Document and Entity Information
Document and Entity Information - shares | 9 Months Ended | |
Sep. 30, 2019 | Nov. 05, 2019 | |
Cover [Abstract] | ||
Document Type | 10-Q | |
Amendment Flag | false | |
Document Period End Date | Sep. 30, 2019 | |
Document Fiscal Year Focus | 2019 | |
Document Fiscal Period Focus | Q3 | |
Trading Symbol | AVRO | |
Entity Registrant Name | AVROBIO, INC. | |
Entity Central Index Key | 0001681087 | |
Current Fiscal Year End Date | --12-31 | |
Entity Filer Category | Non-accelerated Filer | |
Entity Common Stock, Shares Outstanding | 31,667,901 | |
Entity Emerging Growth Company | true | |
Entity Ex Transition Period | false | |
Entity Small Business | true | |
Entity Current Reporting Status | Yes | |
Entity Shell Company | false | |
Entity File Number | 001-38537 | |
Entity Tax Identification Number | 81-0710585 | |
Entity Address, Address Line One | One Kendall Square | |
Entity Address, Address Line Two | Building 300 | |
Entity Address, Address Line Three | Suite 201 | |
Entity Address, City or Town | Cambridge | |
Entity Address, State or Province | MA | |
Entity Address, Postal Zip Code | 02139 | |
City Area Code | 617 | |
Local Phone Number | 914-8420 | |
Document Quarterly Report | true | |
Document Transition Report | false | |
Entity Incorporation, State or Country Code | DE | |
Entity Interactive Data Current | Yes | |
Title of 12(b) Security | Common Stock, $0.0001 par value per share | |
Security Exchange Name | NASDAQ |
Condensed Consolidated Balance
Condensed Consolidated Balance Sheets - USD ($) $ in Thousands | Sep. 30, 2019 | Dec. 31, 2018 |
Current assets: | ||
Cash and cash equivalents | $ 206,362 | $ 126,302 |
Prepaid expenses and other current assets | 7,345 | 3,718 |
Total current assets | 213,707 | 130,020 |
Property and equipment, net | 2,673 | 2,634 |
Other assets | 825 | 825 |
Total assets | 217,205 | 133,479 |
Current liabilities: | ||
Accounts payable | 1,408 | 2,784 |
Accrued expenses and other current liabilities | 8,502 | 7,822 |
Total current liabilities | 9,910 | 10,606 |
Deferred rent, net of current portion | 535 | 689 |
Total liabilities | 10,445 | 11,295 |
Commitments and contingencies (Note 11) | ||
Stockholders’ equity: | ||
Preferred stock, $0.0001 par value; 10,000,000 shares authorized and no shares issued or outstanding as of September 30, 2019 and December 31, 2018 | ||
Common stock, $0.0001 par value; 150,000,000 shares authorized as of September 30, 2019 and December 31, 2018; 31,667,661 and 23,959,903 shares issued as of September 30, 2019 and December 31, 2018, respectively; 31,606,648 and 23,806,628 shares outstanding as of September 30, 2019 and December 31, 2018, respectively | 3 | 2 |
Additional paid-in capital | 328,799 | 193,921 |
Accumulated deficit | (122,042) | (71,739) |
Total stockholders’ equity | 206,760 | 122,184 |
Total liabilities and stockholders’ equity | $ 217,205 | $ 133,479 |
Condensed Consolidated Balanc_2
Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares | Sep. 30, 2019 | Dec. 31, 2018 |
Statement Of Financial Position [Abstract] | ||
Preferred stock, par value | $ 0.0001 | $ 0.0001 |
Preferred stock, authorized | 10,000,000 | 10,000,000 |
Preferred stock, issued | 0 | 0 |
Preferred stock, outstanding | 0 | 0 |
Common stock, par value | $ 0.0001 | $ 0.0001 |
Common stock, authorized | 150,000,000 | 150,000,000 |
Common stock, issued | 31,667,661 | 23,959,903 |
Common stock, outstanding | 31,606,648 | 23,806,628 |
Condensed Consolidated Statemen
Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2019 | Sep. 30, 2018 | Sep. 30, 2019 | Sep. 30, 2018 | |
Operating expenses: | ||||
Research and development | $ 13,042 | $ 9,232 | $ 37,755 | $ 22,286 |
General and administrative | 5,022 | 3,000 | 14,621 | 7,281 |
Total operating expenses | 18,064 | 12,232 | 52,376 | 29,567 |
Loss from operations | (18,064) | (12,232) | (52,376) | (29,567) |
Other income (expense): | ||||
Interest income | 925 | 646 | 2,146 | 1,038 |
Change in fair value of preferred stock warrant liability | 0 | 0 | 0 | (162) |
Change in fair value of derivative liability | 0 | 0 | 0 | (1,629) |
Other expense | (6) | (5) | (73) | (20) |
Total other income (expense), net | 919 | 641 | 2,073 | (773) |
Net loss | (17,145) | (11,591) | (50,303) | (30,340) |
Comprehensive loss | (17,145) | (11,591) | (50,303) | (30,340) |
Reconciliation of net loss to net loss attributable to common stockholders: | ||||
Net loss | (17,145) | (11,591) | (50,303) | (30,340) |
Accretion of issuance costs on redeemable convertible preferred stock | (2,243) | |||
Net loss attributable to common stockholders—basic and diluted | $ (17,145) | $ (11,591) | $ (50,303) | $ (32,583) |
Net loss per share attributable to common stockholders—basic and diluted (Note 10) | $ (0.57) | $ (0.49) | $ (1.93) | $ (3.28) |
Weighted-average number of common shares used in computing net loss per share attributable to common stockholders— basic and diluted | 30,296,595 | 23,747,141 | 26,018,717 | 9,945,538 |
Consolidated Statements of Rede
Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders' (Deficit) - USD ($) $ in Thousands | Total | July 2019 Follow-on Offering [Member] | IPO [Member] | Series Seed Redeemable Convertible Preferred Stock [Member] | Series A Redeemable Convertible Preferred Stock [Member] | Series B Redeemable Convertible Preferred Stock [Member] | Common Stock [Member] | Common Stock [Member]July 2019 Follow-on Offering [Member] | Common Stock [Member]IPO [Member] | Additional Paid-in Capital [Member] | Additional Paid-in Capital [Member]July 2019 Follow-on Offering [Member] | Additional Paid-in Capital [Member]IPO [Member] | Accumulated Deficit [Member] |
Beginning balance at Dec. 31, 2017 | $ (23,135) | $ 1,500 | $ 25,000 | $ 339 | $ (23,474) | ||||||||
Beginning balance, shares at Dec. 31, 2017 | 3,333,333 | 31,450,499 | 2,305,173 | ||||||||||
Issuance of redeemable convertible preferred stock, | $ 58,257 | ||||||||||||
Issuance of redeemable convertible preferred stock, shares | 28,285,557 | ||||||||||||
Issuance of series B redeemable convertible preferred stock to settled accrued liability of license cost | $ 500 | ||||||||||||
Issuance of series B redeemable convertible preferred stock to settle accrued liability of license cost, shares | 233,765 | ||||||||||||
Accretion of issuance costs related to redeemable convertible preferred stock | (2,243) | $ 2,243 | (339) | (1,904) | |||||||||
Stock-based compensation expense | 109 | 109 | |||||||||||
Vesting of restricted stock awards | $ 30,753 | ||||||||||||
Net loss | (8,242) | (8,242) | |||||||||||
Ending balance at Mar. 31, 2018 | (33,511) | $ 1,500 | $ 25,000 | $ 61,000 | 109 | (33,620) | |||||||
Ending balance, shares at Mar. 31, 2018 | 3,333,333 | 31,450,499 | 28,519,322 | 2,335,926 | |||||||||
Beginning balance at Dec. 31, 2017 | (23,135) | $ 1,500 | $ 25,000 | 339 | (23,474) | ||||||||
Beginning balance, shares at Dec. 31, 2017 | 3,333,333 | 31,450,499 | 2,305,173 | ||||||||||
Net loss | (30,340) | ||||||||||||
Ending balance at Sep. 30, 2018 | 137,109 | $ 2 | 192,825 | (55,718) | |||||||||
Ending balance, shares at Sep. 30, 2018 | 23,758,898 | ||||||||||||
Beginning balance at Mar. 31, 2018 | (33,511) | $ 1,500 | $ 25,000 | $ 61,000 | 109 | (33,620) | |||||||
Beginning balance, shares at Mar. 31, 2018 | 3,333,333 | 31,450,499 | 28,519,322 | 2,335,926 | |||||||||
Issuance common stock on public offering, net of issuance or offering costs | $ 104,182 | $ 1 | $ 104,181 | ||||||||||
Issuance common stock on public offering, net of issuance or offering costs, shares | 6,035,151 | ||||||||||||
Stock-based compensation expense | 457 | 457 | |||||||||||
Vesting of restricted stock awards | 0 | $ 0 | $ 0 | $ 0 | $ 0 | 0 | 0 | ||||||
Vesting of restricted stock awards, shares | 30,759 | ||||||||||||
Net loss | (10,507) | (10,507) | |||||||||||
Conversion of redeemable convertible preferred stock into common stock | 87,500 | $ (1,500) | $ (25,000) | $ (61,000) | $ 1 | 87,499 | |||||||
Conversion of redeemable convertible preferred stock into common stock, shares | (3,333,333) | (31,450,499) | (28,519,322) | 15,320,213 | |||||||||
Reclassification of warrants to purchase shares of redeemable convertible preferred stock into warrants to purchase common stock | 197 | 197 | |||||||||||
Ending balance at Jun. 30, 2018 | 148,318 | $ 2 | 192,443 | (44,127) | |||||||||
Ending balance, shares at Jun. 30, 2018 | 23,722,049 | ||||||||||||
Exercise of common stock warrant, shares | 6,091 | ||||||||||||
IPO issuance cost difference | (168) | (168) | |||||||||||
Stock-based compensation expense | 550 | 550 | |||||||||||
Vesting of restricted stock awards | 0 | $ 0 | $ 0 | $ 0 | $ 0 | 0 | 0 | ||||||
Vesting of restricted stock awards, shares | 30,758 | ||||||||||||
Net loss | (11,591) | (11,591) | |||||||||||
Ending balance at Sep. 30, 2018 | 137,109 | $ 2 | 192,825 | (55,718) | |||||||||
Ending balance, shares at Sep. 30, 2018 | 23,758,898 | ||||||||||||
Beginning balance at Dec. 31, 2018 | 122,184 | $ 2 | 193,921 | (71,739) | |||||||||
Beginning balance, shares at Dec. 31, 2018 | 23,806,628 | ||||||||||||
Stock-based compensation expense | 1,455 | 1,455 | |||||||||||
Exercise of stock options | 252 | 252 | |||||||||||
Exercise of stock options, shares | 116,859 | ||||||||||||
Vesting of restricted stock awards | 0 | $ 0 | 0 | 0 | |||||||||
Vesting of restricted stock awards, shares | 30,753 | ||||||||||||
Net loss | (17,103) | (17,103) | |||||||||||
Ending balance at Mar. 31, 2019 | 106,788 | $ 2 | 195,628 | (88,842) | |||||||||
Ending balance, shares at Mar. 31, 2019 | 23,954,240 | ||||||||||||
Beginning balance at Dec. 31, 2018 | $ 122,184 | $ 2 | 193,921 | (71,739) | |||||||||
Beginning balance, shares at Dec. 31, 2018 | 23,806,628 | ||||||||||||
Exercise of stock options, shares | 232,758 | ||||||||||||
Net loss | $ (50,303) | ||||||||||||
Ending balance at Sep. 30, 2019 | 206,760 | $ 3 | 328,799 | (122,042) | |||||||||
Ending balance, shares at Sep. 30, 2019 | 31,606,648 | ||||||||||||
Beginning balance at Mar. 31, 2019 | 106,788 | $ 2 | 195,628 | (88,842) | |||||||||
Beginning balance, shares at Mar. 31, 2019 | 23,954,240 | ||||||||||||
Stock-based compensation expense | 1,663 | 1,663 | |||||||||||
Exercise of stock options | 238 | 238 | |||||||||||
Exercise of stock options, shares | 110,290 | ||||||||||||
Vesting of restricted stock awards | 0 | $ 0 | 0 | 0 | |||||||||
Vesting of restricted stock awards, shares | 30,757 | ||||||||||||
Net loss | (16,055) | (16,055) | |||||||||||
Ending balance at Jun. 30, 2019 | 92,634 | $ 2 | 197,529 | (104,897) | |||||||||
Ending balance, shares at Jun. 30, 2019 | 24,095,287 | ||||||||||||
Issuance common stock on public offering, net of issuance or offering costs | $ 129,465 | $ 1 | $ 129,464 | ||||||||||
Issuance common stock on public offering, net of issuance or offering costs, shares | 7,475,000 | ||||||||||||
Stock-based compensation expense | 1,797 | 1,797 | |||||||||||
Exercise of stock options | 9 | 9 | |||||||||||
Exercise of stock options, shares | 5,609 | ||||||||||||
Vesting of restricted stock awards | 0 | $ 0 | 0 | 0 | |||||||||
Vesting of restricted stock awards, shares | 30,752 | ||||||||||||
Net loss | (17,145) | (17,145) | |||||||||||
Ending balance at Sep. 30, 2019 | $ 206,760 | $ 3 | $ 328,799 | $ (122,042) | |||||||||
Ending balance, shares at Sep. 30, 2019 | 31,606,648 |
Consolidated Statements of Re_2
Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders' (Deficit) (Parenthetical) - USD ($) $ in Thousands | 3 Months Ended | ||
Sep. 30, 2019 | Jun. 30, 2018 | Mar. 31, 2018 | |
Statement Of Stockholders Equity [Abstract] | |||
Issuance of redeemable convertible preferred stock, net of issuance costs | $ 2,243 | ||
Issuance of common stock upon IPO, net of issuance costs | $ 525 | $ 10,487 |
Condensed Consolidated Statem_2
Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2019 | Sep. 30, 2018 | Sep. 30, 2019 | Sep. 30, 2018 | |
Cash flows from operating activities: | ||||
Net loss | $ (50,303) | $ (30,340) | ||
Adjustments to reconcile net loss to net cash used in operating activities: | ||||
Depreciation and amortization expense | 605 | 196 | ||
Stock-based compensation expense | 4,915 | 1,117 | ||
Amortization of deferred offering costs | 33 | |||
Impairment loss of property and equipment | 235 | |||
Deferred rent expense | (123) | (63) | ||
Change in fair value of preferred stock warrant liability | $ 0 | $ 0 | 0 | 162 |
Change in fair value of derivative liability | 0 | 0 | 0 | 1,629 |
Changes in operating assets and liabilities: | ||||
Prepaid expenses and other current assets | (3,616) | (1,138) | ||
Other assets | (13) | (383) | ||
Accounts payable | (1,127) | 829 | ||
Accrued expenses and other current liabilities | 577 | 1,509 | ||
Net cash used in operating activities | (49,085) | (26,214) | ||
Cash flows from investing activities: | ||||
Change in restricted cash | (259) | |||
Purchases of property and equipment | (819) | (1,339) | ||
Net cash used in investing activities | (819) | (1,598) | ||
Cash flows from financing activities: | ||||
Proceeds from issuance of redeemable convertible preferred stock, net of issuance costs | 58,258 | |||
Payment of dilution liability | (2,000) | |||
Proceeds from exercise of stock options | 499 | |||
Proceeds from issuance of common shares upon completion of initial public offering costs, net of offering costs | 104,168 | |||
Proceeds from offering | 129,465 | |||
Net cash provided by financing activities | 129,964 | 160,426 | ||
Net increase in cash, cash equivalents and restricted cash | 80,060 | 132,614 | ||
Cash, cash equivalents and restricted cash at beginning of period | 126,794 | 5,963 | ||
Cash, cash equivalents and restricted cash at end of period | 206,854 | 138,577 | 206,854 | 138,577 |
Supplemental disclosure of non-cash investing and financing activities: | ||||
Purchases of property and equipment included in accounts payable and accrued expenses | 80 | 236 | ||
Property and equipment held for sale | 19 | |||
IPO issuance costs included in accrued expenses | 155 | |||
Purchase of property and equipment paid for by landlord | 842 | |||
Accretion of issuance costs related to redeemable convertible preferred stock | 2,240 | |||
Reconciliation of cash, cash equivalents and restricted cash reported within the condensed consolidated balance sheets: | ||||
Cash and cash equivalents | 206,362 | 138,553 | 206,362 | 138,553 |
Long-term restricted cash (included in other assets) | 492 | 24 | 492 | 24 |
Cash, cash equivalents and restricted cash at end of period | $ 206,854 | $ 138,577 | $ 206,854 | $ 138,577 |
Nature of the Business
Nature of the Business | 9 Months Ended |
Sep. 30, 2019 | |
Organization Consolidation And Presentation Of Financial Statements [Abstract] | |
Nature of the Business | 1. Nature of the Business AVROBIO, Inc. (the “Company” or “AVROBIO”) is a clinical stage gene therapy company focused on developing potentially curative ex vivo The Company is subject to risks and uncertainties common to early-stage companies in the biotechnology industry, including but not limited to, risks associated with completing preclinical studies and clinical trials, receiving regulatory approvals for product candidates, development by competitors of new biopharmaceutical products, 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 revenue from product sales. On June 20, 2018, the Company’s registration statement on Form S-1 relating to its initial public offering (“IPO”) was declared effective by the Securities and Exchange Commission (the “SEC”). The IPO closed on June 25, 2018 and the Company issued and sold 5,247,958 common shares at a public offering price of $19.00 per share for net proceeds of $90,103 after deducting underwriting discounts and commissions of $6,980 and other offering expenses of approximately $2,628. Simultaneously, on June 25, 2018, the Company issued and sold 787,193 additional common shares, pursuant to the full exercise of the underwriters’ option to purchase additional shares, for net proceeds of $13,910 after deducting underwriting discounts and commissions of $1,047. Thus, the aggregate net proceeds to the Company from the IPO, after deducting underwriting discounts and commissions and other offering costs, were $104,013. Upon the closing of the IPO, all series Seed redeemable convertible preferred stock (the “Series Seed Preferred Stock”), series A redeemable convertible preferred stock (the “Series A Preferred Stock”) and series B redeemable convertible preferred stock (the “Series B Preferred Stock”), (the Series Seed Preferred Stock, the Series A Preferred Stock and the Series B Preferred Stock are collectively referred to as the “Preferred Stock”) then outstanding converted into an aggregate of 15,320,213 shares of common stock. In July 2019, the Company closed an underwritten public offering of 7,475,000 shares of its common stock at a public offering price of $18.50 per share, which included 975,000 shares of the Company’s common stock resulting from the full exercise of the underwriters’ option to purchase additional shares at the public offering price, less underwriting discounts and commissions (the “July 2019 Follow-on Offering”). The net proceeds to the Company from the July 2019 Follow-on Offering, after deducting underwriting discounts and commissions and other offering expenses payable by the Company, were approximately $129,500. Through September 30, 2019, the Company has funded its operations primarily with proceeds from the sale of the Preferred Stock and common stock through the Company’s IPO. The Company has incurred recurring losses since its inception, including net losses of $50,303 and $30,340 for the nine months ended September 30, 2019 and 2018, respectively. In addition, as of September 30, 2019, the Company had an accumulated deficit of $122,042. Although the Company has incurred recurring losses and expects to continue to incur losses for the foreseeable future, the Company expects that its existing cash, cash equivalents and marketable securities will be sufficient to fund current planned operations and capital expenditure requirements for at least the next twelve months from the date of issuance of the financial statements contained in this Form 10-Q. However, the future viability of the Company is dependent on its ability to raise additional capital to finance its operations. The Company’s inability to raise capital as and when needed could have a negative impact on its financial condition and ability to pursue its business strategies. There can be no assurance that the current operating plan will be achieved or that additional funding will be available on terms acceptable to the Company, or at all. |
Summary of Significant Accounti
Summary of Significant Accounting Policies | 9 Months Ended |
Sep. 30, 2019 | |
Accounting Policies [Abstract] | |
Summary of Significant Accounting Policies | 2. Summary of Significant Accounting Policies Basis of Presentation The accompanying condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). Any reference in these notes to applicable guidance is meant to refer to the authoritative United States generally accepted accounting principles as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Update (“ASU”) of the Financial Accounting Standards Board (“FASB”). The unaudited condensed consolidated interim financial statements have been prepared on the same basis as the audited annual consolidated financial statements as of and for the year ended December 31, 2018, and, in the opinion of management, reflect all adjustments, consisting of normal recurring adjustments, necessary for the fair presentation of the Company’s financial position as of September 30, 2019, and the results of its operations for the three and nine months ended September 30, 2019 and 2018, its statements of stockholders’ equity for the three and nine months ended September 30, 2019 and 2018 and its statement of cash flows for the nine months ended September 30, 2019 and 2018. The results for the three and nine months ended September 30, 2019 are not necessarily indicative of the results to be expected for the year ending December 31, 2019, any other interim periods, or any future year or period. These interim financial statements should be read in conjunction with the audited financial statements as of and for the year ended December 31, 2018, and the notes thereto, which are included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2018, filed with the Securities and Exchange Commission (“SEC”) on March 25, 2019. The accompanying Unaudited Condensed Consolidated Financial Statements reflect the application of certain significant accounting policies as described below and elsewhere in these notes to the Unaudited Condensed Consolidated Financial Statements. As of September 30, 2019, there have been no changes to the Company’s significant accounting policies as described in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2018, except as it related to the adoption of new accounting standards during the first nine months of 2019 as discussed below. Use of Estimates The preparation of 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 revenue and expenses during the reporting periods. Significant estimates and assumptions reflected in these consolidated financial statements include, but are not limited to, the accrual for research and development expenses, stock-based compensation expense, the valuation of equity and derivative instruments and the recoverability of the Company’s net deferred tax assets and related valuation allowance. 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 materially from those estimates. Emerging Growth Company Status The Company is an “emerging growth company,” as defined in the Jumpstart Our Business Startups Act, or JOBS Act, and may take advantage of certain exemptions from various reporting requirements that are applicable to other public companies that are not emerging growth companies. The Company may take advantage of these exemptions until the Company is no longer an “emerging growth company.” Section 107 of the JOBS Act provides that an “emerging growth company” can take advantage of the extended transition period afforded by the JOBS Act for the implementation of new or revised accounting standards. The Company has elected to use the extended transition period for complying with new or revised accounting standards and as a result of this election, its consolidated financial statements may not be comparable to companies that comply with public company effective dates. The Company may take advantage of these exemptions up until the last day of the fiscal year following the fifth anniversary of an offering or such earlier time that it is no longer an “emerging growth company”. Subsequent Event Considerations The Company considers events or transactions that occur after the balance sheet date but prior to the issuance of the consolidated financial statements to provide additional evidence for certain estimates or to identify matters that require additional disclosure. Subsequent events have been evaluated as required. See Note 13. Recently Issued Accounting Pronouncements In November 2018, the FASB issued ASU No. 2018-18, Collaborative Arrangements (Topic 808)—Clarifying the Interaction between Topic 808 and Topic 606 In August 2018, the FASB issued ASU No. 2018-15, Intangible-Goodwill and Other Internal-Use Software (Subtopic 350-40) In August 2018, The FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows: Classification of Certain Cash Receipts and Cash Payments In February 2016, the FASB issued ASU No. 2016-02 , Leases (Topic 842) Leases |
Fair Value of Financial Assets
Fair Value of Financial Assets and Liabilities | 9 Months Ended |
Sep. 30, 2019 | |
Fair Value Disclosures [Abstract] | |
Fair Value of Financial Assets and Liabilities | 3. Fair Value of Financial Assets and Liabilities The following table presents information about the Company’s financial assets and liabilities measured at fair value on a recurring basis and indicates the level of the fair value hierarchy utilized to determine such fair values as of September 30, 2019 and December 31, 2018: Fair Value Measurements as of September 30, 2019 Using: Level 1 Level 2 Level 3 Total Assets: Money market funds $ 206,121 $ — $ — $ 206,121 Restricted cash 492 — — 492 $ 206,613 $ — $ — $ 206,613 Fair Value Measurements as of December 31, 2018 Using: Level 1 Level 2 Level 3 Total Assets: Money market funds $ 126,047 $ — $ — $ 126,047 Restricted cash 492 — — 492 $ 126,539 $ — $ — $ 126,539 There were no transfers within the hierarchy during the nine months ended September 30, 2019 or the year ended December 31, 2018. Valuation of the Warrant to Purchase Preferred Stock At June 30, 2018, the Company had outstanding a warrant to purchase shares of common stock that was issued to a lender in connection with a loan and security agreement entered into in 2017. The warrant was originally issued as a warrant to purchase shares of Series A Preferred Stock prior to the IPO. The fair value of the warrant to purchase preferred stock was determined based on significant inputs not observable in the market, which represents a Level 3 measurement within the fair value hierarchy. Prior to the IPO, the Company classified the warrant as a liability on its consolidated balance sheets as the warrant is a free-standing financial instrument that may require the Company to transfer assets upon exercise. The preferred stock warrant liability was initially recorded at fair value upon the date of issuance and was subsequently remeasured to fair value at each reporting date. Changes in the fair value of the warrant to purchase preferred stock were recognized as a component of other income (expense), net in the consolidated statements of operations and comprehensive loss. The Company utilized the Black-Scholes option-pricing model, which incorporates assumptions and estimates, to value the warrant. The Company assessed these assumptions and estimates on a quarterly basis as additional information impacting the assumptions was obtained. Estimates and assumptions impacting the fair value measurement included the fair value per share of the underlying redeemable convertible preferred stock issuable upon exercise of the warrant, the remaining contractual term of the warrant, the risk-free interest rate, the expected dividend yield and the expected volatility of the price of the underlying redeemable convertible preferred stock. Upon the IPO, the warrant to purchase preferred stock was converted to a warrant to purchase common stock. The carrying amount of the warrant to purchase preferred stock as of the date of IPO was transferred to additional paid in capital. The Company recognized a loss of $0 and Valuation of Derivative In January 2016, in connection with a license agreement entered into with University Health Network (“UHN”), and as part of the initial consideration for the license, the Company issued 1,161,665 shares of common stock to UHN pursuant to a stock purchase agreement (the “Stock Purchase Agreement”). The Stock Purchase Agreement contained a provision requiring the Company to make a cash payment to UHN of up to $2,000 if UHN’s fully diluted ownership was reduced within specified percentages as part of an IPO by the Company. The Company concluded the anti-dilution feature represented a derivative instrument and should be measured at fair value, with changes in fair value recognized as a gain or loss to other income (expense), net in the consolidated statements of operations and comprehensive loss. The initial fair value of the derivative was recorded as research and development expense in January 2016. On June 21, 2018, in connection with the Company’s IPO, the Company remeasured the fair value of the derivative to $2,000 as the Company was required to pay the dilution payment as mentioned above, which the Company paid in July 2018. An increase in fair value of $0 and $1,629 was recorded in other expense in the accompanying condensed consolidated statements of operations and comprehensive loss for the nine months ended September 30, 2019 and 2018, respectively. The Company did not recognize any expense for the three months ended September 30, 2019 and 2018. |
Prepaid Expenses and Other Curr
Prepaid Expenses and Other Current Assets | 9 Months Ended |
Sep. 30, 2019 | |
Text Block [Abstract] | |
Prepaid Expenses and Other Current Assets | 4. Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consisted of the following: September 30, 2019 December 31, 2018 Tax incentive refund $ 1,806 $ 1,325 Prepaid research and development costs 3,577 981 Prepaid insurance 1,309 316 Interest income receivable 314 220 Prepaid rent 92 81 Other current assets 247 795 $ 7,345 $ 3,718 |
Property and Equipment, Net
Property and Equipment, Net | 9 Months Ended |
Sep. 30, 2019 | |
Property Plant And Equipment [Abstract] | |
Property and Equipment, Net | 5. Property and Equipment, Net Property and equipment, net consisted of the following: September 30, 2019 December 31, 2018 Laboratory and office equipment $ 2,188 $ 1,624 Leasehold improvements 1,260 1,260 Computer equipment and software 134 134 Construction in process 80 — 3,662 3,018 Less: Accumulated depreciation and amortization (989 ) (384 ) $ 2,673 $ 2,634 Depreciation and amortization expense for the three months ended September 30, 2019 and 2018 was $215 and $130, respectively. Depreciation and amortization expense for the nine months ended September 30, 2019 and 2018 was $605 and $196, respectively. |
Accrued Expenses and Other Curr
Accrued Expenses and Other Current Liabilities | 9 Months Ended |
Sep. 30, 2019 | |
Payables And Accruals [Abstract] | |
Accrued Expenses and Other Current Liabilities | 6. Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consisted of the following: September 30, 2019 December 31, 2018 Compensation and benefit costs $ 2,860 $ 2,616 Research and development costs 4,508 3,969 Consulting and professional fees 850 320 Other liabilities 284 917 $ 8,502 $ 7,822 |
Redeemable Convertible Preferre
Redeemable Convertible Preferred Stock and Common Stock | 9 Months Ended |
Sep. 30, 2019 | |
Text Block [Abstract] | |
Redeemable Convertible Preferred Stock and Common Stock | 7. Redeemable Convertible Preferred Stock and Common Stock Redeemable Convertible Preferred Stock Prior to the IPO, the authorized capital stock of the Company included 63,491,857 shares of $0.0001 par value preferred stock, of which 3,333,333 shares have been designated as Series Seed Preferred Stock, 31,639,202 shares have been designated as Series A Preferred Stock and 28,519,322 shares have been designated as Series B Preferred Stock. In January 2018, the Company issued and sold 28,519,322 shares of Series B Preferred Stock, at a price of $2.1389 per share, for total proceeds of $58,757, net of issuance costs of $2,243. Upon closing of the IPO, all outstanding shares of Preferred Stock were converted into 15,320,213 shares of common stock. The holders of the Company’s Preferred Stock had certain voting, dividend, and redemption rights, as well as liquidation preferences and conversion privileges. All rights, preferences, and privileges associated with the preferred stock were terminated at the time of the Company’s IPO in conjunction with the conversion of all outstanding shares of Preferred Stock into shares of common stock. Common Stock As of September 30, 2019 and December 31, 2018, the authorized capital stock of the Company included 150,000,000 shares of common stock, $0.0001 par value and 10,000,000 shares of undesignated preferred stock. As of September 30, 2019 and December 31, 2018, no undesignated preferred stock was outstanding. In accordance with the Fourth Amended and Restated Certificate of Incorporation, the holders of the common stock shall have the exclusive right to vote for the election of directors of the Company and on all other matters requiring stockholder action, each outstanding share entitling the holder thereof to one vote on each matter properly submitted to the stockholders of the Company for their vote; provided, however, that, except as otherwise required by law, holders of common stock, as such, shall not be entitled to vote on any amendment to any amendment to a certificate of designations of any series of undesignated preferred stock that alters or changes the powers, preferences, rights or other terms of one or more outstanding series of undesignated preferred stock if the holders of such affected series of undesignated preferred stock are entitled to vote, either separately or together with the holders of one or more other such series, on such amendment pursuant to a certificate of designations of any series of undesignated preferred stock. Through September 30, 2019, no cash dividends have been declared or paid. Common Stock Reserved for Future Issuance At September 30, 2019 and December 31, 2018, the Company has reserved the following shares of common stock for future issuance: September 30, 2019 December 31, 2018 Shares reserved for vesting of restricted stock awards 63,313 153,276 Shares reserved for exercise of outstanding stock options 3,145,428 2,164,101 Shares reserved for issuance under the 2018 Stock Option and Grant Plan 474,326 385,561 Shares reserved for issuance under the 2018 Employee Stock Purchase Plan 461,266 223,200 Total shares of authorized common stock reserved for future issuance 4,144,333 2,926,138 |
Stock-Based Compensation
Stock-Based Compensation | 9 Months Ended |
Sep. 30, 2019 | |
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] | |
Stock-Based Compensation | 8. Stock-Based Compensation Stock Option Valuation The assumptions that the Company used to determine the grant-date fair value of stock options granted to employees and members of the Board were as follows, presented on a weighted-average basis: Nine Months Ended September 30, 2019 2018 Expected option life (years) 5.97 6.05 Risk-free interest rate 2.40 % 2.73 % Expected volatility 81.25 % 83.42 % Expected dividend yield — % — % The following table summarizes the Company’s stock option activity for the nine months ended September 30, 2019: Number of Options Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (Years) Aggregate Intrinsic Value Outstanding as of December 31, 2018 2,164,100 $ 7.75 8.77 $ 23,083 Granted 1,315,317 $ 16.76 Exercised (232,758 ) $ 2.14 Cancelled or forfeited (101,231 ) $ 10.26 Outstanding as of September 30, 2019 3,145,428 $ 11.86 8.63 $ 15,491 Exercisable as of September 30, 2019 790,343 $ 3.99 7.51 $ 8,759 Vested and expected to vest as of September 30, 2019 3,145,428 $ 11.86 8.63 $ 15,491 The aggregate intrinsic value of stock options is calculated as the difference between the exercise price of the underlying stock options and the estimated fair value of the Company’s common stock for those stock options that had exercise prices lower than the estimated fair value of the Company’s common stock. The weighted-average grant-date fair value of the Company’s stock options granted during the nine months ended September 30, 2019 and 2018 was $11.77 and $9.05, respectively. Restricted Common Stock The following table summarizes the Company’s restricted common stock activity for the nine months ended September 30, 2019: Number of Shares Weighted- Average Grant Date Fair Value Issued and unvested as of December 31, 2018 153,275 $ 0.42 Granted 2,300 $ 15.65 Vested (92,262 ) $ 0.42 Forfeited, canceled or expired — $ — Issued and unvested as of September 30, 2019 63,313 $ 0.42 The total fair value of restricted common stock vested during the nine months ended September 30, 2019 and 2018 was $44 and $39, respectively. Stock-Based Compensation Stock-based compensation expense was allocated as follows: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Research and development $ 889 $ 230 $ 2,649 $ 417 General and administrative 908 320 2,265 700 Total stock-based compensation expense $ 1,797 $ 550 $ 4,914 $ 1,117 As of September 30, 2019, total unrecognized compensation cost related to the unvested stock-based awards was $22,065, which is expected to be recognized over a weighted-average period of 3.24 years. |
License Agreements
License Agreements | 9 Months Ended |
Sep. 30, 2019 | |
Text Block [Abstract] | |
License Agreements | 9. License Agreements Agreements with UHN Fabry License Agreement— On January 27, 2016, the Company entered into an agreement with UHN, pursuant to which UHN granted the Company an option to enter into an exclusive license under the UHN intellectual property related to Fabry disease in accordance with the pre-negotiated licensing terms. On November 4, 2016, the Company exercised its option and entered into a license agreement with UHN, pursuant to which UHN granted the Company an exclusive worldwide license under certain intellectual property rights and a non-exclusive worldwide license under certain know-how, in each case subject to certain retained rights, to develop, commercialize and sell products for use in the treatment of Fabry disease. UHN also granted the Company an exclusive option, exercisable for a period of three years following the execution of the agreement, to obtain a license under certain improvements to the licensed intellectual property rights as well as an option to negotiate a license under certain other improvements. The Company elected not to exercise such option and the option has expired in accordance with its terms. Under this agreement, the Company paid an option fee of CAD $20, an upfront license fee of CAD $75, plus the annual license maintenance fee for the first year. Thereafter, the Company is also required to pay UHN future annual license maintenance fees until the first sale of a licensed product in certain markets. The Company is also obligated to make future milestone payments in an aggregate amount of up to CAD $2,450 upon the achievement of specified milestones as well as royalties on a country-by-country basis of a low to mid-single-digit percentage of annual net sales of licensed products and a lower single-digit royalty percentage in certain circumstances. Additionally, the Company has agreed to pay a low double-digit royalty percentage of all sublicensing revenue. The agreement requires the Company to meet certain performance milestones within specified timeframes. UHN may terminate the agreement if the Company fails to meet these performance milestones despite using commercially reasonable efforts and the Company is unable to reach agreement with UHN on revised timeframes. The Company’s royalty obligation expires on a licensed product-by-licensed product and country-by-country basis upon the latest to occur of the expiration or termination of the last valid claim under the licensed intellectual property rights in such country, the tenth anniversary of the first commercial sale of such licensed product in such country and the expiration of any applicable regulatory exclusivity in such country. Unless terminated earlier, the agreement expires upon the expiration of the Company’s royalty obligation for all licensed products. UHN can terminate the agreement if the Company fails to make any payments within a specified period after receiving written notice of such failure, or in the event that the Company fails to obtain or maintain insurance. Either the Company or UHN may terminate the license agreement in the event of a material breach by the other party and failure to cure such breach within a certain period of time. The Company can voluntarily terminate the agreement with prior notice to UHN. For the three months ended September 30, 2019 and 2018, the Company recorded research and development expense related to this agreement with UHN of $415 and $0, respectively, which consists of reimbursable funded study trial costs. For the nine months ended September 30, 2019 and 2018, the Company recorded research and development expense related to this agreement with UHN of $741 and $0, respectively, which consists of reimbursable funded study trial costs. No milestone or maintenance fees were incurred related to the Fabry license agreement in the nine months ended September 30, 2019 and 2018. Interleukin 12 License Agreement— On January 27, 2016, the Company entered into an exclusive license agreement with UHN, pursuant to which UHN granted the Company a license to certain patent rights for the commercial development, manufacture, distribution and use of any products or processes resulting from development of those patent rights related to Interleukin 12. Upon execution of this agreement, the Company paid an upfront license fee of CAD $264. In addition, as part of the initial consideration for the license, the Company issued to UHN 1,161,665 shares of the Company’s common stock. The fair value of the shares issued to UHN of $480 and the upfront fee was expensed upon the execution of the agreement. In addition, the Company agreed to pay UHN up to $2,000 upon the closing of an IPO if certain criteria are met. This obligation was considered a derivative instrument and was initially recorded at fair value of $49. The Company is also required to pay UHN future annual license maintenance fees of CAD $50 on each anniversary of the effective date of the license agreement prior to expiration or termination and potential future milestone payments of up to CAD $19,275 upon the achievement of specified clinical and regulatory milestones. The Company also agreed to pay UHN royalties of a low single-digit percentage of net sales of licensed products sold by the Company. If the Company grants any sublicense rights under the license agreement, the Company has agreed to pay UHN a low double-digit royalty percentage of any sublicense income received by the Company. The agreement requires the Company to meet certain diligence requirements based upon specified milestones. The agreement expires on the later of the date the last patent rights expire in the last country or ten years from the date of first sale. UHN can terminate the agreement if the Company fails to make any payments within a specified period after receiving written notice of such failure, or in the event that the Company fails to obtain or maintain insurance. The Company can voluntarily terminate the agreement with prior notice to UHN. Either the Company or UHN may terminate the license agreement in the event of a material breach by the other party and failure to cure such breach within a certain period of time. For the nine months ended September 30, 2019 and 2018, the Company recorded research and development expense related to this agreement with UHN of $38 and $41, respectively, which consists of license maintenance fees. No license maintenance fees were recorded in the three months ended September 30, 2019 and 2018. No milestone fees were incurred related to the IL-12 license agreement in the nine months ended September 30, 2019 and 2018. Agreement with BioMarin Pharmaceutical Inc. (“BioMarin”) On August 31, 2017, the Company entered into a license agreement with BioMarin, pursuant to which BioMarin granted the Company an exclusive worldwide license under certain intellectual property rights owned or controlled by BioMarin to develop, commercialize and sell products for use in the treatment of Pompe disease. As consideration for this agreement, the Company paid an upfront license fee of $500 in cash and issued 233,765 shares of Series B Preferred Stock to BioMarin at the time of our Series B Preferred Stock financing in January 2018. Both the upfront cash payment of $500 and the value of the shares Series B Preferred Stock issued of $500 were recorded as research and development expense during the year ended December 31, 2017. The Company is also obligated to make future milestone payments of up to $13,000 upon the achievement of certain specified milestones and agreed to pay BioMarin royalties of a low single-digit percentage of net sales of licensed products sold by the Company or its affiliates covered by patent rights in a relevant country. No milestone fees related to the license were recorded for the nine months ended September 30, 2019 and 2018. Unless terminated earlier, the agreement expires upon the expiration of the Company’s royalty obligation for all licensed products throughout the world. BioMarin and the Company can terminate the agreement in the event of a material breach by the other party and failure to cure such breach within a certain period of time. The Company may terminate the agreement at will upon written notice to BioMarin. BioMarin has the right to terminate the agreement upon the Company’s bankruptcy or insolvency, or in the event of any challenge or opposition to the licensed patent rights or related actions brought by the Company or its affiliates or sublicensees, or if the Company, its affiliates or sublicensees knowingly assist a third-party in challenging or otherwise opposing the licensed patent rights, except as required under a court order or subpoena. Agreement with GenStem Therapeutics, Inc. (“GenStem”) On October 2, 2017, the Company entered into a license agreement with GenStem, pursuant to which GenStem granted the Company an exclusive worldwide license, subject to certain retained rights, under certain intellectual property rights owned or controlled by GenStem to develop, commercialize and sell products for use in the treatment of cystinosis. Under this agreement, the Company paid an upfront license fee of $1,000 and is required to make payments upon completion of certain milestones up to an aggregate of $16,000. In November 2019, the Company made a payment of $2,000 in connection with the dosing of the first patient in the investigator-sponsored Phase 1/2 clinical trial of AVR-RD-04 in cystinosis in the United States. The next anticipated payment under this Agreement is $2,000, which would become due following the dosing of the first patient in the first pivotal clinical trial of AVR-RD-04 in cystinosis in the United States. The Company also agreed to pay GenStem a tiered mid to high single-digit royalty percentage on annual net sales of licensed products as well as a low double-digit percentage of sublicense income received from certain third-party licensees. The Company’s royalty obligation expires on a licensed product-by-licensed product and country-by-country basis on the eleventh anniversary of the first commercial sale of such licensed product in such country or the expiration of the last valid claim under the licensed patent rights covering such licensed product in such country, whichever is later. Unless terminated earlier, the agreement expires upon the expiration of the Company’s royalty obligation for all licensed products throughout the world. GenStem and the Company can terminate the agreement in the event of a material breach by the other party and failure to cure such breach within a certain period of time. The Company may terminate the agreement at will upon the specified prior written notice to GenStem. No milestone fees related to the license were recorded for the nine months ended September 30, 2019 and 2018. Agreement with Lund University Rights Holders On November 17, 2016, the Company entered into a license agreement with affiliates of Lund University, along with certain other relevant rights holders that may be added from time to time, pursuant to which such rights holders granted to the Company an exclusive worldwide license, subject to certain retained rights, under certain intellectual property rights to develop, commercialize and sell products in any and all uses relevant to Gaucher disease. As consideration for the license, the Company is required to make payments in connection with the achievement of certain milestones up to an aggregate of $550. The agreement expires on the latest of (i) the twentieth anniversary of the end of a certain research project the Company is funding pursuant to an agreement with Lund University, (ii) the expiration of the term of any patent filed on the licensed rights that covers a licensed product, (iii) the expiration of any applicable marketing exclusivity right and (iv) such time that neither the Company nor any sublicensees, partners or contractors are commercializing a licensed product. Either the Company or the rights holders acting together may terminate the license agreement if the other such party commits a material breach and fails to cure such breach within a certain period of time, or if the other party enters into liquidation, becomes insolvent, or enters into composition or statutory reorganization proceedings. No milestone fees related to the license were recorded for the nine months ended September 30, 2019 and 2018. |
Net Loss per Share Attributable
Net Loss per Share Attributable to Common Stockholders | 9 Months Ended |
Sep. 30, 2019 | |
Earnings Per Share [Abstract] | |
Net Loss per Share Attributable to Common Stockholders | 10. Net Loss per Share Attributable to Common Stockholders For purposes of the diluted net loss per share calculation, stock options, unvested restricted stock, Preferred Stock and the warrant to purchase shares of Series A Preferred Stock are considered to be common stock equivalents but have been excluded from the calculation of diluted net loss per share, as their effect would be anti-dilutive for all periods presented. Therefore, the weighted-average number of common shares outstanding used to calculate both basic and diluted net loss per share attributable to common stockholders is the same. The following potentially dilutive common stock equivalents, presented based on amounts outstanding at each period end, were excluded from the computation of diluted net loss per share attributable to common stockholders for the periods indicated: Nine Months Ended September 30, 2019 2018 Options to purchase common stock 3,145,428 1,957,839 Restricted common stock 63,313 184,033 Warrants to purchase redeemable convertible preferred stock (as converted to common stock) — — |
Commitments and Contingencies
Commitments and Contingencies | 9 Months Ended |
Sep. 30, 2019 | |
Commitments And Contingencies Disclosure [Abstract] | |
Commitments and Contingencies | 11. Commitments and Contingencies Lease Agreement On January 12, 2018, the Company entered into a lease agreement for office space located in Cambridge, Massachusetts. The lease agreement expires in January 2023, with a landlord who is an affiliate of the landlord of the Company’s prior lease facility. The annual lease payments are subject to a 3% increase each year. The Company recognizes rent expense on a straight-line basis over the lease period and has recorded deferred rent for rent expense incurred but not yet paid. The Company received a tenant incentive allowance of $842 in 2018. Such incentive allowance is being amortized as a reduction of rent expense on a straight-line basis over the lease period. In accordance with the lease agreement, the Company is required to maintain a security deposit of $209, which was recorded in other assets. In contemplation of this agreement, the Company terminated its prior lease agreement. On August 31, 2018, the Company entered into a sub-lease agreement for lab space located in Cambridge, Massachusetts, United States, which expires in October 2020. The annual lease payments are subject to a 3% increase each year. In accordance with the lease agreement, the Company is required to maintain a security deposit of $283, which was recorded in other assets as of September 30, 2018. Legal Proceedings The Company, from time to time, may be party to litigation arising in the ordinary course of business. The Company was not subject to any material legal proceedings during the nine months ended September 30, 2019 and 2018 and to the best of its knowledge, no material legal proceedings are currently pending or threatened. Other The Company is also party to various agreements, principally relating to licensed technology, that require future payments relating to milestones not met at September 30, 2019 and December 31, 2018, or royalties on future sales. No milestone or royalty payments under these agreements are expected to be payable in the immediate future, except as disclosed in Note 9. See Note 9 for discussion of these arrangements. The Company enters into standard indemnification agreements in the ordinary course of business. Pursuant to the agreements, the Company agrees to indemnify, hold harmless, and to reimburse the indemnified party for losses suffered or incurred by the indemnified party, generally the Company’s business partners, in connection with any U.S. patent or any copyright or other intellectual property infringement claim by any third-party with respect to the Company’s products. Further, the Company indemnifies its directors and officers who are, or were, serving at the Company’s request in such capacities. The Company’s maximum exposure under these arrangements is unknown at September 30, 2019. The Company does not anticipate recognizing any significant losses relating to these arrangements. The term of these indemnification agreements is generally perpetual any time after execution of the agreement. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is unlimited. The Company has never incurred costs to defend lawsuits or settle claims related to these indemnification agreements. |
Related Party Transactions
Related Party Transactions | 9 Months Ended |
Sep. 30, 2019 | |
Related Party Transactions [Abstract] | |
Related Party Transactions | 12. Related Party Transactions UHN In connection with the Company’s entry into a license agreement with UHN on January 27, 2016, the Company issued UHN 1,161,665 shares of its common stock. Upon the closing of the IPO, as UHN’s fully-diluted percentage ownership of the Company was reduced within a range of specified percentages, the Company was obligated to pay UHN an amount up to $2,000, which was paid in July 2018. See Note 3 for further discussion on the accounting treatment for this provision. For the three months ended September 30, 2019 and 2018, the Company recognized $415 and $0, respectively, of research and development expense related to the license agreements with UHN (Note 9). For the nine months ended September 30, 2019 and 2018, the Company recognized $779 and $41, respectively, of research and development expense related to the license agreements with UHN (Note 9). Others For the three and nine months ended September 30, 2019, the Company recorded expenses of $369 and $1,090, respectively, related to a sublease to rent lab space, provided by an entity affiliated with a member of the Board. No such expense was recorded for the three and nine months ended September 30, 2018. For the three nine months ended September 30, 2019 and 2018, the Company recognized $0 and $2, respectively, related to consulting services provided by an entity affiliated with an officer of the Company and a member of the Board. For the nine months ended September 30, 2019 and 2018, the Company recognized $0 and $42, respectively, related to consulting services provided by an entity affiliated with an officer of the Company and a member of the Board |
Subsequent Events
Subsequent Events | 9 Months Ended |
Sep. 30, 2019 | |
Subsequent Events [Abstract] | |
Subsequent Events | 13. Subsequent Events In November 2019, the Company made a payment of $2,000 to GenStem in connection with the dosing of the first patient in the investigator-sponsored Phase 1/2 clinical trial of AVR-RD-04 in cystinosis in the United States (Note 9). |
Summary of Significant Accoun_2
Summary of Significant Accounting Policies (Policies) | 9 Months Ended |
Sep. 30, 2019 | |
Accounting Policies [Abstract] | |
Basis of Presentation | Basis of Presentation The accompanying condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). Any reference in these notes to applicable guidance is meant to refer to the authoritative United States generally accepted accounting principles as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Update (“ASU”) of the Financial Accounting Standards Board (“FASB”). The unaudited condensed consolidated interim financial statements have been prepared on the same basis as the audited annual consolidated financial statements as of and for the year ended December 31, 2018, and, in the opinion of management, reflect all adjustments, consisting of normal recurring adjustments, necessary for the fair presentation of the Company’s financial position as of September 30, 2019, and the results of its operations for the three and nine months ended September 30, 2019 and 2018, its statements of stockholders’ equity for the three and nine months ended September 30, 2019 and 2018 and its statement of cash flows for the nine months ended September 30, 2019 and 2018. The results for the three and nine months ended September 30, 2019 are not necessarily indicative of the results to be expected for the year ending December 31, 2019, any other interim periods, or any future year or period. These interim financial statements should be read in conjunction with the audited financial statements as of and for the year ended December 31, 2018, and the notes thereto, which are included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2018, filed with the Securities and Exchange Commission (“SEC”) on March 25, 2019. The accompanying Unaudited Condensed Consolidated Financial Statements reflect the application of certain significant accounting policies as described below and elsewhere in these notes to the Unaudited Condensed Consolidated Financial Statements. As of September 30, 2019, there have been no changes to the Company’s significant accounting policies as described in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2018, except as it related to the adoption of new accounting standards during the first nine months of 2019 as discussed below. |
Use of Estimates | Use of Estimates The preparation of 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 revenue and expenses during the reporting periods. Significant estimates and assumptions reflected in these consolidated financial statements include, but are not limited to, the accrual for research and development expenses, stock-based compensation expense, the valuation of equity and derivative instruments and the recoverability of the Company’s net deferred tax assets and related valuation allowance. 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 materially from those estimates. |
Emerging Growth Company Status | Emerging Growth Company Status The Company is an “emerging growth company,” as defined in the Jumpstart Our Business Startups Act, or JOBS Act, and may take advantage of certain exemptions from various reporting requirements that are applicable to other public companies that are not emerging growth companies. The Company may take advantage of these exemptions until the Company is no longer an “emerging growth company.” Section 107 of the JOBS Act provides that an “emerging growth company” can take advantage of the extended transition period afforded by the JOBS Act for the implementation of new or revised accounting standards. The Company has elected to use the extended transition period for complying with new or revised accounting standards and as a result of this election, its consolidated financial statements may not be comparable to companies that comply with public company effective dates. The Company may take advantage of these exemptions up until the last day of the fiscal year following the fifth anniversary of an offering or such earlier time that it is no longer an “emerging growth company”. |
Subsequent Event Considerations | Subsequent Event Considerations The Company considers events or transactions that occur after the balance sheet date but prior to the issuance of the consolidated financial statements to provide additional evidence for certain estimates or to identify matters that require additional disclosure. Subsequent events have been evaluated as required. See Note 13. |
Recently Issued Accounting Pronouncements | Recently Issued Accounting Pronouncements In November 2018, the FASB issued ASU No. 2018-18, Collaborative Arrangements (Topic 808)—Clarifying the Interaction between Topic 808 and Topic 606 In August 2018, the FASB issued ASU No. 2018-15, Intangible-Goodwill and Other Internal-Use Software (Subtopic 350-40) In August 2018, The FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows: Classification of Certain Cash Receipts and Cash Payments In February 2016, the FASB issued ASU No. 2016-02 , Leases (Topic 842) Leases |
Fair Value of Financial Asset_2
Fair Value of Financial Assets and Liabilities (Tables) | 9 Months Ended |
Sep. 30, 2019 | |
Fair Value Disclosures [Abstract] | |
Summary of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis | The following table presents information about the Company’s financial assets and liabilities measured at fair value on a recurring basis and indicates the level of the fair value hierarchy utilized to determine such fair values as of September 30, 2019 and December 31, 2018: Fair Value Measurements as of September 30, 2019 Using: Level 1 Level 2 Level 3 Total Assets: Money market funds $ 206,121 $ — $ — $ 206,121 Restricted cash 492 — — 492 $ 206,613 $ — $ — $ 206,613 Fair Value Measurements as of December 31, 2018 Using: Level 1 Level 2 Level 3 Total Assets: Money market funds $ 126,047 $ — $ — $ 126,047 Restricted cash 492 — — 492 $ 126,539 $ — $ — $ 126,539 |
Prepaid Expenses and Other Cu_2
Prepaid Expenses and Other Current Assets (Tables) | 9 Months Ended |
Sep. 30, 2019 | |
Text Block [Abstract] | |
Summary of Prepaid Expenses and Other Current Assets | Prepaid expenses and other current assets consisted of the following: September 30, 2019 December 31, 2018 Tax incentive refund $ 1,806 $ 1,325 Prepaid research and development costs 3,577 981 Prepaid insurance 1,309 316 Interest income receivable 314 220 Prepaid rent 92 81 Other current assets 247 795 $ 7,345 $ 3,718 |
Property and Equipment, Net (Ta
Property and Equipment, Net (Tables) | 9 Months Ended |
Sep. 30, 2019 | |
Property Plant And Equipment [Abstract] | |
Summary of Property and Equipment, Net | Property and equipment, net consisted of the following: September 30, 2019 December 31, 2018 Laboratory and office equipment $ 2,188 $ 1,624 Leasehold improvements 1,260 1,260 Computer equipment and software 134 134 Construction in process 80 — 3,662 3,018 Less: Accumulated depreciation and amortization (989 ) (384 ) $ 2,673 $ 2,634 |
Accrued Expenses and Other Cu_2
Accrued Expenses and Other Current Liabilities (Tables) | 9 Months Ended |
Sep. 30, 2019 | |
Payables And Accruals [Abstract] | |
Summary of Accrued Expenses and Other Current Liabilities | Accrued expenses and other current liabilities consisted of the following: September 30, 2019 December 31, 2018 Compensation and benefit costs $ 2,860 $ 2,616 Research and development costs 4,508 3,969 Consulting and professional fees 850 320 Other liabilities 284 917 $ 8,502 $ 7,822 |
Redeemable Convertible Prefer_2
Redeemable Convertible Preferred Stock and Common Stock (Tables) | 9 Months Ended |
Sep. 30, 2019 | |
Text Block [Abstract] | |
Summary of Common Stock Reserved for Future Issuance | At September 30, 2019 and December 31, 2018, the Company has reserved the following shares of common stock for future issuance: September 30, 2019 December 31, 2018 Shares reserved for vesting of restricted stock awards 63,313 153,276 Shares reserved for exercise of outstanding stock options 3,145,428 2,164,101 Shares reserved for issuance under the 2018 Stock Option and Grant Plan 474,326 385,561 Shares reserved for issuance under the 2018 Employee Stock Purchase Plan 461,266 223,200 Total shares of authorized common stock reserved for future issuance 4,144,333 2,926,138 |
Stock-Based Compensation (Table
Stock-Based Compensation (Tables) | 9 Months Ended |
Sep. 30, 2019 | |
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] | |
Summary of Assumptions that Used to Determine Grant-Date Fair Value of Stock Options Granted to Employees and Members of Board | The assumptions that the Company used to determine the grant-date fair value of stock options granted to employees and members of the Board were as follows, presented on a weighted-average basis: Nine Months Ended September 30, 2019 2018 Expected option life (years) 5.97 6.05 Risk-free interest rate 2.40 % 2.73 % Expected volatility 81.25 % 83.42 % Expected dividend yield — % — % |
Summary of Stock Option Activity | The following table summarizes the Company’s stock option activity for the nine months ended September 30, 2019: Number of Options Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (Years) Aggregate Intrinsic Value Outstanding as of December 31, 2018 2,164,100 $ 7.75 8.77 $ 23,083 Granted 1,315,317 $ 16.76 Exercised (232,758 ) $ 2.14 Cancelled or forfeited (101,231 ) $ 10.26 Outstanding as of September 30, 2019 3,145,428 $ 11.86 8.63 $ 15,491 Exercisable as of September 30, 2019 790,343 $ 3.99 7.51 $ 8,759 Vested and expected to vest as of September 30, 2019 3,145,428 $ 11.86 8.63 $ 15,491 |
Summary of Restricted Stock Unit Activity | The following table summarizes the Company’s restricted common stock activity for the nine months ended September 30, 2019: Number of Shares Weighted- Average Grant Date Fair Value Issued and unvested as of December 31, 2018 153,275 $ 0.42 Granted 2,300 $ 15.65 Vested (92,262 ) $ 0.42 Forfeited, canceled or expired — $ — Issued and unvested as of September 30, 2019 63,313 $ 0.42 |
Schedule of Stock-based Compensation Expense | Stock-based compensation expense was allocated as follows: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Research and development $ 889 $ 230 $ 2,649 $ 417 General and administrative 908 320 2,265 700 Total stock-based compensation expense $ 1,797 $ 550 $ 4,914 $ 1,117 |
Net Loss per Share Attributab_2
Net Loss per Share Attributable to Common Stockholders (Tables) | 9 Months Ended |
Sep. 30, 2019 | |
Earnings Per Share [Abstract] | |
Schedule of Dilutive Common Stock Equivalents Excluded from Computation of Diluted Net Loss per Share | The following potentially dilutive common stock equivalents, presented based on amounts outstanding at each period end, were excluded from the computation of diluted net loss per share attributable to common stockholders for the periods indicated: Nine Months Ended September 30, 2019 2018 Options to purchase common stock 3,145,428 1,957,839 Restricted common stock 63,313 184,033 Warrants to purchase redeemable convertible preferred stock (as converted to common stock) — — |
Nature of the Business - Additi
Nature of the Business - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands | Jun. 25, 2018 | Jul. 31, 2019 | Sep. 30, 2019 | Jun. 30, 2019 | Mar. 31, 2019 | Sep. 30, 2018 | Jun. 30, 2018 | Mar. 31, 2018 | Sep. 30, 2019 | Sep. 30, 2018 | Dec. 31, 2018 |
Nature Of Organization And Operations [Line Items] | |||||||||||
Net proceeds from issuance of common stock | $ 104,013 | $ 129,465 | |||||||||
Convertible preferred stock converted into common stock | 15,320,213 | ||||||||||
Net loss | $ (17,145) | $ (16,055) | $ (17,103) | $ (11,591) | $ (10,507) | $ (8,242) | (50,303) | $ (30,340) | |||
Accumulated deficit | $ (122,042) | $ (122,042) | $ (71,739) | ||||||||
IPO [Member] | |||||||||||
Nature Of Organization And Operations [Line Items] | |||||||||||
Common stock, shares issued and sold | 5,247,958 | ||||||||||
Issuance price per shares | $ 19 | ||||||||||
Net proceeds from issuance of common stock | $ 90,103 | ||||||||||
Underwriting discounts and commissions and offering costs | 6,980 | ||||||||||
Other offering expenses | $ 2,628 | ||||||||||
Over-Allotment Option [Member] | |||||||||||
Nature Of Organization And Operations [Line Items] | |||||||||||
Common stock, shares issued and sold | 787,193 | ||||||||||
Net proceeds from issuance of common stock | $ 13,910 | ||||||||||
Underwriting discounts and commissions and offering costs | $ 1,047 | ||||||||||
July 2019 Follow-on Offering [Member] | |||||||||||
Nature Of Organization And Operations [Line Items] | |||||||||||
Net proceeds from issuance of common stock | $ 129,500 | ||||||||||
Common Stock [Member] | Over-Allotment Option [Member] | |||||||||||
Nature Of Organization And Operations [Line Items] | |||||||||||
Common stock, shares issued and sold | 975,000 | ||||||||||
Common Stock [Member] | July 2019 Follow-on Offering [Member] | |||||||||||
Nature Of Organization And Operations [Line Items] | |||||||||||
Common stock, shares issued and sold | 7,475,000 | ||||||||||
Issuance price per shares | $ 18.50 |
Fair Value of Financial Asset_3
Fair Value of Financial Assets and Liabilities - Summary of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Fair Value on Recurring Basis [Member] - USD ($) | Sep. 30, 2019 | Dec. 31, 2018 |
Assets Fair Value Disclosure | ||
Assets Fair Value Disclosure | $ 206,613 | $ 126,539 |
Money Market Funds [Member] | ||
Assets Fair Value Disclosure | ||
Assets Fair Value Disclosure | 206,121 | 126,047 |
Restricted Cash [Member] | ||
Assets Fair Value Disclosure | ||
Assets Fair Value Disclosure | 492 | 492 |
Level 1 [Member] | ||
Assets Fair Value Disclosure | ||
Assets Fair Value Disclosure | 206,613 | 126,539 |
Level 1 [Member] | Money Market Funds [Member] | ||
Assets Fair Value Disclosure | ||
Assets Fair Value Disclosure | 206,121 | 126,047 |
Level 1 [Member] | Restricted Cash [Member] | ||
Assets Fair Value Disclosure | ||
Assets Fair Value Disclosure | $ 492 | $ 492 |
Fair Value of Financial Asset_4
Fair Value of Financial Assets and Liabilities - Additional Information (Detail) - USD ($) | Jan. 27, 2016 | Sep. 30, 2019 | Sep. 30, 2018 | Sep. 30, 2019 | Sep. 30, 2018 | Dec. 31, 2018 | Jul. 31, 2018 |
Fair Value of Assets and Liabilities Measured on Non Recurring Basis [Line Items] | |||||||
Fair value input transfer between levels | $ 0 | $ 0 | $ 0 | ||||
Change in fair value of preferred stock warrant liability | 0 | $ 0 | $ 0 | $ 162,000 | |||
Common stock issued for initial consideration for license | 2,300 | ||||||
Increase in fair value of derivative | $ 0 | $ 0 | $ 0 | $ (1,629,000) | |||
IPO [Member] | |||||||
Fair Value of Assets and Liabilities Measured on Non Recurring Basis [Line Items] | |||||||
Dilution payment | $ 2,000,000 | ||||||
License Agreement [Member] | |||||||
Fair Value of Assets and Liabilities Measured on Non Recurring Basis [Line Items] | |||||||
Provision for maximum cash payment | $ 2,000,000 | ||||||
License Agreement [Member] | Stock Purchase Agreement [Member] | |||||||
Fair Value of Assets and Liabilities Measured on Non Recurring Basis [Line Items] | |||||||
Common stock issued for initial consideration for license | 1,161,665 |
Prepaid Expenses and Other Cu_3
Prepaid Expenses and Other Current Assets - Summary of Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands | Sep. 30, 2019 | Dec. 31, 2018 |
Prepaid Expense And Other Assets Current [Abstract] | ||
Tax incentive refund | $ 1,806 | $ 1,325 |
Prepaid research and development costs | 3,577 | 981 |
Prepaid insurance | 1,309 | 316 |
Interest income receivable | 314 | 220 |
Prepaid rent | 92 | 81 |
Other current assets | 247 | 795 |
Total | $ 7,345 | $ 3,718 |
Property and Equipment, Net - S
Property and Equipment, Net - Summary of Property and Equipment, Net (Detail) - USD ($) $ in Thousands | Sep. 30, 2019 | Dec. 31, 2018 |
Property, Plant and Equipment [Line Items] | ||
Property plant and equipment, gross | $ 3,662 | $ 3,018 |
Less: Accumulated depreciation and amortization | (989) | (384) |
Property plant and equipment, net | 2,673 | 2,634 |
Laboratory and Office Equipment [Member] | ||
Property, Plant and Equipment [Line Items] | ||
Property plant and equipment, gross | 2,188 | 1,624 |
Leasehold Improvements [Member] | ||
Property, Plant and Equipment [Line Items] | ||
Property plant and equipment, gross | 1,260 | 1,260 |
Computer Equipment and Software [Member] | ||
Property, Plant and Equipment [Line Items] | ||
Property plant and equipment, gross | 134 | $ 134 |
Construction in Process [Member] | ||
Property, Plant and Equipment [Line Items] | ||
Property plant and equipment, gross | $ 80 |
Property and Equipment, Net - A
Property and Equipment, Net - Additional Information (Detail) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2019 | Sep. 30, 2018 | Sep. 30, 2019 | Sep. 30, 2018 | |
Property Plant And Equipment [Abstract] | ||||
Depreciation and amortization expense | $ 215 | $ 130 | $ 605 | $ 196 |
Accrued Expenses - Summary of A
Accrued Expenses - Summary of Accrued Expenses and Other Current Liabilities (Detail) - USD ($) $ in Thousands | Sep. 30, 2019 | Dec. 31, 2018 |
Accrued Liabilities Current [Abstract] | ||
Compensation and benefit costs | $ 2,860 | $ 2,616 |
Research and development costs | 4,508 | 3,969 |
Consulting and professional fees | 850 | 320 |
Other liabilities | 284 | 917 |
Accrued expenses | $ 8,502 | $ 7,822 |
Redeemable Convertible Prefer_3
Redeemable Convertible Preferred Stock and Common Stock - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands | 1 Months Ended | 9 Months Ended | |||
Jan. 31, 2018 | Sep. 30, 2019 | Sep. 30, 2018 | Dec. 31, 2018 | Jun. 25, 2018 | |
Temporary Equity [Line Items] | |||||
Redeemable convertible preferred stock, shares authorized | 63,491,857 | ||||
Redeemable convertible preferred stock, par value | $ 0.0001 | ||||
Proceeds from issuance of redeemable convertible preferred stock | $ 58,258 | ||||
Common stock, shares authorized | 150,000,000 | 150,000,000 | |||
Common stock, par value | $ 0.0001 | $ 0.0001 | |||
Undesignated preferred stock | 10,000,000 | 10,000,000 | |||
Undesignated preferred stock outstanding | 0 | 0 | |||
Cash dividends | $ 0 | ||||
IPO [Member] | |||||
Temporary Equity [Line Items] | |||||
Redeemable convertible preferred stock, sales price per share | $ 19 | ||||
Preferred stock converted into common stock | 15,320,213 | ||||
Series Seed Redeemable Convertible Preferred Stock [Member] | |||||
Temporary Equity [Line Items] | |||||
Redeemable convertible preferred stock, shares authorized | 3,333,333 | ||||
Series A Redeemable Convertible Preferred Stock [Member] | |||||
Temporary Equity [Line Items] | |||||
Redeemable convertible preferred stock, shares authorized | 31,639,202 | ||||
Series B Redeemable Convertible Preferred Stock [Member] | |||||
Temporary Equity [Line Items] | |||||
Redeemable convertible preferred stock, shares authorized | 28,519,322 | ||||
Redeemable convertible preferred stock, shares issued and sold | 28,519,322 | ||||
Redeemable convertible preferred stock, sales price per share | $ 2.1389 | ||||
Proceeds from issuance of redeemable convertible preferred stock | $ 58,757 | ||||
Redeemable convertible preferred stock, net of issuance costs | $ 2,243 |
Redeemable Convertible Prefer_4
Redeemable Convertible Preferred Stock - Summary of Common Stock Reserved for Future Issuance (Detail) - shares | Sep. 30, 2019 | Dec. 31, 2018 |
Class of Stock [Line Items] | ||
Total shares of authorized common stock reserved for future issuance | 4,144,333 | 2,926,138 |
2018 Stock Option and Incentive Plan [Member] | ||
Class of Stock [Line Items] | ||
Total shares of authorized common stock reserved for future issuance | 474,326 | 385,561 |
2018 Employee Stock Purchase Plan [Member] | ||
Class of Stock [Line Items] | ||
Total shares of authorized common stock reserved for future issuance | 461,266 | 223,200 |
Restricted Stock [Member] | ||
Class of Stock [Line Items] | ||
Total shares of authorized common stock reserved for future issuance | 63,313 | 153,276 |
Employee Stock Option [Member] | ||
Class of Stock [Line Items] | ||
Total shares of authorized common stock reserved for future issuance | 3,145,428 | 2,164,101 |
Stock-Based Compensation - Summ
Stock-Based Compensation - Summary of Assumptions that Used to Determine Grant-Date Fair Value of Stock Options Granted to Employees and Members of Board (Detail) | 9 Months Ended | |
Sep. 30, 2019 | Sep. 30, 2018 | |
Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions And Methodology [Abstract] | ||
Expected option life (years) | 5 years 11 months 19 days | 6 years 18 days |
Risk-free interest rate | 2.40% | 2.73% |
Expected volatility | 81.25% | 83.42% |
Stock-Based Compensation - Su_2
Stock-Based Compensation - Summary of Stock Option Activity (Detail) $ / shares in Units, $ in Thousands | 9 Months Ended | 12 Months Ended |
Sep. 30, 2019USD ($)$ / sharesshares | Dec. 31, 2018USD ($)$ / sharesshares | |
Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Roll Forward | ||
Number of options, Outstanding beginning balance | shares | 2,164,100 | |
Number of options, Granted | shares | 1,315,317 | |
Number of options, Exercised | shares | (232,758) | |
Number of options, Cancelled or forfeited | shares | (101,231) | |
Number of options, Outstanding ending balance | shares | 3,145,428 | 2,164,100 |
Number of options, Exercisable | shares | 790,343 | |
Number of options, Vested and expected to vest | shares | 3,145,428 | |
Weighted average exercise price, Outstanding beginning balance | $ / shares | $ 7.75 | |
Weighted average exercise price, Granted | $ / shares | 16.76 | |
Weighted average exercise price, Exercised | $ / shares | 2.14 | |
Weighted average exercise price, Cancelled or forfeited | $ / shares | 10.26 | |
Weighted average exercise price, Outstanding ending balance | $ / shares | 11.86 | $ 7.75 |
Weighted average exercise price, Exercisable | $ / shares | 3.99 | |
Weighted average exercise price, Vested and expected to vest | $ / shares | $ 11.86 | |
Weighted average remaining contractual term, Outstanding balance | 8 years 7 months 17 days | 8 years 9 months 7 days |
Weighted average remaining contractual term, Exercisable | 7 years 6 months 3 days | |
Weighted average remaining contractual term, vested and expected to vest | 8 years 7 months 17 days | |
Aggregate intrinsic value, Outstanding balance | $ | $ 15,491 | $ 23,083 |
Aggregate intrinsic value, Exercisable | $ | 8,759 | |
Aggregate intrinsic value, vested and expected to vest | $ | $ 15,491 |
Stock-Based Compensation - Addi
Stock-Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands | 9 Months Ended | |
Sep. 30, 2019 | Sep. 30, 2018 | |
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] | ||
Options Granted, Weighted-average grant-date fair value | $ 11.77 | $ 9.05 |
Total fair value of restricted common stock vested | $ 44 | $ 39 |
Unrecognized stock-based compensation expenses | $ 22,065 | |
Unrecognized stock-based compensation expense, period for recognition | 3 years 2 months 26 days |
Stock-Based Compensation - Su_3
Stock-Based Compensation - Summary of Restricted Stock Unit Activity (Detail) | 9 Months Ended |
Sep. 30, 2019$ / sharesshares | |
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] | |
Number of shares, Issued and unvested beginning balance | 153,275 |
Number of shares, Granted | 2,300 |
Number of shares, Vested | (92,262) |
Number of shares, Forfeited, cancelled or expired | 0 |
Number of shares, Issued and unvested ending balance | 63,313 |
Weighted average grant date fair value, Issued and unvested, beginning balance | $ / shares | $ 0.42 |
Weighted average grant date fair value, Granted | $ / shares | 15.65 |
Weighted average grant date fair value, Vested | $ / shares | 0.42 |
Weighted average grant date fair value, Issued and unvested, ending balance | $ / shares | $ 0.42 |
Stock-Based Compensation - Sche
Stock-Based Compensation - Schedule of Stock-based Compensation Expense (Detail) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | ||
Sep. 30, 2019 | Sep. 30, 2018 | Sep. 30, 2019 | Sep. 30, 2018 | |
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] | ||||
Total stock-based compensation expense | $ 1,797 | $ 550 | $ 4,914 | $ 1,117 |
Research and Development Expense [Member] | ||||
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] | ||||
Total stock-based compensation expense | 889 | 230 | 2,649 | 417 |
General and Administrative Expense [Member] | ||||
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] | ||||
Total stock-based compensation expense | $ 908 | $ 320 | $ 2,265 | $ 700 |
License Agreements - Additional
License Agreements - Additional Information (Detail) $ in Thousands | Nov. 08, 2019USD ($) | Oct. 02, 2017USD ($) | Nov. 17, 2016USD ($) | Jan. 27, 2016USD ($)shares | Jan. 27, 2016CAD ($) | Aug. 31, 2017USD ($)shares | Sep. 30, 2019USD ($)shares | Sep. 30, 2018USD ($) | Sep. 30, 2019USD ($)shares | Sep. 30, 2018USD ($) | Dec. 31, 2017USD ($) | Dec. 31, 2018shares | Jan. 27, 2016CAD ($)shares |
License Agreement [Line Items] | |||||||||||||
Common stock, shares issued | shares | 31,667,661 | 31,667,661 | 23,959,903 | ||||||||||
Research and development | $ 13,042,000 | $ 9,232,000 | $ 37,755,000 | $ 22,286,000 | |||||||||
Preferred stock issued | shares | 0 | 0 | 0 | ||||||||||
UHN Agreement [Member] | |||||||||||||
License Agreement [Line Items] | |||||||||||||
Milestone fees | $ 0 | 0 | |||||||||||
Annual maintenance fees | 0 | 0 | |||||||||||
Research and development expense | $ 415,000 | 0 | 741,000 | 0 | |||||||||
UHN Agreement [Member] | Fabry License Agreement [Member] | |||||||||||||
License Agreement [Line Items] | |||||||||||||
Option fee | $ 20 | ||||||||||||
Upfront license fee | $ 75 | ||||||||||||
Milestone payments | 2,450 | ||||||||||||
UHN Agreement [Member] | Interleukin 12 License Agreement [Member] | |||||||||||||
License Agreement [Line Items] | |||||||||||||
Upfront license fee | 264 | ||||||||||||
Milestone payments | 19,275 | ||||||||||||
Annual maintenance fees | $ 50 | $ 0 | $ 0 | ||||||||||
Common stock, shares issued | shares | 1,161,665 | 1,161,665 | |||||||||||
Fair value of shares issued | $ 480 | ||||||||||||
Payments upon closing of an initial public offering | 2,000,000 | ||||||||||||
Fair value of derivative liability | $ 49,000 | ||||||||||||
Research and development | 38,000 | 41,000 | |||||||||||
BioMarin Pharmaceutical Inc [Member] | |||||||||||||
License Agreement [Line Items] | |||||||||||||
Upfront license fee | $ 500,000 | ||||||||||||
Milestone payments | 13,000,000 | ||||||||||||
Upfront cash payment | $ 500,000 | ||||||||||||
Expenses related to license | 0 | 0 | |||||||||||
BioMarin Pharmaceutical Inc [Member] | Series B Preferred Stock [Member] | |||||||||||||
License Agreement [Line Items] | |||||||||||||
Research and development | $ 500,000 | ||||||||||||
Preferred stock issued | shares | 233,765 | ||||||||||||
GenStem Therapeutics Inc [Member] | |||||||||||||
License Agreement [Line Items] | |||||||||||||
Upfront license fee | $ 1,000,000 | ||||||||||||
Expenses related to license | 0 | 0 | |||||||||||
Milestone payments | 16,000,000 | ||||||||||||
Milestone payment due | $ 2,000,000 | ||||||||||||
GenStem Therapeutics Inc [Member] | Subsequent Event [Member] | |||||||||||||
License Agreement [Line Items] | |||||||||||||
Milestone payment paid | $ 2,000,000 | ||||||||||||
Lund University Rights Holders Agreement [Member] | |||||||||||||
License Agreement [Line Items] | |||||||||||||
Expenses related to license | $ 0 | $ 0 | |||||||||||
Milestone payments | $ 550 |
Net Loss per Share - Schedule o
Net Loss per Share - Schedule of Dilutive Common Stock Equivalents Excluded from Computation of Diluted Net Loss per Share (Detail) - shares | 9 Months Ended | |
Sep. 30, 2019 | Sep. 30, 2018 | |
Employee Stock Option [Member] | ||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||
Antidilutive securities excluded from computation of earnings per share amount | 3,145,428 | 1,957,839 |
Restricted Stock [Member] | ||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||
Antidilutive securities excluded from computation of earnings per share amount | 63,313 | 184,033 |
Commitments and Contingencies -
Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Thousands | Aug. 31, 2018 | Jan. 12, 2018 | Sep. 30, 2019 | Sep. 30, 2018 |
Commitments And Contingencies Disclosure [Line Items] | ||||
Lease agreement expiration date | Jan. 31, 2023 | |||
Percentage of annual increase in rent | 3.00% | |||
Tenant incentive allowance | $ 842 | |||
Security deposit in connection with lease | $ 209 | |||
Sub-lease Agreement [Member] | ||||
Commitments And Contingencies Disclosure [Line Items] | ||||
Lease agreement expiration date | Oct. 31, 2020 | |||
Percentage of annual increase in rent | 3.00% | |||
Security deposit in connection with lease | $ 283 |
Related Party Transactions - Ad
Related Party Transactions - Additional information (Detail) - USD ($) | Jan. 27, 2016 | Sep. 30, 2019 | Sep. 30, 2018 | Sep. 30, 2019 | Sep. 30, 2018 |
Related Party Transaction [Line Items] | |||||
Common stock issued for initial consideration for license | 2,300 | ||||
Research and development expense related to license agreements | $ 13,042,000 | $ 9,232,000 | $ 37,755,000 | $ 22,286,000 | |
Officers and Board Members [Member] | Consulting Services Agreement [Member] | |||||
Related Party Transaction [Line Items] | |||||
Expense related to related party | 0 | 2,000 | 0 | 42,000 | |
License Agreement [Member] | |||||
Related Party Transaction [Line Items] | |||||
Provision for maximum cash payment | $ 2,000,000 | ||||
Research and development expense related to license agreements | 415,000 | $ 0 | 779,000 | $ 41,000 | |
License Agreement [Member] | Stock Purchase Agreement [Member] | |||||
Related Party Transaction [Line Items] | |||||
Common stock issued for initial consideration for license | 1,161,665 | ||||
Sub-lease Agreement [Member] | Officers and Board Members [Member] | |||||
Related Party Transaction [Line Items] | |||||
Expense related to related party | $ 369,000 | $ 1,090,000 |
Subsequent Events - Additional
Subsequent Events - Additional Information (Detail) $ in Thousands | Nov. 08, 2019USD ($) |
GenStem Therapeutics Inc [Member] | Subsequent Event [Member] | |
Subsequent Event [Line Items] | |
Milestone payment paid | $ 2,000 |