Document and Entity Information
Document and Entity Information - USD ($) $ in Billions | 12 Months Ended | ||
Dec. 31, 2020 | Feb. 19, 2021 | Jun. 30, 2020 | |
Cover [Abstract] | |||
Document Type | 10-K | ||
Amendment Flag | false | ||
Document Period End Date | Dec. 31, 2020 | ||
Document Fiscal Year Focus | 2020 | ||
Document Fiscal Period Focus | FY | ||
Trading Symbol | CNST | ||
Entity Registrant Name | CONSTELLATION PHARMACEUTICALS INC | ||
Entity Central Index Key | 0001434418 | ||
Current Fiscal Year End Date | --12-31 | ||
Entity Well-known Seasoned Issuer | Yes | ||
Entity Current Reporting Status | Yes | ||
Entity Voluntary Filers | No | ||
Entity Shell Company | false | ||
Entity Filer Category | Large Accelerated Filer | ||
Entity Emerging Growth Company | false | ||
Entity Small Business | false | ||
Entity Public Float | $ 1.4 | ||
Entity Common Stock, Shares Outstanding | 47,856,552 | ||
Entity Interactive Data Current | Yes | ||
Title of 12(b) Security | Common Stock, $0.0001 par value per share | ||
Security Exchange Name | NASDAQ | ||
Entity File Number | 001-38584 | ||
Entity Incorporation, State or Country Code | DE | ||
Entity Tax Identification Number | 26-1741721 | ||
Entity Address, Address Line One | 215 First Street | ||
Entity Address, Address Line Two | Suite 200 | ||
Entity Address, City or Town | Cambridge | ||
Entity Address, State or Province | MA | ||
Entity Address, Postal Zip Code | 02142 | ||
City Area Code | 617 | ||
Local Phone Number | 714-0555 | ||
Document Annual Report | true | ||
Document Transition Report | false | ||
ICFR Auditor Attestation Flag | true | ||
Documents Incorporated by Reference | The registrant intends to file a definitive proxy statement pursuant to Regulation 14A relating to the 2021 Annual Meeting of Stockholders within 120 days of the end of the registrant’s fiscal year ended December 31, 2020. Portions of such definitive proxy statement are incorporated by reference into Part III of this Annual Report on Form 10-K to the extent stated herein. |
Consolidated Balance Sheets
Consolidated Balance Sheets - USD ($) $ in Thousands | Dec. 31, 2020 | Dec. 31, 2019 |
Current assets: | ||
Cash and cash equivalents | $ 163,693 | $ 334,332 |
Marketable securities | 257,755 | 49,602 |
Prepaid expenses and other current assets | 7,161 | 3,055 |
Total current assets | 428,609 | 386,989 |
Property and equipment, net | 1,497 | 971 |
Restricted cash | 3,233 | 425 |
Operating lease, right-of-use assets | 3,541 | 10,745 |
Other assets | 4,974 | |
Total assets | 441,854 | 399,130 |
Current liabilities: | ||
Accounts payable | 9,853 | 7,278 |
Accrued expenses and other current liabilities | 17,051 | 12,915 |
Current portion of lease liabilities - operating lease | 3,644 | 2,562 |
Total current liabilities | 30,548 | 22,755 |
Long-term debt, net of current portion and discount | 29,642 | |
Operating lease liabilities, net of current portion | 582 | 8,759 |
Other long-term liabilities | 390 | |
Total liabilities | 31,130 | 61,546 |
Stockholders' equity: | ||
Preferred stock, $0.001 par value; 5,000,000 shares authorized; no shares issued or outstanding at December 31, 2020 and 2019, respectively | ||
Common stock, $0.0001 par value; 200,000,000 shares authorized at December 31, 2020 and 2019, respectively; 47,744,486 and 41,719,039 shares issued and outstanding at December 31, 2020 and December 31, 2019, respectively | 5 | 4 |
Additional paid-in capital | 856,460 | 656,973 |
Accumulated other comprehensive loss | 3 | (6) |
Accumulated deficit | (445,744) | (319,387) |
Total stockholders' equity | 410,724 | 337,584 |
Total liabilities and stockholders' equity | $ 441,854 | $ 399,130 |
Consolidated Balance Sheets (Pa
Consolidated Balance Sheets (Parenthetical) - $ / shares | Dec. 31, 2020 | Dec. 31, 2019 |
Statement Of Financial Position [Abstract] | ||
Preferred stock, par value | $ 0.001 | $ 0.001 |
Preferred stock, shares authorized | 5,000,000 | 5,000,000 |
Preferred stock, shares issued | 0 | 0 |
Preferred stock, shares outstanding | 0 | 0 |
Common stock, par value | $ 0.0001 | $ 0.0001 |
Common stock, shares authorized | 200,000,000 | 200,000,000 |
Common stock, shares issued | 47,744,486 | 41,719,039 |
Common stock, shares outstanding | 47,744,486 | 41,719,039 |
Consolidated Statements of Oper
Consolidated Statements of Operations and Comprehensive Loss - USD ($) | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Operating expenses: | |||
Research and development | $ 95,501,000 | $ 66,459,000 | $ 48,769,000 |
General and administrative | 29,346,000 | 19,596,000 | 12,475,000 |
Total operating expenses | 124,847,000 | 86,055,000 | 61,244,000 |
Loss from operations | (124,847,000) | (86,055,000) | (61,244,000) |
Other income (expense): | |||
Interest income | 2,851,000 | 2,644,000 | 1,547,000 |
Gain on disposal of equipment | 41,000 | ||
Loss on extinguishment of debt | (1,501,000) | ||
Interest expense | (2,862,000) | (2,115,000) | (228,000) |
Total other income (expense), net | (1,471,000) | 529,000 | 1,319,000 |
Loss before income taxes | (126,318,000) | (85,526,000) | (59,925,000) |
Income tax expense | 39,000 | 24,000 | 0 |
Net loss | $ (126,357,000) | $ (85,550,000) | $ (59,925,000) |
Net loss per share attributable to common stockholders, basic and diluted | $ (2.81) | $ (3.04) | $ (5) |
Weighted average common shares outstanding, basic and diluted | 44,890,425 | 28,151,763 | 11,984,293 |
Comprehensive loss: | |||
Net loss | $ (126,357,000) | $ (85,550,000) | $ (59,925,000) |
Other comprehensive gain (loss): | |||
Unrealized gain (loss) on marketable securities | 9,000 | (6,000) | |
Total other comprehensive gain (loss) | 9,000 | (6,000) | |
Comprehensive loss | $ (126,348,000) | $ (85,556,000) | $ (59,925,000) |
Consolidated Statements of Conv
Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands | Total | IPO [Member] | Convertible Preferred Stock (Series A, B, D, E, E-1 and F) [Member] | Convertible Preferred Stock (Series A, B, D, E, E-1 and F) [Member]IPO [Member] | Common Stock [Member] | Common Stock [Member]IPO [Member] | Additional Paid-in Capital [Member] | Additional Paid-in Capital [Member]IPO [Member] | Accumulated Other Comprehensive Gain (loss) [Member] | Accumulated Deficit [Member] |
Beginning balance at Dec. 31, 2017 | $ (165,833) | $ 173,228 | $ 8,079 | $ (173,912) | ||||||
Beginning balance, shares at Dec. 31, 2017 | 118,867,177 | |||||||||
Beginning balance, shares at Dec. 31, 2017 | 962,898 | |||||||||
Issuance of stock, net of issuance costs | $ 99,606 | |||||||||
Issuance of stock, net of issuance costs | 99,750,000 | |||||||||
Conversion of convertible preferred stock into common stock upon closing of the initial public offering | $ 272,834 | $ (272,834) | $ 2 | $ 272,832 | ||||||
Conversion of convertible preferred stock into common stock upon closing of the initial public offering, shares | 218,617,177 | |||||||||
Conversion of convertible preferred stock into common stock upon closing of the initial public offering, shares | 20,501,927 | |||||||||
Conversion of preferred stock warrants to common stock warrants upon closing of initial public offering | 364 | 364 | ||||||||
Issuance of common stock sold in initial public offering, net of underwriting discounts, commissions and offering costs | 52,163 | $ 1 | 52,162 | |||||||
Issuance of stock, net of issuance costs, shares | 4,000,000 | |||||||||
Repayment of promissory notes issued upon early exercise of unvested options | 290 | 290 | ||||||||
Repayment of promissory notes issued upon early exercise of unvested options, shares | 229,357 | |||||||||
Stock-based compensation expense | 3,952 | 3,952 | ||||||||
Vesting of common stock issued upon early exercise of unvested options | 4 | 4 | ||||||||
Vesting of common stock issued upon early exercise of unvested options, shares | 664 | |||||||||
Exercise of common stock warrant | 79 | 79 | ||||||||
Exercise of common stock warrant, shares | 51,032 | |||||||||
Stock option exercises | 230 | 230 | ||||||||
Stock option exercises, shares | 57,257 | |||||||||
Net loss | (59,925) | (59,925) | ||||||||
Ending balance at Dec. 31, 2018 | 104,158 | $ 3 | 337,992 | (233,837) | ||||||
Ending balance, shares at Dec. 31, 2018 | 25,803,135 | |||||||||
Conversion of convertible preferred stock into common stock upon closing of the initial public offering | (218,617,177) | |||||||||
Issuance of common stock sold in initial public offering, net of underwriting discounts, commissions and offering costs | 307,027 | $ 1 | 307,026 | |||||||
Issuance of stock, net of issuance costs, shares | 15,161,563 | |||||||||
Stock-based compensation expense | 6,910 | 6,910 | ||||||||
Vesting of common stock issued upon early exercise of unvested options, shares | 340 | |||||||||
Exercise of common stock warrant, shares | 7,919 | |||||||||
Stock option exercises | 5,045 | 5,045 | ||||||||
Stock option exercises, shares | 746,082 | |||||||||
Unrealized loss on marketable securities | (6) | $ (6) | ||||||||
Net loss | (85,550) | (85,550) | ||||||||
Ending balance at Dec. 31, 2019 | 337,584 | $ 4 | 656,973 | (6) | (319,387) | |||||
Ending balance, shares at Dec. 31, 2019 | 41,719,039 | |||||||||
Issuance of common stock sold in initial public offering, net of underwriting discounts, commissions and offering costs | $ 180,727 | $ 1 | $ 180,726 | |||||||
Issuance of stock, net of issuance costs, shares | 5,500,000 | |||||||||
Stock-based compensation expense | 14,786 | 14,786 | ||||||||
Exercise of common stock warrant | 47 | 47 | ||||||||
Exercise of common stock warrant, shares | 30,107 | |||||||||
Stock option exercises | $ 3,928 | 3,928 | ||||||||
Stock option exercises, shares | 495,340 | 495,340 | ||||||||
Unrealized loss on marketable securities | $ 9 | 9 | ||||||||
Net loss | (126,357) | (126,357) | ||||||||
Ending balance at Dec. 31, 2020 | $ 410,724 | $ 5 | $ 856,460 | $ 3 | $ (445,744) | |||||
Ending balance, shares at Dec. 31, 2020 | 47,744,486 |
Consolidated Statements of Co_2
Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) (Parenthetical) $ in Thousands | 12 Months Ended |
Dec. 31, 2018USD ($) | |
Issuance of stock, net of issuance costs | $ 3,638 |
Series F Convertible Preferred Stock [Member] | |
Issuance of stock, net of issuance costs | $ 144 |
Consolidated Statements of Cash
Consolidated Statements of Cash Flows - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Cash flows from operating activities: | |||
Net loss | $ (126,357) | $ (85,550) | $ (59,925) |
Adjustments to reconcile net loss to net cash used in operating activities: | |||
Depreciation and amortization expense | 644 | 758 | 562 |
Stock-based compensation expense | 14,786 | 6,910 | 3,952 |
Non-cash interest expense | 675 | 507 | 45 |
Amortization and accretion on marketable securities | (148) | (698) | |
Change in fair value of preferred stock warrant liability | 110 | ||
Gain on disposal of equipment | (41) | ||
Loss on extinguishment of debt | 1,501 | ||
Changes in operating assets and liabilities: | |||
Prepaid expenses and other current assets | (4,106) | (232) | (1,393) |
Operating lease, right-of-use assets | 3,701 | 3,308 | |
Accounts payable | 2,521 | 1,733 | 2,751 |
Accrued expenses and other current liabilities | 3,966 | 4,177 | 5,184 |
Operating lease liabilities | (3,592) | (3,161) | |
Deferred rent | (127) | ||
Other assets | (4,974) | 18 | |
Net cash used in operating activities | (111,424) | (72,248) | (48,823) |
Cash flows from investing activities: | |||
Purchases of marketable securities | (580,330) | (114,685) | |
Purchases of property and equipment | (946) | (699) | (476) |
Proceeds from sale of property and equipment | 41 | ||
Proceeds from maturities and sales of marketable securities | 372,334 | 65,775 | |
Net cash used in investing activities | (208,901) | (49,609) | (476) |
Cash flows from financing activities: | |||
Proceeds from common stock offerings, net of underwriting discounts and commissions | 180,727 | 307,027 | 55,801 |
Proceeds from issuance of convertible preferred stock, net of issuance costs | 99,606 | ||
Proceeds from issuance of long-term debt | 29,650 | ||
Payment of debt issuance costs | (125) | ||
Payments on long-term debt, including final payment | (32,208) | (4,698) | |
Proceeds from repayment of promissory notes issued upon early exercise of stock options | 290 | ||
Payments of initial public offering costs | (3,638) | ||
Proceeds from issuance of common stock upon stock option exercises | 3,928 | 5,045 | 230 |
Proceeds from exercises of common stock warrants | 47 | 79 | |
Net cash provided by financing activities | 152,494 | 341,597 | 147,670 |
Net increase (decrease) in cash, cash equivalents and restricted cash | (167,831) | 219,740 | 98,371 |
Cash, cash equivalents and restricted cash at beginning of period | 334,757 | 115,017 | 16,646 |
Cash, cash equivalents and restricted cash at end of period | 166,926 | 334,757 | 115,017 |
Supplemental disclosure of cash flow information: | |||
Interest paid | 2,187 | 1,387 | 105 |
Income taxes paid | 24 | $ 1 | |
Supplemental disclosure of noncash investing and financing information: | |||
Purchases of property and equipment included in accounts payable and accrued expenses | $ 224 | 180 | |
Vesting of common stock subject to repurchase | $ 4 |
Nature of the Business and Basi
Nature of the Business and Basis of Presentation | 12 Months Ended |
Dec. 31, 2020 | |
Organization Consolidation And Presentation Of Financial Statements [Abstract] | |
Nature of the Business and Basis of Presentation | 1. Nature of the Business and Basis of Presentation Constellation Pharmaceuticals, Inc. (“Constellation” or the “Company”) is a clinical-stage biopharmaceutical company using its expertise in epigenetics to discover and develop novel therapeutics that address serious unmet medical needs in patients with cancers associated with abnormal gene expression or drug resistance. The Company was incorporated in January 2008 as EpiGenetiX, Inc. under the laws of the State of Delaware. On March 31, 2008, the Company changed its name to Constellation Pharmaceuticals, Inc. 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. The accompanying financial statements have been prepared on the basis of continuity of operations, realization of assets and the satisfaction of liabilities and commitments in the ordinary course of business. Since inception, the Company has funded its operations with the proceeds of sales of convertible preferred stock, payments received in connection with collaboration agreements, borrowings under loan agreements, and proceeds from sales of its common stock public and private offerings. On June 19, 2020, the Company completed a public offering of an aggregate of 5,500,000 shares of its common stock and received net proceeds of approximately $180.7 million. The Company has incurred recurring losses since inception, including net losses of $126.4 million, $85.6 million and $59.9 million for the year ended December 31, 2020, 2019, and 2018, respectively. As of December 31, 2020, the Company had an accumulated deficit of $445.7 million. The Company expects to continue to generate operating losses in the foreseeable future. As of February 24, 2021, the Company expects that its cash and cash equivalents will be sufficient to fund its operating expenses and capital expenditure requirements through at least 12 months from the issuance date of the financial statements. The Company’s financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). |
Summary of Significant Accounti
Summary of Significant Accounting Policies | 12 Months Ended |
Dec. 31, 2020 | |
Accounting Policies [Abstract] | |
Summary of Significant Accounting Policies | 2. Summary of Significant Accounting Policies Principles of Consolidation The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiary, Constellation Securities Corporation, which was established on December 21, 2018. All significant intercompany balances and transactions have been eliminated in consolidation. 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 revenue and expenses during the reporting periods. Management considers many factors in selecting appropriate financial accounting policies and controls, and in developing the estimates and assumptions that are used in the preparation of these consolidated financial statements. Management must apply significant judgment in this process. In addition, other factors may affect estimates, including expected business and operational changes, sensitivity and volatility associated with the assumptions used in developing estimates, and whether historical trends are expected to be representative of future trends. The estimation process often may yield a range of potentially reasonable estimates of the ultimate future outcomes and management must select an amount that falls within that range of reasonable estimates. Estimates are periodically reviewed considering changes in circumstances, facts and historical experience. Actual results may differ from the Company’s estimates. Estimates are used in the following areas: prepaid and accrued research and development expenses, operating lease assets and liabilities, and stock-based compensation expenses. Concentrations of credit risk and of significant suppliers Financial instruments that potentially expose the Company to concentrations of credit risk consist primarily of cash and cash equivalents. The Company maintains most of its cash and cash equivalents at two accredited financial institutions in amounts that exceed federally insured limits. Cash equivalents are invested in an institutional money market fund. The Company does not believe that it is subject to unusual credit risk beyond the normal credit risk associated with commercial banking relationships. The Company is dependent on third-party manufacturers to supply products for research and development activities in its programs. In particular, the Company relies and expects to continue to rely on a small number of manufacturers to supply it with its requirements for the active pharmaceutical ingredients and formulated drugs related to these programs. These programs could be adversely affected by a significant interruption in the supply of active pharmaceutical ingredients and formulated drugs. Deferred offering costs The Company capitalizes certain legal, accounting and other third-party fees that are directly associated with in-process equity financings as deferred offering costs until such financings are consummated. After consummation of such equity financing, these costs are recorded in stockholders’ equity (deficit) as a reduction of additional paid-in capital generated as a result of the offering. Should the in-process equity financing be abandoned, the deferred offering costs will be expensed immediately as a charge to operating expenses in the statements of operations and comprehensive loss. Deferred financing costs The Company capitalizes lender, legal and other third-party fees that are directly associated with obtaining access to capital under credit facilities. Debt issuance costs incurred in connection with obtaining access to capital are recorded in prepaid expenses and other current assets and are amortized over the availability period or term of the credit facility. Debt issuance costs related to a recognized debt liability are recorded as a direct reduction of the carrying amount of the debt liability. Property and equipment Property and equipment are stated at cost less accumulated depreciation and amortization. Depreciation and amortization expense is recognized using the straight-line method over the estimated useful life of each asset as follows: Estimated Useful Life Laboratory equipment 3 years Computer equipment and software 3 years Furniture and fixtures 3 years Leasehold improvements Shorter of useful life or remaining lease term Upon retirement or sale, the cost of assets disposed of and the related accumulated depreciation and amortization are removed from the accounts and any resulting gain or loss is included in loss from operations. Expenditures for repairs and maintenance that do not improve or extend the lives of the respective assets are charged to expense as incurred, while costs of major additions and betterments are capitalized. Impairment of long-lived assets Long-lived assets consist of property and equipment. Long-lived assets to be held and used are tested for recoverability whenever events or changes in business circumstances indicate that the carrying amount of the assets may not be fully recoverable. Factors that the Company considers in deciding when to perform an impairment review include significant underperformance of the business in relation to expectations, significant negative industry or economic trends and significant changes or planned changes in the use of the assets. An impairment loss would be recognized in loss from operations when estimated undiscounted future cash flows expected to result from the use of an asset group are less than its carrying amount. The impairment loss would be based on the excess of the carrying value of the impaired asset group over its fair value, determined based on discounted cash flows. The Company did not record any impairment losses on long-lived assets during the years ended December 31, 2020, 2019, or 2018. The Company reduced the useful life for certain furniture and fixtures and leasehold improvements and therefor accelerated depreciation due to the lease amendment signed in November 2020 (see Note 11). 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 are carried at fair value, determined according to the fair value hierarchy described above (see Note 3). Segment information The Company manages its operations as a single segment for the purposes of assessing performance and making operating decisions. The Company’s singular focus is the development of novel therapeutics in the field of epigenetics. All of the Company’s tangible assets are held in the United States. Revenue recognition On January 1, 2018, the Company adopted the new revenue standard, which amended revenue recognition principles and provides a single, comprehensive set of criteria for revenue recognition within and across all industries (“ASC 606”). The Company will account for a contract with a customer that is within the scope of ASC 606 when all of the following criteria are met: (i) the arrangement has been approved by the parties and the parties are committed to perform their respective obligations, (ii) each party’s rights regarding the goods or services to be transferred can be identified, (iii) the payment terms for the goods or services to be transferred can be identified, (iv) the arrangement has commercial substance and (v) collection of substantially all of the consideration to which the Company will be entitled in exchange for the goods or services that will be transferred to the customer is probable. The Company estimates the transaction price based on the amount of consideration the Company expects to be received for transferring the promised goods or services in the contract. The consideration may include both fixed consideration and variable consideration. For each arrangement that includes variable consideration, the Company evaluates the amount of the potential payments and the likelihood that the payments will be received. The Company utilizes either the most likely amount method or expected value method to estimate the transaction price based on which method better predicts the amount of consideration expected to be received. If it is probable that a significant revenue reversal would not occur, the variable consideration is included in the transaction price. For arrangements that include development and regulatory milestone payments, the Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within the Company’s control or the licensee’s control, such as regulatory approvals, are not considered probable of being achieved until those approvals are received. At the end of each reporting period, the Company re-evaluates the probability of achievement of such milestones and any related constraint, and if necessary, adjusts the estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect collaboration revenue and net income (loss) in the period of adjustment. For sales-based royalties, including milestone payments based on the level of sales, the Company determines whether the sole or predominant item to which the royalties relate is a license. When the license is the sole or predominant item to which the sales-based royalty relates, the Company recognizes revenue at the later of: (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). The Company allocates the transaction price based on the estimated standalone selling price. The Company must develop assumptions that require judgment to determine the standalone selling price for each performance obligation identified in the contract. The Company utilizes key assumptions to determine the standalone selling price, which may include other comparable transactions, pricing considered in negotiating the transaction and the estimated costs. Certain variable consideration is allocated specifically to one or more performance obligations in a contract when the terms of the variable consideration relate to the satisfaction of the performance obligation and the resulting amounts allocated to each performance obligation are consistent with the amounts the Company would expect to receive for each performance obligation. For performance obligations which consist of licenses and other promises, the Company utilizes judgment to assess the nature of the combined performance obligation in order to determine whether the combined performance obligation is satisfied over time or at a point in time. The Company determines the appropriate method of measuring progress of combined performance obligations satisfied over time for purposes of recognizing revenue. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition. If the license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company will recognize revenue from non-refundable, up-front fees allocated to the license when the license is transferred to the customer and the customer is able to use and benefit from the license. Collaboration agreements The Company analyzes its collaboration arrangements to assess whether they are within the scope of Topic 808 to determine whether such arrangements involve joint operating activities performed by parties that are both active participants in the activities and exposed to significant risks and rewards that are dependent on the commercial success of such activities. To the extent the arrangement is within the scope of ASC 808, the Company assesses whether aspects of the arrangement between the Company and its collaboration partner are within the scope of other accounting literature, including ASC 606. If it is concluded that some or all aspects of the arrangement represent a transaction with a customer, the Company will account for those aspects of the arrangement within the scope of ASC 606. Pursuant to ASC 606, a customer is a party that has contracted with an entity to obtain goods or services that are an output of the entity’s ordinary activities in exchange for consideration. Under ASC 606, an entity recognizes revenue when its customer obtains control of promised goods or services in an amount that reflects the consideration which the entity expects to receive in exchange for those goods or services. ASC 808 provides guidance for the presentation and disclosure of transactions in collaborative arrangements, but it does not provide recognition or measurement guidance. Therefore, if the Company concludes a counterparty to a transaction is not a customer or otherwise not within the scope of ASC 606, the Company considers the guidance in other accounting literature, including the guidance in ASC 606, as applicable or by analogy to account for such transaction. The classification of transactions under the Company’s arrangements is determined based on the nature and contractual terms of the arrangement along with the nature of the operations of the participants. In July 2012, the Company entered into a Research, Development and Commercialization Agreement (the “LLS Agreement”) with the Leukemia & Lymphoma Society (“LLS”) pursuant to which LLS committed to provide financial support (the “Funding”) to the Company for research and development services, conditional on (i) the achievement of milestones in accordance with the LLS Agreement and (ii) equal funding being provided by the Company. The Company concluded that the LLS Agreement was within the scope of the accounting guidance for collaboration arrangements (see Note 13). Due to the co-funded nature of the payments and the Company’s assessment that it did not have a vendor/customer relationship with LLS, the Company recognized the nonrefundable payments received under the agreement as a reduction to the research and development expenses incurred, based on a proportional methodology comparing the total expenses incurred in the period under the project to the total expenses expected to be incurred under the project. Research and development costs Research and development costs are expensed as incurred. Research and development expenses are comprised of costs incurred in performing research and development activities, including salaries, stock-based compensation and benefits, facilities costs and laboratory supplies, depreciation, manufacturing expenses and external costs of outside vendors engaged to conduct preclinical development activities and clinical trials as well as the cost of licensing technology. Upfront payments and milestone payments made for the licensing of technology are expensed as research and development in the period in which they are incurred. Nonrefundable advance payments for goods or services to be received in the future for use in research and development activities are recorded as prepaid expenses. The prepaid amounts are expensed as the related goods are delivered or the services are performed. Accrued and prepaid Research and Development expenses The Company has entered into various research and development contracts with companies both inside and outside of the United States. These agreements are generally cancelable, and related payments are based on the terms of the individual arrangements, which may differ from the pattern of costs incurred, and are reflected on the consolidated balance sheet as accrued or prepaid research and development expenses. The Company records accruals for estimated ongoing research and development costs. When evaluating the adequacy of the accrued liabilities and/or prepaid expenses, the Company analyzes progress of the preclinical studies or clinical trials, including the phase or completion of events, invoices received and contracted costs. Significant judgments and estimates, based on information, including actual costs incurred or level of effort expanded, as provided by its vendors, are made in determining the accrued and prepaid balances at the end of any reporting period. Actual results could differ from the Company’s estimates. The Company’s historical accrual estimates have not been materially different from the actual costs. Patent costs All patent-related costs incurred in connection with filing and prosecuting patent applications are expensed as incurred due to the uncertainty about the recovery of the expenditure. Amounts incurred are classified as general and administrative expenses. Stock-based compensation The Company measures stock-based awards granted to employees, directors and non-employees based on the fair value on the date of grant using the Black-Scholes option-pricing model. Compensation expense for those awards is recognized over the requisite service period, which is generally the vesting period of the respective award. The straight-line method of expense recognition is applied to all awards with service-only conditions, while the graded vesting method is applied to all grants with both service and performance conditions. The Company records the expense for stock-based compensation awards subject to performance-based milestone vesting when management determines that achievement of the milestone is probable. Management evaluates when the achievement of a performance-based milestone is probable based on the expected satisfaction of the performance conditions as of the reporting date. The Company classifies stock-based compensation expense in the consolidated statements of operations and comprehensive loss in the same manner, in which the award recipient’s salary and related costs are classified or in which the award recipient’s service payments are classified, as applicable. Marketable Securities All highly liquid investments with maturities of three months or less at the date of purchase are classified as cash equivalents. The Company’s investments in marketable debt securities have been classified and accounted for as available-for-sale. The Company classifies its marketable debt securities as either short-term or long-term based on each instrument’s underlying contractual maturity date. Unrealized gains and losses on marketable debt securities classified as available-for-sale are recognized in other comprehensive income/(loss) (“OCI”). The Company’s investments in marketable equity securities are classified based on the nature of the securities and their availability for use in current operations. The Company’s marketable equity securities are measured at fair value with gains and losses recognized in other income/(expense), net (“OI&E”). The cost of securities sold is determined using the specific identification method. Comprehensive loss The Company’s only element of other comprehensive income (loss) is unrealized gains and losses on available-for-sale marketable securities. Cash, Cash Equivalents and Restricted Cash Cash equivalents consists of highly liquid investments that are readily convertible into cash with original maturities of three months or less from the date of purchase. The Company has a policy of making investments only in government securities or with commercial institutions that have at least an investment grade credit rating. The Company invests its cash primarily in reverse repurchase agreements (RRAs), government securities and obligations, corporate debt securities and money market funds. RRAs are collateralized by deposits in the form of government securities and obligations for an amount not less than 102% of their value. The Company does not record an asset or liability as the Company is not permitted to sell or repledge the associated collateral. The Company has a policy that the collateral has at least the prevailing credit rating of US Government Treasuries and Agencies. The Company utilizes a third party custodian to manage the exchange of funds and ensure that collateral received is maintained at 102% of the value of the RRAs on a daily basis. RRAs have stated maturities of less than 30 days. As of December 31, 2020, the Company classified $3.2 million as restricted cash related to a letter of credit issued as a security deposit in connection with Company's lease of its corporate office facilities (Note 11). Cash, cash equivalents and restricted cash consists of the following (in thousands): December 31, 2020 2019 Cash and cash equivalents $ 163,693 $ 334,332 Restricted cash 3,233 425 Cash, cash equivalents and restricted cash $ 166,926 $ 334,757 Net income (loss) per share Basic net income (loss) per share attributable to common stockholders is computed by dividing the net income (loss) attributable to common stockholders by the weighted average number of common shares outstanding for the period. Diluted net income (loss) attributable to common stockholders is computed by adjusting net income (loss) attributable to common stockholders to reallocate undistributed earnings based on the potential impact of dilutive securities. Diluted net income (loss) per share attributable to common stockholders is computed by dividing the diluted net income (loss) attributable to common stockholders by the weighted average number of common shares outstanding for the period, including potential dilutive common shares assuming the dilutive effect of common stock equivalents. In periods in which the Company reports a net loss attributable to common stockholders, diluted net loss per share attributable to common stockholders is the same as basic net loss per share attributable to common stockholders, since dilutive common shares are not assumed to have been issued if their effect is anti-dilutive. The Company reported a net loss attributable to common stockholders for the years ended December 31, 2020, 2019 and 2018. 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 financial statements or in the Company’s tax returns. Deferred tax assets and liabilities are determined on the basis of the differences between the financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. Changes in deferred tax assets and liabilities are recorded in the provision for income taxes. The Company assesses the likelihood that its deferred tax assets will be recovered from future taxable income and, to the extent it believes, based upon the weight of available evidence, that it is more likely than not that all or a portion of the deferred tax assets will not be realized, a valuation allowance is established through a charge to income tax expense. Potential for recovery of deferred tax assets is evaluated by estimating the future taxable profits expected and considering prudent and feasible tax planning strategies. The Company accounts for uncertainty in income taxes recognized in the financial statements by applying a two-step process to determine the amount of tax benefit to be recognized. First, the tax position must be evaluated to determine the likelihood that it will be sustained upon external examination by the taxing authorities. If the tax position is deemed more-likely-than-not to be sustained, the tax position is then assessed to determine the amount of benefit to recognize in the financial statements. The amount of the benefit that may be recognized is the largest amount that has a greater than 50% likelihood of being realized upon ultimate settlement. The provision for income taxes includes the effects of any resulting tax reserves, or unrecognized tax benefits, that are considered appropriate as well as the related net interest and penalties. Recently adopted accounting pronouncements In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Statements In July 2017, the FASB issued ASU No. 2017-11, Earnings Per Share (Topic 260), Distinguishing Liabilities from Equity (Topic 480), Derivatives and Hedging (Topic 815) I. Accounting for Certain Financial Instruments with Down Round Features II. Replacement of the Indefinite Deferral for Mandatorily Redeemable Financial Instruments of Certain Nonpublic Entities and Certain Mandatorily Redeemable Noncontrolling Interests with a Scope Exception . In August 2018, the FASB issued ASU No. 2018-13, Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement In August 2018, the FASB issued , Intangibles - Goodwill and Other - Internal-Use Software . This ASU addresses the accounting for implementation, setup and other upfront costs paid by a customer in a cloud computing or hosting arrangement. The guidance aligns the accounting treatment of these costs incurred in a hosting arrangement treated as a service contract with the requirements for capitalization and amortization costs to develop or obtain internal-use software. The guidance is effective for fiscal years beginning after December 15, 2019 and early adoption is permitted. The guidance can be adopted either retrospectively or prospectively. The adoption of ASU 2018-15 on January 1, 2020 prospectively did not have a material impact on the Company’s financial position, results of operations or cash flows. In November 2018, the FASB issued ASU No. 2018-18, Collaborative Arrangements (Topic 808), Clarifying the Interaction between Topic 808 and Topic 606. ASC 606 ASC 606 ASU 2018-18 The adoption of ASU 2018-18 on January 1, 2020 did not have a material impact on the Company’s financial position, results of operations or cash flows. In March 2019, the FASB issued ASU No. 2019-01, Leases (Topic 842) Codification Improvements Recently issued accounting pronouncements In December 2019, the FASB issued ASU 2019-12, Simplifying the Accounting for Income Taxes Income Taxes |
Fair Value Measurements
Fair Value Measurements | 12 Months Ended |
Dec. 31, 2020 | |
Fair Value Disclosures [Abstract] | |
Fair Value Measurements | 3. Fair Value Measurements The following tables present information about the Company’s financial assets and liabilities 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): December 31, 2020 Level 1 Level 2 Level 3 Total Cash equivalents: Money market funds $ 163,693 $ — $ — $ 163,693 $ 163,693 $ — $ — $ 163,693 Marketable securities: Corporate debt securities $ — $ 52,531 $ — $ 52,531 Commercial paper — 99,865 — 99,865 U.S. Government debt securities — 105,359 — 105,359 Total $ — $ 257,755 $ — $ 257,755 December 31, 2019 Level 1 Level 2 Level 3 Total Cash equivalents: Money market funds $ 303,345 $ — $ — $ 303,345 Commercial paper — 8,986 — 8,986 Corporate debt securities — 2,001 — 2,001 Reverse Repurchase Agreements (RRAs) — 20,000 — 20,000 $ 303,345 $ 30,987 $ — $ 334,332 Marketable securities: Corporate debt securities $ — $ 12,748 $ — $ 12,748 Commercial paper — 26,808 — 26,808 U.S. Government debt securities — 10,046 — 10,046 Total $ — $ 49,602 $ — $ 49,602 Money market funds were valued by the Company using quoted prices in active markets for similar securities, which represent a Level 1 measurement within the fair value hierarchy. The fair value of Level 2 instruments classified as cash equivalents and marketable debt securities were determined through third-party pricing services. During the years ended December 31, 2020 and 2019, there were no transfers between Level 1, Level 2 and Level 3. |
Marketable Securities
Marketable Securities | 12 Months Ended |
Dec. 31, 2020 | |
Cash And Cash Equivalents [Abstract] | |
Marketable Securities | 4. Marketable Securities The following table summarizes the Company’s marketable securities as of December 31, 2020 and 2019, respectively (in thousands): December 31, 2020 Amortized Cost Unrealized Gains Unrealized Losses Fair Value Marketable securities: Corporate debt securities $ 52,529 $ 6 $ (4 ) $ 52,531 Commercial paper 99,865 — — 99,865 U.S. Government debt securities 105,358 6 (5 ) 105,359 Total marketable securities $ 257,752 $ 12 $ (9 ) $ 257,755 December 31, 2019 Amortized Cost Unrealized Gains Unrealized Losses Fair Value Marketable securities: Corporate debt securities $ 12,753 $ — $ (5 ) $ 12,748 Commercial paper 26,808 — — 26,808 U.S. Government debt securities 10,047 — (1 ) 10,046 Total marketable securities $ 49,608 $ — $ (6 ) $ 49,602 |
Property and Equipment, net
Property and Equipment, net | 12 Months Ended |
Dec. 31, 2020 | |
Property Plant And Equipment [Abstract] | |
Property and Equipment, net | 5. Property and Equipment, net Property and equipment, net consisted of the following (in thousands): December 31, 2020 2019 Laboratory equipment $ 5,741 $ 5,411 Computer equipment and computer software 1,612 1,567 Furniture and fixtures 345 330 Leasehold improvements 624 466 8,322 7,774 Less: Accumulated depreciation and amortization (6,825 ) (6,803 ) $ 1,497 $ 971 Depreciation and amortization expense were $0.6 million, $0.8 million and $0.6 million for the years ended December 31, 2020, 2019 and 2018, respectively. During the year ended December 31, 2020, 2019, the Company disposed of property and equipment with a gross book value and accumulated depreciation of $0.6 million, $1.2 million and less than $0.1 million, respectively. |
Accrued Expenses and Other Curr
Accrued Expenses and Other Current Liabilities | 12 Months Ended |
Dec. 31, 2020 | |
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 (in thousands): December 31, 2020 2019 Accrued employee compensation and benefits $ 5,545 $ 4,527 Accrued external research and development expense 10,698 7,707 Accrued professional fees 467 184 Other 341 497 $ 17,051 $ 12,915 |
Collaboration and Research Agre
Collaboration and Research Agreements | 12 Months Ended |
Dec. 31, 2020 | |
Organization Consolidation And Presentation Of Financial Statements [Abstract] | |
Collaboration and Research Agreements | 7. Collaboration and Research Agreements Leukemia & Lymphoma Society The Company has a collaboration agreement (the “LLS Agreement”) with the Leukemia and Lymphoma Society, (“LLS”) pursuant to which LLS committed to provide funding to the Company for research and development services, conditional on (i) the achievement of milestones in accordance with the LLS Agreement and (ii) equal funding being provided by the Company. Through December 31, 2018, the Company received funding totaling $7.3 million from LLS upon the achievement of specified milestones, which were recorded as a reduction of research and development expense. There was no additional funding received in the year ended December 31, 2019 and 2020. The LLS Agreement requires the Company to make payments to LLS upon the Company’s achievement of specified milestones that could total up to $25.0 million in aggregate. The financial statements as of December 31, 2019 and 2020 do not include liabilities with respect to this agreement as the achievement of the specified milestones is not probable (see Note 13). |
Debt
Debt | 12 Months Ended |
Dec. 31, 2020 | |
Debt Disclosure [Abstract] | |
Debt | 8. Debt On March 20, 2019, the Company entered into the Loan Agreement with Hercules, under a term loan facility, pursuant to which the Company could borrow up to $40.0 million. The Company had borrowed $30.0 million, and its right to borrow the remaining $ 10.0 million has expired. The term loan b ore interest at an annual rate equal to the greater of 8.55% and the prime rate of interest plus 2.55%. The Loan Agreement provide d for interest-only payments until April 30, 2021, and repayment of the aggregate outstanding principal balance of the term loan in monthly installments starting on May 1, 2021 and continuing through April 1, 2023 (the “Maturity Date”). In addition, the Company paid a fee of $ 0.3 million upon closing and was required to pay a fee of 6.35% of the aggregate amount of advances under the Loan Agreement at maturity. At its option, the Company could elect to prepay all or a portion of the outstanding advances by paying the entire principal balance (or a portion thereof) and all accrued and unpaid interest thereon plus a prepayment charge equal to the following percentage of the principal amount being prepaid: 2% if an advance was prepaid during the first 12 months following the applicable advance date, 1% if an advance was prepaid after 12 months but prior to 24 months following the applicable advance date, and 0.5% if an advance wa s prepaid any time after 24 months following the applicable advance date but prior to the Maturity Date. In connection with the Loan Agreement, the Company granted Hercules a security interest in all of its personal property then owned or t hereafter acquired, excluding intellectual property (but including the rights to payment and proceeds from the sale, licensing or disposition of intellectual property), and a negative pledge on intellectual property. The Loan Agreement also contain ed certain events of default, representations, warranties and non-financial covenants of the Company. On November 3, 2020, the Company repaid all amounts due under the Loan Agreement, including $30.0 million in principal repayments, $1.9 million related to a 6.35% fee due at maturity or prepayment, and $0.3 million related to a 1% prepayment fee. Upon prepayment of the outstanding amounts, the Company recorded a loss on extinguishment of debt of $1.5 million, which was classified as other expense in the consolidated statements of operations and comprehensive loss. As of December 31, 2019, notes payable consisted of the following (in thousands): December 31, 2019 Principal amount of term loans $ 30,000 Debt discount current portion — Less: Current portion — Long-term debt, net of current portion 30,000 Debt discount net of current portion (358 ) Long-term debt, net of discount and current portion $ 29,642 There were no notes payable outstanding as of December 31, 2020. |
Equity
Equity | 12 Months Ended |
Dec. 31, 2020 | |
Equity [Abstract] | |
Equity | 9. Equity Preferred Stock The Company has authorized preferred stock amounting to 5,000,000 shares as of December 31, 2020 and 2019, respectively. The authorized preferred stock was classified under stockholders’ equity at December 31, 2020 and 2019. Common Stock As of December 31, 2020, the Company’s certificate of incorporation, as amended and restated, authorized the Company to issue 200,000,000 shares of common stock, $0.0001 par value per share. Each share of common stock entitles the holder to one vote on all matters submitted to a vote of the Company’s stockholders. Common stockholders are not entitled to receive dividends, unless declared by the Company’s board of directors. No dividends have been declared or paid by the Company since its inception. At-the-Market Offering In August 2019, the Company entered into an Open Market Sale Agreement SM December 31, 2020 Equity O ffering On June 19, 2020, the Company completed a follow-on public equity offering, whereby it sold 5,500,000 shares of its common stock at a public offering price of $35.00 per share. The aggregate net proceeds received by the Company from the offering were approximately $180.7 million, net of underwriting discounts and commissions and offering expenses payable by the Company. Warrants to Purchase The Company has outstanding warrants to purchase common stock as follows: Number of Common Shares Issuable under Warrant as of December 31, Issuance Date Term (in years) Exercise Price 2020 2019 May 23, 2011 10 $ 1.55 31,761 61,868 June 28, 2013 10 $ 13.22 7,569 — September 30, 2014 10 $ 13.22 15,139 22,708 54,469 84,576 During the year ended December 31, 2020, 30,107 warrants were exercised. |
Stock-Based Compensation
Stock-Based Compensation | 12 Months Ended |
Dec. 31, 2020 | |
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] | |
Stock-Based Compensation | 10. Stock-based Compensation 2018 Equity Incentive Plan In June 2018, the Company’s stockholders approved the 2018 Plan, which became effective on July 18, 2018. The 2018 Plan provides for the grant of incentive stock options, non-qualified options, stock appreciation rights, restricted stock awards, restricted stock units and other stock-based awards. The number of shares initially reserved for issuance under the 2018 Plan was 3,025,101. The number of shares reserved shall be annually increased on January 1, 2019 and each January 1 thereafter through January 1, 2028 by the least of (i) 2,216,368 shares, (ii) 4% of the number of shares of the Company’s common stock outstanding on the first day of the year or (iii) an amount determined by the Company’s board of directors. The shares of common stock underlying any awards that are expired, forfeited, canceled, held back upon exercise or settlement of an award to satisfy the exercise price or tax withholding, repurchased or are otherwise terminated by the Company under the 2018 Plan or any predecessor plan such as the 2008 Equity Incentive Plan will be added back to the shares of common stock available for issuance under the 2018 Plan. As of December 31, 2020, 1,731,516 shares remained available for future issuance under the 2018 Plan. On January 1, 2021, 1,909,779 additional shares became automatically available for issuance under the 2018 Plan pursuant to the annual increase described above. 2018 Employee Stock Purchase Plan In June 2018, the Company’s stockholders approved the 2018 Employee Stock Purchase Plan which became effective on July 18, 2018. A total of 272,504 shares of common stock were reserved for issuance under this plan. The number of shares reserved shall be annually increased on each January 1 thereafter through January 1, 2028 by the least of (i) 545,008 shares, (ii) 1% of the number of shares of the Company’s common stock outstanding on the first day of the year or (iii) an amount determined by the Company’s board of directors. As of December 31, 2020, no offering periods have commenced, and 689,694 shares remained available for future issuance under the 2018 Plan. Stock option valuation The fair value of stock option grants is estimated using the Black-Scholes option-pricing model. The expected volatility has been measured based on a combination of the Company’s historical stock volatility since its July 2018 IPO and the historical volatility of our publicly traded peer companies. The Company expects in fiscal 2024 to solely utilize its historical stock volatility as it will have adequate historical data regarding the volatility of its traded stock price following the July 2018 IPO. For options with service-based vesting conditions, the expected term of the Company’s stock options has been determined utilizing the simplified method as prescribed by the SEC Staff Accounting Bulletin No. 107, Share-Based Payment contractual term of the option award. The risk-free interest rate is determined by reference to the U.S. Treasury yield curve in effect at the time of grant of the award for time periods approximately equal to the expected term of the award. Expected dividend yield is based on the fact that the Company has never paid cash dividends and does not expect to pay any cash dividends in the foreseeable future. The following table presents, on a weighted average basis, the assumptions used in the Black-Scholes option-pricing model to determine the fair value of stock options granted to employees and directors: Years Ended December 31, 2020 2019 2018 Risk-free interest rate 0.92 % 2.30 % 2.79 % Expected volatility 81.34 % 82.21 % 81.06 % Expected dividend yield — — — Expected term (in years) 6.05 6.03 6.05 The following table summarizes the Company’s option activity since December 31, 2019: Weighted Weighted Average Average Aggregate Number Exercise Contractual Intrinsic of Shares Price Term Value (in years) (in thousands) Outstanding as of December 31, 2019 4,211,068 $ 8.95 8.39 160,689 Granted 1,812,582 32.25 Exercised (495,340 ) 7.93 Forfeited (197,393 ) 16.93 Outstanding as of December 31, 2020 5,330,917 $ 16.68 8.06 $ 74,259 Vested and expected to vest as of December 31, 2020 5,330,917 $ 16.68 8.06 $ 74,259 Options exercisable as of December 31, 2020 2,179,197 $ 10.69 7.33 $ 41,141 The aggregate intrinsic value of stock options is calculated as the difference between the exercise price of the stock options and the fair value of the Company’s common stock for those stock options that had strike prices lower than the fair value of the Company’s common stock. The aggregate intrinsic value of stock options exercised during the years ended December 31, 2020, 2019, and 2018 were $13.5 million, $17.7 million, and $0.2 million, respectively. The weighted average grant-date fair value of awards granted during each of the years ended December 31, 2020, 2019, and 2018, were $32.25, $7.63 and $6.66 per share, respectively. As of December 31, 2020, there were outstanding unvested service-based stock options held by non-employees for the purchase of 7,322 shares of common stock. Stock-based compensation The Company recorded stock-based compensation expense in the following expense categories of its statements of operations and comprehensive loss (in thousands): Years Ended December 31, 2020 2019 2018 Research and development expenses $ 8,943 $ 2,703 $ 1,668 General and administrative expenses 5,843 4,207 2,284 Total $ 14,786 $ 6,910 $ 3,952 As of December 31, 2020, total unrecognized compensation cost related to the unvested stock-based awards was $41.9 million, which is expected to be recognized over a weighted average period of 2.86 years. |
Leases
Leases | 12 Months Ended |
Dec. 31, 2020 | |
Leases [Abstract] | |
Leases | 11. Leases The Company has leases for office and laboratory space. The Company occupies approximately 47,546 square feet of office and laboratory space in Cambridge, Massachusetts under a lease (the “current lease) that originally expired June 30, 2023. The Company also executed an amendment to update the term of the current lease to 60 days after commencement date of new lease. In November 2020, the Company executed a lease in Watertown, Massachusetts (the “new lease”), which will commence around December 2021 upon taking control of the asset. The new lease has a term of 10 years. The Company has the option to extend the term by five years. The base rent is $5.6 million per year, subject to an increase of 3.0%, and the Company is subject to reduced rent for the first nine months. Variable lease payments include the Company’s allocated share of costs incurred and expenditures made by the landlord in the operation and management of the building. In connection with the facility lease, the Company has secured a letter of credit for $2.8 million which renews automatically each year. Since the Company does not obtain the control of the premise until around December 2021, the Company determined that the lease commencement date, for accounting purposes, was not reached and therefore the lease is not included in the Company’s operating lease right-of-use asset or operating lease liabilities as of December 31, 2020. The Company determined that these leases are operating leases. In June 2019, the Company entered into a sublease agreement for a portion of its office space consisting of approximately 4,422 square feet. The sub-lease originally expired on June 20, 2020. On June 19, 2020, the Company executed an amendment to extend the term of the sub-lease until July 31, 2020, on which date the sub-lease expired. The Company recognizes its minimum rental expense on a straight-line basis over the term of the lease beginning with the date of initial control of the asset. With the adoption of ASC 842 the Company recognized all leases with terms greater than 12 months in duration on its Consolidated Balance Sheets as right-of-use assets and lease liabilities as of January 1, 2019. The Company adopted the standard using the modified retrospective approach. The Company has made certain assumptions and judgments when applying ASC 842, the most significant of which are: • The Company elected the package of practical expedients available for transition which allow it to not (i) reassess whether expired or existing contracts contain leases under the new definition of a lease, (ii) determine lease classification for expired or existing leases and (iii) determine whether previously capitalized initial direct costs would qualify for capitalization under ASC 842. • The Company did not elect to use hindsight when considering judgments and estimates such as assessments of lessee options to extend or terminate a lease or purchase the underlying asset. • For all asset classes, the Company elected to not recognize a right-of-use asset and lease liability for short-term leases of less than 12 months. • For all asset classes, the Company elected to not separate non-lease components from lease components to which they relate and have accounted for the combined lease and non-lease components as a single lease component. • The Company use its incremental borrowing rate to calculate the present value of its lease payments, as the implicit rates in its leases are not readily determinable. As of December 31, 2020, assets under current lease were $3.5 million. The elements of lease expense were as follows (in thousands): For the Years Ended December 31, 2020 2019 Lease cost: Operating lease cost $ 3,981 $ 3,735 Sublease income (220 ) (199 ) Total Lease cost 3,761 3,536 Other information: Operating cash flows used for operating leases $ 3,592 $ 3,161 Operating lease liabilities arising from obtaining right-of-use assets $ 4,226 $ 11,321 Weighted-average remaining lease term in years 1.1 3.5 Weighted-average discount rate 10.37 % 10.37 % Future minimum lease payments under the operating lease as of December 31, 2020 are as follows (in thousands), excluding the new lease: Year Ending December 31, 2021 $ 3,880 2022 585 $ 4,465 Present value adjustment (239 ) Present value of lease liabilities $ 4,226 Future minimum lease payments under the operating lease as of December 31, 2019 are as follows (in thousands): Year Ending December 31, 2020 $ 3,592 2021 3,881 2022 3,997 2023 2,033 $ 13,503 Present value adjustment (2,182 ) Present value of lease liabilities $ 11,321 |
Income Taxes
Income Taxes | 12 Months Ended |
Dec. 31, 2020 | |
Income Tax Disclosure [Abstract] | |
Income Taxes | 12. Income Taxes During the years ended December 31, 2020, and 2019, the Company recorded $39.0 thousand, and $24.0 thousand income tax expense, respectively for the net operating losses incurred or for the research and development tax credits generated in each year due to its uncertainty of realizing a benefit from those items. The $39.0 thousand and $24.0 thousand recorded in 2020 and 2019 represent state income taxes. The company did not record income tax expense for the year ended December 31, 2018. A reconciliation of the U.S. federal statutory income tax rate to the Company’s effective income tax rate is as follows: Year Ended December 31, 2020 2019 2018 Federal statutory income tax rate 21.0 % 21.0 % 21.0 % State taxes, net of federal benefit 6.7 7.4 6.2 Federal and state research and development tax credit 6.6 4.7 4.1 Permanent items 1.2 3.3 (0.3 ) Other (0.1 ) — (0.1 ) Change in deferred tax asset valuation allowance (35.4 ) (36.4 ) (30.9 ) Effective income tax rate 0.0 % 0.0 % 0.0 % Net deferred tax assets consisted of the following (in thousands): December 31, 2020 2019 Deferred tax assets: Net operating loss carryforwards $ 120,270 $ 86,575 Research and development tax credit carryforwards 23,841 15,611 Depreciation and amortization 94 73 Other 6,998 6,154 Total deferred tax assets 151,203 108,413 Valuation allowance (150,236 ) (105,478 ) Deferred tax liabilities: $ 967 $ 2,935 Right of use assets (967 ) (2,935 ) Total deferred tax liabilities $ (967 ) $ (2,935 ) As of December 31, 2020, the Company had U.S. federal and state net operating loss carryforwards of $440.5 million and $439.5 million, respectively, which may be available to offset future income tax liabilities. Federal net operating loss carryforwards of $168.9 million will expire at various dates from 2028 to 2037. $271.6 million of the federal net operating loss can be carried forward indefinitely. State net operating loss carryforwards of $ 439.5 million will expire at various dates from 2030 to 203 9 . As of December 31, 2020, the Company had federal orphan drug credits of approximately $ 4.7 million which begin to expire in 2039 . As of December 31, 2020 , the Company also had U.S. federal and state research and development tax credit carryforwards of $ 14.8 million and $ 5.5 million, respectively, which may be available to offset future income tax liabilities and begin to expire in 2028 and 20 25 , respectively. Utilization of the U.S. federal and state net operating loss carryforwards and research and development tax credit carryforwards may be subject to a substantial annual limitation under Section 382 of the Internal Revenue Code of 1986, and corresponding provisions of state law, due to ownership changes that have occurred previously or that could occur in the future. These ownership changes may limit the amount of carryforwards that can be utilized annually to offset future taxable income. In general, an ownership change, as defined by Section 382, results from transactions increasing the ownership of certain stockholders or public groups in the stock of a corporation by more than 50% over a three-year The Company has evaluated the positive and negative evidence bearing upon its ability to realize the deferred tax assets. Management has considered the Company’s history of cumulative net losses incurred since inception and its lack of commercialization of any products or generation of any revenue from product sales since inception and has concluded that it is more likely than not that the Company will not realize all of the benefits of the deferred tax assets. Accordingly, a full valuation allowance has been established against the deferred tax assets as of December 31, 2020 and 2019. Management reevaluates the positive and negative evidence at each reporting period. Changes in the valuation allowance for deferred tax assets during the years ended December 31, 2020, 2019 and 2018 related primarily to the increase in net operating loss carryforwards and research and development tax credit carryforwards in 2020, 2019 and 2018, and were as follows (in thousands): Years Ended December 31, 2020 2019 2018 Valuation allowance as of beginning of year $ 105,478 $ 74,353 $ 55,813 Increases recorded to income tax provision 44,758 31,125 18,540 Valuation allowance as of end of year $ 150,236 $ 105,478 $ 74,353 As of December 31, 2020, 2019 and 2018, the Company had not recorded any amounts for unrecognized tax benefits. The Company’s policy is to record interest and penalties related to income taxes as part of its income tax provision. As of December 31, 2020, 2019, and 2018, the Company had no accrued interest or penalties related to uncertain tax positions and no amounts had been recognized in the Company’s statements of operations and comprehensive loss. The Company files income tax returns in the United States and Massachusetts. The federal and state income tax returns are generally subject to tax examinations for the tax years ended December 31, 2016 through December 31, 2019. To the extent the Company has tax attribute carryforwards, the tax years in which the attribute was generated may still be adjusted upon examination by the Internal Revenue Service or state taxing authorities to the extent utilized in a future period. No federal or state tax audits are currently in process. |
Commitments and Contingencies
Commitments and Contingencies | 12 Months Ended |
Dec. 31, 2020 | |
Commitments And Contingencies Disclosure [Abstract] | |
Commitments and Contingencies | 13. Commitments and Contingencies Research Agreements The LLS Agreement requires the Company to make certain milestone payments to LLS, that could total up to $25.0 million in the aggregate, upon the receipt of payments by the Company associated with the licensing or transfer of rights to the related compound (or a product) to a third party, upon first regulatory approval of a product in the U.S., or upon the first regulatory approval of a product in Europe or Japan. As of December 31, 2020, 2019 and 2018, no events have occurred that would require payment of the milestones. The Company has several in-license agreements with academic organizations. The Company is obligated to pay annual license maintenance fees of less than $0.1 million per year as well as reimburse certain institutions for costs incurred related to the filing, prosecution and maintenance of patent rights licensed under the agreements. In addition, the Company may be obligated to pay contingent milestone payments of up to a maximum of $15.7 million upon the achievement of certain defined events as well as royalties of low single-digit percentages of sales of licensed products. In certain cases, the maximum payments to the academic organizations are capped. If the Company grants any sublicense rights under the license agreements, the Company has agreed to pay a percentage of sublicense fees received by the Company to the licensors. As of December 31, 2020, 2019 and 2018, no events have occurred that would require payment of the milestones, royalties, or sublicense fees. 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 its executive officers that will require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is, in many cases, unlimited. To date, the Company has not incurred any material costs as a result of such indemnifications. The Company does not believe that the outcome of any claims under indemnification arrangements will have a material effect on its financial position, results of operations or cash flows, and it has not accrued any liabilities related to such obligations in its financial statements as of December 31, 2020, and 2019. Legal Proceedings The Company is not currently 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 FASB ASC Topic 450, Contingencies |
Net Loss and Net Loss Per Share
Net Loss and Net Loss Per Share | 12 Months Ended |
Dec. 31, 2020 | |
Earnings Per Share [Abstract] | |
Net Loss and Net Loss Per Share | 14. Net Loss and Net Loss Per Share 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): Years Ended December 31, 2020 2019 2018 Numerator: Net loss $ (126,357 ) $ (85,550 ) $ (59,925 ) Net loss attributable to common stockholders $ (126,357 ) $ (85,550 ) $ (59,925 ) Denominator: Weighted average common shares outstanding, basic and diluted 44,890,425 28,151,763 11,984,293 Net loss per share attributable to common stockholders, basic and diluted $ (2.81 ) $ (3.04 ) $ (5.00 ) 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 Company excluded the following potential common shares, presented based on amounts outstanding at each period end, from the computation of diluted net loss per share attributable to common stockholders for the periods indicated because including them would have had an anti-dilutive effect: December 31, 2020 2019 2018 Warrants for the purchase of common stock 54,469 84,576 95,930 Options to purchase common stock 5,330,917 4,211,068 3,779,403 Total 5,385,386 4,295,644 3,875,333 |
Retirement Plan
Retirement Plan | 12 Months Ended |
Dec. 31, 2020 | |
Compensation And Retirement Disclosure [Abstract] | |
Retirement Plan | 15. Retirement Plan The Company has a defined-contribution plan under Section 401(k) of the Internal Revenue Code (the “401(k) Plan”). The 401(k) Plan covers all employees who meet defined minimum age and service requirements and allows participants to defer a portion of their annual compensation on a pre-tax basis. As currently established, the Company is not required to make contributions to the 401(k) Plan. The Company made matching contributions of $0.6 million, $0.4 million and $0.3 million for the years ended December 31, 2020, 2019 and 2018, respectively. |
Selected Quarterly Financial Da
Selected Quarterly Financial Data (unaudited) | 12 Months Ended |
Dec. 31, 2020 | |
Quarterly Financial Information Disclosure [Abstract] | |
Selected Quarterly Financial Data (unaudited) | 16. Selected Quarterly Financial Data (unaudited) The following table contains selected consolidated quarterly financial information from 2020 and 2019. The Company believes that the following information reflects all normal recurring adjustments necessary for a fair statement of the information for the periods presented. The operating results for any quarter are not necessarily indicative of results for any future period. Three months ended March 31, 2020 June 30, 2020 September 30, 2020 December 31, 2020 (In thousands, except share and per share data) Total operating expenses $ 25,983 $ 29,587 $ 33,378 $ 35,899 Total other income (expense), net 554 (142 ) (398 ) (1,485 ) Net loss $ (25,444 ) $ (29,753 ) $ (33,776 ) $ (37,384 ) Net loss per share attributable to common stockholders, basic and diluted $ (0.61 ) $ (0.70 ) $ (0.71 ) $ (0.79 ) Weighted average common shares outstanding, basic and diluted 41,765,635 42,589,415 47,534,964 47,612,703 Three months ended March 31, 2019 June 30, 2019 September 30, 2019 December 31, 2019 (In thousands, except share and per share data) Total operating expenses $ 20,106 $ 20,841 $ 21,051 $ 24,057 Total other income (expense), net 680 74 (98 ) (127 ) Net loss $ (19,426 ) $ (20,767 ) $ (21,149 ) $ (24,208 ) Net loss per share attributable to common stockholders, basic and diluted $ (0.75 ) $ (0.80 ) $ (0.82 ) $ (0.69 ) Weighted average common shares outstanding, basic and diluted 25,804,595 25,809,556 25,829,105 35,086,817 |
Summary of Significant Accoun_2
Summary of Significant Accounting Policies (Policies) | 12 Months Ended |
Dec. 31, 2020 | |
Accounting Policies [Abstract] | |
Principles of Consolidation | Principles of Consolidation The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiary, Constellation Securities Corporation, which was established on December 21, 2018. All significant intercompany balances and transactions have been eliminated in consolidation. |
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 revenue and expenses during the reporting periods. Management considers many factors in selecting appropriate financial accounting policies and controls, and in developing the estimates and assumptions that are used in the preparation of these consolidated financial statements. Management must apply significant judgment in this process. In addition, other factors may affect estimates, including expected business and operational changes, sensitivity and volatility associated with the assumptions used in developing estimates, and whether historical trends are expected to be representative of future trends. The estimation process often may yield a range of potentially reasonable estimates of the ultimate future outcomes and management must select an amount that falls within that range of reasonable estimates. Estimates are periodically reviewed considering changes in circumstances, facts and historical experience. Actual results may differ from the Company’s estimates. Estimates are used in the following areas: prepaid and accrued research and development expenses, operating lease assets and liabilities, and stock-based compensation expenses. |
Concentrations of credit risk and of significant suppliers | Concentrations of credit risk and of significant suppliers Financial instruments that potentially expose the Company to concentrations of credit risk consist primarily of cash and cash equivalents. The Company maintains most of its cash and cash equivalents at two accredited financial institutions in amounts that exceed federally insured limits. Cash equivalents are invested in an institutional money market fund. The Company does not believe that it is subject to unusual credit risk beyond the normal credit risk associated with commercial banking relationships. The Company is dependent on third-party manufacturers to supply products for research and development activities in its programs. In particular, the Company relies and expects to continue to rely on a small number of manufacturers to supply it with its requirements for the active pharmaceutical ingredients and formulated drugs related to these programs. These programs could be adversely affected by a significant interruption in the supply of active pharmaceutical ingredients and formulated drugs. |
Deferred offering costs | Deferred offering costs The Company capitalizes certain legal, accounting and other third-party fees that are directly associated with in-process equity financings as deferred offering costs until such financings are consummated. After consummation of such equity financing, these costs are recorded in stockholders’ equity (deficit) as a reduction of additional paid-in capital generated as a result of the offering. Should the in-process equity financing be abandoned, the deferred offering costs will be expensed immediately as a charge to operating expenses in the statements of operations and comprehensive loss. |
Deferred financing costs | Deferred financing costs The Company capitalizes lender, legal and other third-party fees that are directly associated with obtaining access to capital under credit facilities. Debt issuance costs incurred in connection with obtaining access to capital are recorded in prepaid expenses and other current assets and are amortized over the availability period or term of the credit facility. Debt issuance costs related to a recognized debt liability are recorded as a direct reduction of the carrying amount of the debt liability. |
Property and equipment | Property and equipment Property and equipment are stated at cost less accumulated depreciation and amortization. Depreciation and amortization expense is recognized using the straight-line method over the estimated useful life of each asset as follows: Estimated Useful Life Laboratory equipment 3 years Computer equipment and software 3 years Furniture and fixtures 3 years Leasehold improvements Shorter of useful life or remaining lease term Upon retirement or sale, the cost of assets disposed of and the related accumulated depreciation and amortization are removed from the accounts and any resulting gain or loss is included in loss from operations. Expenditures for repairs and maintenance that do not improve or extend the lives of the respective assets are charged to expense as incurred, while costs of major additions and betterments are capitalized. |
Impairment of long-lived assets | Impairment of long-lived assets Long-lived assets consist of property and equipment. Long-lived assets to be held and used are tested for recoverability whenever events or changes in business circumstances indicate that the carrying amount of the assets may not be fully recoverable. Factors that the Company considers in deciding when to perform an impairment review include significant underperformance of the business in relation to expectations, significant negative industry or economic trends and significant changes or planned changes in the use of the assets. An impairment loss would be recognized in loss from operations when estimated undiscounted future cash flows expected to result from the use of an asset group are less than its carrying amount. The impairment loss would be based on the excess of the carrying value of the impaired asset group over its fair value, determined based on discounted cash flows. The Company did not record any impairment losses on long-lived assets during the years ended December 31, 2020, 2019, or 2018. The Company reduced the useful life for certain furniture and fixtures and leasehold improvements and therefor accelerated depreciation due to the lease amendment signed in November 2020 (see Note 11). |
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 are carried at fair value, determined according to the fair value hierarchy described above (see Note 3). |
Segment information | Segment information The Company manages its operations as a single segment for the purposes of assessing performance and making operating decisions. The Company’s singular focus is the development of novel therapeutics in the field of epigenetics. All of the Company’s tangible assets are held in the United States. |
Revenue recognition | Revenue recognition On January 1, 2018, the Company adopted the new revenue standard, which amended revenue recognition principles and provides a single, comprehensive set of criteria for revenue recognition within and across all industries (“ASC 606”). The Company will account for a contract with a customer that is within the scope of ASC 606 when all of the following criteria are met: (i) the arrangement has been approved by the parties and the parties are committed to perform their respective obligations, (ii) each party’s rights regarding the goods or services to be transferred can be identified, (iii) the payment terms for the goods or services to be transferred can be identified, (iv) the arrangement has commercial substance and (v) collection of substantially all of the consideration to which the Company will be entitled in exchange for the goods or services that will be transferred to the customer is probable. The Company estimates the transaction price based on the amount of consideration the Company expects to be received for transferring the promised goods or services in the contract. The consideration may include both fixed consideration and variable consideration. For each arrangement that includes variable consideration, the Company evaluates the amount of the potential payments and the likelihood that the payments will be received. The Company utilizes either the most likely amount method or expected value method to estimate the transaction price based on which method better predicts the amount of consideration expected to be received. If it is probable that a significant revenue reversal would not occur, the variable consideration is included in the transaction price. For arrangements that include development and regulatory milestone payments, the Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within the Company’s control or the licensee’s control, such as regulatory approvals, are not considered probable of being achieved until those approvals are received. At the end of each reporting period, the Company re-evaluates the probability of achievement of such milestones and any related constraint, and if necessary, adjusts the estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect collaboration revenue and net income (loss) in the period of adjustment. For sales-based royalties, including milestone payments based on the level of sales, the Company determines whether the sole or predominant item to which the royalties relate is a license. When the license is the sole or predominant item to which the sales-based royalty relates, the Company recognizes revenue at the later of: (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). The Company allocates the transaction price based on the estimated standalone selling price. The Company must develop assumptions that require judgment to determine the standalone selling price for each performance obligation identified in the contract. The Company utilizes key assumptions to determine the standalone selling price, which may include other comparable transactions, pricing considered in negotiating the transaction and the estimated costs. Certain variable consideration is allocated specifically to one or more performance obligations in a contract when the terms of the variable consideration relate to the satisfaction of the performance obligation and the resulting amounts allocated to each performance obligation are consistent with the amounts the Company would expect to receive for each performance obligation. For performance obligations which consist of licenses and other promises, the Company utilizes judgment to assess the nature of the combined performance obligation in order to determine whether the combined performance obligation is satisfied over time or at a point in time. The Company determines the appropriate method of measuring progress of combined performance obligations satisfied over time for purposes of recognizing revenue. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition. If the license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company will recognize revenue from non-refundable, up-front fees allocated to the license when the license is transferred to the customer and the customer is able to use and benefit from the license. |
Collaboration agreements | Collaboration agreements The Company analyzes its collaboration arrangements to assess whether they are within the scope of Topic 808 to determine whether such arrangements involve joint operating activities performed by parties that are both active participants in the activities and exposed to significant risks and rewards that are dependent on the commercial success of such activities. To the extent the arrangement is within the scope of ASC 808, the Company assesses whether aspects of the arrangement between the Company and its collaboration partner are within the scope of other accounting literature, including ASC 606. If it is concluded that some or all aspects of the arrangement represent a transaction with a customer, the Company will account for those aspects of the arrangement within the scope of ASC 606. Pursuant to ASC 606, a customer is a party that has contracted with an entity to obtain goods or services that are an output of the entity’s ordinary activities in exchange for consideration. Under ASC 606, an entity recognizes revenue when its customer obtains control of promised goods or services in an amount that reflects the consideration which the entity expects to receive in exchange for those goods or services. ASC 808 provides guidance for the presentation and disclosure of transactions in collaborative arrangements, but it does not provide recognition or measurement guidance. Therefore, if the Company concludes a counterparty to a transaction is not a customer or otherwise not within the scope of ASC 606, the Company considers the guidance in other accounting literature, including the guidance in ASC 606, as applicable or by analogy to account for such transaction. The classification of transactions under the Company’s arrangements is determined based on the nature and contractual terms of the arrangement along with the nature of the operations of the participants. In July 2012, the Company entered into a Research, Development and Commercialization Agreement (the “LLS Agreement”) with the Leukemia & Lymphoma Society (“LLS”) pursuant to which LLS committed to provide financial support (the “Funding”) to the Company for research and development services, conditional on (i) the achievement of milestones in accordance with the LLS Agreement and (ii) equal funding being provided by the Company. The Company concluded that the LLS Agreement was within the scope of the accounting guidance for collaboration arrangements (see Note 13). Due to the co-funded nature of the payments and the Company’s assessment that it did not have a vendor/customer relationship with LLS, the Company recognized the nonrefundable payments received under the agreement as a reduction to the research and development expenses incurred, based on a proportional methodology comparing the total expenses incurred in the period under the project to the total expenses expected to be incurred under the project. |
Research and development costs | Research and development costs Research and development costs are expensed as incurred. Research and development expenses are comprised of costs incurred in performing research and development activities, including salaries, stock-based compensation and benefits, facilities costs and laboratory supplies, depreciation, manufacturing expenses and external costs of outside vendors engaged to conduct preclinical development activities and clinical trials as well as the cost of licensing technology. Upfront payments and milestone payments made for the licensing of technology are expensed as research and development in the period in which they are incurred. Nonrefundable advance payments for goods or services to be received in the future for use in research and development activities are recorded as prepaid expenses. The prepaid amounts are expensed as the related goods are delivered or the services are performed. |
Accrued and prepaid Research and Development expenses | Accrued and prepaid Research and Development expenses The Company has entered into various research and development contracts with companies both inside and outside of the United States. These agreements are generally cancelable, and related payments are based on the terms of the individual arrangements, which may differ from the pattern of costs incurred, and are reflected on the consolidated balance sheet as accrued or prepaid research and development expenses. The Company records accruals for estimated ongoing research and development costs. When evaluating the adequacy of the accrued liabilities and/or prepaid expenses, the Company analyzes progress of the preclinical studies or clinical trials, including the phase or completion of events, invoices received and contracted costs. Significant judgments and estimates, based on information, including actual costs incurred or level of effort expanded, as provided by its vendors, are made in determining the accrued and prepaid balances at the end of any reporting period. Actual results could differ from the Company’s estimates. The Company’s historical accrual estimates have not been materially different from the actual costs. |
Patent costs | Patent costs All patent-related costs incurred in connection with filing and prosecuting patent applications are expensed as incurred due to the uncertainty about the recovery of the expenditure. Amounts incurred are classified as general and administrative expenses. |
Stock-based compensation | Stock-based compensation The Company measures stock-based awards granted to employees, directors and non-employees based on the fair value on the date of grant using the Black-Scholes option-pricing model. Compensation expense for those awards is recognized over the requisite service period, which is generally the vesting period of the respective award. The straight-line method of expense recognition is applied to all awards with service-only conditions, while the graded vesting method is applied to all grants with both service and performance conditions. The Company records the expense for stock-based compensation awards subject to performance-based milestone vesting when management determines that achievement of the milestone is probable. Management evaluates when the achievement of a performance-based milestone is probable based on the expected satisfaction of the performance conditions as of the reporting date. The Company classifies stock-based compensation expense in the consolidated statements of operations and comprehensive loss in the same manner, in which the award recipient’s salary and related costs are classified or in which the award recipient’s service payments are classified, as applicable. |
Marketable Securities | Marketable Securities All highly liquid investments with maturities of three months or less at the date of purchase are classified as cash equivalents. The Company’s investments in marketable debt securities have been classified and accounted for as available-for-sale. The Company classifies its marketable debt securities as either short-term or long-term based on each instrument’s underlying contractual maturity date. Unrealized gains and losses on marketable debt securities classified as available-for-sale are recognized in other comprehensive income/(loss) (“OCI”). The Company’s investments in marketable equity securities are classified based on the nature of the securities and their availability for use in current operations. The Company’s marketable equity securities are measured at fair value with gains and losses recognized in other income/(expense), net (“OI&E”). The cost of securities sold is determined using the specific identification method. |
Comprehensive loss | Comprehensive loss The Company’s only element of other comprehensive income (loss) is unrealized gains and losses on available-for-sale marketable securities. |
Cash, Cash Equivalents and Restricted Cash | Cash, Cash Equivalents and Restricted Cash Cash equivalents consists of highly liquid investments that are readily convertible into cash with original maturities of three months or less from the date of purchase. The Company has a policy of making investments only in government securities or with commercial institutions that have at least an investment grade credit rating. The Company invests its cash primarily in reverse repurchase agreements (RRAs), government securities and obligations, corporate debt securities and money market funds. RRAs are collateralized by deposits in the form of government securities and obligations for an amount not less than 102% of their value. The Company does not record an asset or liability as the Company is not permitted to sell or repledge the associated collateral. The Company has a policy that the collateral has at least the prevailing credit rating of US Government Treasuries and Agencies. The Company utilizes a third party custodian to manage the exchange of funds and ensure that collateral received is maintained at 102% of the value of the RRAs on a daily basis. RRAs have stated maturities of less than 30 days. As of December 31, 2020, the Company classified $3.2 million as restricted cash related to a letter of credit issued as a security deposit in connection with Company's lease of its corporate office facilities (Note 11). Cash, cash equivalents and restricted cash consists of the following (in thousands): December 31, 2020 2019 Cash and cash equivalents $ 163,693 $ 334,332 Restricted cash 3,233 425 Cash, cash equivalents and restricted cash $ 166,926 $ 334,757 |
Net income (loss) per share | Net income (loss) per share Basic net income (loss) per share attributable to common stockholders is computed by dividing the net income (loss) attributable to common stockholders by the weighted average number of common shares outstanding for the period. Diluted net income (loss) attributable to common stockholders is computed by adjusting net income (loss) attributable to common stockholders to reallocate undistributed earnings based on the potential impact of dilutive securities. Diluted net income (loss) per share attributable to common stockholders is computed by dividing the diluted net income (loss) attributable to common stockholders by the weighted average number of common shares outstanding for the period, including potential dilutive common shares assuming the dilutive effect of common stock equivalents. In periods in which the Company reports a net loss attributable to common stockholders, diluted net loss per share attributable to common stockholders is the same as basic net loss per share attributable to common stockholders, since dilutive common shares are not assumed to have been issued if their effect is anti-dilutive. The Company reported a net loss attributable to common stockholders for the years ended December 31, 2020, 2019 and 2018. |
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 financial statements or in the Company’s tax returns. Deferred tax assets and liabilities are determined on the basis of the differences between the financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. Changes in deferred tax assets and liabilities are recorded in the provision for income taxes. The Company assesses the likelihood that its deferred tax assets will be recovered from future taxable income and, to the extent it believes, based upon the weight of available evidence, that it is more likely than not that all or a portion of the deferred tax assets will not be realized, a valuation allowance is established through a charge to income tax expense. Potential for recovery of deferred tax assets is evaluated by estimating the future taxable profits expected and considering prudent and feasible tax planning strategies. The Company accounts for uncertainty in income taxes recognized in the financial statements by applying a two-step process to determine the amount of tax benefit to be recognized. First, the tax position must be evaluated to determine the likelihood that it will be sustained upon external examination by the taxing authorities. If the tax position is deemed more-likely-than-not to be sustained, the tax position is then assessed to determine the amount of benefit to recognize in the financial statements. The amount of the benefit that may be recognized is the largest amount that has a greater than 50% likelihood of being realized upon ultimate settlement. The provision for income taxes includes the effects of any resulting tax reserves, or unrecognized tax benefits, that are considered appropriate as well as the related net interest and penalties. |
Recently Adopted Accounting Pronouncements | Recently adopted accounting pronouncements In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Statements In July 2017, the FASB issued ASU No. 2017-11, Earnings Per Share (Topic 260), Distinguishing Liabilities from Equity (Topic 480), Derivatives and Hedging (Topic 815) I. Accounting for Certain Financial Instruments with Down Round Features II. Replacement of the Indefinite Deferral for Mandatorily Redeemable Financial Instruments of Certain Nonpublic Entities and Certain Mandatorily Redeemable Noncontrolling Interests with a Scope Exception . In August 2018, the FASB issued ASU No. 2018-13, Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement In August 2018, the FASB issued , Intangibles - Goodwill and Other - Internal-Use Software . This ASU addresses the accounting for implementation, setup and other upfront costs paid by a customer in a cloud computing or hosting arrangement. The guidance aligns the accounting treatment of these costs incurred in a hosting arrangement treated as a service contract with the requirements for capitalization and amortization costs to develop or obtain internal-use software. The guidance is effective for fiscal years beginning after December 15, 2019 and early adoption is permitted. The guidance can be adopted either retrospectively or prospectively. The adoption of ASU 2018-15 on January 1, 2020 prospectively did not have a material impact on the Company’s financial position, results of operations or cash flows. In November 2018, the FASB issued ASU No. 2018-18, Collaborative Arrangements (Topic 808), Clarifying the Interaction between Topic 808 and Topic 606. ASC 606 ASC 606 ASU 2018-18 The adoption of ASU 2018-18 on January 1, 2020 did not have a material impact on the Company’s financial position, results of operations or cash flows. In March 2019, the FASB issued ASU No. 2019-01, Leases (Topic 842) Codification Improvements |
Recently issued accounting pronouncements | Recently issued accounting pronouncements In December 2019, the FASB issued ASU 2019-12, Simplifying the Accounting for Income Taxes Income Taxes |
Summary of Significant Accoun_3
Summary of Significant Accounting Policies (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Accounting Policies [Abstract] | |
Schedule of Estimated Useful Life of Each Asset | Property and equipment are stated at cost less accumulated depreciation and amortization. Depreciation and amortization expense is recognized using the straight-line method over the estimated useful life of each asset as follows: Estimated Useful Life Laboratory equipment 3 years Computer equipment and software 3 years Furniture and fixtures 3 years Leasehold improvements Shorter of useful life or remaining lease term |
Schedule of Cash, Cash Equivalents And Restricted Cash | December 31, 2020 2019 Cash and cash equivalents $ 163,693 $ 334,332 Restricted cash 3,233 425 Cash, cash equivalents and restricted cash $ 166,926 $ 334,757 |
Fair Value Measurements (Tables
Fair Value Measurements (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Fair Value Disclosures [Abstract] | |
Schedule of Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis | The following tables present information about the Company’s financial assets and liabilities 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): December 31, 2020 Level 1 Level 2 Level 3 Total Cash equivalents: Money market funds $ 163,693 $ — $ — $ 163,693 $ 163,693 $ — $ — $ 163,693 Marketable securities: Corporate debt securities $ — $ 52,531 $ — $ 52,531 Commercial paper — 99,865 — 99,865 U.S. Government debt securities — 105,359 — 105,359 Total $ — $ 257,755 $ — $ 257,755 December 31, 2019 Level 1 Level 2 Level 3 Total Cash equivalents: Money market funds $ 303,345 $ — $ — $ 303,345 Commercial paper — 8,986 — 8,986 Corporate debt securities — 2,001 — 2,001 Reverse Repurchase Agreements (RRAs) — 20,000 — 20,000 $ 303,345 $ 30,987 $ — $ 334,332 Marketable securities: Corporate debt securities $ — $ 12,748 $ — $ 12,748 Commercial paper — 26,808 — 26,808 U.S. Government debt securities — 10,046 — 10,046 Total $ — $ 49,602 $ — $ 49,602 |
Marketable Securities (Tables)
Marketable Securities (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Cash And Cash Equivalents [Abstract] | |
Schedule of Marketable Securities and Cash Equivalents | The following table summarizes the Company’s marketable securities as of December 31, 2020 and 2019, respectively (in thousands): December 31, 2020 Amortized Cost Unrealized Gains Unrealized Losses Fair Value Marketable securities: Corporate debt securities $ 52,529 $ 6 $ (4 ) $ 52,531 Commercial paper 99,865 — — 99,865 U.S. Government debt securities 105,358 6 (5 ) 105,359 Total marketable securities $ 257,752 $ 12 $ (9 ) $ 257,755 December 31, 2019 Amortized Cost Unrealized Gains Unrealized Losses Fair Value Marketable securities: Corporate debt securities $ 12,753 $ — $ (5 ) $ 12,748 Commercial paper 26,808 — — 26,808 U.S. Government debt securities 10,047 — (1 ) 10,046 Total marketable securities $ 49,608 $ — $ (6 ) $ 49,602 |
Property and Equipment, net (Ta
Property and Equipment, net (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Property Plant And Equipment [Abstract] | |
Schedule of Property and Equipment, net | Property and equipment, net consisted of the following (in thousands): December 31, 2020 2019 Laboratory equipment $ 5,741 $ 5,411 Computer equipment and computer software 1,612 1,567 Furniture and fixtures 345 330 Leasehold improvements 624 466 8,322 7,774 Less: Accumulated depreciation and amortization (6,825 ) (6,803 ) $ 1,497 $ 971 |
Accrued Expenses and Other Cu_2
Accrued Expenses and Other Current Liabilities (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Payables And Accruals [Abstract] | |
Schedule of Accrued Expenses and Other Current Liabilities | Accrued expenses and other current liabilities consisted of the following (in thousands): December 31, 2020 2019 Accrued employee compensation and benefits $ 5,545 $ 4,527 Accrued external research and development expense 10,698 7,707 Accrued professional fees 467 184 Other 341 497 $ 17,051 $ 12,915 |
Debt (Tables)
Debt (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Debt Disclosure [Abstract] | |
Components of Notes Payable | As of December 31, 2019, notes payable consisted of the following (in thousands): December 31, 2019 Principal amount of term loans $ 30,000 Debt discount current portion — Less: Current portion — Long-term debt, net of current portion 30,000 Debt discount net of current portion (358 ) Long-term debt, net of discount and current portion $ 29,642 |
Equity (Tables)
Equity (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Equity [Abstract] | |
Schedule of Warrant Activities | The Company has outstanding warrants to purchase common stock as follows: Number of Common Shares Issuable under Warrant as of December 31, Issuance Date Term (in years) Exercise Price 2020 2019 May 23, 2011 10 $ 1.55 31,761 61,868 June 28, 2013 10 $ 13.22 7,569 — September 30, 2014 10 $ 13.22 15,139 22,708 54,469 84,576 |
Stock-Based Compensation (Table
Stock-Based Compensation (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] | |
Schedule of Weighted Average Basis Assumptions Used in Black-Scholes Option-Pricing Model | The following table presents, on a weighted average basis, the assumptions used in the Black-Scholes option-pricing model to determine the fair value of stock options granted to employees and directors Years Ended December 31, 2020 2019 2018 Risk-free interest rate 0.92 % 2.30 % 2.79 % Expected volatility 81.34 % 82.21 % 81.06 % Expected dividend yield — — — Expected term (in years) 6.05 6.03 6.05 |
Summary of Company's Option Activity | The following table summarizes the Company’s option activity since December 31, 2019 Weighted Weighted Average Average Aggregate Number Exercise Contractual Intrinsic of Shares Price Term Value (in years) (in thousands) Outstanding as of December 31, 2019 4,211,068 $ 8.95 8.39 160,689 Granted 1,812,582 32.25 Exercised (495,340 ) 7.93 Forfeited (197,393 ) 16.93 Outstanding as of December 31, 2020 5,330,917 $ 16.68 8.06 $ 74,259 Vested and expected to vest as of December 31, 2020 5,330,917 $ 16.68 8.06 $ 74,259 Options exercisable as of December 31, 2020 2,179,197 $ 10.69 7.33 $ 41,141 |
Schedule of Stock Based Compensation Expense Related to Statements of Operations and Comprehensive Loss | The Company recorded stock-based compensation expense in the following expense categories of its statements of operations and comprehensive loss (in thousands): Years Ended December 31, 2020 2019 2018 Research and development expenses $ 8,943 $ 2,703 $ 1,668 General and administrative expenses 5,843 4,207 2,284 Total $ 14,786 $ 6,910 $ 3,952 |
Leases (Tables)
Leases (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Leases [Abstract] | |
Elements of Lease Expense | As of December 31, 2020, assets under current lease were $3.5 million. The elements of lease expense were as follows (in thousands): For the Years Ended December 31, 2020 2019 Lease cost: Operating lease cost $ 3,981 $ 3,735 Sublease income (220 ) (199 ) Total Lease cost 3,761 3,536 Other information: Operating cash flows used for operating leases $ 3,592 $ 3,161 Operating lease liabilities arising from obtaining right-of-use assets $ 4,226 $ 11,321 Weighted-average remaining lease term in years 1.1 3.5 Weighted-average discount rate 10.37 % 10.37 % |
Schedule of Future Minimum Lease Payments Under the Operating Lease | Future minimum lease payments under the operating lease as of December 31, 2020 are as follows (in thousands), excluding the new lease: Year Ending December 31, 2021 $ 3,880 2022 585 $ 4,465 Present value adjustment (239 ) Present value of lease liabilities $ 4,226 Future minimum lease payments under the operating lease as of December 31, 2019 are as follows (in thousands): Year Ending December 31, 2020 $ 3,592 2021 3,881 2022 3,997 2023 2,033 $ 13,503 Present value adjustment (2,182 ) Present value of lease liabilities $ 11,321 |
Income Taxes (Tables)
Income Taxes (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Income Tax Disclosure [Abstract] | |
Reconciliation of U.S. Federal Statutory Income Tax Rate to Company’s Effective Income Tax Rate | A reconciliation of the U.S. federal statutory income tax rate to the Company’s effective income tax rate is as follows: Year Ended December 31, 2020 2019 2018 Federal statutory income tax rate 21.0 % 21.0 % 21.0 % State taxes, net of federal benefit 6.7 7.4 6.2 Federal and state research and development tax credit 6.6 4.7 4.1 Permanent items 1.2 3.3 (0.3 ) Other (0.1 ) — (0.1 ) Change in deferred tax asset valuation allowance (35.4 ) (36.4 ) (30.9 ) Effective income tax rate 0.0 % 0.0 % 0.0 % |
Schedule of Net Deferred Tax Assets | Net deferred tax assets consisted of the following (in thousands): December 31, 2020 2019 Deferred tax assets: Net operating loss carryforwards $ 120,270 $ 86,575 Research and development tax credit carryforwards 23,841 15,611 Depreciation and amortization 94 73 Other 6,998 6,154 Total deferred tax assets 151,203 108,413 Valuation allowance (150,236 ) (105,478 ) Deferred tax liabilities: $ 967 $ 2,935 Right of use assets (967 ) (2,935 ) Total deferred tax liabilities $ (967 ) $ (2,935 ) |
Schedule of Changes in Valuation Allowance for Deferred Tax Assets | Changes in the valuation allowance for deferred tax assets during the years ended December 31, 2020, 2019 and 2018 related primarily to the increase in net operating loss carryforwards and research and development tax credit carryforwards in 2020, 2019 and 2018, and were as follows (in thousands): Years Ended December 31, 2020 2019 2018 Valuation allowance as of beginning of year $ 105,478 $ 74,353 $ 55,813 Increases recorded to income tax provision 44,758 31,125 18,540 Valuation allowance as of end of year $ 150,236 $ 105,478 $ 74,353 |
Net Loss and Net Loss Per Sha_2
Net Loss and Net Loss Per Share (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Earnings Per Share [Abstract] | |
Calculations of Basic and Diluted 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): Years Ended December 31, 2020 2019 2018 Numerator: Net loss $ (126,357 ) $ (85,550 ) $ (59,925 ) Net loss attributable to common stockholders $ (126,357 ) $ (85,550 ) $ (59,925 ) Denominator: Weighted average common shares outstanding, basic and diluted 44,890,425 28,151,763 11,984,293 Net loss per share attributable to common stockholders, basic and diluted $ (2.81 ) $ (3.04 ) $ (5.00 ) |
Schedule of Anti-dilutive Securities Excluded from Computation of Diluted Net Loss Per Share | The Company excluded the following potential common shares, presented based on amounts outstanding at each period end, from the computation of diluted net loss per share attributable to common stockholders for the periods indicated because including them would have had an anti-dilutive effect: December 31, 2020 2019 2018 Warrants for the purchase of common stock 54,469 84,576 95,930 Options to purchase common stock 5,330,917 4,211,068 3,779,403 Total 5,385,386 4,295,644 3,875,333 |
Selected Quarterly Financial _2
Selected Quarterly Financial Data (Unaudited) (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Quarterly Financial Information Disclosure [Abstract] | |
Summary of Quarterly Financial Information | The following table contains selected consolidated quarterly financial information from 2020 and 2019. The Company believes that the following information reflects all normal recurring adjustments necessary for a fair statement of the information for the periods presented. The operating results for any quarter are not necessarily indicative of results for any future period. Three months ended March 31, 2020 June 30, 2020 September 30, 2020 December 31, 2020 (In thousands, except share and per share data) Total operating expenses $ 25,983 $ 29,587 $ 33,378 $ 35,899 Total other income (expense), net 554 (142 ) (398 ) (1,485 ) Net loss $ (25,444 ) $ (29,753 ) $ (33,776 ) $ (37,384 ) Net loss per share attributable to common stockholders, basic and diluted $ (0.61 ) $ (0.70 ) $ (0.71 ) $ (0.79 ) Weighted average common shares outstanding, basic and diluted 41,765,635 42,589,415 47,534,964 47,612,703 Three months ended March 31, 2019 June 30, 2019 September 30, 2019 December 31, 2019 (In thousands, except share and per share data) Total operating expenses $ 20,106 $ 20,841 $ 21,051 $ 24,057 Total other income (expense), net 680 74 (98 ) (127 ) Net loss $ (19,426 ) $ (20,767 ) $ (21,149 ) $ (24,208 ) Net loss per share attributable to common stockholders, basic and diluted $ (0.75 ) $ (0.80 ) $ (0.82 ) $ (0.69 ) Weighted average common shares outstanding, basic and diluted 25,804,595 25,809,556 25,829,105 35,086,817 |
Nature of the Business and Ba_2
Nature of the Business and Basis of Presentation - Additional Information (Detail) - USD ($) $ in Thousands | Jun. 19, 2020 | Dec. 31, 2020 | Sep. 30, 2020 | Jun. 30, 2020 | Mar. 31, 2020 | Dec. 31, 2019 | Sep. 30, 2019 | Jun. 30, 2019 | Mar. 31, 2019 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 |
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items] | ||||||||||||
Issuance of stock, net of issuance costs, shares | 5,500,000 | |||||||||||
Proceeds from common stock offerings, net of underwriting discounts and commissions | $ 180,700 | $ 180,727 | $ 307,027 | $ 55,801 | ||||||||
Net losses | $ 37,384 | $ 33,776 | $ 29,753 | $ 25,444 | $ 24,208 | $ 21,149 | $ 20,767 | $ 19,426 | 126,357 | 85,550 | $ 59,925 | |
Accumulated deficit | $ 445,744 | $ 319,387 | $ 445,744 | $ 319,387 | ||||||||
Common Stock [Member] | ||||||||||||
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items] | ||||||||||||
Issuance of stock, net of issuance costs, shares | 5,500,000 | |||||||||||
Proceeds from common stock offerings, net of underwriting discounts and commissions | $ 180,700 |
Summary of Significant Accoun_4
Summary of Significant Accounting Policies - Schedule of Estimated Useful Life of Each Asset (Detail) | 12 Months Ended |
Dec. 31, 2020 | |
Laboratory Equipment [Member] | |
Property Plant And Equipment [Line Items] | |
Estimated Useful Life | 3 years |
Computer Equipment and Software [Member] | |
Property Plant And Equipment [Line Items] | |
Estimated Useful Life | 3 years |
Furniture and Fixtures [Member] | |
Property Plant And Equipment [Line Items] | |
Estimated Useful Life | 3 years |
Leasehold Improvements [Member] | |
Property Plant And Equipment [Line Items] | |
Estimated Useful Life | Shorter of useful life or remaining lease term |
Summary of Significant Accoun_5
Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Significant Accounting Policies [Line Items] | |||
Impairment loss on long lived assets | $ 0 | $ 0 | $ 0 |
Percentage Securities for Reverse Repurchase Agreements | 102.00% | ||
Restricted cash | $ 3,233,000 | $ 425,000 | |
Letter of Credit [Member] | |||
Significant Accounting Policies [Line Items] | |||
Restricted cash | $ 3,200,000 | ||
Maximum [Member] | |||
Significant Accounting Policies [Line Items] | |||
Percentage Securities for Reverse Repurchase Agreements | 102.00% | ||
Reverse repurchase agreements maturity period | 30 days | ||
Minimum [Member] | |||
Significant Accounting Policies [Line Items] | |||
Percent likelihood for tax benefit amounts to be realized upon settlement | 50.00% |
Summary of Significant Accoun_6
Summary of Significant Accounting Policies - Schedule of Cash, Cash Equivalents and Restricted Cash (Detail) - USD ($) $ in Thousands | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017 |
Accounting Policies [Abstract] | ||||
Cash and cash equivalents | $ 163,693 | $ 334,332 | ||
Restricted cash | 3,233 | 425 | ||
Cash, cash equivalents and restricted cash | $ 166,926 | $ 334,757 | $ 115,017 | $ 16,646 |
Fair Value Measurements - Sched
Fair Value Measurements - Schedule of Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis (Detail) - USD ($) $ in Thousands | Dec. 31, 2020 | Dec. 31, 2019 |
Cash equivalents: | ||
Cash and cash equivalents | $ 163,693 | $ 334,332 |
Marketable securities: | ||
Marketable securities | 257,755 | 49,602 |
Commercial Paper [Member] | ||
Cash equivalents: | ||
Cash and cash equivalents | 8,986 | |
Marketable securities: | ||
Marketable securities | 99,865 | 26,808 |
US Government Corporations and Agencies Securities | ||
Marketable securities: | ||
Marketable securities | 105,359 | 10,046 |
Money Market Funds [Member] | ||
Cash equivalents: | ||
Cash and cash equivalents | 303,345 | |
Reverse Repurchase Agreements (RRAs) | ||
Cash equivalents: | ||
Cash and cash equivalents | 20,000 | |
Fair Value, Inputs, Level 1 [Member] | ||
Cash equivalents: | ||
Cash and cash equivalents | 163,693 | 303,345 |
Fair Value, Inputs, Level 1 [Member] | Money Market Funds [Member] | ||
Cash equivalents: | ||
Cash and cash equivalents | 303,345 | |
Fair Value, Inputs, Level 2 [Member] | ||
Cash equivalents: | ||
Cash and cash equivalents | 30,987 | |
Marketable securities: | ||
Marketable securities | 257,755 | 49,602 |
Fair Value, Inputs, Level 2 [Member] | Commercial Paper [Member] | ||
Cash equivalents: | ||
Cash and cash equivalents | 8,986 | |
Marketable securities: | ||
Marketable securities | 99,865 | 26,808 |
Fair Value, Inputs, Level 2 [Member] | US Government Corporations and Agencies Securities | ||
Marketable securities: | ||
Marketable securities | 105,359 | 10,046 |
Fair Value, Inputs, Level 2 [Member] | Reverse Repurchase Agreements (RRAs) | ||
Cash equivalents: | ||
Cash and cash equivalents | 20,000 | |
Money Market Funds [Member] | ||
Cash equivalents: | ||
Cash and cash equivalents | 163,693 | |
Money Market Funds [Member] | Fair Value, Inputs, Level 1 [Member] | ||
Cash equivalents: | ||
Cash and cash equivalents | 163,693 | |
Corporate Debt Securities [Member] | ||
Cash equivalents: | ||
Cash and cash equivalents | 2,001 | |
Marketable securities: | ||
Marketable securities | 52,531 | 12,748 |
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member] | ||
Cash equivalents: | ||
Cash and cash equivalents | 2,001 | |
Marketable securities: | ||
Marketable securities | $ 52,531 | $ 12,748 |
Fair Value Measurements - Addit
Fair Value Measurements - Additional Information (Detail) - USD ($) | 12 Months Ended | |
Dec. 31, 2020 | Dec. 31, 2019 | |
Fair Value Disclosures [Abstract] | ||
Fair value of assets transfers level 1 to level 2 | $ 0 | $ 0 |
Fair value of assets transfers level 2 to level 1 | 0 | 0 |
Fair value of asset transfers into level 3 | 0 | 0 |
Fair value of asset transfers out of level 3 | 0 | 0 |
Fair value of liabilities transfers level 1 to level 2 | 0 | 0 |
Fair value of liabilities transfers level 2 to level 1 | 0 | 0 |
Fair value of liabilities transfers into level 3 | 0 | 0 |
Fair value of liabilities transfers out of level 3 | $ 0 | $ 0 |
Marketable Securities - Schedul
Marketable Securities - Schedule of Marketable Securities and Cash Equivalents (Details) - USD ($) $ in Thousands | Dec. 31, 2020 | Dec. 31, 2019 |
Total marketable securities [Member] | ||
Cash And Cash Equivalents [Line Items] | ||
Amortized Cost | $ 257,752 | $ 49,608 |
Unrealized Gains | 12 | |
Unrealized Losses | (9) | (6) |
Fair Value | 257,755 | 49,602 |
U S Government Agencies Debt Securities [Member] | ||
Cash And Cash Equivalents [Line Items] | ||
Amortized Cost | 105,358 | 10,047 |
Unrealized Gains | 6 | |
Unrealized Losses | (5) | (1) |
Fair Value | 105,359 | 10,046 |
Corporate Debt Securities [Member] | ||
Cash And Cash Equivalents [Line Items] | ||
Amortized Cost | 52,529 | 12,753 |
Unrealized Gains | 6 | |
Unrealized Losses | (4) | (5) |
Fair Value | 52,531 | 12,748 |
Commercial Paper [Member] | ||
Cash And Cash Equivalents [Line Items] | ||
Amortized Cost | 99,865 | 26,808 |
Fair Value | $ 99,865 | $ 26,808 |
Property and Equipment, net - S
Property and Equipment, net - Schedule of Property and Equipment, net (Detail) - USD ($) $ in Thousands | Dec. 31, 2020 | Dec. 31, 2019 |
Property Plant And Equipment [Line Items] | ||
Property and equipment, gross | $ 8,322 | $ 7,774 |
Less: Accumulated depreciation and amortization | (6,825) | (6,803) |
Property and equipment, net | 1,497 | 971 |
Laboratory Equipment [Member] | ||
Property Plant And Equipment [Line Items] | ||
Property and equipment, gross | 5,741 | 5,411 |
Computer Equipment and Software [Member] | ||
Property Plant And Equipment [Line Items] | ||
Property and equipment, gross | 1,612 | 1,567 |
Furniture and Fixtures [Member] | ||
Property Plant And Equipment [Line Items] | ||
Property and equipment, gross | 345 | 330 |
Leasehold Improvements [Member] | ||
Property Plant And Equipment [Line Items] | ||
Property and equipment, gross | $ 624 | $ 466 |
Property and Equipment, net - A
Property and Equipment, net - Additional Information (Detail) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Property Plant And Equipment [Line Items] | |||
Depreciation and amortization expense | $ 0.6 | $ 0.8 | $ 0.6 |
Disposed of property and equipment gross book value and accumulated depreciation | $ 0.6 | 1.2 | |
Maximum [Member] | |||
Property Plant And Equipment [Line Items] | |||
Disposed of property and equipment gross book value and accumulated depreciation | $ 0.1 |
Accrued Expenses and Other Cu_3
Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Detail) - USD ($) $ in Thousands | Dec. 31, 2020 | Dec. 31, 2019 |
Payables And Accruals [Abstract] | ||
Accrued employee compensation and benefits | $ 5,545 | $ 4,527 |
Accrued external research and development expense | 10,698 | 7,707 |
Accrued professional fees | 467 | 184 |
Other | 341 | 497 |
Accrued expenses and other current liabilities | $ 17,051 | $ 12,915 |
Collaboration and Research Ag_2
Collaboration and Research Agreements - Additional Information (Detail) - LLS Agreement [Member] - USD ($) | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items] | |||
Milestone method revenue recognized | $ 0 | $ 0 | $ 7,300,000 |
Milestone payments maximum amount | $ 25,000,000 |
Debt - Additional Information (
Debt - Additional Information (Detail) - USD ($) $ in Thousands | Nov. 03, 2020 | Mar. 20, 2019 | Dec. 31, 2020 | Dec. 31, 2019 |
Debt Instrument [Line Items] | ||||
Loan amount | $ 30,000 | |||
Loss on extinguishment of debt | $ (1,501) | |||
Notes payable outstanding | 0 | |||
Loan Agreement [Member] | ||||
Debt Instrument [Line Items] | ||||
Loan amount | 30,000 | |||
Unused amount expired | $ 10,000 | |||
Debt instrument, interest rate terms | The term loan bore interest at an annual rate equal to the greater of 8.55% and the prime rate of interest plus 2.55%. | |||
Frequency of periodic payment | The Loan Agreement provided for interest-only payments until April 30, 2021, and repayment of the aggregate outstanding principal balance of the term loan in monthly installments starting on May 1, 2021 and continuing through April 1, 2023 (the “Maturity Date”). | |||
Loan Agreement maturity date | Apr. 1, 2023 | |||
Debt instrument, fee description | The Company paid a fee of $0.3 million upon closing and is required to pay a fee of 6.35% of the aggregate amount of advances under the Loan Agreement at maturity. | |||
Debt instrument closing fee | $ 1,900 | $ 300 | ||
Debt instrument, redemption, description | At its option, the Company could elect to prepay all or a portion of the outstanding advances by paying the entire principal balance (or a portion thereof) and all accrued and unpaid interest thereon plus a prepayment charge equal to the following percentage of the principal amount being prepaid: 2% if an advance was prepaid during the first 12 months following the applicable advance date, 1% if an advance was prepaid after 12 months but prior to 24 months following the applicable advance date, and 0.5% if an advance was prepaid any time after 24 months following the applicable advance date but prior to the Maturity Date. | |||
Debt instrument, Repaid amount | 30,000 | |||
Debt prepayment cost | 300 | |||
Loss on extinguishment of debt | $ (1,500) | |||
Loan Agreement [Member] | Maximum [Member] | ||||
Debt Instrument [Line Items] | ||||
Loan amount | $ 40,000 |
Debt - Components of Notes Paya
Debt - Components of Notes Payable (Detail) $ in Thousands | Dec. 31, 2019USD ($) |
Debt Disclosure [Abstract] | |
Principal amount of term loans | $ 30,000 |
Long-term debt, net of current portion | 30,000 |
Debt discount net of current portion | (358) |
Long-term debt, net of discount and current portion | $ 29,642 |
Equity - Additional Information
Equity - Additional Information (Detail) - USD ($) | Jun. 19, 2020 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 |
Class of Stock [Line Items] | ||||
Preferred stock, shares authorized | 5,000,000 | 5,000,000 | ||
Common stock, shares authorized | 200,000,000 | 200,000,000 | ||
Common stock, par value | $ 0.0001 | $ 0.0001 | ||
Sale of stock | 47,744,486 | 41,719,039 | ||
Shares issued | 5,500,000 | |||
Public offering price | $ 35 | |||
Net proceeds from issuance of initial public offering | $ 180,700,000 | $ 180,727,000 | $ 307,027,000 | $ 55,801,000 |
Warrants exercised | 30,107 | |||
Maximum [Member] | Sales Agreement [Member] | ||||
Class of Stock [Line Items] | ||||
Gross proceeds from issuance of common shares | $ 50,000,000 | |||
Common Stock [Member] | ||||
Class of Stock [Line Items] | ||||
Shares issued | 5,500,000 | |||
Net proceeds from issuance of initial public offering | $ 180,700,000 | |||
Common Stock [Member] | Sales Agreement [Member] | ||||
Class of Stock [Line Items] | ||||
Commission, percentage of gross proceeds of common stock | 3.00% | |||
Sale of stock | 0 |
Equity - Schedule of Warrant Ac
Equity - Schedule of Warrant Activities (Detail) - Common Stock [Member] - $ / shares | 12 Months Ended | |
Dec. 31, 2020 | Dec. 31, 2019 | |
Class Of Warrant Or Right [Line Items] | ||
Number of Common Shares Issuable under Warrant | 54,469 | 84,576 |
Warrant One [Member] | ||
Class Of Warrant Or Right [Line Items] | ||
Warrant Issue date | May 23, 2011 | |
Warrant Term | 10 years | |
Warrants exercise price | $ 1.55 | |
Number of Common Shares Issuable under Warrant | 31,761 | 61,868 |
Warrant Two [Member] | ||
Class Of Warrant Or Right [Line Items] | ||
Warrant Issue date | Jun. 28, 2013 | |
Warrant Term | 10 years | |
Warrants exercise price | $ 13.22 | |
Number of Common Shares Issuable under Warrant | 7,569 | |
Warrant Three [Member] | ||
Class Of Warrant Or Right [Line Items] | ||
Warrant Issue date | Sep. 30, 2014 | |
Warrant Term | 10 years | |
Warrants exercise price | $ 13.22 | |
Number of Common Shares Issuable under Warrant | 15,139 | 22,708 |
Stock-Based Compensation - Addi
Stock-Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions | Jan. 01, 2021 | Jun. 30, 2018 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||
Share-based compensation arrangement aggregate intrinsic value of stock options | $ 13.5 | $ 17.7 | $ 0.2 | ||
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value | $ 32.25 | $ 7.63 | $ 6.66 | ||
Unrecognized compensation cost unvested stock-based awards | $ 41.9 | ||||
Unvested stock based weighted average period | 2 years 10 months 9 days | ||||
Nonemployees [Member] | |||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||
Share-based compensation arrangement by share-based payment award, options, unnvested, number of shares | 7,322 | ||||
2018 Plan [Member] | |||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||
Number of shares reserved for issuance | 3,025,101 | ||||
Shares remained available for future issuance | 1,731,516 | ||||
2018 Plan [Member] | Subsequent Event | |||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||
Number of shares increased reserved for issuance under plan | 1,909,779 | ||||
2018 Plan [Member] | Maximum [Member] | |||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||
Shares of common stock available for issuance | 2,216,368 | ||||
Percentage of shares of common stock available for issuance | 4.00% | ||||
ESPP [Member] | |||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||
Number of shares reserved for issuance | 272,504 | ||||
Shares remained available for future issuance | 689,694 | ||||
ESPP [Member] | Subsequent Event | |||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||
Number of shares increased reserved for issuance under plan | 477,445 | ||||
ESPP [Member] | Maximum [Member] | |||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||||
Shares of common stock available for issuance | 545,008 | ||||
Percentage of shares of common stock available for issuance | 1.00% |
Stock-Based Compensation - Sche
Stock-Based Compensation - Schedule of Weighted Average Basis Assumptions Used in Black-Scholes Option-Pricing Model (Detail) - Valuation Technique, Option Pricing Model | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||
Risk-free interest rate | 0.92% | 2.30% | 2.79% |
Expected volatility | 81.34% | 82.21% | 81.06% |
Expected term (in years) | 6 years 18 days | 6 years 10 days | 6 years 18 days |
Stock-Based Compensation - Summ
Stock-Based Compensation - Summary of Company's Option Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands | 12 Months Ended | |
Dec. 31, 2020 | Dec. 31, 2019 | |
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] | ||
Number of Shares Outstanding, Beginning Balance | 4,211,068 | |
Number of Shares, Granted | 1,812,582 | |
Number of Shares, Exercised | (495,340) | |
Number of Shares, Forfeited | (197,393) | |
Number of Shares Outstanding, Ending Balance | 5,330,917 | 4,211,068 |
Number of Shares, Vested and expected to vest | 5,330,917 | |
Number of Shares, Options exercisable | 2,179,197 | |
Weighted Average Exercise Price Outstanding, Beginning Balance | $ 8.95 | |
Weighted Average Exercise Price, Granted | 32.25 | |
Weighted Average Exercise Price, Exercised | 7.93 | |
Weighted Average Exercise Price, Forfeited | 16.93 | |
Weighted Average Exercise Price Outstanding, Ending Balance | 16.68 | $ 8.95 |
Weighted Average Exercise Price, Vested and expected to vest | 16.68 | |
Weighted Average Exercise Price, Options exercisable | $ 10.69 | |
Weighted Average Contractual Term (in years) Outstanding | 8 years 21 days | 8 years 4 months 20 days |
Weighted Average Contractual Term (in years), Vested and expected to vest | 8 years 21 days | |
Weighted Average Contractual Term (in years), Options exercisable | 7 years 3 months 29 days | |
Aggregate Intrinsic Value Outstanding, Beginning Balance | $ 74,259 | $ 160,689 |
Aggregate Intrinsic Value, Vested and expected to vest | 74,259 | |
Aggregate Intrinsic Value, Options exercisable | $ 41,141 |
Stock-Based Compensation - Stoc
Stock-Based Compensation - Stock-Based Compensation Expense Related to Statements of Operations and Comprehensive Loss (Detail) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] | |||
Stock-based compensation | $ 14,786 | $ 6,910 | $ 3,952 |
Research and Development Expenses [Member] | |||
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] | |||
Stock-based compensation | 8,943 | 2,703 | 1,668 |
General and Administrative Expenses [Member] | |||
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] | |||
Stock-based compensation | $ 5,843 | $ 4,207 | $ 2,284 |
Leases - Additional Information
Leases - Additional Information (Detail) $ in Thousands | Jun. 19, 2020 | Jun. 30, 2019ft² | Dec. 31, 2020USD ($)ft² | Nov. 30, 2020 | Dec. 31, 2019USD ($) |
Leases [Line Items] | |||||
Office and laboratory space | ft² | 47,546 | ||||
Lease expiration date | Jun. 30, 2023 | ||||
Lessee, operating lease, option to extend | true | ||||
Lease term | 10 years | ||||
Description of Lease | In November 2020, the Company executed a lease in Watertown, Massachusetts (the “new lease”), which will commence around December 2021 upon taking control of the asset | ||||
Rent expenses | $ 5,600 | ||||
Percentage increase in ase rent of lease | 3.00% | ||||
Reduced rent duration In lease | 9 months | ||||
Secured letter of credit against facility lease | $ 2,800 | ||||
Operating lease, right-of-use assets | $ 3,541 | $ 10,745 | |||
2019 Sublease | |||||
Leases [Line Items] | |||||
Rentable office space under sublease | ft² | 4,422 | ||||
Sublease commencement date | Jul. 31, 2020 | ||||
Sublease expiration date | Jun. 20, 2020 | ||||
New Lease Term [Member] | |||||
Leases [Line Items] | |||||
Lessee, operating lease, option to extend | The Company has the option to extend the term by five years |
Leases - Elements of Lease Expe
Leases - Elements of Lease Expense (Detail) - USD ($) $ in Thousands | 12 Months Ended | |
Dec. 31, 2020 | Dec. 31, 2019 | |
Lease cost: | ||
Operating lease cost | $ 3,981 | $ 3,735 |
Sublease income | (220) | (199) |
Total Lease cost | 3,761 | 3,536 |
Operating cash flows used for operating leases | 3,592 | 3,161 |
Operating lease liabilities arising from obtaining right-of-use assets | $ 4,226 | $ 11,321 |
Weighted-average remaining lease term in years | 1 year 1 month 6 days | 3 years 6 months |
Weighted-average discount rate | 10.37% | 10.37% |
Leases - Schedule of Future Min
Leases - Schedule of Future Minimum Lease Payments Under the Operating Lease (Detail) - USD ($) $ in Thousands | Dec. 31, 2020 | Dec. 31, 2019 |
Leases [Abstract] | ||
2021 | $ 3,880 | $ 3,592 |
2022 | 585 | 3,881 |
2023 | 3,997 | |
2024 | 2,033 | |
Total future minimum lease payments | 4,465 | 13,503 |
Present value adjustment | (239) | (2,182) |
Present value of lease liabilities | $ 4,226 | $ 11,321 |
Income Taxes - Additional Infor
Income Taxes - Additional Information (Detail) - USD ($) | 12 Months Ended | |||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2011 | |
Income Taxes [Line Items] | ||||
Income tax expense | $ 39,000 | $ 24,000 | $ 0 | |
Operating loss and tax credit carryforwards limitations, threshold period for changes in ownership interest | 3 years | |||
Net operating loss carryforwards restrictive limitations amount | $ 1,900,000 | |||
Tax credit carryforward restrictive limitations amount | 100,000 | |||
Unrecognized tax benefits | 0 | 0 | 0 | |
Interest or penalties related to uncertain tax positions, accrued | $ 0 | 0 | 0 | |
Interest or penalties related to uncertain tax positions, recognized | $ 0 | $ 0 | ||
Income tax examination, description | No federal or state tax audits are currently in process. | |||
Minimum [Member] | ||||
Income Taxes [Line Items] | ||||
Operating loss and tax credit carryforwards limitations, threshold percentage of cumulative changes in ownership interest | 50.00% | |||
Percentage of change in ownership interest | 50.00% | |||
State [Member] | ||||
Income Taxes [Line Items] | ||||
Income tax expense | $ 39,000 | $ 24,000 | ||
Net operating loss carryforwards | 439,500,000 | |||
Income tax returns, tax period under examination | 2016 2017 2018 2019 | |||
State [Member] | Research and Development [Member] | ||||
Income Taxes [Line Items] | ||||
Tax credit carryforwards | $ 5,500,000 | |||
Tax credit carryforwards expiration year | 2025 | |||
State [Member] | Earliest Tax Year [Member] | ||||
Income Taxes [Line Items] | ||||
Operating loss carryforwards expiration year | 2030 | |||
State [Member] | Latest Tax Year [Member] | ||||
Income Taxes [Line Items] | ||||
Operating loss carryforwards expiration year | 2039 | |||
Federal [Member] | ||||
Income Taxes [Line Items] | ||||
Net operating loss carryforwards | $ 440,500,000 | |||
Net operating loss carryforwards, with expiration | 168,900,000 | |||
Net operating loss carryforwards carried forward | 271,600,000 | |||
Income tax returns, tax period under examination | 2016 2017 2018 2019 | |||
Federal [Member] | Research and Development [Member] | ||||
Income Taxes [Line Items] | ||||
Tax credit carryforwards | $ 14,800,000 | |||
Tax credit carryforwards expiration year | 2028 | |||
Federal [Member] | Orphan Drug [Member] | ||||
Income Taxes [Line Items] | ||||
Tax credit carryforwards | $ 4,700,000 | |||
Tax credit carryforwards expiration year | 2039 | |||
Federal [Member] | Earliest Tax Year [Member] | ||||
Income Taxes [Line Items] | ||||
Operating loss carryforwards expiration year | 2028 | |||
Federal [Member] | Latest Tax Year [Member] | ||||
Income Taxes [Line Items] | ||||
Operating loss carryforwards expiration year | 2037 |
Income Taxes - Reconciliation o
Income Taxes - Reconciliation of U.S. Federal Statutory Income Tax Rate to Company's Effective Income Tax Rate (Detail) | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Income Tax Disclosure [Abstract] | |||
Federal statutory income tax rate | 21.00% | 21.00% | 21.00% |
State taxes, net of federal benefit | 6.70% | 7.40% | 6.20% |
Federal and state research and development tax credit | 6.60% | 4.70% | 4.10% |
Permanent items | 1.20% | 3.30% | (0.30%) |
Other | (0.10%) | (0.10%) | |
Change in deferred tax asset valuation allowance | (35.40%) | (36.40%) | (30.90%) |
Effective income tax rate | 0.00% | 0.00% | 0.00% |
Income Taxes - Schedule of Net
Income Taxes - Schedule of Net Deferred Tax Assets (Detail) - USD ($) $ in Thousands | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017 |
Deferred tax assets: | ||||
Net operating loss carryforwards | $ 120,270 | $ 86,575 | ||
Research and development tax credit carryforwards | 23,841 | 15,611 | ||
Depreciation and amortization | 94 | 73 | ||
Other | 6,998 | 6,154 | ||
Total deferred tax assets | 151,203 | 108,413 | ||
Valuation allowance | (150,236) | (105,478) | $ (74,353) | $ (55,813) |
Deferred tax liabilities: | 967 | 2,935 | ||
Right of use assets | (967) | (2,935) | ||
Total deferred tax liabilities | $ (967) | $ (2,935) |
Income Taxes - Schedule of Chan
Income Taxes - Schedule of Changes in Valuation Allowance for Deferred Tax Assets (Detail) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Income Tax Disclosure [Abstract] | |||
Valuation allowance as of beginning of year | $ 105,478 | $ 74,353 | $ 55,813 |
Increase (Decreases) recorded as expense (benefit) to income tax provision | 44,758 | 31,125 | 18,540 |
Valuation allowance as of end of year | $ 150,236 | $ 105,478 | $ 74,353 |
Commitments and Contingencies -
Commitments and Contingencies - Additional Information (Detail) - USD ($) | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Commitments And Contingencies [Line Items] | |||
License maintenance fees | $ 100,000 | ||
Contingent milestone payments | 15,700,000 | ||
Research and development expense | 95,501,000 | $ 66,459,000 | $ 48,769,000 |
Contingency reserve for litigation liabilities | 0 | 0 | |
License Fees [Member] | Maximum [Member] | |||
Commitments And Contingencies [Line Items] | |||
Research and development expense | 0 | $ 0 | $ 0 |
LLS Agreement [Member] | |||
Commitments And Contingencies [Line Items] | |||
Milestone payments maximum amount | $ 25,000,000 |
Net Loss and Net Loss Per Sha_3
Net Loss and Net Loss Per Share - Calculations of Basic and Diluted Net Loss per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands | 3 Months Ended | 12 Months Ended | |||||||||
Dec. 31, 2020 | Sep. 30, 2020 | Jun. 30, 2020 | Mar. 31, 2020 | Dec. 31, 2019 | Sep. 30, 2019 | Jun. 30, 2019 | Mar. 31, 2019 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Numerator: | |||||||||||
Net loss | $ (37,384) | $ (33,776) | $ (29,753) | $ (25,444) | $ (24,208) | $ (21,149) | $ (20,767) | $ (19,426) | $ (126,357) | $ (85,550) | $ (59,925) |
Net loss attributable to common stockholders | $ (126,357) | $ (85,550) | $ (59,925) | ||||||||
Denominator: | |||||||||||
Weighted average common shares outstanding, basic and diluted | 47,612,703 | 47,534,964 | 42,589,415 | 41,765,635 | 35,086,817 | 25,829,105 | 25,809,556 | 25,804,595 | 44,890,425 | 28,151,763 | 11,984,293 |
Net loss per share attributable to common stockholders, basic and diluted | $ (0.79) | $ (0.71) | $ (0.70) | $ (0.61) | $ (0.69) | $ (0.82) | $ (0.80) | $ (0.75) | $ (2.81) | $ (3.04) | $ (5) |
Net Loss and Net Loss Per Sha_4
Net Loss and Net Loss Per Share - Schedule of Anti-dilutive Securities Excluded from Computation of Diluted Net Loss Per Share (Detail) - shares | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | |||
Anti-dilutive securities | 5,385,386 | 4,295,644 | 3,875,333 |
Warrants for the purchase of common stock [Member] | |||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | |||
Anti-dilutive securities | 54,469 | 84,576 | 95,930 |
Options to purchase common stock [Member] | |||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | |||
Anti-dilutive securities | 5,330,917 | 4,211,068 | 3,779,403 |
Retirement Plan - Additional In
Retirement Plan - Additional Information (Detail) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Compensation And Retirement Disclosure [Abstract] | |||
Matching contributions made | $ 0.6 | $ 0.4 | $ 0.3 |
Defined Contribution Plan, Plan Name [Extensible List] | us-gaap:RetirementPlanNameOtherMember |
Selected Quarterly Financial _3
Selected Quarterly Financial Data (unaudited) - Summary of Quarterly Financial Information (Detail) - USD ($) $ / shares in Units, $ in Thousands | 3 Months Ended | 12 Months Ended | |||||||||
Dec. 31, 2020 | Sep. 30, 2020 | Jun. 30, 2020 | Mar. 31, 2020 | Dec. 31, 2019 | Sep. 30, 2019 | Jun. 30, 2019 | Mar. 31, 2019 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Quarterly Financial Information Disclosure [Abstract] | |||||||||||
Total operating expenses | $ 35,899 | $ 33,378 | $ 29,587 | $ 25,983 | $ 24,057 | $ 21,051 | $ 20,841 | $ 20,106 | $ 124,847 | $ 86,055 | $ 61,244 |
Total other income (expense), net | (1,485) | (398) | (142) | 554 | (127) | (98) | 74 | 680 | (1,471) | 529 | 1,319 |
Net loss | $ (37,384) | $ (33,776) | $ (29,753) | $ (25,444) | $ (24,208) | $ (21,149) | $ (20,767) | $ (19,426) | $ (126,357) | $ (85,550) | $ (59,925) |
Net loss per share attributable to common stockholders, basic and diluted | $ (0.79) | $ (0.71) | $ (0.70) | $ (0.61) | $ (0.69) | $ (0.82) | $ (0.80) | $ (0.75) | $ (2.81) | $ (3.04) | $ (5) |
Weighted average common shares outstanding, basic and diluted | 47,612,703 | 47,534,964 | 42,589,415 | 41,765,635 | 35,086,817 | 25,829,105 | 25,809,556 | 25,804,595 | 44,890,425 | 28,151,763 | 11,984,293 |