Document and Entity Information
Document and Entity Information - shares | 6 Months Ended | |
Jun. 30, 2018 | Jul. 31, 2018 | |
Document Information [Line Items] | ||
Document Type | 10-Q | |
Amendment Flag | false | |
Document Period End Date | Jun. 30, 2018 | |
Document Fiscal Year Focus | 2,018 | |
Document Fiscal Period Focus | Q2 | |
Trading Symbol | TBIO | |
Entity Registrant Name | Translate Bio, Inc. | |
Entity Central Index Key | 1,693,415 | |
Current Fiscal Year End Date | --12-31 | |
Entity Filer Category | Non-accelerated Filer | |
Entity Common Stock, Shares Outstanding | 45,141,690 |
Condensed Consolidated Balance
Condensed Consolidated Balance Sheets - USD ($) $ in Thousands | Jun. 30, 2018 | Dec. 31, 2017 |
Current assets: | ||
Cash and cash equivalents | $ 16,495 | $ 48,058 |
Short-term investments | 1,000 | 9,997 |
Prepaid expenses and other current assets | 4,826 | 3,014 |
Restricted cash | 1,966 | 1,966 |
Total current assets | 24,287 | 63,035 |
Property and equipment, net | 9,868 | 6,778 |
Goodwill | 21,359 | 21,359 |
In-process research and development | 106,842 | 106,842 |
Deferred offering costs | 3,976 | 511 |
Other assets | 22 | |
Total assets | 166,332 | 198,547 |
Current liabilities: | ||
Accounts payable | 6,219 | 4,594 |
Accrued expenses | 5,758 | 5,888 |
Current portion of contingent consideration | 2,387 | 1,296 |
Deferred rent | 307 | |
Total current liabilities | 14,364 | 12,085 |
Long-term portion of contingent consideration | 91,382 | 79,713 |
Deferred tax liabilities | 3,437 | 6,039 |
Deferred rent, net of current portion | 2,023 | 1,329 |
Total liabilities | 111,206 | 99,166 |
Commitments and contingencies (Notes 3 and 12) | ||
Redeemable convertible preferred stock (Series A, B and C), $0.001 par value; 145,833,064 shares authorized as of June 30, 2018 and December 31, 2017; 142,288,292 shares issued and outstanding as of June 30, 2018 and December 31, 2017; aggregate liquidation preference of $192,374 as of June 30, 2018 and December 31, 2017 | 193,540 | 192,896 |
Stockholders' equity (deficit): | ||
Common stock, $0.001 par value; 236,092,611 shares authorized as of June 30, 2018 and December 31, 2017; 9,631,939 shares and 9,582,791 shares issued and outstanding as of June 30, 2018 and December 31, 2017, respectively | 10 | 10 |
Additional paid-in capital | 59,096 | 55,204 |
Accumulated deficit | (197,520) | (148,808) |
Accumulated other comprehensive income | 79 | |
Total stockholders' equity (deficit) | (138,414) | (93,515) |
Total liabilities, redeemable convertible preferred stock and stockholders' equity (deficit) | $ 166,332 | $ 198,547 |
Condensed Consolidated Balance3
Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands | Jun. 30, 2018 | Dec. 31, 2017 |
Redeemable convertible preferred stock, shares authorized | 145,833,064 | 145,833,064 |
Redeemable convertible preferred stock, shares Issued | 142,288,292 | 142,288,292 |
Redeemable convertible preferred stock, shares outstanding | 142,288,292 | 142,288,292 |
Redeemable convertible preferred stock, liquidation preference | $ 192,374 | $ 192,374 |
Common stock, par value | $ 0.001 | $ 0.001 |
Common stock, shares authorized | 236,092,611 | 236,092,611 |
Common stock, shares issued | 9,631,939 | 9,582,791 |
Common stock, shares outstanding | 9,631,939 | 9,582,791 |
Series A Series B And Series C Redeemable Convertible Preferred Stock [Member] | ||
Redeemable convertible preferred stock, par value | $ 0.001 | $ 0.001 |
Redeemable convertible preferred stock, shares authorized | 145,833,064 | 145,833,064 |
Redeemable convertible preferred stock, shares Issued | 142,288,292 | 142,288,292 |
Redeemable convertible preferred stock, shares outstanding | 142,288,292 | 142,288,292 |
Redeemable convertible preferred stock, liquidation preference | $ 192,374 | $ 192,374 |
Condensed Consolidated Statemen
Condensed Consolidated Statements of Operations - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended | ||
Jun. 30, 2018 | Jun. 30, 2017 | Jun. 30, 2018 | Jun. 30, 2017 | |
Operating expenses: | ||||
Research and development | $ 15,219 | $ 13,506 | $ 27,921 | $ 23,127 |
General and administrative | 5,991 | 3,125 | 10,769 | 6,099 |
Change in fair value of contingent consideration | 7,852 | 2,324 | 12,760 | 4,599 |
Total operating expenses | 29,062 | 18,955 | 51,450 | 33,825 |
Loss from operations | (29,062) | (18,955) | (51,450) | (33,825) |
Other income (expense): | ||||
Interest income | 91 | 79 | 181 | 158 |
Other income (expense), net | (32) | 73 | (45) | 60 |
Total other income (expense), net | 59 | 152 | 136 | 218 |
Loss before benefit from income taxes | (29,003) | (18,803) | (51,314) | (33,607) |
Benefit from income taxes | 1,500 | 870 | 2,602 | 1,721 |
Net loss | (27,503) | (17,933) | (48,712) | (31,886) |
Accretion of redeemable convertible preferred stock to redemption value | 459 | 192 | 644 | 360 |
Net loss attributable to common stockholders | $ (27,044) | $ (17,741) | $ (48,068) | $ (31,526) |
Net loss per share attributable to common stockholders-basic and diluted | $ (2.94) | $ (2.31) | $ (5.26) | $ (4.13) |
Weighted average common shares outstanding-basic and diluted | 9,187,207 | 7,676,426 | 9,139,638 | 7,631,883 |
Condensed Consolidated Stateme5
Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended | ||
Jun. 30, 2018 | Jun. 30, 2017 | Jun. 30, 2018 | Jun. 30, 2017 | |
Net loss | $ (27,503) | $ (17,933) | $ (48,712) | $ (31,886) |
Other comprehensive income (loss): | ||||
Unrealized gains (losses) on available-for-sale securities, net of tax of $0 | 45 | (79) | 77 | |
Comprehensive loss | $ (27,503) | $ (17,888) | $ (48,791) | $ (31,809) |
Condensed Consolidated Stateme6
Condensed Consolidated Statements of Comprehensive Loss (Parenthetical) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended | ||
Jun. 30, 2018 | Jun. 30, 2017 | Jun. 30, 2018 | Jun. 30, 2017 | |
Unrealized gain (loss) arising during the period, income taxes | $ 0 | $ 0 | $ 0 | $ 0 |
Condensed Consolidated Stateme7
Condensed Consolidated Statements of Cash flows - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended | ||
Jun. 30, 2018 | Jun. 30, 2017 | Jun. 30, 2018 | Jun. 30, 2017 | |
Cash flows from operating activities: | ||||
Net loss | $ (27,503) | $ (17,933) | $ (48,712) | $ (31,886) |
Adjustments to reconcile net loss to net cash used in operating activities: | ||||
Depreciation and amortization expense | 900 | 500 | 1,447 | 740 |
Stock-based compensation expense | 4,258 | 792 | ||
Change in fair value of contingent consideration | 7,852 | 2,324 | 12,760 | 4,599 |
Deferred income tax benefit | (2,602) | (1,721) | ||
Accretion of discount on short-term investments | 43 | (98) | ||
Changes in operating assets and liabilities, net of effects of acquisition: | ||||
Prepaid expenses and other assets | (2,509) | (501) | ||
Accounts payable | 1,081 | 1,071 | ||
Accrued expenses | 266 | 1,651 | ||
Deferred rent | 387 | 4 | ||
Net cash used in operating activities | (33,581) | (25,349) | ||
Cash flows from investing activities: | ||||
Purchases of investments | (6,000) | (60,791) | ||
Sales and maturities of investments | 14,918 | 35,962 | ||
Purchases of property and equipment | (4,757) | (323) | ||
Net cash provided by (used in) investing activities | 4,161 | (25,152) | ||
Cash flows from financing activities: | ||||
Payments of initial public offering costs | (2,421) | |||
Proceeds from option exercises | 278 | |||
Net cash used in financing activities | (2,143) | |||
Net decrease in cash, cash equivalents and restricted cash | (31,563) | (50,501) | ||
Cash, cash equivalents and restricted cash at beginning of period | 50,024 | 58,761 | ||
Cash, cash equivalents and restricted cash at end of period | 18,461 | 8,260 | 18,461 | 8,260 |
Cash, cash equivalents and restricted cash at end of period: | ||||
Cash and cash equivalents | 16,495 | 6,025 | 16,495 | 6,025 |
Restricted cash | 1,966 | 2,235 | 1,966 | 2,235 |
Cash, cash equivalents and restricted cash at end of period | 18,461 | 8,260 | 18,461 | 8,260 |
Supplemental disclosure of non-cash investing and financing activities: | ||||
Purchases of property and equipment included in accrued expenses | 489 | 39 | ||
Deferred offering costs included in accounts payable and accrued expenses | 1,402 | |||
Accretion of redeemable convertible preferred units and stock to redemption value | $ 459 | $ 192 | $ 644 | $ 360 |
Nature of the Business and Basi
Nature of the Business and Basis of Presentation | 6 Months Ended |
Jun. 30, 2018 | |
Nature of the Business and Basis of Presentation | 1. Nature of the Business and Basis of Presentation Translate Bio, Inc. (the “Company”) is a clinical-stage messenger RNA (“mRNA”) therapeutics company developing a new class of potentially transformative medicines to treat diseases caused by protein or gene dysfunction. Using its proprietary mRNA therapeutic platform (“MRT platform”), the Company creates mRNA that encodes functional proteins. The Company’s mRNA is delivered to the target cell where the cell’s own machinery recognizes it and translates it, restoring or augmenting protein function to treat or prevent disease. The Company is initially focused on restoring the expression of intracellular and transmembrane proteins, areas that have eluded conventional protein therapeutics, in patients with genetic diseases where there is high unmet medical need. The Company is a clinical-stage company. The Company is developing its lead MRT product candidate for the lung (“MRT5005”) for the treatment of cystic fibrosis (“CF”). The Company is developing its lead MRT product candidate for the liver (“MRT5201”) for the treatment of ornithine transcarbamylase (“OTC”) deficiency. In December 2016, the Company acquired from Shire Human Genetic Therapies, Inc. (“Shire”), a subsidiary of Shire plc, rights to the assets of Shire’s mRNA therapy platform (the “MRT Program”), including the cystic fibrosis transmembrane conductance regulator (“CFTR”) and OTC deficiency mRNA therapy programs. In connection with this acquisition, Shire received shares of the Company’s common stock, with related anti-dilution rights, and is eligible for future milestone and earnout payments on products developed with the MRT technology (see Note 3). The Company is subject to risks common to early-stage companies in the biotechnology industry, including, but not limited to, development by competitors of new technological innovations, dependence on key personnel, protection of proprietary technology, compliance with government regulations and the ability to secure additional capital to fund operations. Product candidates currently under development will require significant additional research and development efforts, including preclinical and clinical testing and regulatory approval, prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel and infrastructure and extensive compliance-reporting capabilities. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will realize significant revenue from product sales. The accompanying condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and include the accounts of the Company and its two wholly owned subsidiaries, Translate Bio MA and Translate Bio Securities Corporation, from their date of incorporation. All intercompany accounts and transactions have been eliminated in consolidation. Reverse Stock Split On June 15, 2018, the Company effected a one-for-5.5555 Initial Public Offering On June 27, 2018, the Company’s registration statement on Form S-1 Sanofi Pasteur Collaboration and Licensing Agreement On June 8, 2018, the Company entered into a collaboration and license agreement with Sanofi Pasteur Inc. (“Sanofi”), the vaccines global business unit of Sanofi S.A., to develop mRNA vaccines for up to five undisclosed infectious disease pathogens (the “Sanofi Agreement”). The Sanofi Agreement became effective on July 9, 2018, following notice of early termination of the waiting period under the Hart-Scott-Rodino Antitrust Act of 1976. Under the Sanofi Agreement, the Company and Sanofi will jointly conduct research and development activities to advance mRNA vaccines and mRNA vaccine platform development during a three-year research term, which may be extended by mutual agreement. The Company is eligible to receive up to $805.0 million in payments, which includes an upfront payment of $45.0 million, which the Company received on July 18, 2018; certain development, regulatory and sales-related milestones across several vaccine targets; and option exercise fees if Sanofi exercises its option related to development of vaccines for additional pathogens. The Company is also eligible to receive tiered royalty payments associated with worldwide sales of the developed vaccines, if any (see Note 15). Going Concern In accordance with Accounting Standards Update (“ASU”) No. 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern (Subtopic 205-40) The Company’s financial statements have been prepared on the basis of continuity of operations, realization of assets and the satisfaction of liabilities in the ordinary course of business. Through June 30, 2018, the Company has funded its operations with the proceeds from the sale of redeemable convertible preferred stock. The Company has incurred recurring losses since its inception, including net losses of $48.7 million and $31.9 million for the six months ended June 30, 2018 and 2017, respectively. In addition, the Company had an accumulated deficit of $197.5 million as of June 30, 2018. The Company expects to continue to generate operating losses for the foreseeable future. As of August 9, 2018, the date of issuance of these unaudited interim condensed financial statements, the Company expects that its cash, cash equivalents and investments of $17.5 million as of June 30, 2018, together with the approximate $113.4 million of net proceeds received in July 2018 from the Company’s IPO, inclusive of the proceeds from the over-allotment exercise, and the $45.0 million upfront payment received in July 2018 under the Sanofi Agreement, will be sufficient to fund its operating expenses and capital expenditure requirements into the first half of 2020. If the Company is unable to obtain funding, the Company will be forced to delay, reduce or eliminate some or all of its research and development programs, product portfolio expansion or commercialization efforts, which could adversely affect its business prospects, or the Company may be unable to continue operations. Although management continues to pursue these plans, there is no assurance that the Company will be successful in obtaining sufficient funding on terms acceptable to the Company to fund continuing operations, if at all. |
Summary of Significant Accounti
Summary of Significant Accounting Policies | 6 Months Ended |
Jun. 30, 2018 | |
Summary of Significant Accounting Policies | 2. Summary of Significant Accounting Policies Use of Estimates The preparation of the Company’s consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the consolidated financial statements, and the reported amounts of expenses during the reporting period. Actual results could differ from those estimates. Significant estimates and assumptions reflected in these consolidated financial statements include, but are not limited to, the accrual for research and development expenses, the valuation of common stock and stock-based awards, the valuation of assets acquired and liabilities assumed in business combinations, and the impairment of identifiable intangible assets and goodwill. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Changes in estimates are recorded in the period in which they become known. Actual results could differ from those estimates. Unaudited Interim Financial Information The accompanying unaudited condensed consolidated balance sheet as of June 30, 2018, the unaudited condensed consolidated statements of operations and of comprehensive loss for the three and six months ended June 30, 2018 and 2017 and of cash flows for the six months ended June 30, 2018 and 2017 have been prepared by the Company, pursuant to the rules and regulations of the SEC for the interim financial statements. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to rules and regulations. However, the Company believes that the disclosures are adequate to make the information presented not misleading. The accompanying unaudited interim condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and the notes thereto for the year ended December 31, 2017 included in the Company’s prospectus that forms a part of the Company’s Registration Statement on Form S-1 No. 333-225368). The accompanying unaudited interim condensed consolidated financial presentation has been prepared on the same basis as the audited annual consolidated financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for the fair statement of the Company’s financial position as of June 30, 2018, the results of its operations for the three and six months ended June 30, 2018 and 2017, and its cash flows for the six months ended June 30, 2018 and 2017. The financial data and other information disclosed in these notes related to the three and six months ended June 30, 2018 and 2017 are also unaudited. The results for the six months ended June 30, 2018 are not necessarily indicative of results to be expected for the year ending December 31, 2018, any other interim periods, or any future year or period. Cash and Cash Equivalents All highly liquid investments purchased with an original maturity date of three months or less at the date of purchase are considered to be cash equivalents. Cash equivalents consisted of money market funds as of June 30, 2018 and December 31, 2017. Investments The Company’s debt security investments are classified as available-for-sale The Company evaluates its investments with unrealized losses for other-than-temporary impairment. When assessing investments for other-than-temporary declines in value, the Company considers such factors as, among other things, how significant the decline in value is as a percentage of the original cost, how long the market value of the investment has been less than its original cost, the Company’s ability and intent to retain the investment for a period of time sufficient to allow for any anticipated recovery in fair value and market conditions in general. If any adjustment to fair value reflects a decline in the value of the investment that the Company considers to be “other than temporary,” the Company reduces the investment to fair value through a charge to the statement of operations. No such adjustments were necessary during the periods presented. The Company’s investments as of June 30, 2018 and December 31, 2017 had original maturities of less than one year. Concentrations of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of cash and cash equivalents as well as short-term investments. Cash, cash equivalents and short-term investments consist of demand deposits, money market funds and U.S. government agency bonds. The Company generally maintains balances in various operating accounts with financial institutions that management believes to be of high credit quality, in amounts that may exceed federally insured limits. The Company has not experienced any losses related to its cash, cash equivalents and short-term investments and does not believe that it is subject to unusual credit risk beyond the normal credit risk associated with commercial banking relationships. Restricted Cash In connection with its operating lease commitments, the Company issued letters of credit collateralized by cash deposits that are classified as restricted cash in the consolidated balance sheets. Restricted cash amounts have been classified as current assets based on the release dates of the restrictions under the letters of credit, which occur annually. Deferred Offering Costs The Company capitalizes certain legal, professional accounting and other third-party fees that are directly associated with in-process in-process Property and Equipment Property and equipment are stated at cost less accumulated depreciation and amortization. Depreciation and amortization expense is recognized using the straight-line method over the estimated useful lives of each asset. Estimated useful lives are periodically assessed to determine if changes are appropriate. Upon retirement or sale, the related cost and accumulated depreciation and amortization are removed from the accounts and any resulting gain or loss is included in the consolidated statements of operations. Repair and maintenance costs are expensed as incurred. The estimated useful lives of the Company’s property and equipment are as follows: Estimated Useful Life Laboratory equipment 5 years Computer equipment 3 years Office equipment 5 years Leasehold improvements Shorter of lease term or 10 years Costs for capital assets not yet placed into service are capitalized as construction-in-progress Property and equipment are tested for recoverability whenever events or changes in business circumstances indicate that the carrying amount of the assets may not be fully recoverable. Factors that the Company considers in deciding when to perform an impairment review include significant underperformance of the business in relation to expectations, significant negative industry or economic trends and significant changes or planned changes in the use of the assets. If an impairment review is performed to evaluate an asset group for recoverability, the Company compares the forecasted undiscounted cash flows expected to result from the use and eventual disposition of the asset group to its carrying value. An impairment loss would be recognized when estimated undiscounted future cash flows expected to result from the use and eventual disposition of an asset group are less than its carrying amount. The impairment loss would be based on the excess of the carrying value of the impaired asset group over its fair value, determined based on discounted cash flows using market participant assumptions. The Company did not record any impairment losses on property and equipment during the three and six months ended June 30, 2018 and 2017. Business Combinations The Company accounts for business combinations using the acquisition method of accounting. Application of this method of accounting requires that (i) identifiable assets acquired (including identifiable intangible assets) and liabilities assumed generally be measured and recognized at fair value as of the acquisition date and (ii) the excess of the purchase price over the net fair value of identifiable assets acquired and liabilities assumed be recognized as goodwill, which is not amortized for accounting purposes but is subject to testing for impairment at least annually. Acquired in-process Determining the fair value of assets acquired and liabilities assumed in a business combination requires management to use significant judgment and estimates, especially with respect to intangible assets. Critical estimates in valuing certain identifiable assets include, but are not limited to, the selection of valuation methodologies, estimates of future revenue and cash flows, expected long-term market growth, future expected operating expenses, costs of capital and appropriate discount rates. Management’s estimates of fair value are based upon assumptions believed to be reasonable, but which are inherently uncertain and, as a result, actual results may differ materially from estimates. During the measurement period, which extends no later than one year from the acquisition date, the Company may record certain adjustments to the carrying value of the assets acquired and liabilities assumed with the corresponding offset to goodwill. After the measurement period, all adjustments are recorded in the consolidated statements of operations as operating expenses or income. Acquisition-related contingent consideration, which consists of potential milestone and earnout payment obligations as well as anti-dilution rights provided to Shire (see Note 3), was recorded in the consolidated balance sheets at its acquisition-date estimated fair value, in accordance with the acquisition method of accounting. The fair value of the acquisition-related contingent consideration is remeasured each reporting period, with changes in fair value recorded in the consolidated statements of operations. The fair value measurement is based on significant inputs not observable by market participants and thus represents a Level 3 input in the fair value hierarchy (see Note 4). Asset Acquisitions The Company measures and recognizes asset acquisitions that are not deemed to be business combinations based on the cost to acquire the assets, which includes transaction costs. Goodwill is not recognized in asset acquisitions. In an asset acquisition, the cost allocated to acquire IPR&D with no alternative future use is charged to expense at the acquisition date. In-Process The fair value of IPR&D acquired through a business combination is capitalized as an indefinite-lived intangible asset until the completion or abandonment of the related research and development activities. When the related research and development is completed, the asset is reclassified to a definite-lived asset and amortized over its estimated useful life. The fair value of an IPR&D intangible asset is typically determined using an income approach whereby management forecasts the net cash flows expected to be generated by the asset over its estimated useful life. The net cash flows reflect the asset’s stage of completion, the probability of technical success, the projected costs to complete, expected market competition, and an assessment of the asset’s life-cycle. The net cash flows are then adjusted to present value by applying an appropriate discount rate that reflects the risk factors associated with the cash flow streams. Indefinite-lived IPR&D is not subject to amortization, but is tested annually for impairment or more frequently if there are indicators of impairment. The Company tests its indefinite-lived IPR&D annually for impairment on October 1st. In testing indefinite-lived IPR&D for impairment, the Company has the option to first assess qualitative factors to determine whether the existence of events or circumstances would indicate that it is more likely than not that its fair value is less than its carrying amount, or the Company can perform a quantitative impairment analysis to determine the fair value of the indefinite-lives IPR&D without performing a qualitative assessment. Qualitative factors that the Company considers include significant underperformance of the business in relation to expectations, significant negative industry or economic trends and significant changes or planned changes in the use of the assets. If the Company chooses to first assess qualitative factors and the Company determines that it is more likely than not that the fair value of the indefinite-lived IPR&D is less than its carrying amount, the Company would then determine the fair value of the indefinite-lived IPR&D. Under either approach, if the fair value of the indefinite-lived IPR&D is less than its carrying amount, an impairment charge is recognized in the consolidated statements of operations. During the three and six months ended June 30, 2018 and 2017, the Company did not recognize any impairment charges related to its indefinite-lived IPR&D (see Note 3). Definite-lived IPR&D, if any, is tested for recoverability whenever events or changes in business circumstances indicate that the carrying amount of the assets may not be fully recoverable. If an impairment review is performed to evaluate an asset group for recoverability, the Company compares the forecasted undiscounted cash flows expected to result from the use and eventual disposition of the asset group to its carrying value. An impairment loss would be recognized when estimated undiscounted future cash flows expected to result from the use and eventual disposition of an asset group are less than its carrying amount. The impairment loss would be based on the excess of the carrying value of the impaired asset group over its fair value, determined based on discounted cash flows using market participant assumptions. Goodwill Goodwill represents the excess of the fair value of the consideration transferred over the fair value of the net tangible and identifiable intangible assets acquired in a business combination. Goodwill is not subject to amortization, but is tested annually for impairment or more frequently if there are indicators of impairment. The Company tests its goodwill annually for impairment on October 1st. The Company has determined that there is a single reporting unit for purposes of testing goodwill for impairment. In testing goodwill for impairment, the Company has the option to first assess qualitative factors to determine whether the existence of events or circumstances would indicate that it is more likely than not that the fair value of the reporting unit was less than its carrying amount, or the Company can perform a two-step two-step two-step Fair Value Measurements Certain assets and liabilities of the Company are carried at fair value under GAAP. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable: • Level 1—Quoted prices in active markets for identical assets or liabilities. • Level 2—Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data. • Level 3—Unobservable inputs that are supported by little or no market activity that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. The Company’s cash equivalents and short-term investments are carried at fair value, determined based on Level 2 inputs in the fair value hierarchy described above (see Note 4). The Company’s contingent consideration liability is carried at fair value, determined based on Level 3 inputs in the fair value hierarchy described above (see Note 4). The carrying values of the Company’s prepaid expenses and other current assets, accounts payable, accrued expenses and other short-term liabilities approximate their fair values due to the short-term nature of these assets and liabilities. Segment Information The Company manages its operations as a single operating segment for the purposes of assessing performance and making operating decisions. The Company’s primary focus is on the advancement of the Company’s MRT platform to treat diseases caused by protein or gene dysfunction. Research and Development Costs Costs associated with internal research and development and external research and development services, including drug development and preclinical studies, are expensed as incurred. Research and development expenses include costs for salaries, employee benefits, subcontractors, facility-related expenses, depreciation and amortization, stock-based compensation, third-party license fees, laboratory supplies, and external costs of outside vendors engaged to conduct discovery, preclinical and clinical development activities and clinical trials as well as to manufacture clinical trial materials, and other costs. The Company recognizes external research and development costs based on an evaluation of the progress to completion of specific tasks using information provided to the Company by its service providers. Nonrefundable advance payments for goods or services to be received in the future for use in research and development activities are recorded as prepaid expenses. Such prepaid expenses are recognized as an expense when the services have been performed or the goods have been delivered, or when it is no longer expected that the goods will be delivered or the services rendered. Upfront payments, milestone payments (other than those deemed contingent consideration in a business combination) and annual maintenance fees under license agreements are expensed in the period in which they are incurred. Research and Development Contract Costs and Accruals The Company has entered into various research and development-related contracts with companies both inside and outside of the United States. The related costs are recorded as research and development expenses as incurred. The Company records accruals for estimated ongoing research and development costs. When evaluating the adequacy of the accrued liabilities, the Company analyzes progress of the studies or clinical trials, including the phase or completion of events, invoices received and contracted costs. Significant judgments and estimates are made in determining the accrued balances at the end of any reporting period. Actual results could differ materially from the Company’s estimates. The Company’s historical accrual estimates have not been materially different from the actual costs. Stock-Based Compensation The Company measures all stock-based awards granted to employees and directors based on their fair value on the date of the grant and recognizes compensation expense for those awards over the requisite service period, which is generally the vesting period of the respective award. For stock-based awards with service-based vesting conditions, the Company recognizes compensation expense using the straight-line method. For stock-based awards with both performance-based and service-based vesting conditions, the Company recognizes compensation expense using the graded-vesting method over the requisite service period, commencing when achievement of the performance condition becomes probable. The fair value of each stock option grant is estimated on the date of grant using the Black-Scholes option-pricing model, which requires inputs based on certain subjective assumptions, including the expected stock price volatility, the expected term of the option, the risk-free interest rate for a period that approximates the expected term of the option, and the Company’s expected dividend yield (see Note 9). The fair value of each restricted common stock award is estimated on the date of grant based on the fair value of the Company’s common stock on that same date. For stock-based awards granted to non-employee non-employee The Company classifies stock-based compensation expense in its consolidated statements of operations in the same manner in which the award recipient’s payroll costs are classified or in which the award recipient’s service payments are classified. Classification and Accretion of Redeemable Convertible Preferred Units and Redeemable Convertible Preferred Stock The Company has classified its redeemable convertible preferred units and redeemable convertible preferred stock outside of stockholders’ equity (deficit) because the units or shares contain certain redemption features that are not solely within the control of the Company. Costs incurred in connection with the issuance of each series of redeemable convertible preferred units or stock are recorded as a reduction of gross proceeds from issuance. The carrying values of redeemable convertible preferred units and stock are accreted to their redemption values through a charge to additional paid-in Comprehensive Loss Comprehensive loss includes net loss as well as other changes in stockholders’ equity (deficit) that result from transactions and economic events other than those with stockholders. The Company’s only element of other comprehensive income (loss) was unrealized gains (losses) on U.S. government agency bonds, which are classified as available-for-sale-securities. Income Taxes The Company accounts for income taxes using the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been recognized in the consolidated financial statements or in the Company’s tax returns. Deferred tax assets and liabilities are determined on the basis of the differences between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. Changes in deferred tax assets and liabilities are recorded in the provision for income taxes. The Company assesses the likelihood that its deferred tax assets will be recovered from future taxable income and, to the extent it believes, based upon the weight of available evidence, that it is more likely than not that all or a portion of the deferred tax assets will not be realized, a valuation allowance is established through a charge to income tax expense. Potential for recovery of deferred tax assets is evaluated by estimating the future taxable profits expected and considering prudent and feasible tax planning strategies. The Company accounts for uncertainty in income taxes recognized in the consolidated financial statements by applying a two-step more-likely-than-not Net Income (Loss) per Share The Company follows the two-class two-class two-class Basic net income (loss) per share attributable to common stockholders is computed by dividing the net income (loss) attributable to common stockholders by the weighted average number of shares of common stock outstanding for the period. Diluted net income (loss) attributable to common stockholders is computed by adjusting net income (loss) attributable to common stockholders to reallocate undistributed earnings based on the potential impact of dilutive securities. Diluted net income (loss) per share attributable to common stockholders is computed by dividing the diluted net income (loss) attributable to common stockholders by the weighted average number of shares of common stock outstanding for the period, including potential dilutive shares of common stock. For purpose of this calculation, outstanding stock options, unvested restricted common stock and redeemable convertible preferred stock are considered potential dilutive shares of common stock. The Company’s preferred stock contractually entitles the holders of such shares to participate in dividends but does not contractually require the holders of such shares to participate in losses of the Company. Accordingly, in periods in which the Company reports a net loss attributable to common stockholders, such losses are not allocated to such participating securities. In periods in which the Company reports a net loss attributable to common stockholders, diluted net loss per share attributable to common stockholders is the same as basic net loss per share attributable to common stockholders, since dilutive shares of common stock are not assumed to have been issued if their effect is anti-dilutive. The Company reported a net loss attributable to common stockholders for the three and six months ended June 30, 2018 and 2017. Recently Adopted Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) 2014-09”), 2014-09 2014-09 In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows: Classification of Certain Cash Receipts and Cash Payments (Topic 230) 2016-15”), 2016-15 2016-15 In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230) 2016-18”), beginning-of-period end-of-period 2016-18 In May 2017, the FASB issued ASU No. 2017-09, Compensation—Stock Compensation: Scope of Modification Accounting (Topic 718) 2017-09”), 2017-09 Recently Issued Accounting Pronouncements In February 2016, the FASB issued ASU No. 2016-02 , Leases (Topic 842) 2016-02”), right-of-use 2016-02 In January 2017, the FASB issued ASU No. 2017-04, Intangibles—Goodwill and Other: Simplifying the Test for Goodwill Impairment (Topic 350) 2017-04”), 2017-04 2017-04 In July 2017, the FASB issued ASU No. 2017-11, Earnings Per Share (Topic 260), Distinguishing Liabilities from Equity (Topic 480), Derivatives and Hedging (Topic 815) I. Accounting for Certain Financial Instruments with Down Round Features II. Replacement of the Indefinite Deferral for Mandatorily Redeemable Financial Instruments of Certain Nonpublic Entities and Certain Mandatorily Redeemable Noncontrolling Interests with a Scope Exception (“ASU 2017-11”) . 2017-11 2017-11 In June 2018, the FASB issued ASU No. 2018-07, Compensation-Stock Compensation (Topic 718) 2018-07”), non-employees. non-employee |
Acquisitions, Goodwill and Othe
Acquisitions, Goodwill and Other Intangible Assets | 6 Months Ended |
Jun. 30, 2018 | |
Acquisitions, Goodwill and Other Intangible Assets | 3. Acquisitions, Goodwill and Other Intangible Assets Acquisition of Shire’s MRT Program On December 22, 2016, the Company entered into an asset purchase agreement (as amended on June 7, 2018, the “Shire Agreement”) with Shire pursuant to which Shire sold equipment to and assigned to the Company all of its rights to certain patent rights, permits, real property leases, contracts, regulatory documentation, books and records, and materials related to Shire’s MRT Program, including its CFTR and OTC deficiency mRNA therapeutic programs. The Company assumed no liabilities of Shire as part of the Shire Agreement. As part of the acquisition, the scientific founders of the MRT platform and other key members of the Shire program joined the Company to advance the Company’s MRT platform and the development of its product candidates. Under the Shire Agreement, the Company is obligated to use commercially reasonable efforts to develop and seek and obtain regulatory approval for products that include or are composed of MRT compounds covered by or derived from patent rights or know-how The Company accounted for the acquisition of the assets and employees as a business combination. As consideration for the acquisition, the Company issued 5,815,560 shares of common stock to Shire and agreed to make potential future milestone and earnout payments to Shire upon the occurrence of specified commercial milestones. In particular, the Company is obligated to make milestone payments to Shire of up to $60.0 million in the aggregate upon the occurrence of specified commercial milestones, including upon the first commercial sale of an MRT Product for the treatment of CF and upon the achievement of a specified level of annual net sales with respect to an MRT Product. The Company is also obligated to make additional milestone payments of $10.0 million for each non-CF non-CF non-CF non-CF Under the Shire Agreement, the Company is also obligated to pay a quarterly earnout payment of a mid-single-digit product-by-product country-by-country know-how Under the Shire Agreement, the Company was obligated to consummate an equity financing of at least $100.0 million (the “Subsequent Financing”). As part of the Shire Agreement, the Company provided Shire anti-dilution rights whereby it agreed to issue Shire additional common stock such that Shire will own, upon the completion of the Subsequent Financing, either (i) 18.0% of the Company’s common stock on an as-converted Elements of Purchase Consideration As part of its accounting for the business combination, the Company recorded the fair value of the common stock issued on the acquisition date as well as contingent consideration liabilities for the potential future milestone and earnout payments and for the anti-dilution rights provided to Shire through the completion of the Subsequent Financing. The aggregate acquisition-date fair value of consideration transferred was determined to be $112.2 million, consisting of the following (in thousands): Fair value of common stock $ 41,089 Fair value of contingent consideration — potential milestone and earnout payments 62,666 Fair value of contingent consideration — anti-dilution rights 8,407 Total fair value of purchase consideration $ 112,162 Common Stock Issued at Closing. Liabilities for Contingent Consideration. The fair value of the contingent consideration related to Shire’s anti-dilution rights was estimated by the Company at the acquisition date based, in part, on the results of a third-party valuation. The third-party valuation was prepared using a PWERM, which considered as inputs the probability of occurrence of events that would trigger the issuance of additional shares, the expected timing of such events, the expected value of the contingently issuable equity upon the occurrence of a triggering event and a risk-adjusted discount rate. The Company assessed the anti-dilution rights provided to Shire and determined that the rights (i) met the definition of a freestanding financial instrument that was not indexed to the Company’s own stock and (ii) did not meet the definition of a derivative. As the rights did not meet the definition of a derivative and did not qualify for equity classification, the Company determined to classify the anti-dilution rights as a liability. Accordingly, the Company recognized the liability at fair value on the acquisition date and recognizes changes in the fair value of the anti-dilution rights at each subsequent reporting period in the consolidated statements of operations (see Note 4). Allocation of the Purchase Consideration The acquisition of Shire’s MRT Program was accounted for in accordance with the acquisition method of accounting for business combinations. Acquisition-related costs totaling $3.0 million were expensed to general and administrative expenses as incurred. Such acquisition-related costs included $0.5 million for the services of the investment bank that facilitated the acquisition payable in shares of the Company’s common stock, which amount was included in accrued expenses on the consolidated balance sheet as of December 31, 2016 and satisfied in December 2017 through the Company’s issuance of 70,866 shares of common stock. The total consideration transferred was allocated to the tangible and identifiable intangible assets acquired based on their estimated fair values as follows (in thousands): Identifiable intangible assets $ 106,907 Property and equipment 2,416 Deferred tax assets 1,308 Deferred tax liabilities (18,520 ) Valuation allowance for deferred tax assets (1,308 ) Goodwill 21,359 Total purchase price consideration $ 112,162 Identifiable intangible assets acquired in the acquisition consisted of IPR&D and a lease-based asset. The IPR&D included ongoing projects that could further the Company’s preclinical and clinical development activities related to CF, OTC and other potential rare diseases. The lease-based intangible asset related to the below-market rental expense that the Company is expected to benefit from over the remaining lease period at one of its leased facilities. The IPR&D was determined to be indefinite-lived, and the lease-based intangible asset was determined to be definite-lived, with an estimated useful life of 1.5 years. The fair values of the identifiable intangible assets as of the acquisition date were as follows (in thousands): In-process $ 45,992 In-process 42,291 In-process 18,559 Lease agreement 65 Total identifiable intangible assets $ 106,907 The fair value of the IPR&D assets acquired was estimated by the Company at the acquisition date based, in part, on the results of the third-party valuation. The third-party valuation was prepared using the multi-period excess earnings method (“MPEEM”), a form of the income approach, which assumes the fair value of an intangible asset is equal to the present value of the incremental risk-adjusted after-tax after-tax A deferred tax liability of $18.5 million was recorded as part of the business combination for the non-deductible The excess of the fair value of the consideration transferred over the fair value of identifiable assets acquired in the acquisition was allocated to goodwill in the amount of $21.4 million. Goodwill resulting from the acquisition was allocated to the Company’s single reporting unit and was largely attributed to the synergies and economies of scale expected from combining the research and operations of the MRT Program and the Company. Substantially all of the goodwill recorded as part of the MRT Program acquisition is not deductible for U.S. federal income tax purposes. The results of operations of the MRT Program business have been included in the Company’s consolidated statements of operations from the acquisition date. The operations of the MRT Program business were fully integrated into the Company’s operations and no separate financial results of the business were maintained. On June 7, 2018, the Company and Shire entered into an amendment to the Shire Agreement to align certain terms of the Shire Agreement with the collaboration and license agreement that the Company entered into with Sanofi on June 8, 2018. Pursuant to this amendment, a mRNA vaccine that is developed pursuant to the Company’s collaboration with Sanofi will be considered an MRT Product if it includes a MRT compound having a mRNA sequence that encodes a protein that is from, or that binds to, an infectious disease pathogen in a field that has been licensed by the Company to Sanofi. Pursuant to the amended Shire Agreement, the Company is obligated to make milestone payments of $10.0 million for each non-CF non-CF non-CF non-CF |
Fair Value of Financial Assets
Fair Value of Financial Assets and Liabilities | 6 Months Ended |
Jun. 30, 2018 | |
Fair Value of Financial Assets and Liabilities | 4. Fair Value of Financial Assets and Liabilities The following tables present information about the Company’s financial assets and liabilities measured at fair value on a recurring basis (in thousands): Fair Value Measurements as of June 30, 2018 Using: Level 1 Level 2 Level 3 Total Assets: Money market funds $ — $ 11,148 $ — $ 11,148 U.S. government agency bonds — 1,000 — 1,000 $ — $ 12,148 $ — $ 12,148 Liabilities: Contingent consideration $ — $ — $ 93,769 $ 93,769 $ — $ — $ 93,769 $ 93,769 Fair Value Measurements as of December 31, 2017 Using: Level 1 Level 2 Level 3 Total Assets: Money market funds $ — $ 28,636 $ — $ 28,636 U.S. government agency bonds — 9,997 — 9,997 $ — $ 38,633 $ — $ 38,633 Liabilities: Contingent consideration $ — $ — $ 81,009 $ 81,009 $ — $ — $ 81,009 $ 81,009 During the six months ended June 30, 2018 and the year ended December 31, 2017, there were no transfers between Level 1, Level 2 and Level 3. Cash equivalents as of June 30, 2018 and December 31, 2017 consisted of money market funds totaling $11.1 million and $28.6 million, respectively. The money market funds were valued using inputs observable in active markets for similar securities, which represent a Level 2 measurement in the fair value hierarchy. The Company’s short-term investments as of June 30, 2018 and December 31, 2017 consisted of U.S. government agency bonds and were classified as available-for-sale Valuation of Contingent Consideration The contingent consideration liability related to the acquisition of the MRT Program was classified as Level 3 measurement within the fair value hierarchy and includes the potential future milestone and earnout payments that may be due by the Company to Shire (see Note 3) and an anti-dilution liability with respect to shares issuable by the Company to Shire upon a qualified financing event (see Note 3). The fair value of the liability to make potential future milestone and earnout payments was estimated by the Company at each reporting date based, in part, on the results of a third-party valuation using a discounted cash flow analysis based on various assumptions, including the probability of achieving specified events, discount rates, and the period of time until earnout payments are payable and the conditions triggering the milestone payments are met. The actual settlement of contingent consideration could differ from current estimates based on the actual occurrence of these specified events. The fair value of the anti-dilution liability was estimated by the Company at each reporting date based, in part, on the results of a third-party valuation using the PWERM, which considers as inputs the probability of occurrence of events that would trigger the issuance of shares, the expected timing of such events, the expected value of the contingently issuable equity upon the occurrence of a triggering event and a risk-adjusted discount rate. The following tables presents the unobservable inputs and fair value of the components of the contingent consideration (dollar amounts in thousands): Unobservable Inputs at June 30, 2018 and December 31, 2017 Fair Value at Projected Year June 30, December 31, Discount Rate of Payment 2018 2017 Earnout payments 15.0% 2025 - 2039 $ 83,709 $ 72,896 Milestone payments 15.0% 2025 - 2030 7,673 6,817 Anti-dilution rights 1.39% - 1.77% N/A 2,387 1,296 $ 93,769 $ 81,009 The following table presents a roll-forward of the total acquisition-related contingent consideration liability (in thousands): Fair Value Balance as of December 31, 2017 $ 81,009 Change in fair value of contingent consideration 12,760 Balance as of June 30, 2018 $ 93,769 The increase in the fair value of contingent consideration during the six months ended June 30, 2018 was primarily due to the initiation in May 2018 of the Company’s Phase 1/2 clinical trial of MRT5005 for the treatment of patients with CF and the resulting increase in the probability of the potential technical success of the Company’s CF program. In December 2017, as a result of the Company’s issuance and sale of 21,202,710 shares of Series C redeemable convertible preferred stock at that same time (see Note 7), the Company issued to Shire 1,079,765 shares of common stock, with an aggregate fair value of $8.0 million, pursuant to the anti-dilution rights conveyed to Shire in the Shire Agreement (see Note 3). The shares issued to Shire were in partial settlement of the Company’s anti-dilution contingent consideration liability that was recorded in its purchase accounting for the MRT Program in December 2016 and reflected as current portion of contingent consideration on the Company’s consolidated balance sheets as of June 30, 2018 and December 31, 2017. The Company’s obligation related to these anti-dilution rights remained in effect until the Company consummated an additional equity financing of $7.0 million. Pursuant to the anti-dilution rights conveyed to Shire, and after giving effect to the closing of the Company’s IPO, which satisfied the Subsequent Financing requirement, the total shares of common stock that Shire was entitled to own was determined to be 7,078,945 shares. Prior to the Company’s IPO, the Company had issued 6,895,326 shares of common stock to Shire in accordance with these anti-dilution rights. Accordingly, on July 2, 2018, concurrent with the closing of the Company’s IPO, the Company issued an additional 183,619 shares of common stock to Shire in full satisfaction of the Company’s anti-dilution rights obligations to Shire (see Note 15). As of June 30, 2018 and December 31, 2017, the fair value of the anti-dilution contingent consideration liability was $2.4 million and $1.3 million, respectively. The fair value of the liability as of June 30, 2018 was determined based on the 183,619 shares of common stock issuable to Shire, multiplied by the $13.00 initial public offering price determined on June 27, 2018 in the Company’s IPO. |
Property and Equipment, Net
Property and Equipment, Net | 6 Months Ended |
Jun. 30, 2018 | |
Property and Equipment, Net | 5. Property and Equipment, Net Property and equipment, net consisted of the following (in thousands): June 30, December 31, 2018 2017 Laboratory equipment $ 5,914 $ 5,382 Computer equipment 626 481 Office equipment 701 249 Leasehold improvements 5,632 1,131 Construction in progress 950 2,591 13,823 9,834 Less: Accumulated depreciation and amortization (3,955 ) (3,056 ) $ 9,868 $ 6,778 Depreciation and amortization expense related to property and equipment was $0.9 million, $0.5 million, $1.4 million and $0.7 million for the three months ended June 30, 2018 and 2017 and the six months ended June 30, 2018 and 2017, respectively. Construction in progress recorded as of December 31, 2017 primarily related to in-process |
Accrued Expenses
Accrued Expenses | 6 Months Ended |
Jun. 30, 2018 | |
Accrued Expenses | 6. Accrued Expenses Accrued expenses consisted of the following (in thousands): June 30, December 31, 2018 2017 Accrued consultant and professional fees $ 2,204 $ 1,130 Accrued employee compensation and benefits 1,940 2,252 Accrued external research and development expenses 1,132 1,115 Other 482 1,391 $ 5,758 $ 5,888 |
Redeemable Convertible Preferre
Redeemable Convertible Preferred Stock | 6 Months Ended |
Jun. 30, 2018 | |
Redeemable Convertible Preferred Stock | 7. Redeemable Convertible Preferred Stock As of June 30, 2018 and December 31, 2017, the Company’s certificate of incorporation, as amended and restated, authorized the Company to issue 145,833,064 shares of redeemable convertible preferred stock. As of June 30, 2018 and December 31, 2017, the Company had 36,194,026 shares of Series A redeemable convertible preferred stock (the Series A preferred stock”), 59,133,9877 shares of Series B redeemable convertible preferred stock (the Series B preferred stock”) and 46,960,279 shares of Series C redeemable convertible preferred stock (the “Series C preferred stock”) issued and outstanding. The Series A preferred stock, Series B preferred stock and Series C preferred stock were redeemable and convertible by the holders under specified conditions. The redeemable convertible preferred stock is classified outside of stockholders’ equity (deficit) because the shares contain redemption features that are not solely within the control of the Company. The Series A preferred stock, Series B preferred stock and Series C preferred stock are collectively referred to as the “Preferred Stock.” In December 2017, the Company issued and sold 21,202,710 shares of Series C preferred stock at a price of $1.98 per share for aggregate proceeds of $41.9 million, net of issuance costs of $0.1 million. Upon issuance of each class of Preferred Stock, the Company assessed the embedded conversion and liquidation features of the securities and determined that such features did not require the Company to separately account for these features. The Company also concluded that no beneficial conversion feature existed upon the issuance date of each class of Preferred Stock or as of June 30, 2018 and December 31, 2017. Upon the closing of the Company’s IPO on July 2, 2018, all then-outstanding shares of Preferred Stock converted into an aggregate of 25,612,109 shares of common stock according to their terms. As of each balance sheet date, the Preferred Stock consisted of the following (in thousands, except share amounts): June 30, 2018 Preferred Shares Authorized Preferred Shares Issued and Outstanding Carrying Value Liquidation Preference Common Issuable Upon Conversion Series A preferred stock 36,194,026 36,194,026 $ 36,194 $ 36,194 6,514,986 Series B preferred stock 59,133,987 59,133,987 64,365 63,199 10,644,210 Series C preferred stock 50,505,051 46,960,279 92,981 92,981 8,452,913 145,833,064 142,288,292 $ 193,540 $ 192,374 25,612,109 December 31, 2017 Preferred Shares Authorized Preferred Shares Issued and Outstanding Carrying Value Liquidation Preference Common Issuable Upon Conversion Series A preferred stock 36,194,026 36,194,026 $ 36,194 $ 36,194 6,514,986 Series B preferred stock 59,133,987 59,133,987 64,002 63,199 10,644,210 Series C preferred stock 50,505,051 46,960,279 92,700 92,981 8,452,913 145,833,064 142,288,292 $ 192,896 $ 192,374 25,612,109 |
Common Stock
Common Stock | 6 Months Ended |
Jun. 30, 2018 | |
Common Stock | 8. Common Stock Each share of common stock entitles the holder to one vote for each share of common stock held. Common stockholders are entitled to receive dividends, as declared by the board of directors. These dividends are subject to the preferential dividend rights of the holders of the Company’s Preferred Stock. Through June 30, 2018 and December 31, 2017, no cash dividends have been declared or paid. As of June 30, 2018 and December 31, 2017, the Company had reserved 32,115,490 shares of common stock for the conversion of outstanding shares of Preferred Stock (see Note 7), the exercise of outstanding stock options (see Note 9) and the number of shares remaining available for future issuance under the 2018 Equity Incentive Plan. Upon the completion of the Company’s IPO on July 2, 2018, all shares of the Preferred Stock converted to common stock. |
Incentive Stock Options and Res
Incentive Stock Options and Restricted Stock | 6 Months Ended |
Jun. 30, 2018 | |
Incentive Stock Options and Restricted Stock | 9. Incentive Stock Options and Restricted Stock 2018 Equity Incentive Plan On March 7, 2018, the Company’s board of directors, subject to stockholder approval, adopted, and on June 15, 2018, its stockholders approved, the 2018 Equity Incentive Plan (the “2018 Plan”), which became effective on June 27, 2018. The 2018 Plan provides for the grant of incentive stock options, non-qualified The number of shares initially reserved for issuance under the 2018 Plan is the sum of 2,512,187, plus the number of shares (up to 1,013,167 shares) equal to the sum of (i) the number of shares remaining available for issuance under the 2016 Stock Incentive Plan, as amended, (“the 2016 Plan”) upon the effectiveness of the 2018 Plan, which was 360,514 shares, and (ii) the number of shares of common stock subject to outstanding awards under the 2016 Plan that expire, terminate or are otherwise surrendered, canceled, forfeited or repurchased by the Company at their original issuance price pursuant to a contractual repurchase right. The number of shares of common stock that may be issued under the 2018 Plan will automatically increase on the first day of each fiscal year, beginning with the fiscal year ending December 31, 2019 and continuing for each fiscal year until, and including, the fiscal year ending December 31, 2028, equal to the lowest of (i) 3,349,582 shares, (ii) 4% of the outstanding shares of common stock on such date and (iii) an amount determined by the Company’s board of directors. The shares of common stock underlying any awards that are forfeited, canceled, held back upon exercise or settlement of an award to satisfy the exercise price or tax withholding, repurchased or are otherwise terminated by the Company under the 2018 Plan will be added back to the shares of common stock available for issuance under the 2018 Plan. During the six months ended June 30, 2018, there were no grants issued under the 2018 Plan. Shares that are expired, terminated, surrendered or canceled under the 2018 Plan without having been exercised will be available for future grants of awards. In addition, shares of common stock that are tendered to the Company by a participant to exercise an award are added to the number of shares of common stock available for the grant of awards. The 2018 Plan is administered by the board of directors. The exercise prices, vesting periods and other restrictions are determined at the discretion of the board of directors, except that the exercise price per share of options may not be less than 100% of the fair market value of the common stock on the date of grant. Stock options awarded under the 2018 Plan expire ten years after the grant date, unless the board of directors sets a shorter term. Awards granted to employees, officers, members of the board of directors and consultants typically vest over a four-year period. Unvested stock options are forfeited upon the recipient ceasing to provide services to the Company. The Company may, upon notice to the recipient within six months after the date the recipient ceases to provide such services, repurchase some or all of the vested stock options, at a price equal to the amount that would be distributed with respect to such options under the terms of the Company’s certificate of incorporation, as amended and restated. 2018 Employee Stock Purchase Plan On March 7, 2018, the Company’s board of directors, subject to stockholder approval, adopted, and on June 15, 2018, its stockholders approved the 2018 Employee Stock Purchase Plan (the “2018 ESPP”), which became effective on June 27, 2018. A total of 418,697 shares of common stock were initially reserved for issuance under this plan. The number of shares of common stock that may be issued under the 2018 ESPP will automatically increase on the first day of each fiscal year, beginning with the fiscal year commencing on January 1, 2019 and continuing for each fiscal year until, and including, the fiscal year commencing on January 1, 2029, equal to the lowest of (i) 837,395 shares, (ii) 1% of the outstanding shares of common stock on such date and (iii) an amount determined by the Company’s board of directors. As of June 30, 2018, no shares had been issued under the 2018 ESPP. 2016 Stock Incentive Plan The Company’s 2016 Stock Incentive Plan, as amended, (the “2016 Plan”) provided for the Company to issue equity awards to employees, officers and directors, consultants and advisors. Under the 2016 Plan, the Company was allowed to grant stock options, stock appreciation rights, restricted stock and restricted stock units. Shares that are expired, terminated, surrendered or canceled under the 2016 Plan without having been exercised will be available for future grants of awards under the 2018 Plan. In addition, shares of common stock that are tendered to the Company by a participant to exercise an award are added to the number of shares of common stock available for the grant of awards under the 2018 Plan. The 2016 Plan was administered by the board of directors. The exercise prices, vesting periods and other restrictions were determined at the discretion of the board of directors, except that the exercise price per share of options may not be less than 100% of the fair market value of the common stock on the date of grant. Stock options awarded under the 2016 Plan expire ten years after the grant date, unless the board of directors set a shorter term. Stock options and restricted stock granted to employees, officers, members of the board of directors and consultants typically vest over a four-year period. Upon the effectiveness of the 2018 Plan on June 27, 2018, no further awards will be made under the 2016 Plan. Awards outstanding under the 2016 Plan will continue to be governed by their existing terms. Stock Options The following table summarizes the Company’s stock option activity since December 31, 2016 (in thousands, except share and per share amounts): Number of Shares Weighted Average Exercise Price Weighted Remaining Contractual Intrinsic Value (in years) Outstanding as of December 31, 2016 209,797 $ 4.73 9.70 $ — Granted 4,257,593 Forfeited (102,474 ) Outstanding as of December 31, 2017 4,364,916 $ 7.17 9.79 $ 977 Granted 1,966,114 $ 8.76 Exercised (49,459 ) $ 5.62 Forfeited (188,163 ) $ 6.16 Outstanding as of June 30, 2018 6,093,408 $ 7.72 9.23 $ 30,020 Vested as of June 30, 2018 1,182,097 $ 7.08 8.25 $ 6,586 Vested and expected to vest as of June 30, 2018 6,093,408 $ 7.72 9.23 $ 30,020 Vested as of December 31, 2017 661,593 $ 7.04 9.72 $ 231 Vested and expected to vest as of December 31, 2017 4,364,916 $ 7.17 9.79 $ 977 The aggregate intrinsic value of options is calculated as the difference between the exercise price of the options and the fair value of the Company’s common stock for those options that had exercise prices lower than the fair value of the Company’s common stock. The aggregate intrinsic value of stock options exercised during the six months ended June 30, 2018 was $0.3 million. There were no options exercised during the six months ended June 30, 2017. The weighted average grant-date fair value per share of stock options granted was $5.91 and $4.23 during the six months ended June 30, 2018 and 2017, respectively. The total fair value of options vested during the six months ended June 30, 2018 was $2.1 million. Stock Option Valuation The fair value of stock option grants is estimated using the Black-Scholes option-pricing model. The Company historically has been a private company and lacks company-specific historical and implied volatility information. Therefore, it estimates its expected stock volatility based on the historical volatility of a publicly traded set of peer companies and expects to continue to do so until such time as it has adequate historical data regarding the volatility of its own traded stock price. For options with service-based vesting conditions, the expected term of the Company’s stock options has been determined utilizing the “simplified” method for awards that qualify as “plain-vanilla” options. The expected term of stock options granted to non-employees The following table presents, on a weighted average basis, the assumptions used in the Black-Scholes option-pricing model to determine the grant-date fair value of stock options granted to employees and directors: Six Months Ended June 30, 2018 2018 2017 Risk-free interest rate 2.80 % 2.02 % Expected term (in years) 6.0 6.0 Expected volatility 75.7 % 65.0 % Expected dividend yield 0 % 0 % The following table presents the assumptions used in the Black-Scholes option-pricing model to determine the grant-date fair value of stock options granted to a non-employee: Six Months Ended June 30, 2017 Risk-free interest rate 2.08 % Expected term (in years) 10.0 Expected volatility 60.9 % Expected dividend yield 0 % There were no stock options granted to non-employees Restricted Common Stock The following table summarizes the Company’s restricted stock activity since December 31, 2016: Number of Shares Weighted Average Grant-Date Fair Value Unvested restricted common stock outstanding as of December 31, 2016 986,893 $ 1.10 Forfeited restricted common stock (100,563 ) $ 1.10 Vested restricted common stock (359,852 ) $ 1.04 Unvested restricted common stock outstanding as of December 31, 2017 526,478 $ 1.14 Forfeited restricted common stock (311 ) $ 1.28 Vested restricted common stock (157,292 ) $ 1.03 Unvested restricted common stock outstanding as of June 30, 2018 368,875 $ 1.19 The total fair value of restricted common stock vested during the six months ended June 30, 2018 and 2017 was $0.2 million and $0.2 million, respectively, which the Company recorded as stock-based compensation during those periods. Stock-Based Compensation Stock-based compensation expense was classified in the condensed consolidated statements of operations as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Research and development expenses $ 1,671 $ 610 $ 2,453 $ 636 General and administrative expenses 1,204 81 1,805 156 $ 2,875 $ 691 $ 4,258 $ 792 Included in research and development stock-based compensation expense for the three and six months ended June 30, 2018 was $0.3 million related to the modification of options in connection with the resignation of the Company’s former Chief Scientific Officer (“CSO”). In connection with this resignation the Company entered into a separation agreement with the former CSO. Under the terms of the separation agreement, vesting of options for the purchase of 72,871 shares of common stock held by the former CSO was accelerated with no change to the exercise price of such options. Stock options for the purchase of 204,353 shares of common stock, representing all of the options held by the former CSO, will be exercisable for one year following his resignation. As of June 30, 2018, total unrecognized compensation cost related to the unvested stock-based awards was $23.0 million which is expected to be recognized over weighted average periods of 2.79 years. |
Income Taxes
Income Taxes | 6 Months Ended |
Jun. 30, 2018 | |
Income Taxes | 10. Income Taxes 2017 U.S. Tax Reform On December 22, 2017, the Tax Cuts and Jobs Act (the “Tax Act”) was signed into United States law. The Tax Act includes a number of changes to existing tax law, including, among other things, a permanent reduction in the federal corporate income tax rate from 34% to 21%, effective as of January 1, 2018, as well as limitation of the deduction for net operating losses to 80% of annual taxable income and elimination of net operating loss carrybacks, in each case, for losses arising in taxable years beginning after December 31, 2017 (though any such net operating losses may be carried forward indefinitely). The enactment of the Tax Act resulted in the Company recording a net income tax benefit of $6.1 million in the year ended December 31, 2017. The $6.1 million net income tax benefit consisted of (i) the remeasurement of the deferred tax liabilities for the Company’s indefinite-lived intangible assets due to the tax rate reduction, which resulted in a corresponding income tax benefit of $3.7 million, and (ii) a reduction in the valuation allowance for deferred tax assets related to deductible temporary differences that will generate unlimited net operating loss carryforwards when they reverse in future periods, which resulted in a corresponding income tax benefit of $2.4 million. The staff of the Securities and Exchange Commission issued Staff Accounting Bulletin No. 118 to address the application of U.S. GAAP in situations when a registrant does not have the necessary information available, prepared or analyzed (including computations) in reasonable detail to complete the accounting for certain income tax effects of the Tax Act. The Company is still in the process of analyzing the impact to the Company of the Tax Act and its analysis is not yet complete. Where the Company has been able to make reasonable estimates of the effects related to the Tax Act, the Company has recorded provisional amounts. No adjustments to the provisional amounts recorded as of December 31, 2017 were recorded during the three and six months ended June 30, 2018. Income Taxes The Company recognized an income tax benefit of $1.5 million and $0.9 million during the three months ended June 30, 2018 and 2017, respectively, and $2.6 million and $1.7 million during the six months ended June 30, 2018 and 2017, respectively. The $1.5 million and $2.6 million income tax benefit recognized during the three and six months ended June 30, 2018, respectively, resulted from a reduction in the deferred tax liabilities recorded as part of the Company’s acquisition of the MRT Program as well as deferred tax assets recorded for net operating losses generated in 2018 that have an unlimited carryforward period. Under the Tax Act, net operating losses generated in 2018 and years thereafter can be carried forward indefinitely. As a result, the deferred tax liabilities associated with the Company’s indefinite-lived intangible assets may be used as a source of income to support the realization of the federal tax benefit of our indefinite-lived net operating losses generated in 2018. The $0.9 million and $1.7 million income tax benefit recognized during the three and six months ended June 30, 2017, respectively, was due to a reduction of the same amount in the deferred tax liabilities recorded as part of the Company’s acquisition of the MRT Program (see Note 3). The reduction in the deferred tax liabilities during the three and six months ended June 30, 2018 and 2017 resulted from an increase in the tax basis of the indefinite-lived IPR&D recorded in the acquisition. |
Net Loss per Share
Net Loss per Share | 6 Months Ended |
Jun. 30, 2018 | |
Net Loss per Share | 11. Net Loss per Share Basic and diluted net loss per share attributable to common stockholders was calculated as follows (in thousands, except share and per share amounts): Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Numerator: Net loss $ (27,503 ) $ (17,933 ) $ (48,712 ) $ (31,886 ) Accretion of redeemable convertible preferred units and stock to redemption value 459 192 644 360 Net loss attributable to common stockholders $ (27,044 ) $ (17,741 ) $ (48,068 ) $ (31,526 ) Denominator: Weighted average common shares outstanding—basic and diluted 9,187,207 7,676,426 9,139,638 7,631,883 Net loss per share attributable to common stockholders—basic and diluted $ (2.94 ) $ (2.31 ) $ (5.26 ) $ (4.13 ) The Company excluded 412,040 shares and 846,114 shares of restricted common stock, presented on a weighted average basis, from the calculations of basic net loss per share attributable to common stockholders for the three months ended June 30, 2018 and 2017, respectively, because those shares had not vested. The Company excluded 451,286 shares and 887,568 shares of restricted common stock, presented on a weighted average basis, from the calculations of basic net loss per share attributable to common stockholders for the six months ended June 30, 2018 and 2017, respectively, because those shares had not vested. The Company’s potentially dilutive securities, which include stock options, unvested restricted common stock and redeemable convertible preferred stock, have been excluded from the computation of diluted net loss per share attributable to common stockholders as the effect would be to reduce the net loss per share. Therefore, the weighted average number of shares of common stock outstanding used to calculate both basic and diluted net loss per share attributable to common stockholders is the same. The Company excluded the following potential shares of common stock, presented based on amounts outstanding at each period end, from the computation of diluted net loss per share attributable to common stockholders for the periods indicated because including them would have had an anti-dilutive effect: Three and Six Months Ended June 30, 2018 2017 Options to purchase common stock 6,093,408 1,255,347 Unvested restricted common stock 368,875 714,370 Redeemable convertible preferred stock (as converted to common stock) 25,612,109 21,795,593 32,074,392 23,765,310 In addition to the potentially dilutive securities noted above, as of June 30, 2018 and 2017, the Company was obligated to issue common stock to Shire upon the occurrence of specified events (see Notes 3 and 4). Because the necessary conditions for issuance of the shares had not been met as of June 30, 2018 and 2017, the Company excluded these shares from the table above and from the calculations of diluted net loss per share for the three and six months ended June 30, 2018 and 2017. |
Commitments and Contingencies
Commitments and Contingencies | 6 Months Ended |
Jun. 30, 2018 | |
Commitments and Contingencies | 12. Commitments and Contingencies Lease Commitments The Company leases office, laboratory and other space under operating leases that expired between April 2018 and April 2028. The Company recognizes rent expense on a straight-line basis over the respective lease period and has recorded deferred rent for rent expense incurred but not yet paid. The Company recorded rent expense of $0.8 million and $0.5 million during the three months ended June 30, 2018 and 2017, respectively and $1.7 million and $1.1 million during the six months ended June 30, 2018 and 2017, respectively. In May 2015, the Company entered into an operating lease for office and laboratory space in Cambridge, Massachusetts, which was due to expire in May 2022. In connection with entering into this lease agreement, the Company issued a letter of credit collateralized by cash deposits totaling $1.0 million, which was reduced to $0.7 million in December 2017. These cash deposits are classified as restricted cash on the consolidated balance sheets. In September 2017, the Company and the lessor agreed to early terminate the lease as of April 2018 and the Company was relieved of its obligation to pay the remaining lease payments through the expiration date of the original lease. The Company vacated the leased space in April 2018 and the letter of credit was canceled in July 2018. Pursuant to the Shire Agreement (see Note 3), in December 2016, the Company assumed an operating lease, due to expire in May 2018, for office and laboratory space in Lexington, Massachusetts. Monthly lease payments of less than $0.1 million due under the lease include base rent and ancillary charges. In January 2017, in connection with this lease agreement, the Company issued two letters of credit collateralized by cash deposits totaling $0.3 million, which are classified as restricted cash on the consolidated balance sheets. In November 2017, the lease was amended pursuant to which (i) the lease was extended by 12 months, commencing in June 2018 and expiring in May 2019, and (ii) the landlord was granted the option, at its sole discretion, to terminate the lease upon 90 days’ notice, provided that the expiration date will be no earlier than November 30, 2018. On June 22, 2018 the Company entered into a Termination and Surrender Agreement with the landlord relating to this lease subject to certain conditions. On July 27, 2018, following receipt of a $0.3 million termination payment, the landlord released the Company from any further obligations under the lease. The Company expects the letters of credit to be released during the third quarter of 2018. In June 2017, the Company entered into an operating lease for office and laboratory space at a second location in Lexington, Massachusetts. Monthly lease payments include base rent charges of $0.2 million, which are subject to a 3% annual increase each year. The lease expires in April 2028. In June 2017, in connection with this lease agreement, the Company issued a letter of credit collateralized by cash deposits of $1.0 million, which are classified as restricted cash on the consolidated balance sheets as of June 30, 2018 and December 31, 2017. Research, Supply and License Agreements Pursuant to the Shire Agreement (see Note 3), in December 2016, the Company was assigned and assumed several contracts related to the MRT Program. The material agreements that were assigned to and assumed by the Company in connection with the acquisition are described below. Roche Master Supply Agreement The Company is a party to a master supply agreement with Roche Diagnostics Corporation (“Roche”) pursuant to which Roche will custom manufacture certain products for the Company. The agreement requires the Company to purchase from Roche specified manufactured products and the related raw materials in an amount equal to the greater of (i) quantities of raw materials in the Company’s annual forecast to be purchased or (ii) 80% of the Company’s demand for products as the same or similar type. In June 2017, the Company exercised its option under the agreement to extend the agreement through December 31, 2024. As of June 30, 2018 and December 31, 2017, the Company’s purchase commitments under the agreement totaled $7.6 million and $8.8 million, respectively, with $1.3 million committed as payments in each year from 2018 to 2024. Research and development expenses related to this agreement totaled $0.8 million and $0.5 million during the three months ended June 30, 2018 and 2017, respectively, and $1.7 million and $0.6 million during the six months ended June 30, 2018 and 2017, respectively. MIT Research Agreement The Company is a party to a research agreement with the Massachusetts Institute of Technology (“MIT”) pursuant to which the Company is obligated to reimburse MIT in an amount up to $3.1 million for specified direct and indirect costs incurred through October 2019 in specified research activities conducted for the Company. As of June 30, 2018 and December 31, 2017, the Company had paid MIT $1.3 million and $1.0 million, respectively, of the total committed amount. As of June 30, 2018, the Company’s research commitments under the agreement totaled $1.3 million with $0.6 million committed through 2018 and $0.7 million committed in 2019. Research and development expenses related to this agreement totaled $0.3 million and $0.3 million during the three months ended June 30, 2018 and 2017, respectively and $0.6 million and $0.6 million during the six months ended June 30, 2018 and 2017, respectively. As of June 30, 2018, amounts payable by the Company under the agreement totaled $0.5 million. As amended, the agreement expires in October 2019 and may be extended thereafter by mutual agreement of the parties. MIT Exclusive Patent License Agreement The Company is a party to an exclusive patent license agreement with MIT pursuant to which the Company received an exclusive license under the licensed patent rights to develop, manufacture and commercialize any product containing both (i) any RNA sequences, including mRNA, that encode a protein or peptide suitable for human therapeutic use which may include operably linked non-coding non-coding The Company has the right to grant sublicenses under this license. The patent rights licensed to the Company by MIT include claims that cover the Company’s customized lipid-based nanoparticles used for delivery of coding RNA components in its MRT platform and MRT5201. Under the license agreement, the Company is obligated to make annual license maintenance payments to MIT, payable on January 1 of each calendar year, of up to $0.2 million, which may be credited against royalties subsequently due on net sales of licensed products earned in the same calendar year. The Company paid no annual license maintenance fees to MIT during the three months ended June 30, 2018 and 2017 and paid $0.1 million and $0.1 million during the six months ended June 30, 2018 and 2017, respectively. The Company is also obligated to make milestone payments to MIT aggregating up to $1.375 million upon the achievement of specified clinical and regulatory milestones with respect to each licensed product and $1.250 million upon the Company’s first commercial sale of each licensed product, and to pay royalties of a low single-digit percentage to MIT based on the Company’s, and any of its affiliates and sublicensees, net sales of licensed products. The royalties are payable on a product-by-product country-by-country last-to-expire MIT-licensed The agreement obligates the Company to use commercially reasonable efforts and expend a minimum amount of resources each year to develop licensed products in accordance with a development plan, and a development milestone timetable specified in the agreement; to use commercially reasonable efforts to commercialize licensed products; and upon commercialization, to make the licensed products reasonably available to the public. MIT has the right to terminate the agreement if the Company fails to pay amounts when due or otherwise materially breaches the agreement and fails to cure such nonpayment or breach within specified cure periods or in the event the Company ceases to carry on its business related to the agreement. In the event of a termination due to the Company’s breach caused by a due diligence failure of a licensed product, but where the Company has fulfilled its obligations with respect to a different licensed product, MIT may not terminate the agreement with respect to the different licensed product. MIT may immediately terminate the agreement if the Company or any of its affiliates brings specified patent challenges against MIT or assists others in bringing a patent challenge against MIT. The Company has the right to terminate the agreement for its convenience at any time on three months’ prior written notice to MIT and payment of all amounts due to MIT through the date of termination. The Company’s patent rights, and the rights of its affiliates and sublicensees, in specified licensed products may also terminate, if, after November 1, 2018, the Company, its affiliates or MIT receives a request from a third party to develop such licensed product for which the Company is unable to, within nine months of receiving notice of any such request, either demonstrate that the Company has initiated a fully funded project for the commercial development of such licensed product, and provide a business plan with acceptable milestones; demonstrate that the licensed product proposed by such third party would be competitive with a licensed product for which the Company has initiated a fully funded project; or enter into a sublicense agreement with such third party on commercially reasonable terms, and, in each case, MIT, in its sole discretion, grants a license to such third party for the specified patent rights. Research and development expenses related to this agreement totaled less than $0.1 million during each of the three months ended June 30, 2018 and 2017, respectively, and $0.1 million and $0.1 million during the six months ended June 30, 2018 and 2017. As of June 30, 2018 and December 31, 2017, no liabilities related to this agreement were recorded by the Company. Indemnification Agreements In the ordinary course of business, the Company may provide indemnification of varying scope and terms to vendors, lessors, business partners and other parties with respect to certain matters including, but not limited to, losses arising out of breach of such agreements or from intellectual property infringement claims made by third parties. In addition, the Company has entered into indemnification agreements with members of its board of directors that will require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is, in many cases, unlimited. To date, the Company has not incurred any material costs as a result of such indemnifications. The Company does not believe that the outcome of any claims under indemnification arrangements will have a material effect on its financial position, results of operations or cash flows, and it has not accrued any liabilities related to such obligations in its consolidated financial statements as of June 30, 2018 and December 31, 2017. Legal Proceedings The Company is not a party to any litigation and does not have contingency reserves established for any litigation liabilities. |
Related Party Transactions
Related Party Transactions | 6 Months Ended |
Jun. 30, 2018 | |
Related Party Transactions | 13. Related Party Transactions Consulting Agreement with Daniel S. Lynch In 2012, the Company entered into a consulting agreement with Daniel S. Lynch, the chairman of the Company’s board of directors, for the provision of consulting, advisory and related services. Pursuant to the consulting agreement, as amended through March 2015, Mr. Lynch is entitled to base compensation of $100,000 per year and is eligible to receive an annual performance bonus of up to 25% of his base compensation. During the three months ended June 30, 2018 and 2017 and the six months ended June 30, 2018 and 2017, the Company recorded general and administrative expenses of $31,250, $31,250, $0.1 million and $0.1 million, respectively, related to this agreement. During the three months ended June 30, 2018 and 2017 and the six months ended June 30, 2018 and 2017, the Company paid Mr. Lynch $0.1 million, $25,000, $0.1 million and $0.1 million, respectively, in connection with his services provided under the agreement. As of June 30, 2018 and December 31, 2017, amounts due under this agreement totaled $12,500 and $20,000, respectively, which were included in accrued expenses on the consolidated balance sheets. As additional compensation for services provided under the consulting agreement, through December 31, 2016, the Company granted to Mr. Lynch 321,823 shares of restricted common stock, which are fully vested. During the year ended December 31, 2017, the Company granted to Mr. Lynch stock options to purchase 85,170 shares of common stock, at an exercise price of $7.39 per share, which vest monthly over a four-year period. The stock options had a grant-date fair value of $4.06 per share and an aggregate fair value of $0.3 million. Transition Services Agreement with Shire In connection with the entering into the Shire Agreement (see Note 3), the Company and Shire entered into a transition services agreement (the “Transition Agreement”) pursuant to which Shire provided certain transition services, such as information technology, finance, legal, facilities-related and regulatory, for nine months following the acquisition of the MRT Program. During the three and six months ended June 30, 2017, the Company recorded general and administrative expenses of $4,575 and $16,025, respectively, and paid Shire $4,725 and $14,525, respectively, for the services provided under the Transition Agreement, which expired in September 2017. |
Costs Associated with Restructu
Costs Associated with Restructuring | 6 Months Ended |
Jun. 30, 2018 | |
Costs Associated with Restructuring | 14. Costs Associated with Restructuring In June 2017, the Company implemented a reorganization of its operations, which reduced its workforce by 17 positions in connection with a strategic realignment of resources aimed at better supporting the advancement of its MRT platform. The benefits provided to the employees as part of this reorganization were determined to be involuntary termination benefits provided under the terms of a one-time Changes in accrued restructuring costs were as follows (in thousands): Balance at December 31, 2016 $ — Charges 473 Payments (41 ) Balance at June 30, 2017 432 Payments (432 ) Balance at December 31, 2017 $ — |
Subsequent Events
Subsequent Events | 6 Months Ended |
Jun. 30, 2018 | |
Subsequent Events | 15. Subsequent Events Sanofi Collaboration and License Agreement On June 8, 2018, the Company entered into a collaboration and license agreement with Sanofi. The Sanofi Agreement became effective on July 9, 2018, following receipt of clearance under the Hart–Scott–Rodino Antitrust Improvements Act of 1976. Under the Sanofi Agreement, the Company and Sanofi have agreed to collaborate to perform certain research and development activities to advance mRNA vaccines and mRNA vaccine platform development during a three-year research term, which may be extended by mutual agreement. The collaboration activities will be subject to a collaboration plan to be updated annually. The Sanofi Agreement provides that Sanofi make an upfront payment to the Company of $45.0 million, which the Company received on July 18, 2018, as well as certain potential milestone payments and option payments, each as further described below. In addition, the Company is eligible to receive from Sanofi tiered royalty payments on worldwide net sales of mRNA vaccines. Under the terms of the Sanofi Agreement, the Company has granted to Sanofi exclusive, worldwide licenses under applicable patents, patent applications, know-how The Company and Sanofi retain the rights to perform their respective obligations and exercise their respective rights under the Sanofi Agreement, and Sanofi may grant sublicenses to affiliates or third parties. Sanofi has also granted the Company non-exclusive, Under the Sanofi Agreement, the Company and Sanofi created a governance structure, including committees and working groups, to manage the activities under the collaboration. If the Company and Sanofi do not mutually agree on certain decisions, Sanofi would be able to break a deadlock without the Company’s consent. The collaboration plan will include an estimated budget. Sanofi is responsible for paying the Company’s employee costs, out-of-pocket Sanofi has sole responsibility for all commercialization activities for mRNA vaccines in the licensed fields and is obligated to bear all costs in connection with any such commercialization. The Company and Sanofi intend to enter into a supply agreement pursuant to which the Company would be responsible for manufacturing certain non-clinical The Sanofi Agreement provides that the Company is eligible to receive aggregate potential payments of up to $805.0 million from Sanofi, which includes an upfront payment, potential milestone payments and potential option exercise payments. In July 2018, Sanofi paid the Company a $45.0 million upfront payment in respect of the licenses and options granted to Sanofi. Sanofi will also pay the Company $5.0 million with respect to each additional licensed field for which it exercises an option. Sanofi has also agreed to pay the Company milestone payments upon the achievement of specified development, regulatory and commercialization milestones. In particular, the Company is entitled to receive development and regulatory milestone payments of up to $63.0 million per licensed field and sales milestone payments of up to $85.0 million per licensed field. In addition, the Company is entitled to receive a $10.0 million milestone payment from Sanofi following completion of the technology and process transfer. Sanofi has agreed to pay the Company a tiered royalty on worldwide net sales of all mRNA vaccines within each licensed field ranging from a high single-digit percentage to a low teens percentage, depending on quarterly net sales by Sanofi, its affiliates and its sublicensees. The royalty paid to the Company can be reduced with respect to a product once the relevant licensed patent rights expire or if additional licensed technology is required, but the royalty payments generally may not fall below the Company’s royalty obligations to third parties plus a royalty of a low single-digit percentage. Royalty payments under the Sanofi Agreement are payable on a product-by-product country-by-country The Sanofi Agreement provides that it will remain in effect until terminated in accordance with its terms. Either the Company or Sanofi may terminate the Sanofi Agreement in its entirety if the other party is subject to certain insolvency proceedings. Either party may terminate the Sanofi Agreement in its entirety or with respect to a particular licensed field, country or product if the other party materially breaches the Sanofi Agreement and the breach remains uncured for a specified period, which may be extended in certain circumstances. Sanofi may also terminate the Sanofi Agreement its entirety or with respect to a particular licensed field, country or product for safety reasons or for convenience, in each case after a specified notice period. After termination of the Sanofi Agreement, Sanofi may continue to manufacture and commercialize the terminated products for a specified period of time, subject to Sanofi’s payment obligations. The Company is currently evaluating its accounting treatment for the Sanofi Agreement. Initial Public Offering On June 27, 2018, the Company’s registration statement on Form S-1 Issuance of Common Stock to Shire As a result of and concurrent with the closing of the Company’s IPO on July 2, 2018, the Company issued 183,619 shares of common stock to Shire in full satisfaction of the Company’s anti-dilution obligations to Shire. The issued shares of common stock had a fair value of $2.4 million (see Note 4). Changes to Authorized Common and Preferred Shares On July 2, 2018, the Company filed a restated certificate of incorporation in the State of Delaware, which, among other things, restated the number of shares of all classes of stock that the Company has authority to issue to 210,000,000 shares, consisting of (i) 200,000,000 shares of common stock, $0.001 par value per share, and (ii) 10,000,000 shares of preferred stock, $0.001 par value per share. The shares of preferred stock are currently undesignated. |
Summary of Significant Accoun23
Summary of Significant Accounting Policies (Policies) | 6 Months Ended |
Jun. 30, 2018 | |
Use of Estimates | Use of Estimates The preparation of the Company’s consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the consolidated financial statements, and the reported amounts of expenses during the reporting period. Actual results could differ from those estimates. Significant estimates and assumptions reflected in these consolidated financial statements include, but are not limited to, the accrual for research and development expenses, the valuation of common stock and stock-based awards, the valuation of assets acquired and liabilities assumed in business combinations, and the impairment of identifiable intangible assets and goodwill. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Changes in estimates are recorded in the period in which they become known. Actual results could differ from those estimates. |
Unaudited Interim Financial Information | Unaudited Interim Financial Information The accompanying unaudited condensed consolidated balance sheet as of June 30, 2018, the unaudited condensed consolidated statements of operations and of comprehensive loss for the three and six months ended June 30, 2018 and 2017 and of cash flows for the six months ended June 30, 2018 and 2017 have been prepared by the Company, pursuant to the rules and regulations of the SEC for the interim financial statements. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to rules and regulations. However, the Company believes that the disclosures are adequate to make the information presented not misleading. The accompanying unaudited interim condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and the notes thereto for the year ended December 31, 2017 included in the Company’s prospectus that forms a part of the Company’s Registration Statement on Form S-1 No. 333-225368). The accompanying unaudited interim condensed consolidated financial presentation has been prepared on the same basis as the audited annual consolidated financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for the fair statement of the Company’s financial position as of June 30, 2018, the results of its operations for the three and six months ended June 30, 2018 and 2017, and its cash flows for the six months ended June 30, 2018 and 2017. The financial data and other information disclosed in these notes related to the three and six months ended June 30, 2018 and 2017 are also unaudited. The results for the six months ended June 30, 2018 are not necessarily indicative of results to be expected for the year ending December 31, 2018, any other interim periods, or any future year or period. |
Cash and Cash Equivalents | Cash and Cash Equivalents All highly liquid investments purchased with an original maturity date of three months or less at the date of purchase are considered to be cash equivalents. Cash equivalents consisted of money market funds as of June 30, 2018 and December 31, 2017. |
Investments | Investments The Company’s debt security investments are classified as available-for-sale The Company evaluates its investments with unrealized losses for other-than-temporary impairment. When assessing investments for other-than-temporary declines in value, the Company considers such factors as, among other things, how significant the decline in value is as a percentage of the original cost, how long the market value of the investment has been less than its original cost, the Company’s ability and intent to retain the investment for a period of time sufficient to allow for any anticipated recovery in fair value and market conditions in general. If any adjustment to fair value reflects a decline in the value of the investment that the Company considers to be “other than temporary,” the Company reduces the investment to fair value through a charge to the statement of operations. No such adjustments were necessary during the periods presented. The Company’s investments as of June 30, 2018 and December 31, 2017 had original maturities of less than one year. |
Concentrations of Credit Risk | Concentrations of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of cash and cash equivalents as well as short-term investments. Cash, cash equivalents and short-term investments consist of demand deposits, money market funds and U.S. government agency bonds. The Company generally maintains balances in various operating accounts with financial institutions that management believes to be of high credit quality, in amounts that may exceed federally insured limits. The Company has not experienced any losses related to its cash, cash equivalents and short-term investments and does not believe that it is subject to unusual credit risk beyond the normal credit risk associated with commercial banking relationships. |
Restricted Cash | Restricted Cash In connection with its operating lease commitments, the Company issued letters of credit collateralized by cash deposits that are classified as restricted cash in the consolidated balance sheets. Restricted cash amounts have been classified as current assets based on the release dates of the restrictions under the letters of credit, which occur annually. |
Deferred Offering Costs | Deferred Offering Costs The Company capitalizes certain legal, professional accounting and other third-party fees that are directly associated with in-process in-process |
Property and Equipment | Property and Equipment Property and equipment are stated at cost less accumulated depreciation and amortization. Depreciation and amortization expense is recognized using the straight-line method over the estimated useful lives of each asset. Estimated useful lives are periodically assessed to determine if changes are appropriate. Upon retirement or sale, the related cost and accumulated depreciation and amortization are removed from the accounts and any resulting gain or loss is included in the consolidated statements of operations. Repair and maintenance costs are expensed as incurred. The estimated useful lives of the Company’s property and equipment are as follows: Estimated Useful Life Laboratory equipment 5 years Computer equipment 3 years Office equipment 5 years Leasehold improvements Shorter of lease term or 10 years Costs for capital assets not yet placed into service are capitalized as construction-in-progress Property and equipment are tested for recoverability whenever events or changes in business circumstances indicate that the carrying amount of the assets may not be fully recoverable. Factors that the Company considers in deciding when to perform an impairment review include significant underperformance of the business in relation to expectations, significant negative industry or economic trends and significant changes or planned changes in the use of the assets. If an impairment review is performed to evaluate an asset group for recoverability, the Company compares the forecasted undiscounted cash flows expected to result from the use and eventual disposition of the asset group to its carrying value. An impairment loss would be recognized when estimated undiscounted future cash flows expected to result from the use and eventual disposition of an asset group are less than its carrying amount. The impairment loss would be based on the excess of the carrying value of the impaired asset group over its fair value, determined based on discounted cash flows using market participant assumptions. The Company did not record any impairment losses on property and equipment during the three and six months ended June 30, 2018 and 2017. |
Business Combinations | Business Combinations The Company accounts for business combinations using the acquisition method of accounting. Application of this method of accounting requires that (i) identifiable assets acquired (including identifiable intangible assets) and liabilities assumed generally be measured and recognized at fair value as of the acquisition date and (ii) the excess of the purchase price over the net fair value of identifiable assets acquired and liabilities assumed be recognized as goodwill, which is not amortized for accounting purposes but is subject to testing for impairment at least annually. Acquired in-process Determining the fair value of assets acquired and liabilities assumed in a business combination requires management to use significant judgment and estimates, especially with respect to intangible assets. Critical estimates in valuing certain identifiable assets include, but are not limited to, the selection of valuation methodologies, estimates of future revenue and cash flows, expected long-term market growth, future expected operating expenses, costs of capital and appropriate discount rates. Management’s estimates of fair value are based upon assumptions believed to be reasonable, but which are inherently uncertain and, as a result, actual results may differ materially from estimates. During the measurement period, which extends no later than one year from the acquisition date, the Company may record certain adjustments to the carrying value of the assets acquired and liabilities assumed with the corresponding offset to goodwill. After the measurement period, all adjustments are recorded in the consolidated statements of operations as operating expenses or income. Acquisition-related contingent consideration, which consists of potential milestone and earnout payment obligations as well as anti-dilution rights provided to Shire (see Note 3), was recorded in the consolidated balance sheets at its acquisition-date estimated fair value, in accordance with the acquisition method of accounting. The fair value of the acquisition-related contingent consideration is remeasured each reporting period, with changes in fair value recorded in the consolidated statements of operations. The fair value measurement is based on significant inputs not observable by market participants and thus represents a Level 3 input in the fair value hierarchy (see Note 4). |
Asset Acquisitions | Asset Acquisitions The Company measures and recognizes asset acquisitions that are not deemed to be business combinations based on the cost to acquire the assets, which includes transaction costs. Goodwill is not recognized in asset acquisitions. In an asset acquisition, the cost allocated to acquire IPR&D with no alternative future use is charged to expense at the acquisition date. |
In-Process Research and Development | In-Process The fair value of IPR&D acquired through a business combination is capitalized as an indefinite-lived intangible asset until the completion or abandonment of the related research and development activities. When the related research and development is completed, the asset is reclassified to a definite-lived asset and amortized over its estimated useful life. The fair value of an IPR&D intangible asset is typically determined using an income approach whereby management forecasts the net cash flows expected to be generated by the asset over its estimated useful life. The net cash flows reflect the asset’s stage of completion, the probability of technical success, the projected costs to complete, expected market competition, and an assessment of the asset’s life-cycle. The net cash flows are then adjusted to present value by applying an appropriate discount rate that reflects the risk factors associated with the cash flow streams. Indefinite-lived IPR&D is not subject to amortization, but is tested annually for impairment or more frequently if there are indicators of impairment. The Company tests its indefinite-lived IPR&D annually for impairment on October 1st. In testing indefinite-lived IPR&D for impairment, the Company has the option to first assess qualitative factors to determine whether the existence of events or circumstances would indicate that it is more likely than not that its fair value is less than its carrying amount, or the Company can perform a quantitative impairment analysis to determine the fair value of the indefinite-lives IPR&D without performing a qualitative assessment. Qualitative factors that the Company considers include significant underperformance of the business in relation to expectations, significant negative industry or economic trends and significant changes or planned changes in the use of the assets. If the Company chooses to first assess qualitative factors and the Company determines that it is more likely than not that the fair value of the indefinite-lived IPR&D is less than its carrying amount, the Company would then determine the fair value of the indefinite-lived IPR&D. Under either approach, if the fair value of the indefinite-lived IPR&D is less than its carrying amount, an impairment charge is recognized in the consolidated statements of operations. During the three and six months ended June 30, 2018 and 2017, the Company did not recognize any impairment charges related to its indefinite-lived IPR&D (see Note 3). Definite-lived IPR&D, if any, is tested for recoverability whenever events or changes in business circumstances indicate that the carrying amount of the assets may not be fully recoverable. If an impairment review is performed to evaluate an asset group for recoverability, the Company compares the forecasted undiscounted cash flows expected to result from the use and eventual disposition of the asset group to its carrying value. An impairment loss would be recognized when estimated undiscounted future cash flows expected to result from the use and eventual disposition of an asset group are less than its carrying amount. The impairment loss would be based on the excess of the carrying value of the impaired asset group over its fair value, determined based on discounted cash flows using market participant assumptions. |
Goodwill | Goodwill Goodwill represents the excess of the fair value of the consideration transferred over the fair value of the net tangible and identifiable intangible assets acquired in a business combination. Goodwill is not subject to amortization, but is tested annually for impairment or more frequently if there are indicators of impairment. The Company tests its goodwill annually for impairment on October 1st. The Company has determined that there is a single reporting unit for purposes of testing goodwill for impairment. In testing goodwill for impairment, the Company has the option to first assess qualitative factors to determine whether the existence of events or circumstances would indicate that it is more likely than not that the fair value of the reporting unit was less than its carrying amount, or the Company can perform a two-step two-step two-step |
Fair Value Measurements | Fair Value Measurements Certain assets and liabilities of the Company are carried at fair value under GAAP. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three levels of the fair value hierarchy, of which the first two are considered observable and the last is considered unobservable: • Level 1—Quoted prices in active markets for identical assets or liabilities. • Level 2—Observable inputs (other than Level 1 quoted prices), such as quoted prices in active markets for similar assets or liabilities, quoted prices in markets that are not active for identical or similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data. • Level 3—Unobservable inputs that are supported by little or no market activity that are significant to determining the fair value of the assets or liabilities, including pricing models, discounted cash flow methodologies and similar techniques. The Company’s cash equivalents and short-term investments are carried at fair value, determined based on Level 2 inputs in the fair value hierarchy described above (see Note 4). The Company’s contingent consideration liability is carried at fair value, determined based on Level 3 inputs in the fair value hierarchy described above (see Note 4). The carrying values of the Company’s prepaid expenses and other current assets, accounts payable, accrued expenses and other short-term liabilities approximate their fair values due to the short-term nature of these assets and liabilities. |
Segment Information | Segment Information The Company manages its operations as a single operating segment for the purposes of assessing performance and making operating decisions. The Company’s primary focus is on the advancement of the Company’s MRT platform to treat diseases caused by protein or gene dysfunction. |
Research and Development Costs | Research and Development Costs Costs associated with internal research and development and external research and development services, including drug development and preclinical studies, are expensed as incurred. Research and development expenses include costs for salaries, employee benefits, subcontractors, facility-related expenses, depreciation and amortization, stock-based compensation, third-party license fees, laboratory supplies, and external costs of outside vendors engaged to conduct discovery, preclinical and clinical development activities and clinical trials as well as to manufacture clinical trial materials, and other costs. The Company recognizes external research and development costs based on an evaluation of the progress to completion of specific tasks using information provided to the Company by its service providers. Nonrefundable advance payments for goods or services to be received in the future for use in research and development activities are recorded as prepaid expenses. Such prepaid expenses are recognized as an expense when the services have been performed or the goods have been delivered, or when it is no longer expected that the goods will be delivered or the services rendered. Upfront payments, milestone payments (other than those deemed contingent consideration in a business combination) and annual maintenance fees under license agreements are expensed in the period in which they are incurred. |
Research and Development Contract Costs and Accruals | Research and Development Contract Costs and Accruals The Company has entered into various research and development-related contracts with companies both inside and outside of the United States. The related costs are recorded as research and development expenses as incurred. The Company records accruals for estimated ongoing research and development costs. When evaluating the adequacy of the accrued liabilities, the Company analyzes progress of the studies or clinical trials, including the phase or completion of events, invoices received and contracted costs. Significant judgments and estimates are made in determining the accrued balances at the end of any reporting period. Actual results could differ materially from the Company’s estimates. The Company’s historical accrual estimates have not been materially different from the actual costs. |
Stock-Based Compensation | Stock-Based Compensation The Company measures all stock-based awards granted to employees and directors based on their fair value on the date of the grant and recognizes compensation expense for those awards over the requisite service period, which is generally the vesting period of the respective award. For stock-based awards with service-based vesting conditions, the Company recognizes compensation expense using the straight-line method. For stock-based awards with both performance-based and service-based vesting conditions, the Company recognizes compensation expense using the graded-vesting method over the requisite service period, commencing when achievement of the performance condition becomes probable. The fair value of each stock option grant is estimated on the date of grant using the Black-Scholes option-pricing model, which requires inputs based on certain subjective assumptions, including the expected stock price volatility, the expected term of the option, the risk-free interest rate for a period that approximates the expected term of the option, and the Company’s expected dividend yield (see Note 9). The fair value of each restricted common stock award is estimated on the date of grant based on the fair value of the Company’s common stock on that same date. For stock-based awards granted to non-employee non-employee The Company classifies stock-based compensation expense in its consolidated statements of operations in the same manner in which the award recipient’s payroll costs are classified or in which the award recipient’s service payments are classified. |
Classification and Accretion of Redeemable Convertible Preferred Units and Redeemable Convertible Preferred Stock | Classification and Accretion of Redeemable Convertible Preferred Units and Redeemable Convertible Preferred Stock The Company has classified its redeemable convertible preferred units and redeemable convertible preferred stock outside of stockholders’ equity (deficit) because the units or shares contain certain redemption features that are not solely within the control of the Company. Costs incurred in connection with the issuance of each series of redeemable convertible preferred units or stock are recorded as a reduction of gross proceeds from issuance. The carrying values of redeemable convertible preferred units and stock are accreted to their redemption values through a charge to additional paid-in |
Comprehensive Loss | Comprehensive Loss Comprehensive loss includes net loss as well as other changes in stockholders’ equity (deficit) that result from transactions and economic events other than those with stockholders. The Company’s only element of other comprehensive income (loss) was unrealized gains (losses) on U.S. government agency bonds, which are classified as available-for-sale-securities. |
Income Taxes | Income Taxes The Company accounts for income taxes using the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been recognized in the consolidated financial statements or in the Company’s tax returns. Deferred tax assets and liabilities are determined on the basis of the differences between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. Changes in deferred tax assets and liabilities are recorded in the provision for income taxes. The Company assesses the likelihood that its deferred tax assets will be recovered from future taxable income and, to the extent it believes, based upon the weight of available evidence, that it is more likely than not that all or a portion of the deferred tax assets will not be realized, a valuation allowance is established through a charge to income tax expense. Potential for recovery of deferred tax assets is evaluated by estimating the future taxable profits expected and considering prudent and feasible tax planning strategies. The Company accounts for uncertainty in income taxes recognized in the consolidated financial statements by applying a two-step more-likely-than-not |
Net Income (Loss) per Share | Net Income (Loss) per Share The Company follows the two-class two-class two-class Basic net income (loss) per share attributable to common stockholders is computed by dividing the net income (loss) attributable to common stockholders by the weighted average number of shares of common stock outstanding for the period. Diluted net income (loss) attributable to common stockholders is computed by adjusting net income (loss) attributable to common stockholders to reallocate undistributed earnings based on the potential impact of dilutive securities. Diluted net income (loss) per share attributable to common stockholders is computed by dividing the diluted net income (loss) attributable to common stockholders by the weighted average number of shares of common stock outstanding for the period, including potential dilutive shares of common stock. For purpose of this calculation, outstanding stock options, unvested restricted common stock and redeemable convertible preferred stock are considered potential dilutive shares of common stock. The Company’s preferred stock contractually entitles the holders of such shares to participate in dividends but does not contractually require the holders of such shares to participate in losses of the Company. Accordingly, in periods in which the Company reports a net loss attributable to common stockholders, such losses are not allocated to such participating securities. In periods in which the Company reports a net loss attributable to common stockholders, diluted net loss per share attributable to common stockholders is the same as basic net loss per share attributable to common stockholders, since dilutive shares of common stock are not assumed to have been issued if their effect is anti-dilutive. The Company reported a net loss attributable to common stockholders for the three and six months ended June 30, 2018 and 2017. |
Recently Adopted Accounting Pronouncements | Recently Adopted Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) 2014-09”), 2014-09 2014-09 In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows: Classification of Certain Cash Receipts and Cash Payments (Topic 230) 2016-15”), 2016-15 2016-15 In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230) 2016-18”), beginning-of-period end-of-period 2016-18 In May 2017, the FASB issued ASU No. 2017-09, Compensation—Stock Compensation: Scope of Modification Accounting (Topic 718) 2017-09”), 2017-09 |
Recently Issued Accounting Pronouncements | Recently Issued Accounting Pronouncements In February 2016, the FASB issued ASU No. 2016-02 , Leases (Topic 842) 2016-02”), right-of-use 2016-02 In January 2017, the FASB issued ASU No. 2017-04, Intangibles—Goodwill and Other: Simplifying the Test for Goodwill Impairment (Topic 350) 2017-04”), 2017-04 2017-04 In July 2017, the FASB issued ASU No. 2017-11, Earnings Per Share (Topic 260), Distinguishing Liabilities from Equity (Topic 480), Derivatives and Hedging (Topic 815) I. Accounting for Certain Financial Instruments with Down Round Features II. Replacement of the Indefinite Deferral for Mandatorily Redeemable Financial Instruments of Certain Nonpublic Entities and Certain Mandatorily Redeemable Noncontrolling Interests with a Scope Exception (“ASU 2017-11”) . 2017-11 2017-11 In June 2018, the FASB issued ASU No. 2018-07, Compensation-Stock Compensation (Topic 718) 2018-07”), non-employees. non-employee |
Summary of Significant Accoun24
Summary of Significant Accounting Policies (Tables) | 6 Months Ended |
Jun. 30, 2018 | |
Estimated Useful Lives of Property and Equipment | The estimated useful lives of the Company’s property and equipment are as follows: Estimated Useful Life Laboratory equipment 5 years Computer equipment 3 years Office equipment 5 years Leasehold improvements Shorter of lease term or 10 years |
Acquisitions, Goodwill and Ot25
Acquisitions, Goodwill and Other Intangible Assets (Tables) | 6 Months Ended |
Jun. 30, 2018 | |
Summary of Fair Value of Consideration Transferred | The aggregate acquisition-date fair value of consideration transferred was determined to be $112.2 million, consisting of the following (in thousands): Fair value of common stock $ 41,089 Fair value of contingent consideration — potential milestone and earnout payments 62,666 Fair value of contingent consideration — anti-dilution rights 8,407 Total fair value of purchase consideration $ 112,162 |
Summary of Fair Value of Consideration Allocated to Tangible and Intangible Assets Acquired | The total consideration transferred was allocated to the tangible and identifiable intangible assets acquired based on their estimated fair values as follows (in thousands): Identifiable intangible assets $ 106,907 Property and equipment 2,416 Deferred tax assets 1,308 Deferred tax liabilities (18,520 ) Valuation allowance for deferred tax assets (1,308 ) Goodwill 21,359 Total purchase price consideration $ 112,162 |
Fair Values of Identifiable Intangible Assets as of Acquisition Date | The fair values of the identifiable intangible assets as of the acquisition date were as follows (in thousands): In-process $ 45,992 In-process 42,291 In-process 18,559 Lease agreement 65 Total identifiable intangible assets $ 106,907 |
Fair Value of Financial Asset26
Fair Value of Financial Assets and Liabilities (Tables) | 6 Months Ended |
Jun. 30, 2018 | |
Schedule of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis | The following tables present information about the Company’s financial assets and liabilities measured at fair value on a recurring basis (in thousands): Fair Value Measurements as of June 30, 2018 Using: Level 1 Level 2 Level 3 Total Assets: Money market funds $ — $ 11,148 $ — $ 11,148 U.S. government agency bonds — 1,000 — 1,000 $ — $ 12,148 $ — $ 12,148 Liabilities: Contingent consideration $ — $ — $ 93,769 $ 93,769 $ — $ — $ 93,769 $ 93,769 Fair Value Measurements as of December 31, 2017 Using: Level 1 Level 2 Level 3 Total Assets: Money market funds $ — $ 28,636 $ — $ 28,636 U.S. government agency bonds — 9,997 — 9,997 $ — $ 38,633 $ — $ 38,633 Liabilities: Contingent consideration $ — $ — $ 81,009 $ 81,009 $ — $ — $ 81,009 $ 81,009 |
Schedule of Unobservable Inputs and Fair Value Components of Contingent Consideration | The following tables presents the unobservable inputs and fair value of the components of the contingent consideration (dollar amounts in thousands): Unobservable Inputs at June 30, 2018 and December 31, 2017 Fair Value at Projected Year June 30, December 31, Discount Rate of Payment 2018 2017 Earnout payments 15.0% 2025 - 2039 $ 83,709 $ 72,896 Milestone payments 15.0% 2025 - 2030 7,673 6,817 Anti-dilution rights 1.39% - 1.77% N/A 2,387 1,296 $ 93,769 $ 81,009 |
Schedule of Total Acquisition Related Contingent Consideration Liability | The following table presents a roll-forward of the total acquisition-related contingent consideration liability (in thousands): Fair Value Balance as of December 31, 2017 $ 81,009 Change in fair value of contingent consideration 12,760 Balance as of June 30, 2018 $ 93,769 |
Property and Equipment, Net (Ta
Property and Equipment, Net (Tables) | 6 Months Ended |
Jun. 30, 2018 | |
Schedule of Property and Equipment, Net | Property and equipment, net consisted of the following (in thousands): June 30, December 31, 2018 2017 Laboratory equipment $ 5,914 $ 5,382 Computer equipment 626 481 Office equipment 701 249 Leasehold improvements 5,632 1,131 Construction in progress 950 2,591 13,823 9,834 Less: Accumulated depreciation and amortization (3,955 ) (3,056 ) $ 9,868 $ 6,778 |
Accrued Expenses (Tables)
Accrued Expenses (Tables) | 6 Months Ended |
Jun. 30, 2018 | |
Schedule of Accrued Expenses | Accrued expenses consisted of the following (in thousands): June 30, December 31, 2018 2017 Accrued consultant and professional fees $ 2,204 $ 1,130 Accrued employee compensation and benefits 1,940 2,252 Accrued external research and development expenses 1,132 1,115 Other 482 1,391 $ 5,758 $ 5,888 |
Redeemable Convertible Prefer29
Redeemable Convertible Preferred Stock (Tables) | 6 Months Ended |
Jun. 30, 2018 | |
Schedule of Preferred Stock | As of each balance sheet date, the Preferred Stock consisted of the following (in thousands, except share amounts): June 30, 2018 Preferred Shares Authorized Preferred Shares Issued and Outstanding Carrying Value Liquidation Preference Common Issuable Upon Conversion Series A preferred stock 36,194,026 36,194,026 $ 36,194 $ 36,194 6,514,986 Series B preferred stock 59,133,987 59,133,987 64,365 63,199 10,644,210 Series C preferred stock 50,505,051 46,960,279 92,981 92,981 8,452,913 145,833,064 142,288,292 $ 193,540 $ 192,374 25,612,109 December 31, 2017 Preferred Shares Authorized Preferred Shares Issued and Outstanding Carrying Value Liquidation Preference Common Issuable Upon Conversion Series A preferred stock 36,194,026 36,194,026 $ 36,194 $ 36,194 6,514,986 Series B preferred stock 59,133,987 59,133,987 64,002 63,199 10,644,210 Series C preferred stock 50,505,051 46,960,279 92,700 92,981 8,452,913 145,833,064 142,288,292 $ 192,896 $ 192,374 25,612,109 |
Incentive Stock Options and R30
Incentive Stock Options and Restricted Stock (Tables) | 6 Months Ended |
Jun. 30, 2018 | |
Summary of Stock Option Activity | The following table summarizes the Company’s stock option activity since December 31, 2016 (in thousands, except share and per share amounts): Number of Shares Weighted Average Exercise Price Weighted Remaining Contractual Intrinsic Value (in years) Outstanding as of December 31, 2016 209,797 $ 4.73 9.70 $ — Granted 4,257,593 Forfeited (102,474 ) Outstanding as of December 31, 2017 4,364,916 $ 7.17 9.79 $ 977 Granted 1,966,114 $ 8.76 Exercised (49,459 ) $ 5.62 Forfeited (188,163 ) $ 6.16 Outstanding as of June 30, 2018 6,093,408 $ 7.72 9.23 $ 30,020 Vested as of June 30, 2018 1,182,097 $ 7.08 8.25 $ 6,586 Vested and expected to vest as of June 30, 2018 6,093,408 $ 7.72 9.23 $ 30,020 Vested as of December 31, 2017 661,593 $ 7.04 9.72 $ 231 Vested and expected to vest as of December 31, 2017 4,364,916 $ 7.17 9.79 $ 977 |
Summary of Restricted Stock Activity | The following table summarizes the Company’s restricted stock activity since December 31, 2016: Number of Shares Weighted Average Grant-Date Fair Value Unvested restricted common stock outstanding as of December 31, 2016 986,893 $ 1.10 Forfeited restricted common stock (100,563 ) $ 1.10 Vested restricted common stock (359,852 ) $ 1.04 Unvested restricted common stock outstanding as of December 31, 2017 526,478 $ 1.14 Forfeited restricted common stock (311 ) $ 1.28 Vested restricted common stock (157,292 ) $ 1.03 Unvested restricted common stock outstanding as of June 30, 2018 368,875 $ 1.19 |
Summary of Stock-Based Compensation Expense | Stock-based compensation expense was classified in the condensed consolidated statements of operations as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Research and development expenses $ 1,671 $ 610 $ 2,453 $ 636 General and administrative expenses 1,204 81 1,805 156 $ 2,875 $ 691 $ 4,258 $ 792 |
Employee and Board of Directors [Member] | |
Summary of Assumptions Used in Black-Scholes Option-Pricing Model to Determine Grant-Date Fair Value of Stock Option Granted | The following table presents, on a weighted average basis, the assumptions used in the Black-Scholes option-pricing model to determine the grant-date fair value of stock options granted to employees and directors: Six Months Ended June 30, 2018 2018 2017 Risk-free interest rate 2.80 % 2.02 % Expected term (in years) 6.0 6.0 Expected volatility 75.7 % 65.0 % Expected dividend yield 0 % 0 % |
Non Employee [Member] | |
Summary of Assumptions Used in Black-Scholes Option-Pricing Model to Determine Grant-Date Fair Value of Stock Option Granted | The following table presents the assumptions used in the Black-Scholes option-pricing model to determine the grant-date fair value of stock options granted to a non-employee: Six Months Ended June 30, 2017 Risk-free interest rate 2.08 % Expected term (in years) 10.0 Expected volatility 60.9 % Expected dividend yield 0 % |
Net Loss per Share (Tables)
Net Loss per Share (Tables) | 6 Months Ended |
Jun. 30, 2018 | |
Summary of Basic and Diluted Net Loss Per Share Attributable to Common Stockholders | Basic and diluted net loss per share attributable to common stockholders was calculated as follows (in thousands, except share and per share amounts): Three Months Ended June 30, Six Months Ended June 30, 2018 2017 2018 2017 Numerator: Net loss $ (27,503 ) $ (17,933 ) $ (48,712 ) $ (31,886 ) Accretion of redeemable convertible preferred units and stock to redemption value 459 192 644 360 Net loss attributable to common stockholders $ (27,044 ) $ (17,741 ) $ (48,068 ) $ (31,526 ) Denominator: Weighted average common shares outstanding—basic and diluted 9,187,207 7,676,426 9,139,638 7,631,883 Net loss per share attributable to common stockholders—basic and diluted $ (2.94 ) $ (2.31 ) $ (5.26 ) $ (4.13 ) |
Summary of Potential Common Shares Excluded from Computation of Diluted Net Loss per Share Attributable to Common Stockholders | The Company excluded the following potential common shares, presented based on amounts outstanding at each period end, from the computation of diluted net loss per share attributable to common stockholders for the periods indicated because including them would have had an anti-dilutive effect: Three and Six Months Ended June 30, 2018 2017 Options to purchase common stock 6,093,408 1,255,347 Unvested restricted common stock 368,875 714,370 Redeemable convertible preferred stock (as converted to common stock) 25,612,109 21,795,593 32,074,392 23,765,310 |
Costs Associated with Restruc32
Costs Associated with Restructuring (Tables) | 6 Months Ended |
Jun. 30, 2018 | |
Summary of Changes in Accrued Restructuring Costs | Changes in accrued restructuring costs were as follows (in thousands): Balance at December 31, 2016 $ — Charges 473 Payments (41 ) Balance at June 30, 2017 432 Payments (432 ) Balance at December 31, 2017 $ — |
Nature of the Business and Ba33
Nature of the Business and Basis of Presentation - Additional Information (Detail) $ / shares in Units, $ in Thousands | Jul. 24, 2018USD ($)$ / sharesshares | Jul. 18, 2018USD ($) | Jul. 02, 2018$ / sharesshares | Jun. 15, 2018 | Jun. 08, 2018USD ($)Diseases | Jun. 30, 2018USD ($)shares | Jun. 30, 2017USD ($) | Jun. 30, 2018USD ($)Subsidiariesshares | Jun. 30, 2017USD ($) | Jul. 31, 2018USD ($)shares | Dec. 31, 2017USD ($)shares |
Initial Public Offering [Line Items] | |||||||||||
Number of wholly owned subsidiaries | Subsidiaries | 2 | ||||||||||
Reverse stock split description | One-for-5.5555 reverse stock split | ||||||||||
Reverse stock split ratio | 0.1800 | ||||||||||
Common stock outstanding | shares | 9,631,939 | 9,631,939 | 9,582,791 | ||||||||
Accumulated deficit | $ (197,520) | $ (197,520) | $ (148,808) | ||||||||
Net income loss | (27,503) | $ (17,933) | (48,712) | $ (31,886) | |||||||
Cash and cash equivalents | $ 17,500 | $ 17,500 | |||||||||
Subsequent Event [Member] | IPO [Member] | |||||||||||
Initial Public Offering [Line Items] | |||||||||||
Common stock issued and sold | shares | 364,371 | 9,350,000 | |||||||||
Common stock issued and sold, per share | $ / shares | $ 13 | $ 13 | |||||||||
Net proceeds from IPO | $ 113,400 | ||||||||||
Underwriting discounts and commissions | 8,800 | ||||||||||
Offering expenses | $ 4,100 | ||||||||||
Shares of redeemable convertible preferred stock converted | shares | 142,288,292 | ||||||||||
Shares of common stock issued upon conversion of redeemable convertible preferred stock | shares | 25,612,109 | ||||||||||
Common stock outstanding | shares | 45,141,690 | ||||||||||
Sanofi Pasteur Collaboration and Licensing Agreement [Member] | Sanofi Pasteur Inc [Member] | |||||||||||
Initial Public Offering [Line Items] | |||||||||||
Number of undisclosed infectious disease pathogens | Diseases | 5,000,000 | ||||||||||
Period of research term | 3 years | ||||||||||
Receivable from related party collaboration | $ 805,000 | ||||||||||
Sanofi Pasteur Collaboration and Licensing Agreement [Member] | Sanofi Pasteur Inc [Member] | Subsequent Event [Member] | |||||||||||
Initial Public Offering [Line Items] | |||||||||||
Receivable from related party collaboration | $ 805,000 | ||||||||||
Upfront payment received | $ 45,000 | $ 45,000 |
Summary of Significant Accoun34
Summary of Significant Accounting Policies - Additional Information (Detail) | 3 Months Ended | 6 Months Ended | |||
Jun. 30, 2018USD ($) | Jun. 30, 2017USD ($) | Jun. 30, 2018USD ($)Segment | Jun. 30, 2017USD ($) | Dec. 31, 2017USD ($) | |
Indefinite-lived Intangible Assets [Line Items] | |||||
Deferred offering costs | $ 3,976,000 | $ 3,976,000 | $ 511,000 | ||
Goodwill impairment charge | 0 | $ 0 | $ 0 | $ 0 | |
Number of operating segment | Segment | 1 | ||||
ASU 2016-18 [Member] | |||||
Indefinite-lived Intangible Assets [Line Items] | |||||
Increase in cash and cash equivalents as effect of adoption | 2,200,000 | ||||
In-Process Research and Development [Member] | |||||
Indefinite-lived Intangible Assets [Line Items] | |||||
Impairment charges on assets | 0 | 0 | $ 0 | 0 | |
Property and Equipment [Member] | |||||
Indefinite-lived Intangible Assets [Line Items] | |||||
Impairment charges on assets | $ 0 | $ 0 | $ 0 | $ 0 |
Summary of Significant Accoun35
Summary of Significant Accounting Policies - Estimated Useful Lives of Property and Equipment (Detail) | 6 Months Ended |
Jun. 30, 2018 | |
Laboratory Equipment [Member] | |
Property Plant And Equipment Estimated Useful Lives [Line Items] | |
Property plant and equipment useful life | 5 years |
Computer Equipment [Member] | |
Property Plant And Equipment Estimated Useful Lives [Line Items] | |
Property plant and equipment useful life | 3 years |
Office Equipment [Member] | |
Property Plant And Equipment Estimated Useful Lives [Line Items] | |
Property plant and equipment useful life | 5 years |
Leasehold Improvements [Member] | |
Property Plant And Equipment Estimated Useful Lives [Line Items] | |
Property plant and equipment estimated useful life | Shorter of lease term or 10 years |
Acquisitions, Goodwill and Ot36
Acquisitions, Goodwill and Other Intangible Assets - Additional Information (Detail) - USD ($) | Jul. 02, 2018 | Jun. 30, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | Jun. 07, 2018 |
Business Acquisition [Line Items] | |||||
Milestone payments payable | $ 93,769,000 | $ 81,009,000 | |||
Goodwill | 21,359,000 | $ 21,359,000 | |||
Shire's MRT Program [Member] | |||||
Business Acquisition [Line Items] | |||||
Milestone payments payable | $ 10,000,000 | $ 10,000,000 | |||
Common stock issued as consideration | 5,815,560 | ||||
Obligation to consummate equity financing | $ 100,000,000 | ||||
Percentage of common stock to be issued under antidilution right on as converted | 18.00% | ||||
Percentage of common stock outstanding voting power | 19.90% | ||||
Gross proceeds from subsequent financing used for activities and expenses of MRT program | $ 50,000,000 | ||||
Total fair value of purchase consideration | 112,200,000 | ||||
Fair value of common stock | $ 41,089,000 | ||||
Business combination, consideration paid in shares | 5,815,560 | ||||
Common stock issued | 70,866 | ||||
Deferred tax liability | $ 18,520,000 | ||||
Deferred tax assets | 1,308,000 | ||||
Goodwill | 21,359,000 | ||||
Shire's MRT Program [Member] | Maximum [Member] | |||||
Business Acquisition [Line Items] | |||||
Milestone payments payable | $ 60,000,000 | ||||
Shire's MRT Program [Member] | Subsequent Event [Member] | |||||
Business Acquisition [Line Items] | |||||
Common stock issued as consideration | 183,619 | ||||
Shire's MRT Program [Member] | Lease Agreements [Member] | |||||
Business Acquisition [Line Items] | |||||
Estimated useful life of intangible assets | 1 year 6 months | ||||
Shire's MRT Program [Member] | Series C Redeemable Convertible Preferred Stock [Member] | |||||
Business Acquisition [Line Items] | |||||
Consideration transferred, fair value of common stock per share | $ 1.98 | ||||
Shire's MRT Program [Member] | Common Stock [Member] | |||||
Business Acquisition [Line Items] | |||||
Consideration transferred, fair value of common stock per share | $ 7.06 | ||||
Shire's MRT Program [Member] | General and Administrative Expenses [Member] | |||||
Business Acquisition [Line Items] | |||||
Acquisition-related costs | $ 3,000,000 | ||||
Shire's MRT Program [Member] | Bank Service Charges [Member] | Accrued Liabilities [Member] | |||||
Business Acquisition [Line Items] | |||||
Acquisition-related costs | $ 500,000 |
Acquisitions, Goodwill and Ot37
Acquisitions, Goodwill and Other Intangible Assets - Summary of Fair Value of Consideration Transferred (Detail) - Shire's MRT Program [Member] $ in Thousands | 6 Months Ended |
Jun. 30, 2018USD ($) | |
Fair value of common stock | $ 41,089 |
Total fair value of purchase consideration | 112,162 |
Potential Milestone and Earnout Payments [Member] | |
Fair value of contingent consideration | 62,666 |
Anti- Dilution Rights [Member] | |
Fair value of contingent consideration | $ 8,407 |
Acquisitions, Goodwill and Ot38
Acquisitions, Goodwill and Other Intangible Assets - Summary of Fair Value of Consideration Allocated to Tangible and Intangible Assets Acquired (Detail) - USD ($) $ in Thousands | 6 Months Ended | |
Jun. 30, 2018 | Dec. 31, 2017 | |
Business Acquisition [Line Items] | ||
Goodwill | $ 21,359 | $ 21,359 |
Shire's MRT Program [Member] | ||
Business Acquisition [Line Items] | ||
Identifiable intangible assets | 106,907 | |
Property and equipment | 2,416 | |
Deferred tax assets | 1,308 | |
Deferred tax liabilities | (18,520) | |
Valuation allowance for deferred tax assets | (1,308) | |
Goodwill | 21,359 | |
Total purchase price consideration | $ 112,162 |
Acquisitions, Goodwill and Ot39
Acquisitions, Goodwill and Other Intangible Assets - Fair Values of Identifiable Intangible Assets as of Acquisition Date (Detail) - Shire's MRT Program [Member] $ in Thousands | Jun. 30, 2018USD ($) |
Business Acquisition [Line Items] | |
Total identifiable intangible assets | $ 106,907 |
Lease Agreements [Member] | |
Business Acquisition [Line Items] | |
Total identifiable intangible assets | 65 |
In-Process Research and Development [Member] | MRT Product [Member] | |
Business Acquisition [Line Items] | |
Total identifiable intangible assets | 45,992 |
In-Process Research and Development [Member] | Cystic Fibrosis [Member] | |
Business Acquisition [Line Items] | |
Total identifiable intangible assets | 42,291 |
In-Process Research and Development [Member] | OTC Deficiency [Member] | |
Business Acquisition [Line Items] | |
Total identifiable intangible assets | $ 18,559 |
Fair Value of Financial Asset40
Fair Value of Financial Assets and Liabilities - Schedule of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands | Jun. 30, 2018 | Dec. 31, 2017 |
Assets: | ||
Money market funds | $ 12,148 | $ 38,633 |
Total, asset | 12,148 | 38,633 |
Liabilities: | ||
Contingent consideration | 93,769 | 81,009 |
Total, liabilities | 93,769 | 81,009 |
Money Market Funds [Member] | ||
Assets: | ||
Money market funds | 11,148 | 28,636 |
Total, asset | 11,148 | 28,636 |
US Government Agency Bonds [Member] | ||
Assets: | ||
Money market funds | 1,000 | 9,997 |
Total, asset | 1,000 | 9,997 |
Contingent Consideration [Member] | ||
Liabilities: | ||
Contingent consideration | 93,769 | 81,009 |
Total, liabilities | 93,769 | 81,009 |
Fair Value, Inputs, Level 2 [Member] | ||
Assets: | ||
Money market funds | 12,148 | 38,633 |
Total, asset | 12,148 | 38,633 |
Fair Value, Inputs, Level 2 [Member] | Money Market Funds [Member] | ||
Assets: | ||
Money market funds | 11,148 | 28,636 |
Total, asset | 11,148 | 28,636 |
Fair Value, Inputs, Level 2 [Member] | US Government Agency Bonds [Member] | ||
Assets: | ||
Money market funds | 1,000 | 9,997 |
Total, asset | 1,000 | 9,997 |
Fair Value, Inputs, Level 3 [Member] | ||
Liabilities: | ||
Contingent consideration | 93,769 | 81,009 |
Total, liabilities | 93,769 | 81,009 |
Fair Value, Inputs, Level 3 [Member] | Contingent Consideration [Member] | ||
Liabilities: | ||
Contingent consideration | 93,769 | 81,009 |
Total, liabilities | $ 93,769 | $ 81,009 |
Fair Value of Financial Asset41
Fair Value of Financial Assets and Liabilities - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands | Jul. 24, 2018 | Jul. 02, 2018 | Dec. 31, 2017 | Jun. 30, 2018 | Dec. 31, 2017 | Jun. 27, 2018 | Jun. 30, 2017 |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||||||
Cash and cash equivalents | $ 48,058 | $ 16,495 | $ 48,058 | $ 6,025 | |||
Anti-dilution contingent consideration liability | 2,421 | ||||||
Series C Redeemable Convertible Preferred Stock [Member] | |||||||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||||||
Common stock, shares issued | 21,202,710 | ||||||
Contingent Consideration [Member] | |||||||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||||||
Anti-dilution contingent consideration liability | $ 81,009 | 93,769 | $ 81,009 | ||||
Shire Human Genetic Therapies Inc [Member] | Common Stock [Member] | |||||||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||||||
Common stock, shares issued | 1,079,765 | ||||||
Common stock value | $ 8,000 | ||||||
Shire's MRT Program [Member] | |||||||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||||||
Common stock, shares issued | 70,866 | ||||||
Subsequent Event [Member] | IPO [Member] | |||||||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||||||
Common stock, shares issued | 364,371 | 9,350,000 | |||||
Common stock shares issued, per share | $ 13 | $ 13 | |||||
Subsequent Event [Member] | Shire's MRT Program [Member] | |||||||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||||||
Shares of common stock owned | 183,619 | ||||||
Anti- Dilution Rights [Member] | Contingent Consideration [Member] | |||||||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||||||
Anti-dilution contingent consideration liability | 1,296 | 2,387 | $ 1,296 | ||||
Anti- Dilution Rights [Member] | Shire Human Genetic Therapies Inc [Member] | |||||||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||||||
Anti-dilution contingent consideration liability | 7,000 | ||||||
Anti- Dilution Rights [Member] | Shire Human Genetic Therapies Inc [Member] | Contingent Consideration [Member] | |||||||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||||||
Anti-dilution contingent consideration liability | 1,296 | $ 2,387 | 1,296 | ||||
Anti- Dilution Rights [Member] | Shire's MRT Program [Member] | IPO [Member] | |||||||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||||||
Common stock, shares issued | 6,895,326 | ||||||
Common stock shares issued, per share | $ 13 | ||||||
Shares of common stock owned | 7,078,945 | ||||||
Anti- Dilution Rights [Member] | Subsequent Event [Member] | Shire Human Genetic Therapies Inc [Member] | IPO [Member] | |||||||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||||||
Common stock, shares issued | 183,619 | ||||||
Money Market Funds [Member] | Fair Value, Inputs, Level 2 [Member] | |||||||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||||||
Cash and cash equivalents | $ 28,600 | $ 11,100 | $ 28,600 |
Fair Value of Financial Asset42
Fair Value of Financial Assets and Liabilities - Schedule of Unobservable Inputs and Fair Value Components of Contingent Consideration (Detail) - USD ($) $ in Thousands | 6 Months Ended | 12 Months Ended |
Jun. 30, 2018 | Dec. 31, 2017 | |
Measurement Input, Discount Rate [Member] | Earn Out Payment [Member] | ||
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | ||
Anti-dilution rights | 15.00% | |
Measurement Input, Discount Rate [Member] | Milestone Payment [Member] | ||
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | ||
Anti-dilution rights | 15.00% | |
Minimum [Member] | Measurement Input, Discount Rate [Member] | Anti- Dilution Rights [Member] | ||
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | ||
Anti-dilution rights | 1.39% | |
Maximum [Member] | Measurement Input, Discount Rate [Member] | Anti- Dilution Rights [Member] | ||
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | ||
Anti-dilution rights | 1.77% | |
Contingent Consideration [Member] | ||
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | ||
Total, Fair value | $ 93,769 | $ 81,009 |
Contingent Consideration [Member] | Earn Out Payment [Member] | ||
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | ||
Total, Fair value | 83,709 | 72,896 |
Contingent Consideration [Member] | Milestone Payment [Member] | ||
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | ||
Total, Fair value | 7,673 | 6,817 |
Contingent Consideration [Member] | Anti- Dilution Rights [Member] | ||
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | ||
Total, Fair value | $ 2,387 | $ 1,296 |
Contingent Consideration [Member] | Minimum [Member] | Earn Out Payment [Member] | ||
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | ||
Fair value inputs projected year of payment | 2,025 | |
Contingent Consideration [Member] | Minimum [Member] | Milestone Payment [Member] | ||
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | ||
Fair value inputs projected year of payment | 2,025 | |
Contingent Consideration [Member] | Maximum [Member] | Earn Out Payment [Member] | ||
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | ||
Fair value inputs projected year of payment | 2,039 | |
Contingent Consideration [Member] | Maximum [Member] | Milestone Payment [Member] | ||
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | ||
Fair value inputs projected year of payment | 2,030 |
Fair Value of Financial Asset43
Fair Value of Financial Assets and Liabilities - Schedule of Total Acquisition Related Contingent Consideration Liability (Detail) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended | ||
Jun. 30, 2018 | Jun. 30, 2017 | Jun. 30, 2018 | Jun. 30, 2017 | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||||
Beginning Balance | $ 81,009 | |||
Change in fair value of contingent consideration | $ 7,852 | $ 2,324 | 12,760 | $ 4,599 |
Ending Balance | $ 93,769 | $ 93,769 |
Property and Equipment, Net - S
Property and Equipment, Net - Schedule of Property and Equipment, Net (Detail) - USD ($) $ in Thousands | Jun. 30, 2018 | Dec. 31, 2017 |
Property, Plant and Equipment [Line Items] | ||
Property and equipment, gross | $ 13,823 | $ 9,834 |
Less: Accumulated depreciation and amortization | (3,955) | (3,056) |
Property and equipment, net | 9,868 | 6,778 |
Laboratory Equipment [Member] | ||
Property, Plant and Equipment [Line Items] | ||
Property and equipment, gross | 5,914 | 5,382 |
Computer Equipment [Member] | ||
Property, Plant and Equipment [Line Items] | ||
Property and equipment, gross | 626 | 481 |
Office Equipment [Member] | ||
Property, Plant and Equipment [Line Items] | ||
Property and equipment, gross | 701 | 249 |
Leasehold Improvements [Member] | ||
Property, Plant and Equipment [Line Items] | ||
Property and equipment, gross | 5,632 | 1,131 |
Construction in Progress [Member] | ||
Property, Plant and Equipment [Line Items] | ||
Property and equipment, gross | $ 950 | $ 2,591 |
Property and Equipment, Net - A
Property and Equipment, Net - Additional Information (Detail) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended | ||
Jun. 30, 2018 | Jun. 30, 2017 | Jun. 30, 2018 | Jun. 30, 2017 | |
Depreciation and Amortization Expenses For Property Plant And Equipment [Line Items] | ||||
Depreciation and amortization expense | $ 900 | $ 500 | $ 1,447 | $ 740 |
Accrued Expenses - Schedule of
Accrued Expenses - Schedule of Accrued Expenses (Detail) - USD ($) $ in Thousands | Jun. 30, 2018 | Dec. 31, 2017 |
Schedule Of Accrued Expenses [Line Items] | ||
Accrued consultant and professional fees | $ 2,204 | $ 1,130 |
Accrued employee compensation and benefits | 1,940 | 2,252 |
Accrued external research and development expenses | 1,132 | 1,115 |
Other | 482 | 1,391 |
Total accrued Expenses | $ 5,758 | $ 5,888 |
Redeemable Convertible Prefer47
Redeemable Convertible Preferred Stock - Additional Information (Detail) - USD ($) | 1 Months Ended | 6 Months Ended | 12 Months Ended | |
Dec. 31, 2017 | Jun. 30, 2018 | Dec. 31, 2017 | Jul. 02, 2018 | |
Temporary Equity [Line Items] | ||||
Preferred Shares Outstanding | 142,288,292 | 142,288,292 | 142,288,292 | |
Preferred Shares Authorized | 145,833,064 | 145,833,064 | 145,833,064 | |
Payments of stock issuance costs | $ 2,421,000 | |||
Beneficial conversion feature in preferred stock | $ 0 | $ 0 | ||
Convertible stock | 25,612,109 | 25,612,109 | 25,612,109 | |
Subsequent Event [Member] | ||||
Temporary Equity [Line Items] | ||||
Preferred Shares Authorized | 10,000,000 | |||
Convertible stock | 25,612,109 | |||
Series A Redeemable Convertible Preferred Stock [Member] | ||||
Temporary Equity [Line Items] | ||||
Preferred Shares Outstanding | 36,194,026 | 36,194,026 | 36,194,026 | |
Preferred Shares Authorized | 36,194,026 | 36,194,026 | 36,194,026 | |
Convertible stock | 6,514,986 | 6,514,986 | 6,514,986 | |
Series A Redeemable Convertible Preferred Stock [Member] | Convertible Preferred Stock Subject to Mandatory Redemption [Member] | ||||
Temporary Equity [Line Items] | ||||
Preferred Shares Outstanding | 36,194,026 | 36,194,026 | 36,194,026 | |
Series B Redeemable Convertible Preferred Stock [Member] | ||||
Temporary Equity [Line Items] | ||||
Preferred Shares Outstanding | 59,133,987 | 59,133,987 | 59,133,987 | |
Preferred Shares Authorized | 59,133,987 | 59,133,987 | 59,133,987 | |
Convertible stock | 10,644,210 | 10,644,210 | 10,644,210 | |
Series B Redeemable Convertible Preferred Stock [Member] | Convertible Preferred Stock Subject to Mandatory Redemption [Member] | ||||
Temporary Equity [Line Items] | ||||
Preferred Shares Outstanding | 59,133,987 | 59,133,987 | 59,133,987 | |
Series C Redeemable Convertible Preferred Stock [Member] | ||||
Temporary Equity [Line Items] | ||||
Preferred Shares Outstanding | 46,960,279 | 46,960,279 | 46,960,279 | |
Preferred Shares Authorized | 50,505,051 | 50,505,051 | 50,505,051 | |
Convertible stock | 8,452,913 | 8,452,913 | 8,452,913 | |
Series C Redeemable Convertible Preferred Stock [Member] | Convertible Preferred Stock Subject to Mandatory Redemption [Member] | ||||
Temporary Equity [Line Items] | ||||
Preferred Shares Outstanding | 46,960,279 | 46,960,279 | 46,960,279 | |
Preferred Shares Authorized | 145,833,064 | 145,833,064 | 145,833,064 | |
Preferred stock issued and sold | 21,202,710 | 21,202,710 | ||
Sale of stock price per share | $ 1.98 | $ 1.98 | ||
Net proceeds from issuance of redeemable convertible preferred stock | $ 41,900,000 | |||
Payments of stock issuance costs | $ 100,000 |
Redeemable Convertible Prefer48
Redeemable Convertible Preferred Stock - Schedule of Preferred Stock (Detail) - USD ($) $ in Thousands | Jun. 30, 2018 | Dec. 31, 2017 |
Temporary Equity [Line Items] | ||
Preferred Shares Authorized | 145,833,064 | 145,833,064 |
Preferred Shares Issued | 142,288,292 | 142,288,292 |
Preferred Shares Outstanding | 142,288,292 | 142,288,292 |
Carrying Value | $ 193,540 | $ 192,896 |
Liquidation Preference | $ 192,374 | $ 192,374 |
Common Stock Issuable Upon Conversion | 25,612,109 | 25,612,109 |
Series A Redeemable Convertible Preferred Stock [Member] | ||
Temporary Equity [Line Items] | ||
Preferred Shares Authorized | 36,194,026 | 36,194,026 |
Preferred Shares Issued | 36,194,026 | 36,194,026 |
Preferred Shares Outstanding | 36,194,026 | 36,194,026 |
Carrying Value | $ 36,194 | $ 36,194 |
Liquidation Preference | $ 36,194 | $ 36,194 |
Common Stock Issuable Upon Conversion | 6,514,986 | 6,514,986 |
Series B Redeemable Convertible Preferred Stock [Member] | ||
Temporary Equity [Line Items] | ||
Preferred Shares Authorized | 59,133,987 | 59,133,987 |
Preferred Shares Issued | 59,133,987 | 59,133,987 |
Preferred Shares Outstanding | 59,133,987 | 59,133,987 |
Carrying Value | $ 64,365 | $ 64,002 |
Liquidation Preference | $ 63,199 | $ 63,199 |
Common Stock Issuable Upon Conversion | 10,644,210 | 10,644,210 |
Series C Redeemable Convertible Preferred Stock [Member] | ||
Temporary Equity [Line Items] | ||
Preferred Shares Authorized | 50,505,051 | 50,505,051 |
Preferred Shares Issued | 46,960,279 | 46,960,279 |
Preferred Shares Outstanding | 46,960,279 | 46,960,279 |
Carrying Value | $ 92,981 | $ 92,700 |
Liquidation Preference | $ 92,981 | $ 92,981 |
Common Stock Issuable Upon Conversion | 8,452,913 | 8,452,913 |
Common Stock - Additional Infor
Common Stock - Additional Information (Detail) - USD ($) | 6 Months Ended | 12 Months Ended |
Jun. 30, 2018 | Dec. 31, 2017 | |
Class of Stock [Line Items] | ||
Common stock voting rights | Each share of common stock entitles the holder to one vote for each share of common stock held. | |
Cash dividend paid shares | $ 0 | $ 0 |
2018 Stock Incentive Plan [Member] | ||
Class of Stock [Line Items] | ||
Reserved shares of common stock for conversion of outstanding shares of preferred stock | 32,115,490 | 32,115,490 |
Incentive Stock Options and R50
Incentive Stock Options and Restricted Stock - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands | Jun. 15, 2018 | Mar. 07, 2018 | Jun. 30, 2018 | Jun. 30, 2017 | Jun. 30, 2018 | Jun. 30, 2017 | Dec. 31, 2017 |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||
Number of shares issued | 9,631,939 | 9,631,939 | 9,582,791 | ||||
Allocated share based compensation expense | $ 2,875 | $ 691 | $ 4,258 | $ 792 | |||
Unrecognized compensation cost related to unvested stock-based awards | 23,000 | $ 23,000 | |||||
Unrecognized compensation cost, period for recognition | 2 years 9 months 14 days | ||||||
Chief Scientific Officer [Member] | |||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||
Stock options for purchase of common stock held, exercisable period | 1 year | ||||||
Allocated share based compensation expense | $ 300 | $ 300 | |||||
Options vested for purchase of common stock | 72,871 | ||||||
Stock options for purchase of common stock held | 204,353 | 204,353 | |||||
Stock Options [Member] | Non-Employee [Member] | |||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||
Number of share options granted during the period | 0 | 265,854 | |||||
2018 Stock Incentive Plan [Member] | |||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||
Number of common shares reserved for issuance | 32,115,490 | 32,115,490 | 32,115,490 | ||||
Number of shares remaining available for issuance | 360,514 | ||||||
Percentage threshold of outstanding shares under the plan | 4.00% | ||||||
Number of share options granted during the period | 0 | ||||||
Percentage of exercise price per share of fair market value | 100.00% | ||||||
Expiration period of stock options after grant date | 10 years | ||||||
Stock options for purchase of common stock held, exercisable period | 4 years | ||||||
2018 Stock Incentive Plan [Member] | Minimum [Member] | |||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||
Number of stock issued during period under the plan | 3,349,582 | ||||||
2018 Stock Incentive Plan [Member] | Share-based Compensation Award, Tranche One [Member] | |||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||
Number of common shares reserved for issuance | 2,512,187 | ||||||
2018 Stock Incentive Plan [Member] | Share-based Compensation Award, Tranche Two [Member] | |||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||
Number of common shares reserved for issuance | 1,013,167 | ||||||
2016 Stock Incentive Plan [Member] | |||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||
Percentage of exercise price per share of fair market value | 100.00% | ||||||
Expiration period of stock options after grant date | 10 years | ||||||
Stock options for purchase of common stock held, exercisable period | 4 years | ||||||
2018 Employee Stock Purchase Plan [Member] | |||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||
Number of stock issued during period under the plan | 418,697 | ||||||
Percentage threshold of outstanding shares under the plan | 1.00% | ||||||
Number of shares issued | 0 | 0 | |||||
2018 Employee Stock Purchase Plan [Member] | Minimum [Member] | |||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||
Number of stock issued during period under the plan | 837,395 | ||||||
Stock Options [Member] | |||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||
Number of share options granted during the period | 1,966,114 | 4,257,593 | |||||
Intrinsic value of stock options, exercised | $ 300 | ||||||
Number of options exercised | 49,459 | 0 | |||||
Weighted average grant-date fair value | $ 5.91 | $ 4.23 | |||||
Fair value of options vested | $ 2,100 | ||||||
Restricted Common Stock [Member] | |||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||
Allocated share based compensation expense | $ 200 | $ 200 |
Incentive Stock Options and R51
Incentive Stock Options and Restricted Stock - Summary of Stock Option Activity (Detail) - Stock Options [Member] - USD ($) $ / shares in Units, $ in Thousands | 6 Months Ended | 12 Months Ended | ||
Jun. 30, 2018 | Jun. 30, 2017 | Dec. 31, 2017 | Dec. 31, 2016 | |
Number of shares | ||||
Number of shares, beginning balance | 4,364,916 | 209,797 | 209,797 | |
Number of shares, granted | 1,966,114 | 4,257,593 | ||
Number of shares, exercised | (49,459) | 0 | ||
Number of shares, forfeited | (188,163) | (102,474) | ||
Number of shares, ending balance | 6,093,408 | 4,364,916 | 209,797 | |
Number of shares, vested, ending balance | 1,182,097 | 661,593 | ||
Number of shares, vested and expected to vest, ending balance | 6,093,408 | 4,364,916 | ||
Weighted average exercise price | ||||
Weighted average exercise price, beginning balance | $ 7.17 | $ 4.73 | $ 4.73 | |
Weighted average exercise price, granted | 8.76 | |||
Weighted average exercise price, exercised | 5.62 | |||
Weighted average exercise price, forfeited | 6.16 | |||
Weighted average exercise price, ending balance | 7.72 | 7.17 | $ 4.73 | |
Weighted average exercise price, vested and expected to vest, ending balance | 7.72 | 7.17 | ||
Weighted average exercise price, vested, ending balance | $ 7.08 | $ 7.04 | ||
Weighted average remaining contractual term | ||||
Weighted average remaining contractual term, ending balance | 9 years 2 months 23 days | 9 years 9 months 14 days | 9 years 8 months 12 days | |
Weighted average remaining contractual term, vested, ending balance | 8 years 3 months | 9 years 8 months 19 days | ||
Weighted average remaining contractual term, vested and expected to vest, ending balance | 9 years 2 months 23 days | 9 years 9 months 14 days | ||
Intrinsic value | ||||
Intrinsic value, ending balance | $ 30,020 | $ 977 | ||
Intrinsic value, vested, ending balance | 6,586 | 231 | ||
Intrinsic value, vested and expected to vest, ending balance | $ 30,020 | $ 977 |
Incentive Stock Option and Rest
Incentive Stock Option and Restricted Stock - Summary of Assumptions Used in Black-Scholes Option-Pricing Model to Determine Grant-Date Fair Value of Stock Option Granted (Detail) - Stock Options [Member] | 6 Months Ended | 12 Months Ended | |
Jun. 30, 2018 | Jun. 30, 2017 | Dec. 31, 2017 | |
Employees and Directors [Member] | |||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Risk-free interest rate | 2.80% | 2.02% | |
Expected term (in years) | 6 years | 6 years | |
Expected volatility | 75.70% | 65.00% | |
Expected dividend yield | 0.00% | 0.00% | |
Non-Employee [Member] | |||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Risk-free interest rate | 2.08% | ||
Expected term (in years) | 10 years | ||
Expected volatility | 60.90% | ||
Expected dividend yield | 0.00% |
Incentive Stock Option and Re53
Incentive Stock Option and Restricted Stock - Summary of Restricted Stock Activity (Detail) - Restricted Common Stock [Member] - $ / shares | 6 Months Ended | 12 Months Ended |
Jun. 30, 2018 | Dec. 31, 2017 | |
Number of shares | ||
Number of shares, beginning balance | 526,478 | 986,893 |
Number of shares, forfeited | (311) | (100,563) |
Number of shares, vested | (157,292) | (359,852) |
Number of shares, ending balance | 368,875 | 526,478 |
Weighted average grant-date fair value | ||
Weighted average grant-date fair value, beginning balance | $ 1.14 | $ 1.10 |
Weighted average grant-date fair value, forfeited | 1.28 | 1.10 |
Weighted average grant-date fair value, vested | 1.03 | 1.04 |
Weighted average grant-date fair value, ending balance | $ 1.19 | $ 1.14 |
Incentive Stock Option and Re54
Incentive Stock Option and Restricted Stock - Summary of Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended | ||
Jun. 30, 2018 | Jun. 30, 2017 | Jun. 30, 2018 | Jun. 30, 2017 | |
Stock-based compensation expense | $ 2,875 | $ 691 | $ 4,258 | $ 792 |
Research and Development Expenses [Member] | ||||
Stock-based compensation expense | 1,671 | 610 | 2,453 | 636 |
General and Administrative Expenses [Member] | ||||
Stock-based compensation expense | $ 1,204 | $ 81 | $ 1,805 | $ 156 |
Income Taxes - Additional Infor
Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended | 12 Months Ended | ||
Jun. 30, 2018 | Jun. 30, 2017 | Jun. 30, 2018 | Jun. 30, 2017 | Dec. 31, 2017 | |
Income Taxes [Line Items] | |||||
Federal corporate income tax rate | 21.00% | 34.00% | |||
Tax cuts and jobs act of 2017, net operating losses carryforward, maximum percentage of taxable income | 80.00% | ||||
Tax cuts and jobs act of 2017, change in tax rate income tax expense benefit | $ 6,100 | ||||
Tax cuts and jobs act of 2017, change in tax rate income tax expense benefit due to deferred tax liabilities adjustment | $ 3,700 | ||||
Tax cuts and jobs act of 2017, change in tax rate income tax expense benefit due to deferred tax assets adjustment | 2,400 | ||||
Income tax benefits | $ (1,500) | $ (870) | $ (2,602) | $ (1,721) |
Net Loss per Share - Summary of
Net Loss per Share - Summary of Basic and Diluted Net Loss Per Share Attributable to Common Stockholders (Detail) - USD ($) $ / shares in Units, $ in Thousands | 3 Months Ended | 6 Months Ended | ||
Jun. 30, 2018 | Jun. 30, 2017 | Jun. 30, 2018 | Jun. 30, 2017 | |
Numerator: | ||||
Net loss | $ (27,503) | $ (17,933) | $ (48,712) | $ (31,886) |
Accretion of redeemable convertible preferred units and stock to redemption value | 459 | 192 | 644 | 360 |
Net loss attributable to common stockholders | $ (27,044) | $ (17,741) | $ (48,068) | $ (31,526) |
Denominator: | ||||
Weighted average common shares outstanding-basic and diluted | 9,187,207 | 7,676,426 | 9,139,638 | 7,631,883 |
Net loss per share attributable to common stockholders-basic and diluted | $ (2.94) | $ (2.31) | $ (5.26) | $ (4.13) |
Net Loss per Share - Additional
Net Loss per Share - Additional Information (Detail) - shares | 3 Months Ended | 6 Months Ended | ||
Jun. 30, 2018 | Jun. 30, 2017 | Jun. 30, 2018 | Jun. 30, 2017 | |
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items] | ||||
Antidilutive securities excluded from computation of basic net loss per share | 32,074,392 | 23,765,310 | ||
Restricted Common Stock [Member] | ||||
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items] | ||||
Antidilutive securities excluded from computation of basic net loss per share | 412,040 | 846,114 | 368,875 | 714,370 |
Net Loss per Share - Summary 58
Net Loss per Share - Summary of Potential Common Shares Excluded from Computation of Diluted Net Loss per Share Attributable to Common Stockholders (Detail) - shares | 3 Months Ended | 6 Months Ended | ||
Jun. 30, 2018 | Jun. 30, 2017 | Jun. 30, 2018 | Jun. 30, 2017 | |
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items] | ||||
Antidilutive securities excluded from computation of basic net loss per share | 32,074,392 | 23,765,310 | ||
Stock Options [Member] | ||||
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items] | ||||
Antidilutive securities excluded from computation of basic net loss per share | 6,093,408 | 1,255,347 | ||
Restricted Common Stock [Member] | ||||
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items] | ||||
Antidilutive securities excluded from computation of basic net loss per share | 412,040 | 846,114 | 368,875 | 714,370 |
Redeemable Convertible Preferred Stock [Member] | ||||
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items] | ||||
Antidilutive securities excluded from computation of basic net loss per share | 25,612,109 | 21,795,593 |
Commitments and Contingencies -
Commitments and Contingencies - Additional Information (Detail) | 1 Months Ended | 3 Months Ended | 6 Months Ended | 12 Months Ended | |||||
Jun. 30, 2017USD ($) | Jun. 30, 2018USD ($) | Jun. 30, 2017USD ($) | Jun. 30, 2018USD ($) | Jun. 30, 2017USD ($) | Dec. 31, 2017USD ($) | Jul. 31, 2018USD ($) | Jan. 31, 2017USD ($)Letter_Of_Credit | May 31, 2015USD ($) | |
Loss Contingencies [Line Items] | |||||||||
Rent expense | $ 800,000 | $ 500,000 | $ 1,700,000 | $ 1,100,000 | |||||
Research and development expense | 15,219,000 | 13,506,000 | $ 27,921,000 | 23,127,000 | |||||
Roche Diagnostics Corporation Master Supply Agreement [Member] | |||||||||
Loss Contingencies [Line Items] | |||||||||
Raw material to purchase as percentage of demand | 80.00% | ||||||||
Agreement extended date | Dec. 31, 2024 | ||||||||
Commitment amount | $ 7,600,000 | $ 8,800,000 | |||||||
Purchase commitments, remainder of fiscal year 2018 | 1,300,000 | 1,300,000 | |||||||
Purchase commitments, year 2019 | 1,300,000 | 1,300,000 | |||||||
Purchase commitments, year 2020 | 1,300,000 | 1,300,000 | |||||||
Purchase commitments, year 2021 | 1,300,000 | 1,300,000 | |||||||
Purchase commitments, year 2022 | 1,300,000 | 1,300,000 | |||||||
Purchase commitments, year 2023 | 1,300,000 | 1,300,000 | |||||||
Purchase commitments, year 2024 | 1,300,000 | 1,300,000 | |||||||
Research and development expense | 800,000 | 500,000 | 1,700,000 | 600,000 | |||||
MIT Research Agreement [Member] | |||||||||
Loss Contingencies [Line Items] | |||||||||
Research and development expense | 300,000 | 300,000 | 600,000 | 600,000 | |||||
Research agreement, committed amount | $ 3,100,000 | ||||||||
Research agreement, expiration period | 2019-10 | ||||||||
Research agreement, payment | $ 1,300,000 | 1,000,000 | |||||||
Research agreement, committed amount through 2018 | 600,000 | 600,000 | |||||||
Research agreement, committed amount in 2019 | 700,000 | 700,000 | |||||||
Research agreement, payable amount | 500,000 | 500,000 | |||||||
MIT Exclusive Patent License Agreement [Member] | |||||||||
Loss Contingencies [Line Items] | |||||||||
Research and development expense | 100,000 | 100,000 | 100,000 | 100,000 | |||||
Research agreement, payable amount | 0 | 0 | 0 | ||||||
Annual license maintenance payments | 200,000 | ||||||||
Payments of annual license maintenance fees | 0 | $ 0 | 100,000 | $ 100,000 | |||||
MIT Exclusive Patent License Agreement [Member] | Sanofi Pasteur Inc [Member] | Subsequent Event [Member] | |||||||||
Loss Contingencies [Line Items] | |||||||||
Upfront payment received | $ 45,000,000 | ||||||||
MIT Exclusive Patent License Agreement [Member] | Milestone Payment One [Member] | |||||||||
Loss Contingencies [Line Items] | |||||||||
License agreement, milestone payments | 1,375,000 | ||||||||
MIT Exclusive Patent License Agreement [Member] | Milestone Payment Two [Member] | |||||||||
Loss Contingencies [Line Items] | |||||||||
License agreement, milestone payments | $ 1,250,000 | ||||||||
Minimum [Member] | |||||||||
Loss Contingencies [Line Items] | |||||||||
Lease expiration period | 2018-04 | ||||||||
Maximum [Member] | |||||||||
Loss Contingencies [Line Items] | |||||||||
Lease expiration period | 2028-04 | ||||||||
Cambridge, Massachusetts [Member] | |||||||||
Loss Contingencies [Line Items] | |||||||||
Cash deposit collateral | 700,000 | $ 1,000,000 | |||||||
Lexington, Massachusetts [Member] | |||||||||
Loss Contingencies [Line Items] | |||||||||
Lease expiration period | 2028-04 | ||||||||
Cash deposit collateral | $ 1,000,000 | $ 1,000,000 | $ 1,000,000 | $ 300,000 | |||||
Monthly lease payments | $ 200,000 | ||||||||
Number of letter of credit issued | Letter_Of_Credit | 2 | ||||||||
Lease extension period | 12 months | ||||||||
Lease termination notice period | 90 days | ||||||||
Percentage of annual increase in operating lease payments | 3.00% | ||||||||
Lexington, Massachusetts [Member] | Minimum [Member] | |||||||||
Loss Contingencies [Line Items] | |||||||||
Lease expiration period | Nov. 30, 2018 | ||||||||
Lexington, Massachusetts [Member] | Maximum [Member] | |||||||||
Loss Contingencies [Line Items] | |||||||||
Lease expiration period | 2019-05 | ||||||||
Monthly lease payments | $ 100,000 |
Related Party Transactions - Ad
Related Party Transactions - Additional Information (Detail) - USD ($) | 3 Months Ended | 6 Months Ended | 12 Months Ended | |||
Jun. 30, 2018 | Jun. 30, 2017 | Jun. 30, 2018 | Jun. 30, 2017 | Dec. 31, 2017 | Dec. 31, 2012 | |
Restricted Common Stock [Member] | ||||||
Schedule of Other Related Party Transactions [Line Items] | ||||||
Number of restricted common stock vested | 157,292 | 359,852 | ||||
Board of Directors Chairman [Member] | Consulting Agreement [Member] | ||||||
Schedule of Other Related Party Transactions [Line Items] | ||||||
Base compensation per year | $ 100,000 | |||||
General and administrative expenses | $ 31,250 | $ 31,250 | $ 100,000 | $ 100,000 | ||
Amount paid for services | 100,000 | 25,000 | 100,000 | 100,000 | ||
Amount due to related party | 12,500 | $ 12,500 | $ 20,000 | |||
Stock options granted | 85,170 | |||||
Exercise price of options granted | $ 7.39 | |||||
Stock options vesting period | 4 years | |||||
Grant-date fair value of options granted | $ 4.06 | |||||
Aggregate fair value of stock options | $ 300,000 | |||||
Board of Directors Chairman [Member] | Consulting Agreement [Member] | Restricted Common Stock [Member] | ||||||
Schedule of Other Related Party Transactions [Line Items] | ||||||
Number of restricted common stock granted | 321,823 | |||||
Number of restricted common stock vested | 321,823 | |||||
Board of Directors Chairman [Member] | Consulting Agreement [Member] | Maximum [Member] | ||||||
Schedule of Other Related Party Transactions [Line Items] | ||||||
Annual performance bonus | 25.00% | |||||
Shire Human Genetic Therapies Inc [Member] | Transition Services Agreement [Member] | ||||||
Schedule of Other Related Party Transactions [Line Items] | ||||||
General and administrative expenses | 4,575 | 16,025 | $ 4,575 | 16,025 | ||
Amount paid for services | $ 4,725 | $ 14,525 | $ 4,725 | $ 14,525 | ||
Expiration period of transition agreement | 2017-09 |
Costs Associated with Restruc61
Costs Associated with Restructuring - Additional Information (Detail) $ in Millions | 1 Months Ended | 12 Months Ended |
Jun. 30, 2017Position | Dec. 31, 2017USD ($) | |
Research and Development Expenses [Member] | ||
Restructuring Cost and Reserve [Line Items] | ||
Employee severance charges related to restructuring | $ | $ 0.5 | |
MRNA Therapeutic Platform [Member] | ||
Restructuring Cost and Reserve [Line Items] | ||
Reduction in workforce due to reorganization | Position | 17 |
Costs Associated with Restruc62
Costs Associated with Restructuring - Summary of Changes in Accrued Restructuring Costs (Detail) - USD ($) $ in Thousands | 6 Months Ended | |
Dec. 31, 2017 | Jun. 30, 2017 | |
Balance | $ 432 | |
Charges | $ 473 | |
Payments | $ (432) | (41) |
Balance | $ 432 |
Subsequent Events - Additional
Subsequent Events - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions | Jul. 24, 2018 | Jul. 18, 2018 | Jul. 02, 2018 | Jun. 08, 2018 | Jul. 31, 2018 | Jun. 30, 2018 | Dec. 31, 2017 |
Subsequent Event [Line Items] | |||||||
Common stock outstanding | 9,631,939 | 9,582,791 | |||||
Common stock, shares issued | 9,631,939 | 9,582,791 | |||||
Common stock, shares authorized | 236,092,611 | 236,092,611 | |||||
Common stock, par value | $ 0.001 | $ 0.001 | |||||
Preferred stock, shares authorised | 145,833,064 | 145,833,064 | |||||
Subsequent Event [Member] | |||||||
Subsequent Event [Line Items] | |||||||
Number of shares authorized | 210,000,000 | ||||||
Common stock, shares authorized | 200,000,000 | ||||||
Common stock, par value | $ 0.001 | ||||||
Preferred stock, shares authorised | 10,000,000 | ||||||
Preferred stock, par value | $ 0.001 | ||||||
IPO [Member] | Subsequent Event [Member] | |||||||
Subsequent Event [Line Items] | |||||||
Common stock issued and sold | 364,371 | 9,350,000 | |||||
Common stock issued and sold, per share | $ 13 | $ 13 | |||||
Net proceeds from IPO | $ 113.4 | ||||||
Underwriting discounts and commissions | 8.8 | ||||||
Offering expenses | $ 4.1 | ||||||
Shares of redeemable convertible preferred stock converted | 142,288,292 | ||||||
Shares of common stock issued upon conversion of redeemable convertible preferred stock | 25,612,109 | ||||||
Common stock outstanding | 45,141,690 | ||||||
Sanofi Pasteur Collaboration and Licensing Agreement [Member] | |||||||
Subsequent Event [Line Items] | |||||||
Research term | 3 years | ||||||
Sanofi Agreement [Member] | |||||||
Subsequent Event [Line Items] | |||||||
Royalty payments term | 10 years | ||||||
Shire's MRT Program [Member] | Subsequent Event [Member] | |||||||
Subsequent Event [Line Items] | |||||||
Common stock, shares issued | 183,619 | ||||||
Common stock issued fair value | $ 2.4 | ||||||
Sanofi Pasteur Inc [Member] | Sanofi Pasteur Collaboration and Licensing Agreement [Member] | |||||||
Subsequent Event [Line Items] | |||||||
Receivable from related party collaboration | $ 805 | ||||||
Additional license fees for option exercise | 5 | ||||||
Maximum development and regulatory milestone payment receivable | 63 | ||||||
Sales milestone payment receivable | 85 | ||||||
Technology and process transfer milestone payment receivable | $ 10 | ||||||
Sanofi Pasteur Inc [Member] | Sanofi Pasteur Collaboration and Licensing Agreement [Member] | Subsequent Event [Member] | |||||||
Subsequent Event [Line Items] | |||||||
Receivable from related party collaboration | $ 805 | ||||||
Upfront payment received | $ 45 | $ 45 |