Syros Pharmaceuticals (SYRS) 10-Q 16 May 22 2022 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2022	May 12, 2022
Cover [Abstract]
Entity Registrant Name	SYROS PHARMACEUTICALS, INC.
Trading Symbol	SYRS
Entity Central Index Key	0001556263
Document Type	10-Q
Document Period End Date	Mar. 31, 2022
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		62,819,046
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q1
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity File Number	001-37813
Entity Tax Identification Number	45-3772460
Entity Address, Address Line One	35 CambridgePark Drive
Entity Address, Address Line Two	4th Floor
Entity Address, City or Town	Cambridge
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02140
City Area Code	617
Local Phone Number	744-1340
Document Quarterly Report	true
Document Transition Report	false
Entity Interactive Data Current	Yes
Entity Incorporation, State or Country Code	DE
Title of 12(b) Security	Common Stock, $0.001 par value
Security Exchange Name	NASDAQ

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 69,575	$ 92,302
Marketable securities	40,686	38,067
Contract assets	3,182	2,979
Prepaid expenses and other current assets	3,034	3,237
Total current assets	116,477	136,585
Property and equipment, net	12,554	12,844
Marketable securities - noncurrent	2,638	13,038
Other long-term assets	3,155	2,941
Restricted cash	3,086	3,086
Right-of-use asset – operating lease	13,900	14,104
Right-of-use assets – financing leases	271	337
Total assets	152,081	182,935
Current liabilities:
Accounts payable	2,841	3,692
Accrued expenses	13,249	15,624
Deferred revenue	7,773	10,181
Financing lease obligations, current portion	274	291
Operating lease obligation, current portion	1,789	1,720
Debt, current portion	1,667
Total current liabilities	27,593	31,508
Financing lease obligations, net of current portion	12	65
Operating lease obligation, net of current portion	22,378	22,858
Warrant liability	581	3,029
Debt, net of debt discount, long term	38,775	40,257
Commitments and contingencies (See Note 10)
Stockholders' equity:
Preferred stock, $0.001 par value; 10,000,000 shares authorized at March 31, 2022 and December 31, 2021; 0 shares issued and outstanding at March 31, 2022 and December 31, 2021
Common stock, $0.001 par value; 200,000,000 shares authorized at March 31, 2022 and December 31, 2021; 62,801,296 and 62,024,035 shares issued and outstanding at March 31, 2022 and December 31, 2021, respectively	61	61
Additional paid-in capital	551,679	548,815
Accumulated other comprehensive loss	(273)	(79)
Accumulated deficit	(488,725)	(463,579)
Total stockholders' equity	62,742	85,218
Total liabilities and stockholders' equity	$ 152,081	$ 182,935

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (Unaudited) - $ / shares	Mar. 31, 2022	Dec. 31, 2021
Statement Of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	62,801,296	62,024,035
Common stock, shares outstanding	62,801,296	62,024,035

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Income Statement [Abstract]
Revenue	$ 5,467	$ 4,827
Operating expenses:
Research and development	25,171	20,029
General and administrative	6,949	5,739
Total operating expenses	32,120	25,768
Loss from operations	(26,653)	(20,941)
Interest income	35	10
Interest expense	(976)	(967)
Change in fair value of warrant liability	2,448	7,670
Net loss applicable to common stockholders	$ (25,146)	$ (14,228)
Net loss per share applicable to common stockholders - basic and diluted	$ (0.40)	$ (0.23)
Weighted-average number of common shares used in net loss per share applicable to common stockholders - basic and diluted	63,061,423	61,379,641

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (25,146)	$ (14,228)
Other comprehensive loss:
Unrealized holding loss on marketable securities	(194)
Comprehensive loss	$ (25,340)	$ (14,228)

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDER'S EQUITY - USD ($) $ in Thousands	Total	At The Market	Common Stock	Common StockAt The Market	Additional Paid-In Capital	Additional Paid-In CapitalAt The Market	Accumulated Other Comprehensive Gain (Loss)	Accumulated Deficit
Balance at Dec. 31, 2020	$ 90,553		$ 56		$ 467,518			$ (377,021)
Balance (in shares) at Dec. 31, 2020			56,222,746
Exercise of stock options	157				157
Exercise of stock options, Shares			20,134
Vesting of restricted stock units			206,762
Stock-based compensation expense	2,930				2,930
Issuance of common stock at-the-market, net of issuance costs		$ 70,468		$ 5		$ 70,463
Issuance of common stock at-the-market, net of issuance costs,Shares				5,400,000
Net loss	(14,228)							(14,228)
Balance at Mar. 31, 2021	149,880		$ 61		541,068			(391,249)
Balance (in shares) at Mar. 31, 2021			61,849,642
Balance at Dec. 31, 2020	90,553		$ 56		467,518			(377,021)
Balance (in shares) at Dec. 31, 2020			56,222,746
Net loss	(86,600)
Balance at Dec. 31, 2021	$ 85,218		$ 61		548,815		$ (79)	(463,579)
Balance (in shares) at Dec. 31, 2021	62,024,035		62,024,035
Exercise of stock options	$ 1				1
Exercise of stock options, Shares	37,700		37,700
Vesting of restricted stock units			739,561
Stock-based compensation expense	$ 2,863				2,863
Other comprehensive loss	(194)						(194)
Net loss	(25,146)							(25,146)
Balance at Mar. 31, 2022	$ 62,742		$ 61		$ 551,679		$ (273)	$ (488,725)
Balance (in shares) at Mar. 31, 2022	62,801,296		62,801,296

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDER'S EQUITY (Parenthetical) $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)
Common Stock | At The Market
Issuance costs	$ 5,132

CONDENSED CONSOLIDATED STATEM_5

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating activities
Net loss	$ (25,146)	$ (14,228)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	681	666
Amortization of right-of-use asset	66	65
Stock-based compensation expense	2,863	2,930
Change in fair value of warrant liability	(2,448)	(7,670)
Net amortization of premiums and discounts on marketable securities	76
Amortization of debt-discount and accretion of deferred debt costs	185	167
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	203	329
Accounts receivable		7
Contract assets	(203)	(298)
Other long-term assets	(338)	(27)
Accounts payable	(969)	63
Accrued expenses	(2,372)	(1,680)
Deferred revenue	(2,408)	(2,134)
Operating lease asset and liabilities	(207)	(180)
Net cash used in operating activities	(30,017)	(21,990)
Investing activities
Purchases of property and equipment	(128)	(262)
Maturities of marketable securities	7,511
Net cash (used in) provided by investing activities	7,383	(262)
Financing activities
Payments on financing lease obligations	(70)	(64)
Proceeds from issuance of common stock through employee benefit plans		157
Proceeds from the issuance of common stock through exercise of option	1
Proceeds from issuance of common stock and warrants in public offerings, net of issuance costs		70,353
Payment of issuance costs related to out of period offering	(24)	(36)
Net cash (used in) provided by financing activities	(93)	70,410
Net (decrease) increase in cash, cash equivalents and restricted cash	(22,727)	48,158
Cash and cash equivalents, Beginning of period	95,388	177,070
Cash and cash equivalents, End of period	72,661	225,228
Supplemental disclosure of cash flow information:
Cash paid for interest	783	789
Non-cash investing and financing activities:
Property and equipment received but unpaid as of period end	165
Offering costs incurred but unpaid as of period end	$ 10	$ 26

Nature of Business

Nature of Business	3 Months Ended
	Mar. 31, 2022
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Nature of Business	1. Nature of Business Syros Pharmaceuticals, Inc. (the "Company"), a Delaware corporation formed in November 2011, is a biopharmaceutical company seeking to redefine the power of small molecules to control the expression of genes. The Company is subject to a number of risks similar to those of other early stage companies, including dependence on key individuals; risks inherent in the development and commercialization of medicines to treat human disease; competition from other companies, many of which are larger and better capitalized; risks relating to obtaining and maintaining necessary intellectual property protection; and the need to obtain adequate additional financing to fund the development of its product candidates and discovery activities. If the Company is unable to raise capital when needed or on favorable terms, it would be forced to delay, reduce, eliminate or out-license certain of its research and development programs or future commercialization rights to its product candidates. The Company has incurred significant net operating losses in every year since its inception. It expects to continue to incur significant and increasing net operating losses for at least the next several years. The Company’s net losses were $86.6 million, $84.0 million and $75.4 million for the years ended December 31, 2021, 2020 and 2019, respectively. As of March 31, 2022, the Company had an accumulated deficit of $488.7 million. The Company has not generated any revenues from product sales, has not completed the development of any product candidate and may never have a product candidate approved for commercialization. The Company has financed its operations to date primarily through a credit facility, the sale of equity securities and through license and collaboration agreements. The Company has devoted substantially all of its financial resources and efforts to research and development and general and administrative activities to support such research and development. The Company’s net losses may fluctuate significantly from quarter to quarter and year to year. Net losses and negative cash flows have had, and will continue to have, an adverse effect on the Company’s stockholders' equity and working capital. Under ASC Topic 205-40, Presentation of Financial Statements - Going Concern Successful completion of the Company’s development program and, ultimately, the attainment of profitable operations are dependent upon future events, including obtaining adequate financing to support the Company’s cost structure and operating plan. Management’s plans to alleviate its financing requirements include, among other things, pursuing one or more of the following steps to raise additional capital, none of which can be guaranteed or are entirely within the Company’s control: • raise funding through the sale of the Company’s common or preferred stock; • raise funding through debt financing; and • establish collaborations with potential partners to advance the Company’s product pipeline. Based on its current operating plan, the Company’s management believes that its cash, cash equivalents and marketable securities of $112.9 million as of March 31, 2022 If the Company is unable to raise capital when needed or on acceptable terms, or if it is unable to procure collaboration arrangements to advance its programs, the Company would be forced to discontinue some of its operations or develop and implement a plan to further extend payables, reduce overhead or scale back its current operating plan until sufficient additional capital is raised to support further operations. There can be no assurance that such a plan would be successful.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2022
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation The Company’s consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”). Any reference in these notes to applicable guidance is meant to refer to the authoritative U.S. GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASU”) of the Financial Accounting Standards Board (“FASB”). The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited financial statements. In the opinion of the Company’s management, the accompanying unaudited interim condensed consolidated financial statements contain all adjustments that are necessary to present fairly the Company’s financial position as of March 31, 2022, the results of its operations, statements of cash flows and statements of stockholders’ equity for the three months ended March 31, 2022 and 2021. Such adjustments are of a normal and recurring nature. The results for the three months ended March 31, 2022 are not necessarily indicative of the results for the year ending December 31, 2022, or for any future period. Principles of Consolidation The accompanying condensed consolidated financial statements include the accounts of Syros Pharmaceuticals, Inc. and its wholly owned subsidiaries, Syros Securities Corporation, a Massachusetts corporation formed by the Company in December 2014 to exclusively engage in buying, selling and holding securities on its own behalf, and Syros Pharmaceuticals (Ireland) Limited, an Irish limited liability company formed by the Company in January 2019. All intercompany transactions and balances have been eliminated in consolidation. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts in the financial statements and accompanying notes. Management considers many factors in selecting appropriate financial accounting policies and in developing the estimates and assumptions that are used in the preparation of the financial statements. Management must apply significant judgment in this process. In addition, other factors may affect estimates, which include, but are not limited to, expected business and operational changes, sensitivity and volatility associated with the assumptions used in developing estimates and whether historical trends are expected to be representative of future trends. Management’s estimation process may yield a range of potentially reasonable estimates and management must select an amount that falls within that range of reasonable estimates. On an ongoing basis, the Company’s management evaluates its estimates, which include, but are not limited to, estimates related to revenue recognition, warrant liability, stock-based compensation expense, accrued expenses, income taxes Segment Information Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision maker, or decision-making group, in making decisions on how to allocate resources and assess performance. The Company's chief operating decision maker is its chief executive officer. The Company and the chief operating decision maker view the Company's operations and manage its business in one operating segment. The Company operates only in the United States. Cash and Cash Equivalents The Company considers all highly liquid instruments that have original maturities of three months or less when acquired to be cash equivalents. Cash equivalents, which consist of money market funds that invest in U.S. Treasury obligations, as well as overnight repurchase agreements and corporate debt securities , are stated at fair value. The Company maintains its bank accounts at one major financial institution. Off-Balance Sheet Risk and Concentrations of Credit Risk The Company has no financial instruments with off-balance sheet risk, such as foreign exchange contracts, option contracts, or other foreign hedging arrangements. Financial instruments that potentially subject the Company to concentrations of credit risk primarily consist of cash equivalents and marketable securities. Under its investment policy, the Company limits amounts invested in such securities by credit rating, maturity, industry group, investment type and issuer, except for securities issued by the U.S. government. The Company is not exposed to any significant concentrations of credit risk from these financial instruments. The goals of the Company’s investment policy, in order of priority, are safety and preservation of principal and liquidity of investments sufficient to meet cash flow requirements. Fair Value of Financial Instruments ASC 820, Fair Value Measurement ASC 820 identified fair value as the exchange price, or exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As a basis for considering market participant assumptions in fair value measurements, ASC 820 established a three-tier fair value hierarchy that distinguishes between the following: Level 1—Quoted market prices (unadjusted) in active markets for identical assets or liabilities. Level 2—Inputs other than quoted prices included within Level 1 that are either directly or indirectly observable, such as quoted market prices, interest rates and yield curves. Level 3—Unobservable inputs developed using estimates or assumptions developed by the Company, which reflect those that a market participant would use. To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized as Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The carrying amounts reflected in the condensed consolidated balance sheets for cash and cash equivalents, prepaid expenses, other current assets, restricted cash, accounts payable, accrued expenses and deferred revenue approximate their respective fair values due to their short-term nature. Property and Equipment Property and equipment consists of laboratory equipment, computer equipment, furniture and fixtures and leasehold improvements, all of which are stated at cost, less accumulated depreciation. Expenditures for maintenance and repairs that do not improve or extend the lives of the respective assets are recorded to expense as incurred. Major betterments are capitalized as additions to property and equipment. Depreciation and amortization are recognized over the estimated useful lives of the assets using the straight-line method. Construction-in-progress is stated at cost, which relates to the cost of leasehold improvements not yet placed into service. No depreciation expense is recorded on construction-in-progress until such time as the relevant assets are completed and put into use. Impairment of Long-Lived Assets The Company continually evaluates long-lived assets for potential impairment when events or changes in circumstances indicate the carrying value of the assets may not be recoverable. Recoverability is measured by comparing the book values of the assets to the expected future net undiscounted cash flows that the assets are expected to generate. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the book values of the assets exceed their fair value. The Company has no t recognized any impairment losses from inception through March 31, 2022. Other Long-Term Assets Other long-term assets primarily consisted of advance payments made to the contract research organizations responsible for conducting the Company’s tamibarotene Revenue Recognition To date the Company’s only revenue has consisted of collaboration and license revenue. The Company has not generated any revenue from product sales and does not expect to generate any revenue from product sales for the foreseeable future. The Company recognizes revenue in accordance with ASC 606, Revenue from Contracts with Customers (“ASC 606”). (i) (ii) (iii) (iv) (v) The Company only applies the five-step model to contracts when it is probable that the Company will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. If a contract is determined to be within the scope of ASC 606 at inception, the Company assesses the goods or services promised within such contract, determines which of those goods and services are performance obligations, and assesses whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. If the Company performs by transferring goods or services to a customer before the customer pays consideration or before payment is due, the Company records a contract asset, excluding any amounts presented as accounts receivable. The Company includes unbilled accounts receivable as contract assets on its consolidated balance sheets. The Company records accounts receivable for amounts billed to the customer for which the Company has an unconditional right to consideration. The Company assesses contract assets and accounts receivable for impairment and, to date, no impairment losses have been recorded. From time to time, the Company may enter into agreements that are within the scope of ASC 606. The terms of these arrangements typically include payment to the Company of one or more of the following: non-refundable, up-front license fees or prepaid research and development services; development, regulatory and commercial milestone payments; and royalties on net sales of licensed products. Each of these payments results in license and collaboration revenues, except for revenues from royalties on net sales of licensed products, which will be classified as royalty revenues. The Company analyzes its collaboration arrangements to assess whether they are within the scope of ASC 808, Collaborative Arrangements Research and Development Expenditures relating to research and development are expensed in the period incurred. Research and development expenses consist of both internal and external costs associated with the development of the Company’s gene control platform and product candidates. Research and development costs include salaries and benefits, materials and supplies, external research, preclinical and clinical development expenses, stock-based compensation expense and facilities costs. Facilities costs primarily include the allocation of rent, utilities, depreciation and amortization. In certain circumstances, the Company is required to make non-refundable advance payments to vendors for goods or services that will be received in the future for use in research and development activities. In such circumstances, the non-refundable advance payments are deferred and capitalized, even when there is no alternative future use for the research and development, until related goods or services are provided. The Company records accruals for estimated ongoing research costs. When evaluating the adequacy of the accrued liabilities, the Company analyzes progress of the work being performed, including the phase or completion of the event, invoices received and costs. Significant judgements and estimates may be made in determining the accrued balances at the end of any reporting period. Actual results could differ from the Company’s estimates. The Company may in-license the rights to develop and commercialize product candidates. For each in-license transaction the Company evaluates whether it has acquired processes or activities along with inputs that would be sufficient to constitute a “business” as defined under U.S. GAAP. A “business” as defined under U.S. GAAP consists of inputs and processes applied to those inputs that have the ability to create outputs. Although businesses usually have outputs, outputs are not required for an integrated set of activities to qualify as a business. When the Company determines that it has not acquired sufficient processes or activities to constitute a business, any up-front payments, as well as milestone payments, are immediately expensed as acquired research and development in the period in which they are incurred. Warrants The Company accounts for issued warrants either as a liability or equity in accordance with ASC 480-10, Accounting for Certain Financial Instruments with Characteristics of both Liabilities and Equity Accounting for Derivative Financial Instruments Indexed to, and Potentially Settled in, a Company’s Own Stock Stock-Based Compensation Expense The Company accounts for its stock-based compensation awards in accordance with ASC 718, Compensation—Stock Compensation The Company expenses the fair value of its stock-based awards to employees and non-employees on a straight-line basis over the associated service period, which is generally the vesting period. The Company accounts for forfeitures as they occur instead of estimating forfeitures at the time of grant. Ultimately, the actual expense recognized over the vesting period will be for only those options that vest. Compensation expense for discounted purchases under the employee stock purchase plan is measured using the Black-Scholes model to compute the fair value of the lookback provision plus the purchase discount and is recognized as compensation expense over the offering period. For stock-based awards that contain performance-based milestones, the Company records stock-based compensation expense in accordance with the accelerated attribution model. Management evaluates when the achievement of a performance-based milestone is probable based on the expected satisfaction of the performance conditions as of the reporting date. Income Taxes The Company accounts for uncertain tax positions using a more-likely-than-not threshold for recognizing and resolving uncertain tax positions. The evaluation of uncertain tax positions is based on factors including, but not limited to, changes in the law, the measurement of tax positions taken or expected to be taken in tax returns, the effective settlement of matters subject to audit, new audit activity, and changes in facts or circumstances related to a tax position. Net Loss per Share Basic net earnings per share applicable to common stockholders is calculated by dividing net earnings applicable to common stockholders by the weighted average shares outstanding during the period, without consideration for common stock equivalents. Diluted net earnings per share applicable to common stockholders is calculated by adjusting the weighted average shares outstanding for the dilutive effect of common stock equivalents outstanding for the period, determined using the treasury-stock method and the if-converted method. For purposes of the calculation of dilutive net loss per share applicable to common stockholders, stock options, unvested restricted stock units, and warrants are considered to be common stock equivalents but are excluded from the calculation of diluted net loss per share applicable to common stockholders, as their effect would be anti-dilutive; therefore, basic and diluted net loss per share applicable to common stockholders were the same for all periods presented. As of March 31, 2022, 1,000,000 Pre-Funded Warrants to purchase common stock, issued in connection with the December 2020 private placement (refer to Note 10) were included in the basic and diluted net loss per share calculation. The following common stock equivalents were excluded from the calculation of diluted net loss per share applicable to common stockholders for the periods indicated because including them would have had an anti-dilutive effect: As of March 31, 2022 2021 Stock options 7,527,152 6,504,401 Unvested restricted stock units 4,539,729 2,070,150 Warrants* 4,990,156 4,990,156 Total 17,057,037 13,564,707 * As of March 31, 2022 and 2021, this is comprised of 2,117,094 warrants to purchase common stock issued in connection with the Company’s April 2019 financing (refer to Note 10), 27,548 17,389 Recent Accounting Pronouncements In June 2016, the FASB issued ASU 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments Recently Adopted Accounting Pronouncements In August 2020, the FASB issued ASU No. 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity

Collaboration and Research Arra

Collaboration and Research Arrangements	3 Months Ended
	Mar. 31, 2022
Collaborative Arrangement Disclosure [Abstract]
Collaboration and Research Arrangements	3. Collaboration and Research Arrangements Collaboration with Global Blood Therapeutics On December 17, 2019, the Company entered into a license and collaboration agreement (the “GBT Collaboration Agreement”) with Global Blood Therapeutics, Inc. (“GBT”), pursuant to which the parties agreed to a research collaboration to discover novel targets that induce fetal hemoglobin in order to develop new small molecule treatments for sickle cell disease and beta thalassemia. The research term (the “Research Term”) is for an initial period of three years and can be extended for up to two additional one-year Pursuant to the terms of the GBT Collaboration Agreement, GBT paid the Company an upfront payment of $20.0 million. GBT also agreed to reimburse the Company for full-time employee and out-of-pocket costs and expenses incurred by the Company in accordance with the agreed-upon research budget, which is anticipated to total approximately $40.0 million over the initial Research Term. The Company granted to GBT an option (the “Option”) to obtain an exclusive, worldwide license, with the right to sublicense, under relevant intellectual property rights and know-how of the Company arising from the collaboration to develop, manufacture and commercialize any compounds or products resulting from the collaboration th Should GBT exercise its Option, the Company could receive up to $315.0 million in option exercise, development, regulatory, commercialization and sales-based milestones per product candidate and product resulting from the collaboration. The Company will also be entitled to receive, subject to certain reductions, tiered mid-to-high single digit royalties as percentages of calendar year net sales on any product. Either party may terminate the GBT Collaboration Agreement for the other party’s uncured material breach or insolvency, and in certain other specified circumstances, subject to specified notice and cure periods. GBT may unilaterally terminate the GBT Collaboration Agreement in its entirety, for any or no reason, upon nine-months GBT Collaboration Revenue The Company analyzed the GBT Collaboration Agreement and concluded that it represents a contract with a customer within the scope of ASC 606. The Company identified a single performance obligation, which includes a (i) non-exclusive research license that GBT will have access to during the initial Research Term and (ii) research and development services provided during the initial Research Term. The GBT Collaboration Agreement includes the Option. The Option does not provide a material right to GBT that it would receive without entering into the GBT Collaboration Agreement, principally because the Option exercise fee is at least equal to the standalone selling price for the underlying goods. The non-exclusive research license is not distinct as GBT cannot benefit from the license without the research and development services that are separately identifiable in the contract. The non-exclusive research license only allows GBT to evaluate the candidate compounds developed under the research plan or to conduct work allocated to it during the Research Term. GBT cannot extract any benefit from the non-exclusive research license without the research and development services performed by the Company, including the provision of data package information. As such, these two promises are inputs to a combined output (the delivery of data package allowing GBT to make an Option exercise decision) and are bundled into a single performance obligation (the non-exclusive research license and research and development service performance obligation). At inception, the total transaction price was determined to be approximately $60.0 million, which consisted of a $20.0 million upfront non-refundable and non-creditable technology access fee and approximately $40.0 million in reimbursable costs for employee and external research and development expenses. The GBT Collaboration Agreement also provides for development and regulatory milestones which are only payable subsequent to the exercise of the Option, and therefore are excluded from the transaction price at inception. The Company will re-evaluate the transaction price at the end of each reporting period and as uncertain events are resolved or other changes in circumstances occur. As of December 31, 2021, the Company reduced the transaction price from During the three months ended March 31, 2022, there was no change in the total transaction price, which remained at approximately $54.2 million. ASC 606 requires an entity to recognize revenue only when it satisfies a performance obligation by transferring a promised good or service to a customer. A good or service is considered to be transferred when the customer obtains control. As the non-exclusive research license and research and development services represent one performance obligation, the Company has determined that it will satisfy its performance obligation over a period of time as services are performed and GBT receives the benefit of the services, as the overall purpose of the arrangement is for the Company to perform the services. The Company will recognize revenue associated with the performance obligation as the research and development services are provided using an input method, according to the costs incurred as related to the research and development activities and the costs expected to be incurred in the future to satisfy the performance obligation. The transfer of control occurs during this time and is the best measure of progress towards satisfying the performance obligation. During the three months ended March 31, 2022 and 2021, the Company recognized revenue of $5.1 million and $4.0 million, respectively, under the GBT Collaboration Agreement. Agreements with Incyte Corporation In January 2018, the Company and Incyte entered into a Target Discovery, Research Collaboration and Option Agreement (the “Incyte Collaboration Agreement”). The Incyte Collaboration Agreement was amended in November 2019. Under the Incyte Collaboration Agreement, the Company is using its proprietary gene control platform to identify novel therapeutic targets with a focus on myeloproliferative neoplasms, and Incyte has received options to obtain exclusive worldwide rights to intellectual property resulting from the collaboration for the development and commercialization of therapeutic products directed to up to seven validated targets. For each option exercised by Incyte, Incyte will have the exclusive worldwide right to use the licensed intellectual property to develop and commercialize therapeutic products that modulate the target as to which the option was exercised. In January 2018, the Company also entered into a Stock Purchase Agreement with Incyte (the “Stock Purchase Agreement”) whereby, for an aggregate purchase price of $10.0 million, Incyte purchased 793,021 shares of the Company’s common stock at $12.61 per share. Under the terms of the Stock Purchase Agreement, the shares were purchased at a 30% premium over the volume-weighted sale price of the shares of the Company’s common stock over the 15-trading day period immediately preceding the date of the Stock Purchase Agreement. Incyte Collaboration Revenue The Company analyzed the Incyte Collaboration Agreement and concluded that it represents a contract with a customer within the scope of ASC 606. The Company identified a single performance obligation which includes (i) a research license that Incyte retains as long as there remains an unexercised option (the “Research License”), and (ii) research and development services provided during the research term. The Incyte Collaboration Agreement includes options to (x) obtain additional time to exercise the license options for certain targets designated as definitive validation targets, and (y) obtain license rights to each validated target, both of which were not considered by the Company’s management to be material rights, and therefore not performance obligations, at inception. At inception, the total transaction price was determined to be $12.3 million and was subsequently increased to $12.8 million following a November 2019 amendment. As of March 31, 2022, the total transaction price is $12.8 million, consisting of a $2.5 million upfront non-refundable and non-creditable payment, the $7.5 million Prepaid Research Amount, $2.3 million in premium paid on the equity investment made pursuant the Stock Purchase Agreement, and $0.5 million of additional consideration. The Company accounted for the contract amendment as a modification as if it were part of the existing contract as the remaining goods and services are not distinct, and therefore form part of a single performance obligation that was partially satisfied at the date of the amendment. The Incyte Collaboration Agreement also provides for development and regulatory milestones that are only payable subsequent to the exercise of an option and were therefore excluded from the transaction price at inception. The Company re-evaluates the transaction price at the end of each reporting period and as uncertain events are resolved or other changes in circumstances occur. The Company recognizes revenue associated with the performance obligation as the research and development services are provided using an input method, according to the costs incurred as related to the research and development activities and the costs expected to be incurred in the future to satisfy the performance obligation. The transfer of control occurs during this time and is the best measure of progress towards satisfying the performance obligation. During the three months ended March 31, 2022 and 2021, the Company recognized revenue of $0.4 million and $0.8 million, respectively, under the Incyte Collaboration Agreement. The following table presents the changes in accounts receivable, contract assets and liabilities for the three months ended March 31, 2022 (in thousands): Balance at December 31, 2021 Additions Deductions Balance at March 31, 2022 Accounts receivable and contract assets: Billed receivables from collaboration partners $ — $ 2,857 $ (2,857 ) $ — Unbilled receivables from collaboration partners 2,979 3,181 (2,978 ) 3,182 Total accounts receivable and contract assets $ 2,979 $ 6,038 $ (5,835 ) $ 3,182 Contract liabilities: Deferred revenue - Incyte $ 1,268 $ — $ (421 ) $ 847 Deferred revenue - GBT 8,913 — (1,987 ) 6,926 Total contract liabilities $ 10,181 $ — $ (2,408 ) $ 7,773

Cash, Cash Equivalents and Mark

Cash, Cash Equivalents and Marketable Securities	3 Months Ended
	Mar. 31, 2022
Investments Debt And Equity Securities [Abstract]
Cash, Cash Equivalents and Marketable Securities	4. Cash, Cash Equivalents and Marketable Securities Cash equivalents are highly liquid investments that are readily convertible into cash with original maturities of three months or less when purchased. Marketable securities Cash, cash equivalents and marketable securities consisted of the following at March 31, 2022 and December 31, 2021 (in thousands): Unrealized Unrealized Fair March 31, 2022 Amortized Cost Gains Losses Value Cash and cash equivalents: Cash and money market funds $ 69,575 $ — $ — $ 69,575 Marketable securities: Corporate debt securities - due in one year or less 28,915 — (111 ) 28,804 US Treasury obligation - due in one year or less 12,000 — (118 ) 11,882 Corporate debt securities - due in more than one year to five years 2,682 — (44 ) 2,638 Total $ 113,172 $ — $ (273 ) $ 112,899 Unrealized Unrealized Fair December 31, 2021 Amortized Cost Gains Losses Value Cash and cash equivalents: Cash and money market funds $ 92,302 $ — $ — $ 92,302 Marketable securities: Corporate debt securities - due in one year or less 30,100 — (12 ) 30,088 US Treasury obligation - due in one year or less 8,000 — (21 ) 7,979 Corporate debt securities - due in more than one year to five years 9,085 — (33 ) 9,052 US Treasury obligation - due in more than one year to five years 3,999 — (13 ) 3,986 Total $ 143,486 $ — $ (79 ) $ 143,407 Although available to be sold to meet operating needs or otherwise, securities are generally held through maturity. The cost of securities sold is determined based on the specific identification method for purposes of recording realized gains and losses. During the three months ended March 31, 2022 and 2021, there were no realized gains or losses on sales of investments, and no investments were adjusted for other-than-temporary declines in fair value. As of March 31, 2022, marketable securities with maturities of one year or less when purchased are presented in current assets and those with maturities of more than one year are presented in the noncurrent assets in the accompanying condensed consolidated balance sheet. At March 31, 2022, the Company held ten securities that were in an unrealized loss position. The aggregate fair value of securities held by the Company in an unrealized loss position for less than twelve months as of March 31, 2022 was $27.4 million. There were no securities held by the Company in an unrealized loss position for more than twelve months as of March 31, 2022. The Company has the intent and ability to hold such securities until recovery. The Company determined that there was no material change in the credit risk of the above marketable securities. As a result, the Company determined it did not hold any marketable securities with an other-than temporary impairment as of March 31, 2022.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2022
Fair Value Disclosures [Abstract]
Fair Value Measurements	5. Fair Value Measurements Assets and liabilities measured at fair value on a recurring basis as of March 31, 2022 and December 31, 2021 were as follows (in thousands): Active Observable Unobservable Markets Inputs Inputs Description March 31, 2022 (Level 1) (Level 2) (Level 3) Assets: Cash $ 59,769 $ 59,769 — $ — Money market funds 9,806 9,806 — — Corporate debt securities - due in one year or less 28,804 — 28,804 — US Treasury obligation - due in one year or less 11,882 11,882 — — Corporate debt securities - due in more than one year to five years 2,638 — 2,638 — Total $ 112,899 $ 81,457 $ 31,442 $ — Liabilities: Warrant liability $ 581 $ — $ — $ 581 Total $ 581 $ — $ — $ 581 Active Observable Unobservable Markets Inputs Inputs Description December 31, 2021 (Level 1) (Level 2) (Level 3) Assets: Cash $ 57,213 $ 57,213 $ — $ — Money market funds 35,089 35,089 — — Corporate debt securities - due in one year or less 30,088 — 30,088 — US Treasury obligation - due in one year or less 7,979 7,979 — — US Treasury obligation - due in more than one year to five years 3,986 3,986 — — Corporate debt securities - due in more than one year to five years 9,052 — 9,052 — Total $ 143,407 $ 104,267 $ 39,140 $ — Liabilities: Warrant liability $ 3,029 $ — $ — $ 3,029 Total $ 3,029 $ — $ — $ 3,029 Assumptions Used in Determining Fair Value of Warrants The Company issued warrants to purchase an aggregate of up to 2,828,125 shares of common stock in connection with a private placement on December 8, 2020 (see Note 10) (the “Warrants”). In the event of certain fundamental transactions involving the Company, the Warrant holders may require the Company to make a payment based on a Black-Scholes valuation, using specified inputs; therefore, t The Company recorded the A summary of the Black Scholes pricing model assumptions used to record the fair value of the Warrants is as follows: March 31, 2022 December 31, 2021 Stock price $ 1.19 $ 3.26 Risk-free interest rate 2.44 % 1.11 % Dividend yield — — Expected life (in years) 3.69 3.94 Expected volatility 85.49 % 81.14 % Changes in Level 3 Liabilities Measured at Fair Value on a Recurring Basis The following table reflects the change in the Company’s Level 3 Warrant liability for the three months ended March 31, 2022 and the year ended December 31, 2021 (in thousands): March 31, 2022 December 31, 2021 Fair value of warrant liability as of beginning of the period $ 3,029 $ 19,711 Change in fair value (2,448 ) (16,682 ) Fair value of warrant liability as of end of the period $ 581 $ 3,029

Restricted Cash

Restricted Cash	3 Months Ended
	Mar. 31, 2022
Restricted Cash [Abstract]
Restricted Cash	6. Restricted Cash At March 31, 2022 and December 31, 2021, the Company had $3.1 million in restricted cash, which was classified as long-term on the Company’s condensed consolidated balance sheets, and all of which was attributable to the HQ Lease (See Note 9). In connection with the execution of the HQ Lease, the Company was required to provide the landlord with a letter of credit in the amount of $3.1 million that will expire 95 days after expiration or early termination of the HQ Lease. The Company will have the right, under certain conditions, to reduce the amount of the letter of credit to $2.1 million in October 2023. The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the condensed consolidated balance sheets that sum to the total of the amounts shown in the Company’s condensed consolidated statement of cash flows as of March 31, 2022, and December 31, 2021 (in thousands): March 31, 2022 December 31, 2021 Cash and cash equivalents $ 69,575 $ 92,302 Restricted cash, net of current portion 3,086 3,086 Total cash, cash equivalents and restricted cash $ 72,661 $ 95,388

Oxford Finance Loan Agreement

Oxford Finance Loan Agreement	3 Months Ended
	Mar. 31, 2022
Debt Disclosure [Abstract]
Oxford Finance Loan Agreement	7. Oxford Finance Loan Agreement On February 12, 2020, the Company entered into a Loan and Security Agreement (the “Loan Agreement”) with Oxford Finance LLC (the “Lender”). Pursuant to the Loan Agreement, a term loan of up to an aggregate principal amount of $60.0 million is available to the Company. A first tranche term loan for $20.0 million was funded on February 12, 2020, and a second tranche term loan for $20.0 million was funded on December 23, 2020. The remaining $20.0 million is still available under the Loan Agreement, at the sole discretion of the Lender. The term loan bears interest at an annual rate equal to the greater of (i) 7.75% and (ii) the sum of 5.98% and the greater of (A) one-month LIBOR or (B) 1.77%. The Loan Agreement provides for interest-only payments until March 1, 2023, and repayment of the aggregate outstanding principal balance of the term loan in monthly installments starting on March 1, 2023 and continuing through February 1, 2025 (the “Maturity Date”). The Company paid a facility fee of $0.1 million upon the funding of the first tranche, paid a facility fee of $75,000 upon funding of the second tranche and must pay a $50,000 facility fee if and when the third loan tranche is funded. The Company will be required to make a final payment fee of 5.00% of the amount of the term loan drawn payable on the earlier of (i) the prepayment of the term loan or (ii) the Maturity Date. At the Company’s option, the Company may elect to prepay the loans subject to a prepayment fee equal to the following percentage of the principal amount being prepaid: 2% if an advance is prepaid during the first 12 months following the applicable advance date, 1% if an advance is prepaid after 12 months but prior to 24 months following the applicable advance date, and 0.5% if an advance is prepaid any time after 24 months following the applicable advance date but prior to the Maturity Date. In connection with the Loan Agreement, the Company granted the Lender a security interest in all of the Company’s personal property now owned or hereafter acquired, excluding intellectual property (but including the right to payments and proceeds of intellectual property), and a negative pledge on intellectual property. The Loan Agreement also contains certain events of default, representations, warranties and non-financial covenants of the Company. In connection with the funding of the first tranche in February 2020, the Company issued the Lender warrants to purchase 27,548 shares of the Company’s common stock at an exercise price per share of $7.26. In connection with the funding of the second tranche in December 2020, the Company issued the Lender warrants to purchase 17,389 shares of the Company’s common stock at an exercise price of $11.50 per share (collectively, the “Oxford Warrants”). The Oxford Warrants are exercisable within five years from their respective dates of issuance. The Oxford Warrants are classified as a component of permanent equity because they are freestanding financial instruments that are legally detachable and separately exercisable from the shares of common stock with which they were issued, are immediately exercisable, do not embody an obligation for the Company to repurchase its shares, and permit the holders to receive a fixed number of shares of common stock upon exercise. In addition, the Oxford Warrants do not provide any guarantee of value or return. The Company valued the Oxford Warrants at issuance using the Black-Scholes option pricing model and determined the fair value of the Oxford Warrants to be $0.1 million for the first tranche and $0.2 million for the second tranche. The key inputs to the valuation model included an average volatility of 75.43% for the first tranche and 82.41% for the second tranche, and an expected term of 5.0 years The Company has the following minimum aggregate future loan payments as of March 31, 2022 Nine months ending December 31, 2022 $ — Year ending December 31, 2023 16,666 Year ending December 31, 2024 20,000 Year ending December 31, 2025 3,334 Total minimum payments $ 40,000 Less unamortized debt discount (410 ) Plus accumulated accretion of final fees 852 Total carrying value of debt 40,442 Less current portion (1,667 ) Long-term debt, net of current portion $ 38,775 For the three months ended March 31, 2022 and 2021, interest expense related to the Loan Agreement was approximately $1.0 million and $0.9 million, respectively. For the three months ended March 31, 2022, the current portion of debt is $1.7 million and the long-term portion of debt is $38.8 million as classified on the Company’s condensed consolidated balance sheets as of March 31, 2022.

Accrued Expenses

Accrued Expenses	3 Months Ended
	Mar. 31, 2022
Payables And Accruals [Abstract]
Accrued Expenses	8. Accrued Expenses Accrued expenses consisted of the following as of March 31, 2022 and December 31, 2021 (in thousands): March 31, 2022 December 31, 2021 External research and preclinical development 8,521 $ 8,274 Employee compensation and benefits 3,180 6,344 Professional fees 1,495 953 Facilities and other 53 53 Accrued expenses $ 13,249 $ 15,624

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2022
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	9. Commitments and Contingencies Operating Lease On January 8, 2019, the Company entered into a lease (the “HQ Lease”) with respect to approximately 52,859 square feet of space in Cambridge, Massachusetts for a lease term commencing in January 2019 and ending in February 2030. The Company has the option to extend the lease term for one additional ten-year In connection with the execution of the HQ Lease, the Company was required to provide the landlord with a letter of credit in the amount of $3.1 million (See Note 6).The Company determined that, for purposes of applying the lease accounting guidance codified in ASU No. 2016-02, Leases (Topic 842) (“ The Company elected the practical expedient provided under ASC 842 and therefore combined all lease and non-lease components when determining the right-of-use asset and lease liability for the HQ Lease. Financing Lease In March 2019, the Company entered into an equipment lease agreement (the “Equipment Lease”) that has a 48-month term. At the end of the term, the Company has the right to return the leased equipment, extend the lease, or buy the equipment at the then-current fair market value of the equipment. The Company accounted for the Equipment Lease as a financing lease under ASC 842 and recorded a financing lease right-of-use asset and a corresponding financing lease liability of approximately $1.0 million at the time the Equipment Lease was executed. The following is a maturity analysis of the annual undiscounted cash flows reconciled to the carrying value of the operating and financing lease liabilities as of March 31, 2022 (in thousands): Operating Financing Nine months ending December 31, 2022 $ 2,956 $ 234 Year ending December 31, 2023 4,049 66 Year ending December 31, 2024 4,166 — Year ending December 31, 2025 4,287 — Year ending December 31, 2026 and beyond 19,256 — Total minimum lease payments 34,714 300 Less imputed interest (10,547 ) (14 ) Total lease liability $ 24,167 $ 286 The following table outlines the total lease cost for the Company’s operating and financing leases as well as weighted average information for these leases as of March 31, 2022 (in thousands): Three Months Ended March 31, 2022 Lease cost: Operating lease cost $ 772 Financing lease cost: Amortization of right-of-use asset $ 66 Interest on lease liabilities 7 Total financing lease cost $ 73 Cash paid for amounts included in the measurement of liabilities: Operating cash flows from operating lease $ 979 Operating cash flows from financing lease $ 78 Other information: Three Months Ended March 31, 2022 Weighted-average remaining lease term (in years) - operating lease 7.92 Weighted-average discount rate - operating lease 9.30 % Weighted-average remaining lease term (in years) - financing lease 1.07 Weighted-average discount rate - financing lease 9.47 % Following the adoption of ASC 842, the Company has a right-of-use asset and lease liability that results in recording a temporary tax difference. This temporary tax difference is the result of recognizing a right-of-use asset and related lease liability while such asset and liability have no corresponding tax basis. Asset Purchase Agreement Orsenix, LLC On December 4, 2020, the Company entered into an asset purchase agreement (the “Asset Purchase Agreement”) with Orsenix, LLC (“Orsenix”), pursuant to which the Company acquired Orsenix’s assets related to a novel oral form of arsenic trioxide, which the Company refers to as SY-2101. Under the terms of the Asset Purchase Agreement, the Company is required to pay to Orsenix: • an upfront fee of $12.0 million, which was paid with cash on hand upon the closing of the transaction • single-digit million milestone payments related to the development of SY-2101 in indications other than APL; • $6.0 million following the achievement of a regulatory milestone related to the development of SY-2101 in APL; and • up to $10.0 million upon the achievement of certain commercial milestones with respect to SY-2101. The Company’s obligation to pay the commercial milestone payments expires following the tenth anniversary of the first commercial sale of SY-2101. The Asset Purchase Agreement requires the Company to use commercially reasonable efforts to develop and commercialize SY-2101 for APL in the United States during such period, and to use commercially reasonable efforts to dose the first patient in a Phase 3 clinical trial of SY-2101 on or before the third anniversary of the closing of the transaction; however, the Company retains sole discretion to operate the acquired assets as it determines. The assets acquired from Orsenix do not meet the definition of a business under ASC 805 “ Business Combinations” License Agreement TMRC Co. Ltd. In September 2015, the Company entered into an exclusive license agreement with TMRC Co. Ltd. ("TMRC") to develop and commercialize tamibarotene in North America and Europe for the treatment of cancer. This agreement was amended and restated in April 2016 , and further amended in January 2021 to expand the territory under which the Company is licensed to include Central and South America, Australia, Israel, and Russia In exchange for this license, the Company agreed to a non-refundable upfront payment of $1.0 million, for which $0.5 million was paid in September 2015 upon execution of the agreement, and the remaining $0.5 million was paid in May 2016. Under the agreement, the Company is also obligated to make payments upon the successful achievement of clinical and regulatory milestones totaling approximately $13.0 million per indication, defined as a distinct tumor type. The Company paid $1.0 million to TMRC for a development milestone achieved upon the successful dosing of the first patient in its Phase 2 clinical trial of tamibarotene in 2016. In May 2021, the Company paid $2.0 million to TMRC for a development milestone achieved upon the successful dosing of the first patient in its Phase 3 clinical trial of tamibarotene in MDS patients. In September 2021, the Company paid $1.0 million to TMRC for a development milestone achieved upon the successful dosing of the first patient in its Phase 2 clinical trial of tamibarotene in AML patients. In addition, the Company is obligated to pay TMRC a single-digit percentage royalty, on a country-by-country and product-by-product basis, on net product sales of tamibarotene using know-how and patents licensed from TMRC in North America and Europe for a defined royalty term. The Company also entered into a supply management agreement with TMRC under which the Company agreed to pay TMRC a fee for each kilogram of tamibarotene that is produced. The Company did not incur any fees under this supply management agreement during the three months ended March 31, 2022 and 2021.

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2022
Equity [Abstract]
Stockholders' Equity	10 . Stockholders’ equity Issuance of Securities through an Underwritten Public Offering On January 22, 2021, the Company issued and sold an aggregate of 5,400,000 shares of its common stock in an underwritten public offering at a public offering price of $14.00 per share, resulting in gross proceeds of $75.6 million before deducting underwriting discounts and commissions and other transaction expenses of approximately $5.1 million. Issuance of Securities through a Private Placement On December 8, 2020, the Company issued in a private placement 10,312,500 shares of common stock, and, in lieu of shares of common stock, pre-funded warrants (the “Pre-Funded Warrants”) to purchase an aggregate of 1,000,000 shares of common stock, and, in each case, accompanying Warrants to purchase an aggregate of up to 2,828,125 additional shares of common stock (or Pre-Funded Warrants to purchase common stock in lieu thereof) at a price of $8.00 per share and accompanying Warrant (or $7.99 per Pre-Funded Warrant and accompanying Warrant). The private placement resulted in aggregate gross proceeds of $90.5 million, before $0.4 million of transaction costs. In the event of certain fundamental transactions involving the Company, the holders of Warrants may require the Company to make a payment based on a Black-Scholes valuation, using specified inputs. The holders of Pre-Funded Warrants do not have similar rights. Therefore, the Company accounted for the Warrants as liabilities, while the Pre-Funded Warrants met the permanent equity criteria classification. The Pre-Funded Warrants are classified as a component of permanent equity because they are freestanding financial instruments that are legally detachable and separately exercisable from the shares of common stock with which they were issued, are immediately exercisable, do not embody an obligation for the Company to repurchase its shares, and permit the holders to receive a fixed number of shares of common stock upon exercise. In addition, the Pre-Funded Warrants do not provide any guarantee of value or return. The initial fair value of the Warrants at issuance was $19.3 million, determined using the Black-Scholes valuation model. The Company remeasured the Warrants’ fair value at March 31, 2022 and December 31, 2021 as $0.6 million and $3.0 million, respectively. The change in fair value of $2.4 million was recorded in the condensed statement of operations for the three months ended March 31, 2022. Convertible Preferred Stock and 2019 Warrants On April 9, 2019, the Company completed two concurrent underwritten public offerings of its equity securities. In the first public offering, the Company sold 8,667,333 shares of its common stock and accompanying Class A warrants (the “2019 Warrants”) to purchase 1,951,844 shares of the Company’s common stock at a combined price to the public of $7.50 per common share and accompanying 2019 Warrant. In the second public offering, the Company sold 666 shares of its Series A convertible preferred stock (the “Series A Preferred Stock”) and accompanying 2019 Warrants to purchase 166,500 shares of the Company’s common stock at a combined public offering price of $7,500 per share and accompanying 2019 Warrant. The offerings resulted in aggregate gross proceeds to the Company of $70.0 million, before underwriting discounts and commissions and offering expenses payable by the Company of approximately $5.0 million . In November 2019, all 666 shares of Series A Preferred Stock were converted by the holder into 666,000 shares of common stock. As of March 31, 2022, there were no shares of Series A Preferred Stock outstanding. Each 2019 Warrant has an exercise price per share of common stock of $8.625, subject to adjustment in certain circumstances, and will expire on October 10, 2022. Each 2019 Warrant is immediately exercisable, provided that the holder is prohibited, subject to certain exceptions, from exercising the 2019 Warrant for shares of the Company’s common stock to the extent that immediately prior to or after giving effect to such exercise, the holder, together with its affiliates and other attribution parties, would own more than 4.99% of the total number of shares of the Company’s common stock then issued and outstanding. This percentage may be changed at the holders’ election to a higher or lower percentage upon 61 days’ notice to the Company. The Company evaluated the Series A Preferred Stock and 2019 Warrants for liability or equity classification in accordance with the provisions of ASC 480, Distinguishing Liabilities from Equity The Series A Preferred Stock was not mandatorily redeemable and did not embody an obligation to buy back the shares outside of the Company’s control in a manner that could require the transfer of assets. Additionally, the Company determined that the Series A Preferred Stock would be recorded as permanent equity, not temporary equity, given that the holders of equally and more subordinated equity would be entitled to receive the same form of consideration upon the occurrence of the event that gives rise to the redemption or events of redemption that are within the control of the Company. Additionally, as the effective conversion price of the Series A Preferred Stock of $6.57 was below the fair value of the Company’s common stock on the date of issuance of $7.50, the Company determined that the Series A Preferred Stock included a beneficial conversion feature. The Company calculated the beneficial conversion feature to be approximately $0.6 million, which was recorded as a discount to the Series A Preferred Stock at the time of issuance. The 2019 Warrants are classified as a component of permanent equity because they are freestanding financial instruments that are legally detachable and separately exercisable from the shares of common stock with which they were issued, are immediately exercisable, do not embody an obligation for the Company to repurchase its shares, and permit the holders to receive a fixed number of shares of common stock upon exercise. In addition, the 2019 Warrants do not provide any guarantee of value or return. The Company valued the 2019 Warrants at issuance using the Black-Scholes option pricing model and determined the fair value of the 2019 Warrants to purchase 2,118,344 shares of the Company’s common stock was $9.0 million. The key inputs to the valuation model included an average volatility of 86.06% and an expected term of 3.5 years. As of March 31, 2022, the 2019 Warrants to purchase 2,117,094 shares of common stock are outstanding and remain unexercised.

Stock-Based Payments

Stock-Based Payments	3 Months Ended
	Mar. 31, 2022
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Payments	11 . Stock-Based Payments 2016 Stock Incentive Plan The 2016 Stock Incentive Plan (the “2016 Plan”) was adopted by the board of directors on December 15, 2015, approved by the stockholders on June 17, 2016, and became effective on July 6, 2016 upon the closing of the Company’s initial public offering (“IPO”). The 2016 Plan replaced the 2012 Equity Incentive Plan (the “2012 Plan”). Any options or awards outstanding under the 2012 Plan remained outstanding and effective. Under the 2016 Plan, the Company may grant incentive stock options, non-statutory stock options, stock appreciation rights, restricted stock, restricted stock units and other stock-based awards. The number of shares of the Company’s common stock reserved for issuance under the 2016 Plan automatically increases on the first day of each calendar year, through the 2025 calendar year, in an amount equal to the least of (i) 1,600,000 shares of common stock, (ii) 4.0% of the outstanding shares of common stock as of such date, or (iii) such lesser amount as specified by the board of directors. This number is subject to adjustment in the event of a stock split, stock dividend or other change in the Company’s capitalization. For the calendar year beginning January 1, 2022, the number of shares reserved for issuance under the 2016 Plan was increased by 1,600,000 shares. At March 31, 2022, 428,219 shares remained available for future issuance under the 2016 Plan. Under the 2016 Plan, stock options may not be granted at less than fair value on the date of grant. 2016 Employee Stock Purchase Plan The 2016 Employee Stock Purchase Plan (the “2016 ESPP”) was adopted by the board of directors on December 15, 2015, approved by the stockholders on June 17, 2016, and became effective on July 6, 2016 upon the closing of the IPO. The number of shares of the Company’s common stock reserved for issuance under the 2016 ESPP automatically increases on the first day of each calendar year through the 2025 calendar year, in an amount equal to the least of (i) 1,173,333 shares of the Company’s common stock, (ii) 1.0% of the total number of shares of the Company’s common stock outstanding on the first day of the applicable year, and (iii) an amount determined by the Company’s board of directors. For the calendar year beginning January 1, 2022, the number of shares reserved for issuance under the 2016 ESPP was increased by 620,241 I nducement Grant s During the year ended December 31, 2021, the Company granted non-statutory stock options to purchase an aggregate of 1,110,000 shares of the Company’s common stock. These stock options were granted outside of the 2016 Plan as an inducement material to the applicable employee’s acceptance of employment with the Company in accordance with Nasdaq Listing Rule 5635(c)(4).These stock options will vest over a four-year three-years 2022 Inducement Stock Incentive Plan On January 25, 2022, the Company’s board of directors adopted the 2022 Inducement Stock Incentive Plan (the “2022 Plan”), pursuant to which the Company may grant non-statutory stock options, stock appreciation rights, restricted stock, restricted stock units and other stock-based awards with respect to an aggregate of 1,000,000 shares of common stock. Awards under the 2022 Plan may only be granted to persons who (i) were not previously an employee or director of the Company or (ii) are commencing employment with the Company following a bona fide period of non-employment, in either case as an inducement material to the individual’s entering into employment with the Company and in accordance with the requirements of Nasdaq Stock Market Rule 5635(c)(4). Stock Options Terms of stock option agreements, including vesting requirements, are determined by the board of directors, subject to the provisions of the 2016 Plan. Stock option awards granted by the Company generally vest over four years, with 25% vesting on the first anniversary of the vesting commencement date and 75% vesting ratably, on a monthly basis, over the remaining three years. Such awards have a contractual term of ten years from the grant date. The Company has granted certain stock options to management for which vesting accelerates upon the achievement of performance-based criteria. Milestone events are specific to the Company’s corporate goals, including but not limited to certain clinical development milestones for the Company’s product candidates and the Company’s ability to execute on its corporate development and financing strategies. Stock-based compensation expense associated with these performance-based stock options is recognized based on the accelerated attribution model. Management evaluates when the achievement of a performance-based milestone is probable based on the expected satisfaction of the performance conditions as of the reporting date. Notwithstanding any vesting in accordance with the achievement of performance-based milestones, such awards vest in full on the sixth anniversary of the vesting commencement date. As of December 31, 2020, all performance-based milestones related to these stock options were achieved. The Company did not record any additional stock-based compensation expense related to the achievement of performance-based milestones during the three months ended March 31, 2022 and 2021 The Company has granted options to purchase 75,000 shares of common stock to an advisor that vest solely upon the achievement of performance-based criteria. As of March 31, 2022, none of these performance-based criteria had been achieved. As of March 31, 2022, there was $0.3 million of unrecognized compensation cost related to this option, with a remaining contractual period of 4.5 years. A summary of the status of stock options as of December 31, 2021 and March 31, 2022 and changes during the three months ended March 31, 2022 is presented below: Aggregate Weighted Remaining Intrinsic Average Contractual Value Shares Exercise Price Life (in years) (in thousands) Outstanding at December 31, 2021 6,657,268 $ 8.27 7.2 $ 494 Granted 951,300 1.59 Exercised (37,700 ) 0.04 Cancelled (43,716 ) 9.93 Outstanding at March 31, 2022 7,527,152 $ 7.45 6.9 $ 26 Exercisable at March 31, 2022 4,081,501 $ 9.01 5.4 $ 26 The intrinsic value of stock options exercised during the three months ended March 31, 2022 and 2021 was $0.1 million and $0.1 million, respectively As of March 31, 2022, there was $12.1 million of total unrecognized compensation cost related to non-vested stock options granted to employees, which is expected to be recognized over a weighted-average period of 3.1 years. Restricted Stock Units From time to time, upon approval by the Company’s board of directors, certain employees have been granted restricted stock units with time-based vesting criteria. The majority of these restricted stock units vest annually over a four-year three-years A summary of the status of restricted stock units as of December 31, 2021 and March 31, 2022 and changes during the three months ended March 31, 2022 is presented below: Weighted Average Grant Shares Date Fair Value Outstanding at December 31, 2021 2,687,487 $ 6.52 Granted 2,768,128 1.58 Vested (739,561 ) 7.32 Forfeited (176,325 ) 6.76 Outstanding at March 31, 2022 4,539,729 $ 3.37 As of March 31, 2022, there was $13.9 million of unrecognized stock-based compensation expense related to outstanding restricted stock units, with an expected recognition period of 2.9 years. Stock-based Compensation Expense The fair value of each stock option granted was estimated on the date of grant using the Black-Scholes option-pricing model based on the following weighted-average assumptions: Three Months Ended March 31, 2022 2021 Weighted-average risk-free interest rate 1.98 % 0.78 % Expected dividend yield — % — % Expected option term (in years) 6.07 6.08 Volatility 80.70 % 82.10 % The weighted-average grant date fair value per share of options granted in the three months ended March 31, 2022 and 2021 was $1.11 and $7.89, respectively. The following table summarizes the stock-based compensation expense for stock options and restricted stock units granted to employees and non-employees recorded in the Company’s condensed consolidated statements of operations: Three Months Ended March 31, 2022 2021 Research and development $ 1,395 $ 1,323 General and administrative 1,468 1,607 Total stock-based compensation expense $ 2,863 $ 2,930 Due to an operating loss, the Company does not record tax benefits associated with stock‑based compensation or option exercises. Tax benefits will be recorded when realized.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2022
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The Company’s consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”). Any reference in these notes to applicable guidance is meant to refer to the authoritative U.S. GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASU”) of the Financial Accounting Standards Board (“FASB”). The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited financial statements. In the opinion of the Company’s management, the accompanying unaudited interim condensed consolidated financial statements contain all adjustments that are necessary to present fairly the Company’s financial position as of March 31, 2022, the results of its operations, statements of cash flows and statements of stockholders’ equity for the three months ended March 31, 2022 and 2021. Such adjustments are of a normal and recurring nature. The results for the three months ended March 31, 2022 are not necessarily indicative of the results for the year ending December 31, 2022, or for any future period.
Principles of Consolidation	Principles of Consolidation The accompanying condensed consolidated financial statements include the accounts of Syros Pharmaceuticals, Inc. and its wholly owned subsidiaries, Syros Securities Corporation, a Massachusetts corporation formed by the Company in December 2014 to exclusively engage in buying, selling and holding securities on its own behalf, and Syros Pharmaceuticals (Ireland) Limited, an Irish limited liability company formed by the Company in January 2019. All intercompany transactions and balances have been eliminated in consolidation.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts in the financial statements and accompanying notes. Management considers many factors in selecting appropriate financial accounting policies and in developing the estimates and assumptions that are used in the preparation of the financial statements. Management must apply significant judgment in this process. In addition, other factors may affect estimates, which include, but are not limited to, expected business and operational changes, sensitivity and volatility associated with the assumptions used in developing estimates and whether historical trends are expected to be representative of future trends. Management’s estimation process may yield a range of potentially reasonable estimates and management must select an amount that falls within that range of reasonable estimates. On an ongoing basis, the Company’s management evaluates its estimates, which include, but are not limited to, estimates related to revenue recognition, warrant liability, stock-based compensation expense, accrued expenses, income taxes
Segment Information	Segment Information Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision maker, or decision-making group, in making decisions on how to allocate resources and assess performance. The Company's chief operating decision maker is its chief executive officer. The Company and the chief operating decision maker view the Company's operations and manage its business in one operating segment. The Company operates only in the United States.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid instruments that have original maturities of three months or less when acquired to be cash equivalents. Cash equivalents, which consist of money market funds that invest in U.S. Treasury obligations, as well as overnight repurchase agreements and corporate debt securities , are stated at fair value. The Company maintains its bank accounts at one major financial institution.
Off-Balance Sheet Risk and Concentrations of Credit Risk	Off-Balance Sheet Risk and Concentrations of Credit Risk The Company has no financial instruments with off-balance sheet risk, such as foreign exchange contracts, option contracts, or other foreign hedging arrangements. Financial instruments that potentially subject the Company to concentrations of credit risk primarily consist of cash equivalents and marketable securities. Under its investment policy, the Company limits amounts invested in such securities by credit rating, maturity, industry group, investment type and issuer, except for securities issued by the U.S. government. The Company is not exposed to any significant concentrations of credit risk from these financial instruments. The goals of the Company’s investment policy, in order of priority, are safety and preservation of principal and liquidity of investments sufficient to meet cash flow requirements.
Fair Value of Financial Instruments	Fair Value of Financial Instruments ASC 820, Fair Value Measurement ASC 820 identified fair value as the exchange price, or exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As a basis for considering market participant assumptions in fair value measurements, ASC 820 established a three-tier fair value hierarchy that distinguishes between the following: Level 1—Quoted market prices (unadjusted) in active markets for identical assets or liabilities. Level 2—Inputs other than quoted prices included within Level 1 that are either directly or indirectly observable, such as quoted market prices, interest rates and yield curves. Level 3—Unobservable inputs developed using estimates or assumptions developed by the Company, which reflect those that a market participant would use. To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized as Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The carrying amounts reflected in the condensed consolidated balance sheets for cash and cash equivalents, prepaid expenses, other current assets, restricted cash, accounts payable, accrued expenses and deferred revenue approximate their respective fair values due to their short-term nature.
Property and Equipment	Property and Equipment Property and equipment consists of laboratory equipment, computer equipment, furniture and fixtures and leasehold improvements, all of which are stated at cost, less accumulated depreciation. Expenditures for maintenance and repairs that do not improve or extend the lives of the respective assets are recorded to expense as incurred. Major betterments are capitalized as additions to property and equipment. Depreciation and amortization are recognized over the estimated useful lives of the assets using the straight-line method. Construction-in-progress is stated at cost, which relates to the cost of leasehold improvements not yet placed into service. No depreciation expense is recorded on construction-in-progress until such time as the relevant assets are completed and put into use.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets The Company continually evaluates long-lived assets for potential impairment when events or changes in circumstances indicate the carrying value of the assets may not be recoverable. Recoverability is measured by comparing the book values of the assets to the expected future net undiscounted cash flows that the assets are expected to generate. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the book values of the assets exceed their fair value. The Company has no t recognized any impairment losses from inception through March 31, 2022.
Other Long-Term Assets	Other Long-Term Assets Other long-term assets primarily consisted of advance payments made to the contract research organizations responsible for conducting the Company’s tamibarotene
Revenue Recognition	Revenue Recognition To date the Company’s only revenue has consisted of collaboration and license revenue. The Company has not generated any revenue from product sales and does not expect to generate any revenue from product sales for the foreseeable future. The Company recognizes revenue in accordance with ASC 606, Revenue from Contracts with Customers (“ASC 606”). (i) (ii) (iii) (iv) (v) The Company only applies the five-step model to contracts when it is probable that the Company will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. If a contract is determined to be within the scope of ASC 606 at inception, the Company assesses the goods or services promised within such contract, determines which of those goods and services are performance obligations, and assesses whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. If the Company performs by transferring goods or services to a customer before the customer pays consideration or before payment is due, the Company records a contract asset, excluding any amounts presented as accounts receivable. The Company includes unbilled accounts receivable as contract assets on its consolidated balance sheets. The Company records accounts receivable for amounts billed to the customer for which the Company has an unconditional right to consideration. The Company assesses contract assets and accounts receivable for impairment and, to date, no impairment losses have been recorded. From time to time, the Company may enter into agreements that are within the scope of ASC 606. The terms of these arrangements typically include payment to the Company of one or more of the following: non-refundable, up-front license fees or prepaid research and development services; development, regulatory and commercial milestone payments; and royalties on net sales of licensed products. Each of these payments results in license and collaboration revenues, except for revenues from royalties on net sales of licensed products, which will be classified as royalty revenues. The Company analyzes its collaboration arrangements to assess whether they are within the scope of ASC 808, Collaborative Arrangements
Research and Development	Research and Development Expenditures relating to research and development are expensed in the period incurred. Research and development expenses consist of both internal and external costs associated with the development of the Company’s gene control platform and product candidates. Research and development costs include salaries and benefits, materials and supplies, external research, preclinical and clinical development expenses, stock-based compensation expense and facilities costs. Facilities costs primarily include the allocation of rent, utilities, depreciation and amortization. In certain circumstances, the Company is required to make non-refundable advance payments to vendors for goods or services that will be received in the future for use in research and development activities. In such circumstances, the non-refundable advance payments are deferred and capitalized, even when there is no alternative future use for the research and development, until related goods or services are provided. The Company records accruals for estimated ongoing research costs. When evaluating the adequacy of the accrued liabilities, the Company analyzes progress of the work being performed, including the phase or completion of the event, invoices received and costs. Significant judgements and estimates may be made in determining the accrued balances at the end of any reporting period. Actual results could differ from the Company’s estimates. The Company may in-license the rights to develop and commercialize product candidates. For each in-license transaction the Company evaluates whether it has acquired processes or activities along with inputs that would be sufficient to constitute a “business” as defined under U.S. GAAP. A “business” as defined under U.S. GAAP consists of inputs and processes applied to those inputs that have the ability to create outputs. Although businesses usually have outputs, outputs are not required for an integrated set of activities to qualify as a business. When the Company determines that it has not acquired sufficient processes or activities to constitute a business, any up-front payments, as well as milestone payments, are immediately expensed as acquired research and development in the period in which they are incurred.
Warrants	Warrants The Company accounts for issued warrants either as a liability or equity in accordance with ASC 480-10, Accounting for Certain Financial Instruments with Characteristics of both Liabilities and Equity Accounting for Derivative Financial Instruments Indexed to, and Potentially Settled in, a Company’s Own Stock
Stock-Based Compensation Expense	Stock-Based Compensation Expense The Company accounts for its stock-based compensation awards in accordance with ASC 718, Compensation—Stock Compensation The Company expenses the fair value of its stock-based awards to employees and non-employees on a straight-line basis over the associated service period, which is generally the vesting period. The Company accounts for forfeitures as they occur instead of estimating forfeitures at the time of grant. Ultimately, the actual expense recognized over the vesting period will be for only those options that vest. Compensation expense for discounted purchases under the employee stock purchase plan is measured using the Black-Scholes model to compute the fair value of the lookback provision plus the purchase discount and is recognized as compensation expense over the offering period. For stock-based awards that contain performance-based milestones, the Company records stock-based compensation expense in accordance with the accelerated attribution model. Management evaluates when the achievement of a performance-based milestone is probable based on the expected satisfaction of the performance conditions as of the reporting date.
Income Taxes	Income Taxes The Company accounts for uncertain tax positions using a more-likely-than-not threshold for recognizing and resolving uncertain tax positions. The evaluation of uncertain tax positions is based on factors including, but not limited to, changes in the law, the measurement of tax positions taken or expected to be taken in tax returns, the effective settlement of matters subject to audit, new audit activity, and changes in facts or circumstances related to a tax position.
Net Loss per Share	Net Loss per Share Basic net earnings per share applicable to common stockholders is calculated by dividing net earnings applicable to common stockholders by the weighted average shares outstanding during the period, without consideration for common stock equivalents. Diluted net earnings per share applicable to common stockholders is calculated by adjusting the weighted average shares outstanding for the dilutive effect of common stock equivalents outstanding for the period, determined using the treasury-stock method and the if-converted method. For purposes of the calculation of dilutive net loss per share applicable to common stockholders, stock options, unvested restricted stock units, and warrants are considered to be common stock equivalents but are excluded from the calculation of diluted net loss per share applicable to common stockholders, as their effect would be anti-dilutive; therefore, basic and diluted net loss per share applicable to common stockholders were the same for all periods presented. As of March 31, 2022, 1,000,000 Pre-Funded Warrants to purchase common stock, issued in connection with the December 2020 private placement (refer to Note 10) were included in the basic and diluted net loss per share calculation. The following common stock equivalents were excluded from the calculation of diluted net loss per share applicable to common stockholders for the periods indicated because including them would have had an anti-dilutive effect: As of March 31, 2022 2021 Stock options 7,527,152 6,504,401 Unvested restricted stock units 4,539,729 2,070,150 Warrants* 4,990,156 4,990,156 Total 17,057,037 13,564,707 * As of March 31, 2022 and 2021, this is comprised of 2,117,094 warrants to purchase common stock issued in connection with the Company’s April 2019 financing (refer to Note 10), 27,548 17,389
Recent Accounting Pronouncements	Recent Accounting Pronouncements In June 2016, the FASB issued ASU 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments Recently Adopted Accounting Pronouncements In August 2020, the FASB issued ASU No. 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2022
Accounting Policies [Abstract]
Schedule of Common Stock Equivalents Excluded from the Calculation of Diluted Net Loss Per Share	The following common stock equivalents were excluded from the calculation of diluted net loss per share applicable to common stockholders for the periods indicated because including them would have had an anti-dilutive effect: As of March 31, 2022 2021 Stock options 7,527,152 6,504,401 Unvested restricted stock units 4,539,729 2,070,150 Warrants* 4,990,156 4,990,156 Total 17,057,037 13,564,707 * As of March 31, 2022 and 2021, this is comprised of 2,117,094 warrants to purchase common stock issued in connection with the Company’s April 2019 financing (refer to Note 10), 27,548 17,389

Collaboration and Research Ar_2

Collaboration and Research Arrangements (Tables)	3 Months Ended
	Mar. 31, 2022
Collaborative Arrangement Disclosure [Abstract]
Schedule of Change in Accounts Receivable, Contract Assets and Liabilities	The following table presents the changes in accounts receivable, contract assets and liabilities for the three months ended March 31, 2022 (in thousands): Balance at December 31, 2021 Additions Deductions Balance at March 31, 2022 Accounts receivable and contract assets: Billed receivables from collaboration partners $ — $ 2,857 $ (2,857 ) $ — Unbilled receivables from collaboration partners 2,979 3,181 (2,978 ) 3,182 Total accounts receivable and contract assets $ 2,979 $ 6,038 $ (5,835 ) $ 3,182 Contract liabilities: Deferred revenue - Incyte $ 1,268 $ — $ (421 ) $ 847 Deferred revenue - GBT 8,913 — (1,987 ) 6,926 Total contract liabilities $ 10,181 $ — $ (2,408 ) $ 7,773

Cash, Cash Equivalents and Ma_2

Cash, Cash Equivalents and Marketable Securities (Tables)	3 Months Ended
	Mar. 31, 2022
Investments Debt And Equity Securities [Abstract]
Schedule of Cash, Cash Equivalents and Marketable Securities	Cash, cash equivalents and marketable securities consisted of the following at March 31, 2022 and December 31, 2021 (in thousands): Unrealized Unrealized Fair March 31, 2022 Amortized Cost Gains Losses Value Cash and cash equivalents: Cash and money market funds $ 69,575 $ — $ — $ 69,575 Marketable securities: Corporate debt securities - due in one year or less 28,915 — (111 ) 28,804 US Treasury obligation - due in one year or less 12,000 — (118 ) 11,882 Corporate debt securities - due in more than one year to five years 2,682 — (44 ) 2,638 Total $ 113,172 $ — $ (273 ) $ 112,899 Unrealized Unrealized Fair December 31, 2021 Amortized Cost Gains Losses Value Cash and cash equivalents: Cash and money market funds $ 92,302 $ — $ — $ 92,302 Marketable securities: Corporate debt securities - due in one year or less 30,100 — (12 ) 30,088 US Treasury obligation - due in one year or less 8,000 — (21 ) 7,979 Corporate debt securities - due in more than one year to five years 9,085 — (33 ) 9,052 US Treasury obligation - due in more than one year to five years 3,999 — (13 ) 3,986 Total $ 143,486 $ — $ (79 ) $ 143,407

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2022
Fair Value Disclosures [Abstract]
Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis	Assets and liabilities measured at fair value on a recurring basis as of March 31, 2022 and December 31, 2021 were as follows (in thousands): Active Observable Unobservable Markets Inputs Inputs Description March 31, 2022 (Level 1) (Level 2) (Level 3) Assets: Cash $ 59,769 $ 59,769 — $ — Money market funds 9,806 9,806 — — Corporate debt securities - due in one year or less 28,804 — 28,804 — US Treasury obligation - due in one year or less 11,882 11,882 — — Corporate debt securities - due in more than one year to five years 2,638 — 2,638 — Total $ 112,899 $ 81,457 $ 31,442 $ — Liabilities: Warrant liability $ 581 $ — $ — $ 581 Total $ 581 $ — $ — $ 581 Active Observable Unobservable Markets Inputs Inputs Description December 31, 2021 (Level 1) (Level 2) (Level 3) Assets: Cash $ 57,213 $ 57,213 $ — $ — Money market funds 35,089 35,089 — — Corporate debt securities - due in one year or less 30,088 — 30,088 — US Treasury obligation - due in one year or less 7,979 7,979 — — US Treasury obligation - due in more than one year to five years 3,986 3,986 — — Corporate debt securities - due in more than one year to five years 9,052 — 9,052 — Total $ 143,407 $ 104,267 $ 39,140 $ — Liabilities: Warrant liability $ 3,029 $ — $ — $ 3,029 Total $ 3,029 $ — $ — $ 3,029
Summary of Assumptions Used to Record Fair Value of Warrants	A summary of the Black Scholes pricing model assumptions used to record the fair value of the Warrants is as follows: March 31, 2022 December 31, 2021 Stock price $ 1.19 $ 3.26 Risk-free interest rate 2.44 % 1.11 % Dividend yield — — Expected life (in years) 3.69 3.94 Expected volatility 85.49 % 81.14 %
Summary of Changes in Level 3 Warrant Liability Measured at Fair Value on Recurring Basis	The following table reflects the change in the Company’s Level 3 Warrant liability for the three months ended March 31, 2022 and the year ended December 31, 2021 (in thousands): March 31, 2022 December 31, 2021 Fair value of warrant liability as of beginning of the period $ 3,029 $ 19,711 Change in fair value (2,448 ) (16,682 ) Fair value of warrant liability as of end of the period $ 581 $ 3,029

Restricted Cash (Tables)

Restricted Cash (Tables)	3 Months Ended
	Mar. 31, 2022
Restricted Cash [Abstract]
Schedule of Reconciliation of Cash, Cash Equivalents, and Restricted Cash	The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the condensed consolidated balance sheets that sum to the total of the amounts shown in the Company’s condensed consolidated statement of cash flows as of March 31, 2022, and December 31, 2021 (in thousands): March 31, 2022 December 31, 2021 Cash and cash equivalents $ 69,575 $ 92,302 Restricted cash, net of current portion 3,086 3,086 Total cash, cash equivalents and restricted cash $ 72,661 $ 95,388

Oxford Finance Loan Agreement (

Oxford Finance Loan Agreement (Tables)	3 Months Ended
	Mar. 31, 2022
Debt Disclosure [Abstract]
Schedule of Minimum Aggregate Future Loan Payments	The Company has the following minimum aggregate future loan payments as of March 31, 2022 Nine months ending December 31, 2022 $ — Year ending December 31, 2023 16,666 Year ending December 31, 2024 20,000 Year ending December 31, 2025 3,334 Total minimum payments $ 40,000 Less unamortized debt discount (410 ) Plus accumulated accretion of final fees 852 Total carrying value of debt 40,442 Less current portion (1,667 ) Long-term debt, net of current portion $ 38,775

Accrued Expenses (Tables)

Accrued Expenses (Tables)	3 Months Ended
	Mar. 31, 2022
Payables And Accruals [Abstract]
Schedule of Accrued Expenses	Accrued expenses consisted of the following as of March 31, 2022 and December 31, 2021 (in thousands): March 31, 2022 December 31, 2021 External research and preclinical development 8,521 $ 8,274 Employee compensation and benefits 3,180 6,344 Professional fees 1,495 953 Facilities and other 53 53 Accrued expenses $ 13,249 $ 15,624

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2022
Commitments And Contingencies Disclosure [Abstract]
Schedule of Reconciliation of Maturity Analysis of Annual Undiscounted Cash Flows	The following is a maturity analysis of the annual undiscounted cash flows reconciled to the carrying value of the operating and financing lease liabilities as of March 31, 2022 (in thousands): Operating Financing Nine months ending December 31, 2022 $ 2,956 $ 234 Year ending December 31, 2023 4,049 66 Year ending December 31, 2024 4,166 — Year ending December 31, 2025 4,287 — Year ending December 31, 2026 and beyond 19,256 — Total minimum lease payments 34,714 300 Less imputed interest (10,547 ) (14 ) Total lease liability $ 24,167 $ 286
Schedule of Total Lease Cost for Operating and Financing Leases as well as Weighted Average Information for Leases	The following table outlines the total lease cost for the Company’s operating and financing leases as well as weighted average information for these leases as of March 31, 2022 (in thousands): Three Months Ended March 31, 2022 Lease cost: Operating lease cost $ 772 Financing lease cost: Amortization of right-of-use asset $ 66 Interest on lease liabilities 7 Total financing lease cost $ 73 Cash paid for amounts included in the measurement of liabilities: Operating cash flows from operating lease $ 979 Operating cash flows from financing lease $ 78 Other information: Three Months Ended March 31, 2022 Weighted-average remaining lease term (in years) - operating lease 7.92 Weighted-average discount rate - operating lease 9.30 % Weighted-average remaining lease term (in years) - financing lease 1.07 Weighted-average discount rate - financing lease 9.47 %

Stock-Based Payments (Tables)

Stock-Based Payments (Tables)	3 Months Ended
	Mar. 31, 2022
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Status of Stock Options	A summary of the status of stock options as of December 31, 2021 and March 31, 2022 and changes during the three months ended March 31, 2022 is presented below: Aggregate Weighted Remaining Intrinsic Average Contractual Value Shares Exercise Price Life (in years) (in thousands) Outstanding at December 31, 2021 6,657,268 $ 8.27 7.2 $ 494 Granted 951,300 1.59 Exercised (37,700 ) 0.04 Cancelled (43,716 ) 9.93 Outstanding at March 31, 2022 7,527,152 $ 7.45 6.9 $ 26 Exercisable at March 31, 2022 4,081,501 $ 9.01 5.4 $ 26
Summary of Status of Restricted Stock Units	A summary of the status of restricted stock units as of December 31, 2021 and March 31, 2022 and changes during the three months ended March 31, 2022 is presented below: Weighted Average Grant Shares Date Fair Value Outstanding at December 31, 2021 2,687,487 $ 6.52 Granted 2,768,128 1.58 Vested (739,561 ) 7.32 Forfeited (176,325 ) 6.76 Outstanding at March 31, 2022 4,539,729 $ 3.37
Schedule of Weighted-Average Assumptions used in Black-Scholes Option-Pricing Model	The fair value of each stock option granted was estimated on the date of grant using the Black-Scholes option-pricing model based on the following weighted-average assumptions: Three Months Ended March 31, 2022 2021 Weighted-average risk-free interest rate 1.98 % 0.78 % Expected dividend yield — % — % Expected option term (in years) 6.07 6.08 Volatility 80.70 % 82.10 %
Summary of Stock-based Compensation Expense for Stock Options and Restricted Stock Units	The following table summarizes the stock-based compensation expense for stock options and restricted stock units granted to employees and non-employees recorded in the Company’s condensed consolidated statements of operations: Three Months Ended March 31, 2022 2021 Research and development $ 1,395 $ 1,323 General and administrative 1,468 1,607 Total stock-based compensation expense $ 2,863 $ 2,930

Nature of Business - Additional

Nature of Business - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Net Loss	$ 25,146	$ 14,228	$ 86,600	$ 84,000	$ 75,400
Accumulated deficit	(488,725)		$ (463,579)
Cash, cash equivalents and marketable securities, fair value	$ 112,900

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Details)	3 Months Ended
	Mar. 31, 2022USD ($)segmentitemshares	Mar. 31, 2021USD ($)shares
Summary Of Significant Accounting Policies [Line Items]
Number of operating segment | segment	1
Number of financial instruments with off-balance sheet risk | item	0
Depreciation and amortization | $	$ 681,000	$ 666,000
Impairment losses | $	$ 0
Warrant issued to purchase common stock | shares	2,117,094	2,117,094
ASU 2020-06
Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted	true
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2022
Change in accounting principle, accounting standards update, immaterial effect	true
Private Placement
Summary Of Significant Accounting Policies [Line Items]
Warrant issued to purchase common stock | shares	2,828,125	2,828,125
Pre-Funded Warrant | Private Placement
Summary Of Significant Accounting Policies [Line Items]
Warrant issued to purchase common stock | shares	1,000,000
Construction in progress
Summary Of Significant Accounting Policies [Line Items]
Depreciation and amortization | $	$ 0

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Schedule of Common Stock Equivalents Excluded from the Calculation of Diluted Net Loss Per Share (Details) - shares	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Anti-dilutive securities
Total shares excluded from diluted net loss per share applicable to common stockholders	17,057,037	13,564,707
Stock options
Anti-dilutive securities
Total shares excluded from diluted net loss per share applicable to common stockholders	7,527,152	6,504,401
Unvested Restricted Stock Units
Anti-dilutive securities
Total shares excluded from diluted net loss per share applicable to common stockholders	4,539,729	2,070,150
Warrants
Anti-dilutive securities
Total shares excluded from diluted net loss per share applicable to common stockholders	4,990,156	4,990,156

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Schedule of Common Stock Equivalents Excluded from the Calculation of Diluted Net Loss Per Share (Parenthetical) (Details) - shares	Mar. 31, 2022	Mar. 31, 2021
Anti-dilutive securities
Warrant issued to purchase common stock	2,117,094	2,117,094
Private Placement
Anti-dilutive securities
Warrant issued to purchase common stock	2,828,125	2,828,125
Loan Agreement
Anti-dilutive securities
Warrant issued to purchase common stock	27,548	27,548
Second Draw on Loan Agreement
Anti-dilutive securities
Warrant issued to purchase common stock	17,389	17,389

Collaboration and Research Ar_3

Collaboration and Research Arrangements - Additional Information (Details) - USD ($)	Dec. 17, 2019	Jan. 08, 2018	Nov. 30, 2019	Jan. 31, 2018	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	Dec. 31, 2020
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue recognized					$ 5,467,000	$ 4,827,000
Deferred revenue					7,773,000		$ 10,181,000
Global Blood Therapeutics
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue					6,926,000		8,913,000
Global Blood Therapeutics | Collaboration Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Initial period of research term	3 years
Additional extension period for research term upon mutual agreement	1 year
Upfront payment receivable	$ 20,000,000
Reimbursements receivable of full-time employee and out-of-pocket costs and expenses	$ 40,000,000
Agreement termination, prior written notice if notice delivered during the research term	9 months
Agreement termination, prior written notice if notice delivered after the expiration or termination of the research term	90 days
Total transaction price	$ 60,000,000				54,200,000		54,200,000	$ 60,000,000
Upfront non-refundable and non-creditable payment	20,000,000
Reimbursable costs	$ 40,000,000
Change in total transaction price					0
Revenue recognized					5,100,000	4,000,000
Deferred revenue					6,900,000
Global Blood Therapeutics | Collaboration Agreement | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Period of extension of initial research term	2 years
Receivable from option exercise, development, regulatory, commercialization and sales-based milestones per product candidate and product resulting	$ 315,000,000
Incyte
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue recognized					400,000	800,000
Deferred revenue					847,000	$ 800,000	$ 1,268,000
Incyte | Stock Purchase Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Aggregate purchase price				$ 10,000,000
Shares issued				793,021
Share price (in dollars per share)				$ 12.61
Premium to volume-weighted sale price of shares (as a percent)				30.00%
Trading days within which the purchase price represents a thirty percent (30%) premium to the volume-weighted sale price of the shares				15 days
Incyte | Collaboration Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total transaction price		$ 12,300,000	$ 12,800,000		12,800,000
Upfront non-refundable and non-creditable payment					2,500,000
Up-front consideration				$ 10,000,000
Up-front consideration, cash				2,500,000
Up-front consideration, pre-paid research funding				$ 7,500,000
Prepaid research amount					7,500,000
Premium paid on equity investment					2,300,000
Collaboration agreement additional consideration incurred					$ 500,000

Collaboration and Research Ar_4

Collaboration and Research Arrangements - Schedule of Change in Accounts Receivable, Contract Assets and Liabilities (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2022USD ($)
Disaggregation Of Revenue [Line Items]
Accounts receivable and contract assets, Balance at Beginning of Period	$ 2,979
Accounts receivable and contract assets, Additions	6,038
Accounts receivable and contract assets, Deductions	(5,835)
Accounts receivable and contract assets, Balance at End of Period	3,182
Contract liabilities, Balance at Beginning of Period	10,181
Contract liabilities, Deduction	(2,408)
Contract liabilities, Balance at End of Period	7,773
Incyte
Disaggregation Of Revenue [Line Items]
Contract liabilities, Balance at Beginning of Period	1,268
Contract liabilities, Deduction	(421)
Contract liabilities, Balance at End of Period	847
Global Blood Therapeutics
Disaggregation Of Revenue [Line Items]
Contract liabilities, Balance at Beginning of Period	8,913
Contract liabilities, Deduction	(1,987)
Contract liabilities, Balance at End of Period	6,926
Billed receivables from collaboration partners
Disaggregation Of Revenue [Line Items]
Accounts receivable, Additions	2,857
Accounts receivable, Deduction	(2,857)
Unbilled receivables from collaboration partners
Disaggregation Of Revenue [Line Items]
Contract assets, Balance at Beginning of Period	2,979
Contract assets, Additions	3,181
Contract assets, Deduction	(2,978)
Contract assets, Balance at End of Period	$ 3,182

Cash, Cash Equivalents and Ma_3

Cash, Cash Equivalents and Marketable Securities - Schedule of Cash, Cash Equivalents and Marketable Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Cash Equivalents and Marketable Securities
Cash Equivalents and Marketable Securities, Amortized Cost	$ 113,172	$ 143,486
Cash Equivalents and Marketable Securities, Unrealized Losses	(273)	(79)
Cash Equivalents and Marketable Securities, Fair Value	112,899	143,407
Corporate Debt Securities - Due in One Year or Less
Cash Equivalents and Marketable Securities
Marketable Securities, Amortized Cost	28,915	30,100
Marketable Securities, Unrealized Losses	(111)	(12)
Marketable Securities, Fair Value	28,804	30,088
Us Treasury Obligation - Due in One Year or Less
Cash Equivalents and Marketable Securities
Marketable Securities, Amortized Cost	12,000	8,000
Marketable Securities, Unrealized Losses	(118)	(21)
Marketable Securities, Fair Value	11,882	7,979
Corporate Debt Securities - Due in More than One Year to Five Years
Cash Equivalents and Marketable Securities
Marketable Securities, Amortized Cost	2,682	9,085
Marketable Securities, Unrealized Losses	(44)	(33)
Marketable Securities, Fair Value	2,638	9,052
US Treasury Obligation - Due in More Than One Year to Five Years
Cash Equivalents and Marketable Securities
Marketable Securities, Amortized Cost		3,999
Marketable Securities, Unrealized Losses		(13)
Marketable Securities, Fair Value		3,986
Cash and money market funds
Cash Equivalents and Marketable Securities
Cash Equivalents, Amortized Cost	69,575	92,302
Cash Equivalents, Fair value	$ 69,575	$ 92,302

Cash, Cash Equivalents and Ma_4

Cash, Cash Equivalents and Marketable Securities - Additional Information (Details)	3 Months Ended
	Mar. 31, 2022USD ($)itemSecurity	Mar. 31, 2021USD ($)item
Investments Debt And Equity Securities [Abstract]
Realized gains (losses)	$ 0	$ 0
Number of investments adjusted for other-than-temporary declines in fair value | item	0	0
Number of securities held unrealized position | Security	10
Unrealized loss position for less than twelve months	$ 27,400,000
Unrealized loss position for more than twelve months	0
Marketable securities with an other-than temporary impairment	$ 0

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - Recurring - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Assets	$ 112,899	$ 143,407
Total Liabilities	581	3,029
Cash
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Assets	59,769	57,213
Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Assets	9,806	35,089
Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Assets	81,457	104,267
Level 1 | Cash
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Assets	59,769	57,213
Level 1 | Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Assets	9,806	35,089
Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Assets	31,442	39,140
Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Liabilities	581	3,029
Corporate Debt Securities - Due in One Year or Less
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Assets	28,804	30,088
Corporate Debt Securities - Due in One Year or Less | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Assets	28,804	30,088
Us Treasury Obligation - Due in One Year or Less
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Assets	11,882	7,979
Us Treasury Obligation - Due in One Year or Less | Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Assets	11,882	7,979
US Treasury Obligation - Due in More Than One Year to Five Years
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Assets		3,986
US Treasury Obligation - Due in More Than One Year to Five Years | Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Assets		3,986
Corporate Debt Securities - Due in More than One Year to Five Years
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Assets	2,638	9,052
Corporate Debt Securities - Due in More than One Year to Five Years | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Assets	2,638	9,052
Warrants
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Liabilities	581	3,029
Warrants | Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Liabilities	$ 581	$ 3,029

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - shares	Mar. 31, 2022	Mar. 31, 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrant issued to purchase common stock	2,117,094	2,117,094
Private Placement
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrant issued to purchase common stock	2,828,125	2,828,125

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Assumptions Used to Record Fair Value of Warrants (Details)	3 Months Ended	12 Months Ended
	Mar. 31, 2022$ / shares	Dec. 31, 2021$ / shares
Stock Price
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Stock price	$ 1.19	$ 3.26
Risk-free interest rate
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Warrants liability measurement input	0.0244	0.0111
Expected life (in years)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Expected life (in years)	3 years 8 months 8 days	3 years 11 months 8 days
Expected volatility
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Warrants liability measurement input	0.8549	0.8114

Fair Value Measurements - Sum_2

Fair Value Measurements - Summary of Changes in Level 3 Warrant Liability Measured at Fair Value on Recurring Basis (Details) - Level 3 - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Fair value of warrant liability as of beginning of the period	$ 3,029	$ 19,711
Change in fair value	(2,448)	(16,682)
Fair value of warrant liability as of end of the period	$ 581	$ 3,029

Restricted Cash - Additional In

Restricted Cash - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Restricted Cash
Long term restricted cash	$ 3,086	$ 3,086
HQ Lease
Restricted Cash
Letter of credit outstanding	$ 3,100
Letter of credit expiration period	95 days
Operating Lease, October 2023
Restricted Cash
Expected letter of credit amount	$ 2,100

Restricted Cash - Schedule of R

Restricted Cash - Schedule of Reconciliation of Cash, Cash Equivalents, and Restricted Cash (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	$ 69,575	$ 92,302
Restricted cash, net of current portion	3,086	3,086
Total cash, cash equivalents and restricted cash	$ 72,661	$ 95,388	$ 225,228	$ 177,070

Oxford Finance Loan Agreement -

Oxford Finance Loan Agreement - Additional Information (Details)	Dec. 23, 2020USD ($)$ / sharesshares	Feb. 12, 2020USD ($)$ / sharesshares	Mar. 31, 2022USD ($)shares	Mar. 31, 2021USD ($)shares	Dec. 31, 2021USD ($)
Debt Instrument [Line Items]
Term loan			$ 40,000,000
Warrants to purchase common stock | shares			2,117,094	2,117,094
Current portion of debt			$ 1,667,000
Long-term portion of debt			$ 38,775,000		$ 40,257,000
Loan Agreement
Debt Instrument [Line Items]
Term loan, aggregate principal amount		$ 60,000,000
Additional term loan advances, description		A first tranche term loan for $20.0 million was funded on February 12, 2020, and a second tranche term loan for $20.0 million was funded on December 23, 2020. The remaining $20.0 million is still available under the Loan Agreement, at the sole discretion of the Lender.
Each of available additional term loan advances		$ 20,000,000
Term loan, interest rate terms		The term loan bears interest at an annual rate equal to the greater of (i) 7.75% and (ii) the sum of 5.98% and the greater of (A) one-month LIBOR or (B) 1.77%.
Term loan, interest rate		7.75%
Term loan, effective interest rate		5.98%
Term loan, variable interest rate basis		one-month LIBOR
Term loan, variable interest rate basis spread		1.77%
Term loan, maturity date		Feb. 1, 2025
Term loan, final payment fee percentage		5.00%
Warrants to purchase common stock | shares			27,548	27,548
Warrant exercisable period from date of issuance			5 years
Interest expense			$ 1,000,000	$ 900,000
Current portion of debt			1,700,000
Long-term portion of debt			$ 38,800,000
Loan Agreement | Advance Prepaid in First 12 Months
Debt Instrument [Line Items]
Term loan, prepayment fee, equal to percentage of the principal amount being prepaid		2.00%
Loan Agreement | Advance Prepaid After 12 Months But Prior to 24 Months
Debt Instrument [Line Items]
Term loan, prepayment fee, equal to percentage of the principal amount being prepaid		1.00%
Loan Agreement | Advance Prepaid After 24 Months But Prior to Maturity Date
Debt Instrument [Line Items]
Term loan, prepayment fee, equal to percentage of the principal amount being prepaid		0.50%
Loan Agreement | First Loan Tranche
Debt Instrument [Line Items]
Term loan		$ 20,000,000
Term Loan, facilities fee		$ 100,000
Warrants to purchase common stock | shares		27,548
Warrant exercise price of common stock per share | $ / shares		$ 7.26
Fair value of warrants		$ 100,000
Loan Agreement | First Loan Tranche | Expected volatility | Weighted Average
Debt Instrument [Line Items]
Fair value of weighted average volatility		75.43
Loan Agreement | First Loan Tranche | Expected life (in years) | Weighted Average
Debt Instrument [Line Items]
Fair value of weighted expected term		5 years
Loan Agreement | Second Loan Tranche
Debt Instrument [Line Items]
Term loan	$ 20,000,000
Term Loan, facilities fee	$ 75,000
Warrants to purchase common stock | shares	17,389
Warrant exercise price of common stock per share | $ / shares	$ 11.50
Fair value of warrants	$ 200,000
Loan Agreement | Second Loan Tranche | Expected volatility | Weighted Average
Debt Instrument [Line Items]
Fair value of weighted average volatility	82.41
Loan Agreement | Second Loan Tranche | Expected life (in years) | Weighted Average
Debt Instrument [Line Items]
Fair value of weighted expected term	5 years
Loan Agreement | Third Loan Tranche
Debt Instrument [Line Items]
Term loan, facilities fee		$ 50,000

Oxford Finance Loan Agreement_2

Oxford Finance Loan Agreement - Schedule of Minimum Aggregate Future Loan Payments (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Debt Disclosure [Abstract]
Year ending December 31, 2023	$ 16,666
Year ending December 31, 2024	20,000
Year ending December 31, 2025	3,334
Total minimum payments	40,000
Less unamortized debt discount	(410)
Plus accumulated accretion of final fees	852
Total carrying value of debt	40,442
Less current portion	(1,667)
Debt, net of debt discount, long term	$ 38,775	$ 40,257

Accrued Expenses - Schedule of

Accrued Expenses - Schedule of Accrued Expenses (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Accrued Liabilities Current [Abstract]
External research and preclinical development	$ 8,521	$ 8,274
Employee compensation and benefits	3,180	6,344
Professional fees	1,495	953
Facilities and other	53	53
Accrued expenses	$ 13,249	$ 15,624

Commitments and Contingencies -

Commitments and Contingencies - Operating Leases - Additional Information (Details) $ in Thousands	Jan. 08, 2019ft²	Mar. 31, 2022USD ($)	Dec. 31, 2021USD ($)
Lessee Lease Description [Line Items]
Operating lease, right-of-use asset		$ 13,900	$ 14,104
Operating lease liability, short term		1,789	1,720
Operating lease liability, long-term		22,378	$ 22,858
Accounting Standards Update 2016-02
Lessee Lease Description [Line Items]
Operating lease, right-of-use asset		15,800
Operating lease liability, long-term		$ 15,800
Lease operating, discounted borrowing rate		9.30%
Net of tenant allowances expected to be received		$ 9,300
Lease practical expedient		true
HQ Lease
Lessee Lease Description [Line Items]
Area of office and laboratory space leased | ft²	52,859
Term of option to extend the lease		10 years
Letter of credit outstanding		$ 3,100
HQ Lease | Accounting Standards Update 2016-02
Lessee Lease Description [Line Items]
Operating lease liability, short term		1,800
Operating lease liability, long-term		$ 22,400

Commitments and Contingencies_2

Commitments and Contingencies - Finance Lease - Additional Information (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2019
Leases Operating [Abstract]
Equipment lease term			48 months
Financing lease right-of-use asset	$ 271	$ 337	$ 1,000
Financing lease liability	$ 286		$ 1,000

Commitment and Contingencies -

Commitment and Contingencies - Schedule of Reconciliation of Maturity Analysis of Annual Undiscounted Cash Flows (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Mar. 31, 2019
Commitments And Contingencies Disclosure [Abstract]
Nine months ending December 31, 2022	$ 2,956
Year ending December 31, 2023	4,049
Year ending December 31, 2024	4,166
Year ending December 31, 2025	4,287
Year ending December 31, 2026 and beyond	19,256
Operating Lease, Total minimum lease payments	34,714
Operating Lease, Less imputed interest	(10,547)
Operating lease liability	24,167
Nine months ending December 31, 2022	234
Year ending December 31, 2023	66
Finance Lease, Total minimum lease payments	300
Finance Lease, Less imputed interest	(14)
Financing lease liability	$ 286	$ 1,000

Commitment and Contingencies _2

Commitment and Contingencies - Schedule of Total Lease Cost for Operating and Financing Leases as well as Weighted Average Information for Leases (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Lease cost:
Operating lease cost	$ 772
Financing lease cost:
Amortization of right-of-use asset	66	$ 65
Interest on lease liabilities	7
Total financing lease cost	73
Cash paid for amounts included in the measurement of liabilities:
Operating cash flows from operating lease	979
Operating cash flows from financing lease	$ 78
Other information:
Weighted-average remaining lease term (in years) - operating lease	7 years 11 months 1 day
Weighted-average discount rate - operating lease	9.30%
Weighted-average remaining lease term (in years) - financing lease	1 year 25 days
Weighted-average discount rate - financing lease	9.47%

Commitments and Contingencies_3

Commitments and Contingencies - Asset Purchase Agreement (Details) - Orsenix, LLC - Asset Purchase Agreement $ in Millions	Dec. 04, 2020USD ($)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront fee payments	$ 12
Payments made upon achievement of regulatory milestone	6
Payments made upon achievement of commercial milestone	$ 10

Commitments and Contingencies_4

Commitments and Contingencies - License Agreements - Additional Information (Details) - TMRC - USD ($) $ in Millions	1 Months Ended
	Sep. 30, 2021	May 31, 2021	Sep. 30, 2016	May 31, 2016	Sep. 30, 2015
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Up-front license fee					$ 1
Payment of up-front license fee				$ 0.5	0.5
Payments per indication due upon the successful achievement of clinical and regulatory milestones					$ 13
Payments made upon achievement of development milestone	$ 1	$ 2	$ 1

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details) $ / shares in Units, $ in Thousands	Jan. 22, 2021USD ($)$ / sharesshares	Dec. 08, 2020USD ($)$ / sharesshares	Apr. 09, 2019USD ($)Agreement$ / sharesshares	Mar. 31, 2022USD ($)$ / sharesshares	Mar. 31, 2021USD ($)shares	Dec. 31, 2021USD ($)shares	Dec. 31, 2019shares	Nov. 30, 2019shares
Class Of Stock [Line Items]
Warrants to purchase common stock				2,117,094	2,117,094
Remeasured fair value of warrants | $				$ 581		$ 3,029
Change in fair value of warrant liability | $				$ 2,448	$ 7,670
Number of underwriting agreements | Agreement			2
Aggregate gross proceeds from public offerings | $			$ 70,000
Underwriting discounts and commissions and estimated offering expenses payable | $			$ 5,000
Preferred stock, shares outstanding				0		0
Warrant issued to purchase common stock				2,117,094	2,117,094
Series A Preferred Stock
Class Of Stock [Line Items]
Share price (in dollars per share) | $ / shares				$ 6.57
Preferred stock, shares outstanding				0				666
Convertible preferred stock beneficial conversion feature | $				$ 600
Class A Warrants
Class Of Stock [Line Items]
Warrants to purchase common stock							2,118,344
Warrant exercise price of common stock per share | $ / shares				$ 8.625
Warrants expiration date				Oct. 10, 2022
Maximum ownership percentage to total number stock issued and outstanding holder is prohibited from conversion				4.99%
Notice period for change in owning percentage				61 days
Warrant issued to purchase common stock							2,118,344
Fair value of warrants | $				$ 9,000
Class A Warrants
Class Of Stock [Line Items]
Warrants outstanding and remain unexercised excluding Oxford warrants				2,117,094
Weighted Average | Class A Warrants | Weighted Average Volatility
Class Of Stock [Line Items]
Fair value of weighted average volatility				86.06%
Weighted Average | Class A Warrants | Dividend yield
Class Of Stock [Line Items]
Fair value of weighted expected term				3 years 6 months
Common Stock | Series A Preferred Stock
Class Of Stock [Line Items]
Conversion of series A stock into common stock								666,000
Underwritten Public Offering
Class Of Stock [Line Items]
Shares issued	5,400,000
Public offering price per share | $ / shares	$ 14
Gross proceeds from common stock | $	$ 75,600
Underwriting discounts and commissions and other transaction expenses | $	$ 5,100
Private Placement
Class Of Stock [Line Items]
Warrants to purchase common stock				2,828,125	2,828,125
Gross proceeds of private placement | $		$ 90,500
Transaction costs | $		400
Initial fair value of warrants at issuance | $		$ 19,300
Remeasured fair value of warrants | $				$ 600		$ 3,000
Warrant issued to purchase common stock				2,828,125	2,828,125
Private Placement | Common Stock
Class Of Stock [Line Items]
Shares issued		10,312,500
Private Placement | Pre-Funded Warrant
Class Of Stock [Line Items]
Warrants to purchase common stock		1,000,000
Share price (in dollars per share) | $ / shares		$ 8
Warrant issued to purchase common stock		1,000,000
Private Placement | Warrants
Class Of Stock [Line Items]
Share price (in dollars per share) | $ / shares		$ 7.99
Private Placement | Warrants | Maximum
Class Of Stock [Line Items]
Warrants to purchase common stock		2,828,125
Warrant issued to purchase common stock		2,828,125
Public Offering | Common Stock Agreement | Class A Warrants
Class Of Stock [Line Items]
Warrants to purchase common stock			1,951,844
Share price (in dollars per share) | $ / shares			$ 7.50	$ 7.50
Warrant issued to purchase common stock			1,951,844
Public Offering | Preferred Stock Agreement | Series A Preferred Stock
Class Of Stock [Line Items]
Shares issued			666
Public Offering | Preferred Stock Agreement | Class A Warrants
Class Of Stock [Line Items]
Warrants to purchase common stock			166,500
Share price (in dollars per share) | $ / shares			$ 7,500
Warrant issued to purchase common stock			166,500
Public Offering | Common Stock | Common Stock Agreement
Class Of Stock [Line Items]
Shares issued			8,667,333

Stock-Based Payments - 2016 Sto

Stock-Based Payments - 2016 Stock Incentive Plan (Details) - 2016 Plan - shares	Jan. 01, 2022	Mar. 31, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Increase in number of shares of common stock reserved for issuance of awards on the first day of each calendar year (in shares)		1,600,000
Increase in number of shares of common stock reserved for issuance of awards on the first day of each calendar year, as a percentage of outstanding shares		4.00%
Increase in number of shares of common stock reserved for issuance (in shares)	1,600,000
Common stock available for future issuance (in shares)		428,219
Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period		4 years
Term of award		3 years
Stock Option | Vesting on one year anniversary of vesting commencement date
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting (as a percent)		25.00%
Stock Option | Vesting ratably on a monthly basis
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period		10 years
Vesting (as a percent)		75.00%

Stock-Based Payments - 2016 Emp

Stock-Based Payments - 2016 Employee Stock Purchase Plan (Details) - 2016 ESPP - shares	Jan. 01, 2022	Jul. 06, 2016	Mar. 31, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Increase in number of shares of common stock reserved for issuance of awards on the first day of each calendar year (in shares)		1,173,333
Increase in number of shares of common stock reserved for issuance of awards on the first day of each calendar year, as a percentage of outstanding shares		1.00%
Increase in number of shares of common stock reserved for issuance (in shares)	620,241
Common stock available for future issuance (in shares)			2,857,306

Stock-Based Payments - Induceme

Stock-Based Payments - Inducement Grants (Details)	3 Months Ended
	Mar. 31, 2022shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Granted and outstanding (in shares)	951,300
Inducement Grants | Non Statutory Stock options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Granted and outstanding (in shares)	1,110,000
Vesting period	4 years
Term of award	3 years
Inducement Grants | Non Statutory Stock options | Vesting on one year anniversary of vesting commencement date
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting (as a percent)	25.00%
Inducement Grants | Non Statutory Stock options | Vesting ratably on a monthly basis
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting (as a percent)	75.00%

Stock-Based Payments - 2022 Ind

Stock-Based Payments - 2022 Inducement Stock Incentive Plan (Details)	Jan. 25, 2022shares
2022 Inducement Stock Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of common stock shares grant	1,000,000

Stock-Based Payments - Stock Op

Stock-Based Payments - Stock Options (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation costs	$ 12.1
Period in which compensation costs will be recognized	3 years 1 month 6 days
Granted and outstanding (in shares)	951,300
Intrinsic value of options exercised	$ 0.1	$ 0.1
Advisor | Performance-based stock options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation costs	$ 0.3
Period in which compensation costs will be recognized	4 years 6 months
Granted and outstanding (in shares)	75,000

Stock-Based Payments - Summary

Stock-Based Payments - Summary of Status of Stock Options (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Outstanding at beginning of year (in shares)	6,657,268
Granted (in shares)	951,300
Exercised (in shares)	(37,700)
Cancelled (in shares)	(43,716)
Outstanding at end of period (in shares)	7,527,152	6,657,268
Exercisable (in shares)	4,081,501
Outstanding at beginning of year (in dollars per share)	$ 8.27
Granted (in dollars per share)	1.59
Exercised (in dollars per share)	0.04
Cancelled (in dollars per share)	9.93
Outstanding at end of period (in dollars per share)	7.45	$ 8.27
Exercisable (in dollars per share)	$ 9.01
Remaining Contractual Life, Outstanding	6 years 8 months 12 days	7 years 2 months 12 days
Remaining Contractual Life, Exercisable	5 years 4 months 24 days
Aggregate Intrinsic Value, Outstanding	$ 26	$ 494
Aggregate Intrinsic Value, Options Exercisable	$ 26

Stock-Based Payments - Restrict

Stock-Based Payments - Restricted Stock Units (Details) $ in Millions	3 Months Ended
	Mar. 31, 2022USD ($)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation costs	$ 12.1
Period in which compensation costs will be recognized	3 years 1 month 6 days
Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period	4 years
Vesting (as a percent)	25.00%
Unrecognized compensation costs	$ 13.9
Period in which compensation costs will be recognized	2 years 10 months 24 days
Restricted Stock Units | Executive Officers
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period	3 years

Stock-Based Payments - Summar_2

Stock-Based Payments - Summary of Status of Restricted Stock Units (Details) - Restricted Stock Units	3 Months Ended
	Mar. 31, 2022$ / sharesshares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Outstanding at beginning of year (in shares) | shares	2,687,487
Granted (in shares) | shares	2,768,128
Vested (in shares) | shares	(739,561)
Forfeited (in shares) | shares	(176,325)
Outstanding at end of period (in shares) | shares	4,539,729
Weighted Average Grant Date Fair Value, Outstanding at beginning of year (in dollars per share) | $ / shares	$ 6.52
Weighted Average Grant Date Fair Value, Granted (in dollars per share) | $ / shares	1.58
Weighted Average Grant Date Fair Value, Vested (in dollars per share) | $ / shares	7.32
Weighted Average Grant Date Fair Value, Forfeited (in dollars per share) | $ / shares	6.76
Weighted Average Grant Date Fair Value, Outstanding at end of period (in dollars per share) | $ / shares	$ 3.37

Stock-Based Payments - Schedule

Stock-Based Payments - Schedule of Weighted-Average Assumptions used in Black-Scholes Option-Pricing Model (Details) - Stock Option	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average risk-free interest rate	1.98%	0.78%
Expected option term (in years)	6 years 25 days	6 years 29 days
Volatility	80.70%	82.10%

Stock-Based Payments - Weighted

Stock-Based Payments - Weighted-Average Assumptions to Estimate Fair Value of Stock Options (Details) - $ / shares	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average grant date fair value of options granted (in dollars per share)	$ 1.11	$ 7.89

Stock-Based Payments - Summar_3

Stock-Based Payments - Summary of Stock-based Compensation Expense for Stock Options and Restricted Stock Units (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 2,863	$ 2,930
Research and development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	1,395	1,323
General and administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 1,468	$ 1,607