Cover Page
Cover Page - shares | 9 Months Ended | |
Sep. 30, 2019 | Oct. 31, 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 | |
Current Fiscal Year End Date | --12-31 | |
Entity Current Reporting Status | Yes | |
Entity Interactive Data Current | Yes | |
Trading Symbol | MGTA | |
Entity Registrant Name | Magenta Therapeutics, Inc. | |
Entity Central Index Key | 0001690585 | |
Entity Filer Category | Non-accelerated Filer | |
Entity Shell Company | false | |
Entity Small Business | true | |
Entity Emerging Growth Company | true | |
Entity Common Stock, Shares Outstanding | 38,989,517 | |
Entity Ex Transition Period | false | |
Title of 12(b) Security | Common Stock | |
Security Exchange Name | NASDAQ | |
Entity Address, State or Province | MA |
Consolidated Balance Sheets
Consolidated Balance Sheets - USD ($) $ in Thousands | Sep. 30, 2019 | Dec. 31, 2018 |
Current assets: | ||
Cash and cash equivalents | $ 85,507 | $ 58,345 |
Marketable securities | 75,063 | 84,225 |
Prepaid expenses and other current assets | 4,660 | 2,751 |
Total current assets | 165,230 | 145,321 |
Restricted cash | 1,780 | 1,780 |
Property and equipment, net | 10,223 | 10,212 |
Total assets | 177,233 | 157,313 |
Current liabilities: | ||
Accounts payable | 2,038 | 3,492 |
Accrued expenses and other current liabilities | 7,591 | 6,927 |
Total current liabilities | 9,629 | 10,419 |
Deferred rent | 6,075 | 1,246 |
Total liabilities | 15,704 | 11,665 |
Commitments and contingencies (Note 7) | ||
Stockholders' Equity: | ||
Preferred stock, $0.001 par value; 10,000,000 shares authorized; no shares issued or outstanding | ||
Common stock, $0.001 par value; 150,000,000 shares authorized; 39,370,576 shares and 34,327,554 shares issued and 38,942,719 shares and 33,305,033 shares outstanding as of September 30, 2019 and December 31, 2018, respectively | 39 | 33 |
Additional paid-in capital | 317,665 | 248,349 |
Accumulated other comprehensive income (loss) | 83 | (8) |
Accumulated deficit | (156,258) | (102,726) |
Total stockholders' equity | 161,529 | 145,648 |
Total liabilities and stockholders' equity | $ 177,233 | $ 157,313 |
Consolidated Balance Sheets (Pa
Consolidated Balance Sheets (Parenthetical) - $ / shares | Sep. 30, 2019 | Dec. 31, 2018 |
Preferred stock, par value | $ 0.001 | $ 0.001 |
Preferred stock, Shares authorized | 10,000,000 | 10,000,000 |
Preferred stock, Shares issued | 0 | 0 |
Preferred stock, Shares outstanding | 0 | 0 |
Common stock, Par value | $ 0.001 | $ 0.001 |
Common stock, shares authorized | 150,000,000 | 150,000,000 |
Common stock, Shares issued | 39,370,576 | 34,327,554 |
Common stock, Shares outstanding | 38,942,719 | 33,305,033 |
Consolidated Statements of Oper
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 | |
Revenue | $ 0 | $ 0 | $ 0 | $ 0 |
Operating expenses: | ||||
Research and development | 16,524 | 11,418 | 40,494 | 28,950 |
General and administrative | 6,120 | 5,284 | 17,838 | 13,083 |
Total operating expenses | 22,644 | 16,702 | 58,332 | 42,033 |
Loss from operations | (22,644) | (16,702) | (58,332) | (42,033) |
Interest and other income, net | 1,654 | 687 | 4,800 | 1,197 |
Net loss | (20,990) | (16,015) | (53,532) | (40,836) |
Accretion of redeemable convertible preferred stock to redemption value | (88) | |||
Net loss attributable to common stockholders | $ (20,990) | $ (16,015) | $ (53,532) | $ (40,924) |
Net loss per share attributable to common stockholders, basic and diluted | $ (0.54) | $ (0.49) | $ (1.47) | $ (3.05) |
Weighted average common shares outstanding, basic and diluted | 38,824,209 | 32,997,346 | 36,322,804 | 13,396,856 |
Comprehensive loss: | ||||
Net loss | $ (20,990) | $ (16,015) | $ (53,532) | $ (40,836) |
Other comprehensive income (loss): | ||||
Unrealized gains (losses) on marketable securities | (56) | 91 | ||
Total other comprehensive income (loss) | (56) | 91 | ||
Total comprehensive loss | $ (21,046) | $ (16,015) | $ (53,441) | $ (40,836) |
Consolidated Statements of Stoc
Consolidated Statements of Stockholders' Equity (Deficit) - USD ($) $ in Thousands | Total | Series A, B and C Redeemable Convertible Preferred Stock [Member] | Common Stock [Member] | Additional Paid-in Capital [Member] | Accumulated Other Comprehensive Income (Loss) [Member] | Accumulated Deficit [Member] |
Beginning balance at Dec. 31, 2017 | $ 92,439 | |||||
Beginning balance at Dec. 31, 2017 | $ (42,118) | $ 2 | $ 3,091 | $ (45,211) | ||
Beginning balance, shares at Dec. 31, 2017 | 49,178,527 | |||||
Beginning balance, shares at Dec. 31, 2017 | 2,351,247 | |||||
Issuance of Series C redeemable convertible preferred stock, net of issuance cost of $88 | $ 52,212 | |||||
Issuance of Series C redeemable convertible preferred stock, net of issuance cost of $88, shares | 11,223,102 | |||||
Accretion of Series C redeemable convertible preferred stock to redemption value | (88) | $ 88 | (88) | |||
Conversion of preferred stock to common stock | 144,739 | $ (144,739) | $ 23 | 144,716 | ||
Conversion of preferred stock to common stock, shares | (60,401,629) | 23,375,405 | ||||
Issuance of common stock upon initial public offering net of underwriting discounts, commissions and offering costs | 89,906 | $ 7 | 89,899 | |||
Issuance of common stock upon initial public offering net of underwriting discounts, commissions and offering costs, shares | 6,666,667 | |||||
Vesting of restricted stock | $ 1 | (1) | ||||
Vesting of restricted stock, shares | 704,696 | |||||
Issuance of common stock upon exercise of stock options | 29 | 29 | ||||
Issuance of common stock upon exercise of stock options, shares | 4,152 | |||||
Stock-based compensation expense | 8,152 | 8,152 | ||||
Net loss | (40,836) | (40,836) | ||||
Ending balance at Sep. 30, 2018 | 159,784 | $ 33 | 245,798 | (86,047) | ||
Ending balance, shares at Sep. 30, 2018 | 33,102,167 | |||||
Beginning balance at Dec. 31, 2017 | $ 92,439 | |||||
Beginning balance at Dec. 31, 2017 | (42,118) | $ 2 | 3,091 | (45,211) | ||
Beginning balance, shares at Dec. 31, 2017 | 49,178,527 | |||||
Beginning balance, shares at Dec. 31, 2017 | 2,351,247 | |||||
Net loss | (57,500) | |||||
Ending balance at Dec. 31, 2018 | 145,648 | $ 33 | 248,349 | $ (8) | (102,726) | |
Ending balance, shares at Dec. 31, 2018 | 33,305,033 | |||||
Beginning balance at Jun. 30, 2018 | 172,217 | $ 33 | 242,216 | (70,032) | ||
Beginning balance, shares at Jun. 30, 2018 | 32,889,056 | |||||
Initial public offering costs | (123) | (123) | ||||
Vesting of restricted stock, shares | 208,959 | |||||
Issuance of common stock upon exercise of stock options | 29 | 29 | ||||
Issuance of common stock upon exercise of stock options, shares | 4,152 | |||||
Stock-based compensation expense | 3,676 | 3,676 | ||||
Net loss | (16,015) | (16,015) | ||||
Ending balance at Sep. 30, 2018 | 159,784 | $ 33 | 245,798 | (86,047) | ||
Ending balance, shares at Sep. 30, 2018 | 33,102,167 | |||||
Beginning balance at Dec. 31, 2018 | 145,648 | $ 33 | 248,349 | (8) | (102,726) | |
Beginning balance, shares at Dec. 31, 2018 | 33,305,033 | |||||
Issuance of common stock upon initial public offering net of underwriting discounts, commissions and offering costs | 60,276 | $ 5 | 60,271 | |||
Issuance of common stock upon initial public offering net of underwriting discounts, commissions and offering costs, shares | 4,887,500 | |||||
Vesting of restricted stock | $ 1 | (1) | ||||
Vesting of restricted stock, shares | 592,849 | |||||
Issuance of common stock upon exercise of stock options | 1,107 | 1,107 | ||||
Issuance of common stock upon exercise of stock options, shares | 157,337 | |||||
Stock-based compensation expense | 7,939 | 7,939 | ||||
Unrealized gains (losses) on marketable securities | 91 | 91 | ||||
Net loss | (53,532) | (53,532) | ||||
Ending balance at Sep. 30, 2019 | 161,529 | $ 39 | 317,665 | 83 | (156,258) | |
Ending balance, shares at Sep. 30, 2019 | 38,942,719 | |||||
Beginning balance at Jun. 30, 2019 | 179,556 | $ 39 | 314,646 | 139 | (135,268) | |
Beginning balance, shares at Jun. 30, 2019 | 38,710,858 | |||||
Vesting of restricted stock, shares | 197,570 | |||||
Issuance of common stock upon exercise of stock options | 257 | 257 | ||||
Issuance of common stock upon exercise of stock options, shares | 34,291 | |||||
Stock-based compensation expense | 2,762 | 2,762 | ||||
Unrealized gains (losses) on marketable securities | (56) | (56) | ||||
Net loss | (20,990) | (20,990) | ||||
Ending balance at Sep. 30, 2019 | $ 161,529 | $ 39 | $ 317,665 | $ 83 | $ (156,258) | |
Ending balance, shares at Sep. 30, 2019 | 38,942,719 |
Consolidated Statements of St_2
Consolidated Statements of Stockholders' Equity (Deficit) (Parenthetical) $ in Thousands | 9 Months Ended |
Sep. 30, 2018USD ($) | |
Payments of redeemable convertible preferred stock issuance costs | $ 2,618 |
Series C Preferred Stock [Member] | |
Payments of redeemable convertible preferred stock issuance costs | $ 88 |
Consolidated Statements of Cash
Consolidated Statements of Cash Flows - USD ($) $ in Thousands | 9 Months Ended | |
Sep. 30, 2019 | Sep. 30, 2018 | |
Cash flows from operating activities: | ||
Net loss | $ (53,532) | $ (40,836) |
Adjustments to reconcile net loss to net cash used in operating activities: | ||
Stock-based compensation expense | 7,939 | 8,152 |
Depreciation and amortization expense | 1,358 | 516 |
Loss on disposal of property and equipment | 67 | |
Net accretion of discounts on marketable securities | (909) | |
Changes in operating assets and liabilities: | ||
Prepaid expenses and other current assets | (1,909) | (2,085) |
Accounts payable | (629) | 2,104 |
Accrued expenses and other current liabilities | 1,377 | 1,740 |
Deferred rent | 4,829 | 1,080 |
Net cash used in operating activities | (41,476) | (29,262) |
Cash flows from investing activities: | ||
Purchases of property and equipment | (2,907) | (3,321) |
Proceeds from sale of property and equipment | 12 | |
Purchases of marketable securities | (94,176) | |
Maturities of marketable securities | 104,338 | |
Net cash provided by (used in) investing activities | 7,255 | (3,309) |
Cash flows from financing activities: | ||
Proceeds from public offerings, net of underwriting discounts and commissions | 60,874 | 93,000 |
Proceeds from issuance of redeemable convertible preferred stock | 52,300 | |
Payments of public offering costs | (598) | (2,618) |
Payments of redeemable convertible preferred stock issuance costs | (88) | |
Proceeds from exercise of common stock options | 1,107 | 29 |
Net cash provided by financing activities | 61,383 | 142,623 |
Net increase in cash, cash equivalents and restricted cash | 27,162 | 110,052 |
Cash, cash equivalents and restricted cash at beginning of period | 60,125 | 51,567 |
Cash, cash equivalents and restricted cash at end of period | $ 87,287 | 161,619 |
Supplemental disclosure of non-cash investing and financing activities: | ||
Purchase of property and equipment included in accounts payable and accrued expenses | 3,467 | |
Offering costs included in accounts payable and accrued expenses | 476 | |
Conversion of redeemable convertible preferred stock to common stock | 144,739 | |
Accretion of redeemable convertible preferred stock to redemption value | $ 88 |
Nature of the Business and Basi
Nature of the Business and Basis of Presentation | 9 Months Ended |
Sep. 30, 2019 | |
Nature of the Business and Basis of Presentation | 1. Nature of the Business and Basis of Presentation Magenta Therapeutics, Inc. (the “Company”) is a clinical-stage biopharmaceutical company developing novel medicines to bring the curative power of stem cell transplant , gene therapy, genome editing and cell therapy to more patients. The Company was incorporated under the laws of the State of Delaware The Company is subject to risks and uncertainties 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 extensive 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 drug development efforts are successful, it is uncertain when, if ever, the Company will realize significant revenue from product sales. In June 2018, the Company completed its initial public offering (“IPO”) pursuant to which it issued and sold 6,666,667 shares of common stock at a public offering price of $15.00 per share, resulting in net proceeds of $89.9 million, after deducting underwriting discounts and commissions and other offering expenses. Upon the closing of the IPO, the Company’s outstanding redeemable convertible preferred stock automatically converted into shares of common stock. In May 2019, the Company issued and sold 4,887,500 shares of its common stock, including the underwriters’ exercise in full of their option to purchase additional shares of common stock, in a follow-on On August 8, 2019, the Company filed a shelf registration statement on Form S-3 350.0 100.0 “at-the-market” The Company has incurred recurring losses since inception, including net losses of $53.5 million and $57.5 million for the nine months ended September 30, 2019 and the year ended December 31, 2018, respectively. As of September 30, 2019, the Company had an accumulated deficit of $156.3 million. The Company expects to continue to generate operating losses for the foreseeable future. The Company expects that its cash, cash equivalents and marketable securities will be sufficient to fund its operating expenses and capital expenditure requirements through at least 12 months from the issuance date of these consolidated financial statements. The future viability of the Company beyond that point is dependent on its ability to raise additional capital to fund its operations. The Company expects its expenses to increase substantially in connection with ongoing activities, particularly as the Company advances its preclinical activities and clinical trials for its product candidates in development. Accordingly, the Company will need to obtain substantial additional funding in connection with continuing operations. If the Company is unable to raise capital when needed, or on attractive terms, it could be forced to delay, reduce or eliminate its research or drug development programs or any future commercialization efforts. 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. The consolidated financial statements include the accounts of the Company and its wholly owned subsidiary. All intercompany balances and transactions have been eliminated. The consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”). |
Summary of Significant Accounti
Summary of Significant Accounting Policies | 9 Months Ended |
Sep. 30, 2019 | |
Summary of Significant Accounting Policies | 2. Summary of Significant Accounting Policies Use of Estimates The preparation of 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 financial statements and the reported amounts of expenses during the reporting periods. Significant estimates and assumptions reflected in these financial statements include, but are not limited to, the accrual for research and development expenses and the valuation of stock-based awards. 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 consolidated balance sheet at December 31, 2018 was derived from audited financial statements but does not include all disclosures required by GAAP. The accompanying unaudited consolidated financial statements as of September 30, 2019 and for the three and nine months ended September 30, 2019 and 2018 have been prepared by the Company pursuant to the rules and regulations of the SEC for 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 such rules and regulations. The Company believes, however, that the disclosures are adequate to make the information presented not misleading. These consolidated financial statements should be read in conjunction with the Company’s audited financial statements for the year ended December 31, 2018 included in the Company’s Annual Report on Form 10-K, Fair Value Measurements Certain assets and liabilities 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 and 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 marketable securities are carried at fair value, determined according to the fair value hierarchy described above (see Note 3). The carrying values of the Company’s accounts payable and accrued expenses approximate their fair values due to the short-term nature of these assets and liabilities. 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 taxes are determined based on the difference between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect in the years 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 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 its consolidated financial statements by applying a two-step more-likely-than-not Comprehensive Loss Comprehensive loss includes net loss as well as other changes in stockholders’ equity that result from transactions and economic events other than those with stockholders. For the three and nine months ended September 30, 2019, the Company’s only element of other comprehensive loss was unrealized gains (losses) on marketable securities. For the three and nine months ended September 30, 2018, there was no difference between net loss and comprehensive loss. Net Loss per Share Prior to the closing of its IPO, the Company followed the two-class two-class two-class In June 2018, upon the closing of the IPO, all outstanding shares of the Company’s redeemable convertible preferred stock automatically converted into 23,375,405 shares of the Company’s common stock. Subsequent to the IPO, basic net income (loss) per common share is computed by dividing the net income (loss) by the weighted average number of shares of common stock outstanding for the period. Diluted net income (loss) per common share is computed by dividing net income (loss) by the weighted average number of common shares outstanding for the period, including potential dilutive common shares assuming the dilutive effect of outstanding stock options. For periods in which the Company has reported net losses, diluted net loss per common share is the same as basic net loss per common share, since dilutive common shares are not assumed to have been issued if their affect is anti-dilutive. The Company reported a net loss attributable to common stockholders for the three and nine months ended September 30, 2019 and 2018. Classification and Accretion of Redeemable Convertible Preferred Stock Prior to the conversion of the redeemable convertible preferred stock to common stock in connection with the IPO, the Company had classified redeemable convertible preferred stock outside of stockholders’ equity (deficit) because the shares contained certain redemption features that were not solely within the control of the Company. The Company immediately accreted the carrying value of its redeemable convertible preferred stock to redemption value at the end of each reporting period as if the end of the reporting period were the redemption date. Recently Adopted Accounting Pronouncements In June 2018, the Financing Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) No. 2018-07, Compensation – Stock Compensation (Topic 718), Improvements to Nonemployee Share-Based Payment Accounting 2018-07”). 2018-07 non-public 2018-07 No. 2014-09, Revenue from Contracts with Customers (Topic 606) 2018-07 non-employees 2018-07 non-employee non-employee Recently Issued Accounting Pronouncements In February 2016, the FASB issued ASU No. 2016-02, Leases 2016-02”). 2016-02 right-of-use non-public 2016-02 2018-11, Leases (Topic 842) Targeted Improvements 2016-02 right-of-use |
Fair Value of Financial Assets
Fair Value of Financial Assets | 9 Months Ended |
Sep. 30, 2019 | |
Fair Value of Financial Assets | 3. Fair Value of Financial Assets As of September 30, 2019, marketable securities by security type consisted of (in thousands): Gross Gross Estimated Amortized Unrealized Unrealized Fair Cost Gains Losses Value United States Treasury Notes (due within one year) $ 65,871 $ 75 $ — $ 65,946 Agency Bonds (due within one year) 9,109 8 — 9,117 Total $ 74,980 $ 83 $ — $ 75,063 As of December 31, 2018, marketable securities by security type consisted of (in thousands): Gross Gross Estimated Amortized Unrealized Unrealized Fair Cost Gains Losses Value United States Treasury Notes (due within one year) $ 71,944 $ 5 $ (9 ) $ 71,940 Agency Bonds (due within one year) 12,289 1 (5 ) 12,285 Total $ 84,233 $ 6 $ (14 ) $ 84,225 The following tables present information about the Company’s financial assets measured at fair value on a recurring basis and indicate the level of the fair value hierarchy utilized to determine such fair values (in thousands): Fair Value Measurements at September 30, 2019 Using: Level 1 Level 2 Level 3 Total Cash equivalents: Money market funds $ 86,180 $ — $ — $ 86,180 Marketable securities: United States Treasury Notes — 65,946 — 65,946 Agency Bonds — 9,117 — 9,117 Total $ 86,180 $ 75,063 $ — $ 161,243 Fair Value Measurements at December 31, 2018 Using: Level 1 Level 2 Level 3 Total Cash equivalents: Money market funds $ 45,725 $ — $ — $ 45,725 United States Treasury Notes — 12,488 — 12,488 Marketable securities: United States Treasury Notes — 71,940 — 71,940 Agency Bonds — 12,285 — 12,285 Total $ 45,725 $ 96,713 $ — $ 142,438 During the three and nine months ended September 30, 2019 and 2018, there were no transfers between Level 1, Level 2 and Level 3. |
Accrued Expenses and Other Curr
Accrued Expenses and Other Current Liabilities | 9 Months Ended |
Sep. 30, 2019 | |
Accrued Expenses and Other Current Liabilities | 4. Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consisted of the following (in thousands): September 30, 2019 December 31, 2018 Accrued external research and development expenses $ 3,894 $ 2,619 Accrued payroll and related expenses 2,428 2,526 Deferred rent, current portion 601 71 Accrued professional fees 446 787 Accrued property and equipment — 713 Accrued other 222 211 $ 7,591 $ 6,927 |
Stock-Based Awards
Stock-Based Awards | 9 Months Ended |
Sep. 30, 2019 | |
Stock-Based Awards | 5. Stock-Based Awards 2018 Stock Option and Incentive Plan The Company grants stock-based awards under its 2018 Stock Option and Incentive Plan (the “2018 Plan”). The Company also has outstanding stock options under its 2016 Stock Option and Grant Plan (the “2016 Plan”) but is no longer granting awards under this plan. As of September 30, 2019, 2,477,390 shares of common stock were available for issuance under the 2018 Plan. 2019 Employee Stock Purchase Plan The Magenta Therapeutics, Inc. 2019 Employee Stock Purchase Plan (the “ESPP”) was adopted by the Company on April 18, 2019, subject to the approval of stockholders, and became effective following stockholder approval on June 7, 2019. An aggregate of 166,525 shares were reserved for issuance under the ESPP. In addition, on January 1, 2020 and each January 1 thereafter through January 1, 2029, the number of shares available for issuance shall be cumulatively increased by the least of (i) one percent (1%) of the number of shares issued and outstanding on the immediately preceding December 31, (ii) 1,000,000 shares and (iii) such number of shares as determined by the Compensation Committee. The offering periods begin in December and June of each year, with the initial offering period commencing on December 1, 2019. As of September 30, 2019, no shares have been issued under the ESPP and 166,525 shares remained available for issuance. Grant of Stock Options During the nine months ended September 30, 2019, the Company granted options to certain employees and directors with service-based vesting for the purchase of 1,650,066 shares of common stock with a weighted average grant date fair value of $5.98 per share. Stock-Based Compensation Stock-based compensation expense was classified in the statements of operations and comprehensive loss as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Research and development expenses $ 1,293 $ 2,022 $ 3,817 $ 4,612 General and administrative expenses 1,469 1,654 4,122 3,540 $ 2,762 $ 3,676 $ 7,939 $ 8,152 As of September 30, 2019, total unrecognized compensation cost related to unvested share-based awards was $18.0 million, which is expected to be recognized over a weighted average period of 2.3 years. Prior to the adoption of ASU 2018-07 non-employees non-employee 2018-07, non-employees |
Net Loss per Share
Net Loss per Share | 9 Months Ended |
Sep. 30, 2019 | |
Net Loss per Share | 6. 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 September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Numerator: Net loss $ (20,990 ) $ (16,015 ) $ (53,532 ) $ (40,836 ) Accretion of redeemable convertible preferred stock to redemption value — — — (88 ) Net loss attributable to common stockholders $ (20,990 ) $ (16,015 ) $ (53,532 ) $ (40,924 ) Denominator: Weighted average common shares outstanding, basic and diluted 38,824,209 32,997,346 36,322,804 13,396,856 Net loss per share attributable to common stockholders, basic and diluted $ (0.54 ) $ (0.49 ) $ (1.47 ) $ (3.05 ) The following potential dilutive securities, presented based on amounts outstanding at each period end, have been excluded from the calculation of diluted net loss per share because including them would have had an anti-dilutive impact: As of September 30, 2019 2018 Stock options to purchase common stock 4,903,047 3,558,282 Unvested restricted common stock 427,857 1,225,387 5,330,904 4,783,669 |
Commitments and Contingencies
Commitments and Contingencies | 9 Months Ended |
Sep. 30, 2019 | |
Commitments and Contingencies | 7. Commitments and Contingencies Leases In May 2018, the Company entered into a sublease for up to approximately 69,000 June 2018 February 2028 5.2 s The tenant improvement allowance and payment escalations specified in the sublease agreement are accrued or deferred as appropriate such that rent expense per square foot is recognized on a straight-line basis over the terms of occupancy. As of September 30, 2019 and December 31, 2018, the Company had long-term deferred rent of $6.1 million and $1.2 million, respectively, related to lease incentives and payment escalations. As of September 30, 2019 and December 31, 2018, the short-term portion of deferred rent of $0.6 million and $0.1 million, respectively, was included in accrued expenses and other current liabilities. The Company recorded rent expense of $1.5 million and $1.8 million during the three months ended September 30, 2019 and 2018, respectively, and $4.6 million and $2.9 million during the nine months ended September 30, 2019 and 2018, respectively. In the fourth quarter of 2018, with the landlord’s consent, the Company entered into two two-year sub-subleases sub-sublease As of September 30, 2019, the future minimum lease payments due under the noncancelable operating lease is as follows (in thousands): Remainder of 2019 (three months) $ 1,405 2020 5,782 2021 6,072 2022 6,375 2023 6,734 Thereafter 32,000 $ 58,368 Collaboration Agreement In March 2018, the Company entered into a collaboration agreement with Heidelberg Pharma Research GmbH (“HDPR”) whereby the parties agreed to combine the Company’s stem cell platform with proprietary antibodies across up to four exclusive targets with HDPR’s proprietary Antibody Targeted Amanitin Conjugates platform. Under the agreement, the Company may pay upfront technology access fees, research exclusivity fees and payment for research support. Additionally, upon the exercise of certain license rights, the Company may be obligated to pay HDPR development, regulatory and commercial milestone payments of up to $83.5 million per target as well as royalties on net sales of products licensed under the agreement. During the three months ended September 30, 2019 and 2018, the Company recorded $0.5 million and less than $0.1 million, respectively, of research and development expense related to this agreement for upfront technology access fees, research exclusivity fees and research support. During the nine months ended September 30, 2019 and 2018, the Company recorded $0.9 million and $0.8 million, respectively, of research and development expense related to this agreement for upfront technology access fees, research exclusivity fees and research support. Intellectual Property Licenses In November 2016, the Company entered into a license agreement with the President and Fellows of Harvard College (“Harvard”) for an exclusive, worldwide, royalty-bearing license for certain technologies related to conditioning and mobilization. In consideration for these rights the Company paid Harvard an upfront fee of $0.1 million and reimbursed Harvard $0.3 million for costs incurred by Harvard related to the patented technology, which amounts were recorded as research and development expense during the year ended December 31, 2016. The Company also issued 385,063 shares of common stock in connection with the license agreement. The fair value of the shares of $0.3 million as of the issuance date was recorded as research and development expense during the year ended December 31, 2016. The Company is obligated to pay Harvard maintenance fees of less than $0.1 million annually through 2019 and $0.1 million annually thereafter and to reimburse qualified expenses related to the patents. The Company is also obligated to pay milestone payments of up to $7.4 million for the first two licensed products upon the achievement of certain development and regulatory milestones and to pay royalties on a product-by-product country-by-country In April 2017, the Company entered into a license agreement with Novartis International Pharmaceutical Ltd. (“Novartis”) to use and develop certain patent rights (the “Novartis License”). Under the Novartis License, the Company was granted an exclusive, worldwide, sublicensable license to research, develop and commercialize certain licensed products that contain Novartis compounds for the expansion of cord blood derived non-gene-edited/-modified product-by-product country-by-country The Company has agreements with third parties in the normal course of business, under which it can license certain developed technologies. If the Company exercises its rights to license the respective technologies, it may be subject to additional fees and milestone payments. During the three months and nine months ended September 30, 2019 and 2018, the Company did not exercise its rights to the license of certain developed technologies under these agreements. 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 and senior management 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 is not aware of any claims under indemnification arrangements, and it has not accrued any liabilities related to such obligations in its consolidated financial statements as of September 30, 2019 and December 31, 2018. Legal Proceedings The Company is not currently a party to any material legal proceedings. At each reporting date, the Company evaluates whether or not a potential loss amount or a potential range of loss is probable and reasonably estimable under the provisions of the authoritative guidance that addresses accounting for contingencies. The Company expenses the costs related to its legal proceedings as they are incurred. |
401(k) Savings Plan
401(k) Savings Plan | 9 Months Ended |
Sep. 30, 2019 | |
401(k) Savings Plan | 8. 401(k) Savings Plan The Company has a 401(k) available for participating employees who meet certain eligibility requirements. Eligible employees may defer a portion of their salary as defined by the plan. Company contributions to the plan may be made at the discretion of the board of directors of the Company. To date, the Company has not made any contributions to the plan. |
Related Parties
Related Parties | 9 Months Ended |
Sep. 30, 2019 | |
Related Parties | 9. Related Parties National Marrow Donor Program (as successor in interest to Be The Match BioTherapies, LLC) Effective March 2018, the President of Be The Match BioTherapies, LLC became a member of the Company’s board of directors. The Company has a collaboration agreement with the National Marrow Donor Program (as successor in interest to Be The Match BioTherapies, LLC) and a research agreement with an affiliated organization, Center for International Blood and Marrow Transplant Research. During the three months ended September 30, 2019 and 2018, the Company recorded less than $0.1 million and $0.1 million, respectively, to research and development expenses and during each of the three months ended September 30, 2019 and 2018, recorded less than $0.1 million to general and administrative expenses. During each of the three months ended September 30, 2019 and 2018 , , respectively, |
Summary of Significant Accoun_2
Summary of Significant Accounting Policies (Policies) | 9 Months Ended |
Sep. 30, 2019 | |
Use of Estimates | Use of Estimates The preparation of 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 financial statements and the reported amounts of expenses during the reporting periods. Significant estimates and assumptions reflected in these financial statements include, but are not limited to, the accrual for research and development expenses and the valuation of stock-based awards. 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 consolidated balance sheet at December 31, 2018 was derived from audited financial statements but does not include all disclosures required by GAAP. The accompanying unaudited consolidated financial statements as of September 30, 2019 and for the three and nine months ended September 30, 2019 and 2018 have been prepared by the Company pursuant to the rules and regulations of the SEC for 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 such rules and regulations. The Company believes, however, that the disclosures are adequate to make the information presented not misleading. These consolidated financial statements should be read in conjunction with the Company’s audited financial statements for the year ended December 31, 2018 included in the Company’s Annual Report on Form 10-K, |
Fair Value Measurements | Fair Value Measurements Certain assets and liabilities 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 and 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 marketable securities are carried at fair value, determined according to the fair value hierarchy described above (see Note 3). The carrying values of the Company’s accounts payable and accrued expenses approximate their fair values due to the short-term nature of these assets and liabilities. |
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 taxes are determined based on the difference between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect in the years 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 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 its consolidated financial statements by applying a two-step more-likely-than-not |
Comprehensive Loss | Comprehensive Loss Comprehensive loss includes net loss as well as other changes in stockholders’ equity that result from transactions and economic events other than those with stockholders. For the three and nine months ended September 30, 2019, the Company’s only element of other comprehensive loss was unrealized gains (losses) on marketable securities. For the three and nine months ended September 30, 2018, there was no difference between net loss and comprehensive loss. |
Net Loss per Share | Net Loss per Share Prior to the closing of its IPO, the Company followed the two-class two-class two-class In June 2018, upon the closing of the IPO, all outstanding shares of the Company’s redeemable convertible preferred stock automatically converted into 23,375,405 shares of the Company’s common stock. Subsequent to the IPO, basic net income (loss) per common share is computed by dividing the net income (loss) by the weighted average number of shares of common stock outstanding for the period. Diluted net income (loss) per common share is computed by dividing net income (loss) by the weighted average number of common shares outstanding for the period, including potential dilutive common shares assuming the dilutive effect of outstanding stock options. For periods in which the Company has reported net losses, diluted net loss per common share is the same as basic net loss per common share, since dilutive common shares are not assumed to have been issued if their affect is anti-dilutive. The Company reported a net loss attributable to common stockholders for the three and nine months ended September 30, 2019 and 2018. |
Classification and Accretion of Redeemable Convertible Preferred Stock | Classification and Accretion of Redeemable Convertible Preferred Stock Prior to the conversion of the redeemable convertible preferred stock to common stock in connection with the IPO, the Company had classified redeemable convertible preferred stock outside of stockholders’ equity (deficit) because the shares contained certain redemption features that were not solely within the control of the Company. The Company immediately accreted the carrying value of its redeemable convertible preferred stock to redemption value at the end of each reporting period as if the end of the reporting period were the redemption date. |
Recently Adopted Accounting Pronouncements and Recently Issued Accounting Pronouncements | Recently Adopted Accounting Pronouncements In June 2018, the Financing Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) No. 2018-07, Compensation – Stock Compensation (Topic 718), Improvements to Nonemployee Share-Based Payment Accounting 2018-07”). 2018-07 non-public 2018-07 No. 2014-09, Revenue from Contracts with Customers (Topic 606) 2018-07 non-employees 2018-07 non-employee non-employee Recently Issued Accounting Pronouncements In February 2016, the FASB issued ASU No. 2016-02, Leases 2016-02”). 2016-02 right-of-use non-public 2016-02 2018-11, Leases (Topic 842) Targeted Improvements 2016-02 right-of-use |
Fair Value of Financial Assets
Fair Value of Financial Assets (Tables) | 9 Months Ended |
Sep. 30, 2019 | |
Schedule of Marketable Securities by Security Type | As of September 30, 2019, marketable securities by security type consisted of (in thousands): Gross Gross Estimated Amortized Unrealized Unrealized Fair Cost Gains Losses Value United States Treasury Notes (due within one year) $ 65,871 $ 75 $ — $ 65,946 Agency Bonds (due within one year) 9,109 8 — 9,117 Total $ 74,980 $ 83 $ — $ 75,063 As of December 31, 2018, marketable securities by security type consisted of (in thousands): Gross Gross Estimated Amortized Unrealized Unrealized Fair Cost Gains Losses Value United States Treasury Notes (due within one year) $ 71,944 $ 5 $ (9 ) $ 71,940 Agency Bonds (due within one year) 12,289 1 (5 ) 12,285 Total $ 84,233 $ 6 $ (14 ) $ 84,225 |
Schedule of Financial Assets Measured at Fair Value on Recurring Basis | The following tables present information about the Company’s financial assets measured at fair value on a recurring basis and indicate the level of the fair value hierarchy utilized to determine such fair values (in thousands): Fair Value Measurements at September 30, 2019 Using: Level 1 Level 2 Level 3 Total Cash equivalents: Money market funds $ 86,180 $ — $ — $ 86,180 Marketable securities: United States Treasury Notes — 65,946 — 65,946 Agency Bonds — 9,117 — 9,117 Total $ 86,180 $ 75,063 $ — $ 161,243 Fair Value Measurements at December 31, 2018 Using: Level 1 Level 2 Level 3 Total Cash equivalents: Money market funds $ 45,725 $ — $ — $ 45,725 United States Treasury Notes — 12,488 — 12,488 Marketable securities: United States Treasury Notes — 71,940 — 71,940 Agency Bonds — 12,285 — 12,285 Total $ 45,725 $ 96,713 $ — $ 142,438 |
Accrued Expenses and Other Cu_2
Accrued Expenses and Other Current Liabilities (Tables) | 9 Months Ended |
Sep. 30, 2019 | |
Schedule of Accrued Expenses and Other Current Liabilities | Accrued expenses and other current liabilities consisted of the following (in thousands): September 30, 2019 December 31, 2018 Accrued external research and development expenses $ 3,894 $ 2,619 Accrued payroll and related expenses 2,428 2,526 Deferred rent, current portion 601 71 Accrued professional fees 446 787 Accrued property and equipment — 713 Accrued other 222 211 $ 7,591 $ 6,927 |
Stock-Based Awards (Tables)
Stock-Based Awards (Tables) | 9 Months Ended |
Sep. 30, 2019 | |
Schedule of Stock Based Compensation Expense | Stock-based compensation expense was classified in the statements of operations and comprehensive loss as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Research and development expenses $ 1,293 $ 2,022 $ 3,817 $ 4,612 General and administrative expenses 1,469 1,654 4,122 3,540 $ 2,762 $ 3,676 $ 7,939 $ 8,152 |
Net Loss per Share (Tables)
Net Loss per Share (Tables) | 9 Months Ended |
Sep. 30, 2019 | |
Schedule 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 September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Numerator: Net loss $ (20,990 ) $ (16,015 ) $ (53,532 ) $ (40,836 ) Accretion of redeemable convertible preferred stock to redemption value — — — (88 ) Net loss attributable to common stockholders $ (20,990 ) $ (16,015 ) $ (53,532 ) $ (40,924 ) Denominator: Weighted average common shares outstanding, basic and diluted 38,824,209 32,997,346 36,322,804 13,396,856 Net loss per share attributable to common stockholders, basic and diluted $ (0.54 ) $ (0.49 ) $ (1.47 ) $ (3.05 ) |
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share | The following potential dilutive securities, presented based on amounts outstanding at each period end, have been excluded from the calculation of diluted net loss per share because including them would have had an anti-dilutive impact: As of September 30, 2019 2018 Stock options to purchase common stock 4,903,047 3,558,282 Unvested restricted common stock 427,857 1,225,387 5,330,904 4,783,669 |
Commitments and Contingencies (
Commitments and Contingencies (Tables) | 9 Months Ended |
Sep. 30, 2019 | |
Schedule of Future Minimum Lease Payments Due Under Noncancelable Operating Lease | As of September 30, 2019, the future minimum lease payments due under the noncancelable operating lease is as follows (in thousands): Remainder of 2019 (three months) $ 1,405 2020 5,782 2021 6,072 2022 6,375 2023 6,734 Thereafter 32,000 $ 58,368 |
Nature of the Business and Ba_2
Nature of the Business and Basis of Presentation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands | Aug. 08, 2019 | May 31, 2019 | Jun. 30, 2018 | Sep. 30, 2019 | Sep. 30, 2018 | Sep. 30, 2019 | Sep. 30, 2018 | Dec. 31, 2018 |
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items] | ||||||||
Entity incorporation date | Jun. 30, 2015 | |||||||
Entity incorporation state code | DE | |||||||
Net loss | $ (20,990) | $ (16,015) | $ (53,532) | $ (40,836) | $ (57,500) | |||
Accumulated deficit | $ (156,258) | (156,258) | $ (102,726) | |||||
Net proceeds from common stock | $ 60,300 | $ 60,874 | $ 93,000 | |||||
Maximum [Member] | ||||||||
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items] | ||||||||
Shelf offering value | $ 350,000 | |||||||
Common Stock [Member] | ||||||||
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items] | ||||||||
Stock issued, shares | 4,887,500 | 4,887,500 | 6,666,667 | |||||
Stock issued, price per shares | $ 13.25 | |||||||
Common Stock [Member] | IPO [Member] | ||||||||
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items] | ||||||||
Stock issued, shares | 6,666,667 | |||||||
Stock issued, price per shares | $ 15 | |||||||
Net proceeds from initial public offering | $ 89,900 | |||||||
Cowen and Company LLC [Member] | Maximum [Member] | ||||||||
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items] | ||||||||
Common stock reserved for future issuance | $ 100,000 |
Summary of Significant Accoun_3
Summary of Significant Accounting Policies - Additional Information (Detail) | Jun. 25, 2018shares |
Summary Of Significant Accounting Policies [Line Items] | |
Redeemable convertible preferred stock converted into common stock shares | 23,375,405 |
Fair Value of Financial Asset_2
Fair Value of Financial Assets - Schedule of Marketable Securities by Security Type (Detail) - USD ($) $ in Thousands | Sep. 30, 2019 | Dec. 31, 2018 |
Marketable Securities [Line Items] | ||
Amortized Cost | $ 74,980 | $ 84,233 |
Gross Unrealized Gains | 83 | 6 |
Gross Unrealized Losses | (14) | |
Estimated Fair Value | 75,063 | 84,225 |
United States Treasury Notes [Member] | ||
Marketable Securities [Line Items] | ||
Amortized Cost | 65,871 | 71,944 |
Gross Unrealized Gains | 75 | 5 |
Gross Unrealized Losses | (9) | |
Estimated Fair Value | 65,946 | 71,940 |
Agency Bonds [Member] | ||
Marketable Securities [Line Items] | ||
Amortized Cost | 9,109 | 12,289 |
Gross Unrealized Gains | 8 | 1 |
Gross Unrealized Losses | (5) | |
Estimated Fair Value | $ 9,117 | $ 12,285 |
Fair Value of Financial Asset_3
Fair Value of Financial Assets - Schedule of Financial Assets Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands | Sep. 30, 2019 | Dec. 31, 2018 |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Marketable securities | $ 75,063 | $ 84,225 |
Fair Value on Recurring Basis [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Total | 161,243 | 142,438 |
Level 1 [Member] | Fair Value on Recurring Basis [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Total | 86,180 | 45,725 |
Level 2 [Member] | Fair Value on Recurring Basis [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Total | 75,063 | 96,713 |
Money Market Funds [Member] | Fair Value on Recurring Basis [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Cash equivalents | 86,180 | 45,725 |
Money Market Funds [Member] | Level 1 [Member] | Fair Value on Recurring Basis [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Cash equivalents | 86,180 | 45,725 |
United States Treasury Notes [Member] | Fair Value on Recurring Basis [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Cash equivalents | 12,488 | |
United States Treasury Notes [Member] | Level 2 [Member] | Fair Value on Recurring Basis [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Cash equivalents | 12,488 | |
United States Treasury Notes [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Marketable securities | 65,946 | 71,940 |
United States Treasury Notes [Member] | Fair Value on Recurring Basis [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Marketable securities | 65,946 | 71,940 |
United States Treasury Notes [Member] | Level 2 [Member] | Fair Value on Recurring Basis [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Marketable securities | 65,946 | 71,940 |
Agency Bonds [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Marketable securities | 9,117 | 12,285 |
Agency Bonds [Member] | Fair Value on Recurring Basis [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Marketable securities | 9,117 | 12,285 |
Agency Bonds [Member] | Level 2 [Member] | Fair Value on Recurring Basis [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Marketable securities | $ 9,117 | $ 12,285 |
Fair Value of Financial Asset_4
Fair Value of Financial Assets - Additional Information (Detail) - USD ($) | 9 Months Ended | |
Sep. 30, 2019 | Sep. 30, 2018 | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Fair value, assets, level 1 to level 2 transfers, amount | $ 0 | $ 0 |
Fair value, assets, level 2 to level 1 transfers, amount | 0 | 0 |
Fair value, measurement with unobservable inputs reconciliation, recurring basis, asset transfers into level 3 | 0 | 0 |
Fair value, measurement with unobservable inputs reconciliation, recurring basis, asset, transfers out of level 3 | $ 0 | $ 0 |
Accrued Expenses and Other Cu_3
Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Detail) - USD ($) $ in Thousands | Sep. 30, 2019 | Dec. 31, 2018 |
Payables and Accruals [Abstract] | ||
Accrued external research and development expenses | $ 3,894 | $ 2,619 |
Accrued payroll and related expenses | 2,428 | 2,526 |
Deferred rent, current portion | 601 | 71 |
Accrued professional fees | 446 | 787 |
Accrued property and equipment | 713 | |
Accrued other | 222 | 211 |
Total | $ 7,591 | $ 6,927 |
Stock-Based Awards - Additional
Stock-Based Awards - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions | Apr. 18, 2019 | Sep. 30, 2019 |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||
Total unrecognized stock-based compensation expense | $ 18 | |
Period for recognition of unrecognized expense | 2 years 3 months 18 days | |
Employees [Member] | ||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||
Share-based compensation arrangement by share-based payment award, options, grants in period, gross | 1,650,066 | |
Weighted average fair value of stock options granted | $ 5.98 | |
2018 Stock Option and Incentive Plan [Member] | ||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||
Common stock available for issuance | 2,477,390 | |
2019 Employee Stock Purchase Plan [Member] | ||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||
Common stock available for issuance | 166,525 | 166,525 |
Annual Increase In Aggregate Number Of Shares Reserved For Future Issuance | 1,000,000 | |
Minimum percentage of shares issued and outstanding | 1.00% |
Stock-Based Awards - Schedule o
Stock-Based Awards - 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] | ||||
Stock based compensation expense | $ 2,762 | $ 3,676 | $ 7,939 | $ 8,152 |
Research and Development Expenses [Member] | ||||
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] | ||||
Stock based compensation expense | 1,293 | 2,022 | 3,817 | 4,612 |
General and Administrative Expenses [Member] | ||||
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] | ||||
Stock based compensation expense | $ 1,469 | $ 1,654 | $ 4,122 | $ 3,540 |
Net Loss per Share - Schedule o
Net Loss per Share - Schedule of Basic and Diluted Net Loss Per Share Attributable to Common Stockholders (Detail) - USD ($) $ / shares in Units, $ in Thousands | 3 Months Ended | 9 Months Ended | 12 Months Ended | ||
Sep. 30, 2019 | Sep. 30, 2018 | Sep. 30, 2019 | Sep. 30, 2018 | Dec. 31, 2018 | |
Numerator: | |||||
Net loss | $ (20,990) | $ (16,015) | $ (53,532) | $ (40,836) | $ (57,500) |
Accretion of redeemable convertible preferred stock to redemption value | (88) | ||||
Net loss attributable to common stockholders | $ (20,990) | $ (16,015) | $ (53,532) | $ (40,924) | |
Denominator: | |||||
Weighted average common shares outstanding, basic and diluted | 38,824,209 | 32,997,346 | 36,322,804 | 13,396,856 | |
Net loss per share attributable to common stockholders, basic and diluted | $ (0.54) | $ (0.49) | $ (1.47) | $ (3.05) |
Net Loss Per Share - Schedule_2
Net Loss Per Share - Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share (Detail) - shares | 9 Months Ended | |
Sep. 30, 2019 | Sep. 30, 2018 | |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||
Anti-dilutive securities excluded from computation of earnings per share, amount | 5,330,904 | 4,783,669 |
Stock Option [Member] | ||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||
Anti-dilutive securities excluded from computation of earnings per share, amount | 4,903,047 | 3,558,282 |
Restricted Stock [Member] | ||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||
Anti-dilutive securities excluded from computation of earnings per share, amount | 427,857 | 1,225,387 |
Commitments and Contingencies -
Commitments and Contingencies - Additional Information (Detail) | 1 Months Ended | 3 Months Ended | 9 Months Ended | 12 Months Ended | ||||||
May 31, 2018USD ($)ft² | Apr. 30, 2017USD ($)shares | Nov. 30, 2016USD ($)shares | Sep. 30, 2019USD ($)shares | Dec. 31, 2018USD ($)ft²Subleaseshares | Sep. 30, 2018USD ($) | Sep. 30, 2019USD ($)Milestoneshares | Sep. 30, 2018USD ($) | Dec. 31, 2017USD ($) | Dec. 31, 2016USD ($) | |
Other Commitments [Line Items] | ||||||||||
Sublease commencement period | 2018-06 | |||||||||
Sublease expiration period | 2028-02 | |||||||||
Property sublease, description | In May 2018, the Company entered into a sublease for up to approximately 69,000 square feet of office and laboratory space in Cambridge, Massachusetts. The sublease was amended effective March 2019 to increase the lease payments over the lease term and to increase the sublandlord-funded tenant improvements. The sublease is subject and subordinate to a prime lease between the sublandlord and the prime landlord. The term of the sublease commenced in June 2018 and expires in February 2028. The sublandlord has the right to terminate the sublease after five years. | |||||||||
Sublease termination period | 5 years | |||||||||
Long-term deferred rent | $ 6,075,000 | $ 1,246,000 | $ 6,075,000 | |||||||
Deferred rent, current portion | 601,000 | $ 71,000 | 601,000 | |||||||
Rent expense | 1,500,000 | $ 1,800,000 | 4,600,000 | $ 2,900,000 | ||||||
Research and development expense | $ 16,524,000 | 11,418,000 | $ 40,494,000 | 28,950,000 | ||||||
Common stock issued | shares | 39,370,576 | 34,327,554 | 39,370,576 | |||||||
Redeemable convertible preferred stock issued | shares | 0 | 0 | 0 | |||||||
Office and Lab Sublease [Member] | ||||||||||
Other Commitments [Line Items] | ||||||||||
Proceeds from sublease facility | $ 5,200,000 | |||||||||
Maximum [Member] | Office and Lab Sublease [Member] | ||||||||||
Other Commitments [Line Items] | ||||||||||
Square feet of property subject to sublease | ft² | 69,000 | |||||||||
Tenant improvement allowance | $ 5,500,000 | |||||||||
Sub-Sublease [Member] | ||||||||||
Other Commitments [Line Items] | ||||||||||
Square feet of property subject to sublease | ft² | 27,000 | |||||||||
Rental payments receivable | $ 4,500,000 | |||||||||
Lease agreement maturity period | 2 years | |||||||||
Number of Sub-sublease | Sublease | 2 | |||||||||
License Agreement with Novartis International Pharmaceutical Ltd. [Member] | ||||||||||
Other Commitments [Line Items] | ||||||||||
Fair value of shares as of issuance date | $ 9,300,000 | |||||||||
Number of milestones met | Milestone | 0 | |||||||||
License Agreement with Novartis International Pharmaceutical Ltd. [Member] | Maximum [Member] | ||||||||||
Other Commitments [Line Items] | ||||||||||
License agreement royalty percentage | 20.00% | |||||||||
License Agreement with Novartis International Pharmaceutical Ltd. [Member] | Achievement of Clinical and Regulatory Milestones [Member] | Maximum [Member] | ||||||||||
Other Commitments [Line Items] | ||||||||||
Payment obligation | $ 177,000,000 | |||||||||
License Agreement with Novartis International Pharmaceutical Ltd. [Member] | Achievement of Commercial Milestones [Member] | Maximum [Member] | ||||||||||
Other Commitments [Line Items] | ||||||||||
Payment obligation | $ 125,000,000 | |||||||||
License Agreement with Novartis International Pharmaceutical Ltd. [Member] | Series A- Redeemable Convertible Preferred Stock [Member] | ||||||||||
Other Commitments [Line Items] | ||||||||||
Redeemable convertible preferred stock issued | shares | 2,500,000 | |||||||||
License Agreement with Novartis International Pharmaceutical Ltd. [Member] | Series B Redeemable Convertible Preferred Stock [Member] | ||||||||||
Other Commitments [Line Items] | ||||||||||
Redeemable convertible preferred stock issued | shares | 643,550 | |||||||||
Collaboration Agreement [Member] | ||||||||||
Other Commitments [Line Items] | ||||||||||
Research and development expense | $ 500,000 | $ 900,000 | $ 800,000 | |||||||
Collaboration Agreement [Member] | Maximum [Member] | ||||||||||
Other Commitments [Line Items] | ||||||||||
Research and development expense | $ 100,000 | |||||||||
Collaboration Agreement [Member] | Development, Regulatory and Commercial Milestone [Member] | Per Target [Member] | Maximum [Member] | ||||||||||
Other Commitments [Line Items] | ||||||||||
Payment obligation | $ 83,500,000 | 83,500,000 | ||||||||
License Agreement With Harvard [Member] | ||||||||||
Other Commitments [Line Items] | ||||||||||
Payment of upfront fee | $ 100,000 | |||||||||
Common stock issued | shares | 385,063 | |||||||||
Fair value of shares as of issuance date | $ 300,000 | |||||||||
License Agreement With Harvard [Member] | Maintenance [Member] | Annually Thereafter [Member] | ||||||||||
Other Commitments [Line Items] | ||||||||||
Payment obligation | $ 100,000 | |||||||||
License Agreement With Harvard [Member] | Maintenance [Member] | Annually Through 2019 [Member] | Maximum [Member] | ||||||||||
Other Commitments [Line Items] | ||||||||||
Payment obligation | 100,000 | |||||||||
License Agreement With Harvard [Member] | Development and Regulatory Milestones [Member] | ||||||||||
Other Commitments [Line Items] | ||||||||||
Research and development expense | $ 100,000 | |||||||||
License Agreement With Harvard [Member] | Achievement of Development and Regulatory Milestones [Member] | Maximum [Member] | ||||||||||
Other Commitments [Line Items] | ||||||||||
Payment obligation | 7,400,000 | |||||||||
License Agreement With Harvard [Member] | Patents [Member] | ||||||||||
Other Commitments [Line Items] | ||||||||||
Reimbursed costs | $ 300,000 | |||||||||
Letter of Credit [Member] | Office and Lab Sublease [Member] | ||||||||||
Other Commitments [Line Items] | ||||||||||
Cash balance to secure letter of credit associated with sublease | $ 1,800,000 |
Commitments and Contingencies_2
Commitments and Contingencies - Schedule of Future Minimum Lease Payments Due Under Noncancelable Operating Lease (Detail) $ in Thousands | Sep. 30, 2019USD ($) |
Operating Leased Assets [Line Items] | |
Remainder of 2019 (three months) | $ 1,405 |
2020 | 5,782 |
2021 | 6,072 |
2022 | 6,375 |
2023 | 6,734 |
Thereafter | 32,000 |
Operating leases future minimum payments due | $ 58,368 |
Related Parties - Additional In
Related Parties - Additional Information (Detail) - Match Bio Therapies [Member] - USD ($) | 3 Months Ended | 9 Months Ended | |||
Sep. 30, 2019 | Sep. 30, 2018 | Sep. 30, 2019 | Sep. 30, 2018 | Dec. 31, 2018 | |
Related Party Transaction [Line Items] | |||||
Administrative expenses related party | $ 100,000 | $ 100,000 | |||
Expenses paid to related party | $ 100,000 | $ 100,000 | 500,000 | 600,000 | |
Accounts Payable, Accrued Expenses and Other Current Liabilities [Member] | |||||
Related Party Transaction [Line Items] | |||||
Amounts owed to related party | 400,000 | 400,000 | $ 400,000 | ||
Research and Development Expenses [Member] | |||||
Related Party Transaction [Line Items] | |||||
Research and development expense | 100,000 | $ 300,000 | |||
Maximum [Member] | |||||
Related Party Transaction [Line Items] | |||||
Administrative expenses related party | 100,000 | $ 100,000 | |||
Maximum [Member] | Prepaid Expenses and Other Current Assets [Member] | |||||
Related Party Transaction [Line Items] | |||||
Amounts owed from related party | 100,000 | 100,000 | $ 100,000 | ||
Maximum [Member] | Research and Development Expenses [Member] | |||||
Related Party Transaction [Line Items] | |||||
Research and development expense | $ 100,000 | $ 100,000 |