Cover Page
Cover Page - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2021 | Mar. 07, 2022 | Jun. 30, 2021 | |
Cover [Abstract] | |||
Document Type | 10-K | ||
Amendment Flag | false | ||
Document Period End Date | Dec. 31, 2021 | ||
Document Fiscal Year Focus | 2021 | ||
Document Fiscal Period Focus | FY | ||
Entity Registrant Name | Sierra Oncology, Inc. | ||
Entity Central Index Key | 0001290149 | ||
Trading Symbol | SRRA | ||
Current Fiscal Year End Date | --12-31 | ||
Entity Well-known Seasoned Issuer | No | ||
Entity Voluntary Filers | No | ||
Entity Current Reporting Status | Yes | ||
Entity Shell Company | false | ||
Entity Filer Category | Non-accelerated Filer | ||
Entity Emerging Growth Company | false | ||
Entity Small Business | true | ||
Entity Common Stock, Shares Outstanding | 23,665,100 | ||
Entity Interactive Data Current | Yes | ||
Security Exchange Name | NASDAQ | ||
Title of 12(b) Security | Common Stock, $0.001 par value | ||
Entity Address, Address Line One | 1820 Gateway Drive, Suite 110 | ||
Entity Address, City or Town | San Mateo | ||
Entity Address, State or Province | CA | ||
Entity Public Float | $ 128.4 | ||
Document Annual Report | true | ||
Document Transition Report | false | ||
Entity File Number | 001-37490 | ||
Entity Tax Identification Number | 20-0138994 | ||
Entity Address, Postal Zip Code | 94404 | ||
City Area Code | 650 | ||
Local Phone Number | 376-8679 | ||
ICFR Auditor Attestation Flag | false | ||
Entity Incorporation, State or Country Code | DE | ||
Document Information [Text Block] | Portions of the Registrant’s Definitive Proxy Statement (“Proxy Statement”) relating to the 2022 Annual Meeting of Stockholders will be filed with the Commission within 120 days after the end of the Registrant’s 2021 fiscal year and is incorporated by reference into Part III of this Report. | ||
Auditor Firm ID | 34 | ||
Auditor Name | Deloitte & Touche LLP | ||
Auditor Location | Grand Rapids, Michigan |
Consolidated Balance Sheets
Consolidated Balance Sheets - USD ($) $ in Thousands | Dec. 31, 2021 | Dec. 31, 2020 |
CURRENT ASSETS: | ||
Cash and cash equivalents | $ 104,749 | $ 104,055 |
Prepaid expenses and other current assets | 2,644 | 2,415 |
Total current assets | 107,393 | 106,470 |
Property and equipment, net | 141 | 52 |
Operating lease right-of-use assets | 788 | 318 |
Other assets | 1,045 | 647 |
TOTAL ASSETS | 109,367 | 107,487 |
CURRENT LIABILITIES: | ||
Accrued and other liabilities | 10,726 | 7,148 |
Accounts payable | 2,158 | 2,205 |
Total current liabilities | 12,884 | 9,353 |
Operating lease liabilities | 485 | 175 |
TOTAL LIABILITIES | 13,369 | 9,528 |
Commitments and Contingencies (Note 7) | ||
STOCKHOLDERS’ EQUITY: | ||
Preferred stock, $0.001 par value; 10,000,000 shares authorized as of December 31, 2021 and December 31, 2020; nil shares issued and outstanding as of December 31, 2021 and December 31, 2020 | ||
Common stock, $0.001 par value; 500,000,000 shares authorized as of December 31, 2021 and December 31, 2020; 15,571,656 and 11,128,484 shares issued and outstanding as of December 31, 2021 and 2020 | 16 | 11 |
Additional paid-in capital | 1,037,230 | 944,537 |
Accumulated deficit | (941,248) | (846,589) |
TOTAL STOCKHOLDERS’ EQUITY | 95,998 | 97,959 |
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY | $ 109,367 | $ 107,487 |
Consolidated Balance Sheets (Pa
Consolidated Balance Sheets (Parenthetical) - $ / shares | Dec. 31, 2021 | Dec. 31, 2020 |
Statement Of Financial Position [Abstract] | ||
Preferred stock, par value | $ 0.001 | $ 0.001 |
Preferred stock, shares authorized | 10,000,000 | 10,000,000 |
Common stock, par value | $ 0.001 | $ 0.001 |
Common stock, shares authorized | 500,000,000 | 500,000,000 |
Common stock, shares issued | 15,571,656 | 11,128,484 |
Common stock, shares outstanding | 15,571,656 | 11,128,484 |
Condensed Consolidated Statemen
Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019 | |
Income Statement [Abstract] | |||
Collaboration revenue | $ 300 | ||
Operating expenses: | |||
Research and development | $ 67,150 | 45,118 | $ 53,249 |
General and administrative | 27,435 | 20,123 | 13,743 |
Total operating expenses | 94,585 | 65,241 | 66,992 |
Loss from operations | (94,585) | (64,941) | (66,992) |
Other expense (income), net: | |||
Changes in fair value of warrant liabilities | 0 | 16,240 | 20,926 |
Other expense (income), net | 77 | (421) | 517 |
Total other expense (income), net | 77 | 15,819 | 21,443 |
Loss before provision for (benefit from) income taxes, net | (94,662) | (80,760) | (88,435) |
Provision for (benefit from) income taxes, net | (3) | 142 | (160) |
Net loss and comprehensive loss | $ (94,659) | $ (80,902) | $ (88,275) |
Net loss per common share, basic and diluted | $ (7.14) | $ (7.70) | $ (30.30) |
Weighted-average shares used in computing net loss per common share, basic and diluted | 13,252,605 | 10,506,739 | 2,913,487 |
Consolidated Statements of Stoc
Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands | Total | Series A Convertible Voting Preferred Stock [Member] | Common Stock [Member] | Additional Paid-In Capital [Member] | Accumulated Deficit [Member] |
Stockholders Equity, Beginning Balance at Dec. 31, 2018 | $ 94,479 | $ 74 | $ 771,817 | $ (677,412) | |
Stockholders Equity, Beginning Balance, Shares at Dec. 31, 2018 | 1,859,120 | ||||
Issuance of common stock for exercise of common stock options | 445 | 445 | |||
Issuance of common stock for exercise of common stock options, Shares | 8,056 | ||||
Stock-based compensation | 5,695 | 5,695 | |||
Issuance of convertible voting preferredstock, net of offering costs | 74,001 | $ 1 | 74,000 | ||
Issuance of convertible voting preferredstock, net of offering costs, Share | 103,000 | ||||
Net loss | (88,275) | (88,275) | |||
Stockholders Equity, Ending Balance at Dec. 31, 2019 | 86,345 | $ 1 | $ 74 | 851,957 | (765,687) |
Stockholders Equity, Ending Balance, Shares at Dec. 31, 2019 | 103,000 | 1,867,176 | |||
Conversion of Series A convertible voting preferred stock to common stock | $ (1) | $ 8 | (7) | ||
Conversion of Series A convertible voting preferred stock to common stock, Shares | (103,000) | 7,803,273 | |||
Reclassification of warrant liabilities to equity | 62,175 | 62,175 | |||
Issuance of common stock in connection with an amendment to the asset purchase agreement | 8,782 | $ 1 | 8,781 | ||
Number of shares issued in connection with an amendment to asset purchase agreement | 725,283 | ||||
Issuance of warrant in connection with an amendment to the asset purchase agreement | 3,188 | 3,188 | |||
Reverse stock split adjustment | $ (73) | 73 | |||
Stock-based compensation | 9,470 | 9,470 | |||
Issuance of common stock | 8,901 | $ 1 | 8,900 | ||
Issuance of common stock, Shares | 732,752 | ||||
Net loss | (80,902) | (80,902) | |||
Stockholders Equity, Ending Balance at Dec. 31, 2020 | 97,959 | $ 11 | 944,537 | (846,589) | |
Stockholders Equity, Ending Balance, Shares at Dec. 31, 2020 | 11,128,484 | ||||
Stockholders Equity, Beginning Balance at Dec. 31, 2019 | 86,345 | $ 1 | $ 74 | 851,957 | (765,687) |
Stockholders Equity, Beginning Balance, Shares at Dec. 31, 2019 | 103,000 | 1,867,176 | |||
Stockholders Equity, Ending Balance at Dec. 31, 2021 | 95,998 | $ 16 | 1,037,230 | (941,248) | |
Stockholders Equity, Ending Balance, Shares at Dec. 31, 2021 | 15,571,656 | ||||
Stockholders Equity, Beginning Balance at Dec. 31, 2020 | 97,959 | $ 11 | 944,537 | (846,589) | |
Stockholders Equity, Beginning Balance, Shares at Dec. 31, 2020 | 11,128,484 | ||||
Issuance of common stock for exercise of common stock options | 847 | 847 | |||
Issuance of common stock for exercise of common stock options, Shares | 64,847 | ||||
Stock-based compensation | 12,890 | 12,890 | |||
Issuance of common stock | 78,151 | $ 5 | 78,146 | ||
Issuance of common stock, Shares | 4,316,968 | ||||
Issuance of common stock for exercise of common stock warrants | 810 | 810 | |||
Issuance of common stock for exercise of common stock warrant, Shares | 61,357 | ||||
Net loss | (94,659) | (94,659) | |||
Stockholders Equity, Ending Balance at Dec. 31, 2021 | $ 95,998 | $ 16 | $ 1,037,230 | $ (941,248) | |
Stockholders Equity, Ending Balance, Shares at Dec. 31, 2021 | 15,571,656 |
Consolidated Statements of St_2
Consolidated Statements of Stockholders' Equity (Parenthetical) - USD ($) $ in Millions | 12 Months Ended | ||
Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019 | |
At The Market Offering [Member] | |||
Net of offering costs | $ 2.9 | $ 0.4 | |
Series A Convertible Voting Preferred Stock [Member] | |||
Net of offering costs | $ 4 |
Consolidated Statements of Cash
Consolidated Statements of Cash Flows - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019 | |
CASH FLOWS FROM OPERATING ACTIVITIES: | |||
Net loss | $ (94,659) | $ (80,902) | $ (88,275) |
Adjustments to reconcile net loss to net cash used in operating activities: | |||
Stock-based compensation | 12,890 | 9,470 | 5,695 |
Depreciation and amortization | 305 | 238 | 83 |
Changes in fair value of warrant liabilities | 0 | 16,240 | 20,926 |
Securities issuance obligation | 1,485 | 10,485 | |
Asset impairment | 106 | ||
Warrant issuance costs | 1,279 | ||
Term loan repayment fee | 438 | ||
Other | (39) | 201 | 161 |
Changes in operating assets and liabilities: | |||
Prepaid expenses and other assets | (622) | (33) | 336 |
Accrued, other and operating lease liabilities | 3,270 | (366) | (2,034) |
Accounts payable | (109) | 1,194 | (277) |
Net cash used in operating activities | (78,964) | (52,367) | (51,183) |
CASH FLOWS FROM INVESTING ACTIVITIES: | |||
Purchase of property and equipment | (72) | (12) | (39) |
Net cash used in investing activities | (72) | (12) | (39) |
CASH FLOWS FROM FINANCING ACTIVITIES: | |||
Proceeds from exercise of common stock options | 847 | 445 | |
Proceeds from exercise of common stock warrants | 810 | ||
Proceeds from public offering, net of offering costs | 97,731 | ||
Payment of term loan and repayment fee | (5,438) | ||
Net cash provided by financing activities | 79,808 | 8,901 | 92,738 |
Effect of foreign exchange rate changes on cash, cash equivalents and restricted cash | (78) | 5 | (34) |
NET INCREASE (DECREASE) IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH | 694 | (43,473) | 41,482 |
CASH, CASH EQUIVALENTS AND RESTRICTED CASH — Beginning of period | 104,355 | 147,828 | 106,346 |
CASH, CASH EQUIVALENTS AND RESTRICTED CASH — End of period | 105,049 | 104,355 | 147,828 |
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION: | |||
Cash paid for (refund of) income taxes, net | 66 | 28 | (69) |
Cash paid for interest | 336 | ||
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING INFORMATION: | |||
Right-of-use asset obtained in exchange for operating lease obligation | 730 | 771 | |
Property and equipment purchases included in accounts payable | 62 | ||
Offering costs not yet paid | 54 | 10 | |
Issuance of common stock and common stock warrant in connection with an amendment to the asset purchase agreement | 11,970 | ||
Reclassification of warrant liabilities to equity | 62,175 | ||
Issuance costs of convertible voting preferred stock and warrants included in accrued and other liabilities | $ 268 | ||
At-The-Market Offering [Member] | |||
CASH FLOWS FROM FINANCING ACTIVITIES: | |||
Proceeds from issuance of common stock, net of offering costs | $ 78,151 | $ 8,901 |
The Company and Basis of Presen
The Company and Basis of Presentation | 12 Months Ended |
Dec. 31, 2021 | |
Organization Consolidation And Presentation Of Financial Statements [Abstract] | |
Organization | 1. Organization Description of Business Sierra Oncology, Inc. (together with its subsidiaries, collectively referred to as the “Company”), a Delaware corporation, is a late-stage biopharmaceutical company focused on development and potential commercialization of momelotinib, an investigational agent for the treatment in myelofibrosis. Momelotinib is a selective and orally bioavailable JAK1 (Janus kinase 1), JAK2 (Janus kinase 2) and ACVR1 (Activin A receptor type 1) / activin receptor-like kinase-2 (ALK2) inhibitor with a differentiated mechanism of action. In January 2022, the Company announced positive topline results from its global Phase 3 clinical trial, called MOMENTUM, for patients with myelofibrosis who are symptomatic and anemic and previously treated with an approved JAK inhibitior. Momelotinib achieved a statistically significant benefit on symptoms, anemia and splenic size. The MOMENTUNM data, combined with data from earlier clinical trials, will be the basis for a New Drug Application (NDA) that the Company plans to submit in the second quarter of 2022. Approximately 1,000 myelofibrosis patients have received momelotinib through clinical trials at different stages of clinical development, and several of these patients remain on treatment more than 11 years later. In August 2021, the Company acquired an exclusive global license from AstraZeneca AB (AstraZeneca) for SRA515 (formerly AZD5153), a potent and selective bromodomain-containing protein 4 ( The Company’s portfolio also includes SRA737, a selective, orally bioavailable small molecule inhibitor of Checkpoint kinase 1 (Chk1), an emerging target for the treatment of cancer which has a key role in the DNA Damage Response (DDR). The Company’s primary activities since inception have been conducting research and development activities, conducting preclinical and clinical testing, recruiting personnel, preparing for potential commercialization, performing business and financial planning, identifying and evaluating additional drug candidates for potential in-licensing or acquisition, and raising capital to support development activities. The Company has not generated any product revenue related to its primary business purpose to date, nor has it generated any net income, and is subject to a number of risks and uncertainties, which include dependence on key individuals, the need to identify and successfully develop commercially viable products, the need to obtain regulatory approval for its products and commercialize them, and the potential need to obtain additional financing to continue the Company’s clinical development programs and fund pre-commercial and launch activities. As of December 31, 2021, the Company had $104.7 million of cash and cash equivalents. The Company believes that its balance of cash and cash equivalents as of the date of the issuance of these consolidated financial statements is sufficient to fund its current operational plan for at least the next twelve months. Reverse Stock Split On January 21, 2020, the Company’s shareholders approved an amendment to the Company’s certificate of incorporation to effect a reverse split of the Company’s common stock (Reverse Stock Split). On January 21, 2020, the Company’s board of directors approved the specific ratio for the Reverse Stock Split, which became effective on January 22, 2020, at 1-for-40. The authorized shares and par value of the common and preferred stock were not adjusted as a result of the Reverse Stock Split. All issued and outstanding common stock, warrants for common stock, options for common stock and per share amounts contained in the consolidated financial statements have been retroactively adjusted to reflect this Reverse Stock Split for all periods presented. |
Summary of Significant Accounti
Summary of Significant Accounting Policies | 12 Months Ended |
Dec. 31, 2021 | |
Accounting Policies [Abstract] | |
Summary of Significant Accounting Policies | 2. Summary of Significant Accounting Policies Basis of Presentation The accompanying consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (U.S. GAAP). The accompanying consolidated financial statements include the accounts of Sierra Oncology, Inc. and its wholly-owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. Use of Estimates The preparation of the consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of consolidated financial statements and the reported amounts of expense during the reporting period. Significant estimates and assumptions made in the accompanying consolidated financial statements include, but are not limited to, the fair values of stock options and warrants issued, the fair value of the securities issuance obligation, the probability of achieving performance-based milestones of stock options, accruals such as research and development costs, and recoverability of the Company’s net deferred tax assets, and related valuation allowance. The Company evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors and adjusts those estimates and assumptions when facts and circumstances dictate. Actual results could materially differ from those estimates. Foreign Currency The functional currency of the Company’s foreign subsidiaries is the U.S. Dollar. Transactions denominated in currencies other than the functional currency are recorded at prevailing exchange rates during the period. At the end of each reporting period, monetary assets and liabilities are remeasured to the functional currency using exchange rates in effect at the balance sheet date. Non-monetary assets and liabilities are recorded at historical exchange rates. Gains and losses related to remeasurement are recorded in other expense (income), net in the consolidated statements of operations. The net foreign exchange transaction losses (gains) included in other expense (income), net in the accompanying consolidated statements of operations were insignificant for the years ended December 31, 2021, 2020 and 2019. Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity of three months or less from the date of purchase to be cash equivalents. Cash and cash equivalents consist primarily of funds invested in readily available checking and savings accounts and highly liquid investments in money market funds. Restricted Cash Restricted cash, which consists of funds held in a savings account, represents collateral for a corporate credit card facility and is included in other assets in the accompanying consolidated balance sheets. See also Note 5. Concentrations of Credit Risk Financial instruments that subject the Company to significant concentrations of credit risk consist of cash, cash equivalents and restricted cash. All of the Company’s cash, cash equivalents and restricted cash are held at financial institutions in the United States and Canada that management believes to be of high credit quality. Deposits held in the United States and Canada with these financial institutions exceed federally insured limits. The primary focus of the Company’s investment strategy is to preserve capital and meet liquidity requirements. The Company’s investment policy addresses the level of credit exposure by limiting the concentration in any one corporate issuer and establishing a minimum allowable credit rating. Fair Value of Financial Instruments The Company’s cash and cash equivalents, restricted cash, other current assets, accounts payable and accrued and other liabilities approximate their fair values at December 31, 2021 and 2020, due to their short duration. The warrant liabilities and securities issuance obligation contained unobservable inputs that reflected the Company’s own assumptions in which there wa s little, if any, market activity at the measurement date , thus the Company’s warrant liabilities and securities issuance obligation we re measured at their fair value s on a recurring basis using unobservable inputs until such time the warrants were no longer considered derivative instruments and the securities issuance obligation was settled . The Company utilizes valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible. The Company determines the fair value of its financial instruments based on assumptions that market participants would use in pricing an asset or liability in the principal or most advantageous market. When considering market participant assumptions in fair value measurements, the following fair value hierarchy distinguishes between observable and unobservable inputs, which are categorized in one of the following levels: Level 1 —Inputs are unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date; Level 2 —Inputs are observable, unadjusted quoted prices in active markets for similar assets or liabilities, unadjusted quoted prices for identical or similar assets or liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the related assets or liabilities; and Level 3 —Unobservable inputs that are significant to the measurement of the fair value of the assets or liabilities that are supported by little or no market data. Property and Equipment, Net Property and equipment, net are stated at cost, less accumulated depreciation. Depreciation on property and equipment, excluding leasehold improvements, is computed using the straight-line method over the estimated useful lives of the respective assets, generally three to five years. Leasehold improvements are amortized on a straight-line basis over the shorter of the estimated useful lives of the assets or the remaining lease term. Depreciation begins at the time the asset is placed in service. Maintenance and repairs are charged to operations as incurred. Upon sale or retirement of assets, the cost and related accumulated depreciation are removed from the consolidated balance sheet and the resulting gain or loss is reflected in the consolidated statement of operations. Other Assets Other assets consist primarily of restricted cash pledged as collateral for a corporate credit card facility, deferred income tax assets in foreign jurisdictions, noncurrent portion of implementation costs related to cloud-computing arrangements and deferred financing costs. Operating Lease Right-of-Use Assets and Lease Liabilities The Company recognizes operating leases with terms greater than one year as right-of-use (ROU) assets and lease liabilities on its consolidated balance sheet using the portfolio approach. Lease liabilities and ROU assets are recorded based on the present value of future lease payments over the contractual terms of the operating leases. The Company utilizes its incremental borrowing rate from information available as at the date of initial adoption or inception of the lease in determining the present value of the future lease payments. The lease liabilities and ROU assets are amortized over the terms of the leases. Research and Development Costs Research and development costs are expensed as incurred. The Company accounts for non-refundable advance payments for goods and services that will be used in future research and development activities as expenses when the goods have been received or when the service has been performed rather than when the payment is made. Depending on the timing of payments to service providers of research and development costs, the Company recognizes prepaid expenses or accrued expenses related to these costs. These prepaid or accrued expenses are based on management’s estimates of the work performed under service agreements and milestones achieved. Upfront payments made in connection with asset purchase and license agreements are expensed as research and developments costs, as the assets acquired do not have alternative future use. Contingent milestone payment obligations due to third parties under license and asset purchase agreements are expensed when the milestones are considered probable of occurring. To the extent an obligation is to be settled by future issuance of securities, the fair value of these instruments is recorded in research and development expense until the securities are issued. Research and development costs include fees incurred in connection with asset purchase and license agreements and their related amendments, compensation and other related costs for employees engaged in research and development, costs associated with research and preclinical studies, clinical trials, regulatory activities, manufacturing activities to support clinical activities and commercial product supply as the Company approaches potential regulatory approval of momelotinib, fees paid to external service providers that conduct certain research and development, clinical, and manufacturing activities on behalf of the Company and an allocation of overhead expenses. Stock-Based Compensation The Company accounts for stock-based payments at fair value, which is measured using the Black-Scholes option-pricing model. For stock-based awards that vest subject to the satisfaction of a service requirement, the fair value measurement date for stock-based compensation awards is the date of grant and the expense is recognized on a straight-line basis over the vesting period, which is generally the service period. For stock-based awards that vest subject to the satisfaction of a service requirement and a performance component, the fair value measurement date is the date of grant and the expense is recognized over the requisite service period as achievement of the performance objective becomes probable. The Company accounts for forfeitures as they occur. Income Taxes The Company uses the asset and liability method of accounting for income taxes. Under this method, deferred tax assets and liabilities are determined based on the differences between the financial reporting and the tax bases of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. Management makes an assessment of the likelihood that the resulting deferred tax assets will be realized. A valuation allowance is provided when it is more likely than not that some portion or all of a deferred tax asset will not be realized. Due to the Company’s historical operating performance and the recorded cumulative net losses in prior fiscal periods, the net U.S. deferred tax assets have been offset by a full valuation allowance. The Company recognizes uncertain income tax positions at the largest amount that is more likely than not to be sustained upon audit by the relevant taxing authority. An uncertain income tax position will not be recognized if it has less than a 50% likelihood of being sustained. Changes in recognition or measurement are reflected in the period in which judgment occurs. The Company recognizes interest and penalties related to the underpayment of income taxes as a component of provision for (benefit from) income taxes, net. Segment Information Operating segments are components of an enterprise for which separate financial information is available and is evaluated regularly by the Company’s chief operating decision maker in deciding how to allocate resources and assessing performance. The Company’s chief operating decision maker is its Chief Executive Officer. The Company’s Chief Executive Officer views the Company’s operations and manages its business in one operating segment, which is the business of researching, developing and commercializing therapies for the treatment of patients with hematology and oncology needs. Accordingly, the Company has a single reporting segment. |
Net Loss Per Share
Net Loss Per Share | 12 Months Ended |
Dec. 31, 2021 | |
Earnings Per Share [Abstract] | |
Net Loss Per Share | 3. Net Loss Per Share Basic net loss per share is calculated by dividing net loss by the weighted-average number of common stock outstanding during the period without consideration for common stock equivalents. In 2019, preferred stock with characteristics of common stock was also included in the determination of the weighted average. Diluted net loss per share is computed by dividing net loss by the weighted-average number of common stock equivalents outstanding for the period determined using the treasury-stock method. For purposes of this calculation, stock options and warrants for common stock are considered to be common stock equivalents and are only included in the calculation of diluted net loss per share when their effect is dilutive. The following shares of common stock equivalents were excluded from the calculation of diluted net loss per share for the periods presented because including them would have been antidilutive: As of December 31, 2021 2020 2019 Series A warrants for common stock 7,790,879 7,802,241 7,802,241 Series B warrants for common stock 2,524,732 2,574,727 2,574,727 Options to purchase common stock 4,937,189 4,146,928 326,023 Warrants for common stock 727,122 727,122 1,839 Total potential dilutive shares 15,979,922 15,251,018 10,704,830 Also excluded from the calculation of diluted net loss per share are 4,824,075 shares of common stock and pre-funded warrants to purchase up to 925,925 common stock issued subsequent to December 31, 2021 (see Note 11). |
Fair Value Measurements
Fair Value Measurements | 12 Months Ended |
Dec. 31, 2021 | |
Fair Value Disclosures [Abstract] | |
Fair Value Measurements | 4. Fair Value Measurements The Company measures and reports its cash equivalents at fair value. The following table sets forth the fair value of the Company’s financial assets measured on a recurring basis by level within the fair value hierarchy: December 31, 2021 Level 1 Level 2 Level 3 Total (in thousands) Financial Assets Money market funds $ 102,526 $ — $ — $ 102,526 December 31, 2020 Level 1 Level 2 Level 3 Total (in thousands) Financial Assets Money market funds $ 101,919 $ — $ — $ 101,919 Money market funds are measured at fair value on a recurring basis using quoted prices and are classified as a Level 1 input. Prior to reclassification into equity in January 2020, the Company’s warrant liabilities and securities issuance obligation contained unobservable inputs that reflected the Company’s own assumptions in which there was little, if any, market activity at the measurement date. Accordingly, the Company’s warrant liabilities and securities issuance obligation we re measured at fair value on a recurring basis using un observable inputs and we re classified as Level 3 inputs . The fair values of the Series A and Series B warrants (see Note 8) were estimated using the Black-Scholes option-pricing model. The expected terms represented the periods that the warrants are expected to be outstanding. The risk-free interest rates were based on the U.S. Constant Maturity treasury curve commensurate with the time to expiry. The expected dividend was zero as the Company has not paid nor does it anticipate paying any dividends on its common stock in the foreseeable future. The expected volatilities were estimated by backsolving to volatility implied in the transaction price. Discount for lack of marketability was dependent on the restriction period and the estimated volatility during the period. The fair value of the warrant issuance obligation (see Note 7) was estimated using the Black-Scholes option-pricing model. The expected term represented the period that the underlying warrant is expected to be outstanding from the time the issuance obligation arose. The risk-free interest rate was based on the U.S. Constant Maturity treasury curve commensurate with the time to expiry. The expected dividend was zero as the Company has not paid nor does it anticipate paying any dividends on its common stock in the foreseeable future. The expected volatility was estimated by backsolving to volatility implied in the transaction price. The fair value of the common stock issuance obligation was estimated based on the fair value of the underlying common stock. Discount for lack of marketability was dependent on the restriction period and the estimated volatility during the period. The assumptions used in calculating the estimated fair values at the end of the reporting period represent the Company’s best estimate. However, inherent uncertainties are involved. If factors or assumptions change, the estimated fair values could be materially different. At November 13, 2019, upon the issuance of Series A and Series B warrants and when the securities issuance obligation arose, the Company estimated the fair values of the financial liabilities using the following assumptions: Series A Warrant Series B Warrant Warrant Issuance Obligation Common Stock Issuance Obligation Expected term (in years) 5.2 2.3 5.2 N/A Expected volatility 43 % 88 % 43 % N/A Risk-free interest rate 1.70 % 1.64 % 1.70 % N/A Expected dividend yield — % — % — % N/A Discount for lack of marketability 30 % 30 % 32 % 32 % At December 31, 2019, the Company remeasured these liabilities to their fair values using the following assumptions: Series A Warrant Series B Warrant Warrant Issuance Obligation Common Stock Issuance Obligation Expected term (in years) 5.1 2.2 5.1 N/A Expected volatility 43 % 88 % 43 % N/A Risk-free interest rate 1.69 % 1.59 % 1.70 % N/A Expected dividend yield — % — % — % N/A Discount for lack of marketability 25 % 25 % 25 % 25 % At January 22, 2020, Series A and Series B warrants were no longer considered to be derivative instruments. The Company remeasured the fair value of the warrant liabilities at the time of reclassification to equity using the following assumptions: Series A Warrant Series B Warrant Expected term (in years) 5.0 2.1 Expected volatility 43 % 88 % Risk-free interest rate 1.57 % 1.53 % Expected dividend yield — % — % The fair value of the Series A and Series B warrants at the time of issuance in November 2019, at December 31, 2019 and at the time they ceased to be derivative instruments in January 2020 were estimated to be $25.0 million, $45.9 million and $62.1 million, respectively. The Company recorded a $16.2 million and $20.9 million non-cash expense relating to the change in fair value of warrant liabilities in other expense (income), net in the accompanying consolidated statement of operations for the years ended December 31, 2020 and 2019, respectively. On September 8, 2021, the Company amended certain terms of Series A warrants and Series B warrants (see Note 8). The amendments did not result in changes to the fair value of these warrants. At January 31, 2020, the securities issuance obligation was settled by the issuance of common stock and a common stock warrant. The fair value of its common stock issuance obligation was remeasured based on the value of the common stock at the time of issuance. The fair value of the warrant issuance obligation was remeasured using the following assumptions: Warrant Issuance Obligation Expected term (in years) 5.0 Expected volatility 43 % Risk-free interest rate 1.57 % Expected dividend yield — % The fair value of the securities issuance obligation when the obligation arose in November 2019, at December 31, 2019 and at the time the obligation was settled in January 2020 were estimated to be $6.4 million, $10.5 million and $12.0 million, respectively. The Company recognized a $10.5 million and $1.5 million non-cash research and development expense for the years ended December 31, 2020 and 2019, respectively, based on the fair value of the securities to be issued, in the consolidated statement of operations. The following table provides a summary of changes in the estimated fair values of the Company’s Level 3 financial liabilities, which were measured at fair value on a recurring basis using unobservable inputs: Series A Warrant Liability Series B Warrant Liability Warrant Issuance Obligation Common Stock Issuance Obligation Total (in thousands) Balance, December 31, 2019 $ 32,616 $ 13,319 $ 3,036 $ 7,449 $ 56,420 Changes in fair value 11,597 4,643 152 1,333 17,725 Settlement of financial liabilities by securities issuance — — (3,188 ) (8,782 ) (11,970 ) Reclassification to equity (44,213 ) (17,962 ) — — (62,175 ) Balance, December 31, 2020 and 2021 $ — $ — $ — $ — $ — Fluctuations in fair values of the financial liabilities were attributable to changes in the fair value of the underlying stock and non-marketable discount. There were no transfers between Levels 1, 2 or 3 during the years ended December 31, 2021 and 2020. |
Balance Sheet Components
Balance Sheet Components | 12 Months Ended |
Dec. 31, 2021 | |
Organization Consolidation And Presentation Of Financial Statements [Abstract] | |
Balance Sheet Components | 5. Balance Sheet Components Cash and Cash Equivalents Cash and cash equivalents consist of the following: December 31, 2021 December 31, 2020 (in thousands) Cash $ 2,223 $ 2,136 Cash equivalents: Money market accounts 102,526 101,919 Total cash and cash equivalents $ 104,749 $ 104,055 The following table provides a reconciliation of cash, cash equivalents and restricted cash reported in the consolidated balance sheets to the amounts shown in the consolidated statements of cash flows. December 31, 2021 December 31, 2020 (in thousands) Cash and cash equivalents $ 104,749 $ 104,055 Restricted cash included in other assets 300 300 Total cash, cash equivalents and restricted cash shown in the consolidated statement of cash flows $ 105,049 $ 104,355 Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consist of the following: December 31, 2021 December 31, 2020 (in thousands) Prepaid insurance $ 1,029 $ 991 Prepaid software and subscription fees 536 376 Prepaid research and development project costs 290 321 Other receivables 147 311 Other 642 416 Total prepaid expenses and other current assets $ 2,644 $ 2,415 Property and Equipment, net Property and equipment, net consists of the following: December 31, 2021 December 31, 2020 (in thousands) Software $ 456 $ 361 Leasehold improvements 35 — Computer equipment 5 — Property and equipment, gross 496 361 Less: accumulated depreciation (355 ) (309 ) Total property and equipment, net $ 141 $ 52 Depreciation related to the Company’s property and equipment for the year ended December 31, 2021 was $45,000. Depreciation for each of the years ended December 31, 2020 and 2019 was $0.1 million. Accrued and Other Liabilities Accrued and other liabilities consist of the following: December 31, 2021 December 31, 2020 (in thousands) Accrued employee related costs $ 6,725 $ 4,359 Accrued research and development costs 2,727 1,715 Accrued professional fees 739 774 Operating lease liabilities 368 207 Other 167 93 Total accrued and other liabilities $ 10,726 $ 7,148 |
Leases
Leases | 12 Months Ended |
Dec. 31, 2021 | |
Leases [Abstract] | |
Leases | 6. Leases In December 2020, the Company entered into a 48-month operating lease agreement to lease office space in San Mateo, California. The lease commenced on April 30, 2021 and expires on April 30, 2025. The Company also has an operating lease agreement to lease office space in Vancouver, Canada that expires on February 28, 2023. In December 2020, the Company entered into an agreement to sublet the entire office premises to a third party until February 27, 2023. Pursuant to the sublease agreement, the subtenant will pay base rent of $0.2 million per annum to the Company and all operating costs related to the office space. The Company recorded an impairment charge of $0.1 million during the year ended December 31, 2020. The components of lease expense and related cash flows for the years ended December 31, 2021, 2020 and 2019 were as follows: Year ended December 31, 2021 2020 2019 (in thousands) Operating lease cost $ 299 $ 195 $ 203 Short-term lease cost 27 42 117 326 237 320 Operating cash flows used for operating leases $ 286 $ 212 $ 198 As of December 31, 2021, the weighted average remaining lease term and discount rate for the operating leases are 2.9 years and 4.7%, respectively. As of December 31, 2021, maturities of lease liability due under the lease agreement are as follows: Years Ending December 31: Operating Leases (in thousands) 2022 397 2023 223 2024 230 2025 58 Total lease payments 908 Less imputed interest (55 ) Total $ 853 These amounts have not been reduced by future base rent due under the Vancouver sublease of $0.2 million. In addition to base rent, the Vancouver lease requires payment of operating costs. These costs are also not included in the table above or the sublease amount. |
Commitments and Contingencies
Commitments and Contingencies | 12 Months Ended |
Dec. 31, 2021 | |
Commitments And Contingencies Disclosure [Abstract] | |
Commitments and Contingencies | 7 . Commitments and Contingencies Asset Purchase Agreement In August 2018, the Company entered into an Asset Purchase Agreement with Gilead whereby the Company acquired worldwide rights to the pharmaceutical product momelotinib, an investigational orally-bioavailable JAK1, JAK2 and ACVR1/ALK2 inhibitor together with all related intellectual property rights and certain other related assets. Pursuant to the agreement, the Company made a one-time upfront payment of $3.0 million in August 2018. I n October 2019, the Company entered into an amendment to the Asset Purchase Agreement in which the Company agreed to issue, subject to certain conditions, shares of common stock and a warrant to purchase common stock to Gilead in consideration for meaningfully reduced royalty rates and elimination of a near term milestone payment in the Asset Purchase Agreement. Pursuant to the amended agreement, License Agreements In August 2021, the Company entered into a license agreement with AstraZeneca for an exclusive global license for SRA515 and related compounds, which selectively inhibit BRD4. Under the agreement, the Company has an exclusive license to develop, manufacture and commercialize SRA515 for all therapeutic, prophylactic, palliative and diagnostic uses in humans and animals. T he Company made a one-time, non-refundable upfront cash payment of $8.0 million to AstraZeneca, which was expensed as research and development costs during the year ended December 31, 2021. In addition, pursuant to the license agreement, the Company will pay $0.9 million to AstraZeneca for the purchase of drug products and drug substance, which is expected to occur in the first quarter of 2022. Aggregate milestone payments of up to $208.0 million may become payable by the Company upon the achievement of certain development, regulatory and commercial milestones. These milestones will be accrued once they are considered probable of occurring. In addition, the Company is required to pay AstraZeneca a tiered royalty on worldwide net sales ranging from high single-digits to low double-digits. In September 2016, the Company entered into an exclusive license agreement with CRT Pioneer Fund LP (CPF) for worldwide rights, know-how and materials to develop SRA737, a small molecule inhibitor targeting Chk1, a promising therapeutic target to treat cancer. Pursuant to the agreement, the Company made a one-time upfront payment of $7.0 million to CPF in October 2016 and paid $2.0 million to CPF in January 2017 for the successful transfer of two ongoing Phase 1 clinical trials. Pursuant to the original license agreement, additional milestone payments of up to an aggregate of $319.5 million may have become payable to CPF upon the achievement of certain milestones. In November 2020, the Company entered into an amendment to the license agreement with CPF, which amended the terms and reduced the amounts of certain future milestones. Pursuant to the amended agreement, future milestone payments of up to an aggregate of $290.0 million may become payable to CPF upon the achievement of certain developmental, regulatory and commercial milestones, including a milestone payment of $2.0 million upon the dosing of the first patient of the first trial of SRA737 following the effective date of the amendment. These milestones will be accrued once they are considered probable of occurring. In addition, the Company is required to pay CPF, on a product-by-product and country-by-country basis, tiered high single-digit to low double-digit royalties on the net sales of any product successfully developed. In May 2016, the Company entered into an exclusive license agreement (Carna License Agreement) with Carna Biosciences, Inc. (Carna) for worldwide rights to develop and commercialize SRA141, a small molecule kinase inhibitor targeting Cdc7. In exchange for this exclusive right, the Company paid Carna an upfront payment of $0.9 million in June 2016. In June 2020, the Company entered into a collaboration agreement (Carna Collaboration Agreement) with Carna, effectively terminating the Carna License Agreement. Pursuant to the Carna Collaboration Agreement, Carna paid an upfront fee of $0.3 million, which was recognized as collaboration revenue during the year ended December 31, 2020 by the Company, for the exclusive worldwide rights for SRA141 and other transition services. In addition, the Company may be entitled to single-digit royalties on product sales, on a product-by-product basis, and low to mid-teen profit share on royalty and non-royalty income. Legal From time to time, the Company may become subject to other legal proceedings, claims and litigation arising in the ordinary course of business. In addition, the Company may receive letters alleging infringement of patent or other intellectual property rights. The Company is not currently a party to any other material legal proceedings, nor is it aware of any pending or threatened litigation that, in the Company’s opinion, would have a material adverse effect on the business, operating results, cash flows or financial condition should such litigation be resolved unfavorably. COVID-19 The full extent of the impact of the COVID-19 pandemic on financial markets, economies worldwide and our business continues to be highly uncertain. associated with the conduct of clinical trial s and other related business activities. The Company is carefully monitoring the pandemic and the potential length and depth of the resulting economic impact on its financial condition and results of operations. As of December 31, 202 1 , the Company was not aware of any contingencies and no related estimates were recorded i n its financial statements as a result of COVID-19. |
Stockholders' Equity
Stockholders' Equity | 12 Months Ended |
Dec. 31, 2021 | |
Equity [Abstract] | |
Stockholders' Equity | 8 . Stockholders’ Equity At-The-Market Common Stock Offerings In August 2020, the Company filed a prospectus supplement, pursuant to which it sold $20.0 million of its common stock in At-The-Market (ATM) offerings. In February, May and November 2021, the Company filed prospectus supplements pursuant to which it can issue and sell an aggregate of up to an additional $130.0 million of its common stock from time to time in ATM offerings. Common Stock Reserved for Issuance The Company is required to reserve and keep available out of its authorized but unissued shares of common stock a number of shares sufficient to effect the conversion of all outstanding options granted and available for grant under the incentive plans, shares reserved for issuance under the employee stock purchase plan and issued warrants. December 31, 2021 December 31, 2020 Shares reserved under Series A warrant 7,790,879 7,802,241 Shares reserved under Series B warrant 2,524,732 2,574,727 Shares reserved for future option grants under equity plans 1,207,827 1,117,796 Outstanding stock options under equity incentive plans 4,937,189 4,146,928 Outstanding warrants 727,122 727,122 Shares reserved under the 2015 employee stock purchase plan 17,500 17,500 Total common stock reserved for issuance 17,205,249 16,386,314 Preferred Stock On November 13, 2019, the Company completed an underwritten public offering whereby it issued 103,000 shares of Series A convertible voting preferred stock (Series A Preferred Stock) together with Series A warrants and Series B warrants for a combined purchase price of $1,000. The aggregate net proceeds received by the Company from the offering were $97.7 million, net of underwriting discounts and commissions and offering expenses of $5.3 million. Each share of Series A Preferred Stock was convertible into shares of the Company’s common stock equal to the stated value of the Series A Preferred Stock of $1,000 divided by the voting conversion price of $13.20. On January 29, 2020, all shares of Series A Preferred Stock converted into 7,803,273 shares of the Company’s common stock. Common Stock Warrants In connection with the Company’s November 2019 public offering of the Series A Preferred Stock, the Company issued Series A warrants to purchase up to 7,802,241 shares of common stock at an exercise price equal to $13.20, and Series B warrants to purchase up to 2,574,727 shares of common stock at an exercise price equal to $13.20. Both Series A and Series B warrants are exercisable following stockholder approval in January 2020 of an increase in authorized common stock sufficient to allow for the exercise of the warrants, subject to certain beneficial ownership limitations. The Series A warrants will expire five years from the date they first became exercisable or on January 22, 2025 and contain a cash and/or cashless exercise provision. The Series B warrants will expire on the 75 th from the Company’s MOMENTUM Phase 3 clinical trial of momelotinib and may only be exercised by paying the exercise price in cash. With the announcement of topline data by the Company on January 25, 2022, the Series B warrants will expire on April 10, 2022 (see Note 11 for information pertaining to the exercise of Series B warrants subsequent to December 31, 2021). During the year ended December 31, 2021, 151,500 Series B warrants to purchase 49,995 shares of common stock and 11,362 Series A warrants to purchase 11,362 shares of common stock were exercised for proceeds of $ 0.7 million and $ 0.1 million, respectively. There were no warrants exercised during the year ended December 31, 2020. On September 8, 2021, the Company entered into Amendment No. 1 to Series A warrants and Amendment No. 1 to Series B warrants. These amendments clarified the methodology by which Series A warrants and Series B warrants would be assumed or settled in the event of a Fundamental Transaction, as defined under the warrant agreements, and provided for greater consistency in the treatment of these warrants by a publicly-traded or private buyer. The amendments did not result in changes to the fair value of these warrants. As such, no expense was recorded during the year ended December 31, 2021 relating to the modifications to the warrants. In connection with obligations under the amendment to the Asset Purchase Agreement (See Note 7), the Company entered into a securities purchase agreement on January 31, 2020 and issued to Gilead 725,283 shares of the Company’s common stock and a warrant to purchase 725,283 shares of common stock at a price per share of $13.20. The warrant is immediately exercisable, will expire on January 31, 2025 and contains a cash and/or cashless exercise provision (see Note 11 for information pertaining to exercise of the warrant subsequent to December 31, 2021). In August 2018, in connection with a Loan and Security Agreement (Loan Agreement) with Silicon Valley Bank (SVB), the Company issued a warrant to SVB to purchase 1,839 of the Company’s common stock at a price per share of $74.80. The warrant is immediately exercisable, will expire on August 21, 2028 and contains a cashless exercise provision. |
Stock-Based Compensation
Stock-Based Compensation | 12 Months Ended |
Dec. 31, 2021 | |
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] | |
Stock-Based Compensation | 9 . Stock-Based Compensation In the accompanying consolidated statement of operations, the Company recognized stock-based compensation expense for its employees and non-employees as follows: Year ended December 31, 2021 2020 2019 (in thousands) Research and development $ 7,197 $ 4,316 $ 3,873 General and administrative 5,693 5,154 1,822 Total stock-based compensation $ 12,890 $ 9,470 $ 5,695 Determination of Fair Value The estimated grant-date fair value of all the Company’s stock-based awards was calculated using the Black-Scholes option pricing model, based on the following assumptions: Year Ended December 31, 2021 2020 2019 Expected term (in years) 5.3 – 7.0 5.3 – 7.0 5.3 – 6.9 Expected volatility 82 – 85 % 87 – 90 % 89 – 94 % Risk-free interest rate 0.5 – 1.3 % 0.3 – 1.2 % 1.6 – 2.6 % Expected dividend rate — % — % — % The fair value of each stock option grant was determined by the Company on the date of grant using the methods and assumptions discussed below. Each of these inputs is subjective and generally requires significant judgment and estimation by management. Expected Term— The expected term represents the period that stock-based awards are expected to be outstanding. As the Company’s historical share option exercise is limited due to a lack of sufficient data points, and does not provide a reasonable basis upon which to estimate an expected term, the expected term is derived by using the midpoint between the weighted-average vesting term and the contractual expiration period of the stock-based award. Expected Volatility— The expected volatility is determined based on stock volatilities over a period equivalent to the expected term of the stock-based award. Expected volatility was derived from the trading history of the Company’s common stock for the year ended December 31, 2021, a weighted volatility using both the Company’s trading history for its common stock and the historical stock volatilities of comparable peer public companies within its industry for the year ended December 31, 2020, a weighted volatility using solely the historical stock volatilities of comparable peer public companies within its industry for the year ended December 31, 2019 . Risk-Free Interest Rate— The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the date of grant for zero-coupon U.S. Treasury notes with maturities approximately equal to the stock-based awards’ expected term. Expected Dividend Rate— The expected dividend is zero as the Company has not paid nor anticipate paying any dividends on its common stock in the foreseeable future. Forfeiture Rate— The Company accounts for forfeitures when they occur. Equity Incentive Plans 2018 Equity Inducement Plan In September 2018, the Company’s Compensation Committee approved the 2018 Equity Inducement Plan (2018 Plan). The number of shares available for awards under the 2018 Plan was set to 37,500. In June 2020 and February 2021 , amendments to the 2018 Plan were approved by the Company’s Board of Directors and Compensation Committee, respectively, each to increase the authorized number of shares available for issuance by 500,000 shares for an aggregate increase of 1,000,000 shares . As of December 31, 2021, 1,037,500 shares were reserved for issuance under the 2018 Plan. On February 8, 2022, the Company’s Compensation Committee approved an amendment to the 2018 Plan to increase the authorized number of shares available for issuance by 500,000. The exercise price of each stock-based award issued under the 2018 Plan is required to be no less than the fair value of the Company’s common stock. The vesting and exercise provisions of options or restricted awards granted are determined individually with each grant. Stock options have a 10-year life and expire if not exercised within that period or if not exercised within three months of cessation of employment with the Company or such longer period of time as specified in the option agreement. 2015 Plan The 2015 Equity Incentive Plan (2015 Plan) became effective on July 14, 2015. On January 21, 2020, the Company’s stockholders approved the following amendments to the 2015 Plan: (i) increase to the authorized number of shares available for issuance by 4,312,500 shares and proportionately increase the share limit related to incentive stock options, (ii) provide limits on the total value of compensation that may be granted to any non-employee director in each calendar year, and (iii) eliminate the annual individual grant limit to reflect changes to the tax law in 2017 tax legislation. As of December 31, 2021, 5,123,736 shares were reserved for issuance under the 2015 Plan. The number of shares reserved for issuance under the 2015 Plan will increase automatically on January 1 of each calendar year 2016 through 2025 by the number of shares equal to 4 % of the total outstanding shares of the Company’s common stock as of the immediately preceding December 31. The Company’s Board of Directors or Compensation Committee may reduce the amount of the increase in any particular year. The exercise price of each stock-based award issued under the 2015 Plan is required to be no less than the fair value of the Company’s capital stock. The vesting and exercise provisions of options or restricted awards granted are determined individually with each grant. Stock options have a 10-year life and expire if not exercised within that period or if not exercised within three months of cessation of employment with the Company or such longer period of time as specified in the option agreement , unless modified . 2008 Plan The Company granted options under the 2008 Stock Plan (2008 Plan) until July 2015 when it was terminated as to future awards, although it continues to govern the terms of options that remain outstanding under the 2008 Plan. The 2008 Plan provided for the granting of Incentive Stock Options (ISO), nonqualified stock options and stock purchase rights. In connection with the Board of Director’s approval of the 2015 Plan, all remaining shares available for future award under the 2008 Plan were transferred to the 2015 Plan, and the 2008 Plan was terminated. A summary of activity under the 2008 Plan, 2015 Plan and 2018 Plan and related information is as follows: Options Outstanding Shares Available for Grant Number of Shares Outstanding Weighted- Average Exercise Price Per Share Weighted- Average Remaining Contractual Term (Years) Aggregate Intrinsic Value of Outstanding Options (in thousands) Outstanding — December 31, 2020 1,117,796 4,146,928 $ 19.45 8.84 $ 12,227 Awards authorized 945,139 Options granted (1,134,860 ) 1,134,860 17.78 Options exercised — (64,847 ) 13.06 Options forfeited/cancelled 279,752 (279,752 ) 17.99 Outstanding — December 31, 2021 1,207,827 4,937,189 $ 19.23 8.14 $ 36,080 Exercisable — December 31, 2021 1,421,885 $ 30.98 6.56 $ 9,682 Vested and expected to vest — December 31, 2021 4,422,699 $ 20.06 8.07 $ 31,146 The weighted-average grant date fair values of options granted during the years ended December 31, 2021, 2020 and 2019 was $12.54, $8.81 and $50.40 per share. The aggregate intrinsic value of options exercised was $0.5 million In August 2020, the Company granted executives and employees stock options with performance-based conditions. Vesting is achieved based upon the satisfaction of pre-determined milestones. There were 1,029,000 and 1,104,500 of the performance-based options outstanding and unvested as of December 31, 2021 and 2020. In January 2022, the first performance-based milestone was met, and accordingly 257,255 of the performance-based options vested. For the years ended December 31, 2021 and 2020, the Company recognized $3.0 million and $0.9 million in stock-based compensation expense related to the options with performance-based criteria. In May 2020, the Company entered into a separation agreement with the Company’s former President and Chief Executive Officer, in connection with his resignation. Pursuant to the separation agreement, the former executive’s unvested options that would have vested during the one-year period from the date of separation accelerated and vested immediately. The vesting date of all remaining unvested options accelerated by one year and vested in accordance with the accelerated vesting schedule through December 31, 2020. All unvested options were cancelled on December 31, 2020 . Furthermore, the former executive received an extension of the expiration date of his vested stock options to 75 days following the Company’s announcement of the top-line data results from its MOMENTUM clinical trial , which was announced by the Company on January 25, 2022, setting the expiration to April 10, 2022 . Compensation costs relating to the vesting acceleration and the modifications to option terms was $ 2.2 million for the year ended December 31, 2020. As of December 31, 2021, total unrecognized stock-based compensation related to unvested stock options was $25.3 million, which the Company expects to recognize over a remaining weighted-average period of 2.7 years. In addition, as of December 31, 2021, total unrecognized stock-based compensation related to unvested stock options with performance-based conditions was $5.3 million. 2015 Employee Stock Purchase Plan The Company adopted the 2015 Employee Stock Purchase Plan (ESPP) and initially reserved 17,500 shares of common stock as of its effective date of July 15, 2015. The aggregate number of shares issued over the term of the 2015 Employee Stock Purchase Plan will not exceed 85,000 shares of common stock. The ESPP will not become effective until such time as the Compensation Committee determines in the future, and as of December 31, 2021, the initial offering periods had not commenced. As of December 31, 2021, no shares of common stock have been issued to employees participating in the ESPP and 17,500 shares were available for issuance under the ESPP. |
Income Taxes
Income Taxes | 12 Months Ended |
Dec. 31, 2021 | |
Income Tax Disclosure [Abstract] | |
Income Taxes | 1 0 . Income Taxes The geographical breakdown of loss before provision for income taxes is as follows: Year Ended December 31, 2021 2020 2019 (in thousands) United States $ (95,605 ) $ (81,670 ) $ (89,459 ) International $ 943 910 1,024 Loss before provision for (benefit from) income taxes, net $ (94,662 ) $ (80,760 ) $ (88,435 ) The components of the provision for (benefit from) income taxes are as follows: Year Ended December 31, 2021 2020 2019 (in thousands) Current tax provision (benefit): Federal $ — $ — $ — State — — — Foreign 38 59 85 Total current tax provision (benefit) $ 38 $ 59 $ 85 Deferred tax provision (benefit): Foreign (41 ) 83 (245 ) Total deferred tax provision (benefit) $ (41 ) $ 83 $ (245 ) Total provision for (benefit from) income taxes $ (3 ) $ 142 $ (160 ) The reconciliation between income taxes computed at the federal statutory income tax rate and the provision for (benefit from) income taxes is as follows: Year Ended December 31, 2021 2020 2019 Federal statutory rate 21.0 % 21.0 % 21.0 % Effect of: Change in valuation allowance (27.8 ) (23.6 ) 12.4 Federal tax credit 7.4 5.8 1.5 Warrant issuance and remeasurement — (4.2 ) (5.3 ) Effect of ownership change on deferred tax assets (0.1 ) 1.3 (29.0 ) State income tax benefit, net of federal benefit — 0.2 0.2 Other permanent items (0.5 ) (0.7 ) (0.6 ) Total provision for (benefit from) income taxes% 0.0 % (0.2 )% 0.2 % The components of the deferred tax assets are as follows: December 31, 2021 2020 (in thousands) Deferred tax assets: 59 (e) expenditures and amortization $ 21,833 $ 6,222 Net operating loss carryforwards 13,546 14,011 Federal R&D and orphan drug credits 11,992 5,107 Stock based compensation 8,806 6,459 License fee 4,691 3,224 Other 1,468 1,024 Gross deferred tax assets 62,336 36,047 Valuation allowance (61,847 ) (35,513 ) Total deferred tax assets 489 534 Deferred tax liabilities: Lease Asset 19 114 Other 82 73 Total deferred tax liabilities 101 187 Total net deferred tax assets $ 388 $ 347 Recognition of deferred tax assets is appropriate when realization of these assets is more likely than not. Based upon the weight of available evidence, which includes historical operating performance and the recorded cumulative net losses in prior fiscal periods, the Company recorded a full valuation allowance of $61.4 million and $35.2 million against the net U.S. deferred tax assets as of December 31, 2021 and 2020. The U.S. net valuation allowance increased by $26.2 million and $18.8 million for the year ended December 31, 2021 and 2020, respectively. Management assesses the available positive and negative evidence to estimate if sufficient future taxable income will be generated to use the existing U.S. deferred tax assets. Based on the weight of all evidence, including a history of operating losses and the uncertainty of the Company’s ability to generate future taxable income to realize the assets, management has determined that it is more likely than not that the U.S. deferred tax assets will not be realized. As of December 31, 2021, the Company had gross U.S. federal tax net operating loss carryforwards of $52.7 million, that are eligible for an indefinite carryforward, and gross state operating loss carryforwards of $51.8 million expiring in years ranging from 2022 to 2041. The Company also had U.S. net tax credit carryforwards of $ 11.2 million which begin to expire in 20 39 and net tax credit carryforwards in a foreign jurisdiction of $ million which begin to expire in 203 9 . Utilization of the Company’s net operating loss and U.S. research and development credit carryforwards to offset taxable income are subject to an annual limitation, pursuant to Internal Revenue Code (IRC) Sections 382 and 383. As a result of common stock issuances and changes in the stock ownership that occurred subsequent to 2019, an ownership change under Section 382 is deemed to have occurred during the first quarter of 2022. As such, certain of the Company’s tax attributes existing as of the date of the ownership changes may not be available for future use. The loss or ultimate limitation of these attributes will not have any impact on the financial statements since the net U.S. deferred tax assets are offset by a full valuation allowance. Uncertain Tax Positions The activity related to the gross amount of unrecognized tax benefits is as follows: Year Ended December 31, 2021 2020 2019 (in thousands) Beginning balance $ 621 $ 314 $ 264 Increases based on tax positions related to prior years 39 — — Decreases based on tax positions related to prior years (83 ) (54 ) (103 ) Decreases due to ownership change — (207 ) — Increases based on tax positions in current year 780 568 153 Settlement — — — Lapse of statute of limitations — — — Ending balance $ 1,357 $ 621 $ 314 If recognized, gross unrecognized tax benefits would not have a material impact on the Company’s effective tax rate due to the Company’s full valuation allowance position on the U.S. deferred tax assets. From time to time, the Company is subject to review by tax authorities. It is not possible to estimate the impact of changes, if any, to previously recorded uncertain tax positions. However, the Company does not expect the changes, if any, to be materially different from what is recorded and will adjust its estimate and liability as necessary. The Company recognizes interest and penalties related to unrecognized tax benefits in the provision for income taxes in the accompanying consolidated statement of operations. Accrued interest and penalties, if applicable, are included in accrued liabilities in the consolidated balance sheet. For the years ended December 31, 2021 and 2020, the Company did not recognize any accrued interest and penalties. The Company is subject to taxation in the United States, various states, Canada and Australia. Tax years 2018 through 2020 remain open to examination by the United States, various state jurisdictions and Canada. The tax year ended December 31, 2020 remains open to examination in Australia. The Company is not under examination in any tax jurisdiction for any year. |
Subsequent Event
Subsequent Event | 12 Months Ended |
Dec. 31, 2021 | |
Subsequent Events [Abstract] | |
Subsequent Events | 1 1 . Subsequent Event Loan and Security Agreement On January 21, 2022 (Effective Date), the Company entered into a Loan and Security Agreement (Loan Agreement) with Oxford Finance, LLC (Oxford), pursuant to which it may obtain a loan up to an aggregate principal amount of $125.0 million (Term Loans) in four tranches. Contemporaneously with executing the Loan Agreement, the Company drew down the first $5.0 million tranche (Term Loan A). The second and third tranche (Term Loan B and Term Loan C, respectively) may be drawn upon the achievement of certain pre-determined milestones. During the first quarter of 2022, the Company met the milestone required to borrow under Term Loan B but has elected to defer the draw and combine with Term Loan C for a total of a $70.0 million, per the terms of the Loan Agreement. Term Loan C must be drawn within 30 days after the completion of the related milestone but no later than December 31, 2023. The $50.0 million under Term Loan D will only be available at the sole discretion of the lender. The Term Loans will bear interest at a floating per year rate equal to the prime rate, plus a margin of 5.25%, subject to a floor of 8.50%. Interest is payable monthly in arrears on the first calendar day of each calendar month. Beginning (i) March 1, 2025, if either the Term B Loan or the Term C Loan is not made or (ii) September 1, 2025, if both the Term B Loan and the Term C Loan are made, the Company shall repay the Term Loans in consecutive equal monthly payments of principal, together with applicable interest, in arrears. All unpaid principal and accrued and unpaid interest with respect to each Term Loan is due and payable in full on January 1, 2027. The Company will be required to make a final payment of 6.0% of the original principal amount of the Term Loans, payable at maturity or upon any earlier acceleration or prepayment of the Term Loans. The Company may prepay all, but not less than all, of the Term Loans, subject to a prepayment fee equal to (i) 2.0% of the principal amount of the applicable Term Loan if prepaid on or before the first anniversary date of the Effective Date and (ii) 1.0% of the principal amount of the applicable Term Loan if prepaid after the first and on or before the third anniversary of the Effective Date. All Term Loans will be subject to a facility fee of 0.5% of the principal amount. Underwritten Public Offering and Common Stock Issuances On January 31, 2022, the Company completed an underwritten public offering of 4,074,075 shares of common stock and pre-funded warrants to purchase up to 925,925 shares of common stock. As part of the underwritten public offering, on February 3, 2022, the Company issued an additional 750,000 shares of common stock representing the underwriters’ full exercise of their over-allotment option. The shares of common stock and the pre-funded warrants were offered by the company at a price to the public of $27.00 and $26.999 per share, respectively. The aggregate net proceeds received by the Company from the offering were $145.6 million, net of underwriting discounts and commissions and estimated offering expenses of $9.7 million. Subsequent to December 31, 2021, 18,937 and 2,312,257 shares of common stock were issued pertaining to the exercise of Series A and Series B warrants, respectively, providing proceeds of $30.8 million to the Company Subsequent to December 31, 2021, 725,283 shares of common stock were issued pertaining to the exercise of the warrant that was previously issued to Gilead pursuant to the securities purchase agreement, providing $9.6 million of proceeds to the Company. Subsequent to December 31, 2021, 212,892 shares of common stock were issued in connection with the exercise of stock options by former employees and pre-established non-discretionary sales plans, providing proceeds of $2.8 million to the Company |
Summary of Significant Accoun_2
Summary of Significant Accounting Policies (Policies) | 12 Months Ended |
Dec. 31, 2021 | |
Accounting Policies [Abstract] | |
Basis of Presentation | Basis of Presentation The accompanying consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (U.S. GAAP). The accompanying consolidated financial statements include the accounts of Sierra Oncology, Inc. and its wholly-owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. |
Use of Estimates | Use of Estimates The preparation of the consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of consolidated financial statements and the reported amounts of expense during the reporting period. Significant estimates and assumptions made in the accompanying consolidated financial statements include, but are not limited to, the fair values of stock options and warrants issued, the fair value of the securities issuance obligation, the probability of achieving performance-based milestones of stock options, accruals such as research and development costs, and recoverability of the Company’s net deferred tax assets, and related valuation allowance. The Company evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors and adjusts those estimates and assumptions when facts and circumstances dictate. Actual results could materially differ from those estimates. |
Foreign Currency | Foreign Currency The functional currency of the Company’s foreign subsidiaries is the U.S. Dollar. Transactions denominated in currencies other than the functional currency are recorded at prevailing exchange rates during the period. At the end of each reporting period, monetary assets and liabilities are remeasured to the functional currency using exchange rates in effect at the balance sheet date. Non-monetary assets and liabilities are recorded at historical exchange rates. Gains and losses related to remeasurement are recorded in other expense (income), net in the consolidated statements of operations. The net foreign exchange transaction losses (gains) included in other expense (income), net in the accompanying consolidated statements of operations were insignificant for the years ended December 31, 2021, 2020 and 2019. |
Cash and Cash Equivalents | Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity of three months or less from the date of purchase to be cash equivalents. Cash and cash equivalents consist primarily of funds invested in readily available checking and savings accounts and highly liquid investments in money market funds. |
Restricted Cash | Restricted Cash Restricted cash, which consists of funds held in a savings account, represents collateral for a corporate credit card facility and is included in other assets in the accompanying consolidated balance sheets. See also Note 5. |
Concentrations of Credit Risk | Concentrations of Credit Risk Financial instruments that subject the Company to significant concentrations of credit risk consist of cash, cash equivalents and restricted cash. All of the Company’s cash, cash equivalents and restricted cash are held at financial institutions in the United States and Canada that management believes to be of high credit quality. Deposits held in the United States and Canada with these financial institutions exceed federally insured limits. The primary focus of the Company’s investment strategy is to preserve capital and meet liquidity requirements. The Company’s investment policy addresses the level of credit exposure by limiting the concentration in any one corporate issuer and establishing a minimum allowable credit rating. |
Fair Value of Financial Instruments | Fair Value of Financial Instruments The Company’s cash and cash equivalents, restricted cash, other current assets, accounts payable and accrued and other liabilities approximate their fair values at December 31, 2021 and 2020, due to their short duration. The warrant liabilities and securities issuance obligation contained unobservable inputs that reflected the Company’s own assumptions in which there wa s little, if any, market activity at the measurement date , thus the Company’s warrant liabilities and securities issuance obligation we re measured at their fair value s on a recurring basis using unobservable inputs until such time the warrants were no longer considered derivative instruments and the securities issuance obligation was settled . The Company utilizes valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible. The Company determines the fair value of its financial instruments based on assumptions that market participants would use in pricing an asset or liability in the principal or most advantageous market. When considering market participant assumptions in fair value measurements, the following fair value hierarchy distinguishes between observable and unobservable inputs, which are categorized in one of the following levels: Level 1 —Inputs are unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date; Level 2 —Inputs are observable, unadjusted quoted prices in active markets for similar assets or liabilities, unadjusted quoted prices for identical or similar assets or liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the related assets or liabilities; and Level 3 —Unobservable inputs that are significant to the measurement of the fair value of the assets or liabilities that are supported by little or no market data. |
Property and Equipment, Net | Property and Equipment, Net Property and equipment, net are stated at cost, less accumulated depreciation. Depreciation on property and equipment, excluding leasehold improvements, is computed using the straight-line method over the estimated useful lives of the respective assets, generally three to five years. Leasehold improvements are amortized on a straight-line basis over the shorter of the estimated useful lives of the assets or the remaining lease term. Depreciation begins at the time the asset is placed in service. Maintenance and repairs are charged to operations as incurred. Upon sale or retirement of assets, the cost and related accumulated depreciation are removed from the consolidated balance sheet and the resulting gain or loss is reflected in the consolidated statement of operations. |
Other Assets | Other Assets Other assets consist primarily of restricted cash pledged as collateral for a corporate credit card facility, deferred income tax assets in foreign jurisdictions, noncurrent portion of implementation costs related to cloud-computing arrangements and deferred financing costs. |
Operating Lease Right-of-Use Assets and Lease Liabilities | Operating Lease Right-of-Use Assets and Lease Liabilities The Company recognizes operating leases with terms greater than one year as right-of-use (ROU) assets and lease liabilities on its consolidated balance sheet using the portfolio approach. Lease liabilities and ROU assets are recorded based on the present value of future lease payments over the contractual terms of the operating leases. The Company utilizes its incremental borrowing rate from information available as at the date of initial adoption or inception of the lease in determining the present value of the future lease payments. The lease liabilities and ROU assets are amortized over the terms of the leases. |
Research and Development Costs | Research and Development Costs Research and development costs are expensed as incurred. The Company accounts for non-refundable advance payments for goods and services that will be used in future research and development activities as expenses when the goods have been received or when the service has been performed rather than when the payment is made. Depending on the timing of payments to service providers of research and development costs, the Company recognizes prepaid expenses or accrued expenses related to these costs. These prepaid or accrued expenses are based on management’s estimates of the work performed under service agreements and milestones achieved. Upfront payments made in connection with asset purchase and license agreements are expensed as research and developments costs, as the assets acquired do not have alternative future use. Contingent milestone payment obligations due to third parties under license and asset purchase agreements are expensed when the milestones are considered probable of occurring. To the extent an obligation is to be settled by future issuance of securities, the fair value of these instruments is recorded in research and development expense until the securities are issued. Research and development costs include fees incurred in connection with asset purchase and license agreements and their related amendments, compensation and other related costs for employees engaged in research and development, costs associated with research and preclinical studies, clinical trials, regulatory activities, manufacturing activities to support clinical activities and commercial product supply as the Company approaches potential regulatory approval of momelotinib, fees paid to external service providers that conduct certain research and development, clinical, and manufacturing activities on behalf of the Company and an allocation of overhead expenses. |
Stock-Based Compensation | Stock-Based Compensation The Company accounts for stock-based payments at fair value, which is measured using the Black-Scholes option-pricing model. For stock-based awards that vest subject to the satisfaction of a service requirement, the fair value measurement date for stock-based compensation awards is the date of grant and the expense is recognized on a straight-line basis over the vesting period, which is generally the service period. For stock-based awards that vest subject to the satisfaction of a service requirement and a performance component, the fair value measurement date is the date of grant and the expense is recognized over the requisite service period as achievement of the performance objective becomes probable. The Company accounts for forfeitures as they occur. |
Income Taxes | Income Taxes The Company uses the asset and liability method of accounting for income taxes. Under this method, deferred tax assets and liabilities are determined based on the differences between the financial reporting and the tax bases of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. Management makes an assessment of the likelihood that the resulting deferred tax assets will be realized. A valuation allowance is provided when it is more likely than not that some portion or all of a deferred tax asset will not be realized. Due to the Company’s historical operating performance and the recorded cumulative net losses in prior fiscal periods, the net U.S. deferred tax assets have been offset by a full valuation allowance. The Company recognizes uncertain income tax positions at the largest amount that is more likely than not to be sustained upon audit by the relevant taxing authority. An uncertain income tax position will not be recognized if it has less than a 50% likelihood of being sustained. Changes in recognition or measurement are reflected in the period in which judgment occurs. The Company recognizes interest and penalties related to the underpayment of income taxes as a component of provision for (benefit from) income taxes, net. |
Segment Information | Segment Information Operating segments are components of an enterprise for which separate financial information is available and is evaluated regularly by the Company’s chief operating decision maker in deciding how to allocate resources and assessing performance. The Company’s chief operating decision maker is its Chief Executive Officer. The Company’s Chief Executive Officer views the Company’s operations and manages its business in one operating segment, which is the business of researching, developing and commercializing therapies for the treatment of patients with hematology and oncology needs. Accordingly, the Company has a single reporting segment. |
Net Loss Per Share (Tables)
Net Loss Per Share (Tables) | 12 Months Ended |
Dec. 31, 2021 | |
Earnings Per Share [Abstract] | |
Schedule of Outstanding Shares of Common Stock Equivalents Excluded from Calculation of Diluted Net Loss Per Share | The following shares of common stock equivalents were excluded from the calculation of diluted net loss per share for the periods presented because including them would have been antidilutive: As of December 31, 2021 2020 2019 Series A warrants for common stock 7,790,879 7,802,241 7,802,241 Series B warrants for common stock 2,524,732 2,574,727 2,574,727 Options to purchase common stock 4,937,189 4,146,928 326,023 Warrants for common stock 727,122 727,122 1,839 Total potential dilutive shares 15,979,922 15,251,018 10,704,830 |
Fair Value Measurements (Tables
Fair Value Measurements (Tables) | 12 Months Ended |
Dec. 31, 2021 | |
Fair Value Disclosures [Abstract] | |
Schedule of Fair Value of Financial Assets Measured on Recurring Basis | The following table sets forth the fair value of the Company’s financial assets measured on a recurring basis by level within the fair value hierarchy: December 31, 2021 Level 1 Level 2 Level 3 Total (in thousands) Financial Assets Money market funds $ 102,526 $ — $ — $ 102,526 December 31, 2020 Level 1 Level 2 Level 3 Total (in thousands) Financial Assets Money market funds $ 101,919 $ — $ — $ 101,919 |
Summary of Fair Value of Financial Liabilities Assumptions | At November 13, 2019, upon the issuance of Series A and Series B warrants and when the securities issuance obligation arose, the Company estimated the fair values of the financial liabilities using the following assumptions: Series A Warrant Series B Warrant Warrant Issuance Obligation Common Stock Issuance Obligation Expected term (in years) 5.2 2.3 5.2 N/A Expected volatility 43 % 88 % 43 % N/A Risk-free interest rate 1.70 % 1.64 % 1.70 % N/A Expected dividend yield — % — % — % N/A Discount for lack of marketability 30 % 30 % 32 % 32 % At December 31, 2019, the Company remeasured these liabilities to their fair values using the following assumptions: Series A Warrant Series B Warrant Warrant Issuance Obligation Common Stock Issuance Obligation Expected term (in years) 5.1 2.2 5.1 N/A Expected volatility 43 % 88 % 43 % N/A Risk-free interest rate 1.69 % 1.59 % 1.70 % N/A Expected dividend yield — % — % — % N/A Discount for lack of marketability 25 % 25 % 25 % 25 % At January 22, 2020, Series A and Series B warrants were no longer considered to be derivative instruments. The Company remeasured the fair value of the warrant liabilities at the time of reclassification to equity using the following assumptions: Series A Warrant Series B Warrant Expected term (in years) 5.0 2.1 Expected volatility 43 % 88 % Risk-free interest rate 1.57 % 1.53 % Expected dividend yield — % — % The fair value of the Series A and Series B warrants at the time of issuance in November 2019, at December 31, 2019 and at the time they ceased to be derivative instruments in January 2020 were estimated to be $25.0 million, $45.9 million and $62.1 million, respectively. The Company recorded a $16.2 million and $20.9 million non-cash expense relating to the change in fair value of warrant liabilities in other expense (income), net in the accompanying consolidated statement of operations for the years ended December 31, 2020 and 2019, respectively. On September 8, 2021, the Company amended certain terms of Series A warrants and Series B warrants (see Note 8). The amendments did not result in changes to the fair value of these warrants. At January 31, 2020, the securities issuance obligation was settled by the issuance of common stock and a common stock warrant. The fair value of its common stock issuance obligation was remeasured based on the value of the common stock at the time of issuance. The fair value of the warrant issuance obligation was remeasured using the following assumptions: Warrant Issuance Obligation Expected term (in years) 5.0 Expected volatility 43 % Risk-free interest rate 1.57 % Expected dividend yield — % |
Summary of Changes in Fair Values Level Financial Liabilities Recurring Basis Using Unobservable Inputs | The following table provides a summary of changes in the estimated fair values of the Company’s Level 3 financial liabilities, which were measured at fair value on a recurring basis using unobservable inputs: Series A Warrant Liability Series B Warrant Liability Warrant Issuance Obligation Common Stock Issuance Obligation Total (in thousands) Balance, December 31, 2019 $ 32,616 $ 13,319 $ 3,036 $ 7,449 $ 56,420 Changes in fair value 11,597 4,643 152 1,333 17,725 Settlement of financial liabilities by securities issuance — — (3,188 ) (8,782 ) (11,970 ) Reclassification to equity (44,213 ) (17,962 ) — — (62,175 ) Balance, December 31, 2020 and 2021 $ — $ — $ — $ — $ — |
Balance Sheet Components (Table
Balance Sheet Components (Tables) | 12 Months Ended |
Dec. 31, 2021 | |
Organization Consolidation And Presentation Of Financial Statements [Abstract] | |
Summary of Cash and Cash Equivalents | Cash and cash equivalents consist of the following: December 31, 2021 December 31, 2020 (in thousands) Cash $ 2,223 $ 2,136 Cash equivalents: Money market accounts 102,526 101,919 Total cash and cash equivalents $ 104,749 $ 104,055 |
Summary of Reconciliation of Cash, Cash Equivalents and Restricted Cash | The following table provides a reconciliation of cash, cash equivalents and restricted cash reported in the consolidated balance sheets to the amounts shown in the consolidated statements of cash flows. December 31, 2021 December 31, 2020 (in thousands) Cash and cash equivalents $ 104,749 $ 104,055 Restricted cash included in other assets 300 300 Total cash, cash equivalents and restricted cash shown in the consolidated statement of cash flows $ 105,049 $ 104,355 |
Summary of Prepaid Expenses and Other Current Assets | Prepaid expenses and other current assets consist of the following: December 31, 2021 December 31, 2020 (in thousands) Prepaid insurance $ 1,029 $ 991 Prepaid software and subscription fees 536 376 Prepaid research and development project costs 290 321 Other receivables 147 311 Other 642 416 Total prepaid expenses and other current assets $ 2,644 $ 2,415 |
Summary of Property and Equipment, Net | Property and equipment, net consists of the following: December 31, 2021 December 31, 2020 (in thousands) Software $ 456 $ 361 Leasehold improvements 35 — Computer equipment 5 — Property and equipment, gross 496 361 Less: accumulated depreciation (355 ) (309 ) Total property and equipment, net $ 141 $ 52 |
Schedule of Accrued and Other Liabilities | Accrued and other liabilities consist of the following: December 31, 2021 December 31, 2020 (in thousands) Accrued employee related costs $ 6,725 $ 4,359 Accrued research and development costs 2,727 1,715 Accrued professional fees 739 774 Operating lease liabilities 368 207 Other 167 93 Total accrued and other liabilities $ 10,726 $ 7,148 |
Leases (Tables)
Leases (Tables) | 12 Months Ended |
Dec. 31, 2021 | |
Leases [Abstract] | |
Schedule of Components of Lease Expense and Related Cash Flows | The components of lease expense and related cash flows for the years ended December 31, 2021, 2020 and 2019 were as follows: Year ended December 31, 2021 2020 2019 (in thousands) Operating lease cost $ 299 $ 195 $ 203 Short-term lease cost 27 42 117 326 237 320 Operating cash flows used for operating leases $ 286 $ 212 $ 198 |
Schedule of Maturities Lease Liabilities under Leases Agreement | As of December 31, 2021, maturities of lease liability due under the lease agreement are as follows: Years Ending December 31: Operating Leases (in thousands) 2022 397 2023 223 2024 230 2025 58 Total lease payments 908 Less imputed interest (55 ) Total $ 853 |
Stockholders' Equity (Tables)
Stockholders' Equity (Tables) | 12 Months Ended |
Dec. 31, 2021 | |
Equity [Abstract] | |
Schedule of Common Stock Reserved for Issuance | The Company is required to reserve and keep available out of its authorized but unissued shares of common stock a number of shares sufficient to effect the conversion of all outstanding options granted and available for grant under the incentive plans, shares reserved for issuance under the employee stock purchase plan and issued warrants. December 31, 2021 December 31, 2020 Shares reserved under Series A warrant 7,790,879 7,802,241 Shares reserved under Series B warrant 2,524,732 2,574,727 Shares reserved for future option grants under equity plans 1,207,827 1,117,796 Outstanding stock options under equity incentive plans 4,937,189 4,146,928 Outstanding warrants 727,122 727,122 Shares reserved under the 2015 employee stock purchase plan 17,500 17,500 Total common stock reserved for issuance 17,205,249 16,386,314 |
Stock-Based Compensation (Table
Stock-Based Compensation (Tables) | 12 Months Ended |
Dec. 31, 2021 | |
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] | |
Schedule of Stock-based Compensation Expense for Employees and Non-employees | In the accompanying consolidated statement of operations, the Company recognized stock-based compensation expense for its employees and non-employees as follows: Year ended December 31, 2021 2020 2019 (in thousands) Research and development $ 7,197 $ 4,316 $ 3,873 General and administrative 5,693 5,154 1,822 Total stock-based compensation $ 12,890 $ 9,470 $ 5,695 |
Schedule of Estimated Grant-date Fair Value of Stock-based Awards Using Black-Scholes Option Pricing Model Assumptions | The estimated grant-date fair value of all the Company’s stock-based awards was calculated using the Black-Scholes option pricing model, based on the following assumptions: Year Ended December 31, 2021 2020 2019 Expected term (in years) 5.3 – 7.0 5.3 – 7.0 5.3 – 6.9 Expected volatility 82 – 85 % 87 – 90 % 89 – 94 % Risk-free interest rate 0.5 – 1.3 % 0.3 – 1.2 % 1.6 – 2.6 % Expected dividend rate — % — % — % |
Summary of Stock-Based Compensation Activity | A summary of activity under the 2008 Plan, 2015 Plan and 2018 Plan and related information is as follows: Options Outstanding Shares Available for Grant Number of Shares Outstanding Weighted- Average Exercise Price Per Share Weighted- Average Remaining Contractual Term (Years) Aggregate Intrinsic Value of Outstanding Options (in thousands) Outstanding — December 31, 2020 1,117,796 4,146,928 $ 19.45 8.84 $ 12,227 Awards authorized 945,139 Options granted (1,134,860 ) 1,134,860 17.78 Options exercised — (64,847 ) 13.06 Options forfeited/cancelled 279,752 (279,752 ) 17.99 Outstanding — December 31, 2021 1,207,827 4,937,189 $ 19.23 8.14 $ 36,080 Exercisable — December 31, 2021 1,421,885 $ 30.98 6.56 $ 9,682 Vested and expected to vest — December 31, 2021 4,422,699 $ 20.06 8.07 $ 31,146 |
Income Taxes (Tables)
Income Taxes (Tables) | 12 Months Ended |
Dec. 31, 2021 | |
Income Tax Disclosure [Abstract] | |
Schedule of Geographical Breakdown of Loss Before Provision for Income Taxes | The geographical breakdown of loss before provision for income taxes is as follows: Year Ended December 31, 2021 2020 2019 (in thousands) United States $ (95,605 ) $ (81,670 ) $ (89,459 ) International $ 943 910 1,024 Loss before provision for (benefit from) income taxes, net $ (94,662 ) $ (80,760 ) $ (88,435 ) |
Components of Provision (Benefit from) for Income Taxes | The components of the provision for (benefit from) income taxes are as follows: Year Ended December 31, 2021 2020 2019 (in thousands) Current tax provision (benefit): Federal $ — $ — $ — State — — — Foreign 38 59 85 Total current tax provision (benefit) $ 38 $ 59 $ 85 Deferred tax provision (benefit): Foreign (41 ) 83 (245 ) Total deferred tax provision (benefit) $ (41 ) $ 83 $ (245 ) Total provision for (benefit from) income taxes $ (3 ) $ 142 $ (160 ) |
Reconciliation Between Income Taxes Computed at the Federal Statutory Income Tax Rate and the Provision for Income Taxes | The reconciliation between income taxes computed at the federal statutory income tax rate and the provision for (benefit from) income taxes is as follows: Year Ended December 31, 2021 2020 2019 Federal statutory rate 21.0 % 21.0 % 21.0 % Effect of: Change in valuation allowance (27.8 ) (23.6 ) 12.4 Federal tax credit 7.4 5.8 1.5 Warrant issuance and remeasurement — (4.2 ) (5.3 ) Effect of ownership change on deferred tax assets (0.1 ) 1.3 (29.0 ) State income tax benefit, net of federal benefit — 0.2 0.2 Other permanent items (0.5 ) (0.7 ) (0.6 ) Total provision for (benefit from) income taxes% 0.0 % (0.2 )% 0.2 % |
Components of the Deferred Tax Assets | The components of the deferred tax assets are as follows: December 31, 2021 2020 (in thousands) Deferred tax assets: 59 (e) expenditures and amortization $ 21,833 $ 6,222 Net operating loss carryforwards 13,546 14,011 Federal R&D and orphan drug credits 11,992 5,107 Stock based compensation 8,806 6,459 License fee 4,691 3,224 Other 1,468 1,024 Gross deferred tax assets 62,336 36,047 Valuation allowance (61,847 ) (35,513 ) Total deferred tax assets 489 534 Deferred tax liabilities: Lease Asset 19 114 Other 82 73 Total deferred tax liabilities 101 187 Total net deferred tax assets $ 388 $ 347 |
Unrecognized Tax Benefits | The activity related to the gross amount of unrecognized tax benefits is as follows: Year Ended December 31, 2021 2020 2019 (in thousands) Beginning balance $ 621 $ 314 $ 264 Increases based on tax positions related to prior years 39 — — Decreases based on tax positions related to prior years (83 ) (54 ) (103 ) Decreases due to ownership change — (207 ) — Increases based on tax positions in current year 780 568 153 Settlement — — — Lapse of statute of limitations — — — Ending balance $ 1,357 $ 621 $ 314 |
Organization - Additional Infor
Organization - Additional Information (Detail) - USD ($) $ in Thousands | Jan. 22, 2020 | Dec. 31, 2021 | Dec. 31, 2020 |
Organization Consolidation And Presentation Of Financial Statements [Abstract] | |||
Cash and cash equivalents | $ 104,749 | $ 104,055 | |
Description of reverse stock split | 1-for-40 |
Summary of Significant Accoun_3
Summary of Significant Accounting Policies - Additional Information (Detail) | 12 Months Ended |
Dec. 31, 2021Segment | |
Summary Of Significant Accounting Policy [Line Items] | |
Number of operating segment | 1 |
Minimum [Member] | Property Plant and Equipment Other than Leasehold Improvement [Member] | |
Summary Of Significant Accounting Policy [Line Items] | |
Estimated useful lives of assets | 3 years |
Maximum [Member] | Property Plant and Equipment Other than Leasehold Improvement [Member] | |
Summary Of Significant Accounting Policy [Line Items] | |
Estimated useful lives of assets | 5 years |
Net Loss Per Share - Schedule o
Net Loss Per Share - Schedule of Outstanding Shares of Common Stock Equivalents Excluded from Calculation of Diluted Net Loss Per Share (Detail) - shares | 12 Months Ended | ||
Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019 | |
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | |||
Total potential dilutive shares | 15,979,922 | 15,251,018 | 10,704,830 |
Series A Warrants For Common Stock [Member] | |||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | |||
Total potential dilutive shares | 7,790,879 | 7,802,241 | 7,802,241 |
Series B Warrants For Common Stock [Member] | |||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | |||
Total potential dilutive shares | 2,524,732 | 2,574,727 | 2,574,727 |
Options to Purchase Common Stock [Member] | |||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | |||
Total potential dilutive shares | 4,937,189 | 4,146,928 | 326,023 |
Warrants for Common Stock [Member] | |||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | |||
Total potential dilutive shares | 727,122 | 727,122 | 1,839 |
Net Loss Per Share - Additional
Net Loss Per Share - Additional Information (Detail) - shares | Mar. 07, 2022 | Feb. 03, 2022 | Jan. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020 | Mar. 10, 2022 |
Common Stock [Member] | ||||||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||||||
Issuance of common stock, Shares | 4,316,968 | 732,752 | ||||
Common Stock [Member] | Subsequent Event [Member] | Underwritten Public Offering [Member] | ||||||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||||||
Issuance of common stock, Shares | 4,824,075 | 750,000 | 4,074,075 | |||
Pre-funded Warrants [Member] | Subsequent Event [Member] | Underwritten Public Offering [Member] | ||||||
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||||||
Number of warrants issued to purchase of common stock | 925,925 |
Fair Value Measurements - Sched
Fair Value Measurements - Schedule of Fair Value of Financial Assets Measured on Recurring Basis (Detail) - Fair Value Measurements Recurring [Member] - Money Market Funds [Member] - USD ($) $ in Thousands | Dec. 31, 2021 | Dec. 31, 2020 |
Financial Assets | ||
Total financial assets | $ 102,526 | $ 101,919 |
Level 1 [Member] | ||
Financial Assets | ||
Total financial assets | $ 102,526 | $ 101,919 |
Fair Value Measurements - Summa
Fair Value Measurements - Summary of Fair Value of Financial Liabilities Assumptions (Detail) | Jan. 31, 2020yr | Jan. 22, 2020yr | Dec. 31, 2019yr | Nov. 13, 2019yr |
Expected term [Member] | Warrant Issuance Obligation [Member] | ||||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items] | ||||
Warrants and Rights Outstanding, Measurement Input | 5 | 5.1 | 5.2 | |
Expected term [Member] | Series A Warrant [Member] | ||||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items] | ||||
Warrants and Rights Outstanding, Measurement Input | 5 | 5.1 | 5.2 | |
Expected term [Member] | Series B Warrant [Member] | ||||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items] | ||||
Warrants and Rights Outstanding, Measurement Input | 2.1 | 2.2 | 2.3 | |
Expected volatility [Member] | Warrant Issuance Obligation [Member] | ||||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items] | ||||
Warrants and Rights Outstanding, Measurement Input | 0.43 | 0.43 | 0.43 | |
Expected volatility [Member] | Series A Warrant [Member] | ||||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items] | ||||
Warrants and Rights Outstanding, Measurement Input | 0.43 | 0.43 | 0.43 | |
Expected volatility [Member] | Series B Warrant [Member] | ||||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items] | ||||
Warrants and Rights Outstanding, Measurement Input | 0.88 | 0.88 | 0.88 | |
Risk-free interest rate [Member] | Warrant Issuance Obligation [Member] | ||||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items] | ||||
Warrants and Rights Outstanding, Measurement Input | 0.0157 | 0.0170 | 0.0170 | |
Risk-free interest rate [Member] | Series A Warrant [Member] | ||||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items] | ||||
Warrants and Rights Outstanding, Measurement Input | 0.0157 | 0.0169 | 0.0170 | |
Risk-free interest rate [Member] | Series B Warrant [Member] | ||||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items] | ||||
Warrants and Rights Outstanding, Measurement Input | 0.0153 | 0.0159 | 0.0164 | |
Discount for lack of marketability [Member] | Warrant Issuance Obligation [Member] | ||||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items] | ||||
Warrants and Rights Outstanding, Measurement Input | 0.25 | 0.32 | ||
Discount for lack of marketability [Member] | Common stock Issuance Obligation [Member] | ||||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items] | ||||
Warrants and Rights Outstanding, Measurement Input | 0.25 | 0.32 | ||
Discount for lack of marketability [Member] | Series A Warrant [Member] | ||||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items] | ||||
Warrants and Rights Outstanding, Measurement Input | 0.25 | 0.30 | ||
Discount for lack of marketability [Member] | Series B Warrant [Member] | ||||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items] | ||||
Warrants and Rights Outstanding, Measurement Input | 0.25 | 0.30 |
Fair Value Measurements - Addit
Fair Value Measurements - Additonal Information (Detail) - USD ($) $ in Thousands | 12 Months Ended | ||||
Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019 | Jan. 31, 2020 | Nov. 30, 2019 | |
Fair Value Disclosures [Abstract] | |||||
Changes in fair value of warrant liabilities | $ 0 | $ 16,240 | $ 20,926 | ||
Derivative Liability | 45,900 | $ 62,100 | $ 25,000 | ||
Securities issuance obligation | $ 10,500 | 1,500 | |||
Fair value of securities issuance obligation | $ 10,500 | $ 12,000 | $ 6,400 |
Fair Value Measurements - Sum_2
Fair Value Measurements - Summary of Changes in Fair Values Level Financial Liabilities Recurring Basis Using Unobservable Inputs (Detail) - USD ($) $ in Thousands | 12 Months Ended | 24 Months Ended | ||
Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2021 | |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||||
Changes in fair value | $ 0 | $ 16,240 | $ 20,926 | |
Securities issuance obligation | 10,500 | 1,500 | ||
Reclassification of warrant liabilities to equity | 62,175 | |||
Fair Value Measurements Recurring [Member] | ||||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||||
Balance, beginning | 56,420 | $ 56,420 | ||
Changes in fair value | 17,725 | 17,725 | ||
Settlement of financial liabilities by securities issuance | (11,970) | (11,970) | ||
Reclassification of warrant liabilities to equity | (62,175) | (62,175) | ||
Balance, at end | 56,420 | |||
Series A Warrant [Member] | Fair Value Measurements Recurring [Member] | ||||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||||
Balance, beginning | 32,616 | 32,616 | ||
Changes in fair value | 11,597 | 11,597 | ||
Reclassification to equity | (44,213) | (44,213) | ||
Balance, at end | 32,616 | |||
Series B Warrant [Member] | Fair Value Measurements Recurring [Member] | ||||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||||
Balance, beginning | 13,319 | 13,319 | ||
Changes in fair value | 4,643 | 4,643 | ||
Reclassification to equity | (17,962) | (17,962) | ||
Balance, at end | 13,319 | |||
Warrant Issuance Obligation [Member] | Fair Value Measurements Recurring [Member] | ||||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||||
Balance, beginning | 3,036 | 3,036 | ||
Securities issuance obligation | 152 | 152 | ||
Settlement of financial liabilities by securities issuance | (3,188) | (3,188) | ||
Balance, at end | 3,036 | |||
Common stock Issuance Obligation [Member] | Fair Value Measurements Recurring [Member] | ||||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||||
Balance, beginning | 7,449 | 7,449 | ||
Securities issuance obligation | 1,333 | 1,333 | ||
Settlement of financial liabilities by securities issuance | $ (8,782) | $ (8,782) | ||
Balance, at end | $ 7,449 |
Balance Sheet Components - Summ
Balance Sheet Components - Summary of Cash and Cash Equivalents (Detail) - USD ($) $ in Thousands | Dec. 31, 2021 | Dec. 31, 2020 |
Cash And Cash Equivalents [Abstract] | ||
Cash | $ 2,223 | $ 2,136 |
Cash equivalents: | ||
Money market accounts | 102,526 | 101,919 |
Total cash and cash equivalents | $ 104,749 | $ 104,055 |
Balance Sheet Components - Su_2
Balance Sheet Components - Summary of Reconciliation of Cash, Cash Equivalents and Restricted Cash (Detail) - USD ($) $ in Thousands | Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 |
Cash And Cash Equivalents [Abstract] | ||||
Cash and cash equivalents | $ 104,749 | $ 104,055 | ||
Restricted cash included in other assets | 300 | 300 | ||
Total cash, cash equivalents and restricted cash shown in the consolidated statement of cash flows | $ 105,049 | $ 104,355 | $ 147,828 | $ 106,346 |
Balance Sheet Components - Su_3
Balance Sheet Components - Summary of Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands | Dec. 31, 2021 | Dec. 31, 2020 |
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract] | ||
Prepaid insurance | $ 1,029 | $ 991 |
Prepaid software and subscription fees | 536 | 376 |
Prepaid research and development project costs | 290 | 321 |
Other receivables | 147 | 311 |
Other | 642 | 416 |
Total prepaid expenses and other current assets | $ 2,644 | $ 2,415 |
Balance Sheet Components - Su_4
Balance Sheet Components - Summary of Property and Equipment, Net (Detail) - USD ($) $ in Thousands | Dec. 31, 2021 | Dec. 31, 2020 |
Property, Plant and Equipment [Line Items] | ||
Property and equipment, gross | $ 496 | $ 361 |
Less: accumulated depreciation | (355) | (309) |
Total property and equipment, net | 141 | 52 |
Software [Member] | ||
Property, Plant and Equipment [Line Items] | ||
Property and equipment, gross | 456 | $ 361 |
Leasehold Improvements [Member] | ||
Property, Plant and Equipment [Line Items] | ||
Property and equipment, gross | 35 | |
Computer Equipment [Member] | ||
Property, Plant and Equipment [Line Items] | ||
Property and equipment, gross | $ 5 |
Balance Sheet Components - Addi
Balance Sheet Components - Additional Information (Detail) - USD ($) | 12 Months Ended | ||
Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019 | |
Property Plant And Equipment [Abstract] | |||
Depreciation | $ 45,000 | $ 100,000 | $ 100,000 |
Balance Sheet Components - Su_5
Balance Sheet Components - Summary of Accrued and Other Liabilities (Detail) - USD ($) $ in Thousands | Dec. 31, 2021 | Dec. 31, 2020 |
Payables And Accruals [Abstract] | ||
Accrued employee related costs | $ 6,725 | $ 4,359 |
Accrued research and development costs | 2,727 | 1,715 |
Accrued professional fees | 739 | 774 |
Operating lease liabilities | $ 368 | $ 207 |
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] | us-gaap:OtherLiabilitiesCurrent | us-gaap:OtherLiabilitiesCurrent |
Other | $ 167 | $ 93 |
Total accrued and other liabilities | $ 10,726 | $ 7,148 |
Leases - Additional Information
Leases - Additional Information (Detail) - USD ($) $ in Thousands | 12 Months Ended | |
Dec. 31, 2021 | Dec. 31, 2020 | |
Loss Contingencies [Line Items] | ||
Operating lease impairment charge | $ 106 | |
California [Member] | ||
Loss Contingencies [Line Items] | ||
Operating lease agreement term | 48 months | |
Operating lease agreement expiration date | Apr. 30, 2025 | |
Vancouver [Member] | ||
Loss Contingencies [Line Items] | ||
Operating lease agreement expiration date | Feb. 28, 2023 | |
Annual sublease base rent | $ 200 | |
Future sublease base rent | $ 200 | |
Operating lease impairment charge | $ 100 | |
Weighted-average remaining lease term, operating leases (Year) | 2 years 10 months 24 days | |
Weighted-average discount rate, Operating leases | 4.70% |
Leases - Schedule of Components
Leases - Schedule of Components of Lease Expense and Related Cash Flows (Detail) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019 | |
Leases [Abstract] | |||
Operating lease cost | $ 299 | $ 195 | $ 203 |
Short-term lease cost | 27 | 42 | 117 |
Total Lease Cost | 326 | 237 | 320 |
Operating cash flows used for operating leases | $ 286 | $ 212 | $ 198 |
Leases - Schedule of Maturities
Leases - Schedule of Maturities Lease Liabilities under Leases Agreement (Detail) $ in Thousands | Dec. 31, 2021USD ($) |
Leases [Abstract] | |
2022 | $ 397 |
2023 | 223 |
2024 | 230 |
2025 | 58 |
Total lease payments | 908 |
Less imputed interest | (55) |
Total | $ 853 |
Commitments and Contingencies -
Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions | 1 Months Ended | 12 Months Ended | ||||||
Aug. 31, 2021 | Aug. 31, 2018 | Oct. 31, 2016 | Jun. 30, 2016 | Dec. 31, 2021 | Dec. 31, 2020 | Nov. 30, 2020 | Jan. 31, 2017 | |
Carna Collaboration Agreement [Member] | ||||||||
Loss Contingencies [Line Items] | ||||||||
Upfront payment | $ 0.9 | |||||||
Upfront License Fee | $ 0.3 | |||||||
Asset Purchase Agreement [Member] | ||||||||
Loss Contingencies [Line Items] | ||||||||
Upfront payment paid | $ 3 | |||||||
Aggregate milestone payment | $ 190 | |||||||
Asset Purchase Agreement [Member] | Approval from FDA [Member] | ||||||||
Loss Contingencies [Line Items] | ||||||||
Milestone payment | 25 | |||||||
AstraZeneca License Agreement [Member] | ||||||||
Loss Contingencies [Line Items] | ||||||||
Aggregate milestone payment | $ 208 | |||||||
Upfront payment | 8 | |||||||
AstraZeneca License Agreement [Member] | Drug Products and Drug Substance [Member] | ||||||||
Loss Contingencies [Line Items] | ||||||||
Research and development payable | $ 0.9 | |||||||
CPF License Agreements [Member] | ||||||||
Loss Contingencies [Line Items] | ||||||||
Upfront payment | $ 7 | |||||||
Additional milestone payment payable | 319.5 | |||||||
CPF License Agreements [Member] | Transfer of Phase 1 Clinical Trials [Member] | ||||||||
Loss Contingencies [Line Items] | ||||||||
Milestone payment | $ 2 | |||||||
CPF License Agreements [Member] | First patient first trial post amendment [Member] | ||||||||
Loss Contingencies [Line Items] | ||||||||
Milestone payment | $ 2 | |||||||
CPF License Agreement Amendment [Member] | ||||||||
Loss Contingencies [Line Items] | ||||||||
Additional milestone payment payable | $ 290 |
Stockholders' Equity - Addition
Stockholders' Equity - Additional Information (Detail) - USD ($) | Nov. 13, 2019 | Jan. 31, 2020 | Aug. 31, 2018 | Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019 | Jan. 25, 2022 | Nov. 30, 2021 | Aug. 31, 2020 | Jan. 29, 2020 | Nov. 30, 2019 |
Class Of Stock [Line Items] | |||||||||||
Proceeds from warrant exercises | $ 810,000 | ||||||||||
Changes in fair value | $ 0 | $ 16,240,000 | $ 20,926,000 | ||||||||
Silicon Valley Bank [Member] | Term Loans [Member] | Warrants to Purchase Common Stock [Member] | |||||||||||
Class Of Stock [Line Items] | |||||||||||
Exercise price of warrants or rights | $ 74.80 | ||||||||||
Warrant expiration date | Aug. 21, 2028 | ||||||||||
Warrants issued in connection with loan | 1,839 | ||||||||||
Asset Purchase Agreement Amendment [Member] | Gilead [Member] | |||||||||||
Class Of Stock [Line Items] | |||||||||||
Issuance of common stock, Shares | 725,283 | ||||||||||
Number of securities called by warrants and rights | 725,283 | ||||||||||
Exercise price of warrants or rights | $ 13.20 | ||||||||||
Warrant expiration date | Jan. 31, 2025 | ||||||||||
Series A Warrants [Member] | |||||||||||
Class Of Stock [Line Items] | |||||||||||
Number of securities called by warrants and rights | 7,802,241 | ||||||||||
Issuance of common stock for exercise of common stock warrant, Shares | 11,362 | ||||||||||
Exercise price of warrants or rights | $ 13.20 | ||||||||||
Warrant expiration date | Jan. 22, 2025 | ||||||||||
Number of Warrants exercised | 11,362 | ||||||||||
Proceeds from warrant exercises | $ 100,000 | ||||||||||
Series B Warrants [Member] | |||||||||||
Class Of Stock [Line Items] | |||||||||||
Number of securities called by warrants and rights | 2,574,727 | ||||||||||
Issuance of common stock for exercise of common stock warrant, Shares | 49,995 | ||||||||||
Exercise price of warrants or rights | $ 13.20 | ||||||||||
Warrant expiration period after specified event | 75 days | ||||||||||
Number of Warrants exercised | 151,500 | 0 | |||||||||
Proceeds from warrant exercises | $ 700,000 | ||||||||||
Series B Warrants [Member] | Subsequent Event [Member] | |||||||||||
Class Of Stock [Line Items] | |||||||||||
Warrant expiration date | Apr. 10, 2022 | ||||||||||
Series A Convertible Voting Preferred Stock [Member] | |||||||||||
Class Of Stock [Line Items] | |||||||||||
Stock issued, shares | 103,000 | ||||||||||
Share issued price per share | $ 1,000 | ||||||||||
Preferred stock conversion price per share | $ 13.20 | ||||||||||
Preferred Stock converted into of the Company's common stock | 7,803,273 | ||||||||||
Convertible Preferred Stock And Warrants And Underwritten Follow On Offering [Member] | |||||||||||
Class Of Stock [Line Items] | |||||||||||
Share issued price per share | $ 1,000 | ||||||||||
Proceeds from issuance of convertible preferred stock and warrants net of issuance cost | $ 97,700,000 | ||||||||||
Commissions and offering expenses | $ 5,300,000 | ||||||||||
At-The-Market Offering [Member] | |||||||||||
Class Of Stock [Line Items] | |||||||||||
Issuance of common stock, Shares | 4,316,968 | 732,752 | |||||||||
Proceeds from issuance of common stock, net of offering costs | $ 78,200,000 | $ 8,900,000 | |||||||||
Authorized stock issuance value remaining capacity | $ 59,600,000 | ||||||||||
At-The-Market Offering [Member] | Maximum [Member] | |||||||||||
Class Of Stock [Line Items] | |||||||||||
Common stock reserved for issuance | $ 20,000,000 | ||||||||||
Common stock reserved for issuance | $ 130,000,000 |
Stockholders' Equity - Schedule
Stockholders' Equity - Schedule of Common Stock Reserved for Issuance (Detail) - shares | Dec. 31, 2021 | Dec. 31, 2020 | Jul. 15, 2015 |
Class Of Stock [Line Items] | |||
Total common stock reserved for future issuance | 17,205,249 | 16,386,314 | |
Series A Warrant [Member] | |||
Class Of Stock [Line Items] | |||
Total common stock reserved for future issuance | 7,790,879 | 7,802,241 | |
Series B Warrant [Member] | |||
Class Of Stock [Line Items] | |||
Total common stock reserved for future issuance | 2,524,732 | 2,574,727 | |
Equity Incentive Plans [Member] | |||
Class Of Stock [Line Items] | |||
Total common stock reserved for future issuance | 1,207,827 | 1,117,796 | |
Awards outstanding | 4,937,189 | 4,146,928 | |
2015 Employee Stock Purchase Plan [Member] | |||
Class Of Stock [Line Items] | |||
Total common stock reserved for future issuance | 17,500 | 17,500 | 17,500 |
Warrants to Purchase Common Stock [Member] | |||
Class Of Stock [Line Items] | |||
Outstanding warrants | 727,122 | 727,122 |
Stock-Based Compensation - Sche
Stock-Based Compensation - Schedule of Stock-based Compensation Expense for Employees and Non-employees (Detail) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019 | |
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] | |||
Total stock-based compensation | $ 12,890 | $ 9,470 | $ 5,695 |
Research and development [Member] | |||
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] | |||
Total stock-based compensation | 7,197 | 4,316 | 3,873 |
General and administrative [Member] | |||
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] | |||
Total stock-based compensation | $ 5,693 | $ 5,154 | $ 1,822 |
Stock-Based Compensation - Sc_2
Stock-Based Compensation - Schedule of Estimated Grant-date Fair Values of Stock-based Awards Using Black-Scholes Option Pricing Model Assumptions (Detail) | 12 Months Ended | ||
Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019 | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Expected volatility, Minimum | 82.00% | 87.00% | 89.00% |
Expected volatility, Maximum | 85.00% | 90.00% | 94.00% |
Risk-free interest rate, Minimum | 0.50% | 0.30% | 1.60% |
Risk-free interest rate, Maximum | 1.30% | 1.20% | 2.60% |
Minimum [Member] | |||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Expected term (in years) | 5 years 3 months 18 days | 5 years 3 months 18 days | 5 years 3 months 18 days |
Maximum [Member] | |||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Expected term (in years) | 7 years | 7 years | 6 years 10 months 24 days |
Stock-Based Compensation - Addi
Stock-Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands | Feb. 08, 2022 | Jan. 21, 2020 | Jul. 15, 2015 | Jan. 31, 2022 | Feb. 28, 2021 | Jun. 30, 2020 | May 31, 2020 | Feb. 28, 2021 | Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019 | Sep. 30, 2018 |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||||||||
Number of common stock shares reserved for issuance | 17,205,249 | 16,386,314 | ||||||||||
Total stock-based compensation | $ 12,890 | $ 9,470 | $ 5,695 | |||||||||
Total unrecognized stock-based compensation related to unvested stock options | $ 25,300 | |||||||||||
Weighted-average period | 2 years 8 months 12 days | |||||||||||
Performance Options [Member] | ||||||||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||||||||
Options outstanding and unvested | 1,029,000 | 1,104,500 | ||||||||||
Total stock-based compensation | $ 3,000 | $ 900 | ||||||||||
Total unrecognized stock-based compensation related to unvested stock options | $ 5,300 | |||||||||||
Subsequent Event [Member] | Performance Options [Member] | ||||||||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||||||||
Options vested | 257,255 | |||||||||||
2018 Equity Inducement Plan [Member] | ||||||||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||||||||
Number of common stock shares reserved for issuance | 1,037,500 | 37,500 | ||||||||||
Common shares authorized to be issued during the period | 500,000 | 500,000 | 1,000,000 | |||||||||
Stock option life in years | 10 years | |||||||||||
2018 Equity Inducement Plan [Member] | Subsequent Event [Member] | ||||||||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||||||||
Common shares authorized to be issued during the period | 500,000 | |||||||||||
2015 Plan [Member] | ||||||||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||||||||
Number of common stock shares reserved for issuance | 5,123,736 | |||||||||||
Common shares authorized to be issued during the period | 4,312,500 | |||||||||||
Stock option life in years | 10 years | |||||||||||
Percentage threshold of outstanding shares increased annually under the plan | 4.00% | |||||||||||
Employee stock purchase plan description | the number of shares equal to 4% of the total outstanding shares of the Company’s common stock as of the immediately preceding December 31. | |||||||||||
2008 Plan, 2015 Plan and 2018 Plan [Member] | ||||||||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||||||||
Common shares authorized to be issued during the period | 945,139 | |||||||||||
Weighted-average grant date fair values of options granted | $ 12.54 | $ 8.81 | $ 50.40 | |||||||||
Options, exercises in period | 64,847 | 0 | ||||||||||
Aggregate intrinsic value of options exercised | $ 500 | $ 100 | ||||||||||
Total grant date fair value of options vested | $ 11,300 | $ 5,200 | $ 6,000 | |||||||||
2008 Plan, 2015 Plan and 2018 Plan [Member] | Share Based Compensation Arrangement Modification [Member] | ||||||||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||||||||
Warrant expiration period after specified event | 75 days | |||||||||||
Compensation costs relating to vesting acceleration and modification | $ 2,200 | |||||||||||
Option expiration date | Apr. 10, 2022 | |||||||||||
2015 Employee Stock Purchase Plan [Member] | ||||||||||||
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||||||||
Number of common stock shares reserved for issuance | 17,500 | 17,500 | 17,500 | |||||||||
Common shares authorized to be issued during the period | 85,000 | |||||||||||
Employee stock purchase plan description | The aggregate number of shares issued over the term of the 2015 Employee Stock Purchase Plan will not exceed 85,000 shares of common stock. The ESPP will not become effective until such time as the Compensation Committee determines in the future, and as of December 31, 2021, the initial offering periods had not commenced. | |||||||||||
Number of common stock issued | 0 |
Stock-Based Compensation - Summ
Stock-Based Compensation - Summary of Stock-Based Compensation Activity (Detail) - 2008 Plan, 2015 Plan and 2018 Plan [Member] - USD ($) $ / shares in Units, $ in Thousands | 12 Months Ended | |
Dec. 31, 2021 | Dec. 31, 2020 | |
Options Outstanding, Shares Available for Grant | ||
Shares Available for Grant, Beginning balance | 1,117,796 | |
Shares Available for Grant, Awards authorized | 945,139 | |
Shares Available for Grant, Granted | (1,134,860) | |
Shares Available for Grant, forfeited/cancelled | 279,752 | |
Shares Available for Grant, Ending balance | 1,207,827 | 1,117,796 |
Options Outstanding, Number of Shares Outstanding | ||
Number of Shares Outstanding, Beginning balance | 4,146,928 | |
Number of Shares Outstanding, Options granted | 1,134,860 | |
Number of Shares Outstanding, Options exercised | (64,847) | 0 |
Number of Shares Outstanding, Options forfeited/cancelled | (279,752) | |
Number of Shares Outstanding, Ending balance | 4,937,189 | 4,146,928 |
Number of Shares Outstanding, Exercisable | 1,421,885 | |
Number of Shares Outstanding, Vested and expected to vest | 4,422,699 | |
Options Outstanding, Weighted-Average Exercise Price Per Share | ||
Weighted-Average Exercise Price Per Share, Beginning balance | $ 19.45 | |
Weighted-Average Exercise Price Per Share, Options granted | 17.78 | |
Weighted-Average Exercise Price Per Share, Options exercised | 13.06 | |
Weighted-Average Exercise Price Per Share, Options forfeited/cancelled | 17.99 | |
Weighted-Average Exercise Price Per Share, Ending balance | 19.23 | $ 19.45 |
Weighted-Average Exercise Price Per Share, Exercisable | 30.98 | |
Weighted-Average Exercise Price Per Share, Vested and expected to vest | $ 20.06 | |
Options Outstanding, Weighted-Average Remaining Contractual Term (Years) | ||
Weighted-Average Remaining Contractual Term (Years) | 8 years 1 month 20 days | 8 years 10 months 2 days |
Weighted-Average Remaining Contractual Term (Year), Exercisable | 6 years 6 months 21 days | |
Weighted-Average Remaining Contractual Term (Year), Vested and expected to vest | 8 years 25 days | |
Options Outstanding, Aggregate Intrinsic Value of Outstanding Options | ||
Aggregate Intrinsic Value of Outstanding Options | $ 36,080 | $ 12,227 |
Aggregate Intrinsic Value of Outstanding Options, Exercisable | 9,682 | |
Aggregate Intrinsic Value of Outstanding Options, Vested and expected to vest | $ 31,146 |
Income Taxes - Schedule of Geog
Income Taxes - Schedule of Geographical Breakdown of Loss Before Provision for Income Taxes (Detail) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019 | |
Income Tax Disclosure [Abstract] | |||
United States | $ (95,605) | $ (81,670) | $ (89,459) |
International | 943 | 910 | 1,024 |
Loss before provision for (benefit from) income taxes, net | $ (94,662) | $ (80,760) | $ (88,435) |
Income Taxes - Components of Pr
Income Taxes - Components of Provision for (Benefit from) Income Taxes (Detail) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019 | |
Current tax provision (benefit): | |||
Foreign | $ 38 | $ 59 | $ 85 |
Total current tax provision (benefit) | 38 | 59 | 85 |
Deferred tax provision (benefit): | |||
Foreign | (41) | 83 | (245) |
Total deferred tax provision (benefit) | (41) | 83 | (245) |
Total provision for (benefit from) income taxes | $ (3) | $ 142 | $ (160) |
Income Taxes - Reconciliation B
Income Taxes - Reconciliation Between Income Taxes Computed at the Federal Statutory Income Tax Rate and the Provision for Income Taxes (Detail) | 12 Months Ended | ||
Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019 | |
Income Tax Disclosure [Abstract] | |||
Federal statutory rate | 21.00% | 21.00% | 21.00% |
Change in valuation allowance | (27.80%) | (23.60%) | 12.40% |
Federal tax credit | 7.40% | 5.80% | 1.50% |
Warrant issuance and remeasurement | (4.20%) | (5.30%) | |
Effect of ownership change on deferred tax assets | (0.10%) | 1.30% | (29.00%) |
State income tax benefit, net of federal benefit | 0.20% | 0.20% | |
Other permanent items | (0.50%) | (0.70%) | (0.60%) |
Total provision for (benefit from) income taxes% | 0.00% | (0.20%) | 0.20% |
Income Taxes - Components of De
Income Taxes - Components of Deferred Tax Assets (Detail) - USD ($) $ in Thousands | Dec. 31, 2021 | Dec. 31, 2020 |
Deferred tax assets: | ||
59 (e) expenditures and amortization | $ 21,833 | $ 6,222 |
Net operating loss carryforwards | 13,546 | 14,011 |
Federal R&D and orphan drug credits | 11,992 | 5,107 |
Stock based compensation | 8,806 | 6,459 |
License fee | 4,691 | 3,224 |
Other | 1,468 | 1,024 |
Gross deferred tax assets | 62,336 | 36,047 |
Valuation allowance | (61,847) | (35,513) |
Total deferred tax assets | 489 | 534 |
Deferred tax liabilities: | ||
Lease Asset | 19 | 114 |
Other | 82 | 73 |
Total deferred tax liabilities | 101 | 187 |
Total net deferred tax assets | $ 388 | $ 347 |
Income Taxes - Additional Infor
Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands | 12 Months Ended | |
Dec. 31, 2021 | Dec. 31, 2020 | |
Income Tax Contingency [Line Items] | ||
Deferred tax assets, valuation allowance | $ 61,400 | $ 35,200 |
Deferred tax assets, valuation allowance, change in amount | 26,200 | 18,800 |
Unrecognized tax benefits, accrued interest and penalties | $ 0 | $ 0 |
Earliest Tax Year [Member] | ||
Income Tax Contingency [Line Items] | ||
Open Tax Year | 2018 | |
Latest Tax Year [Member] | ||
Income Tax Contingency [Line Items] | ||
Open Tax Year | 2020 | |
Domestic Tax Authority [Member] | ||
Income Tax Contingency [Line Items] | ||
Operating loss carry forwards | $ 52,700 | |
Tax credit carry forwards | $ 11,200 | |
Tax credit carry forwards, year begin to expiration | 2039 | |
State and Local Jurisdiction [Member] | ||
Income Tax Contingency [Line Items] | ||
Operating loss carry forwards | $ 51,800 | |
Operating loss carry forwards, expiry year start | 2022 | |
Operating loss carry forwards, expiry year end | 2041 | |
Foreign Tax Authority [Member] | ||
Income Tax Contingency [Line Items] | ||
Tax credit carry forwards | $ 800 | |
Tax credit carry forwards, year begin to expiration | 2039 |
Income Taxes - Unrecognized Tax
Income Taxes - Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019 | |
Income Tax Disclosure [Abstract] | |||
Beginning balance | $ 621 | $ 314 | $ 264 |
Increases based on tax positions related to prior years | 39 | ||
Decreases based on tax positions related to prior years | (83) | (54) | (103) |
Decreases due to ownership change | (207) | ||
Increases based on tax positions in current year | 780 | 568 | 153 |
Ending balance | $ 1,357 | $ 621 | $ 314 |
Subsequent Event - Additional I
Subsequent Event - Additional Information (Detail) | Mar. 07, 2022USD ($)shares | Feb. 03, 2022USD ($)shares | Jan. 21, 2022USD ($)Tranche | Jan. 31, 2022$ / sharesshares | Dec. 31, 2021USD ($)shares | Dec. 31, 2020shares | Dec. 31, 2019USD ($)shares |
Subsequent Event [Line Items] | |||||||
Proceeds from exercise of common stock warrants | $ 810,000 | ||||||
Proceeds from exercise of common stock options | $ 847,000 | $ 445,000 | |||||
Common Stock [Member] | |||||||
Subsequent Event [Line Items] | |||||||
Issuance of common stock, Shares | shares | 4,316,968 | 732,752 | |||||
Issuance of common stock for exercise of common stock options, Shares | shares | 64,847 | 8,056 | |||||
Subsequent Event [Member] | Former Employees and Non-discretionary Sales [Member] | |||||||
Subsequent Event [Line Items] | |||||||
Issuance of common stock for exercise of common stock options, Shares | shares | 212,892 | ||||||
Proceeds from exercise of common stock options | $ 2,800,000 | ||||||
Subsequent Event [Member] | Series A [Member] | |||||||
Subsequent Event [Line Items] | |||||||
Issuance of common stock pertaining to warrant exercise | shares | 18,937 | ||||||
Subsequent Event [Member] | Series B [Member] | |||||||
Subsequent Event [Line Items] | |||||||
Issuance of common stock pertaining to warrant exercise | shares | 2,312,257 | ||||||
Subsequent Event [Member] | Series A and Series B Warrant [Member] | |||||||
Subsequent Event [Line Items] | |||||||
Proceeds from exercise of common stock warrants | $ 30,800,000 | ||||||
Subsequent Event [Member] | Underwritten Public Offering [Member] | |||||||
Subsequent Event [Line Items] | |||||||
Proceeds from issuance of common stock, net of deferred financing costs | $ 145,600,000 | ||||||
Underwriting discounts and commissions and offering expenses | $ 9,700,000 | ||||||
Subsequent Event [Member] | Underwritten Public Offering [Member] | Common Stock [Member] | |||||||
Subsequent Event [Line Items] | |||||||
Issuance of common stock, Shares | shares | 4,824,075 | 750,000 | 4,074,075 | ||||
Share issued price per share | $ / shares | $ 27 | ||||||
Subsequent Event [Member] | Underwritten Public Offering [Member] | Pre-funded Warrants to Purchase Common Stock [Member] | |||||||
Subsequent Event [Line Items] | |||||||
Number of securities called by warrants and rights | shares | 925,925 | ||||||
Share issued price per share | $ / shares | $ 26.999 | ||||||
Oxford Finance, LLC [Member] | Subsequent Event [Member] | |||||||
Subsequent Event [Line Items] | |||||||
Aggregate principal amount of loan | $ 125,000,000 | ||||||
Number of tranches | Tranche | 4 | ||||||
Floating interest per annum | 5.25% | ||||||
Final payment fee | 6.00% | ||||||
Facility fee | 0.50% | ||||||
Oxford Finance, LLC [Member] | Subsequent Event [Member] | Floor Rate [Member] | |||||||
Subsequent Event [Line Items] | |||||||
Interest rate, stated percentage | 8.50% | ||||||
Oxford Finance, LLC [Member] | Before First Anniversary [Member] | Subsequent Event [Member] | |||||||
Subsequent Event [Line Items] | |||||||
Accrued interest and the final payment fee subject to a prepayment fee | 2.00% | ||||||
Oxford Finance, LLC [Member] | After First and Before Third Anniversary [Member] | Subsequent Event [Member] | |||||||
Subsequent Event [Line Items] | |||||||
Accrued interest and the final payment fee subject to a prepayment fee | 1.00% | ||||||
Oxford Finance, LLC [Member] | Term Loan C [Member] | Subsequent Event [Member] | |||||||
Subsequent Event [Line Items] | |||||||
Aggregate principal amount of loan | $ 70,000 | ||||||
Line of credit facility expiration period | 30 days | ||||||
Line of credit facility expiration date | Dec. 31, 2023 | ||||||
Oxford Finance, LLC [Member] | Term Loan D [Member] | Subsequent Event [Member] | |||||||
Subsequent Event [Line Items] | |||||||
Aggregate principal amount of loan | $ 50,000 | ||||||
Oxford Finance, LLC [Member] | Term Loan A [Member] | |||||||
Subsequent Event [Line Items] | |||||||
Loan agreement, description | Contemporaneously with executing the Loan Agreement, the Company drew down the first $5.0 million tranche (Term Loan A). | ||||||
Gilead [Member] | Subsequent Event [Member] | Securities Purchase Agreement [Member] | |||||||
Subsequent Event [Line Items] | |||||||
Issuance of common stock pertaining to warrant exercise | shares | 725,283 | ||||||
Proceeds from exercise of common stock warrants | $ 9,600,000 | ||||||
Term Loan A [Member] | Oxford Finance, LLC [Member] | Subsequent Event [Member] | |||||||
Subsequent Event [Line Items] | |||||||
Proceeds from issuance of debt | $ 5,000,000 |