Stoke Therapeutics (STOK) 10-K 10 Mar 22 2021 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Mar. 01, 2022	Jun. 30, 2021
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Entity Registrant Name	Stoke Therapeutics, Inc.
Entity Central Index Key	0001623526
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Interactive Data Current	Yes
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Well Known Seasoned Issuer	No
Entity Public Float			$ 665
Entity Common Stock, Shares Outstanding		37,359,218
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity File Number	001-38938
Entity Incorporation State Country Code	DE
Entity Tax Identification Number	47-1144582
Entity Address, Address Line One	45 Wiggins Ave
Entity Address City Or Town	Bedford
Entity Address State Or Province	MA
Entity Address Postal Zip Code	01730
City Area Code	781
Local Phone Number	430-8200
Document Annual Report	true
Document Transition Report	false
ICFR Auditor Attestation Flag	false
Auditor Firm ID	185
Auditor Name	KPMG LLP
Auditor Location	Boston, MA USA
Title of 12(b) Security	Common Stock, $0.0001 par value per share
Trading Symbol	STOK
Security Exchange Name	NASDAQ
Documents Incorporated by Reference	Portions of the registrant’s Definitive Proxy Statement relating to the 2022 Annual Meeting of Stockholders are incorporated by reference into Part III of this Annual Report on Form 10-K to the extent stated herein. The Definitive Proxy Statement will be filed within 120 days of the Registrant’s fiscal year ended December 31, 2021. Except with respect to information specifically incorporated by reference in this Form 10-K, the Definitive Proxy Statement is not deemed to be filed as part of this Form 10-K. Auditor Firm Id: 185 Auditor Name: KPMG LLP Auditor Location: Boston, MA USA

Consolidated balance sheets

Consolidated balance sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 144,895	$ 287,308
Marketable securities	74,915	0
Prepaid expenses and other current assets	9,159	6,435
Deferred financing costs	117	181
Interest receivable	132	6
Total current assets	229,218	293,930
Restricted cash	569	205
Operating lease right-of-use assets	4,939	1,115
Property and equipment, net	4,139	2,675
Total assets	238,865	297,925
Current liabilities:
Accounts payable	2,385	1,495
Accrued and other current liabilities	14,754	9,930
Total current liabilities	17,139	11,425
Long term liabilities	3,949	422
Total liabilities	21,088	11,847
Commitments and contingencies (Note 7)
Stockholders’ equity
Common stock, par value of $0.0001 per share; 300,000,000 shares authorized, 36,902,499 and 36,577,149 shares issued and outstanding as of December 31, 2021 and 2020, respectively	4	4
Additional paid-in capital	414,024	396,352
Accumulated other comprehensive loss	(168)
Accumulated deficit	(196,083)	(110,278)
Total stockholders’ equity	217,777	286,078
Total liabilities and stockholders’ equity	$ 238,865	$ 297,925

Consolidated balance sheets (Pa

Consolidated balance sheets (Parenthetical) - $ / shares	Dec. 31, 2021	Dec. 31, 2020
Statement Of Financial Position [Abstract]
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	300,000,000	300,000,000
Common stock, shares issued	36,902,499	36,577,149
Common stock, shares outstanding	36,902,499	36,577,149

Consolidated statements of oper

Consolidated statements of operations and comprehensive loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Operating expenses:
Research and development	$ 54,168	$ 32,197
General and administrative	31,897	20,847
Total operating expenses	86,065	53,044
Loss from operations	(86,065)	(53,044)
Other income (expense):
Interest income (expense), net	120	700
Other income (expense), net	140	101
Total other income (expense)	260	801
Net loss	$ (85,805)	$ (52,243)
Net loss per share—basic and diluted	$ (2.34)	$ (1.56)
Weighted average common shares outstanding—basic and diluted	36,739,269	33,488,456
Comprehensive loss:
Net loss	$ (85,805)	$ (52,243)
Other comprehensive loss:
Unrealized loss on marketable securities	(168)
Total other comprehensive loss	(168)
Comprehensive loss	$ (85,973)	$ (52,243)

Consolidated statements of stoc

Consolidated statements of stockholders' equity - USD ($) $ in Thousands	Total	Follow-on Offering	Common Stock	Common StockFollow-on Offering	Additional Paid-in Capital	Additional Paid-in CapitalFollow-on Offering	Accumulated Other Comprehensive Gain (Loss)	Accumulated Deficit
Balance at Dec. 31, 2019	$ 224,428		$ 3		$ 282,460			$ (58,035)
Balance, Shares at Dec. 31, 2019			32,861,842
Stock-based compensation	5,768				5,768
Issuance of common stock upon exercise of stock options	2,843				2,843
Issuance of common stock upon exercise of stock options, Shares			822,916
Issuance of common stock related to employee stock purchase plan	352				352
Issuance of common stock related to employee stock purchase plan, Shares			17,391
Issuance of common stock		$ 104,930		$ 1		$ 104,929
Issuance of common stock, Shares				2,875,000
Net loss	(52,243)							(52,243)
Balance at Dec. 31, 2020	286,078		$ 4		396,352			(110,278)
Balance, Shares at Dec. 31, 2020			36,577,149
Unrealized loss on marketable securities	(168)						$ (168)
Stock-based compensation	16,450				16,450
Issuance of common stock upon exercise of stock options	$ 777				777
Issuance of common stock upon exercise of stock options, Shares	287,566		304,857
Issuance of common stock related to employee stock purchase plan	$ 509				509
Issuance of common stock related to employee stock purchase plan, Shares			20,493
Issuance of common stock		$ (64)				$ (64)
Net loss	(85,805)							(85,805)
Balance at Dec. 31, 2021	$ 217,777		$ 4		$ 414,024		$ (168)	$ (196,083)
Balance, Shares at Dec. 31, 2021			36,902,499

Consolidated statements of cash

Consolidated statements of cash flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities:
Net loss	$ (85,805)	$ (52,243)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	974	888
Amortization and accretion of marketable securities	143
Stock-based compensation	16,450	5,768
Loss on disposal of property and equipment	29	3
Reduction in the carrying amount of right of use assets	1,256	1,038
Changes in assets and liabilities:
Prepaid expenses and other current assets	(2,851)	(2,878)
Accounts payable and accrued liabilities	2,897	5,203
Net cash used in operating activities	(66,907)	(42,221)
Cash flows from investing activities:
Purchases of property and equipment	(1,200)	(1,050)
Purchases of marketable securities	(87,226)
Sales of marketable securities	12,000
Net cash used in investing activities	(76,426)	(1,050)
Cash flows from financing activities:
Proceeds from issuance of common stock upon public offerings		105,398
Payment of offering costs		(306)
Proceeds from issuance of common stock upon exercise of stock options	777	2,843
Proceeds from Employee Stock Purchase Plan	509	352
Deferred financing costs		(179)
Other	(2)
Net cash provided by financing activities	1,284	108,108
Net increase (decrease) in cash, cash equivalents and restricted cash	(142,049)	64,837
Cash, cash equivalents and restricted cash—beginning of year	287,513	222,676
Cash, cash equivalents and restricted cash—end of year	145,464	287,513
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Right-of-use assets recognized in exchange for operating leases under Topic 842	5,081	2,153
Property and equipment included in accrued expense and accounts payable	$ 1,267	6
Deferred offering costs not yet paid		$ 162

Nature of the Business and Basi

Nature of the Business and Basis of Presentation	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Nature of the business and basis of presentation	1. Nature of the business and basis of presentation Organization Stoke Therapeutics, Inc. (the Company) was founded in June 2014 and was incorporated under the laws of the State of Delaware. The Company is an early-stage biopharmaceutical company pioneering a new way to treat the underlying causes of severe genetic diseases by precisely upregulating protein expression. Shelf Registration In July 2020, the Company filed a universal Shelf Registration statement on Form S-3 (the “Registration Statement”) with the Securities and Exchange Commission (the “SEC”). The Registration Statement was declared effective by the SEC on July 20, 2020, and contains two prospectuses: a base prospectus, which covers the offering, issuance and sale by the Company of up to a maximum aggregate offering price of $400,000,000 of our common stock, preferred stock, debt securities, warrants to purchase our common stock, preferred stock or debt securities, subscription rights to purchase our common stock, preferred stock or debt securities and/or units consisting of some or all of these securities; and a sales agreement prospectus covering the offering, issuance and sale by us of up to a maximum aggregate offering price of $150,000,000 of our common stock that may be issued and sold under a Controlled Equity Offering Sales Agreement (“Sales Agreement”). The specific terms of any securities to be offered pursuant to the base prospectus will be specified in a prospectus supplement to the base prospectus. The $150,000,000 of common stock that may be offered, issued and sold under the sales agreement prospectus is included in the $400,000,000 of securities that may be offered, issued and sold by the Company under the base prospectus. As of December 31, 2021, the Company had not issued any securities in connection with the Sales Agreement. (see note 12 for sales of common stock subsequent to year end) Follow-on public offering On November 24, 2020, pursuant to a prospectus supplement to the Registration Statement, we completed an underwritten public offering, of our common stock and issued and sold 2,875,000 shares of common stock at a public offering price of $39.00 per share, which included 375,000 shares sold upon full exercise of the underwriters’ option to purchase additional shares of common stock resulting in net proceeds of $104.9 million after deducting underwriting discounts and commissions and estimated offering expenses. Uncertainties The Company is subject to risks and uncertainties common to early-stage companies in the biotechnology industry including, but not limited to, development by competitors of new technological innovations, dependence on key personnel, protection of proprietary technology, compliance with government regulations and ability to secure additional capital to fund operations. Product candidates currently under development will require significant additional research and development efforts, including extensive preclinical and clinical testing and regulatory approval prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel and infrastructure and extensive compliance-reporting capabilities. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will realize significant revenue from product sales. Liquidity The Company expects that its operating losses and negative cash flows will continue for the foreseeable future. As of the issuance date of its consolidated financial statements for the year ended December 31, 2021, the Company expects that its cash and cash equivalents, and marketable securities will be sufficient to fund its operating expenses and capital expenditure requirements into 2024. The Company plans to seek additional funding through public or private equity offerings, debt financings, other collaborations, strategic alliances and licensing arrangements (see note 12 for license and collaboration agreement entered in to January 2022) . The Company may not be able to obtain financing on acceptable terms, or at all, and the Company may not be able to enter into strategic alliances or other arrangements on favorable terms, or at all. The terms of any financing may adversely affect the holdings or the rights of the Company’s stockholders. If the Company is unable to obtain funding, the Company could be required to delay, reduce or eliminate research and development programs, product portfolio expansion or future commercialization efforts, which could adversely affect its business prospects.

Summary of Significant Accounti

Summary of Significant Accounting Policies and Recent Accounting Pronouncements	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Summary of significant accounting policies and recent accounting pronouncements	2. Summary of significant accounting policies and recent accounting pronouncements Basis of presentation and consolidation The accompanying consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (GAAP), and include the accounts of Stoke Therapeutics, Inc. and its wholly-owned subsidiary. Any reference in these notes to applicable guidance is meant to refer to GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Update (“ASU”) of the Financial Accounting Standards Board (“FASB”). All intercompany transactions between and among the Company and its’ consolidated subsidiary have been eliminated. Use of estimates The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, equity, expenses and disclosure of contingent assets and liabilities. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Actual results could differ from those estimates. Cash and cash equivalents The Company considers all highly liquid investments with an original maturity of three months or less at the date of purchase to be cash equivalents. The Company deposits its cash in checking, sweep and money market accounts. Restricted cash At December 31, 2021, restricted cash consisted of money market accounts collateralizing letters of credit issued as security deposits in connection with the Company’s leases of its corporate facilities. The following table reconciles cash and cash equivalents and restricted cash per the consolidated balance sheets to the statement of cash flows: As of December 31, 2021 2020 Cash and cash equivalents $ 144,895 $ 287,308 Restricted cash 569 205 $ 145,464 $ 287,513 Marketable Securities Marketable securities consist of government securities and obligations, corporate bonds and commercial paper with original maturities of more than 90 days. Investments are classified as available-for-sale and are recorded on the balance sheet at fair value with unrealized gains or losses reported as a separate component of other comprehensive income/(loss). Management determines the appropriate classification of its investments at the time of purchase and reevaluates such determination at each balance sheet date. Concentration of credit risk Financial instruments that potentially expose the Company to concentrations of credit risk primarily consist of cash and cash equivalents. The Company maintains its cash and cash equivalents at an accredited financial institution in amounts that exceed federally insured limits. The Company does not believe that it is subject to unusual credit risk beyond the normal credit risk associated with commercial banking relationships. Fair value of financial instruments ASC Topic 820, Fair Value Measurement Level 1—Quoted market prices in active markets for identical assets or liabilities. Level 2—Inputs other than Level 1 inputs that are either directly or indirectly observable, such as quoted market prices, interest rates and yield curves. Level 3—Unobservable inputs developed using estimates of assumptions developed by the Company, which reflect those that a market participant would use. To the extent the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair values 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. Deferred offering costs The Company capitalizes certain legal, professional accounting and other third-party fees that are directly associated with in-process equity financings as deferred offering costs until such financings are consummated. After consummation of the equity financing, these costs are recorded in the consolidated statement of stockholders’ equity as a reduction of additional paid-in capital. Property and equipment Property and equipment are recorded at cost less accumulated depreciation. Cost includes the acquisition costs and all costs necessary to bring the asset to the location and working condition necessary for its intended use. Depreciation expense is recognized using the straight-line method over the estimated useful life of each asset. Upon retirement or sale, the cost of assets disposed of and the related accumulated depreciation are removed from the accounts and any resulting gain or loss is included in the accompanying consolidated statements of operations and comprehensive loss. Expenditures for normal, recurring or periodic repairs and maintenance related to property and equipment are charged to expense as incurred. The cost for planned major maintenance activities, including the related acquisition or construction of assets, is capitalized if it will result in future economic benefits. Estimated useful lives for property and equipment are as follows: Property and equipment Estimated useful life Computer and office equipment 3-5 years Laboratory equipment and Furniture and fixtures 5-7 years Leasehold improvements Lesser of estimated useful life or remaining lease term Impairment of long-lived assets The Company reviews the recoverability of its long-lived assets when events or changes in circumstances occur that indicate that the carrying value of the assets may not be recoverable. The assessment of possible impairment is based on the ability to recover the carrying value of the assets from the expected future cash flows (undiscounted and without interest expense) of the related operations. If these cash flows are less than the carrying value of such assets, an impairment loss for the difference between the estimated fair value and carrying value is recorded. There were no impairment losses recognized during the years ended December 31, 2021 and 2020. Research and development costs Research and development costs are expensed as incurred. Research and development expenses are comprised of costs incurred in performing research and development activities, including salaries and benefits, facilities costs, depreciation, third-party license fees, and costs related to third parties engaged to conduct preclinical research development activities. The Company has entered into various research and development contracts with research institutions and other companies to conduct research on its behalf. These agreements are generally cancellable. The Company records accruals for estimated ongoing research costs. When evaluating the adequacy of the accrued liabilities, the Company analyzes progress of the studies, including the phase or completion of events, invoices received and contracted costs. Significant judgments 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’s historical accrual estimates have not been materially different from the actual costs. Stock options The Company measures its stock-based awards granted based on the estimated fair values of the awards and recognizes the compensation for employees and nonemployees over the requisite service period. The Company uses the Black-Scholes option-pricing model to estimate the fair value of its stock-based awards. The Company has elected the practical expedient to use the midpoint between vesting date and the contractual term as the expected term for certain awards with service or performance conditions. Stock-based compensation is recognized using the straight-line method. Forfeitures of unvested stock-based awards are accounted for when they occur. Patent costs All patent-related costs incurred in connection with filing and prosecuting patent applications are expensed as incurred due to the uncertainty about the recovery of the expenditure. Amounts incurred are classified as general and administrative expenses in the accompanying consolidated statements of operations and comprehensive loss. Leases In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842). This standard established a right-of-use model that requires all lessees to recognize right-of-use assets and lease liabilities on their balance sheet that arise from leases as well as provide disclosures with respect to certain qualitative and quantitative information related to a company's leasing arrangements. The Company adopted Topic 842 on January 1, 2020 using the modified retrospective approach and elected to apply the transition method that allows companies to continue applying guidance under the lease standard in effect at that time in the comparative period financial statements and recognize a cumulative-effect adjustment to the balance sheet on the date of adoption. The Company has also elected the package of practical expedients to not reassess its prior conclusions about lease identification, lease classification and indirect costs and to not separate lease and non-lease components. Upon adoption of Topic 842 on January 1, 2020, the Company recorded right-of-use assets of $2.2 million, operating lease liabilities of $2.2 million and the elimination of deferred rent of $0.03 million. Adoption of the standard did not result in the Company recording a cumulative effect adjustment. The Company determines whether an arrangement is a lease at inception. The Company accounts for a lease when it has the right to control the leased asset for a period of time while obtaining substantially all of the assets’ economic benefits. The Company determined that it held operating leases for office and laboratory space as of January 1, 2020. Operating lease right-of-use assets and operating lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at the lease commencement date. The discount rate used to determine the present value of the lease payments is the Company’s incremental borrowing rate based on the information available at lease inception, as the Company does not have information to determine the rate implicit in the leases. Lease expense for operating leases is recognized on a straight-line basis over the reasonably assured lease term based on the total lease payments (which include initial direct costs and lease incentives). The expense is included in operating expenses in the consolidated statements of operations and comprehensive loss. The Company’s lease agreements also contain variable payments, primarily maintenance-related costs, which are expensed as incurred and not included in the measurement of the right-of-use assets and lease liabilities. Income taxes The Company accounts for income taxes using the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the estimated future tax consequences attributable to temporary differences between the consolidated financial statement carrying amounts of existing assets and liabilities and their respective tax base. Deferred tax assets and liabilities are determined on the basis of the differences between the consolidated financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the temporary differences are expected to be settled or recovered. Changes in deferred tax assets and liabilities are recorded in the provision for income taxes. The Company assesses the likelihood that its deferred tax assets will be recovered from future taxable income and, to the extent it believes, based upon the weight of available evidence that it is more likely than not that all or a portion of the deferred tax assets will not be realized, a valuation allowance is established through a charge to income tax expense. Potential for recovery of deferred tax assets is evaluated by estimating the future taxable profits expected and considering prudent and feasible tax planning strategies. At December 31, 2021 and 2020, the Company has recorded a full valuation allowance. Reserves are provided for tax benefits for which realization is uncertain. Such benefits are only recognized when the underlying tax position is considered more-likely-than-not to be sustained on examination by a taxing authority, assuming they possess full knowledge of the position and facts. Interest and penalties related to uncertain tax positions are recognized in the provision of income taxes; however, the Company currently has no interest or penalties related to uncertain income tax benefits. The Tax Cuts and Jobs Act (the TCJA) was enacted on December 22, 2017. The TCJA reduced the U.S. federal corporate tax rate from a top rate of 35% to a flat rate of 21%. The Company continues to monitor for legislative developments, issuance of regulations and technical memorandum to provide further clarification and/or interpretations of the TCJA and will adjust its consolidated financial statements as needed. Segment and geographic information Operating segments are defined as components of an entity about which separate discrete information is available for evaluation by the chief operating decision maker, or decision-making group, in deciding how to allocate resources and in assessing performance. The Company operates in one segment in the United States. The Company’s chief executive officer, as the chief operating decision-maker, manages and allocates resources to the operations of the Company on a total company basis using consolidated financial information. Emerging growth company and smaller reporting company status The Company is an emerging growth company, as defined in the Jumpstart Our Business Startups Act of 2012 (the JOBS Act). Under the JOBS Act, emerging growth companies can delay adopting new or revised accounting standards issued subsequent to the enactment of the JOBS Act, until such time as those standards apply to private companies. The Company has elected to use this extended transition period for complying with new or revised accounting standards that have different effective dates for public and private companies until the earlier of the date that it is (i) no longer an emerging growth company or (ii) affirmatively and irrevocably opt out of the extended transition period provided in the JOBS Act. As a result, the Company’s consolidated financial statements may not be comparable to companies that comply with the new or revised accounting pronouncements as of public company effective dates. The Company will remain an emerging growth company until the earliest of (i) the last day of its first fiscal year (a) in which the Company has total annual gross revenues of at least $1.07 billion or (b) in which the Company is deemed to be a large accelerated filer, which means the market value of the Company’s common stock that is held by non-affiliates exceeds $700.0 million as of the prior June 30 th The Company is also a “smaller reporting company,” meaning that in the event of an initial public offering the market value of its stock held by non-affiliates plus the proposed aggregate amount of gross proceeds to the Company as a result of such offering is less than $700 million and its annual revenue is less than $100 million during the most recently completed fiscal year. The Company may continue to be a smaller reporting company as long as either (i) the market value of its stock held by non-affiliates is less than $250 million or (ii) its annual revenue is less than $100 million during the most recently completed fiscal year and the market value of its stock held by non-affiliates is less than $700 million. If the Company is a smaller reporting company at the time it ceases to be an emerging growth company, the Company may continue to rely on exemptions from certain disclosure requirements that are available to smaller reporting companies. Specifically, as a smaller reporting company, the Company may choose to present only the two most recent fiscal years of audited financial statements in its Annual Report on Form 10-K and, similar to emerging growth companies, smaller reporting companies have reduced disclosure obligations regarding executive compensation. Recently issued accounting pronouncements In July 2017, the FASB issued ASU 2017-11, Earnings Per Share Distinguishing Liabilities from Equity Derivatives and Hedging I. Accounting for Certain Financial Instruments with Down Round Features; II. Replacement of the Indefinite Deferral for Mandatorily Redeemable Financial Instruments of Certain Nonpublic Entities and Certain Mandatorily Redeemable Noncontrolling Interests with a Scope Exception Distinguishing Liabilities from Equity In August 2018, the FASB issued ASU 2018-13, “Fair Value Measurement (Topic 820), Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement”. In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes. The Company adopted this standard on January 1, 2021 and the adoption of this update did not have a material impact on its consolidated financial statements.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Fair value measurements	3. Fair value measurements The following tables present information about the Company’s financial assets measured at fair value on a recurring basis and indicate the level of the fair value hierarchy utilized to determine such fair values: Fair value measurements as of December 31, 2021 Level 1 Level 2 Level 3 Total Cash equivalents: Money market funds $ 144,897 $ — $ — $ 144,897 Total $ 144,897 $ — $ — $ 144,897 Marketable Securities: Corporate bonds $ — $ 17,524 $ — $ 17,524 Commercial paper $ — $ 27,487 $ — $ 27,487 US Government debt securities $ — $ 29,904 $ — $ 29,904 Total $ — $ 74,915 $ — $ 74,915 Fair value measurements as of December 31, 2020 Level 1 Level 2 Level 3 Total Cash equivalents: Money market funds $ 287,308 $ — $ — $ 287,308 Total $ 287,308 $ — $ — $ 287,308 Marketable Securities: Corporate bonds $ — $ — $ — $ — Commercial paper $ — $ — $ — $ — US Government debt securities $ — $ — $ — $ — Total $ — $ — $ — $ — The Company’s cash equivalents and marketable securities are carried at fair value, determined according to the fair value hierarchy described above and in Note 2. The carrying value of the Company’s accounts payable and accrued expenses approximate their fair values due to the short-term nature of these liabilities. The Company’s assets with fair value categorized as Level 1 within the fair value hierarchy include money market funds. Money market funds are publicly traded mutual funds and are presented as cash equivalents on the consolidated balance sheets as of December 30, 2021 and December 31, 2020. The Company measures its marketable securities at fair value on a recurring basis and classifies those instruments within Level 2 of the fair value hierarchy. There were no transfers to Level 3 in the periods presented.

Marketable Securities

Marketable Securities	12 Months Ended
	Dec. 31, 2021
Investments Debt And Equity Securities [Abstract]
Marketable Securities	4. Marketable Securities The following table summarizes the Company’s marketable securities as of December 31, 2021 (in thousands): December 31, 2021 Amortized Cost Unrealized Gains Unrealized Loss Fair Value Marketable securities: Corporate bonds $ 17,598 $ — $ (74 ) $ 17,524 Commercial paper $ 27,487 $ — $ — $ 27,487 US Government debt securities $ 29,998 $ — $ (94 ) $ 29,904 Total $ 75,083 $ — $ (168 ) $ 74,915 There were no marketable securities as of December 31, 2020. The weighted average maturity of the Company’s marketable securities as of December 31, 2021 ranges from approximately 0.2 years to 1.1 years. The Company did not record an allowance for credit losses as of December 31, 2021 related to our marketable securities. Further, given the lack of significant change in the credit risk of these investments, the Company did not recognize any other-than-temporary impairment losses.

Property and Equipment, Net

Property and Equipment, Net	12 Months Ended
	Dec. 31, 2021
Property Plant And Equipment [Abstract]
Property and equipment, net	5. Property and equipment, net Property and equipment, net consisted of the following: As of December 31, 2021 2020 Laboratory equipment $ 4,670 $ 3,936 Furniture and fixtures 153 108 Leasehold improvements 263 210 Office equipment 108 108 Construction in progress 1,606 5 6,800 4,367 Less accumulated depreciation (2,661 ) (1,692 ) $ 4,139 $ 2,675 Depreciation expense was $1.0 million and $0.9 million for the years ended December 31, 2021 and 2020, respectively.

Accrued and Other Current Liabi

Accrued and Other Current Liabilities	12 Months Ended
	Dec. 31, 2021
Payables And Accruals [Abstract]
Accrued and other current liabilities	6. Accrued and other current liabilities Accrued and other current liabilities consisted of the following: As of December 31, 2021 2020 Accrued employee compensation costs $ 5,383 $ 4,123 Accrued professional 523 593 Accrued research and development costs 6,801 3,689 Current portion of operating lease liabilities 1,507 1,066 Other current liabilities 540 459 $ 14,754 $ 9,930

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2021
Commitments And Contingencies Disclosure [Abstract]
Commitments and contingencies	7. In August 2018, the Company entered into an agreement to lease approximately 23,000 square feet of space for a term of three years. Lease terms are triple net lease commencing at $0.9 million per year, then with 3% annual base rent increases plus operating expenses, real estate taxes, utilities and janitorial fees. The lease commencement date was December 10, 2018. In September 2021, the Company entered into an agreement to extend the initial term of the 23,000 square foot lease for a period of three years commencing on December 15, 2021 and ending December 31, 2024. In addition, this lease provides for the lease of an additional 15,000 square feet of rentable space beginning in April 2022 and ending on December 31, 2024. The Company recognized a right-of-use asset and operating lease liability of $3.5 In December 2018, the Company entered into an agreement to lease 2,485 square feet of space for an initial term of three years. The lease includes one renewal option for an additional two years, however, any time after the initial term the landlord may relocate the Company from the premises to a space reasonably comparable in size and utility. As the Company does not have the right to control the use of the identified asset after the initial term, the renewal option was excluded from the lease liability calculation. Lease terms commence at $0.2 million per annum, with 2.5% annual base rent increases plus operating expenses, real estate taxes, utilities and janitorial fees. The lease commencement date was May 1, 2019. In June 2021, the Company amended the agreement to extend the initial term of the 2,485 square foot lease for a period of three years commencing May 1, 2022 and ending April 30, 2025. In addition, the amendment provided for the lease of an additional 2,357 square feet of rentable space beginning on July 6, 2021 and ending on April 30, 2025. The amended lease provides the Company with the option to extend the term of the lease for an additional two years. The Company recognized a right-of-use asset and operating lease liabilities of $0.7 million for the extension of the lease to April 30, 2025 and a right-of-use asset and operating lease liabilities of $0.8 million for the additional 2,357 square feet of rentable space. Future minimum lease payments under non-cancellable leases as of December 31, 2021, including leases entered into where access has yet to be granted, are as follows (in thousands): 2022 2,124 2023 2,532 2024 2,608 2025 173 Total lease payments $ 7,437 Less imputed interest (462 ) Present value of lease liabilities $ 6,975 Lease balances as of December 31, 2021 and December 31, 2020 are as follows (in thousands): As of December 31, 2021 2020 Operating right-of-use assets $ 4,939 $ 1,115 Current Portion of operating lease liabilities $ 1,507 $ 1,066 Non-current portion of operating lease liabilities 3,532 80 Total operating lease liabilities $ 5,039 $ 1,146 The weighted average remaining lease term and weighted average discount rate of our operating leases as of December 31, 2021 are as follows: Weighted average remaining lease term in years 3.1 Weighted average discount rate 4.14 % In accordance with Topic 842, lease expense incurred under operating leases was approximately $1.4 million for the year ended December 31, 2021, and $1.1 million for the year ended December 31, 2020. Consulting Agreement In October 2014, the Company entered into a consulting agreement with a member of the Company’s board of directors, who is also an employee of Cold Spring Harbor Laboratory (“CSHL”), to provide consulting services related to scientific research related to the development of antisense-based drugs, therapies, diagnostic and research tools, products, services and intellectual property. The Company recognized expenses of $0.02 million for the year ended December 31, 2020. The initial term of this agreement was five years and the parties mutually agreed not to extend the consulting agreement in April 2020. Scientific Advisory Board Agreement In June 2020, the Company entered into a scientific advisory board agreement with a member of the Company’s board of directors, who is also an employee of CSHL, to provide scientific advisory services related to the Company’s Targeted Augmentation of Nuclear Gene Output (“TANGO”) antisense oligonucleotide technology and other antisense oligonucleotide technologies, as well as current and future therapeutic targets and programs. Following the expiration of the initial scientific agreement in June 2021, the parties entered into a subsequent scientific board agreement. The Company recognized expense of $0.05 million each for the years ended December 31, 2021 and 2020 for such scientific advisory services. The term of this agreement is 12 months. License and research agreements In July 2015, the Company entered into a worldwide license agreement, or the CSHL Agreement, with CSHL, with respect to TANGO patents. Under the CSHL Agreement, the Company receives an exclusive (except with respect to certain government rights and non-exclusive licenses), worldwide license under certain patents and applications relating to TANGO. The CSHL Agreement obligates the Company to make payments that are contingent upon certain milestones being achieved. The Company is also required to pay royalties, tiered based on the scope of patent coverage for each licensed product, ranging from a low-single digit percentage to a mid-single digit percentage on annual net sales. These royalty obligations apply on a licensed product-by-licensed product and country-by-country basis until the latest of (i) the expiration of the last valid claim of a CSHL patent covering the applicable licensed product or (ii) the expiration of any regulatory exclusivity for the applicable licensed product. In addition, if the Company sublicenses the rights under the CSHL Agreement, the Company is required to pay a maximum of twenty percent of the sublicense revenue to CSHL, which may be reduced to a mid-teens or a mid-single digit percentage upon achievement of certain clinical milestones for the applicable licensed product. Finally, the Company is required to pay an annual license maintenance fee of $0.01 million, which amount is creditable against any owed royalty or milestone payments. The maximum aggregate potential milestone payments payable total approximately $0.9 million. Additionally, certain licenses under the CSHL Agreement require the Company to reimburse CSHL for certain past and ongoing patent related expenses, however there were no expenses related to these reimbursable patent costs during the years ended December 31, 2021 and 2020. In April 2016, the Company entered into an exclusive, worldwide license agreement with the University of Southampton, or the Southampton Agreement, whereby the Company acquired rights to foundational technologies related to the Company’s TANGO technology. Under the Southampton Agreement, the Company receives an exclusive, worldwide license under certain licensed patents and applications relating to TANGO. Under the Southampton Agreement, the Company may be obligated to make additional payments that are contingent upon certain milestones being achieved, as well as royalties on future product sales. These royalty obligations survive until the latest of (i) the expiration of the last valid claim of a licensed patent covering a subject product or (ii) the expiration of any regulatory exclusivity for the subject product in a country. In addition, if the Company sublicenses its rights under the Southampton Agreement, the Company is required to pay a mid-single digit percentage of the sublicense revenue to the University of Southampton. The maximum aggregate potential milestone payments payable by the Company total approximately 0.4 million pounds sterling (approximately $0.5 million as of December 31, 2021). As of December 31, 2021, and 2020, the Company has recorded no liabilities under the Southampton Agreement. For the year ended December 31, 2021 these expenses were $0.12 million compared to $0.09 million for the year ended December 31, 2020. Additionally, certain licenses under the Southampton Agreement require the Company to reimburse the University of Southampton for certain past and ongoing patent related expenses. (see note 12 for payments to University of Southampton) Litigation The Company may periodically become subject to legal proceedings and claims arising in connection with ongoing business activities, including claims or disputes related to patents that have been issued or that are pending in the field of research on which it is focused. As of December 31, 2021, the Company had no legal proceedings to which it was a party or to which its property was subject.

Share-Based Compensation

Share-Based Compensation	12 Months Ended
	Dec. 31, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Share-Based Compensation	8. Share-Based Compensation In June 2019, the Company’s board of directors and stockholders approved the 2019 Equity Incentive Plan (the “2019 Plan”) which became effective on June 17, 2019 and replaced the Company’s 2014 Equity Incentive Plan (the “2014 Plan”). In addition to the shares of common stock reserved for future issuance under the 2014 Plan that were added to the 2019 Plan upon its effective date, the Company initially reserved 2,200,000 shares of common stock for issuance under the 2019 Plan. The number of shares reserved for issuance under the Company’s 2019 Plan will increase automatically on January 1 of each of 2020 through 2029 by the number of shares equal to 4% of the aggregate number of outstanding shares of the Company’s common stock as of the immediately preceding December 31, or a lesser number as may be determined by the Company’s board of directors. As of December 31, 2021 there were no shares available for future issuance under the 2014 Plan and 2,372,006 shares were available under the 2019 Plan. During the years ended December 31, 2021 and December 31, 2020, the Company granted options to purchase 1,311,897 and 1,231,532 shares of common stock to certain of its employees, and directors, respectively. The options vest up to four years except for certain options granted to members of our board of directors which vest over one or three years and are exercisable at a per share price equal to the fair value of the common stock on the grant date. A summary of stock option activity for awards is presented below: Number of shares Weighted average exercise price Weighted average remaining contractual life (years) Aggregate intrinsic value ( 1) Outstanding as of December 31, 2020 4,454,422 $ 8.80 8.0 $ 236,685 Granted 1,311,897 53.93 Exercised (287,566 ) 2.70 Forfeited (41,973 ) 40.12 Expired (1,476 ) 28.73 Outstanding as of December 31, 2021 5,435,304 $ 19.77 8.0 $ 64,981 Exercisable as of December 31, 2021 3,103,635 $ 9.74 6.9 $ 52,003 (1) The aggregate intrinsic value is calculated as the difference between the exercise price of the underlying options and the estimated fair value of the common stock for the options that were in the money at December 31, 2021 and 2020. The weighted average grant date fair value per share of stock options granted during the years ended December 31, 2021 and 2020 was $34.07 and $14.75, respectively. The aggregate grant date fair value of stock options granted during the years ended December 31, 2021 and 2020 was approximately $44.7 million and $18.2 million, respectively. The aggregate intrinsic value of stock options exercised during the year ended December 31, 2021 and 2020 was approximately $9.9 million and $27.3 million, respectively. Stock-based compensation and stock options The Company recorded stock-based compensation expense of $16.5 million and $5.8 million during the years ended December 31, 2021 and 2020, respectively. As of December 31, 2021, there was $45.0 million of unrecognized compensation cost related to unvested stock-based compensation arrangements granted under the 2014 and the 2019 Plans. The compensation is expected to be recognized over a weighted average period of 2.8 years as of December 31, 2021. Stock-based compensation expense recorded as research and development and general and administrative expenses in the accompanying consolidated statements of operations and comprehensive loss is as follows: Year ended December 31, 2021 2020 Research and development $ 6,215 $ 1,875 General and administrative 10,235 3,893 $ 16,450 $ 5,768 The Company uses the Black-Scholes option pricing model to calculate the grant-date fair value of an award. The fair values of the options granted to employees and directors were calculated using the following assumptions for the years ended December 31, 2021 and 2020: Year ended December 31, 2021 2020 Risk-free interest rate 0.78-1.51% 0.38-1.48% Expected dividend yield 0% 0 % Expected life 5.5-6.25 years 5.5-6.25 years Expected volatility 70-73% 70% 2019 Employee stock purchase plan In June 2019, the Company adopted the 2019 Employee Stock Purchase Plan (“ESPP”), which became effective on June 18, 2019. The Company initially reserved 315,000 shares of common stock for sale under the ESPP. At December 31, 2021, the Company had 634,580 shares available for issuance under the plan. The average grant date fair value per share under the plan was $46.08 for 2021. The total ESPP stock-based compensation expense for the year ended December 31, 2021 was $0.3 million and for the year ended December 31, 2020 was $0.3 million. The number of shares reserved for issuance under the ESPP will increase automatically on January 1st of each of the first ten calendar years following the first offering date by the number of shares equal to the lesser of 1% of the total outstanding shares of the Company’s common stock as of the immediately preceding December 31 or a lower amount determined by the Company’s board of directors. The aggregate number of shares issued over the term of the ESPP will not exceed 3,150,000 shares of the Company’s common stock.

Net Loss Per Share Attributable

Net Loss Per Share Attributable to Common Stockholders	12 Months Ended
	Dec. 31, 2021
Earnings Per Share [Abstract]
Net loss per share attributable to common stockholders	9. Net loss per share attributable to common stockholders The following table summarizes the computation of basic and diluted net loss per share attributable to common stockholders of the Company: Year ended December 31, 2021 2020 Numerator: Net loss $ (85,805 ) $ (52,243 ) Denominator: Weighted-average number of common shares, basic and diluted 36,739,269 33,488,456 Net loss per share, basic and diluted $ (2.34 ) $ (1.56 ) The Company’s potential dilutive securities, which include common stock options and ESPP purchase rights, have been excluded from the computation of diluted net loss per share as the effect would be anti-dilutive. Therefore, the weighted average number of common shares outstanding used to calculate both basic and diluted net loss per share is the same. The Company excluded the following potential common shares, presented based on amounts outstanding at period end, from the computation of diluted net loss per share for the periods indicated because including them would have had an anti-dilutive effect: December 31, 2021 2020 Outstanding options to purchase common stock 5,435,304 4,454,424

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Income taxes	10. Income taxes A reconciliation of the expected income tax expense (benefit) computed using the federal statutory income tax rate the Company’s effective income tax rate is as follows: Year ended December 31, 2021 2020 Expected income tax benefit at the federal statutory rate 21.0 % 21.0 % State income taxes, net of federal benefit 7.9 8.3 Non-deductible items 0.4 6.2 Research and development credit, net 4.1 1.2 Other 0.0 0.2 Change in valuation allowance (33.4 ) (36.9 ) Total 0.0 % 0.0 % The principal components of the Company’s deferred tax assets and liabilities consist of the following: As of December 31, 2021 2020 Deferred tax assets: Federal and state net operating loss carryforwards $ 52,231 $ 32,097 Research and development tax credits 7,726 2,816 Other 6,075 2,293 Gross deferred tax assets 66,032 37,206 Less: valuation allowance (66,032 ) (37,206 ) Net deferred tax assets $ — $ — As of December 31, 2021 and 2020, the Company had federal net operating loss carryforwards of $191.1 million and $116.9 million, respectively, which may be available to reduce future taxable income, and expire at various dates beginning in 2034, for those net operating loss carryforwards generated prior to 2018. Net operating losses generated in 2018 and beyond have no expiration. As of December 31, 2021 and 2020, the Company had state net operating loss carry forwards of $191.4 million and $118.8 million, respectively, which may be available to reduce future taxable income and expire at various dates beginning in 2034. In addition, at December 31, 2021 and 2020, the Company had federal research and development tax credit carryforwards of $5.4 million and $2.0 million, respectively, and state research and development tax credit carry forwards of $3.0 million and $1.0 million, respectively. Both federal and state research and development tax credit carry forwards may be available to reduce future tax liabilities and expire at various dates beginning in 2030. In accordance with ASC 740, Accounting for Income Taxes The CARES Act temporarily repealed the 80% taxable income limitation for tax years beginning before January 1, 2021. Federal NOL carry forwards generated from 2018 or later and Federal NOL carryforwards to taxable years beginning after December 31, 2021 will be subject to the 80% limitation. Also, under the CARES Act, federal NOLs arising in 2018, 2019 and 2020 can be carried back 5 years. New legislation or regulation which could affect our tax burden could be enacted by any governmental authority. The Company cannot predict the timing or extent of such tax-related developments which could have a negative impact on our financial results. Additionally, the Company uses its best judgment in attempting to quantify and reserve for these tax obligations. Utilization of the net operating loss carryforwards and research and development tax credit carryforwards may be subject to a substantial annual limitation under Sections 382 and 383 of the Internal Revenue Code of 1986, as amended (the Code) due to ownership changes that have occurred previously or that could occur in the future. These ownership changes may limit the amount of carryforwards that can be utilized annually to offset future taxable income. The Company has not conducted a formal study to assess whether a change of control has occurred or whether there have been multiple changes of control since inception due to the significant complexity and cost associated with such a study. If the Company has experienced a change of control, as defined for purposes of Section 382 and 383 of the Code, at any time since inception, utilization of the net operating loss carryforwards or research and development tax credit carryforwards may be subject to an annual limitation under Section 382 and 383 of the Code, which is determined by first multiplying the value of the Company’s stock at the time of the ownership change by the applicable long-term tax-exempt rate, and then could be subject to additional adjustments, as required. Any limitation may result in expiration of a portion of the net operating loss carryforwards or research and development tax credit carryforwards before utilization. The Company applies ASC 740 related to accounting for uncertainty in income taxes. The Company’s reserves related to income taxes are based on a determination of whether, and how much of, a tax benefit taken by the Company in its tax filings or positions is more likely than not to be realized following resolution of any potential contingencies present related to the tax benefit. At December 31, 2021, and 2020 the Company had no unrecognized tax benefits. Interest and penalty charges, if any, related to unrecognized tax benefits would be classified as income tax expense in the accompanying consolidated statements of operations and comprehensive loss.

Employee Benefits

Employee Benefits	12 Months Ended
	Dec. 31, 2021
Compensation And Retirement Disclosure [Abstract]
Employee benefits	11. Employee benefits In 2016, the Company established a defined-contribution savings plan under Section 401(k) of the Internal Revenue Code (the “401(k) Plan”). The 401(k) Plan covers all employees who meet defined minimum age and service requirements and allows participants to defer a portion of their annual compensation on a pretax basis. On January 1, 2020, the Company began to make matching contributions up to 4% of annual salary for those employees who are participating in the 401(k) Plan. For the year ended December 31, 2021, the Company made matching contributions of $0.5 million and for the year ended December 31, 2020, the Company made matching contributions of $0.2 million.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2021
Subsequent Events [Abstract]
Subsequent events	12. Subsequent events In January 2022, the Company entered into a license and collaboration agreement with Acadia Pharmaceuticals Inc. (“Acadia”) for the discovery, development and commercialization of novel RNA-based medicines for the treatment of severe and rare genetic neurodevelopmental diseases of the central nervous system (the “CNS”). The agreement focuses on the targets SYNGAP1, MECP2 (Rett syndrome), and an undisclosed neurodevelopmental target of mutual interest. In connection with each target, the Company will collaborate with Acadia to identify potential treatments for further development and commercialization as licensed products. With respect to SYNGAP1, the Company has agreed with Acadia to co-develop and co-commercialize licensed products for such target globally, and in connection therewith the Company granted to Acadia worldwide, co-exclusive (with the Company) licenses for such licensed products. With respect to MECP2 and the neurodevelopmental target, the Company granted to Acadia worldwide, exclusive licenses to develop and commercialize licensed products for such targets. Pursuant to the terms of the agreement, the Company received an upfront payment of $60 million from Acadia. Acadia agreed to fund the research to identify potential licensed products for MECP2 and the neurodevelopmental target, and the Company will equally fund with Acadia the research to identify potential licensed products for SYNGAP1. The Company is eligible to receive up to $907.5 million in potential total milestone payments based upon the achievement of certain development, regulatory, first commercial sales and sales milestone events across the programs for the three targets, assuming each milestone were achieved at least once. With respect to licensed products for MECP2 and the neurodevelopmental target, the Company is also eligible to receive tiered royalties at percentages ranging from the mid-single digits to the mid-teens on future net sales by Acadia of licensed products worldwide. Royalties payable under the agreement are subject to standard royalty reductions. For SYNGAP1 licensed products that the Company is co-developing and co-commercializing, the Company will be responsible for 50% of the development and commercialization costs and will receive 50% of the profits from global commercialization. As a result of and related to the out-license of SYNGAP1, the Company is obligated to make payments to the University of Southampton under certain licensed patents and applications relating to TANGO. Since December 31, 2021, the Company sold approximately 403,000 shares of our common stock and received $7.5 million after deducting commissions related to the Sales Agreement. The Company has evaluated subsequent events through the issuance date of these consolidated financial statements. The Company has concluded that no events or transactions other than those described above have occurred that require disclosure in the accompanying consolidated financial statements.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies and Recent Accounting Pronouncements (Policies)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation and Consolidation	Basis of presentation and consolidation The accompanying consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (GAAP), and include the accounts of Stoke Therapeutics, Inc. and its wholly-owned subsidiary. Any reference in these notes to applicable guidance is meant to refer to GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Update (“ASU”) of the Financial Accounting Standards Board (“FASB”). All intercompany transactions between and among the Company and its’ consolidated subsidiary have been eliminated.
Use of Estimates	Use of estimates The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, equity, expenses and disclosure of contingent assets and liabilities. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Actual results could differ from those estimates.
Cash and Cash Equivalents	Cash and cash equivalents The Company considers all highly liquid investments with an original maturity of three months or less at the date of purchase to be cash equivalents. The Company deposits its cash in checking, sweep and money market accounts.
Restricted Cash	Restricted cash At December 31, 2021, restricted cash consisted of money market accounts collateralizing letters of credit issued as security deposits in connection with the Company’s leases of its corporate facilities. The following table reconciles cash and cash equivalents and restricted cash per the consolidated balance sheets to the statement of cash flows: As of December 31, 2021 2020 Cash and cash equivalents $ 144,895 $ 287,308 Restricted cash 569 205 $ 145,464 $ 287,513
Marketable Securities	Marketable Securities Marketable securities consist of government securities and obligations, corporate bonds and commercial paper with original maturities of more than 90 days. Investments are classified as available-for-sale and are recorded on the balance sheet at fair value with unrealized gains or losses reported as a separate component of other comprehensive income/(loss). Management determines the appropriate classification of its investments at the time of purchase and reevaluates such determination at each balance sheet date.
Concentration of Credit Risk	Concentration of credit risk Financial instruments that potentially expose the Company to concentrations of credit risk primarily consist of cash and cash equivalents. The Company maintains its cash and cash equivalents at an accredited financial institution in amounts that exceed federally insured limits. The Company does not believe that it is subject to unusual credit risk beyond the normal credit risk associated with commercial banking relationships.
Fair Value of Financial Instruments	Fair value of financial instruments ASC Topic 820, Fair Value Measurement Level 1—Quoted market prices in active markets for identical assets or liabilities. Level 2—Inputs other than Level 1 inputs that are either directly or indirectly observable, such as quoted market prices, interest rates and yield curves. Level 3—Unobservable inputs developed using estimates of assumptions developed by the Company, which reflect those that a market participant would use. To the extent the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair values 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.
Deferred Offering Costs	Deferred offering costs The Company capitalizes certain legal, professional accounting and other third-party fees that are directly associated with in-process equity financings as deferred offering costs until such financings are consummated. After consummation of the equity financing, these costs are recorded in the consolidated statement of stockholders’ equity as a reduction of additional paid-in capital.
Property and Equipment	Property and equipment Property and equipment are recorded at cost less accumulated depreciation. Cost includes the acquisition costs and all costs necessary to bring the asset to the location and working condition necessary for its intended use. Depreciation expense is recognized using the straight-line method over the estimated useful life of each asset. Upon retirement or sale, the cost of assets disposed of and the related accumulated depreciation are removed from the accounts and any resulting gain or loss is included in the accompanying consolidated statements of operations and comprehensive loss. Expenditures for normal, recurring or periodic repairs and maintenance related to property and equipment are charged to expense as incurred. The cost for planned major maintenance activities, including the related acquisition or construction of assets, is capitalized if it will result in future economic benefits. Estimated useful lives for property and equipment are as follows: Property and equipment Estimated useful life Computer and office equipment 3-5 years Laboratory equipment and Furniture and fixtures 5-7 years Leasehold improvements Lesser of estimated useful life or remaining lease term
Impairment of Long-Lived Assets	Impairment of long-lived assets The Company reviews the recoverability of its long-lived assets when events or changes in circumstances occur that indicate that the carrying value of the assets may not be recoverable. The assessment of possible impairment is based on the ability to recover the carrying value of the assets from the expected future cash flows (undiscounted and without interest expense) of the related operations. If these cash flows are less than the carrying value of such assets, an impairment loss for the difference between the estimated fair value and carrying value is recorded. There were no impairment losses recognized during the years ended December 31, 2021 and 2020.
Research and Development Costs	Research and development costs Research and development costs are expensed as incurred. Research and development expenses are comprised of costs incurred in performing research and development activities, including salaries and benefits, facilities costs, depreciation, third-party license fees, and costs related to third parties engaged to conduct preclinical research development activities. The Company has entered into various research and development contracts with research institutions and other companies to conduct research on its behalf. These agreements are generally cancellable. The Company records accruals for estimated ongoing research costs. When evaluating the adequacy of the accrued liabilities, the Company analyzes progress of the studies, including the phase or completion of events, invoices received and contracted costs. Significant judgments 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’s historical accrual estimates have not been materially different from the actual costs.
Stock Options	Stock options The Company measures its stock-based awards granted based on the estimated fair values of the awards and recognizes the compensation for employees and nonemployees over the requisite service period. The Company uses the Black-Scholes option-pricing model to estimate the fair value of its stock-based awards. The Company has elected the practical expedient to use the midpoint between vesting date and the contractual term as the expected term for certain awards with service or performance conditions. Stock-based compensation is recognized using the straight-line method. Forfeitures of unvested stock-based awards are accounted for when they occur.
Patent Costs	Patent costs All patent-related costs incurred in connection with filing and prosecuting patent applications are expensed as incurred due to the uncertainty about the recovery of the expenditure. Amounts incurred are classified as general and administrative expenses in the accompanying consolidated statements of operations and comprehensive loss.
Leases	Leases In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842). This standard established a right-of-use model that requires all lessees to recognize right-of-use assets and lease liabilities on their balance sheet that arise from leases as well as provide disclosures with respect to certain qualitative and quantitative information related to a company's leasing arrangements. The Company adopted Topic 842 on January 1, 2020 using the modified retrospective approach and elected to apply the transition method that allows companies to continue applying guidance under the lease standard in effect at that time in the comparative period financial statements and recognize a cumulative-effect adjustment to the balance sheet on the date of adoption. The Company has also elected the package of practical expedients to not reassess its prior conclusions about lease identification, lease classification and indirect costs and to not separate lease and non-lease components. Upon adoption of Topic 842 on January 1, 2020, the Company recorded right-of-use assets of $2.2 million, operating lease liabilities of $2.2 million and the elimination of deferred rent of $0.03 million. Adoption of the standard did not result in the Company recording a cumulative effect adjustment. The Company determines whether an arrangement is a lease at inception. The Company accounts for a lease when it has the right to control the leased asset for a period of time while obtaining substantially all of the assets’ economic benefits. The Company determined that it held operating leases for office and laboratory space as of January 1, 2020. Operating lease right-of-use assets and operating lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at the lease commencement date. The discount rate used to determine the present value of the lease payments is the Company’s incremental borrowing rate based on the information available at lease inception, as the Company does not have information to determine the rate implicit in the leases. Lease expense for operating leases is recognized on a straight-line basis over the reasonably assured lease term based on the total lease payments (which include initial direct costs and lease incentives). The expense is included in operating expenses in the consolidated statements of operations and comprehensive loss. The Company’s lease agreements also contain variable payments, primarily maintenance-related costs, which are expensed as incurred and not included in the measurement of the right-of-use assets and lease liabilities.
Income Taxes	Income taxes The Company accounts for income taxes using the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the estimated future tax consequences attributable to temporary differences between the consolidated financial statement carrying amounts of existing assets and liabilities and their respective tax base. Deferred tax assets and liabilities are determined on the basis of the differences between the consolidated financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the temporary differences are expected to be settled or recovered. Changes in deferred tax assets and liabilities are recorded in the provision for income taxes. The Company assesses the likelihood that its deferred tax assets will be recovered from future taxable income and, to the extent it believes, based upon the weight of available evidence that it is more likely than not that all or a portion of the deferred tax assets will not be realized, a valuation allowance is established through a charge to income tax expense. Potential for recovery of deferred tax assets is evaluated by estimating the future taxable profits expected and considering prudent and feasible tax planning strategies. At December 31, 2021 and 2020, the Company has recorded a full valuation allowance. Reserves are provided for tax benefits for which realization is uncertain. Such benefits are only recognized when the underlying tax position is considered more-likely-than-not to be sustained on examination by a taxing authority, assuming they possess full knowledge of the position and facts. Interest and penalties related to uncertain tax positions are recognized in the provision of income taxes; however, the Company currently has no interest or penalties related to uncertain income tax benefits. The Tax Cuts and Jobs Act (the TCJA) was enacted on December 22, 2017. The TCJA reduced the U.S. federal corporate tax rate from a top rate of 35% to a flat rate of 21%. The Company continues to monitor for legislative developments, issuance of regulations and technical memorandum to provide further clarification and/or interpretations of the TCJA and will adjust its consolidated financial statements as needed.
Segment and Geographic Information	Segment and geographic information Operating segments are defined as components of an entity about which separate discrete information is available for evaluation by the chief operating decision maker, or decision-making group, in deciding how to allocate resources and in assessing performance. The Company operates in one segment in the United States. The Company’s chief executive officer, as the chief operating decision-maker, manages and allocates resources to the operations of the Company on a total company basis using consolidated financial information.
Emerging Growth Company and Smaller Reporting Company Status	Emerging growth company and smaller reporting company status The Company is an emerging growth company, as defined in the Jumpstart Our Business Startups Act of 2012 (the JOBS Act). Under the JOBS Act, emerging growth companies can delay adopting new or revised accounting standards issued subsequent to the enactment of the JOBS Act, until such time as those standards apply to private companies. The Company has elected to use this extended transition period for complying with new or revised accounting standards that have different effective dates for public and private companies until the earlier of the date that it is (i) no longer an emerging growth company or (ii) affirmatively and irrevocably opt out of the extended transition period provided in the JOBS Act. As a result, the Company’s consolidated financial statements may not be comparable to companies that comply with the new or revised accounting pronouncements as of public company effective dates. The Company will remain an emerging growth company until the earliest of (i) the last day of its first fiscal year (a) in which the Company has total annual gross revenues of at least $1.07 billion or (b) in which the Company is deemed to be a large accelerated filer, which means the market value of the Company’s common stock that is held by non-affiliates exceeds $700.0 million as of the prior June 30 th The Company is also a “smaller reporting company,” meaning that in the event of an initial public offering the market value of its stock held by non-affiliates plus the proposed aggregate amount of gross proceeds to the Company as a result of such offering is less than $700 million and its annual revenue is less than $100 million during the most recently completed fiscal year. The Company may continue to be a smaller reporting company as long as either (i) the market value of its stock held by non-affiliates is less than $250 million or (ii) its annual revenue is less than $100 million during the most recently completed fiscal year and the market value of its stock held by non-affiliates is less than $700 million. If the Company is a smaller reporting company at the time it ceases to be an emerging growth company, the Company may continue to rely on exemptions from certain disclosure requirements that are available to smaller reporting companies. Specifically, as a smaller reporting company, the Company may choose to present only the two most recent fiscal years of audited financial statements in its Annual Report on Form 10-K and, similar to emerging growth companies, smaller reporting companies have reduced disclosure obligations regarding executive compensation.
Recently Issued Accounting Pronouncements	Recently issued accounting pronouncements In July 2017, the FASB issued ASU 2017-11, Earnings Per Share Distinguishing Liabilities from Equity Derivatives and Hedging I. Accounting for Certain Financial Instruments with Down Round Features; II. Replacement of the Indefinite Deferral for Mandatorily Redeemable Financial Instruments of Certain Nonpublic Entities and Certain Mandatorily Redeemable Noncontrolling Interests with a Scope Exception Distinguishing Liabilities from Equity In August 2018, the FASB issued ASU 2018-13, “Fair Value Measurement (Topic 820), Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement”. In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes. The Company adopted this standard on January 1, 2021 and the adoption of this update did not have a material impact on its consolidated financial statements.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies and Recent Accounting Pronouncements (Tables)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Schedule of Cash and Cash Equivalents and Restricted Cash	The following table reconciles cash and cash equivalents and restricted cash per the consolidated balance sheets to the statement of cash flows: As of December 31, 2021 2020 Cash and cash equivalents $ 144,895 $ 287,308 Restricted cash 569 205 $ 145,464 $ 287,513
Schedule of Estimated Useful Lives for Property and Equipment	Estimated useful lives for property and equipment are as follows: Property and equipment Estimated useful life Computer and office equipment 3-5 years Laboratory equipment and Furniture and fixtures 5-7 years Leasehold improvements Lesser of estimated useful life or remaining lease term

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Schedule of Financial Assets Measured at Fair Value on Recurring Basis and Level of Fair Value Hierarchy Utilized	The following tables present information about the Company’s financial assets measured at fair value on a recurring basis and indicate the level of the fair value hierarchy utilized to determine such fair values: Fair value measurements as of December 31, 2021 Level 1 Level 2 Level 3 Total Cash equivalents: Money market funds $ 144,897 $ — $ — $ 144,897 Total $ 144,897 $ — $ — $ 144,897 Marketable Securities: Corporate bonds $ — $ 17,524 $ — $ 17,524 Commercial paper $ — $ 27,487 $ — $ 27,487 US Government debt securities $ — $ 29,904 $ — $ 29,904 Total $ — $ 74,915 $ — $ 74,915 Fair value measurements as of December 31, 2020 Level 1 Level 2 Level 3 Total Cash equivalents: Money market funds $ 287,308 $ — $ — $ 287,308 Total $ 287,308 $ — $ — $ 287,308 Marketable Securities: Corporate bonds $ — $ — $ — $ — Commercial paper $ — $ — $ — $ — US Government debt securities $ — $ — $ — $ — Total $ — $ — $ — $ —

Marketable Securities (Tables)

Marketable Securities (Tables)	12 Months Ended
	Dec. 31, 2021
Investments Debt And Equity Securities [Abstract]
Summary of Marketable Securities	The following table summarizes the Company’s marketable securities as of December 31, 2021 (in thousands): December 31, 2021 Amortized Cost Unrealized Gains Unrealized Loss Fair Value Marketable securities: Corporate bonds $ 17,598 $ — $ (74 ) $ 17,524 Commercial paper $ 27,487 $ — $ — $ 27,487 US Government debt securities $ 29,998 $ — $ (94 ) $ 29,904 Total $ 75,083 $ — $ (168 ) $ 74,915

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	12 Months Ended
	Dec. 31, 2021
Property Plant And Equipment [Abstract]
Summary of Property, and Equipment, Net	Property and equipment, net consisted of the following: As of December 31, 2021 2020 Laboratory equipment $ 4,670 $ 3,936 Furniture and fixtures 153 108 Leasehold improvements 263 210 Office equipment 108 108 Construction in progress 1,606 5 6,800 4,367 Less accumulated depreciation (2,661 ) (1,692 ) $ 4,139 $ 2,675

Accrued and Other Current Lia_2

Accrued and Other Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2021
Payables And Accruals [Abstract]
Schedule of Accrued and Other Current Liabilities	Accrued and other current liabilities consisted of the following: As of December 31, 2021 2020 Accrued employee compensation costs $ 5,383 $ 4,123 Accrued professional 523 593 Accrued research and development costs 6,801 3,689 Current portion of operating lease liabilities 1,507 1,066 Other current liabilities 540 459 $ 14,754 $ 9,930

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2021
Commitments And Contingencies Disclosure [Abstract]
Schedule of Future Minimum Lease Payments Under Non-Cancellable Leases	Future minimum lease payments under non-cancellable leases as of December 31, 2021, including leases entered into where access has yet to be granted, are as follows (in thousands): 2022 2,124 2023 2,532 2024 2,608 2025 173 Total lease payments $ 7,437 Less imputed interest (462 ) Present value of lease liabilities $ 6,975
Summary of Lease Balances	Lease balances as of December 31, 2021 and December 31, 2020 are as follows (in thousands): As of December 31, 2021 2020 Operating right-of-use assets $ 4,939 $ 1,115 Current Portion of operating lease liabilities $ 1,507 $ 1,066 Non-current portion of operating lease liabilities 3,532 80 Total operating lease liabilities $ 5,039 $ 1,146
Summary of Weighted Average Remaining Lease Term and Weighted Average Discount Rate of Operating Leases	The weighted average remaining lease term and weighted average discount rate of our operating leases as of December 31, 2021 are as follows: Weighted average remaining lease term in years 3.1 Weighted average discount rate 4.14 %

Share-Based Compensation (Table

Share-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Stock Option Activity for Awards	A summary of stock option activity for awards is presented below: Number of shares Weighted average exercise price Weighted average remaining contractual life (years) Aggregate intrinsic value ( 1) Outstanding as of December 31, 2020 4,454,422 $ 8.80 8.0 $ 236,685 Granted 1,311,897 53.93 Exercised (287,566 ) 2.70 Forfeited (41,973 ) 40.12 Expired (1,476 ) 28.73 Outstanding as of December 31, 2021 5,435,304 $ 19.77 8.0 $ 64,981 Exercisable as of December 31, 2021 3,103,635 $ 9.74 6.9 $ 52,003
Summary of Stock-based Compensation Expense	Stock-based compensation expense recorded as research and development and general and administrative expenses in the accompanying consolidated statements of operations and comprehensive loss is as follows: Year ended December 31, 2021 2020 Research and development $ 6,215 $ 1,875 General and administrative 10,235 3,893 $ 16,450 $ 5,768
Summary of Fair Values of Options Granted to Employees and Directors	The Company uses the Black-Scholes option pricing model to calculate the grant-date fair value of an award. The fair values of the options granted to employees and directors were calculated using the following assumptions for the years ended December 31, 2021 and 2020: Year ended December 31, 2021 2020 Risk-free interest rate 0.78-1.51% 0.38-1.48% Expected dividend yield 0% 0 % Expected life 5.5-6.25 years 5.5-6.25 years Expected volatility 70-73% 70%

Net Loss Per Share Attributab_2

Net Loss Per Share Attributable to Common Stockholders (Tables)	12 Months Ended
	Dec. 31, 2021
Earnings Per Share [Abstract]
Schedule of Computation of Basic and Diluted Net Loss Per Share Attributable to Common Stockholders	The following table summarizes the computation of basic and diluted net loss per share attributable to common stockholders of the Company: Year ended December 31, 2021 2020 Numerator: Net loss $ (85,805 ) $ (52,243 ) Denominator: Weighted-average number of common shares, basic and diluted 36,739,269 33,488,456 Net loss per share, basic and diluted $ (2.34 ) $ (1.56 )
Schedule of Antidilutive Securities Excluded from Computation of Diluted Net Loss Per Share	The Company excluded the following potential common shares, presented based on amounts outstanding at period end, from the computation of diluted net loss per share for the periods indicated because including them would have had an anti-dilutive effect: December 31, 2021 2020 Outstanding options to purchase common stock 5,435,304 4,454,424

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Reconciliation of Expected Income Tax Expense (Benefit) using Federal Statutory Income Tax Rate to Effective Income Tax Rate	A reconciliation of the expected income tax expense (benefit) computed using the federal statutory income tax rate the Company’s effective income tax rate is as follows: Year ended December 31, 2021 2020 Expected income tax benefit at the federal statutory rate 21.0 % 21.0 % State income taxes, net of federal benefit 7.9 8.3 Non-deductible items 0.4 6.2 Research and development credit, net 4.1 1.2 Other 0.0 0.2 Change in valuation allowance (33.4 ) (36.9 ) Total 0.0 % 0.0 %
Schedule of Deferred Tax Assets and Liabilities	The principal components of the Company’s deferred tax assets and liabilities consist of the following: As of December 31, 2021 2020 Deferred tax assets: Federal and state net operating loss carryforwards $ 52,231 $ 32,097 Research and development tax credits 7,726 2,816 Other 6,075 2,293 Gross deferred tax assets 66,032 37,206 Less: valuation allowance (66,032 ) (37,206 ) Net deferred tax assets $ — $ —

Nature of the Business and Ba_2

Nature of the Business and Basis of Presentation - Additional Information (Details) - USD ($)	Nov. 24, 2020	Jul. 31, 2020	Dec. 31, 2021
Nature Of Business And Basis Of Presentation [Line Items]
Entity incorporation state name			DE
Securities issued in connection with shelf registration			$ 0
Common Stock
Nature Of Business And Basis Of Presentation [Line Items]
Net proceeds from underwritten public offering	$ 104,900,000
Base Prospectus
Nature Of Business And Basis Of Presentation [Line Items]
Maximum aggregate offering price		$ 400,000,000
Sales Agreement Prospectus
Nature Of Business And Basis Of Presentation [Line Items]
Maximum aggregate offering price		$ 150,000,000
Stock issued during period, shares			403,000
Net proceeds from underwritten public offering			$ 7,500,000
Underwritten Public Offering | Common Stock
Nature Of Business And Basis Of Presentation [Line Items]
Stock issued during period, shares	2,875,000
Stock issued, price per share	$ 39
Underwriters' Option | Common Stock
Nature Of Business And Basis Of Presentation [Line Items]
Stock issued during period, shares	375,000

Summary of Significant Accoun_4

Summary of Significant Accounting Policies and Recent Accounting Pronouncements - Schedule of Cash and Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Accounting Policies [Abstract]
Cash and cash equivalents	$ 144,895	$ 287,308
Restricted cash	569	205
Total cash, cash equivalents and restricted cash	$ 145,464	$ 287,513	$ 222,676

Summary of Significant Accoun_5

Summary of Significant Accounting Policies and Recent Accounting Pronouncements - Schedule of Estimated Useful Lives for Property and Equipment (Details)	12 Months Ended
	Dec. 31, 2021
Computer and Office Equipment | Minimum
Property Plant And Equipment [Line Items]
Estimated useful life	3 years
Computer and Office Equipment | Maximum
Property Plant And Equipment [Line Items]
Estimated useful life	5 years
Laboratory Equipment and Furniture and Fixtures | Minimum
Property Plant And Equipment [Line Items]
Estimated useful life	5 years
Laboratory Equipment and Furniture and Fixtures | Maximum
Property Plant And Equipment [Line Items]
Estimated useful life	7 years
Leasehold Improvements
Property Plant And Equipment [Line Items]
Estimated useful life	Lesser of estimated useful life or remaining lease term

Summary of Significant Accoun_6

Summary of Significant Accounting Policies and Recent Accounting Pronouncements - Additional Information (Details)	12 Months Ended
	Dec. 31, 2021USD ($)Segment	Dec. 31, 2020USD ($)	Dec. 31, 2017	Jan. 01, 2020USD ($)	Dec. 31, 2019USD ($)
Accounting Policies [Line Items]
Impairment losses recognized	$ 0	$ 0
Operating lease right-of-use assets	4,939,000	1,115,000
Operating lease liabilities	6,975,000
Cumulative effect adjustment	217,777,000	$ 286,078,000			$ 224,428,000
Unrecognized income tax benefits, interest or penalties	$ 0
Federal corporate tax rate	21.00%	21.00%	35.00%
Number of operating segments | Segment	1
ASU 2016-02
Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted	true
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2020
Operating lease right-of-use assets				$ 2,200,000
Operating lease liabilities				2,200,000
Deferred rent				30,000
ASU 2016-02 | Cumulative Effect, Period of Adoption, Adjustment
Accounting Policies [Line Items]
Cumulative effect adjustment				$ 0
ASU 2017-11
Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted	true
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2020
Change in accounting principle, accounting standards update, immaterial effect	true
ASU 2018-13
Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted	true
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2020
Change in accounting principle, accounting standards update, immaterial effect	true
ASU 2019-12
Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted	true
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2021
Change in accounting principle, accounting standards update, immaterial effect	true

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Financial Assets Measured at Fair Value on Recurring Basis and Level of Fair Value Hierarchy Utilized (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Marketable Securities	$ 74,915	$ 0
Corporate Bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Marketable Securities	17,524
Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Marketable Securities	27,487
US Government Debt Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Marketable Securities	29,904
Fair Value, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash equivalents	144,897	287,308
Total Marketable Securities	74,915
Fair Value, Recurring | Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash equivalents	144,897	287,308
Fair Value, Recurring | Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash equivalents	144,897	287,308
Fair Value, Recurring | Level 1 | Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total cash equivalents	144,897	$ 287,308
Fair Value, Recurring | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Marketable Securities	74,915
Fair Value, Recurring | Corporate Bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Marketable Securities	17,524
Fair Value, Recurring | Corporate Bonds | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Marketable Securities	17,524
Fair Value, Recurring | Commercial Paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Marketable Securities	27,487
Fair Value, Recurring | Commercial Paper | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Marketable Securities	27,487
Fair Value, Recurring | US Government Debt Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Marketable Securities	29,904
Fair Value, Recurring | US Government Debt Securities | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Marketable Securities	$ 29,904

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Fair value assets, transfers to level 3, amount	$ 0	$ 0

Marketable Securities - Summary

Marketable Securities - Summary of Marketable Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Marketable Securities [Line Items]
Marketable Securities, Amortized Cost	$ 75,083
Marketable Securities, Unrealized Loss	(168)
Marketable Securities, Fair Value	74,915	$ 0
Corporate Bonds
Marketable Securities [Line Items]
Marketable Securities, Amortized Cost	17,598
Marketable Securities, Unrealized Loss	(74)
Marketable Securities, Fair Value	17,524
Commercial Paper
Marketable Securities [Line Items]
Marketable Securities, Amortized Cost	27,487
Marketable Securities, Fair Value	27,487
US Government Debt Securities
Marketable Securities [Line Items]
Marketable Securities, Amortized Cost	29,998
Marketable Securities, Unrealized Loss	(94)
Marketable Securities, Fair Value	$ 29,904

Marketable Securities - Additio

Marketable Securities - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Marketable Securities [Line Items]
Marketable securities	$ 74,915	$ 0
Allowance for credit losses	$ 0
Minimum
Marketable Securities [Line Items]
Weighted average maturity marketable securities period	2 months 12 days
Maximum
Marketable Securities [Line Items]
Weighted average maturity marketable securities period	1 year 1 month 6 days

Property and Equipment, Net - S

Property and Equipment, Net - Summary of Property, and Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Property Plant And Equipment [Line Items]
Property, and equipment, gross	$ 6,800	$ 4,367
Less accumulated depreciation	(2,661)	(1,692)
Property, and equipment, net	4,139	2,675
Laboratory Equipment
Property Plant And Equipment [Line Items]
Property, and equipment, gross	4,670	3,936
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Property, and equipment, gross	153	108
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property, and equipment, gross	263	210
Office Equipment
Property Plant And Equipment [Line Items]
Property, and equipment, gross	108	108
Construction in Progress
Property Plant And Equipment [Line Items]
Property, and equipment, gross	$ 1,606	$ 5

Property and Equipment, Net - A

Property and Equipment, Net - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Property Plant And Equipment [Abstract]
Depreciation	$ 974	$ 888

Accrued and Other Current Lia_3

Accrued and Other Current Liabilities - Schedule of Accrued and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Payables And Accruals [Abstract]
Accrued employee compensation costs	$ 5,383	$ 4,123
Accrued professional	523	593
Accrued research and development costs	6,801	3,689
Current portion of operating lease liabilities	1,507	1,066
Other current liabilities	540	459
Total accrued and other current liabilities	$ 14,754	$ 9,930

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details)	1 Months Ended					12 Months Ended
	Sep. 30, 2021USD ($)ft²	Jun. 30, 2021USD ($)ft²	Dec. 31, 2018USD ($)ft²Option	Aug. 31, 2018USD ($)ft²	Jul. 31, 2015	Dec. 31, 2021USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2021GBP (£)	Jan. 01, 2020USD ($)
Commitments And Contingencies [Line Items]
Area of space subject to operating lease | ft²			2,485	23,000
Operating lease term			3 years	3 years
Operating lease cost per year			$ 200,000	$ 900,000
Annual base rent increase percentage for operating lease			2.50%	3.00%
Operating lease commencement date			May 1, 2019	Dec. 10, 2018
Operating lease right-of-use assets						$ 4,939,000	$ 1,115,000
Operating lease liabilities						6,975,000
Number of options to renewal operating lease term | Option			1
Operating lease, renewal term			2 years
Liabilities recorded under agreement						21,088,000	11,847,000
CSHL Agreement
Commitments And Contingencies [Line Items]
Percentage of maximum required payment of sublicense revenue					20.00%
Annual license maintenance fee						10,000
Maximum aggregate potential milestone payments payable						900,000
Expenses related to reimbursable patent costs						0	0
Southampton Agreement
Commitments And Contingencies [Line Items]
Maximum aggregate potential milestone payments payable						500,000		£ 400,000
Expenses related to reimbursable patent costs						120,000	90,000
Liabilities recorded under agreement						$ 0	0
Member of Board of Directors
Commitments And Contingencies [Line Items]
Consulting services expenses							20,000
Consulting services agreement term						5 years
Scientific advisory services expenses						$ 50,000	50,000
Scientific advisory services agreement term						12 months
ASU 2016-02
Commitments And Contingencies [Line Items]
Operating lease right-of-use assets									$ 2,200,000
Operating lease liabilities									$ 2,200,000
Operating leases expense						$ 1,400,000	$ 1,100,000
Lease Commencement on December 15, 2021
Commitments And Contingencies [Line Items]
Area of space subject to operating lease | ft²	23,000
Operating lease term	3 years
Operating lease commencement date	Dec. 15, 2021
Operating lease right-of-use assets	$ 3,500,000
Operating lease liabilities	$ 3,500,000
Operating lease expiration date	Dec. 31, 2024
Lease Commencement on April 2022
Commitments And Contingencies [Line Items]
Area of space subject to operating lease | ft²	15,000
Operating lease right-of-use assets	$ 0
Operating lease liabilities	$ 0
Operating lease expiration date	Dec. 31, 2024
Operating lease commencement month and year	2022-04
Lease Extension End Date April 30, 2025
Commitments And Contingencies [Line Items]
Area of space subject to operating lease | ft²		2,485
Operating lease term		3 years
Operating lease commencement date		May 1, 2022
Operating lease right-of-use assets		$ 700,000
Operating lease liabilities		$ 700,000
Operating lease expiration date		Apr. 30, 2025
Operating lease, renewal term		2 years
Area of additional space subject to operating lease | ft²		2,357
Additional operating lease commencement date		Jul. 6, 2021
Additional operating lease expiration date		Apr. 30, 2025
Additional operating lease, right-of-use asset		$ 800,000
Additional operating lease, liabilities		$ 800,000
Operating lease, option to extend		The amended lease provides the Company with the option to extend the term of the lease for an additional two years.
Operating lease, existence of option to extend [true false]		true

Commitments and Contingencies_2

Commitments and Contingencies - Schedule of Future Minimum Lease Payments Under Non-Cancellable Leases (Details) $ in Thousands	Dec. 31, 2021USD ($)
Future minimum lease payments under non-cancellable leases
2022	$ 2,124
2023	2,532
2024	2,608
2025	173
Total lease payments	7,437
Less imputed interest	(462)
Present value of lease liabilities	$ 6,975

Commitments and Contingencies_3

Commitments and Contingencies - Summary of Lease Balances (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Commitments And Contingencies Disclosure [Abstract]
Operating lease right-of-use assets	$ 4,939	$ 1,115
Current portion of operating lease liabilities	$ 1,507	$ 1,066
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:AccountsPayableAndOtherAccruedLiabilitiesCurrent	us-gaap:AccountsPayableAndOtherAccruedLiabilitiesCurrent
Non-current portion of operating lease liabilities	$ 3,532	$ 80
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Long term liabilities	Long term liabilities
Total operating lease liabilities	$ 5,039	$ 1,146

Commitments and Contingencies_4

Commitments and Contingencies - Summary of Weighted Average Remaining Lease Term and Weighted Average Discount Rate of Operating Leases (Details)	Dec. 31, 2021
Commitments And Contingencies Disclosure [Abstract]
Weighted average remaining lease term in years	3 years 1 month 6 days
Weighted average discount rate	4.14%

Share-Based Compensation - Addi

Share-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	12 Months Ended
	Jun. 30, 2019	Dec. 31, 2021	Dec. 31, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Option granted to purchase shares		1,311,897	1,231,532
Weighted average grant date fair value per share of stock options granted		$ 34.07	$ 14.75
Aggregate grant date fair value of stock options granted		$ 44,700	$ 18,200
Aggregate intrinsic value of stock options exercised		9,900	27,300
Stock based compensation expense		16,450	5,768
Unrecognized compensation cost		$ 45,000
Expected weighted average period		2 years 9 months 18 days
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options vest period		4 years
Member of Board of Directors | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options vest period		3 years
Member of Board of Directors | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options vest period		1 year
2019 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares of common stock reserved for issuance	2,200,000
Percentage of increase in reserved common shares	4.00%
Number of common shares available for future issuance		2,372,006
2014 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of common shares available for future issuance		0
2019 ESPP
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares of common stock reserved for issuance	315,000
Number of common shares available for future issuance		634,580
Weighted average grant date fair value per share of stock options granted		$ 46.08
Stock based compensation expense		$ 300	$ 300
2019 ESPP | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares of common stock reserved for issuance	3,150,000
Percentage of increase in reserved common shares	1.00%

Share-Based Compensation - Summ

Share-Based Compensation - Summary of Stock Option Activity for Awards (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of shares, Outstanding balance		4,454,422
Number of shares, Granted		1,311,897	1,231,532
Number of shares, Exercised		(287,566)
Number of shares, Forfeited		(41,973)
Number of shares, Expired		(1,476)
Number of shares, Outstanding balance		5,435,304	4,454,422
Number of shares, Exercisable as of December 31, 2021		3,103,635
Weighted average exercise price, Outstanding balance		$ 8.80
Weighted average exercise price, Granted		53.93
Weighted average exercise price, Exercised		2.70
Weighted average exercise price, Forfeited		40.12
Weighted average exercise price, Expired		28.73
Weighted average exercise price, Outstanding balance		19.77	$ 8.80
Weighted average exercise price, Exercisable as of December 31, 2021		$ 9.74
Weighted average remaining contractual life, Outstanding		8 years	8 years
Weighted average remaining contractual life, Exercisable		6 years 10 months 24 days
Aggregate intrinsic value, Outstanding value	[1]	$ 64,981	$ 236,685
Aggregate intrinsic value, Exercisable as of December 31, 2021	[1]	$ 52,003
[1]	The aggregate intrinsic value is calculated as the difference between the exercise price of the underlying options and the estimated fair value of the common stock for the options that were in the money at December 31, 2021 and 2020.

Share-Based Compensation - Su_2

Share-Based Compensation - Summary of Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock based compensation expense	$ 16,450	$ 5,768
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock based compensation expense	6,215	1,875
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock based compensation expense	$ 10,235	$ 3,893

Share-Based Compensation - Su_3

Share-Based Compensation - Summary of Fair Values of Options Granted to Employees and Directors (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate, minimum	0.78%	0.38%
Risk-free interest rate, maximum	1.51%	1.48%
Expected dividend yield	0.00%	0.00%
Expected volatility, minimum	70.00%
Expected volatility		70.00%
Expected volatility, maximum	73.00%
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected life	5 years 6 months	5 years 6 months
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected life	6 years 3 months	6 years 3 months

Net Loss Per Share Attributab_3

Net Loss Per Share Attributable to Common Stockholders - Schedule of Computation of Basic and Diluted Net Loss Per Share Attributable to Common Stockholders (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Numerator:
Net loss	$ (85,805)	$ (52,243)
Denominator:
Weighted-average number of common shares, basic and diluted	36,739,269	33,488,456
Net loss per share, basic and diluted	$ (2.34)	$ (1.56)

Net Loss Per Share Attributab_4

Net Loss Per Share Attributable to Common Stockholders - Schedule of Antidilutive Securities Excluded from Computation of Diluted Net Loss Per Share (Details) - shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Outstanding Options to Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share, amount	5,435,304	4,454,424

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Income Taxes [Line Items]
Unrecognized tax benefits	$ 0	$ 0
Valuation allowance	66,032,000	37,206,000
Change in valuation allowance	$ 28,800,000	19,300,000
Percentage of taxable income, limitation repealed under CARES act	80.00%
Percentage of federal NOL carry forwards subject to limitation under CARES act	80.00%
Federal NOL carry back period under CARES act	5 years
Federal
Income Taxes [Line Items]
Operating loss carryforwards	$ 191,100,000	$ 116,900,000
Operating loss carryforwards, expiration beginning year	2034	2034
Federal | Research and Development Tax Credit
Income Taxes [Line Items]
Tax credit carryforwards	$ 5,400,000	$ 2,000,000
Tax credit carryforwards, expiration beginning year	2030	2030
State
Income Taxes [Line Items]
Operating loss carryforwards	$ 191,400,000	$ 118,800,000
Operating loss carryforwards, expiration beginning year	2034	2034
State | Research and Development Tax Credit
Income Taxes [Line Items]
Tax credit carryforwards	$ 3,000,000	$ 1,000,000
Tax credit carryforwards, expiration beginning year	2030	2030

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Expected Income Tax Expense (Benefit) using Federal Statutory Income Tax Rate to Effective Income Tax Rate (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Expected income tax benefit at the federal statutory rate	21.00%	21.00%	35.00%
State income taxes, net of federal benefit	7.90%	8.30%
Non-deductible items	0.40%	6.20%
Research and development credit, net	4.10%	1.20%
Other	0.00%	0.20%
Change in valuation allowance	(33.40%)	(36.90%)
Total	0.00%	0.00%

Income Taxes - Schedule of Defe

Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Federal and state net operating loss carryforwards	$ 52,231	$ 32,097
Research and development tax credits	7,726	2,816
Other	6,075	2,293
Gross deferred tax assets	66,032	37,206
Less: valuation allowance	$ (66,032)	$ (37,206)

Employee Benefits - Additional

Employee Benefits - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Defined Contribution Plan Disclosure [Line Items]
Contributions to 401(k) Plan	$ 0.5	$ 0.2
Maximum
Defined Contribution Plan Disclosure [Line Items]
Maximum matching contribution percentage of employees salary	4.00%

Subsequent Events - Additional

Subsequent Events - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Jan. 31, 2022
Sales Agreement Prospectus
Subsequent Event [Line Items]
Issuance of common stock, Shares	403,000
Net proceeds from underwritten public offering	$ 7.5
Subsequent Event | Acadia Pharmaceuticals Inc.
Subsequent Event [Line Items]
Upfront Payment received		$ 60
Potential milestone payments receivable		$ 907.5