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UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 14A
Proxy Statement Pursuant to SectionPROXY STATEMENT PURSUANT TO SECTION 14(a) ofOF
the Securities Exchange Act ofTHE SECURITIES EXCHANGE ACT OF 1934 (Amendment No.     )
Filed by the Registrant ☒
Filed by a Partyparty other than the Registrant ☐
Check the appropriate box:
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Preliminary Proxy Statement
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☐
Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))
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Definitive Proxy Statement
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Definitive Additional Materials
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Soliciting Material under §240.14a-12§ 240.14a-12
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AXCELLA HEALTH INC.Axcella Health Inc.
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(Name of Registrant as Specified Inin Its Charter)​
   
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(Name of Person(s) Filing Proxy Statement, if other than the Registrant)
Payment of Filing Fee (Check all boxes that apply):
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No fee required.required
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Fee paid previously with preliminary materials;materials
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Fee computed on table in exhibit required by Item 25(b) per Exchange Act Rules 14a-6(i)(1) and 0-11
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AXCELLA HEALTH INC. D/B/A AXCELLA THERAPEUTICS
P.O. Box 1270
Littleton, Massachusetts 01460
NOTICE OF 2023 ANNUALSPECIAL MEETING OF
STOCKHOLDERS
To be held on September 11,December 4, 2023
Notice is hereby given that the 2023 Annual MeetingYou are invited to attend a special meeting of Stockholders, or Annual Meeting,stockholders (the “Special Meeting”) of Axcella Health Inc. (d/b/, a Axcella Therapeutics) (the “Company” or “Axcella”Delaware corporation (“Axcella”), which will be held on December 4, 2023 at 9:00 a.m. Eastern Time, as it may be adjourned or postponed from time to time. Our Special Meeting will be held in a virtual-only format. You may attend the meeting, submit questions, and vote your shares electronically during the meeting via live webcast by visiting: www.virtualshareholdermeeting.com/AXLA2023SM.
The attached Notice of Special Meeting of Stockholders and proxy statement contain details of the business to be held on September 11, 2023, at 10:00 AM Eastern Time. The purpose of the virtual Annual Meeting is the following:
1.
To elect three Class I directors to our board of directors, to serve until the 2026 annual meeting of stockholders and until his or her successor has been duly elected and qualified, or until his or her earlier death, resignation or removal;
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2.
To ratify the appointment of Deloitte & Touche LLP as our independent registered public accounting firm for the fiscal year ending December 31, 2023;
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3.
To approve amendments to our restated certificate of incorporation to effect a reverse stock split of our common stock at a ratio ranging from any whole number between 1-for-2 and 1-for-25, as determined by our board of directors in its discretion, subject to the board of directors’ authority to abandon such amendments;
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4.
To approve an adjournment of the Annual Meeting, if necessary, to solicit additional proxies if there are not sufficient votesconducted at the time ofSpecial Meeting.
Whether or not you attend the AnnualSpecial Meeting, it is important that your shares be represented and voted at the meeting. Therefore, I urge you to approve Proposal No. 3 (as defined below);promptly vote and
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5.
To transact any other business properly brought before submit your proxy via the AnnualInternet, by phone, or by signing, dating and returning the enclosed proxy card in the enclosed envelope. If you decide to attend the Special Meeting, you will be able to change your vote or any adjournment or postponement of the Annual Meeting.
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The proposal for the election of the directors relates solely to the election of the Class I directors nominated by the board of directors.revoke your proxy, even if you have previously submitted your proxy.
Only Axcella stockholders of record at the close of business on August 17,November 13, 2023, will be entitled to vote at the AnnualSpecial Meeting and any adjournment or postponement thereof.
Your vote is important. Whether or not you are able to attend the meeting, it is important that your shares be represented. To ensure that your vote is recorded, please vote as soon as possible, even if you plan to attend the meeting, by submitting your proxy via the Internet at the address listed on the proxy card or by signing, dating and returning the proxy card.
Our AnnualSpecial Meeting will be held in a virtual-only format. You may attend the meeting, submit questions, and vote your shares electronically during the meeting via live webcast by visiting: www.virtualshareholdermeeting.com/AXLA2023.AXLA2023SM.
We urge you to vote your shares over the Internet or by telephone as provided in the instructions set forth on the enclosed proxy card, or complete, date, sign and promptly return the enclosed proxy card whether or not you expect to attend the AnnualSpecial Meeting. A postage-prepaid envelope, addressed to

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Broadridge Financial Solutions, which is serving as proxy tabulator, has been enclosed for your convenience. If you attend the AnnualSpecial Meeting in person, your proxy will, upon your written request, be returned to you and you may vote your shares in person.
By orderOn behalf of the board of directors,Axcella, I would like to thank you for your continued support.
Sincerely,
/s/ WilliamCraig R. Hinshaw, Jr.Jalbert
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WilliamCraig R. Hinshaw, Jr.
Jalbert
President and Chief Executive Officer
Littleton, Massachusetts
August 18, 2023
 
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​​​Page​
General Information
​​​​2​​
Overview of Proposals
​​​​7​​
Proposal No. 1 – Election of Class I Directors
​​​​8​​
Proposal No. 2 – Ratification of the Appointment of Deloitte & Touche LLP as Axcella’s Independent Registered Public Accounting Firm for the Fiscal Year Ending December 31, 2023
​​​​13​​
Proposal No. 3 – To approve amendments to our restated certificate of incorporation to effect a
reverse stock split of our Common Stock at a ratio ranging from any whole number between
1-for-2 and 1-for-25, as determined by our board of directors in its discretion, subject to the board
of directors’ authority to abandon such amendments
​​​​14​​
Proposal No. 4 – To approve an adjournment of the Annual Meeting, if necessary, to solicit additional proxies if there are not sufficient votes at the time of the Annual Meeting to approve Proposal No. 3
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Information Regarding The Board Of Directors And Corporate Governance
​​​​25​​
Director Compensation
​​​​33​​
Executive Compensation
​​​​36​​
Certain Relationships and Related Party Transactions
​​​​44​​
Principal Stockholders
​​​​46​​
Delinquent Section 16(a) Reports
​​​​49​​
Report of the Audit Committee
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General Matters
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AXCELLA HEALTH INC. D/B/A AXCELLA THERAPEUTICS
P.O. Box 1270
Littleton, Massachusetts 01460
PROXY STATEMENT
FOR THE 2023 ANNUALNOTICE OF SPECIAL MEETING OF
STOCKHOLDERS TO BE HELD SEPTEMBER 11, 2023
This proxy statement contains information about the 2023 Annual Meeting of Stockholders, or the Annual Meeting, of Axcella Health Inc. (d/b/a Axcella Therapeutics), which will be a virtual-only meeting held on September 11, 2023, at 10:00 AM Eastern Time. The board of directors of Axcella is using this proxy statement to solicit proxies for use at the virtual Annual Meeting. In this proxy statement, the terms “we,” “us,” and “our” refer to Axcella. The mailing address of our principal executive offices is P.O. Box 1270, Littleton, Massachusetts 01460.
All properly submitted proxies will be voted in accordance with the instructions contained in those proxies. If no instructions are specified, the proxies will be voted in accordance with the recommendation of our board of directors with respect to each of the matters set forth in this proxy statement. You may revoke your proxy at any time before it is exercised at the meeting by giving our Corporate Secretary written notice to that effect.
We made this proxy statement and our Annual Report to Stockholders for the fiscal year ended December 31, 2022 first available to stockholders on or around August 18, 2023.
We are an “emerging growth company” under applicable federal securities laws and therefore permitted to conform with certain reduced public company reporting requirements. As an emerging growth company, we provide in this proxy statement the scaled disclosure permitted under the Jumpstart Our Business Startups Act of 2012 (the JOBS Act). In addition, as an emerging growth company, we are not required to conduct votes seeking approval, on an advisory basis, of the compensation of our named executive officers or the frequency with which such votes must be conducted. We will remain an “emerging growth company” until the earliest of (i) the last day of the fiscal year following the fifth anniversary of our initial public offering in May 2019; (ii) the last day of the fiscal year in which our total annual gross revenue is equal to or more than $1.235 billion; (iii) the date on which we have issued more than $1 billion in nonconvertible debt during the previous three years; or (iv) the date on which we are deemed to be a large accelerated filer under the rules of the Securities and Exchange Commission, or SEC.
​Time and Date​​December 4, 2023 at 9:00 a.m. Eastern Time​
​Place​​The special meeting of stockholders (the “Special Meeting”) of Axcella Health Inc. (“Axcella,” the “Company,” “we,” “us” and “our”) will be held in a virtual format only at www.virtualshareholdermeeting.com/AXLA2023SM.​
​Items of Business​​
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To consider and vote upon a proposal to approve the resolutions attached hereto as Exhibit A, approving and authorizing the board of directors’ (the “Board”) determination to effect the transfer of all or substantially all of Axcella’s assets through an assignment for the benefit of creditors (the “Assignment,” and such proposal, the “Assignment Proposal”).
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The approval of the liquidation and dissolution of the Company (the “Dissolution”) and the Plan of Liquidation and Dissolution (the “Plan of Dissolution”), attached hereto as Exhibit B, which, if approved, will authorize the Board to liquidate and dissolve the Company in accordance with the Plan of Dissolution (the “Dissolution Proposal”).
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To grant discretionary authority to the Board to adjourn the Special Meeting, from time to time, to a later date or dates, even if a quorum is present, to solicit additional proxies in the event that there are insufficient shares present in person or by proxy voting in favor of the Assignment Proposal or the Dissolution Proposal (the “Adjournment Proposal”).
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To transact such other business as may properly come before the Special Meeting or any adjournments, postponements or continuations thereof.
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​Board Recommendations​​
After careful consideration of a number of factors, as described in the attached proxy statement, the Board has unanimously determined that the Assignment Proposal, Dissolution Proposal, and Adjournment Proposal are advisable and in the best interests of Axcella and its stockholders.
The Board unanimously recommends that you vote “FOR” each of the Assignment Proposal, Dissolution Proposal and the Adjournment Proposal.
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​Record Date​​The close of business on November 13, 2023 (the “Record Date”). Only stockholders on the Record Date are entitled to receive notice of, and to vote at, the Special Meeting.​
​Proxy Voting​​IMPORTANT​
​​​​Please vote your shares at your earliest convenience. Promptly voting your shares via the Internet, by telephone, or by signing, dating and returning the enclosed proxy card will save the expenses and extra work of additional solicitation. If you wish to vote by mail, an addressed envelope is enclosed, postage prepaid if mailed in the United States. Submitting your proxy now will not prevent you from voting your shares at the Special Meeting, as your proxy is revocable at your option.​
Important Notice Regarding the Availability of Proxy Materials for
the AnnualSpecial Meeting of Stockholders to beBe Held on September 11, 2023:December 4, 2023 at 9:00 a.m. Eastern Time.
This proxy statement is available on our website at www.axcellatx.com and our 2022 Annual Reportit is being mailed to Stockholders,stockholders on or 2022 Annual Report, are
available for viewing, printing and downloading at www.proxyvote.com.about November 17, 2023.

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Because we have elected to utilize the “full set delivery” option, we are delivering paper copies of all of the proxy materials to all our stockholders, as well as providing access to those proxy materials on a publicly accessible website. A copy of our Annual Report on Form 10-K for the fiscal year ended December 31, 2022, as filed with the Securities and Exchange Commission (SEC) on March 30, 2023, except for exhibits, will be furnished without charge to any stockholder upon written request to Axcella Therapeutics, P.O. Box 1270, Littleton, Massachusetts 01460, Attention: Corporate Secretary. This proxy statement and our Annual Report on Form 10-K for the fiscal year ended December 31, 2022, are also available on the SEC’s website at www.sec.gov.
By order of the Board of Directors,
/s/ Craig Jalbert
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Craig Jalbert
President and Chief Executive Officer
November 17, 2023

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CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS
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WEBSITES
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SUMMARY
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QUESTIONS AND ANSWERS REGARDING THIS SOLICITATION AND VOTING AT THE
SPECIAL MEETING
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THE SPECIAL MEETING
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PROPOSAL 1: APPROVAL OF THE ASSIGNMENT
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PROPOSAL 2: APPROVAL OF THE DISSOLUTION PURSUANT TO THE PLAN OF DISSOLUTION
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PROPOSAL 3: APPROVAL OF ADJOURNMENT OF SPECIAL MEETING TO SOLICIT ADDITIONAL PROXIES
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SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT
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WHERE YOU CAN FIND ADDITIONAL INFORMATION
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HOUSEHOLDING
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OTHER MATTERS
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EXHIBIT A – STOCKHOLDER RESOLUTIONS
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EXHIBIT B – PLAN OF DISSOLUTION
​​​​39​​

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CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS
This proxy statement, and the documents incorporated by reference into this proxy statement, contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, including, but not limited to, statements regarding: Axcella’s ability to effect the Assignment, the Dissolution, projected cash runways, and stockholder approval of the Assignment Proposal and Dissolution Proposal. The use of words such as, but not limited to, “anticipate,” “believe,” “continue,” “could,” “estimate,” “expect,” “intend,” “may,” “might,” “plan,” “potential,” “predict,” “project,” “should,” “target,” “will,” or “would” and similar words and expressions are intended to identify forward-looking statements. Forward-looking statements are neither historical facts nor assurances of future performance. Instead, they are based on our current beliefs, expectations and assumptions regarding the future of our business, future plans and strategies, our clinical results and other future conditions. New risks and uncertainties may emerge from time to time, and it is not possible to predict all risks and uncertainties. No representations or warranties (expressed or implied) are made about the accuracy of any such forward-looking statements.
Forward-looking statements in this proxy statement include, but are not limited to:
•
plans and expectations for the Assignment and Dissolution;
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•
beliefs about the Company’s available options and financial condition;
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•
all statements regarding the tax and accounting consequences of the transactions contemplated by the Assignment and Dissolution; and
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•
all statements regarding the amount and timing of distributions made to stockholders, if any, in connection with the Assignment and Dissolution.
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We may not actually achieve the forecasts disclosed in our forward-looking statements, and you should not place undue reliance on our forward-looking statements. Such forward-looking statements are subject to a number of material risks and uncertainties including but not limited to those set forth under the caption “Risk Factors” in Axcella’s most recent Annual Report on Form 10-K and Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission (the “SEC”), as well as discussions of potential risks, uncertainties, and other important factors in our subsequent filings with the SEC. Any forward-looking statement speaks only as of the date on which it was made. Neither we, nor our affiliates, advisors or representatives, undertake any obligation to publicly update or revise any forward-looking statement, whether as a result of new information, future events or otherwise, except as required by law. These forward-looking statements should not be relied upon as representing our views as of any date subsequent to the date hereof.
WEBSITES
Website addresses referenced in this proxy statement are provided for convenience only, and the content on the referenced websites does not constitute a part of this proxy statement.
 
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AXCELLARISK FACTORS
PROXY STATEMENT
FOR THE 2023 ANNUAL MEETING OF STOCKHOLDERSThe following risk factors, together with the other information in this proxy statement and in the “Risk Factors” sections included in the documents incorporated by reference into this proxy statement (see the section entitled “Where You Can Find More Information; Incorporation by Reference” beginning on page 37 of this proxy statement), should be carefully considered before deciding whether to vote to approve the Dissolution Proposal as described in this proxy statement. In addition, stockholders should keep in mind that the risks described below are not the only risks that are relevant to your voting decision. The risks described below are the risks that we currently believe are the material risks of which our stockholders should be aware. Nonetheless, additional risks that are not presently known to us, or that we currently believe are not material, may also prove to be important. Notably, the Company cautions that trading in the Company’s securities is highly speculative and poses substantial risks.
GENERAL INFORMATIONTrading prices for the Company’s securities may bear little or no relationship to the actual value realized, if any, by holders of the Company’s securities. Accordingly, the Company urges extreme caution with respect to existing and future investments in its securities.
RISKS RELATED TO THE ASSIGNMENT AND DISSOLUTION
We cannot assure you as to the amount of distributions, if any, to be made to our stockholders.
Our current intention is that, if approved by our stockholders, the Assignment would be effected, and the Certificate of Dissolution would be filed, promptly after approval of the Assignment Proposal and the Dissolution Proposal. No further stockholder approval would be required to effect the Assignment or Dissolution.
However, we cannot predict with certainty the timing or amount of distributions, if any, to our stockholders. As described in the section entitled “Proposal 1: Approval of Assignment” beginning on page 16 of this proxy statement, the Assignment will entail the assignment by the Company of all of its right, title, interest in, and custody and control of its property to a third-party assignee (the “Assignee”) who will liquidate the property and distribute the proceeds to the Company’s creditors to satisfy the Company’s obligations. If any proceeds remain after all of the Company’s obligations and costs associated with the liquidation process have been satisfied, any remaining proceeds will be distributed to the Company’s stockholders. We cannot predict the timing or amount of any such distributions to stockholders, as uncertainties as to the ultimate amount of the Company’s liabilities, the operating costs and amounts to be set aside for claims, obligations and provisions during the Assignment and Dissolution processes, and the related timing to complete such transactions, make it impossible to predict with certainty the actual net cash amount that will ultimately be available for distribution to stockholders or the timing of any such distributions. Examples of uncertainties that could reduce the value of distributions to our stockholders include: unanticipated costs of the Assignee relating to the Assignment process, amounts necessary to satisfy claims of any creditors or other third parties, and delays in the liquidation of the Company’s assets by the Assignee and the ultimate success of the Assignment process to liquidate the assets.
The Assignee will determine the timing of the distribution of the remaining amounts, if any, to our stockholders. We can provide no assurance as to if or when any such distribution will be made, and we cannot provide any assurance as to the amount to be paid to stockholders in any such distribution, if one is made. Stockholders may receive substantially less than the amount that we currently estimate that they may receive, or they may receive no distribution at all.
If our stockholders do not approve the Assignment Proposal and Dissolution Proposal, we would not be able to continue our business operations.
If our stockholders do not approve the Assignment Proposal and Dissolution Proposal, the Board will continue to explore what, if any, alternatives are available for the future of the Company in light of its discontinued business activities; however, those alternatives are likely limited to seeking voluntary dissolution at a later time with potentially diminished assets, seeking bankruptcy protection (should our net assets decline to levels that would require such action) or investing our cash in another operating business. It is unlikely that these alternatives would result in greater stockholder value than the proposed Assignment and Dissolution.

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Our stockholders of record will not be able to buy or sell shares of our common stock after we close our stock transfer books on the Effective Time.
If the Board determines to proceed with the Dissolution, we intend to close our stock transfer books and discontinue recording transfers of our common stock at the time of the filing of the Certificate of Dissolution (the “Effective Time”). After we close our stock transfer books, we will not record any further transfers of our common stock on our books except by will, intestate succession or operation of law. Therefore, shares of our common stock will not be freely transferable after the Effective Time. As a result of the closing of the stock transfer books, any liquidating distributions by the Assignee to stockholders will likely be made pro rata to the same stockholders of record as the stockholders of record as of the Effective Time.
We plan to initiate steps to exit from certain reporting requirements under the Exchange Act, which may substantially reduce publicly available information about us. If the exit process is protracted, we will continue to bear the expense of being a public reporting company despite having no source of revenue.
Our common stock is currently registered under the Exchange Act, which requires that we, and our officers and directors with respect to Section 16 of the Exchange Act, comply with certain public reporting and proxy statement requirements thereunder. Compliance with these requirements is costly and time-consuming. We recently had a hearing before the Nasdaq Hearings Panel with respect to the delisting of our common stock on Nasdaq and plan to initiate steps to exit from such reporting requirements in order to curtail expenses; however, such process may be protracted and we may be required to continue to file Current Reports on Form 8-K or other reports to disclose material events, including those related to the Assignment and/or Dissolution. Accordingly, we will continue to incur expenses that will reduce the amount available for distribution by the Assignee, including expenses of complying with public company reporting requirements and paying the Company’s service providers, among others. If our reporting obligations cease, publicly available information about us will be substantially reduced.
Stockholders may not be able to recognize a loss for U.S. federal income tax purposes until they receive a final distribution from the Assignee.
As a result of the Assignment and Dissolution, for U.S. federal income tax purposes, a stockholder that is a U.S. person generally will recognize gain or loss on a share-by-share basis equal to the difference between (1) the sum of the amount of cash and the fair market value of property, if any, distributed to the stockholder with respect to each share, less any known liabilities assumed by the stockholder or to which the distributed property (if any) is subject, and (2) the stockholder’s adjusted tax basis in each share of our common stock. A distribution by the Assignee may occur at various times and in more than one tax year. Any loss generally will be recognized by a stockholder only in the tax year in which the stockholder receives a final distribution, and then only if the aggregate value of all distributions with respect to a share of our common stock is less than the stockholder’s tax basis for that share. Stockholders are urged to consult with their own tax advisors as to the specific tax consequences to them of the Assignment and Dissolution.
The tax treatment of any distribution may vary from stockholder to stockholder, and the discussions in this proxy statement regarding tax consequences are general in nature.
We have not requested a ruling from the IRS with respect to the anticipated tax consequences of the Assignment and Dissolution, and we will not seek an opinion of counsel with respect to the anticipated tax consequences of any distributions. If any of the anticipated tax consequences described in this proxy statement prove to be incorrect, the result could be increased taxation at the corporate or stockholder level, thus reducing the benefit to our stockholders from the Assignment and Dissolution. Tax considerations applicable to particular stockholders may vary with and be contingent on the stockholder’s individual circumstances. You should consult your own tax advisor for tax advice instead of relying on the discussions of tax consequences in this proxy statement.

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SUMMARY
This summary highlights selected information contained in this proxy statement and may not contain all of the information that is important to you. To understand fully the legal requirements for the transfer of all or substantially all of the assets of Axcella Health Inc. (“Axcella,” the “Company,” “we,” “us,” and “our”) through an assignment for the benefit of creditors under Delaware law and the Special Meeting (as defined below), you should carefully read this entire proxy statement and the documents delivered with this proxy statement.
About Axcella
We are a clinical-stage biotechnology company focused on pioneering a new approach to treat complex diseases using compositions of endogenous metabolic modulators, or EMMs. Our product candidates are comprised of multiple EMMs that are engineered in distinct combinations and ratios with the goal of simultaneously impacting multiple biological pathways. Our pipeline includes lead therapeutic candidates for the treatment of Long COVID (also known as Post COVID-19 Condition and Post-Acute Sequelae of COVID-19, or “PASC”) associated fatigue, and the treatment of non-alcoholic steatohepatitis, or NASH. Axcella’s common stock, par value $0.001 per share (the “Common Stock”), is traded on the Nasdaq Global Market under the symbol “AXLA.”
On September 19, 2023, we effected a reverse stock split at a ratio of 1-for-25 (the “Reverse Stock Split”). Unless otherwise noted in this proxy statement, all share amounts are reflected on a post-Reverse Stock Split basis.
General
Axcella’s Board of Directors (the “Board”) has determined that due to, among other things, an inability to raise the additional capital needed to continue to fund Axcella’s operations and service its obligations in the future, it is advisable and in the best interests of Axcella and Axcella’s stockholders that Axcella assign all or substantially all of Axcella’s assets for the benefit of Axcella’s creditors (the “Assignment”). The Assignment is a state-law governed insolvency procedure, which, assuming approval of the Assignment Proposal by Axcella’s stockholders, is commenced by Axcella entering a contractual assignment (the “Assignment Agreement”) that effectuates the assignment, grant, conveyance, transfer, and setting over to a third-party assignee (the “Assignee”) of all of Axcella’s currently existing right, title, and interest in all real or personal property and all other assets, whatsoever and where so ever situated. Upon the execution of the Assignment Agreement, the Assignee will have sole control over Axcella’s assets and Axcella will no longer control the liquidation or distribution of its assets or the resolution of claims. Following execution of the Assignment Agreement, the Assignee will file an application in the Delaware Court of Chancery, which commences a judicial proceeding for recognition of the assignment for the benefit of creditors. The Assignee will then liquidate the assets for the general benefit of all of Axcella’s creditors according to their respective priorities at law to satisfy Axcella’s obligations. If any proceeds remain after all of Axcella’s obligations to creditors have been satisfied in full, those remaining proceeds will be distributed to you, the stockholders. Since Axcella does not know the final amount that the Assignee will recover from a liquidation of Axcella’s assets, Axcella does not know the amounts, if any, that will be available for distribution to the stockholders.
Following the Assignment, assuming approval of the Dissolution Proposal by Axcella’s stockholders, the Company will follow the dissolution and winding-up procedures prescribed by the General Corporation Law of the State of Delaware (“DGCL”) pursuant to the Plan of Dissolution, which requires, among other things, that the Company file a Certificate of Dissolution with the Secretary of State of the state of Delaware (the “Secretary of State”); however, the decision of whether or not to proceed with the Dissolution and when to file the Certificate of Dissolution will be made by the Board in its sole discretion.
If the Assignment Proposal and/or Dissolution Proposal is approved, Axcella will delist from the Nasdaq Global Market. Whether or not the Assignment Proposal is approved, Axcella continues to have an obligation to comply with the applicable reporting requirements of the Securities Exchange Act of 1934, as amended (the “Exchange Act”).
In furtherance of the Assignment and the Dissolution, and consistent with requirements under Delaware law, the Board is presenting the Assignment Proposal (as defined below) and the Dissolution Proposal (as defined below) for approval by Axcella’s stockholders.

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At the Special Meeting, Axcella’s stockholders will be asked to consider and vote upon proposals to (i) approve the resolutions attached hereto as Exhibit A, which approve and authorize the Assignment (the “Assignment Proposal”), (ii) approve the Company’s Dissolution in accordance with the Plan of Dissolution (the “Dissolution Proposal”), and (iii) grant discretionary authority to the Board to adjourn the Special Meeting, from time to time, to a later date or dates, even if a quorum is present, to solicit additional proxies in the event that there are insufficient shares present in person or by proxy voting in favor of the Assignment Proposal or the Dissolution Proposal (the “Adjournment Proposal”).

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QUESTIONS AND ANSWERS REGARDING THIS SOLICITATION
AND VOTING AT THE SPECIAL MEETING
The following are some of the questions you may have as an Axcella stockholder and answers to those questions. These questions and answers highlight only some of the information contained in this proxy statement. You should read carefully this entire document, including all exhibits and annexes hereto, to fully understand the Assignment Proposal, the Dissolution Proposal, the Adjournment Proposal and the voting procedures for the Special Meeting.
Special Meeting and Voting
Why am I receiving these materials, and who is soliciting my vote?
We sent you this proxy statement because our Board is soliciting your proxy to vote at the Special Meeting that Axcella is holding to seek stockholder approval of the Assignment Proposal, Dissolution Proposal, and the Adjournment Proposal, as described in further detail herein. This proxy statement summarizes the information you need to vote at the Special Meeting. You do not need to attend the Special Meeting to vote your shares.
When are this Proxy Statementproxy statement and the accompanying materials scheduled to be sent to stockholders?
This Proxy Statement,On or about November 17, 2023, we will begin mailing our Annual Report to Stockholders for the fiscal year ended December 31, 2022,proxy materials, including this proxy statement, and the accompanying proxy card are first being mailed to our stockholders on or, about August 22, 2023.for shares held in street name (i.e., shares held for your account by a broker or other nominee), a voting instruction form. In accordance with SEC rules, we are advising our stockholders of the availability on the Internet of our proxy materials related to our forthcoming AnnualSpecial Meeting. Because we have elected to utilize the “full set delivery” option, we are delivering to all stockholders paper copies of all of the proxy materials, as well as providing access to those proxy materials on a publicly accessible website. This Proxy Statement, and our Annual Report on Form 10-K for the fiscal year ended December 31, 2022 are available to our stockholders at www.virtualshareholdermeeting.com/AXLA2023.Axcellatx.com.
Why hold a virtual meeting?
We believe that hosting a virtual meeting this year is in the best interest of the Company and its stockholders, enabling increased stockholder attendance and participation because stockholders can participate from any location around the world. Additionally, we believe a virtual format significantly contributes to our efforts to maintain a safe and healthy environment for our directors, members of management and stockholders who wish to attend the AnnualSpecial Meeting. You will be able to attend the AnnualSpecial Meeting online and submit your questions by visiting www.virtualshareholdermeeting.com/AXLA2023.AXLA2023SM. You also will be able to vote your shares electronically at the AnnualSpecial Meeting by following the instructions below.
WhoWhat is soliciting my vote?the purpose of the Special Meeting?
Our boardAt the Special Meeting, stockholders will vote on the matters described in the accompanying Notice of directorsSpecial Meeting and this proxy statement. The only matters expected to be voted upon at the Special Meeting are the Assignment Proposal, the Dissolution Proposal, and the Adjournment Proposal.
The Board is soliciting your voteproposing the Assignment and Dissolution and asking stockholders to approve the Assignment Proposal and Dissolution Proposal because we are unable to continue our ongoing operations with our current cash and anticipated future cash flow and we have been unable to secure additional equity, debt or other financing. The Board has a duty to take the actions that it believes will result in the best recovery for Axcella’s creditors while preserving, if possible, the potential for a distribution of any residual value to stockholders. The Board has therefore deemed it advisable and in the best interests of Axcella and its stockholders to effectuate the Assignment and Dissolution. The Board believes that the Assignment and Dissolution presents the best opportunity for the Annual Meeting.highest possible recovery under the circumstances for creditors, and while uncertain, preserving the opportunity for future payments to Axcella’s stockholders depending on the results of the Assignee’s liquidation process.

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When is the record dateRecord Date for the AnnualSpecial Meeting?
The record dateRecord Date for determination of stockholders entitled to vote at the AnnualSpecial Meeting is the close of business on August 17,November 13, 2023.
How many votes canWhich stockholders may vote?
The Board has fixed the close of business on November 13, 2023 as the Record Date for determining the stockholders of Axcella who are entitled to receive notice of the Special Meeting and to vote their shares at the Special Meeting. Only stockholders as of the Record Date will be cast by all stockholders?
There were 73,692,745entitled to notice of, and to vote at, the Special Meeting. Each share of Axcella’s Common Stock is entitled to one vote. As of the Record Date, Axcella had issued and outstanding 2,947,661 shares of our common stock, par value $0.001 per share, outstandingCommon Stock.
What am I being asked to vote on?
The Board is asking Axcella’s stockholders of record at the close of business on November 13, 2023, the Record Date for the Special Meeting, to consider and vote upon the Assignment Proposal, Dissolution Proposal and Adjournment Proposal. The Board currently knows of no other business that will be presented for consideration at the Special Meeting. In the event any matters other than those referred to in the accompanying Notice of Special Meeting and this proxy statement should properly come before and be considered at the Special Meeting, it is intended that any proxy holder may vote on the matter in his or her discretion on behalf of the stockholder or stockholders granting such proxy.
Why is Axcella seeking a stockholder vote on the Adjournment Proposal?
Adjourning the Special Meeting to a later date will give the Board additional time to solicit proxies and obtain sufficient votes in favor of approval of the Assignment Proposal or the Dissolution Proposal if there are not sufficient votes in favor of the proposal. Consequently, Axcella is seeking your approval of the Adjournment Proposal to ensure that, if necessary, Axcella will have enough time to solicit the required votes for approval of the Assignment Proposal or the Dissolution Proposal.
What are the recommendations of the Board for how I should vote my shares?
The Board unanimously recommends that you vote “FOR” the Assignment Proposal, “FOR” the Dissolution Proposal and “FOR” the Adjournment Proposal.
Who can attend the Special Meeting?
Only stockholders of record as of the close of business on August 17,the Record Date, or their duly appointed proxies, may attend the Special Meeting. To attend and participate in the Special Meeting, you will need the control number included on your proxy card. The Special Meeting will begin promptly on December 4, 2023 allat 9:00 a.m. Eastern Time. You are encouraged to arrive at the meeting prior to the start time. Check-in will begin at 8:30 a.m. Eastern Time and you should allow ample time for the check-in procedures. A list of which arestockholders entitled to vote with respect to all matters to be acted upon at the virtual AnnualSpecial Meeting will be available (i) ten days prior to the Special Meeting during ordinary business hours at the principal place of business of Axcella and (ii) consistent with the provisions of Axcella’s Amended and Restated By-Laws or bylaws, during the Special Meeting. Each stockholder of record is entitled to one vote for each share of our common stock held by such stockholder. None of our shares of undesignated preferred stock were outstanding as of August 17, 2023.
How doDo I vote?need an admission ticket to attend the Special Meeting?
Admission to the Special Meeting will be by proxy card control number only. If you are a stockholder of record and plan to attend the Special Meeting, you will need the control number included on your proxy card. We may ask you to present evidence of share ownership as of the Record Date, such as an account statement indicating ownership on that date, and valid identification, to enter the Special Meeting.
What do I need to do to attend the Special Meeting?
If you were a stockholder of record at the close of business on November 13, 2023, you do not need to do anything in advance to attend and/or vote your shares at the Special Meeting.

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If you were a beneficial owner at the close of business on the Record Date (meaning your shares are held in “street name” through a bank, broker or other nominee), you may not vote your shares at the Special Meeting unless you obtain a “legal proxy” from your broker, bank or other nominee who is the stockholder of record with respect to your shares.
How is a quorum reached?
Our bylaws, provide that a majority of the shares entitled to vote, present in person or represented by proxy, will constitute a quorum for the transaction of business at the Special Meeting. There are 2,947,661 shares of our Common Stock outstanding and entitled to vote on the Record Date. Therefore, a quorum will be present if 1,473,831 shares of our Common Stock are present in person or represented by proxy at the Special Meeting. Shares present virtually during the Special Meeting will be considered shares of Common Stock represented in person at the meeting.
Under the DGCL, shares that “abstain” or are “withheld” from voting and “broker non-votes” are counted as present for purposes of determining whether a quorum is present at the Special Meeting. If a quorum is not present, the presiding officer of the meeting or the holders of voting stock representing a majority of the voting power present at the meeting may adjourn the meeting to a later time until a quorum is obtained.
What vote is needed for each of the proposals to be adopted?
Under the DGCL, the affirmative vote of a majority of the outstanding shares of outstanding stock of Axcella entitled to vote thereon is required to approve the Assignment Proposal and to approve the Dissolution Proposal. Abstentions and broker non-votes for the Assignment Proposal and Dissolution Proposal will have the same effect as votes “Against” the Assignment Proposal and the Dissolution Proposal, as applicable.
If a quorum is present at the Special Meeting, the affirmative vote of the holders of a majority of the votes properly cast is required for the approval of the Adjournment Proposal. Broker non-votes (if any) and abstentions will not be counted as votes cast on the matter and will have no effect on the outcome of the Adjournment Proposal.
What is a broker non-vote?
Generally, a broker non-vote occurs when shares held by a bank, broker or other nominee for a beneficial owner are not voted with respect to a particular proposal because (i) the nominee has not received voting instructions from the beneficial owner and (ii) the nominee lacks discretionary voting power to vote such shares. Under applicable stock exchange rules, banks, brokers and other nominees who hold shares of Axcella’s Common Stock for beneficial owners have the discretion to vote on routine matters when they have not received voting instructions from those beneficial owners. On a non-routine matter, banks, brokers and other nominees do not have the discretion to direct the voting of the beneficial owners’ shares (as they do on a routine matter), and, if the beneficial owner has not provided voting instructions with respect to that matter, there will be a “broker non-vote” on the matter. Axcella urges you to provide instructions to your bank, broker or other nominee so that your votes may be counted for each proposal to be voted upon. You should provide voting instructions for your shares by following the instructions provided on the voting instruction form that you receive from your bank, broker or other nominee.
It is expected that the Assignment Proposal, Dissolution Proposal, and Adjournment Proposal will be considered non-routine matters.
How can I vote?
You can have your shares voted on your behalf by submitting a valid proxy by telephone, via the Internet, or by mail. If you plan to attend the Special Meeting, you may vote your shares during the meeting. Please have your proxy card in hand when you join the meeting virtually. If you are unable to attend the Special Meeting, Axcella urges you to submit a proxy by doing one of the following ways:following:
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By Internet.Submit a proxy by telephone:   You may vote by submitting a proxy using a touch-tone telephone by calling 1-800-690-6903, 24 hours a day, seven days a week. You will be required to provide the
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control number provided in the proxy card. Proxies submitted by telephone must be received no later than 11:59 p.m. Eastern Time on December 3, 2023. Beneficial owners may vote using a touch-tone telephone by calling 1-800-454-8683, 24 hours a day, seven days a week.
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Submit a proxy via the Internet:   You may vote by submitting a proxy at www.proxyvote.com, 24 hours a day, seven days a week, by following the instructions at that site for submitting your proxy electronically. You will be required to enter the control number provided in the proxy card. VotesProxies submitted through the Internet must be received no later than 11:59 p.m. Eastern Time on September 10,December 3, 2023.
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By QR Code.Code:   You may vote by submitting a proxy using your mobile device to scan the QR code on your proxy card. Votes submitted by scanning your QR code must be received no later than 11:59 p.m. Eastern Time on September 10,December 3, 2023.
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By Mail.Submit a proxy by mail:   You may submit a proxy to vote by completing, dating and signing the proxy card that accompanies this proxy statement and promptly mailing it in the enclosed postage- prepaid envelope and return it to Vote Processing, c/o Broadridge, 51 Mercedes Way, Edgewood, NY 11717. You do not need to put a stamp on the enclosed envelope if you mail it in the United States. If you are mailed or otherwise receive or obtain a proxy card or voting instruction form, and you choose to vote by submitting a proxy by telephone or by internet, you do not have to return your proxy card or voting instruction form. VotesProxies submitted through the mail must be received no later than September 10,December 3, 2023.
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By Telephone.   You may vote using a touch-tone telephone by calling 1-800-690-6903, 24 hours a day, seven days a week. You will be required to provide the control number provided in the proxy card. Votes submitted by telephone must be received no later than 11:59 p.m. Eastern Time on September 10, 2023. Beneficial owners may vote using a touch-tone telephone by calling 1-800-454-8683, 24 hours a day, seven days a week.
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If the AnnualSpecial Meeting is adjourned or postponed, the deadlines above may be extended.
If your shares are held in “street name” through a bank, broker or other nominee, you completemay vote through your bank, broker or other nominee by completing and submit your proxy beforereturning the virtual Annual Meeting, the persons named as proxies will vote the shares representedvoting instruction form provided by your proxy in accordance withbank, broker or other nominee, or, if such a service is provided by your instructions. Ifbank, broker or other nominee, electronically over the Internet or by telephone. To vote over the Internet or by telephone through your bank, broker or other nominee, you submit a proxy without givingshould follow the instructions on the voting instructions,instruction form provided by your bank, broker or nominee.
If your shares will be votedare held in “street name,” you may not vote your shares at the manner recommended bySpecial Meeting unless you obtain a “legal proxy” from your broker, bank or other nominee who is the boardstockholder of directors on all matters presented in this proxy statement, and as the persons named as proxies may determine in their discretionrecord with respect to any other matters properly presented at the virtual Annual Meeting. You may also authorize another person or persons to act for you as proxy in a writing, signed by you or your authorized representative, specifying the details of those proxies’ authority. The original writing must be given to each of the named proxies, although it may be sent to them by electronic transmission if, from that transmission, it can be determined that the transmission was authorized by you.
If any other matters are properly presented for consideration at the virtual Annual Meeting, including, among other things, consideration of a motion to adjourn the virtual Annual Meeting to another time or place (including, without limitation, for the purpose of soliciting additional proxies), the persons named in your proxy and acting thereunder will have discretion to vote on those matters in accordance with their best judgment. We do not currently anticipate that any other matters will be raised at the virtual Annual Meeting.shares.
How doCan I revokechange my proxy?vote?
You may revoke your proxy by (1) following the instructions on the enclosed proxy card and entering a new vote by mail that we receive before the start of the virtual AnnualSpecial Meeting or over the Internet by the cutoff time of 11:59 p.m. Eastern Time on September 10,December 3, 2023, (2) attending and voting at the virtual AnnualSpecial Meeting (although attendance at the virtual AnnualSpecial Meeting will not in and of itself revoke a proxy), or (3) by filing an instrument in writing revoking the proxy or another duly executed proxy bearing a later date with our Corporate Secretary. Any written notice of revocation or subsequent proxy card must be received by our Corporate Secretary prior to the taking of the vote at the virtual AnnualSpecial Meeting. Such written notice of revocation or subsequent proxy card should be hand delivered to our Corporate Secretary or sent to our principal executive offices at Axcella Therapeutics, P.O. Box 1270, Littleton, Massachusetts 01460, Attention: Corporate Secretary.
If a broker, bank, or other nominee holds your shares, you must contact such broker, bank, or nominee in order to find out how to change your vote.
What if I vote for one, but not all, of the proposals?
Shares of Axcella’s Common Stock represented by proxies received by Axcella (whether received through the return of the enclosed proxy card or received by telephone or via the Internet) where the stockholder has provided voting instructions with respect to the proposals described in this proxy statement will be voted in accordance with the voting instructions so made. If your proxy card is properly executed and returned but does not contain voting instructions as to one or more of the proposals to be voted upon

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at the Special Meeting, or if you give your proxy by telephone or via the Internet without indicating how you want to vote on each of the proposals to be voted upon at the Special Meeting, your shares will be voted “FOR” the Assignment Proposal, Dissolution Proposal, and Adjournment Proposal.
Who will pay for the cost of this proxy solicitation?
Axcella is making the solicitation and will bear the costs of soliciting proxies. In addition to solicitations by mail, our directors, Chief Executive Officer, and employees, without additional remuneration, may solicit proxies by telephone, text message, facsimile, email, personal interviews, and other means. We have requested that brokerage houses, custodians, nominees, and fiduciaries forward copies of the proxy materials to the persons for whom they hold shares and request instructions for voting the proxies. We will reimburse the brokerage houses and other persons for their reasonable out-of-pocket expenses in connection with this distribution.
How can I access the proxy materials electronically?
Copies of the Notice of Special Meeting, this proxy statement and Axcella’s Annual Report on Form 10-K for the year ended December 31, 2022, as well as other materials filed by Axcella with the SEC, are available without charge to stockholders on Axcella’s corporate website at ir.Axcellatx.com or upon request at info@axcellatx.com.
May I still sell my shares of Common Stock?
Yes, for a limited period of time. We expect that our Common Stock will continue to be traded on the Nasdaq Global Market prior to the Special Meeting. However, the Board may direct that our stock transfer books be closed and that recording of transfers of Common Stock discontinued upon the transfer of our assets to the Assignee and the stock transfer books will be closed upon the Effective Time.
Do I have appraisal rights?
No. Under Delaware law, you do not have appraisal rights in connection with any of the proposals.
Who can help answer my questions?
If you have any additional questions about the Special Meeting, Assignment, Assignment Proposal, Dissolution, Plan of Dissolution, Dissolution Proposal or Adjournment Proposal, how to submit your proxy, or if you need additional copies of this proxy statement or the enclosed proxy card or voting instructions, please contact Axcella at info@Axcellatx.com or (857) 320-2200.
How can I know the voting results?
We plan to announce preliminary voting results at the virtual Special Meeting and will publish final results in a Current Report on Form 8-K to be filed with the SEC within four business days following the virtual Special Meeting.
Proposed Assignment for the Benefit of Creditors
Why is Axcella seeking a stockholder vote on the Assignment Proposal?
Under Section 271(a) of the DGCL, a Delaware corporation must obtain the approval of the holders of a majority of the outstanding stock of the corporation entitled to vote thereon before proceeding with a sale of all or substantially all of its property and assets. The Assignment contemplates the assignment of all or substantially all of the property and assets of Axcella. The Board therefore is seeking stockholder approval of the Assignment Proposal in order to comply with Delaware law.
Why is the Board recommending approval of the Assignment Proposal?
After due consideration of the potential strategic alternatives available to Axcella based on the costs and benefits of continuing its operations, the Board has determined that the Assignment, followed by the

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Dissolution, is advisable and in the best interests of Axcella and Axcella’s stockholders. Axcella is unable to continue its ongoing operations with its current cash and anticipated future cash flow and has been unable to secure sufficient equity, debt or other financing. The Board believes that the Assignment presents the best opportunity to maximizing recoveries for creditors while preserving an opportunity for future payments of any residual value to stockholders.
What will happen if the Assignment is approved?
The Board proposes that Axcella assign all or substantially all of its assets to an Assignee for the benefit of Axcella’s creditors. The Assignment is a quorum reached?state-law governed insolvency procedure, which, if approved by Axcella’s stockholders, is commenced by Axcella entering into the Assignment Agreement that effectuates the assignment, grant, conveyance, transfer, and setting over to the Assignee all of Axcella’s currently existing right, title, and interest in all real or personal property and all other assets, whatsoever and where so ever situated. The Assignee will then file an application in the Delaware Court of Chancery, which commences a judicial proceeding for recognition of the assignment for the benefit of creditors. The Assignee will then liquidate the assets for the general benefit of all Axcella’s creditors according to their respective priorities at law to satisfy Axcella’s obligations. If any proceeds remain after all of Axcella’s obligations to creditors have been satisfied in full, those remaining proceeds, if any, will be distributed to you, the stockholders. Because Axcella does not know the final amount that the Assignee will recover from a liquidation of Axcella’s assets, Axcella does not know the amounts, if any, that will be available for distribution to the stockholders.
When do you expect the Assignment to be effected?
OurAxcella anticipates that the Assignment will be effected shortly after the date of the Special Meeting.
What will Axcella’s business be after completion of the Assignment?
Upon the effectiveness of the Assignment, the Assignee will have sole control over Axcella’s assets and Axcella will no longer control the liquidation or distribution of its assets or the resolution of claims. Axcella will delist from the Nasdaq Global Market and terminate its status as a reporting company with the SEC.
Will I receive anything in this transaction?
Based upon information available at this time, Axcella cannot forecast the amounts, if any, that will be available to Axcella’s stockholders in connection with, or as a result of, the Assignment. Depending on the results of the Assignee’s liquidation and claims resolution process, both of which will determine the extent of Axcella’s debts and the amounts available to satisfy such debts, it is possible that residual value will be available for distribution to stockholders from the liquidation proceeds. However, there are too many variables and uncertainties for us to estimate whether any amounts will actually be paid or the amount of any such payments to stockholders.
Do I have appraisal rights in connection with the Assignment?
No. Under Delaware law, Axcella’s stockholders are not entitled to appraisal, dissenters’ or similar rights in connection with the Assignment.
Are there any risks related to the Assignment?
Yes. You should carefully review the section entitled “Risk Factors” beginning on page 2 of this proxy statement for a description of risks related to the Assignment.
Proposed Dissolution of the Company
Why is Axcella seeking a stockholder vote on the Dissolution Proposal?
Under Section 275(b) of the DGCL, a Delaware corporation must obtain the approval of the holders of a majority of the outstanding stock of the corporation entitled to vote thereon before proceeding with a

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dissolution of the corporation. The Board therefore is seeking stockholder approval of the Dissolution Proposal in order to comply with Delaware law.
Why is the Board recommending approval of the Dissolution pursuant to the Plan of Dissolution?
The Board carefully reviewed and considered its options in light of the financial position of the Company, including our available cash, resources and operations following and in light of our previously announced review and pursuit of strategic alternatives. After due consideration of the options available to the Company, our Board has determined that the Assignment and subsequent Dissolution pursuant to the Plan of Dissolution, is advisable and in the best interests of the Company and our stockholders. See “Proposal 2: Approval of the Dissolution Pursuant to the Plan of Dissolution — Reasons for the Proposed Dissolution.”
What does the Plan of Dissolution entail?
The Plan of Dissolution provides an outline of the steps for the Dissolution of the Company under Delaware law. The Plan of Dissolution provides that we will file the Certificate of Dissolution following stockholder approval of the Dissolution; however, the decision of whether or not to proceed with the Dissolution and when to file the Certificate of Dissolution will ultimately be made by the Board in its sole discretion.
What will happen if the Dissolution is approved?
If the Dissolution is approved by our stockholders, our Board will have sole discretion to determine if and when (at such time as they deem appropriate following stockholder approval of the Dissolution) to proceed with the Dissolution. If the Board decides to proceed with the Dissolution, we will follow the dissolution and winding-up procedures prescribed by the DGCL and Plan of Dissolution, which requires, among other things, that the Company file a Certificate of Dissolution.
If our Board determines that the Dissolution is not in our best interests or not in the best interests of our stockholders, our Board may direct that the Dissolution be abandoned, or may amend or modify the Plan of Dissolution to the extent permitted by Delaware law without the necessity of further stockholder approval. After the Certificate of Dissolution has been filed, revocation of the Dissolution would require stockholder approval under Delaware law.
Do I have appraisal rights in connection with the Dissolution?
None of Delaware law, our Amended and Restated Certificate of Incorporation, or our Amended and Restated Bylaws provides for appraisal or other similar rights for dissenting stockholders in connection with the Dissolution, and we do not intend to independently provide stockholders with any such right.
Are there any risks related to the Dissolution?
Yes. You should carefully review the section entitled “Risk Factors” beginning on page 2 of this proxy statement for a description of risks related to the Dissolution.
Will I owe any U.S. federal income taxes as a result of the Dissolution?
If the Dissolution is approved and implemented, a stockholder that is a U.S. person generally will recognize gain or loss on a share-by-share basis equal to the difference between (1) the sum of the amount of cash and the fair market value of property, if any, distributed to the stockholder with respect to each share, less any known liabilities assumed by the stockholder or to which the distributed property (if any) is subject, and (2) the stockholder’s adjusted tax basis in each share of our Common Stock.
What will happen to our Common Stock if the Certificate of Dissolution is filed with the Secretary of State of Delaware?
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Act when we take action to do so. From and after the Effective Time, which we refer to as the effective time of the Certificate of Dissolution as filed with the Secretary of State of Delaware, and subject to applicable law, each holder of shares of our Common Stock shall cease to have any rights in respect of that stock, except the right to receive distributions, if any, pursuant to and in accordance with the Plan of Dissolution and the DGCL. After the Effective Time, our stock transfer records shall be closed, and we will not record or recognize any transfer of our Common Stock occurring after the Effective Time, except such transfers occurring by will, intestate succession or operation of law. Under the DGCL, no stockholder shall have any appraisal rights in connection with the Dissolution.
We expect to file the Certificate of Dissolution and for the Dissolution to become effective as soon as reasonably practicable after the Dissolution is approved by our stockholders and following the effectiveness of the Assignment; however, the decision of whether or not to proceed with the Dissolution will be made by the Board in its sole discretion.

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THE SPECIAL MEETING
This proxy statement is being furnished in connection with the solicitation of proxies on behalf of the Board for use at the Special Meeting to be held on December 4, 2023 at 9:00 a.m. Eastern Time online at www.virtualshareholdermeeting.com/AXLA2023SM.
Purpose
The Special Meeting is being held to request that stockholders consider and vote upon the Assignment Proposal, Dissolution Proposal, and Adjournment Proposal, each as described in this proxy statement.
Record Date; Stockholders Entitled to Vote
The Board has specified the close of business on November 13, 2023 as the Record Date for purpose of determining the stockholders of Axcella who are entitled to receive notice of and to vote at the Special Meeting. Only Axcella’s stockholders as of the Record Date are entitled to notice of and to vote at the Special Meeting. As of the Record Date, there were 2,947,661 shares of Axcella’s Common Stock issued and outstanding and entitled to notice of and to vote at the Special Meeting. Each share of Axcella’s Common Stock entitles its holder to one vote on each matter that properly comes before the Special Meeting.
Quorum; Required Votes
Our bylaws provide that a majority of the shares entitled to vote, present in person or represented by proxy, will constitute a quorum for the transaction of business at the AnnualSpecial Meeting. There are 73,692,7452,947,661 shares of our common stockCommon Stock outstanding and entitled to vote on the record date.Record Date. Therefore, a quorum will be present if 36,846,3731,473,831 shares of our common stockCommon Stock are present in person or represented by executed proxies timely received by usproxy at the AnnualSpecial Meeting. Shares present virtually during the AnnualSpecial Meeting will be considered shares of common stockCommon Stock represented in person at the meeting.

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Under the General Corporation Law of the State of Delaware, shares that are voted “abstain” or “withheld” and broker “non-votes” are counted as present for purposes of determining whether a quorum is present at the Annual Meeting. If a quorum is not present, the presiding officer of the meeting or the holders of voting stock representing a majority of the voting power present at the meeting may be adjournedadjourn the meeting to a later time until a quorum is obtained.
How is theThe affirmative vote counted?
Under our bylaws, any proposal other than an election of directors is decided by a majority of the votes properly cast for and against such proposal, except where a largeroutstanding shares of outstanding stock of Axcella entitled to vote thereon is required by law or by our Restated Certificate of Incorporation, or certificate of incorporation, or bylaws. Each holder of common stock is entitled to one vote for each share held by such shareholder as ofapprove the record date on each matter to come before the Annual Meeting, including the election of a director. Votes cast during the Annual Meeting or by proxy by mail, via the Internet or by telephone will be tabulated by the inspector of election appointedAssignment Proposal and Dissolution Proposal. Abstentions and broker non-votes for the Annual Meeting, whoAssignment Proposal and Dissolution Proposal will also determine whetherhave the same effect as votes “Against” the Assignment Proposal and Dissolution Proposal.
If a quorum is present. Abstentions and broker “non-votes” are not included inpresent at the tabulation ofSpecial Meeting, the voting results on any such proposal and, therefore, do not have an impact on such proposals. A broker “non-vote” occurs when a nominee holding shares for a beneficial owner does not vote on a particular proposal because the nominee does not have discretionary voting power with respect to that item and has not received instructions from the beneficial owner.
If your shares are held in “street name”Adjournment Proposal must be approved by a brokerage firm, your brokerage firm is required to vote your shares according to your instructions. If you do not give instructions to your brokerage firm, the brokerage firm will still be able to vote your shares with respect to certain “discretionary” items but will not be allowed to vote your shares with respect to “non-discretionary” items. Proposal No. 1 is a “non-discretionary” item. If you do not instruct your broker how to vote with respect to this proposal, your broker may not vote for this proposal, and those votes will be counted as broker “non-votes.” Proposal No. 2, Proposal No. 3 and Proposal No. 4 are each considered to be a “discretionary” item, and your brokerage firm will be able to vote on this proposal even if it does not receive instructions from you.
To be elected, the directors nominated via Proposal No. 1 must receive a plurality of the votes cast on the election of directors, meaning that the director nominees receiving the most votes will be elected. Shares voting “withheld” have no effect on the election of directors. Proposal No. 2, Proposal No. 3 and Proposal No. 4 must receive the affirmative vote of the holders of a majority of the votes cast properly thereon. You may vote “for,” “against” or “abstain” with respect to such proposals. Abstentionson the matter. Broker non-votes (if any) and broker non-votes, if any,abstentions will not be counted as votes cast on the matter and will have no effect on the outcome of the vote on these proposals.Adjournment Proposal.
What if a quorum is not present atBroker Non-Votes and Abstentions
For each proposal, you may vote “FOR,” “AGAINST” or “ABSTAIN.” Abstentions will count for the Annual Meeting?
If a quorum is not present or represented at the scheduled timepurpose of the Annual Meeting, (i) the chairperson of the Annual Meeting or (ii) a majority in voting power of the stockholders entitled to vote at the Annual Meeting, present in person, including by remote communication, or represented by proxy, may adjourn the Annual Meeting untildetermining whether a quorum is present at the Special Meeting.
Generally, a “broker non-vote” occurs when shares held by a bank, broker or represented.
Who paysother nominee for a beneficial owner are not voted with respect to a particular proposal because (i) the cost for soliciting proxies?
We are making this solicitationnominee has not received voting instructions from the beneficial owner and will pay(ii) the entire costnominee lacks discretionary voting power to vote such shares. Under applicable stock exchange rules, banks, brokers and other nominees who hold shares of preparing and distributing our proxy materials and soliciting votes. If you choose to access the proxy materials or vote over the Internet, you are responsible for any Internet access charges that you may incur. Our officers and employees may, without compensation other than their regular compensation, solicit proxies through further mailings, personal conversations, facsimile transmissions, e-mails, or otherwise. We have hired Broadridge Financial Solutions, Inc. to assist us in the distribution of proxy materials. Proxy solicitation expenses that we will pay include those for preparation, mailing, returning, and tabulating the proxies.
How does the Board of Directors recommend that I vote?
The board of directors recommends that you vote:
•
FOR the nominees to the board of directors set forth in this Proxy Statement (Proposal No. 1).
​

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•
FOR the ratification of the appointment of Deloitte & Touche LLP as our independent registered public accounting firm for the fiscal year ending December 31, 2023 (Proposal No. 2).
​
•
FOR the approval of amendments to our Certificate of Incorporation to effect a reverse stock split of ourAxcella’s Common Stock (Proposal No. 3).
​
•
FOR the adjournment of the Annual Meeting, if necessary, to solicit additional proxies if there are not sufficient votes at the time of the Annual Meeting to approve Proposal No. 3 (Proposal No. 4).
​
How many votes are required to approve each proposal?
The table below summarizes the proposals that will be voted on, the vote required to approve each item and how votes are counted:
Proposal​​Votes Required​​Voting Options​​
Impact of
“Withhold” or
“Abstain” Votes
​​
Broker
Discretionary
Voting Allowed
​
Proposal No. 1: Election of Directors​​The plurality of the votes cast. This means that the three nominees receiving the highest number of affirmative “FOR” votes will be elected as Class I directors.​​
“FOR ALL”
“WITHHOLD ALL”
“FOR ALL EXCEPT”
​​
None(1)
​​
No(3)
​
Proposal No. 2: Ratification of Appointment of Independent Registered Public Accounting Firm​​The affirmative vote of the holders of a majority in voting power of the votes cast affirmatively or negatively (excluding abstentions) at the Annual Meeting by the holders entitled to vote thereon.​​
“FOR”
“AGAINST”
“ABSTAIN”
​​
None(2)
​​
Yes(4)
​
Proposal No. 3: Approval of amendments to our restated certificate of incorporation to effect a reverse stock split of our Common Stock​​The affirmative vote of holders of a majority of the outstanding shares of our Common Stock entitled to vote at the Annual Meeting.​​
“FOR”
“AGAINST”
“ABSTAIN”
​​
None(2)
​​
Yes(4)
​
Proposal No. 4: Approval of an adjournment of the Annual Meeting, if necessary, to solicit additional proxies if there are not sufficient votes at the time of the Annual Meeting to approve Proposal No. 3​​The affirmative vote of the holders of a majority in voting power of the votes cast affirmatively or negatively (excluding abstentions) at the Annual Meeting by the holders entitled to vote thereon.​​
“FOR”
“AGAINST”
“ABSTAIN”
​​
None(2)
​​
Yes(4)
​
​
(1)
Votes that are “withheld” willfor beneficial owners have the same effect as an abstention and will not count as a vote “FOR” or “AGAINST” a director, because directors are elected by plurality voting. A vote marked as “withhold” will, therefore, not affect the outcome of this proposal.
​
(2)
A vote marked as an “Abstention” is not considered a vote cast and will, therefore, not affect the outcome of this proposal.
​
(3)
As this proposal is not considered a discretionary matter, brokers lack authority to exercise their discretion to vote uninstructed shares on this proposal.
​

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(4)
As this proposal is consideredroutine matters when they have not received voting instructions from those beneficial owners. On a discretionarynon-routine matter, banks, brokers are permitted to exercise theirand other nominees do not have the discretion to vote uninstructed shares on this proposal. We do not expect any broker non-votes on this proposal.
​
How may stockholders submit matters for consideration at an annual meeting?
The required notice must be in writing and received by our corporate secretary at our principal executive offices not less than 90 days nor more than 120 days prior todirect the first anniversaryvoting of the preceding year’s annual meeting. However, inbeneficial owners’ shares (as they do on a routine matter), and, if the eventbeneficial owner has not provided voting instructions with respect to that the date of the annual meeting is advanced by more than 30 days, or delayed by more than 60 days, from the first anniversary of the preceding year’s annual meeting, or if no annual meeting were held in the preceding year,matter, there will be a stockholder’s notice must be so received no earlier than the 120th day prior to such annual meeting and not later than the close of business“broker non-vote” on the later of (A) the 90th day priormatter. Axcella urges you to such annual meeting and (B) the tenth day following the day on which notice of the date of such annual meeting was mailedprovide instructions to your bank, broker or public disclosure of the date of such annual meeting was made, whichever first occurs.
In addition, any stockholderother nominee so that your votes may be counted for each proposal intended to be included in the proxy statement for the next annual meeting of our stockholders in 2024 must also satisfy the requirements of SEC Rule 14a-8 under the Securities Exchange Act of 1934, as amended, or the Exchange Act, and be received no later than April 21, 2024. If the date of the annual meeting is moved by more than 30 days from the date contemplated at the time of the previous year’s proxy statement, then notice must be received within a reasonable time before we begin to print and send proxy materials. If that happens, we will publicly announce the deadline for submitting a proposal in a press release or in a document filed with the SEC.
How can I know the voting results?
We plan to announce preliminary voting results at the virtual Annual Meeting and will publish final results in a Current Report on Form 8-K to be filed with the SEC within four business days following the virtual Annual Meeting.

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OVERVIEW OF PROPOSALS
This proxy statement contains four proposals requiring stockholder action. Proposal No. 1 requests the election of three Class I directors to the board of directors. Proposal No. 2 requests the ratification of the appointment of Deloitte & Touche LLP as our independent registered public accounting firm for the fiscal year ending December 31, 2023. Proposal No. 3 requests the stockholders to approve an amendment to our restated certificate of incorporation to effect a reverse stock split of our Common Stock at a ratio ranging from any whole number between 1-for-2 and 1-for-25, as determined by our board of directors in its discretion, subject to the board of directors’ authority to abandon such amendments. Proposal No. 4 requests the stockholders approve an adjournment of the Annual Meeting, if necessary, to solicit additional proxies if there are not sufficient votes at the time of the Annual Meeting to approve Proposal No. 3. Each of the proposals is discussed in more detail in the pages that follow.

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PROPOSAL NO. 1 — ELECTION OF CLASS III DIRECTORS
Our board of directors currently consists of ten members. In accordance with the terms of our certificate of incorporation and bylaws, our board of directors is divided into three classes, Class I, Class II and Class III, with members of each class serving staggered three-year terms. The members of the classes are divided as follows:
•
The Class I directors are Torben Straight Nissen, Ph.D., Michael Rosenblatt, M.D. and William D. “Chip” Baird, and their terms will expire at the annual meeting of stockholders to be held in 2023.
​
•
The Class II directors are Gary P. Pisano, Ph.D., Cristina M. Rondinone, Ph.D. and Paul J. Sekhri, their terms will expire at the annual meeting of stockholders to be held in 2024.
​
•
The Class III directors are William R. Hinshaw, Jr., Martin Hendrix, Robert Rosiello and Catherine Angell Sohn, Pharm.D., and their terms will expire at the 2025 Annual Meeting.
​
Upon the expiration of the term of a class of directors, directors in that class will be eligible to be elected for a new three-year term at the annual meeting of stockholders in the year in which their term expires.
Our certificate of incorporation and bylaws provide that the authorized number of directors may be changed only by resolution of our board of directors. Our certificate of incorporation also provides that our directors may be removed only for cause by the affirmative vote of the holders of at least two-thirds (2/3) of the outstanding shares then entitled to vote in an annual election of directors, and that any vacancy on our board of directors, including a vacancy resulting from an enlargement of our board of directors, may be filled only by vote of a majority of our directors then in office.
Our board of directors has nominated Torben Straight Nissen, Ph.D., Michael Rosenblatt, M.D. and William D. “Chip” Baird, for election as the Class I directors at the virtual 2023 Annual Meeting. Each of Dr. Straight Nissen, Dr. Rosenblatt and Mr. Baird are presently directors and have indicated a willingness to continue to serve as directors, if elected. If the nominees become unable or unwilling to serve, however, the proxies may be voted for a substitute nominee selected by our board of directors.
Nominees for Election as Class I Director
The following table identifies our director nominees and sets forth their principal occupation and business experience during the last five years and their age as of July 24, 2023.
Name​​Positions and Offices Held with Axcella​​
Director
Since
​​Age​
Torben Straight Nissen, Ph.D.​​Director​​2022​​52​
Michael Rosenblatt, M.D.​​Director​​2022​​75​
William D. “Chip” Baird​​Director​​2018​​51​
Torben Straight Nissen, Ph.D., has served as a member of our board of directors since October 2022. Dr. Straight Nissen is a senior partner at Flagship Pioneering, he joined Flagship in November 2016. Dr. Straight Nissen served on the board of directors of Ring Therapeutics, Inc. from August 2018 to December 2021 and since March 2021 has served as founding chief executive officer of FL84 Inc. From November 2016 to July 2019, he served as president of Rubius Therapeutics (Nasdaq: RUBY), he also served on the board of directors of Rubius from November 2016 to August 2018. From July 2011 to November 2016 Dr. Straight Nissen held positions of increasing responsibility at Pfizer, with his last position as Vice President, heading up Pfizer’s Worldwide R&D Strategic Portfolio Management. In this role, he oversaw Pfizer’s portfolio spanning from discovery up to Phase 3 trials across multiple therapeutic areas, including oncology, inflammation and immunology, rare diseases, cardiovascular and metabolic disease, neuroscience, and vaccines. Previously, he was responsible for the portfolio, strategy and operations functions within Pfizer’s BioTherapeutics Division and ensured efficient advancement of protein therapeutics, cell therapies, gene therapies and vaccines from discovery through development. He also served as chief operating officer for the Centers for Therapeutic Innovation, a pioneering R&D unit within Pfizer that drives product development partnerships with world-leading academic medical centers. As COO, Dr. Straight Nissen

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headed up that organization’s portfolio management, business development, finance and operations functions, and he was one of the key drivers behind establishing the unit. Prior to joining Pfizer, Dr. Straight Nissen served as chief operating officer at Ascendis Pharma (Nasdaq: ASND) from April 2008 to June 2011, advancing the company’s portfolio of new, innovative prodrugs from discovery to clinical proof-of-concept. Earlier, Dr. Straight Nissen served in various leadership positions at Maxygen, a molecular evolution and advanced protein engineering company, including the role of managing director of R&D and senior vice president of global project management. He began his career at Novo Nordisk with a focus on protein engineering. Dr. Straight Nissen holds a Ph.D. in molecular biology and biochemical engineering from the Technical University of Denmark and Carlsberg Laboratories and a Master of Science degree in chemical engineering from the Technical University of Denmark. We believe that Dr. Straight Nissen’s extensive business and financial experience qualifies him to serve on our board of directors.
Michael Rosenblatt, M.D., has served as a member of our board of directors since May 2022. Dr. Rosenblatt is currently a Senior Partner at Flagship Pioneering. From September 2016 to December 2020, Dr. Rosenblatt served as Chief Medical Officer of Flagship Pioneering. From December 2009 to June 2016, he served as the Executive Vice President and Chief Medical Officer of Merck & Co. Inc. Dr. Rosenblatt serves on the board of directors of Rubius Therapeutics, Inc. (Nasdaq: RUBY) and Azenta, Inc. (Nasdaq: AZTA) and has previously served on the board of directors of Radius Health, Inc. (Nasdaq: RDUS). Dr. Rosenblatt received an M.D. from Harvard Medical School and an A.B. in chemistry from Columbia University. We believe that Dr. Rosenblatt’s extensive business and financial experience qualifies him to serve on our board of directors.
William D. “Chip” Baird has served as a member of our board of directors since June 2018. He joined 2seventy bio, Inc. as Chief Financial Officer in November 2021, as Chief Financial Officer for bluebird bio, Inc. from February 2019 to October 2021, and as Chief Financial Officer of Amicus Therapeutics, Inc., a pharmaceutical company, from April 2012 to December 2018. Mr. Baird holds an M.B.A. in finance from The Wharton School of the University of Pennsylvania and a B.S.F.S. in international affairs from the Edmund A. Walsh School of Foreign Service of Georgetown University. We believe Mr. Baird’s broad experience in pharmaceutical finance and executive management roles qualifies him to serve on our board of directors.
Vote Required and Board of Directors’ Recommendation
To be elected, the directors nominated via Proposal No. 1 must receive a plurality of the votes cast, meaning that the director nominees receiving the most votes will be elected. You may vote FOR all the nominees, FOR any one of the nominees, WITHHOLD your vote from all the nominees or WITHHOLD your vote from any one of the nominees. Shares voting “withheld” and broker non-votes, if any, will have no effect on the election of directors.
The proxies will be voted in favor of the above nominee unless a contrary specification is made in the proxy. The nominees have consented to serve as our directors if elected. However, if the nominees are unable to serve or for good cause will not serve as directors, the proxies will be voted for the election of such substitute nominee as our board of directors may designate.
The proposal for the election of directors relates solely to the election of Class I directors nominated by our board of directors.
The board of directors recommends voting FOR the election of Torben Straight Nissen, Ph.D., Michael Rosenblatt, M.D. and William D. “Chip” Baird, as the Class I directors, to serve for a three-year term ending at the annual meeting of stockholders to be held in 2026.
Directors Continuing in Office
The following table identifies our directors and sets forth their principal occupation and business experience during the last five years and their ages as of July 24, 2023.

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Name​​Position and Offices Held with Axcella​​
Director
Since
​​
Class and Year in Which
Term Will Expire
​​Age​
Gary P. Pisano, Ph.D.​​Director​​2011​​Class II – 2024​​61​
Cristina M. Rondinone, Ph.D.​​Director​​2018​​Class II – 2024​​63​
Paul J. Sekhri​​Director​​2020​​Class II – 2024​​65​
William R. Hinshaw, Jr.​​President, Chief Executive Officer and Director​​2018​​Class III – 2025​​54​
Martin Hendrix​​Director​​2022​​Class III – 2025​​55​
Robert Rosiello​​Director, Chairman​​2022​​Class III – 2025​​65​
Catherine Angell Sohn, Pharm. D.​​Director​​2019​​Class III – 2025​​70​
Class II Directors (Term Expires at 2024 Annual Meeting)
Gary P. Pisano, Ph.D., has served as a member of our board of directors since October 2011. Dr. Pisano is the Harry E. Figgie, Jr. Professor of Business Administration and Senior Associate Dean for Promotions and Tenure at the Harvard Business School. He has served on the Harvard faculty since 1988. Dr. Pisano’s research and teaching focus on technology and operations strategy, the management of innovation and intellectual property, and competitive strategy. For more than two decades, he has consulted extensively on these issues with companies in the pharmaceutical, biotechnology, medical device, specialty chemical and healthcare industries. He has previously served as a director of Axovant Sciences Ltd. (Nasdaq: AXON) and Patheon NV (NYSE: PTHN). Dr. Pisano holds a Ph.D. in business administration from the University of California, Berkeley and a B.A. in economics from Yale University. We believe that Dr. Pisano’s knowledge of business administration, innovation, and strategy, particularly within the healthcare industry, qualifies him to serve on our board of directors.
Cristina M. Rondinone, Ph.D., has served as a member of our board since June 2018. Since June of 2020, Dr. Rondinone has consulted for pharmaceutical and biotechnology companies at CMR Pharma Consulting and in 2022 became Founder and CEO of a new startup company in stealth mode. Dr. Rondinone served as President of Cellarity Inc. from September 2019 to June 2020. Prior to this position, from March 2011 to September 2019, Dr. Rondinone served in roles of increasing responsibility at MedImmune, LLC, a wholly owned subsidiary of AstraZeneca, most recently as Senior Vice President R&D, Head of Cardiovascular, Renal and Metabolic Diseases Innovative Medicines and Early Development. Dr. Rondinone served in different roles in research and development at Hoffmann-La Roche (2005-2011) and Abbott Laboratories (1998-2005). Dr. Rondinone holds a Docent in molecular medicine from the University of Goteborg, Sweden School of Medicine and a M.Sc. and Ph.D. in biological sciences from the University of Buenos Aires. We believe that Dr. Rondinone’s extensive biopharmaceutical research and development experience qualifies her to serve on our board of directors.
Paul J. Sekhri has served as a member of our board of directors since May 2022. Mr. Sekhri is a Director of Longboard Pharmaceuticals, Inc., Ipsen S.A., Compugen Ltd., Pharming N.V., where he is Chairman, Oryn Therapeutics, and Veeva Systems. He most recently served as the chief executive officer of eGenesis where he is now a member of the Board and a Senior Advisor to the Chairman. Before eGenesis, Mr. Sekhri served as president and chief executive officer of Lycera Corp. Prior to Lycera, Mr. Sekhri served as Senior Vice President, Integrated Care at Sanofi. Prior to Sanofi, he served as group executive vice president, global business development, and chief strategy officer for Teva Pharmaceuticals Industries, Ltd., and earlier, operating partner and head of the Biotechnology Operating Group at TPG Biotech. Previously, Mr. Sekhri founded Cerimon Pharmaceuticals where he served as president and chief executive officer. Prior to founding Cerimon, he was president and chief business officer of ARIAD Pharmaceuticals. Earlier in his career, Mr. Sekhri held various senior positions at Novartis AG, including senior vice president, head of global search and evaluation, business development and licensing, and global head, early commercial development. Mr. Sekhri completed graduate work in neuroscience at the University of Maryland School of Medicine in Baltimore and received his B.S. in zoology from the University of Maryland, College Park. We believe that Mr. Sekhri’s extensive business and financial experience qualifies him to serve on our board of directors.

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Class III Directors (Term Expires at 2025 Annual Meeting)
William R. Hinshaw, Jr. has served as our President and Chief Executive Officer and as a member of our board of directors since June 2018. Prior to joining us, Mr. Hinshaw served in increasing roles of responsibility at Novartis Pharmaceuticals Corporation, a pharmaceutical company, from December 2003 until November 2017, most recently as the Executive Vice President and Head of U.S. Oncology. Mr. Hinshaw holds a B.S. in molecular biology from the University of Wisconsin. We believe that Mr. Hinshaw’s qualifications, attributes and skills, including his experience in operations management and executive leadership, qualify him to serve on our board of directors.
Martin Hendrix, Ph.D., has served as a member of our board of directors since May 2022. Dr. Hendrix joined Nestlé Health Science US in April 2012, and currently serves as its Head of Global Business Development and M&A. In this position, Dr. Hendrix oversees all deal flow of Nestlé Health Science and is also responsible for its venture capital partnerships and direct equity investments. Dr. Hendrix has represented Nestlé on the boards of Enterome, Microbiome Diagnostic Partners, Procise Dx, Bodymed AG, as well as board observer roles for Evelo, Kaleido and Senda. Prior to joining Nestlé, from January 1998 to March 2012, Dr. Hendrix was a research chemist and subsequently a member of the Strategic Planning Group, as well as a Senior Director of Business Strategy at Bayer AG. Dr. Hendrix currently serves on the board of directors of Procise Dx, Bodymed AG, Prometheus Biosciences Inc., and Senda (observer). Dr. Hendrix holds a Ph.D. in Chemistry from The Scripps Research Institute, an M.S. in Chemistry from the Georgia Institute of Technology. We believe that Dr. Hendrix’s extensive technical and business experience qualifies him to serve on our board of directors.
Robert Rosiello has served as a member of our board of directors since October 2022. Mr. Rosiello is an Executive Partner at Flagship Pioneering, which he joined in 2018 and where he focuses on building capability to help originate, manage, and grow new Flagship companies. He also works with senior leadership to drive Flagship’s strategy, institution building, and growth initiatives. From September 1984 to June 2015, Mr. Rosiello worked at McKinsey & Company advising CEOs and boards of leading health care, technology, and consumer companies. He served as a senior partner for 18 years and was a member of McKinsey’s Senior Partner Review and Compensation Committees. From July 2015 to August 2016, Mr. Rosiello was both Executive Vice President and Chief Financial Officer at Valeant Pharmaceuticals, where he led the finance, human resources, and IT functions. He has served on the Board Evelo Biosciences, Inc. (NASDAQ: EVLO) since April 2023. He currently serves on the Board and Executive Committee of Catholic Charities of New York and the Central Selection Committee of the Morehead-Cain Foundation. He previously served on the Boards of the Pew Research Center and Inari Agriculture. Mr. Rosiello received his B.A. in economics from the University of North Carolina, where he was a Morehead Scholar and graduated Phi Beta Kappa, an M.Sc. in economics from the London School of Economics, and an M.B.A. from Harvard Business School. We believe that Mr. Rosiello’s extensive business and financial experience qualifies him to serve on our board of directors.
Catherine Angell Sohn, Pharm.D., has served as a member of our board of directors since August 2019. Dr. Sohn has over 30 years of biopharmaceutical leadership and operational experience at GlaxoSmithKline and currently serves on the boards of directors of Jazz Pharmaceuticals plc (Nasdaq: JAZZ), Maze Therapeutics (private) and BioEclipse Therapeutics (private). Dr. Sohn is also Adjunct Professor at UCSF, her alma mater. Since January 2011, as President of Sohn Health Strategies, Dr. Sohn has advised CEOs and Boards of life science companies on strategy, strategic product development, partnering/M&A, commercialization of new medicines and vaccines. Dr. Sohn was formerly senior vice president, worldwide business development, and a member of the global executive committee at GlaxoSmithKline’s Consumer Healthcare division where she led U.S. and global transactions. Previously she was vice president worldwide strategic product development for the cardiovascular, metabolic and pulmonary therapeutic areas at SmithKline Beecham Pharmaceuticals where along with the senior vice president of R&D, she was responsible for decisions to move assets into phase 1, strategic product development and portfolio prioritization, and where she had global responsibility for commercial strategy and global commercialization, including overseeing the global launch of Coreg for congestive heart failure which became a $1 billion indication. Earlier in her career, as an entrepreneur within a large company, she started the U.S. Vaccine Business, built the team, and led the launch of SB’s first vaccine in the U.S. and helped shape the global vaccine portfolio pipeline as a member of the International Vaccine Steering Committee. Subsequently, she

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led the U.S. commercialization of the company’s largest neuroscience product which grew to >$1 billion in sales and as a member of the Global CNS Therapeutic Area Steering Team, led the focus to expand development into anxiety disorders. Dr. Sohn earned a Doctor of Pharmacy degree from the University of California, San Francisco, a Corporate Directors Certificate from Harvard Business School, a Certificate of Professional Development from Wharton, a Certificate from Berkeley Law for ESG: Navigating the Board’s Role and is a Certified Licensing Professional Emeritus. We believe that Dr. Sohn’s extensive experience with product development, strategic marketing, and business development transactions in the pharmaceutical industry qualifies her to serve on our board of directors.
There are no family relationships between or among any of our directors or executive officers. The principal occupation and employment during the past five years of each of our directors was carried on, in each case except as specifically identified above, with a corporation or organization that is not a parent, subsidiary or other affiliate of us. There is no arrangement or understanding between any of our directors and any other person or persons pursuant to which he or she is to be selected as a director.
There are no material legal proceedings to which any of our directors is a party adverse to us or our subsidiaries or in which any such person has a material interest adverse to us or our subsidiaries.
Executive Officers Who Are Not Directors
The following table identifies our executive officers and sets forth their current positions at Axcella and their ages as of July 31, 2023. Biographical information for Mr. Hinshaw, our President and Chief Executive Officer, is set forth under the heading “Directors Continuing in Office” above.
Name​​Position Held with Axcella​​
Officer
Since
​​Age​
Paul Fehlner, J.D., Ph.D.​​Senior Vice President, Chief Legal Officer and Corporate Secretary​​2018​​60​
Paul Fehlner, J.D., Ph.D., has served as our Senior Vice President, Chief Legal Officer and Corporate Secretary since September 2020 and previously served as our Senior Vice President and Chief Intellectual Property Officer from April 2018 to September 2020. In addition, Dr. Fehlner has served as a Principal at Life Sciences Innovation LLC, a consulting firm that he founded, since December 2017. From November 2008 through November 2017, Dr. Fehlner served as Global Head of Intellectual Property at Novartis Pharma AG in Basel, Switzerland. Prior to joining Novartis, Dr. Fehlner practiced IP law in leading firms in the U.S. along with working in-house at Rhone-Poulenc Rorer. Dr. Fehlner holds a J.D. from Fordham University School of Law, a Ph.D. in immunology and biochemistry from The Rockefeller University and a B.S. in chemistry from Haverford College.
The principal occupation and employment during the past five years of each of our executive officers was carried on, in each case except as specifically identified above, with a corporation or organization that is not a parent, subsidiary or other affiliate of us. There is no arrangement or understanding between any of our executive officers and any other person or persons pursuant to which he or she was or is to be selected as an executive officer.
There are no material legal proceedings to which any of our executive officers is a party adverse to us or our subsidiaries or in which any such person has a material interest adverse to us or our subsidiaries.

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PROPOSAL NO. 2 — RATIFICATION OF THE APPOINTMENT OF DELOITTE & TOUCHE LLP AS AXCELLA’S INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM FOR THE
FISCAL YEAR ENDING DECEMBER 31, 2023
Axcella’s stockholders are being asked to ratify the appointment by the audit committee of the board of directors of Deloitte & Touche LLP as Axcella’s independent registered public accounting firm for the fiscal year ending December 31, 2023. Deloitte & Touche LLP has served as Axcella’s independent registered public accounting firm since 2012.
The audit committee is solely responsible for selecting Axcella’s independent registered public accounting firm for the fiscal year ending December 31, 2023. Stockholder approval is not required to appoint Deloitte & Touche LLP as Axcella’s independent registered public accounting firm. However, the board of directors believes that submitting the appointment of Deloitte & Touche LLP to the stockholders for ratification is good corporate governance. If the stockholders do not ratify this appointment, the audit committee will reconsider whether to retain Deloitte & Touche LLP. If the selection of Deloitte & Touche LLP is ratified, the audit committee, at its discretion, may direct the appointment of a different independent registered public accounting firm at any time it decides that such a change would be in the best interest of Axcella and its stockholders.
A representative of Deloitte & Touche LLP is expected to be present at the virtual Annual Meeting and will have an opportunity to make a statement if he or she desires to do so and to respond to appropriate questions from our stockholders.
Axcella incurred the following fees from Deloitte & Touche LLP for the audit of the consolidated financial statements and for other services provided during the years ended December 31, 2022, and 2021.
Fee Category​​
Fiscal Year
2022 ($)
​​
Fiscal Year
2021 ($)
​
Audit and audit-related fees(1)
​​​$628,893​​​​$588,307​​
Tax fees​​​​—​​​​​—​​
All other fees​​​​—​​​​​—​​
Total Fees​​​$628,893​​​​$588,307​​
​
(1)
Consists of fees for the audit of our annual financial statements, reviews of quarterly financial statements included in Quarterly Reports on Form 10-Q, services provided in connection with SEC filings, including consents and comfort letters, and a subscription to the Deloitte Accounting Research Tool.
​
Audit Committee Pre-approval Policy and Procedures
Our audit committee has adopted policies and procedures relating to the approval of all audit and non-audit services that are to be performed by our independent registered public accounting firm. This policy provides that we will not engage our independent registered public accounting firm to render audit or non-audit services unless the service is specifically approved in advance by our audit committee, or the engagement is entered into pursuant to the pre-approval procedure described below.
From time to time, our audit committee may pre-approve specified types of services that are expected to be provided to us by our independent registered public accounting firm during the next 12 months. Any such pre-approval details the particular service or type of services to be provided and is also generally subject to a maximum dollar amount.
During our 2022 and 2021 fiscal years, no services were provided to us by Deloitte & Touche LLP other than in accordance with the pre-approval policies and procedures described above.
Vote Required and Board of Directors’ Recommendation
The approval of Proposal No. 2 requires the affirmative vote of a majority of the votes properly cast on the proposal. Shares that are voted “abstain” and broker non-votes, if any, will not affect the outcome of this proposal.
The board of directors recommends voting FOR Proposal No. 2 to ratify the appointment of Deloitte & Touche LLP as Axcella’s independent registered public accounting firm for the fiscal year ending December 31, 2023.

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PROPOSAL No. 3 — APPROVAL OF AN AMENDMENT TO OUR RESTATED CERTIFICATE OF INCORPORATION TO EFFECT A REVERSE STOCK SPLIT OF OUR COMMON STOCK
General
Our board of directors has approved and, subject to stockholder approval, adopted a resolution (1) declaring advisable, and recommending to our stockholders for their approval, amendment to the Certificate of Incorporation (the “Reverse Stock Split Amendment”), to give our board of directors discretionary authority to effect a reverse stock split of all of the outstanding shares of our Common Stock at a ratio ranging from any whole number between 1-for-2 and 1-for-25 (“Reverse Stock Split”), with the exact ratio within such range to be determined by the board of directors at its discretion, subject to the board of directors’ authority to determine when to file the amendment and to abandon the other amendments notwithstanding prior stockholder approval of such amendments, (2) directing that such proposed amendments to our Certificate of Incorporation be submitted to our stockholders for their approval and adoption, and (3) recommending that our stockholders approve and adopt each of the proposed amendments. The text of the form of Reverse Stock Split Amendment, which would be filed with the Delaware Secretary of State by means of the Certificate of Amendment to effect the Reverse Stock Split, are set forth in Exhibit A to this Proxy Statement.
By approving this proposal, stockholders will approve alternative amendments to our Certificate of Incorporation pursuant to which a number of outstanding shares of our Common Stock between 2 and 25, inclusive, would be combined into one share of our Common Stock. The number of shares of Common Stock underlying outstanding equity awards and available for future awards under our equity incentive plans, as well as the number of shares issuable upon exercise of outstanding warrants, would also be proportionately reduced in the same manner as a result of the Reverse Stock Split. Upon receiving the stockholder approval, the board of directors will have the authority, but not the obligation, in its sole discretion, to elect, without further action on the part of the stockholders, whether to effect the Reverse Stock Split and, if so, to determine the Reverse Stock Split ratio from among the approved range described above and to effect the Reverse Stock Split by filing a Certificate of Amendment with the Secretary of State of the State of Delaware to be effective as of the Effective Time (as defined below), and all other amendments will be abandoned.
The board of directors’ decision as to whether and when to effect the Reverse Stock Split, and the ratio at which the Reverse Stock Split will be effected, will be based on a number of factors, including, without limitation, general market and economic conditions, the historical and then-prevailing trading price and trading volume of our Common Stock, the anticipated impact of the Reverse Stock Split on the trading price and trading volume of our Common Stock, the anticipated impact on our market capitalization, and the continued listing requirements of The Nasdaq Stock Market LLC (“Nasdaq”). Although our stockholders may approve the Reverse Stock Split, we will not effect the Reverse Stock Split if the board of directors does not deem it to be in the best interests of the Company and its stockholders.
Because the Reverse Stock Split will decrease the number of outstanding shares of our Common Stock by a ratio in the range of 1-for-2 to 1-for-25 but would not effect a decrease to the number of shares of Common Stock that the Company will be authorized to issue, the proposed Reverse Stock Split Amendments would result in a relative increase in the number of authorized and unissued shares of our Common Stock. For more information on the relative increase in the number of authorized shares of our Common Stock, see “— Principal Effects of the Reverse Stock Split-Issued and Outstanding Shares of Common Stock” below.
Purpose of the Reverse Stock Split
The board of directors submits the Reverse Stock Split Proposal to our stockholders for approval and adoption with the primary intent of increasing the per share price of our Common Stock for the following principal reasons:
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to ensure compliance with the $1.00 per share of common stock minimum bid price requirement for continued listing on Nasdaq;
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to encourage increased investor interest in our Common Stock and promote greater liquidity for our stockholders; and
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upon. You should provide voting instructions for your shares by following the instructions provided on the voting instruction form that you receive from your bank, broker or other nominee.
to help attract, retain, and motivate employees.
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Nasdaq RequirementsBroker non-votes, if any, will be counted for Continued Listing
Our Common Stockpurposes of calculating whether a quorum is quoted on Nasdaq underpresent at the symbol “AXLA.” For our Common Stock to continue trading on Nasdaq, the Company must comply with various listing standards, includingSpecial Meeting. It is expected that the Company maintain a minimum closing bid priceAssignment Proposal, Dissolution Proposal, and Adjournment Proposal will be considered non-routine matters. For non-routine matters, broker non-votes will have the effect of $1.00 per share of common stock.
On December 30, 2022, we received a letter fromvoting against that proposal. If you want to approve the Listing Qualifications Department of Nasdaq notifying us that, for 30 consecutive business days, the closing bid price for the Company’s Common Stock closed below the minimum $1.00 per share required for continued listing on Nasdaq pursuant to Nasdaq Listing Rule 5450(a)(1) (the “Minimum Bid Price Requirement”). Under Nasdaq Listing Rule 5810(c)(3)(A), the Company was granted an initial 180 calendar day grace period, or until June 28, 2023, to regain compliance with the Minimum Bid Price Requirement, which required our Common Stock to have a minimum closing bid price of at least $1.00 per share for a minimum of 10 consecutive business days during the 180 calendar-day grace period. The Company did not regain compliance with minimum bid price requirement by June 28, 2023Assignment and the Listing Qualifications Department of Nasdaq didDissolution, you must vote FOR the Assignment Proposal and the Dissolution Proposal. If you do not grantinstruct your broker on how to vote your shares with respect to the Company a second grace period to do so. The Company has a hearing before a Nasdaq Hearings Panel (the “Hearings Panel”) scheduled for September 7, 2023 to addressAssignment Proposal and the deficiencies and present a plan to regain compliance. There can be no assurance that the CompanyDissolution Proposal, your broker will not be able to regain compliance orvote your shares with respect to the Assignment Proposal and the Dissolution Proposal, and it will have the effect of a vote against that Nasdaq will extendproposal.
Recommendation of the compliance period.Board
If we failThe Board has unanimously approved the Assignment and Dissolution and has determined that proceeding with the Assignment, Dissolution, and any other agreements and transactions contemplated by the Assignment and Dissolution are advisable to regain compliance within the applicable compliance period, Nasdaq will provide written notification that the Company’s securities will be delisted. At that time, we may appeal Nasdaq’s determination to a Hearings Panel. If we appeal, the Hearings Panel will request a plan to regain compliance. Hearings Panels have generally viewed a reverse stock split as the only definitive plan to resolve a bid price deficiency. There can be no assurance that such an appeal would be successful.
If our Common Stock is delisted from Nasdaq, the board of directors believes that the trading market for our Common Stock could become significantly less liquid, which could reduce the trading price of our Common Stock and increase the transaction costs of trading in shares of our Common Stock. Such delisting from Nasdaq and continued or further decline in our stock price could also impair our ability to raise additional necessary capital through equity or debt financing.
If the Reverse Stock Split is effected, it would cause a decrease in the total number of shares of our Common Stock outstanding and increase the market price of our Common Stock. The board of directors intends to effect the Reverse Stock Split only if it believes that a decrease in the number of shares outstanding is in the best interests of Axcella and Axcella’s stockholders. The Board unanimously recommends that Axcella’s stockholders vote “FOR” the CompanyAssignment Proposal and vote “FOR” the Dissolution Proposal. For a description of the factors considered by the Board in making its stockholders.
determinations with respect to the Assignment Proposal, see the section of this proxy statement captioned “IF THIS PROPOSAL IS NOT APPROVED, WE MAY BE UNABLE TO MAINTAIN THE LISTING OF OUR COMMON STOCK ON NASDAQ, WHICH COULD ADVERSELY AFFECT THE LIQUIDITY AND MARKETABILITY OF OUR COMMON STOCK AND ADVERSELY IMPACT OUR ABILITY TO COMPLY WITH CERTAIN CONTRACTUAL OBLIGATIONS REQUIRED BY OUR SECURED LOAN AGREEMENTS.Reasons for the Proposed Assignment.” For a description of the factors considered by the Board in making its determinations with respect to the Dissolution Proposal, see the section of this proxy statement captioned “Reasons for the Proposed Dissolution.” The Board also unanimously recommends that Axcella’s stockholders vote “FOR” the Adjournment Proposal.
Investor InterestTHE BOARD UNANIMOUSLY RECOMMENDS THAT YOU VOTE “FOR” THE ASSIGNMENT PROPOSAL, DISSOLUTION PROPOSAL AND ADJOURNMENT PROPOSAL.
Solicitation of Proxies and LiquidityVoting Procedures
In addition,Your shares may be voted at the Special Meeting only if you are present or represented by proxy. Whether or not you plan to attend the Special Meeting, you are encouraged to submit a proxy to ensure that your shares will be represented and voted. See the section of this proxy statement captioned “Questions and Answers Regarding This Solicitation and Voting at the Special Meeting — How do I vote?” for additional information.
Voting by, and Revocability of, Proxies
If you submit a proxy via the Internet, by telephone or by returning a signed proxy card by mail, your shares will be voted at the Special Meeting as you indicate. If you sign your proxy card without indicating your vote, your shares will be voted “FOR” each of the Assignment Proposal, Dissolution Proposal and Adjournment Proposal. If you hold your shares through an account with a bank or a broker, you will receive instructions from your broker, bank or other nominee that you must follow in approvingorder to have your shares voted. If you fail to correctly follow the proposed Reverse Stock Split Amendments,instructions you receive from your broker, bank or other nominee, your shares may not be voted. See the boardsection of directors considered thatthis proxy statement captioned “Broker Non-Votes and Abstentions” above for additional information.
A proxy may be revoked at any time prior to the Reverse Stock Splitvoting at the Special Meeting by submitting a later dated proxy in accordance with the requirements outlined in this proxy statement (including a proxy authorization submitted by telephone or electronically via the Internet prior to the deadline for submitting a proxy by telephone or via the Internet), by sending a properly signed written notice of such revocation to Axcella’s Corporate Secretary in advance of the Special Meeting or by attending the Special Meeting and voting by ballot. If your shares are held through a bank, broker or other nominee, you may change your voting instructions by submitting a later dated voting instruction form to your broker, bank or other nominee or fiduciary, or if you obtained a legal proxy from your broker, bank nominee or fiduciary giving you the resulting increase inright to vote your shares at the per share priceSpecial Meeting, by attending the Special Meeting and voting by ballot. You should direct any written notices of our Common Stock could encourage increased investor interest in our Common Stockrevocation and promote greater liquidity for our stockholders.
In the event that our Common Stock wererelated correspondence to be delisted from Nasdaq, our Common Stock would likely trade in the over-the-counter market. If our Common Stock were to trade on the over-the-counter market, selling our Common Stock could be more difficult because smaller quantities of shares would likely be bought and sold, and transactions could be delayed. In addition, many brokerage houses and institutional investors have internal policies and practices that prohibit them from investing in low-priced stocks or tend to discourage individual brokers from recommending low-priced stocks to their customers,Axcella’s Corporate Secretary at info@Axcellatx.com.
 
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further limitingQuestions and Additional Information
If you have questions about the liquidityAssignment, the Assignment Proposal, Dissolution, Dissolution Proposal, Adjournment Proposal or how to submit your proxy, or if you need additional copies of our Common Stock. These factors could result in lower prices and larger spreads inthis proxy statement or the bid and ask prices for our Common Stock. Additionally, investors may be dissuaded from purchasing lower priced stocks because the brokerage commissions, as a percentage of the total transaction, tend to be higher for such stocks. Moreover, the analystsenclosed proxy card or voting instructions, please contact Axcella at many brokerage firms do not monitor the trading activityinfo@Axcellatx.com or otherwise provide coverage of lower priced stocks. A greater price per share of our Common Stock could allow a broader range of institutions to invest in our Common Stock. For all of these reasons, we believe the Reverse Stock Split could potentially increase marketability, trading volume, and liquidity of our Common Stock.(857) 320-2200.
Employee RetentionPROPOSAL 1: APPROVAL OF ASSIGNMENT
The board of directors believesGeneral
On November 1, 2023, the Board determined that the Company’s employeesit is advisable and directors who are compensated in the form of our equity-based securities may be less incentivized and invested in the Company if we are no longer listed on Nasdaq. Accordingly, the board of directors believes that maintaining Nasdaq listing qualifications for our Common Stock, can help attract, retain, and motivate employees and members of our board of directors.
In light of the factors mentioned above, our board of directors unanimously approved the proposed Reverse Stock Split Amendments to effect the Reverse Stock Split as our best means of increasing and maintaining the price of our Common Stock to above $1.00 per share in compliance with Nasdaq requirements.
Board of Directors Discretion to Implement the Reverse Stock Split
The board of directors believes that stockholder approval of a range of ratios (as opposed to a single reverse stock split ratio) is in the best interests of our CompanyAxcella and Axcella’s stockholders because it is not possible to predict market conditions at the time the Reverse Stock Split would be effected. We believe that a range of Reverse Stock Split ratios provides us with the most flexibility to achieve the desired results of the Reverse Stock Split. The Reverse Stock Split ratio to be selected by our board of directors will be a whole number in a range of 1-for-2 to 1-for-25. The board of directors can only authorize the filing of one Reverse Stock Split Amendment and all other Reverse Stock Split Amendments will be abandoned. The board of directors also has the authority to abandon all Reverse Stock Split Amendments.
In determining the Reverse Stock Split ratio and whether and when to effect the Reverse Stock Splitassignment of all or substantially all of Axcella’s assets for the benefit of Axcella’s creditors through the Assignment. In furtherance of the Assignment, and pursuant to Delaware law, the Board is presenting the Assignment Proposal for approval by Axcella’s stockholders.
If the Assignment is approved by Axcella’s stockholders, Axcella expects to assign all of Axcella’s right, title, interest in, and custody and control of Axcella’s property to a third-party assignee, as the Assignee. The Assignee will then liquidate the property and distribute the proceeds to Axcella’s creditors to satisfy Axcella’s obligations. If any proceeds remain after all of Axcella’s obligations have been satisfied, those remaining proceeds, if any, will be distributed to the stockholders. Because Axcella does not know the final amount that the Assignee will recover from a liquidation of Axcella’s assets, Axcella does not know whether any amounts will be available for distribution to the stockholders. The Board will determine the Assignee.
Summary of the Proposed Assignment
Upon the effectiveness of the Assignment, the Assignee will have sole control over Axcella’s assets and Axcella will no longer control the liquidation or distribution of its assets or the resolution of claims. Axcella will delist from the Nasdaq Global Market and terminate Axcella’s status as a reporting company with the SEC.
Based upon information available at this time, Axcella cannot forecast whether any amounts will be available to Axcella’s stockholders in connection with, or as a result of, the Assignment. There is a possibility that, assuming the Assignee can resolve all of Axcella’s obligations, some amount of liquidation proceeds could be paid to stockholders. However, there are too many variables and uncertainties for us to estimate whether any amounts will actually be paid or the amount of any such potential payments.
Any distributions made to stockholders by Axcella, following the receiptdistributions made to creditors to satisfy the Company’s obligations, will be made pro rata according to the stockholders’ holdings of stockholder approval,Common Stock as of the boardEffective Time.
Reasons for the Proposed Assignment
After seeking potential funding sources and other ways to continue operating Axcella’s business, and after exploring all of directors will consider a numberits options, the Board believes that the Assignment presents the best opportunity for Axcella to satisfy its obligations to creditors and may provide an opportunity for future payments to stockholders. At this time, the Board has considered these options and, on November 1, 2023, determined that the Assignment is in Axcella’s best interests and in the best interests of factors, including, without limitation:Axcella’s stockholders.
In arriving at this determination, the Board considered such terms and alternatives, as well as the following factors:
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our ability to maintain the listing of our Common Stock on Nasdaq;Axcella’s financial projections and continuing negative cash flow;
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the historical trading price and trading volume of our Common Stock;Axcella’s overall debts;
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the number of shares of our Common Stock outstanding immediately before and after the Reverse Stock Split;Axcella’s inability to continue to fund its existing operations with its current cash flow;
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the then-prevailing trading price and trading volume of our Common Stock and the anticipated impact of the Reverse Stock Split on the trading price and trading volume of our Common Stock;
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the anticipated impact of a particular ratio on our market capitalization;Axcella’s inability to raise additional capital; and
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prevailing general market and economic conditions.
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We believe that granting our board of directors the authority to set the ratio for the Reverse Stock Split is essential because it allows us to take these factors into consideration and to react to changing market conditions. If our board of directors chooses to implement the Reverse Stock Split, we will make a public announcement regarding the determination of the Reverse Stock Split ratio.
Risks Associated with the Reverse Stock Split
There are risks associated with the Reverse Stock Split, including that the Reverse Stock Split may not result in a sustained increase in the per share price of our Common Stock. There is no assurance that:
 
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•
general economic conditions.
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The Board also considered the market price per sharefollowing risks in arriving at its conclusion that the Assignment is in Axcella’s best interests and the best interests of our Common Stock after Axcella’s stockholders:
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the Reverse Stock Split will rise in proportionuncertainty of the timing, nature and amount of any distributions to the reduction in the number of shares of our Common Stock outstanding immediately before the Reverse Stock Split;stockholders;
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the Reverse Stock Split will resultpossibility that the Assignment would not yield distributions to stockholders in excess of the amount that stockholders could have received upon a per share price that will increasesale or other transaction involving Axcella or a sale of shares on the level of investment in our Common Stock by institutional investors or increase analyst and broker interest in the Company;
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the Reverse Stock Split will result in a per share price that will increase our ability to attract and retain employees and other service providers who receive compensation in the form of our equity-based securities;open market; and
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the market price per sharepossibility that certain of our Common Stock will either exceedAxcella’s executive officers and directors may have financial interests in the Assignment that may be different from, or remain in excessaddition to, the interests of Axcella’s stockholders generally.
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In view of the $1.00 minimum bid price as required by Nasdaq, or that we will otherwise meet the requirementsvariety of Nasdaq for continued inclusion for trading on Nasdaq.
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Stockholders should note that the effectfactors considered in connection with its evaluation of the Reverse Stock Split,Assignment, the Board did not find it practical, and did not quantify or otherwise attempt, to assign relative weight to the specific factors considered in reaching its conclusions. In addition, the Board did not undertake to make any specific determination as to whether any particular factor, or any aspect of any particular factor, was favorable or unfavorable to its ultimate determination, but rather conducted an overall analysis of the factors described above. In considering the factors described above, individual members of the Board may have given different weight to different factors.
Axcella cannot offer any assurance that distributions, if any, uponto Axcella’s stockholders following the trading price of our Common Stock cannot be accurately predicted. In particular, we cannot assure you thatAssignment will equal or exceed the price for a share of our Common Stock after the Reverse Stock Split will increase in proportion to the reduction in the number ofor prices at which shares of our Common Stock outstanding before the Reverse Stock Split or, even if it does, that such price will be maintained for any period of time.
Even if an increased per share price can be maintained, the Reverse Stock Split may not achieve the desired results that have been outlined above under “— Purpose of the Reverse Stock Split.” Moreover, because some investors may view the Reverse Stock Split negatively, we cannot assure you that the Reverse Stock Split will not adversely impact the market price of our Common Stock.
While our aim is that the Reverse Stock Split will be sufficient to maintain our listing on Nasdaq, it is possible that, even if the Reverse Stock Split results in a bid price for our Common Stock that exceeds $1.00 per share of Common Stock we may not be able to continue to satisfy Nasdaq’s additional requirements and standards for continued listing of our Common Stockrecently have traded on Nasdaq.
We believeNasdaq Global Market or could trade over-the-counter in the future. However, the Board believes that the Reverse Stock Split may result in greater liquidity for our stockholders. However, it is also possible that such liquidity could be adversely affected byin Axcella’s best interests and the reduced numberbest interests of shares outstanding afterAxcella’s stockholders to approve the Reverse Stock Split, particularlyAssignment.
Consequences to Stockholders
Based upon information available at this time, we cannot forecast if the price of our Common Stock does not increaseAxcella’s stockholders will receive any cash, stock or other property in connection with, or as a result of, the ReverseAssignment. Our Common Stock Split.
Additionally, ifwill be, subject to regulatory considerations, delisted following the Reverse Stock Split is implemented, it may increaseAssignment and we plan to take steps to terminate our status as a reporting company with the numberSEC following the Special Meeting. As a result, we expect that our stockholders will have no readily available means to dispose of stockholders who own “odd lots” of less than 100their shares of common stock. A purchase or sale of less than 100 shares (an “odd lot” transaction) may result in incrementally higher trading costs through certain brokers, particularly “full service” brokers. Therefore, those stockholders who own fewer than 100 shares of our Common Stock following the Reverse Stock SplitEffective Time.
Assignment Under Delaware Law
Delaware law provides that a corporation may be requiredmake an assignment for the benefit of creditors upon the approval of a corporation’s board of directors followed by the approval of a majority of its outstanding stock entitled to pay higher transaction costs if they sell their sharesvote thereon. If such assignment is approved by the corporation’s stockholders, such corporation then executes an assignment agreement, which transfers all of our Common Stock.
Principal Effectsits right, title, interest in, and custody and control of its property to a third-party assignee. Following execution of the Reverse Stock Split
Issuedassignment agreement, the assignee will file an application in the Delaware Court of Chancery, which commences a judicial proceeding for recognition of the assignment for the benefit of creditors. Such assignee then liquidates the property and Outstanding Sharesdistributes the proceeds to such corporation’s creditors according to their respective priorities at law to satisfy the corporation’s obligations. If any proceeds remain after all of Common Stock
If the Reverse Stock Split is approvedcorporation’s obligations and effected, each holder of our Common Stock outstanding immediately priorcosts associated with the liquidation process have been satisfied, remaining proceeds will be distributed to the effectivenesscorporation’s stockholders.
Absence of Appraisal Rights
Under Delaware law, Axcella’s stockholders are not entitled to appraisal, dissenters’ or similar rights in connection with the Assignment.
Conduct of Axcella Following the Approval of the Reverse Stock Split will own a reduced number of shares of our Common Stock upon effectivenessAssignment
This section of the Reverse Stock Split. The Reverse Stock Split would be effected simultaneously atproxy statement describes material aspects of the same exchange ratio for all outstanding shares of Common Stock, as required by our Certificate of Incorporation. Except for adjustments that may result from the treatment of fractional shares (as described below), the Reverse Stock Split would affect all stockholders uniformly and would not change any stockholder’s relative percentage ownership interest in the Company, voting rights, or other rights that accompany shares of our Common Stock. Shares of our Common Stock issued pursuant to the Reverse Stock Split will remain fully paid and non-assessable,proposed Assignment and the par value per share of Common Stock will remain $0.001.steps Axcella and the Board expect to take in connection with the Assignment. While Axcella believes that
 
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Relative Increase in Numberthis description covers the material terms of Authorized Sharesthe Assignment, this summary may not contain all of the information that is important to you. You should carefully read this entire proxy statement, including the section captioned “Summary of the Assignment.”
Approval of Assignment
To proceed with the Assignment, the Assignment Proposal must be approved by the affirmative vote of a majority of the outstanding shares of stock of Axcella entitled to vote thereon. The approval of the Assignment Proposal by the requisite vote of the holders of Axcella’s Common Stock will constitute complete approval and authorization for Issuancethe Board, without further stockholder action, to proceed with the Assignment in accordance with any applicable provision of Delaware law.
Assignment
The Reverse Stock SplitIf the Assignment Proposal is approved by the requisite vote of Axcella’s stockholders, the steps set forth below may be completed at such times as the Board, in its discretion and in accordance with Delaware law, deems necessary, appropriate or advisable in Axcella’s best interests and the best interests of Axcella’s stockholders:
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the cessation of all of Axcella’s business activities except those relating to the Assignment; and
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the taking of any and all other actions permitted or required by Delaware law and any other applicable laws and regulations.
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Distributions
Based upon information available at this time, Axcella cannot forecast whether any amounts will not affect the number of authorized sharesbe available to Axcella’s stockholders in connection with, or the par value of our capital stock, which will remain at 150,000,000 shares of Common Stock, par value $0.001 per share, and 10,000,000 shares of preferred stock, par value $0.001 per share (“Preferred Stock,” and together with our Common Stock, our “Capital Stock”).
Although the number of authorized shares of our Capital Stock will not change as a result of, the ReverseAssignment or the liquidation of the Company’s assets. There is a possibility that if the Assignee is able to resolve all of Axcella’s obligations, that some amount of liquidation proceeds could be paid to stockholders. However, there are too many variables and uncertainties for us to estimate whether any amounts will actually be paid or the amount of any such payments.
Regulatory Approvals
We are not aware of any U.S. federal or state regulatory requirements or governmental approvals or actions that may be required to consummate the Assignment, except for compliance with applicable SEC regulations in connection with this Proxy Statement and compliance with Delaware law. If Axcella’s stockholders approve the Assignment Proposal and Axcella enters into the Assignment Agreement, the Assignee will file an application in the Delaware Court of Chancery, which commences a judicial proceeding for recognition of the assignment for the benefit of creditors. If Axcella’s stockholders approve the Assignment Proposal, we intend to enter into the Assignment Agreement as soon as reasonably practicable after the Special Meeting.
Cessation of Trading of Common Stock Split,
We anticipate that we will notify the numberFinancial Industry Regulatory Authority (FINRA) of shares ofthe Assignment and request that our Common Stock issued and outstanding will be reduced in proportionstop trading on the Nasdaq Global Market as soon after the Assignment as is reasonably practicable. We also currently expect to close our stock transfer books subsequent to the ratio selected bySpecial Meeting and to discontinue recording transfers and issuing stock certificates at the board of directors. Thus, the Reverse Stock Split will effectively increase the number of authorized and unissued shares ofEffective Time. Accordingly, it is expected that trading in our Common Stock available for future issuance by the amount of the reduction effected by the Reverse Stock Split.
If the proposed Reverse Stock Split Amendments are approved, all or any of the authorized and unissued shares of our Common Stock may be issued in the future for such corporate purposes and such consideration as the board of directors deems advisable from time to time, without further action by the stockholders of our Company and without first offering such shares to our stockholders. When and if additional shares of our Common Stock are issued, these new shares would have the same voting and other rights and privileges as the currently issued and outstanding shares of Common Stock, including the right to cast one vote per share.
Except pursuant to our equity incentive plans, we presently have no plan, commitment, arrangement, understanding, or agreement regarding the issuance of Common Stock. However, the Company regularly considers its capital requirements and may conduct securities offerings, including equity and/or equity linked offerings, in the future.
Because our stockholders have no preemptive rights to purchase or subscribe for any of our unissued shares of Common Stock, the future issuance of additional shares of Common Stock will reduce our current stockholders’ percentage ownership interest incease on or very soon after the total outstanding shares of Common Stock. InAssignment.
Reporting Requirements
Whether or not the absence of a proportionate increase in our future earnings and book value, an increase in the number of our outstanding shares of Common Stock would dilute our projected future earnings per share, if any, and book value per share of all our outstanding shares of Common Stock. If these factors were reflected in the price per share of our Common Stock, the potential realizable value of a stockholder’s investment could be adversely affected. An issuance of additional shares could thereforeAssignment Proposal is approved, we have an adverse effect onobligation to continue to comply with the potential realizable value of a stockholder’s investment.
Equity Compensation Plans and Outstanding Equity-Based Awards
We maintain the Axcella Health Inc. Amended and Restated 2010 Stock Incentive Plan (the “2010 Plan”), the Axcella Health Inc. 2019 Stock Option and Incentive Plan (the “2019 Plan”), as amended, the 2019 Plan, and the Axcella Health Inc. 2019 Employee Stock Purchase Plan (the “ESPP”) (collectively and together with any sub-plans thereunder, the “Plans”), which are designed primarily to provide stock-based incentives to individual service providersapplicable reporting requirements of the Company.
Our boardExchange Act, even though compliance with such reporting requirements may be economically burdensome and of directors generally hasminimal value to stockholders. If our stockholders approve the discretionAssignment Proposal, in order to determinecurtail expenses, we intend, following the appropriate adjustmentsSpecial Meeting, to the Plans and outstanding awards and purchase rights under the Plans in the event of a reverse stock split. Accordingly, if the Reverse Stock Split is approved and effected, consistent with the terms of the Plans and outstanding award agreements, the total number of shares of Common Stock issuable upon exercise, vesting or settlement of such awards and the total number of shares of Common Stock remaining available for future awards under the Plans, as well as any share-based limits in the Plans, would be proportionately reduced based on the Reverse Stock Split ratio selected by our board of directors, and any fractional shares that may result therefrom shall be rounded down to the nearest whole share. Furthermore, the exercise or purchase price of any outstanding options or purchase rights would be proportionately increased based on the Reverse Stock Split ratio selected by our board of directors, and any fractional cents that may result therefrom shall be rounded up to the nearest whole cent. In addition, the numbers of shares subject to awards to be granted in the future under the 2019 Plan pursuant to our non-employee director compensation program will be proportionately reduced based on the Reverse Stock Split ratio selected by our board of
 
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directors. Our board of directors has authorizedseek relief from the CompanySEC to effect any changes necessary, desirable or appropriate to give effect to the Reverse Stock Splitsuspend our reporting obligations under the Plans, including any applicable technical, conforming changes thereunder.
Illustration
For purposes of illustration,Exchange Act, and ultimately to terminate the following table contains approximate information relating to our Common Stock if the Reverse Stock Split is effected at a ratio of: 1-for-2, 1-for-5, 1-for-10, 1-for-20, or 1-for-25, based on share information as of the close of business on March 31, 2023, but does not give effect to any other changes, including any issuance of securities after June 30, 2023:
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Pre-Reverse
Split
​​1-for-2​​1-for-5​​1-for-10​​1-for-20​​1-for-25​
Authorized​​​​150,000,000​​​​​150,000,000​​​​​150,000,000​​​​​150,000,000​​​​​150,000,000​​​​​150,000,000​​
Issued​​​​74,102,008​​​​​37,051,004​​​​​14,820,401​​​​​7,410,200​​​​​3,705,100​​​​​2,964,080​​
Outstanding​​​​73,683,027​​​​​36,841,513​​​​​14,736,605​​​​​7,368,302​​​​​3,684,151​​​​​2,947,321​​
Reserved for future issuance pursuant
to equity incentive and employee
benefit plans
​​​​5,700,933​​​​​2,850,466​​​​​1,140,186​​​​​570,093​​​​​285,046​​​​​228,037​​
Number of shares issuable upon exercise of outstanding options​​​​6,099,724​​​​​3,049,862​​​​​1,219,944​​​​​609,972​​​​​304,986​​​​​243,988​​
Number of shares issuable upon release of outstanding restricted stock units​​​​47,426​​​​​23,713​​​​​9,485​​​​​4,742​​​​​2,371​​​​​1,897​​
Authorized but unissued and unreserved​​​​64,468,890​​​​​107,234,445​​​​​132,893,780​​​​​141,446,890​​​​​145,723,446​​​​​146,578,757​​
Procedure for Effecting the Reverse Stock Split and Exchange of Stock Certificates, if Applicable
If the proposed Reverse Stock Split Amendments are approved by the Company’s stockholders and our board of directors determines to effect the Reverse Stock Split, the Reverse Stock Split will become effective at 5:00 p.m., Eastern time, on the date the Certificate of Amendment is filed with the Secretary of State of the State of Delaware (the “Effective Time”). At the Effective Time, sharesregistration of our Common Stock issued and outstanding immediately prior theretoStock. If we are unable to suspend our obligation to file periodic reports with the SEC, we will be combined, automatically and without any action onobligated to continue complying with the partapplicable reporting requirements of the Exchange Act and will be required to continue to incur the expenses associated with these reporting requirements, including legal and accounting expenses.
Accounting Treatment
If Axcella’s stockholders into newapprove the Assignment Proposal, Axcella will change its basis of accounting to the liquidation basis of accounting. Under the liquidation basis of accounting, assets are stated at their estimated net realizable values, and liabilities are stated at their estimated settlement amounts. Recorded liabilities will include the estimated expenses associated with carrying out the Assignment and Dissolution. For periodic reporting, a statement of net assets in liquidation will summarize the liquidation value per outstanding share of Common Stock. Valuations presented in the statement will represent management’s estimates, based on present facts and circumstances, of the net realizable values of assets, satisfaction of liabilities, and expenses associated with carrying out the Assignment and Dissolution based upon management assumptions. The valuation of assets and liabilities will necessarily require many estimates and assumptions, and there will be substantial uncertainties in carrying out the provisions of the Assignment and Dissolution. Ultimate values realized for Axcella’s assets and ultimate amounts paid to satisfy Axcella’s liabilities are expected to differ from estimates recorded in annual or interim financial statements.
Interests of Certain Persons in the Assignment
Certain of Axcella’s current and former executive officers and directors may have financial interests in the Assignment that may be different from, or in addition to, the interests of Axcella’s stockholders generally. In particular:
•
during the Assignment, Axcella will pay Craig Jalbert, the sole director and President, Treasurer and Corporate Secretary of Axcella, and service providers and agents, or any of them, compensation for services rendered in connection with continued operation of the Company’s business and the implementation of the Assignment. Such compensation is not expected to be materially different from the compensation that would be paid to an outside party for similar services;
​
•
as of October 31, 2023, Axcella’s certain former directors and executive officers beneficially held 9,634 shares of Axcella’s Common Stock, and 90,165 shares of Common Stock subject to outstanding stock options that are exercisable within 60 days after October 31, 2023. The estimated value of such shares of Axcella’s Common Stock as of October 31, 2023 (based upon the $5.47 per share closing price of Axcella’s Common Stock as of such date) is $52,698. Certain of Axcella’s former directors and executive officers who own shares of Axcella’s Common Stock will be entitled to receive, on the same terms and conditions as Axcella’s other stockholders, the same distributions and other benefits that Axcella’s stockholders would receive when Axcella makes any distributions to Axcella’s stockholders of record; and
​
•
Certain of Axcella’s former directors and officers may be entitled to deferred compensation payments and indemnification and insurance coverage from Axcella.
​
The Board was aware of those potentially differing interests and considered them, among other matters, in accordanceevaluating the Assignment and in reaching its decision to approve such plan and the actions contemplated thereby, as more fully discussed in the section of this proxy statement captioned “Reasons for the Proposed Assignment.”
In connection with the Reverse Stock Split ratio contained inAssignment and the CertificateDissolution, the Board appointed a sole director, Mr. Craig Jalbert, and all other directors resigned. Mr. Jalbert was also appointed President, Treasurer and Corporate Secretary of Amendment.Axcella.
Registered “Book-Entry” HoldersEquity Compensation Plan Information
The following table provides information as of Common Stock
As soon as practicable after the Effective Time, stockholders will be notified by our transfer agent that the Reverse Stock Split has been effected. As all of the outstandingOctober 31, 2023 with respect to shares of ourAxcella’s Common Stock are held in book-entry form, you will not need to take any action to receive post-reverse stock split shares of our Common Stock. As soon as practicable after the Effective Time, the Company’s transfer agent will send to your registered address a transmittal letter along with a statement of ownership indicating the number of post-reverse stock split shares of Common Stock you hold. If applicable, a check representing a cash payment in lieu of fractional shares will alsothat may be mailed to your registered address as soon as practicable after the Effective Time (see “— Fractional Shares” below).
Beneficial Holders of Common Stock
Upon the implementation of the Reverse Stock Split, we intend to treat shares of Common Stock held by stockholders in “street name” ​(i.e., through a bank, broker, custodian, or other nominee), in the same manner as registered “book-entry” holders of Common Stock. Banks, brokers, custodians or other nominees will be instructed to effect the Reverse Stock Split for their beneficial holders holding our Common Stock in street name. However, these banks, brokers, custodians or other nominees may have different procedures than registered stockholders for processing the Reverse Stock Split and making payment for fractional shares.issued under its existing equity compensation plans.
 
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If a stockholder holds shares of our Common Stock with a bank, broker, custodian, or other nominee and has any questions in this regard, stockholders are encouraged to contact their bank, broker, custodian, or other nominee.
Holders of Certificated Shares of Common Stock
Our transfer agent will act as exchange agent for purposes of implementing the exchange of stock certificates, if applicable. If you are a stockholder holding pre-reverse stock split shares in certificate form, you will receive a transmittal letter from the Company’s transfer agent as soon as practicable after the Effective Time. The transmittal letter will be accompanied by instructions specifying how you can exchange your certificate or certificates representing the pre-reverse stock split shares of our Common Stock for a statement of ownership. When you submit your certificate or certificates representing the pre-reverse stock split shares of our Common Stock, your post-reverse stock split shares of our Common Stock will be held electronically in book-entry form in the Direct Registration System. This means that, instead of receiving a new stock certificate representing the aggregate number of post-reverse stock split shares you own, you will receive a statement indicating the number of post-reverse stock split shares you own in book-entry form. We will no longer issue physical stock certificates unless you make a specific request for a certificate representing your post-reverse stock split ownership interest.
Fractional Shares
No scrip or fractional shares would be issued if, as a result of the Reverse Stock Split, a stockholder would otherwise become entitled to a fractional share because the number of shares of Common Stock they hold before the Reverse Stock Split is not evenly divisible by the split ratio ultimately determined by the board of directors. Instead, each stockholder will be entitled to receive a cash payment in lieu of such fractional share. The cash payment to be paid will be equal to the fraction of a share to which such holder would otherwise be entitled multiplied by the closing price per share of Common Stock on the date of the Effective Time as reported by Nasdaq (as adjusted to give effect to the Reverse Stock Split). No transaction costs would be assessed to stockholders for the cash payment. Stockholders would not be entitled to receive interest for their fractional shares for the period of time between the Effective Time and the date payment is issued or received.
After the Reverse Stock Split, then-current stockholders would have no further interest in our Company with respect to their fractional shares. A person entitled to a fractional share would not have any voting, dividend or other rights in respect of their fractional share except to receive the cash payment as described above. Such cash payments would reduce the number of post-reverse stock split stockholders to the extent that there are stockholders holding fewer than that number of pre-reverse stock split shares within the reverse stock split ratio that is determined by the board of directors as described above. Reducing the number of post-reverse stock split stockholders, however, is not the purpose of this proposal.
Stockholders should be aware that, under the escheat laws of the various jurisdictions where stockholders reside, where we are domiciled and where the funds for fractional shares would be deposited, sums due to stockholders in payment for fractional shares that are not timely claimed after the Effective Time may be required to be paid to the designated agent for each such jurisdiction. Thereafter, stockholders otherwise entitled to receive such funds may have to seek to obtain them directly from the state to which they were paid.
No Appraisal Rights
Under the Delaware General Corporation Law, the Company’s stockholders will not be entitled to appraisal rights with respect to the Reverse Stock Split, and we do not intend to independently provide stockholders with any such right.
No Going Private Transaction
Notwithstanding the decrease in the number of outstanding shares following the Reverse Stock Split, the board of directors does not intend for this transaction to be the first step in a series of plans or proposals of a “going private transaction” within the meaning of Rule 13e-3 of the Exchange Act.

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Interests of Certain Persons in the Proposal
Certain of our officers and directors have an interest in this proposal as a result of their ownership of shares of our Common Stock, as set forth below in the section entitled “Security Ownership of Certain Beneficial Owners and Management.” However, we do not believe that our officers or directors have interests in this proposal that are different from or greater than those of any of our other stockholders.
Anti-takeover Effects of Proposed Amendment
Release No. 34-15230 of the staff of the SEC requires disclosure and discussion of the effects of any action, including the proposed Reverse Stock Split Amendments discussed herein, that may be used as an anti-takeover mechanism. An additional effect of the Reverse Stock Split would be to increase the relative amount of authorized but unissued shares of Common Stock, which may, under certain circumstances, be construed as having an anti-takeover effect. Although not designed or intended for such purposes, the effect of the increased available shares might be to make more difficult or to discourage an attempt to take over or otherwise acquire control of the Company (for example, by permitting issuances that would dilute the stock ownership of a person or entity seeking to effect a change in the composition of the board of directors or contemplating a tender offer or other change in control transaction). In addition, our Certificate of Incorporation and our Bylaws include provisions that may have an anti-takeover effect. These provisions, among things, permit the board of directors to issue Preferred Stock with rights senior to those of the Common Stock without any further vote or action by the stockholders and do not provide for cumulative voting rights, which could make it more difficult for stockholders to effect certain corporate actions and may delay or discourage a change in control.
Our board of directors is not presently aware of any attempt, or contemplated attempt, to acquire control of the Company, and the Reverse Stock Split Proposal is not part of any plan by our board of directors to recommend or implement a series of anti-takeover measures.
Accounting Treatment of the Reverse Stock Split
If the Reverse Stock Split is effected, the par value per share of our Common Stock will remain unchanged at $0.001. Accordingly, at the Effective Time, the stated capital on the Company’s consolidated balance sheets attributable to our Common Stock will be reduced in proportion to the size of the Reverse Stock Split ratio, and the additional paid-in-capital account will be increased by the amount by which the stated capital is reduced. Our stockholders’ equity, in the aggregate, will remain unchanged. Per share net income or loss will be increased because there will be fewer shares of Common Stock outstanding. Any Common Stock held in treasury will be reduced in proportion to the Reverse Stock Split Ratio. The Company does not anticipate that any other accounting consequences, including changes to the amount of stock-based compensation expense to be recognized in any period, will arise as a result of the Reverse Stock Split.
Certain U.S. Federal Income Tax Consequences of the Reverse Stock Split
The following discussion is a summary of certain U.S. federal income tax consequences of the Reverse Stock Split that may be relevant to U.S. Holders (as defined below) of our Common Stock, but does not purport to be a complete analysis of all potential tax effects. The effects of other U.S. federal tax laws, such as estate and gift tax laws, and any applicable state, local, or non-U.S. tax laws are not discussed. This discussion is based on the Internal Revenue Code of 1986, as amended (the “Code”), Treasury Regulations promulgated thereunder, judicial decisions, and published rulings and administrative pronouncements of the U.S. Internal Revenue Service (the “IRS”), in each case in effect as of the date hereof. These authorities may change or be subject to differing interpretations. Any such change or differing interpretation may be applied retroactively in a manner that could adversely affect a U.S. Holder. We have not sought and will not seek an opinion of counsel or any rulings from the IRS regarding the matters discussed below. There can be no assurance the IRS or a court will not take a contrary position to that discussed below regarding the tax consequences of the Reverse Stock Split.
This discussion is limited to U.S. Holders that hold our common stock as a “capital asset” within the meaning of Section 1221 of the Code (generally, property held for investment). This discussion does not

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address all U.S. federal income tax consequences relevant to a U.S. Holder’s particular circumstances, including the impact of the Medicare contribution tax on net investment income and the alternative minimum tax. In addition, it does not address consequences relevant to U.S. Holders subject to special rules, including, without limitation:
•
persons that are not U.S. Holders (as defined below);
​
•
persons subject to the alternative minimum tax;
​
•
U.S. Holders (as defined below) whose functional currency is not the U.S. dollar;
​
•
persons holding our common stock as part of a hedge, straddle or other risk reduction strategy or as part of a conversion transaction or other integrated investment;
​
•
banks, insurance companies, and other financial institutions;
​
•
real estate investment trusts or regulated investment companies;
​
•
brokers, dealers, or traders in securities;
​
•
S corporations, partnerships or other entities or arrangements treated as partnerships for U.S. federal income tax purposes (and investors therein);
​
•
tax-exempt organizations or governmental organizations;
​
•
persons deemed to sell our common stock under the constructive sale provisions of the Code;
​
•
persons who hold or receive our common stock pursuant to the exercise of any employee stock option or otherwise as compensation;
​
•
tax-qualified retirement plans; and
​
•
“qualified foreign pension funds” as defined in Section 897(l)(2) of the Code and entities all of the interests of which are held by qualified foreign pension funds.
​
If an entity treated as a partnership for U.S. federal income tax purposes holds our common stock, the tax treatment of a partner in the partnership will depend on the status of the partner, the activities of the partnership, and certain determinations made at the partner level. Accordingly, partnerships holding our common stock and the partners in such partnerships should consult their tax advisors regarding the U.S. federal income tax consequences to them.
THIS DISCUSSION IS FOR INFORMATIONAL PURPOSES ONLY AND IS NOT TAX ADVICE. HOLDERS OF OUR COMMON STOCK SHOULD CONSULT THEIR TAX ADVISORS WITH RESPECT TO THE APPLICATION OF THE U.S. FEDERAL INCOME TAX LAWS TO THEIR PARTICULAR SITUATIONS AS WELL AS ANY TAX CONSEQUENCES OF THE REVERSE STOCK SPLIT ARISING UNDER OTHER U.S. FEDERAL TAX LAWS (INCLUDING ESTATE AND GIFT TAX LAWS), UNDER THE LAWS OF ANY STATE, LOCAL, OR NON-U.S. TAXING JURISDICTION OR UNDER ANY APPLICABLE TAX TREATY.
For purposes of the discussion below, a “U.S. Holder” is any beneficial owner of shares of our Common Stock that is not a partnership and, for U.S. federal income tax purposes, is or is treated as:
•
an individual who is a citizen or resident of the United States;
​
•
a corporation created or organized under the laws of the United States, any state thereof, or the District of Columbia;
​
•
an estate the income of which is subject to U.S. federal income tax regardless of its source; or
​
•
a trust that (1) is subject to the primary supervision of a U.S. court and all substantial decisions of which are subject to the control of one or more “United States persons” ​(within the meaning of Section 7701(a)(30) of the Code), or (2) has a valid election in effect to be treated as a United States person for U.S. federal income tax purposes.
​
The Reverse Stock Split should constitute a “recapitalization” for U.S. federal income tax purposes. As a result, a U.S. Holder generally should not recognize gain or loss upon the Reverse Stock Split, except as

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described below with respect to cash received in lieu of fractional shares. A U.S. Holder’s aggregate tax basis in the shares of the Common Stock received pursuant to the Reverse Stock Split should equal such holder’s aggregate tax basis in the shares of the Common Stock surrendered (excluding any portion of such basis that is allocated to any fractional share of our Common Stock), and such holder’s holding period in the shares of the Common Stock received should include the holding period of the shares of the Common Stock surrendered. Treasury Regulations promulgated under the Code provide detailed rules for allocating the tax basis and holding period of the shares of Common Stock surrendered to the shares of Common Stock received pursuant to the Reverse Stock Split. U.S. Holders holding shares of Common Stock that were acquired on different dates and at different prices should consult their tax advisors regarding the allocation of the tax basis and holding period of such shares.
A U.S. Holder who receives cash in lieu of a fractional share of Common Stock should be treated as first receiving such fractional share and then receiving cash in redemption of such fractional share. A U.S. Holder who receives cash in lieu of a fractional share in the Reverse Stock Split should recognize capital gain or loss in an amount equal to the difference between the amount of the cash received and the portion of such holder’s adjusted tax basis in the shares of Common Stock surrendered that is allocated to the fractional share. Such capital gain or loss should be long-term capital gain or loss if the U.S. Holder’s holding period for the Common Stock surrendered exceeded one year at the effective time of the Reverse Stock Split. U.S. Holders should consult their tax advisors regarding the tax effects to them of receiving cash in lieu of fractional shares based on their particular circumstances.
U.S. Holders (other than corporations and certain other exempt recipients) may be subject to information reporting with respect to any cash received in exchange for a fractional share interest in a new share in the Reverse Stock Split. U.S. Holders who are subject to information reporting and who do not provide a correct taxpayer identification number and other required information (such as by submitting a properly completed IRS Form W-9) may also be subject to backup withholding at the applicable rate. Backup withholding is not an additional tax. Any amounts withheld under the backup withholding rules may be refunded or credited against the U.S. Holder’s U.S. federal income tax liability, if any, provided that the required information is properly furnished in a timely manner to the IRS. U.S. Holders should consult their tax advisors regarding their qualification for an exemption from backup withholding and the procedures for obtaining such an exemption.
Vote Required and Board of Directors’ Recommendation
The approval of Proposal No. 3 requires that a majority of the votes properly cast vote FOR this proposal. Shares that are voted “abstain” will not affect the outcome of this proposal.
The board of directors unanimously recommends a vote FOR the approval of the Reverse Stock Split Proposal.

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PROPOSAL No. 4 — APPROVAL OF AN ADJOURNMENT OF THE ANNUAL MEETING, IF NECESSARY, TO SOLICIT ADDITIONAL PROXIES IF THERE ARE NOT SUFFICIENT VOTES AT THE TIME OF THE ANNUAL MEETING TO APPROVE PROPOSAL No. 3
Background of and Rationale for the Adjournment Proposal
The board of directors believes that if the number of shares of the Company’s Common Stock outstanding and entitled to vote at the Annual Meeting is insufficient to approve the Reverse Stock Split, it is in the best interests of the stockholders to enable the board of directors to continue to seek to obtain a sufficient number of additional votes to approve the Reverse Stock Split Proposal.
In the adjournment proposal (the “Adjournment Proposal”), we are asking stockholders to authorize the holder of any proxy solicited by the board of directors to vote in favor of adjourning the Annual Meeting or any adjournment or postponement thereof. If our stockholders approve this proposal, we could adjourn the Annual Meeting, and any adjourned session of the Annual Meeting, to use the additional time to solicit additional proxies in favor of the Reverse Stock Split Proposal.
Additionally, approval of the Adjournment Proposal could mean that, in the event we receive proxies indicating that a majority of the outstanding shares of our Common Stock entitled to vote on the Reverse Stock Split Proposal, have voted against the Reverse Stock Split Proposal, we could adjourn the Annual Meeting without a vote on the Reverse Stock Split Proposal and use the additional time to solicit the holders of those shares to change their vote in favor of the Reverse Stock Split Proposal.
Vote Required and Board of Directors’ Recommendation
The affirmative vote of a majority of the votes cast FOR this proposal is required to approve the adjournment of the Annual Meeting. Abstentions will have no effect on the results of this vote. If your shares are held in “street name” by a broker, bank or other nominee, your broker, bank or other nominee has authority to vote your unvoted shares held by that firm on this proposal. If your broker, bank or other nominee does not exercise this authority, such broker non-votes will have no effect on the results of this vote. The board of directors unanimously recommends a vote FOR the adjournment of the Annual Meeting, if necessary, to solicit additional proxies if there are not sufficient votes at the time of the Annual Meeting to approve Proposal No. 3.

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INFORMATION REGARDING THE BOARD OF
DIRECTORS AND CORPORATE GOVERNANCE
Director Nomination Process
Our nominating and corporate governance committee is responsible for identifying individuals qualified to serve as directors, consistent with criteria approved by our board, and recommending such persons to be nominated for election as directors, except where we are legally required by contract, law or otherwise to provide third parties with the right to nominate.
The process followed by our nominating and corporate governance committee to identify and evaluate director candidates includes requests to board members and others for recommendations, meetings from time to time to evaluate biographical information and background material relating to potential candidates, and interviews of selected candidates by management, recruiters, members of the committee and our board. The qualifications, qualities and skills that our nominating and corporate governance committee believes must be met by a committee-recommended nominee for a position on our board of directors are as follows:
•
Nominees should have experience at a strategic or policymaking level in a business, government, non- profit or academic organization of high standing.
​
•
Nominees should be highly accomplished in his or her respective field, with superior credentials and recognition.
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•
Nominees should be well regarded in the community and shall have a long-term reputation for the high ethical and moral standards.
​
•
Nominees should have sufficient time and availability to devote to the affairs of the company, particularly considering the number of boards of directors on which such nominee may serve.
​
•
To the extent such nominee serves or has previously served on other boards, the nominee shall have a demonstrated history of actively contributing at board meetings.
​
•
Axcella is committed to fair treatment and equality of opportunity, building a culture of diversity and inclusion, and proactively addressing inequality in all aspects of its business, including the selection of directors for its board.
​
In addition, every nominee must have sufficient time and availability to devote to Axcella’s affairs, a reputation for high ethical and moral standards, an understanding of the fiduciary responsibilities assumed by public company directors, and a demonstrated commitment to our values of ownership, determination, collaboration, and learning.
In building our board of directors, we also believe that the following skills and experiences are among those that are helpful in ensuring that our directors collectively possess the skills and backgrounds necessary for us to execute on our strategic plans, have a diversity of expertise and experience relevant to Axcella’s current and future business objectives and relative to other directors, and enable the board of directors’s oversight responsibilities on behalf of our shareholders. Skills and experiences shown below are generally reflective of the individual having worked in the area, rather than experience obtained as a director in the relevant field.

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Director​​R. Rosiello​​P. Sekhri​​M. Rosenblatt​​
W. Baird(1)
​​S. Nissen​​
W. Hinshaw(2)
​​M. Hendrix​​G. Pisano​​C. Rondinone​​C. Sohn​
Class​​III​​II​​I​​II​​I​​I​​III​​III​​II​​II​
Committees​
Audit​​​​​​​​​​​Chair​​​​​​​​X​​X​​​​​​​
Compensation​​​​​X​​​​​X​​​​​​​​​​​​​​​​​Chair​
Nominating & Corporate Governance​​​​​​​​​​​​​​​​​​​​​​​​​​X​​Chair​
Skills & Experience​
Business Development​​X​​X​​​​​X​​X​​X​​X​​​​​X​​X​
CEO Experience​​​​​X​​​​​​​​X​​X​​​​​​​​​​​​​
Commercialization​​X​​X​​​​​​​​​​​X​​X​​​​​​​​X​
Digital​​X​​X​​​​​​​​​​​​​​​​​​​​​​​​​
Drug Development​​X​​X​​X​​​​​X​​X​​X​​​​​X​​​​
Finance/ Accounting​​X​​X​​​​​X​​X​​X​​X​​X​​​​​​​
Government/ Regulatory​​X​​​​​​​​​​​​​​X​​​​​​​​​​​X​
Healthcare Industry​​X​​X​​X​​X​​X​​X​​X​​​​​X​​X​
Human Relations​​X​​X​​​​​​​​X​​X​​​​​​​​X​​X​
International​​X​​X​​X​​​​​​​​X​​X​​​​​X​​X​
Investor Relations​​X​​X​​​​​X​​X​​X​​​​​​​​​​​X​
Manufacturing​​​​​X​​​​​​​​​​​​​​​​​​​​​​​​​
Science/ Technology​​​​​​​​X​​​​​X​​X​​X​​​​​X​​X​
Strategy​​X​​X​​​​​X​​X​​X​​X​​X​​X​​X​
Treating Physician​​​​​​​​X​​​​​​​​​​​​​​​​​​​​​​
​
Notes
(1)
Financial expert
​
(2)
Non-independent Director
​
Stockholders may recommend individuals to the nominating and corporate governance committee for consideration as potential director candidates. Any such proposals should be submitted to our corporate secretary at our principal executive offices no later than the close of business on the 90th day nor earlier than the close of business on the 120th day prior to the one-year anniversary of the date of the preceding year’s annual meeting and should include appropriate biographical and background material to allow the nominating and corporate governance committee to properly evaluate the potential director candidate and the number of shares of our stock beneficially owned by the stockholder proposing the candidate. Stockholder proposals should be addressed to Axcella Therapeutics, P.O. Box 1270, Littleton, Massachusetts 01460, Attention: Corporate Secretary. Assuming that biographical and background material has been provided on a timely basis in accordance with our bylaws, any recommendations received from stockholders will be evaluated in the same manner as potential nominees proposed by the nominating and corporate governance committee. If our board of directors determines to nominate a stockholder-recommended candidate and recommends his or her election, then his or her name will be included on our proxy card for the next annual meeting of stockholders. See “Stockholder Proposals” for a discussion of submitting stockholder proposals.

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Diversity in Board Membership
As noted above, our nominating and corporate governance committee is committed to fair treatment and equality of opportunity, building a culture of diversity and inclusion, and proactively addressing inequality in the selection of directors for our board. Thus, the backgrounds and qualifications of our directors, considered as a group, should provide a composite mix of experience, knowledge and abilities that will allow our board to promote our strategic objectives and fulfill its responsibilities to our stockholders, and considers diversity of gender, race, national origin, education, professional experience, and differences in viewpoints and skills when evaluating proposed director candidates. We comply Nasdaq Rule 5605 by having 3 diverse directors (33%), including one from an underrepresented minority and/or LGBTQ+.
Board Diversity Matrix (As of August 1, 2023)​
Total Number of Directors​​10​
​​​Female​​Male​​
Non-
Binary
​​
Did Not
Disclose
Gender
​
Part I: Gender Identity​​​​​​​​​​​​​
Directors​​2​​7​​​​​1​
Part II: Demographic Background​​​​​​​​​​​​​
African American or Black​​​​​​​​​​​​​
Alaskan Native or Native American​​​​​​​​​​​​​
Asian​​​​​​​​​​​​​
Hispanic or Latinx​​1​​​​​​​​​​
Native Hawaiian or Pacific Islander​​​​​​​​​​​​​
White​​1​​6​​​​​​​
Two or More Races or Ethnicities​​​​​1​​​​​​​
LGBTQ+​​​​​1​​​​​​​
Did Not Disclose Demographic Background​​​​​​​​​​​1​
Director Independence
Applicable Nasdaq Stock Market LLC, or Nasdaq, rules require a majority of a listed company’s board of directors to be comprised of independent directors within one year of listing. In addition, the Nasdaq rules require that, subject to specified exceptions, each member of a listed company’s audit, compensation and nominating and corporate governance committees be independent and that audit committee members also satisfy independence criteria set forth in Rule 10A-3 under the Exchange Act and that compensation committee members satisfy independence criteria set forth in Rule 10C-1 under the Exchange Act. Under applicable Nasdaq rules, a director will only qualify as an “independent director” if, in the opinion of the listed company’s board of directors, that person does not have a relationship that would interfere with the exercise of independent judgment in carrying out the responsibilities of a director. In order to be considered independent for purposes of Rule 10A-3, a member of an audit committee of a listed company may not, other than in his or her capacity as a member of the audit committee, the board of directors, or any other board committee, accept, directly or indirectly, any consulting, advisory, or other compensatory fee from the listed company or any of its subsidiaries or otherwise be an affiliated person of the listed company or any of its subsidiaries. In addition, in affirmatively determining the independence of any director who will serve on a company’s compensation committee, Rule 10C-1 under the Exchange Act requires that a company’s board of directors must consider all factors specifically relevant to determining whether a director has a relationship to such company which is material to that director’s ability to be independent from management in connection with the duties of a compensation committee member, including: the source of compensation to the director, including any consulting, advisory or other compensatory fee paid by such company to the director, and whether the director is affiliated with the company or any of its subsidiaries or affiliates.
Our board of directors has determined that all members of the board of directors, except Mr. Hinshaw, are independent directors, including for purposes of the rules of Nasdaq and the SEC. In making such

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independence determination, our board of directors considered the relationships that each non- employee director has with us and all other facts and circumstances that our board of directors deemed relevant in determining their independence, including the beneficial ownership of our capital stock by each non-employee director. In considering the independence of the directors listed above, our board of directors considered the association of our directors with the holders of more than 5% of our common stock. There are no family relationships among any of our directors or executive officers. Mr. Hinshaw is not an independent director under these rules because he is an executive officer of Axcella.
Board Committees
Our board of directors has established an audit committee, a compensation committee, and a nominating and corporate governance committee. Each of the audit committee, compensation committee, and nominating and corporate governance committee operates under a charter that satisfies the applicable standards of the SEC and Nasdaq. Each such committee reviews its respective charter at least annually.
A current copy of the charter for each of the audit committee, compensation committee, and nominating and corporate governance committee is posted on the corporate governance section of our website, https://ir.axcellatx.com/corporate-governance/documents-and-charters.
Audit Committee
William D. “Chip” Baird, Martin Hendrix and Gary P. Pisano, Ph.D., serve on the audit committee, which is chaired by Mr. Baird. Our board of directors has determined that each member of the audit committee is “independent” for audit committee purposes as that term is defined in the rules of the SEC and the applicable Nasdaq rules, and each has sufficient knowledge in financial and auditing matters to serve on the audit committee. Our board of directors has designated Mr. Baird as an “audit committee financial expert,” as defined under the applicable rules of the SEC. During the fiscal year ended December 31, 2022, the audit committee met four times. The report of the audit committee is included in this proxy statement under “Report of the Audit Committee.” The audit committee’s responsibilities include:
•
appointing, approving the compensation of, and assessing the independence of our independent registered public accounting firm;
​
•
pre-approving auditing and permissible non-audit services, and the terms of such services, to be provided by our independent registered public accounting firm;
​
•
reviewing the overall audit plan with our independent registered public accounting firm and members of management responsible for preparing our financial statements;
​
•
reviewing and discussing with management and our independent registered public accounting firm our annual and quarterly financial statements and related disclosures as well as critical accounting policies and practices used by us;
​
•
coordinating the oversight and reviewing the adequacy of our internal control over financial reporting;
​
•
establishing policies and procedures for the receipt and retention of accounting-related complaints and concerns;
​
•
recommending based upon the audit committee’s review and discussions with management and our independent registered public accounting firm whether our audited financial statements shall be included in our Annual Report on Form 10-K;
​
•
monitoring the integrity of our financial statements and our compliance with legal and regulatory requirements as they relate to our financial statements and accounting matters;
​
•
preparing the audit committee report required by SEC rules to be included in our annual proxy statement;
​
•
reviewing all related person transactions for potential conflict of interest situations and approving all such transactions;
​
•
reviewing quarterly earnings releases;
​

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•
reviewing and overseeing our Environmental, Social, and Governance (“ESG”) commitments with respect to risk assessment and management policies and activities, including financial controls, whistleblower policies, and compliance; and
​
•
reviewing and overseeing our information security and technology risks, including cybersecurity and data protection programs and policies to manage those risks.
​
All audit and non-audit services, other than de minimis non-audit services, to be provided to us by our independent registered public accounting firm must be approved in advance by our audit committee.
Oversight of Cybersecurity Matters.   Our audit committee is responsible for the general oversight of our information security and technology risks, including our cybersecurity and data protection policies and programs. As part of our cybersecurity risk mitigation, we provide employees with annual cybersecurity training and we engage third parties to review our security controls and enhance our information and security team, including providing ongoing response and monitoring. We also have entered into a cybersecurity insurance policy. We have not experienced any material information security breaches within the last three years.
Compensation Committee
Paul Sekhri, William D. “Chip” Baird, and Catherine Angell Sohn, Pharm.D., serve on the compensation committee, which is chaired by Mr. Sekhri. Our board of directors has determined that each member of the compensation committee including Mr. Sekhri and Dr. Sohn “independent” as defined in the applicable Nasdaq rules. During the fiscal year ended December 31, 2022, the compensation committee met ten times. The compensation committee’s responsibilities include:
•
annually reviewing and recommending to the board of directors the corporate goals and objectives relevant to the compensation of our Chief Executive Officer;
​
•
evaluating the performance of our Chief Executive Officer in light of such corporate goals and objectives and based on such evaluation: (i) recommending to the board of directors the cash compensation of our Chief Executive Officer and (ii) recommending grants and awards to our Chief Executive Officer under equity-based plans;
​
•
reviewing and approving the cash compensation of our other executive officers;
​
•
reviewing and discussing with the board of directors corporate succession plans for the Chief Executive Officer and all executive officers as defined by Rule 3b-7;
​
•
reviewing and establishing our overall management compensation, philosophy and policy;
​
•
reviewing and overseeing our ESG commitments with respect to human capital and social responsibility, including diversity, equality, and inclusion (DEI), employment policies, and employee health and safety;
​
•
overseeing and administering our compensation and similar plans;
​
•
evaluating and assessing potential and current compensation advisors in accordance with the independence standards identified in the applicable Nasdaq rules;
​
•
reviewing and approving our policies and procedures for the grant of equity-based awards;
​
•
reviewing and recommending to the board of directors the compensation of our directors;
​
•
preparing the compensation committee report required by SEC rules, if and when required, to be included in our annual proxy statement; and
​
•
reviewing and approving the retention, termination or compensation of any consulting firm or outside advisor to assist in the evaluation of compensation matters.
​
Nominating and Corporate Governance Committee
Catherine Angell Sohn, Pharm.D., and Cristina Rondinone, Ph.D., serve on the nominating and corporate governance committee, which is chaired by Dr. Sohn. Our board of directors has determined that

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both of the members of the nominating and corporate governance committee are “independent” as defined in the applicable Nasdaq rules. During the fiscal year ended December 31, 2022, the nominating and corporate governance committee met six times. The nominating and corporate governance committee’s responsibilities include:
•
developing and recommending to the board of directors’ criteria for board and committee membership;
​
•
establishing procedures for identifying and evaluating board of director candidates, including nominees recommended by stockholders;
​
•
reviewing the size and composition of the board of directors to ensure that it is composed of members containing the appropriate skills and expertise to advise us;
​
•
identifying individuals qualified to become members of the board of directors;
​
•
recommending to the board of directors the persons to be nominated for election as directors and to each of the board’s committees;
​
•
developing and recommending to the board of directors a code of business conduct and ethics and a set of corporate governance guidelines;
​
•
overseeing the evaluation of our board of directors and management; and
​
•
reviewing and overseeing our ESG commitments directly, including working with the Audit Committee and Compensation Committee on their ESG responsibilities and commitments.
​
The board of directors has delegated to the nominating and corporate governance committee the responsibility of identifying prospective candidates for board of director membership and recommending such candidates to the board of directors. Additionally, in selecting nominees for directors, the nominating and corporate governance committee will review candidates recommended by stockholders in the same manner and using the same general criteria as candidates recruited by the committee and/or recommended by our board of directors. Any stockholder who wishes to recommend a candidate for consideration by the committee as a nominee for director should follow the procedures described later in this proxy statement under the heading “Stockholder Proposals.” The nominating and corporate governance committee will also consider whether to nominate any person proposed by a stockholder in accordance with the provisions of our bylaws relating to stockholder nominations as described later in this proxy statement under the heading “Stockholder Proposals.”
Identifying and Evaluating Director Nominees.   Our board of directors is responsible for filling vacancies on our board of directors and for nominating candidates for election by our stockholders each year in the class of directors whose term expires at the relevant annual meeting. The board of directors delegates the selection and nomination process to the nominating and corporate governance committee, with the expectation that other members of the board of directors, and of management, will be requested to take part in the process as appropriate.
Generally, the nominating and corporate governance committee identifies candidates for director nominees in consultation with management, through the use of search firms or other advisors, through the recommendations submitted by stockholders or through such other methods as the nominating and corporate governance committee deems to be helpful to identify candidates. Once candidates have been identified, the nominating and corporate governance committee confirms that the candidates meet all of the minimum qualifications for director nominees established by the nominating and corporate governance committee. The nominating and corporate governance committee may gather information about the candidates through interviews, detailed questionnaires, comprehensive background checks or any other means that the nominating and corporate governance committee deems to be appropriate in the evaluation process. The nominating and corporate governance committee then meets as a group to discuss and evaluate the qualities and skills of each candidate, both on an individual basis and considering the overall composition and needs of our board of directors. Based on the results of the evaluation process, the nominating and corporate governance committee recommends candidates for the board of directors’ approval to fill a vacancy or as director nominees for election to the board of directors by our stockholders each year in the class of directors whose term expires at the relevant annual meeting.

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Minimum Qualifications.   Our nominating and corporate governance committee and our board of directors may consider a broad range of factors relating to the qualifications and background of nominees. Our nominating and corporate governance committee’s and our board of directors’ priority in selecting board members is the identification of persons who will further the interests of our stockholders through their established record of professional accomplishment, the ability to contribute positively to the collaborative culture among board members, knowledge of our business, understanding of the competitive landscape, and professional and personal experiences and expertise relevant to our growth strategy. We have no formal policy regarding board diversity.
Oversight of Environmental, Social and Governance (ESG) Matters.   Our nominating and corporate governance committee has primary responsibility for the general oversight of our ESG commitments, initiatives, and programs, including collaborating with the audit committee and compensation committee with their ESG responsibilities. In 2021, the board approved amendment of the nominating and corporate governance committee charter to specifically include undertaking primary responsibility for ESG oversight; amendment of the audit committee charter to include responsibility for ESG matters related to risk assessment and management policies and activities, including financial controls, whistleblower policies, and compliance, and the compensation committee amended its charter to include responsibility for ESG matters related to human capital and social responsibility, including diversity, equality, and inclusion (DEI), employment policies, and employee health and safety. These amendments reflect our commitment to ESG matters.
Board and Committee Meetings Attendance
The full board of directors met thirteen times during 2022. During 2022, each member of the board of directors attended in person or participated in 75% or more of the aggregate of (i) the total number of meetings of the board of directors (held during the period for which such person has been a director) and (ii) the total number of meetings held by all committees of the board of directors on which such person served (during the periods that such person served).
Director Attendance at Annual Meeting of Stockholders
Directors are responsible for attending the annual meeting of stockholders to the extent practicable. All members of the board of directors then in office attended the annual meeting of stockholders on May 19, 2022. Paul Sekhri and Michael Rosenblatt, M.D. joined the board of directors subsequent to last year’s annual meeting of stockholders.
Policy on Trading, Pledging and Hedging of Company Stock
Certain transactions in our securities (such as purchases and sales of publicly traded put and call options, and short sales) create a heightened compliance risk or could create the appearance of misalignment between management and stockholders. In addition, securities held in a margin account or pledged as collateral may be sold without consent if the owner fails to meet a margin call or defaults on the loan, thus creating the risk that a sale may occur at a time when an officer or director is aware of material, non-public information or otherwise is not permitted to trade in Axcella securities. Our insider trading policy expressly prohibits short sales, purchases or sales of puts or calls, and other derivative transactions of our stock, including any transaction that provides the economic equivalent of ownership, by our executive officers, directors, employees and certain designated consultants and contractors. Our insider trading policy also prohibits using our securities as collateral in a margin account and pledging our securities as collateral for a loan (or modifying an existing pledge).
Code of Business Conduct and Ethics
We have adopted a written code of business conduct and ethics that applies to our directors, officers and employees, including our principal executive officer, principal financial officer, principal accounting officer or controller, or persons performing similar functions. A current copy of the code is posted on the corporate governance section of our website, which is located at https://ir.axcellatx.com/corporate-governance/​documents-and-charters. If we make any substantive amendments to, or grant any waivers from, the code of business conduct and ethics for any officer or director, we will disclose the nature of such amendment or waiver on our website or in a current report on Form 8-K.

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Board of Directors Leadership Structure and Board of Directors’ Role in Risk Oversight
Robert Rosiello is the current Chairman of our board of directors and William R. Hinshaw, Jr. is our current Chief Executive Officer, hence the roles of Chairman of our board of directors and Chief Executive Officer are separated. We believe that separating these positions allows our Chief Executive Officer to focus on our day-to-day business, while allowing our Chairman of the board to lead the board of directors in its fundamental role of providing advice to and independent oversight of management. Our board of directors recognizes the time, effort and energy that the Chief Executive Officer is required to devote to his position in the current business environment, as well as the commitment required to serve as our Chairman, particularly as the board of directors’ oversight responsibilities continue to grow. While our bylaws and corporate governance guidelines do not require that our Chairman and Chief Executive Officer positions be separate, our board of directors believes that having separate positions is the appropriate leadership structure for us at this time and demonstrates our commitment to good corporate governance.
Risk is inherent to every business, and how well a business manages risk can ultimately determine its success. We face a number of risks, including risks relating to our financial condition, development and commercialization activities, operations, strategic direction, and intellectual property. Management is responsible for the day-to-day management of risks we face, while our board of directors, as a whole and through its committees, has responsibility for the oversight of risk management. In its risk oversight role, our board of directors has the responsibility to satisfy itself that the risk management processes designed and implemented by management are adequate and functioning as designed.
The role of the board of directors in overseeing the management of our risks is conducted primarily through committees of the board of directors, as disclosed in the descriptions of each of the committees above and in the charters of each of the committees. The full board of directors (or the appropriate board committee in the case of risks that are under the purview of a particular committee) discusses with management our major risk exposures, their potential impact on us, and the steps we take to manage them. When a board committee is responsible for evaluating and overseeing the management of a particular risk or risks, the chairman of the relevant committee reports on the discussion to the full board of directors during the committee reports portion of the next board meeting. This enables the board of directors and its committees to coordinate the risk oversight role, particularly with respect to risk interrelationships.
Communication with the Directors of Axcella
Any interested party with concerns about our company may report such concerns to the board of directors or the chairman of our board of directors and nominating and corporate governance committee, by submitting a written communication to the attention of such director at the following address:
c/o Axcella Therapeutics
P.O. Box 1270
Littleton, Massachusetts 01460 United States
You may submit your concern anonymously or confidentially by postal mail. You may also indicate whether you are a stockholder, customer, supplier, or other interested party.
A copy of any such written communication may also be forwarded to Axcella’s legal counsel and a copy of such communication may be retained for a reasonable period of time. The director may discuss the matter with Axcella’s legal counsel, with independent advisors, with non-management directors, or with Axcella’s management, or may take other action or no action as the director determines in good faith, using reasonable judgment, and applying his or her own discretion.
Communications may be forwarded to other directors if they relate to important substantive matters and include suggestions or comments that may be important for other directors to know. In general, communications relating to corporate governance and long-term corporate strategy are more likely to be forwarded than communications relating to ordinary business affairs, personal grievances, and matters as to which we tend to receive repetitive or duplicative communications.
The audit committee oversees the procedures for the receipt, retention, and treatment of complaints received by Axcella regarding accounting, internal accounting controls, or audit matters, and the confidential, anonymous submission by employees of concerns regarding questionable accounting, internal accounting controls, or auditing matters.

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DIRECTOR COMPENSATION
The table below shows all compensation paid to each individual who served as non-employee member of our board of directors during 2022 for their services as directors in 2022, other than Mr. Hinshaw. Amounts paid to Mr. Hinshaw are presented below in the Summary Compensation Table.
Name​​
Fees Earned
or Paid
in Cash ($)
​​
Stock
Awards
($)(1)
​​
Option
Awards
($)(1)(3)
​​
Non-Equity
Incentive
Plan
Compensation
($)
​​
Nonqualified
Deferred
Compensation
Earnings ($)
​​
All Other
Compensation ($)
​​Total ($)​
Martin Hendrix, Ph.D​​​​41,236​​​​​​​​52,628​​​​​​​​​​​​​​​​​93,864​​
Catherine Angell Sohn, Pharm.D.​​​​57,165​​​​​​​​25,952​​​​​​​​​​​​​​​​​83,117​​
William D. “Chip” Baird​​​​67,500​​​​​​​​25,952​​​​​​​​​​​​​​​​​93,452​​
Gary P. Pisano, Ph.D.​​​​47,500​​​​​​​​25,952​​​​​​​​​​​​​​​​​73,452​​
Cristina M. Rondinone, Ph.D.​​​​44,000​​​​​​​​25,952​​​​​​​​​​​​​​​​​69,952​​
Paul Sekhri​​​​33,832​​​​​​​​52,628​​​​​​​​​​​​​​​​​86,460​​
Michael Rosenblatt​​​​34,725​​​​​​​​52,628​​​​​​​​​​​10,000(2)​​​​​97,353​​
Robert Rosiello​​​​15,750(4)​​​​​​​​29,680​​​​​​​​​​​​​​​​​45,430​​
Torben Straight Nissen​​​​9,000(4)​​​​​​​​29,680​​​​​​​​​​​​​​​​​38,680​​
​
(1)
The amounts reported represent the aggregate grant date fair value of the stock options awarded to the non-employee directors in the fiscal year ended December 31, 2022, calculated in accordance with FASB ASC Topic 718. Such grant date fair values do not take into account any estimated forfeitures. The assumptions used in calculating the grant date fair value of the stock options reported in this column are set forth in Note 9 to our audited Consolidated Financial Statements included in our Annual Report. The amounts reported in this column reflect the accounting cost for these stock options and stock awarded and do not correspond to the actual economic value actually received by the non-employee directors or that may be received by the non-employee directors upon the exercise of the stock options or any sale of the underlying shares of common stock.
​
(2)
The amount reported represents $10,000 in cash payments made to Mr. Rosenblatt in consideration for services on the Scientific Advisory Board.
​
(3)
As of December 31, 2022, each non-employee director held unexercised options to purchase the number of shares of the Company’s common stock as set forth below:
​
​​​
Option Awards(1)
​
Name​​Exercisable (#)​​Unexercisable (#)​
Martin Hendrix, Ph.D​​​​6,667​​​​​33,333​​
Catherine Angell Sohn, Pharm.D.​​​​53,000​​​​​20,000​​
William D. “Chip” Baird​​​​93,031​​​​​20,000​​
Gary P. Pisano, Ph.D.​​​​42,000​​​​​20,000​​
Cristina M. Rondinone, Ph.D.​​​​88,144​​​​​20,000​​
Paul Sekhri​​​​6,667​​​​​33,333​​
Michael Rosenblatt​​​​19,898​​​​​33,333​​
Robert Rosiello​​​​—​​​​​40,000​​
Torben Straight Nissen​​​​—​​​​​40,000​​
​
(1)
The amounts reported represent the aggregate number of unexercised options to purchase shares of the Company’s common stock held by each non-employee director, including awards granted prior to the completion of the Company’s IPO in May of 2019.
​

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(4)
The annual retainers earned by Mr. Rosiello and Dr. Straight Nissen were prorated based on the date they joined the board of directors.
​
Non-Employee Director Compensation
Under our director compensation program, we pay our non-employee directors a cash retainer for service on the board of directors and for service on each committee on which the director is a member. The chairman of each committee receives a higher retainer for such service. These fees are payable in arrears in four equal quarterly installments on the last day of each quarter, provided that the amount of such payment is prorated for any portion of such quarter that the director is not serving on our board of directors. The annual retainer paid to the chairman of the board is $70,000. The fees paid to non-employee directors, other than our chairman, for service on the board of directors and for service on each committee of the board of directors on which the director is a member are as follows:
​​​
Annual
Retainer
​
Board of Directors:​​​​​​​
All non-employee members, except chairman​​​$40,000​​
Audit Committee:​​​​​​​
Members​​​$7,500​​
Chairman​​​$15,000​​
Compensation Committee:​​​​​​​
Members​​​$5,000​​
Chairman​​​$10,000​​
Nominating and Corporate Governance Committee:​​​​​​​
Members​​​$4,000​​
Chairman​​​$8,000​​
We also reimburse our non-employee directors for reasonable travel and out-of-pocket expenses incurred in connection with attending our board of directors and committee meetings.
In addition, each new non-employee director elected to our board of directors will be granted an initial, one-time equity award of an option to purchase 40,000 shares of our common stock, which shall vest in equal quarterly installments during the 12 quarters following the grant date, subject to continued service as a director through such vesting date. On the date of each annual meeting of stockholders of Axcella, each non-employee director will receive an annual equity award of an option to purchase 20,000 shares of common stock, which shall vest on the earlier of the one-year anniversary of the grant date and Axcella’s next annual meeting of stockholders, subject to continued service as a director through such vesting date.
This program is intended to provide a total compensation package that enables us to attract and retain qualified and experienced individuals to serve as directors and to align our directors’ interests with those of our stockholders.
The Directors have agreed to suspend their cash remuneration for service on the board of directors until the Company has clarity on its financial condition.
Securities Authorized for Issuance under Equity Compensation Plans
The following table sets forth information as of December 31, 2022, regarding shares of common stock that may be issued under our equity compensation plans.

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​​Equity Compensation Plan Information​​Equity Compensation Plan Information​
Plan Category​
Number of
securities
to be issued
upon exercise
of outstanding
options, warrants
and rights
​
Weighted
average
exercise
price of
outstanding
options,
warrants
and rights
​
Number of securities
remaining available
for future
issuance
under equity
compensation
plan (excluding
securities in
first column)
​​
Number of
securities
to be issued
upon exercise
of outstanding
options, warrants
and rights
​
Weighted
average
exercise
price of
outstanding
options,
warrants
and rights
​
Number of securities
remaining available
for future
issuance
under equity
compensation
plan (excluding
securities in
first column)
​
Equity compensation plans approved by security
holders (1)
​​​6,612,210(2)​​​$5.05​​​​3,015,476(3)(4)​​​​​205,694(2)​​​$119.55​​​​305,222(3)(4)​​
Equity compensation plans not approved by security holders​​​—​​​​—​​​​—​​​​​—​​​​—​​​​—​​
Total​​​6,612,210​​​$5.05​​​​3,015,476​​​​​205,694​​​$119.55​​​​305,222​​
​
(1)
Includes the Axcella Health Inc. Amended and Restated 2010 Stock Incentive Plan (the “2010 Plan”), the 2019 Plan and the Axcella Health Inc. 2019 Employee Stock Purchase Plan (the “2019 Employee Stock Purchase Plan”).
​
(2)
Includes 6,536,977204,560 of common stockCommon Stock issuable upon the exercise of outstanding stock options and 75,2331,134 shares of common stockCommon Stock issuable upon settlement of restricted stock units.
​
(3)
As of DecemberOctober 31, 2022,2023, there were 2,317,471267,814 shares available for grant under the 2019 Plan and 698,00537,407 shares available for grant under the 2019 Employee Stock Purchase Plan. As of the closing of our initial public offering, no additional equity awards may be granted under the 2010 Plan. The shares of common stockCommon Stock underlying any awards granted under the 2010 Plan or 2019 Plan that are forfeited, canceled, reacquired by us prior to vesting, satisfied without the issuance of stock, or otherwise terminated (other than by exercise) and the shares of common stockCommon Stock that are withheld upon exercise of a stock option or settlement of such award to cover the exercise price or tax withholding will be added to the shares of common stockCommon Stock available for issuance under the 2019 Plan.
​
(4)
The 2019 Plan provides that an additional number of shares will automatically be added to the shares authorized for issuance under the 2019 Plan on January 1 of each year. The number of shares added each year will be equal to the lesser of: (i) 4% of the outstanding shares on the immediately preceding December 31 or (ii) such amount as determined by the compensation committee of our board of directors. The 2019 Employee Stock Purchase Plan provides that an additional number of shares will automatically be added to the shares authorized for issuance under the 2019 Employee Stock Purchase Plan on January 1 of each year through January 1, 2029. The number of shares added each year will be equal to the least of: (i) 1% of the outstanding shares on the immediately preceding December 31, (ii) 237,181 shares or (iii) such amount as determined by the compensation committee of our board of directors.
​
Indemnification and Insurance
In connection with the Assignment, Axcella will continue to indemnify its current and former directors and officers to the maximum extent permitted in accordance with applicable law, Axcella’s Amended and Restated Certificate of Incorporation and Amended and Restated By-laws, and any contractual arrangements, for actions taken in connection with the Assignment. The Board is authorized to obtain and maintain insurance as may be necessary, appropriate or advisable to satisfy such indemnification obligations, including seeking an extension in time and coverage of Axcella’s insurance policies currently in effect.
Other than as set forth above, it is not currently anticipated that the Assignment will result in any material benefit to any of Axcella’s executive officers or to directors who participated in the vote to adopt the Assignment.
Certain Material U.S. Federal Income Tax Consequences
The following is a summary of certain material United States federal income tax consequences of the Assignment that are applicable to stockholders. This discussion is included for general information purposes
 
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only and is not intended to be, and is not, legal or tax advice to any particular stockholder. This summary is based on the current provisions of the Internal Revenue Code of 1986, as amended (the “Code”), and other legal authorities, all of which are subject to change, possibly with retroactive effect. No rulings from the Internal Revenue Service (the “IRS”) or opinions of counsel have been or will be requested concerning the matters discussed below. The tax consequences set forth in the following discussion are not binding on the IRS or the courts, and no assurance can be given that contrary positions will not be successfully asserted by the IRS or adopted by a court.
This discussion does not describe all of the U.S. federal tax consequences that may be relevant to you in light of your particular circumstances, such as consequences arising under the federal estate and gift tax, the alternative minimum tax or the Medicare tax on net investment income or the consequences to you if you are an accrual-method taxpayer that is required to conform the timing of recognition of items of income to an “applicable financial statement” under Section 451(b) of the Code, or differing tax consequences applicable to you if you are a beneficial owner of Common Stock (“stockholder”) subject to special rules. Such special rules and circumstances include stockholders who are dealers in securities, financial institutions, insurance companies, entities classified as partnerships for income tax purposes, tax-exempt organizations, foreign persons, stockholders who acquired their Common Stock through stock option or stock purchase programs or in other compensatory transactions, stockholders who are subject to alternative minimum tax, stockholders who hold their Common Stock as part of an integrated investment, including a straddle, comprising shares of Common Stock and one or more other positions, or stockholders who have entered into a constructive sale of Common Stock under the Code.
For the avoidance of doubt, this summary applies to you only if you are a U.S. Holder. You are a U.S. Holder if, for U.S. federal income tax purposes, you are a stockholder that is:
•
an individual who is a citizen or resident of the United States;
​
•
a corporation created or organized in or under the laws of the United States, any state thereof or the District of Columbia; or
​
•
an estate or trust the income of which is subject to U.S. federal income taxation regardless of its source.
​
EACH STOCKHOLDER SHOULD CONSULT THE STOCKHOLDER’S OWN TAX ADVISOR TO DETERMINE THE STOCKHOLDER’S PARTICULAR U.S. FEDERAL INCOME TAX CONSEQUENCES AND OTHER TAX CONSEQUENCES TO THE STOCKHOLDER OF THE ASSIGNMENT, INCLUDING ANY STATE, LOCAL AND FOREIGN TAX LAWS AND THE EFFECT OF ANY CHANGES IN SUCH LAWS.
Worthless Stock.   Under U.S. federal income tax law, if stock becomes worthless, the resulting loss is treated as a loss from the sale or exchange of a capital asset on the last day of the tax year during which the stock first becomes worthless. Stock is generally treated as worthless if there is no current liquidating value, no reasonable hope and expectation that the stock will become valuable at some future time and there is an identifiable event establishing the worthlessness of the stock.
Upon completion of the Assignment, Axcella’s shares will be delisted from trading on the Nasdaq Global Market. If the stockholders do not receive any liquidating distributions, it is likely that the Assignment will be the identifiable event that establishes the worthlessness of the stock of Axcella, and that each stockholder should recognize a capital loss equal to the stockholder’s adjusted tax basis in the stockholder’s shares. For purposes of determining a stockholder’s holding period in Axcella’s stock, and whether the capital loss is a long-term or a short-term capital loss, a stockholder’s holding period should be determined as if the stock were sold on the last day of the stockholder’s taxable year (December 31 for individual stockholders).
Potential Subsequent Liquidation.   If there is a subsequent liquidating distribution in the same tax year as the Assignment, amounts received by stockholders in complete liquidation of Axcella should be treated as payments made in exchange for their Common Stock. In general, each Axcella stockholder should recognize capital gain or loss equal to the difference between the amount of consideration received by such Axcella stockholder and the Axcella stockholder’s adjusted tax basis in the shares of Axcella stock surrendered.

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If a liquidating distribution is received in a year subsequent to the Assignment and if a stockholder has treated the Assignment and other events as establishing worthlessness, then the stockholder should consider filing an amended return to undo the effect of the worthless stock loss and report a gain or loss solely with respect to the subsequent year’s liquidating distribution.
Gain or loss should be determined separately for each block of shares, with a “block” consisting of shares acquired at the same cost in a single transaction. That gain or loss will be long-term capital gain or loss, provided the shares are held for investment and the stockholder’s holding period for such shares is more than one year. For non-corporate Axcella stockholders, long-term capital gains are generally subject to a maximum federal income tax rate of 20% and short-term capital gains are subject to tax at ordinary income tax rates. Capital losses not offset by capital gains may be deducted against a non-corporate stockholder’s ordinary income only up to a maximum annual amount of $3,000. A non-corporate stockholder may not carry back capital losses, but such losses may be carried forward to subsequent tax years. All net capital gains for a corporate stockholder are subject to tax at regular corporate tax rates. Although a corporate stockholder can generally deduct capital losses only to the extent of capital gains, any unused capital losses of a corporate stockholder may generally be carried forward.
Backup Withholding if there are Liquidating Distributions.   Federal income tax laws require that, to avoid backup withholding with respect to “reportable payments” ​(currently at a rate of 24%), each Company stockholder must (a) provide Axcella with such stockholder’s correct taxpayer identification number (“TIN”) on Form W-9 and certify as to no loss of exemption from backup withholding, or (b) establish a basis for exemption from backup withholding on an appropriate Form W-8 (including a Form W-8BEN, W-8ECI, W-8EXP and W-8IMY) or Form W-9, as applicable. Exempt stockholders (including, among others, all corporations and certain foreign individuals) are not subject to backup withholding and reporting requirements. Backup withholding is not an additional tax. The amount of any backup withholding from a payment to you will be allowed as a credit against your U.S. federal income tax liability, if any, and may entitle you to a refund, provided that the required information is timely furnished to the IRS. Reportable payments, if any, made to stockholders pursuant to a liquidation of Axcella will be reported by Axcella to the IRS to the extent required by law.
Votes Required
The affirmative vote of a majority of the shares of our Common Stock outstanding on the Record Date and entitled to vote on the Assignment Proposal is required to approve the Assignment Proposal. Abstentions, broker non-votes, and failures to vote will have the same effect as a vote “AGAINST” the Assignment Proposal.
Recommendation of the Board
On November 1, 2023, the Board determined that the Assignment and the other transactions contemplated thereby are advisable and in the best interests of Axcella and its stockholders, approved submitting the Assignment Proposal to the Company’s stockholders and recommended the approval thereof.
The Board Unanimously recommends that you vote “FOR” the Assignment Proposal.

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EXECUTIVE COMPENSATIONPROPOSAL 2 — APPROVAL OF THE DISSOLUTION PURSUANT TO THE PLAN OF DISSOLUTION
Our named executive officers (“NEOs”)Board has (i) determined that, following the Assignment (assuming approval of the Assignment Proposal), the Dissolution is advisable and in the best interests of the Company and our stockholders, (ii) approved the Dissolution and (iii) adopted the Plan of Dissolution. The reasons for the year ended December 31, 2022 who appearDissolution are described under “Proposal 2 — Approval of the Dissolution Pursuant to the Plan of Dissolution — Background of the Proposed Dissolution” beginning on page 24 of this proxy statement. The Dissolution requires approval by the holders of a majority of our outstanding Common Stock entitled to vote at the Special Meeting that is the subject of this proxy statement. Our Board unanimously recommends that our stockholders authorize the Dissolution.
In general terms, when we dissolve, we will cease conducting our business, wind up our affairs, dispose of any remaining non-cash assets, pay or otherwise provide for our obligations, and distribute our remaining assets, if any, during a post-dissolution period of at least three years, as required by the DGCL. With respect to the Dissolution, we will follow the liquidation, dissolution and winding-up procedures prescribed by the DGCL and our Plan of Dissolution, as described in further detail under “Proposal 2 — Approval of the Summary Compensation table are:Dissolution Pursuant to the Plan of Dissolution — Delaware Law Applicable to Our Dissolution” beginning on page 37 of this proxy statement. You should carefully consider the risk factors relating to our complete liquidation and dissolution as described under “Risk Factors — Risks Related to The Assignment and Dissolution” beginning on page 2 of this proxy statement.
Subject to the requirements of the DGCL and our Plan of Dissolution, and subject to the Assignment process (assuming approval of the Assignment Proposal) described in this proxy statement, we or the Assignee, as applicable, will use our existing cash to pay for our winding up procedures, including:
•
William R. Hinshaw, Jr., our chief executive officer;income and other taxes;
​
•
Paul Fehlner, J.D., Ph.D,the costs associated with our chiefDissolution and winding up over the Survival Period; these costs may include, among others, expenses necessary to the implementation and administration of our Plan of Dissolution and fees and other amounts payable to professional advisors (including legal officer;counsel, financial advisors and others) and to consultants and others assisting us with our Dissolution;
​
•
Margaret James Koziel, M.D., our former chief medical officer;any claims by others against us that we do not reject as part of the dissolution process;
​
•
any amounts owed by us under contracts with third parties;
​
•
the funding of any reserves or other security we are required to establish, or deem appropriate to establish, to pay for asserted claims (including lawsuits) and possible future claims, as further described below; and
​
•
Robert Crane,solely to the extent remaining after provision for the above-described payments, liquidating distributions to be made to our former chief financial officer.stockholders, which distributions may be made from time to time as available and in accordance with the procedures required by the DGCL as described below.
​
Summary Compensation TableEstimated Distributions to Stockholders
The following table presents the compensation awardedBased upon information available at this time, Axcella cannot forecast whether any amounts will be available to earned by or paid to each of our named executive officers for the years indicated.
Name and Principal Position​​Year​​Salary ($)​​
Stock
Awards ($)
​​
Option
Awards ($)(1)
​​
Non-Equity
Incentive Plan
Compensation
($)(2)
​​
All Other
Compensation
($)
​​Total ($)​
William R. Hinshaw, Jr.
President and CEO
​​​​2022​​​​​571,875​​​​​​​​435,679​​​​​291,741​​​​​8,061(4)​​​​​1,307,356​​
​​​2021​​​​​546,250​​​​​​​​1,913,241(3)​​​​​275,275​​​​​8,700(4)​​​​​2,743,466​​
Paul Fehlner, J.D., Ph.D
Chief Legal Officer
​​​​2022​​​​​398,491​​​​​​​​86,215​​​​​150,769​​​​​8,700(4)​​​​​644,175​​
Margaret James Koziel, M.D.(5)
Former Senior Vice President and Chief Medical Officer
​​​​2022​​​​​415,000​​​​​​​​41,133​​​​​157,389​​​​​7,380(4)​​​​​620,902​​
Robert Crane(6)
Former Senior Vice President and Chief Financial Officer
​​​​2022​​​​​214,103​​​​​​​​401,801​​​​​121,812​​​​​8,202(4)​​​​​745,918​​
​
(1)
The amounts reported represent the aggregate grant date fair value of stock options awarded to the named executive officers in 2022 and 2021, as applicable, calculated in accordance with FASB ASC Topic 718. Such grant date fair value does not take into account any estimated forfeitures. The assumptions used in calculating the grant date fair value are set forth in Note 9 to our audited consolidated financial statements inour Annual Report. These amounts do not correspond to the actual value that may be recognized by the named executive officers upon vesting or exercise of the applicable awards. The amount reported for Mr. Crane includes the grant date fair value of a performance-based option award assuming probable achievement. Assuming maximum achievement, the grant date fair value is $801,551.
​
(2)
The amounts reported represent cash incentive compensation based on the board of directors’ assessment of the achievement of company and individual performance objectives for the years ended December 31, 2022, and December 31, 2021, respectively. The cash incentive compensation for 2022 performance was paid in two installments, with the first installment paid in August 2022 and based on achievement of objectives for the first half of 2022, and the second installment paid in February 2023 and based on achievement of objectives for the second half of 2022. The cash incentive compensation for 2021 performance was paid in February 2022. The amount reported for Mr. Crane includes a one-time cash bonus of $75,000 paid in February 2022 and $46,812 cash incentive compensation paid in August 2022.
​
(3)
In 2021, Mr. Hinshaw was granted a total of 375,000 time-based option awards.
​
(4)
The amounts reported represent matching contributions under the Company’s 401(k) plan.
​
(5)
On June 23, 2023, Margaret Koziel, M.D., resigned from the Company, effective immediately. The Company expects to engage Dr. Koziel to consult with and support the CompanyAxcella’s stockholders in connection with, its previously announced program reprioritizationor as a result of, the Assignment and/or Dissolution. There is a possibility that, assuming the Assignee can resolve all of Axcella’s obligations, some amount of liquidation proceeds could be paid to stockholders. However, there are too many variables and corporate restructuring.uncertainties for us to estimate whether any amounts will actually be paid or the amount of any such payments.
​Subject to the Assignment process, any distributions made to stockholders by Axcella following the distributions made to creditors to satisfy Axcella’s obligations, will be made to stockholders pro rata according to the stockholders’ holdings of Common Stock as of the Effective Time.
(6)
Robert Crane’s employment terminated effective December 15, 2022. In connectionWe cannot predict the timing or amount of any distributions, as uncertainties as to the ultimate amount of our liabilities, the operating costs and amounts to be set aside for claims, obligations and provisions during the liquidation and winding-up process, and the related timing to complete such transactions make it impossible to predict with his termination,
​certainty the actual net cash amount that will ultimately be
 
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Mr. Crane forfeited 325,000 of performance-based option awards granted to him in 2022. On December 16, 2022, Mr. Crane entered into a consulting agreement, and, in addition to receiving cash compensation consideration in January 2023 under the arrangement, the vesting period for his service-based option awards was extended to February 24, 2023. Mr. Crane will forfeit an aggregate 568,750 option awards.
Narrative to Summary Compensation Table
Our board of directors and compensation committee review compensation annually for all employees, including our executives. In setting executive base salaries and bonuses and granting equity incentive awards, we consider compensation for comparable positions in the market, the historical compensation levels of our executives, individual performance as compared to our expectations and objectives, our desire to motivate our employees to achieve short- and long-term results that are in the best interests of our stockholders, and a long-term commitment to our company. We target a general competitive position, based on independent third-party benchmark analytics to inform the mix of compensation of base salary, bonus or long-term incentives.
Our compensation committee discharges our board of directors’ responsibilities relating to compensation of our directors and executives, oversees our company’s overall compensation structure, policies and programs, and reviews our processes and procedures for the consideration and determination of director and executive compensation. Our compensation committee typically reviews and approves grants and awards under equity-based plans for all service providers, including our executive officers. In addition, our compensation committee reviews and recommends to the board of directors for determination the corporate goals and objectives that may be relevant to the compensation of our chief executive officer, and evaluates our chief executive officer’s performance, and recommends to the board of directors for determination our chief executive officer’s equity and non-equity compensation. Our board of directors discusses the compensation committee’s recommendations and ultimately approves the compensation of our executive officers without members of management present.
Annual base salary
Each named executive officer’s base salary is a fixed component of annual compensation for performing specific duties and functions and has been established by our board of directors taking into account each individual’s role, responsibilities, skills, and experience. Base salaries for our named executive officers are reviewed annually by our compensation committee, typically in connection with our annual performance review process, and adjusted from time to time, based on the recommendation of the compensation committee, to realign salaries with market levels after considering individual responsibilities, performance, and experience.
Cash bonus
Our annual bonus program is intended to reward our named executive officers for meeting objective or subjective performance goals for a fiscal year. From time to time, our board of directors or compensation committee may approve annual bonuses for our named executive officers based on individual performance, company performance, or as otherwise determined appropriate.
Name​​
Target Bonus
(% of base
salary)
​
William R. Hinshaw, Jr.​​​​55​​
Paul Fehlner, J.D., Ph.D​​​​40​​
Margaret James Koziel, M.D.​​​​40​​
Robert Crane​​​​​​​
Long-term equity incentives
Our equity grant program is intended to align the interests of our named executive officers with those of our stockholders and to motivate them to make important contributions to our performance. We granted

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awards to our named executive officers in 2022, as described in the “Outstanding Equity Awards at 2022 Fiscal Year End Table.”
Outstanding Equity Awards at 2022 Fiscal Year End Table
The following table presents information regarding all outstanding equity awards held by each of our named executive officers on December 31, 2022.
​​​Option Awards​​Stock Awards​
Name​​
Number of
Securities
Underlying
Unexercised
Options (#)
Exercisable
​​
Number of
Securities
Underlying
Unexercised
Options (#)
Unexercisable
​​
Equity
Incentive
Plan Awards:
Number of
Securities
Underlying
Unexercised
Unearned
Options (#)
​​
Option
Exercise
Price ($)
​​
Option
Expiration
Date
​​
Number
of Shares
or Units
of Stock
that have
not
Vested (#)
​​
Market
Value of
Shares or
Units of
Stock that
have not
Vested ($)(1)
​
William R. Hinshaw
President and CEO
​​​​939,028(2)​​​​​0(2)​​​​​​​​6.21​​​​​6/21/2028​​​​​​​​​​​​​​
​​​57,000(3)​​​​​3,800(3)​​​​​​​​13.83​​​​​3/22/2029​​​​​​​​​​​​​​
​​​117,525(4)​​​​​39,175(4)​​​​​​​​4.12​​​​​1/2/2030​​​​​​​​​​​​​​
​​​164,063(5)​​​​​210,937(5)​​​​​​​​6.59​​​​​2/8/2031​​​​​​​​​​​​​​
​​​0(6)​​​​​275,000(6)​​​​​​​​1.63​​​​​2/7/2032​​​​​​​​​​​​​​
​​​0(6)​​​​​100,000(6)​​​​​​​​5.00​​​​​2/7/2032​​​​​​​​​​​​​​
Paul Fehlner, J.D., Ph.D
Chief Legal Officer
​​​​97,828(7)​​​​​0(7)​​​​​​​​6.21​​​​​4/24/2028​​​​​42,500(10)​​​​​13,919(10)​​
​​​13,500(8)​​​​​4,500(8)​​​​​​​​3.40​​​​​12/18/2029​​​​​​​​​​​​​​
​​​16,875(9)​​​​​13,125(9)​​​​​​​​4.73​​​​​9/15/2030​​​​​​​​​​​​​​
​​​37,188(5)​​​​​47,812(5)​​​​​​​​6.59​​​​​2/8/2031​​​​​​​​​​​​​​
​​​0(6)​​​​​70,000(6)​​​​​​​​1.63​​​​​2/7/2032​​​​​​​​​​​​​​
Margaret James Koziel, M.D.
Former Senior Vice President and Chief Medical Officer
​​​​18,200(11)​​​​​2,600(11)​​​​​​​​9.31​​​​​6/27/2029​​​​​13,125(16)​​​​​4,298(16)​​
​​​7,688(12)​​​​​2,562(12)​​​​​​​​4.12​​​​​1/2/2030​​​​​​​​​​​​​​
​​​5,500(13)​​​​​5,500(13)​​​​​​​​5.04​​​​​11/10/2030​​​​​​​​​​​​​​
​​​13,584(5)​​​​​17,466(5)​​​​​​​​6.59​​​​​2/08/2031​​​​​​​​​​​​​​
​​​3,750(14)​​​​​6,250(14)​​​​​​​​4.11​​​​​6/25/2031​​​​​​​​​​​​​​
​​​18,750(15)​​​​​56,250(15)​​​​​​​​2.60​​​​​12/10/2031​​​​​​​​​​​​​​
​​​0(6)​​​​​33,397(6)​​​​​​​​1.63​​​​​2/7/2032​​​​​​​​​​​​​​
Robert Crane
Former Senior Vice President and Chief Financial Officer
​​​​0(17)​​​​​200,000(17)​​​​​​​​1.63​​​​​5/25/2023​​​​​​​​​​​​​​
​​​0(17)​​​​​125,000(17)​​​​​​​​1.63​​​​​5/25/2023​​​​​​​​​​​​​​
​
(1)
Based on $0.33 per share, the last sale price of Axcella common stock on December 30, 2022.
​
(2)
25% of this option vested and became exercisable on May 31, 2019, and the remainder vested in 12 equal quarterly installments thereafter.
​
(3)
This option was granted on March 22, 2019. Following the closing of our initial public offering on May 13, 2019, the vesting period for the stock option commenced subject to approval of performance criteria by the board of directors, which occurred on May 22, 2019. 25% of this option vested and became exercisable on March 1, 2020, and the remainder shall vest in 12 equal quarterly installments thereafter.
​
(4)
25% of this option vested and became exercisable on January 2, 2021, with the remainder to vest in 12 equal quarterly installments thereafter.
​
(5)
25% of this option vested and became exercisable on February 9, 2022, with the remainder vesting in 12 equal quarterly installments thereafter.
​

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(6)
25%available for distribution to stockholders or the timing of any such distributions. Therefore, we are unable to estimate when we, or the Assignee, as applicable, would be able to make any distributions to our stockholders. See the section entitled “Risk Factors — Risks Related to The Assignment and Dissolution” beginning on page 2 of this option shall vest and become exercisable on February 8, 2023, with the remainder vesting in 12 equal quarterly installments thereafter.proxy statement.
​
(7)
25% of this option vested and became exercisable on April 2, 2019, and the remainder vested in 12 equal quarterly installments thereafter.
​
(8)
25% of this option vested and became exercisable on December 18, 2020, and the remainder shall vest in 12 equal quarterly installments thereafter.
​
(9)
25% of this option vested and became exercisable on September 16, 2021, and the remainder shall vest in 12 equal quarterly installments thereafter.
​
(10)
1/3The description of the restricted stock units vested on February 9, 2023Dissolution contained in this introductory section is general in nature and the remaining 2/3 of the grant shall vest on February 9, 2024.
​
(11)
25% of the shares underlying this option vested and became exercisable on June 27, 2020, with the remainder vesting in 12 equal quarterly installments thereafter.
​
(12)
25% of the shares underlying this option vested and became exercisable on January 2, 2021, with the remainder vesting in 12 equal quarterly installments thereafter.
​
(13)
25% of the shares underlying this option vested and became exercisable on November 10, 2021, with the remainder vesting in 12 equal quarterly installments thereafter.
​
(14)
25% of the shares underlying this option vested and became exercisable on June 25, 2022, with the remainder vesting in 12 equal quarterly installments thereafter.
​
(15)
25% of this option vested and became exercisable on December 10, 2022, with the remainder vesting in 12 equal quarterly installments thereafter.
​
(16)
25% of the restricted stock units vested on August 31, 2021, with the remainder vesting in 12 equal quarterly installments thereafter.
​
(17)
25% of each option was scheduled to vest on February 8, 2023, with the remainder vesting in 12 equal quarterly installments thereafter. Mr. Crane was terminated effective December 15, 2022. His separation agreement provided for continued vesting during a consulting period, which ended on February 24, 2023. A total of 81,250 shares vested and became exercisable on February 8, 2023.
​
Employment arrangements with our named executive officers
William R. Hinshaw, Jr.
Under our Amended and Restated Employment Agreement with Mr. Hinshaw, dated December 20, 2018, or the Hinshaw Employment Agreement, he will continue to serve as our President and Chief Executive Officer on an at will basis. Mr. Hinshaw initially received a base salary of $500,000 per year, which is subject to periodic reviewvarious other factors and adjustment. Mr. Hinshawrequirements, as described in greater detail below.
Background of the Proposed Dissolution
In the ordinary course from time to time, our Board and management team have evaluated and considered a variety of financial and strategic opportunities for the Company as part of our long-term strategy to enhance value for our stockholders, including potential acquisitions, divestitures, business combinations and other transactions.
As part of the ongoing consideration and evaluation of our long-term prospects and strategies, our Board frequently reviews, with our management, strategic and financial alternatives in light of developments in our business, the competitive landscape, the economy generally and financial markets, all with the goal of enhancing value for our stockholders and making a positive impact in patients’ lives. As part of this process, from time to time, our management has engaged in business development and/or strategic discussions with industry participants. This includes contacts with numerous companies regarding potential global and regional partnerships, as well as a number of discussions with companies about strategic transactions.
Historically, we were a clinical-stage biotechnology company focused on pioneering a new approach to treat complex diseases using compositions of endogenous metabolic modulators, or EMMs. Our product candidates are comprised of multiple EMMs that are engineered in distinct combinations and ratios with the goal of simultaneously impacting multiple biological pathways. Our pipeline includes lead therapeutic candidates for the treatment of Long COVID (also known as Post COVID-19 Condition and Post-Acute Sequelae of COVID-19, or “PASC”) associated fatigue, and the treatment of non-alcoholic steatohepatitis, or NASH.
On December 12, 2022, the Board of Directors approved a reprioritization of the Company’s programs and a restructuring of operations to support its streamlined set of priorities. As part of this restructuring, the Board approved a reduction in force of approximately 85% of the Company’s workforce. Since the reorganization, the Company has taken several actions including terminating its EMMPACT Phase 2b clinical trial of AXA1125 for the treatment of NASH to focus on AXA1125 for the treatment of Long COVID associated fatigue, and executing a plan to vacate its facility and to sell its non-leased laboratory equipment.
After seeking potential funding sources and other ways to continue to operate Axcella’s business, Axcella has been unable to find a viable alternative to the Assignment. The Board believes that the Assignment presents the best opportunity for the best recovery for creditors and also may provide an opportunity for future payments to stockholders.
In light of this, our Board determined that approving the Plan of Dissolution gives our Board the most flexibility in optimizing value for our stockholders and as a result, on November 1, 2023, our Board adopted resolutions approving the Plan of Dissolution and the Dissolution and recommending that our stockholders approve the Plan of Dissolution and the Dissolution.
Reasons for the Proposed Dissolution
The Board believes that the Dissolution is also eligible for an annual performance bonus targetedin Axcella’s best interests and the best interests of our stockholders. The Board considered and pursued at 55% of his base salary and is eligible to participate in the employee benefit plans generallylength potential strategic alternatives available to our employees, subject toAxcella such as a merger, asset sale, strategic partnership or other business combination transaction, and, following the termsresults of those plans.
The Hinshaw Employment Agreement further providessuch review, now believe that if Mr. Hinshaw’s employment is terminated by us without Cause (as defined in the Hinshaw Employment Agreement) or Mr. Hinshaw resigns for Good Reason (as defined in the Hinshaw Employment Agreement), he will be entitled to receive: (i) base salary continuation for 12 months following termination, or the Hinshaw Severance Amount, and, (ii) if Mr. Hinshaw is enrolled in our health care program immediately prior to the date of termination and properly elects to receive Consolidated Omnibus Budget Reconciliation Act (“COBRA”) benefits, 12 months of COBRA premiums for himself and his eligible dependents at our normal rate of contribution for employees for coverage at the level in effect immediately prior to the date of termination (orpursuing a monthly cash payment in lieu thereof if we determine we cannot pay such amounts without potentially violating applicable law). Paymentwind-up of the Hinshaw Severance Amount shall immediately cease if Mr. Hinshaw breachesCompany in accordance with the termsPlan of Dissolution gives our Board the Restrictive Covenants Agreement between him and us. most flexibility in optimizing value for our stockholders.
In lieu ofmaking its determination to approve the severance payments and benefits set forth above,Dissolution, the Board considered, in addition to other pertinent factors, the event Mr. Hinshaw’s employment is terminated by us without Causefact that Axcella currently has no significant remaining business operations or he resigns for Good Reason, in either case within 12 months following a Change in Control (as defined in the Hinshaw Employment Agreement), he will be entitled to receive: (i) a lump sum cash amount equal to 1.5 times the sum of (A) his current base salary (or his base salary in effect prior to the Change in Control, if higher) plusbusiness
 
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(B) his target annual cash incentive compensation forprospects; the yearfact that Axcella will continue to incur substantial accounting, legal and other expenses associated with being a public company despite having no source of termination, (ii) if Mr. Hinshawrevenue or financing alternatives; and the fact that Axcella has conducted an evaluation to identify remaining strategic alternatives involving Axcella’s assets or Axcella as a whole, such as a merger, asset sale, strategic partnership or other business combination transaction, that would have a reasonable likelihood of providing value to our stockholders in excess of the amount the stockholders would receive in a liquidation. As a result of its evaluation, the Board concluded that the Dissolution is enrolledthe preferred strategy among the alternatives now available to Axcella and is in the best interests of Axcella and its stockholders. Accordingly, the Board approved the Dissolution of Axcella pursuant to the Plan of Dissolution and recommends that our health care program immediatelystockholders approve the Dissolution Proposal.
Delaware Law Applicable to our Dissolution
We are a corporation organized under the laws of the State of Delaware and the Dissolution will be governed by the DGCL. The following is a brief summary of some of the DGCL provisions applicable to the Dissolution. The following summary is qualified in its entirely by Sections 275 through 283 of the DGCL, which are attached to this proxy statement as Annex A.
Delaware Law Generally
Authorization of Board and Stockholders.   If a corporation’s board of directors deems it advisable that the corporation should dissolve, it may adopt a resolution to that effect by a majority vote of the whole board and notify the corporation’s stockholders entitled to vote on the dissolution of the adoption of the resolution and the calling of a meeting of stockholders to act on the resolution. Our Board has unanimously adopted a resolution approving the Dissolution and the Plan of Dissolution and declaring them advisable and recommending them to our stockholders. The Dissolution must be authorized and approved by the holders of a majority of our outstanding Common Stock on the Record Date entitled to vote on the Dissolution Proposal.
Certificate of Dissolution.   If a corporation’s stockholders authorize its dissolution, to consummate the dissolution the corporation must file a certificate of dissolution with the Secretary of State. If our stockholders authorize the Dissolution at the Special Meeting, we intend to file the Certificate of Dissolution with the Secretary of State as soon as practicable after the receipt of such approval. However, the timing of such filing is subject to the discretion of the Board.
Possible Permitted Abandonment of Dissolution.   The resolution authorizing a dissolution adopted by a corporation’s board of directors may provide that, notwithstanding authorization of the dissolution by the corporation’s stockholders, the board of directors may abandon the dissolution without further action by the stockholders. While we do not currently foresee any reason that our Board would abandon our proposed Dissolution once it is authorized by our stockholders, to provide our Board with the maximum flexibility to act in the best interests of our stockholders, the resolutions adopted by our Board included language providing the Board with the flexibility to abandon the Dissolution without further action of our stockholders at any time prior to the datefiling of terminationthe Certificate of Dissolution.
Time of Dissolution.   When a corporation’s certificate of dissolution is filed with the Secretary of State and properly electshas become effective, along with the corporation’s tender of all taxes (including Delaware franchise taxes) and fees authorized to receive COBRA benefits, 18 monthsbe collected by the Secretary of COBRA premiums for himself and his eligible dependents at our normal rate of contribution for employees for coverage atState, the level in effect immediately priorcorporation will be dissolved. We refer to the date of termination (or a monthly cash payment in lieu thereof if we determine we cannot pay such amounts without potentially violating applicable law), and (iii) notwithstanding anything to the contrary provided in the applicable award agreement, accelerated vesting of 100% of all time-based stock options and other stock-based awards subject to time-based vesting, or “Time-Based Equity Awards”, held by Mr. Hinshaw.
On February 14, 2023, the severance provisionseffective time of the Hinshaw Employment Agreement were amendedCertificate of Dissolution herein as described below under the heading “— Retention Agreements.“Effective Time.”
Margaret KozielContinuation of Corporation After Dissolution
Under our Employment Agreement with Dr. Koziel, dated December 1, 2021,A dissolved corporation continues its existence for three years after dissolution, or such longer period as the Koziel Employment Agreement, Dr. KozielDelaware Court of Chancery may direct, for the purpose of prosecuting and defending suits and enabling the corporation to settle and close its business, to dispose of and convey its property, to discharge its liabilities and to distribute to its stockholders any remaining assets. A dissolved corporation may not, however, continue the business for which it was engaged to serve as our Senior Vice President and Chief Medical Officer an at will basis. Dr. Koziel initially received a base salary of $415,000 per year, which was subject to periodic review and adjustment. Dr. Koziel was also eligible for an annual performance bonus targeted at 40% of her base salary and was eligible to participate inorganized. Any action, suit or proceeding begun by or against the employee benefit plans generally available to our employees, subject tocorporation before or during the terms of those plans.
The Koziel Employment Agreement further provides that if Dr. Koziel’s employment is terminated by us without CauseSurvival Period (as defined in the Koziel Employment Agreement) or Dr. Koziel resigns for Good Reason (as defined in the Koziel Employment Agreement), she will be entitled to receive: (i) base salary continuation for nine months following termination, or the Koziel Severance Amount, and, (ii) if Dr. Koziel is enrolled in our health care program immediately prior to the date of termination and properly elects to receive COBRA benefits, nine months of COBRA premiums for herself and her eligible dependents at our normal rate of contribution for employees for coverage at the level in effect immediately prior to the date of termination (or a monthly cash payment in lieu thereof if we determine we cannot pay such amounts without potentially violating applicable law). Paymentbelow) does not abate by reason of the Koziel Severance Amount shall immediately cease if Dr. Koziel breaches the terms of the Restrictive Covenants Agreement between herdissolution, and us. In lieu of the severance payments and benefits set forth above, in the event Dr. Koziel’s employment is terminated by us without Cause or she resigns for Good Reason, in either case within 12 months following a Change in Control (as defined in the Koziel Employment Agreement), she will be entitled to receive: (i) a lump sum cash amount equal to one times the sum of (A) her current base salary (or her base salary in effect prior to the Change in Control, if higher) plus (B) her target annual cash incentive compensation for the yearpurpose of termination, (ii) if Dr. Koziel is enrolled in our health care program immediately prior toany such action, suit or proceeding, the date of termination and properly elects to receive COBRA benefits, 12 months of COBRA premiums for herself and her eligible dependents at our normal rate of contribution for employees for coverage atcorporation will continue beyond the level in effect immediately prior toSurvival Period until any related judgments, orders or decrees are fully executed, without the date of termination (or a monthly cash payment in lieu thereof if we determine we cannot pay such amounts without potentially violating applicable law), and (iii) notwithstanding anything to the contrary provided in the applicable award agreement, accelerated vesting of 100% of all Time-Based Equity Awards held by Dr. Koziel.
On February 14, 2023, the severance provisions of the Koziel Employment Agreement were amended as described below under the heading “— Retention Agreements” and on June 23, 2023, Dr. Koziel resigned as Senior Vice President and Chief Medical Officer, effective immediately.
Paul Fehlner
Under our Amended and Restated Employment Agreement with Dr. Fehlner, dated December 20, 2018 and amended September 16, 2020, or the Fehlner Employment Agreement, Dr. Fehlner serves as our Chief Legal Officer and Corporate Secretary on an at will basis. Dr. Fehlner initially received a base salary of $370,000 per year, which is subject to periodic review and adjustment. Dr. Fehlner is also eligible for an annual performance bonus targeted at 40% of his base salary and is eligible to participate in the employee benefit plans generally available to our employees, subject to the terms of those plans.
 
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necessity for any special direction by the Delaware Court of Chancery. Our Plan of Dissolution will govern our winding up process after Dissolution. See the section entitled “Proposal 2 — Approval of the Dissolution Pursuant to the Plan of Dissolution — Our Plan of Dissolution” beginning on page 28 of this proxy statement.
Payment and Distribution to Claimants and Stockholders
A dissolved corporation must make provision for the payment (or reservation of funds as security for payment) of claims against the corporation in accordance with the applicable provisions of the DGCL and the distribution of remaining assets to the corporation’s stockholders. The Fehlner Employment Agreement furtherdissolved corporation may do this by following one of two procedures, as described below.
Safe Harbor Procedures under DGCL Sections 280 and 281(a)(the “Safe Harbor Procedures”)
A dissolved corporation may elect to give notice of its dissolution to persons having a claim against the corporation (other than claims against the corporation in any pending actions, suits or proceedings to which the corporation is a party) (“Current Claimants”) and to persons with contractual claims contingent on the occurrence or nonoccurrence of future events or otherwise conditional or unmatured (“Contingent Contractual Claimants”), and after giving these notices, following the procedures set forth in the DGCL, as described below.
The Plan of Dissolution provides that if Dr. Fehlner’s employment is terminated by us without Causethe Board with the discretion to elect to follow the Safe Harbor Procedures rather than the Alternative Procedures (as defined below).
Current Claimants
Notices and Publication.   The notice to Current Claimants must state (1) that all such claims must be presented to the corporation in writing and must contain sufficient information that will reasonably inform the Fehlner Employment Agreement) or Dr. Fehlner resigns for Good Reason (as defined incorporation of the Fehlner Employment Agreement), he willidentity of the claimant and the substance of the claim; (2) the mailing address to which the claim must be entitled to receive: (i) base salary continuation for nine months following termination, orsent; (3) the Fehlner Severance Amount, and, (ii) if Dr. Fehlner is enrolled in our health care program immediately prior todate (the “Claim Date”) by which the claim must be received by the corporation, which must be no earlier than 60 days from the date of terminationthe corporation’s notice; (4) that the claim will be barred if not received by the Claim Date; (5) that the corporation may make distributions to other claimants and properly electsthe corporation’s stockholders without further notice to receive COBRA benefits, nine monthsthe Current Claimant; and (6) the aggregate annual amount of COBRA premiumsall distributions made by the corporation to its stockholders for himself and his eligible dependents at our normal rateeach of contribution for employees for coverage at the level in effect immediately prior tothree years before the date of termination (ordissolution. The notice must be published at least once a monthly cash paymentweek for two consecutive weeks in lieu thereof if we determine we cannot pay such amounts without potentially violating applicable law). Paymenta newspaper of the Fehlner Severance Amount shall immediately cease if Mr. Fehlner breaches the terms of the Restrictive Covenants Agreement between him and us. In lieu of the severance payments and benefits set forth above,general circulation in the event Dr. Fehlner’s employmentcounty in which the corporation’s registered agent in Delaware is terminated by us without Cause or he resigns for Good Reason, in either case within 12 months following a Change in Control (as definedlocated and in the Fehlner Employment Agreement), he will be entitled to receive: (i)corporation’s principal place of business and, in the case of a lump sum cash amount equal to one timescorporation having $10 million or more in total assets at the sumtime of (A) his current base salary (or his base salarydissolution, at least once in effect prior to the Change in Control, if higher) plus (B) his target annual cash incentive compensation for the yearall editions of termination, (ii) if Dr. Fehlner is enrolled in our health care program immediately prior toa daily newspaper with a national circulation. On or before the date of termination and properly electsthe first publication of the notice, the corporation must also mail a copy of the notice by certified or registered mail, return receipt requested, to each known claimant of the corporation, including persons with claims asserted against the corporation in a pending action, suit or proceeding to which the corporation is a party.
Effect of Non-Responses to Notices.   If the dissolved corporation does not receive COBRA benefits, 12 monthsa response to the corporation’s notice by the Claim Date from a Current Claimant who was given actual notice according to the foregoing paragraph, then the claimant’s claim will be barred.
Treatment of COBRA premiums for himself and his eligible dependentsResponses to Notices.   If the dissolved corporation receives a response to the corporation’s notice by the Claim Date, the dissolved corporation may accept or reject, in whole or in part, the claim. If the dissolved corporation rejects a claim, it must mail a notice of the rejection to the Current Claimant by certified or registered mail, return receipt requested, within 90 days after receipt of the claim (or, if earlier, at our normal rateleast 150 days before the expiration of contribution for employees for coverage at the level in effect immediately priorSurvival Period). The notice must state that any claim so rejected will be barred if the Current Claimant does not commence an action, suit or proceeding with respect to the claim within 120 days of the date of termination (orthe rejection.
Effect of Non-Responses to Rejections of Claims.   If the dissolved corporation rejects a monthly cash payment in lieu thereof if we determine we cannot pay such amounts without potentially violating applicable law),claim and (iii) notwithstanding anythingthe Current Claimant does not commence an action suit or proceeding with respect to the contrary provided inclaim within the applicable award agreement, accelerated vesting of 100% of all time-based stock options and other stock-based awards subject to Time-Based Equity Awards held by Dr. Fehlner.
On February 14, 2023,120-day post-rejection period, then the severance provisions of the Fehlner Employment Agreement were amended as described below under the heading “— Retention Agreements.”
Robert Crane
Under our Employment Agreement with Mr. Crane, dated January 24, 2022, or the Crane Employment Agreement, he was engaged to serve as our Chief Financial Officer on an atCurrent Claimant’s claim will basis. Mr. Crane initially received a base salary of $250,000 per year, which was subject to periodic review and adjustment. Mr. Crane was also eligible for an annual performance bonus targeted at 40% of his base salary and is eligible to participate in the employee benefit plans generally available to our employees, subject to the terms of those plans.
Retention Agreementsbe barred.
On February 14, 2023, we entered into retention agreements, or the Retention Agreements, with each of (i) Mr. Hinshaw, (ii) Dr. Koziel, and (iii) Dr. Fehlner to provide an incentive for their continued service with us subsequent to the restructuring event on December 14, 2022.
The Retention Agreements provide for retention bonuses of cash and equity in the event of certain actions by us as further described below. In connection with the retention bonuses provided under the Retention Agreements, each of Mr. Hinshaw, Dr. Koziel and Dr. Fehlner agreed to waive their rights to severance payments provided under their respective employment agreements in the event of a Terminations Without Cause or for Good Reason (as such terms are currently defined in their respective employment agreements).
The Company will pay $517,500 to Mr. Hinshaw in the event of (i) an affirmative decision by the board of directors that the Company will cease to do business, (ii) Mr. Hinshaw’s Termination Without Cause or resignation for Good Reason (as such terms are currently defined in the Hinshaw Employment Agreement) or (iii) the board of directors approving a sale of the Company or a corporate transaction that allows the Company to continue its operations, with fifty percent of the total retention payment payable on June 30, 2023 and the remainder payable on September 30, 2023.
The Company will pay $280,125 to Dr. Koziel in the event of (i) an affirmative decision by the board of directors that the Company will cease to do business, (ii) Dr. Koziel’s Termination Without Cause or resignation for Good Reason (as such terms are currently defined in the Koziel Employment Agreement) and
 
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(iii) the board of directors approving a sale of the Company or a corporate transaction that allows the Company to continue its operations, with fifty percent of the total retention payment payable on June 30, 2023 and the remainder payable on September 30, 2023. Dr. Koziel resigned from the Company on June 23, 2023 and upon her resignation, she forfeited her right to receive these payments.
The Company will pay $270,123 to Dr. Fehlner in the event of (i) an affirmative decision by the board of directors that the Company will cease to do business, (ii) Dr. Fehlner’s Termination Without Cause or resignation for Good Reason (as such terms are currently defined in the Fehlner Employment Agreement) and (iii) the board of directors approving a sale of the Company or a corporate transaction that allows the Company to continue its operations, with fifty percent of the total retention payment payable on June 30, 2023 and the remainder payable on September 30, 2023.
In addition, the Company may, subject to review by the board of directors, offer a further equity incentive grant to each of Mr. Hinshaw and Dr. Fehlner equal to 50% of such individual’s 2023 target annual bonus to continue employment with the Company in the event of a transaction referenced in (iii) above of an appropriate scale and that allows the Company to continue its operations indefinitely. Such equity incentive would vest fifty percent (50%) on the date six (6) months after grant, with the remaining fifty percent (50%) vesting on the date twelve (12) months after grant, provided that such individual remains employed by the Company on each vesting day.
Other agreements
We have also entered into employee confidentiality, inventions, non-solicitation and non-competition agreements with each of our named executive officers. Under such agreements, each named executive officer has agreed (1) not to compete with us during his or her employment and for a period of one year after the termination of such employment, (2) not to solicit our employees during his or her employment and for a period of one year after the termination of such employment, (3) to protect our confidential and proprietary information and (4) to assign to us related intellectual property developed during the course of his or her employment.
Additional Narrative Disclosure
401(k) Savings Plan. We maintain a 401(k)-retirement savings plan for the benefit of our employees, including our named executive officers, who satisfy certain eligibility requirements. Under the 401(k) plan, eligible employees may elect to defer a portion of their compensation, within the limits prescribed by Internal Revenue Code of 1986, as amended, (the “Code”) on a pre-tax or after tax (Roth) basis through contributions to the 401(k) plan. We are permitted to make discretionary profit-sharing contributions to the 401(k) plan. In 2020 the Company began matching 50% of every employee’s first 6% of contributions and the contributions will be 100% vested after 1 year of employment. The 401(k) plan is intended to qualify under Section 401(a) of the Code. As a tax qualified retirement plan, pre-tax contributions to the 401(k) plan and earnings on those pre-tax contributions are not taxable to the employees until distributed from the 401(k) plan, and earnings on Roth contributions are not taxable when distributed from the 401(k) plan.
Health and Welfare Benefits. All of our full-time employees, including our named executive officers, are eligible to participate in our health and welfare plans, including medical and dental benefits, short-term and long-term disability insurance, and life insurance. We believe these perquisites are necessary and appropriate to provide a competitive compensation package to our named executive officers.
Compensation Risk Assessment
We believe that although a portion of the compensation provided to our executive officers and other employees is performance-based, our executive compensation program does not encourage excessive or unnecessary risk taking. Our compensation programs are designed to encourage our executive officers and other employees to remain focused on both short-term and long-term strategic goals, in particular in connection with our pay-for-performance compensation philosophy. In line with this philosophy, we do not provide guaranteed bonuses to the above NEOs, and the bonuses to the above NEOs are only awarded upon approval of the compensation committee (or in the case of our CEO, the board) based upon satisfactorily

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meeting goals set by the board of directors. As a result, we do not believe that our compensation programs are reasonably likely to have a material adverse effect on us.
Rule 10b5-1 Sales Plans
Our policy governing transactions in our securities by directors, officers, and employees permits our officers, directors, and certain other persons to enter into trading plans complying with Rule 10b5-1 under the Exchange Act. Generally, under these trading plans, the individual relinquishes control over the transactions once the trading plan is put into place. Accordingly, sales under these plans may occur at any time, including possibly before, simultaneously with, or immediately after significant events involving our company.

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CERTAIN RELATIONSHIPS AND RELATED PARTY TRANSACTIONSContingent Contractual Claims
OtherNotices.   The notice to Contingent Contractual Claimants (persons with contractual claims contingent on the occurrence or nonoccurrence of future events or otherwise conditional or unmatured) must be in substantially the same form and sent and published in the same manner, as notices to Current Claimants and shall request that Contingent Contractual Claimants present their claims in accordance with the terms of such notice.
Responses to Contractual Claimants.   If the dissolved corporation receives a response by the date specified in the notice by which the claims from Contingent Contractual Claimants must be received by the corporation, which must be no earlier than 60 days from the date of the corporation’s notice to Contingent Contractual Claimants, the dissolved corporation must offer to the Contingent Contractual Claimant such security as the dissolved corporation determines is sufficient to provide compensation agreementsto the claimant if the claim matures. This offer must be mailed to the Contingent Contractual Claimant by certified or registered mail, return receipt requested, within 90 days of the dissolved corporation’s receipt of the claim (or, if earlier, at least 150 days before the expiration of the post- dissolution survival period). If the Contingent Contractual Claimant does not deliver to the dissolved corporation a written notice rejecting the offer within 120 days after receipt of the offer for security, the claimant is deemed to have accepted the security as the sole source from which to satisfy the claim against the dissolved corporation.
Determinations by Delaware Court of Chancery
A dissolved corporation that has complied with the Safe Harbor Procedures must petition the Delaware Court of Chancery to determine the amount and form of security that will be (1) reasonably likely to be sufficient to provide compensation for any claim against the dissolved corporation that is the subject of a pending action, suit or proceeding to which the dissolved corporation is a party, other arrangements described under “Executive Compensation”than a claim barred pursuant to the Safe Harbor Procedures, (2) sufficient to provide compensation to any Contingent Contractual Claimant who has rejected the dissolved corporation’s offer for security for such person’s claims made pursuant to the Safe Harbor Procedures, and “Director Compensation” in this proxy statement and the transactions described below, since January 1, 2022, there has(3) reasonably likely to be sufficient to provide compensation for claims that have not been and there is not currently proposed, any transaction or series of similar transactions to which we were, or will be, a party in which the amount involved exceeded, or will exceed, $120,000 and in which any director, executive officer, holder of five percent or more of any class of our capital stock or any member of the immediate family of, or entities affiliated with, any of the foregoing persons, had, or will have, a direct or indirect material interest.
Agreements with our stockholders
Investors’ Rights Agreement
In connection with the initial closing of our Series E Preferred Stock financing on November 30, 2018, we entered into a fifth amended and restated investors’ rights agreement, or investors’ rights agreement, with certain of our stockholders, including affiliates of Flagship Pioneering Funds, or Flagship. The investors’ rights agreement, among other things, granted investors party thereto certain registration rights (the “Registration Rights”), including demand registration rights, short-form registration rights, and piggyback registration rights, with respect to shares of our common stock, including shares of common stock issued or issuable upon conversion of our convertible preferred stock.
The Registration Rights will terminate on the earlier to occur of May 13, 2024, or, as to each holder, such earlier time at which such holder (i) can sell all shares held by it in compliance with SEC Rule 144(b)(1)(i) or (ii) holds 1% or less of our common stock and all registrable securities held by such holder can be sold in any three-month period without registration in compliance with SEC Rule 144.
Agreement with Flagship Pioneering
In December 2008, we entered into a services agreement with Flagship Ventures Management, Inc., nowmade known as Flagship Pioneering, Inc., an affiliate of the Flagship Pioneering Funds, under which Flagship Pioneering, Inc. provides us with advisory and administrative services on an as-needed basis. The agreement, which is invoiced monthly, may be terminated by either party upon 30 days’ prior written notice. Our transactions with Flagship Pioneering, Inc. were immaterial for the year ended December 31, 2022, for services provided under the services agreement.
Limitation of Liability and Indemnification of Officers and Directors
Our restated certificate of incorporation contains provisions that limit the liability of our directors for monetary damages to the fullest extent permitteddissolved corporation or that have not arisen but that, based on facts known to the dissolved corporation, are likely to arise or to become known to the dissolved corporation within five years after the date of dissolution or such longer period of time as the Delaware Court of Chancery may determine, not to exceed ten years after the date of dissolution.
Payments and Distributions
If a dissolved corporation has followed the Safe Harbor Procedures, then it will (1) pay the current claims made but not rejected, (2) post the security offered and not rejected for contractual claims that are contingent, conditional or unmatured, (3) post any security ordered by the Delaware General Corporation Law,Court of Chancery in response to the dissolved corporation’s petition to the court described above, and (4) pay or DGCL. Consequently, our directorsmake provision for all other claims that are mature, known and uncontested or that have been finally determined to be owing by the dissolved corporation. If there are insufficient assets to make these payments and provisions, then they will be satisfied ratably in accordance with legal priorities, to the extent that assets are available.
All remaining assets will be distributed to the dissolved corporation’s stockholders, but not personally liableearlier than 150 days after the date of the last notice of rejection given by the dissolved corporation to usa Current Claimant pursuant to the Safe Harbor Procedures.
Alternative Procedures under DGCL Section 281(b) (the “Alternative Procedures”)
If a dissolved corporation does not elect to follow the Safe Harbor Procedures, it must adopt a plan of distribution pursuant to which it will (1) pay or our stockholders for monetary damagesmake reasonable provision to pay all claims and obligations, including all contingent, conditional or unmatured contractual claims known to the corporation, (2) make such provision as will be reasonably likely to be sufficient to provide compensation for any breachclaim against the dissolved corporation that is the subject of fiduciary dutiesa pending action, suit or proceeding to which the dissolved corporation is a party and (3) make such provision as directors, except liability for:
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any breach ofwill be reasonably likely to be sufficient to provide compensation for claims that have not been made known to the director’s duty of loyalty to us or our stockholders;
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any act or omission not in good faithdissolved corporation or that involves intentional misconduct or a knowing violation of law;
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unlawful payments of dividends or unlawful stock repurchases, or redemptions as provided in Section 174 of the DGCL; or
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any transaction from which the director derived an improper personal benefit.
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Our amended and restated bylaws require us to indemnify our directors and officershave not arisen but that, based on facts known to the maximum extent not prohibited by the DGCL and allow usdissolved corporation, are likely to indemnify other employees and agents as set forth in the DGCL. Subjectarise or to certain limitations, our amended and restated bylaws also require us to advance expenses incurred by our directors and officers for the defense of any action for which indemnification is required or permitted.
We have entered, and intend to continue to enter, into separate indemnification agreements with our directors, officers and certain of our key employees, in additionbecome known to the indemnification provided for in our
 
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restated certificatedissolved corporation within ten years after the date of incorporationdissolution. If there are insufficient assets to make these payments and amendedprovisions, then they will be satisfied ratably in accordance with legal priorities, to the extent assets are available. All remaining assets will be distributed to the dissolved corporation’s stockholders.
The Plan of Dissolution adopted by the Board and restated bylaws. These agreements, among other things, require usproposed to indemnify our directors, officersthe stockholders for approval constitutes the plan of distribution for purposes of the Alternative Procedures. The Board currently anticipates dissolving Axcella in accordance with the Alternative Procedures, but retains the discretion to elect to follow the Safe Harbor Procedures.
Liabilities of Stockholders and key employeesDirectors
If a dissolved corporation follows either the Safe Harbor Procedures or the Alternative Procedures, then (1) a stockholder of the dissolved corporation’s will not be liable for certain expenses, including attorneys’ fees, judgments, penalties, finesany claim against the dissolved corporation in an amount in excess of the lesser of (a) the stockholder’s pro rata share of the claim and settlement amounts actually incurred by these individuals in(b) the amount distributed to the stockholder. If a dissolved corporation follows the Safe Harbor Procedures, then a stockholder of the dissolved corporation will not be liable for any claim against the dissolved corporation pursuant to any action, suit or proceeding arising outthat is not begun before the expiration of their servicethe Survival Period. In no event will the aggregate liability of a stockholder of a dissolved corporation for claims against the dissolved corporation exceed the amount distributed to usthe stockholder in dissolution. If a dissolved corporation fully complies with either the Safe Harbor Procedures or our subsidiaries or any other company or enterprisethe Alternative Procedures, then the dissolved corporation’s directors will not be personally liable to which these individuals provide services at our request. Subject to certain limitations, our indemnification agreements also require us to advance expenses incurred by our directors, officers and key employees for the defense of any action for which indemnification is required or permitted.dissolved corporation’s claimants.
Policies forApplication of These Procedures to Us
We currently plan to elect to follow the Alternative Procedures. However, our Plan of Dissolution specifically provides our Board with the discretion to decide to instead follow the Safe Harbor Procedures. For more information about our liquidation, winding up and distribution procedures, see the section entitled “Proposal 2 — Approval of Related Party Transactionsthe Dissolution Pursuant to the Plan of Dissolution — Our Plan of Dissolution” beginning on page 28 of this proxy statement.
Our Plan of Dissolution
The Dissolution will be conducted in accordance with the Plan of Dissolution, which is attached to this proxy statement as Exhibit B and incorporated by reference into this proxy statement. The following is a summary of our Plan of Dissolution and does not purport to be complete or contain all of the information that is important to you. To understand our Plan of Dissolution more fully, you are urged to read this proxy statement as well as the Plan of Dissolution. Our Plan of Dissolution may be modified, clarified or amended by action of our Board at any time and from time to time, as further described below.
Authorization and Effectiveness
Our boardPlan of directors reviews and approves transactions with directors, officers andDissolution will be deemed approved if the holders of five percent or more of our voting securities and their affiliates, each a related party. Prior to this offering, upon consideration of a potential related party transaction, the material facts as to the related party’s relationship or interest in the transaction are disclosed to our board of directors prior to their consideration of such transaction, and the transaction is not considered approved by our board of directors unless a majority of the directors who are not interested in the transaction approve the transaction. Further, when stockholders areoutstanding stock entitled to vote on a transaction with a related party, the material factsDissolution Proposal approve the Dissolution Proposal and will constitute our authorized plan of distribution pursuant to Section 280(b) of the related party’s relationship or interestDGCL and will evidence our authority to take all actions described in the transaction are disclosed toPlan of Dissolution. Following the stockholders, who must approveauthorization of the transaction in good faith.
In connection with our initial public offering, we adopted a written related party transactions policy that provides that such transactions must be approvedDissolution by our audit committee. This policy became effective on May 9, 2019. Pursuantstockholders, at such time as our Board determines to this policy,be appropriate, we will file the audit committee hasCertificate of Dissolution with the primary responsibility for reviewingSecretary of State and approving or disapproving “related party transactions,” whichensure that all relevant taxes (including Delaware franchise taxes) and fees are transactions between us and related persons in which the aggregate amount involved exceeds or may be expected to exceed $120,000 and in which a related person has or will have a direct or indirect material interest. For purposespaid. The Effective Time of this policy, a related personour Dissolution will be definedwhen the Certificate of Dissolution is filed with the office of the Secretary of State or such later date and time that is stated in the Certificate of Dissolution.
Survival Period
For three years after the Effective Time (or such longer period as the Delaware Court of Chancery may direct) (the “Survival Period”), we will continue as a director, executive officer, nomineebody corporate for director,the purpose of prosecuting and defending lawsuits (civil, criminal or greater than 5% beneficial owneradministrative) by or against us; settling and closing our business; disposing of and conveying our common stock,property; discharging our liabilities in each case sinceaccordance with the beginning of the most recently completed year,DGCL; and their immediate family members.
 
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distributing our remaining assets to our stockholders. We will no longer engage in the development of treatments for cancer and autoimmune diseases, except to the extent necessary to preserve the value of our assets and wind up our business affairs in accordance with our Plan of Dissolution. We anticipate that distributions, if any, to our stockholders will be made in cash, and may be made at any time, from time to time, in accordance with the DGCL.
General Liquidation, Winding Up and Distribution Process
We intend to elect to follow the Alternative Procedures described under the section entitled “Proposal 2 — Approval of the Dissolution Pursuant to the Plan of Dissolution — Delaware Law Applicable to Our Dissolution — Alternative Procedures under DGCL Section 281(b)” beginning on page 27 of this proxy statement but our Board retains the discretion to opt to dissolve the Company in accordance with the Safe Harbor Procedures.
Continuing Employees and Consultants
During the Survival Period, we may retain, hire, employ or contract with employees, consultants, agents, trustees, independent professional advisors (including legal counsel, accountants and financial advisors) and others, as the Board may determine, from time to time, to be necessary or advisable to effect the Dissolution as described in our Plan of Dissolution. The Board expects that during the Dissolution, the Company will continue to retain Verdolino & Lowey, P.C. to help with the winding-up activities and administering the Dissolution. The Board also expects that outside legal and financial advisors will continue to advise on and assist with the Dissolution.
After filing the Certificate of Dissolution, the Board expects it will maintain the size of the Board at three or fewer Board seats to save costs.
We may, in the absolute discretion of the Board, pay the Company’s directors, any employees it may hire, consultants, agents and other representatives, compensation or additional compensation above their regular compensation, including pursuant to severance and retention agreements, in money or other property, in recognition of the extraordinary efforts they will be required to undertake in connection with the implementation of the Plan of Dissolution; however, given the Company’s already streamlined operations, the Board does not expect to need to hire any employees or otherwise expand the team of advisors and consultants currently in place.
Sale of Our Remaining Assets
We have a broad portfolio of patent applications, know how, trade secrets, and other intellectual property that covers our platform technologies as well as our product discoveries. We believe the breadth and depth of our intellectual property is a strategic asset that has the potential to provide a significant competitive advantage over other cell therapy companies. As explained in this proxy statement, assuming approval of the Assignment Proposal, all or substantially all of our assets will be assigned to an Assignee who will liquidate such assets for the benefit of our creditors. See the section entitled “Proposal 1: Approval of Assignment” beginning on page 16 of this proxy statement. However, the Plan of Dissolution also contemplates the sale of all of our remaining assets, if any, if and at such time as the Board may approve, without further stockholder approval. The Plan of Dissolution does not specify the manner in which we may sell our assets. Such sales could take the form of sales of individual assets, sales of groups of assets organized by type of asset or otherwise, a single sale of all or substantially all of our assets, or some other form of sale. The assets may be sold to one or more purchasers in one or more transactions over a period of time. It is not anticipated that any further stockholder votes will be solicited with respect to the approval of the specific terms of any particular sales of assets approved by the Board. We do not anticipate amending or supplementing this proxy statement to reflect any such agreement or sale, unless required by applicable law, or selling any additional assets in the future. See the section entitled “Risk Factors — Risks Related to the Assignment and Dissolution” beginning on page 2 of this proxy statement.
Costs and Expenses
We, or the Assignee (assuming approval of the Assignment Proposal), will pay all costs and expenses that the Board may determine from time to time to be necessary or advisable to effect the Dissolution in

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accordance with the Plan of Dissolution and as may be necessary or advisable to continue our existence and operations. These costs and expenses may include, without limitation, brokerage, agency, professional, consulting and other fees and expenses of persons rendering services to the Company in connection with the matters described in the Plan of Dissolution and costs incurred to comply with contracts to which the Company is a party.
Indemnification
We will continue to indemnify our current and former officers, directors, employees and agents in accordance with, and to the extent required or permitted by, the DGCL, our Amended and Restated Certificate of Incorporation, our Amended and Restated Bylaws and any contractual arrangements, whether these arrangements existed before the Dissolution or were entered into after the Dissolution. During the Survival Period, acts and omissions of any indemnified or insured person in connection with the implementation of the Plan of Dissolution will be covered to the same extent that they were covered before the effective time of the Dissolution. The Board is authorized to obtain and maintain insurance as may be necessary to cover the Company’s indemnification obligations, including seeking an extension in time and coverage of our insurance policies currently in effect.
Stockholder Consent
Authorization of the Dissolution by the holders of a majority of the outstanding stock of the Company entitled to vote thereon shall, to the fullest extent permitted by law, constitute approval of all matters described in this proxy statement relating to the Dissolution, including our Plan of Dissolution.
Authorization of the Dissolution by the holders of a majority of the outstanding stock of the Company shall constitute the authorization of the sale, exchange or other disposition in liquidation of all of the remaining property and assets (if any) of the Company after the effective time of the Dissolution, whether the sale, exchange or other disposition occurs in one transaction or a series of transactions, and shall constitute ratification of any and all contracts for sale, exchange or other disposition that are conditioned on stockholder approval. However, as explained in this proxy statement, assuming approval of the Assignment Proposal, all or substantially all of the our assets will be assigned to an Assignee who will liquidate such assets for the benefit of our creditors. See the section entitled “Proposal 1: Approval of Assignment” beginning on page 16 of this proxy statement.
Subsidiaries
As part of the Dissolution, we may take actions with respect to our subsidiaries, based on the advice and counsel of our legal and other advisors and in accordance with the requirements of the laws and charter documents governing such subsidiary, to liquidate, dissolve or otherwise wind up such subsidiaries.
Legal Claims
We will defend any claims against us, our current and former officers or directors or our subsidiaries, whether a claim exists before the Effective Time or is brought during the Survival Period, based on advice and counsel of our legal and other advisors and in such manner, at such time and with such costs and expenses as our Board may approve from time to time. During the Survival Period, and subject to the Assignment process (assuming approval of the Assignment Proposal), we may continue to prosecute any claims that we had against others before the Effective Time and may institute any new claims against any person as the Board may determine necessary or advisable to protect the Company and its assets and rights or to implement the Plan of Dissolution. At the Board’s discretion, and subject to the Assignment process (assuming approval of the Assignment Proposal), we may defend, prosecute or settle any lawsuits, as applicable.
Effective Time; Stock of the Company
The Effective Time will be the time the Certificate of Dissolution is filed with the office of the Secretary of State or such later date and time that is stated in the Certificate of Dissolution.
From and after the Effective Time, and subject to applicable law, each holder of shares of our Common Stock shall cease to have any rights in respect of that stock, except the right to receive distributions, if any,

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pursuant to and in accordance with the Plan of Dissolution and the DGCL. After the Effective Time, our stock transfer records shall be closed, and we will not record or recognize any transfer of our Common Stock occurring after the Effective Time, except such transfers occurring by will, intestate succession or operation of law. We expect the Effective Time to be as soon as reasonably practicable after the Dissolution is approved by our stockholders. No stockholder shall have any appraisal rights in connection with our Dissolution and winding-up. It is anticipated that no further trading of our shares will occur after the Effective Time.
Unclaimed Distributions
If any distribution to a stockholder cannot be made by the Company, whether because the stockholder cannot be located, has not surrendered a certificate evidencing ownership of the Company’s Common Stock or provided other evidence of ownership as required in the Plan of Dissolution or by the Board or for any other reason, the distribution to which the stockholder is otherwise entitled will be transferred, at such time as the final liquidating distribution is made by us, or as soon as practicable after that distribution, to the official of such state or other jurisdiction authorized by applicable law to receive the proceeds of the distribution. The proceeds of such distribution will thereafter be held solely for the benefit of and for ultimate distribution to the stockholder as the sole equitable owner of the distribution and will be treated as abandoned property and escheat to the applicable state or other jurisdiction in accordance with applicable law. The proceeds of any such distribution will not revert to or become the property of us or any other stockholder. The foregoing applies only to distributions (if any) made by the Company. To the extent the Assignment is effected, the Assignee may employ other procedures for unclaimed distributions.
Liquidating Trust
While we do not currently propose transferring our assets to a liquidating trust, we may do so if deemed appropriate by our Board, based on advice of our legal, tax and accounting advisors. We may, for example, transfer assets to a liquidating trust if we are unable to complete the Dissolution within the initial three-years of the Survival Period. However, as explained in this proxy statement, assuming approval of the Assignment Proposal, all or substantially all of the our assets will be assigned to an Assignee who will liquidate such assets for the benefit of our creditors. See the section entitled “Proposal 1: Approval of Assignment” beginning on page 16 of this proxy statement.
Abandonment, Exceptions, Modifications, Clarifications and Amendments
Notwithstanding the authorization of the Dissolution by our stockholders as described in this proxy statement, our Board will have the right, as permitted by the DGCL, to abandon the Dissolution at any time before the Effective Time and terminate our Plan of Dissolution, without any action by our stockholders, if our Board determines that doing so is in the best interest of us and our stockholders. Without further action by our stockholders, our Board may, to the extent permitted by Delaware law, waive, modify or amend any part of our Plan of Dissolution, and may provide for exceptions to or clarifications of the terms of our Plan of Dissolution. After the Effective Time, revocation of the Dissolution would require stockholder approval under Delaware law.
Contingent Liabilities; Reserves
Under Delaware law, we are required, in connection with the Dissolution, to pay or make reasonable provision for payment of our liabilities and obligations. Subject to the Assignment process (assuming approval of the Assignment Proposal), we will pay all of our expenses (including operating and wind-up expenses to be incurred throughout the Dissolution and wind-up process) and other known, non-contingent liabilities. We have used and, subject to the Assignment process (assuming approval of the Assignment Proposal), anticipate continuing to use cash until the end of the Survival Period for a number of items, including, but not limited to, the following:
•
ongoing operating and reporting expenses;
​
•
expenses, including retention amounts, incurred in connection with extending our directors’ and officers’ insurance coverage;
​

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•
expenses incurred in connection with the Dissolution;
​
•
taxes imposed upon us and any of our assets; and
​
•
professional, legal, consulting and accounting fees.
​
Subject to the Assignment process (assuming approval of the Assignment Proposal), we will maintain a reserve, consisting of cash or other assets that we believe will be adequate for the satisfaction of all of our current unknown, contingent and/or conditional claims and liabilities. We may also take other steps to provide for the satisfaction of the reasonably estimated amount of such claims and liabilities, including acquiring insurance coverage with respect to certain claims and liabilities.
The estimated amount of the reserve (if any) would be based upon certain estimates and assumptions and a review of our estimated operating expenses and future estimated liabilities, including, without limitation, estimated operating costs, directors’ and officers’ insurance, legal, accounting and consulting fees and miscellaneous expenses, and accrued expenses reflected in our financial statements. There can be no assurance that the reserve will be sufficient. If any of our estimates regarding the expenses to be incurred in the liquidation process, including expenses of personnel required and other operating expenses (including legal, accounting and consulting fees) necessary to dissolve and liquidate the Company and the expenses to satisfy outstanding obligations, liabilities and claims during the liquidation process, are inaccurate, we may be required to increase the amount of the reserve. After the liabilities, expenses and obligations for which the reserve is established have been satisfied in full (or determined not to be owed), we will distribute to our stockholders any remaining portion of the reserve.
In the event we fail to create an adequate reserve for the payment of our expenses and liabilities and amounts have been distributed to the stockholders under the Plan of Dissolution, our creditors may be able to pursue claims against our stockholders directly to the extent that they have claims co-extensive with such stockholders’ receipt of liquidating distributions. See the section entitled “Risk Factors — Risk Factors Related to the Dissolution — Our stockholders may be liable to third parties for part or all of the amount received from us in our liquidating distributions if reserves are inadequate” beginning on page 2 of this proxy statement.
If it was determined by a court that we failed to make adequate provision for our expenses and liabilities or if the amount required to be paid in respect of such liabilities exceeded the amount available from the reserve and any assets of the liquidating trust or trusts, a creditor of ours could seek an injunction against the making of liquidating distributions under the Plan of Dissolution on the grounds that the amounts to be distributed were needed to provide for the payment of our expenses and liabilities. Any such action could delay or substantially diminish the cash distributions to be made to stockholders under the Plan of Dissolution.
Reporting Requirements
Whether or not the Dissolution is approved, we will have an obligation to continue to comply with the applicable reporting requirements of the Exchange Act until we have exited from such reporting requirements. We plan to initiate steps to exit from certain reporting requirements under the Exchange Act. However, such process may be protracted and we may be required to continue to file Current Reports on Form 8-K to disclose material events, including those related to the Dissolution. Accordingly, we will continue to incur expenses that will reduce the amount available for distribution, including expenses of complying with public company reporting requirements and paying its service providers, among others.
Interests of Certain Persons in the Dissolution
After the Effective Time, we expect that our Board (or some subset thereof) and our officer will continue in his positions for the purpose of winding up our business and affairs. If the stockholders approve the Assignment Proposal and Dissolution Proposal, our sole officer and director, Mr. Jalbert, will be compensated in the amount of $50,000 for his first year of service, and thereafter $25,000 per year for a period of three years total.
See “Security Ownership of Certain Beneficial Owners and Management” for information regarding the number of shares of Common Stock owned by our directors and executive officers.

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Our Amended and Restated Certificate of Incorporation and Amended and Restated Bylaws and the DGCL
During the Survival Period, we will continue to be governed by our Amended and Restated Certificate of Incorporation and Amended and Restated Bylaws, insofar as their terms apply and insofar as necessary or appropriate to implement our Plan of Dissolution. Our Board will continue to have the authority to amend our Amended and Restated Bylaws as it may deem necessary or advisable. To any extent that the provisions of our Plan of Dissolution conflict with any provision of the DGCL, the provisions of the DGCL shall prevail.
Authority of the Board
Our Board, without further action by our stockholders, is authorized to take all actions as they deem necessary or advisable to implement our Plan of Dissolution. All determinations and decisions to be made by our Board will be at the absolute and sole discretion of our Board.
Votes Required
The affirmative vote of a majority of the shares of our Common Stock outstanding on the Record Date and entitled to vote on the Dissolution Proposal is required to approve the Dissolution Proposal. Abstentions, broker non-votes, and failures to vote will have the same effect as a vote “AGAINST” the Dissolution Proposal.
Board Recommendation
The Board recommends that the stockholders vote “FOR” the Dissolution Proposal to approve the Dissolution in accordance with the terms and conditions of the Plan of Dissolution.

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PRINCIPAL STOCKHOLDERSPROPOSAL 3: APPROVAL OF ADJOURNMENT OF SPECIAL MEETING
TO SOLICIT ADDITIONAL PROXIES
General
If at the Special Meeting the number of shares voting in favor of the approval of the Assignment Proposal and/or the Dissolution Proposal is insufficient to approve such proposal under Delaware law, Axcella intends to move to adjourn the Special Meeting in order to enable the Board to solicit additional proxies in respect of the approval of the Assignment Proposal and/or Dissolution Proposal. In that event, Axcella may ask Axcella’s stockholders to vote only upon the Adjournment Proposal during such portion of the Special Meeting.
Axcella is asking that you approve the Adjournment Proposal, which will authorize the adjournment of the Special Meeting, from time to time, to a later date or dates, for the purpose of soliciting additional proxies. If the stockholders approve the Adjournment Proposal, Axcella could adjourn the Special Meeting and use the additional time to solicit additional proxies, including the solicitation of proxies from stockholders that have previously voted.
Votes Required
If a quorum is present at the Special Meeting, the affirmative vote of the holders a majority of the votes properly cast is required for the approval of the Adjournment Proposal. Broker non-votes (if any) and abstentions will not be counted as votes cast on the matter and will have no effect on the outcome of the Adjournment Proposal.
Recommendation of the Board
The Board believes that if the number of shares voting in favor of the Assignment Proposal and/or Dissolution Proposal is insufficient to approve such proposal, it is in the best interests of Axcella to enable Axcella to continue to solicit proxies until a sufficient number of votes are obtained to approve the Assignment Proposal and/or Dissolution Proposal.
The Board unanimously recommends that you vote “FOR” the Adjournment Proposal.

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SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT
The following table sets forth information, to the extent known by us or ascertainable from public filings, with respect to the beneficial ownership of our common stockCommon Stock as of JulyOctober 31, 2023, by:
•
each of our directors;
​
•
each of our named executive officers;
​
•
all of our directors and executive officers as a group; and
​
•
each person, or group of affiliated persons, who is known by us to beneficially own 5% or more of our common stock.Common Stock.
​
The column entitled “Shares Beneficially Owned” is based on a total of 73,692,7452,947,661 shares of our common stockCommon Stock outstanding as of JulyOctober 31, 2023.
Beneficial ownership is determined in accordance with the rules and regulations of the SEC and includes voting or investment power with respect to our common stock.Common Stock. Shares of our common stockCommon Stock subject to options that are currently exercisable or exercisable within 60 days of JulyOctober 31, 2023, are considered outstanding and beneficially owned by the person holding the options for the purpose of calculating the percentage ownership of that person but not for the purpose of calculating the percentage ownership of any other person. Except as otherwise noted, the persons and entities in this table have sole voting and investing power with respect to all of the shares of our common stockCommon Stock beneficially owned by them, subject to community property laws, where applicable. Except as otherwise indicated in the table below, addresses of named beneficial owners are in care of Axcella Therapeutics, P.O. Box 1270, Littleton, Massachusetts 04160.
Name of Beneficial Owner​​
Shares
Beneficially
Owned
​​
Percentage
of Shares
Beneficially
Owned
​
5% or Greater Stockholders:​​​​​​​​​​​​​
Flagship Pioneering(1)
​​​​29,251,545​​​​​39.7%​​
FMR LLC(2)
​​​​11,033,193​​​​​15.0%​​
Nestlé S.A.(3)
​​​​11,105,438​​​​​15.1%​​
HarbourVest Partners, LLC(4)
​​​​6,207,929​​​​​8.4%​​
Directors, Named Executive Officers and Other Executive Officers​​​​​​​​​​​​​
William R. Hinshaw, Jr.(5)
​​​​1,595,869​​​​​2.2%​​
Paul Fehlner, J.D., Ph.D.(6)
​​​​273,534​​​​​*​​
Margaret James Koziel, M.D.(7)
​​​​24,283​​​​​*​​
Robert Crane(8)
​​​​45,364​​​​​*​​
Martin Hendrix, Ph.D.(9)
​​​​16,667​​​​​*​​
Catherine Angell Sohn, Pharm.D.(10)
​​​​80,097​​​​​*​​
William D. “Chip” Baird(11)
​​​​113,031​​​​​*​​
Gary P. Pisano, Ph.D.(12)
​​​​153,798​​​​​*​​
Cristina M. Rondinone, Ph.D.(13)
​​​​108,144​​​​​*​​
Paul Sekhri(14)
​​​​16,667​​​​​*​​
Michael Rosenblatt(15)
​​​​29,898​​​​​*​​
Robert Rosiello(16)
​​​​10,000​​​​​*​​
Torben Straight Nissen(17)
​​​​10,000​​​​​*​​
All executive officers and directors as a group (13 persons)​​​​2,477,352​​​​​3.4%​​
Name of Beneficial Owner​​
Shares
Beneficially
Owned
​​
Percentage
of Shares
Beneficially
Owned
​
5% or Greater Stockholders:​​​​​​​​​​​​​
Flagship Pioneering(1)
​​​​1,170,061​​​​​39.7%​​
Nestlé S.A.(2)
​​​​444,217​​​​​15.1%​​
HarbourVest Partners, LLC(3)
​​​​248,317​​​​​8.4%​​
Directors, Named Executive Officers and Other Executive Officers​​​​​​​​​​​​​
William R. Hinshaw, Jr.(4)
​​​​66,099​​​​​2.2%​​
Paul Fehlner, J.D., Ph.D.(5)
​​​​11,492​​​​​*​​
Martin Hendrix, Ph.D.(6)
​​​​802​​​​​*​​
Catherine Angell Sohn, Pharm.D.(7)
​​​​3,203​​​​​*​​
William D. “Chip” Baird(8)
​​​​4,521​​​​​*​​
Gary P. Pisano, Ph.D.(9)
​​​​6,151​​​​​*​​
Cristina M. Rondinone, Ph.D.(10)
​​​​4,325​​​​​*​​
Paul Sekhri(11)
​​​​802​​​​​*​​
Michael Rosenblatt(12)
​​​​1,332​​​​​*​​
Robert Rosiello(13)
​​​​536​​​​​*​​
Torben Straight Nissen(14)
​​​​536​​​​​*​​
Craig Jalbert​​​​—​​​​​*​​
All executive officers and directors as a group (12 persons)​​​​99,799​​​​​2.2%​​
​
*
Represents beneficial ownership of less than one percent. Share amounts in footnotes 1 through 4 below do not provide for the Reverse Stock Split.
​

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(1)
Based solely on a Schedule 13D/A filed with the SEC on October 17, 2022, consists of (i) 2,035,830 shares of common stockCommon Stock held by Flagship VentureLabs IV, LLC (“VentureLabs IV”) (ii) 14,101,638 shares of common stockCommon Stock held by Flagship Ventures Fund IV, L.P. (“Flagship Ventures Fund IV General
​

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Partner LLC”) (iii) 2,004,657 shareshares of common stockCommon Stock held by Flagship Ventures Fund IV-Rx, L.P (Flagship Ventures Fund IV General Partner LLC) (iv) 1,761,029 shares of common stockCommon Stock held by Flagship Ventures Fund 2007, L.P. (Flagship Ventures 2007 General Partner LLC) (v) 6,299,611 shares of common stockCommon Stock held by Flagship Ventures Opportunities Fund I, L.P. (“Flagship Ventures Opportunities Fund I General Partner LLC”) (vi) 3,048,780 shares of common stockCommon Stock held by FPA, L.P. Noubar B. Afeyan, Ph.D. is the sole manager of Flagship Fund IV GP, Flagship Fund 2007 GP and Flagship Opportunities GP, and he may be deemed to beneficially own the shares directly held by the Flagship Fund IV Funds, Flagship Fund 2007, and Flagship Opportunities. Effective May 11, 2020, Mr. Kania retired from Flagship Pioneering, Inc. and as manager of Flagship Fund IV GP and Flagship Fund 2007 GP. The address of each of the entities and individuals listed above is 55 Cambridge Parkway, Suite 800E, Cambridge, MA 02142.
​
(2)
Based solely on a Schedule 13G/A filed with the SEC on February 9, 2023, FMR LLC has sole voting power with respect to 11,033,193 shares and sole dispositive power over 11,033,193 shares and Abigail P. Johnson has sole dispositive power over 11,033,193 shares. Abigail P. Johnson is a Director, the Chairman and the Chief Executive Officer of FMR LLC. Members of the Johnson family, including Abigail P. Johnson, are the predominant owners, directly or through trusts, of Series B voting common shares of FMR LLC, representing 49% of the voting power of FMR LLC. The Johnson family group and all other Series B shareholders have entered into a shareholders’ voting agreement under which all Series B voting common shares will be voted in accordance with the majority vote of Series B voting common shares. Accordingly, through their ownership of voting common shares and the execution of the shareholders’ voting agreement, members of the Johnson family may be deemed, under the Investment Company Act of 1940, to form a controlling group with respect to FMR LLC. Neither FMR LLC nor Abigail P. Johnson has the sole power to vote or direct the voting of the shares owned directly by the various investment companies registered under the Investment Company Act (“Fidelity Funds”) advised by Fidelity Management & Research Company (“FMR Co. LLC”), a wholly owned subsidiary of FMR LLC, which power resides with the Fidelity Funds’ Boards of Trustees. FMR Co. LLC carries out the voting of the shares under written guidelines established by the Fidelity Funds’ Boards of Trustees. The address of FMR LLC is 245 Summer Street, Boston, Massachusetts 02210.
​
(3)
Based solely on a Schedule 13G/A filed with the SEC on February 2, 2023, (i) Société des Produits Nestlé S.A. (“SPN”) and (ii) Nestlé S.A. (“Nestlé”), the ultimate parent of SPN, each has shared voting power and shared dispositive power with respect to 11,105,438 shares. Nestlé disclaims beneficial ownership of such shares of Common Stock except to the extent of its pecuniary interest therein. The principal executive office of SPN and Nestlé is Avenue Nestlé 55, CH-1800, Vevey Switzerland.
​
(4)(3)
Based solely on a Schedule 13G/A filed with the SEC on February 14, 2023, consists of 6,207,929 shares common stockCommon Stock owned directly by SMRS-TOPE LLC. HarbourVest Partners, LLC (“HarbourVest”) is the General Partner of HarbourVest Partners L.P., which is the Manager of HVST-TOPE LLC, which is the Managing Member of SMRS-TOPE LLC. Each of HarbourVest, HarbourVest Partners L.P. and HVST-TOPE LLC may be deemed to have a beneficial interest in the shares held by SMRS-TOPE LLC. SMRS-TOPE LLC has the sole power to vote or to direct the vote of; and, to dispose or to direct the disposition of 6,207,929 shares of common stock.Common Stock. HarbourVest, HarbourVest Partners L.P. and HVST-TOPE LLC may be deemed to have shared power to vote or to direct the vote of; and, to dispose or to direct the disposition of 6,207,929 shares of common stock.Common Stock. Voting and investment power over the securities owned directly by SMRS-TOPE LLC is exercised by the Investment Committee of HarbourVest. Each of HarbourVest, HarbourVest Partners L.P. and HVST-TOPE LLC and the members of the HarbourVest Investment Committee disclaim beneficial ownership of the shares held directly by SMRS-TOPE LLC. The principal business office of each HarbourVest Partners, LLC, HarbourVest Partners L.P., HVST-TOPE LLC and SMRS-TOPE LLC is One Financial Center, Boston, MA 02111.
​
(5)(4)
Consists of 83,9283,357 shares of common stockCommon Stock and 1,511,94162,742 shares of common stockCommon Stock underlying options exercisable within 60 days of JulyOctober 31, 2023.
​

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(6)(5)
Consists of 58,0812,323 shares of common stockCommon Stock and 215,4539,169 shares of common stockCommon Stock underlying options exercisable within 60 days of JulyOctober 31, 2023.
​
(7)(6)
Consists entirely of shares of common stock.Common Stock.
​
(7)
Consists of 283 shares of Common Stock and 2,920 shares of Common Stock underlying options exercisable within 60 days of October 31, 2023.
​
(8)
Consists entirely of shares of common stock.
​
(9)
Consists entirely of shares of common stockCommon Stock underlying options exercisable within 60 days of JulyOctober 31, 2023.
​
(9)
Consists of 3,671 shares of Common Stock and 2,480 shares of Common Stock underlying options exercisable within 60 days of October 31, 2023.
​
(10)
Consists entirely of 7,097 shares of common stock and 73,000 shares of common stockCommon Stock underlying options exercisable within 60 days of JulyOctober 31, 2023.
​
(11)
Consists entirely of shares of common stockCommon Stock underlying options exercisable within 60 days of JulyOctober 31, 2023.
​
(12)
Consists entirely of 91,798 shares of common stock and 62,000 shares of common stockCommon Stock underlying options exercisable within 60 days of JulyOctober 31, 2023.
​
(13)
Consists entirely of shares of common stockCommon Stock underlying options exercisable within 60 days of JulyOctober 31, 2023.
​
(14)
Consists entirely of shares of common stockCommon Stock underlying options exercisable within 60 days of July 31, 2023.
​
(15)
Consists entirely of shares of common stock underlying options exercisable within 60 days of July 31, 2023.
​
(16)
Consists entirely of shares of common stock underlying options exercisable within 60 days of July 31, 2023.
​
(17)
Consists entirely of shares of common stock underlying options exercisable within 60 days of JulyOctober 31, 2023.
​
 
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DELINQUENT SECTION 16(a) REPORTS
Section 16(a) of the Exchange Act requires our directors, executive officers, and persons holding more than 10% of our common stock to report their initial ownership of the common stock and other equity securities and any changes in that ownership in reports that must be filed with the SEC. The SEC has designated specific deadlines for these reports, and we must identify in our Annual Report on Form 10-K those persons who did not file these reports when due.
Based solely on a review of reports furnished to us, or written representations from reporting persons, we believe all directors, executive officers, and 10% owners timely filed all reports regarding transactions in our securities required to be filed for 2022 by Section 16(a) under the Exchange Act, except that Mr. Epstein filed two late Forms 4 for the transactions that occurred on February 18, 2022 that was filed on February 23, 2022 and on May 19, 2022 that was filed on June 3, 2022, each due to an administrative error, and Mr. Sekhri filed one late Form 4 for the transaction that occurred on May 19, 2022 that was filed on May 25, 2022 due to an administrative error.

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REPORT OF THE AUDIT COMMITTEEWHERE YOU CAN FIND ADDITIONAL INFORMATION
We file annual and quarterly reports and other reports and information with the SEC. The audit committee is appointed by the board of directors to assist the board of directors in fulfilling its oversight responsibilities with respect to (1) the integrity of Axcella’s financialSEC maintains an Internet website that contains reports, proxy and information statements, and financial reporting process and systems of internal controlsother information regarding finance, accounting, and complianceissuers, including us, that file electronically with legal and regulatory requirements, (2) the qualifications, independence, and performance of Axcella’s independent registeredSEC. The public accounting firm, (3)can obtain any documents that we file electronically with the performance of Axcella’s internal audit function, if any, and (4) other matters as set forth in the charterSEC at http://www.sec.gov. We will provide without charge to you, upon written or oral request, a copy of the audit committee approved by the board of directors.
Management is responsible for the preparation of Axcella’s financial statementsreports and the financial reporting process, including its system of internal control over financial reporting and its disclosure controls and procedures. The independent registered public accounting firm is responsible for performing an audit of Axcella’s financial statements in accordance with the standards of the Public Company Accounting Oversight Board (PCAOB) and issuing a report thereon. The audit committee’s responsibility is to monitor and oversee these processes.
In connection with these responsibilities, the audit committee reviewed and discussed with management and the independent registered public accounting firm the audited consolidated financial statements of Axcella for the fiscal year ended December 31, 2022. The audit committee also discussed with the independent registered public accounting firm the matters required to be discussed by the PCAOB’s Auditing Standard No. 1301, Communication with Audit Committees. In addition, the audit committee received written communications from the independent registered public accounting firm confirming their independence as required by the applicable requirements of the PCAOB and has discussed with the independent registered public accounting firm their independence.
Based on the reviews and discussions referred to above, the audit committee recommended to the board of directors that the audited consolidated financial statements of Axcella be included in Axcella’s Annual Report on Form 10-K for the fiscal year ended December 31, 2022, that wasother information filed with the SEC. The
Any requests for copies of information, contained in this report shall not be deemed to be (1) “soliciting material,” ​(2) “filed”reports or other filings with the SEC (3) subjectshould be directed to Regulations 14A or 14CAxcella Health Inc., PO Box 1270, Littleton, MA 01460, Attention: Corporate Secretary. In order to receive timely delivery of the Exchange Act, or (4) subject to the liabilities of Section 18documents in advance of the Exchange Act. This report shall not be deemed incorporated by reference into any of our other filings under the Exchange Act or the Securities Act, except to the extent that we specifically incorporate it by reference into such filing.Special Meeting, you must make your request for information no later than November 27, 2023.
THE AUDIT COMMITTEE OF THE BOARD
OF DIRECTORS OF AXCELLA HEALTH INC.
William D. “Chip” Baird, Chairperson
Gary P. Pisano, Ph.D.
Martin Hendrix, Ph.D.
August 18, 2023

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GENERAL MATTERS
Householding of Proxy MaterialsHOUSEHOLDING
Some banks, brokers, and other nominee record holders may be participating in the practice of “householding”“house holding” proxy statements and annual reports. This means that only one copy of our documents, including the annual report to stockholders and proxy statement, may have been sent to multiple stockholders in yoursharing the same household. We will promptly deliver a separate copy of either documentthe proxy statement to you upon written or oral request to Axcella Therapeutics, Axcella Therapeutics, P.O.Health Inc., PO Box 1270, Littleton, Massachusetts 04160,MA 01460, Attention: Corporate Secretary, telephone: (857) 320-2200.Secretary. If you want to receive separate copies of the proxy statement or annual reportreports to stockholders in the future, or if you are receiving multiple copies and would like to receive only one copy per household, you should contact your bank, broker, or other nominee record holder, or you may contact us at the above address and phone number.address.
Stockholder Proposals
A stockholder who would like to have a proposal considered for inclusion in our 2024 proxy statement must submit the proposal in accordance with the procedures outlined in Rule 14a-8 of the Exchange Act so that it is received by us no later than May 18, 2024. However, if the date of the 2023 Annual Meeting of Stockholders is changed by more than 30 days from the date of the previous year’s meeting, then the deadline is a reasonable time before we begin to print and send our proxy statement for the 2022 Annual Meeting of Stockholders. SEC rules set standards for eligibility and specify the types of stockholder proposals that may be excluded from a proxy statement. Stockholder proposals should be addressed to Axcella Therapeutics, Axcella Therapeutics, P.O. Box 1270, Littleton, Massachusetts 04160. A proposal submitted outside the requirements of Rule 14a-8 under the Exchange Act will be considered untimely if received after July 9, 2024.
If a stockholder wishes to propose a nomination of persons for election to our board of directors or present a proposal at an annual meeting but does not wish to have the proposal considered for inclusion in our proxy statement and proxy card, our bylaws establish an advance notice procedure for such nominations and proposals. Stockholders at an annual meeting may only consider proposals or nominations specified in the notice of meeting or brought before the meeting by or at the direction of the board of directors or by a stockholder of record on the record date for the meeting, who is entitled to vote at the meeting and who has delivered timely notice in proper form to our corporate secretary of the stockholder’s intention to bring such business before the meeting.
The required notice must be in writing and received by our corporate secretary at our principal executive offices not less than 90 days nor more than 120 days prior to the first anniversary of the preceding year’s annual meeting. However, in the event that the date of the annual meeting is advanced by more than 30 days, or delayed by more than 60 days, from the first anniversary of the preceding year’s annual meeting, a stockholder’s notice must be so received no earlier than the 120th day prior to such annual meeting and not later than the close of business on the later of (A) the 90th day prior to such annual meeting and (B) the tenth day following the day on which notice of the date of such annual meeting was mailed or public disclosure of the date of such annual meeting was made, whichever first occurs. For stockholder proposals to be brought before the 2024 Annual Meeting of Stockholders, the required notice must be received by our corporate secretary at our principal executive offices no earlier than May 15, 2024, and no later than June 14, 2024. To comply with the universal proxy rules, stockholders who intend to solicit proxies in support of director nominees other than the Company’s nominees must provide notice by the same deadline noted herein to submit a notice of nomination at an annual meeting of stockholders. Such notice must comply with the additional requirements of Rule 14a-19(b). Stockholder proposals and the required notice should be addressed to Axcella Therapeutics, 840 Memorial Drive, Cambridge, Massachusetts 02139, Attention: Corporate Secretary.
Other MattersOTHER MATTERS
Our board of directorsBoard does not know of any other matters to be brought before the virtual AnnualSpecial Meeting. If any other matters not mentioned in this proxy statement are properly brought before the meeting,Special Meeting, the individuals named in the enclosed proxy intend to use their discretionary voting authority under the proxy to vote the proxy in accordance with their best judgment on those matters.
 
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EXHIBIT A​
AXCELLA HEALTH INC.
STOCKHOLDER RESOLUTIONS
WHEREAS, the Board of Directors (the “Board”) of Axcella Health Inc., a Delaware corporation (“Axcella”), has determined that effecting the transfer of all or substantially all of Axcella’s assets through an assignment for the benefit of creditors (the “Assignment”) is advisable and in the best interests of Axcella and Axcella’s stockholders;
WHEREAS, the Board has authorized and approved the Assignment and has recommended that Axcella’s stockholders authorize and approve the Assignment;
WHEREAS, Section 271 of the Delaware General Corporation Law provides that the affirmative vote of a majority of the voting power of the outstanding shares of capital stock of Axcella is required to approve the Assignment; and
WHEREAS, such holders of a majority of the voting power of the outstanding shares of capital stock of Axcella desire to authorize and approve the Assignment pursuant to the resolutions set forth below.
NOW THEREFORE, BE IT RESOLVED, that the Assignment is hereby approved and authorized in all respects; and be it further
RESOLVED, that the appropriate officers of Axcella are hereby authorized to take or cause to be taken all such further actions as the Board deems necessary or advisable to consummate and perform on behalf of Axcella the transactions contemplated by the Assignment, including the execution and delivery of such agreements, certificates, documents and instruments as shall be necessary or desirable to effect the Assignment and to carry out the purposes and intent of the foregoing resolutions, and the paying of all necessary fees and expenses in connection with the Assignment.
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EXHIBIT B​
PLAN OF LIQUIDATION AND DISSOLUTION
OF
AXCELLA HEALTH INC.
This Plan of Liquidation and Dissolution (the “Plan”) is intended to accomplish the complete liquidation and dissolution of AXCELLA HEALTH INC., a Delaware corporation (such corporation or a successor entity, the “Company”), in accordance with Section 281(b) of the General Corporation Law of the State of Delaware (the “DGCL”).
Approval of Plan.   The Board of Directors of the Company (the “Board”) has adopted this Plan and presented the Plan to the Company’s stockholders to take action on the Plan. If the Plan is adopted by the requisite vote of the Company’s stockholders, the Plan shall constitute the adopted Plan of the Company.
Certificate of Dissolution.   Subject to Section 14 hereof, after the stockholders of the Company approve the dissolution of the Company, the Company shall file with the Secretary of State of the State of Delaware a certificate of dissolution (the “Certificate of Dissolution”) in accordance with the DGCL at such time as determined by the Board in its sole discretion (the time of such filing, or such later time as stated therein, the “Effective Time”).
Cessation of Business Activities.   After the Effective Time, the Company shall not engage in any business activities except to the extent necessary to preserve the value of its assets, wind up its business affairs and distribute its assets in accordance with this Plan.
Continuing Employees and Consultants.   For the purpose of effecting the dissolution of the Company, the Company may hire or retain such employees, consultants and advisors as the Company deems necessary or desirable to supervise or facilitate the dissolution and winding up of the Company.
Dissolution Process.
From and after the Effective Time, the Company (or any successor entity of the Company) shall complete the following corporate actions:
(i)   The Company (a) shall pay or make reasonable provision to pay all claims and obligations, including all contingent, conditional or unmatured contractual claims known to the Company, (b) shall make such provision as will be reasonably likely to be sufficient to provide compensation for any claim against the Company which is the subject of a pending action, suit or proceeding to which the Company is a party, and (c) shall make such provision as will be reasonably likely to be sufficient to provide compensation for claims that have not been made known to the Company or that have not arisen but that, based on facts known to the Company, are likely to arise or to become known to the Company within 10 years after the date of dissolution. All such claims shall be paid in full and any such provision for payment made shall be made in full if there are sufficient assets. If there are insufficient assets, such claims and obligations shall be paid or provided for according to their priority and, among claims of equal priority, ratably to the extent of assets legally available therefor.
(ii)   After the payments are made pursuant to clause (i) above, if there are any assets remaining, the Company shall distribute to its stockholders, in accordance with the Company’s certificate of incorporation, as amended and/or restated through the Effective Time, all remaining assets, including all available cash, including the cash proceeds of any sale, exchange or disposition, except such cash, property or assets as are required for paying or making reasonable provision for the claims and obligations of the Company. Such distribution may occur all at once or in a series of distributions and shall be in cash or assets, in such amounts, and at such time or times, as the Board in its absolute discretion, may determine. If and to the extent deemed necessary, appropriate or desirable by the Board, in its absolute discretion, the Company may establish and set aside a reasonable amount of cash and/or property to satisfy claims against the Company, including, without limitation, tax obligations, all expenses related to the sale of the Company’s property and assets, all expenses related to the collection and defense of the Company’s property and assets, and the liquidation and dissolution provided for in this Plan.

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Notwithstanding anything contained herein to the contrary, the Company, at the discretion of the Board, may opt to dissolve and wind-up the Company in accordance with the procedures set forth in Sections 280 and 281(a) of the DGCL.
Cancellation of Stock.   The distributions to the Company’s stockholders pursuant to Section 5 hereof shall be deemed to be in complete cancellation of all of the outstanding shares of capital stock of the Company as of the date that the continuation of the Company’s legal existence terminates in accordance with Section 278 of the DGCL. From and after the Effective Time, and subject to applicable law, the holder of all outstanding shares of capital stock of the Company shall cease to have any rights in respect thereof, except the right to receive distributions, if any, pursuant to and in accordance with Section 5 hereof. As a condition to receipt of any distribution to the Company’s stockholders, the Company may require the Company’s stockholders to (i) surrender their certificates evidencing its shares of capital stock to the Company, or (ii) furnish the Company with evidence satisfactory to the Company of the loss, theft or destruction of such certificates, together with such surety bond or other security or indemnity as may be required by and satisfactory to the Company. The Company will close its stock transfer books and discontinue recording transfers of shares of capital stock of the Company at the Effective Time, and thereafter any certificate representing shares of capital stock of the Company will not be assignable or transferable on the books of the Company except by will, intestate succession, operation of law or upon the dissolution of the stockholders or their successors.
Conduct of the Company Following Approval of the Plan.   Under Delaware law, dissolution is effective upon the filing of a certificate of dissolution with the Secretary of State of the State of Delaware or upon such future effective date as may be set forth in the certificate of dissolution. Section 278 of the DGCL provides that a dissolved corporation shall be continued for the term of 3 years from such dissolution or for such longer period as the Court of Chancery shall in its discretion direct, bodies corporate for the purpose of prosecuting and defending suits, whether civil, criminal or administrative, by or against it, and of enabling it gradually to settle and close its business, to dispose of and convey its property, to discharge its liabilities and to distribute to its stockholders any remaining assets, but not for the purpose of continuing the business for which the corporation was organized. With respect to any action, suit or proceeding begun by or against the corporation either prior to or within 3 years after the date of its dissolution, the action shall not abate by reason of the dissolution of the corporation; the corporation shall, solely for the purpose of such action, suit or proceeding, be continued as a body corporate beyond the 3-year period and until any judgments, orders or decrees therein shall be fully executed, without the necessity for any special direction to that effect by the Court of Chancery. The powers of the officers and directors of the corporation shall continue during this time period in order to allow them to take the necessary steps to wind up the affairs of the corporation.
Absence of Appraisal Rights.   Under Delaware law, the Company’s stockholders are not entitled to appraisal rights for shares of capital stock of the Company in connection with the transactions contemplated by the Plan.
Abandoned Property.   If any distribution to the stockholders of the Company cannot be made, whether because such stockholder cannot be located, has not surrendered its certificate evidencing the capital stock as required hereunder or for any other reason, the distribution to which such stockholder is entitled shall be transferred, at such time as the final liquidating distribution is made by the Company, to the official of such state or other jurisdiction authorized by applicable law to receive the proceeds of such distribution. The proceeds of such distribution shall thereafter be held solely for the benefit of and for ultimate distribution to such stockholders as the sole equitable owner thereof and shall be treated as abandoned property and escheat to the applicable state or other jurisdiction in accordance with applicable law. In no event shall the proceeds of any such distribution revert to or become the property of the Company.
Stockholder Consent to Sale of Assets.   Adoption of this Plan by the stockholders of the Company shall constitute the approval of such stockholders of the sale, exchange or other disposition in liquidation of all of the property and assets of the Company, whether such sale, exchange or other disposition occurs in one transaction or a series of transactions, and shall constitute ratification of all contracts for sale, exchange or other disposition that are conditioned on adoption of this Plan.

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Exhibit AExpenses of Dissolution.​
CERTIFICATE OF AMENDMENT   In connection with and for the purposes of implementing and assuring completion of this Plan, the Company may pay any brokerage, agency, professional and other fees and expenses of persons rendering services to the Company in connection with the collection, sale, exchange or other disposition of the Company’s property and assets and the implementation of this Plan.
TOCompensation.   In connection with and for the purpose of implementing and assuring the completion of this Plan, the Company may pay the Company’s officers, directors, employees, agents and representatives, or any of them, compensation or additional compensation above their regular compensation, including pursuant to severance and retention agreements, in money or other property, in recognition of the extraordinary efforts they, or any of them, will be required to undertake, or actually undertake, in connection with the implementation of this Plan. Adoption of this Plan by the requisite vote of the outstanding capital stock of the Company shall constitute the approval of the Company’s stockholders of the payment of any such compensation.
RESTATED CERTIFICATE OF INCORPORATIONIndemnification.
OF
AXCELLA HEALTH INC.
Axcella Health Inc., a corporation organized   The Company shall continue to indemnify its officers, directors, employees, agents and existing under and by virtue of the General Corporation Law of the State of Delaware (the “Corporation”), does hereby certify as follows:
FIRST:
That the Board of Directors of the Corporation duly adopted resolutions recommending and declaring advisable that the Restatedtrustee in accordance with its Certificate of Incorporation, Bylaws, and contractual arrangements as therein or elsewhere provided, the Company’s existing directors’ and officers’ liability insurance policy and applicable law, and such indemnification shall apply to acts or omissions of such persons in connection with the implementation of this Plan and the winding up of the Corporationaffairs of the Company. The Company is authorized to obtain and maintain insurance as may be amended and that such amendment be submittednecessary to cover the Company’s indemnification obligations.
Modification or Abandonment of the Plan.   Notwithstanding adoption of this Plan by the stockholders of the Corporation for their consideration, as follows:
​
RESOLVED, thatCompany, the first sentence of Article FOURTH ofBoard may modify, amend or abandon this Plan and the Restated Certificate of Incorporation be, andtransactions contemplated hereby is, amended and restated in its entiretywithout further action by such stockholders to read as follows:the extent permitted by the DGCL.
“That, effective at 5:00 p.m., Eastern time, on the date this Certificate of Amendment to the Restated Certificate of IncorporationAuthorization.   The Board is filed with the Secretary of State of the State of Delaware (the “Effective Time”), a one-for-[      ]1 reverse stock split of the Common Stock (as defined below) shall become effective, pursuant to which each [      ]1 shares of Common Stock issued and held of record by each stockholder of the Corporation (including treasury shares) immediately prior to the Effective Time shall be reclassified and combined into one validly issued, fully paid and nonassessable share of Common Stock automatically andhereby authorized, without anyfurther action by the holder thereof upon the Effective Time and shall represent one share of Common Stock from and after the Effective Time (such reclassification and combination of shares, the “Reverse Stock Split”). No fractional shares of Common Stock shall be issued as a resultstockholders of the Reverse Stock SplitCompany, to do and in lieu thereof, (a) with respect to holders of oneperform or more certificates, if any, which formerly represented shares of Common Stock that were issued and outstanding immediately prior tocause the Effective Time, upon surrender after the Effective Time of such certificate or certificates, any holder who would otherwise be entitled to a fractional share of Common Stock as a resultofficers of the Reverse Stock Split, followingCompany to do and perform, any and all acts, and to make, execute, deliver or adopt any and all agreements, resolutions, conveyances, certificates and other documents of every kind that are deemed necessary, appropriate or desirable, to implement this Plan and the Effective Time, shall be entitledtransactions contemplated hereby, including, without limiting the foregoing, all filings or acts required by any state or federal law or regulation to receive a cash payment (the “Fractional Share Payment”) equal towind up the fraction of which such holder would otherwise be entitled multiplied by the closing price per share of Common Stock on the dateaffairs of the Effective Time as reported by The Nasdaq Global Select Market (as adjusted to give effect to the Reverse Stock Split); provided that, whether or not fractional shares would be issuable as a result of the Reverse Stock Split shall be determined on the basis of (i) the total number of shares of Common Stock that were issued and outstanding immediately prior to the Effective Time formerly represented by certificates that the holder is at the time surrendering and (ii) the aggregate number of shares of Common Stock after the Effective Time into which the shares of Common Stock formerly represented by such certificates shall have been reclassified; and (b) with respect to holders of shares of Common Stock in book-entry form in the records of the Corporation’s transfer agent that were issued andCompany.
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1
Shall be a whole number between and including two and twenty-five, which number is referred to as the “Reverse Split Factor” ​(it being understood that any Reverse Split Factor within such range shall, together with the remaining provisions of this Certificate of Amendment not appearing in brackets, constitute a separate amendment being approved and adopted by the board of directors and stockholders in accordance with Section 242 of the Delaware General Corporation Law).
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outstanding immediately prior to the Effective Time, any holder who would otherwise be entitled to a fractional share of Common Stock as a resultANNEX A​
Sections 275 through 283 of the Reverse Stock Split (after aggregating all fractional shares), followingDGCL
§ 275. Dissolution generally; procedure.
(a)   If it should be deemed advisable in the Effective Time,judgment of the board of directors of any corporation that it should be dissolved, the board, after the adoption of a resolution to that effect by a majority of the whole board at any meeting called for that purpose, shall be entitled to receivecause notice of the Fractional Share Payment automaticallyadoption of the resolution and without any action by the holder.
The total number of shares of all classes of stock which the Corporation shall have authority to issue is 160,000,000 shares, consisting of (a) 150,000,000 shares of Common Stock, $0.001 par value per share (“Common Stock”), and (b) 10,000,000 shares of Preferred Stock, $0.001 par value per share (“Preferred Stock”).”
SECOND:
That, at a meeting of stockholders to take action upon the resolution to be given to each stockholder entitled to vote thereon as of the Corporation,record date for determining the aforesaid amendmentstockholders entitled to notice of the meeting.
(b)   At the meeting a vote shall be taken upon the proposed dissolution. If a majority of the outstanding stock of the corporation entitled to vote thereon shall vote for the proposed dissolution, a certification of dissolution shall be filed with the Secretary of State pursuant to subsection (d) of this section.
(c)   Dissolution of a corporation may also be authorized without action of the directors if all the stockholders entitled to vote thereon shall consent in writing and a certificate of dissolution shall be filed with the Secretary of State pursuant to subsection (d) of this section.
(d)   If dissolution is authorized in accordance with this section, a certificate of dissolution shall be executed, acknowledged and filed, and shall become effective, in accordance with § 103 of this title. Such certificate of dissolution shall set forth:
(1)   The name of the corporation;
(2)   The date dissolution was duly adoptedauthorized;
(3)   That the dissolution has been authorized by the board of directors and stockholders of the corporation, in accordance with subsections (a) and (b) of this section, or that the dissolution has been authorized by all of the stockholders of the Corporation.
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THIRD:
That the aforesaid amendment was duly adoptedcorporation entitled to vote on a dissolution, in accordance with the applicable provisionssubsection (c) of Section 242this section;
(4)   The names and addresses of the General Corporation Lawdirectors and officers of the Statecorporation; and
(5)   The date of Delaware.filing of the corporation’s original certificate of incorporation with the Secretary of State.
​(e)   The resolution authorizing a proposed dissolution may provide that notwithstanding authorization or consent to the proposed dissolution by the stockholders, or the members of a nonstock corporation pursuant to § 276 of this title, the board of directors or governing body may abandon such proposed dissolution without further action by the stockholders or members.
IN WITNESS WHEREOF,(f)   If a corporation has included in its certificate of incorporation a provision limiting the Corporation has causedduration of its existence to a specified date in accordance with § 102(b)(5) of this Certificatetitle, a certificate of Amendmentdissolution shall be executed, acknowledged and filed in accordance with § 103 of this title within 90 days before such specified date and shall become effective on such specified date. Such certificate of dissolution shall set forth:
(1)   The name of the corporation;
(2)   The date specified in the corporation’s certificate of incorporation limiting the duration of its existence;
(3)   The names and addresses of the directors and officers of the corporation; and
(4)   The date of filing of the corporation’s original certificate of incorporation with the Secretary of State.
The failure to be signed bytimely file a certificate of dissolution pursuant to this subsection with respect to any corporation shall not affect the expiration of such corporation’s existence on the date specified in its oncertificate of incorporation pursuant to § 102(b)(5) of this day of        2023.
AXCELLA HEALTH INC.
By:
​
​
Name:
Title:title and shall not eliminate the requirement to
 
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file a certificate of dissolution as contemplated by this subsection. If a certificate of good standing is issued by the Secretary of State after the date specified in a corporation’s certificate of incorporation pursuant to § 102(b)(5) of this title, such certificate of good standing shall be of no force or effect.
(g)   A corporation shall be dissolved upon the earlier of:
(1)   The date specified in such corporation’s certificate of incorporation pursuant to § 102(b)(5) of this title; or
(2)   The effectiveness in accordance with § 103 of this title of a certificate of dissolution filed in accordance with this section.
§ 276. Dissolution of nonstock corporation; procedure.
(a)   Whenever it shall be desired to dissolve any nonstock corporation, the governing body shall perform all the acts necessary for dissolution which are required by § 275 of this title to be performed by the board of directors of a corporation having capital stock. If any members of a nonstock corporation are entitled to vote for the election of members of its governing body or are entitled to vote for dissolution under the certificate of incorporation or the bylaws of such corporation, such members shall perform all the acts necessary for dissolution which are contemplated by § 275 of this title to be performed by the stockholders of a corporation having capital stock, including dissolution without action of the members of the governing body if all the members of the corporation entitled to vote thereon shall consent in writing and a certificate of dissolution shall be filed with the Secretary of State pursuant to § 275(d) of this title. If there is no member entitled to vote thereon, the dissolution of the corporation shall be authorized at a meeting of the governing body, upon the adoption of a resolution to dissolve by the vote of a majority of members of its governing body then in office. In all other respects, the method and proceedings for the dissolution of a nonstock corporation shall conform as nearly as may be to the proceedings prescribed by § 275 of this title for the dissolution of corporations having capital stock.
(b)   If a nonstock corporation has not commenced the business for which the corporation was organized, a majority of the governing body or, if none, a majority of the incorporators may surrender all of the corporation rights and franchises by filing in the office of the Secretary of State a certificate, executed and acknowledged by a majority of the incorporators or governing body, conforming as nearly as may be to the certificate prescribed by § 274 of this title.
(c)   If a nonstock corporation has included in its certificate of incorporation a provision limiting the duration of its existence to a specified date in accordance with § 102(b)(5) of this title, a certificate of dissolution shall be executed, acknowledged and filed in accordance with § 103 of this title within 90 days before such specified date and shall become effective on such specified date. Such certificate of dissolution shall include the information required by § 275(f) of this title. The failure to timely file a certificate of dissolution pursuant to this subsection with respect to any nonstock corporation shall not affect the expiration of such corporation’s existence on the date specified in its certificate of incorporation pursuant to § 102(b)(5) of this title and shall not eliminate the requirement to file a certificate of dissolution as contemplated by this subsection. If a certificate of good standing is issued by the Secretary of State after the date specified in a nonstock corporation’s certificate of incorporation pursuant to § 102(b)(5) of this title, such certificate of good standing shall be of no force or effect.
§ 277. Payment of franchise taxes before dissolution, merger, transfer or conversion.
No corporation shall be dissolved, merged, transferred (without continuing its existence as a corporation of this State) or converted under this chapter until:
(1)   All franchise taxes due to or assessable by the State including all franchise taxes due or which would be due or assessable for the entire calendar month during which such dissolution, merger, transfer or conversion becomes effective have been paid by the corporation; and
(2)   All annual franchise tax reports including a final annual franchise tax report for the year in which such dissolution, merger, transfer or conversion becomes effective have been filed by the corporation;

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notwithstanding the foregoing, if the Secretary of State certifies that an instrument to effect a dissolution, merger, transfer or conversion has been filed in the Secretary of State’s office, such corporation shall be dissolved, merged, transferred or converted at the effective time of such instrument.
§ 278. Continuation of corporation after dissolution for purposes of suit and winding up affairs.
All corporations, whether they expire by their own limitation or are otherwise dissolved, shall nevertheless be continued, for the term of 3 years from such expiration or dissolution or for such longer period as the Court of Chancery shall in its discretion direct, bodies corporate for the purpose of prosecuting and defending suits, whether civil, criminal or administrative, by or against them, and of enabling them gradually to settle and close their business, to dispose of and convey their property, to discharge their liabilities and to distribute to their stockholders any remaining assets, but not for the purpose of continuing the business for which the corporation was organized. With respect to any action, suit or proceeding begun by or against the corporation either prior to or within 3 years after the date of its expiration or dissolution, the action shall not abate by reason of the dissolution of the corporation; the corporation shall, solely for the purpose of such action, suit or proceeding, be continued as a body corporate beyond the 3-year period and until any judgments, orders or decrees therein shall be fully executed, without the necessity for any special direction to that effect by the Court of Chancery.
Sections 279 through 282 of this title shall apply to any corporation that has expired by its own limitation, and when so applied, all references in those sections to a dissolved corporation or dissolution shall include a corporation that has expired by its own limitation and to such expiration, respectively.
§ 279. Trustees or receivers for dissolved corporations; appointment; powers; duties.
When any corporation organized under this chapter shall be dissolved in any manner whatever, the Court of Chancery, on application of any creditor, stockholder or director of the corporation, or any other person who shows good cause therefor, at any time, may either appoint 1 or more of the directors of the corporation to be trustees, or appoint 1 or more persons to be receivers, of and for the corporation, to take charge of the corporation’s property, and to collect the debts and property due and belonging to the corporation, with power to prosecute and defend, in the name of the corporation, or otherwise, all such suits as may be necessary or proper for the purposes aforesaid, and to appoint an agent or agents under them, and to do all other acts which might be done by the corporation, if in being, that may be necessary for the final settlement of the unfinished business of the corporation. The powers of the trustees or receivers may be continued as long as the Court of Chancery shall think necessary for the purposes aforesaid.
§ 280. Notice to claimants; filing of claims.
(a)
(1)   After a corporation has been dissolved in accordance with the procedures set forth in this chapter, the corporation or any successor entity may give notice of the dissolution, requiring all persons having a claim against the corporation other than a claim against the corporation in a pending action, suit or proceeding to which the corporation is a party to present their claims against the corporation in accordance with such notice. Such notice shall state:
a.   That all such claims must be presented in writing and must contain sufficient information reasonably to inform the corporation or successor entity of the identity of the claimant and the substance of the claim;
b.   The mailing address to which such a claim must be sent;
c.   The date by which such a claim must be received by the corporation or successor entity, which date shall be no earlier than 60 days from the date thereof; and
d.   That such claim will be barred if not received by the date referred to in paragraph (a)(1)c. of this section; and

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e.   That the corporation or a successor entity may make distributions to other claimants and the corporation’s stockholders or persons interested as having been such without further notice to the claimant; and
f.   The aggregate amount, on an annual basis, of all distributions made by the corporation to its stockholders for each of the 3 years prior to the date the corporation dissolved.
Such notice shall also be published at least once a week for 2 consecutive weeks in a newspaper of general circulation in the county in which the office of the corporation’s last registered agent in this State is located and in the corporation’s principal place of business and, in the case of a corporation having $10,000,000 or more in total assets at the time of its dissolution, at least once in all editions of a daily newspaper with a national circulation. On or before the date of the first publication of such notice, the corporation or successor entity shall mail a copy of such notice by certified or registered mail, return receipt requested, to each known claimant of the corporation including persons with claims asserted against the corporation in a pending action, suit or proceeding to which the corporation is a party.
(2)   Any claim against the corporation required to be presented pursuant to this subsection is barred if a claimant who was given actual notice under this subsection does not present the claim to the dissolved corporation or successor entity by the date referred to in paragraph (a)(1)c. of this section.
(3)   A corporation or successor entity may reject, in whole or in part, any claim made by a claimant pursuant to this subsection by mailing notice of such rejection by certified or registered mail, return receipt requested, to the claimant within 90 days after receipt of such claim and, in all events, at least 150 days before the expiration of the period described in § 278 of this title; provided however, that in the case of a claim filed pursuant to § 295 of this title against a corporation or successor entity for which a receiver or trustee has been appointed by the Court of Chancery the time period shall be as provided in § 296 of this title, and the 30-day appeal period provided for in § 296 of this title shall be applicable. A notice sent by a corporation or successor entity pursuant to this subsection shall state that any claim rejected therein will be barred if an action, suit or proceeding with respect to the claim is not commenced within 120 days of the date thereof, and shall be accompanied by a copy of §§ 278-283 of this title and, in the case of a notice sent by a court-appointed receiver or trustee and as to which a claim has been filed pursuant to § 295 of this title, copies of §§ 295 and 296 of this title.
(4)   A claim against a corporation is barred if a claimant whose claim is rejected pursuant to paragraph (a)(3) of this section does not commence an action, suit or proceeding with respect to the claim no later than 120 days after the mailing of the rejection notice.
(b)
(1)   A corporation or successor entity electing to follow the procedures described in subsection (a) of this section shall also give notice of the dissolution of the corporation to persons with contractual claims contingent upon the occurrence or nonoccurrence of future events or otherwise conditional or unmatured, and request that such persons present such claims in accordance with the terms of such notice. Provided however, that as used in this section and in § 281 of this title, the term “contractual claims” shall not include any implied warranty as to any product manufactured, sold, distributed or handled by the dissolved corporation. Such notice shall be in substantially the form, and sent and published in the same manner, as described in paragraph (a)(1) of this section.
(2)   The corporation or successor entity shall offer any claimant on a contract whose claim is contingent, conditional or unmatured such security as the corporation or successor entity determines is sufficient to provide compensation to the claimant if the claim matures. The corporation or successor entity shall mail such offer to the claimant by certified or registered mail, return receipt requested, within 90 days of receipt of such claim and, in all events, at least 150 days before the expiration of the period described in § 278 of this title. If the claimant offered such security does not deliver in writing to the corporation or successor entity a notice rejecting the offer within 120 days after receipt of such offer for security, the claimant shall be deemed to have accepted such security as the sole source from which to satisfy the claim against the corporation.

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(c)
(1)   A corporation or successor entity which has given notice in accordance with subsection (a) of this section shall petition the Court of Chancery to determine the amount and form of security that will be reasonably likely to be sufficient to provide compensation for any claim against the corporation which is the subject of a pending action, suit or proceeding to which the corporation is a party other than a claim barred pursuant to subsection (a) of this section.
(2)   A corporation or successor entity which has given notice in accordance with subsections (a) and (b) of this section shall petition the Court of Chancery to determine the amount and form of security that will be sufficient to provide compensation to any claimant who has rejected the offer for security made pursuant to paragraph (b)(2) of this section.
(3)   A corporation or successor entity which has given notice in accordance with subsection (a) of this section shall petition the Court of Chancery to determine the amount and form of security which will be reasonably likely to be sufficient to provide compensation for claims that have not been made known to the corporation or that have not arisen but that, based on facts known to the corporation or successor entity, are likely to arise or to become known to the corporation or successor entity within 5 years after the date of dissolution or such longer period of time as the Court of Chancery may determine not to exceed 10 years after the date of dissolution. The Court of Chancery may appoint a guardian ad litem in respect of any such proceeding brought under this subsection. The reasonable fees and expenses of such guardian, including all reasonable expert witness fees, shall be paid by the petitioner in such proceeding.
(d)   The giving of any notice or making of any offer pursuant to this section shall not revive any claim then barred or constitute acknowledgment by the corporation or successor entity that any person to whom such notice is sent is a proper claimant and shall not operate as a waiver of any defense or counterclaim in respect of any claim asserted by any person to whom such notice is sent.
(e)   As used in this section, the term “successor entity” shall include any trust, receivership or other legal entity governed by the laws of this State to which the remaining assets and liabilities of a dissolved corporation are transferred and which exists solely for the purposes of prosecuting and defending suits, by or against the dissolved corporation, enabling the dissolved corporation to settle and close the business of the dissolved corporation, to dispose of and convey the property of the dissolved corporation, to discharge the liabilities of the dissolved corporation and to distribute to the dissolved corporation’s stockholders any remaining assets, but not for the purpose of continuing the business for which the dissolved corporation was organized.
(f)   The time periods and notice requirements of this section shall, in the case of a corporation or successor entity for which a receiver or trustee has been appointed by the Court of Chancery, be subject to variation by, or in the manner provided in, the Rules of the Court of Chancery.
(g)   In the case of a nonstock corporation, any notice referred to in the last sentence of paragraph (a)(3) of this section shall include a copy of § 114 of this title. In the case of a nonprofit nonstock corporation, provisions of this section regarding distributions to members shall not apply to the extent that those provisions conflict with any other applicable law or with that corporation’s certificate of incorporation or bylaws.
§ 281. Payment and distribution to claimants and stockholders.
(a)   A dissolved corporation or successor entity which has followed the procedures described in § 280 of this title:
(1)   Shall pay the claims made and not rejected in accordance with § 280(a) of this title,
(2)   Shall post the security offered and not rejected pursuant to § 280(b)(2) of this title,
(3)   Shall post any security ordered by the Court of Chancery in any proceeding under § 280(c) of this title, and

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(4)   Shall pay or make provision for all other claims that are mature, known and uncontested or that have been finally determined to be owing by the corporation or such successor entity.
Such claims or obligations shall be paid in full and any such provision for payment shall be made in full if there are sufficient assets. If there are insufficient assets, such claims and obligations shall be paid or provided for according to their priority, and, among claims of equal priority, ratably to the extent of assets legally available therefor. Any remaining assets shall be distributed to the stockholders of the dissolved corporation; provided, however, that such distribution shall not be made before the expiration of 150 days from the date of the last notice of rejections given pursuant to § 280(a)(3) of this title. In the absence of actual fraud, the judgment of the directors of the dissolved corporation or the governing persons of such successor entity as to the provision made for the payment of all obligations under paragraph (a)(4) of this section shall be conclusive.
(b)   A dissolved corporation or successor entity which has not followed the procedures described in § 280 of this title shall, prior to the expiration of the period described in § 278 of this title, adopt a plan of distribution pursuant to which the dissolved corporation or successor entity (i) shall pay or make reasonable provision to pay all claims and obligations, including all contingent, conditional or unmatured contractual claims known to the corporation or such successor entity, (ii) shall make such provision as will be reasonably likely to be sufficient to provide compensation for any claim against the corporation which is the subject of a pending action, suit or proceeding to which the corporation is a party and (iii) shall make such provision as will be reasonably likely to be sufficient to provide compensation for claims that have not been made known to the corporation or that have not arisen but that, based on facts known to the corporation or successor entity, are likely to arise or to become known to the corporation or successor entity within 10 years after the date of dissolution. The plan of distribution shall provide that such claims shall be paid in full and any such provision for payment made shall be made in full if there are sufficient assets. If there are insufficient assets, such plan shall provide that such claims and obligations shall be paid or provided for according to their priority and, among claims of equal priority, ratably to the extent of assets legally available therefor. Any remaining assets shall be distributed to the stockholders of the dissolved corporation.
(c)   Directors of a dissolved corporation or governing persons of a successor entity which has complied with subsection (a) or (b) of this section shall not be personally liable to the claimants of the dissolved corporation.
(d)   As used in this section, the term “successor entity” has the meaning set forth in § 280(e) of this title.
(e)   The term “priority,” as used in this section, does not refer either to the order of payments set forth in paragraph (a)(1)-(4) of this section or to the relative times at which any claims mature or are reduced to judgment.
(f)   In the case of a nonprofit nonstock corporation, provisions of this section regarding distributions to members shall not apply to the extent that those provisions conflict with any other applicable law or with that corporation’s certificate of incorporation or bylaws.
§ 282. Liability of stockholders of dissolved corporations.
(a)   A stockholder of a dissolved corporation the assets of which were distributed pursuant to § 281(a) or (b) of this title shall not be liable for any claim against the corporation in an amount in excess of such stockholder’s pro rata share of the claim or the amount so distributed to such stockholder, whichever is less.
(b)   A stockholder of a dissolved corporation the assets of which were distributed pursuant to § 281(a) of this title shall not be liable for any claim against the corporation on which an action, suit or proceeding is not begun prior to the expiration of the period described in § 278 of this title.
(c)   The aggregate liability of any stockholder of a dissolved corporation for claims against the dissolved corporation shall not exceed the amount distributed to such stockholder in dissolution.

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§ 283. Jurisdiction.
The Court of Chancery shall have jurisdiction of any application prescribed in this subchapter and of all questions arising in the proceedings thereon, and may make such orders and decrees and issue injunctions therein as justice and equity shall require.

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SCAN TOVIEW MATERIALS & VOTE AXCELLA HEALTH INC.P.O. BOX 1270LITTLETON, MASSACHUSETTS 01460SCAN TOVIEW MATERIALS & VOTEVOTE01460 VOTE BY INTERNETBefore The Meeting - Go to www.proxyvote.com or scan the QR Barcode aboveUse the Internet to transmit your voting instructions and for electronic delivery of informationupinformation up until 11:59 p.m. Eastern Time on September 10,[•], 2023. Have your proxy card in hand whenyouwhen you access the web site and follow the instructions to obtain your records and to create anelectronican electronic voting instruction form.During The Meeting - Go to www.virtualshareholdermeeting.com/AXLA2023YouAXLA2023SMYou may attend the meeting via the Internet and vote during the meeting. Have the informationthatinformation that is printed in the box marked by the arrow available and follow the instructions.VOTE BY PHONE - 1-800-690-6903Use any touch-tone telephone to transmit your voting instructions up until11:until 11:59 p.m. Eastern Time on September 10,[•], 2023. Have your proxy card in hand when youcallyou call and then follow the instructions.VOTE BY MAILMark, sign and date your proxy card and return it in the postage-paid envelope wehavewe have provided or return it to Vote Processing, c/o Broadridge, 51 Mercedes Way,Edgewood, NY 11717. Proxy cards submitted by mail must be received no later than11:than 11:59 p.m. Eastern Time on September 10,[•], 2023 to be voted at the annual meeting.TOspecial meeting. TO VOTE, MARK BLOCKS BELOW IN BLUE OR BLACK INK AS FOLLOWS:V21517-P98096KEEP V25746-TBD KEEP THIS PORTION FOR YOUR RECORDSTHISRECORDS THIS PROXY CARD IS VALID ONLY WHEN SIGNED AND DATED.DETACHDATED. DETACH AND RETURN THIS PORTION ONLYAXCELLA HEALTH INC.ForAllWithholdAllFor AllExceptThe Board of Directors recommends you vote FOR thefollowing:To withhold authority to vote for any individualnominee(s), mark "For All Except" and write thenumber(s) of the nominee(s) on the line below.1. To elect three Class I directors to our board of directors,to serve until the 2026 annual meeting of stockholdersand until his or her successor has been duly elected andqualified, or until his or her earlier death, resignation orremoval.Nominees:01) Torben Straight Nissen, Ph.D.02) Michael Rosenblatt, M.D.03) William D. “Chip” BairdTheINC.The Board of Directors recommends you vote FOR the following proposals:For Against Abstain2.Abstain1. To ratifyapprove the appointmenttransfer of Deloitte & Touche LLP as our independent registered public accounting firmall or substantially all of Axcella Health Inc.'s (the "Company") assets through an assignment for the fiscal year ending December 31, 2023.3.benefit of creditors.2. To approve amendmentsthe liquidation and dissolution of the Company and the Plan of Liquidation and Dissolution (the "Plan of Dissolution") which, if approved,will authorize the Company's Board of Directors to our restated certificateliquidate and dissolve the Company in accordance with the Plan of incorporationDissolution.3. To approve the grant of discretionary authority to effect a reverse stock split of our Common Stock at a ratio ranging from anywhole number between 1-for-2 and 1-for-25, as determined by ourthe Company's board of directors in its discretion, subject to adjourn the board of directors' authority toabandon such amendments.4. To approve an adjournment of the Annual Meeting,special meeting, from time to time, to a laterdate or dates, even if necessary,a quorum is present, to solicit additionalin person or by proxy voting in favor of proposal 1 and proposal 2.NOTE: In their discretion, the proxies if there are not sufficient votes atauthorized to vote on such other business as may properly come before the time of the AnnualMeeting to approve Proposal 3.Pleasemeeting or any adjournment, postponement,or continuation thereof.Please sign exactly as your name(s) appear(s) hereon. When signing as attorney, executor,administrator, or other fiduciary, please give full title as such. Joint owners should each signpersonally. All holders must sign. If a corporation or partnership, please sign in full corporateor partnership name by authorized officer.Signature [PLEASE SIGN WITHIN BOX] DateSignatureDate Signature (Joint Owners) Date
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ImportantPRELIMINARY PROXY CARD SUBJECT TO COMPLETION, DATED NOVEMBER 6, 2023Important Notice Regarding the Availability of Proxy Materials for the AnnualSpecial Meeting:The Notice and Proxy Statement and Annual Report areis available at www.proxyvote.com.V21518-P98096AXCELLA[•]V25747-TBDAXCELLA HEALTH INC.ANNUALINC. SPECIAL MEETING OF STOCKHOLDERSSeptember 11,STOCKHOLDERS[•], 2023 10:00[•] AM Eastern TimeTHIS PROXY IS SOLICITED ON BEHALF OF THE BOARD OF DIRECTORSThe stockholder(s) hereby appoint(s) William R. Hinshaw, Jr. and Paul Fehlner, or either of them,Craig Jalbert, as proxies, eachproxy, with the power to appoint his substitute, and hereby authorize(s) themhim to represent and to vote, as designated on the reverse side of this ballot, all of the shares of Common Stock of AXCELLA HEALTH INC. that the stockholder(s) is/are entitled to vote at the AnnualSpecial Meeting of Stockholders to be held on September 11,[•], 2023 10:00[•] AM Eastern Time virtually atwww.virtualshareholdermeeting.com/AXLA2023at www.virtualshareholdermeeting.com/AXLA2023SM and any adjournment or postponement thereof. The stockholder(s) acknowledge(s) receipt from the Company prior to the execution of the proxy of the Proxy Statement, and Annual Report,revokes any proxy heretofore given with respect to the Special Meeting.This proxy, when properly executed, will be voted in the manner directed herein. If no such direction is made, this proxy will be voted in accordance with the Board of Directors' recommendations.AXCELLA HEALTH INC.SPECIAL MEETING OF STOCKHOLDERS[•], 2023 [•] AM Eastern TimeTHIS PROXY IS SOLICITED ON BEHALF OF THE BOARD OF DIRECTORSThe stockholder(s) hereby appoint(s) Craig Jalbert, as proxy, with the power to appoint his substitute, and hereby authorize(s) him to represent and to vote, as designated on the reverse side of this ballot, all of the shares of Common Stock ofAXCELLA HEALTH INC. that the stockholder(s) is/are entitled to vote at the Special Meeting of Stockholders to be held on[•], 2023 [•] AM Eastern Time virtually at www.virtualshareholdermeeting.com/AXLA2023SM and any adjournment or postponement thereof. The stockholder(s) acknowledge(s) receipt from the Company prior to the execution of the proxy of the Proxy Statement, and revokes any proxy heretofore given with respect to the AnnualSpecial Meeting.This proxy, when properly executed, will be voted in the manner directed herein. If no such direction is made, this proxy will be voted in accordance with the Board of Directors' recommendations.Continued and to be signed on reverse side