Applied Molecular Transport (AMTI) 10-K 24 Feb 22 2021 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Feb. 17, 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	APPLIED MOLECULAR TRANSPORT INC.
Entity Central Index Key	0001801777
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Interactive Data Current	Yes
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Well-known Seasoned Issuer	No
Entity Public Float			$ 947,543,802
Entity Shell Company	false
Entity Small Business	false
Entity Emerging Growth Company	false
Entity File Number	001-39306
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	81-4481426
Entity Address, Address Line One	450 East Jamie Court
Entity Address, City or Town	South San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94080
City Area Code	650
Local Phone Number	392-0420
Document Annual Report	true
Document Transition Report	false
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Trading Symbol	AMTI
Security Exchange Name	NASDAQ
Entity Common Stock Shares Outstanding		38,653,392
ICFR Auditor Attestation Flag	true
Auditor Name	Deloitte & Touche LLP
Auditor Firm ID	34
Auditor Location	San Francisco, California
Documents Incorporated by Reference	DOCUMENTS INCORPORATED BY REFERENCE Certain sections of the Registrant’s definitive Proxy Statement to be filed in connection with the Registrant’s 2022 Annual Meeting of Stockholders are incorporated by reference into Part III of this Annual Report on Form 10-K where indicated. Such definitive Proxy Statement will be filed with the Securities and Exchange Commission pursuant to Regulation 14A within 120 of the Registrant’s fiscal year ended December 31, 2021.

Balance Sheets

Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 159,821	$ 5,843
Short-term investments		124,026
Prepaid expenses	6,685	1,311
Other current assets	594	321
Total current assets	167,100	131,501
Property and equipment, net	6,998	8,447
Operating lease ROU assets, net	38,142
Finance lease ROU assets, net	652
Restricted cash	1,025	108
Other assets	121	127
Total assets	214,038	140,183
Current liabilities:
Accounts payable	2,211	3,174
Accrued expenses	8,226	4,173
Lease liabilities, operating lease - current	3,584
Lease liabilities, finance lease - current	237
Deferred rent, current		83
Capital lease obligations, current		232
Total current liabilities	14,258	7,662
Lease liabilities, operating lease	35,785
Lease liabilities, finance lease	167
Other liabilities	241
Deferred rent		444
Capital lease obligations		404
Total liabilities	50,451	8,510
Commitments and contingencies (Note 7)
Stockholders’ equity:
Common stock, $0.0001 par value, 450,000,000 shares authorized as of December 31, 2021 and 2020; 38,619,957 and 35,121,360 shares issued and outstanding as of December 31, 2021 and 2020, respectively	4	4
Additional paid-in capital	403,228	271,000
Accumulated other comprehensive income		27
Accumulated deficit	(239,645)	(139,358)
Total stockholders’ equity	163,587	131,673
Total liabilities and stockholders’ equity	$ 214,038	$ 140,183

Balance Sheets (Parenthetical)

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	450,000,000	450,000,000
Common stock, shares issued	38,619,957	35,121,360
Common stock, shares outstanding	38,619,957	35,121,360

Statements of Operations and Co

Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating expenses:
Research and development	$ 71,448	$ 53,936	$ 24,316
General and administrative	29,341	12,746	3,974
Total operating expenses	100,789	66,682	28,290
Loss from operations	(100,789)	(66,682)	(28,290)
Interest income, net	626	229	273
Other expense, net	(124)	(111)	(26)
Net loss	$ (100,287)	$ (66,564)	$ (28,043)
Net loss per share, basic and diluted	$ (2.67)	$ (2.91)	$ (3.81)
Weighted-average shares of common stock outstanding, basic and diluted	37,591,505	22,878,325	7,360,738
Comprehensive loss:
Net loss	$ (100,287)	$ (66,564)	$ (28,043)
Other comprehensive income (loss):
Net unrealized gains on investments	(27)	33	13
Amounts recognized for net realized gain included in net loss		(19)
Total comprehensive loss	$ (100,314)	$ (66,550)	$ (28,030)

Statements of Convertible Prefe

Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Series A Convertible Preferred Stock	Series B Convertible Preferred Stock	Series C Convertible Preferred Stock	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income	Accumulated Deficit
Balance at Dec. 31, 2018	$ (44,140)				$ 1	$ 610		$ (44,751)
Convertible preferred stock balance, shares at Dec. 31, 2018		5,157,213	3,992,919
Convertible preferred stock balance at Dec. 31, 2018		$ 32,826	$ 30,921
Balance, shares at Dec. 31, 2018					7,360,738
Issuance of Series C convertible preferred stock, net of issuance costs of $81				$ 41,868
Issuance of Series C convertible preferred stock, net of issuance costs of $81, shares				4,816,160
Stock-based compensation expense	468					468
Net unrealized gains on investments	13						$ 13
Net loss	(28,043)							(28,043)
Balance at Dec. 31, 2019	$ (71,702)				$ 1	1,078	13	(72,794)
Convertible preferred stock balance, shares at Dec. 31, 2019	13,966,292	5,157,213	3,992,919	4,816,160
Convertible preferred stock balance at Dec. 31, 2019	$ 105,615	$ 32,826	$ 30,921	$ 41,868
Balance, shares at Dec. 31, 2019					7,360,738
Conversion of convertible preferred stock into common stock	105,615				$ 1	105,614
Conversion of convertible preferred stock into common stock, shares		(5,157,213)	(3,992,919)	(4,816,160)
Conversion of convertible preferred stock into common stock		$ (32,826)	$ (30,921)	$ (41,868)
Conversion of convertible preferred stock into common stock, shares					13,966,292
Issuance of common stock upon initial public offering and follow-on offering, net of underwriters' commission and issuance costs	160,623				$ 1	160,622
Issuance of common stock upon initial public offering and follow-on offering, net of underwriters' commission and issuance costs, shares					12,650,000
Exercise of common stock options	$ 631				$ 1	630
Exercise of common stock, shares	1,144,330				1,144,330
Stock-based compensation expense	$ 3,056					3,056
Net unrealized gains on investments	33
Net unrealized gains on investments	14						14
Net loss	(66,564)							(66,564)
Balance at Dec. 31, 2020	$ 131,673				$ 4	271,000	27	(139,358)
Convertible preferred stock balance, shares at Dec. 31, 2020	0
Balance, shares at Dec. 31, 2020	35,121,360				35,121,360
Issuance of common stock upon initial public offering and follow-on offering, net of underwriters' commission and issuance costs	$ 112,801					112,801
Issuance of common stock upon initial public offering and follow-on offering, net of underwriters' commission and issuance costs, shares					2,875,000
Issuance of common stock from employee stock purchase plan	607					607
Issuance of common stock from employee stock purchase plan, shares					28,258
Exercise of common stock options	$ 2,122					2,122
Exercise of common stock, shares	595,339				595,339
Stock-based compensation expense	$ 16,698					16,698
Net unrealized gains on investments	(27)						$ (27)
Net loss	(100,287)							(100,287)
Balance at Dec. 31, 2021	$ 163,587				$ 4	$ 403,228		$ (239,645)
Convertible preferred stock balance, shares at Dec. 31, 2021	0
Convertible preferred stock balance at Dec. 31, 2021		$ 0	$ 0	$ 0
Balance, shares at Dec. 31, 2021	38,619,957				38,619,957

Statements of Convertible Pre_2

Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Issuance of common stock upon initial public offering and follow-on offering, underwriters' commission and issuance costs	$ 7,947	$ 16,477
Series C Convertible Preferred Stock
Issuance of convertible preferred stock, issuance costs			$ 81

Statements of Cash Flows

Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating activities
Net loss	$ (100,287)	$ (66,564)	$ (28,043)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	16,698	3,056	468
Depreciation and amortization	3,251	1,842	706
Non-cash operating lease expense	4,363
Loss on disposal of property and equipment	74	2
Net accretion of discounts on investments	(71)	(116)
Changes in operating assets and liabilities:
Prepaid expenses	(5,374)	(779)	(316)
Other current assets	(273)	(315)	(98)
Other assets	6	505	(468)
Accounts payable	(1,557)	840	(363)
Accrued expenses	3,983	2,647	1,009
Operating lease liabilities	(3,663)
Other liabilities	241
Deferred rent, current		70	13
Capital lease obligations, current			42
Deferred rent		(82)	25
Capital lease obligations			58
Net cash used in operating activities	(82,609)	(58,894)	(26,967)
Investing activities
Proceeds from sales and maturities of investments	124,070	84,236	639
Purchases of property and equipment	(1,864)	(5,315)	(2,153)
Purchases of investments		(188,207)	(20,620)
Net cash provided by (used in) investing activities	122,206	(109,286)	(22,134)
Financing activities
Proceeds from follow-on offering, net of underwriters' commission	113,505
Proceeds from exercise of common stock options	2,122	631
Proceeds from issuance of common stock from employee stock purchase plan	607
Payments of issuance costs for follow-on offering	(704)
Principal payments on capital lease obligations	(232)	(90)	(88)
Proceeds from issuance of common stock upon initial public offering, net of underwriters' commission		164,703
Payments of issuance costs for initial public offering		(3,948)
Proceeds from issuance of convertible preferred stock			41,868
Payments of issuance costs for convertible preferred stock			(132)
Net cash provided by financing activities	115,298	161,296	41,648
Net decrease in cash, cash equivalents and restricted cash	154,895	(6,884)	(7,453)
Cash, cash equivalents and restricted cash beginning of year	5,951	12,835	20,288
Cash, cash equivalents and restricted cash end of year	160,846	5,951	12,835
Supplemental cash flow data:
Cash paid for interest on capital lease obligations	32	14	2
Supplemental disclosure of non-cash investing and financing activities:
Property and equipment included in accrued expenses and accounts payable	$ 664	506	394
Conversion of convertible preferred stock into common stock		105,615
Equipment acquired through capital lease		$ 626
Issuance costs for initial public offering included in accounts payable			$ 234

Organization and Principal Acti

Organization and Principal Activities	12 Months Ended
	Dec. 31, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization and Principal Activities	1. Organization and Principal Activities Business Description Applied Molecular Transport Inc. (the Company) is a clinical-stage biopharmaceutical company leveraging its proprietary technology platform to design and develop a pipeline of novel oral biologic product candidates to treat autoimmune, inflammatory, metabolic, and other diseases. The Company is building a portfolio of oral product candidates based on its technology platform including its most advanced product candidate, AMT-101, a gastrointestinal (GI)-selective oral fusion of interleukin-10 (IL-10) and our proprietary carrier molecule. The Company is actively enrolling and dosing patients globally across multiple Phase 2 clinical trials of AMT-101 in ulcerative colitis (UC) and other inflammatory indications following the completion of a Phase 1b clinical trial in patients with UC. The Company’s second product candidate, AMT-126, is a GI-selective oral fusion of interleukin-22 (IL-22) and the Company’s proprietary carrier molecule currently in development for diseases related to intestinal epithelial (IE) barrier function defects driven by activation of the innate immune system. The Company is currently enrolling subjects in a Phase 1 clinical trial with AMT-126. The Company’s proprietary technology platform enables it to design and develop various oral biologic therapeutic modalities, such as peptides, proteins, full-length antibodies, antibody fragments, and ribonucleic acid (RNA) therapeutics, with potentially significant advantages over existing marketed and development-stage drugs. Since the date of incorporation in Delaware on November 21, 2016, the Company has devoted substantially all of its resources to research and development activities, including research activities such as drug discovery, preclinical studies, and clinical trials as well as development activities such as the manufacturing of clinical and research material, establishing and maintaining an intellectual property portfolio, hiring personnel, raising capital, and providing general and administrative support for these operations. Initial Public Offering On June 4, 2020, the Company’s registration statement on Form S-1 (File No. 333-238464) relating to its initial public offering (IPO) of common stock became effective. The IPO closed on June 9, 2020 at which time the Company issued an aggregate of 12,650,000 shares of its common stock at a price of $14.00 per share which included 1,650,000 shares of common stock issued in connection with the full exercise by the underwriters of their option to purchase additional shares of common stock. In addition, immediately prior to the closing of the IPO, all outstanding shares of the Company’s convertible preferred stock automatically converted into 13,966,292 shares of common stock. The aggregate offering price for shares sold in the IPO was $177.1 million. After deducting underwriting discounts and commissions of $12.4 million and offering costs paid by the Company of $4.1 million, the net proceeds from the offering were approximately $160.6 million, net of offering costs of $0.2 million paid in 2019. Follow-On Offering On April 6, 2021, the Company completed a follow-on offering and issued 2,875,000 shares of its common stock, including 375,000 shares of common stock issued in connection with the full exercise by the underwriters of their options to purchase additional shares of common stock at a price of $42.00 per share. The aggregate gross proceeds from the follow-on offering were $120.8 million. After deducting underwriting discounts and commissions of $7.2 million and deferred offering costs of $0.8 million, the net proceeds from the follow-on offering were approximately $112.8 million. Liquidity and Capital Resources Management believes that its existing cash, cash equivalents, and investments as of December 31, 2021 will be sufficient to allow the Company to fund its current operating plan through at least the next 12 months from the date of issuance of these financial statements. The Company has incurred significant losses and negative cash flows from operations since its inception. As of December 31, 2021, the Company had an accumulated deficit of $239.6 million and does not expect positive cash flows from operations in the foreseeable future. The Company expects to incur significant and increasing losses until regulatory approval is granted and successful commercialization is achieved for any of its product candidates. Regulatory approval is not guaranteed and may never be obtained. The Company has historically financed its operations primarily through private placements of its convertible preferred stock and sale of common stock upon the completion of the IPO and follow-on equity offering. In addition, on January 27, 2022, the Company entered into a Sales Agreement with SVB Leerink LLC and JMP Securities LLC, as the Company’s sales agents (Agents), pursuant to which the Company may offer and sell from time to time through the Agents up to $150 million in shares of the Company’s common stock through an “at-the-market” program. See Note 11. The Company may seek to raise capital through debt financings, private or public equity financings, license agreements, collaborative agreements or other arrangements with other companies, or other sources of financing. There can be no assurance that such financing will be available or will be at terms acceptable to the Company. Risks and Uncertainties Since the COVID-19 virus was reported in December 2019 in Wuhan, China, the virus has spread extensively throughout the world, resulting in the World Health Organization characterizing COVID-19 as a pandemic. While significant progress in addressing the pandemic has been made with multiple vaccines and treatment options now available, the emergence of highly transmissible variants of the virus, such as the Delta and Omicron variants, have resulted in periodic surges in infection rates around the world and a cycle of fluctuating public health restrictions designed to mitigate the spread of the virus. The extent to which the COVID-19 pandemic impacts the Company’s business will depend on future developments, which are highly uncertain and cannot be predicted, such as the spread or emergence of new variants, the duration and severity of surges in outbreaks, travel restrictions and social distancing in the United States and other countries, business closures or business disruptions, and the effectiveness of actions taken in the United States and other countries to contain and treat the disease and to address its impact, including on financial markets or otherwise. Beginning the week of March 16 th

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation The financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP). Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. The Company bases its estimates on historical experience and market-specific or other relevant assumptions that it believes are reasonable under the circumstances. Assets and liabilities reported in the Company’s balance sheet and expenses and income reported are affected by estimates and assumptions, which are used for, but are not limited to, determining the fair value of assets and liabilities, including research and development expenses, income tax uncertainties, and measurement of stock-based compensation expense. The Company assessed certain accounting matters that generally require consideration of forecasted financial information in context with the information reasonably available to the Company and the unknown future impacts of the COVID-19 pandemic. Actual results could differ from such estimates or assumptions . Concentration of Credit Risk and Other Risks and Uncertainties Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash, cash equivalents, and investments. The Company invests in U.S. Treasury securities. The Company maintains bank deposits in federally insured financial institutions and these deposits may exceed federally insured limits. The Company is exposed to credit risk in the event of default by the financial institutions holding its cash, cash equivalents, and investments to the extent recorded in the balance sheet. The Company has not experienced any losses on its deposits of cash, cash equivalents, and investments. The Company is subject to a number of risks similar to other early-stage biopharmaceutical companies, including, but not limited to, the need to obtain adequate additional funding, possible failure of current or future preclinical studies or clinical trials, its reliance on third parties to conduct its clinical trials, the need to obtain regulatory and marketing approvals for its product candidates, competitors developing new technological innovations, the need to successfully commercialize and gain market acceptance of the Company’s product candidates, protection of its proprietary technology, and the need to secure and maintain adequate manufacturing arrangements with third parties. If the Company does not successfully commercialize or partner any of its product candidates, it will be unable to generate product revenue or achieve profitability. Operating Segment The Company operates and manages its business as one reportable and operating segment, which is the business of designing and developing a pipeline of novel oral biologic product candidates to treat autoimmune, inflammatory, metabolic, and other diseases. The Company’s chief executive officer, who is the chief operating decision maker, reviews financial information on an aggregate basis for allocating and evaluating financial performance. Cash and Cash Equivalents Cash and cash equivalents are held in accounts at financial institutions. Such deposits have and will continue to exceed federally insured limits in the foreseeable future. The Company considers all highly liquid investments purchased with original maturities of 90 days or less from the purchase date to be cash equivalents. Cash equivalents consist of amounts invested in money market funds exclusively composed of U.S. government obligations. Restricted Cash The Company has cash in collateral accounts related to two letters of credit issued on behalf of the Company for security deposits. As of December 31, 2021, the collateralized cash in connection with the letters of credit was classified as restricted cash on the balance sheets. The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the statements of cash flows (in thousands): As of December 31, 2021 2020 Cash and cash equivalents $ 159,821 $ 5,843 Restricted cash 1,025 108 Total cash, cash equivalents and restricted cash $ 160,846 $ 5,951 Investments The Company’s investments have been classified and accounted for as available-for-sale securities. Fixed income securities consist of U.S. Treasury securities. The specific identification method is used to determine the cost basis of fixed income securities sold. These securities are recorded on the balance sheets at fair value. Unrealized gains and losses on these securities are included as a separate component of accumulated other comprehensive income. The cost of investment securities is adjusted for amortization of premiums and accretion of discounts to maturity. Such amortization and accretion are included in other expense, net. The Company classifies its investments as short or long term based on the remaining contractual maturity of the securities. Property and Equipment, Net Property and equipment are presented at cost, net of accumulated depreciation. Depreciation is recorded using the straight-line method. Depreciation begins at the time the asset is placed in service. Maintenance and repairs are charged to expense as incurred and costs of major replacement or improvement are capitalized. The Company’s estimated useful lives of its property and equipment are as follows: Laboratory and manufacturing equipment 5 years Computer and office equipment 3 years Leasehold improvements Shorter of remaining lease Impairment of Long-Lived Assets The Company evaluates the carrying amount of its long-lived assets whenever events or changes in circumstances indicate that the assets may not be recoverable. An impairment loss is recognized when the remaining book value of an asset is not recoverable. There was no impairment of long-lived assets during the years ended December 31, 2021, 2020 and 2019. Leases For the years ended December 31, 2020 and 2019, the Company classified lease arrangements as either operating or capital leases under Accounting Standards Codification (ASC) 840, Leases In February 2016, the Financial Accounting Standards Board (FASB) issued an Accounting Standard Update (ASU) No. 2016-02, Leases (ASC 842), and its associated amendments, that established a right-of-use (ROU) model that requires a lessee to recognize a ROU asset and lease liability on the balance sheet for all leases with a term longer than 12 months and disclose key information about leasing arrangements. The Company adopted ASC 842 on January 1, 2021 using the modified retrospective approach. Leases have been classified as either finance or operating, with classification affecting the pattern and classification of expense recognition in the statements of operations and comprehensive loss. At the inception of an arrangement, the Company determines if an arrangement is, or contains, a lease based on the facts and circumstances present in that arrangement. Lease classification, recognition, and measurement are then determined at the lease commencement date. For arrangements that contain a lease, the Company (i) identifies lease and non-lease components, (ii) determines the consideration in the contract, (iii) determines whether the lease is an operating or finance lease; and (iv) recognizes lease ROU assets and liabilities. Lease liabilities and their corresponding ROU assets are recorded based on the present value of lease payments over the expected lease term. The interest rate implicit in lease contracts is typically not readily determinable. Accordingly, the Company uses the incremental borrowing rate based on the information available at the lease commencement date, which represents an internally developed rate that would be incurred to borrow, on a collateralized basis, over a similar term, an amount equal to the lease payments in a similar economic environment. Building improvements continue to be capitalized as leasehold improvements and are included in property and equipment , net in the balance sheet s . Most leases include options to renew and/or terminate the lease, which can impact the lease term. The exercise of these options is at the Company’s discretion. The Company’s lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise such options. The Company has operating leases for its corporate offices, laboratory, manufacturing and warehouse facilities, and a contract research organization (CRO) embedded lease arrangement. Fixed lease payments on operating leases are recognized as lease expense over the expected term of the lease on a straight-line basis. Variable lease expenses that are not considered fixed are recognized as incurred. Fixed and variable lease expense on operating leases is recognized within operating expenses within the Company’s statements of operations and comprehensive loss. The Company has finance leases for lab and manufacturing equipment. Interest expense from fixed payments on finance leases is recognized using the effective interest method. Finance lease ROU asset amortization and interest expense are recorded within operating expenses and interest income, net, respectively, within the Company’s statements of operations and comprehensive loss. The Company has elected the short-term lease exemption and, therefore, does not recognize an ROU asset or corresponding liability for lease arrangements with an original term of 12 months or less. Research and Development Expenses Research and development expenses are charged to expense as incurred. Research and development expenses include personnel costs related to research and development activities, materials costs, external clinical drug product manufacturing costs, outside services costs, repair, maintenance and depreciation costs for research and development equipment, as well as facility costs for laboratory space used for research and development activities. Accrued Research and Development Expenses The Company accrues for estimated costs of research, preclinical studies, clinical trials, and manufacturing development services performed but not yet invoiced and such accruals are included within accrued expenses which are significant components of research and development expenses. A substantial portion of the Company’s ongoing research and development activities is conducted by third-party service providers including contract research organizations (CROs) and contract development and manufacturing organizations (CDMOs). The Company’s contracts, amendments thereto, statements of work and change orders with the CROs and CDMOs generally include fees such as initiation fees, reservation fees, costs related to animal studies and safety tests, verification run costs, materials and reagents expenses, and taxes. Payments made to third parties under these arrangements in advance of the performance of the related services are recorded as prepaid expenses and are expensed as services are rendered. The financial terms of these arrangements are subject to negotiations, which vary from contract to contract and may result in the timing of payments that do not match the periods over which materials or services are provided to the Company under such contracts. The Company accrues the costs incurred under agreements with these third parties and/or adjusts the prepaid expenses based on estimates of work completed in accordance with the respective agreements. The Company determines the estimated costs through information obtained from third-party providers as to the progress, stage of completion or actual timeline (start-date and end-date) of the services and the agreed-upon fees to be paid for such services and corroboration with internal personnel responsible for the oversight of the research and development activities. If the actual timing of the performance of services or the level of effort varies from the estimate, the Company adjusts accrued expenses or prepaid expenses accordingly, which impact research and development expenses. Although the Company does not expect its estimates to be materially different from amounts actually incurred, the Company’s understanding of the status and timing of services performed relative to the actual status and timing of services performed may vary and may result in reporting amounts that are too high or too low in any particular period . To date, there have not been any material adjustments to the Company’s prior estimates of research and development expenses . Stock-Based Compensation Expense The Company maintains an equity incentive plan as a long-term incentive for employees, consultants, and directors. The plan allows for the issuance of incentive stock options, non-statutory stock options, stock appreciation rights, restricted stock grants, and restricted stock units. As of December 31, 2021 and 2020, no stock appreciation rights, or performance-based awards were issued. The Company accounts for stock-based compensation expense by measuring and recognizing compensation expense for all share-based payments made to employees and non-employees based on estimated grant-date fair values. The Company uses the straight-line method to allocate compensation cost to reporting periods over each recipient’s requisite service period, which is generally the vesting period. The Company recognizes actual forfeitures by reducing the stock-based compensation expense in the same period as the forfeitures occur. The Company estimates the fair value of stock options granted to employees and non-employees using the Black-Scholes model. The Black-Scholes model requires the input of subjective assumptions, including expected volatility, expected dividend yield, expected term and the risk-free rate of return. Income Taxes The Company accounts for income taxes using the asset and liability method. The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements or tax returns subject to a determinable valuation allowance. Deferred tax assets and liabilities are determined based on the difference between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. In evaluating the ability to recover its deferred income tax assets, the Company considers all available positive and negative evidence, including its operating results, ongoing tax planning and forecasts of future taxable income on a jurisdiction-by-jurisdiction basis. In the event the Company determines that it would be able to realize its deferred income tax assets in the future in excess of their net recorded amount, it would make an adjustment to the valuation allowance that would reduce the provision for income taxes. Conversely, in the event that all or part of the net deferred tax assets are determined not to be realizable in the future, an adjustment to the valuation allowance would be charged to earnings in the period when such determination is made. As of December 31, 2021 and 2020, the Company recorded a full valuation allowance on its deferred tax assets. Tax benefits related to uncertain tax positions are recognized when it is more likely than not that a tax position will be sustained during an audit. It is the Company’s policy to classify interest and penalties related to unrecognized tax benefits as a component of income tax expense. Fair Value Measurement Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability, or an exit price, in the principal or most advantageous market for that asset or liability in an orderly transaction between market participants on the measurement date. Fair value measurement establishes a fair value hierarchy that requires an entity to maximize the use of observable inputs, where available, and minimize the use of unobservable inputs when measuring fair value. The Company determined the fair value of financial assets and liabilities using the fair value hierarchy that describes three levels of inputs that may be used to measure fair value, as follows: • Level 1—Quoted prices in active markets for identical assets and liabilities; • Level 2—Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities; and • Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. As of December 31, 2021 and 2020, fair value measurements consisted mainly of cash equivalents and investments. The carrying amounts of these instruments approximate their fair value. Certain of the Company’s financial instruments are recorded at amounts that approximate their fair value, rather than at fair value on a recurring basis, due to their liquid or short-term nature, such as cash, restricted cash, prepaid expenses, other current assets, accounts payable and accrued expenses. Comprehensive Loss Comprehensive loss includes net loss and other comprehensive income (loss) for the period. Other comprehensive income (loss) consists of unrealized gains on investments and amounts recognized for net realized gain included in net loss. Deferred Offering Costs Deferred offering costs, consisting of legal, accounting, and filing fees directly related to the IPO, were capitalized and offset against proceeds from the IPO and follow-on offering, upon completion of each offering. For the year ended December 31, 2019, $0.4 million of deferred offering costs were incurred. Upon completion of the IPO in June 2020, approximately $4.1 million of deferred offering costs were offset against the IPO proceeds classified in additional paid-in capital. Upon completion of the follow-on offering in April 2021, approximately $0.8 million of deferred offering costs were offset against the follow-on offering proceeds classified in additional paid-in capital. Emerging Growth Company Status For the years ended December 31, 2020 and 2019, the Company is an emerging growth company (EGC) as defined in the JOBS Act and has taken advantage of reduced reporting requirements that are otherwise applicable to public companies. Specifically, section 107 of the JOBS Act exempts EGCs from being required to comply with new or revised financial accounting standards until private companies are required to comply with those standards. The Company has elected to use the extended transition period for complying with new or revised accounting standards. For the year ended December 31, 2021, the Company is no longer an emerging growth company due to the public float of the company’s shares exceeding $700 million as of June 30, 2021. Commitments and Contingencies Liabilities for loss contingencies arising from claims, assessments, litigation, fines, and penalties and other sources are recorded if and when it is probable that a liability has been incurred and the amount can be reasonably estimated. Legal costs incurred in connection with loss contingencies are expensed as incurred. Recent Accounting Pronouncements From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (FASB) or other standard setting bodies and adopted by the Company as of the specified effective date. Unless otherwise discussed, the impact of recently issued standards that are not yet effective will not have a material impact on the Company’s financial position or results of operations upon adoption. Recently Adopted Accounting Pronouncements In February 2016, the FASB issued Accounting Standards Update (ASU) 2016-02, Leases (Topic 842) that requires a lessee to recognize leases of greater than 12 months on the balance sheet and disclose key information about leasing arrangements. The Company adopted the new standard on January 1, 2021 using the modified retrospective approach. The Company has elected to apply the transition method that allows companies to continue applying the guidance under the lease standard in effect at that time in the comparative periods presented in the financial statements and recognize a cumulative-effect adjustment to the opening balance of accumulated deficit on the date of adoption. The Company has elected to combine lease components (for example fixed rent payments) with non-lease components (for example, common-area maintenance costs) on the facilities, lab equipment and CRO embedded lease asset classes. The Company also elected the “package of practical expedients”, which permits the Company not to reassess under the new standard its prior conclusions about lease identification, lease classification and initial direct costs. Lastly, the Company elected a practical expedient to use hindsight in determining the lease term for all its leases. Results for reporting periods beginning after January 1, 2021 are presented under the new standard, while prior period amounts have not been adjusted and continue to be reported under the accounting standards in effect for the prior period. Upon adoption of the new lease standard on January 1, 2021, the Company capitalized operating lease ROU assets of $6.0 million, with opening adjustments of $0.5 million related to deferred rent existing as of the transition date, and $6.5 million of operating lease liabilities, within the Company’s balance sheets. There was no impact to the finance lease ROU asset and the finance lease liabilities upon adoption. In connection with operating and finance leases, there was no impact to the accumulated deficit upon the adoption of the new standard on January 1, 2021. In October 2020, the FASB issued ASU 2020-10, Codification Improvements. The guidance contains improvements to the Codification by ensuring that all guidance that requires or provides an option for an entity to provide information in the notes to financial statements is codified in the Disclosure Section of the Codification. The guidance also contains Codifications that are varied in nature and may affect the application of the guidance in cases in which the original guidance may have been unclear. The Company adopted the new standard on January 1, 2021. The adoption did not have a material impact on the Company’s financial statements. In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes In August 2018, the FASB issued ASU 2018-13, Disclosure Framework (Topic 820) – Changes to the Disclosure Requirements for Fair Value Measurement In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	3. Fair Value Measurements As of December 31, 2021 and 2020, the Company held zero and $124.0 million, respectively, of investment securities, comprised of U.S. Treasury securities. In determining fair value, the Company utilizes valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible as well as considers counterparty credit risk in its assessment of fair value. Financial instruments classified within Level 2 of the fair value hierarchy are valued based on other observable inputs. When quoted prices in active markets for identical assets or liabilities are not available, the Company relies on non-binding quotes from its investment managers, which are based on proprietary valuation models of independent pricing services. These models generally use inputs such as observable market data, quoted market prices for similar instruments, or historical pricing trends of a security relative to its peers. To validate the fair value determination provided by its investment managers, the Company reviews the pricing movement in the context of overall market trends and trading information from its investment managers. In addition, the Company assesses the inputs and methods used in determining the fair value in order to determine the classification of securities in the fair value hierarchy. The carrying amounts of cash equivalents and marketable securities approximate their fair value based upon quoted market prices. Certain of the Company’s financial instruments are recorded at amounts that approximate their fair value, rather than at fair value on a recurring basis, due to their liquid or short-term nature, such as cash, restricted cash, prepaid expenses, other current assets, accounts payable and accrued expenses. The unrealized losses on short-term investments as of December 31, 2021 and 2020 were insignificant. The Company does not believe that these unrealized losses are credit related but are rather a reflection of current market yields and/or current marketplace bid/ask spreads. The Company has not recognized an allowance for credit losses as of December 31, 2021. The following tables summarize the Company’s financial assets measured at fair value on a recurring basis by level within the fair value hierarchy as of December 31, 2021 (in thousands): December 31, 2021 Fair Value Hierarchy Level Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash equivalents Money Market Funds Invested in U.S. government obligations (1) Level 1 $ 159,010 $ — $ — $ 159,010 Short-term investments U.S. Treasury securities Level 2 — — — — Total $ 159,010 $ — $ — $ 159,010 (1) Included in cash and cash equivalents on the balance sheet The following tables summarize the Company’s financial assets measured at fair value on a recurring basis by level within the fair value hierarchy as of December 31, 2020 (in thousands): December 31, 2020 Fair Value Hierarchy Level Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash equivalents Money Market Funds Invested in U.S. government obligations (1) Level 1 $ 4,844 $ — $ — $ 4,844 Short-term investments U.S. Treasury securities Level 2 123,998 28 — 124,026 Total $ 128,842 $ 28 $ — $ 128,870 (1) Included in cash and cash equivalents on the balance sheet There were no transfers between Levels 1, 2, or 3 during the years ended December 31, 2021 and 2020, respectively.

Balance Sheet Components

Balance Sheet Components	12 Months Ended
	Dec. 31, 2021
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Components	4. Balance Sheet Components Prepaid Expenses Prepaid clinical expenses were $5.2 million and $0.1 million as of December 31, 2021 and 2020, respectively. Other prepaid expenses as of December 31, 2021 and 2020 included prepaid amounts for insurance and other services. Property and Equipment, Net Property and equipment, net, consisted of the following (in thousands): December 31, 2021 2020 Laboratory and manufacturing equipment $ 9,375 $ 8,022 Leasehold improvements 2,607 2,550 Construction in progress 870 162 Computer and office equipment 293 201 Capital leases — 959 13,145 11,894 Accumulated depreciation (6,147 ) (3,447 ) Total property and equipment, net $ 6,998 $ 8,447 Depreciation was $3.1 million, $1.8 million and $0.7 million for the years ended December 31, 2021, 2020 and 2019, respectively. Prior to the adoption of ASC 842 on January 1, 2021, capital leases consisted of laboratory and manufacturing equipment. Depreciation on capital lease assets was insignificant for the years ended December 31, 2020 and 2019. Accumulated depreciation on capital lease assets was $0.1 million as of December 31, 2020 and insignificant as of December 31, 2019. There were insignificant disposals during the years ended December 31, 2021, 2020 and 2019. Right-of-Use Assets, Net Right-of-use assets, net consisted of the following as of December 31, 2021 (in thousands): Operating Leases Finance Leases Total Right-of-use assets $ 41,141 $ 959 $ 42,100 Accumulated amortization (2,999 ) (307 ) (3,306 ) Right-of-use assets, net $ 38,142 $ 652 $ 38,794 Lease expense from operating lease right-of-use assets during the year ended December 31, 2021 was $4.4 million. Amortization expense from finance lease right-of-use assets during the year ended December 31, 2021 was $0.2 million. Accrued Expenses Accrued expenses consisted of the following (in thousands): December 31, 2021 2020 Compensation expenses $ 3,636 $ 2,389 Research and development expenses 2,917 1,303 Professional services 881 241 Property and equipment 215 125 Other 577 115 Total accrued expenses $ 8,226 $ 4,173 Accrued research and development expenses were comprised of clinical trials, preclinical studies, contract manufacturing, materials, compensation and facilities related expenses.

Leases

Leases	12 Months Ended
	Dec. 31, 2021
Leases [Abstract]
Leases	5. Leases Operating Leases In December 2016, the Company entered into an operating lease agreement for its former principal office in South San Francisco, California. The lease term expires in In October 2019, the Company entered into a sublease, as lessee, for office and laboratory space five-year In September 2020, the Company entered into a lease agreement for warehouse space in In February 2021, the Company entered into a lease agreement for laboratory, manufacturing, warehouse and office space in South San Francisco, California. In June 2021, the Company began occupying a portion of the property. In October 2021, the Company occupied the remainder of the space as its principal office. The lease term is eight years from full occupancy, which occurred in October 2021. Under the lease agreement, the Company has two five-year renewal options. Total minimum future lease payments for the lease term are $47.2 million. Finance Leases During 2019, the Company entered into three finance lease agreements for certain laboratory and manufacturing equipment. Two of the leases commenced during 2019 and the third lease commenced during 2020. The following table summarizes total lease expense during the year ended December 31, 2021 (in thousands): Statements of Operations and Comprehensive Loss Classification Year Ended December 31, 2021 Operating lease expense Operating expenses $ 4,363 Finance lease expense: Amortization of right-of-use assets Operating expenses 192 Interest on lease liabilities Interest income, net 32 Variable lease expense Operating expenses 947 Short-term lease expense Operating expenses 33 Total lease expense $ 5,567 Rent expense was $2.0 million and $1.5 million for the years ended December 31, 2020 and 2019, respectively. The following table summarizes supplemental cash flow information during the year ended December 31, 2021 (in thousands): Year Ended December 31, 2021 Cash paid for amounts included in measurement of liabilities: Operating cash flows from operating leases $ 3,663 Operating cash flows from finance leases 32 Financing cash flows from finance leases 232 Right-of-use asset obtained in exchange for new operating lease liability 35,554 The following table summarizes maturities of lease liabilities and the reconciliation of lease liabilities as of December 31, 2021 (in thousands): Operating Leases Finance Leases Total 2022 $ 7,078 254 $ 7,332 2023 8,401 171 8,572 2024 7,636 — 7,636 2025 6,471 — 6,471 2026 6,653 — 6,653 Thereafter 19,111 — 19,111 Total undiscounted Lease liabilities 55,350 425 55,775 Less: Interest (15,981 ) (21 ) (16,002 ) Total discounted Lease liabilities 39,369 404 39,773 Less: Lease liabilities, current (3,584 ) (237 ) (3,821 ) Lease liabilities, non-current $ 35,785 $ 167 $ 35,952 The following table summarizes lease terms and discount rates as of December 31, 2021: Operating Leases Finance Leases Weighted-average remaining lease term (years) 6.79 1.60 Weighted-average discount rate 9.73 % 5.93 %

Capital Structure

Capital Structure	12 Months Ended
	Dec. 31, 2021
Stockholders Equity Note [Abstract]
Capital Structure	6. Capital Structure Common Stock As of December 31, 2021 and 2020, the Company was authorized to issue 450,000,000 shares of $0.0001 par value common stock. Common stockholders are entitled to dividends if and when declared by the Board of Directors of the Company (Board of Directors). The holder of each share of common stock is entitled to one vote. Since the Company’s inception, no dividends have been declared or paid by the Company. Common stock reserved for future issuance, on an as converted basis, consisted of the following: December 31, 2021 2020 2019 Total stock options outstanding 4,442,864 3,506,599 2,143,368 Unvested restricted stock units 717,440 — — Stock options and restricted stock units, authorized for future issuance 2,876,270 3,369,246 1,435,402 Employee stock purchase plan, available for future grants 636,962 314,006 — Series A convertible preferred stock — — 5,157,213 Series B convertible preferred stock — — 3,992,919 Series C convertible preferred stock — — 4,816,160 Total 8,673,536 7,189,851 17,545,062 Convertible Preferred Stock Issued and outstanding convertible preferred stock and its principal terms as of December 31, 2019 were as follows (in thousands, except for share and per share amounts): As of December 31, 2019 Series Shares Authorized Shares Issued and Outstanding Original Issue Price Per Share Aggregate Liquidation Amount Net Carrying Value Series A 5,157,213 5,157,213 $ 6.3988 $ 33,000 $ 32,826 Series B 3,992,919 3,992,919 $ 7.7700 31,025 30,921 Series C 4,816,160 4,816,160 $ 8.7100 41,949 41,868 Total 13,966,292 13,966,292 $ 105,974 $ 105,615 Immediately prior to the closing of the IPO, all outstanding shares of the Company’s convertible preferred stock converted into 13,966,292 shares of common stock and the related carrying value was reclassified to common stock and additional paid-in capital. There were no shares of convertible preferred stock outstanding as of December 31, 2021 and 2020, respectively. Optional Conversion Each share of convertible preferred stock was convertible, at the option of the holder, into such number of fully paid shares of common stock as is determined by dividing the original issue price by the conversion price in effect at the time of conversion. As of December 31, 2019 and prior to the closing of the IPO, the initial conversion price per share of convertible preferred stock was equivalent to the original issue price and as such convert on a one-for-one basis prior to any adjustments. The respective applicable conversion price was subject to adjustment upon any future stock splits or stock combinations, reclassifications or exchanges of similar stock, upon a reorganization, merger or consolidation of the Company, upon the issuance or sale by the Company of common stock for consideration less than the applicable conversion price. Mandatory Conversion Each share of Series A, Series B and Series C was automatically convertible into the number of shares of common stock determined in accordance with the conversion rate upon the earlier of (i) the closing of an IPO in which the offering price per share was not less than $13.065 (as adjusted for recapitalizations) and the aggregate gross cash proceeds were at least $50.0 million, or (ii) written request for such conversion from the holders of a majority shares of convertible preferred stock then outstanding, voting together as a single class. Mandatory conversion pursuant to the clause (ii) also required a separate approval from the holders of a majority of Series B and the holders of a majority of Series C then outstanding. Liquidation Preference In the event of any liquidation, dissolution or winding up of the Company, either voluntary or involuntary, the holders of convertible preferred stock was entitled to receive, out of the assets of the Company, prior and in preference to any distribution to the holders of the common stock, an amount equal to the original issuance prices of each series and all declared but unpaid dividends, if any. If the assets and funds to be distributed among the holders of convertible preferred stock were insufficient to permit the payment to such holders, then the entire assets and funds of the Company legally available for distribution would have been distributed ratably among the holders of convertible preferred stock in proportion to the preferential amount each such holder is otherwise entitled to receive. After the payment to the holders of convertible preferred stock of the full preferential amount specified above, any remaining assets of the Company would have been distributed pro rata among the holders of common stock. Dividends The holders of the outstanding shares of convertible preferred stock were entitled to receive noncumulative dividends of $0.5119 per share of Series A, $0.6216 per share of Series B, and $0.6968 per share of Series C if and when declared by the Board of Directors. Such dividends were payable in preference to any dividends for common stock declared by the Board of Directors. No dividends were declared between date of incorporation and prior to the closing of the IPO. Voting Each holder of convertible preferred stock was entitled to the number of votes equal to the number of shares of common stock into which such shares of convertible preferred stock could then be converted as of the record date. The holders of Series A, Series B and Series C each voting as a separate series, were entitled to elect one director to the Board of Directors. Additionally, holders of common stock, voting as a separate class, had the right to elect two directors to the Board of Directors. All common and preferred stockholders, voting together as a single class on an as-converted basis, were entitled to elect the balance of the total number of directors to the Board of Directors.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2021
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	7. Commitments and Contingencies Contingencies From time to time, the Company may become involved in legal proceedings arising in the ordinary course of business. The Company was not subject to any material legal proceedings during the years ended December 31, 2021, 2020 and 2019, and no material legal proceedings are subsequently outstanding or pending. Indemnification In the ordinary course of business, the Company enters into agreements that may include indemnification provisions. As permitted under Delaware law and in accordance with its bylaws, the Company indemnifies its officers and directors for certain events or occurrences while the officer or director is or was serving in such capacity. The Company is also party to indemnification agreements with its officers and directors. In some cases, the indemnification will continue after the termination of the agreement. The maximum potential amount of future payments that the Company could be required to make under these provisions is not determinable. The Company has never incurred material costs to defend lawsuits or settle claims related to these indemnification provisions. The Company is not currently aware of any indemnification claims. The Company also maintains director and officer insurance, which may cover certain liabilities arising from our obligation to indemnify our directors and officers . Accordingly, the Company has not recorded any liabilities for these indemnification rights and agreements as of December 31, 2021 and 2020 . COVID-19 The full extent of the impact of the COVID-19 pandemic on financial markets, economies worldwide and our business is highly uncertain. As of December 31, 2021, the Company was not aware of any contingencies and no estimates were recorded on its financial statements as a result of COVID-19.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	8. Income Taxes No provision for, or benefit from, income taxes was recorded for the years ended December 31, 2021, 2020 and 2019. The Company has established a full valuation allowance against its net deferred tax assets due to the uncertainty regarding the realization of such assets. All losses to date have been incurred domestically. The effective income tax rate of the Company’s provision for income taxes differed from the federal statutory rate as follows: Year Ended December 31, 2021 2020 2019 Statutory income tax rate 21.0 % 21.0 % 21.0 % Stock-based compensation expense 2.2 8.2 (0.3 ) State income tax 2.1 1.2 9.8 Tax credits 2.0 1.8 4.7 Other (0.8 ) — (0.1 ) Valuation allowance (26.5 ) (32.2 ) (35.1 ) Total effective income tax rate — % — % — % Significant components of deferred tax assets for federal and state income taxes were as follows (in thousands): December 31, 2021 2020 Deferred tax assets: Net operating losses $ 58,025 $ 37,785 Tax credits 9,874 5,805 Lease liabilities 8,274 — Stock-based compensation expense 2,129 350 Accrued expenses 728 617 Other current assets 135 6 Total deferred tax assets 79,165 44,563 Deferred tax liabilities: Right-of-use assets (8,016 ) — Total deferred tax liabilities (8,016 ) — Valuation allowance (71,149 ) (44,563 ) Net deferred tax assets $ — $ — In March 2020, the Coronavirus Aid, Relief, and Economic Security Act (CARES Act) was enacted in response to the COVID-19 pandemic. The tax relief measures under the CARES Act for businesses include a five-year net operating loss carryback, suspension of the annual deduction limitation of 80% of taxable income from net operating losses generated in a tax year beginning after December 31, 2017, changes in the deductibility of interest, acceleration of alternative minimum tax credit refunds, payroll tax relief, and a technical correction to allow accelerated deductions for qualified improvement property. None of the tax relief measures had a current material effect on the Company. Realization of future tax benefits is dependent on the Company’s ability to generate sufficient taxable income within the carryforward period. Due to the Company’s history of operating losses and future sources of taxable income, the Company believes that the recognition of the deferred tax assets is currently not more likely than not to be realized and, accordingly, have provided a full valuation allowance against net deferred tax assets. For the years ended December 31, 2021 and 2020, the net increase in the valuation allowance was $26.6 million and $21.4 million, respectively. As of December 31, 2021, the Company had federal net operating loss carryforwards of $252.1 million, of which $13.3 million federal net operating losses generated before January 1, 2018 will begin to expire in 2036. Federal net operating losses of $238.4 million generated after December 31, 2017 will carryforward indefinitely. As of December 31, 2021, the Company had state net operating loss carryforwards of $69.4 million, which will begin to expire in 2030. As of December 31, 2021, the Company had federal general business credits from research and development expenses totaling $8.0 million, as well as state research and development credits of $5.7 million. The federal credits will begin to expire in 2037, if not utilized. The state research and development tax credits can be carried forward indefinitely. The amount of benefit from net operating loss and tax credit carryforwards may be impaired or limited in certain circumstances. Events which may cause a limitation in the amount of net operating losses and tax credits the Company can utilize include a cumulative ownership change of more than 50%, as defined by Internal Revenue Code Section 382, over a three-year testing period. The Company performed a Section 382 analysis through December 31, 2021. Although the Company has experienced an ownership change in the past, it did not result in a limitation that will materially reduce the total amount of net operating loss carryforwards and credits that can be utilized. Subsequent ownership changes may result in limitations on the Company’s ability to utilize the losses in future periods. The Company files U.S. federal and state tax returns with varying statutes of limitations. Due to net operating loss and credit carryforwards, all of the tax years since the date of incorporation through the 2021 tax year remain subject to examination by the U.S. federal and some state authorities. The actual amount of any taxes due could vary significantly depending on the ultimate timing and nature of any settlement. Uncertain Tax Benefits The Company uses the “more likely than not” criterion for recognizing the income tax benefit of uncertain income tax positions and establishing measurement criteria for income tax benefits. It is reasonably possible that certain unrecognized tax benefits may increase or decrease within the next 12 months as of December 31, 2021 due to tax examination changes, settlement activities, expirations of statute of limitations, or the impact on recognition and measurement considerations related to the results of published tax cases or other similar activities. The Company does not anticipate any significant changes to unrecognized tax benefits over the next 12 months as of December 31, 2021. A reconciliation of the beginning and ending amounts of unrecognized tax benefits was as follows (in thousands): Year Ended December 31, 2021 2020 2019 Gross unrecognized tax benefit as of January 1 $ 1,499 $ 1,012 $ 390 Additions for tax positions taken in the current year 1,080 626 407 Reductions for tax positions taken in the current year — (139 ) — Additions for tax positions taken in prior years — — 215 Gross unrecognized tax benefit as of December 31 $ 2,579 $ 1,499 $ 1,012 None of the unrecognized tax benefits at December 31, 2021 or December 31, 2020 would affect the effective tax rate due to the Company’s valuation allowance. During the years ended December 31, 2021, 2020 and 2019, no interest or penalties were required to be recognized relating to unrecognized tax benefits. In the event the Company should need to recognize interest and penalties related to unrecognized income tax liabilities, this amount will be recorded as an accrued expense and an increase to income tax expense.

Equity Incentive Plan and Stock

Equity Incentive Plan and Stock-Based Compensation Expense	12 Months Ended
	Dec. 31, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Equity Incentive Plan and Stock-Based Compensation Expense	9. Equity Incentive Plan and Stock-Based Compensation Expense 2015 Equity Incentive Plan In 2015, prior to the Company’s conversion to a C-corporation, the Board of Directors of its predecessor entity adopted its 2015 Equity Incentive Plan (the 2015 Plan). Following the adoption of its 2016 Equity Incentive Plan (the 2016 Plan), no awards were granted under its 2015 Plan. The Company’s 2015 Plan allowed it to provide stock options not intended to be qualified as incentive stock options within the meaning of Section 422 of the Code and restricted stock unit awards to its employees, directors and consultants and its subsidiary corporations’ employees and consultants. In connection with its 2016 conversion to a C-corporation, each outstanding stock option agreement under the 2015 Plan was assumed by it and converted into stock options covering shares of its common stock rather than Class B common stock of its predecessor entity. Except with respect to the shares underlying such options, no other terms were amended with respect to such stock option agreements. The Company’s 2015 Plan was terminated in 2020; however, shares subject to awards granted under the 2015 Plan continue to be governed by the 2015 Plan. 2016 Equity Incentive Plan The Company adopted the 2016 Plan which provided for the granting of incentive stock options (ISO), non-statutory stock options (NSO) and restricted shares to employees, directors, and consultants. Under the 2016 Plan, the Company issued stock options to its employees and consultants. Options under the 2016 Plan could have been granted for periods of up to 10 years and at prices no less than 100% of the estimated fair value of the underlying shares of common stock on the date of grant as determined by the Board of Directors provided that the exercise price of an ISO and NSO granted to a 10% stockholder shall not be less than 110% of the estimated fair value of the shares on the date of grant. The 2016 Plan required that options be exercised no later than 10 years after the grant. Options granted to employees generally vest ratably on a monthly basis over four years, subject to cliff vesting restrictions. In March 2020, the Company reserved for issuance of 1,250,000 shares of common stock pursuant to the 2016 plan. The Company’s 2016 Plan was terminated subsequent to its IPO in June 2020; however, shares subject to awards granted under the 2016 Plan continue to be governed by the 2016 Plan. During 2020, 576,670 previously authorized and unissued shares from the 2015 plan and the 2016 plan expired. 2020 Equity Incentive Plan The Company’s 2020 Equity Incentive Plan (the 2020 Plan) provides for the granting of ISOs, NSOs, restricted stock, restricted stock units, stock appreciation rights, performance units, and performance shares to employees, directors, and consultants. The Company initially reserved for issuance 3,768,075 shares of common stock pursuant to the 2020 Plan. Shares subject to awards granted under the 2015 Plan or 2016 Plan were added to the available shares in the 2020 Plan. Shares subject to awards granted under the 2015 Plan and 2016 Plan that are repurchased by, or forfeited to, the Company will also be reserved for issuance under the 2020 Plan. Since the date of incorporation and through December 31, 2021, the Company issued stock options and restricted stock units (“RSUs”) to its employees and consultants. In most instances, the options vest over a four year period, subject to continuing service and the restricted stock units vest over a two year period. Options under the 2020 Plan may be granted for periods of up to 10 years and at prices no less than 100% of the estimated fair value of the underlying shares of common stock on the date of grant as determined by the Board of Directors provided that the exercise price of an ISO and NSO granted to a 10% stockholder shall not be less than 110% of the estimated fair value of the shares on the date of grant. The 2020 Plan requires that options be exercised no later than 10 years after the grant. Options granted to employees generally vest ratably on a monthly basis over four years , subject to cliff vesting restrictions. 2020 Employee Stock Purchase Plan The Company’s 2020 Employee Stock Purchase Plan (ESPP) has two components: a component that is intended to qualify as an “employee stock purchase plan” under Section 423 of the Code (the 423 Component) and a component that is not intended to qualify (the Non-423 Component). The ESPP allows eligible employees to purchase shares of the Company’s common stock at a discount through payroll deductions of up to 15% of their eligible compensation. At the end of each offering period, employees are able to purchase shares at 85% of the lower of the fair market value of the Company’s common stock at the beginning of the offering period or at the end of each applicable purchase period. Subject to adjustment in the case of certain capitalization events, 314,006 shares of the Company’s common stock were available for purchase at the adoption of the ESPP. Pursuant to the ESPP, the annual share increase pursuant to the evergreen provision is determined based on the least of (i) 628,012 shares, (ii) 1% of the Company’s common stock outstanding as of December 31 of the immediately preceding year, or (iii) such number of shares as determined by the Company’s Board of Directors. As of December 31, 2021, 636,962 shares of common stock remained available for issuance under the ESPP. During the year ended December 31, 2021, the Company recognized $0.3 million in stock-based compensation expense related to the ESPP. During the years ended December 31, 2020 and 2019, the Company recognized no stock-based compensation expense related to the ESPP. As of December 31, 2021, the maximum number of stock options and restricted stock unit awards available for future issuance under the Company’s plans is 2,876,270. Repricing of Stock Options In May 2020, the Board of Directors approved a one-time repricing of certain stock options granted to our service providers with an exercise price of $6.14 per share under our 2016 Plan. Pursuant to such approval, in May 2020, the exercise prices of 1,998,677 stock options (including any cancelled stock options) were automatically repriced to $4.61 per share, which the Board of Directors determined represented the fair value of the Company’s common stock as of the date of the repricing. As a result of the repricing, the weighted-average exercise price for options granted during the six months ended June 30, 2020 decreased from $6.48 per share to $5.18 per share. The Company used the Black-Scholes option pricing model to estimate the fair value of the modified option grants immediately before and immediately after the modification in order to determine the increase in the fair value of $0.5 million for the modified option grants, which is recognized over the weighted-average remaining requisite service period of 3.3 years. Stock-Based Compensation Expense The following table summarizes the components of stock-based compensation expense recognized in the Company’s statement of operations and comprehensive loss during the years ended December 31, 2021, 2020 and 2019 (in thousands): Year Ended December 31, 2021 2020 2019 Research and development $ 8,596 $ 1,943 $ 338 General and administrative 8,102 1,113 130 Total stock-based compensation expense $ 16,698 $ 3,056 $ 468 Stock Options The following summarizes stock option activity (in thousands, except share, per share and year amounts): Options Outstanding Total Options Outstanding Weighted- Average Exercise Price Weighted- Average Remaining Contractual Life Aggregate Intrinsic Value Outstanding as of January 1, 2019 1,774,858 $ 0.84 $ 2,815 Granted 773,688 2.38 Cancelled (405,178 ) 1.81 Outstanding as of December 31, 2019 2,143,368 1.22 7.30 10,555 Granted 2,598,319 7.82 Exercised (1,144,330 ) 0.55 Cancelled (90,758 ) 3.43 Outstanding as of December 31, 2020 3,506,599 6.27 8.79 85,975 Granted 2,026,976 49.49 Exercised (595,339 ) 3.57 Cancelled (495,372 ) 21.69 Outstanding as of December 31, 2021 4,442,864 $ 24.63 8.38 $ 22,850 Exercisable as of December 31, 2021 1,492,153 $ 11.68 7.64 $ 12,480 Weighted-average grant-date fair value of the options granted during the years ended December 31, 2021, 2020 and 2019 was $32.05 per share, $5.88 per share and $1.61 per share, respectively. The intrinsic value of the options exercised during the years ended December 31, 2021, 2020 and 2019 was $20.8 million, $29.5 million and zero, respectively. As of December 31, 2021, the total unrecognized stock-based compensation expense related to stock options was $55.1 million, which is expected to be recognized over a weighted-average period of approximately 2.59 years. Fair Value Measurement The Company estimated the fair value of stock options using the Black-Scholes option pricing model. The fair value of employee and non-employee stock options is being amortized on the straight-line basis over the requisite service period of the awards. The Black-Scholes option-pricing model requires the use of highly subjective assumptions which determine the fair value of stock-based awards. These assumptions include: • Risk-free interest rate —The risk-free interest rate is based on the U.S. Treasury zero coupon issues in effect at the time of grant for periods corresponding with the expected term of option. • Expected volatility —Since the Company does not have enough trading history for its common stock, the expected volatility was estimated based on the average volatility for comparable publicly traded biotechnology companies over a period equal to the expected term of the stock option grants. The comparable companies were chosen based on their similar size, stage in the life cycle or area of specialty. The Company will continue to apply this process until enough historical information regarding the volatility of its own stock becomes available. • Expected term —The expected term represents the period that stock-based awards are expected to be outstanding. The expected term for option grants is determined using the simplified method. The simplified method deems the term to be the average of the time-to-vesting and the contractual life of the stock-based awards. • Expected dividend yield —The Company has never paid dividends on its common stock and has no plans to pay dividends on its common stock. Therefore, the Company used an expected dividend yield of zero. For options granted to non-employee consultants, the fair value of these options is also remeasured using the Black-Scholes option-pricing model reflecting the same assumptions as applied to employee options in each of the reported periods, other than the expected life, which is assumed to be the remaining contractual life of the option. The fair value of each employee stock option grant during the years ended December 31, 2021, 2020 and 2019 was estimated using the following weighted-average assumptions: Year Ended December 31, 2021 2020 2019 Risk-free interest rate 1.0 % 0.6 % 2.3 % Expected volatility 73.9 % 75.6 % 70.0 % Expected term (years) 6.05 6.10 6.08 Expected dividend yield — — — Restricted Stock Units The following summarizes restricted stock unit activity: RSUs Outstanding Number of Shares Weighted-Average Grant Date Fair Value per Share Outstanding as of December 30, 2020 — $ — Granted 717,440 14.54 Outstanding as of December 31, 2021 717,440 $ 14.54 As of December 31, 2021, the total unrecognized stock-based compensation expense related to unvested restricted stock units and awards was $10.0 million, which is expected to be recognized over a weighted-average period of approximately 1.92 years.

Net Loss and Net Loss Per Share

Net Loss and Net Loss Per Share	12 Months Ended
	Dec. 31, 2021
Earnings Per Share [Abstract]
Net Loss and Net Loss Per Share	10. Net Loss and Net Loss Per Share The following table sets forth the computation of the basic and diluted net loss per share (except share and per share amounts): Year Ended December 31, 2021 2020 2019 Numerator: Net loss $ (100,287 ) $ (66,564 ) $ (28,043 ) Denominator: Weighted-average shares of common stock outstanding used in the calculation of basic and diluted net loss per share 37,591,505 22,878,325 7,360,738 Net loss per share, basic and diluted $ (2.67 ) $ (2.91 ) $ (3.81 ) Since the Company was in a loss position for all periods presented, basic net loss per share is the same as diluted net loss per share for all periods as the inclusion of all common stock equivalents outstanding would have been anti- dilutive. Potentially dilutive securities that were not included in the diluted per share calculations because they would be anti-dilutive were as follows : December 31, 2021 2020 2019 Total stock options outstanding 4,442,864 3,506,599 2,143,368 Unvested restricted stock units 717,440 — — Series A convertible preferred stock — — 5,157,213 Series B convertible preferred stock — — 3,992,919 Series C convertible preferred stock — — 4,816,160 Total 5,160,304 3,506,599 16,109,660

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2021
Subsequent Events [Abstract]
Subsequent Events	11. Subsequent Event On January 27, 2022, the Company entered into a Sales Agreement with SVB Leerink LLC and JMP Securities LLC, as the Company’s sales agents (the “Agents”), pursuant to which the Company may offer and sell from time to time through the Agents up to $150 million in shares (the “Shares”) of the Company’s common stock through an “at-the-market” program. The Shares will be offered and sold pursuant to the Company’s shelf registration statement on Form S-3ASR (File No. 333-257592) which was automatically effective upon filing with the Securities and Exchange Commission the on July 1, 2021. The Company filed a prospectus supplement, dated January 27, 2022, with the SEC in connection with the offer and sale of the Shares.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP).
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. The Company bases its estimates on historical experience and market-specific or other relevant assumptions that it believes are reasonable under the circumstances. Assets and liabilities reported in the Company’s balance sheet and expenses and income reported are affected by estimates and assumptions, which are used for, but are not limited to, determining the fair value of assets and liabilities, including research and development expenses, income tax uncertainties, and measurement of stock-based compensation expense. The Company assessed certain accounting matters that generally require consideration of forecasted financial information in context with the information reasonably available to the Company and the unknown future impacts of the COVID-19 pandemic. Actual results could differ from such estimates or assumptions .
Concentration of Credit Risk and Other Risks and Uncertainties	Concentration of Credit Risk and Other Risks and Uncertainties Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash, cash equivalents, and investments. The Company invests in U.S. Treasury securities. The Company maintains bank deposits in federally insured financial institutions and these deposits may exceed federally insured limits. The Company is exposed to credit risk in the event of default by the financial institutions holding its cash, cash equivalents, and investments to the extent recorded in the balance sheet. The Company has not experienced any losses on its deposits of cash, cash equivalents, and investments. The Company is subject to a number of risks similar to other early-stage biopharmaceutical companies, including, but not limited to, the need to obtain adequate additional funding, possible failure of current or future preclinical studies or clinical trials, its reliance on third parties to conduct its clinical trials, the need to obtain regulatory and marketing approvals for its product candidates, competitors developing new technological innovations, the need to successfully commercialize and gain market acceptance of the Company’s product candidates, protection of its proprietary technology, and the need to secure and maintain adequate manufacturing arrangements with third parties. If the Company does not successfully commercialize or partner any of its product candidates, it will be unable to generate product revenue or achieve profitability.
Operating Segment	Operating Segment The Company operates and manages its business as one reportable and operating segment, which is the business of designing and developing a pipeline of novel oral biologic product candidates to treat autoimmune, inflammatory, metabolic, and other diseases. The Company’s chief executive officer, who is the chief operating decision maker, reviews financial information on an aggregate basis for allocating and evaluating financial performance.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents are held in accounts at financial institutions. Such deposits have and will continue to exceed federally insured limits in the foreseeable future. The Company considers all highly liquid investments purchased with original maturities of 90 days or less from the purchase date to be cash equivalents. Cash equivalents consist of amounts invested in money market funds exclusively composed of U.S. government obligations.
Restricted Cash	Restricted Cash The Company has cash in collateral accounts related to two letters of credit issued on behalf of the Company for security deposits. As of December 31, 2021, the collateralized cash in connection with the letters of credit was classified as restricted cash on the balance sheets. The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the statements of cash flows (in thousands): As of December 31, 2021 2020 Cash and cash equivalents $ 159,821 $ 5,843 Restricted cash 1,025 108 Total cash, cash equivalents and restricted cash $ 160,846 $ 5,951
Investments	Investments The Company’s investments have been classified and accounted for as available-for-sale securities. Fixed income securities consist of U.S. Treasury securities. The specific identification method is used to determine the cost basis of fixed income securities sold. These securities are recorded on the balance sheets at fair value. Unrealized gains and losses on these securities are included as a separate component of accumulated other comprehensive income. The cost of investment securities is adjusted for amortization of premiums and accretion of discounts to maturity. Such amortization and accretion are included in other expense, net. The Company classifies its investments as short or long term based on the remaining contractual maturity of the securities.
Property and Equipment, Net	Property and Equipment, Net Property and equipment are presented at cost, net of accumulated depreciation. Depreciation is recorded using the straight-line method. Depreciation begins at the time the asset is placed in service. Maintenance and repairs are charged to expense as incurred and costs of major replacement or improvement are capitalized. The Company’s estimated useful lives of its property and equipment are as follows: Laboratory and manufacturing equipment 5 years Computer and office equipment 3 years Leasehold improvements Shorter of remaining lease
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets The Company evaluates the carrying amount of its long-lived assets whenever events or changes in circumstances indicate that the assets may not be recoverable. An impairment loss is recognized when the remaining book value of an asset is not recoverable. There was no impairment of long-lived assets during the years ended December 31, 2021, 2020 and 2019.
Leases	Leases For the years ended December 31, 2020 and 2019, the Company classified lease arrangements as either operating or capital leases under Accounting Standards Codification (ASC) 840, Leases In February 2016, the Financial Accounting Standards Board (FASB) issued an Accounting Standard Update (ASU) No. 2016-02, Leases (ASC 842), and its associated amendments, that established a right-of-use (ROU) model that requires a lessee to recognize a ROU asset and lease liability on the balance sheet for all leases with a term longer than 12 months and disclose key information about leasing arrangements. The Company adopted ASC 842 on January 1, 2021 using the modified retrospective approach. Leases have been classified as either finance or operating, with classification affecting the pattern and classification of expense recognition in the statements of operations and comprehensive loss. At the inception of an arrangement, the Company determines if an arrangement is, or contains, a lease based on the facts and circumstances present in that arrangement. Lease classification, recognition, and measurement are then determined at the lease commencement date. For arrangements that contain a lease, the Company (i) identifies lease and non-lease components, (ii) determines the consideration in the contract, (iii) determines whether the lease is an operating or finance lease; and (iv) recognizes lease ROU assets and liabilities. Lease liabilities and their corresponding ROU assets are recorded based on the present value of lease payments over the expected lease term. The interest rate implicit in lease contracts is typically not readily determinable. Accordingly, the Company uses the incremental borrowing rate based on the information available at the lease commencement date, which represents an internally developed rate that would be incurred to borrow, on a collateralized basis, over a similar term, an amount equal to the lease payments in a similar economic environment. Building improvements continue to be capitalized as leasehold improvements and are included in property and equipment , net in the balance sheet s . Most leases include options to renew and/or terminate the lease, which can impact the lease term. The exercise of these options is at the Company’s discretion. The Company’s lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise such options. The Company has operating leases for its corporate offices, laboratory, manufacturing and warehouse facilities, and a contract research organization (CRO) embedded lease arrangement. Fixed lease payments on operating leases are recognized as lease expense over the expected term of the lease on a straight-line basis. Variable lease expenses that are not considered fixed are recognized as incurred. Fixed and variable lease expense on operating leases is recognized within operating expenses within the Company’s statements of operations and comprehensive loss. The Company has finance leases for lab and manufacturing equipment. Interest expense from fixed payments on finance leases is recognized using the effective interest method. Finance lease ROU asset amortization and interest expense are recorded within operating expenses and interest income, net, respectively, within the Company’s statements of operations and comprehensive loss. The Company has elected the short-term lease exemption and, therefore, does not recognize an ROU asset or corresponding liability for lease arrangements with an original term of 12 months or less.
Research and Development Expenses	Research and Development Expenses Research and development expenses are charged to expense as incurred. Research and development expenses include personnel costs related to research and development activities, materials costs, external clinical drug product manufacturing costs, outside services costs, repair, maintenance and depreciation costs for research and development equipment, as well as facility costs for laboratory space used for research and development activities.
Accrued Research and Development Expenses	Accrued Research and Development Expenses The Company accrues for estimated costs of research, preclinical studies, clinical trials, and manufacturing development services performed but not yet invoiced and such accruals are included within accrued expenses which are significant components of research and development expenses. A substantial portion of the Company’s ongoing research and development activities is conducted by third-party service providers including contract research organizations (CROs) and contract development and manufacturing organizations (CDMOs). The Company’s contracts, amendments thereto, statements of work and change orders with the CROs and CDMOs generally include fees such as initiation fees, reservation fees, costs related to animal studies and safety tests, verification run costs, materials and reagents expenses, and taxes. Payments made to third parties under these arrangements in advance of the performance of the related services are recorded as prepaid expenses and are expensed as services are rendered. The financial terms of these arrangements are subject to negotiations, which vary from contract to contract and may result in the timing of payments that do not match the periods over which materials or services are provided to the Company under such contracts. The Company accrues the costs incurred under agreements with these third parties and/or adjusts the prepaid expenses based on estimates of work completed in accordance with the respective agreements. The Company determines the estimated costs through information obtained from third-party providers as to the progress, stage of completion or actual timeline (start-date and end-date) of the services and the agreed-upon fees to be paid for such services and corroboration with internal personnel responsible for the oversight of the research and development activities. If the actual timing of the performance of services or the level of effort varies from the estimate, the Company adjusts accrued expenses or prepaid expenses accordingly, which impact research and development expenses. Although the Company does not expect its estimates to be materially different from amounts actually incurred, the Company’s understanding of the status and timing of services performed relative to the actual status and timing of services performed may vary and may result in reporting amounts that are too high or too low in any particular period . To date, there have not been any material adjustments to the Company’s prior estimates of research and development expenses .
Stock-Based Compensation Expense	Stock-Based Compensation Expense The Company maintains an equity incentive plan as a long-term incentive for employees, consultants, and directors. The plan allows for the issuance of incentive stock options, non-statutory stock options, stock appreciation rights, restricted stock grants, and restricted stock units. As of December 31, 2021 and 2020, no stock appreciation rights, or performance-based awards were issued. The Company accounts for stock-based compensation expense by measuring and recognizing compensation expense for all share-based payments made to employees and non-employees based on estimated grant-date fair values. The Company uses the straight-line method to allocate compensation cost to reporting periods over each recipient’s requisite service period, which is generally the vesting period. The Company recognizes actual forfeitures by reducing the stock-based compensation expense in the same period as the forfeitures occur. The Company estimates the fair value of stock options granted to employees and non-employees using the Black-Scholes model. The Black-Scholes model requires the input of subjective assumptions, including expected volatility, expected dividend yield, expected term and the risk-free rate of return.
Income Taxes	Income Taxes The Company accounts for income taxes using the asset and liability method. The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements or tax returns subject to a determinable valuation allowance. Deferred tax assets and liabilities are determined based on the difference between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. In evaluating the ability to recover its deferred income tax assets, the Company considers all available positive and negative evidence, including its operating results, ongoing tax planning and forecasts of future taxable income on a jurisdiction-by-jurisdiction basis. In the event the Company determines that it would be able to realize its deferred income tax assets in the future in excess of their net recorded amount, it would make an adjustment to the valuation allowance that would reduce the provision for income taxes. Conversely, in the event that all or part of the net deferred tax assets are determined not to be realizable in the future, an adjustment to the valuation allowance would be charged to earnings in the period when such determination is made. As of December 31, 2021 and 2020, the Company recorded a full valuation allowance on its deferred tax assets. Tax benefits related to uncertain tax positions are recognized when it is more likely than not that a tax position will be sustained during an audit. It is the Company’s policy to classify interest and penalties related to unrecognized tax benefits as a component of income tax expense.
Fair Value Measurement	Fair Value Measurement Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability, or an exit price, in the principal or most advantageous market for that asset or liability in an orderly transaction between market participants on the measurement date. Fair value measurement establishes a fair value hierarchy that requires an entity to maximize the use of observable inputs, where available, and minimize the use of unobservable inputs when measuring fair value. The Company determined the fair value of financial assets and liabilities using the fair value hierarchy that describes three levels of inputs that may be used to measure fair value, as follows: • Level 1—Quoted prices in active markets for identical assets and liabilities; • Level 2—Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities; and • Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. As of December 31, 2021 and 2020, fair value measurements consisted mainly of cash equivalents and investments. The carrying amounts of these instruments approximate their fair value. Certain of the Company’s financial instruments are recorded at amounts that approximate their fair value, rather than at fair value on a recurring basis, due to their liquid or short-term nature, such as cash, restricted cash, prepaid expenses, other current assets, accounts payable and accrued expenses.
Comprehensive Loss	Comprehensive Loss Comprehensive loss includes net loss and other comprehensive income (loss) for the period. Other comprehensive income (loss) consists of unrealized gains on investments and amounts recognized for net realized gain included in net loss.
Deferred Offering Costs	Deferred Offering Costs Deferred offering costs, consisting of legal, accounting, and filing fees directly related to the IPO, were capitalized and offset against proceeds from the IPO and follow-on offering, upon completion of each offering. For the year ended December 31, 2019, $0.4 million of deferred offering costs were incurred. Upon completion of the IPO in June 2020, approximately $4.1 million of deferred offering costs were offset against the IPO proceeds classified in additional paid-in capital. Upon completion of the follow-on offering in April 2021, approximately $0.8 million of deferred offering costs were offset against the follow-on offering proceeds classified in additional paid-in capital.
Emerging Growth Company Status	Emerging Growth Company Status For the years ended December 31, 2020 and 2019, the Company is an emerging growth company (EGC) as defined in the JOBS Act and has taken advantage of reduced reporting requirements that are otherwise applicable to public companies. Specifically, section 107 of the JOBS Act exempts EGCs from being required to comply with new or revised financial accounting standards until private companies are required to comply with those standards. The Company has elected to use the extended transition period for complying with new or revised accounting standards. For the year ended December 31, 2021, the Company is no longer an emerging growth company due to the public float of the company’s shares exceeding $700 million as of June 30, 2021.
Commitments and Contingencies	Commitments and Contingencies Liabilities for loss contingencies arising from claims, assessments, litigation, fines, and penalties and other sources are recorded if and when it is probable that a liability has been incurred and the amount can be reasonably estimated. Legal costs incurred in connection with loss contingencies are expensed as incurred.
Recent Accounting Pronouncements and Recently Adopted Accounting Pronouncements	Recent Accounting Pronouncements From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (FASB) or other standard setting bodies and adopted by the Company as of the specified effective date. Unless otherwise discussed, the impact of recently issued standards that are not yet effective will not have a material impact on the Company’s financial position or results of operations upon adoption. Recently Adopted Accounting Pronouncements In February 2016, the FASB issued Accounting Standards Update (ASU) 2016-02, Leases (Topic 842) that requires a lessee to recognize leases of greater than 12 months on the balance sheet and disclose key information about leasing arrangements. The Company adopted the new standard on January 1, 2021 using the modified retrospective approach. The Company has elected to apply the transition method that allows companies to continue applying the guidance under the lease standard in effect at that time in the comparative periods presented in the financial statements and recognize a cumulative-effect adjustment to the opening balance of accumulated deficit on the date of adoption. The Company has elected to combine lease components (for example fixed rent payments) with non-lease components (for example, common-area maintenance costs) on the facilities, lab equipment and CRO embedded lease asset classes. The Company also elected the “package of practical expedients”, which permits the Company not to reassess under the new standard its prior conclusions about lease identification, lease classification and initial direct costs. Lastly, the Company elected a practical expedient to use hindsight in determining the lease term for all its leases. Results for reporting periods beginning after January 1, 2021 are presented under the new standard, while prior period amounts have not been adjusted and continue to be reported under the accounting standards in effect for the prior period. Upon adoption of the new lease standard on January 1, 2021, the Company capitalized operating lease ROU assets of $6.0 million, with opening adjustments of $0.5 million related to deferred rent existing as of the transition date, and $6.5 million of operating lease liabilities, within the Company’s balance sheets. There was no impact to the finance lease ROU asset and the finance lease liabilities upon adoption. In connection with operating and finance leases, there was no impact to the accumulated deficit upon the adoption of the new standard on January 1, 2021. In October 2020, the FASB issued ASU 2020-10, Codification Improvements. The guidance contains improvements to the Codification by ensuring that all guidance that requires or provides an option for an entity to provide information in the notes to financial statements is codified in the Disclosure Section of the Codification. The guidance also contains Codifications that are varied in nature and may affect the application of the guidance in cases in which the original guidance may have been unclear. The Company adopted the new standard on January 1, 2021. The adoption did not have a material impact on the Company’s financial statements. In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes In August 2018, the FASB issued ASU 2018-13, Disclosure Framework (Topic 820) – Changes to the Disclosure Requirements for Fair Value Measurement In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Schedule of Reconciliation of Cash, Cash Equivalents and Restricted Cash	The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the statements of cash flows (in thousands): As of December 31, 2021 2020 Cash and cash equivalents $ 159,821 $ 5,843 Restricted cash 1,025 108 Total cash, cash equivalents and restricted cash $ 160,846 $ 5,951
Schedule of Estimated Useful Lives of Property, Plant and Equipment, Net	The Company’s estimated useful lives of its property and equipment are as follows: Laboratory and manufacturing equipment 5 years Computer and office equipment 3 years Leasehold improvements Shorter of remaining lease Property and equipment, net, consisted of the following (in thousands): December 31, 2021 2020 Laboratory and manufacturing equipment $ 9,375 $ 8,022 Leasehold improvements 2,607 2,550 Construction in progress 870 162 Computer and office equipment 293 201 Capital leases — 959 13,145 11,894 Accumulated depreciation (6,147 ) (3,447 ) Total property and equipment, net $ 6,998 $ 8,447

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Summary of Financial Assets Measured at Fair Value on Recurring Basis	The following tables summarize the Company’s financial assets measured at fair value on a recurring basis by level within the fair value hierarchy as of December 31, 2021 (in thousands): December 31, 2021 Fair Value Hierarchy Level Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash equivalents Money Market Funds Invested in U.S. government obligations (1) Level 1 $ 159,010 $ — $ — $ 159,010 Short-term investments U.S. Treasury securities Level 2 — — — — Total $ 159,010 $ — $ — $ 159,010 (1) Included in cash and cash equivalents on the balance sheet The following tables summarize the Company’s financial assets measured at fair value on a recurring basis by level within the fair value hierarchy as of December 31, 2020 (in thousands): December 31, 2020 Fair Value Hierarchy Level Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash equivalents Money Market Funds Invested in U.S. government obligations (1) Level 1 $ 4,844 $ — $ — $ 4,844 Short-term investments U.S. Treasury securities Level 2 123,998 28 — 124,026 Total $ 128,842 $ 28 $ — $ 128,870 (1) Included in cash and cash equivalents on the balance sheet

Balance Sheet Components (Table

Balance Sheet Components (Tables)	12 Months Ended
	Dec. 31, 2021
Balance Sheet Related Disclosures [Abstract]
Schedule of Estimated Useful Lives of Property, Plant and Equipment, Net	The Company’s estimated useful lives of its property and equipment are as follows: Laboratory and manufacturing equipment 5 years Computer and office equipment 3 years Leasehold improvements Shorter of remaining lease Property and equipment, net, consisted of the following (in thousands): December 31, 2021 2020 Laboratory and manufacturing equipment $ 9,375 $ 8,022 Leasehold improvements 2,607 2,550 Construction in progress 870 162 Computer and office equipment 293 201 Capital leases — 959 13,145 11,894 Accumulated depreciation (6,147 ) (3,447 ) Total property and equipment, net $ 6,998 $ 8,447
Schedule of Right-of-Use Assets, Net	Right-of-use assets, net consisted of the following as of December 31, 2021 (in thousands): Operating Leases Finance Leases Total Right-of-use assets $ 41,141 $ 959 $ 42,100 Accumulated amortization (2,999 ) (307 ) (3,306 ) Right-of-use assets, net $ 38,142 $ 652 $ 38,794
Schedule of Accrued Liabilities	Accrued expenses consisted of the following (in thousands): December 31, 2021 2020 Compensation expenses $ 3,636 $ 2,389 Research and development expenses 2,917 1,303 Professional services 881 241 Property and equipment 215 125 Other 577 115 Total accrued expenses $ 8,226 $ 4,173

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2021
Leases [Abstract]
Summary of Lease Expense	The following table summarizes total lease expense during the year ended December 31, 2021 (in thousands): Statements of Operations and Comprehensive Loss Classification Year Ended December 31, 2021 Operating lease expense Operating expenses $ 4,363 Finance lease expense: Amortization of right-of-use assets Operating expenses 192 Interest on lease liabilities Interest income, net 32 Variable lease expense Operating expenses 947 Short-term lease expense Operating expenses 33 Total lease expense $ 5,567
Summary of Supplemental Cash Flow Information	The following table summarizes supplemental cash flow information during the year ended December 31, 2021 (in thousands): Year Ended December 31, 2021 Cash paid for amounts included in measurement of liabilities: Operating cash flows from operating leases $ 3,663 Operating cash flows from finance leases 32 Financing cash flows from finance leases 232 Right-of-use asset obtained in exchange for new operating lease liability 35,554
Schedule of Future Minimum Payments under Noncancelable Leases	The following table summarizes maturities of lease liabilities and the reconciliation of lease liabilities as of December 31, 2021 (in thousands): Operating Leases Finance Leases Total 2022 $ 7,078 254 $ 7,332 2023 8,401 171 8,572 2024 7,636 — 7,636 2025 6,471 — 6,471 2026 6,653 — 6,653 Thereafter 19,111 — 19,111 Total undiscounted Lease liabilities 55,350 425 55,775 Less: Interest (15,981 ) (21 ) (16,002 ) Total discounted Lease liabilities 39,369 404 39,773 Less: Lease liabilities, current (3,584 ) (237 ) (3,821 ) Lease liabilities, non-current $ 35,785 $ 167 $ 35,952
Summary of Lease Terms and Discount Rates	The following table summarizes lease terms and discount rates as of December 31, 2021: Operating Leases Finance Leases Weighted-average remaining lease term (years) 6.79 1.60 Weighted-average discount rate 9.73 % 5.93 %

Capital Structure (Tables)

Capital Structure (Tables)	12 Months Ended
	Dec. 31, 2021
Stockholders Equity Note [Abstract]
Schedule of Common Stock Reserved for Future Issuance	Common stock reserved for future issuance, on an as converted basis, consisted of the following: December 31, 2021 2020 2019 Total stock options outstanding 4,442,864 3,506,599 2,143,368 Unvested restricted stock units 717,440 — — Stock options and restricted stock units, authorized for future issuance 2,876,270 3,369,246 1,435,402 Employee stock purchase plan, available for future grants 636,962 314,006 — Series A convertible preferred stock — — 5,157,213 Series B convertible preferred stock — — 3,992,919 Series C convertible preferred stock — — 4,816,160 Total 8,673,536 7,189,851 17,545,062
Schedule of Issued and Outstanding Convertible Preferred Stock and its Principal Terms	Issued and outstanding convertible preferred stock and its principal terms as of December 31, 2019 were as follows (in thousands, except for share and per share amounts): As of December 31, 2019 Series Shares Authorized Shares Issued and Outstanding Original Issue Price Per Share Aggregate Liquidation Amount Net Carrying Value Series A 5,157,213 5,157,213 $ 6.3988 $ 33,000 $ 32,826 Series B 3,992,919 3,992,919 $ 7.7700 31,025 30,921 Series C 4,816,160 4,816,160 $ 8.7100 41,949 41,868 Total 13,966,292 13,966,292 $ 105,974 $ 105,615

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Schedule of Effective Income Tax Rate Provision for Income Taxes Differed from Federal Statutory Rate	The effective income tax rate of the Company’s provision for income taxes differed from the federal statutory rate as follows: Year Ended December 31, 2021 2020 2019 Statutory income tax rate 21.0 % 21.0 % 21.0 % Stock-based compensation expense 2.2 8.2 (0.3 ) State income tax 2.1 1.2 9.8 Tax credits 2.0 1.8 4.7 Other (0.8 ) — (0.1 ) Valuation allowance (26.5 ) (32.2 ) (35.1 ) Total effective income tax rate — % — % — %
Schedule of Significant Components of Deferred Tax Assets for Federal and State Income Taxes	Significant components of deferred tax assets for federal and state income taxes were as follows (in thousands): December 31, 2021 2020 Deferred tax assets: Net operating losses $ 58,025 $ 37,785 Tax credits 9,874 5,805 Lease liabilities 8,274 — Stock-based compensation expense 2,129 350 Accrued expenses 728 617 Other current assets 135 6 Total deferred tax assets 79,165 44,563 Deferred tax liabilities: Right-of-use assets (8,016 ) — Total deferred tax liabilities (8,016 ) — Valuation allowance (71,149 ) (44,563 ) Net deferred tax assets $ — $ —
Schedule of Reconciliation of Beginning and Ending Amounts of Unrecognized Tax Benefits	A reconciliation of the beginning and ending amounts of unrecognized tax benefits was as follows (in thousands): Year Ended December 31, 2021 2020 2019 Gross unrecognized tax benefit as of January 1 $ 1,499 $ 1,012 $ 390 Additions for tax positions taken in the current year 1,080 626 407 Reductions for tax positions taken in the current year — (139 ) — Additions for tax positions taken in prior years — — 215 Gross unrecognized tax benefit as of December 31 $ 2,579 $ 1,499 $ 1,012

Equity Incentive Plan and Sto_2

Equity Incentive Plan and Stock-Based Compensation Expense (Tables)	12 Months Ended
	Dec. 31, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Components of Stock-Based Compensation Expense	Stock-Based Compensation Expense The following table summarizes the components of stock-based compensation expense recognized in the Company’s statement of operations and comprehensive loss during the years ended December 31, 2021, 2020 and 2019 (in thousands): Year Ended December 31, 2021 2020 2019 Research and development $ 8,596 $ 1,943 $ 338 General and administrative 8,102 1,113 130 Total stock-based compensation expense $ 16,698 $ 3,056 $ 468
Summary of Stock Option Activity	The following summarizes stock option activity (in thousands, except share, per share and year amounts): Options Outstanding Total Options Outstanding Weighted- Average Exercise Price Weighted- Average Remaining Contractual Life Aggregate Intrinsic Value Outstanding as of January 1, 2019 1,774,858 $ 0.84 $ 2,815 Granted 773,688 2.38 Cancelled (405,178 ) 1.81 Outstanding as of December 31, 2019 2,143,368 1.22 7.30 10,555 Granted 2,598,319 7.82 Exercised (1,144,330 ) 0.55 Cancelled (90,758 ) 3.43 Outstanding as of December 31, 2020 3,506,599 6.27 8.79 85,975 Granted 2,026,976 49.49 Exercised (595,339 ) 3.57 Cancelled (495,372 ) 21.69 Outstanding as of December 31, 2021 4,442,864 $ 24.63 8.38 $ 22,850 Exercisable as of December 31, 2021 1,492,153 $ 11.68 7.64 $ 12,480
Schedule of Weighted-Average Assumptions Used for Estimating Fair Value of Each Employee Stock Option	The fair value of each employee stock option grant during the years ended December 31, 2021, 2020 and 2019 was estimated using the following weighted-average assumptions: Year Ended December 31, 2021 2020 2019 Risk-free interest rate 1.0 % 0.6 % 2.3 % Expected volatility 73.9 % 75.6 % 70.0 % Expected term (years) 6.05 6.10 6.08 Expected dividend yield — — —
Summary of Restricted Stock Unit Activity	The following summarizes restricted stock unit activity: RSUs Outstanding Number of Shares Weighted-Average Grant Date Fair Value per Share Outstanding as of December 30, 2020 — $ — Granted 717,440 14.54 Outstanding as of December 31, 2021 717,440 $ 14.54

Net Loss and Net Loss Per Sha_2

Net Loss and Net Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2021
Earnings Per Share [Abstract]
Schedule of Computation of Basic and Diluted Net Loss Per Share	The following table sets forth the computation of the basic and diluted net loss per share (except share and per share amounts): Year Ended December 31, 2021 2020 2019 Numerator: Net loss $ (100,287 ) $ (66,564 ) $ (28,043 ) Denominator: Weighted-average shares of common stock outstanding used in the calculation of basic and diluted net loss per share 37,591,505 22,878,325 7,360,738 Net loss per share, basic and diluted $ (2.67 ) $ (2.91 ) $ (3.81 )
Summary of Potentially Dilutive Securities	Since the Company was in a loss position for all periods presented, basic net loss per share is the same as diluted net loss per share for all periods as the inclusion of all common stock equivalents outstanding would have been anti- dilutive. Potentially dilutive securities that were not included in the diluted per share calculations because they would be anti-dilutive were as follows : December 31, 2021 2020 2019 Total stock options outstanding 4,442,864 3,506,599 2,143,368 Unvested restricted stock units 717,440 — — Series A convertible preferred stock — — 5,157,213 Series B convertible preferred stock — — 3,992,919 Series C convertible preferred stock — — 4,816,160 Total 5,160,304 3,506,599 16,109,660

Organization and Principal Ac_2

Organization and Principal Activities - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	Jan. 27, 2022	Apr. 06, 2021	Jun. 09, 2020	Jun. 04, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Organization And Principal Activities [Line Items]
Offering costs paid						$ 3,948
Net proceeds from offering						164,703
Deferred offering costs						3,948
Accumulated deficit					$ 239,645	139,358
Number of shares offered and sold from time to time					$ 112,801	$ 160,623
At The Market | Sales Agreement | Agents | Subsequent Event
Organization And Principal Activities [Line Items]
Number of shares offered and sold from time to time	$ 150,000
Common Stock
Organization And Principal Activities [Line Items]
Share issued					2,875,000	12,650,000
Conversion of convertible preferred stock into common stock, shares						13,966,292
Number of shares offered and sold from time to time						$ 1
Common Stock | Initial Public Offering
Organization And Principal Activities [Line Items]
Share issued			12,650,000
Share price			$ 14
Share issued with exercise by underwriters			1,650,000
Conversion of convertible preferred stock into common stock, shares			13,966,292	13,966,292
Aggregate offering price for shares sold			$ 177,100
Underwriting discounts and commissions			12,400
Offering costs paid			4,100				$ 200
Net proceeds from offering			160,600
Deferred offering costs			$ 4,100				$ 200
Common Stock | Follow-on Offering
Organization And Principal Activities [Line Items]
Share issued		2,875,000
Share price		$ 42
Share issued with exercise by underwriters		375,000
Aggregate offering price for shares sold		$ 120,800
Underwriting discounts and commissions		7,200
Offering costs paid		800
Deferred offering costs		800
Net proceeds from offering		$ 112,800

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Details)	1 Months Ended	6 Months Ended	12 Months Ended
	Apr. 30, 2021USD ($)	Jun. 30, 2020USD ($)	Dec. 31, 2021USD ($)Segmentshares	Dec. 31, 2020USD ($)shares	Dec. 31, 2019USD ($)	Jun. 30, 2021USD ($)	Jan. 01, 2021USD ($)
Summary Of Significant Accounting Policies [Line Items]
Number of reportable segment | Segment			1
Number of operating segment | Segment			1
Impairment of long-lived assets			$ 0	$ 0	$ 0
Number of shares issued under share based compensation | shares			0	0
Deferred offering costs					$ 400,000
Entity Public Float						$ 947,543,802,000
Operating lease ROU assets, net			$ 38,142,000
Lease liabilities			39,369,000
Finance lease ROU assets, net			652,000
Finance lease liabilities			404,000
Accumulated deficit			$ (239,645,000)	$ (139,358,000)
ASU 2016-02
Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle accounting standards update adopted			true
Change in accounting principle accounting standards update adoption date			Jan. 1, 2021
Change in accounting principle accounting standards update immaterial effect			true
Operating lease ROU assets, net							$ 6,000,000
Deferred rent							500,000
Lease liabilities							6,500,000
Finance lease ROU assets, net							0
Finance lease liabilities							0
ASU 2016-02 | Cumulative Effect, Period of Adoption, Adjustment
Summary Of Significant Accounting Policies [Line Items]
Accumulated deficit							$ 0
ASU 2020-10
Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle accounting standards update adopted			true
Change in accounting principle accounting standards update adoption date			Jan. 1, 2021
Change in accounting principle accounting standards update immaterial effect			true
ASU 2019-12
Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle accounting standards update adopted			true
Change in accounting principle accounting standards update adoption date			Jan. 1, 2020
Change in accounting principle accounting standards update immaterial effect			true
ASU 2018-13
Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle accounting standards update adopted			true
Change in accounting principle accounting standards update adoption date			Jan. 1, 2020
Change in accounting principle accounting standards update immaterial effect			true
ASU 2016-13
Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle accounting standards update adopted			true
Change in accounting principle accounting standards update adoption date			Jan. 1, 2020
Change in accounting principle accounting standards update immaterial effect			true
Minimum
Summary Of Significant Accounting Policies [Line Items]
Entity Public Float						$ 700,000,000
Initial Public Offering
Summary Of Significant Accounting Policies [Line Items]
Deferred offering costs offset against IPO proceeds in additional paid-in capital	$ 800,000	$ 4,100,000

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Schedule of Reconciliation of Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Cash and cash equivalents	$ 159,821	$ 5,843
Restricted cash	1,025	108
Total cash, cash equivalents and restricted cash	$ 160,846	$ 5,951

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Schedule of Estimated Useful Lives of Property and Equipment (Details)	12 Months Ended
	Dec. 31, 2021
Laboratory and Manufacturing Equipment
Property Plant And Equipment [Line Items]
Estimated useful lives of property and equipment	5 years
Computer and Office Equipment
Property Plant And Equipment [Line Items]
Estimated useful lives of property and equipment	3 years
Leasehold Improvements
Property Plant And Equipment [Line Items]
Estimated useful lives of property and equipment	Shorter of remaining leaseterm or estimated useful life

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair value assets transfers from level 1 to level 2	$ 0	$ 0
Fair value assets transfers from level 2 to level 1	0	0
Fair value liabilities transfers from level 1 to level 2	0	0
Fair value liabilities transfers from level 2 to level 1	0	0
Fair value assets transfers into level 3	0	0
Fair value assets transfers out of level 3	0	0
Fair value liabilities transfers into level 3	0	0
Fair value liabilities transfers out of level 3	0	0
U.S. Treasury Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Investment securities	0	$ 124,000,000
Allowance for credit losses	$ 0

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Financial Assets Measured at Fair Value on Recurring Basis (Details) - Fair Value, Recurring - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	$ 159,010	$ 128,842
Gross Unrealized Gains		28
Fair Value	159,010	128,870
Level 1 | Money Market Funds Invested in U.S. Government Obligations
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	159,010	4,844
Fair Value	$ 159,010	4,844
Level 2 | U.S. Treasury Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost		123,998
Gross Unrealized Gains		28
Fair Value		$ 124,026

Balance Sheet Components - Addi

Balance Sheet Components - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Balance Sheet Related Disclosures [Abstract]
Prepaid clinical expenses	$ 5,200	$ 100
Depreciation expense	3,100	1,800	$ 700
Accumulated depreciation on capital lease assets	307	$ 100
Lease expense from operating lease right-of-use assets	4,400
Amortization expense from finance lease right-of-use asset	$ 192

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Property, Plant and Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Property Plant And Equipment [Line Items]
Total property and equipment, gross	$ 13,145	$ 11,894
Accumulated depreciation	(6,147)	(3,447)
Total property and equipment, net	6,998	8,447
Laboratory and Manufacturing Equipment
Property Plant And Equipment [Line Items]
Total property and equipment, gross	9,375	8,022
Leasehold Improvements
Property Plant And Equipment [Line Items]
Total property and equipment, gross	2,607	2,550
Capital Leases
Property Plant And Equipment [Line Items]
Total property and equipment, gross		959
Computer and Office Equipment
Property Plant And Equipment [Line Items]
Total property and equipment, gross	293	201
Construction in Progress
Property Plant And Equipment [Line Items]
Total property and equipment, gross	$ 870	$ 162

Balance Sheet Components - Sc_2

Balance Sheet Components - Schedule of Right-of-Use Assets, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Balance Sheet Related Disclosures [Abstract]
Operating Leases, Right-of-use assets	$ 41,141
Operating Leases, Accumulated amortization	(2,999)
Operating Leases, Right-of-use assets, net	38,142
Finance Leases, Right-of-use assets	959
Finance Leases, Accumulated amortization	(307)	$ (100)
Finance Leases, Right-of-use assets, net	652
Right-of-use assets	42,100
Accumulated amortization	(3,306)
Right-of-use assets, net	$ 38,794

Balance Sheet Components - Sc_3

Balance Sheet Components - Schedule of Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Balance Sheet Related Disclosures [Abstract]
Compensation expenses	$ 3,636	$ 2,389
Research and development expenses	2,917	1,303
Professional services	881	241
Property and equipment	215	125
Other	577	115
Total accrued expenses	$ 8,226	$ 4,173

Leases - Additional Information

Leases - Additional Information (Details) $ in Thousands	1 Months Ended				12 Months Ended
	Jul. 31, 2021	Feb. 28, 2021USD ($)	Oct. 31, 2019	Dec. 31, 2016	Dec. 31, 2021USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)Lease
Lessee Lease Description [Line Items]
Operating lease expiration period				2024-08
Minimum future lease payments for initial lease term					$ 55,350
Sublease, expiration period			2022-05
Sublease, renewal term			5 years
Sublease expiration period including possible renewal options			2027-05
Number of capital lease agreements for laboratory equipment | Lease							3
Rent Expense						$ 2,000	$ 1,500
Warehouse Space | Renewed Lease Agreement
Lessee Lease Description [Line Items]
Lessee, operating lease, description					In September 2020, the Company entered into a lease agreement for warehouse space in South San Francisco, California. In July 2021, the Company amended the lease agreement to extend the term of the lease for an additional 96 months to July 2029 and expand the leased premises. In July 2021, the Company occupied the expanded space. Under the amended lease agreement, the Company has a two-year renewal option through July 2031.
Operating lease term, option to extend					two-year renewal option through July 2031
Operating lease, existence of option to extend	true
Operating lease expiration period including possible renewal options	2031-07
Lessee, operating lease, renewal term	96 months
Lessee operating lease renewed agreement expire	2029-07
Laboratory, Manufacturing, Warehouse and Office Space
Lessee Lease Description [Line Items]
Lessee, operating lease, description					In February 2021, the Company entered into a lease agreement for laboratory, manufacturing, warehouse and office space in South San Francisco, California. In June 2021, the Company began occupying a portion of the property. In October 2021, the Company occupied the remainder of the space as its principal office. The lease term is eight years from full occupancy, which occurred in October 2021. Under the lease agreement, the Company has two five-year renewal options. Total minimum future lease payments for the lease term are $47.2 million.
Operating lease term, option to extend					two five-year renewal
Operating lease, existence of option to extend		true
Minimum future lease payments for initial lease term		$ 47,200
Initial lease term		8 years
Lease Agreement
Lessee Lease Description [Line Items]
Lessee, operating lease, description					In December 2016, the Company entered into an operating lease agreement for its former principal office in South San Francisco, California. The lease term expires in August 2024. Under the lease agreement, the Company has two three-year renewal options through August 2030. In October 2021, the Company obtained consent from the landlord to sublease the space. In November 2021, a sublessee took possession of the premises for the remaining lease term.
Operating lease term, option to extend					two three-year renewal options through August 2030.
Operating lease, existence of option to extend				true
Operating lease expiration period including possible renewal options				2030-08
Security deposit					$ 200
Minimum future lease payments for initial lease term					$ 4,300

Leases - Summary of Lease Expen

Leases - Summary of Lease Expense (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021USD ($)
Leases [Abstract]
Operating lease expense	$ 4,363
Finance lease expense:
Amortization expense from finance lease right-of-use asset	192
Interest on lease liabilities	32
Variable lease expense	947
Short-term lease expense	33
Total lease expense	$ 5,567

Leases - Summary of Supplementa

Leases - Summary of Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash paid for amounts included in measurement of liabilities:
Operating cash flows from operating leases	$ 3,663
Operating cash flows from finance leases	32
Financing cash flows from finance leases	232	$ 90	$ 88
Right-of-use asset obtained in exchange for new operating lease liability	$ 35,554

Leases - Schedule of Future Min

Leases - Schedule of Future Minimum Payments under Noncancelable Leases (Details) $ in Thousands	Dec. 31, 2021USD ($)
Operating Lease
2022	$ 7,078
2023	8,401
2024	7,636
2025	6,471
2026	6,653
Thereafter	19,111
Total undiscounted Lease liabilities	55,350
Less: Interest	(15,981)
Total discounted Lease liabilities	39,369
Less: Lease liabilities, current	(3,584)
Lease liabilities, operating lease	35,785
Finance Leases
2022	254
2023	171
Total undiscounted Lease liabilities	425
Less: Interest	(21)
Total discounted Lease liabilities	404
Less: Lease liabilities, current	(237)
Lease liabilities, finance lease	167
Total
2022	7,332
2023	8,572
2024	7,636
2025	6,471
2026	6,653
Thereafter	19,111
Total undiscounted Lease liabilities	55,775
Less: Interest	(16,002)
Total discounted Lease liabilities	39,773
Less: Lease liabilities, current	(3,821)
Lease liabilities, non-current	$ 35,952

Leases - Summary of Lease Terms

Leases - Summary of Lease Terms and Discount Rates (Details)	Dec. 31, 2021
Leases [Abstract]
Operating Leases, Weighted-average remaining lease term (years)	6 years 9 months 14 days
Operating Leases, Weighted-average discount rate	9.73%
Finance Leases, Weighted-average remaining lease term (years)	6 years 9 months 14 days
Finance Leases, Weighted-average discount rate	5.93%

Capital Structure - Additional

Capital Structure - Additional Information (Details)	Jun. 09, 2020shares	Jun. 04, 2020USD ($)$ / sharesshares	Jun. 30, 2020$ / shares	Dec. 31, 2021Vote$ / sharesshares	Dec. 31, 2020$ / sharesshares	Dec. 31, 2020USD ($)$ / sharesshares	Dec. 31, 2019shares	Dec. 31, 2018shares
Class Of Stock [Line Items]
Common stock, shares authorized				450,000,000	450,000,000	450,000,000
Common stock, par value | $ / shares				$ 0.0001	$ 0.0001	$ 0.0001
Common stock, voting rights				The holder of each share of common stock is entitled to one vote.
Number of voting rights for each common stock held | Vote				1
Common stock, dividends declared or paid | $						$ 0
Convertible preferred stock, shares outstanding				0	0	0	13,966,292
Series A Convertible Preferred Stock
Class Of Stock [Line Items]
Convertible preferred stock, shares outstanding							5,157,213	5,157,213
Non-cumulative dividend, convertible preferred stock | $ / shares			$ 0.5119
Series B Convertible Preferred Stock
Class Of Stock [Line Items]
Convertible preferred stock, shares outstanding							3,992,919	3,992,919
Non-cumulative dividend, convertible preferred stock | $ / shares			0.6216
Series C Convertible Preferred Stock
Class Of Stock [Line Items]
Convertible preferred stock, shares outstanding							4,816,160
Non-cumulative dividend, convertible preferred stock | $ / shares			$ 0.6968
Common Stock
Class Of Stock [Line Items]
Conversion of convertible preferred stock into common stock, shares					13,966,292
Initial Public Offering
Class Of Stock [Line Items]
Preferred stock mandatory conversion into common stock offering price trigger | $ / shares		$ 13.065
Minimum proceeds from mandatory conversion triggers of preferred stock into common stock | $		$ 50,000,000
Initial Public Offering | Common Stock
Class Of Stock [Line Items]
Conversion of convertible preferred stock into common stock, shares	13,966,292	13,966,292

Capital Structure - Schedule of

Capital Structure - Schedule of Common Stock Reserved for Future Issuance (Details) - shares	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Class Of Stock [Line Items]
Common stock reserved for future issuance	8,673,536	7,189,851	17,545,062
Total Stock Options Outstanding
Class Of Stock [Line Items]
Common stock reserved for future issuance	4,442,864	3,506,599	2,143,368
Unvested Restricted Stock Units
Class Of Stock [Line Items]
Common stock reserved for future issuance	717,440
Stock Options and Restricted Stock Units, Authorized for Future Issuance
Class Of Stock [Line Items]
Common stock reserved for future issuance	2,876,270	3,369,246	1,435,402
Employee Stock Purchase Plan, Available for Future Grants
Class Of Stock [Line Items]
Common stock reserved for future issuance	636,962	314,006
Series A Convertible Preferred Stock
Class Of Stock [Line Items]
Common stock reserved for future issuance			5,157,213
Series B Convertible Preferred Stock
Class Of Stock [Line Items]
Common stock reserved for future issuance			3,992,919
Series C Convertible Preferred Stock
Class Of Stock [Line Items]
Common stock reserved for future issuance			4,816,160

Capital Structure - Schedule _2

Capital Structure - Schedule of Issued and Outstanding Convertible Preferred Stock and its Principal Terms (Details) - USD ($) $ / shares in Units, $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Temporary Equity [Line Items]
Shares Authorized			13,966,292
Shares Issued			13,966,292
Shares Outstanding	0	0	13,966,292
Aggregate Liquidation Amount			$ 105,974
Net Carrying Value			$ 105,615
Series A
Temporary Equity [Line Items]
Shares Authorized			5,157,213
Shares Issued			5,157,213
Shares Outstanding			5,157,213	5,157,213
Original Issue Price Per Share			$ 6.3988
Aggregate Liquidation Amount			$ 33,000
Net Carrying Value	$ 0		$ 32,826	$ 32,826
Series B
Temporary Equity [Line Items]
Shares Authorized			3,992,919
Shares Issued			3,992,919
Shares Outstanding			3,992,919	3,992,919
Original Issue Price Per Share			$ 7.7700
Aggregate Liquidation Amount			$ 31,025
Net Carrying Value	0		$ 30,921	$ 30,921
Series C
Temporary Equity [Line Items]
Shares Authorized			4,816,160
Shares Issued			4,816,160
Shares Outstanding			4,816,160
Original Issue Price Per Share			$ 8.7100
Aggregate Liquidation Amount			$ 41,949
Net Carrying Value	$ 0		$ 41,868

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	1 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax [Line Items]
Provision for, or benefit from, income taxes		$ 0	$ 0	$ 0
Net increase in valuation allowance		$ 26,600,000	21,400,000
Income tax examination description		Due to net operating loss and credit carryforwards, all of the tax years since the date of incorporation through the 2021 tax year remain subject to examination by the U.S. federal and some state authorities.
Significant changes to unrecognized tax benefits over next 12 months		$ 0
Interest or penalties recognized relating to unrecognized tax benefits		0	0	$ 0
Tax impact related to unrecognized tax benefit in relation to valuation allowance positions		$ 0	$ 0
Minimum
Income Tax [Line Items]
Cumulative ownership percentage change		50.00%
Federal
Income Tax [Line Items]
Net operating loss carryforwards		$ 252,100,000
Federal | General Business Credits
Income Tax [Line Items]
Tax credit carryforward		$ 8,000,000
Tax credit carryforward expiration year		2037
State
Income Tax [Line Items]
Net operating loss carryforwards		$ 69,400,000
Operating loss carryforwards expiration year		2030
State | Research and Development Credits
Income Tax [Line Items]
Tax credit carryforward		$ 5,700,000
Operating Losses Generated after December 31, 2017
Income Tax [Line Items]
Operating loss carryforwards percentage of taxable income limitation	80.00%
Operating Losses Generated after December 31, 2017 | Federal
Income Tax [Line Items]
Net operating loss carryforwards		238,400,000
Operating Losses Generated before January 1, 2018 | Federal
Income Tax [Line Items]
Net operating loss carryforwards		$ 13,300,000
Operating loss carryforwards expiration year		2036

Income Taxes - Schedule of Effe

Income Taxes - Schedule of Effective Income Tax Rate Provision for Income Taxes Differed from Federal Statutory Rate (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Statutory income tax rate	21.00%	21.00%	21.00%
Stock-based compensation expense	2.20%	8.20%	(0.30%)
State income tax	2.10%	1.20%	9.80%
Tax credits	2.00%	1.80%	4.70%
Other	(0.80%)		(0.10%)
Valuation allowance	(26.50%)	(32.20%)	(35.10%)

Income Taxes - Schedule of Sign

Income Taxes - Schedule of Significant Components of Deferred Tax Assets for Federal and State Income Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Net operating losses	$ 58,025	$ 37,785
Tax credits	9,874	5,805
Lease liabilities	8,274
Stock-based compensation expense	2,129	350
Accrued expenses	728	617
Other current assets	135	6
Total deferred tax assets	79,165	44,563
Deferred tax liabilities:
Right-of-use assets	(8,016)
Total deferred tax liabilities	(8,016)
Valuation allowance	$ (71,149)	$ (44,563)

Income Taxes - Schedule of Reco

Income Taxes - Schedule of Reconciliation of Beginning and Ending Amounts of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Gross unrecognized tax benefit as of January 1	$ 1,499	$ 1,012	$ 390
Additions for tax positions taken in the current year	1,080	626	407
Reductions for tax positions taken in the current year		(139)
Additions for tax positions taken in prior years			215
Gross unrecognized tax benefit as of December 31	$ 2,579	$ 1,499	$ 1,012

Equity Incentive Plan and Sto_3

Equity Incentive Plan and Stock-Based Compensation Expense - Additional Information (Details) - USD ($)	May 31, 2020	May 14, 2020	May 31, 2020	Jun. 30, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Mar. 31, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award granted					2,026,976	2,598,319	773,688
Common stock reserved for future issuance					8,673,536	7,189,851	17,545,062
Share expirations during period						576,670
Stock-based compensation expense					$ 16,698,000	$ 3,056,000	$ 468,000
Options granted in period weighted average exercise price					$ 49.49	$ 7.82	$ 2.38
Increase in fair value of modified option grants		$ 500,000
Remaining requisite service period		3 years 3 months 18 days
Weighted-average grant-date fair value of the options granted					$ 32.05	$ 5.88	$ 1.61
Intrinsic value of options exercised					$ 20,800,000	$ 29,500,000	$ 0
Total unrecognized stock-based compensation expense related to stock options granted					$ 55,100,000
Total unrecognized stock-based compensation expense related to nonvested awards weighted average period of recognition					2 years 7 months 2 days
Employee Stock Purchase Plan, Available for Future Grants
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Purchase price of common stock percent	85.00%
Common stock reserved for future issuance					636,962	314,006
Shares available for issuance	314,006		314,006		636,962
Outstanding stock percent	1.00%
Stock-based compensation expense					$ 300,000	$ 0	$ 0
Sock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for future issuance					4,442,864	3,506,599	2,143,368
Stock Options and Restricted Stock Unit | Employee Stock Purchase Plan, Available for Future Grants
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares available for issuance					2,876,270
Unvested Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for future issuance					717,440
Total unrecognized stock-based compensation expense related to nonvested awards weighted average period of recognition					1 year 11 months 1 day
Total stock-based compensation expense related to unvested restricted stock units and awards					$ 10,000,000
Maximum [Member] | Employee Stock Purchase Plan, Available for Future Grants
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Discount rate	15.00%
Minimum | Employee Stock Purchase Plan, Available for Future Grants
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Increase in number of shares	628,012		628,012
2015 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award granted					0
Equity Incentive plan term					In connection with its 2016 conversion to a C-corporation, each outstanding stock option agreement under the 2015 Plan was assumed by it and converted into stock options covering shares of its common stock rather than Class B common stock of its predecessor entity. Except with respect to the shares underlying such options, no other terms were amended with respect to such stock option agreements.
2016 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period					4 years
Common stock reserved for future issuance								1,250,000
Number of stock option approved for one-time repricing			1,998,677
Options granted in period weighted average exercise price			$ 6.14	$ 5.18		$ 6.48
Stock options exercise price at the repricing date			$ 4.61
2016 Plan | 10% Stockholder
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of voting power					10.00%
2016 Plan | Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Term of options					10 years
2016 Plan | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Purchase price of common stock percent					100.00%
Percentage of exercise price of stock option on estimated fair value of shares					110.00%
2020 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity Incentive plan term					Shares subject to awards granted under the 2015 Plan or 2016 Plan were added to the available shares in the 2020 Plan. Shares subject to awards granted under the 2015 Plan and 2016 Plan that are repurchased by, or forfeited to, the Company will also be reserved for issuance under the 2020 Plan
Vesting period					4 years
Common stock reserved for future issuance					3,768,075
2020 Plan | Sock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period					4 years
2020 Plan | Unvested Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period					2 years
2020 Plan | 10% Stockholder
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of voting power					10.00%
2020 Plan | Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Term of options					10 years
2020 Plan | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Purchase price of common stock percent					100.00%
Percentage of exercise price of stock option on estimated fair value of shares					110.00%

Equity Incentive Plan and Sto_4

Equity Incentive Plan and Stock-Based Compensation Expense - Summary of Components of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 16,698	$ 3,056	$ 468
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	8,596	1,943	338
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 8,102	$ 1,113	$ 130

Equity Incentive Plan and Sto_5

Equity Incentive Plan and Stock-Based Compensation Expense - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Options Outstanding, Total Options Outstanding, Beginning Balance	3,506,599	2,143,368	1,774,858
Options Outstanding, Total Options Outstanding, Granted	2,026,976	2,598,319	773,688
Options Outstanding, Total Options Outstanding, Exercised	(595,339)	(1,144,330)
Options Outstanding, Total Options Outstanding, Cancelled	(495,372)	(90,758)	(405,178)
Options Outstanding, Total Options Outstanding, Ending Balance	4,442,864	3,506,599	2,143,368
Options Outstanding, Total Options Outstanding, Exercisable as of December 31, 2020	1,492,153
Options Outstanding, Weighted-Average Exercise Price, Beginning Balance	$ 6.27	$ 1.22	$ 0.84
Options Outstanding, Weighted-Average Exercise Price, Granted	49.49	7.82	2.38
Options Outstanding, Weighted-Average Exercise Price, Exercised	3.57	0.55
Options Outstanding, Weighted-Average Exercise Price, Cancelled	21.69	3.43	1.81
Options Outstanding, Weighted-Average Exercise Price, Ending Balance	24.63	$ 6.27	$ 1.22
Options Outstanding, Weighted-Average Exercise Price, Exercisable	$ 11.68
Options Outstanding, Weighted-Average Remaining Contractual Life (in years)	8 years 4 months 17 days	8 years 9 months 14 days	7 years 3 months 18 days
Options Outstanding, Weighted-Average Remaining Contractual Life (in years), Exercisable	7 years 7 months 20 days
Options Outstanding, Aggregate Intrinsic Value	$ 22,850	$ 85,975	$ 10,555	$ 2,815
Options Outstanding, Aggregate Intrinsic Value, Exercisable	$ 12,480

Equity Incentive Plan and Sto_6

Equity Incentive Plan and Stock-Based Compensation Expense - Schedule of Weighted-Average Assumptions Used for Estimating Fair Value of Each Employee Stock Option (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Risk-free interest rate	1.00%	0.60%	2.30%
Expected volatility	73.90%	75.60%	70.00%
Expected term (years)	6 years 18 days	6 years 1 month 6 days	6 years 29 days

Equity Incentive Plan and Sto_7

Equity Incentive Plan and Stock-Based Compensation Expense - Summary of Restricted Stock Unit Activity (Details) - Restricted Stock Units (RSUs)	12 Months Ended
	Dec. 31, 2021$ / sharesshares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares, Granted | shares	717,440
Number of Shares, Outstanding as of December 31, 2021 | shares	717,440
Weighted-Average Grant Date Fair Value per Share, Granted | $ / shares	$ 14.54
Weighted-Average Grant Date Fair Value per Share, Outstanding as of December 31, 2021 | $ / shares	$ 14.54

Net Loss and Net Loss Per Sha_3

Net Loss and Net Loss Per Share - Schedule of Computation of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Numerator:
Net loss	$ (100,287)	$ (66,564)	$ (28,043)
Denominator:
Weighted-average shares of common stock outstanding used in the calculation of basic and diluted net loss per share	37,591,505	22,878,325	7,360,738
Net loss per share, basic and diluted	$ (2.67)	$ (2.91)	$ (3.81)

Net Loss and Net Loss Per Sha_4

Net Loss and Net Loss Per Share - Summary of Potentially Dilutive Securities (Details) - shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of net loss per share	5,160,304	3,506,599	16,109,660
Total Stock Options Outstanding
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of net loss per share	4,442,864	3,506,599	2,143,368
Restricted Stock Units (RSUs)
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of net loss per share	717,440
Series A Convertible Preferred Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of net loss per share			5,157,213
Series B Convertible Preferred Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of net loss per share			3,992,919
Series C Convertible Preferred Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of net loss per share			4,816,160

Subsequent Event - Additional I

Subsequent Event - Additional Information (Details) - USD ($) $ in Thousands	Jan. 27, 2022	Dec. 31, 2021	Dec. 31, 2020
Subsequent Event [Line Items]
Number of shares offered and sold from time to time		$ 112,801	$ 160,623
Subsequent Event | At The Market | Sales Agreement | Agents
Subsequent Event [Line Items]
Number of shares offered and sold from time to time	$ 150,000