting to deliver physical certificates should allot sufficient time to obtain physical certificates from the transfer agent and time to effect delivery. It is AHPAC's understanding that shareholders should generally allot at least two weeks to obtain physical certificates from the transfer agent. However, AHPAC does not have any control over this process and it may take longer than two weeks. Shareholders who hold their shares in street name will have to coordinate with their bank, broker or other nominee to have the shares certificated or delivered electronically.

Shareholders seeking to exercise their redemption rights, whether they are record holders or hold their shares in "street name" are required to either tender their certificates to AHPAC's transfer agent prior to the date set forth in these proxy materials, or to deliver their shares to the transfer agent electronically using DTC's Deposit/Withdrawal At Custodian (DWAC) system, at such shareholder's option.The requirement for physical or electronic delivery prior to the general meeting ensures that a redeeming shareholder's election to redeem is irrevocable once the business combination is approved.

There is a nominal cost associated with the above-referenced tendering process and the act of certificating the shares or delivering them through the DWAC system. The transfer agent will typically charge a tendering broker a fee and it is in the broker's discretion whether or not to pass this cost on to the redeeming shareholder. However, this fee would be incurred regardless of whether or not we require shareholders seeking to exercise redemption rights to tender their shares, as the need to deliver shares is a requirement to exercising redemption rights, regardless of the timing of when such delivery must be effectuated.

Q:

What are the U.S. federal income tax consequences of exercising my redemption rights or choosing not to exercise such redemption rights?



A:

Please see the section entitled "Material U.S. Federal Income Tax Considerations" for a discussion of material U.S. federal income tax consequences of exercising your redemption rights or choosing not to exercise such redemption rights.



Q:

If I am a Company warrant holder, can I exercise redemption rights with respect to my public warrants?



A:

No. The holders of public warrants have no redemption rights with respect to the public warrants.



Q:

Do I have appraisal rights if I object to the proposed business combination?



A:

No. Appraisal rights are not available to holders of public shares in connection with the business combination.



Q:

What happens if the business combination is not consummated?



A:

There are certain circumstances under which the Transaction Agreement may be terminated. Please see the section entitled "The Transaction Agreement—Termination" for information regarding the parties' specific termination rights.

If AHPAC does not consummate the business combination, we may continue to try to complete a business combination with a different target business until October 14, 2018. If AHPAC fails to




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complete an initial business combination by October 14, 2018, then we will: (i) cease all operations except for the purpose of winding up; (ii) as promptly as reasonably possible but not more than




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ten business days thereafter, redeem public shares, at a per-share price, payable in cash, equal to the aggregate amount then on deposit in the trust account, including interest (which interest shall be net of taxes payable, and less up to $50,000 of interest to pay dissolution expenses), divided by the number of then outstanding public shares, which redemption will completely extinguish public shareholders' rights as shareholders (including the right to receive further liquidation distributions, if any), subject to applicable law; and (iii) as promptly as reasonably possible following such redemption, subject to the approval of AHPAC's remaining shareholders and the AHPAC Board, dissolve and liquidate, subject in each case to AHPAC's obligations under Cayman Islands law to provide for claims of creditors and the requirements of other applicable law. In the event of such distribution, it is possible that the per share value of the residual assets remaining available for distribution (including trust account assets) will be less than the initial public offering price per unit in the IPO. Please see the section entitled "Risk Factors—Risks Related to AHPAC and the Business Combination."

Holders of AHPAC founder shares have waived any right to any liquidation distribution with respect to such shares. In addition, if AHPAC fails to complete a business combination by October 14, 2018, there will be no redemption rights or liquidating distributions with respect to AHPAC's outstanding warrants, which will expire worthless.

Q:

What do I need to do now?



A:

You are urged to read carefully and consider the information contained in this proxy statement/prospectus, including the Annexes, and to consider how the business combination will affect you as a shareholder. You should then vote as soon as possible in accordance with the instructions provided in this proxy statement/prospectus and on the enclosed proxy card or, if you hold your shares through a brokerage firm, bank or other nominee, on the voting instruction form provided by the broker, bank or nominee.



Q:

How do I vote?



A:

If you were a holder of record of AHPAC ordinary shares on [    ·    ], 2017,January 16, 2018, the record date for the general meeting, you may vote with respect to the proposals in person at the general meeting, or by completing, signing, dating and returning the enclosed proxy card in the postage-paid envelope provided.

Voting by Mail.    By signing the proxy card and returning it in the enclosed prepaid and addressed envelope, you are authorizing the individuals named on the proxy card to vote your shares at the general meeting in the manner you indicate. We encourage you to sign and return the proxy card even if you plan to attend the general meeting so that your shares will be voted if you are unable to attend the general meeting. If you receive more than one proxy card, it is an indication that your shares are held in multiple accounts. Please sign and return all proxy cards to ensure that all of your shares are voted. Votes submitted by mail must be received by [    ·    ]5:00 p.m. Eastern Time on [    ·    ].], 2018.

Voting in Person at the Meeting.    If you attend the general meeting and plan to vote in person, we will provide you with a ballot at the general meeting. If your shares are registered directly in your name, you are considered the shareholder of record and you have the right to vote in person at the general meeting. If you hold your shares in "street name," which means your shares are held of record by a broker, bank or other nominee, you should follow the instructions provided by your broker, bank or nominee to ensure that votes related to the shares you beneficially own are properly counted. In this regard, you must provide the record holder of your shares with




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instructions on how to vote your shares or, if you wish to attend the general meeting and vote in person, you will need to bring to the general meeting a legal proxy from your broker, bank or nominee authorizing you to vote these shares. For additional information, please see the section




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entitled "Annual General Meeting of AHPAC Shareholders" beginning on page [    ·    ]73 of this proxy statement/prospectus.

Q:

What will happen if I sign and return my proxy card without indicating how I wish to vote?



A:

Signed and dated proxies received by us without an indication of how the shareholder intends to vote on a proposal will be voted"FOR" each proposal presented to the shareholders. The proxy holders may use their discretion to vote on any other matters which properly come before the general meeting.



Q:

If I am not going to attend the general meeting in person, should I return my proxy card instead?



A:

Yes. Whether you plan to attend the general meeting or not, please read the enclosed proxy statement/prospectus carefully, and vote your shares by completing, signing, dating and returning the enclosed proxy card in the postage-paid envelope provided.



Q:

If my shares are held in "street name," will my broker, bank or nominee automatically vote my shares for me?



A:

No. Under the rules of various national and regional securities exchanges, your broker, bank, or nominee cannot vote your shares with respect to non-discretionary matters unless you provide instructions on how to vote in accordance with the information and procedures provided to you by your broker, bank, or nominee. AHPAC believes the proposals presented to the shareholders at this general meeting will be considered non-discretionary and, therefore, your broker, bank, or nomineecannot vote your shares without your instruction on any of the proposals presented at the general meeting. If you do not provide instructions with your proxy, your broker, bank, or other nominee may deliver a proxy card expressly indicating that it is NOT voting your shares; this indication that a broker, bank, or nominee is not voting your shares is referred to as a "broker non-vote." Broker non-votes will not be counted for the purposes of determining the existence of a quorum or for purposes of determining the number of votes cast at the general meeting. Your bank, broker, or other nominee can vote your shares only if you provide instructions on how to vote. You should instruct your broker to vote your shares in accordance with directions you provide.



Q:

May I change my vote after I have mailed my signed proxy card?



A:

Yes. You may change your vote by sending a later-dated, signed proxy card to AHPAC's Secretary at the address listed below so that it is received by AHPAC's Secretary prior to the general meeting or attend the general meeting in person and vote. You also may revoke your proxy by sending a notice of revocation to AHPAC's Secretary, which must be received by AHPAC's Secretary prior to the general meeting.



Q:

What should I do if I receive more than one set of voting materials?



A:

You may receive more than one set of voting materials, including multiple copies of this proxy statement/prospectus and multiple proxy cards or voting instruction cards. For example, if you hold your shares in more than one brokerage account, you will receive a separate voting instruction card for each brokerage account in which you hold shares. If you are a holder of record and your shares are registered in more than one name, you will receive more than one proxy card. Please




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complete, sign, date and return each proxy card and voting instruction card that you receive in order to cast your vote with respect to all of your shares.




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Q:

Who will solicit and pay the cost of soliciting proxies for the general meeting?



A:

AHPAC will pay the cost of soliciting proxies for the general meeting. AHPAC has engaged MacKenzie Partners, Inc. ("MacKenzie Partners") to assist in the solicitation of proxies for the general meeting. AHPAC has agreed to pay MacKenzie Partners a fee of $15,000, plus disbursements, and will reimburse MacKenzie Partners for its reasonable out-of-pocket expenses and indemnify MacKenzie Partners and its affiliates against certain claims, liabilities, losses, damages and expenses. AHPAC will also reimburse banks, brokers and other custodians, nominees and fiduciaries representing beneficial owners of shares of AHPAC's ordinary shares for their expenses in forwarding soliciting materials to beneficial owners of AHPAC's ordinary shares and in obtaining voting instructions from those owners. AHPAC's directors, officers and employees may also solicit proxies by telephone, by facsimile, by mail, on the Internet or in person. They will not be paid any additional amounts for soliciting proxies.



Q:

Who can help answer my questions?



A:

If you have questions about the proposals or if you need additional copies of this proxy statement/prospectus or the enclosed proxy card you should contact AHPAC's Secretary:

Avista Healthcare Public Acquisition Corp.
65 East 55th Street
18th Floor
New York, NY 10022
(212) 593-6900
Attention: Benjamin Silbert
Email: silbert@avistacap.com

You may also contact AHPAC's proxy solicitor at:


MacKenzie Partners
105 Madison Avenue
New York, New York 10016
1-800-322-2885 (Toll-Free)
or
1-212-929-5500 (call collect)
Email: proxy@mackenziepartners.com

To obtain timely delivery, AHPAC's shareholders must request the materials no later than five business days prior to the general meeting.

You may also obtain additional information about us from documents filed with the SEC by following the instructions in the section entitled "Where You Can Find More Information."

If you intend to seek redemption of your public shares, you will need to send a letter demanding redemption and deliver your stock (either physically or electronically) to AHPAC's transfer agent prior to the general meeting in accordance with the procedures detailed under the question "How do I exercise my redemption rights?" If you have questions regarding the certification of your position or delivery of your stock, please contact AHPAC's transfer agent:

Continental Stock Transfer & Trust Company
1 State Street- 30th Floor
New York, NY 10004
Attn: Mark Zimkind
Email: mzimkind@continentalstock.com




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SUMMARY TERM SHEET


        This summary term sheet, together with the sections entitled "Questions and Answers About the Proposals for Shareholders" and "Summary of the Proxy Statement/Prospectus," summarizes certain information contained in this proxy statement/prospectus, but does not contain all of the information that is important to you. You should read carefully this entire proxy statement/prospectus, including the attached Annexes, for a more complete understanding of the matters to be considered at the general meeting. In addition, for definitions used commonly throughout this proxy statement/prospectus, including this summary term sheet, please see the section entitled "Frequently Used Terms."

•

Avista Healthcare Public Acquisition Corp., a Cayman Islands exempted company, or AHPAC, is a blank check company formed for the purpose of effecting a merger, capital stock exchange, asset acquisition, stock purchase, reorganization or similar business combination with one or more businesses.



•

On August 21, 2017, AHPAC, AHPAC Merger Sub, AHPAC NewCo, Envigo and the shareholder representative entered into the Transaction Agreement, a copy of which is attached to this proxy statement/prospectus asAnnex A. Pursuant to the terms of the Transaction Agreement, the parties thereto agreed to an integrated transaction consisting of (i) the merger of AHPAC Merger Sub with and into Envigo, with Envigo surviving the merger (the "first merger"), and then (ii) immediately thereafter, the merger of Envigo with and into AHPAC NewCo, with AHPAC NewCo surviving the merger (the "second merger," and together with the first merger, the "mergers"). Prior to the mergers, AHPAC will change its jurisdiction of incorporation from the Cayman Islands to the State of Delaware by deregistering as an exempted company in the Cayman Islands under the Cayman Islands Companies Law (2016 Revision), and domesticating as a corporation incorporated under the laws of the State of Delaware under Section 388 of the Delaware General Corporation Law.



•

There are currently 38,750,000 AHPAC ordinary shares issued and outstanding, consisting of (i) 31,000,000 AHPAC Class A ordinary shares originally issued in the IPO, and (ii) 7,750,000 AHPAC Class B ordinary shares that were initially issued to the sponsor, a portion of which was transferred to certain independent directors following the IPO. There are currently no shares of AHPAC preferred stock issued and outstanding. In addition, AHPAC issued 31,000,000 public warrants to purchase AHPAC Class A ordinary shares as part of the units sold in the IPO and 16,400,000 private placement warrants to the sponsor in a private placement concurrently with the IPO. Each warrant entitles its holder to purchase one-half of one AHPAC Class A ordinary share where two warrants must be exercised for one whole AHPAC Class A ordinary share at an exercise price of $11.50 per share, and can be exercised only for a whole number of AHPAC Class A ordinary shares. The warrants will become exercisable on the later of 30 days after the completion of the business combination and October 14, 2017, and they expire five years after the completion of the business combination or earlier upon their redemption or liquidation. Once the warrants become exercisable, the public warrants may be redeemed, at a price of $0.01 per warrant, if the last sale price of the AHPAC Class A ordinary shares equals or exceeds $24.00 per share for any 20 trading days within a 30 trading day period ending on the third business day before the notice of redemption is sent to the warrant holders. The private placement warrants, however, are non-redeemable so long as they are held by the sponsor or its permitted transferees. For more information regarding the warrants, please see the section entitled "Description of Securities."



•

On the effective date of the domestication, each currently issued and outstanding AHPAC Class A ordinary share will be exchanged, on a one-for-one basis, for a share of ENVG Class A common stock. Similarly, each currently issued and outstanding AHPAC Class B ordinary share will be exchanged, on a one-for-one basis, for a share of ENVG Class B common stock. In




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addition, all outstanding warrants to acquire AHPAC Class A ordinary shares will become warrants to acquire a corresponding number of shares of ENVG Class A common stock on the same terms as in effect immediately prior to the effective time of the domestication. No other changes will be made to the terms of any outstanding warrants to acquire AHPAC Class A ordinary shares as a result of the domestication. See the section entitled "Proposal No. 2—The Domestication Proposal."

•

Envigo is a full service, non-clinical contract research organization (CRO) providing mission-critical research services and products for biopharmaceutical, crop protection and chemical companies, as well as universities, governments and other research organizations. Envigo provides its customers with animal research models used in basic research and product development, and nonclinical testing of compounds to support product registration. Utilizing its portfolio of services and products, Envigo enables its clients to create a more flexible product development model and reduce their costs, enhance their productivity, and increase speed to market.

        For more information about Envigo, please see the sections entitled "Information about Envigo," "Envigo Management's Discussion and Analysis of Financial Condition and Results of Operations", "Envigo Management" and "Management after the Business Combination."

•

Subject to the terms of the Transaction Agreement and customary adjustments set forth therein, the aggregate purchase price payable to the Selling Equityholders in connection with the business combination and related transactions is expected to consist of approximately (a) $428.88$322.44 million (the "purchase price"), subject to adjustment as described in the following sentence, in cash and shares of ENVG Class A common stock, (b) 4.10 million warrants to purchase one-half of one share of ENVG Class A common stock and (c) rights to certain payments under the Tax Receivables Agreement. The purchase price will be reduced by, among other things, the aggregate amount of transaction expenses incurred by Envigo in connection with the negotiation and consummation of the business combination plus the cost of the 4.10 million warrants being purchased from the sponsor for distribution to the Selling Equityholders.combination. It is anticipated that this adjustment will result in a deduction toreduction of the purchase price ofby approximately $38.5$42.3 million (including non-cash expenses in the amount of $8.3$7.8 million). The cash and stock consideration to be paid to thecertain Selling Equityholders will be funded with approximately 39.8728.80 million newly issued shares of ENVG Class A common stock, which amount is reduced to the extent Selling Equityholders elect to receive $10.00 in cash in lieu of each share of ENVG Class A common stock such Selling Equityholder would otherwise be entitled to receive, subject to an aggregate limit on cash consideration of $100 million (which amount may be increased or reduced as described in the Transaction Agreement), and the aforementioned cash. For more information about the Transaction Agreement, please see the section entitled "The Transaction Agreement."



•

It is anticipated that, upon completion of the business combination: (i) AHPAC's public shareholders will retain an ownership interest of approximately 47.9%57.7% in ENVG; (ii) the sponsor will own approximately 6.0%5.6% of ENVG and (iii) the Selling Equityholders will own approximately 46.1%36.7% of ENVG. The ownership percentages of ENVG following the business combination assume that no shares are elected to be redeemed and do not take into account (a) the warrants to purchase ENVG Class A common stock that will be issued in connection with and remain outstanding following the business combination, or (b) the issuance of any ENVG Class A common stock in connection with the equity financing (if any) or (c) the consummation of a Debt Refinancing (if any). For more information, please see the sections entitled "Summary of the Proxy Statement/Prospectus— Ownership of AHPAC" and "Unaudited Pro Forma Condensed Combined Financial Information." See the section titled "The Business Combination—The Transaction Agreement—Equity Financing" beginning on page [    ·    ]86 of this proxy statement/




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prospectus for further details regarding AHPAC's obligations in connection with the equity financing. See the section titled "The Transaction Agreement—Related Agreements—Financing Arrangements" beginning on page [    ·    ]129 of this proxy




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statement/prospectus for further details regarding Envigo's obligations in connection with a Debt Refinancing.

•

AHPAC's management and the AHPAC Board considered various factors in determining whether to approve the Transaction Agreement and the transactions contemplated thereby, including the business combination. See the section entitled "The Business Combination—The AHPAC Board's Reasons for the Approval of the Business Combination" on page [    ·    ]93 of this proxy statement/prospectus.



•

In addition to voting on the proposals to approve the business combination and the domestication, at the general meeting, the shareholders of AHPAC will be asked to vote on:



•

The Charter Proposals— To consider and vote upon nine separate proposals to approve, assuming the Business Combination Proposal and the Domestication Proposal are approved and adopted, certain material differences between AHPAC's existing amended and restated memorandum and articles of association and the proposed certificate and proposed bylaws of ENVG following the domestication, which we refer to collectively as the "Charter Proposals";



•

Proposal No. 12—The Director Election Proposal—To consider and vote upon a proposal to elect seven directors to serve staggered terms on ENVG's Board of Directors until the 2019, 2020 and 2021 annual meeting of shareholders, respectively, and until their respective successors are duly elected and qualified, which we refer to as the "Director Election Proposal";



•

Proposal No. 13—The Management Incentive Plan Proposal—To consider and vote on a proposal to approve and adopt, assuming the Charter Proposals, the Domestication Proposal and the Business Combination Proposal are all approved and adopted, the Envigo International Holdings, Inc. 2017 Omnibus2018 Equity Incentive Plan (the "2017 Omnibus"2018 Equity Incentive Plan") and the material terms thereunder, which we refer to as the "Management Incentive Plan Proposal". A copy of the 2017 Omnibus2018 Equity Incentive Plan is attached to the accompanying proxy statement/prospectus asAnnex G;



•

Proposal No.��14—The NASDAQ Proposal—To consider and vote upon a proposal to approve, assuming the Charter Proposals, the Domestication Proposal and the Business Combination Proposal are all approved and adopted, for purposes of complying with applicable provisions of NASDAQ Listing Rule 5635, the issuance of more than 20% of AHPAC's issued and outstanding ordinary shares (or issued and outstanding common stock following the domestication) to the Selling Equityholders in connection with the business combination and to participants in the equity financing (if any), that may be deemed a change of control, which we refer to as the "NASDAQ Proposal"; and



•

Proposal No. 15—Adjournment Proposal—To consider and vote upon a proposal to approve the adjournment of the general meeting to a later date or dates, if necessary, to permit further solicitation and vote of proxies in the event that there are insufficient votes for, or otherwise in connection with, the approval of one or more proposals to be submitted for shareholder approval at the general meeting, which we refer to as the "Adjournment Proposal."

Please see the sections entitled"Proposal No. 1—The Business Combination Proposal,""Proposal No. 2—The Domestication Proposal," "The Charter Proposals,""Proposal No. 12—The Director Election Proposal," "Proposal No. 13—The Management Incentive Plan Proposal," "Proposal No. 14—The NASDAQ Proposal" and"Proposal No. 15—The Adjournment Proposal." The




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transactions contemplated by the Transaction Agreement will be consummated only if the Business Combination Proposal, the Domestication Proposal, the Charter Proposals and the




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NASDAQ Proposal are approved at the general meeting. Each other proposal is conditioned on the approval of the Business Combination Proposal, the Domestication Proposal, the Charter Proposals and the NASDAQ Proposal, other than the Adjournment Proposal, which is not conditioned on the approval of any other proposal set forth in this proxy statement/prospectus.

•

Unless waived by the parties to the Transaction Agreement, and subject to applicable law, the consummation of the business combination is subject to a number of conditions set forth in the Transaction Agreement including, among others, termination of the waiting period under the HSR Act and receipt of certain shareholder approvals contemplated by this proxy statement/prospectus. For more information about the closing conditions to the business combination, please see the section entitled "The Transaction Agreement —Conditions to Closing of the Business Combination."



•

The Transaction Agreement may be terminated at any time prior to the consummation of the business combination upon agreement of AHPAC and Envigo. For more information about the termination rights under the Transaction Agreement, please see the section entitled "The Transaction Agreement—Termination."



•

The proposed business combination involves numerous risks. For more information about these risks, please see the section entitled "Risk Factors."



•

In considering the recommendation of the AHPAC Board to vote for the proposals presented at the general meeting, including the Business Combination Proposal, you should be aware that aside from their interests as shareholders, the sponsor and certain members of the AHPAC Board and officers have interests in the business combination that are different from, or in addition to, the interests of AHPAC's shareholders generally. The AHPAC Board was aware of and considered these interests, among other matters, in evaluating and negotiating the business combination and transaction agreements and in recommending to AHPAC's shareholders that they vote in favor of the proposals presented at the general meeting, including the Business Combination Proposal. Shareholders should take these interests into account in deciding whether to approve the proposals presented at the general meeting, including the Business Combination Proposal. See the sections "The Business Combination—Interests of Certain Persons in the Business Combination" and "—The AHPAC Board's Reasons for the Approval of the Business Combination" for more information.




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SUMMARY OF THE PROXY STATEMENT/PROSPECTUS


        This summary highlights selected information contained in this proxy statement/prospectus and does not contain all of the information that is important to you. You should read carefully this entire proxy statement/prospectus, including the Annexes and accompanying financial statements of AHPAC and Envigo, to fully understand the proposed business combination (as described below) before voting on the proposals to be considered at the general meeting (as described below). Please see the section entitled "Where You Can Find More Information" beginning on page[    ·    ] 267 of this proxy statement/prospectus.

        Unless otherwise specified, all share calculations assume (i) no exercise of redemption rights by AHPAC's public shareholders; (ii) no inclusion of any AHPAC Class A ordinary shares issuable upon the exercise of AHPAC's warrants; (iii) the consummation of a Lender Consent and Amendment, and not athe Debt Refinancing; and (iv) anno equity raise of approximately $[    ·    ] of gross proceeds from the equity financing at $10.00 per share will fund a portion of the cash consideration payable to Selling Equityholders pursuant to the Transaction Agreement for the business combination and related transactions.financing.

Parties to the Business Combination


AHPAC


        AHPAC is a blank check company incorporated on December 4, 2015 as a Cayman Islands exempted company formed for the purpose of effecting a merger, share exchange, asset acquisition, share purchase, reorganization or similar business combination with one or more businesses.

        AHPAC's publicly traded ordinary shares, units and warrants are currently listed on the NASDAQ Capital Market under the symbols "AHPA," "AHPAU" and "AHPAW," respectively. AHPAC intends to apply to continue the listing of our publicly traded ENVG common stock and warrants on NASDAQ under the symbols "ENVG" and "ENVGW," respectively, upon the closing of the business combination. As a result, AHPAC's publicly traded units may separate into the component securities upon consummation of the business combination and, as a result, may no longer trade as a separate security.

        The mailing address of AHPAC's principal executive office is 65 East 55th Street, 18th Floor, New York, New York.

AHPAC Merger Sub


        AHPAC Merger Sub, a Delaware corporation, is a wholly-owned subsidiary of AHPAC, formed by AHPAC on August 17, 2017, to consummate the business combination. In the business combination, AHPAC Merger Sub will merge with and into Envigo, with Envigo continuing as the surviving entity.

        The mailing address of AHPAC's principal executive office is 65 East 55th Street, 18th Floor, New York, New York.

AHPAC NewCo


        AHPAC NewCo, a Delaware limited liability company, is a wholly-owned subsidiary of AHPAC, formed by AHPAC on August 17, 2017, to consummate the business combination. In the business combination, immediately following the merger of AHPAC Merger Sub with and into Envigo, Envigo will merge with and into AHPAC NewCo, with AHPAC NewCo continuing as the surviving entity and changing its name to "Envigo Intermediate Holdings, LLC".

        The mailing address of AHPAC's principal executive office is 65 East 55th Street, 18th Floor, New York, New York.




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Envigo


        Envigo is a full service, non-clinical contract research organization ("CRO") providing mission-critical research services and products for biopharmaceutical, crop protection and chemical companies,




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as well as universities, governments and other research organizations. Envigo provides its customers with non-clinical testing of compounds to support product registration and animal research models used in basic research and product development. Utilizing its portfolio of services and products, Envigo enables its clients to create a more flexible product development model and reduce their costs, enhance their productivity, and increase speed to market. Envigo has two reporting segments: Contract Research Services ("CRS") and Research Models and Services ("RMS").

        Envigo's CRS business segment provides laboratory-based, non-clinical testing services that enables its clients to outsource their critical, regulatory-required safety assessment testing and related product development activities to Envigo. The demand for these services has historically been driven by the needs of multinational companies that exceeded their internal capacity or for which it was more efficient to outsource, and by the needs of small companies and non-profits that traditionally outsourced most of their R&D activities. Envigo is one of the three largest providers of non-clinical development testing services worldwide, offering a comprehensive portfolio of non-clinical services, including safety assessment studies required for regulatory submission. Envigo has extensive expertise in the design, execution and reporting of studies for all classes of drug candidates, as well as crop protection and industrial chemical entities. Envigo currently provides non-clinical research services at multiple facilities located in the United States (US), United Kingdom (UK), mainland Europe, and Israel. Envigo's CRS segment represented approximately 60% of our total revenue in 2016 and employed approximately 2,000 people.

        Envigo is the second largest provider of RMS globally. Through its RMS segment, Envigo has been supplying research models since 1931. With over 120 different strains, Envigo is a global leader in the production and sale of the most widely used rodent research model strains, among other species. Envigo manufactures and sells premium Teklad brand diets and bedding for laboratory animals. Envigo also provides a variety of related services that are designed to assist its clients in the use of animal models in research and development. Envigo maintains production centers, including barrier and isolator facilities, in North America, UK, Europe, the Middle East and Asia. In 2016, RMS accounted for approximately 40% of Envigo's total revenue and employed approximately 1,200 people.

Envigo's Market


        The market for Envigo's services includes biopharmaceutical, crop protection and chemical companies that outsource non-clinical testing, as well as universities, governments and other research organizations. Envigo believes that it is well positioned to benefit from the following market trends:

        Increased R&D spending by biopharmaceutical companies.    Multiple market reports indicate that global biopharmaceutical R&D expenditure will grow 3-5% over the next 5 years. Drivers of this growth include the increased complexity of studies required by global drug regulators to better predict safety and efficacy of compounds in development and growth in personalized medicine leading to more targets for discovery and safety assessment work.

        Higher outsourcing penetration.    The rate of outsourcing for non-clinical research is currently estimated at approximately 50% and has been growing for over 20 years. The drivers of increased outsourcing include the need to maximize R&D productivity and the increasing technical complexity of product development. Biopharmaceutical companies are streamlining operations and continue to shift research activities to external providers in order to lower their fixed costs.

        Focus on partnering with strategic suppliers.    Multinational companies have recognized the high costs and organizational inefficiency of working with a large number of suppliers. They wish to develop




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more strategic relationships with a limited number of vendors to accelerate product development and lower costs. As a result, they preferentially seek to partner with larger CROs that possess the necessary resources, global network, capacity, and expertise to support all products in their portfolios.




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        Increasingly stringent government regulation of chemicals and crop protection products.    Global consumers and regulators are concerned about the potential impact of chemicals and crop protection products on human health and the environment. Moreover, the science and technology used in safety testing has advanced over time, yet many chemicals in use today were tested for safety decades ago. These factors drive a strong regulatory environment that generates demand for Envigo's services.

Envigo's Competitive Strengths


        Envigo believes that it is well positioned to capitalize on favorable trends in the CRO industry and provide differentiated solutions to its customers based on our key competitive strengths set forth below:

•

Full service capabilities with global reach.  Envigo is one of only three global companies that can perform end-to-end non-clinical testing from early development to product registration for biologics and small molecules. Envigo's CRS business has a global presence with the full service capabilities necessary to win preferred provider contracts with large multinational customers. Envigo believes its extensive service and product offering, combined with its global infrastructure, provides Envigo with a significant advantage over smaller, more regionally focused CROs, especially among multinational companies seeking long term preferred partnerships with a short-list of vendors that can support all of the products in their portfolios.



•

Diversified, loyal and growing customer base.  In 2016, Envigo provided non-clinical research services to more than 800 clients, many among the largest global pharmaceutical, industrial chemical and crop protection companies. Due to the quality of Envigo's services and long-standing relationships, approximately 84% of Envigo's CRS orders in 2016 came from repeat customers. Furthermore, Envigo's business with crop protection and industrial chemical companies is independent of the pharmaceutical R&D cycle. Envigo's RMS business served more than 3,000 customers in the most recent year with high repeat orders, and supplies many of the largest biopharmaceutical, biotechnology, academic, government and contract research organizations globally.



•

Deep scientific expertise in providing mission-critical services and products.  Envigo provides a breadth and depth of scientific expertise and capabilities that are costly for its clients to build and/or maintain in-house, including biomarkers, biologics, in vitro screening, in vivo pharmacology, immunology, pathology, and other specialty services. Envigo's long track record and reputation for high quality work with all relevant regulatory agencies provides a distinct competitive advantage in the market. Its functional expertise includes in vitro and in vivo assay development, toxicology, veterinary pathology, and bioanalysis.



•

Commitment to Animal Welfare.  Envigo is on the forefront of humane care of laboratory animals and implementation of the "3Rs" (Replacement, Reduction and Refinement). Envigo maintains the highest standards of animal welfare as evidenced by its strong compliance record with regulators across the globe. Envigo frequently advises its clients in matters relating to animal welfare, including enrichment, housing, animal husbandry, and study design refinement.



•

Experienced management team and stable, high quality workforce.  Each of the members of Envigo's senior management has 15 years or more of relevant experience, including significant experience across the CRO and pharmaceutical industries. Envigo maintains a staff which includes PhD-level scientists across a variety of disciplines, providing its customers with deep scientific expertise.




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Envigo's Growth Strategy


        Envigo's objective is to be a preferred strategic partner for its clients. Envigo's strategy is to deliver a comprehensive portfolio of non-clinical development services and products to support its customers'




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research, development and product stewardship requirements, and enable them to conduct essential research faster and more cost effectively.

•

Strengthen existing and develop new strategic partnerships.  Envigo believes its long-term relationships with a wide range of customers are a key driver of its success. The combination of its CRS and RMS offerings provides cross-selling opportunities and enhances Envigo's position with customers. Envigo believes its global reach, high quality facilities and full service capabilities will enable Envigo to capitalize upon the trend toward greater outsourcing by providing additional services to its existing customers and developing relationships with new ones.



•

Improve margins through focus on operational efficiencies.  Envigo's management team is focused on improving efficiencies and optimizing its cost structure. Envigo is implementing an ongoing program of business optimization that will continue to expand its margins, including consolidating certain back office functions currently located at the divisional level, rolling out sales organization changes to increase revenue and focusing on RMS footprint and logistics to continue driving RMS margin expansion.



•

Continuously improve its quality and customer experience.  Envigo uses LEAN and other proven operational excellence methodologies to optimize its processes and eliminate variability in client service levels. Envigo employs dedicated business process excellence staff to support continuous improvement initiatives across the company.



•

Drive its human capital asset base to grow existing relationships.  As a CRO, Envigo's employees are critical to its ability to deliver its operational model by engaging with customers, delivering services in a complex environment and supporting and executing our growth strategy. Envigo's recruiting and retention efforts are geared towards maintaining a stable work force focused on delivering results for customers.



•

Acquisitions.  In addition to organic development of services, Envigo considers acquisitions that are complementary to its existing services and that expand Envigo's ability to serve its clients. Envigo generally expects acquisitions to enhance its existing services either qualitatively or geographically or to add new services that can be integrated with its existing services.

        The mailing address of Envigo's principal executive office is 100 Mettlers Road, East Millstone, NJ 08873, c/o Envigo International Holdings, Inc. For more information about Envigo, please see the sections entitled "Information About Envigo," "Envigo Management's Discussion and Analysis of Financial Condition and Results of Operations" and "Management after the business combination."

Shareholder Representative


        Jermyn Street Associates LLC is a Delaware limited liability company with a mailing address of 401 Hackensack Avenue, Hackensack, NJ 07601.

The Business Combination Proposal


        On August 21, 2017, AHPAC entered into the Transaction Agreement, which provides for, among other things, an integrated transaction consisting of (i) the merger of AHPAC Merger Sub with and into Envigo, with Envigo surviving the merger (the "first merger"), and then (ii) immediately thereafter, the merger of Envigo with and into AHPAC NewCo, with AHPAC NewCo surviving the merger (the "second merger," and together with the first merger, the "mergers").For more information about the transactions contemplated in the Transaction Agreement, please see the sections




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entitled "The Business Combination" and "The Transaction Agreement." A copy of the Transaction Agreement, including each amendment thereto through the date hereof is attached to this proxy statement/prospectus asAnnex A.




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Consideration to Selling Equityholders in the Business Combination


Tax Receivable Consideration


        Subject to the terms and conditions of the Transaction Agreement, each Selling Equityholder will receive certain payments under the Tax Receivable Agreement (the "Tax Receivable Consideration"), as described in the section titled "The Transaction Agreement—Related Agreements—Tax Receivable Agreement".

        The Tax Receivable Consideration received by each Selling Equityholder will be such holder's pro rata share (based on the ratio of the number of shares of Envigo Class A common stock (including any shares underlying any options, stock appreciation rights or warrants) held by such holder to the fully diluted total shares of Envigo) of certain payments under the Tax Receivable Agreement.

Holders of Envigo Class A common stock


        Subject to the terms and conditions of the Transaction Agreement, each share of Envigo Class A common stock will be converted into the right to receive, in addition to the Tax Receivable Consideration, (i) cash consideration (the "Cash Consideration"), or stock consideration (the "Stock Consideration") or a combination thereof (at such holder's election, subject to the limitations described below), and (ii) a number of warrants to purchase one-half of one share of ENVG Class A common stock as described below (the "New Warrant Consideration").

        The Cash Consideration will be an amount in cash equal to:

•

the quotient obtained by dividing (x) $390,133,441(subject$283,686,737 (subject to certain adjustments described in the Transaction Agreement) by (y) the fully diluted total shares of Envigo (the "Per Share Merger Value"); plus



•

the product of (x) $10.00 multiplied by (y) the quotient obtained by dividing (A) 3,875,000 by (B) the fully diluted total shares of Envigo (the "Cash Election Value").

        The Stock Consideration will be calculated as follows:

•

a number of newly issued shares of ENVG Class A common stock equal to the quotient obtained by dividing (x) the Per Share Merger Value by (y) $10.00; plus



•

a number of newly issued shares of ENVG common stock equal to the quotient obtained by dividing (x) 3,875,000 by (y) the fully diluted total shares of Envigo.

        The New Warrant Consideration will be a number of warrants to purchase one-half of one share of ENVG Class A common stock, where two warrants may be exercised for one whole share of ENVG Class A common stock at an exercise price of $11.50 per share, equal to the quotient obtained by dividing (x) 4,100,000 by (y) the fully diluted total shares of Envigo.

        The Cash Consideration, the New Warrant Consideration and the Tax Receivable Consideration are referred to, collectively, as the "Per Share Total Cash Consideration"; and the Stock Consideration, the New Warrant Consideration and the Tax Receivable Consideration are referred to, collectively, as the "Per Share Total Stock Consideration".

Holders of Envigo Warrants


        Subject to the terms and conditions of the Transaction Agreement, each warrant to purchase one share of Envigo Class A common stock ("Envigo Series A Warrant") and each warrant to purchase one share of Envigo Class B common stock ("Envigo Series B Warrant") (only if they become exercisable




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in the case of the Series B Warrants) will be converted into the right to receive, in addition to the Tax Receivable Consideration, (i) the New Warrant Consideration, plus (ii) a warrant to purchase, at such




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holder's election, either (a) the Per Share Total Cash Consideration (net of the exercise price) or (b) the Per Share Total Stock Consideration (net of the exercise price).

Holders of Envigo Options


        Subject to the terms and conditions of the Transaction Agreement, each option to purchase shares of Envigo Class A common stock for which the Per Share Merger Value is greater than the exercise price ("Envigo option") will be exchanged for the right to receive in addition to the Tax Receivable Consideration payable during the first five years after the Closing Date, (i) the New Warrant Consideration plus (ii) (a) in the case of Envigo options for which cash consideration is elected, an amount in cash equal to the Cash Consideration less the exercise price, or (b) in the case of Envigo options for which stock consideration is elected or deemed elected, (1) a number of newly issued shares of ENVG common stock equal to the quotient obtained by dividing the Cash Election Value (less the exercise price) by $10.00, and (2) a number of shares of ENVG Class A common stock equal to the quotient obtained by dividing 3,875,000 by the fully diluted shares of Envigo.

Holders of Envigo SARs


        Subject to the terms and conditions of the Transaction Agreement, each stock appreciation right granted in respect of Envigo Class A common stock for which the Per Share Merger Value is greater than the base price ("Envigo SAR") will be converted into the right to receive, in addition to the Tax Receivable Consideration payable during the first five years after the Closing Date, (i) the Cash Consideration, less the base price and (ii) an additional amount in cash commensurate in value to the New Warrant Consideration.

Limitations on ability of Selling Equityholders to make cash elections


        Each Selling Equityholder (other than a holder of Envigo SARs) who does not make any election will be deemed to have made an election to receive the Stock Consideration. If the aggregate amount of cash otherwise payable in respect of the cash elections exceeds the Cash Component (as described below), the elections of Selling Equityholders (other than holders of Envigo SARs) to receive the Cash Consideration will be subject to adjustment as described below.

Cash Component


        Notwithstanding the ability of the Selling Equityholders (other than the holders of Envigo SARs) to make a cash election, the Transaction Agreement provides a limit on the amount of aggregate cash consideration to be to such holders of $100 million, subject to certain adjustments (the "Cash Component"). If the aggregate amount of cash payable in respect the cash elections exceeds the Cash Component, the Exchange Agent will reduce all cash elections pro rata by the amount of such excess, no election shall be deemed made with respect to such shares and, as set forth in the Transaction Agreement, such shares will be converted into and become the right to receive the Stock Consideration.

        For more information about the consideration to the Selling Equityholders, please see the section entitled "The Business Combination—Consideration to Selling Equityholders in the Business Combination".

The Domestication Proposal


        As a condition to consummating the mergers pursuant to the terms of the Transaction Agreement, the AHPAC Board has unanimously approved a change of AHPAC's jurisdiction of incorporation by




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deregistering as an exempted company in the Cayman Islands and continuing and domesticating as a corporation incorporated under the laws of the State of Delaware. To effect the domestication, AHPAC




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will file a notice of de-registration with the Cayman Islands Registrar of Companies, together with the necessary accompanying documents, and file a certificate of incorporation and a certificate of corporate domestication with the Secretary of State of the State of Delaware, under which AHPAC will be domesticated and continue as a Delaware corporation. After the domestication, AHPAC will change its name to "Envigo International Holdings, Inc." We refer to AHPAC following effectiveness of the domestication as "ENVG." On the effective date of the domestication, each currently issued and outstanding AHPAC Class A ordinary share will be exchanged, on a one-for-one basis, for a share of ENVG Class A common stock. Similarly, each currently issued and outstanding AHPAC Class B ordinary share will be exchanged, on a one-for-one basis, for a share of ENVG Class B common stock. In addition, all outstanding warrants to acquire AHPAC Class A ordinary shares will become warrants to acquire a corresponding number of shares of ENVG Class A common stock on the same terms as in effect immediately prior to the effective time of the domestication. No other changes will be made to the terms of any outstanding warrants to acquire AHPAC Class A ordinary shares as a result of the domestication. See the section entitled "Proposal No. 2—The Domestication Proposal".

Related Agreements


Tax Receivable Agreement


        At the closing of the business combination, ENVG will enter into a Tax Receivable Agreement, substantially in the form attached hereto asAnnex D, with Envigo Holdings, Inc. and the shareholder representative on behalf of the Selling Equityholders. See the sections titled "The Transaction Agreement—Related Agreements—Tax Receivable Agreement" and "AHPAC's Management's Discussion and Analysis of Financial Condition and Results of Operations—Liquidity and Capital Resources—Tax Receivable Agreement" beginning on page [    ·    ]175 of this proxy statement/prospectus for more information.

Amended and Restated Registration Rights Agreement


        At the closing of the business combination, AHPAC, the sponsor and the restricted stockholders will enter into an Amended and Restated Registration Rights Agreement in respect of the shares of ENVG common stock and ENVG warrants issued to the restricted stockholders in connection with the business combination, providing for, among other things, customary registration rights, including demand and piggy-back rights, subject to cut-back provisions. See the section titled "The Transaction Agreement—Related Agreements—Amended and Restated Registration Rights Agreement" beginning on page [    ·    ]127 of this proxy statement/prospectus for more information.

Organizational Structure


        The following diagram depicts the current ownership structure of Envigo:






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        The following diagram, which is subject to change based upon any redemptions by AHPAC's current public shareholders in connection with the business combination, illustrates the ownership structure of ENVG immediately following the business combination:



Redemption Rights


        Pursuant to AHPAC's existing amended and restated memorandum and articles of association, a holder of AHPAC's public shares may request that AHPAC redeem all or a portion of such shareholder's public shares (which will become shares of ENVG Class A common stock in the domestication) for cash if the business combination is consummated. Holders of units of AHPAC (the "AHPAC units") must elect to separate the underlying public shares and warrants ("public warrants") prior to exercising redemption rights with respect to the public shares. If holders hold their AHPAC units in an account at a brokerage firm or bank, holders must notify their broker or bank that they elect to separate the AHPAC units into the underlying public shares and public warrants, or if a holder holds units registered in its own name, the holder must contact the transfer agent directly and instruct it to do so. For the purposes of Article 49.3 of AHPAC's amended and restated memorandum and articles of association and the Cayman Islands Companies Law (2016 Revision), the exercise of redemption rights shall be treated as an election to have such public shares repurchased for cash and references in this proxy statement/prospectus shall be interpreted accordingly.

        If a public shareholder properly exercises its right to redeem its public shares and timely delivers its shares to the transfer agent, AHPAC will redeem each public share for a per-share price, payable in cash, equal to the aggregate amount then on deposit in the trust account, calculated as of two business days prior to the consummation of the business combination, including interest, less income taxes payable, divided by the number of then issued and outstanding public shares;provided that AHPAC will not redeem any AHPAC Class A ordinary shares issued in the IPO to the extent that such redemption




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would result in AHPAC having net tangible assets (as determined in accordance with Rule 3a51-1(g)(1) of the Exchange Act) of less than $5,000,001. For illustrative purposes, as of NovemberJanuary 17, 2017,2018, this would have amounted to approximately $10.07$10.08 per public share. Notwithstanding the foregoing, a holder of the public shares, together with any affiliate of his or her or any other person with whom he or she is acting in concert or as a "group" (as defined in Section 13(d)-(3) of the Exchange Act) will be restricted from seeking redemption rights with respect to more than 15% of the AHPAC Class A ordinary shares included in the units sold in the IPO.

        If a public shareholder exercises its redemption rights, then it will be exchanging its redeemed public shares for cash and will no longer own such shares. Such a holder will be entitled to receive cash for its public shares only if it properly demands redemption and delivers its shares (either physically or electronically) to AHPAC's transfer agent in accordance with the procedures described herein. If the business combination is not consummated, the public shares will not be redeemed for cash. Please see the section entitled "Annual General Meeting of AHPAC Shareholders—Redemption Rights" for the procedures to be followed if you wish to redeem your shares for cash.

Ownership of AHPAC


        It is anticipated that, upon completion of the business combination: (i) AHPAC's public shareholders will retain an ownership interest of approximately 47.9%57.7% in ENVG; (ii) the sponsor will own approximately 6.0%5.6% of ENVG and (iii) the Selling Equityholders will own approximately 46.1%36.7% of ENVG. The ownership percentages of ENVG following the business combination assume that no shares are elected to be redeemed and do not take into account (a) the warrants to purchase ENVG Class A common stock that will be issued in connection with and remain outstanding following the business combination, or (b) the issuance of any ENVG Class A common stock in connection with the equity financing (if any) or (c) the consummation of a Debt Refinancing (if any). See the section titled "The Business Combination—The Transaction Agreement—Equity Financing" beginning on page [    ·    ]86 of this proxy statement/prospectus for further details regarding AHPAC's obligations in connection with the equity financing. See the section titled "The Transaction Agreement—Related Agreements—Financing Arrangements" beginning on page [    ·    ]129 of this proxy statement/prospectus for further details regarding Envigo's obligations in connection with a Debt Refinancing.

        The following table illustrates varying ownership levels in ENVG following the business combination, assuming varying levels of redemptions by AHPAC's public shareholders:

		No Redemptions						[·] Million Public Shares Redeemed							No Redemptions						9 Million Public Shares Redeemed
		No Exercise of Private Placement Warrants			Assuming Exercise of Private Placement Warrants			No Exercise of Private Placement Warrants			Assuming Exercise of Private Placement Warrants				No Exercise of Private Placement Warrants			Assuming Exercise of Private Placement Warrants			No Exercise of Private Placement Warrants			Assuming Exercise of Private Placement Warrants
Public shareholders			[·]	%		[·]	%		[·]	%		[·]	%			57.7	%		57.8	%		41.4	%		41.9	%
Private placement investors (other than the sponsor)			[·]	%		[·]	%		[·]	%		[·]	%
Sponsor			[·]	%		[·]	%		[·]	%		[·]	%			5.6	%		6.0	%		5.7	%		6.1	%
Selling Equityholders (other than management)			[·]	%		[·]	%		[·]	%		[·]	%			34.7	%		34.2	%		50.5	%		49.7	%
Envigo management			[·]	%		[·]	%		[·]	%		[·]	%			2.0	%		1.9	%		2.3	%		2.3	%
​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​
			100	%		100	%		100	%		100	%			100	%		100	%		100	%		100	%
​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​
​
​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​

Board of Directors of AHPAC Following the Business Combination


        Upon consummation of the business combination, the AHPAC Board anticipates increasing its initial size from six directors to seven directors, which will be comprised of three classes: Class I will have 2 members, Class II will have 2 members and Class III will have 3 members. Each Class I director




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will have a term that expires at AHPAC's annual meeting of shareholders in 2019, each Class II




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director will have a term that expires at AHPAC's annual meeting of shareholders in 2020 and each Class III director will have a term that expires at AHPAC's annual meeting of shareholders in 2021, or in each case until their respective successors are duly elected and qualified, or until their earlier resignation, removal or death. Please see the sections entitled "Proposal No. 12—The Director Election Proposal" and "Management After the Business Combination" for additional information.

The Charter Proposals


        To consider and vote upon nine separate proposals to approve, assuming the Business Combination Proposal and the Domestication Proposal are approved and adopted, the following material differences between AHPAC's existing amended and restated memorandum and articles of association and the proposed certificate and proposed bylaws of ENVG upon the domestication:

3.

Proposal No. 3—To consider and vote upon an amendment to AHPAC's existing organizational documents to authorize the classification of the Board into three classes of directors, which shall consist of, as nearly as may be possible, one-third of the total number of directors on the Board, which will initially be seven (7) and then as may be set by the Board from time to time;



4.

Proposal No. 4—To consider and vote upon an amendment to AHPAC's existing organizational documents to authorize that directors may only be removed for cause;



5.

Proposal No. 5—To consider and vote upon an amendment to AHPAC's existing organizational documents to authorize that only the Board, chairperson of the board of directors or chief executive offer may call a meeting of stockholders;



6.

Proposal No. 6—To consider and vote upon an amendment to AHPAC's existing organizational documents to authorize removal of the ability of stockholders to take action by written consent in lieu of a meeting;



7.

Proposal No. 7—To consider and vote upon an amendment to AHPAC's existing organizational documents to require the affirmative vote of holders of a majority of the voting power of ENVG's then issued and outstanding shares of stock entitled to amend the proposed certificate;



8.

Proposal No. 8—To consider and vote upon an amendment to AHPAC's existing organizational documents to authorize the adoption of Delaware as the exclusive forum for certain stockholder litigation;



9.

Proposal No. 9—To consider and vote upon an amendment to AHPAC's existing organizational documents to authorize ENVG to permit the ENVG Sponsors to engage in competitive businesses and renounce certain corporate opportunities offered to the ENVG Sponsors or any of their managers, officers, directors, agents, stockholders, members, partners, affiliates and subsidiaries (other than ENVG and its subsidiaries) that are not expressly offered to them in their capacities as directors or officers of ENVG;



10.

Proposal No. 10—To consider and vote upon an amendment to AHPAC's existing organizational documents to approve the authorized number of shares of ENVG common stock contained in the proposed certificate; and



11.

Proposal No. 11—To consider and vote upon an amendment to AHPAC's existing organizational documents to authorize other changes to ENVG's organizational documents resulting from the domestication and business combination, including changing the post-business combination corporate name from "Avista Healthcare Public Acquisition Corp." to "Envigo International Holdings, Inc." and removing certain provisions relating to our status




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as a blank-check company that will no longer apply upon consummation of the business combination;

        We refer to Proposals No. 3-11 collectively as the "Charter Proposals". Please see the sections entitled "The Charter Proposals" for more information.

Other Proposals


        In addition, the shareholders of AHPAC will be asked to vote on:

•

a proposal to elect seven directors to ENVG's Board, effective upon the consummation of the business combination, with each Class I director having a term that expires at AHPAC's annual meeting of shareholders in 2019, each Class II director having a term that expires at AHPAC's annual meeting of shareholders in 2020 and each Class III director having a term that expires at AHPAC's annual meeting of shareholders in 2021 or in each case until their respective successors are duly elected and qualified, or until their earlier resignation, removal or death, which we refer to as Proposal No. 12—the Director Election Proposal;



•

a proposal to approve and adopt, assuming the Charter Proposals, the Domestication Proposal and the Business Combination Proposal are all approved and adopted, the Envigo International Holdings, Inc. 2017 Omnibus2018 Equity Incentive Plan (the "2017 Omnibus"2018 Equity Incentive Plan") and the material terms thereunder, which we refer to as Proposal No. 13—the Management Incentive Plan Proposal;



•

a proposal to approve, assuming the Charter Proposals, the Domestication Proposal and the Business Combination Proposal are all approved and adopted, for purposes of complying with applicable provisions of NASDAQ Listing Rule 5635, the issuance of more than 20% of AHPAC's issued and outstanding ordinary shares (or issued and outstanding common stock following the domestication) to the Selling Equityholders in connection with the business combination and to participants in the equity financing (if any), that may be deemed a change of control, which we refer to as Proposal No. 14—the NASDAQ Proposal; and



•

a proposal to adjourn the general meeting to a later date or dates, if necessary, to permit further solicitation and vote of proxies if there are insufficient votes for, or otherwise in connection with, the approval of one or more proposals to be submitted for shareholder approval at the general meeting, which we refer to as Proposal No. 15—the Adjournment Proposal.

        Please see the sections entitled "The Charter Proposals," "Proposal No. 12—The Director Election Proposal," "Proposal No. 13—The Management Incentive Plan Proposal," "Proposal No. 14—The NASDAQ Proposal" and "Proposal No. 15—The Adjournment Proposal" for more information.

Date, Time and Place of general meeting


        The general meeting will be held on [    ·    ] at [    ·    ] Eastern Time at the offices of Weil, Gotshal & Manges, LLP located at 767 Fifth Avenue, New York, New York, 10153, or at such other date, time and place to which such meeting may be adjourned or postponed, to consider and vote upon the proposals.

Voting Power; Record Date


        Only AHPAC's shareholders of record at the close of business on [    ·    ],January 16, 2018, the record date for the general meeting, will be entitled to vote at the general meeting. You are entitled to one vote for each AHPAC ordinary share that you owned as of the close of business on the record date. If your shares are held in "street name" or are in a margin or similar account, you should contact your broker, bank or other nominee to ensure that votes related to the shares you beneficially own are properly counted.




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properly counted. On the record date, there were [    ·    ]38,750,000 ordinary shares outstanding and entitled to vote, of which [    ·    ]31,000,000 are AHPAC Class A ordinary shares and [    ·    ]7,750,000 are AHPAC Class B ordinary shares held by the initial shareholders.

Accounting Treatment


        The business combination will be accounted for as a business combination in accordance with Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) No. 805, Business Combinations (ASC 805), which provides guidance on the accounting and reporting for transactions that represent business combinations to be accounted for under the acquisition method of accounting.

        Pursuant to ASC 805, AHPAC has been determined to be the accounting acquirer based on the evaluation of the facts and circumstances including, among other things, the following:

•

AHPAC pays cash and equity consideration for all of the equity in Envigo; and



•

The existing stockholders of AHPAC retain relatively more voting rights in the post-combination business than the Selling Equityholders.

        Additionally, Envigo meets the definition of a business in accordance with ASC 805 which defines a business as an integrated set of activities and assets that is capable of being conducted and managed for the purpose of providing a return in the form of dividends, lower costs, or other economic benefits directly to investors or other owners, members, or participants.

        Under the acquisition method of accounting, the identifiable assets acquired and the liabilities assumed are measured at fair value as of the acquisition date and the difference between the consideration paid and those fair values is recorded as goodwill. Management of AHPAC has made significant estimates and assumptions in the preliminary allocation of the purchase price as reflected in the unaudited pro forma financial information. As the unaudited pro forma financial information has been prepared based on these preliminary estimates, the final amounts recorded may differ materially from the information presented.

        In historical financial statements presented in AHPAC's periodic reporting after the completion of the business combination, the historical financial information of Envigo will be presented as the predecessor for comparative purposes.

        In accordance with ASC 805, acquisition-related costs (such as advisory, legal, valuation and other professional fees) to effect a business combination are accounted for as expenses in the periods in which the costs are incurred and the services are received. AHPAC expects to incur approximately $17 million of acquisition-related costs in connection with the business combination.

        The determination of the acquirer will ultimately be made on the closing date of the transaction and as noted above will be based on the facts and circumstances including, among others, the voting rights in ENVG of the existing AHPAC shareholders post-business combination relative to the voting rights of the Selling Equityholders. There are various scenarios that could change the current expectation that the existing AHPAC shareholders will retain relatively more voting rights post combination than the Selling Equityholders, including the level of AHPAC redemptions (if any), the number of Selling Equityholders that elect to receive cash, whether a Debt Refinancing is consummated, and the value of the equity financing (if any). Changes in the equity ownership under various scenarios relating to redemptions of AHPAC shares, the equity financing, the consummation or terms of a Debt Refinancing or the number of Selling Equityholders who elect to receive cash could result in Envigo being the acquirer for accounting purposes. For further discussion of the impacts of a change in the acquirer, please see the fourth paragraph under the section titled "Unaudited Pro Forma




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Condensed Combined Financial Information" commencing on page [    ·    ]139 of this proxy statement/prospectus.

Appraisal Rights


        Appraisal rights are not available to AHPAC's shareholders in connection with the business combination.

Proxy Solicitation


        Proxies may be solicited by mail. AHPAC has engaged MacKenzie Partners to assist in the solicitation of proxies.

        If a shareholder grants a proxy, it may still vote its shares in person if it revokes its proxy before the general meeting. A shareholder may also change its vote by submitting a later-dated proxy, as described in the section entitled "Annual General Meeting of AHPAC Shareholders—Revoking Your Proxy."

Interests of Certain Persons in the Business Combination


        In considering the recommendation of the AHPAC Board to vote in favor of the business combination, shareholders should be aware that aside from their interests as shareholders, the sponsor and certain members of the AHPAC Board and officers have interests in the business combination that are different from, or in addition to, those of other shareholders generally. The AHPAC Board was aware of and considered these interests, among other matters, in evaluating and negotiating the business combination, and in recommending to shareholders that they approve the business combination. Shareholders should take these interests into account in deciding whether to approve the business combination.

        See the section titled "The Business Combination—Interests of Certain Persons in the Business Combination" for more information.

Reasons for the Approval of the Business Combination


        After careful consideration, the AHPAC Board recommends that the shareholders vote "FOR" each proposal being submitted to a vote at the general meeting. For more information about AHPAC's decision-making process, please see the section entitled "The Business Combination—The AHPAC Board's Reasons for the Approval of the Business Combination."

Conditions to Closing of the Business Combination


Conditions to Each Party's Obligations


        The respective obligations of each of the parties to the Transaction Agreement to effect the transactions contemplated by the Transaction Agreement are subject to the satisfaction, or written waiver by both AHPAC and Envigo, of each of the following conditions:

•

The affirmative vote (in person or by proxy) of the holders of a majority or a two-thirds majority (as applicable) of the issued and outstanding ordinary shares entitled to vote thereon in favor of the Business Combination Proposal, the Domestication Proposal, the NASDAQ Proposal, the Charter Proposals, the Director Election Proposal and the Adjournment Proposal shall have been obtained;



•

The applicable waiting period under the HSR Act shall have expired or been terminated or such approval shall have otherwise been obtained;




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There must not be any legal proceeding by any governmental entity that challenges or seeks to make the business combination illegal or otherwise prohibited instituted, pending or threatened in writing;



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AHPAC shall have at least $5,000,001 of net tangible assets (as determined in accordance with Rule 3a51-1(g)(1) of the Exchange Act) remaining; and



•

(i) Envigo shall have received a Lender Consent and Amendment with respect to each Envigo Credit Agreement and the Existing Third Lien Indenture (as each such term is defined in the Transaction Agreement), (ii) a Debt Refinancing (as such term is defined in the Transaction Agreement) will be consummated at or prior to closing on terms reasonably acceptable to AHPAC or (iii) a combination of the foregoing, which upon the consummation of the transactions contemplated by the Transaction Agreement do not result in a Default or Event of Default (as each such term is defined in each Envigo Credit Agreement) under any Envigo Credit Agreement or the Existing Third Lien Indenture. See the section titled "The Business Combination—Related Agreements—Financing Arrangements" for additional information.

Conditions to AHPAC's Obligations


        The obligations of AHPAC, Merger Sub and NewCo to effect the transactions contemplated by the Transaction Agreement are subject to the satisfaction of certain conditions (any or all of which may be waived in writing in whole or in part exclusively by AHPAC), including, among others, (i) Envigo must have performed and complied in all material respects with all obligations required to be performed or complied with by Envigo under the Transaction Agreement at or prior to the Closing Date and (ii) Envigo and its respective affiliates and subsidiaries shall have terminated, effective as of the closing, all Related Party Agreements (as defined in the Transaction Agreement) of Envigo and/or any of its subsidiaries that have not been specifically disclosed to AHPAC as remaining in effect, with such termination to be effective as of the closing.

Conditions to Envigo's Obligations


        The obligations of Envigo to effect the transactions contemplated by the Transaction Agreement are subject to the satisfaction at or prior to the Closing Date of certain conditions (any or all of which may be waived in writing in whole or in part exclusively by Envigo), including, among others, (i) AHPAC, Merger Sub and NewCo must have performed and complied in all material respects with all obligations required to be performed or complied with under the Transaction Agreement at or prior to the Closing Date, (ii) the ENVG Class A common stock shall have been approved for listing on NASDAQ, AHPAC shall be a listed public company on NASDAQ and the ENVG Class A common stock tradable over NASDAQ and immediately following the first merger effective time, AHPAC shall meet all of the continuing listing requirements of NASDAQ and shall not have received any notice of non-compliance (other than any notice to the extent related to AHPAC's failure to conduct an annual meeting in 2017) and (iii) the funds contained in the trust account (after giving effect to redemptions of public shares) and the proceeds of the equity financing, if any, shall together equal or exceed $260$220 million.

        Please see the section entitled "The Transaction Agreement—Conditions to Closing of the Business Combination" for additional information.

Regulatory Matters


        Under the HSR Act and the rules that have been promulgated thereunder by the U.S. Federal Trade Commission ("FTC"), certain transactions may not be consummated unless information has been furnished to the Antitrust Division of the Department of Justice ("Antitrust Division") and the FTC and certain waiting period requirements have been satisfied. The business combination is subject to




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these requirements and may not be completed until the expiration of a 30-day waiting period following the filing of the required Notification and Report Forms with the Antitrust Division and the FTC or until early termination is granted. On August 31, 2017, AHPAC and Envigo filed the required forms under the HSR Act with the Antitrust Division and the FTC and requested early termination. Early termination of the HSR waiting period was granted on September 13, 2017.

        At any time before or after consummation of the business combination, notwithstanding termination of the waiting period under the HSR Act, the applicable competition authorities could take such action under applicable antitrust laws as each deems necessary or desirable in the public interest, including seeking to enjoin the consummation of the business combination. Private parties may also seek to take legal action under the antitrust laws under certain circumstances. AHPAC cannot assure you that the Antitrust Division, the FTC, any state attorney general, or any other government authority will not attempt to challenge the business combination on antitrust grounds, and, if such a challenge is made, AHPAC cannot assure you as to its result. Neither AHPAC nor Envigo is aware of any material regulatory approvals or actions that are required for completion of the business combination other than the expiration or early termination of the waiting period under the HSR Act. It is presently contemplated that if any such additional regulatory approvals or actions are required, those approvals or actions will be sought. There can be no assurance, however, that any additional approvals or actions will be obtained.

Quorum and Required Vote for Proposals for the general meeting


        A quorum of AHPAC's shareholders is necessary to hold a valid meeting. A quorum will be present at the general meeting if a majority of the ordinary shares outstanding and entitled to vote at the general meeting is represented in person or by proxy. Abstentions will count as present for the purposes of establishing a quorum.

        The approval of each of the Domestication Proposal and each of the Charter Proposals requires the affirmative vote of holders of two-thirds of the ordinary shares represented in person or by proxy and entitled to vote thereon at the general meeting. Accordingly, if an AHPAC shareholder fails to vote by proxy or to vote in person at the general meeting, their shares will not be counted in connection with the determination of whether a valid quorum is established, however, if a valid quorum is otherwise established, such failure to vote will have no effect on the outcome of any vote on the Domestication Proposal or any of the Charter Proposals. Abstentions will be counted in connection with the determination of whether a valid quorum is established and will have the same effect as a vote"AGAINST" the Domestication Proposal and the Charter Proposals.

        The approval of the Business Combination Proposal requires the affirmative vote of holders of a majority of the ordinary shares represented in person or by proxy and entitled to vote thereon at the general meeting. Accordingly, if an AHPAC shareholder fails to vote by proxy or to vote in person at the general meeting, their shares will not be counted in connection with the determination of whether a valid quorum is established, however, if a valid quorum is otherwise established, such failure to vote will have no effect on the outcome of any vote on the Business Combination Proposal. Abstentions will be counted in connection with the determination of whether a valid quorum is established and will have the same effect as a vote"AGAINST" the Business Combination Proposal. The initial shareholders have agreed to vote their founder shares and any public shares they may hold in favor of the business combination. Currently, the initial shareholders own approximately 20% of AHPAC's issued and outstanding ordinary shares, including all of the founder shares.

        The approval of the NASDAQ Proposal, the Director Election Proposal, the Management Incentive Plan Proposal and the Adjournment Proposal requires the affirmative vote of holders of a majority of the ordinary shares represented in person or by proxy and entitled to vote thereon at the general meeting. Accordingly, if an AHPAC shareholder fails to vote by proxy or to vote in person at




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the general meeting, their shares will not be counted in connection with the determination of whether a valid quorum is established, however, if a valid quorum is otherwise established, such failure to vote will have no effect on the outcome of any vote on the NASDAQ Proposal or the Director Election Proposal. Abstentions will be counted in connection with the determination of whether a valid quorum is established and will have the same effect as a vote"AGAINST" the NASDAQ Proposal, the Director Election Proposal and the Adjournment Proposal.

        The transactions contemplated by the Transaction Agreement will be consummated only if the Business Combination Proposal, the Domestication Proposal, the NASDAQ Proposal and the Charter Proposals are approved at the general meeting. Each of the Business Combination Proposal, the Domestication Proposal, the NASDAQ proposal and the Charter Proposals are cross-conditioned on the approval of each other. Each other proposal is conditioned on the approval of the Business Combination Proposal, the Domestication Proposal, the NASDAQ Proposal and the Charter Proposals, other than the Adjournment Proposal, which is not conditioned on the approval of any other proposal set forth in this proxy statement/prospectus.It is important for you to note that in the event that the Business Combination Proposal, the Domestication Proposal, the NASDAQ Proposal or the Charter Proposals do not receive the requisite vote for approval, we will not consummate the business combination. If AHPAC does not consummate the business combination and fail to complete an initial business combination by October 14, 2018, AHPAC will be required to dissolve and liquidate the trust account by returning the then remaining funds in such account to public shareholders.

Recommendation to AHPAC's Shareholders


        The AHPAC Board believes that each of the Business Combination Proposal, the Domestication Proposal, the NASDAQ Proposal, the Charter Proposals, the Director Election Proposal, the Management Incentive Plan Proposal and the Adjournment Proposal to be presented at the general meeting is in the best interests of AHPAC and AHPAC's shareholders and unanimously recommends that its shareholders vote "FOR" each of the proposals.

        When you consider the recommendation of the AHPAC Board in favor of approval of the Business Combination Proposal, you should keep in mind that the sponsor and certain members of the AHPAC Board and officers have interests in the business combination that are different from or in addition to (or which may conflict with) your interests as a shareholder. Shareholders should take these interests into account in deciding whether to approve the business combination. For a discussion of these interests, please see the section titled "Annual General Meeting of AHPAC Shareholders—Recommendation to AHPAC's Shareholders" beginning on page [    ·    ]77 of this proxy statement/prospectus.

Risk Factors


        In evaluating the business combination and the proposals to be considered and voted on at the general meeting, you should carefully review and consider the risk factors set forth under the section entitled "Risk Factors" beginning on page [    ·    ]37 of this proxy statement/prospectus. The occurrence of one or more of the events or circumstances described in that section, alone or in combination with other events or circumstances, may have a material adverse effect on (i) the ability of AHPAC and Envigo to complete the business combination, and (ii) the business, cash flows, financial condition and results of operations of ENVG following consummation of the business combination.




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RISK FACTORS

        You should carefully review and consider the following risk factors and the other information contained in this proxy statement/prospectus, including the financial statements and notes to the financial statements included herein, in evaluating the business combination and the proposals to be voted on at the general meeting. The following risk factors apply to the business and operations of Envigo and will also apply to the business and operations of ENVG following the completion of the business combination. The occurrence of one or more of the events or circumstances described in these risk factors, alone or in combination with other events or circumstances, may adversely affect the ability to complete or realize the anticipated benefits of the business combination, and may have a material adverse effect on the business, cash flows, financial condition and results of operations of ENVG. You should carefully consider the following risk factors in addition to the other information included in this proxy statement/prospectus, including matters addressed in the section entitled "Cautionary Note Regarding Forward-Looking Statements." ENVG may face additional risks and uncertainties that are not presently known to us, or that we currently deem immaterial, which may also impair ENVG's business or financial condition. The following discussion should be read in conjunction with the financial statements and notes to the financial statements included herein.

Risks Related to Envigo and its business


Changes in government regulation or in practices relating to the biopharmaceutical industry or the contract research industry could decrease the need for the services Envigo provides or result in increased costs for Envigo.

        Governmental agencies throughout the world strictly regulate the drug development process. Envigo's business involves, among other things, helping biopharmaceutical companies navigate the drug approval process. Changes in regulation, such as a relaxation in regulatory requirements or the introduction of simplified drug approval procedures, or an increase in regulatory requirements that Envigo has difficulty satisfying or that make its services less competitive, could substantially reduce the demand for Envigo's services. In addition, if new legislation were to mandate a significant reduction in safety testing procedures which utilize laboratory animals (as has been advocated by certain groups, including petitions by anti-vivisection groups for the European Union ("EU") to ban all animal experimentation) Envigo's business could be materially adversely affected. Also, if the government were to introduce measures to contain drug costs (as has been advocated by the United States' current administration) or biopharmaceutical company profits from new drugs, Envigo's customers may spend less, or reduce their growth in spending on research and development.

        For example, in the United States in March 2010, the US Congress enacted The Patient Protection and Affordable Care Act, health care reform legislation intended to expand, over time, health insurance coverage and impose health industry cost containment measures. This legislation may significantly impact the biopharmaceutical industry. Regulations under that Act were promulgated in 2013 and approximately 20 million people have enrolled under that law. Efforts to repeal that law have been introduced in Congress and undertaken in the courts. The current U.S. administration has announced a desire to repeal and replace this law and Congress has made efforts to do so thus far without success. It is not possible to predict whether and when any such repeal or change will occur. In addition, the US Congress, various state legislatures and European and Asian governments may consider various types of health care reform in order to control growing health care costs. Implementation of health care reform legislation that contains costs could limit the profits that can be made from the development of new drugs. This could adversely affect research and development expenditures by biopharmaceutical companies which could in turn decrease the business opportunities available to us both in the United States and abroad. In addition, new laws or regulations may create a risk of liability, increase Envigo's costs or limit its service offerings. Envigo is unable to predict what legislative proposals will be adopted in the future, if any.




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Failure to comply with applicable governmental regulations could harm Envigo's business.

        As a company in the contract research industry, Envigo is subject to a variety of governmental regulations, particularly in the US, Europe, and the UK, relating to animal welfare and the conduct of its business, including Good Laboratory Practice regulations, the UK Animals (Scientific Procedures) Act 1986 and United States Department of Agriculture ("USDA") Animal Welfare Regulations. Envigo's laboratories are therefore subject to routine formal inspections by regulatory and supervisory authorities, including the US Food and Drug Administration ("FDA"), the USDA and the UK Home Office, as well as by representatives from client companies. Envigo is regularly inspected by governmental agencies because of the number and complexities of the studies it undertakes. Envigo must also maintain records and reports for each study for specified periods for auditing by the study sponsor and by any regulatory authorities. Failure to comply with applicable laws and regulations could result in material liabilities, the suspension of licenses, disqualification of trials, the disqualification of data collected by Envigo, the termination of ongoing research, harm to relationships with customers or harm to Envigo's reputation and prospects for future work, and could have a material adverse effect on their business, prospects or financial condition. For example, if Envigo were to fail to properly monitor compliance by its personnel with study protocols, the data collected from that study and other studies could be disqualified. If this were to happen, Envigo could be contractually required to repeat the study or studies at no further cost to the customer, but at potentially substantial cost to Envigo, or could be exposed to a lawsuit seeking substantial monetary damages. If Envigo's operations are found to violate any applicable law or governmental regulation, it might be subject to civil and criminal penalties, damages and fines and other penalties. Any action against Envigo for violation of applicable laws, even if Envigo successfully defends against it, could cause Envigo to incur significant legal expenses, divert its management's attention from the operation of its business and damage its reputation. In addition, applicable laws and regulations could significantly restrict Envigo's ability to expand its facilities or require it to acquire costly equipment or incur other material costs to comply with regulations, or otherwise increase costs.

        Envigo expends significant resources on compliance efforts. Regulations and guidance worldwide concerning the production and use of laboratory animals for research purposes continue to be updated. For example, the European Directive 2010/63/EU established new standards for animal housing and accommodations that require implementation by 2017. Similarly, guidance has been and continues to be developed for other areas that impact the biomedical research community on both a national and international basis, including transportation, import and export requirements of biological materials, and animal housing and welfare. Certain of Envigo's customers may require Envigo to comply with any new guidance in advance of its implementation as a condition to being awarded contracts. Conforming to new guidelines may result in increased costs attributable to adding or upgrading facilities, the addition of personnel to address new processes and increased administrative burden.

Envigo depends on the biopharmaceutical industry.

        Envigo's business depends greatly on the expenditures made by the biopharmaceutical industry in research and development. Accordingly, economic factors and industry trends that affect Envigo's customers in these industries also affect Envigo's business. Also, at any given time, biopharmaceutical customers can choose to allocate their research and development expenditures more heavily towards clinical testing than the non-clinical testing that Envigo performs. As well, if payers were to change their practices with respect to reimbursements for pharmaceutical products, Envigo's customers may spend less, or reduce their growth in spending on research and development.




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Several of Envigo's service and product offerings are dependent on a limited source of supply, which if interrupted could adversely affect its business.

        Envigo depends on a limited international source of supply for certain products, such as large research models. Disruptions to their continued supply may arise from health problems, export or import laws/restrictions or embargoes, international trade regulations, foreign government or economic instability, severe weather conditions, increased competition for models, disruptions to the air travel system, commercial disputes, supplier insolvency, activist intervention, or other normal-course or unanticipated events. Any disruption of supply could harm Envigo's business if it cannot address the disruption or are unable to secure an alternative or secondary supply source on comparable commercial terms.

Changes in aggregate spending, research and development budgets and outsourcing trends in the biopharmaceutical industry could adversely affect Envigo's operating results.

        Envigo's ability to continue to grow and win new business is dependent in large part upon the ability and willingness of the biopharmaceutical industry to continue to spend on compounds in the non-clinical phase of research and development and to outsource the services and products Envigo provides. Fluctuations in the expenditure amounts in each phase of the research and development budgets of these industries could have a significant effect on the demand for Envigo's services and products. Research and Development ("R&D") budgets fluctuate due to changes in available resources, mergers of biopharmaceutical companies, spending priorities, general economic conditions and institutional budgetary policies. Envigo's business could be adversely affected by any significant decrease in non-clinical research and development expenditures by biopharmaceutical companies.

        In addition to the growth in R&D budgets, the practice of many companies in the biopharmaceutical industry to hire external organizations such as Envigo to conduct non-clinical research projects has been critical to Envigo's growth. Over the past decade, the CRO industry has grown faster than the growth of R&D spending as a result of the increase in biopharmaceutical companies outsourcing their non-clinical research support activities. If they reduce their outsourcing for any reason, Envigo's operations and financial condition could be materially adversely affected. Envigo also believes that it may be negatively impacted by certain consolidation in the biopharmaceutical industry, including business reductions or failures due to a lack of financing, which could result in development pipelines being rationalized, a shift in focus from development to integration, the delay or cancellation of certain existing projects or a decrease in the number of Envigo's potential customers. If the number of Envigo's potential customers declines, existing customers may be able to negotiate price discounts or other terms for Envigo's services that are less favorable to Envigo than has historically been the case.

Envigo competes in a highly competitive market.

        The CRO and Research Models industries are highly competitive. Competition in both the biopharmaceutical and chemical market segments ranges from in-house research and development divisions of large pharmaceutical, crop protection and industrial chemical companies, that perform their own safety assessments, to contract research organizations like Envigo that provide a full range of services and products to the industries and niche suppliers focusing on specific services, geographies or industries. Some of these competitors have greater capital, technical and other resources than Envigo, while Envigo's competitors that are smaller specialized companies might compete effectively against Envigo based on price and their concentrated size and focus.

        Providers of outsourced drug development and research models and services compete on the basis of many factors, including the following:

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reputation for on-time quality performance;




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reputation for regulatory compliance;



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expertise, experience and operational stability;



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scope of service offerings;



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how well services are integrated;



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quality of facilities;



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quality and stability of the animal models;



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assurance of supply;



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technical and scientific support;



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strength in various geographic markets;



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price;



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payment terms;



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financial stability; and



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technological expertise and efficient drug development processes.

        Envigo has traditionally competed effectively in the above areas, but there can be no assurance that it will be able to continue to do so. The biopharmaceutical industry generally is subject to rapid technological changes. Envigo's competitors or others might develop technologies, services or products that are more effective or commercially attractive than Envigo's current or future technologies, services or products, or that render Envigo's technologies, services or products less competitive or obsolete. If competitors introduce superior technologies, services or products and Envigo cannot make enhancements to its offerings to remain competitive, it could be materially adversely affected.

New technologies may be developed, validated and increasingly used in biomedical research that could reduce demand for some of Envigo's services and products.

        For many years, groups within the scientific and research communities have attempted to develop models, methods and systems that would replace or supplement the use of living animals as test subjects in biomedical research. In addition, technological improvements to existing or new processes, such as imaging and biomarker technology, could result in a refinement in the number of animal research models necessary to conduct the required research. Alternative research methods could decrease the need for research models, and Envigo may not be able to develop new products effectively or in a timely manner to replace any lost sales. In addition, other companies or entities may develop research models with characteristics different than the ones that Envigo produces, and which may be viewed as more desirable by Envigo's customers.

        It is Envigo's policy to adopt and implement the 3R's of replacement, reduction and refinement, which may decrease the number of animals used in biomedical research.

Contract research and research model services create a risk of liability.

        In contracting to work on product development studies, Envigo faces a range of potential liabilities, for example:

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risks associated with Envigo's possible failure to properly care for its clients' property, such as samples, study compounds, records, work in progress, other archived materials while in Envigo's possession, or goods and materials in transit;




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errors and omissions from a test that may undermine the usefulness of a study or data from the study;



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although Envigo does not conduct clinical trials, errors or omissions that result in harm to study volunteers during a trial or after regulatory approval of the product to consumers of the product; and



•

risks that Envigo's research models may be contaminated or infected, which could harm the models or humans coming into contact with them despite Envigo's best efforts to implement appropriate protections.

        Envigo tries to limit these risks. In its RMS business, Envigo implements testing, quarantine and veterinary measures to control animal disease. Nevertheless, Envigo has in the past suffered disease in its population, and may suffer outbreaks in the future. In Envigo's CRS and RMS businesses while it endeavors to include in its contracts provisions entitling Envigo to be indemnified or entitling Envigo to a limitation of liability, these provisions do not uniformly protect Envigo against liability arising from certain of Envigo's own actions, such as negligence or misconduct. Moreover, in certain circumstances Envigo may agree to use contracts drafted by its clients, which may not contain clauses that indemnify Envigo or limit Envigo's liability. Envigo could be materially adversely affected if it were required to pay damages or bear the costs of defending any claim which is not covered by a contractual indemnification provision or in the event that a party who must indemnify Envigo does not fulfill its indemnification obligations or which is beyond the level of Envigo's insurance coverage or for which insurance coverage is not available. There can be no assurance that Envigo will be able to maintain such insurance coverage on terms acceptable to it.

Envigo's animal populations may suffer diseases that can damage Envigo's inventory, harm its reputation or result in other liability to it.

        It is important that Envigo's research products be free of diseases, including infectious diseases. Envigo houses in its CRS business a number of different species at close proximity, with new batches being acquired frequently. In its RMS business, the models in its animal production facilities must similarly remain free of contamination. The presence of diseases or infectious agents has the potential to cause substantial loss of animals in Envigo's inventory, to result in harm to humans or the public if the disease cannot be contained to animals in inventory and/or to negatively impact the quality of the research results. These risks may differ substantially according to species. In rodents most infections are without any apparent clinical signs and therefore pose a risk to the scientific quality of the research performed on the animals rather than to humans. Envigo seeks to minimize the risk of these species being infected by the stringent health monitoring programs in place at the supplier and Envigo itself in Envigo's RMS facilities. The same applies to a certain degree to primates, where all animals are serologically tested for specific diseases. The main concern in this species is the potential of any zoonotic infectious disease to cause harm to humans. Again, the risk is substantially minimized by efficient quarantine and health monitoring programs at supplies and after acquisition. Nevertheless, Envigo has in the past suffered disease in its animal populations, and may suffer outbreaks in the future. Diseases in cats and dogs bear less risk to Envigo as efficient vaccination programs are available and followed in these species. Farm animals may be carriers of diseases, which may cause significant losses in animal numbers and are of particular public interest, including foot and mouth disease. Any significant disease outbreak at Envigo has the potential to harm Envigo's reputation or have a material adverse effect on its financial condition, results of operations, and cash flows. There is also the risk that disease from research models Envigo produces may affect customer facilities.

        If disease or contamination occurs in Envigo's animal population, it typically requires remediation and cleanup efforts that could be costly and time consuming. In certain circumstances, it can require the temporary or permanent closure of an affected facility. Envigo has experienced such closures in the




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past. The possibility for genetic mix ups or mutations also exists and may adversely affect Envigo's relationship with customers affected by such mix ups or mutations and may result in an affected customer requesting compensation for damages. Such mix ups or mutations may also affect Envigo's customers' animal colonies.

Envigo is subject to environmental, health and safety requirements and risks as a result of which it may incur significant costs, liabilities and obligations.

        Envigo is subject to a variety of federal, state, local and foreign environmental laws, regulations, initiatives and permits that govern, among other things: the emission and discharge of materials, including greenhouse gases, in air, land and water; the remediation of soil, surface water and groundwater contamination; the generation, storage, handling, use, disposal and transportation of regulated materials and wastes, including biomedical and radioactive wastes; and health and safety. Failure to comply with these laws, regulations or permits could result in fines or sanctions, obligations to investigate or remediate existing or potential contamination, third-party property damage claims, personal injury claims, natural resource damages claims, or modification or revocation of operating permits and may lead to temporary or permanent business interruptions. Pursuant to certain environmental laws, Envigo may be held strictly, and under certain circumstances jointly and severally liable for costs of investigation and remediation of contaminated sites which Envigo currently owns or operates, or sites Envigo or its predecessors have owned or operated in the past. Further, Envigo could be held liable at sites where it has sent waste for disposal.

        Environmental laws, regulations and permits, and the enforcement thereof, change frequently and have tended to become more stringent over time. Compliance with the requirements of laws and regulations may increase capital costs and operating expenses, or necessitate changes to Envigo's production processes.

        Envigo endeavors to conduct its operations according to all legal requirements, but it may not be in complete compliance with such laws and regulations at all times. Envigo uses, and in the past has used, hazardous materials and generates, and in the past has generated, hazardous wastes. Envigo cannot eliminate the risk of accidental contamination or injury from these materials. In the event of such an accident, Envigo could be held liable for any resulting damages and incur liabilities which exceed Envigo's resources. Envigo's costs, liabilities and obligations relating to environmental matters may have a material adverse effect on its business, financial condition, prospect, results of operations and cash flows.

Envigo may not be able to successfully develop and market or acquire new services.

        Envigo may seek to develop and market new services that complement or expand its existing business or expand its service offerings through acquisition. If Envigo is unable to develop new services and/or create demand for those newly developed services, or expand its service offerings through acquisition, its future business growth, results of operations, prospects, financial condition, and cash flows could be adversely affected.

Upgrading and integrating newly acquired business systems could result in implementation issues and business disruptions.

        Envigo has embarked upon an integration and upgrade, as appropriate, to many of its legacy business systems including Customer Relationship Management and Enterprise Resource Planning ("ERP") systems and financial, accounting and information technology systems. In general, the process of planning and preparing for these types of integrated, wide-scale implementations is complex, and Envigo is required to address a number of challenges including data conversion, system cutover and user training. Problems in any of these areas could cause operational problems during implementation




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including delayed shipments, missed sales, billing and accounting errors, delayed or reduced collections and other operational issues. There have been numerous instances of companies experiencing difficulties with the implementation of ERP and other systems which resulted in negative business consequences.

A cyber attack against Envigo's computer systems and information could adversely affect Envigo's operating results and financial condition.

        As a routine element of Envigo's business, it collects, analyzes and retains substantial amounts of data pertaining to the non-clinical studies Envigo conducts for its customers, much of which is highly sensitive and confidential. As a result, Envigo operates large and complex computer systems that contain significant amounts of confidential client data. Envigo's information technology systems also contain proprietary and other confidential information related to its business, such as business plans and employee information.

        Envigo has taken measures to protect the data on its computer systems from unauthorized access or intrusion, including through its information technology systems, and where Envigo considers it to be appropriate, through the implementation of security measures at its research facilities and by entering into confidentiality agreements with employees and consultants. However, any systems and processes that are designed to protect confidential information and prevent data loss and other security attacks cannot provide absolute security. Failure to prevent or mitigate data loss or future security incidents could expose Envigo or its customers to a risk of loss or misuse of such information, cause customers to lose confidence in its data protection measures, damage its reputation, adversely affect its operating results or result in litigation or potential liability. In addition, given the extensive reliance of Envigo's business on information technology and the potentially substantial investment that would be required for new technology infrastructure, any substantial disruption or resulting loss of data that is not avoided or corrected by backup measures could adversely affect Envigo's business and operations.

        In January 2018, Envigo experienced criminal cyber-attacks that involved unauthorized access to its corporate network that led to disruptions of Envigo's operations. Envigo is in the process of restoring its operations and remedying the effects of the cyber-attacks, but the business disruption and related business consequences may have a material adverse impact on Envigo's business, customer relations and financial performance.

        Envigo maintains insurance coverage that may, subject to policy terms and conditions, cover certain aspects of cyber risks. Nevertheless, this insurance coverage is subject to a retention amount and, depending on the incident, the insurance coverage may not be sufficient to cover all of Envigo's losses beyond any retention.

If Envigo is unable to identify and successfully complete acquisitions, its business could be adversely affected.

        Envigo may seek to expand its business through acquisitions. However, business and technologies may not be available on terms and conditions Envigo finds acceptable. The terms of Envigo's financing arrangements may impose restrictions on Envigo's ability to make acquisitions. Envigo may devote time and resources investigating and negotiating with potential acquisition targets, but not consummate the transactions. Even if consummated, factors which may affect Envigo's ability to grow successfully through acquisitions include:

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difficulties and expenses in connection with integrating the acquired companies and achieving the expected benefits;



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diversion of management's attention from current operations;



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the possibility that Envigo may be adversely affected by risk factors facing the acquired companies;




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potential losses resulting from undiscovered liabilities of acquired companies not covered by the indemnification Envigo may obtain from the seller;



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difficulties in retaining customers of the acquired business;



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risks of not being able to overcome differences in foreign business practices, language and other cultural barriers in connection with the acquisition of foreign companies; and



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loss of key employees of the acquired companies.

        In the event that an acquired business or technology does not meet Envigo's expectations, Envigo's results of operations may be adversely affected.

Envigo's non-US locations account for a significant percentage of its revenues, exposing Envigo to risks associated with operating internationally.

        In 2016, more than 60% of Envigo's net revenues from continuing operations were generated by its facilities outside the United States. As a result of these foreign sales and facilities, Envigo's operations are subject to a variety of risks unique to international operations, including the following:

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exposure to local economic conditions;



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currency exchange rate fluctuations;



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changes in tax law;



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potential restrictions on the transfer of funds;



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unexpected changes in regulatory requirements;



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exposure to liabilities under the US Foreign Corrupt Practices Act or the UK Antibribery Act;



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government imposed investment and other restrictions or requirements;



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exposure to local social unrest, including any resultant acts of war, terrorism or similar events;



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exposure to local public health issues and the resultant impact on economic and political conditions;






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difficulty enforcing agreements and collecting receivables through certain legal systems;



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more expansive legal rights of employees, including specifically those applicable to Envigo's European operations;



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variations in protection of intellectual property and other legal rights; and



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export and import and trade restrictions (such as antidumping duties, tariffs or embargoes).

Envigo is exposed to exchange rate fluctuations.

        Envigo operates on a worldwide basis and generally invoices its customers in the currency of the country in which the customer operates. Envigo does not hedge against this exposure. While exposure to exchange rate fluctuations may be limited since Envigo's sales are generally denominated in the same currency as its costs, trading exposures to currency fluctuations may nonetheless occur as a result of certain sales contracts, performed for customers in a different country than the testing site, which are denominated in a currency different from the site's currency. There can be no assurance Envigo will not suffer adverse impacts from currency fluctuations in the future. Moreover, since Envigo operates on an international basis, movements in exchange rates, particularly of British pounds, can have a significant impact on Envigo's price competitiveness vis a vis competitors who operate in currencies other than British pounds or US dollars. Exchange rate fluctuations against the British




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pound have shown increased volatility since Brexit. Envigo's indebtedness is denominated almost entirely in US dollars whereas Envigo earns significant revenues (approximately 64% of total net revenues from continuing operations in 2016) in other currencies. This may adversely impact Envigo's ability to meet its debt obligations.

Envigo is exposed to changes in interest rates.

        Envigo is exposed to changes in interest rates while conducting normal business operations as a result of ongoing financing activities. The majority of Envigo's debt is comprised of floating interest rate borrowings linked to London Interbank Offered Rate ("LIBOR"). As of September 30, 2017, a 100-basis point increase in LIBOR would increase Envigo's annual pre-tax interest expense by approximately $4.4 million.

Envigo's backlog may not be indicative of future results.

        Envigo's backlog of approximately $146 million as of December 31, 2016 is based on anticipated CRS revenue from uncompleted projects that Envigo customers have awarded and Envigo believes to be firm commitments. Once work begins on a project, net revenue is recognized over the duration of the project. Backlog is the amount of revenue that remains to be earned and recognized on signed contracts. Contracts included in backlog are generally subject to termination by Envigo's customers at any time. In the event that a customer cancels a contract, Envigo typically would be entitled to receive payment for all services performed up to the cancellation date and subsequent customer-authorized services related to terminating the cancelled project. However, it may be difficult to collect such post-termination payments from certain customers. The duration of the projects included in Envigo's backlog range from a few days to several years.

        Envigo's backlog may not be indicative of its future results and Envigo cannot assure you that it will realize all the anticipated future revenue reflected in its backlog. A number of factors may affect backlog, including:

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the variable size and duration of the projects;



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the delay of projects;



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the change in the scope of work during the course of a project; and






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the cancellation of such contracts by Envigo's customers.

        Also, if projects are delayed, they will remain in backlog but will not generate revenue at the time originally expected. Cancellation or delay of a large contract or multiple smaller contracts could result in under-utilized resources and could require an adjustment to Envigo's backlog, negatively affecting Envigo's net revenue and results of operations. The historical relationship of backlog to revenues actually realized by Envigo should not be considered indicative of future results.

Envigo's contracts are generally terminable on little or no notice. Termination of a large contract for services or multiple contracts for services or product purchases could adversely affect Envigo's revenue and profitability.

        In general, Envigo's customers may terminate the agreements that they enter into with Envigo or reduce the scope of services under these contracts upon little or no notice. Contracts may be terminated for various reasons, including:

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unexpected or undesired study results;



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the loss of funding for the particular research study;



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the failure of products to satisfy technical or safety requirements;




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production problems resulting in shortages of the product being tested;



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adverse reactions to the product being tested;



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regulatory restrictions placed on the product being tested; or



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the customer's decision to forego or terminate a particular study or compound.

        The loss, reduction in scope or delay of a large contract or the loss or delay of multiple smaller contracts could materially adversely affect Envigo's business.

Because most of Envigo's CRS revenues are from fixed price contracts, these contracts may be subject to under-pricing and cost overruns.

        The majority of Envigo's CRS contracts with its customers are fixed price contracts with set limits on amounts Envigo can charge for its services, creating the risk of cost overruns under these contracts. Envigo typically has some flexibility under these contracts to adjust the price to be charged if it is asked to provide additional services. If Envigo did have to bear significant costs of under-pricing or cost overruns under these contracts, its business, financial condition and operating results could be adversely affected.

Envigo depends heavily on its senior management team, and the loss of any member may adversely affect it.

        Envigo believes its success depends on the continued availability of its senior management team, including Adrian Hardy (CEO) and Patricia Henahan (CFO). If one or more members of the senior management team were unable or unwilling to continue in their present positions, those persons would likely be difficult to replace and Envigo's business would likely be harmed. If any of Envigo's key employees were to join a competitor or to form a competing company, some of Envigo's customers might choose to use the services of that competitor or new company instead of Envigo. Furthermore, customers or other companies seeking to develop in-house capabilities may hire away some of Envigo's senior management or key employees. The loss of one or more of these key employees could adversely affect Envigo's business.




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Envigo must recruit and retain qualified personnel.

        Because of the specialized scientific nature of Envigo's business, it is highly dependent upon qualified scientific, technical and managerial personnel. There is intense competition for qualified personnel in the biopharmaceutical field. The shortage of qualified scientific, technical and managerial personnel, or other factors, might lead to increased recruiting, relocation and compensation costs for these professionals. These increased costs might reduce Envigo's profit margins or make hiring new personnel impracticable. In the future it may not be able to attract and retain the qualified personnel necessary for the conduct and further development of its business. The loss of the services of existing personnel, as well as the failure to recruit additional key scientific, technical and managerial personnel in a timely manner, could have a material adverse effect on Envigo's ability to expand its businesses and remain competitive in the segments in which it participates.

Actions of animal rights activists may affect Envigo's business.

        Envigo's CRS business utilizes animals (predominantly rodents) to test the safety and efficacy of drugs. Envigo's RMS business provides animal research models (predominantly rodents) to its customers. Such activities are required for the registration of products under regulatory regimes in the United States, Europe, Japan and other countries. CROs, including Envigo, biopharmaceutical companies and other research organizations have been targeted by animal rights activists who oppose all testing on animals, for whatever purpose, including the animal testing activities in support of safety and efficacy testing for drug development. These groups, which include groups directed at the industry




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and Envigo, have publicly stated that their goal is to stop animal testing. Acts of vandalism and other acts by animal rights activists who object to the use of animals in product development could have a material adverse effect on Envigo's business. These groups have targeted not only CROs and biopharmaceutical companies, but also third parties including customers, suppliers, advisors, financial advisors, lenders and investors.

Unfavorable global economic conditions could negatively impact Envigo's operating results and financial condition.

        Unfavorable global economic conditions could negatively affect Envigo's business. While it is difficult for Envigo to predict the impact of general economic conditions on its business, these conditions could reduce customer demand for some of its services, which could cause its revenue to decline. Also, Envigo's customers, particularly smaller biotechnology companies which are especially reliant on the credit and capital markets, may not be able to obtain adequate access to credit or equity funding, which could affect their ability to retain Envigo's services or make timely payments to Envigo. If that were to occur, Envigo could be required to increase its allowance for doubtful accounts, and the number of days of sales outstanding for its accounts receivable could increase. For these reasons, among others, if the global economic conditions stagnate or decline, Envigo's operating results and financial condition could be adversely affected.

Envigo relies on its facilities and any disruption in their operation could materially adversely impact Envigo.

        Envigo relies on of its facilities. In particular, Envigo's CRS laboratories and RMS isolator and barrier breeding facilities are highly specialized and would be difficult to replace in a short period of time. Any event that causes a disruption of the operation of these facilities might impact Envigo's ability to provide services and products to its customers and therefore could have a material adverse effect on its financial condition, results of operations and cash flows.




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If Envigo experiences a breach of the confidentiality of the information it holds or of the security of its computer systems, it could adversely affect Envigo's operating results and financial condition.

        As a routine element of Envigo's business, it collects, analyzes and retains substantial amounts of data pertaining to the non-clinical studies Envigo conducts for its customers, much of which is highly sensitive and confidential. As a result, Envigo operates large and complex computer systems that contain significant amounts of confidential client data. Envigo's contracts with its customers typically contain provisions that require Envigo to keep confidential the information received from its customers and generated from these studies. Unauthorized persons could attempt to gain entry to this confidential information for the purpose of stealing or otherwise accessing confidential data or other information. Envigo believes that it has taken adequate measures to protect its data and its customers' confidential information from unauthorized access or intrusion, including, where Envigo considers it to be appropriate, through the implementation of security measures at its research facilities and by entering into confidentiality agreements with employees and consultants. While Envigo continues to monitor, and to improve and enhance where appropriate, its systems in this regard, in the event that Envigo's efforts are unsuccessful and the confidentiality of any information is compromised, Envigo could suffer significant harm. In addition, as with all information technology, Envigo's systems could become vulnerable to potential damage or interruptions from fires, blackouts, telecommunications failures and other unexpected events, as well as to break-ins, sabotage or intentional acts of vandalism. Given the extensive reliance of Envigo's business on information technology and the substantial investment that would be required for new technology infrastructure, any substantial disruption or resulting loss of data that is not avoided or corrected by backup measures could adversely affect Envigo's business and operations.




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Potential changes in tax law in the United States, Europe and the United Kingdom could adversely affect Envigo's operating results and financial condition.

        In the US, there are proposals to reform corporate tax law that are currently under consideration. Changes in the US tax laws could impact Envigo's effective tax rate and profitability.

        Envigo has substantial operations in the UK, which currently benefit from favorable corporate tax arrangements. Envigo receives benefits from enhanced deductions and accelerated tax depreciation allowances in the UK. Any reduction in the availability or amount of these deductions would be likely to have a material adverse effect on profits, cash flow and Envigo's effective tax rate.

        On July 18, 2013, a change was enacted in UK Tax Legislation in relation to research and development expenditures, giving companies the option of recognizing research and development credits as a reduction of cost of sales. Envigo adopted the new approach effective April 1, 2013. Envigo has significant tax losses that can be offset against future trading profits and help to minimize cash tax payments. There are limitations in the amount of losses that can be utilized each year. Envigo continues to maintain a full valuation allowance against the deferred tax assets in the UK until sufficient positive evidence exists to reduce or eliminate the allowance.

Some of Envigo's customers depend on government funding of research and development and a reduction in that funding may adversely affect Envigo's business.

        A portion of sales in Envigo's RMS business is derived from customers at academic institutions and research laboratories whose funding is partially dependent on funding from government sources, including the US National Institutes of Health ("NIH") and UK/EU equivalents. Such funding can be difficult to forecast as it may be subject to the political process. Envigo's sales may be adversely affected if its customers delay purchases as a result of uncertainties surrounding the approval of government budget proposals. A reduction in government funding for the NIH or other government research agencies could adversely affect Envigo's business and its financial results. There can be no




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certainty that government research funding will be directed towards projects and studies that require use of Envigo's services and products.

Impairment of goodwill or other intangible assets may adversely impact future results of operations.

        Envigo has intangible assets, including goodwill and other indefinite-lived intangible assets on its balance sheet due to acquisitions of businesses. The initial identification and valuation of these intangible assets and the determination of the estimated useful lives at the time of acquisition involve use of management judgement and estimates. The estimates are based on input from accredited valuation consultants and reviews of projected future income cash flows. The use of alternative estimates and assumptions might have increased or decreased the estimated fair value of Envigo's intangible assets. If the future growth and operating results of the business are not as strong as anticipated this could impact the assumptions in calculating the fair value of intangible assets. To the extent that intangible assets are impaired, their carrying value will be written down to their implied fair value and a charge made to the income from continuing operations that could materially affect Envigo's operating results. As of September 30, 2017 and December 31, 2016, the carrying amount of goodwill and other intangible assets was approximately $232.4 million and $235.3 million, respectively, on Envigo's consolidated balance sheet.

Envigo's substantial levels of outstanding indebtedness could adversely affect its financial condition, limit its ability to react to changes in the economy or its industry and prevent Envigo from meeting its obligations under the Envigo Credit Agreements and/or the Existing Third Lien Indenture.

        As of September 30, 2017 and December 31, 2016, Envigo had approximately $458.0 million and $443.6 million, respectively, of indebtedness, net of unamortized financing costs, warrants and discounts.

        Effective March 15, 2012, Envigo completed an offering of approximately $22.4 million principal amount of 15.00% Third Lien Debt due 2020 issued by Envigo Laboratories, Inc. (the "Third Lien Debt") which has since grown to approximately $46.3 million due to payment in kind interest.




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        Effective April 29, 2014, in connection with the acquisition of Harlan Laboratories Holdings Corp. ("Harlan"), Envigo incurred additional indebtedness of $310.4 million, comprised of (a) $150.0 million of First Lien Notes pursuant to that certain First Lien Credit Agreement, dated as of April 29, 2014 (the "First Lien Credit Agreement") among Envigo Laboratories, the several guarantors from time to time party thereto, the lenders from time to time party thereto and Wilmington Trust, National Association ("Wilmington") as Administrative Agent and Collateral Agent to the First Lien Credit Agreement, (b) $130.475 million of Second Lien Notes pursuant to that certain Second Lien Credit Agreement, dated as of April 29, 2014 (the "Second Lien Credit Agreement") among Envigo Laboratories, the several guarantors from time to time party thereto, the lenders from time to time party thereto and Wilmington as Administrative Agent and Collateral Agent to the Second Lien Credit Agreement, and (c) $30.0 million of Second Lien Liquidity Notes pursuant to that certain Second Lien Liquidity Facility Credit Agreement, dated as of April 29, 2014 (the "Second Lien Liquidity Facility Credit Agreement"), among Envigo Laboratories, the several guarantors from time to time party thereto, the lenders from time to time party thereto and Wilmington as Administrative Agent and Collateral Agent to the Second Lien Liquidity Facility Credit Agreement.

        Effective November 3, 2016, Envigo incurred additional indebtedness of approximately $130 million pursuant to that certain First Lien Credit Agreement dated as of November 3, 2016 among Envigo Holdings, Inc., Envigo Laboratories, Inc., the several guarantors party thereto from time to time and Jefferies Finance LLC as Administrative Agent (the "New First Lien Credit Agreement" and together with the First Lien Credit Agreement, Second Lien Credit Agreement and Second Lien Liquidity Facility Credit Agreement, the "Envigo Credit Agreements"). As of September 30, 2017, Envigo's net indebtedness, of approximately $458.0 million consisted of $46.3 million of indebtedness




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related to the Third Lien Debt, $268.0 million of indebtedness of the First and Second Lien Notes, $25.6 million of indebtedness of the Second Lien Liquidity Notes and $128.3 million relating to the New First Lien Credit Agreement. This debt represents approximately 76% of Envigo's total capitalization. Envigo's substantial level of indebtedness increases the risk that it may be unable to generate cash sufficient to pay amounts due in respect of its indebtedness. Envigo's substantial indebtedness could have other important consequences to you and significant effects on Envigo's business, including:

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increasing Envigo's vulnerability to adverse changes in general economic, industry and competitive conditions;



•

requiring a substantial portion of cash flow from operations to be dedicated to the payment of principal and interest on Envigo's indebtedness, thereby reducing its ability to use its cash flow to fund its operations, capital expenditures and future business opportunities;



•

making it more difficult for Envigo to satisfy its obligations with respect to its indebtedness, and any failure to comply with the obligations of any of its debt instruments, including financial or restrictive covenants and borrowing conditions, could result in an event of default under the Existing Third Lien Indenture governing the Third Lien Debt or the agreements governing other indebtedness and result in the acceleration of Envigo's outstanding debt;



•

require Envigo to repatriate cash for debt service from its foreign subsidiaries resulting in dividend tax costs or require it to adopt other disadvantageous tax structures to accommodate debt service payments;



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restricting Envigo from making strategic acquisitions or causing it to make non-strategic divestitures;




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limiting Envigo's ability to obtain additional financing for working capital, capital expenditures, product development, debt service requirements, acquisitions and general corporate or other purposes, including to repurchase the notes from the holders upon a change of control; and



•

limiting Envigo's flexibility in planning for, or reacting to, changes in its business or market conditions and placing it at a competitive disadvantage compared to its competitors who have less debt and who, therefore, may be able to take advantage of opportunities that Envigo's leverage prevents it from pursuing.

        Envigo's liquidity needs could vary significantly and may be affected by general economic conditions, industry trends, performance and many other factors not within Envigo's control. If it is unable to generate sufficient cash flow from operations in the future to service its debt, Envigo may be required to refinance all or a portion of its existing debt. However, Envigo may not be able to refinance its debt or obtain any new or additional debt on favorable terms or at all.

Envigo may incur additional amounts of debt, including secured indebtedness, which could further exacerbate the risks associated with its current level of indebtedness and allow holders of the future secured debt to exercise certain rights and remedies with respect to the collateral securing the notes.

        Envigo may incur additional indebtedness in the future, including secured indebtedness. Although the Existing Third Lien Indenture and the Envigo Credit Agreements governing its debt contain restrictions on the incurrence of additional indebtedness, these restrictions are subject to a number of qualifications and exceptions, and under certain circumstances, the amount of indebtedness that could be incurred in compliance with these restrictions could be substantial. If new debt is added to Envigo's existing debt levels, the related risks that it now faces would increase.




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Envigo's debt agreements contain or future debt agreements may contain restrictions that will limit its flexibility in operating its business.

        The Existing Third Lien Indenture and the Envigo Credit Agreements contain, and future debt agreements may contain, various covenants that limit Envigo's ability to engage in specified types of transactions. These covenants limit Envigo's ability to, among other things:

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incur or guarantee additional indebtedness and issue preferred stock;



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pay dividends and make other restricted payments;



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enter into agreements restricting the payment of dividends or other distributions from Envigo's restricted subsidiaries;



•

create or incur liens;



•

make investments;



•

transfer or sell assets;



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engage in transactions with affiliates; and



•

merge or consolidate with other companies or transfer all or substantially all of Envigo's or their assets.

Envigo's pension plans are underfunded and may require increased contribution payments.

        Envigo provides defined benefit plans for certain of its past or current UK employees. While these plans have been closed to future participants, the plans are as of December 31, 2016 underfunded by approximately $57.1 million to meet prospective obligations to plan participants. Obligations under these plans reflect certain actuarial and other assumptions. The funding requirements and cost of these plans are dependent upon these assumptions and various other factors, including the actual return on




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plan assets, discount rates, participant demographics and changes in pension regulations. Envigo's future costs and funding obligations can increase or decrease significantly depending upon these factors.

Brexit may adversely affect Envigo's business.

        On June 23, 2016, the UK held a referendum in which voters approved an exit from the European Union, commonly referred to as Brexit. Brexit has caused significant disruption and uncertainty in the UK and worldwide business communities and has resulted in volatile currency exchange fluctuations. Approximately 46.5% of Envigo's revenue, and an even greater proportion of Envigo's earnings, are generated in the UK in pounds sterling. The procedures and timings for Brexit are uncertain. Brexit could potentially lead to divergent laws throughout the EU, including in countries where Envigo does business, which could lead to uncertain business relations and revenue generation in those countries.

Envigo may not be able to timely and effectively implement controls and procedures required by Section 404 of the Sarbanes Oxley Act of 2002 that will be applicable to us after the business combination.

        Envigo is currently not subject to Section 404 of the Sarbanes Oxley Act of 2002. However, following the business combination, the combined company may be required to provide management's attestation on internal controls commencing with the Company's annual report for fiscal 2017.2018. The standards required for a public company under Section 404 of the Sarbanes-Oxley Act of 2002 are significantly more stringent than those required of Envigo as a privately-held company. Management may not be able to effectively and timely implement controls and procedures that adequately respond to the regulatory compliance and reporting requirements that will be applicable to Envigo after the business combination. If we are not able to implement the additional requirements of Section 404 in a timely manner or with adequate compliance, we may not be able to assess whether our internal




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controls over financial reporting are effective, which may subject us to adverse regulatory consequences and could harm investor confidence and the market price of ENVG common stock.

New U.S. tax legislation could adversely affect Envigo's business.

        On December 22, 2017, the current U.S. administration signed an act referred to as the "Tax Cuts and Jobs Act" (the "TCJA"), generally effective for taxable years beginning after December 31, 2017. The TCJA is complex and includes significant amendments to the Internal Revenue Code of 1986 (as amended, the "Code"), including amendments that significantly change the taxation of offshore earnings and the deductibility of interest. Envigo is currently assessing the impact of the TCJA on its business and consolidated financial statements. In connection with that ongoing assessment, Envigo has identified at least three provisions that may have a material and adverse effect on Envigo's business. First, the TCJA generally will require Envigo to include in income with respect to its 2017 taxable year any undistributed and previously untaxed earnings of its foreign subsidiaries, subject to adjustments. Second, going forward, the TCJA generally will subject Envigo to a current tax on any undistributed earnings of its foreign subsidiaries to the extent such earnings are considered to be "global intangible low-taxed income ("GILTI"), subject to certain deductions and adjustments. Third, the TCJA generally will disallow Envigo's U.S. interest deductions going forward to the extent such deductions exceed 30% of its U.S. "adjusted taxable income" (which will be roughly equivalent to EBITDA through 2022 and to EBIT thereafter). These, and other provisions of the TCJA, may have a material and adverse impact on Envigo's business and financial condition and the value of ENVG's common shares. Envigo is continuing to assess the impact of the TCJA. Holders should consult their tax advisors about the TCJA and its potential impact on Envigo's business and their ownership of ENVG common shares.




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Risks Related to AHPAC and the Business Combination


The initial shareholders and management team have agreed to vote in favor of the business combination, regardless of how public shareholders vote.

        As of the date hereof, the initial shareholders own 100% of AHPAC's outstanding Class B shares and approximately 20% of AHPAC's outstanding ordinary shares in total. AHPAC's amended and restated memorandum and articles of association provide that the business combination will be approved if AHPAC receives the affirmative vote of a majority of the ordinary shares voted at the general meeting, including the Class B ordinary shares. Accordingly, the agreement by the initial shareholders to vote in favor of the business combination will increase the likelihood that AHPAC will receive the requisite shareholder approval for the business combination.

The sponsor, certain members of the AHPAC Board and AHPAC's officers have interests in the business combination that are different from or are in addition to other shareholders in recommending that shareholders vote in favor of approval of the Business Combination Proposal and approval of the other proposals described in this proxy statement/prospectus.

        When considering the AHPAC Board's recommendation that AHPAC's shareholders vote in favor of the approval of the Business Combination Proposal, AHPAC's shareholders should be aware that the directors and officers of AHPAC have interests in the business combination that may be different from, or in addition to, the interests of AHPAC's shareholders. See the section titled "The Business Combination—Interests of Certain Persons in the Business Combination" for further information.

The initial shareholders, including the sponsor and AHPAC's independent directors, hold a significant number of AHPAC Common Shares. They will lose their entire investment in AHPAC if a business combination is not completed.

        The initial shareholders currently own 7,750,000 AHPAC Class B ordinary shares. The AHPAC Class B ordinary shares will be worthless if AHPAC does not complete an initial business combination. In addition, the initial shareholders own, in the aggregate, 16,400,000 private placement warrants exercisable for an aggregate of 8,200,000 AHPAC Class A ordinary shares at an exercise price of $11.50 per share, which will also be worthless if AHPAC does not complete a business combination by October 14, 2018. The personal and financial interests of the sponsor, AHPAC's executive officers and directors may influence their motivation in completing the business combination and influencing the operation of ENVG after the business combination has been consummated.

The sponsor, officers and directors will not be eligible to be reimbursed for their out-of-pocket expenses if a business combination is not completed.

        At the closing of the business combination, the sponsor, executive officers and directors, or any of their respective affiliates, will be reimbursed for any out-of-pocket expenses incurred in connection with activities on AHPAC's behalf, such as identifying potential target businesses and performing due diligence on suitable business combinations. There is no cap or ceiling on the reimbursement of out-of-pocket expenses incurred in connection with activities on AHPAC's behalf. The personal and financial interests of the sponsor, executive officers and directors may influence their motivation in identifying and selecting a target business combination and completing the business combination.




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The sponsor, directors or officers or their affiliates may elect to purchase shares from public shareholders, which may influence a vote on a proposed business combination and reduce the public "float" of ENVG Class A common stock.

        The sponsor, ENVG's directors or executive officers or their affiliates may purchase shares in privately negotiated transactions or in the open market either prior to or following the completion of the business combination, although they are under no obligation to do so. Such a purchase may include




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a contractual acknowledgement that such shareholder, although still the record holder of shares of ENVG common stock, is no longer the beneficial owner thereof and therefore agrees not to exercise its redemption rights. In the event that the sponsor, directors, officers or their affiliates purchase shares in privately negotiated transactions from public shareholders who have already elected to exercise their redemption rights, such selling shareholders would be required to revoke their prior elections to redeem their shares. The purpose of such purchases could be to vote such shares in favor of the business combination and thereby increase the likelihood of obtaining shareholder approval of the business combination or to satisfy closing conditions in the Transaction Agreement regarding required amounts in the trust account and the proceeds from the private placement equaling or exceeding certain thresholds where it appears that such requirements would otherwise not be met. This may result in the completion of the business combination that may not otherwise have been possible.

        In addition, if such purchases are made, the public "float" of ENVG Class A common stock and the number of beneficial holders of ENVG's securities may be reduced, possibly making it difficult to maintain or obtain the quotation, listing or trading of AHPAC's securities on NASDAQ or another national securities exchange or reducing the liquidity of the trading market for ENVG Class A common stock.

Public shareholders may experience dilution as a consequence of, among other transactions, the issuance of ENVG Class A common stock as consideration in the business combination, the equity financing (if any) and the Debt Refinancing (if any). Having a minority share position may reduce the influence that AHPAC's current shareholders have on the management of AHPAC.

        It is anticipated that, upon completion of the business combination: (i) AHPAC's public shareholders will retain an ownership interest of approximately 47.9%57.7% in ENVG; (ii) the sponsor will own approximately 6.0%5.6% of ENVG and (iii) the Selling Equityholders will own approximately 46.1%36.7% of ENVG. The ownership percentages of ENVG following the business combination assume that no shares are elected to be redeemed and do not take into account (a) the warrants to purchase ENVG Class A common stock that will be issued in connection with and remain outstanding following the business combination, or (b) the issuance of any ENVG Class A common stock in connection with the equity financing (if any) or (c) the consummation of a Debt Refinancing (if any). For more information, please see the sections entitled "Summary of the Proxy Statement/Prospectus—Ownership of AHPAC" and "Unaudited Pro Forma Condensed Combined Financial Information." See the section titled "The Business Combination—The Transaction Agreement—Equity Financing" beginning on page [    ·    ]86 of this proxy statement/prospectus for further details regarding AHPAC's obligations in connection with the equity financing. See the section titled "The Transaction Agreement—Related Agreements—Financing Arrangements" beginning on page [    ·    ]129 of this proxy statement/prospectus for further details regarding Envigo's obligations in connection with a Debt Refinancing.

        To the extent that any warrants to purchase ENVG Class A common stock that will be issued in connection with and remain outstanding following the business combination are exercised, current shareholders may experience substantial dilution. Such dilution could, among other things, limit the ability of AHPAC's current shareholders to influence management of AHPAC through the election of directors following the business combination.




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There can be no assurance that ENVG Class A common stock that will be issued in connection with the business combination will be approved for listing on NASDAQ following the consummation of the business combination, or that AHPAC will be able to comply with the continued listing standards of NASDAQ.

        The AHPAC Class A ordinary shares and public warrants are currently listed on NASDAQ. AHPAC's continued eligibility for listing may depend on, among other things, the number of public shares that are redeemed. If, after the business combination, NASDAQ delists ENVG Class A common




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stock from trading on its exchange for failure to meet the listing standards, ENVG's stockholders could face significant material adverse consequences including:

•

a limited availability of market quotations for ENVG's securities;



•

reduced liquidity for ENVG's securities;



•

a determination that ENVG Class A common stock are a "penny stock" which will require brokers trading in ENVG Class A common stock to adhere to more stringent rules and possibly result in a reduced level of trading activity in the secondary trading market for ENVG's securities;



•

a limited amount of news and analyst coverage; and



•

a decreased ability to issue additional securities or obtain additional financing in the future.

        The National Securities Markets Improvement Act of 1996, which is a federal statute, prevents or preempts the states from regulating the sale of certain securities, which are referred to as "covered securities." Because AHPAC Class A ordinary shares and public warrants are listed on NASDAQ, they are covered securities. Although the states are preempted from regulating the sale of AHPAC's securities, the federal statute does allow the states to investigate companies if there is a suspicion of fraud, and, if there is a finding of fraudulent activity, then the states can regulate or bar the sale of covered securities in a particular case. While AHPAC is not aware of a state, other than the state of Idaho, having used these powers to prohibit or restrict the sale of securities issued by blank check companies, certain state securities regulators view blank check companies unfavorably and might use these powers, or threaten to use these powers, to hinder the sale of securities of blank check companies in their states. Further, if the shares were no longer listed on NASDAQ, AHPAC's securities would not be covered securities and AHPAC would be subject to regulation in each state in which AHPAC offers securities.

A significant portion of ENVG Class A common stock following the business combination will be restricted from immediate resale, but may be sold into the market in the future. This could cause the market price of ENVG Class A common stock to drop significantly, even if our business is doing well.

        Sales of a substantial number of shares of common stock in the public market could occur at any time. These sales, or the perception in the market that the holders of a large number of shares intend to sell shares, could reduce the market price of ENVG Class A common stock.

        It is anticipated that, upon completion of the business combination: (i) AHPAC's public shareholders will retain an ownership interest of approximately 47.9%57.7% in ENVG; (ii) the sponsor will own approximately 6.0%5.6% of ENVG and (iii) the Selling Equityholders will own approximately 46.1%36.7% of ENVG. The ownership percentages of ENVG following the business combination assume that no shares are elected to be redeemed and do not take into account (a) the warrants to purchase ENVG Class A common stock that will be issued in connection with and remain outstanding following the business combination, or (b) the issuance of any ENVG Class A common stock in connection with the equity financing (if any) or (c) the consummation of a Debt Refinancing (if any). For more information, please see the sections entitled "Summary of the Proxy Statement/Prospectus—Ownership of AHPAC" and "Unaudited Pro Forma Condensed Combined Financial Information."




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        At the closing of the business combination, AHPAC, the sponsor and the restricted stockholders will enter into the Amended and Restated Registration Rights Agreement, pursuant to which, among other things. the restricted stockholders will agree not to sell, transfer, pledge or otherwise dispose of shares of common stock or warrants in ENVG it receives in connection with the business combination for either three or six months from the closing of the business combination. As restrictions on resale end, the market price of ENVG Class A common stock could decline if the holders of currently restricted shares sell them or are perceived by the market as intending to sell them.




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AHPAC has no operating history and is subject to a mandatory liquidation and subsequent dissolution requirement. As such, there is a risk that AHPAC will be unable to continue as a going concern if it does not consummate an initial business combination by October 14, 2018. If AHPAC is unable to effect a business combination by October 14, 2018, AHPAC will be forced to liquidate and AHPAC's warrants will expire worthless.

        AHPAC is a blank check company, and as such has no operating history and is subject to a mandatory liquidation and subsequent dissolution requirement. There is a risk that AHPAC will be unable to continue as a going concern if it does not consummate an initial business combination by October 14, 2018. Unless AHPAC amends its memorandum and articles of association to extend the life of AHPAC and certain other agreements into which AHPAC has entered, if it does not complete an initial business combination by October 14, 2018, it will: (i) cease all operations except for the purpose of winding up; (ii) as promptly as reasonably possible but not more than ten business days thereafter, redeem the public shares, at a per-share price, payable in cash, equal to the aggregate amount then on deposit in the trust account, including interest (which interest shall be net of taxes payable, and less up to $100,000 of interest to pay dissolution expenses) divided by the number of then issued and outstanding public shares, which redemption will completely extinguish public shareholders' rights as shareholders (including the right to receive further liquidation distributions, if any), subject to applicable law; and (iii) as promptly as reasonably possible following such redemption, subject to the approval of AHPAC's remaining shareholders and the AHPAC Board, dissolve and liquidate, subject in each case to AHPAC's obligations under the Cayman Islands law to provide for claims of creditors and the requirements of other applicable law. In the event of such distribution, it is possible that the per share value of the residual assets remaining available for distribution (including trust account assets) will be less than the initial public offering price per public unit in the IPO. In addition, if AHPAC fails to complete an initial business combination by October 14, 2018, there will be no redemption rights or liquidating distributions with respect to AHPAC's public warrants or the private placement warrants, which will expire worthless, unless AHPAC amends AHPAC's amended and restated memorandum and articles of association to extend the life of AHPAC and certain other agreements into which AHPAC has entered.

AHPAC is not required to obtain and has not obtained an opinion from an independent investment banking or accounting firm, and consequently, you may have no assurance from an independent source that the price AHPAC is paying for Envigo is fair from a financial point of view.

        AHPAC is not required to obtain an opinion from an independent investment banking or accounting firm that the price it is paying to acquire Envigo is fair from a financial point of view. The AHPAC Board did not obtain a third-party valuation or fairness opinion in connection with their determination to approve the business combination. In analyzing the business combination, the AHPAC Board and AHPAC's management conducted due diligence on Envigo and researched the industry in which Envigo operates and concluded that the business combination was in the best interests of AHPAC and its stockholders. Accordingly, investors will be relying solely on the judgment of the AHPAC Board in valuing Envigo's business, and the AHPAC Board may not have properly valued the business. The lack of a third-party valuation or fairness opinion may also lead an increased number of




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public stockholders to vote against the business combination or demand redemption of their shares, which could potentially impact AHPAC's ability to consummate the business combination.

        For more information about AHPAC's decision-making process, see the section entitled "The Business Combination—The AHPAC Board's Reasons for the Approval of the Business Combination."




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AHPAC and Envigo have incurred and expect to incur significant costs associated with the business combination. Whether or not the business combination is completed, the incurrence of these costs will reduce the amount of cash available to be used for other corporate purposes by AHPAC if the business combination is not completed.

        AHPAC and Envigo expect to incur significant costs associated with the business combination. Even if the business combination is not completed, AHPAC expects to incur approximately $4 million in expenses. These expenses will reduce the amount of cash available to be used for other corporate purposes by AHPAC if the business combination is not completed.

Even if the domestication qualifies as a reorganization under Section 368(a) of the Code, a U.S. Holder generally may still recognize gain with respect to AHPAC Class A ordinary shares at the effective time of the domestication.

        U.S. holders (as defined in "Material U.S. Federal Income Tax Considerations" below) of AHPAC ordinary shares may be subject to U.S. federal income tax as a result of the domestication.

        A U.S. holder who on the day of the domestication beneficially owns (actually or constructively) AHPAC ordinary shares with a fair market value of $50,000 or more, but less than 10% of the total combined voting power of all classes of AHPAC ordinary shares entitled to vote and less than 10% of the total value of all classes of AHPAC ordinary shares, generally will recognize gain (but not loss) in respect of the domestication as if such holder exchanged its AHPAC ordinary shares for ENVG common stock in a taxable transaction, unless such U.S. holder elects in accordance with applicable Treasury regulations to include in income the "all earnings and profits amount" (as defined in the Treasury regulations) attributable to the AHPAC ordinary shares held directly by such holder.

        Additionally, proposed Treasury Regulations with a retroactive effective date have been promulgated under Section 1291(f) of the Code which generally require that, a U.S. person who disposes of stock of a PFIC (as defined in "Material U.S. Federal Income Tax Considerations" below) must recognize gain equal to the excess of the fair market value of such PFIC stock over its adjusted tax basis, notwithstanding any other provision of the Code.

        If AHPAC is considered a PFIC for U.S. federal income tax purposes, these regulations, if finalized in their current form, would generally require U.S. holders of AHPAC ordinary shares to recognize gain on the exchange of AHPAC ordinary shares for ENVG common stock pursuant to the domestication. The tax on any such gain would be imposed at the rate applicable to ordinary income and an interest charge would apply based on complex rules designed to offset the tax deferral to such holders on the undistributed earnings, if any, of AHPAC. The same rule may also apply to a U.S. holder who exchanges AHPAC warrants for ENVG warrants. It is not possible to determine at this time whether, in what form, and with what effective date, final Treasury regulations under Section 1291(f) of the Code will be adopted.

        Because the domestication will occur prior to the redemption of U.S. Holders that exercise redemption rights, U.S. Holders exercising redemption rights will be subject to the foregoing tax consequences regardless of whether they exercise their redemption rights.

        All holders should consult their tax advisors regarding the tax consequences of the domestication. For a more detailed explanation of the tax consequences, see the discussion below in the section entitled "Material U.S. Federal Income Tax Consequences."




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Even if AHPAC consummates the business combination, there is no guarantee that the public warrants will ever be in the money, and they may expire worthless and the terms of AHPAC's warrants may be amended.

        The exercise price for AHPAC's warrants is $11.50 per whole AHPAC Class A ordinary share. There is no guarantee that the public warrants will ever be in the money prior to their expiration, and as such, the warrants may expire worthless.




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AHPAC's ability to successfully effect the business combination and to be successful thereafter will be dependent upon the efforts of AHPAC's key personnel, including the key personnel of Envigo whom AHPAC expects to stay with Envigo following the business combination. The loss of key personnel could negatively impact the operations and profitability of AHPAC post-combination business and its financial condition could suffer as a result.

        AHPAC's ability to successfully effect the business combination is dependent upon the efforts of certain key personnel, including the key personnel of Envigo. Although some of AHPAC's key personnel may remain with Envigo in senior management or advisory positions following the business combination, it is possible that AHPAC will lose some key personnel, the loss of which could negatively impact the operations and profitability of AHPAC's post-combination business. AHPAC anticipates that some or all of the management of Envigo will remain in place.

        Envigo's success depends to a significant degree upon the continued contributions of senior management, certain of whom would be difficult to replace. Departure by certain of Envigo's officers could have a material adverse effect on Envigo's business, financial condition, or operating results. Envigo does not maintain key-man life insurance on any of its officers. The services of such personnel may not continue to be available to Envigo.

AHPAC and Envigo will be subject to business uncertainties and contractual restrictions while the business combination is pending.

        Uncertainty about the effect of the business combination on employees and third parties may have an adverse effect on AHPAC and Envigo. These uncertainties may impair AHPAC or Envigo's ability to retain and motivate key personnel and could cause third parties that deal with any of us or them to defer entering into contracts or making other decisions or seek to change existing business relationships. If key employees depart because of uncertainty about their future roles and the potential complexities of the business combination, AHPAC or Envigo's business could be harmed.

AHPAC may waive one or more of the conditions to the business combination.

        AHPAC may agree to waive, in whole or in part, one or more of the conditions to AHPAC's obligations to complete the business combination, to the extent permitted by AHPAC's amended and restated memorandum and articles of association and applicable laws. For example, it is a condition to AHPAC's obligations to close the business combination Envigo performed and complied in all material respects with the obligations required to be performed or complied with by Envigo under the Transaction Agreement. However, if the AHPAC Board determines that a breach of this obligation is not material, then the Board may elect to waive that condition and close the business combination. AHPAC may not waive the condition that AHPAC's shareholders approve the business combination. Please see the section entitled "The Transaction Agreement—Conditions to Closing of the Business Combination" for additional information.




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The exercise of discretion by AHPAC's directors and officers in agreeing to changes to the terms of or waivers of closing conditions in the Transaction Agreement may result in a conflict of interest when determining whether such changes to the terms of the Transaction Agreement or waivers of conditions are appropriate and in the best interests of AHPAC's shareholders.

        In the period leading up to the consummation of the business combination, other events may occur that, pursuant to the Transaction Agreement, would require AHPAC to agree to amend the Transaction Agreement, to consent to certain actions or to waive rights that it is entitled to under those agreements. Such events could arise because of changes in the course of Envigo's business, a request by Envigo or Envigo to undertake actions that would otherwise be prohibited by the terms of the Transaction Agreement or the occurrence of other events that would have a material adverse effect on Envigo's business and would entitle AHPAC to terminate the Transaction Agreement. In any of such




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circumstances, it would be in the discretion of AHPAC, acting through the AHPAC Board, to grant its consent or waive its rights. The existence of the financial and personal interests of the directors described elsewhere in this proxy statement/prospectus may result in a conflict of interest on the part of one or more of the directors between what he or she may believe is best for AHPAC and AHPAC's shareholders and what he or she may believe is best for himself or herself or his or her affiliates in determining whether or not to take the requested action. As of the date of this proxy statement/prospectus, AHPAC does not believe there will be any changes or waivers that AHPAC's directors and officers would be likely to make after shareholder approval of the business combination has been obtained. While certain changes could be made without further shareholder approval, if there is a change to the terms of the business combination that would have a material impact on the shareholders, AHPAC will be required to circulate a new or amended proxy statement/prospectus or supplement thereto and resolicit the vote of AHPAC's shareholders with respect to the Business Combination Proposal.

AHPAC will incur significant transaction and transition costs in connection with the business combination.

        AHPAC has incurred and expects to incur significant, non-recurring costs in connection with consummating the business combination and operating as a public company following the consummation of the business combination. AHPAC may incur additional costs to retain key employees. All expenses incurred in connection with the Transaction Agreement and the transactions contemplated thereby (including the business combination), including all legal, accounting, consulting, investment banking and other fees, expenses and costs, will be for the account of the party incurring such fees, expenses and costs.

        AHPAC's transaction expenses as a result of the business combination are currently estimated at approximately $17 million.

If AHPAC is unable to complete an initial business combination, public shareholders may receive only approximately $10.00 per share on the liquidation of the trust account (or less than $10.00 per share in certain circumstances where a third party brings a claim against us that the sponsor is unable to indemnify), and AHPAC's warrants will expire worthless.

        If AHPAC is unable to complete an initial business combination by October 14, 2018, public shareholders may receive only approximately $10.00 per share on the liquidation of the trust account (or less than $10.00 per share in certain circumstances where a third-party brings a claim against us that the sponsor unable to indemnify (as described herein)) and AHPAC's warrants will expire worthless.




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If third parties bring claims against AHPAC, the proceeds held in the trust account could be reduced and the per-share redemption amount received by shareholders may be less than $10.00 per share.

        AHPAC's placing of funds in the trust account may not protect those funds from third-party claims against it. Although AHPAC will seek to have all vendors, service providers (other than AHPAC's independent auditors), prospective target businesses or other entities with which AHPAC does business execute agreements with it waiving any right, title, interest or claim of any kind in or to any funds held in the trust account for the benefit of public shareholders, such parties may not execute such agreements, or even if they execute such agreements they may not be prevented from bringing claims against the trust account, including, but not limited to, fraudulent inducement, breach of fiduciary responsibility or other similar claims, as well as claims challenging the enforceability of the waiver, in each case in order to gain advantage with respect to a claim against AHPAC's assets, including the funds held in the trust account. If any third party refuses to execute an agreement waiving such claims to the funds held in the trust account, AHPAC's management will perform an analysis of the alternatives available to it and will only enter into an agreement with a third-party that has not




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executed a waiver if management believes that such third party's engagement would be significantly more beneficial to it than any alternative.

        Examples of possible instances where AHPAC may engage a third party that refuses to execute a waiver include the engagement of a third party consultant whose particular expertise or skills are believed by management to be significantly superior to those of other consultants that would agree to execute a waiver or in cases where management is unable to find a service provider willing to execute a waiver. In addition, there is no guarantee that such entities will agree to waive any claims they may have in the future as a result of, or arising out of, any negotiations, contracts or agreements with AHPAC and will not seek recourse against the trust account for any reason. Upon redemption of public shares, if AHPAC is unable to complete the business combination within the prescribed timeframe, or upon the exercise of a redemption right in connection with the business combination, AHPAC will be required to provide for payment of claims of creditors that were not waived that may be brought against it within the ten years following redemption. Accordingly, the per-share redemption amount received by public shareholders could be less than the $10.00 per share initially held in the trust account, due to claims of such creditors. The sponsor has agreed that it will be liable to us if and to the extent any claims by a vendor for services rendered or products sold to AHPAC, or a prospective target business with which AHPAC has discussed entering into a transaction agreement, reduce the amount of funds in the trust account to below (i) $10.00 per public share or (ii) such lesser amount per public share held in the trust account as of the date of the liquidation of the trust account due to reductions in the value of the trust assets, in each case net of the interest which may be withdrawn to pay taxes, except as to any claims by a third party who executed a waiver of any and all rights to seek access to the trust account and except as to any claims under indemnity of the underwriters of the IPO against certain liabilities, including liabilities under the Securities Act. Moreover, in the event that an executed waiver is deemed to be unenforceable against a third party, the sponsor will not be responsible to the extent of any liability for such third party claims. AHPAC has not independently verified whether the sponsor has sufficient funds to satisfy its indemnity obligations and AHPAC has not asked the sponsor to reserve for such indemnification obligations.

AHPAC's directors may decide not to enforce the indemnification obligations of the sponsor, resulting in a reduction in the amount of funds in the trust account available for distribution to public shareholders.

        In the event that the proceeds in the trust account are reduced below the lesser of (i) $10.00 per share and (ii) the actual amount per share held in the trust account as of the date of the liquidation of the trust account if less than $10.00 per share due to reductions in the value of the trust assets, in each case less taxes payable, and the sponsor asserts that it is unable to satisfy his obligations or that he has no indemnification obligations related to a particular claim, AHPAC's independent directors would




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determine whether to take legal action against The sponsor to enforce its indemnification obligations. While AHPAC currently expects that its independent directors would take legal action on AHPAC's behalf against the sponsor to enforce its indemnification obligations to us, it is possible that AHPAC's independent directors in exercising their business judgment and subject to their fiduciary duties may choose not to do so in any particular instance. If AHPAC's independent directors choose not to enforce these indemnification obligations, the amount of funds in the trust account available for distribution to public shareholders may be reduced below $10.00 per share.




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If, before distributing the proceeds in the trust account to public shareholders, AHPAC files a bankruptcy petition or an involuntary bankruptcy petition is filed against AHPAC that is not dismissed, the claims of creditors in such proceeding may have priority over the claims of AHPAC's shareholders and the per-share amount that would otherwise be received by AHPAC's shareholders in connection with AHPAC's liquidation may be reduced.

        If, before distributing the proceeds in the trust account to public shareholders, AHPAC files a bankruptcy petition or an involuntary bankruptcy petition is filed against AHPAC that is not dismissed, the proceeds held in the trust account could be subject to applicable bankruptcy law, and may be included in AHPAC's bankruptcy estate and subject to the claims of third parties with priority over the claims of AHPAC's shareholders. To the extent any bankruptcy claims deplete the trust account, the per-share amount that would otherwise be received by AHPAC's shareholders in connection with AHPAC's liquidation may be reduced.

If AHPAC's due diligence investigation of Envigo was inadequate, then shareholders of AHPAC following the business combination could lose some or all of their investment.

        Even though AHPAC conducted a due diligence investigation of Envigo, AHPAC cannot be sure that this diligence uncovered all material issues that may be present inside Envigo or its business, or that it would be possible to uncover all material issues through a customary amount of due diligence, or that factors outside of Envigo and its business and outside of its control will not later arise.

Following the consummation of the business combination, ENVG's only significant asset will be its ownership interest in Envigo and such ownership may not be sufficiently profitable or valuable to enable ENVG to pay any dividends on ENVG Class A common stock or satisfy ENVG's other financial obligations, including its obligations under the Tax Receivable Agreement.

        Following the consummation of the business combination, ENVG will have no direct operations and no significant assets other than its ownership interest in Envigo. The initial shareholders, the Selling Equityholders that receive ENVG common stock in the business combination, and directors and officers of Envigo and its affiliates will become shareholders of AHPAC at that time. ENVG will depend on Envigo for distributions, loans and other payments to generate the funds necessary to meet its financial obligations, including its expenses as a publicly traded company, to pay any dividends with respect to ENVG Class A common stock, and to satisfy its obligations under the Tax Receivable Agreement. The financial condition and operating requirements of Envigo may limit ENVG's ability to obtain cash from Envigo. The earnings from, or other available assets of, Envigo may not be sufficient to pay dividends or make distributions or loans to enable ENVG to pay any dividends on the common stock or satisfy its other financial obligations, including its obligations under the Tax Receivable Agreement.

        In addition, payments under the Tax Receivable Agreement are not expressly permitted under Envigo's existing credit facilities and therefore would be required to comply with applicable covenants contained in each applicable credit facility in order to be paid. In accordance with the terms of the Tax Receivable Agreement, if a payment otherwise required under the Tax Receivable Agreement is not permitted by the terms of then outstanding indebtedness for borrowed money, any payment obligation




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under the Tax Receivable Agreement will be deferred and accrue interest at LIBOR plus 500 basis points from the date that such payment originally became due and payable through the actual payment date.




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We will be required to pay Selling Equityholders for a significant portion of the tax benefit relating to the utilization of certain net operating losses available to be carried forward after the business combination and imputed interest deductions arising from the payments under the Tax Receivable Agreement. In certain instances, we may be required to make payments that exceed, and may be payable years in advance of, the actual realization of future tax benefits, if any.

        At the closing of the business combination, ENVG will enter into a Tax Receivable Agreement with Envigo Holdings, Inc. and the shareholder representative on behalf of the Selling Equityholders. The Tax Receivable Agreement will generally provide for future payments by ENVG to the Selling Equityholders related to 85% of the net cash savings, if any, in U.S. federal, state and local and U.K. income tax that ENVG and its subsidiaries actually realizes (or is deemed to realize in certain circumstances) in periods after the consummation of the business combination as a result of (i) the utilization of net operating losses available to be carried forward as of the consummation of the business combination and (ii) imputed interest deductions arising from payments under the Tax Receivable Agreement. Although the amount and timing of any payments under the Tax Receivable Agreement will vary depending upon a number of factors, including the amount and timing of ENVG's income, AHPAC expects that the payments that ENVG may make thereunder could be substantial. Under certain circumstances, ENVG's obligations under the Tax Receivable Agreement may be accelerated as specified therein.

        As a result of the foregoing, (i) ENVG could be required to make payments under the Tax Receivable Agreement that are greater than or less than the specified percentage of the actual tax savings ENVG realizes in respect of the tax attributes subject to the agreements and (ii) ENVG may be required to make an immediate lump sum payment equal to the present value of the anticipated future tax savings, which payment may be made years in advance of the actual realization of such future benefits, if any of such benefits are ever realized. In these situations, ENVG's obligations under the Tax Receivable Agreement could have a negative impact on ENVG's liquidity and could have the effect of delaying, deferring or preventing certain mergers, asset sales, other forms of business combinations or other changes of control. There can be no assurance that ENVG will be able to finance its obligations under the Tax Receivable Agreement in a manner that does not adversely affect its working capital and growth requirements.

        See the section titled "AHPAC's Management's Discussion and Analysis of Financial Condition and Results of Operations—Liquidity and Capital Resources—Tax Receivable Agreement" beginning on page [    ·    ]175 of this proxy statement/prospectus for more information.

Subsequent to the completion of the business combination, ENVG may be required to take write-downs or write-offs, restructuring and impairment or other charges that could have a significant negative effect on ENVG's financial condition, results of operations and ENVG's stock price, which could cause you to lose some or all of your investment.

        Although AHPAC has conducted due diligence on Envigo, ENVG cannot assure you that this diligence will surface all material issues that may be present in Envigo's business, that it would be possible to uncover all material issues through a customary amount of due diligence, or that factors outside of Envigo's business and outside of ENVG and Envigo's control will not later arise. As a result of these factors, ENVG may be forced to later write-down or write-off assets, restructure operations, or incur impairment or other charges that could result in losses. Even if AHPAC's due diligence successfully identifies certain risks, unexpected risks may arise and previously known risks may materialize in a manner not consistent with AHPAC's preliminary risk analysis. Even though these




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charges may be non-cash items and not have an immediate impact on ENVG's liquidity, the fact that ENVG charges of this nature could contribute to negative market perceptions about ENVG or its securities. Accordingly, any of AHPAC's shareholders who choose to remain stockholders of ENVG following the business combination could suffer a reduction in the value of their shares. Such




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stockholders are unlikely to have a remedy for such reduction in value unless they are able to successfully claim that the reduction was due to the breach by AHPAC's officers or fiduciary duty owed to them, or if they are able to successfully bring a private claim under securities laws that this proxy statement/prospectus relating to the business combination contained an actionable material misstatement or material omission.

AHPAC has no operating or financial history and AHPAC's results of operations may differ significantly from the unaudited pro forma financial data included in this proxy statement/prospectus.

        AHPAC is a blank check company and AHPAC has no operating history and no revenues. This proxy statement/prospectus includes unaudited pro forma condensed combined financial statements for AHPAC. The unaudited pro forma condensed combined statement of operations of AHPAC combines the historical audited results of operations of AHPAC for the period ended December 31, 2016, with the historical audited results of operations of Envigo for the year ended December 31, 2016, and gives pro forma effect to the business combination as if it had been consummated on January 1, 2016. The unaudited pro forma condensed combined balance sheet of AHPAC combines the historical balance sheets of AHPAC as of September 30, 2017 and of Envigo as of September 30, 2017 and gives pro forma effect to the business combination as if it had been consummated on September 30, 2017.

        The unaudited pro forma condensed combined financial statements are presented for illustrative purposes only, are based on certain assumptions, address a hypothetical situation and reflect limited historical financial data. Therefore, the unaudited pro forma condensed combined financial statements are not necessarily indicative of the results of operations and financial position that would have been achieved had the business combination been consummated on the dates indicated above, or the future consolidated results of operations or financial position of AHPAC. Accordingly, AHPAC's business, assets, cash flows, results of operations and financial condition may differ significantly from those indicated by the unaudited pro forma condensed combined financial statements included in this document. For more information, please see the section entitled "Unaudited Pro Forma Condensed Combined Financial Information."

Unanticipated changes in effective tax rates or adverse outcomes resulting from examination of ENVG's income or other tax returns could adversely affect ENVG's financial condition and results of operations.

        ENVG will be subject to income taxes in the United States, and ENVG's domestic tax liabilities will be subject to the allocation of expenses in differing jurisdictions. ENVG's future effective tax rates could be subject to volatility or adversely affected by a number of factors, including:

•

changes in the valuation of ENVG's deferred tax assets and liabilities;



•

expected timing and amount of the release of any tax valuation allowances;



•

tax effects of stock-based compensation;



•

costs related to intercompany restructurings;



•

changes in tax laws, regulations or interpretations thereof; and



•

lower than anticipated future earnings in jurisdictions where ENVG has lower statutory tax rates and higher than anticipated future earnings in jurisdictions where ENVG has higher statutory tax rates.




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        In addition, ENVG may be subject to audits of ENVG's income, sales and other taxes by U.S. federal, state, local and non-U.S. taxing authorities. Outcomes from these audits could have an adverse effect on ENVG's financial condition and results of operations.




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AHPAC may be a PFIC, which could result in adverse United States federal income tax consequences to U.S. investors.

        If AHPAC is a PFIC for any taxable year (or portion thereof) that is included in the holding period of a U.S. holder of AHPAC Class A ordinary shares or warrants, the U.S. holder may be subject to adverse U.S. federal income tax consequences and may be subject to additional reporting requirements. Our PFIC status forBased on the composition of AHPAC's currentincome and subsequent taxable years will depend on whether we qualify for the PFIC start-up exception (see the discussion of the start-up exception below under "Material U.S. Federal Income Tax Considerations—U.S. Holders—Passive Foreign Investment Company Rules—Start-up Exception"). AHPAC's actual PFIC status for any taxable year will not be determinable until after the end of such year. Accordingly, there can be no assurance with respect to AHPAC's status asassets, AHPAC believes it was a PFIC for its taxable years ended December 31, 2016 or 2017.and December 31, 2017 and that it will be treated as a PFlC for its current taxable year which will end as a result of the domestication. U.S. holders should consult their tax advisors regarding the possible application of the PFIC rules. For a more detailed explanation of the tax consequences of PFIC classification to U.S. holders, see "Material U.S. Federal Income Tax Considerations—U.S. Holders—Passive Foreign Investment Company Rules."

A market for ENVG's securities may not continue, which would adversely affect the liquidity and price of ENVG's securities.

        Following the business combination, the price of ENVG's securities may fluctuate significantly due to the market's reaction to the business combination and general market and economic conditions. An active trading market for ENVG's securities following the business combination may never develop or, if developed, it may not be sustained. In addition, the price of ENVG's securities after the business combination can vary due to general economic conditions and forecasts, ENVG's general business condition and the release of ENVG's financial reports. Additionally, if ENVG's securities are not listed on, or become delisted from, NASDAQ for any reason, and are quoted on the OTC Bulletin Board, an inter-dealer automated quotation system for equity securities that is not a national securities exchange, the liquidity and price of ENVG's securities may be more limited than if ENVG was quoted or listed on NASDAQ or another national securities exchange. You may be unable to sell your securities unless a market can be established or sustained.

If the business combination's benefits do not meet the expectations of investors, shareholders or financial analysts, the market price of AHPAC's securities may decline.

        If the benefits of the business combination do not meet the expectations of investors, shareholders or securities analysts, the market price of AHPAC's securities prior to the consummation of the business combination may decline. The market values of AHPAC's securities at the time of the business combination may vary significantly from their prices on the date the Transaction Agreement was executed, the date of this proxy statement/prospectus, or the date on which AHPAC's shareholders vote on the business combination.

        In addition, following the business combination, fluctuations in the price of AHPAC's securities could contribute to the loss of all or part of your investment. Immediately prior to the business combination, there has not been a public market for Envigo's stock and trading in AHPAC Class A ordinary shares has not been active. Accordingly, the valuation ascribed to Envigo and AHPAC Class A ordinary shares in the business combination may not be indicative of the price that will prevail in the trading market following the business combination. If an active market for AHPAC's securities develops and continues, the trading price of AHPAC's securities following the business combination could be volatile and subject to wide fluctuations in response to various factors, some of which are beyond its




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control. Any of the factors listed below could have a material adverse effect on your investment in AHPAC's securities and AHPAC's securities may trade at prices significantly below the price you paid for them. In such circumstances, the trading price of AHPAC's securities may not recover and may experience a further decline.




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        Factors affecting the trading price of ENVG's securities following the business combination may include:

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actual or anticipated fluctuations in ENVG's quarterly financial results or the quarterly financial results of companies perceived to be similar to us;



•

changes in the market's expectations about ENVG's operating results;



•

the public's reaction to ENVG's press releases, ENVG's other public announcements and ENVG's filings with the SEC;



•

speculation in the press or investment community;



•

success of competitors;



•

the operating results failing to meet the expectation of securities analysts or investors in a particular period;



•

changes in financial estimates and recommendations by securities analysts concerning ENVG or the market in general;



•

operating and stock price performance of other companies that investors deem comparable to ENVG;



•

ENVG's ability to market new and enhanced products on a timely basis;



•

changes in laws and regulations affecting ENVG's business;



•

commencement of, or involvement in, litigation involving ENVG;



•

changes in ENVG's capital structure, such as future issuances of securities or the incurrence of additional debt;



•

the volume of ENVG Class A common stock available for public sale;



•

any major change in ENVG's Board or management;



•

sales of substantial amounts of ENVG Class A common stock by ENVG's directors, officers or significant shareholders or the perception that such sales could occur;



•

general economic and political conditions such as recessions, interest rates, fuel prices, international currency fluctuations and acts of war or terrorism; and



•

other risk factors listed under "Risk Factors" starting on page [    ·    ].37.

        Broad market and industry factors may materially harm the market price of ENVG's securities irrespective of ENVG's operating performance. The stock market in general and NASDAQ have experienced price and volume fluctuations that have often been unrelated or disproportionate to the operating performance of the particular companies affected. The trading prices and valuations of these stocks, and of ENVG's securities, may not be predictable. A loss of investor confidence in the market for the stocks of other companies which investors perceive to be similar to ENVG could depress ENVG's stock price regardless of ENVG's business, prospects, financial conditions or results of operations. A decline in the market price of ENVG's securities also could adversely affect ENVG's ability to issue additional securities and ENVG's ability to obtain additional financing in the future.




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        In the past, securities class action litigation has often been initiated against companies following periods of volatility in their stock price. This type of litigation could result in substantial costs and divert AHPAC's management's attention and resources, and could also require us to make substantial payments to satisfy judgments or to settle litigation.




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ENVG's quarterly operating results may fluctuate significantly and could fall below the expectations of securities analysts and investors due to seasonality and other factors, some of which are beyond ENVG's control, resulting in a decline in ENVG's stock price.

        ENVG's quarterly operating results may fluctuate significantly because of several factors, including:

•

labor availability and costs for hourly and management personnel;



•

profitability of ENVG's products, especially in new markets and due to seasonal fluctuations;



•

changes in interest or exchange rates;



•

impairment of long-lived assets;



•

macroeconomic conditions, both nationally and locally;



•

negative publicity relating to products we serve;



•

changes in consumer preferences and competitive conditions;



•

expansion to new markets; and



•

fluctuations in commodity prices.

If, following the business combination, securities or industry analysts do not publish or cease publishing research or reports about ENVG, its business, or its market, or if they change their recommendations regarding ENVG Class A common stock adversely, then the price and trading volume of ENVG Class A common stock could decline.

        The trading market for ENVG Class A common stock will be influenced by the research and reports that industry or securities analysts may publish about us, ENVG's business, ENVG's market, or ENVG's competitors. Securities and industry analysts do not currently, and may never, publish research on AHPAC or ENVG. If no securities or industry analysts commence coverage of ENVG, ENVG's stock price and trading volume would likely be negatively impacted. If any of the analysts who may cover ENVG change their recommendation regarding ENVG's stock adversely, or provide more favorable relative recommendations about ENVG's competitors, the price of ENVG Class A common stock would likely decline. If any analyst who may cover AHPAC were to cease coverage of ENVG or fail to regularly publish reports on it, we could lose visibility in the financial markets, which could cause ENVG's stock price or trading volume to decline.

ENVG may be unable to obtain additional financing to fund its operations or growth.

        ENVG may require additional financing to fund its operations or growth. The failure to secure additional financing could have a material adverse effect on the continued development or growth of ENVG. None of AHPAC's officers, directors or shareholders is required to provide any financing to us in connection with or after the business combination.

Some of Envigo's existing debt will incur increased interest costs beginning in April 2018 if it is not refinanced before that time.

        Envigo's current first lien and second lien term debt will see an increase in interest rates in April 2018 if that debt is not refinanced before then. Specifically, the First Lien Credit Agreement, which




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currently carries an interest rate of LIBOR plus 2.5%, would increase to LIBOR plus 5.75% and the Second Lien Credit Agreement, which currently carries an interest rate of LIBOR plus 2.5%, would increase to LIBOR plus 7.75%.




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Changes in laws, regulations or rules, or a failure to comply with any laws, regulations or rules, may adversely affect ENVG's business, investments and results of operations.

        ENVG will be subject to laws, regulations and rules enacted by national, regional and local governments and NASDAQ. In particular, ENVG will be required to comply with certain SEC, NASDAQ and other legal or regulatory requirements. Compliance with, and monitoring of, applicable laws, regulations and rules may be difficult, time consuming and costly. Those laws, regulations or rules and their interpretation and application may also change from time to time and those changes could have a material adverse effect on ENVG's business, investments and results of operations. In addition, a failure to comply with applicable laws, regulations or rules, as interpreted and applied, could have a material adverse effect on ENVG's business and results of operations.

The Sponsor, Jermyn Street Associates LLC and Savanna Holdings LLC will have significant influence over ENVG after completion of the business combination.

        Upon completion of the business combination, the sponsor, Jermyn Street Associates LLC and Savanna Holdings LLC will beneficially own approximately 6%5.6%, [    ·    ]%16.9% and [    ·    ]%9.9%, respectively, of ENVG Class A common stock. As long as the sponsor, Jermyn Street Associates LLC or Savanna Holdings LLC own or control a significant percentage of ENVG's outstanding voting power, they will have the ability to significantly influence all corporate actions requiring shareholder approval, including the election and removal of directors and the size of ENVG's Board, any amendment to ENVG's organizational documents, or the approval of any merger or other significant corporate transaction, including a sale of substantially all of ENVG's assets.

        The sponsor, Jermyn Street Associates LLC or Savanna Holdings LLC's interests may not align with the interests of ENVG's other shareholders. The sponsor, Jermyn Street Associates LLC and Savanna Holdings LLC are each in the business of making investments in companies and may acquire and hold interests in businesses that compete directly or indirectly with ENVG. The sponsor, Jermyn Street Associates LLC or Savanna Holdings LLC may also pursue acquisition opportunities that may be complementary to ENVG's business, and, as a result, those acquisition opportunities may not be available to us. In addition, ENVG's proposed certificate and proposed bylaws provide that the ENVG Sponsors may engage in competitive businesses and renounce certain corporate opportunities offered to the ENVG Sponsors or any of their managers, officers, directors, agents, stockholders, members, partners, affiliates and subsidiaries (other than ENVG and its subsidiaries) that are not expressly offered to them in their capacities as directors or officers of ENVG. The proposed certificate and proposed bylaws also provide that the ENVG Sponsors or any of their managers, officers, directors, agents, stockholders, members, partners, affiliates and subsidiaries (other than ENVG and its subsidiaries), do not have any fiduciary duty to refrain from engaging directly or indirectly in the same or similar business activities or lines of business as ENVG or any of its subsidiaries.

Registration of the ENVG Class A common stock underlying the warrants may not be in place when an investor desires to exercise warrants, thus precluding such investor from being able to exercise its warrants except on a cashless basis and potentially causing such warrants to expire worthless.

        AHPAC has not registered the ENVG Class A common stock issuable upon exercise of the warrants under the Securities Act or any state securities laws at this time. However, under the terms of the warrant agreement, AHPAC has agreed, as soon as practicable, but in no event later than 15 business days after the consummation of the business combination, to use its best efforts to file a registration statement under the Securities Act covering such shares and maintain a current prospectus




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relating to the ENVG Class A common stock issuable upon exercise of the warrants, until the expiration of the warrants in accordance with the provisions of the warrant agreement. AHPAC cannot assure you that it will be able to do so if, for example, any facts or events arise which represent a fundamental change in the information set forth in such registration statement or prospectus, the




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financial statements contained or incorporated by reference therein are not current or correct or the SEC issues a stop order. If the shares issuable upon exercise of the warrants are not registered under the Securities Act, ENVG will be required to permit holders to exercise their warrants on a cashless basis. However, no warrant will be exercisable for cash or on a cashless basis, and we will not be obligated to issue any shares to holders seeking to exercise their warrants, unless the issuance of the shares upon such exercise is registered or qualified under the securities laws of the state of the exercising holder or an exemption is available. Notwithstanding the above, if ENVG Class A common stock are at the time of any exercise of a warrant not listed on a national securities exchange such that it satisfies the definition of a "covered security" under Section 18(b)(1) of the Securities Act, we may, at ENVG's option, require holders of warrants who exercise their warrants to do so a "cashless basis" in accordance with Section 3(a)(9) of the Securities Act and, in the event we so elect, we will not be required to file or maintain in effect a registration statement, but we will use its best efforts to register or qualify the shares under applicable blue sky laws to the extent an exemption is not available. In no event will we be required to net cash settle any warrant, or issue securities or other compensation in exchange for the warrants in the event that we are unable to register or qualify the shares underlying the warrants under applicable state securities laws. If the issuance of the shares upon exercise of the warrants is not so registered or qualified or exempt from registration or qualification, the holder of such warrant shall not be entitled to exercise such warrant and such warrant may have no value and expire worthless. In such event, holders who acquired their warrants as part of a purchase of units will have paid the full unit purchase price solely for the ENVG Class A common stock included in the units. If and when the warrants become redeemable by us, ENVG may exercise its redemption right even If ENVG is unable to register or qualify the underlying ENVG Class A common stock for sale under all applicable state securities laws.

ENVG may amend the terms of the warrants in a manner that may be adverse to holders with the approval by the holders of at least 65% of the then-outstanding warrants.

        ENVG warrants will be issued in registered form under a warrant agreement between Continental Stock Transfer & Trust Company, as warrant agent, and AHPAC. The warrant agreement provides that the terms of the warrants may be amended without the consent of any holder to cure any ambiguity or correct any defective provision, but requires the approval by the holders of at least 65% of the then-outstanding public warrants to make any change that adversely affects the interests of the registered holders. Accordingly, AHPAC may amend the terms of the warrants in a manner adverse to a holder if holders of at least 65% of the then-outstanding public warrants approve of such amendment. Although ENVG's ability to amend the terms of the warrants with the consent of at least 65% of the then-outstanding public warrants is unlimited, examples of such amendments could be amendments to, among other things, increase the exercise price of the warrants, shorten the exercise period or decrease the number of shares of ENVG Class A common stock purchasable upon exercise of a warrant.

ENVG may redeem your unexpired warrants prior to their exercise at a time that is disadvantageous to you, thereby making your warrants worthless.

        ENVG will have the ability to redeem outstanding warrants at any time after they become exercisable and prior to their expiration, at a price of $0.01 per warrant, provided that the closing price of ENVG Class A common stock equals or exceeds $24.00 per share (as adjusted for share splits, share capitalizations, reorganizations, recapitalizations and the like) for any 20 trading days within a 30 trading-day period ending on the third trading day prior to proper notice of such redemption provided




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that on the date we give notice of redemption. If and when the warrants become redeemable, ENVG may exercise its redemption right even if it is unable to register or qualify the underlying securities for sale under all applicable state securities laws. Redemption of the outstanding warrants could force you to (i) exercise your warrants and pay the exercise price therefor at a time when it may be




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disadvantageous for you to do so, (ii) sell your warrants at the then-current market price when you might otherwise wish to hold your warrants or (iii) accept the nominal redemption price which, at the time the outstanding warrants are called for redemption, is likely to be substantially less than the market value of your warrants. None of the private placement warrants will be redeemable by us so long as they are held by their initial purchasers or their permitted transferees.

The exercise of outstanding warrants would increase the number of shares eligible for future resale in the public market and result in dilution to shareholders.

        AHPAC issued warrants to purchase 15,500,000 AHPAC Class A ordinary shares as part of the IPO and prior to the IPO, AHPAC issued private placement warrants to the initial shareholders to purchase 8,200,000 AHPAC Class A ordinary shares, in each case at $11.50 per share. In addition, prior to consummating an initial business combination, subject to the terms of the Transaction Agreement, AHPAC may issue additional securities in the equity financing so long as they do not participate in any manner in the trust account or vote as a class with the common stock on a business combination. The shares of ENVG Class A common stock issued in the equity financing (if any) and additional shares of ENVG Class A common stock issued upon exercise of AHPAC's warrants will result in dilution to the then existing holders of AHPAC Class A ordinary shares and increase the number of shares eligible for resale in the public market. Sales of substantial numbers of such shares in the public market could adversely affect the market price of AHPAC Class A ordinary shares and ENVG Class A common stock.

Because AHPAC is incorporated under the laws of the Cayman Islands, you may face difficulties in protecting your interests, and your ability to protect your rights through the U.S. Federal courts may be limited.

        AHPAC is an exempted company incorporated under the laws of the Cayman Islands. As a result, it may be difficult for investors to effect service of process within the United States upon AHPAC's directors or executive officers, or enforce judgments obtained in the United States courts against AHPAC's directors or officers.

        AHPAC corporate affairs are governed by AHPAC's amended and restated memorandum and articles of association, the Companies Law (as the same may be supplemented or amended from time to time) and the common law of the Cayman Islands. AHPAC will also be subject to the federal securities laws of the United States. The rights of shareholders to take action against the directors, actions by minority shareholders and the fiduciary responsibilities of AHPAC's directors to us under Cayman Islands law are to a large extent governed by the common law of the Cayman Islands. The common law of the Cayman Islands is derived in part from comparatively limited judicial precedent in the Cayman Islands as well as from English common law, the decisions of whose courts are of persuasive authority, but are not binding on a court in the Cayman Islands. The rights of AHPAC's shareholders and the fiduciary responsibilities of AHPAC's directors under Cayman Islands law are different from what they would be under statutes or judicial precedent in some jurisdictions in the United States. In particular, the Cayman Islands has a different body of securities laws as compared to the United States, and certain states, such as Delaware, may have more fully developed and judicially interpreted bodies of corporate law. In addition, Cayman Islands companies may not have standing to initiate a shareholders derivative action in a Federal court of the United States.

        AHPAC has been advised by AHPAC Cayman Islands legal counsel that the courts of the Cayman Islands are unlikely (i) to recognize or enforce against us judgments of courts of the United States predicated upon the civil liability provisions of the federal securities laws of the United States or any




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state; and (ii) in original actions brought in the Cayman Islands, to impose liabilities against us predicated upon the civil liability provisions of the federal securities laws of the United States or any state, so far as the liabilities imposed by those provisions are penal in nature. In those circumstances, although there is no statutory enforcement in the Cayman Islands of judgments obtained in the United




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States, the courts of the Cayman Islands will recognize and enforce a foreign money judgment of a foreign court of competent jurisdiction without retrial on the merits based on the principle that a judgment of a competent foreign court imposes upon the judgment debtor an obligation to pay the sum for which judgment has been given provided certain conditions are met. For a foreign judgment to be enforced in the Cayman Islands, such judgment must be final and conclusive and for a liquidated sum, and must not be in respect of taxes or a fine or penalty, inconsistent with a Cayman Islands judgment in respect of the same matter, impeachable on the grounds of fraud or obtained in a manner, or be of a kind the enforcement of which is, contrary to natural justice or the public policy of the Cayman Islands (awards of punitive or multiple damages may well be held to be contrary to public policy). A Cayman Islands Court may stay enforcement proceedings if concurrent proceedings are being brought elsewhere.

        As a result of all of the above, public shareholders may have more difficulty in protecting their interests in the face of actions taken by management, members of the board of directors or controlling shareholders than they would as public shareholders of a United States company.

Provisions in ENVG's proposed charter may inhibit a takeover of ENVG, which could limit the price investors might be willing to pay in the future for ENVG Class A common stock and could entrench management.

        ENVG's proposed certificate of incorporation contains provisions that may discourage unsolicited takeover proposals that shareholders may consider to be in their best interests. These provisions include a staggered board of directors and the ability of the board of directors to designate the terms of and issue new series of preferred shares, which may make more difficult the removal of management and may discourage transactions that otherwise could involve payment of a premium over prevailing market prices for AHPAC's securities.

The JOBS Act permits "emerging growth companies" like us to take advantage of certain exemptions from various reporting requirements applicable to other public companies that are not emerging growth companies.

        AHPAC qualifies as an "emerging growth company" as defined in Section 2(a)(19) of the Securities Act, as modified by the Jumpstart Our Business Startups Act of 2012, which we refer to as the "JOBS Act." As such, following the consummation of the business combination, ENVG will take advantage of certain exemptions from various reporting requirements applicable to other public companies that are not emerging growth companies for as long as it continues to be an emerging growth company, including (i) the exemption from the auditor attestation requirements with respect to internal control over financial reporting under Section 404 of the Sarbanes-Oxley Act, (ii) the exemptions from say-on-pay, say-on-frequency and say-on-golden parachute voting requirements and (iii) reduced disclosure obligations regarding executive compensation in its periodic reports and proxy statements. As a result, ENVG's stockholders may not have access to certain information they deem important. ENVG will remain an emerging growth company until the earliest of (i) the last day of the fiscal year (a) following October 14, 2021, the fifth anniversary of the IPO, (b) in which ENVG has total annual gross revenue of at least $1.0 billion or (c) in which ENVG is deemed to be a large accelerated filer, which means the market value of ENVG Class A common stock that are held by non-affiliates exceeds $700 million as of the last business day of ENVG's prior second fiscal quarter, and (ii) the date on which ENVG has issued more than $1.0 billion in non-convertible debt during the prior three-year period.

        In addition, Section 107 of the JOBS Act also provides that an emerging growth company can take advantage of the exemption from complying with new or revised accounting standards provided in




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Section 7(a)(2)(B) of the Securities Act as long as ENVG is an emerging growth company. An emerging growth company can therefore delay the adoption of certain accounting standards until those standards would otherwise apply to private companies. The JOBS Act provides that a company can elect to opt out of the extended transition period and comply with the requirements that apply to




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non-emerging growth companies, but any such election to opt out is irrevocable. ENVG has elected not to opt out of such extended transition period, which means that when a standard is issued or revised and it has different application dates for public or private companies, we, as an emerging growth company, can adopt the new or revised standard at the time private companies adopt the new or revised standard. This may make comparison of ENVG's financial statements with another public company which is neither an emerging growth company nor an emerging growth company which has opted out of using the extended transition period difficult or impossible because of the potential differences in accounting standards used.

        AHPAC cannot predict if investors will find ENVG Class A common stock less attractive because ENVG will rely on these exemptions. If some investors find ENVG Class A common stock less attractive as a result, there may be a less active trading market for ENVG Class A common stock and ENVG's stock price may be more volatile.

Risks Related to the Redemption


You must tender your AHPAC Class A ordinary shares in order to validly seek redemption at the annual general meeting.

        In connection with tendering your shares for redemption, you must elect either to physically tender your ordinary share certificates to AHPAC's transfer agent in each case by two business days prior to the consummation of the business combination, or to deliver your ordinary shares to the transfer agent electronically using The Depository Trust Company's DWAC (Deposit/Withdrawal At Custodian) System, which election would likely be determined based on the manner in which you hold your ordinary shares. The requirement for physical or electronic delivery by the business day prior to the consummation of the business combination ensures that a redeeming holder's election to redeem is irrevocable once the business combination is consummated. Any failure to observe these procedures will result in your loss of redemption rights in connection with the vote on the business combination.

AHPAC does not have a specified maximum redemption threshold. The absence of such a redemption threshold may make it possible for us to complete a business combination with which a substantial majority of AHPAC's shareholders do not agree.

        AHPAC's amended and restated memorandum and articles of association does not provide a specified maximum redemption threshold, except that AHPAC will not redeem public shares in an amount that would cause AHPAC net tangible assets to be less than $5,000,001 (as determined in accordance with Rule 3a51-1(g)(1) of the Exchange Act). However, the Transaction Agreement provides the obligations of Envigo to consummate the business combination is conditioned on there being at least $260$220 million of available funds from the trust account and proceeds from the equity financing (if any), after giving effect to redemptions of public shares. As a result, AHPAC may be able to complete the business combination even though a substantial portion of public shareholders do not agree with the transaction and have redeemed their shares or have entered into privately negotiated agreements to sell their shares to the sponsor, directors or officers or their affiliates. As of the date of this proxy statement/prospectus, no agreements with respect to the private purchase of public shares by AHPAC or the persons described above have been entered into with any such investor or holder. AHPAC will file a Current Report on Form 8-K with the SEC to disclose private arrangements entered into or significant private purchases made by any of the aforementioned persons that would affect the vote on the Business Combination Proposal or other proposals (as described in this proxy statement/prospectus) at the general meeting.




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        In the event the aggregate cash consideration AHPAC would be required to pay for all AHPAC Class A ordinary shares that are validly submitted for redemption plus any amount required to satisfy cash conditions pursuant to the terms of the Transaction Agreement exceeds the aggregate exchange




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amount of cash available to us, AHPAC may not complete the business combination or redeem any shares, all AHPAC Class A ordinary shares submitted for redemption will be returned to the holders thereof, and AHPAC instead may search for an alternate business combination.

If you or a "group" of shareholders of which you are a part are deemed to hold an aggregate of more than fifteen percent (15%) of the AHPAC Class A ordinary shares issued in the IPO, you (or, if a member of such a group, all of the members of such group in the aggregate) will lose the ability to redeem all such shares in excess of 15% of the AHPAC Class A ordinary shares issued in the IPO.

        A public shareholder, together with any of his, her or its affiliates or any other person with whom it is acting in concert or as a "group" (as defined under Section 13 of the Exchange Act), will be restricted from redeeming in the aggregate his, her or its shares or, if part of such a group, the group's shares, in excess of 15% of the AHPAC Class A ordinary shares included in the units sold in the IPO. In order to determine whether a shareholder is acting in concert or as a group with another shareholder, AHPAC will require each public shareholder seeking to exercise redemption rights to certify to AHPAC whether such shareholder is acting in concert or as a group with any other shareholder. Such certifications, together with other public information relating to stock ownership available to AHPAC at that time, such as Section 13D, Section 13G and Section 16 filings under the Exchange Act, will be the sole basis on which AHPAC makes the above-referenced determination. Your inability to redeem any such excess shares will reduce your influence over AHPAC's ability to consummate the business combination and you could suffer a material loss on your investment in AHPAC if you sell such excess shares in open market transactions. Additionally, you will not receive redemption distributions with respect to such excess shares if AHPAC consummates the business combination. As a result, you will continue to hold that number of shares aggregating to more than 15% of the shares sold in the IPO and, in order to dispose of such excess shares, would be required to sell your stock in open market transactions, potentially at a loss. AHPAC cannot assure you that the value of such excess shares will appreciate over time following the business combination or that the market price of AHPAC Class A ordinary shares will exceed the per-share redemption price. Notwithstanding the foregoing, shareholders may challenge AHPAC's determination as to whether a shareholder is acting in concert or as a group with another shareholder in a court of competent jurisdiction.

        However, AHPAC's shareholders' ability to vote all of their shares (including such excess shares) for or against the business combination is not restricted by this limitation on redemption.

There is no guarantee that a shareholder's decision whether to redeem its shares for a pro rata portion of the trust account will put the shareholder in a better future economic position.

        AHPAC can give no assurance as to the price at which a shareholder may be able to sell its public shares in the future following the completion of the business combination or any alternative business combination. Certain events following the consummation of any initial business combination, including the business combination, may cause an increase in AHPAC share price, and may result in a lower value realized now than a shareholder of AHPAC might realize in the future had the shareholder not redeemed its shares. Similarly, if a shareholder does not redeem its shares, the shareholder will bear the risk of ownership of the public shares after the consummation of any initial business combination, and there can be no assurance that a shareholder can sell its shares in the future for a greater amount than the redemption price set forth in this proxy statement/prospectus. A shareholder should consult the shareholder's own tax and/or financial advisor for assistance on how this may affect his, her or its individual situation.




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Shareholders of AHPAC who wish to redeem their shares for a pro rata portion of the trust account must comply with specific requirements for redemption that may make it more difficult for them to exercise their redemption rights prior to the deadline. If shareholders fail to comply with the redemption requirements specified in this proxy statement/ prospectus, they will not be entitled to redeem their AHPAC Class A ordinary shares for a pro rata portion of the funds held in the trust account.

        Public shareholders who wish to redeem their shares for a pro rata portion of the trust account must, among other things (i) submit a request in writing and (ii) tender their certificates to AHPAC's transfer agent or deliver their shares to the transfer agent electronically through the DWAC system at least two business days prior to the general meeting. In order to obtain a physical stock certificate, a shareholder's broker and/or clearing broker, DTC and AHPAC's transfer agent will need to act to facilitate this request. It is AHPAC's understanding that shareholders should generally allot at least two weeks to obtain physical certificates from the transfer agent. However, because AHPAC does not have any control over this process or over the brokers, which AHPAC refers to as "DTC," it may take significantly longer than two weeks to obtain a physical stock certificate. If it takes longer than anticipated to obtain a physical certificate, shareholders who wish to redeem their shares may be unable to obtain physical certificates by the deadline for exercising their redemption rights and thus will be unable to redeem their shares.

        Shareholders electing to redeem their shares will receive their pro rata portion of the trust account less franchise and income taxes payable, calculated as of two business days prior to the anticipated consummation of the business combination. Please see the section entitled "Annual General Meeting of AHPAC Shareholders—Redemption Rights" for additional information on how to exercise your redemption rights.

If a shareholder fails to receive notice of AHPAC offer to redeem public shares in connection with the business combination, or fails to comply with the procedures for tendering its shares, such shares may not be redeemed.

        If, despite AHPAC compliance with the proxy rules, a shareholder fails to receive AHPAC proxy materials, such shareholder may not become aware of the opportunity to redeem its shares. In addition, the proxy materials that AHPAC is furnishing to holders of public shares in connection with the business combination describes the various procedures that must be complied with in order to validly redeem public shares. In the event that a shareholder fails to comply with these procedures, its shares may not be redeemed.




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ANNUAL GENERAL MEETING OF AHPAC SHAREHOLDERS


        This proxy statement/prospectus is being provided to AHPAC's shareholders as part of a solicitation of proxies by the AHPAC Board for use at the general meeting of AHPAC's shareholders to be held on [    ·    ],] 2018, and at any adjournment or postponement thereof. This proxy statement/prospectus contains important information regarding the general meeting, the proposals on which you are being asked to vote and information you may find useful in determining how to vote and voting procedures.

        This proxy statement/prospectus is being first mailed on or about [    ·    ]], 2018 to all shareholders of record of AHPAC as of [    ·    ],January 16, 2018, the record date for the general meeting. Shareholders of record who owned AHPAC ordinary shares at the close of business on the record date are entitled to receive notice of, attend and vote at the general meeting. On the record date, there were [    ·    ]38,750,000 ordinary shares outstanding.

Date, Time and Place of general meeting


        The general meeting will be held at [    ·    ] Eastern Time on [    ·    ]], 2018 at the offices of Weil, Gotshal & Manges, 767 Fifth Avenue, New York NY 10153, or such other date, time and place to which such meeting may be adjourned or postponed, to consider and vote upon the proposals.

Voting Power; Record Date


        As a shareholder of AHPAC, you have a right to vote on the matters presented at the general meeting, which are summarized above and fully set forth in this proxy statement/prospectus. You will be entitled to vote or direct votes to be cast at the general meeting if you owned AHPAC ordinary shares at the close of business on [    ·    ],January 16, 2018, which is the record date for the general meeting. You are entitled to one vote for each AHPAC ordinary share that you owned as of the close of business on the record date. If your shares are held in "street name" or are in a margin or similar account, you should contact your broker, bank or other nominee to ensure that votes related to the shares you beneficially own are properly counted. On the record date, there were [    ·    ]38,750,000 AHPAC ordinary shares outstanding, of which [    ·    ]31,000,000 are AHPAC Class A ordinary shares and [    ·    ]7,750,000 are AHPAC Class B ordinary shares held by the initial shareholders.

Proposals at the general meeting


        At the general meeting, AHPAC's shareholders will vote on the following proposals:

1.

Proposal No. 1—The Business Combination Proposal—To consider and vote upon a proposal to approve and adopt the Transaction Agreement and the transactions contemplated thereby, which we refer to as the "Business Combination Proposal";



2.

Proposal No. 2—The Domestication Proposal—To consider and vote upon a proposal to approve by special resolution, assuming the Business Combination Proposal is approved and adopted, the domestication, which we refer to as the "Domestication Proposal";


The Charter Proposals—To consider and vote upon nine separate proposals to approve by special resolution, assuming the Business Combination Proposal is approved and adopted, the following material differences between AHPAC's existing amended and restated memorandum and articles of association and the proposed certificate and the proposed bylaws of ENVG upon the domestication:

3.

Proposal No. 3—To consider and vote upon an amendment to AHPAC's existing organizational documents to authorize the classification of the Board into three classes of directors, which shall consist of, as nearly as may be possible, one-third of the total number of




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directors on the Board, which will initially be seven (7) and then as may be set by the Board from time to time;

4.

Proposal No. 4—To consider and vote upon an amendment to AHPAC's existing organizational documents to authorize that directors may only be removed for cause;



5.

Proposal No. 5—To consider and vote upon an amendment to AHPAC's existing organizational documents to authorize that only the Board, chairperson of the board of directors or chief executive offer may call a meeting of stockholders;



6.

Proposal No. 6—To consider and vote upon an amendment to AHPAC's existing organizational documents to authorize removal of the ability of stockholders to take action by written consent in lieu of a meeting;



7.

Proposal No. 7—To consider and vote upon an amendment to AHPAC's existing organizational documents to require the affirmative vote of holders of a majority of the voting power of ENVG's then issued and outstanding shares of stock entitled to amend the proposed certificate;



8.

Proposal No. 8—To consider and vote upon an amendment to AHPAC's existing organizational documents to authorize the adoption of Delaware as the exclusive forum for certain stockholder litigation;



9.

Proposal No. 9—To consider and vote upon an amendment to AHPAC's existing organizational documents to authorize ENVG to permit the ENVG Sponsors to engage in competitive businesses and renounce certain corporate opportunities offered to the ENVG Sponsors or any of their managers, officers, directors, agents, stockholders, members, partners, affiliates and subsidiaries (other than ENVG and its subsidiaries) that are not expressly offered to them in their capacities as directors or officers of ENVG;



10.

Proposal No. 10—To consider and vote upon an amendment to AHPAC's existing organizational documents to approve the authorized number of shares of ENVG common stock contained in the proposed certificate; and



11.

Proposal No. 11—To consider and vote upon an amendment to AHPAC's existing organizational documents to authorize other changes to the organizational documents resulting from the domestication and business combination, including changing the post-business combination corporate name from "Avista Healthcare Public Acquisition Corp." to "Envigo International Holdings, Inc." and removing certain provisions relating to our status as a blank-check company that will no longer apply upon consummation of the business combination;

We refer to Proposals No. 3-11 collectively as the "Charter Proposals";

12.

Proposal No. 12—The Director Election Proposal—To consider and vote upon a proposal to elect seven directors to serve staggered terms on ENVG's Board of Directors until the 2019, 2020 and 2021 annual meeting of shareholders, respectively, and until their respective successors are duly elected and qualified, which we refer to as the "Director Election Proposal";



13.

Proposal No. 13—The Management Incentive Plan Proposal—To consider and vote on a proposal to approve and adopt, assuming the Charter Proposals, the Domestication Proposal and the Business Combination Proposal are all approved and adopted, 2017 Omnibus2018 Equity Incentive Plan and the material terms thereunder, which we refer to as the "Management Incentive Plan Proposal". A copy of the 2017 Omnibus2018 Equity Incentive Plan is attached to the accompanying proxy statement/prospectus asAnnex G;




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14.

Proposal No. 14—The NASDAQ Proposal—To consider and vote upon a proposal to approve, assuming the Charter Proposals, the Domestication Proposal and the Business Combination Proposal are all approved and adopted, for purposes of complying with applicable provisions of NASDAQ Listing Rule 5635, the issuance of more than 20% of AHPAC's issued and outstanding ordinary shares (or issued and outstanding common stock following the domestication) to the Selling Equityholders in connection with the business combination and to participants in the equity financing (if any), that may be deemed a change of control, which we refer to as the "NASDAQ Proposal". and



15.

Proposal No. 15—Adjournment Proposal—To consider and vote upon a proposal to approve the adjournment of the general meeting to a later date or dates, if necessary, to permit further solicitation and vote of proxies in the event that there are insufficient votes for, or otherwise in connection with, the approval of one or more proposals to be submitted for shareholder approval at the general meeting, which we refer to as the "Adjournment Proposal."




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THE AHPAC BOARD UNANIMOUSLY RECOMMENDS THAT YOU VOTE "FOR" EACH OF THESE PROPOSALS.


Vote of AHPAC's Sponsor, Directors and Officers


        In connection with the IPO, the initial shareholders agreed to vote their founder shares and any public shares purchased during or after the IPO in favor of the business combination. Currently, the initial shareholders own approximately 20% of AHPAC's issued and outstanding ordinary shares, including all of the founder shares. These agreements apply to the initial shareholders, including the sponsor, as it relates to the founder shares and the requirement to vote all of the founder shares in favor of the Business Combination Proposal and for all other proposals presented to AHPAC's shareholders in this proxy statement/prospectus.

        The initial shareholders, other current directors and officers have waived any redemption rights, including with respect to AHPAC Class A ordinary shares purchased in the IPO or in the aftermarket, in connection with business combination. The founder shares held by the initial shareholders have no redemption rights upon AHPAC's liquidation and will be worthless if no business combination is effected by us by October 14, 2018. However, the initial shareholders are entitled to redemption rights upon AHPAC's liquidation with respect to any public shares they may own.

Quorum and Required Vote for Proposals for the General Meeting


        The approval of each of the Domestication Proposal and the Charter Proposals requires the affirmative vote of the holders of two-thirds of the ordinary shares represented in person or by proxy and entitled to vote thereon at the general meeting. Accordingly, if an AHPAC shareholder fails to vote by proxy or to vote in person at the general meeting, their shares will not be counted in connection with the determination of whether a valid quorum is established, however, if a valid quorum is otherwise established, such failure to vote will have no effect on the outcome of any vote on the Domestication Proposal or any of the Charter Proposals. Abstentions will be counted in connection with the determination of whether a valid quorum is established and will have the same effect as a vote "AGAINST" the Domestication Proposal and the Charter Proposals.

        The approval of the Business Combination Proposal requires the affirmative vote of holders of a majority of the ordinary shares represented in person or by proxy and entitled to vote thereon at the general meeting. Accordingly, if an AHPAC shareholder fails to vote by proxy or to vote in person at the general meeting, their shares will not be counted in connection with the determination of whether a valid quorum is established, however, if a valid quorum is otherwise established, such failure to vote will have no effect on the outcome of any vote on the Business Combination Proposal. Abstentions will be counted in connection with the determination of whether a valid quorum is established and will have the same effect as a vote "AGAINST" the Business Combination Proposal. The initial shareholders have agreed to vote their founder shares and any public shares they may hold in favor of the business combination. Currently, the initial shareholders own approximately 20% of AHPAC's issued and outstanding ordinary shares, including all of the founder shares.

        The approval of each of the Director Election Proposal, the Management Incentive Plan Proposal, the NASDAQ Proposal and the Adjournment Proposal requires the affirmative vote of holders of a majority of the ordinary shares represented in person or by proxy and entitled to vote thereon at the general meeting. Accordingly, if an AHPAC shareholder fails to vote by proxy or to vote in person at the general meeting, their shares will not be counted in connection with the determination of whether a valid quorum is established, however, if a valid quorum is otherwise established, such failure to vote will have no effect on the outcome of any vote on the NASDAQ Proposal, the Director Election Proposal or the Adjournment Proposal. Abstentions will be counted in connection with the determination of whether a valid quorum is established and will have the same effect as a vote "AGAINST" the NASDAQ Proposal, the Director Election Proposal and the Adjournment Proposal.




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        The transactions contemplated by the Transaction Agreement will be consummated only if the Business Combination Proposal, the Domestication Proposal, the NASDAQ Proposal and the Charter Proposals are approved at the general meeting. Each of the Business Combination Proposal, the Domestication Proposal, the NASDAQ proposal and the Charter Proposals are cross-conditioned on the approval of each other. Each other proposal is conditioned on the approval of the Business Combination Proposal, the Domestication Proposal, the NASDAQ Proposal and the Charter Proposals, other than the Adjournment Proposal, which is not conditioned on the approval of any other proposal set forth in this proxy statement/prospectus.It is important for you to note that in the event that the Business Combination Proposal, the Domestication Proposal, the NASDAQ Proposal or the Charter Proposals do not receive the requisite vote for approval, we will not consummate the business combination. If AHPAC does not consummate the business combination and fail to complete an initial business combination by October 14, 2018, AHPAC will be required to dissolve and liquidate the trust account by returning the then remaining funds in such account to public shareholders.

Recommendation to AHPAC's Shareholders


        The AHPAC Board believes that each of the Business Combination Proposal, the Domestication Proposal, the NASDAQ Proposal, the Charter Proposals, the Director Election Proposal, the Management Incentive Plan Proposal and the Adjournment Proposal to be presented at the general meeting is in the best interests of AHPAC and AHPAC's shareholders and unanimously recommends that its shareholders vote "FOR" each of the proposals.

        When you consider the recommendation of the AHPAC Board in favor of approval of the Business Combination Proposal, you should keep in mind that the sponsor and certain members of the AHPAC Board and officers have interests in the business combination that are different from or in addition to (or which may conflict with) your interests as a shareholder. Shareholders should take these interests into account in deciding whether to approve the proposals presented at the general meeting, including the Business Combination Proposal. These interests include, among other things:

•

the fact that the initial shareholders have agreed not to redeem any of the founder shares in connection with a shareholder vote to approve a proposed initial business combination;



•

the fact that AHPAC issued to the sponsor on August 11, 2017, an unsecured promissory note pursuant to which AHPAC is permitted to borrow up to $300,000 in aggregate principal amount;



•

the fact that the sponsor paid an aggregate of $25,000 for the founder shares for approximately $0.003 per share which, if valued based on the closing price of $[    ·    ]$10.05 per share on the NASDAQ Capital Market on [    ·    ], 2017February 6, 2018 would be valued at approximately $[    ·    ]$77,887,500 (after giving effect to the conversion) but will expire worthless if AHPAC fails to complete a business combination by October 14, 2018;



•

the fact that the initial shareholders have agreed to waive their rights to liquidating distributions from the trust account with respect to their founder shares if AHPAC fails to complete an initial business combination by October 14, 2018;



•

the fact that the initial shareholders paid an aggregate of $8,200,000 for their 16,400,000 private placement warrants, to purchase AHPAC Class A ordinary shares, which, if valued based on the closing price of $[    ·    ]$0.41 per sharewarrant on the NASDAQ Capital Market on [    ·    ], 2017February 6, 2018 would be valued at approximately $[    ·    ] (after giving effect to the conversion)$6,724,000 but will expire worthless if AHPAC fails to complete a business combination by October 14, 2018;



•

the fact that if AHPAC consummates a business combination, any amounts outstanding under any loan made by the sponsor to AHPAC will be repayable in cash or at the option of the sponsor, an aggregate amount up to $1,500,000 may be converted into warrants with identical terms as the private placement warrants, at the price of $0.50 per warrant, and if AHPAC fails




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to complete a business combination there may be insufficient assets outside the trust account to satisfy such loans;

•

the fact that if AHPAC consummates the transactions contemplated by the transaction agreement, the Class B Holders will surrender to AHPAC an aggregate 3,875,0004,715,576 AHPAC Class B ordinary shares and AHPAC will repurchase from the Class B Holders 4,100,000 private placement warrants for $0.50 per warrant in cash;warrants;



•

if the trust account is liquidated in the event AHPAC is unable to complete an initial business combination within the required time period, the sponsor has agreed to indemnify AHPAC to ensure that the proceeds in the trust account are not reduced below $10.00 per public share, or such lesser amount per public share held in the trust account as of the date of the liquidation of the trust account due to reductions in the value of the trust assets, in each case net of the interest which may be withdrawn to pay taxes, except as to any claims by a third party who executed a waiver of any and all rights to seek access to the trust account and except as to any claims under our indemnity of the underwriters of this offering against certain liabilities, including liabilities under the Securities Act;



•

the anticipated election of Messrs. Dean and Burgstahler, each as a director of AHPAC;



•

the continued indemnification of AHPAC's existing directors and officers and the continuation of AHPAC's directors' and officers' liability insurance after the business combination;



•

the fact that the sponsor, officers and directors may not participate in the formation of, or become a director or officer of, any other blank check company until AHPAC (i) has entered into a definitive agreement regarding an initial business combination or (ii) fails to complete an initial business combination by October 14, 2018; and



•

the fact that the sponsor, officers and directors will not be reimbursed for any out-of-pocket expenses if an initial business combination is not consummated by October 14, 2018.

Broker Non-Votes

        In general, if your shares are held in "street" name and you do not instruct your broker, bank or other nominee on a timely basis on how to vote your shares, your broker, bank or other nominee, in its sole discretion, may either leave your shares unvoted or vote your shares on routine matters, but not on any non-routine matters.None of the proposals at the general meeting are routine matters. As such, without your voting instructions, your brokerage firm cannot vote your shares on any proposal to be voted on at the general meeting.

Voting Your Shares—Shareholders of Record


        If you are an AHPAC shareholder of record, you may vote by mail or in person at the general meeting. Each AHPAC ordinary share that you own in your name entitles you to one vote on each of the proposals for the general meeting. Your one or more proxy cards show the number of AHPAC ordinary shares that you own.

        Voting by Mail.    You can vote your shares by completing, signing, dating and returning the enclosed proxy card in the postage-paid envelope provided. By signing the proxy card and returning it in the enclosed prepaid and addressed envelope, you are authorizing the individuals named on the proxy card to vote your shares at the general meeting in the manner you indicate. We encourage you to sign and return the proxy card even if you plan to attend the general meeting so that your shares will be voted if you are unable to attend the general meeting. If you receive more than one proxy card, it is an indication that your shares are held in multiple accounts. Please sign and return all proxy cards to ensure that all of your shares are voted. If you hold your shares in "street name" through a bank,




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broker or other nominee, you will need to follow the instructions provided to you by your bank, broker




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or other nominee to ensure that your shares are represented and voted at the general meeting. If you sign and return the proxy card but do not give instructions on how to vote your shares, your ordinary shares will be voted as recommended by the AHPAC Board. The AHPAC Board recommends voting"FOR" the Domestication Proposal,"FOR" the Business Combination Proposal,"FOR" the NASDAQ Proposal,"FOR" the Charter Proposals,"FOR" the Director Election Proposal,"FOR" the Management Incentive Plan Proposal, and"FOR" the Adjournment Proposal. Votes submitted by mail must be received by [    ·    ]5:00 p.m. Eastern Time on [    ·    ].], 2018.

        Voting in Person at the Meeting.    If you attend the general meeting and plan to vote in person, we will provide you with a ballot at the general meeting. If your shares are registered directly in your name, you are considered the shareholder of record and you have the right to vote in person at the general meeting. If you hold your shares in "street name," which means your shares are held of record by a broker, bank or other nominee, you should follow the instructions provided by your broker, bank or nominee to ensure that votes related to the shares you beneficially own are properly counted. In this regard, you must provide the record holder of your shares with instructions on how to vote your shares or, if you wish to attend the general meeting and vote in person, you will need to bring to the general meeting a legal proxy from your broker, bank or nominee authorizing you to vote these shares. That is the only way we can be sure that the broker, bank or nominee has not already voted your ordinary shares.

Voting Your Shares—Beneficial Owners


        If your shares are held in an account at a brokerage firm, bank or other nominee, then you are the beneficial owner of shares held in "street name" and this proxy statement/prospectus is being sent to you by that broker, bank or other nominee. The broker, bank or other nominee holding your account is considered to be the shareholder of record for purposes of voting at the general meeting. As a beneficial owner, you have the right to direct your broker, bank or other nominee regarding how to vote the shares in your account by following the instructions that the broker, bank or other nominee provides you along with this proxy statement/prospectus. As a beneficial owner, if you wish to vote at the general meeting, you will need to bring to the general meeting a legal proxy from your broker, bank or other nominee authorizing you to vote those shares. Please see "Attending the general meeting" below for more details.

Attending the general meeting


        Only AHPAC's shareholders on the record date or their legal proxy holders may attend the general meeting. To be admitted to the general meeting, you will need a form of photo identification and valid proof of ownership of ordinary shares or a valid legal proxy. If you have a legal proxy from a shareholder of record, you must bring a form of photo identification and the legal proxy to the general meeting. If you have a legal proxy from a "street name" shareholder, you must bring a form of photo identification, a legal proxy from the record holder (that is, the bank, broker or other holder of record) to the "street name" shareholder that is assignable, and the legal proxy from the "street name" shareholder to you. Shareholders may appoint only one proxy holder to attend on their behalf.

Revoking Your Proxy


        If you give a proxy, you may revoke it at any time before the general meeting or at the general meeting by doing any one of the following:

•

you may send another proxy card with a later date;



•

you may notify AHPAC's Secretary in writing to Benjamin Silbert at silbert@avistacap.com, before the general meeting that you have revoked your proxy; or




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•

you may attend the general meeting, revoke your proxy, and vote in person, as indicated above.

No Additional Matters


        The general meeting has been called only to consider the approval of the Business Combination Proposal, the Domestication Proposal, the NASDAQ Proposal, the Charter Proposals, the Director Election Proposal, the Management Incentive Plan Proposal and the Adjournment Proposal. Other than procedural matters incident to the conduct of the general meeting, no other matters may be considered at the general meeting if they are not included in this proxy statement/prospectus, which serves as the notice of the general meeting.

Who Can Answer Your Questions About Voting


        If you have any questions about how to vote or direct a vote in respect of your AHPAC ordinary shares, you may call MacKenzie Partners, AHPAC's proxy solicitor, at 1-800-322-2885 (toll free), or 1-212-929-5500 (call collect).

Redemption Rights


        Pursuant to AHPAC's existing amended and restated memorandum and articles of association, a holder of AHPAC's public shares may request that AHPAC redeem all or a portion of such shareholder's public shares (which will become shares of ENVG Class A common stock in the domestication) for cash if the business combination is consummated. For the purposes of Article 49.3 of AHPAC's amended and restated memorandum and articles of association and the Cayman Islands Companies Law (2016 Revision), the exercise of redemption rights shall be treated as an election to have such public shares repurchased for cash and references in this proxy statement/prospectus shall be interpreted accordingly. If a public shareholder properly exercises its right to redeem its public shares and timely delivers its shares to the transfer agent, AHPAC will redeem each public share for a per-share price, payable in cash, equal to the aggregate amount then on deposit in the trust account, calculated as of two business days prior to the consummation of the business combination, including interest, divided by the number of then issued and outstanding public shares. For illustrative purposes, as of NovemberJanuary 17, 2017,2018, this would have amounted to approximately $10.07$10.08 per public share.

        In order to exercise your redemption rights, you must:

•

if you hold public units, separate the underlying public shares and public warrants;



•

check the box on the enclosed proxy card to elect redemption;



•

check the box on the enclosed proxy card marked "Shareholder Certification" if you are not acting in concert or as a "group" (as defined in Section 13d-3 of the Exchange Act) with any other shareholder with respect to ordinary shares and



•

prior to [5:5:00 p.m. Eastern Time]Time on [    ·    ]], 2018 (two business days before the general meeting), tender your shares physically or electronically and submit a request in writing that we redeem your public shares for cash to the transfer agent, at the following address:

Continental Stock Transfer & Trust Company
1 State Street- 30th Floor
New York, NY 10004
Attn: Mark Zimkind
Email: mzimkind@continentalstock.com

        and




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•

deliver your public shares either physically or electronically through DTC's DWAC system to the transfer agent at least two business days before the general meeting. Shareholders seeking to exercise their redemption rights and opting to deliver physical certificates should allot sufficient time to obtain physical certificates from the transfer agent and time to effect delivery. It is AHPAC's understanding that shareholders should generally allot at least two weeks to obtain physical certificates from the transfer agent. However, AHPAC does not have any control over this process and it may take longer than two weeks. Shareholders who hold their shares in street name will have to coordinate with their bank, broker or other nominee to have the shares certificated or delivered electronically. If you do not submit a written request and deliver your public shares as described above, your shares will not be redeemed.

        Shareholders seeking to exercise their redemption rights, whether they are record holders or hold their shares in "street name" are required to either tender their certificates to the transfer agent prior to the date set forth in these proxy materials, or up to two business days prior to the vote on the proposal to approve the business combination at the general meeting, or to deliver their shares to the transfer agent electronically using DTC's DWAC system, at such shareholder's option.The requirement for physical or electronic delivery prior to the general meeting ensures that a redeeming shareholder's election to redeem is irrevocable once the business combination is approved.

        Holders of outstanding public units must separate the underlying public shares and public warrants prior to exercising redemption rights with respect to the public shares.

        If you hold public units registered in your own name, you must deliver the certificate for such public units to the transfer agent, with written instructions to separate such public units into public shares and public warrants. This must be completed far enough in advance to permit the mailing of the public share certificates back to you so that you may then exercise your redemption rights upon the separation of the public shares from the public units.

        If a broker, dealer, commercial bank, trust company or other nominee holds your public units, you must instruct such nominee to separate your public units. Your nominee must send written instructions by facsimile to the transfer agent. Such written instructions must include the number of public units to be split and the nominee holding such public units. Your nominee must also initiate electronically, using DTC's DWAC system, a withdrawal of the relevant units and a deposit of an equal number of public shares and public warrants. This must be completed far enough in advance to permit your nominee to exercise your redemption rights upon the separation of the public shares from the public units. While this is typically done electronically on the same business day, you should allow at least one full business day to accomplish the separation. If you fail to cause your public shares to be separated in a timely manner, you will likely not be able to exercise your redemption rights.

        Each redemption of AHPAC Class A ordinary shares by public shareholders will reduce the amount in the trust account, which held marketable securities with a fair value of approximately $[    ·    ]$312,497,921 as of [    ·    ].January 17, 2018. The Transaction Agreement provides that Envigo's obligation to consummate the business combination is conditioned on there being at least $260$220 million of available funds collectively from the trust account and proceeds from the equity financing (if any), after giving effect to redemptions of public shares. This condition to closing in the Transaction Agreement is for the sole benefit of Envigo and may be waived only by Envigo. If, as a result of redemptions of public shares by public shareholders, these conditions are not met (or waived), then AHPAC or Envigo (as applicable) may elect not to consummate the business combination. In addition, in no event will AHPAC redeem public shares in an amount that would cause our net tangible assets to be less than $5,000,001. Holders of public warrants do not have redemption rights in connection with the business combination.

        Prior to exercising redemption rights, shareholders should verify the market price of AHPAC Class A ordinary shares as they may receive higher proceeds from the sale of their AHPAC Class A




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ordinary shares in the public market than from exercising their redemption rights if the market price




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per share is higher than the redemption price. AHPAC cannot assure you that you will be able to sell your AHPAC Class A ordinary shares in the open market, even if the market price per share is higher than the redemption price stated above, as there may not be sufficient liquidity in AHPAC Class A ordinary shares when you wish to sell your shares.

        If you exercise your redemption rights, the AHPAC Class A ordinary shares will cease to be outstanding immediately prior to the business combination and will only represent the right to receive a pro rata share of the aggregate amount on deposit in the trust account. You will no longer own those shares and will have no right to participate in, or have any interest in, the future growth of AHPAC, if any. You will be entitled to receive cash for these shares only if you properly and timely demand redemption.

        If the business combination is not approved and AHPAC does not consummate an initial business combination by October 14, 2018, AHPAC will be required to dissolve and liquidate the trust account by returning the then remaining funds in such account to the public shareholders and AHPAC's warrants will expire worthless.

Appraisal Rights


        Appraisal rights are not available to holders of public shares in connection with the business combination.

Proxy Solicitation Costs


        AHPAC is soliciting proxies on behalf of the AHPAC Board. This proxy solicitation is being made by mail, but also may be made by telephone or in person. AHPAC has engaged MacKenzie Partners to assist in the solicitation of proxies for the general meeting. AHPAC and its directors, officers and employees may also solicit proxies in person. AHPAC will ask banks, brokers and other institutions, nominees and fiduciaries to forward the proxy materials to their principals and to obtain their authority to execute proxies and voting instructions.

        AHPAC will bear the entire cost of the proxy solicitation, including the preparation, assembly, printing, mailing and distribution of the proxy materials. AHPAC will pay MacKenzie Partners a fee of $15,000, plus disbursements, reimburse MacKenzie Partners for its reasonable out-of-pocket expenses and indemnify MacKenzie Partners and its affiliates against certain claims, liabilities, losses, damages and expenses for their services as AHPAC proxy solicitor. We will reimburse brokerage firms and other custodians for their reasonable out-of-pocket expenses for forwarding the proxy materials to AHPAC's shareholders. Directors, officers and employees of AHPAC who solicit proxies will not be paid any additional compensation for soliciting proxies.




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THE BUSINESS COMBINATION


General


        On August 21, 2017, AHPAC, Merger Sub and NewCo entered into the Transaction Agreement with Envigo and the shareholder representative, pursuant to which, among other things and subject to the terms and conditions contained in the Transaction Agreement, (i) AHPAC will transfer by way of continuation out of the Cayman Islands into the State of Delaware or domesticate as a Delaware corporation in accordance with Section 388 of the Delaware General Corporation Law, as amended and the Cayman Islands Companies Law (2016 Revision); (ii) Merger Sub will merge with and into Envigo, the separate corporate existence of Merger Sub will cease and Envigo will be the surviving corporation and a direct wholly-owned subsidiary of AHPAC and (iii) Envigo will merge with and into NewCo, the separate corporate existence of Envigo will cease and NewCo will be the surviving company and a direct wholly-owned subsidiary of AHPAC.For more information about the transactions contemplated in the Transaction Agreement, please see the section entitled "The Transaction Agreement and Related Agreements." A copy of the Transaction Agreement, including each amendment thereto through the date hereof is attached to this proxy statement/prospectus as Annex A.

Structure of the Business Combination


        In connection with the closing of the business combination contemplated by the Transaction Agreement, the parties will undertake the following transactions:

•

The Class B Holders (as defined below) will surrender to AHPAC an aggregate 3,875,0004,715,576 AHPAC Class B ordinary shares and AHPAC will repurchase 4,100,000 private placement warrants, in each case, pursuant to the Parent Sponsor Letter Agreement.



•

AHPAC will take the actions necessary to become a Delaware corporation unless it previously became a Delaware corporation in accordance with the Transaction Agreement.



•

AHPAC will make any payments required to be made by AHPAC in connection with giving effect to redemptions of public shares.



•

AHPAC will contribute to Merger Sub the amount of cash remaining in the trust account and the proceeds of the equity financing (net of underwriting fees) after giving effect to redemptions of public shares and the payment of $2,050,000 to the Class B Holders in cash in connection with the repurchase of 4,100,000 private placement warrants pursuant to the Parent Sponsor Letter Agreement.shares.



•

The certificate of merger with respect to the first merger will be prepared and executed in accordance with the relevant provisions of the DGCL and filed with the Secretary of State of the State of Delaware.



•

The certificate of merger with respect to the second merger will be prepared and executed in accordance with the relevant provisions of the DGCL and the Delaware Limited Liability Company Act (the "DLLCA") and filed with Secretary of State of the State of Delaware.



•

AHPAC will deposit (or cause to be deposited) with Envigo's exchange agent the aggregate amount of the cash portion of the aggregate consideration payable with respect to the first merger (the "Merger Consideration") and the aggregate amount of the equity portion of the Merger Consideration, in each case, without regard to any amounts in respect of the Envigo Series B Warrants or under the Tax Receivable Agreement.



•

AHPAC will (on behalf of the Company) pay, or, to the extent NewCo has sufficient immediately available funds at such time, instruct NewCo to pay, Envigo's expenses related to the business combination set forth on the statement to be delivered by the Company to AHPAC




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prior to the Closing, that are unpaid as of such time, by wire transfer of immediately available funds as directed by Envigo.




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•

AHPAC, Envigo Holdings, Inc. and the shareholder representative on behalf of Envigo stockholders entitled to receive payments under the Tax Receivable Agreement pursuant to Section 2.1 of the Transaction Agreement will enter into the Tax Receivable Agreement.



•

AHPAC will pay, or, to the extent NewCo has sufficient immediately available funds at such time, instruct NewCo to pay, the applicable Indebtedness Amount (as defined in the Transaction Agreement) required to be paid pursuant to the Debt Financing and/or the Lender Consent and Amendment (as each such term is defined in the Transaction Agreement), if any, set forth on the statement to be delivered by Envigo to AHPAC prior to the Closing, that are unpaid as of such time, by wire transfer of immediately available funds as directed by Envigo.

        As a result of the foregoing transactions, at the consummation of the business combination, AHPAC will own 100% of NewCo.

Consideration to Selling Equityholders in the Business Combination

        Subject to the terms and conditions of the Transaction Agreement, each Selling Equityholder will receive certain payments under the Tax Receivable Agreement (the "Tax Receivable Consideration"), as described in the section titled "The Transaction Agreement—Related Agreements—Tax Receivable Agreement".

        The Tax Receivable Consideration received by each Selling Equityholder will be such holder's pro rata share (based on the ratio of the number of shares of Envigo Class A common stock held by such holder to the fully diluted total shares of Envigo) of certain payments under the Tax Receivable Agreement.

Holders of Envigo Class A common stock


        Subject to the terms and conditions of the Transaction Agreement, each share of Envigo Class A common stock will be converted into the right to receive, in addition to the Tax Receivable Consideration, (i) cash consideration (the "Cash Consideration"), or stock consideration (the "Stock Consideration") or a combination thereof (at such holder's election, subject to the limitations described below), and (ii) a number of warrants to purchase one-half of one share of ENVG Class A common stock as described below (the "New Warrant Consideration").

        The Cash Consideration will be an amount in cash equal to:

•

the quotient obtained by dividing (x) $390,133,441(subject$283,686,737 (subject to certain adjustments described in the Transaction Agreement) by (y) the fully diluted total shares of Envigo (the "Per Share Merger Value"); plus



•

the product of (x) $10.00 multiplied by (y) the quotient obtained by dividing (A) 3,875,000 by (B) the fully diluted total shares of Envigo (the "Cash Election Value").

        The Stock Consideration will be calculated as follows:

•

a number of newly issued shares of ENVG Class A common stock equal to the quotient obtained by dividing (x) the Per Share Merger Value by (y) $10.00; plus



•

a number of newly issued shares of ENVG common stock equal to the quotient obtained by dividing (x) 3,875,000 by (y) the fully diluted total shares of Envigo.

        The New Warrant Consideration will be a number of warrants to purchase one-half of one share of ENVG Class A common stock, where two warrants may be exercised for one whole share of ENVG




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Class A common stock at an exercise price of $11.50 per share, equal to the quotient obtained by dividing (x) 4,100,000 by (y) the fully diluted total shares of Envigo.




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        The Cash Consideration, the New Warrant Consideration and the Tax Receivable Consideration are referred to, collectively, the "Per Share Total Cash Consideration"; and the Stock Consideration, the New Warrant Consideration and the Tax Receivable Consideration are referred to, collectively, the "Per Share Total Stock Consideration".

Holders of Envigo Warrants


        Subject to the terms and conditions of the Transaction Agreement, each warrant to purchase one share of Envigo Class A common stock ("Envigo Series A Warrant") and each warrant to purchase one share of Envigo Class B common stock ("Envigo Series B Warrant") (in the case of Series B Warrant only if they become exercisable) will be converted into the right to receive, in addition to the Tax Receivable Consideration, (i) the New Warrant Consideration, plus (ii) a warrant to purchase, at such holder's election, either (a) the Per Share Total Cash Consideration (net of the exercise price) or (b) the Per Share Total Stock Consideration (net of the exercise price).

Holders of Envigo Options


        Subject to the terms and conditions of the Transaction Agreement, each option to purchase shares of Envigo Class A common stock for which the Per Share Merger Value is greater than the exercise price ("Envigo option") will be exchanged for the right to receive in addition to the Tax Receivable Consideration payable during the first five years after the Closing Date, (i) the New Warrant Consideration plus (ii) (a) in the case of Envigo options for which cash consideration is elected, an amount in cash equal to the Cash Consideration less the exercise price, or (b) in the case of Envigo options for which stock consideration is elected or deemed elected, (1) a number of newly issued shares of ENVG common stock equal to the quotient obtained by dividing the Cash Election Value (less the exercise price) by $10.00, and (2) a number of shares of ENVG Class A common stock equal to the quotient obtained by dividing 3,875,000 by the fully diluted shares of Envigo.

Holders of Envigo SARs


        Subject to the terms and conditions of the Transaction Agreement, each stock appreciation right granted in respect of Envigo Class A common stock for which the Per Share Merger Value is greater than the base price ("Envigo SAR") will be converted into the right to receive, in addition to the Tax Receivable Consideration payable during the first five years after the Closing Date, (i) the Cash Consideration, less the base price and (ii) an additional amount in cash commensurate in value to the New Warrant Consideration.

Limitations on ability of Selling Equityholders to make cash elections


        Each Selling Equityholder (other than a holder of Envigo SARs) who does not make any election will be deemed to have made an election to receive the Stock Consideration. If the aggregate amount of cash otherwise payable in respect of the cash elections exceeds the Cash Component (as described below), the elections of Selling Equityholders (other than holders of Envigo SARs) to receive the Cash Consideration will be subject to adjustment as described below.

Cash Component


        Notwithstanding the ability of the Selling Equityholders (other than holders of Envigo SARs) to make a cash election, the Transaction Agreement provides a limit on the amount of aggregate cash consideration to be paid to such holders of $100 million, which amount may be increased or reduced as described in the Transaction Agreement (the "Cash Component"). If the aggregate amount of cash payable in respect the cash elections exceeds the Cash Component, the Exchange Agent will reduce all




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cash elections pro rata by the amount of such excess, and no election shall be deemed made with




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respect to such shares and, as set forth in the Transaction Agreement, such shares will be converted into and become the right to receive the Stock Consideration.

Equity Financing


        AHPAC may enter into equity financing in connection with the proposed business combination through a private placement offered to a limited number of accredited investors (as defined by Rule 501 of Regulation D) pursuant to Section 4(a)(2) of the Securities Act of 1933, as amended (the "equity financing"). The purpose of the equity financing includes raising additional funds, up to a maximum of $75 million, to fund the business combination and related transactions. Pursuant to the terms of the Transaction Agreement, AHPAC must use its commercially reasonable efforts to obtain such equity financing prior to the consummation of the business combination, on terms reasonably acceptable to Envigo.

Conditions to Closing of the Business Combination

Conditions to Each Party's Obligations

        The respective obligations of each of the parties to the Transaction Agreement to effect the transactions contemplated by the Transaction Agreement are subject to the satisfaction, or written waiver by both AHPAC and Envigo, of each of the following conditions:

•

The affirmative vote (in person or by proxy) of the holders of a majority or a two-thirds majority (as applicable) of the issued and outstanding ordinary shares entitled to vote thereon in favor of the Business Combination Proposal, the Domestication Proposal, the NASDAQ Proposal, the Charter Proposals, the Director Election Proposal, the Management Incentive Plan Proposal and the Adjournment Proposal shall have been obtained;



•

The applicable waiting period under the HSR Act shall have expired or been terminated or such approval shall have otherwise been obtained;



•

There must not be any legal proceeding by any governmental entity that challenges or seeks to make the business combination illegal or otherwise prohibited instituted, pending or threatened in writing;



•

AHPAC shall have at least $5,000,001 of net tangible assets (as determined in accordance with Rule 3a51-1(g)(1) of the Exchange Act) remaining; and



•

Either (i) Envigo shall have received a Lender Consent and Amendment with respect to each Envigo Credit Agreement and the Existing Third Lien Indenture (as each such term is defined in the Transaction Agreement), (ii) the consummation of a Debt Refinancing on terms reasonably acceptable to AHPAC) or (iii) a combination of the foregoing (as each such term is defined in the Transaction Agreement) which upon the consummation of the transactions contemplated by the Transaction Agreement do not result in a Default or Event of Default (as each such term is defined in each Envigo Credit Agreement) under any Envigo Credit Agreement or the Existing Third Lien Indenture (as each such term is defined in the Transaction Agreement). See the section titled "The Transaction Agreement—Related Agreements—Financing Arrangements" beginning on page [    ·    ]129 of this proxy statement/prospectus for further details regarding Envigo's obligations in connection with a Debt Refinancing.

Conditions to AHPAC's Obligations


        The obligations of AHPAC, Merger Sub and NewCo to effect the transactions contemplated by the Transaction Agreement are subject to the satisfaction at or prior to the Closing Date of certain




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conditions (any or all of which may be waived in writing in whole or in part exclusively by AHPAC),




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including, among others, (i) Envigo must have performed and complied in all material respects with all obligations required to be performed or complied with by Envigo under the Transaction Agreement at or prior to the Closing Date and (ii) Envigo and its respective affiliates and subsidiaries shall have terminated, effective as of the closing, all Related Party Agreements (as defined in the Transaction Agreement) of Envigo and/or any of its subsidiaries that are not set forth on Section 5.19 of the Schedules, with such termination to be effective as of the closing.

Conditions to Envigo's Obligations

        The obligations of Envigo to effect the transactions contemplated by the Transaction Agreement are subject to the satisfaction at or prior to the Closing Date of certain conditions (any or all of which may be waived in writing in whole or in part exclusively by Envigo), including, among others, (i) AHPAC, Merger Sub and NewCo must have performed and complied in all material respects with all obligations required to be performed or complied with under the Transaction Agreement at or prior to the Closing Date, (ii) the ENVG Class A common stock shall have been approved for listing on NASDAQ, AHPAC shall be a listed public company on, and for the ENVG Class A common stock to be tradable over NASDAQ and immediately following the first merger effective time, AHPAC shall meet all of the continuing listing requirements of NASDAQ and shall not have received any notice of non-compliance (other than any notice to the extent related to AHPAC's failure to conduct an annual meeting in 2017) and (iii) the funds contained in the trust account (after giving effect to redemptions of public shares) and the proceeds of the equity financing, if any, shall together equal or exceed $260$220 million.

Related Agreements

        For a discussion regarding certain additional agreements to be entered into in connection with the Transaction Agreement, please see the section titled "The Transaction Agreement—Related Agreements" beginning on page [    ·    ]127 of this proxy statement/prospectus.

Background of the business combination

        AHPAC is a blank check company incorporated in the Cayman Islands on December 4, 2015 for the purpose of effecting a merger, capital stock exchange, asset acquisition, stock purchase, reorganization or similar business combination with one or more businesses with the intention of focusing its search for a target business in the healthcare industry. The business combination was the result of a thorough search for a potential transaction utilizing the investing and operating experience of AHPAC's management team and board of directors. The terms of the business combination were the result of extensive negotiations between AHPAC's directors, AHPAC's management team, representatives of the sponsor, management teams of Envigo's majority stockholders, Jermyn Street Associates LLC ("Jermyn") and Savanna Holdings LLC ("Savanna"), representatives of Envigo, and representatives of Credit Suisse Securities (USA) LLC, financial advisor to AHPAC ("Credit Suisse"), Jefferies LLC, financial advisor to Envigo ("Jefferies"), Weil, Gotshal & Manges LLP, legal counsel to AHPAC ("Weil") and Cahill Gordon & Reindel LLP, legal counsel to Envigo ("Cahill"). The following is a brief description of the background of these negotiations, the business combination and related transactions.

        On October 14, 2016, AHPAC consummated its IPO of 30,000,000 units at a price of $10.00 per unit generating gross proceeds of $300,000,000 before underwriting discounts and expenses. Simultaneously with the closing of its IPO, AHPAC completed the private sale of an aggregate of 16,000,000 private placement warrants, at a purchase price of $0.50 per private placement warrant, to the initial shareholders, generating gross proceeds to AHPAC of $8,000,000.




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        On November 28, 2016, AHPAC completed the sale of an additional 1,000,000 units to the underwriters of the IPO at the public offering price of $10.00 per unit pursuant to the partial exercise of the over-allotment option granted to the underwriters in connection with AHPAC's IPO (the "Over-allotment Option"). On November 28, 2016, AHPAC sold an additional 400,000 private placement warrants for an aggregate purchase price of $200,000 in connection with the exercise of the Over-allotment Option. Following the partial exercise of the Over-allotment Option, 875,000 founder shares were forfeited in order to maintain the ownership of the initial shareholders at 20% of the issued and outstanding ordinary shares. On November 28, 2016, the sponsor sold 161,180 founder shares and 350,114 private placement warrants to one of AHPAC's independent directors at their original purchase price.

        AHPAC received gross proceeds from the IPO, including the partial exercise of the Over-allotment Option, and the sale of the private placement warrants of $310,000,000 and $8,200,000, respectively, for an aggregate of $318,200,000. Of such amount, $310,000,000 was deposited into the trust account by trustee. The remaining $8,200,000 was held outside of the trust account, of which $6,200,000 was used to pay underwriting discounts, with the balance used to repay a note to the sponsor and to pay accrued offering and formation costs, and the remainder was reserved for business, legal and accounting due diligence on prospective acquisitions and continuing general and administrative expenses. At December 31, 2016, funds held in the trust account consisted solely of cash.

        Prior to the consummation of the IPO on October 14, 2016, neither AHPAC, nor anyone on its behalf, contacted any prospective target business or had any substantive discussions, formal or otherwise, with respect to a transaction between AHPAC and Envigo.

        After the IPO, AHPAC commenced an active search for prospective businesses and assets to acquire. Representatives of AHPAC contacted and were contacted by a number of individuals and entities with respect to acquisition opportunities.

        During that period, AHPAC's management and the sponsor:

•

considered or conducted an analysis of over 20 potential acquisition targets; and



•

ultimately engaged in discussions or additional due diligence with eight target businesses or their representatives, entering into non-disclosure agreements with five of those eight potential acquisition targets.

        Ultimately, AHPAC's decision not to pursue each of the alternative acquisition targets was the result of one or more of (i) AHPAC's determination that such business did not represent as attractive a target as Envigo due to a combination of factors such as business prospects, strategy, management teams, preparedness to operate as a public company or structure, (ii) a difference in valuation expectations between AHPAC, on the one hand, and the seller, on the other hand, or (iii) a potential target's inability to engage in advanced transaction negotiations with AHPAC in a timely manner.

        On October 19, 2016, David Burgstahler, President, chief executive officer and a director of AHPAC, and Robert Girardi, representative of the sponsor, met with Michael Gerardi and Matthew Miller of Jefferies to discuss Envigo as a potential target for a business combination with AHPAC, at the invitation of Mr. Gerardi. On October 21, 2016, AHPAC and Envigo entered into a non-disclosure agreement.

        On October 26, 2016, Mr. Burgstahler, Mr. Girardi and other representatives of AHPAC and its sponsor met with Scott Cragg and another representative of Jermyn at Jermyn's offices to discuss a potential business combination between AHPAC and Envigo. Representatives of Jefferies were also present at the meeting. On November 2, 2016, representatives of Jefferies provided AHPAC with due diligence reports prepared for purposes of Envigo's debt financing, which had been prepared by Alvarez & Marsal, Ernst & Young and L.E.K. Consulting at the instruction of Envigo. On November 9,




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2016, representatives of AHPAC met with Adrian Hardy, President and chief executive officer of




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Envigo, and Patricia Henahan, chief financial officer of Envigo, at Envigo's offices to conduct due diligence on Envigo. A representative of Jermyn and representatives from Credit Suisse and Jefferies were also present at the meeting. Over the next two weeks, AHPAC continued its due diligence review of Envigo based on information provided by, and discussions with, Envigo management.

        On November 22, 2016, AHPAC submitted to Envigo a non-binding offer to acquire Envigo on a cash-free, debt-free basis at an enterprise value of $635 million (the "November 22 Offer"), with an opportunity for Envigo equity holders to receive AHPAC equity. On November 30, 2016, representatives of AHPAC discussed the November 22 Offer with representatives of Jefferies who notified AHPAC that Envigo had considered the November 22 Offer and had decided not to accept such offer.

        On January 6, 2017, Mr. Cragg provided representatives of AHPAC with an update on Envigo's recent financial performance. On January 10, 2017, Mr. Burgstahler, Mr. Girardi, Charles Harwood and other representatives of AHPAC met with Dr. Hardy, Ms. Henahan and Mr. Cragg to receive an update on Envigo's operating performance.

        From January 18, 2017 to January 23, 2017, representatives of AHPAC held discussions with representatives of Jefferies to better understand Envigo's business prospects. During that time period, representatives from AHPAC also held discussions with representatives from Credit Suisse to discuss Envigo's potential growth opportunities. After careful consideration and review of the business prospects for Envigo, AHPAC developed a revised proposal.

        On January 24, 2017, Mr. Burgstahler, Mr. Girardi and other representatives of AHPAC conducted a conference call with representatives of Credit Suisse and Jefferies to discuss a potential transaction between AHPAC and Envigo, and to receive information on a potential add-on acquisition that Envigo was evaluating.

        On January 25, 2017, AHPAC submitted to Envigo a revised letter of intent outlining a non-binding proposal to acquire Envigo on a cash-free, debt-free basis at an enterprise value of $800 million. The proposal additionally provided for the surrender of a portion of the sponsor's founder shares and an increase in the total consideration to be paid to to Envigo's existing shareholders by an amount corresponding to the value of those shares (the "January 25 Offer"). On February 7, 2017, representatives of Jefferies notified AHPAC that Envigo had considered the January 25 Offer and had decided not to accept such offer.

        During the period of February 7, 2017 to February 9, 2017, AHPAC and Credit Suisse conducted further financial analysis on Envigo. On February 19, 2017, AHPAC indicated to representatives of Jefferies that, based on further financial analysis from Credit Suisse, AHPAC was willing to submit a non-binding offer to acquire Envigo on the same terms as the January 25 Offer, except that it would increase the enterprise value to $825 million (the "February 19 Offer"). On March 15, 2017, Mr. Burgstahler and Mr. Girardi met with Mr. Cragg and Alan Willis, a representative of Savanna, at the sponsor's offices to discuss the February 19 Offer. AHPAC continued discussions regarding the February 19 Offer with representatives from Jefferies throughout the months of April and May 2017. Throughout the winter and spring, Mr. Burgstahler periodically updated the members of the board of directors of AHPAC regarding discussions with potential targets.

        On June 2, 2017, Mr. Burgstahler, Mr. Girardi, Mr. Harwood and other representatives of AHPAC conducted a conference call with Dr. Hardy and Ms. Henahan to receive an update on Envigo's operating performance.

        On June 16, 2017, AHPAC submitted to Envigo a revised letter of intent outlining a non-binding proposal to acquire Envigo on a cash-free, debt-free basis at an enterprise value range of $800-825 million in addition to the surrender of a portion of the sponsor's founder shares and an




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increase in the total consideration to be paid to Envigo's existing shareholders by an amount corresponding to the value of those shares (the "June 16 Offer"). On June 28, 2017, Mr. Burgstahler and Mr. Girardi conducted a conference call with representatives of Jefferies to discuss the June 16




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Offer. During that conference call, representatives of Jefferies communicated to Mr. Burgstahler and Mr. Girardi a tax receivable agreement, which would provide Envigo's existing shareholders with the right to receive cash payments relating to the Company's realization of the Company's net operating loss position attributable to periods prior to a transaction, would be a required part of the consideration payable to Envigo's existing shareholders in any potential transaction. On that call, representatives of Jefferies and AHPAC also discussed that, in order to adequately address the post-business combination needs of the company, the board of directors post-business combination should include representatives of each of AHPAC, Envigo and Jermyn. The representatives of Jefferies and AHPAC also discussed that the existing management team of Envigo had indicated to Jermyn that they would be interested in remaining in their roles following the potential business combination, to which representatives of AHPAC agreed. On July 8, 2017, representatives of Credit Suisse and Jefferies discussed Envigo's response to the June 16 Offer. On July 11, 2017, Mr. Burgstahler and Mr. Girardi conducted a conference call with representatives of Jefferies to further discuss the June 16 Offer, which Envigo communicated would not be accepted.

        On July 12, 2017, AHPAC continued its due diligence process on Envigo by submitting a comprehensive due diligence request list to Jefferies. On the basis of its further due diligence, on July 14, 2017, AHPAC submitted to Envigo a revised letter of intent outlining a non-binding proposal to acquire Envigo on a cash-free, debt-free basis at an enterprise value of $830 million in addition to (i) the surrender of a portion of the sponsor's founder shares and an increase in the total consideration to be paid to Envigo's existing shareholders by an amount corresponding to the value of those shares, (ii) the surrender of a portion of the private placement warrants, with newly-issued warrants on similar terms and of commensurate value to be included in the total consideration to be paid to Envigo's existing stockholders (with a corresponding deduction to purchase price representing the cost of such private placement warrants), and (iii) entry into a Tax Receivable Agreement with Envigo's existing stockholders, which, subject to certain exceptions, is intended as a mechanism to provide Envigo's existing stockholders some of the value of Envigo's existing net operating losses on an as and when used basis (the "July 14 Offer"). Also on July 14, 2017, representatives of AHPAC, Envigo, Jermyn, Credit Suisse, Jefferies, Weil and Cahill attended a conference call to discuss a potential business combination transaction between AHPAC and Envigo.

        On July 19, 2017, AHPAC submitted to Envigo a revised draft letter of intent outlining in greater detail its non-binding proposal to acquire Envigo on a cash-free, debt-free basis at an enterprise value of $830 million, with consideration to be paid in stock and cash, plus (i) the surrender of a portion of the sponsor's founder shares and an increase in the total consideration to be paid to Envigo's existing shareholders by an amount corresponding to the value of those shares, (ii) the surrender of a portion of the private placement warrants, with newly-issued warrants on similar terms and of commensurate value to be included in the total consideration to be paid to Envigo's existing stockholders (with a corresponding deduction to purchase price representing the cost of such private placement warrants), and (iii) entry into a Tax Receivable Agreement with Envigo's existing stockholders, which, subject to certain exceptions, is intended as a mechanism to provide Envigo's existing stockholders some of the value of Envigo's existing net operating losses on an as and when used basis (the "July 19 Offer").

        On July 21, 2017, representatives of AHPAC, Credit Suisse and Weil attended a combined due diligence session and drafting session in respect of investor presentation materials (the "investor presentation materials") at Envigo's offices. Representatives of Envigo, Jefferies and Jermyn were also present. On July 25, 2017, representatives of AHPAC, Envigo, Jermyn, Credit Suisse, Jefferies and Weil attended a telephonic drafting session in respect of the investor presentation materials. Also on July 25, 2017, representatives of Weil sent Cahill a document outlining a proposed structure for a potential




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business combination between Envigo and AHPAC; and Weil received a revised draft of the letter of intent from Cahill. On July 27, 2017, representatives of Credit Suisse attended a teleconference with representatives of Jermyn and Jefferies to further discuss and negotiate the terms of a potential business combination between AHPAC and Envigo. Also on July 27, 2017, representatives of AHPAC, Envigo, Jermyn, Credit Suisse, Jefferies and Weil attended a telephonic drafting and preparation session in respect of the investor presentation materials.




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        On July 27, 2017, representatives of Weil and Cahill held a teleconference to discuss Envigo's debt financing in connection with the proposed business combination. On July 28, 2017, representatives of Weil, Cahill, Credit Suisse, Jefferies, Jermyn, and AHPAC held a teleconference to discuss the need to obtain lender consents under Envigo's existing outstanding credit agreements.

        On July 31, 2017, representatives of Weil sent Cahill an initial draft of a term sheet in respect of the tax receivable agreement proposed to be entered into in connection with the business combination, and Weil also sent Cahill a revised draft of the letter of intent. On August 1, 2017, representatives of AHPAC, Envigo, Jermyn, Credit Suisse, Jefferies and Weil attended a telephonic meeting to finalize the investor presentation materials, and later that evening Weil sent Cahill an initial draft of the transaction agreement in connection with the potential business combination. Further on August 1, 2017, representatives of Weil and Cahill held a teleconference regarding certain proposed amendments to the draft letter of intent, and representatives of Weil sent representatives of Cahill a further revised draft of the transaction agreement following that call.

        During the period of August 1, 2017 to August 20, 2017, AHPAC and its representatives continued to conduct due diligence on Envigo, and AHPAC, Envigo and their respective representatives continued to negotiate the terms of a potential business combination between AHPAC and Envigo. During July and August 2017, Mr. Burgstahler periodically updated the members of the AHPAC Board regarding discussions with Envigo.

        On August 11, 2017, representatives of AHPAC, Envigo, Jermyn, Savanna, Credit Suisse, Jefferies, Weil and Cahill attended a telephonic meeting regarding an update regarding feedback on the potential business combination received during a recent non-deal roadshow, and on progress of negotiations of definitive terms of the potential business combination. Also on August 11, 2017, representatives of Cahill sent representatives of Weil initial drafts of amendments to each of Envigo's existing credit agreements (the "credit agreement amendments") which amendments would, among other things, (i) provide lender consent to the change of control resulting from the transactions with AHPAC (the "transactions"), (ii) permit the payment of certain junior lien indebtedness of Envigo, (iii) permit the payment of customary public company costs and expenses after giving effect to the transactions and (iv) otherwise permit the transactions. On August 12, 2017, representatives of Weil sent Cahill an initial draft of the tax receivables agreement proposed to be entered into in connection with the transactions. On August 13, 2017, representatives of Weil sent Cahill an initial draft of the amended and restated registration rights agreement proposed to be entered into in connection with the transactions. Also on August 13, 2017, Weil received a revised draft of the transaction agreement from Cahill.

        On August 14, 2017, representatives of AHPAC, Envigo, Jermyn, Savanna, Credit Suisse, Jefferies, Weil and Cahill attended a telephonic meeting regarding an update on progress of the potential business combination. Also on August 14, 2017, representatives of Weil and Cahill met via teleconference to negotiate the terms of the draft transaction agreement.

        On the morning of August 16, 2017, Weil sent Cahill a further draft of the transaction agreement, and later that day Weil sent Cahill an initial draft of the parent sponsor letter agreement proposed to be entered into in connection with the transactions. On August 16, 2017, representatives of AHPAC, Envigo, Jermyn, Savanna, Credit Suisse, Jefferies, Weil and Cahill attended a telephonic meeting regarding an update on progress of the potential business combination.




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        On August 17, 2017, the board of directors of AHPAC met to review the terms of the proposed business combination between AHPAC and Envigo. Representatives of Weil attended the meeting. The board discussed with representatives of Weil, among other things, their duties as directors of a Cayman Islands corporation, the process that AHPAC had conducted since its IPO to find a suitable target for AHPAC's initial business combination, and the process that had been conducted to date to negotiate the terms of the potential business combination between AHPAC and Envigo. The board also reviewed the key terms of the draft transaction agreement and related agreements, and discussed the




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reasonableness of the consideration to be paid to Envigo and whether a potential business combination on the terms outlined in the transaction agreement was in the best interests of AHPAC's shareholders. After discussion, the board came to a preliminary view that the consideration proposed to be paid to Envigo was reasonable and that the potential business combination was in the best interests of AHPAC's shareholders, and authorized representatives of Weil and members of management of AHPAC and the sponsor to continue to negotiate and finalize the terms of the transaction agreement and related documents. Also on August 17, 2017, representatives of AHPAC, Envigo, Jermyn, Savanna, Credit Suisse, Jefferies, Weil and Cahill attended a telephonic meeting regarding an update on progress of the potential business combination; and Weil received a revised draft of the transaction agreement from Cahill.

        Also on August 17, 2017, representatives of Weil sent representatives of Cahill a draft consent agreement in relation to the indenture governing Envigo's existing 15.00% Third Lien Senior Secured Notes due 2020 (the "Notes"), pursuant to which it was proposed that the holders of the Notes, AHPAC and Envigo agreed to enter into a supplemental indenture upon closing of the business combination to effectuate certain changes to the terms of the Note, including a reduction in the coupon to 6.00%. Representatives of Cahill responded with a revised draft consent agreement on August 20, 2017, which was signed by the parties thereto that day.

        On the morning of August 18, 2017, representatives of Weil sent Cahill a revised draft of the transaction agreement. On August 18, 2017, representatives of AHPAC, Envigo, Jermyn, Savanna, Credit Suisse, Jefferies, Weil and Cahill attended a telephonic meeting regarding an update on progress of the potential business combination. Also on August 18, 2017, representatives of Weil and Cahill met via teleconference to negotiate the terms of the draft transaction agreement; and Weil received revised drafts of the tax receivable agreement and registration rights agreement from Cahill. Weil sent Cahill revised drafts of the registration rights agreement and tax receivable agreement on the evening of August 18, 2017.

        On August 19, 2017 and August 20, 2017, representatives of AHPAC, Envigo and their respective representatives exchanged several drafts of the transaction agreement and the ancillary agreements, and met via teleconference on multiple occasions to continue negotiating the terms thereof. Representatives of Cahill also furnished Weil with a draft of the written consent of Envigo shareholders proposed to be signed in connection with the transactions, which Weil reviewed and discussed with Cahill.

        On August 20, 2017, the AHPAC Board met to review the terms of the proposed business combination between AHPAC and Envigo, and to consider and vote on the approval of such business combination. Representatives of Weil and Credit Suisse attended the meeting. After discussion, the board of directors of AHPAC unanimously resolved, among other things, that (i) it is in AHPAC's commercial interests that AHPAC should approve and enter into the transaction agreement and the ancillary agreements, and enter into the transactions, (ii) an extraordinary general meeting of the shareholders of AHPAC (the "EGM") be convened in accordance with the articles of association with AHPAC, and (iii) any director or any officer of AHPAC be authorized to finalize this proxy statement/prospectus in connection with the EGM. For further details, see the Section titled "The AHPAC Board's Reasons for Approval of the Business Combination" commencing on page [    93.




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        On the morning of August 21, 2017, AHPAC, Merger Sub, NewCo, Envigo and the shareholders representative executed the transaction agreement, and AHPAC issued a press release announcing the business combination between AHPAC and Envigo. Also on August 21, 2017, fully executed lender consents under Envigo's existing outstanding credit agreements were obtained from the required lenders of each class of Envigo's existing indebtedness.




        Subsequent to this, as the parties prepared the proxy statement/prospectus, the parties discussed that the "Outside Date" (as that term is defined in the Transaction Agreement) should be extended to allow sufficient time to finalize the proxy statement/prospectus. On November 6, 2017, Weil sent Cahill an initial draft of Amendment No. 1 to the Transaction Agreement. During the period of November 6, 2017 to November 22, 2017, the parties discussed and revised Amendment No. 1 to the Transaction Agreement, including adding a provision to clarify that the receipt by Parent of any notice of non-compliance from NASDAQ, to the extent related to Parent's failure to hold an annual meeting in 2017, would not constitute a breach of Section 6.3(e)(iii) of the Transaction Agreement. Envigo, Parent, Merger Sub, NewCo and the Shareholder Representative entered into Amendment No. 1 to the Transaction Agreement on November 22, 2017. Subsequent to this, the parties agreed that the Transaction Agreement should be further amended to simplify the consideration to be paid to the holders of Envigo SARs in the transaction, and to clarify that holders of Envigo SARs would not receive equity of ENVG in the transaction. On December 21, 2017, Cahill sent Weil a substantially final draft of Amendment No. 2 to the Transaction Agreement. On December 22, 2017, the parties signed Amendment No. 2 to the Transaction Agreement.

Table        On January 12, 2018, representatives of Contentsthe Sponsor, Jermyn, Envigo, Jefferies and Credit Suisse met to discuss various matters related to the transaction, including market reaction to the transaction. As a result of the information discussed at this meeting, and the Sponsor's observations regarding market reaction to the proposed transaction as of that date, the Sponsor asked Jermyn and Envigo to consider an amendment to the Transaction Agreement which would (a) decrease the aggregate consideration paid to Selling Equityholders by $27 million, (b) eliminate the payment by the Company to the Class B Holders for the warrants to be transferred by the Class B Holders to the Company (which payment would have reduced the purchase price to Selling Equityholders by an equivalent amount) and (c) reduce the threshold in the condition regarding minimum proceeds from $260 million to $220 million. On January 17, 2018, Weil sent Cahill an initial draft of Amendment No. 3 to the Transaction Agreement. During the period of January 17, 2018 to January 21, 2018, the parties negotiated the terms of this amendment. On January 21, 2018, the parties signed Amendment No. 3 to the Transaction Agreement in substantially the form originally proposed.

        On February 2, 2018, as a result of market reaction to Amendment No. 3 to the Transaction Agreement, representatives of Sponsor and Credit Suisse had a call with representatives of Jermyn and Jefferies regarding consideration of a further reduction of overall consideration to Selling Equityholders. On February 7, 2018, representatives of the Sponsor and Jermyn met to discuss various matters related to the transaction, including market reaction to Amendment No. 3 to the Transaction Agreement. Sponsor proposed the Transaction Agreement be amended to further reduce the aggregate purchase price. Jermyn suggested that a portion of the reduction in purchase price should be borne by the Class B Holders, including the Sponsor. The parties discussed the appropriate aggregate reduction to the purchase price and allocation of that reduction among the key stakeholders. On February 8, 2018, Weil sent Cahill an initial draft of Amendment No. 4 to the Transaction Agreement, which proposed a further reduction in aggregate consideration of $79 million, paired with an increase in the number of founders shares to be surrendered by the Class B Holders of 840,576 shares. On February 9, 2018, the parties signed Amendment No. 4 to the Transaction Agreement.

The AHPAC Board's Reasons for the Approval of the Business Combination

        The AHPAC Board, in evaluating the transaction with Envigo, consulted with AHPAC's management and its legal counsel, financial advisors and other advisors. In reaching its unanimous resolution (i) that the terms and conditions of the Transaction Agreement and the transactions




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contemplated thereby, including the business combination, are advisable, fair to and in the best interests of AHPAC and its shareholders and (ii) to recommend that the shareholders adopt the Transaction Agreement and approve the transactions contemplated thereby, including the business combination, the AHPAC Board considered and evaluated a number of factors, including, but not limited to, the factors discussed below. In light of the number and wide variety of factors considered in connection with its evaluation of the business combination, the AHPAC Board did not consider it practicable to, and did not attempt to, quantify or otherwise assign relative weights to the specific factors that it considered in reaching its determination and supporting its decision. The AHPAC Board did not seek to obtain a third-party valuation or fairness opinion in connection with their determination to approve the business combination. The AHPAC Board viewed its decision as being based on all of the information available and the factors presented to and considered by it. In addition, individual directors may have given different weight to different factors. This explanation of AHPAC's reasons for the business combination and all other information presented in this section is forward-looking in nature and, therefore, should be read in light of the factors discussed under "Cautionary Note Regarding Forward-Looking Statements" beginning on page [    ·    ]156 of this document.

        The AHPAC Board considered a number of factors pertaining to the business combination as generally supporting its decision to enter into the Transaction Agreement and the transactions contemplated thereby, including but not limited to, the following material factors:

        Consideration to be paid to Envigo is reasonable and the business combination is in the best interests of AHPAC's stockholders. The AHPAC Board considered the following factors:

•

the financial data reviewed by AHPAC included Envigo's historical and projected financial statements and comparable publicly traded company analyses;



•

AHPAC conducted a due diligence review of Envigo that included an analysis of Envigo's existing business model, historical and projected financial results, and a valuation analysis in order to enable its board of directors to ascertain the reasonableness of the consideration being paid;



•

during its negotiations with Envigo, AHPAC received services from its financial advisor, Credit Suisse, to assist it in evaluating the reasonableness of the consideration to be paid to Envigo stockholders;



•

the board concluded that the consideration to be paid to Envigo stockholders represents an attractive entry point valuation relative to the publicly traded comparables; and



•

the board considered the risk that the current public stockholders of AHPAC would convert their public shares for cash upon consummation of the transactions, thereby reducing the amount of cash available to AHPAC following the transactions or cause a condition under the transaction agreement not to be met. The board noted that AHPAC had conducted a non-deal roadshow in respect of the potential business combination with selected investors, and had received substantial interest from investors. The board therefore deemed this risk to be low, and in any event no worse with regard to Envigo than it would be with regard to other target companies.




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        Strategic Considerations.    The AHPAC Board considered that the business combination with Envigo is expected to provide a number of significant strategic opportunities, including the following:

•

Envigo represents an ideal target for AHPAC given its financial profile, growth opportunities, leading market position in an attractive industry, diverse blue-chip customer base and strong business fundamentals;



•

the team at AHPAC is highly experienced in investing in the CRO sector, and the fact that Envigo falls squarely in one of AHPAC's areas of expertise provides the opportunity for us to leverage that expertise in realizing the investment potential from the business combination;



•

Envigo has an experienced management team with a strong track record of growing EBITDA, generating free cash flow and integrating acquisitions;



•

the non-clinical CRO market remains highly attractive and is expected to grow at close to 10% annually over the next 4 years. It is a large, $4 billion market globally, but still meaningfully




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underpenetrated from an outsourcing perspective and thus represents favorable industry dynamics for an investment by AHPAC;



•

Envigo's positioning within the CRO market relative to other existing CROs is favorable, with Envigo being one of the leading players globally in its CRS business, most notably in safety assessment, serving customers ranging from big pharma to biotech. In Envigo's RMS business, 16 of the top 20 customers have been repeat customers for more than 15 years;



•

Envigo has a diverse, blue-chip customer base in both CRS and RMS, with limited concentration. Envigo's largest customer represented less than 6% of revenue in the past 2 years, and Envigo's top 5 customers represent less than 13% of all revenue;



•

the margin enhancement opportunities that AHPAC expects to be able to implement into Envigo's business following the transactions;



•

Envigo's existing global footprint represents a strong platform for AHPAC to achieve accelerate growth and achieve scale via consolidation; and



•

the fact that members of Envigo's management, led by Adrian Hardy (CEO) and Patricia Henahan (CFO), will continue to oversee Envigo's business following the transactions.

        Other Factors Considered by the AHPAC Board.    In addition to considering the strategic factors described above, the AHPAC Board considered the following additional factors, all of which it viewed as supporting its decision to approve the transaction agreement:

•

AHPAC raised $310 million in October of 2016 with the objective of consummating an attractive business combination;



•

AHPAC has evaluated a number of businesses since then, but are most impressed by Envigo;



•

the board's knowledge of Envigo's business, operations, financial condition, earnings and prospects, taking into account the results of AHPAC's due diligence review of Envigo;



•

the current and prospective business climate in the industry in which Envigo operates, including the position of current and likely competitors of Envigo;



•

the alternatives reasonably available to AHPAC, including pursuing other potential targets, and the board's belief that the business combination with Envigo creates the best reasonably available opportunity to maximize value for the AHPACs shareholders given the potential risks, rewards and uncertainties associated with each alternative;






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•

the fact that 2 members of the 7-member post-transaction board will be comprised of members from AHPAC; and



•

the terms and conditions of the transaction agreement, including the strong commitments by both AHPAC and Envigo to complete the transactions.

        The AHPAC Board weighed these advantages and opportunities against a number of other factors identified in its deliberations weighing negatively against the business combination with Envigo, including:

•

the risk that AHPAC shareholders may object to and challenge the transactions and take actions that may prevent or delay the consummation of the transactions, including to vote down the proposals at the AHPAC general meeting or convert their shares;



•

the potential for diversion of management and employee attention during the period prior to completion of the transactions, and the potential negative effects on Envigo's business;



•

the risk that, despite the efforts of AHPAC and Envigo prior to the consummation of the transactions, Envigo may lose key personnel, and the potential resulting negative effects on Envigo's business;



•

the possibility that Envigo might not achieve its projected financial results;



•

the fact that the transaction agreement prohibits AHPAC from soliciting or engaging in discussions regarding alternative transactions during the pendency of the transactions;




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•

the risk that changes in the regulatory and legislative landscape or new industry developments, including changes in consumer preferences, may adversely affect the business benefits anticipated to result from the transactions; and



•

the risks of the type and nature described under "Risk Factors" beginning on page [    ·    ]37 and the matters described under "Cautionary Statement Regarding Forward-Looking Statements" beginning on page [    ·    ].156.

Satisfaction of 80% Test

        It is a requirement under AHPAC's existing amended and restated memorandum and articles of association and NASDAQ listing requirements that the business or assets acquired in AHPAC's initial business combination have a fair market value equal to at least 80% of the balance of the funds in the trust account (excluding the deferred underwriting commissions and taxes payable on the income earned on the trust account) at the time of the execution of a definitive agreement for AHPAC's initial business combination. As of August 21, 2017, the date of the execution of the Transaction Agreement, the fair value of marketable securities held in the trust account was approximately $311,360,861 (excluding $10,850,000 of deferred underwriting commissions) and 80% thereof represents approximately $249,088,689. In reaching its conclusion that the business combination meets the 80% asset test, the AHPAC Board reviewed the enterprise value of Envigo of approximately $924 million implied by adding: (i) approximately $301 million of equity consideration in ENVG to be issued to the Selling Equityholders; (ii) approximately $100 million (excluding transaction costs incurred by Envigo) of cash consideration payable to the Selling Equityholders at the consummation of the business combination; (iii) the assumption of approximately $274 million of Envigo's existing net indebtedness; (iv) the repayment of approximately $166 million of Envigo's existing indebtedness; (v) the payment of approximately $44 million of certain transaction costs; and (vi) approximately $39 million of founder shares retained by the initial shareholders. In determining whether the enterprise value described above represents the fair market value of Envigo, the AHPAC Board considered all of the factors described above in this section and the fact that the purchase price for Envigo was the result of an arm's length negotiation. As a result, the AHPAC Board concluded that the fair market value of the business




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acquired was significantly in excess of 80% of the assets held in the trust account (excluding the deferred underwriting commissions and taxes payable on the income earned on the trust account).

Certain Envigo Projected Financial Information

        Envigo provided AHPAC with its internally prepared projections for the fiscal years ended December 31, 2017 and 2018. The prospective financial information was not prepared with a view toward compliance with published guidelines of the SEC or the guidelines established by the American Institute of Certified Public Accountants for preparation and presentation of prospective financial information. These projections were prepared solely for internal use, capital budgeting and other management purposes, and are therefore subjective in many respects and susceptible to varying interpretations and the need for periodic revision based on actual experience and business developments, and were not intended for third party use, including by investors or holders. You are cautioned not to rely on the projections in making a decision regarding the transaction, as the projections may be materially different than actual results.

        The projections reflect numerous assumptions including assumptions with respect to general business, economic, market, regulatory, and financial conditions and various other factors, all of which are difficult to predict and many of which are beyond Envigo's control, such as the risks and uncertainties contained in the section entitled "Risk Factors." The projections reflect the consistent application of accounting policies of Envigo and should be read in conjunction with the accounting policies included in Note 1 accompanying the historical audited consolidated financial statement of Envigo included in this proxy statement.

  ��     The financial projections for revenue and costs are forward looking statements that are based on growth assumptions that are inherently subject to significant uncertainties and contingencies, many of which are beyond Envigo's control. While all projections are necessarily speculative, Envigo believes




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that the prospective financial information covering periods beyond 12 months from its date of preparation carries even higher levels of uncertainty and should be read in that context. There will be differences between actual and projected financial results, and actual results may be materially greater or materially less than those contained in the projections. The inclusion of the projections in this proxy statement should not be regarded as an indication that Envigo or its representatives considered or consider the projections to be a reliable prediction of future events.

        The projections were requested by, and disclosed to, AHPAC for use as a component in its overall evaluation of Envigo, and are included in this proxy statement on that account. Envigo has not warranted the accuracy, reliability, appropriateness or completeness of the projections to anyone, including AHPAC. Neither Envigo's management nor any of its representatives has made or makes any representation to any person regarding the ultimate performance of Envigo compared to the information contained in the projections, and none of them intends to or undertakes any obligation to update or otherwise revise the projections to reflect the circumstances existing after the date when made or to reflect the occurrence of future events in the event that any or all of the assumptions underlying the projections are shown to be in error. Accordingly, they should not be looked at as "guidance" of any sort. Envigo will not refer back to these forecasts in its future periodic reports filed under the Exchange Act.

        The projections were prepared by, and the responsibility of, Envigo's management. KPMG, Envigo's auditor, has neither examined, compiled nor performed any procedures with respect to the accompanying prospective financial information and, accordingly KPMG does not express any opinion or any other form of assurance with respect thereto. The KPMG report included in this proxy statement relates to historical financial information of Envigo. They do not extend to the projections and should not be read as if they do.




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        The key elements of the projections provided to AHPAC are summarized in the table below (in millions of dollars):

		Fiscal Year Ended December 31,
($ in millions)		2017E			2018E
Revenue		$	407		$	432
% Growth			–1.9	%		6.1	%
Gross Profit(a)		$	138		$	155
% Margin			33.8	%		35.9	%
Adjusted EBITDA(b)		$	73		$	87
% Margin			17.9	%		20.2	%
Capital Expenditures(c)		$	15		$	22

---

(a)

Calculated in accordance with US GAAP.



(b)

Adjusted EBITDA is net income (loss) before depreciation, amortization, interest expense and income taxes (EBITDA) adjusted to exclude the impact of foreign exchange gains and losses, pension expense, stock compensation, sponsor management fees and expenses, discontinued operations and certain significant items (some of which may recur, such as restructuring, but which management does not believe are reflective of ongoing core operations).



(c)

Net of asset dispositions.

Interests of Certain Persons in the Business Combination

        In considering the recommendation of the AHPAC Board to vote in favor of the business combination, shareholders should be aware that aside from their interests as shareholders, the sponsor and certain members of the AHPAC Board and officers have interests in the business combination that are different from, or in addition to, those of other shareholders generally. The AHPAC Board was aware of and considered these interests, among other matters, in evaluating and negotiating the




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business combination, and in recommending to shareholders that they approve the business combination. Shareholders should take these interests into account in deciding whether to approve the business combination.

        For a discussion of these interests, please see the section titled "Annual General Meeting of AHPAC Shareholders—Recommendation to AHPAC's Shareholders" beginning on page [    ·    ]77 of this proxy statement/prospectus. These interests may influence AHPAC's directors in making their recommendation that you vote in favor of the approval of the business combination.

Potential Purchases of Public Shares

        In connection with the shareholder vote to approve the proposed business combination, the sponsor, AHPAC's directors or officers or their respective affiliates may privately negotiate transactions to purchase shares from shareholders who would have otherwise elected to have their shares redeemed in conjunction with the vote to approve the business combination. None of AHPAC's directors or officers or their respective affiliates will make any such purchases when they are in possession of any material non-public information not disclosed to the seller or during a restricted period under Regulation M under the Exchange Act. Such a purchase would include a contractual acknowledgement that such shareholder, although still the record holder of AHPAC shares, is no longer the beneficial owner thereof and therefore agrees not to exercise its redemption rights, and would include a contractual provision that directs such shareholder to vote such shares in a manner directed by the purchaser. In the event that the sponsor, AHPAC's directors or officers or their affiliates purchase




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shares in privately negotiated transactions from public shareholders who have already elected to exercise their redemption rights, such selling shareholders would be required to revoke their prior elections to redeem their shares. Any such privately negotiated purchases may be effected at purchase prices that are in excess of the per-share pro rata portion of the trust account. The purpose of such purchases would be to increase the likelihood of obtaining shareholder approval of the business combination.

Total AHPAC Shares to be Issued in the Business Combination

        It is anticipated that, upon completion of the business combination: (i) AHPAC's public shareholders will retain an ownership interest of approximately 47.9%57.7% in ENVG; (ii) the sponsor will own approximately 6.0%5.6% of ENVG and (iii) the Selling Equityholders will own approximately 46.1%36.7% of ENVG. The ownership percentages of ENVG following the business combination assume that no shares are elected to be redeemed and do not take into account (a) the warrants to purchase ENVG Class A common stock that will be issued in connection with and remain outstanding following the business combination, or (b) the issuance of any ENVG Class A common stock in connection with the equity financing (if any) or (c) the consummation of a Debt Refinancing (if any).

        For more information, please see the sections entitled "Summary of the Proxy Statement/Prospectus—Ownership of AHPAC" and "Unaudited Pro Forma Condensed Combined Financial Information." See the section titled "The Business Combination—The Transaction Agreement—Equity Financing" beginning on page [    ·    ]86 of this proxy statement/prospectus for further details regarding AHPAC's obligations in connection with the equity financing. See the section titled "The Transaction Agreement—Related Agreements—Financing Arrangements" beginning on page [    ·    ]129 of this proxy statement/prospectus for further details regarding Envigo's obligations in connection with a Debt Refinancing.




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Sources and Uses for the Business Combination

        The following tables summarize the sources and uses for funding the business combination (all numbers in millions):

Sources and Uses—assuming no redemptions and no equity financing and no Debt Refinancing


($ in millions)		$ Amount					$ Amount
Uses					Sources
Equity Issued to Selling Equityholders		$	189.5		AHPAC Trust Account		$	311.8
Cash to Selling Equityholders		$	98.4		Selling Equityholders Rollover Equity		$	150.8
Founder Shares Retained		$	30.3		Founder Shares		$	69.1
Paydown of Debt & Accrued Interest Net of Cash(1)		$	433.0		New Term Loan (Net of Cash on Balance Sheet)		$	280.0
Estimated Cash Transaction Fees & Expenses		$	60.4
​	​	​	​	​	​	​	​	​	​
Total Uses		$	811.7		Total Sources		$	811.7
​	​	​	​	​	​	​	​	​	​

---

($ in millions)		$ Amount					$ Amount
Uses					Sources
Equity Issued to Selling Equityholders		$	298.7		AHPAC Trust Account		$	311.7
Cash to Selling Equityholders		$	100.0		Selling Equityholders Rollover Equity		$	260.0
Founder Shares Retained		$	38.8		Founder Shares		$	77.5
Rollover Net Debt		$	269.0		Rollover Net Debt		$	269.0
Paydown of Debt and Accrued Interest Net of Excess Cash		$	164.2
Estimated Cash Transaction Fees & Expenses		$	47.5
​	​	​	​	​	​	​	​	​	​
Total Uses		$	918.2		Total Sources		$	918.2
​	​	​	​	​	​	​	​	​	​




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Cash balance includes Envigo excess cash and cash remaining in balance sheet. Note: Sources & uses reflect $8 million of Contentscash proceeds received from sale of dog business in October 2017; pro forma balance sheet is not reflective of this transaction.

Sources and Uses—assuming maximum redemptions and no equity financing and no Debt Refinancing


($ in millions)		$ Amount					$ Amount
Uses					Sources
Equity Issued to Selling Equityholders		$	279.5		AHPAC Trust Account		$	221.8
Cash to Selling Equityholders		$	8.4		Selling Equityholders Rollover Equity		$	240.8
Founder Shares Retained		$	30.3		Founder Shares		$	69.1
Paydown of Debt & Accrued Interest Net of Cash(1)		$	433.0		New Term Loan (Net of Cash on Balance Sheet)		$	280.0
Estimated Cash Transaction Fees & Expenses		$	60.4
​	​	​	​	​	​	​	​	​	​
Total Uses		$	811.7		Total Sources		$	811.7
​	​	​	​	​	​	​	​	​	​

---

($ in millions)		$ Amount					$ Amount
Uses					Sources
Equity Issued to Selling Equityholders		$	298.7		AHPAC Trust Account		$	261.7
Cash to Selling Equityholders		$	100.0		Selling Equityholders Rollover Equity		$	260.0
Founder Shares Retained		$	38.8		Founder Shares		$	77.5
Rollover Net Debt		$	318.7		Rollover Net Debt		$	318.7
Paydown of Debt and Accrued Interest Net of Excess Cash		$	114.2
Estimated Cash Transaction Fees & Expenses		$	47.5
​	​	​	​	​	​	​	​	​	​
Total Uses		$	917.8		Total Sources		$	917.8
​	​	​	​	​	​	​	​	​	​

(1)

Cash balance includes Envigo excess cash and cash remaining in balance sheet. Note: Sources & uses reflect $8 million of cash proceeds received from sale of dog business in October 2017; pro forma balance sheet is not reflective of this transaction.

        As of the date of this proxy statement/prospectus, assuming there were no proceeds from the equity financing, a maximum of 29% of the outstanding AHPAC Class A ordinary shares could be redeemed and allow satisfaction of the condition that there be at least $220 million of available funds in the trust account after giving effect to redemptions.

Board of Directors of AHPAC Following the Business Combination

        Upon the closing of the business combination, the board of directors of ENVG will consist of seven directors, each of whom will be voted upon by AHPAC's shareholders at the general meeting. Please see the sections entitled "Proposal No. 12—The Director Election Proposal" and "Management after the Business Combination" for additional information.

AHPAC Certificate of Incorporation

        If the Domestication Proposal is approved and the business combination is to be consummated, AHPAC will replace its amended and restated memorandum and articles of association, under the Cayman Islands Companies Law (which are also referred to as the "Existing Organizational




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Documents"), with the proposed certificate and the proposed bylaws, in each case, under the DGCL (which are collectively referred to as the "Proposed Organizational Documents").

        The Proposed Organizational Documents differ materially from the Existing Organizational Documents. For a table setting forth a summary of the proposed principal changes between the Existing Organizational Documents and the Proposed Organizational Documents, please see the section entitled "The Charter Proposals." Additionally, as the Existing Organizational Documents are governed by the Cayman Islands Companies Law and the Proposed Organizational Documents will be governed by the DGCL, we encourage shareholders to carefully consult the information set out under the "Comparison of Corporate Governance and Shareholder Rights" section of this proxy statement/prospectus commencing on page [    ·    ].236.

Name; Headquarters

        The name of AHPAC after the business combination will be "Envigo International Holdings, Inc." and its headquarters will be located at 100 Mettlers Road, East Millstone, New Jersey 08875 .08873.

Redemption Rights

        If a public shareholder properly exercises its right to redeem its public shares and timely delivers its shares to the transfer agent, AHPAC will redeem each public share for a per-share price, payable in cash, equal to the aggregate amount then on deposit in the trust account, calculated as of two business days prior to the consummation of the business combination, including interest, divided by the number of then issued and outstanding public shares;provided that AHPAC will not redeem any AHPAC Class A ordinary shares issued in the IPO to the extent that such redemption would result in AHPAC having net tangible assets (as determined in accordance with Rule 3a51-1(g)(1) of the Exchange Act) of less than $5,000,001. For illustrative purposes, as of NovemberJanuary 17, 2017,2018, this would have amounted to approximately $10.07$10.08 per public share. Notwithstanding the foregoing, a holder of the public shares,




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together with any affiliate of his or her or any other person with whom he or she is acting in concert or as a "group" (as defined in Section 13(d)-(3) of the Exchange Act) will be restricted from seeking redemption rights with respect to more than 20% of the AHPAC Class A ordinary shares included in the units sold in the IPO.

        If a public shareholder exercises its redemption rights, then it will be exchanging its redeemed public shares for cash and will no longer own such shares. Such a holder will be entitled to receive cash for its public shares only if it properly demands redemption and delivers its shares (either physically or electronically) to AHPAC's transfer agent in accordance with the procedures described herein. If the business combination is not consummated, the public shares will not be redeemed for cash.

        There is no specified maximum redemption threshold under its memorandum and articles of association, other than the aforementioned 15% threshold. Each redemption of AHPAC Class A ordinary shares by public shareholders will reduce the amount in the trust account, which held marketable securities with a fair value of approximately $[    ·    ]$312,497,921 as of [    ·    ], 2017.January 17, 2018. The Transaction Agreement provides that AHPAC's obligation to consummate the business combination and the obligations of Envigo to consummate the business combination are each conditioned on there being at least $260$220 million of available funds from the trust account and proceeds from the equity financing (if any), after giving effect to redemptions of public shares. These conditions to closing in the Transaction Agreement are for the sole benefit of the parties thereto and may be waived by such parties. If, as a result of redemptions of public shares by public shareholders, these conditions are not met (or waived), then AHPAC or Envigo (as applicable) may elect not to consummate the business combination. In addition, in no event will AHPAC redeem public shares in an amount that would cause our net tangible assets to be less than $5,000,001. Holders of public warrants do not have redemption rights in connection with the business combination. Please see the section entitled "Annual General Meeting of AHPAC Shareholders— Redemption Rights" for the procedures to be followed if you wish to redeem your shares for cash. See the section titled "The Business Combination—The Transaction Agreement—Equity Financing" beginning on page [    ·    ]86 of this proxy statement/prospectus for further details regarding AHPAC's obligations in connection with the equity financing.




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Appraisal Rights

        Appraisal rights are not available to AHPAC's shareholders in connection with the business combination.

Accounting Treatment

        The business combination will be accounted for as a business combination in accordance with Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) No. 805, Business Combinations (ASC 805), which provides guidance on the accounting and reporting for transactions that represent business combinations to be accounted for under the acquisition method of accounting.

        Pursuant to ASC 805, AHPAC has been determined to be the accounting acquirer based on the evaluation of the facts and circumstances including, among other things, the following:

•

AHPAC pays cash and equity consideration for all of the equity in Envigo; and



•

The existing stockholders of AHPAC retain relatively more voting rights in the post-combination business than the Selling Equityholders.

        Additionally, Envigo meets the definition of a business in accordance with ASC 805 which defines a business as an integrated set of activities and assets that is capable of being conducted and managed for the purpose of providing a return in the form of dividends, lower costs, or other economic benefits directly to investors or other owners, members, or participants.




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        Under the acquisition method of accounting, the identifiable assets acquired and the liabilities assumed in are measured at fair value as of the acquisition date and the difference between the consideration paid and those fair values is recorded as goodwill. Management of AHPAC has made significant estimates and assumptions in the preliminary allocation of the purchase price as reflected in the unaudited pro forma financial information. As the unaudited pro forma financial information has been prepared based on these preliminary estimates, the final amounts recorded may differ materially from the information presented.

        In historical financial statements presented in AHPAC's periodic reporting after the completion of the business combination, the historical financial information of Envigo will be presented as the predecessor for comparative purposes.

        In accordance with ASC 805, acquisition-related costs (such as advisory, legal, valuation and other professional fees) to effect a business combination are accounted for as expenses in the periods in which the costs are incurred and the services are received. AHPAC expects to incur approximately $17 million of acquisition-related costs in connection with the business combination.

        The determination of the acquirer will ultimately be made on the closing date of the transaction and as noted above will be based on the facts and circumstances including, among others, the voting rights in ENVG of the existing AHPAC shareholders post-business combination relative to the voting rights of the Selling Equityholders. There are various scenarios that could change the current expectation that the existing AHPAC shareholders will retain relatively more voting rights post combination than the Selling Equityholders, including the level of AHPAC redemptions (if any), the number of Selling Equityholders that elect to receive cash, whether a Debt Refinancing is consummated, and the value of the equity financing (if any). Changes in the equity ownership under various scenarios relating to redemptions of AHPAC shares, the equity financing, the consummation or terms of a Debt Refinancing or the number of Selling Equityholders who elect to receive cash could result in Envigo being the acquirer for accounting purposes. For further discussion of the impacts of a change in the acquirer, please see the fourth paragraph under the section titled "Unaudited Pro Forma Condensed Combined Financial Information" commencing on page [    ·    ]139 of this proxy statement/prospectus.




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MATERIAL TAX CONSIDERATIONS

Material U.S. Federal Income Tax Considerations

        The following is a discussion of material U.S. federal income tax considerations for beneficial owners of AHPAC Class A ordinary shares and AHPAC warrants (collectively, the "AHPAC securities") relating to the business combination (including the Domestication) and the ownership and disposition of ENVG Class A common stock and ENVG warrants (collectively, the "ENVG securities") acquired pursuant to the domestication. This discussion applies only to AHPAC securities and ENVG securities held as capital assets for U.S. federal income tax purposes, and does not describe all of the U.S. federal income tax consequences that may be relevant to beneficial owners of AHPAC securities and ENVG securities in light of their particular circumstances, including alternative minimum tax and Medicare contribution tax consequences, or beneficial owners who are subject to special rules, such as:

•

financial institutions or financial service entities;



•

governments or agencies or instrumentalities thereof;



•

insurance companies;



•

dealers or traders subject to a mark-to-market method of tax accounting with respect to the AHPAC securities or ENVG securities;



•

persons holding the AHPAC securities or ENVG securities as part of a "straddle," hedge, integrated transaction or similar transaction, or persons deemed to sell the securities under constructive sale provisions of the Code;



•

U.S. holders (as defined below) whose functional currency is not the U.S. dollar;



•

partnerships or other pass-through entities for U.S. federal income tax purposes or investors in such entities;



•

holders who are controlled foreign corporations or passive foreign investment companies;



•

regulated investment companies;



•

real estate investment trusts;



•

U.S. holders (as defined below) owning or considered as owning 10 percent or more of the total combined voting power of all classes of stock entitled to vote of, or 10% or more of the total value of all classes of shares of, AHPAC Class A ordinary shares or the ENVG Class A common stock;ENVG;



•

anchor investors;



•

U.S. holders (as defined below) that hold their AHPAC securities or ENVG securities through a non-U.S. broker or other non-U.S. intermediary;



•

persons who are, or may become, subject to the expatriation provisions of the Code; or



•

tax-exempt entities.

        If you are a partnership for U.S. federal income tax purposes, the U.S. federal income tax treatment of your partners will generally depend on the status of the partners and your activities.

        This discussion is based on the Code, and administrative pronouncements, judicial decisions and final, temporary and proposed U.S. Treasury Regulations all as of the date hereof, changes to any of which subsequent to the date of this prospectus may affect the tax consequences described herein (possibly with retroactive effect). This discussion does not take into account proposed changes in such tax laws and does not address any aspect of state, local or non-U.S. taxation, or any U.S. federal taxes other than income taxes (such as estate or gift tax consequences). Each of the foregoing is subject to




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change, possibly with retroactive effect. You should consult your tax advisors with respect to the




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application of U.S. federal tax laws to your particular situation, as well as any tax consequences arising under the laws of any state, local or non-U.S. jurisdiction.

        Because AHPAC public units (each unit consisting of one AHPAC Class A ordinary share and one AHPAC warrant) can be separated into their component parts at the option of the holder, a beneficial owner of an AHPAC public unit should be treated as the owner of the underlying AHPAC securities for U.S. federal income tax purposes. The discussion below with respect to AHPAC securities should also apply to holders of AHPAC public units (as the deemed owner of the underlying AHPAC securities). References in this discussion to "ordinary shares" or "shares" refers to AHPAC Class A ordinary shares and references in this discussion to "common stock" or "stock" refers to ENVG Class A common stock and references to "warrants" refer to AHPAC warrants or ENVG warrants, as the context may require.

        Because ENVG is acquiring Envigo in the merger for U.S. federal income tax purposes, there are no adverse tax consequences to the beneficial owners of AHPAC securities and there are no adverse tax consequences to ENVG, in each case, as a result of the merger.

U.S. Holders

        This section applies to you if you are a "U.S. holder." A U.S. holder is a beneficial owner of AHPAC securities or ENVG securities who or that is, for U.S. federal income tax purposes:

•

an individual who is a citizen or resident of the United States;



•

a corporation organized under the laws of the United States, any state thereof or the District of Columbia;



•

an estate the income of which is includible in gross income for U.S. federal income tax purposes regardless of its source; or



•

a trust, if (i) a court within the United States is able to exercise primary supervision over the administration of such trust and one or more "United States persons" (within the meaning of the Code) have the authority to control all substantial decisions of the trust, or (ii) the trust has validly elected to be treated as a United States person for U.S. federal income tax purposes.

        ALL HOLDERS OF AHPAC SECURITIES SHOULD CONSULT THEIR TAX ADVISORS REGARDING THE TAX CONSEQUENCES OF THE BUSINESS COMBINATION (INCLUDING THE DOMESTICATION) TO THEM, INCLUDING THE EFFECTS OF U.S. FEDERAL, STATE, LOCAL, NON-U.S. AND OTHER TAX LAWS.

Consequences of the Domestication—F Reorganization.

        The discussion under this heading "Consequences of the Domestication—F Reorganization" constitutes the opinion of Weil, Gotshal & Manges LLP, counsel to AHPAC ("Weil"), as to the material U.S. federal income tax consequences of the domestication to U.S. holders of AHPAC securities. In the opinion of Weil, although no authority directly addressing the tax consequences of the domestication exists, the domestication should qualify as a "reorganization" within the meaning of section 368(a)(1)(F) of the Code (an "F Reorganization"). Pursuant to the domestication, AHPAC will change its jurisdiction of incorporation from the Cayman Islands to Delaware, and, after the domestication will change its name to ENVG. Because the domestication should qualify as an F Reorganization, U.S. holders generally should not recognize taxable gain or loss on the domestication for U.S. federal income tax purposes, except as provided below under the caption headings "—Effects of Section 367"and "—Passive Foreign Investment Company Rules", and the domestication should be treated for U.S. federal income tax purposes as if AHPAC (i) transferred all of its assets and liabilities




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to ENVG in exchange for all of the outstanding common stock and warrants of ENVG; and (ii) then




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distributed the common stock and warrants of ENVG to the shareholders and warrant holders of AHPAC in liquidation of AHPAC. The taxable year of AHPAC will be deemed to end on the date of the domestication. Assuming the domestication qualifies as an F Reorganization: (i) the tax basis of a share of ENVG common stock or an ENVG warrant received by a U.S. holder in the domestication will equal the U.S. holder's adjusted tax basis in the AHPAC ordinary share or warrant, as the case may be, surrendered in exchange therefor, increased by any amount included in the income of such U.S. holder as a result of Section 367 of the Code (as discussed below) and (ii) the holding period for a share of ENVG common stock or an ENVG warrant received by a U.S. holder will include such U.S. holder's holding period for the AHPAC ordinary shares or warrant surrendered in exchange therefor.

        If the domestication fails to qualify as an F Reorganization, a U.S. holder generally would recognize gain or loss with respect to his AHPAC securities in an amount equal to the difference between the fair market value of ENVG securities received in the domestication and the U.S. holder's adjusted tax basis in his AHPAC securities surrendered in the domestication. In such event, such U.S. holder's basis in ENVG securities would be equal to their fair market value on the date of the domestication, and such U.S. holder's holding period for ENVG securities would begin on the day following the date of the domestication.

        Because the domestication will occur prior to the redemption of U.S. holders that exercise redemption rights, U.S. holders exercising such redemption rights will be subject to the potential tax consequences of the domestication.

        All U.S. holders considering exercising redemption rights should consult their tax advisors with respect to the potential tax consequences of the domestication and an exercise of redemption rights to them.

Effect of Section 367


        Section 367 of the Code applies to certain nonrecognition transactions involving foreign corporations, including a domestication of a foreign corporation in an F Reorganization. Section 367 of the Code imposes income tax on certain U.S. persons in connection with transactions that would otherwise be tax-free. Section 367(b) of the Code generally will apply to U.S. holders that exchange AHPAC ordinary shares (but not warrants) for ENVG common stock as part of the domestication.

U.S. Holders That Own Less Than 10 Percent of AHPAC


        A U.S. holder who, at the time of the domestication, beneficially owns (actually or constructively) AHPAC ordinary shares with a fair market value of $50,000 or more but less than ten percent (10%) of the total combined voting power of all classes of AHPAC ordinary shares entitled to vote and less than 10% of the total value of all classes of AHPAC ordinary shares must either recognize gain with respect to the domestication or, in the alternative, may elect to recognize the "all earnings and profits" amount attributable to such holder as described below.

        Unless a U.S. holder makes the "all earnings and profits" election as described below, such holder generally must recognize gain (but not loss) with respect to its AHPAC ordinary shares exchanged for ENVG common stock pursuant to the domestication. Any such gain would be equal to the excess of the fair market value of such ENVG common stock received over the U.S. holder's adjusted tax basis in the AHPAC ordinary shares deemed to be surrendered in exchange therefor. Subject to the PFIC rules discussed below, such gain would be capital gain, and should be long-term capital gain if the U.S. holder held the AHPAC ordinary shares for longer than one year.

        In lieu of recognizing any gain as described in the preceding paragraph, a U.S. holder may elect to include in income the all earnings and profits amount attributable to its AHPAC ordinary shares. There




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are, however, strict conditions for making this election. This election must comply with applicable Treasury regulations and generally must include, among other things:

•

a statement that the domestication is a Section 367(b) exchange;



•

a complete description of the domestication;



•

a description of any stock, securities or other consideration transferred or received in the domestication;



•

a statement describing the amounts required to be taken into account for U.S. federal income tax purposes as income or as an adjustment to basis, earnings and profits or other tax attributes;



•

a statement that the U.S. holder is making the election that includes (A) a copy of the information that the U.S. holder received from AHPAC (or ENVG) establishing and substantiating the U.S. holder's all earnings and profits amount with respect to the U.S. holder's AHPAC ordinary shares, and (B) a representation that the U.S. holder has notified AHPAC (or ENVG) that the U.S. holder is making the election; and



•

certain other information required to be furnished with the U.S. holder's tax return or otherwise furnished pursuant to the Code or the Treasury Regulations.

        The election must be attached by the U.S. holder to its timely filed U.S. federal income tax return for the year of the domestication, and the U.S. holder must send notice of making the election to ENVG no later than the date such tax return is filed. In connection with this election, AHPAC intends to provide each U.S. holder eligible to make such an election with information regarding AHPAC's earnings and profits upon request.

        U.S. HOLDERS ARE STRONGLY URGED TO CONSULT A TAX ADVISOR REGARDING THE CONSEQUENCES OF MAKING AN ALL EARNINGS AND PROFITS ELECTION AND THE APPROPRIATE FILING REQUIREMENTS WITH RESPECT TO SUCH AN ELECTION.

U.S. Holders that Own AHPAC Securities with a Fair Market Value of Less Than $50,000


        A U.S. holder who, at the time of the domestication, owns (or is considered to own) AHPAC ordinary shares with a fair market value of less than $50,000 should not be required to recognize any gain or loss under Section 367(b) of the Code in connection with the domestication, and generally should not be required to include any part of the all earnings and profits amount in income.

        The opinion described above under the heading "—F Reorganization" is based on customary assumptions and representations from AHPAC and ENVG. If any of the assumptions or representations is incorrect, incomplete or inaccurate, the validity of the opinion described above may be affected and the tax consequences of the domestication could differ from those described above. Further, an opinion of counsel represents counsel's best legal judgment but is not binding on the IRS or any court, so there can be no certainty that the IRS will not challenge the conclusion reflected above or that a court would not sustain such a challenge. AHPAC does not intend to obtain a ruling from the IRS regarding the qualification of the domestication as an F Reorganization.

        U.S. holders should consult their tax advisors regarding the potential tax consequences to them if the domestication were to fail to qualify as an F Reorganization.

Redemption of AHPAC Class A Ordinary Shares

        In the event that a U.S. holder's AHPAC Class A ordinary shares (which become ENVG common stock in the domestication) are redeemed pursuant to the redemption provisions described in this registration statement, the treatment of the transaction for U.S. federal income tax purposes will depend on whether the redemption qualifies as a sale of ENVG common stock under section 302 of




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the Code. If the redemption qualifies as a sale of ENVG common stock, the U.S. holder will be treated in the same manner as described under "—U.S. Holders—Gain or Loss on Sale, Taxable Exchange or Other Taxable Disposition of ENVG Stock and Warrants" below. If the redemption does not qualify as a sale of ENVG common stock, the U.S. holder will be treated as receiving a corporate distribution with similar tax consequences to those described below under "—U.S. Holders—Taxation of Distributions." Whether a redemption qualifies for sale treatment will depend largely on the total number of ENVG common stock treated as held by the U.S. holder (including any stock constructively owned by the U.S. holder as a result of owning warrants) relative to all of the ENVG common stock outstanding both before and after the redemption (for this purpose, the stock outstanding after the redemption should include stock issued pursuant to the mergers). The redemption of ENVG common stock generally will be treated as a sale of ENVG common stock (rather than as a corporate distribution) if the redemption (i) is "substantially disproportionate" with respect to the U.S. holder, (ii) results in a "complete termination" of the U.S. holder's interest in ENVG or (iii) is "not essentially equivalent to a dividend" with respect to the U.S. holder. These tests are explained more fully below.

        In determining whether any of the foregoing tests are satisfied, a U.S. holder takes into account not only stock actually owned by the U.S. holder, but also ENVG common stock that is constructively owned by it. A U.S. holder may constructively own, in addition to stock owned directly, stock owned by certain related individuals and entities in which the U.S. holder has an interest or that have an interest in such U.S. holder, as well as any stock the U.S. holder has a right to acquire by exercise of an option, which would generally include ENVG common stock that could be acquired pursuant to the exercise of the warrants.

        In order to meet the substantially disproportionate test, the percentage of the ENVG outstanding voting shares actually and constructively owned by the U.S. holder immediately following the redemption of ENVG common stock must, among other requirements, be less than 80% of the percentage of the ENVG outstanding voting shares actually and constructively owned by the U.S. holder immediately before the redemption. Prior to the business combination, the AHPAC/ENVG common stock may not be considered voting shares for this purpose and, consequently, this substantially disproportionate test may not be applicable. There will be a complete termination of a U.S. holder's interest if either (i) all of ENVG common stock actually and constructively owned by the U.S. holder are redeemed or (ii) all of ENVG common stock actually owned by the U.S. holder are redeemed and the U.S. holder is eligible to waive, and effectively waives in accordance with specific rules, the attribution of stock owned by certain family members and the U.S. holder does not constructively own any other ENVG stock. The redemption of ENVG common stock will not be essentially equivalent to a dividend if a U.S. holder's redemption results in a "meaningful reduction" of the U.S. holder's proportionate interest in ENVG. Whether the redemption will result in a meaningful reduction in a U.S. holder's proportionate interest in ENVG will depend on the particular facts and circumstances. However, the IRS has indicated in a published ruling that even a small reduction in the proportionate interest of a small minority shareholder in a publicly held corporation who exercises no control over corporate affairs may constitute such a "meaningful reduction." A U.S. holder should consult with its tax advisors as to the tax consequences of a redemption.

        If none of the foregoing tests is satisfied, then the redemption will be treated as a corporate distribution from ENVG. Such distribution will generally be treated as a dividend for U.S. federal income tax purposes to the extent the distribution is paid out of ENVG's current or accumulated earnings and profits (as determined under U.S. federal income tax principles). Distributions in excess of any such earnings and profits will generally be applied against and reduce the U.S. holder's basis (but not below zero) in its other ENVG common stock (determined separately for each share) and, to the extent in excess of such basis, will be treated as capital gain from the sale or exchange of ENVG stock. While not free from doubt, any tax basis of the U.S. holder in the redeemed ENVG common stock




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should be added to the U.S. holder's adjusted tax basis in its remaining stock, or, if it has none, to the U.S. holder's adjusted tax basis in its warrants or possibly in other stock constructively owned by it.

        U.S. holders who actually or constructively own at least five percent (5%) (or, if ENVG common stock is not then publicly traded, at least one percent (1%)) or more of ENVG common stock may be subject to special reporting requirements with respect to a redemption of ENVG common stock, and such holders should consult with their tax advisors with respect to their reporting requirements.

Passive Foreign Investment Company Rules

        General.    A foreign corporation generally will be a passive foreign investment company ("PFIC") for U.S. federal income tax purposes with respect to a taxable year of the foreign corporation if at least 75% of its gross income in such taxable year, including its pro rata share of the gross income of any corporation in which it is considered to own at least 25% of the shares by value, is passive income. Alternatively, a foreign corporation will be a PFIC with respect to a taxable year of the foreign corporation if at least 50% of its assets in such taxable year, ordinarily determined based on fair market value and averaged quarterly over the year, including its pro rata share of the assets of any corporation in which it is considered to own at least 25% of the shares by value, are held for the production of, or produce, passive income. Passive income generally includes dividends, interest, rents and royalties (other than rents or royalties derived from the active conduct of a trade or business) and gains from the disposition of passive assets.

        AHPAC believes that AHPAC met the PFIC asset test for 2016 and consequently, unlessthe asset and income tests for 2017 and will meet such tests for the current taxable year that will end on the date of the domestication. Consequently, AHPAC qualifies under the start-up exception, discussed below, it will be a PFIC at least for 2016. Moreover, if2016, 2017 and the domestication does not qualify as an F Reorganization, AHPAC will not qualify for the start-up exception, and AHPAC will be a PFIC in 2016 and 2017.

        Start-up Exception.    Pursuant to a start-up exception, a corporation will not be a PFIC for the firstcurrent taxable year that will end on the corporation has gross income (the "start-up year"), if (1) no predecessordate of the corporation was a PFIC; (2) the corporation satisfies the IRS that it will not be a PFIC for either of the first two taxable years following the start-up year; and (3) the corporation is not in fact a PFIC for either of those years.

        The net proceeds from AHPAC's IPO were held in a non-interest bearing trust account until January 2017 and, consequently, AHPAC did not have any gross income in 2016. AHPAC believes, although subject to uncertainty, the start-up year under the startup exception will be 2017, and AHPAC should not be treated as a PFIC for 2016 or 2017 assuming AHPAC qualifies for the start-up exception in 2017, which requires that ENVG is not considered a PFIC in either 2018 or 2019. Based on the fact that ENVG will be a U.S. corporation and the expected operations, and composition of assets and income of ENVG and its subsidiaries after the business combination and ENVG's market capitalization (which will fluctuate from time to time), assuming the domestication is completed before the close of 2017, AHPAC does not expect that ENVG will be considered a PFIC in 2018 or 2019, or for the foreseeable future. AHPAC's actual PFIC status for any taxable year will not be determinable until after the end of such year. Accordingly, there can be no assurance with respect to AHPAC's status as a PFIC for 2016 or 2017, and, there can be no assurances with respect to ENVG's status as a PFIC for the current or any future taxable year.domestication.

        Consequences if a PFIC.    If AHPAC is determined to be a PFIC for any taxable year (or portion thereof) that is included in the holding period of a U.S. holder of AHPAC's ordinary shares or warrants (e.g., because AHPAC did not qualify under the start-up exception, as described above) and, in the case of ordinary shares, the U.S. holder did not make either a timely qualified electing fund ("QEF") election for AHPAC's first taxable year as a PFIC in which the U.S. holder held (or was deemed to hold) such ordinary shares, or did not make a timely mark-to-market election as discussed below, then as described below, such holder generally will be subject to special rules with respect to:




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(i) any gain recognized by the U.S. holder on the sale or other disposition of its AHPAC ordinary shares or warrants; and (ii) any "excess distribution" made to the U.S. holder (generally, any distributions to such U.S. holder during a taxable year of the U.S. holder that are greater than 125% of the average annual distributions received by such U.S. holder in respect of the ordinary shares during the three preceding taxable years of such U.S. holder or, if shorter, such U.S. holder's holding period for the AHPAC ordinary shares).

        Under these rules:

•

the U.S. holder's gain or excess distribution will be allocated ratably over the U.S. holder's holding period for the AHPAC ordinary shares or warrants;



•

the amount allocated to the U.S. holder's taxable year in which the U.S. holder recognized gain or received the excess distribution, or to the period in the U.S. holder's holding period before the first day of the first taxable year in which AHPAC is a PFIC, will be taxed as ordinary income;



•

the amount allocated to other taxable years (or portions thereof) of the U.S. holder and included in its holding period will be taxed at the highest tax rate in effect for that year and applicable to the U.S. holder; and




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•

the interest charge generally applicable to underpayments of tax will be imposed in respect of the tax attributable to each such other taxable year of the U.S. holder.

        QEF Election.    In general, if AHPAC is determined to be a PFIC, a U.S. holder may avoid the PFIC tax consequences described above in respect to its AHPAC ordinary shares by making a timely QEF election to include in income its pro rata share of AHPAC's net capital gains (as long-term capital gain) and other earnings and profits (as ordinary income), on a current basis, in each case whether or not distributed, in each taxable year of the U.S. holder in which or with which AHPAC's taxable year ends. However, in order to comply with the requirements of a QEF election, a U.S. holder must receive a PFIC annual information statement from AHPAC. AHPAC did not provide a PFIC annual information statement for 2016 and does not expect2016. AHPAC will endeavor to provide such statement for 2017 or any subsequent year. Without such statementsto a U.S. holder will not be ablesuch information as the IRS may require, including a PFIC annual information statement, in order to enable the U.S. holder to make and maintain a QEF election, with respect to AHPAC (for 2016 or 2017).but there can be no assurance that we will timely provide such required information.

        A U.S. holder may not make a QEF election with respect to its AHPAC warrants. As a result, if a U.S. holder of AHPAC warrants sells or otherwise disposes of such warrants, any gain recognized will be subject to the special tax and interest charge rules treating the gain as an excess distribution, as described above, if AHPAC was a PFIC at any time during the period the U.S. holder held the AHPAC warrants.

        Mark-to-Market Election.    Alternatively, if a U.S. holder, at the close of its taxable year, owns shares in a PFIC that are treated as marketable stock, the U.S. holder may make a mark-to-market election with respect to such shares for such taxable year. If the U.S. holder makes a valid mark-to-market election for the first taxable year of the U.S. holder in which the U.S. holder holds (or is deemed to hold) AHPAC ordinary shares and for which AHPAC is determined to be a PFIC, such holder generally will not be subject to the PFIC rules described above in respect of its ordinary shares. Instead, in general, the U.S. holder will include as ordinary income each year the excess, if any, of the fair market value of its ordinary shares at the end of its taxable year over the adjusted basis in its ordinary shares. The U.S. holder also will be allowed to take an ordinary loss in respect of the excess, if any, of the adjusted basis of its ordinary shares over the fair market value of its ordinary shares at the end of its taxable year (but only to the extent of the net amount of previously included income as a result of the mark-to-market election). The U.S. holder's basis in its AHPAC ordinary shares will be adjusted to reflect any such income or loss amounts, and any further gain recognized on a sale or other




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taxable disposition of the AHPAC ordinary shares will be treated as ordinary income. Currently, a mark-to-market election may not be made with respect to warrants.

        The mark-to-market election is available only for stock that is regularly traded on a national securities exchange that is registered with the Securities and Exchange Commission, including NASDAQ Capital Market (on which AHPAC ordinary shares have been listed), or on a foreign exchange or market that the IRS determines has rules sufficient to ensure that the market price represents a legitimate and sound fair market value. U.S. holders should consult their tax advisors regarding the availability and tax consequences of a mark-to-market election in respect to our ordinary shares under their particular circumstances.

        Effect of PFIC Rules on the domestication.    Even if the domestication qualifies as an F Reorganization, Section 1291(f) of the Code requires that, to the extent provided in regulations, a U.S. person that disposes of stock of a PFIC (including rights to acquire stock of a PFIC) must recognize gain notwithstanding any other provision of the Code. No final Treasury regulations are currently in effect under Section 1291(f) of the Code. Proposed Treasury regulations under Section 1291(f), or the "Proposed Regulations", were promulgated in 1992, with a retroactive effective date once they become finalized. If finalized in their current form, those regulations may require taxable gain recognition by a U.S. holder subject to the PFIC rules with respect to its exchange of




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AHPAC securities for ENVG securities in the domestication if AHPAC were classified as a PFIC at any time during such U.S. holder's holding period in AHPAC securities. Any such gain would be treated as an "excess distribution" made in the year of the domestication and subject to the special tax and interest charge rules discussed above. In addition, the regulations would provide coordinating rules with Section 367(b) of the Code, whereby, if the gain recognition rule of the Proposed Regulations applied to a disposition of PFIC stock that results from a transfer with respect to which Section 367(b) requires the shareholder to recognize gain or include an amount in income as a distribution under Section 301 of the Code, the gain realized on the transfer is taxable as an excess distribution under Section 1291 of the Code, and the excess, if any, of the amount to be included in income under Section 367(b) over the gain realized under Section 1291 is taxable as provided under Section 367(b). See the discussion above under the section entitled"—Effect of Section 367". The Proposed Regulations should not apply to an Electing Shareholder with respect to its AHPAC ordinary shares for which a timely QEF election is made. An Electing Shareholder may, however, be subject to the rules discussed above under the section entitled"—Effect of Section 367". In addition, as discussed above, since a QEF election cannot be made with respect to AHPAC warrants, if the Proposed Regulations applied, they would likely cause gain recognition under the PFIC rules on the exchange of AHPAC warrants for ENVG warrants pursuant to the domestication.

        It is difficult to predict whether, in what form and with what effective date, final Treasury Regulations under Section 1291(f) of the Code will be adopted. The rules dealing with PFIC and with the QEF election and purging election (or a mark-to-market election) are very complex and are affected by various factors in addition to those described above. Accordingly, a U.S. holder of AHPAC securities should consult its tax advisors concerning the application of the PFIC rules to such securities under such holder's particular circumstances.

        Reporting.    A U.S. holder that owns (or is deemed to own) shares in a PFIC during any taxable year of the U.S. holder, may have to file an IRS Form 8621 (whether or not a QEF or market-to-market election is made) and such other information as may be required by the U.S. Treasury Department. Failure to do so, if required, will extend the statute of limitations until such required information is furnished to the IRS and may result in significant penalties.

        The rules dealing with PFICs and with the QEF and mark-to-market elections are very complex and are affected by various factors in addition to those described above. Accordingly, U.S. holders of




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the AHPAC or ENVG securities should consult their tax advisors concerning the application of the PFIC rules to such securities under their particular circumstances.

Taxation of Distributions on ENVG Common Stock

        A U.S. holder generally will be required to include in gross income the amount of any cash dividend paid on ENVG common stock. A cash distribution on such stock generally will be treated as a dividend for U.S. federal income tax purposes to the extent the distribution is paid out of ENVG's current or accumulated earnings and profits (as determined under U.S. federal income tax principles). Such dividends paid by ENVG will be taxable to a corporate U.S. holder at regular rates but will be eligible (subject to applicable requirements and limitations) for the dividends-received deduction.

        Distributions in excess of such earnings and profits generally will be applied against and reduce the U.S. holder's basis in its stock (but not below zero), determined separately for each share, and any excess will be treated as gain from the sale or exchange of such stock as described below under "—U.S. Holders—Gain or Loss on Sale, Taxable Exchange or Other Taxable Disposition of ENVG Stock and Warrants."

        With respect to non-corporate U.S. holders, dividends generally will be taxed at the lower applicable long-term capital gains rate (see "—U.S. Holders—Gain or Loss on Sale, Taxable Exchange or




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Other Taxable Dispositionof ENVG Stock and Warrants" below), subject to applicable requirements and limitations.

Gain or Loss on Sale, Taxable Exchange or Other Taxable Disposition of ENVG Stock and Warrants

        Upon a sale or other taxable disposition of ENVG common stock or ENVG warrants, a U.S. holder of such securities generally will recognize capital gain or loss in an amount equal to the difference between the amount realized and the U.S. holder's adjusted tax basis in ENVG common stock or ENVG warrants.

        Any such capital gain or loss generally will be long-term capital gain or loss if the U.S. holder's holding period for ENVG common stock or ENVG warrants so disposed of exceeds one year. It is unclear, however, whether the redemption rights with respect to the AHPAC Class A ordinary shares described in this registration statement may suspend the running of the applicable holding period for this purpose. Long-term capital gains recognized by non-corporate U.S. holders will be eligible to be taxed at reduced rates. The deductibility of capital losses is subject to limitations.

        Generally, the amount of gain or loss recognized by a U.S. holder is an amount equal to the difference between (i) the sum of the amount of cash and the fair market value of any property received in such disposition and (ii) the U.S. holder's adjusted tax basis in its shares or warrants so disposed of.

Exercise or Lapse of a Warrant

        Except as discussed below with respect to the cashless exercise of an ENVG warrant, a U.S. holder generally will not recognize gain or loss upon the acquisition of ENVG common stock on the exercise of a warrant for cash. A U.S. holder's tax basis in a share of ENVG common stock received upon exercise of the warrant generally will be an amount equal to the sum of the U.S. holder's tax basis in the AHPAC warrant (or portion thereof) exchanged therefor and the exercise price. The U.S. holder's holding period for a share of ENVG common stock received upon exercise of an ENVG warrant will begin on the date following the date of exercise of the ENVG warrant and will not include the period during which the U.S. holder held the ENVG warrant. If a warrant is allowed to lapse unexercised, a U.S. holder generally will recognize a capital loss equal to such holder's tax basis in the public warrant.




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        The tax consequences of a cashless exercise of a warrant are not clear under current tax law. A cashless exercise may be tax-free, either because the exercise is not a gain realization event or because the exercise is treated as a recapitalization for U.S. federal income tax purposes. In either tax-free situation, a U.S. holder's basis in the ENVG common stock received would equal the holder's basis in the ENVG warrants exchanged therefor. If the cashless exercise were treated as not being a gain realization event, a U.S. holder's holding period in ENVG common stock would be treated as commencing on the date following the date of exercise of ENVG warrants. If the cashless exercise were treated as a recapitalization, the holding period of ENVG common stock would include the holding period of ENVG warrants.

        It is also possible that a cashless exercise could be treated in part as a taxable exchange in which gain or loss would be recognized. In such event, a U.S. holder would recognize gain or loss with respect to the portion of the exercised ENVG warrants treated as surrendered (the "surrendered warrants") to pay the exercise price of the portion of the ENVG warrants not surrendered. The U.S. holder would recognize capital gain or loss with respect to the surrendered warrants in an amount generally equal to the difference between (i) the fair market value of ENVG common stock that would have been received with respect to the surrendered warrants in a regular exercise of such surrendered warrants and (ii) the sum of the U.S. holder's tax basis in the surrendered warrants and the aggregate cash exercise price of such warrants (if they had been exercised in a regular exercise). In this case, a U.S. holder's tax basis in ENVG common stock received would equal the U.S. holder's tax basis in ENVG




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warrants deemed exercised plus the exercise price deemed paid. A U.S. holder's holding period for ENVG common stock would commence on the date following the date of exercise of ENVG warrants.

        Due to the absence of authority on the U.S. federal income tax treatment of a cashless exercise, there can be no assurance which, if any, of the alternative tax consequences and holding periods described above would be adopted by the IRS or a court of law. Accordingly, U.S. holders should consult their tax advisors regarding the tax consequences of a cashless exercise.

Possible Constructive Distributions

        The terms of each ENVG warrant provide for an adjustment to the number of ENVG common stock for which the ENVG warrant may be exercised or to the exercise price of ENVG warrant in certain events, as discussed in the section of this registration statement captioned "Description of Securities—Warrants." An adjustment which has the effect of preventing dilution generally is not taxable. The U.S. holders of the warrants would, however, be treated as receiving a constructive distribution from ENVG if, for example, the adjustment increases the warrant holders' proportionate interest in ENVG's assets or earnings and profits (e.g., through an increase in the number of ENVG common stock that would be obtained upon exercise) as a result of a distribution of cash to the holders of the ENVG common stock which is taxable to the U.S. holders of such stock as described under "Taxation of Distributions" above. Such constructive distribution would be subject to tax as described under that section in the same manner as if the U.S. holders of the warrants received a cash distribution from ENVG equal to the fair market value of such increased interest.

Non-U.S. Holders

        This section applies to you if you are a "Non-U.S. holder." A Non-U.S. holder is a beneficial owner of AHPAC ordinary shares or warrants and ENVG common stock or warrants who or that is, for U.S. federal income tax purposes:

•

a non-resident alien individual;



•

a foreign corporation; or



•

a foreign estate or trust.




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Dividends

        Any cash distribution (or a constructive distribution) ENVG makes to a Non-U.S. holder of ENVG securities, to the extent paid out of ENVG's current or accumulated earnings and profits (as determined under U.S. federal income tax principles), generally will constitute a dividend for U.S. federal income tax purposes. Any such dividends paid or deemed paid to a Non-U.S. holder in respect of ENVG common stock (or warrants) that is not effectively connected with the Non-U.S. holder's conduct of a trade or business within the United States, as described below, generally will be subject to U.S. federal withholding tax at a rate of 30% of the gross amount of the dividend, unless such Non-U.S. holder is eligible for a reduced rate of withholding tax under an applicable income tax treaty and provides proper certification of its eligibility for such reduced rate (usually on an IRS Form W-8BEN or W-8BEN-E, as applicable). In satisfying the foregoing withholding obligation with respect to a distribution, the applicable withholding agent may withhold up to 30% of either (i) the gross amount of the entire distribution, even if the amount of the distribution is greater than the amount constituting a dividend, as described above, or (ii) the amount of the distribution ENVG projects will be a dividend, based upon a reasonable estimate of both its current and accumulated earnings and profits for the taxable year in which the distribution is made. If U.S. federal income tax is withheld on the amount of a distribution in excess of the amount constituting a dividend, the Non-U.S. holder may obtain a refund of all or a portion of the excess amount withheld by timely filing a claim




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for refund with the IRS. Any such distribution not constituting a dividend generally will be treated, for U.S. federal income tax purposes, first as reducing the Non-U.S. holder's adjusted tax basis in such securities (but not below zero), determined separately for each share, and, to the extent such distribution exceeds the Non-U.S. holder's adjusted tax basis, as gain from the sale or other taxable disposition of such securities, which will be treated as described under "—Gain on Sale, Taxable Exchange or Other Taxable Disposition of ENVG Stock and Warrants" below.

        Dividends (including constructive dividends) ENVG pays to a Non-U.S. holder that are effectively connected with such Non-U.S. holder's conduct of a trade or business within the United States generally will not be subject to the foregoing U.S. federal withholding tax, provided such Non-U.S. holder complies with certain certification and disclosure requirements (usually by providing an IRS Form W-8ECI). Instead, unless an applicable income tax treaty provides otherwise, such dividends generally will be subject to U.S. federal income tax, net of certain deductions, at the same regular U.S. federal income tax rates applicable to a comparable U.S. holder. In addition, if the Non-U.S. holder is a corporation, such holder's effectively connected earnings and profits (subject to adjustments) may be subject to a U.S. federal "branch profits tax" at a rate of 30% (or such lower rate as may be specified by an applicable income tax treaty).

Gain on Sale, Taxable Exchange or Other Taxable Disposition of ENVG Stock and Warrants


        A Non-U.S. holder generally will not be subject to U.S. federal income tax in respect of gain recognized on a sale, exchange or other disposition of ENVG common stock or warrants unless:

•

the gain is effectively connected with the conduct of a trade or business by the Non-U.S. holder within the United States ;



•

the Non-U.S. holder is an individual who is present in the United States for 183 days or more in the taxable year of disposition and certain other conditions are met; or



•

ENVG is or has been a "United States real property holding corporation" ("USRPHC") for U.S. federal income tax purposes at any time during the shorter of the five year period ending on the date of disposition or the Non-U.S. holder's holding period for such securities disposed of, and, generally, in the case where ENVG securities are regularly traded on an established securities market, the Non-U.S. holder has owned, actually or constructively, more than five percent (5%) of such securities, as applicable, at any time during the shorter of the five year




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period ending on the date of disposition or the Non-U.S. holder's holding period for the security disposed of. There can be no assurance that ENVG securities will be treated as regularly traded on an established securities market for this purpose.

        Unless an applicable tax treaty provides otherwise, any gain described in the first or third bullet points above generally will be subject to U.S. federal income tax, net of certain deductions, at the same regular U.S. federal income tax rates applicable to a comparable U.S. holder and, in addition, a Non-U.S. holder described in the first bullet point that is a foreign corporation will be subject to U.S. federal "branch profits tax" at a 30% rate (or a lower applicable tax treaty rate) on such non-U.S. holder's effectively connected earnings and profits (subject to adjustments). Any gain of a Non-U.S. holder described in the second bullet point above (which may be offset by U.S. source capital losses during the taxable year of the disposition) generally will be subject to a flat 30% U.S. federal income tax rate (or a lower applicable tax treaty rate).

Information Reporting and Backup Withholding


        Dividend payments with respect to ENVG common stock and proceeds from the sale, exchange or redemption of ENVG common stock or ENVG warrants may be subject to information reporting to the IRS and possible U.S. backup withholding. Backup withholding will not apply, however, to a U.S.




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holder who furnishes a correct taxpayer identification number and makes other required certifications, or who is otherwise exempt from backup withholding and establishes such exempt status.

        A Non-U.S. holder generally will eliminate the requirement for information reporting (other than with respect to dividends) and backup withholding by providing certification of its non-U.S. status on a duly-executed applicable IRS Form W-8 or by otherwise establishing an exemption.

        Backup withholding is not an additional tax. Amounts withheld as backup withholding may be credited against a holder's U.S. federal income tax liability, and a holder generally may obtain a refund of any excess amounts withheld under the backup withholding rules by timely filing the appropriate claim for refund with the IRS and furnishing any required information.

Foreign Account Tax Compliance Act


        Sections 1471 through 1474 of the Code and the Treasury Regulations and administrative guidance promulgated thereunder (commonly referred as the "Foreign Account Tax Compliance Act" or "FATCA") generally impose withholding at a rate of 30% in certain circumstances on dividends in respect of, and, after December 31, 2018, gross proceeds from the sale or other disposition of, securities (including AHPAC ordinary shares or warrants and ENVG common stock or warrants) which are held by or through certain foreign financial institutions (including investment funds), as a beneficial owner or as an intermediary, unless any such institution (i) enters into, and complies with, an agreement with the IRS to report, on an annual basis, information with respect to interests in, and accounts maintained by, the institution that are owned by certain U.S. persons and by certain non-U.S. entities that are wholly or partially owned by U.S. persons and to withhold on certain payments, or (ii) if required under an intergovernmental agreement between the United States and an applicable foreign country, reports such information to its local tax authority, which will exchange such information with the U.S. authorities. An intergovernmental agreement between the United States and an applicable foreign country may modify these requirements. Accordingly, the entity through which AHPAC ordinary shares or warrants or ENVG common stock or warrants are held will affect the determination of whether such withholding is required. Similarly, dividends in respect of, and, after December 31, 2018, gross proceeds from the sale or other disposition of, AHPAC ordinary shares or warrants or ENVG common stock or warrants held by an investor that is a non-financial non-U.S. entity (as a beneficial owner or as an intermediary) that does not qualify under certain exceptions will generally be subject to withholding at a rate of 30%, unless such entity either (i) certifies to the




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applicable withholding agent that such entity does not have any"substantial United States owners" or (ii) provides certain information regarding the entity's"substantial United States owners", which will in turn be provided to the U.S. Department of Treasury. All holders should consult their tax advisors regarding the possible implications of FATCA on their investment in AHPAC ordinary shares or warrants or ENVG common stock or warrants.

Material Cayman Islands Tax Considerations


        Prospective investors should consult their professional advisers on the possible tax consequences of buying, holding or selling any Shares under the laws of their country of citizenship, residence or domicile.

Cayman Islands Taxation


        The following is a discussion on certain Cayman Islands income tax consequences of an investment in shares of a Cayman Islands company which constitutes an opinion from AHPAC's Cayman Islands legal counsel Maples and Calder. The discussion is a general summary of present law, which is subject to prospective and retroactive change. It is not intended as tax advice, does not consider any investor's




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particular circumstances, and does not consider tax consequences other than those arising under Cayman Islands law.

Under Existing Cayman Islands Laws


        Payments of dividends and capital in respect of shares will not be subject to taxation in the Cayman Islands and no withholding will be required on the payment of interest and principal or a dividend or capital to any holder of shares, as the case may be, nor will gains derived from the disposal of the Shares be subject to Cayman Islands income or corporation tax. The Cayman Islands currently have no income, corporation or capital gains tax and no estate duty, inheritance tax or gift tax.

        No stamp duty is payable in respect to the issue of shares or on an instrument of transfer in respect of a share.

        AHPAC has been incorporated under the laws of the Cayman Islands as an exempted company with limited liability and, as such, has obtained an undertaking from the Financial Secretary of the Cayman Islands in the following form:

The Tax Concessions Law

(2011 Revision)

Undertaking as to Tax Concessions

        In accordance with Section 6 of the Tax Concessions Law (2011 Revision) the Financial Secretary undertakes with Avista Healthcare Public Acquisition Corp. (the "Company").

(a)

that no Law which is hereafter enacted in the Islands imposing any tax to be levied on profits, income, gains or appreciations shall apply to the Company or its operations; and



(b)

in addition, that no tax to be levied on profits, income, gains or appreciations or which is in the nature of estate duty or inheritance tax shall be payable:



(i)

on or in respect of the shares, debentures or other obligations of the Company; or



(ii)

by way of the withholding in whole or part, of any relevant payment as defined in Section 6(3) of the Tax Concessions Law (2011 Revision).

        These concessions shall be for a period of TWENTY years from January 12, 2016.




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THE TRANSACTION AGREEMENT AND RELATED AGREEMENTS


The Transaction Agreement


        This subsection of the proxy statement/prospectus describes the material provisions of the Transaction Agreement, but does not purport to describe all of the terms of the Transaction Agreement. The following summary is qualified in its entirety by reference to the complete text of the Transaction Agreement, including each amendment thereto through the dute hereof, which is attached asAnnex A hereto. You are urged to read the Transaction Agreement in its entirety because it is the primary legal document that governs the business combination. The legal rights and obligations of the parties to the Transaction Agreement are governed by the specific language of the Transaction Agreement, and not this summary.

        The Transaction Agreement contains representations, warranties and covenants that the respective parties made to each other as of the date of the Transaction Agreement or other specific dates. The assertions embodied in those representations, warranties and covenants were made for purposes of the contract among the respective parties and are subject to important qualifications and limitations agreed to by the parties in connection with negotiating the Transaction Agreement. The representations, warranties and covenants in the Transaction Agreement are also modified in important part by the underlying disclosure schedules, which are referred to as the "Schedules," which are not filed publicly and which are subject to a contractual standard of materiality different from that generally applicable to shareholders and were used for the purpose of allocating risk among the parties rather than establishing matters as facts. AHPAC does not believe that the Schedules contain information that is material to an investment decision. Moreover, certain representations and warranties in the Transaction Agreement may or may not have been accurate as of any specific date and do not purport to be accurate as of the date of this proxy statement/prospectus.

General Description of the Transaction Agreement


        On August 21, 2017, AHPAC, Merger Sub and NewCo entered into the Transaction Agreement (as amended on November 22, 2017, and on December 22, 2017)2017 and January 21, 2018) with Envigo and the shareholder representative, pursuant to which, among other things and subject to the terms and conditions contained in the Transaction Agreement, (i) AHPAC will transfer by way of continuation out of the Cayman Islands into the State of Delaware or domesticate as a Delaware corporation in accordance with Section 388 of the Delaware General Corporation Law, as amended and the Cayman Islands Companies Law (2016 Revision); (ii) Merger Sub will merge with and into Envigo, the separate corporate existence of Merger Sub will cease and Envigo will be the surviving corporation and a direct wholly-owned subsidiary of AHPAC and (iii) Envigo will merge with and into NewCo, the separate corporate existence of Envigo will cease and NewCo will be the surviving company and a direct wholly-owned subsidiary of AHPAC.

        Subject to the terms of the Transaction Agreement and customary adjustments set forth therein, the aggregate purchase price payable to the Selling Equityholders in connection with the business combination and related transactions is expected to be approximately (a) $428.88$322.44 million (the "purchase price"), subject to adjustment as described in the following sentence, in cash and shares of ENVG Class A common stock, (b) 4.10 million warrants to purchase one half of one share of ENVG Class A common stock and (c) amounts payable to the Selling Equityholders under the Tax Receivable Agreement. The purchase price will be reduced by, among other things, the aggregate amount of transaction expenses incurred by Envigo in connection with the negotiation and consummation of the business combination plus the cost of the 4.10 million warrants being purchased from the sponsor for distribution to the Selling Equityholders.combination. It is anticipated that this adjustment will result in a deduction to the purchase price of approximately $38.5$42.3 million (including non-cash expenses in the amount of $8.3$7.8 million). The cash component of the purchase price is subject to an aggregate limit on cash consideration of $100 million (which amount may be increased or reduced as described in the Transaction Agreement). The cash and stock consideration to be paid to thecertain Selling Equityholders will




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be funded with approximately 39.8728.80 million newly issued shares of ENVG Class A common stock, which amount is




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reduced to the extent Selling Equityholders elect to receive $10.00 in cash in lieu of each share of ENVG Class A common stock such Selling Equityholder would otherwise be entitled to receive, subject to an aggregate limit on cash consideration of $100 million (which amount may be increased or reduced as described in the Transaction Agreement), and the aforementioned cash.

        The first merger will become effective at the time specified in the certificate of merger with respect to the first merger (the "first merger effective time"). At the first merger effective time:

          (i)  each share of Envigo common stock that is owned by AHPAC, Merger Sub, NewCo or Envigo (as treasury stock or otherwise), or any of their respective direct or indirect wholly owned subsidiaries ("excluded shares"), will automatically be cancelled and retired and will cease to exist, and no consideration will be delivered in exchange therefor,

         (ii)  each share of Envigo common stock (other than excluded shares and shares of Envigo common stock that are issued and outstanding immediately prior to the first merger effective time and which are held by holders of such shares of Envigo common stock who properly exercise appraisal rights with respect thereto in accordance with Section 262 of the DGCL) issued and outstanding immediately prior to the first merger effective time with respect to which an election to receive cash has been effectively made and not revoked or deemed revoked pursuant to the Transaction Agreement, will be cancelled and exchanged for the right to receive the Per Share Total Cash Consideration,

        (iii)  each share of Envigo common stock (other than excluded shares and other than shares as described in (ii)) issued and outstanding immediately prior to the first merger effective time will be cancelled and exchanged for the right to receive the Per Share Total Stock Consideration,

        (iv)  each Envigo Series A Warrant outstanding and unexercised immediately prior to the first merger effective time with respect to which an election to receive cash has been effectively made and not revoked or deemed revoked will be amended so that such Envigo Series A Warrant will entitle the holder thereof, when exercised, to receive for each share of Envigo common stock subject to such Envigo Series A Warrant, the Per Share Total Cash Consideration (net of the exercise price),

         (v)  each Envigo Series A Warrant (other than warrants as described in (iv)) outstanding and unexercised immediately prior to the first merger effective time will be amended so that such Envigo Series A Warrant will entitle the holder thereof, when exercised, to receive for each share of Envigo common stock subject to such Envigo Series A Warrant(as defined below), the Per Share Total Stock Consideration (net of the exercise price),

        (vi)  each Envigo Series B Warrant outstanding and unexercised immediately prior to the first merger effective time will be amended so that such Envigo Series B Warrant will entitle the holder thereof (if such Envigo Series B Warrant becomes exercisable), when exercised, to receive for each share of Envigo common stock subject to such Envigo Series B Warrant, the Per Share Total Cash Consideration or the Per Share Total Stock Consideration (in each case, net of the exercise price),

       (vii)  each Envigo option and Envigo SAR outstanding and unexercised immediately prior to the first merger effective time with respect to which the applicable exercise price or base price per share of Envigo common stock underlying such Envigo option or Envigo SAR equals or exceeds the Per Share Merger Value, will be canceled and no longer be exercisable by the holder thereof,

      (viii)  each Envigo option with respect to which an election to receive cash has been effectively made and not revoked or deemed revoked pursuant to the Transaction Agreement, and each Envigo SAR (in each case other than as described in (vii)) outstanding and unexercised immediately prior to the first merger effective time, will be cancelled and exchanged for the right




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to receive for each share of Envigo common stock subject to such Envigo option or Envigo SAR, the Per SAR/Option Total Cash Consideration,

        (ix)  each Envigo option (other than as described in (vii) and (viii)) outstanding and unexercised immediately prior to the first merger effective time, will be cancelled and exchanged for the right to receive for each share of Envigo common stock subject to such Envigo option the Per Option Total Stock Consideration, and

         (x)  each issued and outstanding share of common stock of AHPAC Merger Sub will be converted into one (1) validly issued fully paid and non-assessable share of common stock of Envigo, as the surviving corporation of the first merger, and all such shares together shall constitute the only outstanding shares of capital stock of Envigo.

        At the effective time of the second merger, which will be immediately following the first merger effective time, (i) the separate existence of Envigo will cease and NewCo will continue its existence under the DLLCA as the surviving company and (ii) by virtue of the second merger and without any action on the part of any party or the holder of any of their securities, each share of common stock of Envigo issued and outstanding immediately prior to the second merger effective time will automatically be cancelled and retired and will cease to exist, and no consideration will be delivered in exchange therefor.

Consideration to Selling Equityholders in the Business Combination


Tax Receivable Consideration


        Subject to the terms and conditions of the Transaction Agreement, each Selling Equityholder will receive certain payments under the Tax Receivable Agreement (the "Tax Receivable Consideration"), as described in the section titled "The Transaction Agreement—Related Agreements—Tax Receivable Agreement".

        The Tax Receivable Consideration received by each Selling Equityholder will be such holder's pro rata share (based on the ratio of the number of shares of Envigo Class A common stock held by such holder to the fully diluted total shares of Envigo) of certain payments under the Tax Receivable Agreement.

Holders of Envigo Class A common stock


        Subject to the terms and conditions of the Transaction Agreement, each share of Envigo Class A common stock will be converted into the right to receive, in addition to the Tax Receivable Consideration, (i) cash consideration (the "Cash Consideration"), or stock consideration (the "Stock Consideration") or a combination thereof (at such holder's election, subject to the limitations described below), and (ii) a number of warrants to purchase one-half of one share of ENVG Class A common stock as described below (the "New Warrant Consideration").

        The Cash Consideration will be an amount in cash equal to:

•

the quotient obtained by dividing (x) $390,133,441(subject$283,686,737 (subject to certain adjustments described in the Transaction Agreement) by (y) the fully diluted total shares of Envigo (the "Per Share Merger Value"); plus



•

the product of (x) $10.00 multiplied by (y) the quotient obtained by dividing (A) 3,875,000 by (B) the fully diluted total shares of Envigo (the "Cash Election Value").

        The Stock Consideration will be calculated as follows:

•

a number of newly issued shares of ENVG Class A common stock equal to the quotient obtained by dividing (x) the Per Share Merger Value by (y) $10.00; plus




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•

a number of newly issued shares of ENVG common stock equal to the quotient obtained by dividing (x) 3,875,000 by (y) the fully diluted total shares of Envigo.

        The New Warrant Consideration will be a number of warrants to purchase one-half of one share of ENVG Class A common stock, where two warrants may be exercised for one whole share of ENVG Class A common stock at an exercise price of $11.50 per share, equal to the quotient obtained by dividing (x) 4,100,000 by (y) the fully diluted total shares of Envigo.

        The Cash Consideration, the New Warrant Consideration and the Tax Receivable Consideration are referred to, collectively, the "Per Share Total Cash Consideration"; and the Stock Consideration, the New Warrant Consideration and the Tax Receivable Consideration are referred to, collectively, the "Per Share Total Stock Consideration".

Holders of Envigo Warrants


        Subject to the terms and conditions of the Transaction Agreement, each warrant to purchase one share of Envigo Class A common stock ("Envigo Series A Warrant") and each warrant to purchase one share of Envigo Class B common stock ("Envigo Series B Warrant") (only if they become exercisable in the case of Series B Warrants) will be converted into the right to receive, in addition to the Tax Receivable Consideration, (i) the New Warrant Consideration, plus (ii) a warrant to purchase, at such holder's election, either (a) the Per Share Total Cash Consideration (net of the exercise price) or (b) the Per Share Total Stock Consideration (net of the exercise price).

Holders of Envigo Options


        Subject to the terms and conditions of the Transaction Agreement, each option to purchase shares of Envigo Class A common stock for which the Per Share Merger Value is greater than the exercise price ("Envigo option") will be exchanged for the right to receive in addition to the Tax Receivable Consideration payable during the first five years after the Closing Date, (i) the New Warrant Consideration plus (ii) (a) in the case of Envigo options for which cash consideration is elected, an amount in cash equal to the Cash Consideration less the exercise price, or (b) in the case of Envigo options for which stock consideration is elected or deemed elected, (1) a number of newly issued shares of ENVG common stock equal to the quotient obtained by dividing the Cash Election Value (less the exercise price) by $10.00, and (2) a number of shares of ENVG Class A common stock equal to the quotient obtained by dividing 3,875,000 by the fully diluted shares of Envigo.

Holders of Envigo SARs


        Subject to the terms and conditions of the Transaction Agreement, each stock appreciation right granted in respect of Envigo Class A common stock for which the Per Share Merger Value is greater than the base price ("Envigo SAR") will be converted into the right to receive, in addition to the Tax Receivable Consideration payable during the first five years after the Closing Date, (i) the Cash Consideration, less the base price and (ii) an additional amount in cash commensurate in value to the New Warrant Consideration.

Limitations on ability of Selling Equityholders to make cash elections


        Each Selling Equityholder (other than a holder of Envigo SARs) who does not make any election will be deemed to have made an election to receive the Stock Consideration. If the aggregate amount of cash otherwise payable in respect of the cash elections exceeds the Cash Component (as described below), the elections of Selling Equityholders (other than holders of Envigo SARs) to receive the Cash Consideration will be subject to adjustment as described below.




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Cash Component


        Notwithstanding the ability of the Selling Equityholders (other than the holders of Envigo SARs) to make a cash election, the Transaction Agreement provides a limit on the amount of aggregate cash consideration to be paid to such holders of $100 million, which amount may be increased or reduced as described in the Transaction Agreement (the "Cash Component"). If the aggregate amount of cash payable in respect the cash elections exceeds the Cash Component, the Exchange Agent will reduce all cash elections pro rata by the amount of such excess, no election shall be deemed made with respect to such shares and, as set forth in the Transaction Agreement, such shares will be converted into and become the right to receive the Stock Consideration.

Material Adverse Effect


        Under the Transaction Agreement, certain representations and warranties of Envigo are qualified in whole or in part by a material adverse effect standard for purposes of determining whether a breach of such representations and warranties has occurred. Pursuant to the Transaction Agreement, an "Envigo Material Adverse Effect" means any occurrence, condition, change, development, event or effect that, individually or in the aggregate, has had or would reasonably be expected to have a material adverse effect on the financial condition, business, assets, liabilities or results of operations of Envigo and its subsidiaries, taken as a whole, or that prevents or materially delays or impairs, or would reasonably be expected to prevent or materially delay or impair, the ability of Envigo to consummate the transactions contemplated by the Transaction Agreement; provided, however, that in no event will any of the following constitute an Envigo Material Adverse Effect: (A) any occurrence, condition, change, development, event or effect resulting from or relating to changes in general economic, regulatory or political conditions or conditions in the United States, the markets where Envigo and its subsidiaries operate or anywhere else in the world; (B) any occurrence, condition, change, development, event or effect that affects the industries in which Envigo and its subsidiaries operate generally (including changes in commodity prices, general market prices and regulatory changes); (C) the outbreak or escalation of hostilities, the declaration of a national emergency or war, the issuance of health advisories or the occurrence of any other similar calamity or crisis, including natural disasters and acts of terrorism; (D) any change or proposed change in any applicable statute or Law, or the interpretation or enforcement policy thereof; (E) any change or proposed change in the requirements or principles imposed upon Envigo, its subsidiaries or their respective businesses after the date of the Transaction Agreement by GAAP, (F) any occurrence, condition, change, development, event or effect resulting from the announcement of the transactions contemplated by the Transaction Agreement, (G) actions or omission of Envigo or any of its subsidiaries taken with the prior written consent of AHPAC or required by the Transaction Agreement; (H) the failure to meet any projections, forecasts, guidance estimates, milestones, budgets or financial or operating predictions of revenue, earnings, cash flow or cash position of Envigo or its subsidiaries (provided that the underlying cause of such failure can be considered for purposes hereunder to the extent not otherwise excluded); and further provided that the exceptions in clauses (A) through (H) will only apply so long as Envigo or its subsidiaries are not, or would not reasonably be expected to be, materially adversely affected in a disproportionate manner relative to other participants in the markets or industries in which Envigo and its subsidiaries operate.

Closing and Effective Time of the business combination


        The closing of the transactions contemplated by the Transaction Agreement will take place at 8:00 a.m. Eastern Time, on the third (3rd) business day after the satisfaction (or waiver in accordance with the Transaction Agreement) of the last to occur of the conditions described below under the subsection entitled "Conditions to Closing of the Business Combination" (other than any such conditions which by their nature cannot be satisfied until the Closing Date, which will be required to be so




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satisfied or (to the extent permitted by applicable Laws and the Transaction Agreement) waived on the Closing Date), at the offices of Weil, Gotshal & Manges LLP in New York, New York, unless another date or place is agreed to in writing by the parties.

Conditions to Closing of the Business Combination


Conditions to Each Party's Obligations


        The respective obligations of each of the parties to the Transaction Agreement to effect the transactions contemplated by the Transaction Agreement are subject to the satisfaction, or written waiver by both AHPAC and Envigo, of each of the following conditions:

•

The affirmative vote (in person or by proxy) of the holders of a majority or a two-thirds majority (as applicable) of the issued and outstanding ordinary shares entitled to vote thereon in favor of the Business Combination Proposal, the Domestication Proposal, the NASDAQ Proposal, the Charter Proposals, the Director Election Proposal, the Management Incentive Plan Proposal and the Adjournment Proposal shall have been obtained;



•

The applicable waiting period under the HSR Act shall have expired or been terminated or such approval shall have otherwise been obtained;



•

There must not be any legal proceeding by any governmental entity that challenges or seeks to make the business combination illegal or otherwise prohibited instituted, pending or threatened in writing;



•

AHPAC shall have at least $5,000,001 of net tangible assets (as determined in accordance with Rule 3a51-1(g)(1) of the Exchange Act) remaining; and



•

Either (i) Envigo shall have received a Lender Consent and Amendment with respect to each Envigo Credit Agreement and the Existing Third Lien Indenture, (ii) the consummation of a Debt Refinancing on terms reasonably acceptable to AHPAC) or (iii) a combination of the foregoing which upon the consummation of the transactions contemplated by the Transaction Agreement do not result in a Default or Event of Default under any Envigo Credit Agreement or the Existing Third Lien Indenture.




Conditions to AHPAC's Obligations


        The obligations of AHPAC, Merger Sub and NewCo to effect the transactions contemplated by the Transaction Agreement are subject to the satisfaction at or prior to the Closing Date of certain conditions (any or all of which may be waived in writing in whole or in part exclusively by AHPAC), including, among others, (i) Envigo must have performed and complied in all material respects with all obligations required to be performed or complied with by Envigo under the Transaction Agreement at or prior to the Closing Date and (ii) Envigo and its respective affiliates and subsidiaries shall have terminated, effective as of the closing, all Related Party Agreements (as defined in the Transaction Agreement) of Envigo and/or any of its subsidiaries that are not set forth on Section 5.19 of the Schedules, with such termination to be effective as of the closing.

Conditions to Envigo's Obligations


        The obligations of Envigo to effect the transactions contemplated by the Transaction Agreement are subject to the satisfaction at or prior to the Closing Date of certain conditions (any or all of which may be waived in writing in whole or in part exclusively by Envigo), including, among others, (i) AHPAC, Merger Sub and NewCo must have performed and complied in all material respects with all obligations required to be performed or complied with under the Transaction Agreement at or prior to the Closing Date, (ii) the ENVG Class A common stock shall have been approved for listing on




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NASDAQ, AHPAC shall be a listed public company on, and for the ENVG Class A common stock to be tradable over NASDAQ and immediately following the first merger effective time, AHPAC shall meet all of the continuing listing requirements of NASDAQ and shall not have received any notice of non-compliance (other than any notice to the extent related to AHPAC's failure to conduct an annual meeting in 2017) and (iii) the funds contained in the trust account (after giving effect to redemptions of public shares) and the proceeds of the equity financing, if any, shall together equal or exceed $260$220 million.

Representations and Warranties


        Under the Transaction Agreement, Envigo made customary representations and warranties relating to: organization, standing and power; capital structure; authority, no violations, consents and approvals; information supplied; absence of certain changes or events; financial statements, no undisclosed liabilities; compliance with laws; international trade matters; anti-corruption matters; litigation; taxes; compensation and benefits; United Kingdom pension plans; labor matters; intellectual property; real property; environmental matters; insurance; affiliate transactions; brokers; material contracts; healthcare regulatory matters; and accredited investors.

        Under the Transaction Agreement, AHPAC, Merger Sub and NewCo made customary representations and warranties relating to: organization, standing and power; capital structure; authority, no violations, consents and approvals; U.S. Securities and Exchange Commission documents; information supplied; absence of certain changes or events; no default; compliance with applicable laws; litigation; listing on NASDAQ; trust account; no business conduct; affiliate transactions; and AHPAC material contracts.

Covenants of the Parties


Covenants of Envigo


        Envigo made certain covenants under the Transaction Agreement, including, among others, the following:

•

Each of Envigo and its subsidiaries will conduct its businesses in the ordinary course and will use commercially reasonable efforts to preserve intact its present business organization, keep available services of its officers and key employees, and preserve its relationships with its material customers and suppliers;



•

Except for transactions solely among Envigo and its subsidiaries, Envigo will not and will not permit any of its subsidiaries to: (i) split, combine, or reclassify any membership interests, capital stock or any other equity interests, as applicable, in Envigo or any subsidiary of Envigo, (ii) repurchase, redeem or otherwise acquire, or offer to repurchase, redeem or otherwise acquire, any membership interests, capital stock or any other equity interests, as applicable, in Envigo or any subsidiary of Envigo; (iii) grant, issue sell or otherwise dispose, or authorize to issue sell, or otherwise dispose any membership interests, capital stock or any other equity interests (such as stock options, stock units, restricted stock or other contracts for the purchase or acquisition of such capital stock), as applicable, in Envigo or any subsidiary of Envigo or (iv) declare, set aside or pay any dividend or make any other distribution;



•

Envigo will not amend or propose to amend Envigo's certificate of incorporation and will not permit any of its subsidiaries to amend or propose to amend its certificate of incorporation or bylaws or other similar or organizational documents;



•

Envigo will not, and will not permit any of its subsidiaries to, (i) merge, consolidate, combine or amalgamate with any individual, partnership, limited liability company, corporation, joint stock company, trust, estate, joint venture, association or unincorporated organization, or any other




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form of business or professional entity ("Person"), (ii) acquire or agree to acquire by merging or consolidating with, purchasing any equity interest in or a substantial portion of the assets of, or by any other manner, any business or any corporation, partnership, association or other business organization or division thereof, (iii) buy, purchase or otherwise acquire (by merger, consolidation, acquisition of stock or assets or otherwise), directly or indirectly, any assets, securities, properties, interests or businesses, other than (A) inventory and supplies in the ordinary course of business consistent with past practice, (B) other assets in the ordinary course of business, consistent with past practice, in an amount not to exceed $500,000 individually or $1,000,000 in the aggregate or (iv) make any loans, advances or capital contributions to, or investments in, any person other than Envigo or any wholly owned subsidiary or joint venture investment of Envigo except for loans, advances or capital contributions pursuant to and in accordance with the terms of agreements or legal obligations, in each case (A) existing as of the date of the Transaction Agreement or (B) in the ordinary course of business consistent with past practice and not in excess of $500,000 individually or $3.0 million in the aggregate;

•

Envigo will not, and will not permit any of its subsidiaries to, sell, lease, license, abandon, permit to lapse or expire, dedicate to the public, or otherwise dispose of, or agree to sell, lease, license, abandon, permit to lapse or expire, dedicate to the public, or otherwise dispose of, any portion of its assets or properties, other than any sale, lease or disposition in the ordinary course of business consistent with past practice or pursuant to agreements existing on the date hereof and set forth on Schedule 4.1 of the Schedules;



•

Envigo will not, and will not permit any of its subsidiaries to, authorize, recommend, propose or announce an intention to adopt a plan of complete or partial liquidation, restructuring, recapitalization, dissolution or winding-up;



•

Envigo will not, and will not permit any of its subsidiaries to (i) change in any material respect their material accounting methods or policies, except as required by GAAP or (ii) make any material change to any of the cash management practices of Envigo or any of its subsidiaries, including materially deviating from or materially altering any of its practices, policies or procedures in paying accounts payable or collecting accounts receivable;



•

Envigo will not (i) except in the ordinary course of business, make or rescind any material express or deemed election or change any annual accounting period or material method of accounting relating to taxes (including any such election, period or method for any controlled joint venture, partnership, limited liability company or other investment where Envigo has the capacity to make such binding election, but excluding any election that must be made periodically and is made consistent with past practice), (ii) amend any material tax return or (iii) settle or compromise any material claim, action, suit, litigation, proceeding, arbitration, investigation, audit or controversy relating to Taxes;



•

Envigo will not, and will not permit its subsidiaries to, enter into or amend any related party agreement (including the Management Agreement, dated as of November 24, 2009, between Life Sciences Research, Inc. and LAB Holdings LLC, as amended by Amendment No. 1 thereto, dated as of August 4, 2016) other than the terminations provided for in Section 5.19 of the Transaction Agreement;



•

Envigo will not, and will not permit its subsidiaries to, (i) increase the compensation of any current or former employee, director or individual independent contractor of Envigo, except for increases consistent with past practice or required by a material "employee benefit plan" within the meaning of Section 3(3) of the Employee Retirement Income Security Act of 1974, as amended ("Employee Benefit Plan") in effect on the date hereof or applicable Law, (ii) merge, terminate or amend any Employee Benefit Plan, or establish or adopt any arrangement that would be an Employee Benefit Plan if in effect on the date of the Transaction Agreement,




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(iii) hire, engage or terminate any employee or individual independent contractor, or change the classification or status in respect of any employee or independent contractor, other than (A) terminations for cause and (B) new hires to fill non-executive vacancies occurring following the date hereof, (iv) except in the ordinary course of business and consistent with past practice, loan or advance any money or other property to any present or former director, officer, employee or consultant of Envigo or any of its subsidiaries, other than an advance to any employee or consultant in the ordinary course of business in connection with reasonable, out-of-pocket expenses related to their employment or service and in accordance with Envigo policy in effect on the date of the Transaction Agreement, (v) grant any severance, except in the ordinary course of business, in connection with new hires, or change in control benefits or (vi) take any action to accelerate the vesting or payment of, otherwise fund or secure the payment of, any compensation or benefits under any Employee Benefit Plan;

•

Envigo will not, and will not permit any of its subsidiaries to: (i) incur, create or assume any Indebtedness for borrowed money or guarantee any such Indebtedness of another Person or issue or sell any debt securities or rights to acquire any debt securities of Envigo or any of its subsidiaries or guarantee any debt securities of another Person, (ii) except in the ordinary course of business consistent with past practice, create any material Encumbrances (as defined in the Transaction Agreement) on any material property or assets of Envigo or any of its subsidiaries in connection with any Indebtedness thereof other than certain permitted encumbrances, (iii) cancel or forgive any Indebtedness in excess of $100,000 owed to Envigo or any of its subsidiaries or (iv) make or incur any capital expenditures, except for capital expenditures (A) in the ordinary course of business consistent with past practice or (B) other capital expenditures in an amount not to exceed $1,000,000 individually or $10,000,000 in the aggregate;



•

Envigo will not, and will not permit any of its subsidiaries to, (i) enter into any lease of real property or modify, amend or terminate any lease, except in the ordinary course of business consistent with past practice or (ii) amend in any adverse respect or terminate or extend any Envigo Material Contract (as defined in the Transaction Agreement) except extensions, renewals and non-renewals of existing Material Contracts in the ordinary course of business consistent with past practice;



•

Envigo will not, and will not permit any of its subsidiaries to, (i) enter into any lease of real property or modify, amend or terminate any lease, except in the ordinary course of business consistent with past practice or (ii) amend in any adverse respect or terminate or extend any Envigo Material Contract except extensions, renewals and non-renewals of existing Material Contracts in the ordinary course of business consistent with past practice;



•

Envigo will not, and will not permit any of its subsidiaries to, agree to take any action that is prohibited by Section 4.1 of the Transaction Agreement (Conduct of Business by the Company and its subsidiaries Pending the Transaction);



•

From and after the date of the Transaction Agreement until the earlier of the Closing and the termination of the Transaction Agreement in accordance with its terms, Envigo will not, and will cause its subsidiaries not to, and will use reasonable best efforts to cause their respective officers, directors, employees, accountants, consultants, agents, legal counsel, and other representatives (collectively, the "Representatives") not to, directly or indirectly: (i) enter into, knowingly solicit, initiate or continue any discussions or negotiations with, or knowingly encourage or respond to any inquiries or proposals by, or participate in any negotiations with, or provide any information to, any Person or other entity or group (other than AHPAC, its subsidiaries and their Representatives), concerning any sale of any material assets of Envigo or its subsidiaries or any of the outstanding equity interests in Envigo or its subsidiaries, or any conversion, consolidation, liquidation, dissolution or similar transaction involving Envigo or its




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subsidiaries, other than with AHPAC and its Representatives (an "Alternative Transaction"), (ii) enter into any agreement regarding, continue or otherwise participate in any discussions regarding, or furnish to any Person any information with respect to, any Alternative Transaction or (iii) commence, continue or renew any due diligence investigation regarding any Alternative Transaction; provided that the execution, delivery and performance of the Transaction Agreement and the other Related Agreements and the consummation of the transactions contemplated by the Transaction Agreement will not be deemed a violation of Section 4.3 of the Transaction Agreement (No Solicitation). Envigo will, and will cause its affiliates and instruct its Representatives to, immediately cease any and all existing discussions or negotiations with any Person conducted heretofore with respect to any Alternative Transaction. If Envigo, its subsidiaries or any of their respective Representatives receives any inquiry or proposal with respect to an Alternative Transaction at any time prior to the Closing, then Envigo will promptly (and in no event later than twenty-four (24) hours after Envigo becomes aware of such inquiry or proposal) (A) advise AHPAC orally and in writing of such inquiry or proposal (including the identity of the Person making such inquiry or submitting such proposal, and the terms thereof), (B) provide AHPAC a copy of such inquiry or proposal, if in writing, and (C) notify such Person in writing that Envigo is subject to an exclusivity agreement with respect to the sale of Envigo or its subsidiaries that prohibits Envigo from considering such inquiry or proposal. Without limiting the foregoing, parties agree that any violation of the restrictions set forth in Section 4.3(a) of the Transaction Agreement (No Solicitation) by any of Envigo, its subsidiaries, affiliates or any of their respective Representatives will be deemed to be a breach of Section 4.3(a) of the Transaction Agreement (No Solicitation) by Envigo;

Covenants of AHPAC


        AHPAC made certain covenants under the Transaction Agreement, including, among others, the following:

•

Each of AHPAC and its subsidiaries will conduct its businesses in the ordinary course consistent with past practice;



•

Except for transactions solely among AHPAC and its subsidiaries, AHPAC will not and will not permit any of its subsidiaries to: (i) declare, set aside or pay any dividends on, or make any other distribution in respect of any outstanding capital stock of, or other equity interests in, AHPAC or its subsidiaries; (ii) split, combine or reclassify any capital stock of, or other equity interests in, AHPAC; or (iii) other than required by any Related Agreement or as otherwise required by AHPAC's organizational documents in order to consummate the transactions contemplated hereby or thereby, repurchase, redeem or otherwise acquire, or offer to repurchase, redeem or otherwise acquire, any capital stock of, or other equity interests in, AHPAC, except as required by the terms of any capital stock of, or other equity interests in, AHPAC or any of its subsidiaries outstanding on the date of the Transaction Agreement or as contemplated by any existing director compensation plan, Employee Benefit Plan or employment agreement of AHPAC;



•

AHPAC will not, and will not permit any of its subsidiaries to, offer, issue, deliver, grant or sell, or authorize or propose to offer, issue, deliver, grant or sell, any capital stock of, or other equity interests in, AHPAC or any of its subsidiaries or any securities convertible into, or any rights, warrants or options to acquire, any such capital stock or equity interests;



•

Other than pursuant to the Transaction Agreement, AHPAC will not amend or propose to amend the Organizational Documents of AHPAC and will not permit any of its subsidiaries to amend or propose to amend its Organizational Documents;




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•

Except as contemplated hereby, AHPAC will not, and will not permit any of its subsidiaries to, (i) merge, consolidate, combine or amalgamate with any Person other than another wholly owned subsidiary of AHPAC, (ii) acquire or agree to acquire by merging or consolidating with, purchasing any equity interest in or a substantial portion of the assets of, or by any other manner, any business or any corporation, partnership, association or other business organization or division thereof, or (iii) make any loans, advances or capital contributions to, or investments in, any Person other than AHPAC or any wholly owned subsidiary;



•

AHPAC will not amend the Investment Management Trust Agreement dated as of October 10, 2016 by and between AHPAC and Continental Stock Transfer & Trust Company, a New York corporation, or any other agreement related to the trust account;



•

AHPAC will not, and will not permit any of its subsidiaries to, authorize, recommend, propose or announce an intention to adopt a plan of complete or partial liquidation, dissolution or winding-up;



•

AHPAC will not, and will not permit any of its subsidiaries to, change in any material respect their material accounting methods or policies, except as required by GAAP;



•

AHPAC will not enter into or amend any contract, agreement or commitment with any former or present director or officer of AHPAC or any of its subsidiaries or with any affiliate of any of the foregoing Persons or any other Person covered under Item 404 of Regulation S-K under the Securities Act;



•

AHPAC will not, and will not permit any of its subsidiaries to, (i) incur, create or assume any Indebtedness for borrowed money (except for trade credit incurred in the ordinary course) or guarantee any such Indebtedness of another Person or issue or sell any debt securities or rights to acquire any debt securities of AHPAC or any of its subsidiaries or guarantee any debt securities of another Person or (ii) create any material encumbrances on any material property or assets of AHPAC or any of its subsidiaries in connection with any Indebtedness thereof other than certain permitted encumbrances;



•

AHPAC will not, and will not permit any of its subsidiaries to, agree to take any action that is prohibited by Section 4.2 of the Transaction Agreement (Conduct of Business of AHPAC Pending the Merger); and



•

From and after the date of the Transaction Agreement until the earlier of the Closing or the termination of the Transaction Agreement in accordance with its terms, AHPAC will not, and will cause its affiliates not to, and will use reasonable best efforts to cause their respective Representatives not to, directly or indirectly: (i) enter into, knowingly solicit, initiate or continue any discussions or negotiations with, or knowingly encourage or respond to any inquiries or proposals by, or participate in any negotiations with, or provide any information to, any Person or other entity or group (other than AHPAC, its subsidiaries and their Representatives), concerning any offer, inquiry, proposal or indication of interest, written or oral (whether binding or non-binding and other than an offer, inquiry, proposal or indication of interest) relating to a business combination ("business combination proposal"), (ii) enter into any agreement regarding, continue or otherwise participate in any discussions or negotiations regarding, or furnish to any Person any information with respect to, or cooperate in any way that would otherwise reasonably be expected to lead to, any business combination proposal or (iii) commence, continue or renew any due diligence investigation regarding any business combination proposal. AHPAC will, and will cause each of its affiliates and instruct their respective Representatives to, immediately cease any and all existing discussions or negotiations with any Person conducted heretofore with respect to any business combination proposal. If AHPAC, its affiliates or any of their respective Representatives receives any inquiry or proposal




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with respect to a business combination proposal at any time prior to the Closing, then AHPAC will promptly (and in no event later than twenty-four (24) hours after AHPAC becomes aware of such inquiry or proposal) (A) advise Envigo orally and in writing of such inquiry or proposal (including the identity of the Person making such inquiry or submitting such proposal, and the terms thereof) and (B) provide Envigo a copy of such inquiry or proposal, if in writing. Without limiting the foregoing, the parties agree that any violation of the restrictions set forth in Section 4.3(b) of the Transaction Agreement (No Solicitation) by any of AHPAC or its affiliates or their respective Representatives will be deemed to be a breach of Section 4.3(b) of the Transaction Agreement (No Solicitation) by AHPAC.

Survival of Representations and Warranties; Indemnification


        The representations and warranties of the parties contained in the Transaction Agreement or any instrument delivered pursuant to the Transaction Agreement (other than the Related Agreements) will terminate and be of no further force and effect as of the closing and any liability for breach or violation thereof will terminate absolutely.

Termination


        The Transaction Agreement may be terminated and the business combination may be abandoned any time prior to the closing, whether before or after shareholder approval of the Transaction Agreement, as follows:

•

by mutual written consent of AHPAC and Envigo;



•

by either AHPAC or Envigo:



•

if any governmental entity having jurisdiction over any party hereto has issued any order, decree, ruling or injunction or taken any other action permanently restraining, enjoining or otherwise prohibiting the consummation of the transactions contemplated by the Transaction Agreement and such order, decree, ruling or injunction or other action has become final and non-appealable or if there is adopted any Law that makes consummation of the transactions contemplated by the Transaction Agreement illegal or otherwise prohibited; provided, however, that this right to terminate the Transaction Agreement will not be available to any party whose failure to fulfill any obligation or condition under the Transaction Agreement proximately caused such order, decree, ruling, injunction or other action;



•

if the mergers are not consummated by March 31, 2018; provided, however, that the right to terminate the Transaction Agreement will not be available to any party in breach of the Transaction Agreement such that certain conditions will not be satisfied on or prior to the Closing; or



•

in the event of a breach by the other party of any representation, warranty, covenant or other agreement contained in the Transaction Agreement which (A) would give rise to the failure of certain conditions and (B) cannot be or has not been cured by the earlier of thirty (30) days after the giving of written notice to the breaching party of such breach and March 31, 2018 (a "terminable breach"); provided that the terminating party is not then in terminable breach of any representation, warranty, covenant or other agreement contained in the Transaction Agreement.



•

by Envigo:



•

if the AHPAC Shareholder Approval is not obtained by reason of the failure to obtain the required vote upon a vote held at the general meeting of AHPAC's shareholders; or




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•

if the AHPAC Board publicly withdraws, modifies or changes, in any manner that is adverse to Envigo, its approval or recommendation to the shareholders of AHPAC with respect to any of the Transaction Proposals (including the "Parent Recommendation" or the "Parent Board Recommendation", as each such term is defined in the Transaction Agreement).



•

by AHPAC:



•

if and for so long as a written consent of a majority of the outstanding common stock of Envigo approving the business combination is not delivered to AHPAC by 5:00 p.m. ET on the first business day after the date of the Transaction Agreement.

        In the event of termination of the Transaction Agreement by any party thereto as provided thereunder, the Transaction Agreement will forthwith become void and there will be no liability or obligation on the part of any party thereto except with certain exceptions; provided, however, that no such termination will relieve any party from liability for damages for fraud or an intentional breach of any representation, warranty or obligation under the Transaction Agreement; provided that, notwithstanding anything to the contrary contained in the Transaction Agreement, no party thereto will be liable under the Transaction Agreement for any consequential (including lost profits) damages, punitive or special damages, irrespective of whether such damages are available under applicable Law. "Intentional Breach" means a material breach or material default that is a consequence of an act knowingly undertaken by the breaching party with the intent of causing a breach of the Transaction Agreement.

Amendments


        The Transaction Agreement may be amended by the parties thereto, at any time before or after the receipt of the AHPAC Shareholder Approval, but, after any such adoption, no amendment shall be made which by Law would require the further approval by such shareholders without first obtaining such further approval. The Transaction Agreement may not be amended except by an instrument in writing signed (including by electronic means) on behalf of each of the parties thereto; provided that notwithstanding anything to the contrary set forth in the Transaction Agreement, certain customary provisions may not be amended, modified, waived or terminated in a manner that is materially adverse to the Debt Financing Sources (as defined in the Transaction Agreement) without the prior written consent of such Debt Financing Sources.

Related Agreements


        This section describes certain additional agreements to be entered into pursuant to the Transaction Agreement, which we refer to as the "related agreements," but does not purport to describe all of the terms thereof. The following summary is qualified in its entirety by reference to the complete text of each of the related agreements. A form of the Amended and Restated Registration Rights Agreement is attached hereto asAnnex E, a form of the Tax Receivable Agreement is attached hereto asAnnex D and a form of the Parent Sponsor Letter Agreement is attached hereto asAnnex F. Shareholders and other interested parties are urged to read such related agreements in their entirety prior to voting on the proposals presented at the general meeting.

Amended and Restated Registration Rights Agreement


        At the closing of the business combination, AHPAC, the sponsor and the restricted stockholders will enter into the Amended and Restated Registration Rights Agreement in respect of the shares of ENVG Class A common stock, ENVG warrants and shares of ENVG Class A common stock issued with respect to ENVG warrants (the "ENVG restricted securities") issued to the restricted stockholders in connection with the business combination. The restricted stockholders and their permitted transferees will be entitled to certain registration rights described in the Amended and Restated




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Registration Rights Agreement, including, among other things, customary registration rights, including demand and piggy-back rights, subject to cut-back provisions. ENVG will bear the expenses incurred in connection with the filing of any such registration statements, other than certain underwriting discounts, selling commissions and expenses related to the sale of shares to fund the indemnification obligations of the Selling Equityholders under the Transaction Agreement.

        Pursuant to the Amended and Restated Registration Rights Agreement, the restricted stockholders will agree not to sell, transfer, pledge grant any option to purchase, make any short sale or otherwise dispose of ENVG restricted securities it receives in connection with the business combination for either three or six months (as applicable to such restricted holder) from the closing of the business combination, except for transfers to certain affiliates or family members, to the beneficial owners of a restricted stockholder (where such restricted stockholder is an entity), or with the prior written consent of ENVG. The foregoing restriction expressly precludes each restricted stockholder from engaging in any hedging or other transaction which could result in a sale or disposition of the ENVG restricted securities even if such securities would be disposed of by someone other than such restricted stockholder.

        The Amended and Restated Registration Rights Agreement amends and restates the Registration Rights Agreement that was entered into on the effective date of AHPAC's IPO (the "Original Registration Rights Agreement"), by and among the holders of the founder shares, private placement warrants and warrants that may be issued on conversion of working capital loans (and any AHPAC Class A ordinary shares issuable upon the exercise of the private placement warrants or warrants issued upon conversion of the working capital loans and upon conversion of the founder shares). The Amended and Restated Registration Rights Agreement is on substantially similar terms to the Original Registration Rights Agreement.

Tax Receivable Agreement


        At the closing of the business combination, ENVG will enter into the Tax Receivable Agreement with Envigo Holdings, Inc. and the shareholder representative on behalf of the Selling Equityholders. The Tax Receivable Agreement will generally provide for future payments by ENVG to the holders of common stock and certain other interests in Envigo, as of the time immediately before the consummation of the business combination, related to 85% of the net cash savings, if any, in U.S. federal, state and local and U.K. income tax that ENVG and its subsidiaries actually realizes (or is deemed to realize in certain circumstances) in periods after the consummation of the business combination as a result of (i) the utilization of net operating losses available to be carried forward as of the consummation of the business combination and (ii) imputed interest deductions arising from payments under the Tax Receivable Agreement. Although the amount and timing of any payments under the Tax Receivable Agreement will vary depending upon a number of factors, including the amount and timing of ENVG's income, AHPAC expects that the payments that ENVG makes thereunder could be substantial.

        The Tax Receivable Agreement provides, among other things, that (i) in the event that ENVG materially breaches the Tax Receivable Agreement, (ii) if, at any time, ENVG elects an early termination of the Tax Receivable Agreement, or (iii) upon certain mergers, asset sales, other forms of business combinations or other divestitures or changes of control as specified therein, ENVG's obligations under the Tax Receivable Agreement would accelerate and become payable in a lump sum amount. The lump sum amount would be equal to the present value of the anticipated future tax benefits calculated based on certain assumptions, including that ENVG and its subsidiaries will generate an amount of taxable income in accordance with management's pre-existing projections as of the time of the relevant event described above.




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        See the section titled "AHPAC's Management's Discussion and Analysis of Financial Condition and Results of Operations—Liquidity and Capital Resources—Tax Receivable Agreement" beginning on page [    ·    ]173 of this proxy statement/prospectus for more information.

Parent Sponsor Letter Agreement


        In connection with the execution and delivery of the Transaction Agreement, the Class B Holders have entered into the Parent Sponsor Letter Agreement pursuant to which, immediately prior to the consummation of the first merger, the Class B Holders will surrender to AHPAC an aggregate 3,875,0004,715,576 AHPAC Class B ordinary shares and AHPAC will repurchase 4,100,000 private placement warrants for $0.50 per warrant in cash.warrants.

Financing Arrangements


Lender Consents


        In connection with the execution and delivery of the Transaction Agreement, Envigo obtained (i) signed amendments to each Envigo Credit Agreement (each such amendment a "Credit Agreement Amendment" and collectively the "Credit Agreement Amendments") and (ii) a signed consent agreement (the "Indenture Consent Agreement") among Envigo Laboratories Inc., AHPAC, and the noteholders, pursuant to which holders of 100% of the aggregate principal amount of notes outstanding agreed to consent to a supplemental indenture (the "Third Lien Supplemental Indenture"), among Envigo Laboratories Inc., U.S. Bank National Association as trustee and collateral trustee and the guarantors party thereto amending and waiving certain terms of the Existing Third Lien Indenture and the notes issued thereunder. The Credit Agreement Amendments will only become effective upon the satisfaction of certain conditions, including, without limitation, (i) the consummation of the business combination on or prior to February 7, 2018, (ii) the prepayment of certain outstanding indebtedness in an amount not less than $143 million in the aggregate and (iii) obtaining an amendment in respect of indebtedness issued pursuant to the Existing Third Lien Indenture to reduce the rate of interest thereon to no more than 6.0% per annum and to otherwise permit the transactions. Pursuant to the terms of the Indenture Consent Agreement, the Third Lien Supplemental Indenture shall amend the Existing Third Lien Indenture and the notes to (i) reduce the interest rate of the notes to 6.0%; (ii) amend certain definitions and covenants and (iii) waive the requirement for any change of control offer that would otherwise be required as a result of the transactions contemplated by the Transaction Agreement. Upon effectiveness of each Credit Agreement Amendment and the Third Lien Supplemental Indenture, each Credit Agreement Amendment and the Third Lien Supplemental Indenture constitutes a "Lender Consent and Amendment" under the terms of the Transaction Agreement.

        The Transaction Agreement alternatively permits Envigo to obtain a full or partial refinancing of its existing outstanding indebtedness (a "Debt Refinancing") in lieu of implementing Lender Consents and Amendments for each applicable existing credit facility.

        It is a condition to AHPAC and Envigo's obligations under the Transaction Agreement that Envigo shall have either received the Lender Consent & Amendment, or consummated a Debt Refinancing, or a combination thereof.

Credit Facilities


        Prior to or concurrently with the closing of the proposed business combination, we expect Envigo Holdings, Inc. (the "Borrower") to enter into a new credit facility consisting of (i) a new $300.0 million senior secured term loan facility (the "Term Facility") and (ii) a new $50.0 million senior secured revolving credit facility (the "Revolving Facility" and, together with the Term Facility, the "Credit Facilities"), the proceeds of which are expected to refinance substantially all of the Borrower's existing third party indebtedness (including all indebtedness issued pursuant to the Envigo Credit Agreements




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and the Existing Third Lien Indenture) (the "Refinancing") and pay related fees and expenses and, in the case of the Revolving Facility, on and after the Closing date, for working capital and general corporate purposes. The Term Facility will mature six years after the closing of the Acquisition and the Revolving Facility will mature five years after the closing of the Credit Facilities (the "Closing Date"). The Credit Facilities are being negotiated on a "best efforts" basis and, if consummated, will constitute a "Debt Refinancing" as defined in the Transaction Agreement and will replace the Lender Consents and Amendments that have been obtained. The below is a summary of the expected terms of the Credit Facilities. There can be no assurance that the final terms of the Credit Facilities will be consistent with those described below.

        The obligations of the Borrower under the Credit Facilities will be guaranteed jointly and severally by EVNG, Envigo Intermediate Holdings, LLC, a Delaware limited liability company ("Holdings") and each of the Borrower's direct and indirect, existing and future, wholly-owned domestic subsidiaries (collectively, the "Guarantors"), subject to certain customary exceptions.

        The Credit Facilities will be secured by a perfected first-priority security interest (subject to certain permitted liens and other customary exceptions) in substantially all tangible and intangible personal property of the Borrower and the Guarantors, including all of the capital stock of the Borrower and its direct and indirect subsidiaries (subject to certain customary exceptions, including for foreign subsidiaries) (the "Collateral"). In this proxy statement/prospectus, we refer to these transactions as the "Financing Transactions."

Description of New Financing


        The below is a summary of the expected terms of the Credit Facilities. There can be no assurance that the final terms of the Credit Facilities will be consistent with those described below. Availability of the Credit Facilities will be subject to specified conditions precedent, including the consummation of the business combination. Subject to the satisfaction of these conditions, we expect to draw the full amount of the Term Facility on the Closing Date to finance a portion of the business combination (including the Refinancing) and the payment of related fees, expenses and other costs. The proceeds of the Revolving Facility are expected to be used to finance working capital needs and for general corporate purposes. In addition, we will be permitted to borrow up to $10 million under the Revolving Facility on the Closing Date to finance a portion of the business combination (including the Refinancing) and the payment of related fees, expenses and other costs. Availability of the Revolving Facility after the Closing Date will be subject to additional conditions precedent.

Voluntary Prepayments


        We may voluntarily reduce the unutilized portion of the revolving commitments under the Revolving Facility and prepay outstanding loans under the Term Facility at any time without premium or penalty other than (a) customary breakage costs and (b) with respect to the Term Facility, (i) with respect to any such prepayment occurring prior to the first anniversary of the Closing Date, a prepayment premium of 2.00% of the principal amount of the term loans being prepaid and (ii) with respect to any such prepayment occurring prior to the second anniversary of the Closing Date but on or after the first anniversary of the Closing Date, a prepayment premium of 1.00% of the principal amount of the Initial Term Loans being prepaid.

Amortization and Final Maturity


        We will be required to make scheduled quarterly amortization payments equal to (i) 0.625% of the original principal amount of the term loans under the Term Facility for the first eight fiscal quarters after the Closing Date (beginning with the fiscal quarter ending on June 30, 2018) and (ii) thereafter, 1.25% of the original principal amount of the term loans under the Term Facility made on the Closing




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Date, with the balance due six years after the Closing Date. The Revolving Facility will terminate and all outstanding loans thereunder shall be payable five years after the Closing Date. No amortization will be required in respect of the Revolving Facility.

Guarantees and Security


        All obligations under our Credit Facilities, and under any interest rate protection or other swap or hedging arrangements (subject to certain customary exceptions), will be guaranteed jointly and severally by the Guarantors.

        The Borrower and each Guarantor will grant a security interest in the Collateral to JPMorgan Chase Bank, N.A., in its capacity as administrative agent and collateral agent (in such capacities, the "Agent") under the Credit Facilities.

Certain Covenants and Events of Default


        The Credit Facilities will contain a number of restrictive covenants that, among other things and subject to certain exceptions, will restrict the ability of the Borrower, the Guarantors, and certain of their subsidiaries to:

•

incur additional indebtedness;



•

incur liens;



•

engage in transactions with affiliates;



•

sell, transfer, lease or otherwise dispose of assets;



•

make dividends and other payments in respect of capital stock;



•

make investments;



•

prepay subordinated debt or modify subordinated debt and organizational documents in a manner materially adverse to the lenders under the Credit Facility; and



•

consolidate, merge, liquidate or dissolve.

        In addition, the Credit Facilities will contain a financial maintenance covenant requiring the Parent to maintain a maximum consolidated leverage ratio of not more than 5.50 to 1.00 (the "Financial Covenant"). The Financial Covenant will be tested quarterly commencing with the fiscal quarter ending on June 30, 2018.

        The Credit Facilities will also contain certain customary representations and warranties, affirmative covenants and reporting obligations. In addition, the lenders under the Credit Facilities will be permitted to accelerate the loans and terminate commitments thereunder or exercise other specified remedies available to secured creditors upon the occurrence of certain events of default, subject to certain grace periods and exceptions, which will include, among others, payment defaults, breaches of representations and warranties, covenant defaults, cross-defaults to certain material indebtedness, certain events of bankruptcy, certain events under the Employee Retirement Income Security Act of 1974, as amended, material judgments and changes of control.




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REGULATORY APPROVALS RELATED TO THE BUSINESS COMBINATION


        Neither AHPAC nor Envigo is aware of any material regulatory approvals or actions that are required for completion of the business combination other than the expiration or early termination of the waiting period under the HSR Act. It is presently contemplated that if any such additional regulatory approvals or actions are required, those approvals or actions will be sought. There can be no assurance, however, that any additional approvals or actions will be obtained.

Regulatory Matters


        Under the HSR Act and the rules that have been promulgated thereunder by the U.S. Federal Trade Commission ("FTC"), certain transactions may not be consummated unless information has been furnished to the Antitrust Division of the Department of Justice ("Antitrust Division") and the FTC and certain waiting period requirements have been satisfied. The business combination is subject to these requirements and may not be completed until the expiration of a 30-day waiting period following the filing of the required Notification and Report Forms with the Antitrust Division and the FTC or until early termination is granted. On August 31, 2017, AHPAC and Envigo filed the required forms under the HSR Act with the Antitrust Division and the FTC and requested early termination. Early termination of the HSR waiting period was granted on September 13, 2017.

        At any time before or after consummation of the business combination, notwithstanding termination of the waiting period under the HSR Act, the applicable competition authorities could take such action under applicable antitrust laws as each deems necessary or desirable in the public interest, including seeking to enjoin the consummation of the business combination. Private parties may also seek to take legal action under the antitrust laws under certain circumstances. AHPAC cannot assure you that the Antitrust Division, the FTC, any state attorney general, or any other government authority will not attempt to challenge the business combination on antitrust grounds, and, if such a challenge is made, AHPAC cannot assure you as to its result. Neither AHPAC nor Envigo is aware of any material regulatory approvals or actions that are required for completion of the business combination other than the expiration or early termination of the waiting period under the HSR Act. It is presently contemplated that if any such additional regulatory approvals or actions are required, those approvals or actions will be sought. There can be no assurance, however, that any additional approvals or actions will be obtained.




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SELECTED HISTORICAL FINANCIAL INFORMATION OF AHPAC


        AHPAC is providing the following selected historical financial information to assist you in your analysis of the financial aspects of the business combination.

        AHPAC's balance sheet data as of September 30, 2017 and statement of operations data for the nine months ended September 30, 2017 and September 30, 2016 are derived from AHPAC's unaudited financial statements, which are included in the Index to Financial Statements section of this proxy statement/prospectus. AHPAC's balance sheet data as of December 31, 2016 and December 31, 2015 and statement of operations data for the year ended December 31, 2016 and for the period from December 4, 2015 (inception) through December 31, 2015 are derived from AHPAC's audited financial statements, audited by Marcum LLP, independent registered public accounts, included in the Index to Financial Statements section of this proxy statement/prospectus.

Selected Historical Financial Information—AHPAC


Income Statement Data:		For the nine months ended September 30, 2017			For the nine months ended September 30, 2016			For the year ended December 31, 2016			Period from December 4, 2015 (inception) through December 31, 2015
Revenue		$	—		$	—		$	—		$	—
Loss from operations			3,293,587			(30,542	)		(208,698	)		(25,162	)
Interest income			1,697,781			—			—			—
Net loss			(1,595,806	)		(30,542	)		(208,698	)		(25,162	)
Weighted average shares outstanding excluding
shares subject to possible conversion—basic and diluted			9,259,196			7,500,000			7,919,906			7,500,000
Basic and diluted net loss per share			(0.35	)		(0.00	)		(0.03	)		(0.00	)

 


Balance Sheet Data:		As of September 30, 2017			As of December 31, 2016			As of December 31, 2015
Trust account, restricted			311,697,781			310,000,000			—
Total assets			312,057,811			311,435,911			416,271
Total liabilities			13,546,066			11,328,360			416,433
Value of common stock which may be redeemed for cash			293,511,740			295,107,550			—
Stockholders' equity (deficit)			5,000,005			5,000,001			(162	)




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ENVIGO SELECTED CONSOLIDATED HISTORICAL FINANCIAL AND OTHER INFORMATION


        The selected data presented below under the headings "Selected Statement of Operations Data" and "Selected Balance Sheet Data" for, and as of the end of, December 31, 2016 and 2015, are derived from the consolidated financial statements of Envigo and subsidiaries, which financial statements have been audited by KPMG LLP, an independent registered public accounting firm. The consolidated financial statements as of December 31, 2016 and 2015, and the report thereon, are included elsewhere in this prospectus. The selected data presented below for the nine-month periods ended September 30, 2017 and 2016, are derived from the unaudited financial statements of Envigo International Holdings, Inc. included elsewhere in this proxy statement/prospectus.

        The information presented below under the heading "Other Financial Information" is not derived from Envigo's financial statements.

        The unaudited condensed consolidated financial data presented has been prepared on a basis consistent with our audited consolidated financial statements. In the opinion of management, such unaudited financial data reflects all adjustments, consisting only of normal and recurring adjustments, necessary for a fair presentation of the results for those periods. The results of operations for the interim periods are not necessarily indicative of the results to be expected for the full year or any future period.

        You should read the information contained in this table in conjunction with "Organizational Structure," "Envigo Management's Discussion and Analysis of Financial Condition and Results of Operations" and Envigo's audited consolidated and unaudited condensed consolidated financial statements and the accompanying notes included in this proxy statement/prospectus.

		Year ended December 31						Nine months ended September 30							Year ended December 31						Nine months ended September 30
		2016			2015			2017			2016				2016			2015			2017			2016
		(amounts in thousands)													(amounts in thousands)
Selected Statement of Operations Data:
Net revenues			415,429			429,514			303,650			321,033				415,429			429,514			303,650			321,033
Cost of sales			(280,199	)		(308,505	)		(201,719	)		(217,975	)			(280,199	)		(308,505	)		(201,719	)		(217,975	)
Selling, general and administrative expenses			(88,282	)		(97,449	)		(62,505	)		(66,909	)			(88,282	)		(97,449	)		(62,505	)		(66,909	)
Amortization			(7,755	)		(8,591	)		(5,317	)		(5,858	)			(7,755	)		(8,591	)		(5,317	)		(5,858	)
Other operating expense			(6,866	)		(11,357	)		(3,946	)		(4,609	)			(6,866	)		(11,357	)		(3,946	)		(4,609	)
Operating income			32,327			3,612			30,163			25,682				32,327			3,612			30,163			25,682
Interest expense, net			(47,395	)		(45,172	)		(35,242	)		(35,565	)			(47,395	)		(45,172	)		(35,242	)		(35,565	)
Foreign exchange gain (loss)			(20,524	)		(11,709	)		11,226			(11,480	)			(20,524	)		(11,709	)		11,226			(11,480	)
Other expense			(6,495	)		1,255			(738	)		(4,272	)			(6,495	)		1,255			(738	)		(4,272	)
Income (loss) from continuing operations, before income taxes			(42,087	)		(52,014	)		5,409			(25,635	)			(42,087	)		(52,014	)		5,409			(25,635	)
Income tax (expense) benefit			3,902			(1,706	)		(4,151	)		908				3,902			(1,706	)		(4,151	)		908
Income (loss) from continuing operations			(38,185	)		(53,720	)		1,258			(24,727	)			(38,185	)		(53,720	)		1,258			(24,727	)
Loss from discontinued operations, net of tax			(1,449	)		(13,954	)		—			(3,810	)			(1,449	)		(13,954	)		—			(3,810	)
Consolidated net income (loss)			(39,634	)		(67,674	)		1,258			(28,537	)			(39,634	)		(67,674	)		1,258			(28,537	)
Net loss (income) attributable to non-controlling interests			208			(185	)		68			(20	)			208			(185	)		68			(20	)
Net income (loss) attributable to the stockholders		$	(39,426	)	$	(67,859	)	$	1,326			(28,557	)		$	(39,426	)	$	(67,859	)	$	1,326			(28,557	)
Other financial information (in $ millions)
EBITDA (a)			26.9			8.5			56.9			23.6				26.9			8.5			56.9			23.6
Adjusted EBITDA (a)			64.4			58.0			51.9			49.0				63.8			57.3			51.3			48.4
Normalized Adjusted EBITDA (b)			65.9			59.5			53.0			50.2
Adjusted Revenue (c)			410.3			422.4			303.7			316.2
Adjusted Revenue (b)																405.3			417.2			299.5			312.1




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		December 31, 2016			December 31, 2015			September 30, 2017
Selected Balance Sheet Data, as of:
Total assets			549,351			596,364			604,469
Total long term debt, net of current portion			442,238			420,524			456,622		��
Total liabilities			653,339			646,996			707,116
Stockholders' deficit			(103,988	)		(50,632	)		(102,467	)

---

(a)

Envigo defines EBITDA as net income (loss) before depreciation, amortization, interest expense and income taxes. Envigo defines Adjusted EBITDA as EBITDA adjusted to exclude the impact of foreign exchange gains and losses, pension expense, stock compensation, sponsor management fees and expenses, discontinued and divested operations and and certain significant items (some of which may recur, such as restructuring, but which management does not believe are reflective of ongoing core operations).






Envigo's management believes that Adjusted EBITDA, when considered along with other performance measures, is a useful measure as it reflects certain drivers of Envigo's business, such as sales growth and operating costs. Envigo believes that Adjusted EBITDA can be useful in providing enhanced understanding of the underlying operating results, trends, and prospects for the future. While Adjusted EBITDA is not a recognized measure under GAAP, Envigo's management uses this financial measure to evaluate and forecast business performance. Adjusted EBITDA is not intended to be a measure of liquidity or cash flows from operations or a measure comparable to net income as it does not take into account certain requirements, such as capital expenditures and related depreciation, principal and interest payments, and tax payments. Adjusted EBITDA is not a presentation made in accordance with GAAP, and Envigo's use of the term Adjusted EBITDA may vary from the use of similarly-titled measures by others in our industry due to potential inconsistencies in the method of calculation and differences due to items subject to interpretation. For further discussion on Envigo's use of Non-GAAP financial measures, please see the section entitled "Non-GAAP Financial Measures" beginning on page [    ·    ]191 of this proxy statement/prospectus.



(b)

Normalized Adjusted EBITDA represents Adjusted EBITDA further modified to reflect management's estimate of the reduction in its cost structure as a public company. The estimate is based on management's estimate of excess costs incurred in the historical periods related primarily to private company executive and board compensation partially offset by additional costs it expects to incur as a public company. Management believes the presentation of Normalized Adjusted EBITDA is a useful measure to investors as it excludes the impact of costs that do not recur in future periods.






Normalized Adjusted EBITDA is not a GAAP measure and reflects management's estimates. Envigo's use of the term Normalized Adjusted EBITDA may vary from the use of similarly-titled measures by other companies and should not be considered as a substitute to profitability measures determined in accordance with GAAP.



(c)

Adjusted Revenue represents historical revenue adjusted to exclude revenue from Envigo's ILS operations that were divested in October 2016.2016, and revenue from Envigo's dog breeding business that was divested in October 2017. Envigo's management believes that Adjusted Revenue, when considered along with other performance measures, is a useful measure as it excludes the impact of revenues not expected to recur in future periods.






Adjusted Revenue is not a recognized measure under GAAP. Envigo's management uses this financial measure to evaluate and forecast business performance. Envigo's use of the term Adjusted Revenue may vary from the use of similarly-titled measures by others in our industry due to potential inconsistencies in the method of calculation and differences of interpretation.






The presentation of non-GAAP financial information should not be considered in isolation or as a substitute for, or superior to, the financial information prepared and presented in accordance with GAAP. You should read this discussion and analysis of Envigo's financial condition and results of operations together with the condensed consolidated financial statements and the related notes thereto also included within. See the section entitled "Non-GAAP Financial Measures."

        The selected data presented below under the heading "Selected Statement of Operations Data" for the year ended December 31, 2014, are derived from the unaudited consolidated financial statements of Envigo Holdings, Inc. and its subsidiaries ("BPAL"). The unaudited consolidated statement of operations and unaudited consolidated statement of cash flows (together "BPAL's financial information") for the year ended December 31, 2014, are included elsewhere in this prospectus.

        The unaudited condensed consolidated financial data presented has not been prepared on a basis that is fully consistent with our audited consolidated financial statements; the data reported here is for BPAL, a direct wholly-owned subsidiary of Envigo International Holdings, Inc. In the opinion of




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management, such unaudited financial data reflects all adjustments, consisting only of normal and recurring adjustments, necessary for a fair presentation of the results for this period.

        You should read the information contained in this table in conjunction with "Explanatory Note", "Organizational Structure," "Envigo Management's Discussion and Analysis of Financial Condition and Results of Operations" and BPAL's financial information and the accompanying notes included in this proxy statement/prospectus.

		Year ended December 31
		2014
		(amounts in thousands)
Selected Statement of Operations Data:
Net revenues			350,999
Cost of sales			(260,506	)
Selling, general and administrative expenses			(69,462	)
Amortization			(6,524	)
Other operating expense			(35,050	)
Operating loss			(20,543	)
Interest expense, net			(36,822	)
Foreign exchange loss			(14,475	)
Other income			1,629
Loss from continuing operations, before income taxes			(70,211	)
Income tax benefit			4,842
Loss from continuing operations			(65,369	)
Loss from discontinued operations, net of tax			(3,736	)
Consolidated net loss			(69,105	)
Net loss attributable to non-controlling interests			27
Net loss attributable to the stockholders			(69,078	)




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SELECTED UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL INFORMATION


        The following unaudited pro forma financial data is derived from the unaudited pro forma condensed consolidated balance sheet and statement of operations.

        The unaudited pro forma condensed combined financial statements are based on AHPAC's historical consolidated financial statements and Envigo's historical consolidated financial statements as adjusted to give effect to the business combination. The unaudited pro forma condensed combined statements of operations for the nine months ended September 30, 2017 and the year ended December 31, 2016 give effect to the business combination as if it had occurred on January 1, 2016. The unaudited pro forma condensed combined balance sheet as of September 30, 2017 gives effect to the business combination as if it had occurred on September 30, 2017.

        The historical financial information has been adjusted to give pro forma effect to events that are related and/or directly attributable to the business combination, are factually supportable and, with respect to the pro forma statement of operations, are expected to have a continuing impact on the results of the combined company. The adjustments presented on the unaudited pro forma condensed combined financial statements have been identified and presented to provide relevant information necessary for an accurate understanding of the combined company upon consummation of the business combination.

        The unaudited pro forma condensed combined financial information is for illustrative purposes only. The financial results may have been different had the companies always been combined. You should not rely on the unaudited pro forma condensed combined financial information as being indicative of the historical results that would have been achieved had the companies always been combined or the future results that the combined company will experience. AHPAC and Envigo have not had any historical relationship prior to the business combination. Accordingly, no pro forma adjustments were required to eliminate activities between the companies. Other than the Transactions described in this proxy statement, the unaudited pro forma condensed combined financial statements do not include pro forma adjustments for subsequent events as disclosed in the notes to Envigo's financial statements for the year ended December 31, 2016 and the nine months ended September 30, 2017, as these are not related and/or directly attributable to the business combination.

        The unaudited pro forma condensed combined financial information has been prepared assuming two redemption scenarios as follows:

•

Assuming No Redemptions:  This scenario assumes that no AHPAC Class A ordinary shares are redeemed; and



•

Assuming Maximum Redemptions:  This scenario assumes that 5,000,0009,000,000 AHPAC Class A ordinary shares, or 16.1%29% of the outstanding AHPAC Class A ordinary shares, are redeemed, resulting in an aggregate payment of $50,000,000$90,000,000 out of the trust account, and that the fair value of the marketable securities held in the trust account following such redemption along with the proceeds from the private placement are sufficient to satisfy closing cash conditions pursuant to the terms of the Transaction Agreement.

This information should be read together with AHPAC's and Envigo's financial statements and related notes, "Unaudited Pro Forma Condensed Combined Financial Information," "Envigo Management's




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Discussion and Analysis of Financial Condition and Results of Operations," and other financial information included elsewhere in this proxy statement/prospectus.

		Year ended December 31						Nine months ended September 30							Year ended December 31						Nine months ended September 30
		2016 (assuming no redemptions)			2016 (assuming redemptions)			2017 (assuming no redemptions)			2017 (assuming redemptions)				2016 (assuming no redemptions)			2016 (assuming redemptions)			2017 (assuming no redemptions)			2017 (assuming redemptions)
		(amounts in thousands)													(amounts in thousands)
Statement of Operations data:
Net revenues			415,429			415,429			303,650			303,650				415,429			415,429			303,650			303,650
Cost of sales			(280,199	)		(280,199	)		(201,719	)		(201,719	)			(280,199	)		(280,199	)		(201,719	)		(201,719	)
Selling, general and administrative expenses			(118,400	)		(118,400	)		(86,830	)		(86,830	)			(116,367	)		(116,367	)		(85,356	)		(85,356	)
Other operating expense			(6,866	)		(6,866	)		(3,946	)		(3,946	)			(6,866	)		(6,866	)		(3,946	)		(3,946	)
Operating income			9,964			9,964			11,155			11,155				11,997			11,997			12,629			12,629
Interest expense, net			(29,408	)		(33,308	)		(20,464	)		(23,632	)			(23,972	)		(23,972	)		(17,932	)		(17,932	)
Foreign exchange gain (loss)			(20,524	)		(20,524	)		11,226			11,226				(20,524	)		(20,524	)		11,226			11,226
Other expense			(6,495	)		(6,495	)		(738	)		(738	)			(6,495	)		(6,495	)		(738	)		(738	)
Income (loss) from continuing operations, before income taxes			(46,463	)		(50,363	)		1,179			(1,989	)			(38,994	)		(38,994	)		5,185			5,185
Income tax (expense) benefit			5,360			6,725			(3,229	)		(2,120	)			2,746			2,746			(4,631	)		(4,631	)
Income (loss) from continuing operations			(41,103	)		(43,638	)		(2,050	)		(4,109	)
Loss from continuing operations																(36,248	)		(36,248	)		554			554
Balance sheet data (at end of period):
Total assets									1,149,164			1,146,358										1,080,915			1,074,368
Total long term debt, net of current portion									273,860			320,689										287,281			287,281
Total liabilities									556,398			603,592										587,606			587,606
Stockholders' deficit									592,766			542,766
Shareholders' equity																						493,309			486,762




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UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL INFORMATION


        AHPAC is providing the following unaudited pro forma condensed combined financial information to aid you in your analysis of the financial aspects of the business combination.

        The unaudited pro forma condensed combined financial statements are based on our historical consolidated financial statements and Envigo's historical consolidated financial statements as adjusted to give effect to the business combination. The unaudited pro forma condensed combined statements of operations for the nine months ended September 30, 2017 and the 12 months ended December 31, 2016 give effect to the business combination as if it had occurred on January 1, 2016. The unaudited pro forma condensed combined balance sheet as of September 30, 2017 gives effect to the business combination as if it had occurred on September 30, 2017.

        The unaudited pro forma condensed combined financial statements were prepared using the acquisition method of accounting and based on the historical financial information of AHPAC and Envigo, assuming that AHPAC is the acquirer for accounting purposes. Pursuant to AHPAC's existing amended and restated memorandum and articles of association, a holder of public shares may request that AHPAC redeem all or a portion of such shareholder's public shares (which will become shares of ENVG Class A common stock following the domestication) for cash if the business combination is consummated. If a public shareholder properly exercises its right to redeem its public shares and timely delivers its shares to the transfer agent, AHPAC will redeem each public share for a per-share price, payable in cash, equal to the aggregate amount then on deposit in the trust account, calculated as of two business days prior to the consummation of the business combination, including interest, less income taxes payable, divided by the number of then issued and outstanding public shares. Pursuant to the terms of the Transaction Agreement, the Selling Equityholders may elect to receive up to $100 million of their consideration in cash, subject to certain adjustments.

        The unaudited pro forma condensed combined financial statements have been prepared assuming (i) either no redemptions or that any redemptions of AHPAC shares would be entirely funded through the equity financing; (ii) the consummation of a Lender Consent and Amendment, and not athe Debt Refinancing and (iii) that Selling Equityholders would elect to receive $100 million of their consideration in cash.cash, subject to certain adjustments. Changes in the equity ownership under various scenarios relating to redemptions of AHPAC shares, the equity financing, the consummation or terms of a Debt Refinancing or the number of Selling Equityholders who elect to receive cash could result in Envigo being the acquiror for accounting purposes. If it were determined that Envigo is the accounting acquirer, the proposed transaction would not be accounted for as business combination but instead as a financing transaction, which would materially impact the unaudited pro forma condensed combined financial statements. The changes would include the elimination of all impacts of the fair value adjustments reflected in the accompanying pro forma financial information.

        The pro forma financial statements were prepared in accordance with Article 11 of SEC Regulation S-X. The pro forma adjustments reflecting the completion of the business combination are based upon the acquisition method of accounting in accordance with GAAP, and upon the assumptions set forth in the notes to the pro forma financial statements.

        The preliminary estimated purchase consideration, as calculated and described in Footnote 2 to the unaudited pro forma condensed combined financial statements, has been allocated to net tangible and intangible assets acquired based on their respective estimated fair values. We have made significant assumptions and estimates in determining the preliminary estimated purchase price consideration and the preliminary allocation of the estimated purchase price in the unaudited pro forma condensed combined financial statements. These preliminary estimates and assumptions are subject to change during the estimated purchase price allocation period (not to exceed one year from the Acquisition date) as we finalize the valuations of the net tangible and intangible assets. Differences between these preliminary estimates and the final acquisition accounting could have a material impact on the




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accompanying unaudited pro forma condensed combined financial statements and the combined company's future results of operations and financial position. Accordingly, the pro forma adjustments are preliminary and have been made solely for the purpose of providing unaudited pro forma condensed combined financial statements.

        The pro forma financial statements are not intended to represent or be indicative of the consolidated results of operations or financial position that would have been reported had the business combination been completed as of the dates presented, and should not be taken as representative of the future consolidated results of operations or financial position of the combined company following the business combination. The pro forma financial statements are based upon available information and certain assumptions that management believes are reasonable.




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UNAUDITED PRO FORMA CONDENSED COMBINED STATEMENT OF OPERATIONS

FOR THE FISCAL YEAR ENDED DECEMBER 31, 2016


(In thousands, except per share amounts)		Historical AHPAC FY16			Historical Envigo FY16			Pro-Forma Adjustments (3g)			Note Reference			Pro Forma Condensed Combined (Assuming No Redemptions)			Redemption Adj.(5)			Note Reference			Pro Forma Condensed Combined (Assuming $50M Redemptions)				Historical AHPAC FY16			Historical Envigo FY16			Pro-Forma Adjustments (3g)			Note Reference			Pro Forma Condensed Combined (Assuming No Redemptions)			Redemption Adj.(5)			Note Reference			Pro Forma Condensed Combined (Assuming $90M Redemptions)
Net revenues		$	—		$	415,429		$	—					$	415,429		$	—					$	415,429			$	—		$	415,429		$	—					$	415,429		$	—					$	415,429
Cost of sales			—			(280,199	)		—						(280,199	)		—						(280,199	)			—			(280,199	)		—						(280,199	)		—						(280,199	)
​	​	​	​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​		​	​	​	​	​
Gross profit			—			135,230			—						135,230			—						135,230				—			135,230			—						135,230			—						135,230
Selling, general and administrative expenses			(209	)		(96,037	)		(22,154	)		3(a), 3(h)			(118,400	)		—						(118,400	)			(209	)		(96,037	)		(20,121	)		3(a), 3(h)			(116,367	)		—						(116,367	)
Other operating (expense) income			—			(6,866	)		—						(6,866	)		—						(6,866	)			—			(6,866	)		—						(6,866	)		—						(6,866	)
​	​	​	​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​		​	​	​	​	​
Operating income			(209	)		32,327			(22,154	)					9,964			—						9,964				(209	)		32,327			(20,121	)					11,997			—						11,997
Interest expense, net			—			(41,360	)		17,987			3(c)			(23,373	)		(3,900	)		3	(c)		(27,273	)			—			(41,360	)		17,388			3(c)			(23,972	)		—						(23,972	)
Interest expense, related parties			—			(6,035	)		—						(6,035	)		—						(6,035	)			—			(6,035	)		6,035			3(c)			—			—						—
Loss on extinguishment of debt			—			(3,002	)		—						(3,002	)		—						(3,002	)			—			(3,002	)		—						(3,002	)		—						(3,002	)
Goodwill impairment loss			—			(678	)		—						(678	)		—						(678	)			—			(678	)		—						(678	)		—						(678	)
Foreign exchange gain (loss)			—			(20,524	)		—						(20,524	)		—						(20,524	)			—			(20,524	)		—						(20,524	)		—						(20,524	)
Other (expense) income			—			(2,815	)		—						(2,815	)		—						(2,815	)			—			(2,815	)		—						(2,815	)		—						(2,815	)
​	​	​	​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​		​	​	​	​	​
Income (loss) from continuing operations, before income taxes			(209	)		(42,087	)		(4,167	)					(46,463	)		(3,900	)					(50,363	)			(209	)		(42,087	)		3,302						(38,994	)		—						(38,994	)
Income tax (expense) benefit			—			3,902			1,458			3(d)			5,360			1,365			3	(d)		6,725				—			3,902			(1,156	)		3(d)			2,746			—						2,746
​	​	​	​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​		​	​	​	​	​
Net income (loss) from continuing operations		$	(209	)	$	(38,185	)	$	(2,709	)				$	(41,103	)	$	(2,535	)				$	(43,638	)		$	(209	)	$	(38,185	)	$	2,146					$	(36,248	)	$	—					$	(36,248	)
​	​	​	​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​		​	​	​	​	​
​
​	​	​	​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​		​	​	​	​	​
Net income (loss) per share:
Basic		$	(0.03	)										$	(0.63	)							$	(0.73	)		$	(0.03	)										$	(0.67	)							$	(0.68	)
Diluted		$	(0.03	)										$	(0.63	)							$	(0.73	)		$	(0.03	)										$	(0.67	)							$	(0.68	)
Shares used in computing net income (loss) per share:
Basic			7,920						29,872			3(e)																7,920						19,711			3(e)
									26,955			3(f)			64,747			(5,000	)		3	(f)		59,747										26,115			3(f)			53,746			(655	)		3(f)			53,091
Diluted			7,920						29,872			3(e)																7,920						19,711			3(e)
									26,955			3(f)			64,747			(5,000	)		3	(f)		59,747										26,115			3(f)			53,746			(655	)		3(f)			53,091

   

See accompanying Notes to the Unaudited Pro Forma Condensed Combined Financial Statements




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UNAUDITED PRO FORMA CONDENSED COMBINED STATEMENT OF OPERATIONS

FOR THE NINE MONTHS ENDED SEPTEMBER 30, 2017


(In thousands, except per share amounts)		Historical AHPAC YTD Sep-17			Historical Envigo YTD Sep-17			Pro-Forma Adjustments (3g)			Note Reference			Pro Forma Condensed Combined (Assuming No Redemptions)			Redemption Adj. (5)			Note Reference			Pro Forma Condensed Combined (Assuming $50M Redemptions)				Historical AHPAC YTD Sep-17			Historical Envigo YTD Sep-17			Pro-Forma Adjustments (3g)			Note Reference			Pro Forma Condensed Combined (Assuming No Redemptions)			Redemption Adj. (5)			Note Reference			Pro Forma Condensed Combined (Assuming $90M Redemptions)
Net revenues		$	—		$	303,650		$	—					$	303,650		$	—					$	303,650			$	—		$	303,650		$	—					$	303,650		$	—					$	303,650
Cost of sales			—			(201,719	)		—						(201,719	)		—						(201,719	)			—			(201,719	)		—						(201,719	)		—						(201,719	)
​	​	​	​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​		​	​	​	​	​
Gross profit			—			101,931			—						101,931			—						101,931				—			101,931			—						101,931			—						101,931
Selling, general and administrative expenses			(3,294	)		(67,822	)		(15,714	)		3(a), 3(h)			(86,830	)		—						(86,830	)			(3,294	)		(67,822	)		(14,240	)		3(a), 3(h)			(85,356	)		—						(85,356	)
Other operating (expense) income			—			(3,946	)		—						(3,946	)		—						(3,946	)			—			(3,946	)		—						(3,946	)		—						(3,946	)
​	​	​	​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​		​	​	​	​	​
Operating income			(3,294	)		30,163			(15,714	)					11,155			—						11,155				(3,294	)		30,163			(14,240	)					12,629			—						12,629
Interest expense, net			1,698			(30,140	)		13,080			3(b), 3(c)			(15,362	)		(3,168	)		3	(c)		(18,530	)			1,698			(30,140	)		10,510			3(b), 3(c)			(17,932	)		—						(17,932	)
Interest expense, related parties			—			(5,102	)		—						(5,102	)		—						(5,102	)			—			(5,102	)		5,102			3(c)			—			—						—
Loss on extinguishment of debt			—			—			—						—			—						—				—			—			—						—			—						—
Goodwill impairment loss			—			—			—						—			—						—				—			—			—						—			—						—
Foreign exchange gain (loss)			—			11,226			—						11,226			—						11,226				—			11,226			—						11,226			—						11,226
Other (expense) income			—			(738	)		—						(738	)		—						(738	)			—			(738	)		—						(738	)		—						(738	)
​	​	​	​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​		​	​	​	​	​
Income (loss) from continuing operations, before income taxes			(1,596	)		5,409			(2,634	)					1,179			(3,168	)					(1,989	)			(1,596	)		5,409			1,372						5,185			—						5,185
Income tax (expense) benefit			—			(4,151	)		922			3	(d)		(3,229	)		1,109			3	(d)		(2,120	)			—			(4,151	)		(480	)		3	(d)		(4,631	)		—						(4,631	)
​	​	​	​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​		​	​	​	​	​
Net income (loss) from continuing operations		$	(1,596	)	$	1,258		$	(1,712	)				$	(2,050	)	$	(2,059	)				$	(4,109	)		$	(1,596	)	$	1,258		$	892					$	554		$	—					$	554
​	​	​	​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​		​	​	​	​	​
​
​	​	​	​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​		​	​	​	​	​
Net income (loss) per share:
Basic		$	(0.35	)										$	(0.03	)							$	(0.07	)		$	(0.35	)										$	0.01								$	0.01
Diluted		$	(0.35	)										$	(0.03	)							$	(0.07	)		$	(0.35	)										$	0.01								$	0.01
Shares used in computing net income (loss) per share:
Basic			9,259						29,872			3	(e)															9,259						19,711			3	(e)
									25,616			3	(f)		64,747			(5,000	)		3	(f)		59,747										24,775			3	(f)		53,746			(655	)		3(f)			53,091
Diluted			9,259						29,872			3	(e)															9,259						19,711			3	(e)
									25,616			3	(f)		64,747			(5,000	)		3	(f)		59,747										24,775			3	(f)		53,746			(655	)		3(f)			53,091

   

See accompanying Notes to the Unaudited Pro Forma Condensed Combined Financial Statements




Table of Contents


UNAUDITED PRO FORMA CONDENSED COMBINED BALANCE SHEET

AT SEPTEMBER 30, 2017


(In thousands)		Historical AHPAC Sep-17			Historical Envigo Sep-17			Pro-Forma Adjustments*			Note Reference			Pro Forma Condensed Combined (Assuming No Redemptions)			Redemption Adj. (5)			Note Reference			Pro Forma Condensed Combined (Assuming $90M Redemptions)
ASSETS
Current assets
Cash and cash equivalents		$	118		$	56,123		$	(36,241	)		4	(a)	$	20,000		$	(6,547	)		4	(a)	$	13,453
Account receivable			—			58,593			—						58,593			—						58,593
Unbilled receivables			—			38,036			—						38,036			—						38,036
Inventories			—			14,067			4,449			4	(b)		18,516			—						18,516
Research and development credit receivable			—			7,497			—						7,497			—						7,497
Prepaid expenses and other current assets			242			10,724			—						10,966			—						10,966
​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​
Total current assets			360			185,040			(31,792	)					153,608			(6,547	)					147,061
Cash and cash equivalents held in trust account			311,658			—			(311,658	)		4	(c)		—			—						—
Accrued interest receivable held in trust account			40			—			(40	)		4	(c)		—			—						—
Property plant and equipment, net			—			159,074			—						159,074			—						159,074
Goodwill			—			168,930			327,526			4	(d)		496,456			—						496,456
Intangible assets, net			—			63,510			163,690			4	(e)		227,200			—						227,200
Research and development credit receivable			—			3,495			—						3,495			—						3,495
Other assets			—			1,497			—						1,497			—						1,497
Deferred income taxes			—			22,923			16,662			4	(f)		39,585			—						39,585
​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​
Total assets		$	312,058		$	604,469		$	164,388					$	1,080,915		$	(6,547	)				$	1,074,368
​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​
​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​
​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​
LIABILITIES AND EQUITY
Current liabilities
Accounts payable		$	—		$	26,362		$	—					$	26,362		$	—					$	26,362
Accrued payroll and other benefits			—			12,491			—						12,491			—						12,491
Accrued expenses and other liabilities			2,696			19,920			—						22,616			—						22,616
Accrued loan interest			—			8,993			(8,993	)		4	(g)		—			—						—
Short-term debt			—			1,384			(1,384	)		4	(i)		—			—						—
Fees invoiced in advance			—			67,350			(6,350	)		4	(h)		61,000			—						61,000
​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​
Total current liabilities			2,696			136,500			(16,727	)					122,469			—						122,469
Long-term debt, net			—			412,632			(125,351	)		4	(i)		287,281			—						287,281
Related party long term debt, net						43,990			(43,990	)		4	(i)		—			—						—
Deferred underwriting commission			10,850			—			(10,850	)		4	(j)		—			—						—
Contingent consideration			—			—			14,128			4	(k)		14,128			—						14,128
Other liabilities			—			45,606			(11,338	)		4	(l)		34,268			—						34,268
Pension liabilities			—			56,958			—						56,958			—						56,958
Long-term deferred tax liabilities			—			11,430			61,072			4	(m)		72,502			—						72,502
​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​
Total liabilities			13,546			707,116			(133,056	)					587,606									587,606
Redeemable Equity			293,512			—			(293,512	)		4	(n)		—			—						—
Company stockholder's equity (deficit)
Additional paid in capital			6,829			200,125			299,380			4	(o), 4(n)		506,334			(7,382	)		4	(n)		498,952
Class A Ordinary shares			—			—			1,972			4	(p)		1,972			835			4	(n)		2,807
Class B Ordinary shares			1			—			(1	)		4	(q)		—			—						—
Accumulated earnings (deficit)			(1,830	)		(272,059	)		258,892			4	(o), 4(r)		(14,997	)		—						(14,997	)
Accumulated other comprehensive loss			—			(32,068	)		32,068			4	(o)		—			—						—
​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​
Total company stockholder's equity (deficit)			5,000			(104,002	)		592,311			4	(s)		493,309			(6,547	)					486,762
Non-controlling interests in subsidiaries			—			1,355			(1,355	)		4	(o)		—			—						—
​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​
Total equity (deficit)			5,000			(102,647	)		590,956						493,309			(6,547	)					486,762
​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​
Total liabilities and equity (deficit)		$	312,058		$	604,469		$	164,388					$	1,080,915		$	(6,547	)				$	1,074,368
​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​
​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​
​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​

---

(In thousands)		Historical AHPAC Sep-17			Historical Envigo Sep-17			Pro-Forma Adjustments			Note Reference			Pro Forma Condensed Combined (Assuming No Redemptions)			Redemption Adj. (5)			Note Reference			Pro Forma Condensed Combined (Assuming $50M Redemptions)
ASSETS
Current assets
Cash and cash equivalents		$	118		$	56,123		$	(30,190	)		4	(a)	$	26,051		$	365			4	(a)	$	26,416
Account receivable			—			58,593			—						58,593			—						58,593
Unbilled receivables			—			38,036			—						38,036			—						38,036
Inventories			—			14,067			4,449			4	(b)		18,516			—						18,516
Research and development credit receivable			—			7,497			—						7,497			—						7,497
Prepaid expenses and other current assets			242			10,724			—						10,966			—						10,966
​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​
Total current assets			360			185,040			(25,741	)					159,659			365						160,024
Cash and cash equivalents held in trust account			311,658			—			(311,658	)		4	(c)		—			—						—
Accrued interest receivable held in trust account			40			—			(40	)		4	(c)		—			—						—
Property plant and equipment, net			—			159,074			—						159,074			—						159,074
Goodwill			—			168,930			278,753			4	(d)		447,683			(3,171	)		4	(d)		444,512
Intangible assets, net			—			63,510			183,290			4	(e)		246,800			—						246,800
Research and development credit receivable			—			3,495			—						3,495			—						3,495
Other assets			—			1,497			—						1,497			—						1,497
Deferred income taxes			—			22,923			108,033			4	(f)		130,956			—						130,956
​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​
Total assets		$	312,058		$	604,469		$	232,637					$	1,149,164		$	(2,806	)				$	1,146,358
​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​
​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​
​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​
LIABILITIES AND EQUITY
Current liabilities
Accounts payable		$	—		$	26,362		$	—					$	26,362		$	—					$	26,362
Accrued payroll and other benefits			—			12,491			—						12,491			—						12,491
Accrued expenses and other liabilities			2,696			19,920			—						22,616			—						22,616
Accrued loan interest			—			8,993			(1,409	)		4	(g)		7,584			365			4	(g)		7,949
Short-term debt			—			1,384			—						1,384			—						1,384
Fees invoiced in advance			—			67,350			(6,350	)		4	(h)		61,000			—						61,000
​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​
Total current liabilities			2,696			136,500			(7,759	)					131,437			365						131,802
Long-term debt, net			—			412,632			(182,762	)		4	(i)		229,870			46,829			4	(i)		276,699
Related party long term debt, net						43,990									43,990			—						43,990
Deferred underwriting commission			10,850			—			(10,850	)		4	(j)		—			—						—
Contingent consideration			—			—			14,781			4	(k)		14,781			—						14,781
Other liabilities			—			45,606			(45,606	)		4	(l)		—			—						—
Pension liabilities			—			56,958			—						56,958			—						56,958
Long-term deferred tax liabilities			—			11,430			67,932			4	(m)		79,362			—						79,362
​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​
Total liabilities			13,546			707,116			(164,264	)					556,398			47,194						603,592
Redeemable Equity			293,512			—			(293,512	)		4	(n)		—			—						—
Company stockholder's equity (deficit)
Additional paid in capital			6,829			200,125			399,968			4	(o), 4(n)		606,922			(50,000	)		4	(n)		556,922
Class A Ordinary shares			—			—			2,988			4	(p)		2,988			—						2,988
Class B Ordinary shares			1			—			(1	)		4	(q)		—			—						—
Accumulated earnings (deficit)			(1,830	)		(272,059	)		256,745			4	(o), 4(r)		(17,144	)		—						(17,144	)
Accumulated other comprehensive loss			—			(32,068	)		32,068			4	(o)		—			—						—
​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​
Total company stockholder's equity (deficit)			5,000			(104,002	)		691,768			4	(s)		592,766			(50,000	)					542,766
Non-controlling interests in subsidiaries			—			1,355			(1,355	)		4	(o)		—			—						—
​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​
Total equity (deficit)			5,000			(102,647	)		690,413						592,766			(50,000	)					542,766
​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​
Total liabilities and equity (deficit)		$	312,058		$	604,469		$	232,637					$	1,149,164		$	(2,806	)				$	1,146,358
​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​
​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​
​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​	​

*

Note: Pro forma balance sheet does not reflect $8 million of cash proceeds received from sale of dog business in October 2017 as shown in sources and uses on page 99.

   

See accompanying Notes to the Unaudited Pro Forma Condensed Combined Financial Statements




Table of Contents


NOTES TO UNAUDITED PRO FORMA CONDENSED

COMBINED FINANCIAL STATEMENTS


1. Description of the Transaction and Basis of Presentation

Description of the Transaction


        AHPAC entered into the Transaction Agreement to acquire 100% of the outstanding shares of Envigo. Based on the terms of the Transaction Agreement, the consideration paid by AHPAC will consist of cash, shares, warrants, and a Tax Receivable Agreement ("TRA"). AHPAC has estimated the transaction price and associated fees to be approximately $413.5$302.1 million comprised of (a) $398.7$288.0 million in cash and shares of ENVG, successor to AHPAC, Class A common stock ($428.8322.4 million offset by estimated Envigo transaction expenses incurred of $38.5$42.3 million, including non-cash expenses in the amount of $8.3$7.8 million) and (b) amounts contingently payable to the Selling Equityholders under the TRA. See Footnote 2 below for further discussion of the purchase consideration.

Basis of Presentation


        The unaudited pro forma condensed combined financial statements are based on AHPAC's and Envigo's historical consolidated financial statements as adjusted to give effect to the business combination. The unaudited pro forma condensed combined statements of operations for the nine months ended September 30, 2017 and the 12 months ended December 31, 2016 give effect to the business combination as if it had occurred on January 1, 2016. The unaudited pro forma condensed combined balance sheet as of September 30, 2017 gives effect to the business combination as it if had occurred on September 30, 2017.

        The unaudited pro forma condensed combined financial statements were prepared using the acquisition method of accounting and based on the historical financial information of AHPAC and Envigo. The acquisition method of accounting in accordance with ASC 805, "Business Combinations" (ASC 805) requires, among other things, that assets acquired and liabilities assumed in a business combination be recognized at their fair values as of the acquisition date, as defined in ASC 820, "Fair Value Measurement" (ASC 820). The historical consolidated financial information has been adjusted in the unaudited pro forma condensed combined financial statements to give effect to pro forma events that are (1) directly attributable to the transaction, (2) factually supportable, and (3) with respect to the unaudited pro forma condensed combined statement of operations, expected to have a continuing impact on the consolidated results.

        Under ASC 805, acquisition-related transaction costs are not included as a component of consideration transferred but are accounted for as expenses in the periods in which such costs are incurred, or if related to the issuance of debt, capitalized as debt issuance costs. Acquisition-related transaction costs expected to be incurred as part of the Acquisition include estimated fees related to the issuance of long-term debt, as well as advisory, legal and accounting fees.

        The unaudited pro forma condensed combined financial statements were prepared using the acquisition method of accounting and based on the historical financial information of AHPAC and Envigo, assuming that AHPAC is the acquirer for accounting purposes. Pursuant to AHPAC's existing amended and restated memorandum and articles of association, a holder of public shares may request that AHPAC redeem all or a portion of such shareholder's public shares (which will become shares of ENVG Class A common stock following the domestication) for cash if the business combination is consummated. If a public shareholder properly exercises its right to redeem its public shares and timely delivers its shares to the transfer agent, AHPAC will redeem each public share for a per-share price, payable in cash, equal to the aggregate amount then on deposit in the trust account, calculated as of two business days prior to the consummation of the business combination, including interest, less income taxes payable, divided by the number of then issued and outstanding public shares.




Table of Contents


NOTES TO UNAUDITED PRO FORMA CONDENSED

COMBINED FINANCIAL STATEMENTS (Continued)

1. Description of the Transaction and Basis of Presentation (Continued)

        In addition, Selling Equityholders may elect to receive up to $100 million of their consideration in cash, subject to certain adjustments. The unaudited pro forma condensed combined financial statements have been prepared assuming (i) either no redemptions or that any redemptions of AHPAC shares would be entirely funded through the equity financing; (ii) the consummation of a Lender Consent and Amendment, and not athe Debt Refinancing and (iii) that Selling Equityholders would elect to receive $100 million of their consideration in cash.cash, subject to certain adjustments. Changes in the equity ownership under various scenarios relating to redemptions of AHPAC shares, the equity financing, the consummation or terms of a Debt Refinancing or the number of Selling Equityholders who elect to receive cash could result in accounting for the transaction as a financing transaction which could materially change the presentation of the unaudited pro forma condensed combined financial statements.

        The unaudited pro forma condensed combined financial information does not reflect the impact of possible revenue or earnings enhancements, cost savings initiatives, or asset dispositions. Also, the unaudited pro forma condensed combined financial information does not reflect possible adjustments related to restructuring or integration activities that have yet to be determined or transaction or other costs following the business combination that are not expected to have a continuing impact. The unaudited pro forma condensed combined financial statements have been compiled using the significant accounting policies as set forth in the audited consolidated financial statements included in this proxy statement / prospectus. During the preparation of the unaudited pro forma condensed combined financial information, AHPAC's management performed an analysis of accounting policies at Envigo, and is not aware of any differences that could have a material impact on the unaudited pro forma condensed combined financial statements.

2. Preliminary Estimate of Purchase Price Consideration and Related Allocation

        The preliminary purchase price is based on an assumed purchase price of approximately $413.5$302.1 million, which is subject to change as described below. The final purchase price will be determined at the date of close.

        The preliminary purchase price allocation and the estimated fair value of the assets acquired and liabilities assumed is based on management's best estimates of fair value. The Company has assumed for the purpose of the pro forma financials that the fair value of property, plant, and equipment is equivalent to book value. The Company believes that book value is a good approximation for fair value for preliminary purchase accounting because the fair values of property, plant and equipment are based on relatively recent transactions. Legacy LSR fixed assets were fair valued during the 2012 sale lease back transaction. Legacy Harlan fixed assets were fair valued during the 2014 acquisition by LSR. A fair value analysis of property, plant, and equipment will be completed in connection with the finalization of the purchase price allocation.

        The final allocation of the purchase consideration will be determined after completion of a thorough analysis to determine the fair value of all assets acquired and liabilities assumed but in no event later than one year following completion of the business combination. Accordingly, the final acquisition accounting adjustments could differ materially from the unaudited pro forma adjustments presented herein. Any increase or decrease in the fair value of the assets acquired or liabilities assumed, as compared to the information shown herein, could also change the portion of the purchase price consideration allocable to goodwill and could impact the operating results of the Company following the business combination due to differences in the allocation of the purchase consideration, depreciation and amortization related to some of these assets and liabilities.




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NOTES TO UNAUDITED PRO FORMA CONDENSED

COMBINED FINANCIAL STATEMENTS (Continued)

2. Preliminary Estimate of Purchase Price Consideration and Related Allocation (Continued)

Preliminary Estimate of Purchase Price Consideration


        The following table represents the preliminary estimate of total purchase consideration:

(In thousands)		September 30, 2017				September 30, 2017
Cash consideration(1)			100,000				90,847
Stock Issued(1)			298,718				197,114
Plus: Contingent Consideration—Tax Receivable Agreement(2)			14,781				14,128
​	​	​	​	​	​	​	​	​
Total Purchase Consideration		$	413,499			$	302,089
​	​	​	​	​	​	​	​	​
​
​	​	​	​	​	​	​	​	​

---

(1)

The Selling Equityholders will have an option to elect to receive either cash or shares. The Company has estimated the total value of the shares and cash to be approximately $428.8$322.4 million, which is reduced by the estimated Envigo cash transaction expenses of $30.2$34.5 million resulting in an adjusted value of $398.7$288.0 million. The total cash and number of shares are subject to change based on the amount of redemptions of AHPAC shares (if any), the consummation of the equity financing (if any), the consummation of a Debt Refinancing (if any), and the election of the Selling Equityholders as described below.


Cash—The Transaction Agreement provides a limit on the amount of aggregate cash consideration to be paid to the Selling Equityholders of $100.0 million, subject to certain adjustments.adjustments as defined in the Transaction Agreement. This includes an adjustment, as applicable, to reduce the total cash paid to the Selling Equityholders by an amount necessary to maintain a minimum $20 million of estimated pro forma cash on the balance sheet. In the case of such adjustment, a corresponding increase would be made to shares issued to offset the reduction of cash considerations. The amount of cash consideration paid to the Selling Equityholders will be reduced pro rata amongst all such holders electing cash consideration so that the aggregate amount of cash consideration paid to all Selling Equityholders does not exceed the cash component. Cash consideration totalled $90.8 million which included an adjustment of $9.2 million from the maximum cash election of $100.0 million to maintain a minimum $20 million of pro forma cash on the balance sheet. Accordingly, there was a $9.2 million increase in stock issued due to the reduction of cash considerations. The pro forma financial statements are prepared under the assumptionassumptions that (a) there are no redemptions or that any redemptions of AHPAC shares would be fundedoffset through the equity financing, (b) there is a consummation of a Lender Consent and Amendment, and not a Debt Refinancing and (c) that Selling Equityholders will elect to receive the maximum amount of cash consideration permitted under the transaction agreement. In turn, the Selling Equityholders will receive $298.7$197.1 million of shares of Class A common stock.

Additionally, the $90.8 million of total cash paid to selling equity holders includes the cash settlement of Envigo SARs.

Shares—AHPAC issued its shares at $10.00 per share. Management has determined that the $10.00 per share represents the best estimate of the fair value of the stock price upon consummation of the business combination. The actual price per share will be based on the share price at the time of close, and as a result the value of the shares is subject to change. The table below provides a sensitivity analysis which indicates the impact to goodwill and equity when using a range of $10.00 per share to $11.50 per share as the estimated fair value of the ENVG Class A common stock.

(In thousands)		September 30, 2017 @ $10.00 per share			September 30, 2017 @ $10.50 per share			September 30, 2017 @ $11.00 per share			September 30, 2017 @ $11.50 per share
Shares			29,872			29,872			29,872			29,872
Stock Issued		$	298,718		$	313,654		$	328,590		$	343,526
Equity		$	592,766		$	607,702		$	622,638		$	637,574
Goodwill		$	447,683		$	462,619		$	477,555		$	492,491




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NOTES TO UNAUDITED PRO FORMA CONDENSED

COMBINED FINANCIAL STATEMENTS (Continued)

2. Preliminary Estimate of Purchase Price Consideration and Related Allocation (Continued)

goodwill and equity when using a range of $10.00 per share to $11.50 per share as the estimated fair value of the ENVG Class A common stock.

(In thousands)		September 30, 2017 @ $10.00 per share			September 30, 2017 @ $10.50 per share			September 30, 2017 @ $11.00 per share			September 30, 2017 @ $11.50 per share
Shares			19,711			19,711			19,711			19,711
Stock Issued		$	197,114		$	206,970		$	216,826		$	226,681
Equity		$	493,309		$	503,165		$	513,020		$	522,876
Goodwill		$	496,456		$	506,312		$	516,167		$	526,023

See the section titled "The Business Combination—The Transaction Agreement—Equity Financing" beginning on page [    ·    ]86 of this proxy statement/prospectus for further details regarding AHPAC's obligations in connection with the equity financing.

See the section titled "The Transaction Agreement—Related Agreements—Financing Arrangements" beginning on page [    ·    ]129 of this proxy statement/prospectus for further details regarding Envigo's obligations in connection with a Debt Refinancing.

(2)

As part of the business combination, the Company will enter into the TRA with the Selling Equityholders. The TRA will generally provide for the future payments by ENVG to the Selling Equityholders of 85% of the U.S. federal, state, local and U.K. cash tax savings deemed realized by ENVG and its subsidiaries in post-closing taxable periods as a result of the utilization of net operating losses available to be carried forward as of the date of consummation of the business combination and the imputed interest deductions arising from payments under the TRA. Although the amount and timing of any payments under the TRA will vary depending on a number of factors, including the amount and timing of income, the Company expects that the payments it may be required to make could be substantial. This reflects the estimated fair value of the contingent consideration related to the TRA.




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NOTES TO UNAUDITED PRO FORMA CONDENSED

COMBINED FINANCIAL STATEMENTS (Continued)

2. Preliminary Estimate of Purchase Price Consideration and Related Allocation (Continued)

Preliminary Allocation of Estimated Purchase Price to Assets Acquired and Liabilities Assumed


        The following represents the preliminary allocation of the purchase price to the assets acquired and the liabilities assumed in the business combination.

(In thousands)		Estimated Fair Value at September 30, 2017				Estimated Fair Value at September 30, 2017
Tangible Assets Acquired:
Acquired cash		$	56,123			$	56,123
Inventory			18,516				18,516
Other current assets(3)			114,850				114,850
Property, plant & equipment			159,074				159,074
Other non-current assets(4)			4,992				4,992
​	​	​	​	​	​	​	​	​
Total tangible assets		$	353,555			$	353,555
Liabilities Assumed
Debt assumed		$	479,237			$	496,730
Current liabilities assumed			119,773				119,773
Pension liabilities assumed			56,958				56,958
Other liabilities assumed							34,268
​	​	​	​	​	​	​	​	​
Total liabilities assumed		$	655,968			$	707,729
Envigo transaction expenses			(30,165	)			(34,475	)
Long-term deferred tax liabilities, net			51,594				(32,917	)
Identifiable intangible assets(1)			246,800				227,200
​	​	​	​	​	​	​	​	​
Goodwill(2)			447,683				496,456
​	​	​	​	​	​	​	​	​
Total Purchase Consideration		$	413,499			$	302,089
​	​	​	​	​	​	​	​	​
​
​	​	​	​	​	​	​	​	​

---

(1)

As of the effective date of the business combination, identifiable intangible assets are required to be measured at fair value. For purposes of these unaudited pro forma condensed combined financial statements, it is assumed that all assets will be used and that all assets will be used in a manner that represents the highest and best use of those assets. AHPAC used an income approach to estimate the preliminary fair value of intangible assets. The acquired intangibles have an estimated weighted-average useful life of approximately 12.112.0 years and will be amortized using the straight-line method. The definite-lived intangible assets include CRS customer relationships, RMS customer relationships, trademark/tradename, technology, and backlog assets. There were no indefinite-lived intangible assets.



(2)

Goodwill is calculated as the difference between the estimated fair value of the consideration transferred and the estimated fair values of the assets acquired and liabilities assumed. Goodwill is not amortized.



(3)

Other current assets is comprised of various receivables, prepaids and other current assets.



(4)

Other non-current assets is comprised of long term research and development credit receivables and other non-current assets.




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NOTES TO UNAUDITED PRO FORMA CONDENSED

COMBINED FINANCIAL STATEMENTS (Continued)

2. Preliminary Estimate of Purchase Price Consideration and Related Allocation (Continued)

(4)

Other non-current assets is comprised of long term research and development credit receivables and other non-current assets.

3. Pro-Forma Adjustments to the Statements of Operations

(a)

Represents the adjustment to record the incremental intangible asset amortization expense as follows:

(In thousands)		FY16			YTD Sep-17				FY16			YTD Sep-17
Prelim. Amortization Exp.		$	29,909		$	21,031			$	27,876		$	19,557
Historical Amortization Exp.			(7,755	)		(5,317	)			(7,755	)		(5,317	)
​	​	​	​	​	​	​	​	​	​	​	​	​	​	​
Adjustment		$	22,154		$	15,714			$	20,121		$	14,240
​	​	​	​	​	​	​	​	​	​	​	​	​	​	​
​
​	​	​	​	​	​	​	​	​	​	​	​	​	​	​

Refer to Footnote 4(e) within the Pro Forma Adjustments to the Balance Sheet section for additional detail as to the computation of the pro-forma intangible amortization expense.

(b)

Represents the adjustment to eliminate $1.7 million of historical interest income of AHPAC associated with the funds that were previously held in trust, which will be used to fund the purchase consideration to effectuate the Acquisition.



(c)

In connection with the acquisition there will be certain modifications toa refinancing of Envigo's borrowing arrangements and AHPAC intends to repay approximately $193.0$487.7 million of Envigo's debt will be repaid in connection with the business combination. As part of the refinancing, Envigo will also enter into a Term Loan Agreement for an aggregate amount of $300.0 million. The interest rate per annum applicable to the Term Loan is equal to the London Interbank Offered Rate ("LIBOR") rate plus 5.50%. The Term Loan was issued with a 2.0% of original issue discount. Additionally, Envigo will enter into a Revolving Credit Agreement which allows borrowings up to $50.0 million. The interest rate per annum applicable to the Revolving Credit Agreement is equal to the LIBOR rate plus 3.75%. The Revolving Credit Agreement was issued with 0.5% of original issue discount. The Revolving Credit Agreement also includes an annual commitment fee of 50-basis points on the $50.0 million less any outstanding borrowings which is included as Interest Expense, net. As of the close of the business combination ENVG will not have any borrowings under the Revolving Credit Agreement. The following represents an adjustment to historical interest expense to reflect the impact of these transactions The adjustment includestransaction including the following:

(In thousands)		FY16			YTD Sep-17				FY16			YTD Sep-17
Change in Interest Expense		$	7,349		$	6,071	(1)
Change in Amortization Expense—Discounts & Warrants			6,083			4,917	(2)
Change in Amortization Expense—Deferred Financing Costs			1,234			954	(3)
Additional Amortization Expense—New Deferred Financing Costs			(300	)		(225	)(4)
Change in Interest Expense—Related Party Debt			3,621			3,061	(5)
Historical Interest Expense									$	47,395		$	35,242	(1)
New Financing Interest Expense										(21,850	)		(16,343	)(2)
Amortization Expense—Discount										(1,042	)		(779	)(3)
Amortization Expense—New Deferred Financing Costs										(1,080	)		(810	)(4)
​	​	​	​	​	​	​	​	​	​	​	​	​	​	​
Total Adjustment		$	17,987		$	14,778			$	23,423		$	17,310
​	​	​	​	​	​	​	​	​	​	​	​	​	​	​
​
​	​	​	​	​	​	​	​	​	​	​	​	​	​	​

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(1)

Reflects a decrease in historical interest expense resulting from the repayment of $193.0$487.7 million of Envigo's debt.



(2)

Decreasedebt in association with the debt refinancing. This includes historical amortization expense associated with the original issue discount and warrants associated with the repaid borrowings.



(3)

Decrease in historical amortization expense associated with deferred financing costs associated with the repaid borrowings.



(4)

In connection with the debt modifications by Envigo there were additional debt issuance costs capitalized that will be amortized over the term of the borrowings. This represents the increase in amortization expense related to these deferred financing costs.



(5)

Envigo agreed with noteholders under the existing Third Lien Indenture to a modification of certain terms of the existing Third Lien Indenture, subject to the consummation of the business combination. Under the modification the noteholders have agreed, among other things, to reduce the interest rate from 15.0% to 6.0%. This adjustment reflects the reduction in interest expense associated with the interest rate decrease.pre-existing debt.




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NOTES TO UNAUDITED PRO FORMA CONDENSED

COMBINED FINANCIAL STATEMENTS (Continued)

3. Pro-Forma Adjustments to the Statements of Operations (Continued)

The redemption scenario assumes that a $50

(2)

Represents interest expense recorded for the $300.0 million redemption of AHPAC shares would result in an equal reduction in the pay down of long-term debt. As such, redemption adjustments are included to reflect a decrease in the change in interest and amortization expense as a lower portionprincipal amount outstanding of the outstanding debt would be paid down in this scenario.

Envigo expects to record various transaction expensesnewly issued Term Loan as well as interest expense associated with the 50-basis points commitment fee on the Revolving Credit Agreement.



(3)

Amortization expense associated with the original issue discount of the newly issued Term Loan and Revolving Credit facility.



(4)

In connection with the debt modifications inrefinancing and issuance of the period incurredTerm Loan and Revolving Credit Facility by Envigo there were additional debt issuance costs capitalized that will recognize a gainbe amortized over the term of the borrowings. This represents amortization expense related to the modification of the related party loan. The gain has not been reflected in the pro-forma statements of operations due to the fact that this is non-recurring.

these deferred financing costs.

(d)

Reflects the income tax effect of the pro-forma adjustments which have been calculated based on an estimated effective marginal tax rate of 35.0%. The effective tax rate of the combined company could be significantly different depending on post-acquisition income and other activities in various foreign tax jurisdictions.



(e)

Reflects the increase in the weighted average shares in connection with the issuance of 29.8719.71 million common shares to finance the business combination at $10.00 per share.



(f)

AHPAC's common stock prior to the consummation of the business combination is subject to a possible redemption and, as such, was recorded as temporary equity in AHPAC's historical consolidated balance sheet as of September 30, 2017. In connection with the consummation of the business combination, the AHPAC shareholders have the option to exercise their right to redeem these shares. If the shareholders do not elect redemption at such time, the shares are no longer redeemable. The Company has assumed for the purpose of the pro forma basic and diluted shares outstanding that no shareholders will request redemption of their shares.


As part of the consummation of the business combination, 50% of AHPAC's existing Class B ordinary shares (3.875 million) are being surrendered by the sponsor and an equivalent number of Class A ordinary shares are being issued to Envigo shareholders and included in the issuance of common shares as discussed in Footnote 3(e). This adjustment reflects the reduction of such shares as they are currently included within the total 29.8719.71 million common shares being issued. Additionally, 841 thousand of AHPAC's existing Class B ordinary shares are being forfeited.

For the redemption scenario, the number of shares outstanding has been reduced by 5a total of 655 thousand shares. This includes a reduction of 9.0 million shares ($5090 million of redemptions at $10.00 per share) assuming max redemptions. This is partially offset by the issuance of 8.3 million shares ($83.5 million of additional shares issued to selling equity holders at $10.00 per share). Refer to Footnote 4(n) for additional detail.

(g)

The pro forma statements of operations do not reflect certain non-recurring items or items that are not expected have a continuing impact. (i.e., an impact greater than 12 months) such as the Company's transaction expenses, debt modification costs, and impact of fair value adjustment to fees invoiced in advance and inventory.



(h)

The Tax Receivable Agreement will be accounted for as a contingent liability and recorded at estimated fair value at each reporting date with the change in value reflected as a period expense in the statements of operations. The pro forma statements of operations do not reflect an adjustment for the potential change in fair value of the Tax Receivable Agreement as potential changes in fair value cannot be determined at this time.




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NOTES TO UNAUDITED PRO FORMA CONDENSED

COMBINED FINANCIAL STATEMENTS (Continued)

4. Pro Forma Adjustments to the Balance Sheet

(a)

Represents the net adjustment to cash associated with the business combination and associated transactions:

(In thousands)		Sep-17				Sep-17
Cash from Trust Account		$	311,698	(1)		$	311,698	(1)
Paydown of Envigo debt			(193,000	)(2)			(487,724	)(2)
Cash consideration to Envigo shareholders			(100,000	)(3)			(90,847	)(3)
Payment of debt amendment costs			(2,000	)(4)
Payment of debt amendment costs including OID							(12,733	)(4)
Payment of Envigo cash transaction expenses			(30,165	)(5)			(34,475	)(5)
Payment of AHPAC transaction expenses			(15,314	)(6)			(13,167	)(6)
Payment of accrued interest			(1,409	)(7)			(8,993	)(7)
Term Loan issuance							300,000	(8)
​	​	​	​	​	​	​	​	​
Total Adjustment		$	(30,190	)(8)		$	(36,241	)(9)
​	​	​	​	​	​	​	​	​
​
​	​	​	​	​	​	​	​	​

---

(1)

Represents the adjustment related to the reclassification of the cash equivalents held in the trust account in the form of investments to cash and cash equivalents to reflect the fact that these investments are available for use in connection with the business combination and the payment of the cash purchase consideration and repayment of a portion of historical Envigo long-term debt.



(2)

Represents the repayment of certain EnvigoEnvigo's debt in accordance with certain modifications torefinancing of Envigo's borrowing arrangements.



(3)

Represents the cash consideration paid to Selling Equityholders related to the business combination assuming there are no redemptions or that (a) any redemptions of AHPAC shares would be fundedoffset through additional equity investments from third parties, (b) there is a consummation of a Lender Consent and Amendment, and not a Debt Refinancing and (c) that Selling Equityholders will elect to receive the maximum amount of cash consideration permitted under the Transaction Agreement.Agreement, subject to certain adjustments.



(4)

Represents capitalizable debt amendment costs including fees paid to lenders and related legal expenses.expenses as well as the OID of the newly issued Term Loan and Revolving Credit Agreement.



(5)

Represents an adjustment to record estimated Envigo acquisition-related cash transaction costs.



(6)

Represents an adjustment to record estimated AHPAC acquisition-related transaction costs.



(7)

Represents the payment of the pro-rata portion of accrued interest resulting frombalance in association with the repayment of $193.0$487.7 million of Envigo debt at closing.closing due to the refinancing.



(8)

Represents the gross cash proceeds from the newly issued Term Loan.



(9)

The AHPAC public shareholders have the right to request redemption of their ordinary shares in connection with the business combination as described below in Footnote 4(l)4(n). For purposes of the pro forma balance sheet, the Company has presented scenarios assuming no redemptions and $50$90 million of redemptions. When assuming $50$90 million of redemptions, cash is reduced by $6.5 million. Although there is no net impacta requirement to the cash balance as $50maintain a minimum of $20 million of lessestimated pro forma cash proceedson the balance sheet, such requirement is offsetgoverned by $50payouts to shareholders beyond the SARs payments. To the extent cash sources are not adequate to cover the SARs payments ($7.4 million) the amount of cash can be reduced below the $20 million less pay down of Envigo debt.threshold.




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NOTES TO UNAUDITED PRO FORMA CONDENSED

COMBINED FINANCIAL STATEMENTS (Continued)

4. Pro Forma Adjustments to the Balance Sheet (Continued)

Under the assumption of $50 million redemptions, less accrued interest would be paid down which is reflected in the redemption adjustment of $365 thousand.

(b)

Represents the adjustment to increase the inventory balance by $4.4 million to its preliminary fair value of $18.5 million.



(c)

Represents an adjustment to reflect the reclassification of funds held in trust by AHPAC to cash and cash equivalents to be used to fund a portion of the overall purchase consideration.



(d)

Represents the adjustment to goodwill based on the preliminary purchase price allocation. Refer to Footnote 2 for additional detail as to the purchase price calculation.

(In thousands)		Sep-17				Sep-17
Elimination of Envigo's historical goodwill		$	(168,930	)		$	(168,930	)
Goodwill from preliminary allocation of purchase consideration			447,683				496,456
​	​	​	​	​	​	​	​	​
Net adjustment to goodwill		$	278,753			$	327,526
​	​	​	​	​	​	​	​	​
​
​	​	​	​	​	​	​	​	​

Under the assumption of $50 million redemptions, goodwill would be reduced by $3.2 million, as the anticipated pay down of debt would be $50 million less which in turn reduces the write-down of deferred financing costs and discounts and warrants.

(e)

Represents the net adjustment to intangible assets based on the preliminary purchase price allocation and calculated as follows:

(In thousands)		Sep-17				Sep-17
Elimination of Envigo's historical intangible assets		$	(63,510	)		$	(63,510	)
Intangible assets from preliminary allocation of purchase consideration			246,800				227,200
​	​	​	​	​	​	​	​	​
Net adjustment to intangible assets		$	183,290			$	163,690
​	​	​	​	​	​	​	​	​
​
​	​	​	​	​	​	​	​	​

        The estimated intangible assets, and the associated amortization expense, are as follows:

(In thousands)		Prelim FV			Prelim Est. Useful Life (Years)			FY16 Amort. Exp.			Nine Months Ended Sep-17 Exp.				Prelim FV			Prelim Est. Useful Life (Years)			FY16 Amort. Exp.			Nine Months Ended Sep-17 Exp.
CRS—Customer Relationships		$	129,000			7		$	18,429		$	13,821			$	120,000			7		$	17,143		$	12,857
RMS—Customer Relationships			52,000			20			2,600			1,950				47,100			20			2,355			1,766
Trademark/Tradename—Envigo			36,200			20			1,810			1,358				32,500			20			1,625			1,219
Animal Strains—DT			13,000			15			867			650				11,900			15			793			595
RMS—Teklad IP			6,500			15			433			325				6,000			15			400			300
CRS—Inhalation IP			1,700			10			170			128				1,600			10			160			120
Backlog Asset (CRS)			8,400			1.5			5,600			2,800				8,100			1.5			5,400			2,700
​	​	​	​	​		​	​	​	​	​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​
Total Intangible Assets		$	246,800					$	29,909		$	21,031			$	227,200					$	27,876		$	19,557
​	​	​	​	​		​	​	​	​	​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​
​	��	​	​	​		​	​		​	​		​	​	​		​	​		​	​		​	​		​	​
​	​	​	​	​		​	​	​	​	​	​	​	​	​	​	​	​		​	​	​	​	​	​	​	​

Amortization expense of intangible assets is reflected within Selling, General, and Administrative in the Statement of Operations.




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NOTES TO UNAUDITED PRO FORMA CONDENSED

COMBINED FINANCIAL STATEMENTS (Continued)

4. Pro Forma Adjustments to the Balance Sheet (Continued)

(f)

Reflects a $108.0$16.7 million increase in deferred tax assets as a result of an increase in intangible assets which represents a reversing temporary difference and creates sufficient taxable income for book purposes to utilize existing NOL's. The offset to this adjustment is a corresponding decrease in goodwill.



(g)

Reflects a pro-rata decrease in accrued interest resulting from the repayment of $193.0 millionrefinancing of Envigo's debt.




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NOTES TO UNAUDITED PRO FORMA CONDENSED

COMBINED FINANCIAL STATEMENTS (Continued)

4. Pro Forma Adjustments to the assumption of a $50 million redemption of AHPAC shares by AHPAC shareholders, the debt pay down is reduced by $50 million. As a result, less accrued interest would be paid down in this scenario which is reflected a redemption adjustment.Balance Sheet (Continued)

(h)

Represents the adjustment to reflect the fees invoiced in advance at estimated fair value. The Company has assumed that the fair value of the fees invoiced in advance balance represented approximately 91% of the carrying value of Envigo's fees invoiced in advance balance at September 30, 2017, or $61.0 million. Upon closing of the acquisition, AHPAC will record the assumed fees invoiced in advance at its acquisition date fair values, which will represent AHPAC's future performance obligation.



(i)

Reflects the adjustment to long term debt associated with the debt modificationsrefinancing and anticipated debt repaymentnew Term Loan and Revolving Credit Agreement and is calculated as follows:

(In thousands)		Sep-17				Sep-17
Paydown of Envigo long-term debt		$	(193,000	)		$	(439,906	)
Paydown of Envigo related party long term debt							(46,434	)
Paydown of Envigo short-term debt							(1,384	)
Write-down of unamortized discounts & warrants			10,408				19,435
Write-down of unamortized deferred financing costs			1,830				10,297
Capitalizable debt amendment costs			(2,000	)
Term loan issuance							300,000
Capitalizable debt amendment costs including OID							(12,733	)
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Adjustment		$	(182,762	)		$	(170,725	)
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As discussed in Footnote 3(c), Envigo has agreed withwill refinance its noteholders topre-existing debt and enter into a modification of certain terms of its existing Third Lien Indenture which among other things reduces the interest rate from 15.0% to 6.0%.new Term Loan and Revolving Credit Agreement. As a result of the modification,refinancing, the existingpre-existing debt will be derecognizedpaid down and the amended debtnew Term Loan and Revolving Credit Agreement will be recorded at fair value which management has estimated approximates face value for purposeson the balance sheet. As noted in Footnote 3(c), Envigo does not plan to draw down on the Revolving Credit Agreement as of the pro forma financial statements.

Underclose of the assumptionbusiness combination and therefore there are no outstanding borrowings as of a $50 million redemptionSeptember 30, 2017. Additionally, the adjustment to the long-term debt balance above includes capitalizable debt amendment costs in connection with the refinancing and original issue discount of AHPAC shares by AHPAC shareholders, the debt pay down is reduced by $50 million. This is partially offset by a $3.2 million reduction in the write-down of deferred financing costsnew Term Loan and discounts and warrants.Revolving Credit Agreement.

(j)

Represents the payment of deferred underwriting commissions upon closing of the business combination and removal of the corresponding liability.



(k)

Represents the estimated fair value of the contingent consideration liability related to the Tax Receivable Agreement.



(l)

Envigo's historical balance sheet reflects a liability of $11.3 million included in other liabilities associated with stock appreciation rights (SARs) held by certain individuals that require settlement. In connection with the business combination, these SARs will be settled in cash by the Company.Company and included as part of the $90.8 million of cash paid to selling equityholders as noted in Footnote 2. This adjustment reflects the elimination of the historical liability. There were additional SARs held by certain individuals at Envigo that were exercisable only upon the occurrence of contingent events and, as a result, there was no historical compensation expense recorded in relation to these SARs. There will be no expense recorded in relation to these awards at the time of business combination as they will be out-of-the money.



(m)

Represents the adjustment to record the deferred tax liability associated with the fair value adjustment associated with inventory, intangible assets and fees invoiced in advance based on an




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NOTES TO UNAUDITED PRO FORMA CONDENSED

COMBINED FINANCIAL STATEMENTS (Continued)

4. Pro Forma Adjustments to the Balance Sheet (Continued)

exercisable only upon the occurrence of contingent events and, as a result, there was no historical compensation expense recorded in relation to these SARs. There will be approximately $1.8 million of expense recorded in relation to these awards at the time of business combination. This has not been reflected in the pro forma statements of operations due to the non-recurring nature of the expense.

(m)

Represents the adjustment to record the deferred tax liability associated with the fair value adjustment associated with inventory, intangible assets and fees invoiced in advance based on an estimated tax rate of 35.0%. See Footnote 3(d) for further consideration of the 35.0% tax rate utilized.