Document and Entity Information
Document and Entity Information - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Mar. 12, 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 | AGLE | ||
Entity Registrant Name | AEGLEA BIOTHERAPEUTICS, INC. | ||
Entity Central Index Key | 0001636282 | ||
Current Fiscal Year End Date | --12-31 | ||
Entity Filer Category | Non-accelerated Filer | ||
Entity Well-known Seasoned Issuer | No | ||
Entity Current Reporting Status | Yes | ||
Entity Voluntary Filers | No | ||
Entity Common Stock Shares Outstanding | 48,015,892 | ||
Entity Public Float | $ 386 | ||
Entity Shell Company | false | ||
Entity Emerging Growth Company | true | ||
Entity Ex Transition Period | true | ||
Entity Small Business | true | ||
ICFR Auditor Attestation Flag | false | ||
Title of 12(b) Security | Common Stock, $0.0001 Par Value Per Share | ||
Security Exchange Name | NASDAQ | ||
Entity File Number | 001-37722 | ||
Entity Tax Identification Number | 46-4312787 | ||
Entity Address, Address Line One | 805 Las Cimas Parkway | ||
Entity Address, Address Line Two | Suite 100 | ||
Entity Address, City or Town | Austin | ||
Entity Address, Postal Zip Code | 78746 | ||
City Area Code | 512 | ||
Local Phone Number | 942-2935 | ||
Entity Address, State or Province | TX | ||
Entity Incorporation, State or Country Code | DE | ||
Document Annual Report | true | ||
Document Transition Report | false | ||
Entity Interactive Data Current | Yes | ||
Documents Incorporated by Reference [Text Block] | Portions of the Registrant’s Definitive Proxy Statement (“Proxy Statement”) relating to the 2021 Annual Meeting of Stockholders will be filed with the Commission within 120 days after the end of the Registrant’s 2020 fiscal year and is incorporated by reference into Part III of this Report. |
Consolidated Balance Sheets
Consolidated Balance Sheets - USD ($) $ in Thousands | Dec. 31, 2020 | Dec. 31, 2019 |
CURRENT ASSETS | ||
Cash and cash equivalents | $ 90,095 | $ 19,253 |
Marketable securities | 56,178 | 52,696 |
Prepaid expenses and other current assets | 3,516 | 2,556 |
Total current assets | 149,789 | 74,505 |
Restricted cash | 1,842 | 1,500 |
Property and equipment, net | 5,642 | 2,385 |
Operating lease right-of-use assets | 4,230 | 4,726 |
Other non-current assets | 115 | 67 |
TOTAL ASSETS | 161,618 | 83,183 |
CURRENT LIABILITIES | ||
Accounts payable | 2,254 | 3,154 |
Operating lease liabilities | 319 | 351 |
Accrued and other current liabilities | 13,870 | 14,854 |
Total current liabilities | 16,443 | 18,359 |
Non-current operating lease liabilities | 5,129 | 4,712 |
Other non-current liabilities | 214 | 31 |
TOTAL LIABILITIES | 21,786 | 23,102 |
Commitments and Contingencies (Note 14) | ||
STOCKHOLDERS’ EQUITY | ||
Preferred stock, $0.0001 par value; 10,000,000 shares authorized as ofDecember 31, 2020 and 2019; no shares issued and outstanding as ofDecember 31, 2020 and 2019 | ||
Common stock, $0.0001 par value; 500,000,000 shares authorized as of December 31, 2020 and 2019, 47,959,086 shares and 29,084,437 shares issued and outstanding as of December 31, 2020 and 2019, respectively | 5 | 3 |
Additional paid-in capital | 415,824 | 255,142 |
Accumulated other comprehensive income | 11 | 51 |
Accumulated deficit | (276,008) | (195,115) |
TOTAL STOCKHOLDERS’ EQUITY | 139,832 | 60,081 |
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY | $ 161,618 | $ 83,183 |
Consolidated Balance Sheets (Pa
Consolidated Balance Sheets (Parenthetical) - $ / shares | Dec. 31, 2020 | Dec. 31, 2019 |
Statement Of Financial Position [Abstract] | ||
Preferred stock, par value | $ 0.0001 | $ 0.0001 |
Preferred stock, shares authorized | 10,000,000 | 10,000,000 |
Preferred stock, shares issued | 0 | 0 |
Preferred stock, shares outstanding | 0 | 0 |
Common stock, par value | $ 0.0001 | $ 0.0001 |
Common stock, shares authorized | 500,000,000 | 500,000,000 |
Common stock, shares issued | 47,959,086 | 29,084,437 |
Common stock, shares outstanding | 47,959,086 | 29,084,437 |
Consolidated Statements of Oper
Consolidated Statements of Operations - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Revenues: | |||
Grant | $ 0 | $ 0 | $ 3,888 |
Type of revenue [extensible list] | us-gaap:GrantMember | us-gaap:GrantMember | us-gaap:GrantMember |
Operating expenses: | |||
Research and development | $ 59,638 | $ 64,600 | $ 36,719 |
General and administrative | 21,843 | 15,734 | 12,632 |
Total operating expenses | 81,481 | 80,334 | 49,351 |
Loss from operations | (81,481) | (80,334) | (45,463) |
Other income (expense): | |||
Interest income | 593 | 2,143 | 1,172 |
Other expense, net | (5) | (63) | (57) |
Total other income | 588 | 2,080 | 1,115 |
Net loss | $ (80,893) | $ (78,254) | $ (44,348) |
Net loss per share, basic and diluted | $ (1.52) | $ (2.45) | $ (2.13) |
Weighted-average common shares outstanding, basic and diluted | 53,371,730 | 31,949,633 | 20,822,560 |
Consolidated Statements of Comp
Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Statement Of Income And Comprehensive Income [Abstract] | |||
Net loss | $ (80,893) | $ (78,254) | $ (44,348) |
Other comprehensive income (loss): | |||
Foreign currency translation adjustment | 19 | ||
Unrealized (loss) gain on marketable securities | (59) | 78 | 75 |
Total comprehensive loss | $ (80,933) | $ (78,176) | $ (44,273) |
Consolidated Statements of Chan
Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands | Total | Common Stock | Additional Paid-in Capital | Accumulated Other Comprehensive Income (Loss) | Accumulated Deficit |
Balances at Dec. 31, 2017 | $ 50,337 | $ 2 | $ 122,950 | $ (102) | $ (72,513) |
Balances (in shares) at Dec. 31, 2017 | 16,670,000 | ||||
Issuance of common stock in connection with employee stock purchase plan | 207 | 207 | |||
Issuance of common stock in connection with employee stock purchase plan (in shares) | 56,000 | ||||
Issuance of common stock in connection with exercise of stock options | 2,829 | 2,829 | |||
Issuance of common stock in connection with exercise of stock options (in shares) | 521,000 | ||||
Issuance of common stock in connection with public and at-the-market offerings, net of offering costs | 54,048 | 54,048 | |||
Issuance of common stock in connection with public and at-the-market offerings, net of offering costs (in shares) | 6,893,000 | ||||
Stock-based compensation expense | 4,280 | 4,280 | |||
Unrealized (loss) gain on marketable securities | 75 | 75 | |||
Net loss | (44,348) | (44,348) | |||
Balances at Dec. 31, 2018 | 67,428 | $ 2 | 184,314 | (27) | (116,861) |
Balances (in shares) at Dec. 31, 2018 | 24,140,000 | ||||
Issuance of common stock in connection with employee stock purchase plan | 307 | 307 | |||
Issuance of common stock in connection with employee stock purchase plan (in shares) | 45,000 | ||||
Issuance of common stock in connection with exercise of stock options | 1,143 | 1,143 | |||
Issuance of common stock in connection with exercise of stock options (in shares) | 274,000 | ||||
Issuance of common stock and pre-funded warrants in connection with public and at-the-market offerings, net of offering costs | 64,503 | $ 1 | 64,502 | ||
Issuance of common stock and pre-funded warrants in connection with public and at-the-market offerings, net of offering costs (in shares) | 4,625,000 | ||||
Stock-based compensation expense | 4,876 | 4,876 | |||
Unrealized (loss) gain on marketable securities | 78 | 78 | |||
Net loss | (78,254) | (78,254) | |||
Balances at Dec. 31, 2019 | 60,081 | $ 3 | 255,142 | 51 | (195,115) |
Balances (in shares) at Dec. 31, 2019 | 29,084,000 | ||||
Issuance of common stock in connection with employee stock purchase plan | 366 | 366 | |||
Issuance of common stock in connection with employee stock purchase plan (in shares) | 60,000 | ||||
Issuance of common stock in connection with exercise of stock options | $ 490 | 490 | |||
Issuance of common stock in connection with exercise of stock options (in shares) | 127,376 | 127,000 | |||
Issuance of common stock and pre-funded warrants in connection with public and at-the-market offerings, net of offering costs | $ 153,572 | $ 2 | 153,570 | ||
Issuance of common stock and pre-funded warrants in connection with public and at-the-market offerings, net of offering costs (in shares) | 18,688,000 | ||||
Stock-based compensation expense | 6,256 | 6,256 | |||
Foreign currency translation adjustment | 19 | 19 | |||
Unrealized (loss) gain on marketable securities | (59) | (59) | |||
Net loss | (80,893) | (80,893) | |||
Balances at Dec. 31, 2020 | $ 139,832 | $ 5 | $ 415,824 | $ 11 | $ (276,008) |
Balances (in shares) at Dec. 31, 2020 | 47,959,000 |
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 | $ (80,893) | $ (78,254) | $ (44,348) |
Adjustments to reconcile net loss to net cash used in operating activities: | |||
Depreciation and amortization | 996 | 418 | 293 |
Purchase net (premium) discount on marketable securities | (286) | 504 | 907 |
Net amortization of premium (accretion of discount) on marketable securities | 73 | (818) | (593) |
Stock-based compensation | 6,256 | 4,876 | 4,280 |
Research and development services settled with stock | 107 | ||
Non-cash operating lease expense | 628 | 483 | |
Other | (9) | (5) | (40) |
Changes in operating assets and liabilities: | |||
Accounts receivable - grant | 3,078 | ||
Prepaid expenses and other assets | (1,101) | (346) | (261) |
Accounts payable | (544) | 2,583 | 239 |
Deferred revenue | (20) | ||
Operating lease liabilities | 251 | (258) | |
Accrued and other liabilities | (1,146) | 5,125 | 4,165 |
Net cash used in operating activities | (75,775) | (65,692) | (32,193) |
CASH FLOWS FROM INVESTING ACTIVITIES | |||
Purchases of property and equipment | (4,280) | (1,492) | (422) |
Purchases of marketable securities | (129,000) | (91,926) | (62,179) |
Proceeds from maturities and sales of marketable securities | 125,676 | 91,679 | 47,370 |
Net cash used in investing activities | (7,604) | (1,739) | (15,231) |
CASH FLOWS FROM FINANCING ACTIVITIES | |||
Proceeds from issuance of common stock and pre-funded warrants in public and at-the-market offerings, net of offering costs | 153,716 | 64,298 | 54,048 |
Proceeds from employee stock plan purchases and stock option exercises | 816 | 1,450 | 3,020 |
Principal payments on finance lease obligation | (20) | (25) | |
Net cash provided by financing activities | 154,512 | 65,723 | 57,068 |
Effect of exchange rate on cash, cash equivalents, and restricted cash | 51 | ||
NET INCREASE (DECREASE) IN CASH, CASH EQUIVALENTS, AND RESTRICTED CASH | 71,184 | (1,708) | 9,644 |
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH | |||
Beginning of period | 20,753 | 22,461 | 12,817 |
End of period | 91,937 | 20,753 | 22,461 |
Supplemental Disclosure of Non-Cash Investing and Financing Information: | |||
Leased assets obtained in exchange for lease obligations | 172 | 5,294 | |
Unpaid amounts related to purchase of property and equipment | $ 224 | $ 356 | $ 92 |
The Company and Basis of Presen
The Company and Basis of Presentation | 12 Months Ended |
Dec. 31, 2020 | |
Organization Consolidation And Presentation Of Financial Statements [Abstract] | |
The Company and Basis of Presentation | 1. The Company and Basis of Presentation Aeglea BioTherapeutics, Inc. (“Aeglea” or the “Company”) is a clinical-stage biotechnology company redefining the potential of human enzyme therapeutics to benefit people with rare metabolic diseases with limited treatment options. The Company was formed as a Limited Liability Company (LLC) in Delaware on December 16, 2013 under the name Aeglea BioTherapeutics Holdings, LLC and was converted from a Delaware LLC to a Delaware corporation on March 10, 2015. The Company operates in one segment and has its principal offices in Austin, Texas. Liquidity As of December 31, 2020, the Company had working capital of $133.3 million, an accumulated deficit of $276.0 million, and cash, cash equivalents, marketable securities, and restricted cash of $148.1 million. The Company has not generated any product revenues and has not achieved profitable operations. There is no assurance that profitable operations will ever be achieved, and, if achieved, could be sustained on a continuing basis. In addition, development activities, clinical and nonclinical testing, and commercialization of the Company’s products will require significant additional financing. The Company is subject to a number of risks similar to other life science companies, including, but not limited to, risks related to the successful discovery, development, and commercialization of product candidates, raising additional capital, development of competing drugs and therapies, protection of proprietary technology and market acceptance of the Company’s products. As a result of these and other factors and the related uncertainties, there can be no assurance of the Company’s future success. Based upon the Company’s current operating plans, the Company believes that it has sufficient resources to fund operations into 2023 with its existing cash, cash equivalents, and marketable securities. The Company will need to secure additional funding in the future, in order to carry out all of its planned research and development activities. If the Company is unable to obtain additional financing or generate license or product revenue, the lack of liquidity could have a material adverse effect on the Company’s future prospects. Basis of Presentation The consolidated financial statements have been prepared in conformity with generally accepted accounting principles in the United States (“U.S. GAAP”) as defined by the Financial Accounting Standards Board (“FASB”) and include the accounts of the Company and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. |
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 Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Such management estimates include those related to accruals of research and development related costs, stock-based compensation, and certain company income tax related items. Management bases its estimates on historical experience and on various other market-specific and relevant assumptions that management believes to be reasonable under the circumstances. Actual results could differ significantly from those estimates. Cash and Cash Equivalents The Company considers all highly liquid investments with original maturities of three months or less from the date of purchase to be cash equivalents. Cash equivalents consist of money market funds and debt securities and are stated at fair value. Marketable Securities All investments have been classified as available-for-sale and are carried at estimated fair value as determined based upon quoted market prices or pricing models for similar securities. Management determines the appropriate classification of its investments in debt securities at the time of purchase. The Company may or may not hold securities with stated maturities greater than one year until maturity. All available-for-sale securities are considered available to support current operations and are classified as current assets. The Company presents credit losses as an allowance rather than as a reduction in the amortized cost of the available-for-sale securities. For available-for-sale debt securities in an unrealized loss position, the Company first assesses whether it intends to sell, or it is more likely than not that it will be required to sell the security before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the security’s amortized cost basis is written down to fair value and recognized in other income (expense) in the results of operations. For available-for-sale debt securities that do not meet the aforementioned criteria, the Company evaluates whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, management considers the extent to which fair value is less than amortized cost, any changes to the rating of the security by a rating agency, and adverse conditions specifically related to the security, among other factors. If this assessment indicates that a credit loss exists, an allowance is recorded for the difference between the present value of cash flows expected to be collected and the amortized cost basis of the security. Impairment l Any unrealized losses from declines in fair value below the amortized cost basis as a result of non-credit loss factors is recognized as a component of accumulated other comprehensive (loss) income, along with unrealized gains. Realized gains and losses and declines in fair value, if any, on available-for-sale securities are included in other income (expense) in the results of operations. The cost of securities sold is based on the specific-identification method. Restricted Cash Restricted cash consists of money market accounts held by financial institutions as collateral for the Company’s obligations under a credit agreement and a facility lease for the Company’s corporate headquarters in Austin, TX. Concentration of Credit Risk Financial instruments that potentially subject the Company to a concentration of credit risk consist of cash, cash equivalents, marketable securities, and restricted cash. The Company’s investment policy limits investments to high credit quality securities issued by the U.S. government, U.S. government-sponsored agencies, highly rated banks, and corporate issuers, subject to certain concentration limits and restrictions on maturities. The Company’s cash, cash equivalents, marketable securities, and restricted cash are held by financial institutions that management believes are of high credit quality. Amounts on deposit may at times exceed federally insured limits. The Company has not experienced any losses on its deposits of cash, cash equivalents, and restricted cash and its accounts are monitored by management to mitigate risk. The Company is exposed to credit risk in the event of default by the financial institutions holding its cash, cash equivalents, and restricted cash, and bond issuers. Property and Equipment Property and equipment are stated at cost, net of accumulated depreciation and amortization. Depreciation and amortization are computed using the straight-line method over the estimated useful lives of the assets. Repairs and maintenance that do not extend the life or improve an asset are expensed as incurred. Upon retirement or sale, the cost of disposed assets and their related accumulated depreciation and amortization are removed from the balance sheet. Any gain or loss is credited or charged to operations. The useful lives of the property and equipment are as follows: Laboratory equipment 5 years Furniture and office equipment 5 years Computer equipment 3 years Software 3 years Leasehold improvements Shorter of remaining lease term or estimated useful life Impairment of Long-Lived Assets Long-lived assets are reviewed for indications of possible impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability is measured by comparison of the carrying amounts to the future undiscounted cash flows attributable to these assets. An impairment loss is recognized to the extent an asset group is not recoverable, and the carrying amount exceeds the projected discounted future cash flows arising from these assets. There were no impairments of long-lived assets for the years ended December 31, 2020, 2019, and 2018. Accrued Research and Development Costs The Company records the costs associated with research nonclinical studies, clinical trials, and manufacturing development as incurred. These costs are a significant component of the Company’s research and development expenses, with a substantial portion of the Company’s on-going research and development activities conducted by third-party service providers, including contract research and manufacturing organizations. The Company accrues for expenses resulting from obligations under agreements with contract research organizations (“CROs”), contract manufacturing organizations (“CMOs”), and other outside service providers for which payment flows do not match the periods over which materials or services are provided to the Company. Accruals are recorded based on estimates of services received and efforts expended pursuant to agreements established with CROs, CMOs, and other outside service providers. These estimates are typically based on contracted amounts applied to the proportion of work performed and determined through analysis with internal personnel and external service providers as to the progress or stage of completion of the services. The Company makes significant judgments and estimates in determining the accrual balance in each reporting period. In the event advance payments are made to a CRO, CMO, or outside service provider, the payments will be recorded as a prepaid asset which will be amortized as the contracted services are performed. As actual costs become known, the Company adjusts its accruals. Inputs, such as the services performed, the number of patients enrolled, or the study duration, may vary from the Company’s estimates, resulting in adjustments to research and development expense in future periods. Changes in these estimates that result in material changes to the Company’s accruals could materially affect the Company’s results of operations. Historically, the Company has not experienced any material deviations between accrued and actual research and development expenses. Leases The Company determines if an arrangement is a lease at inception. Right-of-use ("ROU") assets represent the Company's right to use an underlying asset for the lease term and lease liabilities represent the Company's obligation to make lease payments arising from the lease. The classification of the Company's leases as operating or finance leases along with the initial measurement and recognition of the associated ROU assets and lease liabilities is performed at the lease commencement date. The measurement of lease liabilities is based on the present value of future lease payments over the lease term. As the Company's leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at the lease commencement date in determining the present value of future lease payments. The ROU asset is based on the measurement of the lease liability and also includes any lease payments made prior to or on lease commencement and excludes lease incentives and initial direct costs incurred, as applicable. The lease terms may include options to extend or terminate the lease when it is reasonably certain the Company will exercise any such options. Rent expense for the Company's operating leases is recognized on a straight-line basis over the lease term. Amortization expense for the ROU asset associated with its finance leases is recognized on a straight-line basis over the term of the lease and interest expense associated with its finance leases is recognized on the balance of the lease liability using the effective interest method based on the estimated incremental borrowing rate. The Company has lease agreements with lease and non-lease components. As allowed under Topic 842, the Company has elected to not separate lease and non-lease components for any leases involving real estate and office equipment classes of assets and, as a result, accounts for the lease and non-lease components as a single lease component. The Company has also elected to not apply the recognition requirement of Topic 842 to leases with a term of 12 months or less for all classes of assets. Fair Value of Financial Instruments The Company uses fair value measurements to record fair value adjustments to certain financial and non-financial assets and liabilities and to determine fair value disclosures. The accounting standards define fair value, establish a framework for measuring fair value, and require disclosures about fair value measurements. Fair value is defined as the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. When determining the fair value measurements for assets and liabilities required to be recorded at fair value, the principal or most advantageous market in which the Company would transact are considered along with assumptions that market participants would use when pricing the asset or liability, such as inherent risk, transfer restrictions, and risk of nonperformance. The accounting standard for fair value establishes a fair value hierarchy based on three levels of inputs, the first two of which are considered observable and the last unobservable, that requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. A financial instrument’s categorization within the fair value hierarchy is based upon the lowest level of input that is significant to the fair value measurement. The three levels of inputs that may be used to measure fair value are as follows: Level 1: Observable inputs, such as quoted prices in active markets for identical assets or liabilities. Level 2: Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3: Valuations based on unobservable inputs to the valuation methodology and including data about assumptions that market participants would use in pricing the asset or liability based on the best information available under the circumstances. Financial instruments carried at fair value include cash, cash equivalents, marketable securities, and restricted cash. The carrying amount of accounts payable and accrued liabilities approximate fair value due to their relatively short maturities. Revenue Recognition The Company’s sole source of revenue was grant revenue related to a $19.8 million research grant received from the Cancer Prevention and Research Institute of Texas (“CPRIT”), covering a four-year period from June 1, 2014 through May 31, 2018. Grant revenue was recognized when qualifying costs were incurred and there was reasonable assurance that the conditions of the award had been met for collection. Proceeds received prior to the costs being incurred or the conditions of the award being met were recognized as deferred revenue until the services were performed and the conditions of the award were met (see Note 9). Research and Development Costs Research and development costs are expensed as incurred. Research and development costs include, but are not limited to, salaries, benefits, travel, stock-based compensation, consulting costs, contract research service costs, laboratory supplies and facilities, contract manufacturing costs, and costs paid to other third parties that conduct research and development activities on the Company’s behalf. Amounts incurred in connection with license agreements are also included in research and development expense. Advance payments for goods or services to be rendered in the future for use in research and development activities are recorded as a prepaid asset and expensed as the related goods are delivered or the services are performed. Stock-Based Compensation The Company recognizes the cost of stock-based awards granted to employees and non-employees based on the estimated grant-date fair values of the awards. The fair values of stock options are estimated on the date of grant using the Black-Scholes option pricing model. The fair values of restricted stock units (“RSUs”) are based on the fair value of the Company’s common stock on the date of the grant. The value of the award is recognized as compensation expense on a straight-line basis over the requisite service period. Forfeitures are recognized when they occur, which may result in the reversal of compensation costs in subsequent periods as the forfeitures arise. Compensation expense for employee and non-employee share-based payment awards with performance conditions is recognized when the performance condition is deemed probable. Income Taxes The Company and its nine wholly owned subsidiary corporations use the asset and liability method of accounting for income taxes. Under this method, deferred tax assets and liabilities are recognized for the expected future tax consequences of temporary differences between the financial statements and the tax bases of assets and liabilities. Additionally, any changes in income tax laws are immediately recognized in the year of enactment. A valuation allowance is established against the deferred tax assets to reduce their carrying value to an amount that is more likely than not to be realized. The deferred tax assets and liabilities are classified as noncurrent along with the related valuation allowance. Due to a lack of earnings history, the net deferred tax assets have been fully offset by a valuation allowance. The Company recognizes benefits of uncertain tax positions if it is more likely than not that such positions will be sustained upon examination based solely on the technical merits, as the largest amount of benefits that is more likely than not to be realized upon the ultimate settlement. The Company’s policy is to recognize interest and penalties related to the unrecognized tax benefits as a component of income tax expense, if applicable. On March 27, 2020, the Coronavirus Aid, Relief and Economic Security (“CARES”) Act was enacted and signed into law in response to COVID-19. The CARES Act includes changes to the tax provisions that benefit business entities and makes certain technical corrections to the 2017 Tax Cuts and Jobs Act. The tax relief measures for businesses include a five-year Comprehensive Loss Comprehensive loss is the change in stockholders’ equity from transactions and other events and circumstances other than those resulting from investments by stockholders and distributions to stockholders. The Company’s other comprehensive income (loss) is currently comprised of changes in unrealized losses and gains on available-for-sale securities and foreign currency translation adjustments reflecting the cumulative effect of changes in exchange rates between the foreign entity’s functional currency and the reporting currency. 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 Instruments, which changes the impairment model for most financial assets and certain other instruments. For available-for-sale debt securities with unrealized credit losses, the credit losses will be recognized as allowances rather than as reductions in the amortized cost of the securities. On January 1, 2020, the Company adopted ASU 2016-13 using the modified retrospective approach and no cumulative effect adjustment to accumulated deficit was needed as of the adoption date. Additionally, no prior period amounts were adjusted and continue to be reported in accordance with the legacy other-than-temporary impairment model. The adoption of ASU 2016-13 did not have a material impact on the Company’s consolidated financial statements. In August 2018, the FASB issued ASU No. 2018-15, Intangibles – Goodwill and Other – Internal Use Software (Subtopic 350-40), to align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal-use software license). The amendments in the update require an entity in a hosting arrangement that is a service contract to follow the guidance in Subtopic 350-40 to determine which implementation costs to capitalize as an asset related to the service contract and which costs to expense. Capitalized implementation costs are recorded in prepaid expenses and other current assets or other non-current assets on the statement of financial position and the related amortization expense is recorded in operating expenses in the results of operations. On January 1, 2020, the Company adopted ASU 2018-15 on a prospective basis and no prior period amounts were adjusted. The adoption of ASU 2018-15 did not have a material impact on the Company’s consolidated financial statements. |
Fair Value Measurements
Fair Value Measurements | 12 Months Ended |
Dec. 31, 2020 | |
Fair Value Disclosures [Abstract] | |
Fair Value Measurements | 3. The Company measures and reports certain financial instruments as assets and liabilities at fair value on a recurring basis. The following tables sets forth the fair value of the Company’s financial assets and liabilities at fair value on a recurring basis based on the three-tier fair value hierarchy (in thousands): December 31, 2020 Level 1 Level 2 Level 3 Total Financial Assets Money market funds $ 6,700 $ — $ — $ 6,700 U.S. treasury securities — 57,181 — 57,181 U.S. government agency securities — 66,893 — 66,893 Corporate bonds — 3,001 — 3,001 Total financial assets $ 6,700 $ 127,075 $ — $ 133,775 December 31, 2019 Level 1 Level 2 Level 3 Total Financial Assets Money market funds $ 7,023 $ — $ — $ 7,023 Reverse repurchase agreements — 6,250 — 6,250 Commercial paper — 15,193 — 15,193 Corporate bonds — 39,750 — 39,750 Total financial assets $ 7,023 $ 61,193 $ — $ 68,216 The Company measures the fair value of money market funds and U.S. treasury securities on quoted prices in active markets for identical asset or liabilities. The Level 2 assets include U.S. treasury securities, U.S. government agency securities, reverse repurchase agreements, commercial paper, and corporate bonds and are valued based on quoted prices for similar assets in active markets and inputs other than quoted prices that are derived from observable market data. The Company evaluates transfers between levels at the end of each reporting period. There were no transfers between Level 1 and Level 2 during the periods presented. |
Cash Equivalents and Marketable
Cash Equivalents and Marketable Securities | 12 Months Ended |
Dec. 31, 2020 | |
Investments Debt And Equity Securities [Abstract] | |
Cash Equivalents and Marketable Securities | 4. Cash Equivalents and Marketable Securities The following tables summarize the estimated fair value of the Company’s cash equivalents and marketable securities and the gross unrealized gains and losses (in thousands): December 31, 2020 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Cash equivalents: Money market funds $ 6,700 $ — $ — $ 6,700 U.S. treasury securities 4,005 — (1 ) 4,004 U.S. government agency securities 66,895 — (2 ) 66,893 Total cash equivalents 77,600 — (3 ) 77,597 Marketable securities: U.S. treasury securities 53,183 1 (7 ) 53,177 Corporate bonds 3,000 1 — 3,001 Total marketable securities $ 56,183 $ 2 $ (7 ) $ 56,178 December 31, 2019 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Cash equivalents: Money market funds $ 7,023 $ — $ — $ 7,023 Reverse repurchase agreements 6,250 — — 6,250 Commercial paper 2,247 — — 2,247 Total cash equivalents 15,520 — — 15,520 Marketable securities: Commercial paper 12,931 15 — 12,946 Corporate bonds 39,714 45 (9 ) 39,750 Total marketable securities $ 52,645 $ 60 $ (9 ) $ 52,696 The reverse repurchase agreements are settled in cash nightly, and as such are classified as cash equivalents. The following table summarizes the available-for-sale securities in an unrealized loss position for which an allowance for credit losses has not been recorded as of December 31, 2020 and 2019, aggregated by major security type and length of time in a continuous unrealized loss position: December 31, 2020 Less Than 12 Months 12 Months or Longer Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses U.S. treasury securities $ 43,183 $ (8 ) $ — $ — $ 43,183 $ (8 ) U.S. government agency securities 66,893 (2 ) — — 66,893 (2 ) Total marketable securities $ 110,076 $ (10 ) $ — $ — $ 110,076 $ (10 ) December 31, 2019 Less Than 12 Months 12 Months or Longer Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Corporate bonds $ 13,022 $ (9 ) $ — $ — $ 13,022 $ (9 ) As of December 31, 2020 and 2019, the Company held 16 and 13 debt securities, respectively, that were in an unrealized loss position. The Company evaluated its securities for credit losses and considered the decline in market value to be primarily attributable to current economic and market conditions and not to a credit loss or other factors. Additionally, the Company does not intend to sell the securities in an unrealized loss position and does not expect they will be required to sell the securities before recovery of the unamortized cost basis. As of December 31, 2020 and 2019, an allowance for credit losses had not been recognized. Given our intent and ability to hold such securities until recovery, and the lack of significant change in credit risk of these investments, we do not consider these marketable securities to be impaired as of December 31, 2020 and 2019. There were no realized gains or losses on marketable securities for the years ended December 31, 2020 and 2018. A realized gain is included in other expense, net for the year ended December 31, 2019. Interest on marketable securities is included in interest income. Accrued interest receivable on available-for-sale debt securities totaled $0.2 million and $0.3 million as of December 31, 2020 and 2019, respectively, and is excluded from the estimate of credit losses. The following table summarizes the contractual maturities of the Company's marketable securities at estimated fair value (in thousands): December 31, 2020 2019 Due in one year or less $ 56,178 $ 49,687 Due in 1 - 2 years — 3,009 Total marketable securities $ 56,178 $ 52,696 The Company may sell investments at any time for use in current operations even if they have not yet reached maturity. As a result, the Company classifies marketable securities, including securities with maturities beyond twelve months as current assets. |
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 consist of the following (in thousands): December 31, 2020 2019 Laboratory equipment $ 1,916 $ 1,085 Furniture and office equipment 747 396 Computer equipment 56 50 Software 132 96 Leasehold improvements 4,774 1,813 Property and equipment, gross 7,625 3,440 Less: Accumulated depreciation and amortization (1,983 ) (1,055 ) Property and equipment, net $ 5,642 $ 2,385 Depreciation and amortization expense for the years ended December 31, 2020, 2019, and 2018 was $1.0 million, $0.4 million, and $0.3 million, respectively. All of the Company’s long-lived assets are located in the United States. |
Accrued and Other Current Liabi
Accrued and Other Current Liabilities | 12 Months Ended |
Dec. 31, 2020 | |
Accrued Liabilities And Other Liabilities [Abstract] | |
Accrued and Other Current Liabilities | 6. Accrued and Other Current Liabilities Accrued and other current liabilities consist of the following (in thousands): December 31, 2020 2019 Accrued compensation $ 3,712 $ 3,273 Accrued contracted research and development costs 8,620 10,485 Accrued professional and consulting fees 1,074 627 Other 464 469 Total accrued and other current liabilities $ 13,870 $ 14,854 |
Leases
Leases | 12 Months Ended |
Dec. 31, 2020 | |
Leases [Abstract] | |
Leases | 7. Leases The Company leases certain office space, laboratory facilities, and equipment. These leases require monthly lease payments that may be subject to annual increases throughout the lease term. Certain of these leases also include renewal options at the election of the Company to renew or extend the lease for an additional three to five years. These optional periods have not been considered in the determination of the right-of-use-assets or lease liabilities associated with these leases as the Company did not consider it reasonably certain it would exercise the options. The Company performed evaluations of its contracts and determined it has both operating and finance leases. Variable lease expense for these leases primarily consists of common area maintenance and other operating costs. In April 2019, the Company entered into a lease agreement (the “Las Cimas Lease”) for its corporate headquarters and laboratory space located in Austin, TX. The Las Cimas Lease includes approximately 30,000 square feet and commenced on April 30, 2019, with an expiration on April 30, 2028. The Company posted a customary letter of credit in the amount of $1.5 million as security, which is subject to automatic reductions per the terms of the Las Cimas Lease. A tenant allowance of up to $1.0 million is provided by the lessor. As of December 31, 2020, the Company has been reimbursed $0.9 million of the tenant allowance. The following table summarizes the Company’s recognition of its operating and finance leases (in thousands): December 31, Classification 2020 2019 Assets Operating Operating lease right-of-use assets $ 4,230 $ 4,726 Finance Other non-current assets 68 56 Total leased assets 4,298 4,782 Leases Current Operating Operating lease liabilities 319 351 Finance Accrued and other current liabilities 27 28 Non-current Operating Non-current operating lease liabilities 5,129 4,712 Finance Other non-current liabilities 45 31 Total lease liabilities $ 5,520 $ 5,122 The following table summarizes the weighted-average remaining lease term and discount rates for the Company’s operating and finance leases: December 31, 2020 2019 Lease term (years) Operating leases 7.3 7.7 Finance leases 2.6 2.0 Discount rate Operating leases 10.7 % 10.6 % Finance leases 10.2 % 9.5 % The following table summarizes the lease costs pertaining to the Company’s operating leases (in thousands): Year Ended December 31, 2020 2019 2018 Operating lease cost $ 1,258 $ 946 $ 401 Variable lease cost 665 331 198 Total lease cost $ 1,923 $ 1,277 $ 599 Cash paid for amounts included in the measurement of operating lease liabilities during the years ended December 31, 2020 and 2019 was $1.3 million and $0.7 million, respectively, and was included within net cash used in operating activities in the cash flows. The maturities of the Company’s operating and finance lease liabilities as of December 31, 2020 were as follows (in thousands): Operating Leases Finance Leases 2021 $ 995 $ 32 2022 1,033 32 2023 1,064 17 2024 1,096 — 2025 1,129 — Thereafter 2,765 — Total lease payments 8,082 81 Less: Imputed interest (2,525 ) (9 ) Tenant allowance (109 ) — Total $ 5,448 $ 72 |
Stockholders' Equity
Stockholders' Equity | 12 Months Ended |
Dec. 31, 2020 | |
Equity [Abstract] | |
Stockholders' Equity | 8. Stockholders’ Equity The Company is authorized to issue 510,000,000 shares of capital stock of which 500,000,000 shares are designated as common stock and 10,000,000 shares are designated as preferred stock, all with a par value of $0.0001 per share. Follow-on Public Offerings In April 2018, the Company issued and sold 5,046,510 shares of common stock in an underwritten public offering pursuant to a shelf registration statement on Form S-3 at a public offering price of $8.00 per share, including 546,510 shares of common stock issued upon the partial exercise by the underwriters of their option to purchase additional shares. The net proceeds to the Company from this public offering were $37.7 million, after deducting underwriting discounts and commissions of $2.4 million and offering costs of $0.3 million. In February 2019, the Company issued and sold 4,625,000 shares of common stock at a public offering price of $8.00 per share and pre-funded warrants to purchase up to 4,000,000 shares of common stock at a public offering price of $7.9999 per warrant in an underwritten public offering pursuant to a shelf registration statement on Form S-3. This includes the full exercise by the underwriters of their option to purchase up to 1,125,000 additional shares of common stock. The net proceeds to the Company from this public offering were $64.5 million, after deducting underwriting discounts and commissions of $4.1 million and offering costs of $0.4 million. In April 2020, the Company issued and sold 15,442,303 shares of common stock at a public offering price of $4.75 per share and pre-funded warrants to purchase up to 13,610,328 shares of common stock at a public offering price of $4.7499 per warrant in an underwritten public offering pursuant to a shelf registration statement on Form S-3. This includes the full exercise by the underwriters of their option to purchase up to 3,789,473 additional shares of common stock. The net proceeds to the Company from this public offering were $129.0 million, after deducting underwriting discounts and commissions of $8.2 million and offering costs of $0.8 million. The public offering price for the pre-funded warrants sold in February 2019 and April 2020 was equal to the public offering price of the common stock, less the $0.0001 per share exercise price of each warrant. The warrants were recorded as a component of stockholders’ equity within additional paid-in capital and have no expiration date. Per the terms of the warrant agreements, the outstanding warrants to purchase shares of common stock may not be exercised if the holder’s ownership of the Company’s common stock would exceed 4.99% As of December 31, 2020, the following pre-funded warrants to purchase common stock were issued and outstanding: Issue Date Expiration Date Exercise Price Number of Warrants Outstanding February 8, 2019 None $ 0.0001 4,000,000 April 30, 2020 None $ 0.0001 13,610,328 Total pre-funded warrants 17,610,328 At-The-Market Offering In May 2017, the Company entered into a sales agreement with JonesTrading Institutional Services LLC, as sales agent and underwriter, to issue and sell shares of its common stock for an aggregate offering price of $20.0 million under an at-the-market (“2017 ATM’) offering program. In October 2018, the Company issued and sold 1,845,820 shares of common stock in a single transaction under the 2017 ATM, for gross proceeds $17.0 million, resulting in net proceeds of $16.4 million, after deducting underwriting discounts, commissions, and offering costs. The 2017 ATM agreement was subsequently terminated in December 2018. In April 2020, the Company entered into a new sales agreement with JonesTrading Institutional Services LLC, as sales agent, to issue and sell shares of its common stock for an aggregate offering price of $60.0 million under an at-the-market (“2020 ATM”) offering program. In the fourth quarter of 2020, the Company issued and sold 3,245,077 shares of common stock under the 2020 ATM for gross proceeds of $25.3 million, resulting in net proceeds of $24.6 million, after deducting underwriting discounts, commissions, and offering costs. As of the date of the filing of this report, $34.7 million of our common stock remained available for sale pursuant to the 2020 ATM. |
Grant Revenues
Grant Revenues | 12 Months Ended |
Dec. 31, 2020 | |
Grant Revenues [Abstract] | |
Grant Revenues | 9. Grant Revenues In June 2015, the Company entered into a Cancer Research Grant Contract (“Grant Contract”) with CPRIT, under which CPRIT awarded a grant not to exceed $19.8 million for use in developing cancer treatments by exploiting the metabolism of cancer cells. The Grant Contract covered a four-year Upon commercialization of the product, the terms of the Grant Contract require the Company to pay tiered royalties in the low to mid-single digit percentages. Such royalties reduce to less than one percent after a mid-single-digit multiple of the grant funds have been paid to CPRIT as royalties. The contract ended in May 2018 with the full $19.8 million grant recognized as revenue over the life of the award. For the years ended December 31, 2020 and 2019, the Company recognized no grant revenue. For the year ended December 31, 2018, the Company recognized $3.9 million in grant revenues for qualified expenditures under the grant. |
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 2015 Equity Incentive Plan In March 2015, the Company adopted the 2015 Equity Incentive Plan (“2015 Plan”), administered by the board of directors, and provides for the Company to sell or issue common stock or restricted common stock, or to grant incentive stock options or nonqualified stock options for the purchase of common stock, to employees, members of the board of directors and consultants of the Company. Under the terms of the 2015 Plan, the exercise prices, vesting and other restrictions may be determined at the discretion of the board of directors, or their committee if so delegated, except that the exercise price per share of stock options may not be less than 100% of the fair market value of the share of common stock on the date of grant, the term of stock options may not be greater than ten years for all grants, and for grantees holding more than 10% of the total combined voting power of all classes of stock, the term may not be greater than five years. The Company granted options under the 2015 Plan until April 2016 when it was terminated as to future awards, although it continues to govern the terms of options that remain outstanding under the 2015 Plan. As of December 31, 2020, a total of 204,482 shares of common stock are subject to options outstanding under the 2015 Plan and will become available under the 2016 Equity Incentive Plan (“2016 Plan”) to the extent the options are forfeited or lapse unexercised. 2016 Equity Incentive Plan The 2016 Plan became effective in April 2016 and serves as the successor to the 2015 Plan. Under the 2016 Plan, the Company may grant stock options, stock appreciation rights, restricted stock awards, restricted stock units, performance awards, and stock bonuses. The 2016 Plan provides for an initial reserve of 1,100,000 shares of common stock, plus 509,869 shares of common stock remaining under the 2015 Plan, and any share awards that subsequently are forfeited or lapse unexercised under the 2015 Plan. The shares reserved exclude shares of common stock reserved for issuance under the 2015 Plan. In October 2018, the 2016 plan was amended to increase the number of shares of common stock reserved for issuance thereunder by 1,759,602 shares, extend the term of the 2016 Plan through August 7, 2028, and provide for an automatic increase in the number of shares reserved for issuance thereunder on January 1 of each year for the remaining term of the plan equal to (a) 4.0% of the number of issued and outstanding shares of common stock on December 31 of the immediately preceding year, or (b) a lesser amount as approved by the board each year. The superseded 2016 Plan provision to provide an annual increase in the number of shares available for issuance required the Company’s board of directors to approve the increase, up to 4%, prior to January 1 of each relevant year. As a result of the operation of each of these provisions, on January 1, 2020, 2019, and 2018, an additional 1,163,377, 965,603, and 666,807 shares, respectively, became available for issuance under the 2016 Plan. As of December 31, 2020, the total number of shares reserved for issuance under the 2016 Plan was 6,883,659, of which 5,299,662 shares were subject to outstanding option awards and restricted unit awards. 2018 Equity Inducement Plan In February 2018, the board of directors approved and adopted the 2018 Equity Inducement Plan (“2018 Plan”), which became effective on the same date. The board of directors approved an initial reserve of 1,100,000 shares of common stock to be used exclusively for individuals who were not previously employees or directors, or following a bona fide period of non-employment, as an inducement material to the individual entering into employment with the Company. Nonqualified stock options or restricted stock units may be granted under the 2018 Plan at the discretion of the Compensation Committee or the board of directors. The Company did not seek stockholder approval of the 2018 Plan pursuant to Nasdaq Rule 5635(c)(4). As of December 31, 2020, the total number of shares reserved for issuance under the 2018 Plan was 1,100,000, of which 81,900 shares were subject to outstanding option awards. Under the 2016 Plan and 2018 Plan, the Company may grant stock-based awards with service conditions (“service-based” awards), performance conditions (“performance-based” awards), and market conditions (“market-based” awards). Service-based awards granted under the 2018 Plan, 2016 Plan, and 2015 Plan generally vest over four years and expire after ten years, although awards have been granted with vesting terms less than four years. 2016 Employee Stock Purchase Plan The 2016 Employee Stock Purchase Plan (“2016 ESPP”) became effective in April 2016. A total of 165,000 shares of common stock were reserved for issuance under the 2016 ESPP. Eligible employees may purchase shares of common stock under the 2016 ESPP at 85% of the lower of the fair market value of the Company’s common stock as of the first or the last day of each offering period. Employees are limited to contributing 15% of the employee’s eligible compensation and may not purchase more than $25,000 of stock during any calendar year or more than 2,000 shares during any one purchase period or a lesser amount determined by the board of directors. The 2016 ESPP will terminate ten years from the first purchase date under the plan, unless terminated earlier by the board of directors. In June 2018, the 2016 ESPP was amended to provide for an automatic annual increase in the number of shares reserved for issuance thereunder on January 1 of each year for the remaining term of the year equal to (a) 1.0% of the number of issued and outstanding shares of common stock on December 31 of the immediately preceding year, or (b) a lesser amount as approved by the board of directors each year. As a result of the operation of this provision, on January 1, 2020 and 2019, an additional 290,844 and 241,400 shares, respectively, became available for issuance under the 2016 ESPP. As of December 31, 2020, the reserve remaining and available for future issuance under the 2016 ESPP was 478,298 shares. The following table summarizes employee and non-employee stock option activity for the year ended December 31, 2020: Shares Issuable Under Options Weighted Average Exercise Price Weighted Average Remaining Contractual Term Aggregate Intrinsic Value (in years) (in Outstanding as of December 31, 2019 3,889,188 $ 7.37 8.10 $ 3,642 Granted 1,963,100 7.97 Exercised (127,376 ) 3.85 Forfeited (367,068 ) 7.84 Outstanding as of December 31, 2020 5,357,844 $ 7.64 7.92 $ 3,788 Options vested and expected to vest as of December 31, 2020 5,003,406 $ 7.58 7.86 $ 3,783 Options exercisable as of December 31, 2020 2,654,899 $ 7.24 7.11 $ 3,041 The aggregate intrinsic value of options outstanding, exercisable, vested and expected to vest were calculated as the difference between the exercise price of the options and the fair value of the Company’s common stock as of the reporting date. For the years ended December 31, 2020, 2019, and 2018, the weighted-average grant date fair value of options granted was $4.68, $8.09, and $8.03, respectively. The total intrinsic value of options exercised during the years ended December 31, 2020, 2019, and 2018 was $0.4 million, $1.0 million and $1.9 million, respectively. There were no stock options issued to non-employees during the years ended December 31, 2020, 2019, and 2018. For the years ended December 31, 2020 and 2018, 1,663 and 6,626 non-employee stock options, respectively, vested in the period. For the year ended December 31, 2019, no non-employee stock options vested in the period. Restricted Common Stock Units The Company granted 228,200 restricted stock units (“RSUs”) during the year ended December 31, 2020 to certain employees with regulatory, commercial, and clinical milestones in addition to a service condition. As of December 31, 2020, the performance conditions of these RSUs were not probable of being achieved. If and when the performance milestones are deemed probable of being achieved within the required time frame, the Company may recognize up to $1.9 million of stock-based compensation. The following table summarizes employee restricted stock activity for the year ended December 31, 2020: Shares Weighted Average Grant Date Fair Value Unvested restricted stock units as of December 31, 2019 — $ — Granted 228,200 8.13 Vested — — Forfeited — — Unvested restricted stock units as of December 31, 2020 228,200 $ 8.13 There were no RSUs granted to non-employees during the year ended December 31, 2020. Stock-Based Compensation Expense Total stock-based compensation expense recognized from the Company’s equity incentive plans, 2018 Plan, and the 2016 ESPP for the years ended December 31, 2020, 2019, and 2018 was as follows (in thousands): Year Ended December 31, 2020 2019 2018 Employees Non- Employees Employees Non- Employees Employees Non- Employees Research and development $ 2,168 $ 36 $ 1,828 $ — $ 1,440 $ 234 General and administrative 4,052 — 3,048 — 2,606 — Total stock-based compensation expense $ 6,220 $ 36 $ 4,876 $ — $ 4,046 $ 234 No related tax benefits were recognized for the years ended December 31, 2020, 2019, and 2018 (see Note 12). The employee and non-employee awards contain both performance and service-based vesting conditions. No expense was recognized for the unvested employee and non-employee awards with only a performance condition for the years ended December 31, 2020, 2019, and 2018. The performance-based vesting conditions represent specific performance targets. Compensation expense for employee and non-employee share-based payment awards with performance conditions is recognized when the performance condition is deemed probable of achievement. In November 2018, one of the board of directors resigned. Upon his resignation, the Company’s board of directors approved the immediate vesting of all unvested stock options and restricted stock and an extension in the exercise period for all outstanding equity awards from 90 days to 180 days. The result was a modification of 86,252 outstanding stock options and 43,290 restricted stock awards. The incremental fair value of $0.3 million, in connection with the modification of the awards, was recognized as stock compensation expense upon resignation with no future service or performance conditions required. As of December 31, 2020, the Company had an aggregate of $12.3 million of unrecognized stock-based compensation expense for options outstanding, which is expected to be recognized over a weighted average period of 2.5 years. In determining the fair value of the stock-based awards, the Company uses the Black-Scholes option-pricing model and assumptions discussed below. Each of these inputs is subjective and generally requires significant judgment to determine. Expected Term The Company’s expected term represents the period that the Company’s stock-based awards are expected to be outstanding and is determined using the simplified method (based on the mid-point between the vesting date and the end of the contractual term). The Company utilizes this method due to lack of historical exercise data and the plain-vanilla nature of the Company’s stock-based awards. Expected Volatility Since the Company was privately held through April 2016, it alone does not have the relevant company-specific historical data to support its expected volatility. As such, the Company has used an average of expected volatilities based on the volatilities of a representative group of publicly traded biopharmaceutical companies over a period equal to the expected term of the stock option grants. Subsequent to the Company’s initial public offering, it began to consider the Company’s own historic volatility. However, due to its limited history as a public company, the Company still uses peer company data to assist in this analysis. For purposes of identifying comparable companies, the Company selected companies with comparable characteristics to it, including enterprise value, risk profiles, position within the industry, and with historical share price information sufficient to meet the expected life of the stock-based awards. The historical volatility data was computed using the daily closing prices for the selected companies’ shares during the equivalent period of the calculated expected term of the stock-based awards. The Company intends to consistently apply this process using the same or similar comparable entities until a sufficient amount of historical information regarding the volatility of the Company’s own share price becomes available. Risk-Free Interest Rate The risk-free interest rate is based on the U.S. Treasury zero coupon issues in effect at the time of grant for periods corresponding with the expected term of option. Expected Dividend The Company has never paid dividends on its common stock and has no plans to pay dividends on its common stock. Therefore, the Company used an expected dividend yield of zero. The fair value of the stock options granted under the 2018 Plan, 2016 Plan, and 2015 Plan and the shares available for purchase under the 2016 ESPP were determined using the Black-Scholes option-pricing model. The following table summarizes the weighted-average assumptions used in calculating the fair value of the awards: Year Ended December 31, 2020 2019 2018 2018 Plan, 2016 Plan, and 2015 Plan Expected term (in years) 6.10 6.01 5.20 Expected volatility 76 % 80 % 74 % Risk-free interest 1.06 % 2.32 % 2.42 % Dividend yield 0 % 0 % 0 % 2016 ESPP Expected term (in years) 0.50 0.50 0.50 Expected volatility 76 % 70 % 66 % Risk-free interest 0.75 % 2.11 % 2.20 % Dividend yield 0 % 0 % 0 % |
Defined Contribution Plan
Defined Contribution Plan | 12 Months Ended |
Dec. 31, 2020 | |
Compensation And Retirement Disclosure [Abstract] | |
Defined Contribution Plan | 11. Defined Contribution Plan The Company sponsors a 401(k) retirement plan in which substantially all of its full-time employees are eligible to participate. Participants may contribute a percentage of their annual compensation to this plan, subject to statutory limitations. During the years ended December 31, 2020, 2019, 2018, the Company provided $0.5 million, $0.3 million, and $0.2 million, respectively, in contributions to the plan. |
Income Taxes
Income Taxes | 12 Months Ended |
Dec. 31, 2020 | |
Income Tax Disclosure [Abstract] | |
Income Taxes | 12. Income Taxes For the years ended December 31, 2020, 2019, and 2018, the Company recognized no provision or benefit from income taxes. The difference between the Company’s provision for income taxes and the amounts computed by applying the statutory federal income tax rate to income before income taxes is as follows (in thousands): Year Ended December 31, 2020 2019 2018 Tax provision derived by applying the federal statutory rate to income before income taxes $ (16,988 ) $ (16,433 ) $ (9,313 ) Permanent differences and other 482 (98 ) 264 Federal tax credits (3,905 ) (3,599 ) (1,211 ) State tax credits (251 ) (229 ) 464 Change in the valuation allowance 20,662 20,359 9,796 Income tax expense /(benefit) $ — $ — $ — The components of the deferred tax assets and liabilities consist of the following (in thousands): December 31, 2020 2019 Deferred tax assets Net operating loss carryforward $ 51,708 $ 36,093 Intangible assets 51 45 Accrued expense 598 605 Stock-based compensation 2,087 1,237 Federal tax credits 14,764 10,859 State tax credits 839 588 Other 299 126 Total deferred tax assets 70,346 49,553 Deferred tax liabilities Depreciable assets (203 ) (72 ) Total deferred tax liabilities (203 ) (72 ) Less: Valuation allowance (70,143 ) (49,481 ) Deferred tax assets, net $ — $ — The Company has established a full federal and state valuation allowance equal to the net deferred tax assets due to uncertainties regarding the realization of the deferred tax asset based on the Company’s lack of earnings history. The valuation allowance increased by $20.7 million, $20.4 million, and $9.8 million during the years ended December 31, 2020, 2019, and 2018, respectively, primarily due to continuing loss from operations. As of December 31, 2020 and 2019, the Company had U.S. net operating loss carryforwards (“NOL”) of $246.2 million and $171.9 million, respectively. As of December 31, 2020 and 2019, the Company had U.S. tax credit carryforwards of $14.8 million and $10.9 million, respectively, and state tax credit carryforwards of $0.8 million and $0.6 million, respectively. The net operating loss and tax credit carryforwards of $58.4 million and $11.1 million, respectively, will begin to expire in 2033, if not utilized. The net operating loss and credit carryforwards are subject to Internal Revenue Service adjustments until the statute closes on the year the net operating loss or tax credits are utilized. The Company has not completed a study to assess whether an ownership change has occurred or whether there have been multiple ownership changes since the Company’s formation due to the complexity and cost associated with such a study, and the fact that there may be additional such ownership changes in the future. If the Company has experienced an ownership change at any time since its formation, utilization of the NOL or R&D credit carryforwards would be subject to an annual limitation under Section 382 or 383 of the Internal Revenue Code, which is determined by first multiplying the value of the Company’s stock at the time of the ownership change by the applicable long-term, tax-exempt rate, and then could be subject to additional adjustments, as required. Additionally, the separate return limitation year (“SRLY”) rules may apply to losses of the Company’s seven wholly owned U.S. subsidiary corporations. The SRLY rules limit the consolidated group’s use of a subsidiary corporation’s net operating losses to the amount of income generated by the subsidiary corporation after it becomes a member of the group. Any limitation may result in expiration of a portion of the NOL or R&D credit carryforwards before utilization. Further, until a study is completed and any limitation known, no amounts are being considered as an uncertain tax position or disclosed as an unrecognized tax benefit. Additionally, the Company does not expect any unrecognized tax benefits to change significantly over the next twelve months. Due to the existence of the valuation allowance, future changes in the Company’s unrecognized tax benefits will not impact its effective tax rate. Any carryforwards that will expire prior to utilization as a result of such limitations will be removed from deferred tax assets with a corresponding reduction of the valuation allowance. The Company is subject to examination by taxing authorities in its significant jurisdictions for the 2017 and subsequent years. However, due to NOL and tax attribute carryovers, the taxing authorities have the ability to adjust the NOLs and other tax attributes related to closed years. As of December 31, 2020 and 2019, there were no amounts recorded for uncertain tax positions. As of December 31, 2020, undistributed earnings of the Company’s newly incorporated foreign subsidiaries are immaterial. Under the Global Intangible Low-Taxed Income (“GILTI”) provisions of the 2017 Tax Cuts and Jobs Act, U.S. income taxes have been incurred on the undistributed earnings of the foreign subsidiaries and therefore, the tax impact upon distribution is limited to state income and withholding taxes and is not material. |
Net Loss Per Share
Net Loss Per Share | 12 Months Ended |
Dec. 31, 2020 | |
Earnings Per Share [Abstract] | |
Net Loss Per Share | 13. Net Loss Per Share Basic and diluted net loss per share is computed by dividing net loss by the weighted-average number of common stock and pre-funded warrants outstanding during the period. The pre-funded warrants are included in the computation of basic net loss per share as the exercise price is negligible and they are fully vested and exercisable. For periods in which the Company generated a net loss, the Company does not include the potential impact of dilutive securities in diluted net loss per share, as the impact of these items is anti-dilutive. The following weighted-average equity instruments were excluded from the calculation of diluted net loss per share because their effect would have been anti-dilutive for the periods presented: Year Ended December 31, 2020 2019 2018 Options to purchase common stock 5,049,435 3,874,817 3,014,984 Unvested restricted stock units 105,995 — — |
Research and License Agreements
Research and License Agreements | 12 Months Ended |
Dec. 31, 2020 | |
Licensing Agreements [Abstract] | |
Research and License Agreements | 14. Research and License Agreements License Agreements In December 2013, two of the Company’s wholly owned subsidiaries AECase, Inc. and AEMase, Inc. each entered into an exclusive, worldwide license agreement, including the right to grant sublicenses, with the University of Texas at Austin (the “University”) for certain intellectual property owned by the University related to cystinase and methioninase. In January 2017, the Company and the University entered into an Amended and Restated Patent License Agreement (the “Restated License”), which consolidated the two license agreements, revised certain obligations, and licensed additional patent applications and invention disclosures to us. The Restated License was amended in August 2017, December 2017, and December 2018 to revise diligence milestones and license additional patent applications, including our program candidates under the AGLE177 and Cystinuria Programs. Pursuant to the terms of the Restated License, the Company may be required to pay the University up to $6.4 million in milestone payments based on the achievement of certain development milestones, including clinical trials and regulatory approvals, the majority of which are due upon the achievement of later development milestones, including a $5.0 million payment due on regulatory approval of a product and a $0.5 million payment payable on final regulatory approval of a product for a second indication. In addition, the Company is required to pay the University a low single-digit royalty on worldwide-net sales of products covered under the Restated License, together with a revenue share on non-royalty consideration received from sublicensees. The rate of the revenue share ranges from 6.5% to 25% depending on the date the sublicense agreement is signed. For the years ended December 31, 2020, 2019 and 2018, the Company paid $0.1 million in license fees annually. |
Selected Quarterly Financial Da
Selected Quarterly Financial Data (Unaudited) | 12 Months Ended |
Dec. 31, 2020 | |
Selected Quarterly Financial Information [Abstract] | |
Selected Quarterly Financial Data (Unaudited) | 15. Selected Quarterly Financial Data (Unaudited) Selected quarterly results from operations for the years ended December 31, 2020 and 2019 are as follows (in thousands, except per share amounts): 2020 Quarter Ended March 31, June 30, September December Loss from operations $ (19,022 ) $ (21,560 ) $ (18,123 ) $ (22,776 ) Net loss (18,728 ) (21,418 ) (18,033 ) (22,714 ) Basic and diluted net loss per common share $ (0.57 ) $ (0.40 ) $ (0.29 ) $ (0.35 ) 2019 Quarter Ended March 31, June 30, September December Loss from operations $ (17,657 ) $ (18,622 ) $ (22,146 ) $ (21,909 ) Net loss (17,167 ) (18,019 ) (21,573 ) (21,495 ) Basic and diluted net loss per common share $ (0.59 ) $ (0.55 ) $ (0.66 ) $ (0.65 ) |
Subsequent Events
Subsequent Events | 12 Months Ended |
Dec. 31, 2020 | |
Subsequent Events [Abstract] | |
Subsequent Events | 16. Subsequent Events On December 9, 2020 certain pre-funded warrant holders notified the Company that pursuant to the terms of its warrant to purchase common stock they would like to raise the amount of the Maximum Ownership Percentage to 9.9% from its current level of 4.99%. This change became effective on February 8, 2021. |
Summary of Significant Accoun_2
Summary of Significant Accounting Policies (Policies) | 12 Months Ended |
Dec. 31, 2020 | |
Accounting Policies [Abstract] | |
Use of Estimates | Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Such management estimates include those related to accruals of research and development related costs, stock-based compensation, and certain company income tax related items. Management bases its estimates on historical experience and on various other market-specific and relevant assumptions that management believes to be reasonable under the circumstances. Actual results could differ significantly from those estimates. |
Cash and Cash Equivalents | Cash and Cash Equivalents The Company considers all highly liquid investments with original maturities of three months or less from the date of purchase to be cash equivalents. Cash equivalents consist of money market funds and debt securities and are stated at fair value. |
Marketable Securities | Marketable Securities All investments have been classified as available-for-sale and are carried at estimated fair value as determined based upon quoted market prices or pricing models for similar securities. Management determines the appropriate classification of its investments in debt securities at the time of purchase. The Company may or may not hold securities with stated maturities greater than one year until maturity. All available-for-sale securities are considered available to support current operations and are classified as current assets. The Company presents credit losses as an allowance rather than as a reduction in the amortized cost of the available-for-sale securities. For available-for-sale debt securities in an unrealized loss position, the Company first assesses whether it intends to sell, or it is more likely than not that it will be required to sell the security before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the security’s amortized cost basis is written down to fair value and recognized in other income (expense) in the results of operations. For available-for-sale debt securities that do not meet the aforementioned criteria, the Company evaluates whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, management considers the extent to which fair value is less than amortized cost, any changes to the rating of the security by a rating agency, and adverse conditions specifically related to the security, among other factors. If this assessment indicates that a credit loss exists, an allowance is recorded for the difference between the present value of cash flows expected to be collected and the amortized cost basis of the security. Impairment l Any unrealized losses from declines in fair value below the amortized cost basis as a result of non-credit loss factors is recognized as a component of accumulated other comprehensive (loss) income, along with unrealized gains. Realized gains and losses and declines in fair value, if any, on available-for-sale securities are included in other income (expense) in the results of operations. The cost of securities sold is based on the specific-identification method. |
Restricted Cash | Restricted Cash Restricted cash consists of money market accounts held by financial institutions as collateral for the Company’s obligations under a credit agreement and a facility lease for the Company’s corporate headquarters in Austin, TX. |
Concentration of Credit Risk | Concentration of Credit Risk Financial instruments that potentially subject the Company to a concentration of credit risk consist of cash, cash equivalents, marketable securities, and restricted cash. The Company’s investment policy limits investments to high credit quality securities issued by the U.S. government, U.S. government-sponsored agencies, highly rated banks, and corporate issuers, subject to certain concentration limits and restrictions on maturities. The Company’s cash, cash equivalents, marketable securities, and restricted cash are held by financial institutions that management believes are of high credit quality. Amounts on deposit may at times exceed federally insured limits. The Company has not experienced any losses on its deposits of cash, cash equivalents, and restricted cash and its accounts are monitored by management to mitigate risk. The Company is exposed to credit risk in the event of default by the financial institutions holding its cash, cash equivalents, and restricted cash, and bond issuers. |
Property and Equipment | Property and Equipment Property and equipment are stated at cost, net of accumulated depreciation and amortization. Depreciation and amortization are computed using the straight-line method over the estimated useful lives of the assets. Repairs and maintenance that do not extend the life or improve an asset are expensed as incurred. Upon retirement or sale, the cost of disposed assets and their related accumulated depreciation and amortization are removed from the balance sheet. Any gain or loss is credited or charged to operations. The useful lives of the property and equipment are as follows: Laboratory equipment 5 years Furniture and office equipment 5 years Computer equipment 3 years Software 3 years Leasehold improvements Shorter of remaining lease term or estimated useful life |
Impairment of Long-Lived Assets | Impairment of Long-Lived Assets Long-lived assets are reviewed for indications of possible impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability is measured by comparison of the carrying amounts to the future undiscounted cash flows attributable to these assets. An impairment loss is recognized to the extent an asset group is not recoverable, and the carrying amount exceeds the projected discounted future cash flows arising from these assets. There were no impairments of long-lived assets for the years ended December 31, 2020, 2019, and 2018. |
Accrued Research And Development Costs | Accrued Research and Development Costs The Company records the costs associated with research nonclinical studies, clinical trials, and manufacturing development as incurred. These costs are a significant component of the Company’s research and development expenses, with a substantial portion of the Company’s on-going research and development activities conducted by third-party service providers, including contract research and manufacturing organizations. The Company accrues for expenses resulting from obligations under agreements with contract research organizations (“CROs”), contract manufacturing organizations (“CMOs”), and other outside service providers for which payment flows do not match the periods over which materials or services are provided to the Company. Accruals are recorded based on estimates of services received and efforts expended pursuant to agreements established with CROs, CMOs, and other outside service providers. These estimates are typically based on contracted amounts applied to the proportion of work performed and determined through analysis with internal personnel and external service providers as to the progress or stage of completion of the services. The Company makes significant judgments and estimates in determining the accrual balance in each reporting period. In the event advance payments are made to a CRO, CMO, or outside service provider, the payments will be recorded as a prepaid asset which will be amortized as the contracted services are performed. As actual costs become known, the Company adjusts its accruals. Inputs, such as the services performed, the number of patients enrolled, or the study duration, may vary from the Company’s estimates, resulting in adjustments to research and development expense in future periods. Changes in these estimates that result in material changes to the Company’s accruals could materially affect the Company’s results of operations. Historically, the Company has not experienced any material deviations between accrued and actual research and development expenses. |
Leases | Leases The Company determines if an arrangement is a lease at inception. Right-of-use ("ROU") assets represent the Company's right to use an underlying asset for the lease term and lease liabilities represent the Company's obligation to make lease payments arising from the lease. The classification of the Company's leases as operating or finance leases along with the initial measurement and recognition of the associated ROU assets and lease liabilities is performed at the lease commencement date. The measurement of lease liabilities is based on the present value of future lease payments over the lease term. As the Company's leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at the lease commencement date in determining the present value of future lease payments. The ROU asset is based on the measurement of the lease liability and also includes any lease payments made prior to or on lease commencement and excludes lease incentives and initial direct costs incurred, as applicable. The lease terms may include options to extend or terminate the lease when it is reasonably certain the Company will exercise any such options. Rent expense for the Company's operating leases is recognized on a straight-line basis over the lease term. Amortization expense for the ROU asset associated with its finance leases is recognized on a straight-line basis over the term of the lease and interest expense associated with its finance leases is recognized on the balance of the lease liability using the effective interest method based on the estimated incremental borrowing rate. The Company has lease agreements with lease and non-lease components. As allowed under Topic 842, the Company has elected to not separate lease and non-lease components for any leases involving real estate and office equipment classes of assets and, as a result, accounts for the lease and non-lease components as a single lease component. The Company has also elected to not apply the recognition requirement of Topic 842 to leases with a term of 12 months or less for all classes of assets. |
Fair Value of Financial Instruments | Fair Value of Financial Instruments The Company uses fair value measurements to record fair value adjustments to certain financial and non-financial assets and liabilities and to determine fair value disclosures. The accounting standards define fair value, establish a framework for measuring fair value, and require disclosures about fair value measurements. Fair value is defined as the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. When determining the fair value measurements for assets and liabilities required to be recorded at fair value, the principal or most advantageous market in which the Company would transact are considered along with assumptions that market participants would use when pricing the asset or liability, such as inherent risk, transfer restrictions, and risk of nonperformance. The accounting standard for fair value establishes a fair value hierarchy based on three levels of inputs, the first two of which are considered observable and the last unobservable, that requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. A financial instrument’s categorization within the fair value hierarchy is based upon the lowest level of input that is significant to the fair value measurement. The three levels of inputs that may be used to measure fair value are as follows: Level 1: Observable inputs, such as quoted prices in active markets for identical assets or liabilities. Level 2: Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3: Valuations based on unobservable inputs to the valuation methodology and including data about assumptions that market participants would use in pricing the asset or liability based on the best information available under the circumstances. Financial instruments carried at fair value include cash, cash equivalents, marketable securities, and restricted cash. The carrying amount of accounts payable and accrued liabilities approximate fair value due to their relatively short maturities. |
Revenue Recognition | Revenue Recognition The Company’s sole source of revenue was grant revenue related to a $19.8 million research grant received from the Cancer Prevention and Research Institute of Texas (“CPRIT”), covering a four-year period from June 1, 2014 through May 31, 2018. Grant revenue was recognized when qualifying costs were incurred and there was reasonable assurance that the conditions of the award had been met for collection. Proceeds received prior to the costs being incurred or the conditions of the award being met were recognized as deferred revenue until the services were performed and the conditions of the award were met (see Note 9). |
Research and Development Costs | Research and Development Costs Research and development costs are expensed as incurred. Research and development costs include, but are not limited to, salaries, benefits, travel, stock-based compensation, consulting costs, contract research service costs, laboratory supplies and facilities, contract manufacturing costs, and costs paid to other third parties that conduct research and development activities on the Company’s behalf. Amounts incurred in connection with license agreements are also included in research and development expense. Advance payments for goods or services to be rendered in the future for use in research and development activities are recorded as a prepaid asset and expensed as the related goods are delivered or the services are performed. |
Stock-Based Compensation | Stock-Based Compensation The Company recognizes the cost of stock-based awards granted to employees and non-employees based on the estimated grant-date fair values of the awards. The fair values of stock options are estimated on the date of grant using the Black-Scholes option pricing model. The fair values of restricted stock units (“RSUs”) are based on the fair value of the Company’s common stock on the date of the grant. The value of the award is recognized as compensation expense on a straight-line basis over the requisite service period. Forfeitures are recognized when they occur, which may result in the reversal of compensation costs in subsequent periods as the forfeitures arise. Compensation expense for employee and non-employee share-based payment awards with performance conditions is recognized when the performance condition is deemed probable. |
Income Taxes | Income Taxes The Company and its nine wholly owned subsidiary corporations use the asset and liability method of accounting for income taxes. Under this method, deferred tax assets and liabilities are recognized for the expected future tax consequences of temporary differences between the financial statements and the tax bases of assets and liabilities. Additionally, any changes in income tax laws are immediately recognized in the year of enactment. A valuation allowance is established against the deferred tax assets to reduce their carrying value to an amount that is more likely than not to be realized. The deferred tax assets and liabilities are classified as noncurrent along with the related valuation allowance. Due to a lack of earnings history, the net deferred tax assets have been fully offset by a valuation allowance. The Company recognizes benefits of uncertain tax positions if it is more likely than not that such positions will be sustained upon examination based solely on the technical merits, as the largest amount of benefits that is more likely than not to be realized upon the ultimate settlement. The Company’s policy is to recognize interest and penalties related to the unrecognized tax benefits as a component of income tax expense, if applicable. On March 27, 2020, the Coronavirus Aid, Relief and Economic Security (“CARES”) Act was enacted and signed into law in response to COVID-19. The CARES Act includes changes to the tax provisions that benefit business entities and makes certain technical corrections to the 2017 Tax Cuts and Jobs Act. The tax relief measures for businesses include a five-year |
Comprehensive Loss | Comprehensive Loss Comprehensive loss is the change in stockholders’ equity from transactions and other events and circumstances other than those resulting from investments by stockholders and distributions to stockholders. The Company’s other comprehensive income (loss) is currently comprised of changes in unrealized losses and gains on available-for-sale securities and foreign currency translation adjustments reflecting the cumulative effect of changes in exchange rates between the foreign entity’s functional currency and the reporting currency. |
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 Instruments, which changes the impairment model for most financial assets and certain other instruments. For available-for-sale debt securities with unrealized credit losses, the credit losses will be recognized as allowances rather than as reductions in the amortized cost of the securities. On January 1, 2020, the Company adopted ASU 2016-13 using the modified retrospective approach and no cumulative effect adjustment to accumulated deficit was needed as of the adoption date. Additionally, no prior period amounts were adjusted and continue to be reported in accordance with the legacy other-than-temporary impairment model. The adoption of ASU 2016-13 did not have a material impact on the Company’s consolidated financial statements. In August 2018, the FASB issued ASU No. 2018-15, Intangibles – Goodwill and Other – Internal Use Software (Subtopic 350-40), to align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal-use software license). The amendments in the update require an entity in a hosting arrangement that is a service contract to follow the guidance in Subtopic 350-40 to determine which implementation costs to capitalize as an asset related to the service contract and which costs to expense. Capitalized implementation costs are recorded in prepaid expenses and other current assets or other non-current assets on the statement of financial position and the related amortization expense is recorded in operating expenses in the results of operations. On January 1, 2020, the Company adopted ASU 2018-15 on a prospective basis and no prior period amounts were adjusted. The adoption of ASU 2018-15 did not have a material impact on the Company’s consolidated financial statements. |
Summary of Significant Accoun_3
Summary of Significant Accounting Policies (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Accounting Policies [Abstract] | |
Schedule Of Estimated Useful Lives Of Property Plant And Equipment | The useful lives of the property and equipment are as follows: Laboratory equipment 5 years Furniture and office equipment 5 years Computer equipment 3 years Software 3 years Leasehold improvements Shorter of remaining lease term or estimated useful life |
Fair Value Measurement (Tables)
Fair Value Measurement (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Fair Value Disclosures [Abstract] | |
Financial Assets and Liabilities Measured at Fair Value on Recurring Basis | The following tables sets forth the fair value of the Company’s financial assets and liabilities at fair value on a recurring basis based on the three-tier fair value hierarchy (in thousands): December 31, 2020 Level 1 Level 2 Level 3 Total Financial Assets Money market funds $ 6,700 $ — $ — $ 6,700 U.S. treasury securities — 57,181 — 57,181 U.S. government agency securities — 66,893 — 66,893 Corporate bonds — 3,001 — 3,001 Total financial assets $ 6,700 $ 127,075 $ — $ 133,775 December 31, 2019 Level 1 Level 2 Level 3 Total Financial Assets Money market funds $ 7,023 $ — $ — $ 7,023 Reverse repurchase agreements — 6,250 — 6,250 Commercial paper — 15,193 — 15,193 Corporate bonds — 39,750 — 39,750 Total financial assets $ 7,023 $ 61,193 $ — $ 68,216 |
Cash Equivalents and Marketab_2
Cash Equivalents and Marketable Securities (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Investments Debt And Equity Securities [Abstract] | |
Schedule of Estimated Fair Value of Cash Equivalents and Marketable Securities | The following tables summarize the estimated fair value of the Company’s cash equivalents and marketable securities and the gross unrealized gains and losses (in thousands): December 31, 2020 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Cash equivalents: Money market funds $ 6,700 $ — $ — $ 6,700 U.S. treasury securities 4,005 — (1 ) 4,004 U.S. government agency securities 66,895 — (2 ) 66,893 Total cash equivalents 77,600 — (3 ) 77,597 Marketable securities: U.S. treasury securities 53,183 1 (7 ) 53,177 Corporate bonds 3,000 1 — 3,001 Total marketable securities $ 56,183 $ 2 $ (7 ) $ 56,178 December 31, 2019 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Cash equivalents: Money market funds $ 7,023 $ — $ — $ 7,023 Reverse repurchase agreements 6,250 — — 6,250 Commercial paper 2,247 — — 2,247 Total cash equivalents 15,520 — — 15,520 Marketable securities: Commercial paper 12,931 15 — 12,946 Corporate bonds 39,714 45 (9 ) 39,750 Total marketable securities $ 52,645 $ 60 $ (9 ) $ 52,696 |
Schedule of Gross Unrealized Losses and Fair Value by Investment Category and Age | The following table summarizes the available-for-sale securities in an unrealized loss position for which an allowance for credit losses has not been recorded as of December 31, 2020 and 2019, aggregated by major security type and length of time in a continuous unrealized loss position: December 31, 2020 Less Than 12 Months 12 Months or Longer Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses U.S. treasury securities $ 43,183 $ (8 ) $ — $ — $ 43,183 $ (8 ) U.S. government agency securities 66,893 (2 ) — — 66,893 (2 ) Total marketable securities $ 110,076 $ (10 ) $ — $ — $ 110,076 $ (10 ) December 31, 2019 Less Than 12 Months 12 Months or Longer Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Corporate bonds $ 13,022 $ (9 ) $ — $ — $ 13,022 $ (9 ) |
Summary of Contractual Maturities of Marketable Securities at Estimated Fair Value | The following table summarizes the contractual maturities of the Company's marketable securities at estimated fair value (in thousands): December 31, 2020 2019 Due in one year or less $ 56,178 $ 49,687 Due in 1 - 2 years — 3,009 Total marketable securities $ 56,178 $ 52,696 |
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 consist of the following (in thousands): December 31, 2020 2019 Laboratory equipment $ 1,916 $ 1,085 Furniture and office equipment 747 396 Computer equipment 56 50 Software 132 96 Leasehold improvements 4,774 1,813 Property and equipment, gross 7,625 3,440 Less: Accumulated depreciation and amortization (1,983 ) (1,055 ) Property and equipment, net $ 5,642 $ 2,385 |
Accrued and Other Current Lia_2
Accrued and Other Current Liabilities (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Accrued Liabilities And Other Liabilities [Abstract] | |
Accrued and Other Current Liabilities | Accrued and other current liabilities consist of the following (in thousands): December 31, 2020 2019 Accrued compensation $ 3,712 $ 3,273 Accrued contracted research and development costs 8,620 10,485 Accrued professional and consulting fees 1,074 627 Other 464 469 Total accrued and other current liabilities $ 13,870 $ 14,854 |
Leases (Tables)
Leases (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Leases [Abstract] | |
Summary of Operating and Finance Leases Presented in Balance Sheet | The following table summarizes the Company’s recognition of its operating and finance leases (in thousands): December 31, Classification 2020 2019 Assets Operating Operating lease right-of-use assets $ 4,230 $ 4,726 Finance Other non-current assets 68 56 Total leased assets 4,298 4,782 Leases Current Operating Operating lease liabilities 319 351 Finance Accrued and other current liabilities 27 28 Non-current Operating Non-current operating lease liabilities 5,129 4,712 Finance Other non-current liabilities 45 31 Total lease liabilities $ 5,520 $ 5,122 |
Summary of Weighted Average Remaining Lease Term and Discount Rates For Company's Operating and Finance Leases | The following table summarizes the weighted-average remaining lease term and discount rates for the Company’s operating and finance leases: December 31, 2020 2019 Lease term (years) Operating leases 7.3 7.7 Finance leases 2.6 2.0 Discount rate Operating leases 10.7 % 10.6 % Finance leases 10.2 % 9.5 % |
Summary of Lease Cost | The following table summarizes the lease costs pertaining to the Company’s operating leases (in thousands): Year Ended December 31, 2020 2019 2018 Operating lease cost $ 1,258 $ 946 $ 401 Variable lease cost 665 331 198 Total lease cost $ 1,923 $ 1,277 $ 599 |
Schedule of Maturities of Operating and Finance Lease Liabilities | The maturities of the Company’s operating and finance lease liabilities as of December 31, 2020 were as follows (in thousands): Operating Leases Finance Leases 2021 $ 995 $ 32 2022 1,033 32 2023 1,064 17 2024 1,096 — 2025 1,129 — Thereafter 2,765 — Total lease payments 8,082 81 Less: Imputed interest (2,525 ) (9 ) Tenant allowance (109 ) — Total $ 5,448 $ 72 |
Stockholders' Equity (Tables)
Stockholders' Equity (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] | |
Summary of Pre-funded Warrants for Common Stock Issued and Outstanding | As of December 31, 2020, the following pre-funded warrants to purchase common stock were issued and outstanding: Issue Date Expiration Date Exercise Price Number of Warrants Outstanding February 8, 2019 None $ 0.0001 4,000,000 April 30, 2020 None $ 0.0001 13,610,328 Total pre-funded warrants 17,610,328 |
Stock-Based Compensation (Table
Stock-Based Compensation (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] | |
Summary of Employee and Non-Employee Stock Option Activity | The following table summarizes employee and non-employee stock option activity for the year ended December 31, 2020: Shares Issuable Under Options Weighted Average Exercise Price Weighted Average Remaining Contractual Term Aggregate Intrinsic Value (in years) (in Outstanding as of December 31, 2019 3,889,188 $ 7.37 8.10 $ 3,642 Granted 1,963,100 7.97 Exercised (127,376 ) 3.85 Forfeited (367,068 ) 7.84 Outstanding as of December 31, 2020 5,357,844 $ 7.64 7.92 $ 3,788 Options vested and expected to vest as of December 31, 2020 5,003,406 $ 7.58 7.86 $ 3,783 Options exercisable as of December 31, 2020 2,654,899 $ 7.24 7.11 $ 3,041 |
Summary of Employee Restricted Stock Activity | The following table summarizes employee restricted stock activity for the year ended December 31, 2020: Shares Weighted Average Grant Date Fair Value Unvested restricted stock units as of December 31, 2019 — $ — Granted 228,200 8.13 Vested — — Forfeited — — Unvested restricted stock units as of December 31, 2020 228,200 $ 8.13 |
Summary of Stock-Based Compensation Expense | Total stock-based compensation expense recognized from the Company’s equity incentive plans, 2018 Plan, and the 2016 ESPP for the years ended December 31, 2020, 2019, and 2018 was as follows (in thousands): Year Ended December 31, 2020 2019 2018 Employees Non- Employees Employees Non- Employees Employees Non- Employees Research and development $ 2,168 $ 36 $ 1,828 $ — $ 1,440 $ 234 General and administrative 4,052 — 3,048 — 2,606 — Total stock-based compensation expense $ 6,220 $ 36 $ 4,876 $ — $ 4,046 $ 234 |
Summary of Weighted-Average Assumptions Used in Calculating Fair Value of Awards | The following table summarizes the weighted-average assumptions used in calculating the fair value of the awards: Year Ended December 31, 2020 2019 2018 2018 Plan, 2016 Plan, and 2015 Plan Expected term (in years) 6.10 6.01 5.20 Expected volatility 76 % 80 % 74 % Risk-free interest 1.06 % 2.32 % 2.42 % Dividend yield 0 % 0 % 0 % 2016 ESPP Expected term (in years) 0.50 0.50 0.50 Expected volatility 76 % 70 % 66 % Risk-free interest 0.75 % 2.11 % 2.20 % Dividend yield 0 % 0 % 0 % |
Income Taxes (Tables)
Income Taxes (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Income Tax Disclosure [Abstract] | |
Summary of Difference Between Provision for Income Taxes and Amounts Computed by Applying Statutory Federal Income Tax Rate to Income Before Income Taxes | The difference between the Company’s provision for income taxes and the amounts computed by applying the statutory federal income tax rate to income before income taxes is as follows (in thousands): Year Ended December 31, 2020 2019 2018 Tax provision derived by applying the federal statutory rate to income before income taxes $ (16,988 ) $ (16,433 ) $ (9,313 ) Permanent differences and other 482 (98 ) 264 Federal tax credits (3,905 ) (3,599 ) (1,211 ) State tax credits (251 ) (229 ) 464 Change in the valuation allowance 20,662 20,359 9,796 Income tax expense /(benefit) $ — $ — $ — |
Components of Deferred Tax Assets and Liabilities | The components of the deferred tax assets and liabilities consist of the following (in thousands): December 31, 2020 2019 Deferred tax assets Net operating loss carryforward $ 51,708 $ 36,093 Intangible assets 51 45 Accrued expense 598 605 Stock-based compensation 2,087 1,237 Federal tax credits 14,764 10,859 State tax credits 839 588 Other 299 126 Total deferred tax assets 70,346 49,553 Deferred tax liabilities Depreciable assets (203 ) (72 ) Total deferred tax liabilities (203 ) (72 ) Less: Valuation allowance (70,143 ) (49,481 ) Deferred tax assets, net $ — $ — |
Net Loss Per Share (Tables)
Net Loss Per Share (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Earnings Per Share [Abstract] | |
Weighted-Average Equity Instruments Excluded from Calculation of Diluted Net Loss Per Share | The following weighted-average equity instruments were excluded from the calculation of diluted net loss per share because their effect would have been anti-dilutive for the periods presented: Year Ended December 31, 2020 2019 2018 Options to purchase common stock 5,049,435 3,874,817 3,014,984 Unvested restricted stock units 105,995 — — |
Selected Quarterly Financial _2
Selected Quarterly Financial Data (Unaudited) (Tables) | 12 Months Ended |
Dec. 31, 2020 | |
Selected Quarterly Financial Information [Abstract] | |
Schedule of Selected Quarterly Results from Operations | Selected quarterly results from operations for the years ended December 31, 2020 and 2019 are as follows (in thousands, except per share amounts): 2020 Quarter Ended March 31, June 30, September December Loss from operations $ (19,022 ) $ (21,560 ) $ (18,123 ) $ (22,776 ) Net loss (18,728 ) (21,418 ) (18,033 ) (22,714 ) Basic and diluted net loss per common share $ (0.57 ) $ (0.40 ) $ (0.29 ) $ (0.35 ) 2019 Quarter Ended March 31, June 30, September December Loss from operations $ (17,657 ) $ (18,622 ) $ (22,146 ) $ (21,909 ) Net loss (17,167 ) (18,019 ) (21,573 ) (21,495 ) Basic and diluted net loss per common share $ (0.59 ) $ (0.55 ) $ (0.66 ) $ (0.65 ) |
The Company and Basis of Pres_2
The Company and Basis of Presentation - Additional Information (Details) $ in Thousands | 12 Months Ended | |
Dec. 31, 2020USD ($)Segment | Dec. 31, 2019USD ($) | |
Organization Consolidation And Presentation Of Financial Statements [Abstract] | ||
Number of operating segments | Segment | 1 | |
Working capital | $ 133,300 | |
Accumulated deficit | (276,008) | $ (195,115) |
Cash, cash equivalents, marketable securities, and restricted cash | $ 148,100 |
Summary of Significant Accoun_4
Summary of Significant Accounting Policies - Additional Information (Details) | Mar. 27, 2020 | Jun. 01, 2014USD ($) | Dec. 31, 2020USD ($)Subsidary | Dec. 31, 2019USD ($) | Dec. 31, 2018USD ($) |
Summary Of Significant Accounting Policies [Line Items] | |||||
Impairments of long-lived assets | $ 0 | $ 0 | $ 0 | ||
Net operating loss carryback period | 5 years | ||||
Net operating loss carryforwards taxable income suspension of annual deduction limitation percentage | 80.00% | ||||
United States | |||||
Summary Of Significant Accounting Policies [Line Items] | |||||
Number of subsidiary corporations owned | Subsidary | 9 | ||||
Maximum | |||||
Summary Of Significant Accounting Policies [Line Items] | |||||
Marketable securities stated maturity period | 1 year | ||||
Maximum | CPRIT | |||||
Summary Of Significant Accounting Policies [Line Items] | |||||
Research grant contract amount | $ 19,800,000 |
Summary of Significant Accoun_5
Summary of Significant Accounting Policies - Summary of Useful Lives of Property and Equipment (Details) | 12 Months Ended |
Dec. 31, 2020 | |
Laboratory Equipment | |
Property Plant And Equipment [Line Items] | |
Useful lives of the property and equipment | 5 years |
Furniture and Office Equipment | |
Property Plant And Equipment [Line Items] | |
Useful lives of the property and equipment | 5 years |
Computer Equipment | |
Property Plant And Equipment [Line Items] | |
Useful lives of the property and equipment | 3 years |
Software | |
Property Plant And Equipment [Line Items] | |
Useful lives of the property and equipment | 3 years |
Leasehold Improvements | |
Property Plant And Equipment [Line Items] | |
Useful lives of the property and equipment | Shorter of remaining lease term or estimated useful life |
Fair Value Measurements - Finan
Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands | Dec. 31, 2020 | Dec. 31, 2019 |
Financial Assets | ||
Financial assets, fair value | $ 133,775 | $ 68,216 |
Commercial paper | ||
Financial Assets | ||
Financial assets, fair value | 15,193 | |
Corporate bonds | ||
Financial Assets | ||
Financial assets, fair value | 3,001 | 39,750 |
Money market funds | ||
Financial Assets | ||
Financial assets, fair value | 6,700 | 7,023 |
U.S. treasury securities | ||
Financial Assets | ||
Financial assets, fair value | 57,181 | |
U.S. government agency securities | ||
Financial Assets | ||
Financial assets, fair value | 66,893 | |
Reverse repurchase agreements | ||
Financial Assets | ||
Financial assets, fair value | 6,250 | |
Level 1 | ||
Financial Assets | ||
Financial assets, fair value | 6,700 | 7,023 |
Level 1 | Money market funds | ||
Financial Assets | ||
Financial assets, fair value | 6,700 | 7,023 |
Level 2 | ||
Financial Assets | ||
Financial assets, fair value | 127,075 | 61,193 |
Level 2 | Commercial paper | ||
Financial Assets | ||
Financial assets, fair value | 15,193 | |
Level 2 | Corporate bonds | ||
Financial Assets | ||
Financial assets, fair value | 3,001 | 39,750 |
Level 2 | U.S. treasury securities | ||
Financial Assets | ||
Financial assets, fair value | 57,181 | |
Level 2 | U.S. government agency securities | ||
Financial Assets | ||
Financial assets, fair value | $ 66,893 | |
Level 2 | Reverse repurchase agreements | ||
Financial Assets | ||
Financial assets, fair value | $ 6,250 |
Fair Value Measurements - Addit
Fair Value Measurements - Additional Information (Details) | Dec. 31, 2020USD ($) |
Fair Value Disclosures [Abstract] | |
Fair value assets transferred from level 1 to level 2 | $ 0 |
Cash Equivalents and Marketab_3
Cash Equivalents and Marketable Securities - Schedule of Estimated Fair Value of Cash Equivalents and Marketable Securities (Details) - USD ($) $ in Thousands | Dec. 31, 2020 | Dec. 31, 2019 |
Schedule Of Available For Sale Securities [Line Items] | ||
Cash equivalents, amortized cost | $ 77,600 | $ 15,520 |
Cash equivalents, gross unrealized losses | (3) | |
Cash equivalents, estimated fair value | 77,597 | 15,520 |
Marketable securities, amortized cost | 56,183 | 52,645 |
Marketable securities, gross unrealized gains | 2 | 60 |
Marketable securities, gross unrealized losses | (7) | (9) |
Marketable securities, estimated fair value | 56,178 | 52,696 |
Corporate bonds | ||
Schedule Of Available For Sale Securities [Line Items] | ||
Marketable securities, amortized cost | 3,000 | 39,714 |
Marketable securities, gross unrealized gains | 1 | 45 |
Marketable securities, gross unrealized losses | (9) | |
Marketable securities, estimated fair value | 3,001 | 39,750 |
Commercial paper | ||
Schedule Of Available For Sale Securities [Line Items] | ||
Cash equivalents, amortized cost | 2,247 | |
Cash equivalents, estimated fair value | 2,247 | |
Marketable securities, amortized cost | 12,931 | |
Marketable securities, gross unrealized gains | 15 | |
Marketable securities, estimated fair value | 12,946 | |
Money market funds | ||
Schedule Of Available For Sale Securities [Line Items] | ||
Cash equivalents, amortized cost | 6,700 | 7,023 |
Cash equivalents, estimated fair value | 6,700 | 7,023 |
U.S. treasury securities | ||
Schedule Of Available For Sale Securities [Line Items] | ||
Cash equivalents, amortized cost | 4,005 | |
Cash equivalents, gross unrealized losses | (1) | |
Cash equivalents, estimated fair value | 4,004 | |
Marketable securities, amortized cost | 53,183 | |
Marketable securities, gross unrealized gains | 1 | |
Marketable securities, gross unrealized losses | (7) | |
Marketable securities, estimated fair value | 53,177 | |
U.S. government agency securities | ||
Schedule Of Available For Sale Securities [Line Items] | ||
Cash equivalents, amortized cost | 66,895 | |
Cash equivalents, gross unrealized losses | (2) | |
Cash equivalents, estimated fair value | $ 66,893 | |
Reverse repurchase agreements | ||
Schedule Of Available For Sale Securities [Line Items] | ||
Cash equivalents, amortized cost | 6,250 | |
Cash equivalents, estimated fair value | $ 6,250 |
Cash Equivalents and Marketab_4
Cash Equivalents and Marketable Securities - Schedule of Gross Unrealized Losses and Fair Value by Investment Category and Age (Details) - USD ($) $ in Thousands | Dec. 31, 2020 | Dec. 31, 2019 |
Schedule Of Available For Sale Securities [Line Items] | ||
Less than 12 Months, Fair Value | $ 110,076 | |
Less than 12 Months, Unrealized Loss | (10) | |
Total, Fair Value | 110,076 | |
Total, Unrealized Loss | (10) | |
Corporate bonds | ||
Schedule Of Available For Sale Securities [Line Items] | ||
Less than 12 Months, Fair Value | $ 13,022 | |
Less than 12 Months, Unrealized Loss | (9) | |
Total, Fair Value | 13,022 | |
Total, Unrealized Loss | $ (9) | |
U.S. treasury securities | ||
Schedule Of Available For Sale Securities [Line Items] | ||
Less than 12 Months, Fair Value | 43,183 | |
Less than 12 Months, Unrealized Loss | (8) | |
Total, Fair Value | 43,183 | |
Total, Unrealized Loss | (8) | |
U.S. government agency securities | ||
Schedule Of Available For Sale Securities [Line Items] | ||
Less than 12 Months, Fair Value | 66,893 | |
Less than 12 Months, Unrealized Loss | (2) | |
Total, Fair Value | 66,893 | |
Total, Unrealized Loss | $ (2) |
Cash Equivalents and Marketab_5
Cash Equivalents and Marketable Securities - Additional Information (Details) - US Government Agencies Debt Securities $ in Thousands | 12 Months Ended | |
Dec. 31, 2020USD ($)Security | Dec. 31, 2019USD ($)Security | |
Cash Equivalents And Marketable Securities [Line Items] | ||
Number of debt securities held | Security | 16 | 13 |
Allowance for Credit Loss | $ 0 | $ 0 |
Impairment of marketable securities | $ 0 | $ 0 |
Cash Equivalents and Marketab_6
Cash Equivalents and Marketable Securities - Summary of Contractual Maturities of Marketable Securities at Estimated Fair Value (Details) - USD ($) $ in Thousands | Dec. 31, 2020 | Dec. 31, 2019 |
Investments Debt And Equity Securities [Abstract] | ||
Due in one year or less | $ 56,178 | $ 49,687 |
Due in 1 - 2 years | 3,009 | |
Total marketable securities | $ 56,178 | $ 52,696 |
Property and Equipment, Net - S
Property and Equipment, Net - Schedule of Property and Equipment Net (Details) - USD ($) $ in Thousands | Dec. 31, 2020 | Dec. 31, 2019 |
Property Plant And Equipment [Line Items] | ||
Property and equipment, gross | $ 7,625 | $ 3,440 |
Less: Accumulated depreciation and amortization | (1,983) | (1,055) |
Property and equipment, net | 5,642 | 2,385 |
Laboratory Equipment | ||
Property Plant And Equipment [Line Items] | ||
Property and equipment, gross | 1,916 | 1,085 |
Furniture and Office Equipment | ||
Property Plant And Equipment [Line Items] | ||
Property and equipment, gross | 747 | 396 |
Computer Equipment | ||
Property Plant And Equipment [Line Items] | ||
Property and equipment, gross | 56 | 50 |
Software | ||
Property Plant And Equipment [Line Items] | ||
Property and equipment, gross | 132 | 96 |
Leasehold Improvements | ||
Property Plant And Equipment [Line Items] | ||
Property and equipment, gross | $ 4,774 | $ 1,813 |
Property and Equipment, Net - A
Property and Equipment, Net - Additional Information (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Property Plant And Equipment [Abstract] | |||
Depreciation and amortization | $ 996 | $ 418 | $ 293 |
Accrued and Other Current Lia_3
Accrued and Other Current Liabilities (Details) - USD ($) $ in Thousands | Dec. 31, 2020 | Dec. 31, 2019 |
Accrued Liabilities And Other Liabilities [Abstract] | ||
Accrued compensation | $ 3,712 | $ 3,273 |
Accrued contracted research and development costs | 8,620 | 10,485 |
Accrued professional and consulting fees | 1,074 | 627 |
Other | 464 | 469 |
Total accrued and other current liabilities | $ 13,870 | $ 14,854 |
Leases - Additional Information
Leases - Additional Information (Details) | 1 Months Ended | 12 Months Ended | |
Apr. 30, 2019USD ($)ft² | Dec. 31, 2020USD ($) | Dec. 31, 2019USD ($) | |
Schedule Of Operating And Finance Leased Assets [Line Items] | |||
Area of land | ft² | 30,000 | ||
Lease expiration date | Apr. 30, 2028 | ||
Reimbursement of Tenant Allowance | $ 900,000 | ||
Operating lease, payments | $ 1,300,000 | $ 700,000 | |
Letter of Credit | |||
Schedule Of Operating And Finance Leased Assets [Line Items] | |||
Letter of credit | $ 1,500,000 | ||
Minimum | |||
Schedule Of Operating And Finance Leased Assets [Line Items] | |||
Lessee, operating lease, renewal term | 3 years | ||
Lessee, finance lease, renewal term | 3 years | ||
Maximum | |||
Schedule Of Operating And Finance Leased Assets [Line Items] | |||
Lessee, operating lease, renewal term | 5 years | ||
Lessee, finance lease, renewal term | 5 years | ||
Tenant improvement allowance | $ 1,000,000 |
Leases - Schedule of Operating
Leases - Schedule of Operating and Financing Leases Presented in Balance Sheet (Details) - USD ($) $ in Thousands | Dec. 31, 2020 | Dec. 31, 2019 |
Leases [Abstract] | ||
Operating | $ 4,230 | $ 4,726 |
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List] | us-gaap:OperatingLeaseRightOfUseAsset | |
Finance | $ 68 | 56 |
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List] | us-gaap:OtherAssetsNoncurrent | |
Total leased assets | $ 4,298 | 4,782 |
Operating lease liabilities, current | $ 319 | 351 |
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List] | us-gaap:OperatingLeaseLiabilityCurrent | |
Finance lease liabilities, current | $ 27 | 28 |
Finance Lease, Liabilities, Current, Statement of Financial Position [Extensible List] | us-gaap:AccruedLiabilitiesAndOtherLiabilities | |
Operating lease liabilities, noncurrent | $ 5,129 | 4,712 |
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List] | us-gaap:OperatingLeaseLiabilityNoncurrent | |
Finance lease liabilities, noncurrent | $ 45 | 31 |
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List] | us-gaap:OtherLiabilitiesNoncurrent | |
Total lease liabilities | $ 5,520 | $ 5,122 |
Leases - Summary of Weighted-Av
Leases - Summary of Weighted-Average Remaining Lease Term and Discount Rates for Operating and Finance Leases (Details) | Dec. 31, 2020 | Dec. 31, 2019 |
Leases [Abstract] | ||
Operating leases, Weighted-average remaining lease term | 7 years 3 months 18 days | 7 years 8 months 12 days |
Finance leases, Weighted-average remaining lease term | 2 years 7 months 6 days | 2 years |
Operating leases, Weighted-average discount rate | 10.70% | 10.60% |
Finance leases, Weighted-average discount rate | 10.20% | 9.50% |
Leases - Summary of Lease Cost
Leases - Summary of Lease Cost (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Leases [Abstract] | |||
Operating lease cost | $ 1,258 | $ 946 | $ 401 |
Variable lease cost | 665 | 331 | 198 |
Total lease cost | $ 1,923 | $ 1,277 | $ 599 |
Leases - Schedule of Maturities
Leases - Schedule of Maturities of Operating and Finance Lease Liabilities (Details) $ in Thousands | Dec. 31, 2020USD ($) |
Operating Leases | |
2021 | $ 995 |
2022 | 1,033 |
2023 | 1,064 |
2024 | 1,096 |
2025 | 1,129 |
Thereafter | 2,765 |
Total lease payments | 8,082 |
Imputed interest | (2,525) |
Tenant allowance | (109) |
Total | 5,448 |
Total lease payments | 8,082 |
Finance Lease Liabilities, Payments, Due [Abstract] | |
2021 | 32 |
2022 | 32 |
2023 | 17 |
Total lease payments | 81 |
Imputed interest | (9) |
Total | $ 72 |
Stockholders' Equity - Addition
Stockholders' Equity - Additional Information (Details) | 1 Months Ended | 3 Months Ended | 12 Months Ended | ||||||
Apr. 30, 2020USD ($)$ / sharesshares | Feb. 28, 2019USD ($)$ / sharesshares | Oct. 31, 2018USD ($)shares | Apr. 30, 2018USD ($)$ / sharesshares | May 31, 2017USD ($) | Dec. 31, 2020USD ($)Vote$ / sharesshares | Dec. 31, 2020USD ($)Vote$ / sharesshares | Dec. 31, 2019USD ($)$ / sharesshares | Dec. 31, 2018USD ($)shares | |
Class Of Stock [Line Items] | |||||||||
Proceeds from issuance of common stock in public offering, net | $ 54,048,000 | ||||||||
Underwriting discounts and commissions | $ 8,200,000 | $ 4,100,000 | |||||||
Offering costs | 800,000 | 400,000 | |||||||
Shares authorized | shares | 510,000,000 | 510,000,000 | |||||||
Common stock, shares authorized | shares | 500,000,000 | 500,000,000 | 500,000,000 | ||||||
Preferred stock, shares authorized | shares | 10,000,000 | 10,000,000 | 10,000,000 | ||||||
Common stock, par value | $ / shares | $ 0.0001 | $ 0.0001 | $ 0.0001 | ||||||
Preferred stock, par value | $ / shares | $ 0.0001 | $ 0.0001 | $ 0.0001 | ||||||
Number of common stock holders voting right | Vote | 1 | 1 | |||||||
Common stock voting rights | Each holder of common stock is entitled to one vote for each share of common stock held | ||||||||
Common stock dividends declared | $ 0 | $ 0 | |||||||
Preferred stock, shares outstanding | shares | 0 | 0 | 0 | ||||||
Net proceeds from sale of common stock | $ 129,000,000 | $ 64,500,000 | |||||||
Reduction in exercise price of each warrant from public offering price for pre-funded warrants per share | $ / shares | $ 0.0001 | $ 0.0001 | |||||||
Maximum ownership percentage for outstanding warrants to purchase shares of common stock to be exercised | 4.99% | 4.99% | |||||||
Period after notice received by company maximum ownership percentage to be effective description | The revised Maximum Ownership Percentage would be effective 61 days after the notice is received by the Company. | ||||||||
Maximum | |||||||||
Class Of Stock [Line Items] | |||||||||
Maximum ownership percentage for outstanding warrants to purchase shares of common stock to be exercised | 19.99% | ||||||||
Common Stock | |||||||||
Class Of Stock [Line Items] | |||||||||
Number of shares issued | shares | 5,046,510 | 6,893,000 | |||||||
Public offering price | $ / shares | $ 8 | ||||||||
Underwriting discounts and commissions | $ 2,400,000 | ||||||||
Offering costs | 300,000 | ||||||||
Follow-on Public Offering | Common Stock | |||||||||
Class Of Stock [Line Items] | |||||||||
Number of shares issued | shares | 15,442,303 | 4,625,000 | |||||||
Public offering price | $ / shares | $ 4.75 | $ 8 | |||||||
Proceeds from issuance of common stock in public offering, net | $ 37,700,000 | ||||||||
Public offering price of warrant | $ / shares | $ 4.7499 | $ 7.9999 | |||||||
Follow-on Public Offering | Common Stock | Maximum | |||||||||
Class Of Stock [Line Items] | |||||||||
Warrants to purchase shares | shares | 13,610,328 | 4,000,000 | |||||||
At-the-Market (ATM) Sales Agreement | JonesTrading Institutional Services LLC | |||||||||
Class Of Stock [Line Items] | |||||||||
Number of shares issued | shares | 1,845,820 | 3,245,077 | |||||||
Aggregate offering price of common stock | $ 60,000,000 | $ 20,000,000 | |||||||
Net proceeds from sale of common stock | $ 16,400,000 | $ 24,600,000 | |||||||
Proceeds from issuance of common stock gross | $ 17,000,000 | $ 25,300,000 | |||||||
ATM aggregate amount remaining | $ 34,700,000 | ||||||||
Underwriters' Over-allotment Option | |||||||||
Class Of Stock [Line Items] | |||||||||
Number of shares issued | shares | 3,789,473 | 1,125,000 | |||||||
Underwriters' Over-allotment Option | Common Stock | |||||||||
Class Of Stock [Line Items] | |||||||||
Number of shares issued | shares | 546,510 |
Stockholders' Equity - Summary
Stockholders' Equity - Summary of Pre-funded Warrants for Common Stock Issued and Outstanding (Details) - Pre-funded Warrants | 12 Months Ended |
Dec. 31, 2020$ / sharesshares | |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |
Number of Warrants Outstanding | 17,610,328 |
February 8, 2019 | |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |
Issue Date | Feb. 8, 2019 |
Expiration Date | None |
Exercise Price | $ / shares | $ 0.0001 |
Number of Warrants Outstanding | 4,000,000 |
April 30, 2020 | |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |
Issue Date | Apr. 30, 2020 |
Expiration Date | None |
Exercise Price | $ / shares | $ 0.0001 |
Number of Warrants Outstanding | 13,610,328 |
Grant Revenues - Additional Inf
Grant Revenues - Additional Information (Details) - USD ($) $ in Thousands | Jun. 01, 2014 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | May 31, 2018 |
Research And Development Arrangement Contract To Perform For Others [Line Items] | |||||
Grant revenues | $ 0 | $ 0 | $ 3,888 | ||
Type of revenue [extensible list] | us-gaap:GrantMember | us-gaap:GrantMember | us-gaap:GrantMember | ||
CPRIT | |||||
Research And Development Arrangement Contract To Perform For Others [Line Items] | |||||
Grant contract term | 4 years | ||||
Grant contract beginning date | Jun. 1, 2014 | ||||
Grant contract expiration date | May 31, 2018 | ||||
Grant revenues | $ 19,800 | ||||
Type of revenue [extensible list] | us-gaap:GrantMember | ||||
CPRIT | Maximum | |||||
Research And Development Arrangement Contract To Perform For Others [Line Items] | |||||
Research grant contract amount | $ 19,800 |
Stock-Based Compensation - Addi
Stock-Based Compensation - Additional Information (Details) - USD ($) | 1 Months Ended | 12 Months Ended | ||||||||||
Nov. 30, 2018 | Oct. 31, 2018 | Jun. 30, 2018 | Feb. 28, 2018 | Apr. 30, 2016 | Mar. 31, 2015 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | Jan. 01, 2020 | Jan. 01, 2019 | Jan. 01, 2018 | |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Outstanding option awards and restricted unit awards | 5,357,844 | 3,889,188 | ||||||||||
Stock-based compensation | $ 6,256,000 | $ 4,876,000 | $ 4,280,000 | |||||||||
Tax benefits recognized | $ 0 | 0 | 0 | |||||||||
Expected dividend yield | 0.00% | |||||||||||
Restricted Common Stock | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Shares, Granted | 228,200 | |||||||||||
Stock-based compensation | $ 1,900,000 | |||||||||||
Non-Employees | Restricted Common Stock | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Shares, Granted | 0 | |||||||||||
Employees and Non-Employees | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Expense recognized for unvested employee and non-employee awards | $ 0 | $ 0 | $ 0 | |||||||||
Director | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Incremental fair value of outstanding equity awards | $ 300,000 | |||||||||||
Director | Stock Options | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Modification of outstanding award | 86,252 | |||||||||||
Director | RSAs | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Modification of outstanding award | 43,290 | |||||||||||
Stock Options | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Weighted-average grant date fair value | $ 4.68 | $ 8.09 | $ 8.03 | |||||||||
Intrinsic value of options exercised | $ 400,000 | $ 1,000,000 | $ 1,900,000 | |||||||||
Unrecognized stock-based compensation expense for options | $ 12,300,000 | |||||||||||
Weighted average period over which unrecognized compensation is expected to be recognized | 2 years 6 months | |||||||||||
Stock Options | Non-Employees | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Stock option issued | 0 | 0 | 0 | |||||||||
Stock option vested | 1,663 | 0 | 6,626 | |||||||||
2015 Equity Incentive Plan | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Awards granted, expiration period | 10 years | |||||||||||
Combined voting power of all classes of stock | 10.00% | |||||||||||
Option vesting, year | 5 years | |||||||||||
Number of common stock to option outstanding | 204,482 | |||||||||||
Number of common stock available for issuance | 509,869 | |||||||||||
2015 Equity Incentive Plan | Minimum | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Percentage of market value of common stock | 100.00% | |||||||||||
2016 Equity Incentive Plan | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Initial reserves of common stock | 1,100,000 | |||||||||||
Increase in number of shares of common stock reserved for issuance | 1,759,602 | |||||||||||
Share based compensation plan expiration date | Aug. 7, 2028 | |||||||||||
Percentage of outstanding share of common stock | 4.00% | |||||||||||
Additional number of shares available for issuance | 1,163,377 | 965,603 | 666,807 | |||||||||
Total number of common stock reserved for issuance | 6,883,659 | |||||||||||
Outstanding option awards and restricted unit awards | 5,299,662 | |||||||||||
2018 Equity Inducement Plan | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Initial reserves of common stock | 1,100,000 | |||||||||||
Total number of common stock reserved for issuance | 1,100,000 | |||||||||||
Outstanding option awards and restricted unit awards | 81,900 | |||||||||||
2018 Plan, 2016 Plan and 2015 Plan | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Awards granted, expiration period | 10 years | |||||||||||
2018 Plan, 2016 Plan and 2015 Plan | Four Year Vesting | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Option vesting, year | 4 years | |||||||||||
2018 Plan, 2016 Plan and 2015 Plan | Maximum | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Option vesting, year | 4 years | |||||||||||
2016 Employee Stock Purchase Plan | ||||||||||||
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||||||||||||
Percentage of outstanding share of common stock | 1.00% | |||||||||||
Additional number of shares available for issuance | 290,844 | 241,400 | ||||||||||
Total number of common stock reserved for issuance | 165,000 | 478,298 | ||||||||||
Percentage of discount through payroll deductions to eligible employees to purchase common stock | 15.00% | |||||||||||
Percentage of fair market value of common stock | 85.00% | |||||||||||
Maximum number of shares permitted for per employee | 2,000 | |||||||||||
Maximum purchase value per employee under employee stock purchase plan | $ 25,000 | |||||||||||
Employee stock purchase plan termination period | 10 years | |||||||||||
Expected dividend yield | 0.00% | 0.00% | 0.00% |
Stock-Based Compensation - Summ
Stock-Based Compensation - Summary of Employee and Non-Employee Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands | 12 Months Ended | |
Dec. 31, 2020 | Dec. 31, 2019 | |
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] | ||
Shares Issuable Under Options, Outstanding | 3,889,188 | |
Shares Issuable Under Options, Granted | 1,963,100 | |
Shares Issuable Under Options, Exercised | (127,376) | |
Shares Issuable Under Options, Forfeited | (367,068) | |
Shares Issuable Under Options, Outstanding | 5,357,844 | 3,889,188 |
Shares Issuable Under Options, Options vested and expected to vest | 5,003,406 | |
Shares Issuable Under Options, Options exercisable | 2,654,899 | |
Weighted Average Exercise Price, Outstanding | $ 7.37 | |
Weighted Average Exercise Price, Granted | 7.97 | |
Weighted Average Exercise Price, Exercised | 3.85 | |
Weighted Average Exercise Price, Forfeited | 7.84 | |
Weighted Average Exercise Price, Outstanding | 7.64 | $ 7.37 |
Weighted Average Exercise Price, Options vested and expected to vest | 7.58 | |
Weighted Average Exercise Price, Options exercisable | $ 7.24 | |
Weighted Average Remaining Contractual Term, Outstanding | 7 years 11 months 1 day | 8 years 1 month 6 days |
Weighted Average Remaining Contractual Term, Options vested and expected to vest | 7 years 10 months 9 days | |
Weighted Average Remaining Contractual Term, Options exercisable | 7 years 1 month 9 days | |
Aggregate Intrinsic Value, Outstanding | $ 3,788 | $ 3,642 |
Aggregate Intrinsic Value, Options vested and expected to vest | 3,783 | |
Aggregate Intrinsic Value, Options exercisable | $ 3,041 |
Stock-Based Compensation - Su_2
Stock-Based Compensation - Summary of Employee Restricted Stock Activity (Details) - Restricted Common Stock - Employees | 12 Months Ended |
Dec. 31, 2020$ / sharesshares | |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |
Shares, Granted | shares | 228,200 |
Shares, Unvested restricted common stock, Ending balance | shares | 228,200 |
Weighted Average Grant Date Fair Value, Granted | $ / shares | $ 8.13 |
Weighted Average Grant Date Fair Value, Unvested restricted common stock, Ending balance | $ / shares | $ 8.13 |
Stock-Based Compensation - Su_3
Stock-Based Compensation - Summary of Stock-Based Compensation Expense (Details) - 2018 Equity Inducement Plan and 2016 Employee Stock Purchase Plan - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Employees | |||
Employee Service Share Based Compensation Allocation of Recognized Period Costs [Line Items] | |||
Total stock-based compensation expense | $ 6,220 | $ 4,876 | $ 4,046 |
Non-Employees | |||
Employee Service Share Based Compensation Allocation of Recognized Period Costs [Line Items] | |||
Total stock-based compensation expense | 36 | 234 | |
Research and Development | Employees | |||
Employee Service Share Based Compensation Allocation of Recognized Period Costs [Line Items] | |||
Total stock-based compensation expense | 2,168 | 1,828 | 1,440 |
Research and Development | Non-Employees | |||
Employee Service Share Based Compensation Allocation of Recognized Period Costs [Line Items] | |||
Total stock-based compensation expense | 36 | 234 | |
General and Administrative | Employees | |||
Employee Service Share Based Compensation Allocation of Recognized Period Costs [Line Items] | |||
Total stock-based compensation expense | $ 4,052 | $ 3,048 | $ 2,606 |
Stock-Based Compensation - Su_4
Stock-Based Compensation - Summary of Weighted-Average Assumptions Used in Calculating Fair Value of Awards (Details) | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Employee Service Share Based Compensation Allocation of Recognized Period Costs [Line Items] | |||
Dividend yield | 0.00% | ||
2018 Plan, 2016 Plan and 2015 Plan | |||
Employee Service Share Based Compensation Allocation of Recognized Period Costs [Line Items] | |||
Expected term (in years) | 6 years 1 month 6 days | 6 years 3 days | 5 years 2 months 12 days |
Expected volatility | 76.00% | 80.00% | 74.00% |
Risk-free interest | 1.06% | 2.32% | 2.42% |
Dividend yield | 0.00% | 0.00% | 0.00% |
2016 Employee Stock Purchase Plan | |||
Employee Service Share Based Compensation Allocation of Recognized Period Costs [Line Items] | |||
Expected term (in years) | 6 months | 6 months | 6 months |
Expected volatility | 76.00% | 70.00% | 66.00% |
Risk-free interest | 0.75% | 2.11% | 2.20% |
Dividend yield | 0.00% | 0.00% | 0.00% |
Defined Contribution Plan - Add
Defined Contribution Plan - Additional Information (Details) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Compensation And Retirement Disclosure [Abstract] | |||
Defined contribution plan, contribution amount | $ 0.5 | $ 0.3 | $ 0.2 |
Income Taxes - Additional Infor
Income Taxes - Additional Information (Details) - USD ($) | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Income Taxes [Line Items] | |||
Provision or benefit from income taxes | $ 0 | $ 0 | $ 0 |
Net operating loss carryforwards | 246,200,000 | 171,900,000 | |
Net operating loss and tax credit carryforwards | 58,400,000 | 11,100,000 | |
Unrecognized tax benefit | $ 0 | 0 | 0 |
Earliest Tax Year | |||
Income Taxes [Line Items] | |||
Net operating loss carryforwards, expiration year | 2033 | ||
Tax credit carryforwards, expiration year | 2033 | ||
Tax Cuts and Jobs Act of 2017 | |||
Income Taxes [Line Items] | |||
Increase in valuation allowance | $ 20,700,000 | 20,400,000 | $ 9,800,000 |
Federal | |||
Income Taxes [Line Items] | |||
Tax credit carryforwards | 14,800,000 | 10,900,000 | |
State | |||
Income Taxes [Line Items] | |||
Tax credit carryforwards | $ 800,000 | $ 600,000 |
Income Taxes - Difference Betwe
Income Taxes - Difference Between Provision for Income Taxes and Amounts Computed by Applying Statutory Federal Income Tax Rate to Income Before Income Taxes (Details) - USD ($) | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Income Taxes [Line Items] | |||
Tax provision derived by applying the federal statutory rate to income before income taxes | $ (16,988,000) | $ (16,433,000) | $ (9,313,000) |
Permanent differences and other | 482,000 | (98,000) | 264,000 |
Change in the valuation allowance | 20,662,000 | 20,359,000 | 9,796,000 |
Income tax expense /(benefit) | 0 | 0 | 0 |
Federal | |||
Income Taxes [Line Items] | |||
Tax credits | (3,905,000) | (3,599,000) | (1,211,000) |
State | |||
Income Taxes [Line Items] | |||
Tax credits | $ (251,000) | $ (229,000) | $ 464,000 |
Income Taxes - Components of De
Income Taxes - Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands | Dec. 31, 2020 | Dec. 31, 2019 |
Deferred tax assets | ||
Net operating loss carryforward | $ 51,708 | $ 36,093 |
Intangible assets | 51 | 45 |
Accrued expense | 598 | 605 |
Stock-based compensation | 2,087 | 1,237 |
Other | 299 | 126 |
Total deferred tax assets | 70,346 | 49,553 |
Deferred tax liabilities | ||
Depreciable assets | (203) | (72) |
Total deferred tax liabilities | (203) | (72) |
Less: Valuation allowance | (70,143) | (49,481) |
Deferred tax assets, net | 0 | 0 |
Federal | ||
Deferred tax assets | ||
Tax credits | 14,764 | 10,859 |
State | ||
Deferred tax assets | ||
Tax credits | $ 839 | $ 588 |
Net Loss Per Share - Weighted-A
Net Loss Per Share - Weighted-Average Equity Instruments Excluded from Calculation of Diluted Net Loss Per Share (Details) - shares | 12 Months Ended | ||
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | |
Restricted Common Stock | |||
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] | |||
Antidilutive securities excluded from computation of earnings per share | 105,995 | ||
Options to Purchase Common Stock | |||
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] | |||
Antidilutive securities excluded from computation of earnings per share | 5,049,435 | 3,874,817 | 3,014,984 |
Research and License Agreemen_2
Research and License Agreements - Additional Information (Detail) - License Agreements $ in Millions | 1 Months Ended | 12 Months Ended | ||
Jan. 31, 2017USD ($) | Dec. 31, 2020USD ($)LicenseAgreement | Dec. 31, 2019USD ($) | Dec. 31, 2018USD ($) | |
Research And Development Arrangement Contract To Perform For Others [Line Items] | ||||
Research agreement date | 2013-12 | |||
Number of license agreements | LicenseAgreement | 2 | |||
Maximum future contingent license payment | $ 6.4 | |||
Aggregate potential milestone payments for receipt of regulatory approval | 5 | |||
Aggregate potential milestone payments for final regulatory approval of second indication | $ 0.5 | |||
Annual license fees paid | $ 0.1 | $ 0.1 | $ 0.1 | |
Minimum | ||||
Research And Development Arrangement Contract To Perform For Others [Line Items] | ||||
Rate of revenue share | 6.50% | |||
Maximum | ||||
Research And Development Arrangement Contract To Perform For Others [Line Items] | ||||
Rate of revenue share | 25.00% |
Selected Quarterly Financial _3
Selected Quarterly Financial Data (Unaudited) - Schedule of Selected Quarterly Results from Operations (Details) - 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 | |
Selected Quarterly Financial Information [Abstract] | |||||||||||
Grant revenues | $ 0 | $ 0 | $ 3,888 | ||||||||
Type of revenue [extensible list] | us-gaap:GrantMember | us-gaap:GrantMember | us-gaap:GrantMember | ||||||||
Loss from operations | $ (22,776) | $ (18,123) | $ (21,560) | $ (19,022) | $ (21,909) | $ (22,146) | $ (18,622) | $ (17,657) | $ (81,481) | $ (80,334) | $ (45,463) |
Net loss | $ (22,714) | $ (18,033) | $ (21,418) | $ (18,728) | $ (21,495) | $ (21,573) | $ (18,019) | $ (17,167) | $ (80,893) | $ (78,254) | $ (44,348) |
Basic and diluted net loss per common share | $ (0.35) | $ (0.29) | $ (0.40) | $ (0.57) | $ (0.65) | $ (0.66) | $ (0.55) | $ (0.59) | $ (1.52) | $ (2.45) | $ (2.13) |
Subsequents Events - Additional
Subsequents Events - Additional Information (Details) | Dec. 09, 2020 |
Subsequent Events [Abstract] | |
Maximum ownership percentage to be raised for warrants to purchase shares of common stock | 9.90% |
Maximum ownership percentage for warrants to purchase shares of common stock | 4.99% |