Applied Molecular Transport (AMTI) 10-K 9 Mar 23 2022 FY Annual report Financial data

Cover Page

Cover Page - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Mar. 02, 2023	Jun. 30, 2022
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2022
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-39306
Entity Registrant Name	APPLIED MOLECULAR TRANSPORT INC.
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
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Trading Symbol	AMTI
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	false
Entity Shell Company	false
Entity Public Float			$ 60.3
Entity Common Stock Shares Outstanding		39,200,952
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 2023 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, 2022.
Entity Central Index Key	0001801777
Document Fiscal Period Focus	FY
Amendment Flag	false
Document Fiscal Year Focus	2022

Audit Information

Audit Information	12 Months Ended
	Dec. 31, 2022
Auditor Information [Abstract]
Auditor Firm ID	34
Auditor Name	Deloitte & Touche LLP
Auditor Location	San Francisco, California

Balance Sheets

Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 61,145	$ 159,821
Prepaid expenses	2,688	6,685
Other current assets	186	594
Total current assets	64,019	167,100
Property and equipment, net	8,183	6,998
Operating lease right-of-use assets	33,222	38,142
Finance lease right-of-use assets	584	652
Restricted cash	916	1,025
Other assets	522	121
Total assets	107,446	214,038
Current liabilities:
Accounts payable	1,583	2,211
Accrued expenses	8,660	8,226
Lease liabilities, operating lease - current	4,639	3,584
Lease liabilities, finance lease - current	205	237
Total current liabilities	15,087	14,258
Lease liabilities, operating lease	31,228	35,785
Lease liabilities, finance lease	49	167
Other liabilities	244	241
Total liabilities	46,608	50,451
Commitments and contingencies (Note 8)
Stockholders’ equity:
Preferred stock, $0.0001 par value: 50,000,000 shares authorized; none issued and outstanding	0	0
Common stock, $0.0001 par value: 450,000,000 shares authorized; 39,181,801 and 38,619,957 shares issued and outstanding as of December 31, 2022 and 2021, respectively	4	4
Additional paid-in capital	426,804	403,228
Accumulated deficit	(365,970)	(239,645)
Total stockholders’ equity	60,838	163,587
Total liabilities and stockholders’ equity	$ 107,446	$ 214,038

Balance Sheets (Parenthetical)

Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)	50,000,000	50,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	450,000,000	450,000,000
Common stock, shares issued (in shares)	39,181,801	38,619,957
Common stock, shares outstanding (in shares)	39,181,801	38,619,957

Statements of Operations and Co

Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating expenses:
Research and development	$ 89,826	$ 71,448	$ 53,936
General and administrative	37,393	29,341	12,746
Total operating expenses	127,219	100,789	66,682
Loss from operations	(127,219)	(100,789)	(66,682)
Interest income, net	898	626	229
Other expense, net	(4)	(124)	(111)
Net loss	$ (126,325)	$ (100,287)	$ (66,564)
Net loss per share, basic (in dollars per share)	$ (3.25)	$ (2.67)	$ (2.91)
Net loss per share, diluted (in dollars per share)	$ (3.25)	$ (2.67)	$ (2.91)
Weighted-average shares of common stock outstanding, basic (in shares)	38,837,001	37,591,505	22,878,325
Weighted-average shares of common stock outstanding, diluted (in shares)	38,837,001	37,591,505	22,878,325
Comprehensive loss:
Net loss	$ (126,325)	$ (100,287)	$ (66,564)
Other comprehensive income (loss):
Net unrealized gains (losses) on investments	0	(27)	33
Amounts recognized for net realized gain included in net loss	0	0	(19)
Total comprehensive loss	$ (126,325)	$ (100,314)	$ (66,550)

Statements of Stockholders_ Equ

Statements of Stockholders’ Equity - USD ($) $ in Thousands	Total	Series A Convertible Preferred Stock [Member]	Series B	Series C	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2019		5,157,213	3,992,919	4,816,160
Beginning balance at Dec. 31, 2019		$ 32,826	$ 30,921	$ 41,868
Increase (Decrease) in Temporary Equity [Roll Forward]
Conversion of convertible preferred stock into common stock, shares (in shares)		(5,157,213)	(3,992,919)	(4,816,160)
Conversion of convertible preferred stock into common stock		$ (32,826)	$ (30,921)	$ (41,868)
Ending balance (in shares) at Dec. 31, 2020		0	0	0
Ending balance at Dec. 31, 2020		$ 0	$ 0	$ 0
Beginning balance (in shares) at Dec. 31, 2019					7,360,738
Beginning balance at Dec. 31, 2019	$ (71,702)				$ 1	$ 1,078	$ 13	$ (72,794)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of convertible preferred stock into common stock, shares (in shares)					13,966,292
Conversion of convertible preferred stock into common stock	105,615				$ 1	105,614
Issuance of common stock upon initial public offering, net of underwriters’ commission and issuance costs (in shares)					12,650,000
Issuance of common stock upon initial public offering, net of underwriters’ commission and issuance costs	$ 160,623				$ 1	160,622
Exercise of common stock, shares (in shares)	1,144,330				1,144,330
Exercise of common stock options	$ 631				$ 1	630
Stock-based compensation expense	3,056					3,056
Other comprehensive loss	14						14
Net loss	(66,564)							(66,564)
Ending balance (in shares) at Dec. 31, 2020					35,121,360
Ending balance at Dec. 31, 2020	131,673				$ 4	271,000	27	(139,358)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon initial public offering, net of underwriters’ commission and issuance costs (in shares)					2,875,000
Issuance of common stock upon initial public offering, net of underwriters’ commission and issuance costs	112,801					112,801
Issuance of common stock from employee stock purchase plan (in shares)					28,258
Issuance of common stock from employee stock purchase plan	$ 607					607
Exercise of common stock, shares (in shares)	595,339				595,339
Exercise of common stock options	$ 2,122					2,122
Stock-based compensation expense	16,698					16,698
Other comprehensive loss	(27)						(27)
Net loss	$ (100,287)							(100,287)
Ending balance (in shares) at Dec. 31, 2021	38,619,957				38,619,957
Ending balance at Dec. 31, 2021	$ 163,587				$ 4	403,228	0	(239,645)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock from employee stock purchase plan (in shares)					150,369
Issuance of common stock from employee stock purchase plan	$ 311					311
Exercise of common stock, shares (in shares)	53,709				53,709
Exercise of common stock options	$ 98					98
Issuance of common stock upon vesting of restricted stock units (in shares)	357,766
Stock-based compensation expense	$ 23,167					23,167
Net loss	$ (126,325)							(126,325)
Ending balance (in shares) at Dec. 31, 2022	39,181,801				39,181,801
Ending balance at Dec. 31, 2022	$ 60,838				$ 4	$ 426,804	$ 0	$ (365,970)

Statements of Stockholders_ E_2

Statements of Stockholders’ Equity (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Statement of Stockholders' Equity [Abstract]
Issuance of common stock upon initial public offering and follow-on offering, underwriters' commission and issuance costs	$ 7,947	$ 16,477

Statements of Cash Flows

Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating activities
Net loss	$ (126,325)	$ (100,287)	$ (66,564)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	23,167	16,698	3,056
Depreciation and amortization	3,128	3,251	1,842
Non-cash operating lease expense	8,294	4,363	0
Loss on impairment of property and equipment	80	0	0
(Gain) loss on disposal of property and equipment	(1)	74	2
Net accretion of discounts on investments	0	(71)	(116)
Changes in operating assets and liabilities:
Prepaid expenses	3,997	(5,374)	(779)
Other current assets	1,252	(273)	(315)
Other assets	(401)	6	505
Accounts payable	(645)	(1,557)	840
Accrued expenses	427	3,983	2,647
Operating lease liabilities	(6,876)	(3,663)	0
Other liabilities	3	241	(12)
Net cash used in operating activities	(93,900)	(82,609)	(58,894)
Investing activities
Proceeds from sales and maturities of investments	0	124,070	84,236
Purchases of property and equipment	(4,152)	(1,864)	(5,315)
Purchases of investments	0	0	(188,207)
Net cash (used in) provided by investing activities	(4,152)	122,206	(109,286)
Financing activities
Proceeds from follow-on offering, net of underwriters' commission	0	113,505	0
Proceeds from exercise of common stock options	98	2,122	631
Proceeds from issuance of common stock from employee stock purchase plan	311	607	0
Principal payments on finance leases	(266)	(232)	(90)
Proceeds from issuance of common stock upon initial public offering, net of underwriters' commission	0	0	164,703
Payments for financing and offering costs	(876)	(704)	(3,948)
Net cash (used in) provided by financing activities	(733)	115,298	161,296
Net (decrease) increase in cash, cash equivalents and restricted cash	(98,785)	154,895	(6,884)
Cash, cash equivalents and restricted cash beginning of year	160,846	5,951	12,835
Cash, cash equivalents and restricted cash end of year	62,061	160,846	5,951
Supplemental cash flow data:
Cash paid for interest on finance leases	27	32	14
Supplemental disclosure of non-cash investing and financing activities:
Property and equipment included in accrued expenses and accounts payable	23	664	506
Conversion of convertible preferred stock into common stock	0	0	105,615
Equipment acquired through capital lease	$ 0	$ 0	$ 626

Organization and Principal Acti

Organization and Principal Activities	12 Months Ended
	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Principal Activities	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. The Company’s principal operations are in the United States with its headquarters in South San Francisco, California. Since the date of incorporation in Delaware on November 21, 2016, the Company has devoted substantial 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. Liquidity and Substantial Doubt about Going Concern The Company has incurred net losses in each reporting period since inception, including net losses of $126.3 million and $100.3 million for the years ended December 31, 2022 and 2021, respectively, resulting in an accumulated deficit of $366.0 million at December 31, 2022. As of December 31, 2022, the Company had approximately $61.1 million in cash and cash equivalents and anticipates it will continue to incur net losses for the foreseeable future. Without additional funding, the Company’s current liquidity is not sufficient to fund its projected operating requirements for a twelve-month period. Based upon the foregoing, management has concluded that there is substantial doubt about the Company’s ability to continue as a going concern within one year after the date the financial statements are issued. The financial statements as of December 31, 2022 have been prepared under the assumption that the Company will continue as a going concern, which contemplates continuity of operations, the realization of assets and the satisfaction of liabilities and commitments in the normal course of business. The Company’s ability to continue as a going concern is dependent upon its ability to obtain additional capital, reduce expenditures and/or execute on its business plan. The financial statements as of December 31, 2022 do not include any adjustments that might result from the outcome of this uncertainty. The Company has invested significant financial resources in research and development activities and has historically financed its operations primarily through private placements of convertible preferred stock and the sale of common stock in public equity issuances, such as an IPO in June 2020 and a follow-on equity offering in April 2021. The Company plans to secure additional capital through a combination of public or private equity offerings, debt financings, licensing arrangements, collaboration agreements or other arrangements with other companies, asset sales, 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. If the Company is unable to obtain sufficient funds on acceptable terms when needed, the Company may be required to reduce operating expenses, delay or reduce the scope of its development efforts, obtain funds through arrangements with others that may require the Company to relinquish rights to certain of its technologies or products that the Company would otherwise seek to develop or commercialize, or cease operations. In January 2022, the Company entered into a Sales Agreement with SVB Securities 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 $150.0 million in shares of the Company’s common stock through an “at-the-market” program (ATM Facility). The shares will be offered and sold pursuant to the Company’s shelf registration statement on Form S-3 (File No. 333-263501) and the final prospectus supplement, which was filed on March 11, 2022. For so long as the Company’s non-affiliate public float does not exceed $75 million, the amount of securities that the Company may sell pursuant to registration statements on Form S-3 will be limited to the equivalent of one-third of its public float, which will limit its ability to raise capital. As of December 31, 2022, the Company has not yet sold any shares under the ATM facility. Strategic Plan Announcement In May 2022, the Company implemented a strategic plan to focus the business on its clinical program for AMT-101 (Strategic Plan). The Strategic Plan is intended to preserve capital, ensuring that the Company is appropriately resourced to advance AMT-101 through key development milestones. Under the Strategic Plan, the Company reduced its then current workforce by approximately 40%. Impacted employees were eligible to receive severance benefits and company-funded COBRA premiums, contingent upon an impacted employee’s execution (and non-revocation) of a customary separation agreement, which included a general release of claims against the Company. In connection with the Strategic Plan, the Company recognized restructuring charges of approximately $3.8 million for the year ended December 31, 2022. These restructuring charges were primarily related to severance payments and other employee-related separation costs of $3.3 million, contract termination fees of $0.5 million, a lease termination fee of $0.3 million, impairment of property and equipment of $0.1 million and insignificant legal expenses, partially offset by a $0.4 million reduction in stock-based compensation expense as a result of applying modification accounting for accelerated vesting of RSUs. As of December 31, 2022, accrued contract termination fees of $0.4 million remained unpaid and are expected to be paid within one year. Risks and Uncertainties The COVID-19 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 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. The Company continues to have a hybrid work environment with a majority of the Company’s workforce either working exclusively from home or working from home for part of their work week. The Company’s financial results could be affected by the COVID-19 pandemic in various ways. As a result of the COVID-19 pandemic, the Company has experienced and could experience disruptions that could severely impact the Company’s business, current and planned critical trials and preclinical studies. For example, the COVID-19 pandemic could result in delays to the Company’s clinical trials and preclinical studies for numerous reasons including difficulties in enrolling patients or healthy volunteers, diversion of healthcare resources away from the conduct of clinical trials, delays in receiving regulatory authorities to initiate clinical trials, and delays in receiving supplies to conduct clinical trials and preclinical studies. There has also been an increase in infections from COVID-19 variants which has impacted patient recruitment at certain of the Company’s clinical trial sites and could result in increased costs and delays. In addition, as a result of ongoing COVID-19 research and the current global supply chain issues, there is currently limited availability for certain resources required to conduct some of the Company’s preclinical studies and clinical trials, which may result in longer lead times, increased costs, and delays in completing preclinical studies and clinical trials. As a result, research and development expenses and general and administrative expenses may vary significantly if there is an increased impact from COVID-19 on the costs and timing associated with the conduct of the clinical trial and other related business activities. The Company is carefully monitoring the pandemic and the potential length and depth of the resulting economic impact on the Company’s financial condition and results of operations as of December 31, 2022. In addition, currently there is a conflict between Russia and Ukraine. Certain of the Company’s completed clinical trials included clinical trial sites located in Ukraine, Russia, and other Eastern European countries. The Board of Directors of the Company (Board of Directors) is receiving management reports and discusses with management at board meetings macro-economic and geopolitical developments, including the conflict between Russia and Ukraine and the impact on the Company’s personnel, cybersecurity, sanctions and the Company’s clinical trial sites located in the region so that the Company can be prepared to react to new developments as they arise. This conflict has and may continue to impact the Company’s ability to conduct certain of its clinical trials in Ukraine, Russia and other Eastern European countries. This could negatively impact the completion of the Company’s clinical trials and/or analyses of clinical results or result in increased costs, all of which could materially harm the Company’s business. The Board of Directors is monitoring and continues to assess and monitor risks related to the conflict between Russia and Ukraine.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	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 (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 sheets and expenses and income reported are affected by estimates and assumptions, which are used for, but are not limited to, recording research and development expenses and related accruals, and determining the fair value of stock options for 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 and cash equivalents. 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 to the extent recorded in the balance sheets. The Company’s cash equivalents consist of money market funds that invests all of its assets in direct obligations of the U.S. Treasury. Although the fund invests in U.S. government obligations, an investment in such funds is neither insured nor guaranteed by the U.S. government. The Company has not experienced any losses on its deposits of cash or holdings of money market funds. The Company is subject to a number of risks similar to other clinical-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 or develop internal manufacturing capabilities. The Company’s product candidates will require approval from the U.S. Food and Drug Administration (FDA) and/or comparable foreign regulatory agencies prior to commercialization in their respective jurisdictions. 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. 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 As of December 31, 2022, the Company had $0.9 million in restricted cash, which was classified as long-term on the Company’s balance sheets. The restricted cash was attributable to a letter of credit issued by the Company in connection with the operating lease for the Company’s headquarters (See Note 5). The letter of credit will expire 90 days after the expiration of the lease in 2029. For the year ended December 31, 2022, the Company collected its $0.1 million letter of credit associated with the expiration of an operating lease. The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the statements of cash flows for the periods indicated (in thousands): December 31, 2022 2021 Cash and cash equivalents $ 61,145 $ 159,821 Restricted cash 916 1,025 Total cash, cash equivalents and restricted cash $ 62,061 $ 160,846 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 were no material impairments of long-lived assets during the years ended December 31, 2022, 2021 and 2020. Leases In February 2016, the Financial Accounting Standards Board (FASB) issued an Accounting Standard Update (ASU) No. 2016-02, Leases (Topic 842) , and its associated amendments, that established a right-of-use (ROU) model that requires a lessee to recognize an 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 Topic 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 sheets. 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. Fixed lease payments on operating leases are recognized as lease expense over the expected term of the lease on a straight-line basis. The Company’s real estate operating leases require payment of common area maintenance, real estate taxes, and insurance. These components are recognized as variable lease expense in the period in which the obligation is incurred. As these costs are generally variable in nature, they are not included in the measurement of the operating lease ROU asset and related lease liability. Fixed and variable lease expense on operating leases is recognized within operating expenses within the Company’s statements of operations and comprehensive loss. Sublease income is recognized on a straight-line basis over the sublease term and is recorded net against the head lease expense. The Company has various finance leases for laboratory 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. 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 both an equity incentive plan and an employee stock purchase plan (ESPP) as long-term incentives for its employees, consultants, and non-employee directors. Under the equity incentive plan, the Company is authorized to grant various equity-based incentives including stock options and restricted stock units (RSUs). The ESPP provides for 24-month offering periods and each offering period may contain up to four six-month purchase periods. The ESPP allows employees to purchase shares of the Company’s common stock each purchase period based on a percentage of their compensation subject to certain limits. 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 grant-date fair values for options and RSUs are recorded as stock-based compensation expense on a straight-line basis over the grantee’s requisite service period, which is generally over a four-year period, subject to continuing service. The grant-date fair values for purchase rights granted under the ESPP are recorded as stock-based compensation expense on a straight-line basis over the applicable offering period. Actual forfeitures of unvested equity awards are recognized as they occur by reversing any expense previously recorded for the award. The Company estimates the fair value of stock options granted to employees and non-employees using the Black-Scholes model. The Company estimates the fair value of purchase rights granted under the ESPP for an offering period 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 objective of the asset and liability method is to establish deferred tax assets and liabilities for the temporary differences between the financial reporting basis and the income tax basis of the Company’s assets and liabilities at enacted tax rates expected to be in effect when such amounts are realized or settled. Deferred income tax assets represent amounts available to reduce income taxes payable on taxable income in future years. Such assets arise because of temporary differences between the financial reporting and tax bases of assets and liabilities, as well as from net operating loss and tax credit carryforwards. The Company records net deferred tax assets to the extent these assets will more likely than not be realized. In making such determination, all available positive and negative evidence are considered, including scheduled reversals of deferred tax liabilities, projected future taxable income, tax planning strategies and recent financial performance. Valuation allowances are established when necessary on a jurisdictional basis to reduce deferred tax assets to the amounts expected to be realized. As of December 31, 2022 and 2021, a full valuation allowance has been established to offset the net deferred tax assets due to the uncertainties surrounding the Company’s ability to generate future taxable income to realize these assets. In the event the Company determines that it would be able to realize all or a portion of its deferred income tax assets in the future, it would make an adjustment to the valuation allowance which would reduce the provision for income taxes in the period in which the adjustments are determined. 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 of Financial Instruments The Company’s financial instruments, including cash, restricted cash, other current assets, accounts payable and accrued expenses are carried at cost which approximates their fair value because of the short-term nature of these financial instruments. See Note 3 for cash equivalents, which are carried at fair value on a recurring basis. 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, which consist of direct incremental legal, consulting, banking and accounting fees relating to anticipated equity offerings, are capitalized and will be offset against proceeds upon the consummation of the offerings within stockholders’ equity. In the event an anticipated offering is terminated or significantly delayed, deferred offering costs will be immediately expensed as part of general and administrative expenses. There were no capitalized deferred offering costs recorded on the balance sheets as of December 31, 2022 and 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 lease agreements that contain both lease components (for example fixed rent payments) and non-lease components (for example, common-area maintenance costs), and has elected to combine lease and non-lease components for all classes of assets. The Company also elected the package of practical expedients available for existing contracts, 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 . ASU 2019-12 eliminates certain exceptions for recognizing deferred taxes for investments, performing intraperiod allocation and calculating income taxes in interim periods. This ASU also includes guidance to reduce complexity in certain areas, including recognizing deferred taxes for tax goodwill and allocating taxes to members of a consolidated group. ASU 2019-12 is effective for annual and interim periods in fiscal years beginning after December 15, 2020. Early adoption is permitted. The Company adopted this ASU effective January 1, 2020 on a prospective basis. The adoption did not have a material impact on the Company’s financial statements. In August 2018, the FASB issued ASU 2018-13, Disclosure Framework (Topic 820) – Changes to the Disclosure Requirements for Fair Value Measurement , which amended Accounting Standards Codification 820, Fair Value Measurement. This standard modifies the disclosure requirements for fair value measurements by removing, modifying, or adding certain disclosures. The Company adopted this ASU effective January 1, 2020. The adoption did not have a material impact on the Company’s financial statements and related disclosures. 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, 2022
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements 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, 2022 and 2021, money market funds were the only financial instrument measured and recorded at fair value on a recurring basis on the Company’s balance sheets. Money market funds were recorded within cash and cash equivalents. The following tables present money market funds at their level within the fair value hierarchy for the periods indicated (in thousands): December 31, 2022 Fair Value Hierarchy Level Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash equivalents: Money market funds Level 1 $ 40,729 $ — $ — $ 40,729 December 31, 2021 Fair Value Hierarchy Level Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash equivalents: Money market funds Level 1 $ 159,010 $ — $ — $ 159,010

Balance Sheet Components

Balance Sheet Components	12 Months Ended
	Dec. 31, 2022
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Components	Balance Sheet Components Prepaid Expenses Prepaid clinical expenses were $1.2 million and $5.2 million as of December 31, 2022 and 2021, respectively. As of December 31, 2022 and 2021, prepaid expenses also consisted of amounts for insurance and other services. Property and Equipment, Net Property and equipment, net, consisted of the following (in thousands): December 31, 2022 2021 Laboratory and manufacturing equipment $ 11,421 $ 9,375 Leasehold improvements 5,246 2,607 Construction in progress 72 870 Computer and office equipment 491 293 17,230 13,145 Accumulated depreciation (9,047) (6,147) Total property and equipment, net $ 8,183 $ 6,998 Depreciation was $2.9 million, $3.1 million and $1.8 million for the years ended December 31, 2022, 2021 and 2020, respectively. There were insignificant disposals during the years ended December 31, 2022, 2021 and 2020. Accrued Expenses Accrued expenses consisted of the following (in thousands): December 31, 2022 2021 Compensation expenses $ 3,985 $ 3,636 Research and development expenses 3,508 2,917 Professional services 728 881 Property and equipment 7 215 Other 432 577 Total accrued expenses $ 8,660 $ 8,226 Accrued research and development expenses were primarily related to clinical trials, preclinical studies, contract manufacturing and materials.

Leases

Leases	12 Months Ended
	Dec. 31, 2022
Leases [Abstract]
Leases	Leases Operating Leases The Company has operating leases for its corporate offices, laboratory, and manufacturing and warehouse facilities. The leases include renewal options to extend the lease term, which were not included in the measurement of the right-of-use asset and the associated lease liability as it was not reasonably certain that the Company would exercise the options. In February 2021, the Company entered into an operating lease for its headquarters comprising 84,321 of rentable square feet of office, laboratory and manufacturing space in South San Francisco, California (HQ Lease), delivered in two phases. In July 2021, the Company began occupying a portion of the building and in October 2021, the Company occupied the remaining portion. The lease expires in October 2029 with options to renew for two five-year terms each. The HQ Lease has escalating rent payments and includes an abatement period in which the Company was not required to remit monthly rent payments until October 2021. Under the terms of the HQ Lease, the Company was required to provide the landlord with a letter of credit in the amount of $0.9 million (See Note 2). In connection with implementing the Strategic Plan to preserve capital, in July 2022, the Company entered into an agreement to sublease approximately 22,000 rentable square feet of space in its headquarters. The sublease agreement has a term of 30 months from the commencement date of August 1, 2022 and provides that the Company will receive monthly base rent amounts escalating over the term of the sublease plus reimbursement of the subtenant’s proportionate share of operating expenses. The subtenant was not provided any renewal or extension options. The Company’s future sublease income exceeded the amount required to be paid to the Company’s landlord for the subleased space for the term of the sublease. As such, no impairment of the related ROU asset or leasehold improvements was warranted. In December 2016, the Company entered into an operating lease for approximately 18,748 rentable square feet of office and laboratory space in South San Francisco, California, which previously served as the Company’s headquarters. The lease expires in August 2024 with options to renew for two three-year terms each. In September 2021, the Company entered into a sublease of its former headquarters facility in which the rental period was co-terminus with the term of the head lease. The subtenant was not provided any renewal or extension options. The Company received a security deposit of approximately $0.2 million which was classified as non-current other assets on the balance sheets. The Company’s future sublease income exceeded the amount required to be paid to the Company’s landlord for the subleased space and no impairment of the related ROU asset or leasehold improvements was warranted. In September 2020, the Company entered into an operating lease for approximately 4,000 rentable square feet of warehouse space in South San Francisco, California, which was amended to approximately 20,000 rentable square feet in July 2021. The lease expires in July 2029 with an option to renew for an additional two-year term. The landlord provided the Company with a tenant improvement allowance of $0.3 million, which was received in September 2022. The Company included the landlord incentive in the measurement of the initial operating lease liability, which was reflected as a reduction to the initial ROU asset. Finance Leases The Company has various finance lease agreements for laboratory and manufacturing equipment. The terms of the Company’s finance leases generally range from three The following table summarizes components of lease expense for the periods indicated (in thousands): Classification in Statements of Operations and Comprehensive Loss Year Ended December 31 Component of lease expense 2022 2021 Operating lease expense Operating expenses $ 8,293 $ 4,363 Finance lease expense: Amortization of right-of-use assets Operating expenses 217 192 Interest on lease liabilities Interest income, net 27 32 Variable lease expense Operating expenses 2,260 947 Short-term lease expense Operating expenses 81 33 Sublease income Operating expenses (2,446) — Total lease expense $ 8,432 $ 5,567 Total rent expense for operating leases was $2.0 million for the year ended December 31, 2020, which was recorded under the previous lease accounting standard, ASC 840. The following table summarizes supplemental cash flow information for the periods indicated (in thousands): Year Ended December 31 2022 2021 Cash paid for amounts included in measurement of liabilities: Operating cash outflows from operating leases $ 6,876 $ 3,663 Operating cash outflows from finance leases 27 32 Financing cash outflows from finance leases 266 232 Right-of-use assets obtained in exchange for lease liabilities: Operating leases 1,384 35,554 Finance leases 148 — The following table summarizes maturities of lease liabilities and sublease income as of December 31, 2022 (in thousands): Operating Leases Sublease Income Finance Leases 2023 $ 7,867 $ (3,327) $ 216 2024 7,577 (2,898) 45 2025 6,717 (158) 8 2026 6,898 — — 2027 7,082 — — Thereafter 12,704 — — Total lease payments 48,845 $ (6,383) 269 Less: Interest or imputed interest (12,978) (15) Total discounted lease liabilities 35,867 254 Less: Lease liabilities, current (4,639) (205) Lease liabilities, non-current $ 31,228 $ 49 The following table summarizes weighted-average remaining lease terms and discount rates: December 31, 2022 December 31, 2021 Operating Leases Finance Leases Operating Leases Finance Leases Weighted-average remaining lease term (years) 6.3 1.2 6.8 1.6 Weighted-average discount rate 10.4 % 7.8 % 9.7 % 5.9 %

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2022
Stockholders' Equity Note [Abstract]
Stockholders' Equity	Stockholders’ Equity 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. Convertible Preferred Stock Upon closing of the IPO, all outstanding shares of the Company’s convertible preferred stock automatically converted into 13,966,292 shares of common stock and the related carrying value was reclassified to common stock and additional paid-in capital. Preferred Stock After conversion of the above mentioned convertible preferred stock into common stock upon closing of the IPO, the Company has the authority to issue 50,000,000 shares of preferred stock with a par value of $0.0001 per share. There were no shares of preferred stock outstanding as of December 31, 2022 and 2021, respectively. Common Stock As of December 31, 2022 and 2021, the Company was authorized to issue 450,000,000 shares of common stock with a par value of $0.0001 per share. Common stockholders are entitled to dividends if and when declared by the Company’s board of directors. The holder of each share of common stock is entitled to one vote. Since inception, no dividends have been declared or paid by the Company. Common stock reserved for future issuance consisted of the following: December 31, 2022 2021 2020 Stock options outstanding 5,369,808 4,442,864 3,506,599 RSUs outstanding 531,366 717,440 — Shares available for future grants under equity incentive plans 4,654,922 2,876,270 3,369,246 Shares available for issuance under ESPP 872,792 636,962 314,006 11,428,888 8,673,536 7,189,851

Stock-Based Compensation Expens

Stock-Based Compensation Expense	12 Months Ended
	Dec. 31, 2022
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation Expense	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. 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), nonstatutory 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 (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 available for issuance under the 2020 Plan. As of December 31, 2022, 3,654,922 shares of common stock remained available for future issuance under the 2020 Plan. Since the date of incorporation and through December 31, 2022, the Company issued stock options and restricted stock units (“RSUs”) to its employees and consultants. Generally, stock options and restricted stock unit awards vest over a four-year period, subject to continuing service. Option awards granted under the 2020 Plan have a contractual term of up to 10 years with exercise 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. 2022 Inducement Equity Incentive Plan The Company’s 2022 Inducement Equity Incentive Plan (2022 Inducement Plan) adopted in March 2022 reserved 1,000,000 shares of the Company’s common stock pursuant to equity awards granted under the 2022 Inducement Plan. The Inducement Plan provides for the grant of equity-based awards, including nonstatutory stock options, restricted stock units, restricted stock, stock appreciation rights, performance shares and performance stock units, and its terms are substantially similar to the Company’s 2020 Plan. In accordance with the Nasdaq Listing Rules, awards under the Inducement Plan may only be made to individuals not previously employees or non-employee directors of the Company (or following such individuals’ bona fide period of non-employment with the Company), as an inducement material to the individuals’ entry into employment with the Company, or, to the extent permitted by the Nasdaq Listing Rules, in connection with a merger or acquisition. As of December 31, 2022, 1,000,000 shares of common stock remained available for future issuance under the 2022 Inducement Plan. 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 for certain capitalization events, 314,006 shares of the Company’s common stock were initially available for purchase upon adoption of the ESPP. Under 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, 2022, 872,792 shares of common stock remained available for future issuance under the ESPP. For the years ended December 31, 2022 and 2021, the Company recognized $0.3 million and $0.3 million in stock-based compensation expense related to the ESPP, respectively. For the year ended December 31, 2020, no stock-based compensation expense was recognized for ESPP. Accelerated RSU Vesting under Strategic Plan In connection with the Strategic Plan, the Company accelerated vesting from the original vesting date of June 1, 2022 to May 16, 2022 for certain employees. Vesting was accelerated for a total of 43,711 RSUs for 30 employees. The Company accounted for the acceleration of vesting as a Type III (improbable-to-probable) modification because the RSUs were not expected to vest under the original terms of the award. As a result of the modification, the Company reversed previously recognized stock-based compensation expense and recognized compensation cost for the modified award based on the modification date fair value of the awards, which was lower than the original grant date fair value. This resulted in a reduction in stock-based compensation of $0.4 million for the year ended December 31, 2022. Stock-Based Compensation Expense Allocation The following table summarizes the components of stock-based compensation expense recognized in the Company’s statements of operations and comprehensive loss for the periods indicated (in thousands): Year Ended December 31, 2022 2021 2020 Research and development $ 10,842 $ 8,596 $ 1,943 General and administrative 12,325 8,102 1,113 Total stock-based compensation expense $ 23,167 $ 16,698 $ 3,056 Stock Options Activity The following summarizes stock option activity: Options Weighted- Weighted- Aggregate Outstanding as of December 31, 2019 2,143,368 $ 1.22 7.3 $ 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 8.8 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 8.4 22,850 Granted 2,625,018 7.55 Exercised (53,709) 1.83 Cancelled (1,644,365) 22.12 Outstanding as of December 31, 2022 5,369,808 $ 17.28 7.6 $ 11 Exercisable as of December 31, 2022 2,557,181 $ 17.08 6.4 $ 11 Weighted-average grant-date fair value of options granted during the years ended December 31, 2022, 2021 and 2020 was $5.36 per share, $32.05 per share and $5.88 per share, respectively. The aggregate intrinsic value of stock option exercises during the years ended December 31, 2022, 2021 and 2020 was $0.3 million, $20.8 million and $29.5 million, respectively. As of December 31, 2022, the total unrecognized stock-based compensation expense related to stock options was $31.5 million, which is expected to be recognized over a weighted-average period of approximately 2.5 years. Valuation of Equity Awards The Company estimated the fair value of option awards 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. This model requires the input of highly subjective assumptions, changes to which can materially affect the fair value estimate. These assumptions include the following: • Expected term —The expected term of the option awards represents the period of time between the grant date of the option awards and the date the option awards are either exercised, converted or canceled. The Company used the simplified method as it does not have sufficient historical exercise data to provide a reasonable basis upon which to estimate the expected term. Under the simplified method, the expected term equals the average of the vesting term and the original contractual term of the option award. • Expected volatility —The expected stock price volatility for option awards granted prior to the fourth quarter of 2022 was determined based on an average of the historical volatilities of the common stock of several peer companies with characteristics similar to those of the Company. The peer companies were chosen based on their similar size, stage in the life cycle or area of specialty. Beginning in the fourth quarter of 2022, the Company used a blended volatility estimate consisting of its own historical stock price volatility (as the Company had at least two years of historical stock price data) supplemented by historical volatilities of peer companies such that the time period over which historical volatility data used was at least equal to the expected term of the option award. • Expected dividend yield —The Company has never paid dividends on its common stock and has no plans to pay dividends on its common stock in the foreseeable future. Therefore, the Company used an expected dividend yield of zero. • 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 the option award. The Company’s weighted-average assumptions used in the Black-Scholes option pricing model for option awards granted during the years ended December 31, 2022, 2021 and 2020 were as follows: Year Ended December 31, 2022 2021 2020 Expected term (years) 6.0 6.1 6.1 Expected volatility 83.3 % 73.9 % 75.6 % Expected dividend yield — — — Risk-free interest rate 2.1 % 1.0 % 0.6 % The fair value of RSUs is measured on the grant date based on the closing fair market value of the Company’s common stock. Restricted Stock Units Activity The following summarizes restricted stock unit activity: Number of Shares Weighted-Average Grant Date Fair Value per Share Unvested and outstanding as of December 31, 2020 — $ — Granted 717,440 $ 14.54 Vested — $ — Cancelled — $ — Unvested and outstanding as of December 31, 2021 717,440 $ 14.54 Granted 465,372 $ 7.21 Vested (357,766) $ 13.10 Cancelled (293,680) $ 12.67 Unvested and outstanding as of December 31, 2022 531,366 $ 10.12 The aggregate fair value of restricted stock units that vested during the year ended December 31, 2022 was $0.8 million, which represents the market value of the Company’s common stock on the date that the restricted stock units vested. No restricted stock units vested in the years ended December 31, 2021 and 2020. As of December 31, 2022, the total unrecognized stock-based compensation expense related to unvested restricted stock units was $5.0 million, which is expected to be recognized over a weighted-average period of approximately 2.2 years.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	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, 2022, 2021 and 2020, 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

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes For the years ended December 31, 2022, 2021 and 2020, no provision for income taxes has been made due to net operating losses incurred in each year. The Company maintains a full valuation allowance against its net deferred tax assets due to the uncertainty regarding the realization of such assets. The Company’s historical operating losses were generated in the United States. 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, 2022 2021 2020 Statutory income tax rate 21.0 % 21.0 % 21.0 % Stock-based compensation expense (2.9) 2.2 8.2 State income tax 1.2 2.1 1.2 Tax credits 1.7 2.0 1.8 Other (0.1) (0.8) — Valuation allowance (20.9) (26.5) (32.2) Total effective income tax rate — % — % — % Significant components of deferred tax assets for federal and state income taxes were as follows (in thousands): December 31, 2022 2021 Deferred tax assets: Federal and state net operating loss carryforwards $ 63,653 $ 58,025 Tax credit carryforwards 13,403 9,874 Capitalized research expenditures 15,448 — Lease liabilities 7,539 8,274 Stock-based compensation expense 3,312 2,129 Accrued expenses 903 728 Other 202 135 Total deferred tax assets 104,460 79,165 Deferred tax liabilities: Right-of-use assets (6,983) (8,016) Total deferred tax liabilities (6,983) (8,016) Valuation allowance (97,477) (71,149) Net deferred tax assets $ — $ — Under the Tax Cuts and Jobs Act of 2017, research and development costs are no longer fully deductible in the year incurred for tax years beginning on or after January 1, 2022. Instead, taxpayers are required to amortize such expenditures over five years if incurred in the U.S. and over fifteen years if incurred in a foreign jurisdiction. The mandatory capitalization requirement increased the Company’s deferred tax assets before valuation allowance, but had no impact on cash tax liabilities. 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, the Company believes recognizing deferred tax assets is currently not more likely than not to be realized and, accordingly, have provided a full valuation allowance against its net deferred tax assets. For the years ended December 31, 2022 and 2021, the net increase in the valuation allowance was $26.3 million and $26.6 million, respectively. As of December 31, 2022, the Company had federal net operating loss carryforwards of $278.8 million. Of this amount, $13.3 million was generated before January 1, 2018 and will begin to expire in 2036. Federal net operating losses of $265.5 million generated after December 31, 2017 will carryforward indefinitely. As of December 31, 2022, the Company had state net operating loss carryforwards of $69.5 million, which will begin to expire in 2036. As of December 31, 2022, the Company had federal general business credits from research and development expenses totaling $10.9 million, as well as state research and development credits of $7.5 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 net operating loss and tax credit carryforwards are subject to review and possible adjustment by the Internal Revenue Service and state tax authorities. In addition, under Sections 382 and 383 of the United States Internal Revenue Code of 1986, as amended (the Code), if a corporation undergoes an “ownership change” (generally defined as a greater than 50-perentage-point cumulative change (by value) in the equity ownership of certain stockholders over a rolling three-year period), the corporation’s ability to use its pre-change NOL carryforwards and other pre-change tax attributes to offset its post-change taxable income or taxes may be limited. The Company completed an analysis under Section 382 through December 31, 2020 and concluded the Company had experienced an ownership change in the past. However, it did not result in a limitation that would materially reduce the total amount of net operating loss carryforwards and credits that can be utilized. Net operating loss and tax credit carryforwards generated during the years ended December 31, 2021 and 2022 may be subject to an annual limitation under Section 382. 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 2022 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, 2022 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, 2022. A reconciliation of the beginning and ending amounts of unrecognized tax benefits was as follows (in thousands): Year Ended December 31, 2022 2021 2020 Gross unrecognized tax benefit as of January 1 $ 2,579 $ 1,499 $ 1,012 Additions for tax positions taken in the current year 927 1,080 626 Reductions for tax positions taken in the current year — — (139) Additions for tax positions taken in prior years — — — Gross unrecognized tax benefit as of December 31 $ 3,506 $ 2,579 $ 1,499 None of the unrecognized tax benefits at December 31, 2022 or December 31, 2021 would affect the effective tax rate due to the Company’s full valuation allowance. During the years ended December 31, 2022, 2021 and 2020, no interest or penalties were required to be recognized relating to unrecognized tax benefits. The Company recognizes interest and penalties related to uncertain tax positions in income tax expense.

Net Loss Per Share

Net Loss Per Share	12 Months Ended
	Dec. 31, 2022
Earnings Per Share [Abstract]
Net Loss Per Share	Net Loss Per Share The following table sets forth the computation of the basic and diluted net loss per share for the periods indicated (except share and per share amounts): Year Ended December 31, 2022 2021 2020 Numerator: Net loss $ (126,325) $ (100,287) $ (66,564) Denominator: Weighted-average shares of common stock outstanding used in the calculation of basic and diluted net loss per share 38,837,001 37,591,505 22,878,325 Net loss per share, basic and diluted $ (3.25) $ (2.67) $ (2.91) 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 any common stock equivalents outstanding would have been anti-dilutive. Potentially dilutive common stock equivalents outstanding that were not included in the diluted per share calculations were as follows: December 31, 2022 2021 2020 Stock options outstanding 5,369,808 4,442,864 3,506,599 RSUs outstanding 531,366 717,440 — Total 5,901,174 5,160,304 3,506,599

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2022
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events In March 2023, the board of directors of the Company approved a reduction in force intended to preserve the Company’s current cash resources. The Company will reduce its workforce by approximately 21% of its current employees, or 16 employees, resulting in a total of 61 remaining full-time employees. The Company currently estimates that it will incur one-time cash charges of approximately $1.8 million consisting of customary separation benefits, including severance payments, payments to cover premiums for continuation of healthcare coverage for a limited period, and other benefits. The Company expects that the one-time cash charges will be incurred in the first quarter of 2023, and that the reduction in force will be substantially complete by the end of the second quarter of 2023. The Company may also incur other charges or cash expenditures not currently contemplated due to events that may occur as a result of, or associated with, the workforce reduction or retention efforts.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Basis of Presentation	Basis of PresentationThe financial statements have been prepared in accordance with accounting principles generally accepted in the United States (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 sheets and expenses and income reported are affected by estimates and assumptions, which are used for, but are not limited to, recording research and development expenses and related accruals, and determining the fair value of stock options for 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 and cash equivalents. 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 to the extent recorded in the balance sheets. The Company’s cash equivalents consist of money market funds that invests all of its assets in direct obligations of the U.S. Treasury. Although the fund invests in U.S. government obligations, an investment in such funds is neither insured nor guaranteed by the U.S. government. The Company has not experienced any losses on its deposits of cash or holdings of money market funds. The Company is subject to a number of risks similar to other clinical-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 or develop internal manufacturing capabilities. The Company’s product candidates will require approval from the U.S. Food and Drug Administration (FDA) and/or comparable foreign regulatory agencies prior to commercialization in their respective jurisdictions. 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. 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 As of December 31, 2022, the Company had $0.9 million in restricted cash, which was classified as long-term on the Company’s balance sheets. The restricted cash was attributable to a letter of credit issued by the Company in connection with the operating lease for the Company’s headquarters (See Note 5). The letter of credit will expire 90 days after the expiration of the lease in 2029. For the year ended December 31, 2022, the Company collected its $0.1 million letter of credit associated with the expiration of an operating lease. The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the statements of cash flows for the periods indicated (in thousands): December 31, 2022 2021 Cash and cash equivalents $ 61,145 $ 159,821 Restricted cash 916 1,025 Total cash, cash equivalents and restricted cash $ 62,061 $ 160,846
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 were no material impairments of long-lived assets during the years ended December 31, 2022, 2021 and 2020.
Leases	Leases In February 2016, the Financial Accounting Standards Board (FASB) issued an Accounting Standard Update (ASU) No. 2016-02, Leases (Topic 842) , and its associated amendments, that established a right-of-use (ROU) model that requires a lessee to recognize an 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 Topic 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 sheets. 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. Fixed lease payments on operating leases are recognized as lease expense over the expected term of the lease on a straight-line basis. The Company’s real estate operating leases require payment of common area maintenance, real estate taxes, and insurance. These components are recognized as variable lease expense in the period in which the obligation is incurred. As these costs are generally variable in nature, they are not included in the measurement of the operating lease ROU asset and related lease liability. Fixed and variable lease expense on operating leases is recognized within operating expenses within the Company’s statements of operations and comprehensive loss. Sublease income is recognized on a straight-line basis over the sublease term and is recorded net against the head lease expense. The Company has various finance leases for laboratory 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. 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 both an equity incentive plan and an employee stock purchase plan (ESPP) as long-term incentives for its employees, consultants, and non-employee directors. Under the equity incentive plan, the Company is authorized to grant various equity-based incentives including stock options and restricted stock units (RSUs). The ESPP provides for 24-month offering periods and each offering period may contain up to four six-month purchase periods. The ESPP allows employees to purchase shares of the Company’s common stock each purchase period based on a percentage of their compensation subject to certain limits. 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 grant-date fair values for options and RSUs are recorded as stock-based compensation expense on a straight-line basis over the grantee’s requisite service period, which is generally over a four-year period, subject to continuing service. The grant-date fair values for purchase rights granted under the ESPP are recorded as stock-based compensation expense on a straight-line basis over the applicable offering period. Actual forfeitures of unvested equity awards are recognized as they occur by reversing any expense previously recorded for the award. The Company estimates the fair value of stock options granted to employees and non-employees using the Black-Scholes model. The Company estimates the fair value of purchase rights granted under the ESPP for an offering period 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 objective of the asset and liability method is to establish deferred tax assets and liabilities for the temporary differences between the financial reporting basis and the income tax basis of the Company’s assets and liabilities at enacted tax rates expected to be in effect when such amounts are realized or settled. Deferred income tax assets represent amounts available to reduce income taxes payable on taxable income in future years. Such assets arise because of temporary differences between the financial reporting and tax bases of assets and liabilities, as well as from net operating loss and tax credit carryforwards. The Company records net deferred tax assets to the extent these assets will more likely than not be realized. In making such determination, all available positive and negative evidence are considered, including scheduled reversals of deferred tax liabilities, projected future taxable income, tax planning strategies and recent financial performance. Valuation allowances are established when necessary on a jurisdictional basis to reduce deferred tax assets to the amounts expected to be realized. As of December 31, 2022 and 2021, a full valuation allowance has been established to offset the net deferred tax assets due to the uncertainties surrounding the Company’s ability to generate future taxable income to realize these assets. In the event the Company determines that it would be able to realize all or a portion of its deferred income tax assets in the future, it would make an adjustment to the valuation allowance which would reduce the provision for income taxes in the period in which the adjustments are determined.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The Company’s financial instruments, including cash, restricted cash, other current assets, accounts payable and accrued expenses are carried at cost which approximates their fair value because of the short-term nature of these financial instruments.
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
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 lease agreements that contain both lease components (for example fixed rent payments) and non-lease components (for example, common-area maintenance costs), and has elected to combine lease and non-lease components for all classes of assets. The Company also elected the package of practical expedients available for existing contracts, 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 . ASU 2019-12 eliminates certain exceptions for recognizing deferred taxes for investments, performing intraperiod allocation and calculating income taxes in interim periods. This ASU also includes guidance to reduce complexity in certain areas, including recognizing deferred taxes for tax goodwill and allocating taxes to members of a consolidated group. ASU 2019-12 is effective for annual and interim periods in fiscal years beginning after December 15, 2020. Early adoption is permitted. The Company adopted this ASU effective January 1, 2020 on a prospective basis. The adoption did not have a material impact on the Company’s financial statements. In August 2018, the FASB issued ASU 2018-13, Disclosure Framework (Topic 820) – Changes to the Disclosure Requirements for Fair Value Measurement , which amended Accounting Standards Codification 820, Fair Value Measurement. This standard modifies the disclosure requirements for fair value measurements by removing, modifying, or adding certain disclosures. The Company adopted this ASU effective January 1, 2020. The adoption did not have a material impact on the Company’s financial statements and related disclosures. 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, 2022
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 for the periods indicated (in thousands): December 31, 2022 2021 Cash and cash equivalents $ 61,145 $ 159,821 Restricted cash 916 1,025 Total cash, cash equivalents and restricted cash $ 62,061 $ 160,846
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, 2022 2021 Laboratory and manufacturing equipment $ 11,421 $ 9,375 Leasehold improvements 5,246 2,607 Construction in progress 72 870 Computer and office equipment 491 293 17,230 13,145 Accumulated depreciation (9,047) (6,147) Total property and equipment, net $ 8,183 $ 6,998

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Summary of Financial Assets Measured at Fair Value on Recurring Basis	The following tables present money market funds at their level within the fair value hierarchy for the periods indicated (in thousands): December 31, 2022 Fair Value Hierarchy Level Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash equivalents: Money market funds Level 1 $ 40,729 $ — $ — $ 40,729 December 31, 2021 Fair Value Hierarchy Level Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash equivalents: Money market funds Level 1 $ 159,010 $ — $ — $ 159,010

Balance Sheet Components (Table

Balance Sheet Components (Tables)	12 Months Ended
	Dec. 31, 2022
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, 2022 2021 Laboratory and manufacturing equipment $ 11,421 $ 9,375 Leasehold improvements 5,246 2,607 Construction in progress 72 870 Computer and office equipment 491 293 17,230 13,145 Accumulated depreciation (9,047) (6,147) Total property and equipment, net $ 8,183 $ 6,998
Schedule of Accrued Liabilities	Accrued expenses consisted of the following (in thousands): December 31, 2022 2021 Compensation expenses $ 3,985 $ 3,636 Research and development expenses 3,508 2,917 Professional services 728 881 Property and equipment 7 215 Other 432 577 Total accrued expenses $ 8,660 $ 8,226

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2022
Leases [Abstract]
Summary of Lease Expense	The following table summarizes components of lease expense for the periods indicated (in thousands): Classification in Statements of Operations and Comprehensive Loss Year Ended December 31 Component of lease expense 2022 2021 Operating lease expense Operating expenses $ 8,293 $ 4,363 Finance lease expense: Amortization of right-of-use assets Operating expenses 217 192 Interest on lease liabilities Interest income, net 27 32 Variable lease expense Operating expenses 2,260 947 Short-term lease expense Operating expenses 81 33 Sublease income Operating expenses (2,446) — Total lease expense $ 8,432 $ 5,567
Summary of Supplemental Cash Flow Information	The following table summarizes supplemental cash flow information for the periods indicated (in thousands): Year Ended December 31 2022 2021 Cash paid for amounts included in measurement of liabilities: Operating cash outflows from operating leases $ 6,876 $ 3,663 Operating cash outflows from finance leases 27 32 Financing cash outflows from finance leases 266 232 Right-of-use assets obtained in exchange for lease liabilities: Operating leases 1,384 35,554 Finance leases 148 —
Schedule of Future Minimum Payments under Noncancelable Leases	The following table summarizes maturities of lease liabilities and sublease income as of December 31, 2022 (in thousands): Operating Leases Sublease Income Finance Leases 2023 $ 7,867 $ (3,327) $ 216 2024 7,577 (2,898) 45 2025 6,717 (158) 8 2026 6,898 — — 2027 7,082 — — Thereafter 12,704 — — Total lease payments 48,845 $ (6,383) 269 Less: Interest or imputed interest (12,978) (15) Total discounted lease liabilities 35,867 254 Less: Lease liabilities, current (4,639) (205) Lease liabilities, non-current $ 31,228 $ 49
Summary of Lease Terms and Discount Rates	The following table summarizes weighted-average remaining lease terms and discount rates: December 31, 2022 December 31, 2021 Operating Leases Finance Leases Operating Leases Finance Leases Weighted-average remaining lease term (years) 6.3 1.2 6.8 1.6 Weighted-average discount rate 10.4 % 7.8 % 9.7 % 5.9 %

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2022
Stockholders' Equity Note [Abstract]
Schedule of Common Stock Reserved for Future Issuance	Common stock reserved for future issuance consisted of the following: December 31, 2022 2021 2020 Stock options outstanding 5,369,808 4,442,864 3,506,599 RSUs outstanding 531,366 717,440 — Shares available for future grants under equity incentive plans 4,654,922 2,876,270 3,369,246 Shares available for issuance under ESPP 872,792 636,962 314,006 11,428,888 8,673,536 7,189,851

Stock-Based Compensation Expe_2

Stock-Based Compensation Expense (Tables)	12 Months Ended
	Dec. 31, 2022
Share-Based Payment Arrangement [Abstract]
Summary of Components of Stock-Based Compensation Expense	Stock-Based Compensation Expense Allocation The following table summarizes the components of stock-based compensation expense recognized in the Company’s statements of operations and comprehensive loss for the periods indicated (in thousands): Year Ended December 31, 2022 2021 2020 Research and development $ 10,842 $ 8,596 $ 1,943 General and administrative 12,325 8,102 1,113 Total stock-based compensation expense $ 23,167 $ 16,698 $ 3,056
Summary of Stock Option Activity	The following summarizes stock option activity: Options Weighted- Weighted- Aggregate Outstanding as of December 31, 2019 2,143,368 $ 1.22 7.3 $ 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 8.8 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 8.4 22,850 Granted 2,625,018 7.55 Exercised (53,709) 1.83 Cancelled (1,644,365) 22.12 Outstanding as of December 31, 2022 5,369,808 $ 17.28 7.6 $ 11 Exercisable as of December 31, 2022 2,557,181 $ 17.08 6.4 $ 11
Schedule of Weighted-Average Assumptions Used for Estimating Fair Value of Each Employee Stock Option	The Company’s weighted-average assumptions used in the Black-Scholes option pricing model for option awards granted during the years ended December 31, 2022, 2021 and 2020 were as follows: Year Ended December 31, 2022 2021 2020 Expected term (years) 6.0 6.1 6.1 Expected volatility 83.3 % 73.9 % 75.6 % Expected dividend yield — — — Risk-free interest rate 2.1 % 1.0 % 0.6 %
Summary of Restricted Stock Unit Activity	The following summarizes restricted stock unit activity: Number of Shares Weighted-Average Grant Date Fair Value per Share Unvested and outstanding as of December 31, 2020 — $ — Granted 717,440 $ 14.54 Vested — $ — Cancelled — $ — Unvested and outstanding as of December 31, 2021 717,440 $ 14.54 Granted 465,372 $ 7.21 Vested (357,766) $ 13.10 Cancelled (293,680) $ 12.67 Unvested and outstanding as of December 31, 2022 531,366 $ 10.12

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2022
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, 2022 2021 2020 Statutory income tax rate 21.0 % 21.0 % 21.0 % Stock-based compensation expense (2.9) 2.2 8.2 State income tax 1.2 2.1 1.2 Tax credits 1.7 2.0 1.8 Other (0.1) (0.8) — Valuation allowance (20.9) (26.5) (32.2) 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, 2022 2021 Deferred tax assets: Federal and state net operating loss carryforwards $ 63,653 $ 58,025 Tax credit carryforwards 13,403 9,874 Capitalized research expenditures 15,448 — Lease liabilities 7,539 8,274 Stock-based compensation expense 3,312 2,129 Accrued expenses 903 728 Other 202 135 Total deferred tax assets 104,460 79,165 Deferred tax liabilities: Right-of-use assets (6,983) (8,016) Total deferred tax liabilities (6,983) (8,016) Valuation allowance (97,477) (71,149) 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, 2022 2021 2020 Gross unrecognized tax benefit as of January 1 $ 2,579 $ 1,499 $ 1,012 Additions for tax positions taken in the current year 927 1,080 626 Reductions for tax positions taken in the current year — — (139) Additions for tax positions taken in prior years — — — Gross unrecognized tax benefit as of December 31 $ 3,506 $ 2,579 $ 1,499

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2022
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 for the periods indicated (except share and per share amounts): Year Ended December 31, 2022 2021 2020 Numerator: Net loss $ (126,325) $ (100,287) $ (66,564) Denominator: Weighted-average shares of common stock outstanding used in the calculation of basic and diluted net loss per share 38,837,001 37,591,505 22,878,325 Net loss per share, basic and diluted $ (3.25) $ (2.67) $ (2.91)
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 any common stock equivalents outstanding would have been anti-dilutive. Potentially dilutive common stock equivalents outstanding that were not included in the diluted per share calculations were as follows: December 31, 2022 2021 2020 Stock options outstanding 5,369,808 4,442,864 3,506,599 RSUs outstanding 531,366 717,440 — Total 5,901,174 5,160,304 3,506,599

Organization and Principal Ac_2

Organization and Principal Activities - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Jan. 31, 2022	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Organization And Principal Activities [Line Items]
Net loss		$ (126,325)	$ (100,287)	$ (66,564)
Accumulated deficit		(365,970)	(239,645)
Cash and cash equivalents		61,145	$ 159,821
Strategic Plan
Organization And Principal Activities [Line Items]
Restructuring charges		3,800
Strategic Plan | Employee Severance
Organization And Principal Activities [Line Items]
Restructuring charges		3,300
Strategic Plan | Contract Termination
Organization And Principal Activities [Line Items]
Restructuring charges		500
Strategic Plan | Lease Termination
Organization And Principal Activities [Line Items]
Restructuring charges		300
Strategic Plan | Property and Equipment
Organization And Principal Activities [Line Items]
Restructuring charges		100
Strategic Plan | Reduction in Stock Based Compensation Expense
Organization And Principal Activities [Line Items]
Restructuring charges		400
Strategic Plan | Accrued Contract Termination
Organization And Principal Activities [Line Items]
Restructuring charges		400
At The Market | Sales Agreement | Agents
Organization And Principal Activities [Line Items]
Shares reserved for issuance of common stock upon initial public offering, net of underwriter's' commission and issuance costs (in shares)	150,000,000
Maximum public float limit to raise capital		$ 75,000
Issuance of common stock upon initial public offering, net of underwriters’ commission and issuance costs (in shares)	0

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Details)	12 Months Ended
	Dec. 31, 2022 USD ($) Segment	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Jan. 01, 2021 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Number of reportable segment | Segment	1
Number of operating segment | Segment	1
Restricted cash	$ 916,000	$ 1,025,000
Proceeds from letter of credit	100,000
Impairment of long-lived assets	$ 0	0	$ 0
Remaining requisite service period	4 years
Deferred offering costs	$ 0	0
Operating lease, right-of-use asset	33,222,000	38,142,000
Lease liabilities	35,867,000
Finance lease, right-of-use asset, after accumulated amortization	584,000	652,000
Finance lease liabilities	254,000
Accumulated deficit	$ 365,970,000	$ 239,645,000
ASU 2016-02
Summary Of Significant Accounting Policies [Line Items]
Operating lease, right-of-use asset				$ 6,000,000
Deferred rent				500,000
Lease liabilities				6,500,000
Finance lease, right-of-use asset, after accumulated amortization				0
Finance lease liabilities				0
ASU 2016-02 | Cumulative Effect, Period of Adoption, Adjustment
Summary Of Significant Accounting Policies [Line Items]
Accumulated deficit				$ 0

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, 2022	Dec. 31, 2021
Accounting Policies [Abstract]
Cash and cash equivalents	$ 61,145	$ 159,821
Restricted cash	916	1,025
Total cash, cash equivalents and restricted cash	$ 62,061	$ 160,846

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, 2022
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]
Leasehold improvements	Shorter of remaining leaseterm or estimated useful life

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Financial Assets Measured at Fair Value on Recurring Basis (Details) - Fair Value, Recurring - Level 1 - Money market funds - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	$ 40,729	$ 159,010
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	$ 40,729	$ 159,010

Balance Sheet Components - Addi

Balance Sheet Components - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Balance Sheet Related Disclosures [Abstract]
Prepaid clinical expenses	$ 1.2	$ 5.2
Depreciation expense	$ 2.9	$ 3.1	$ 1.8

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Property, Plant and Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Property Plant And Equipment [Line Items]
Total property and equipment, gross	$ 17,230	$ 13,145
Accumulated depreciation	(9,047)	(6,147)
Total property and equipment, net	8,183	6,998
Laboratory and manufacturing equipment
Property Plant And Equipment [Line Items]
Total property and equipment, gross	11,421	9,375
Leasehold improvements
Property Plant And Equipment [Line Items]
Total property and equipment, gross	5,246	2,607
Construction in progress
Property Plant And Equipment [Line Items]
Total property and equipment, gross	72	870
Computer and office equipment
Property Plant And Equipment [Line Items]
Total property and equipment, gross	$ 491	$ 293

Balance Sheet Components - Sc_2

Balance Sheet Components - Schedule of Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Balance Sheet Related Disclosures [Abstract]
Compensation expenses	$ 3,985	$ 3,636
Research and development expenses	3,508	2,917
Professional services	728	881
Property and equipment	7	215
Other	432	577
Total accrued expenses	$ 8,660	$ 8,226

Leases - Additional Information

Leases - Additional Information (Details) $ in Millions	1 Months Ended		12 Months Ended
	Jul. 31, 2022 ft²	Feb. 28, 2021 ft² Vote	Dec. 31, 2020 USD ($)	Dec. 31, 2022 USD ($)	Sep. 30, 2022 USD ($)	Dec. 31, 2021 USD ($)	Jul. 31, 2021 ft²	Sep. 30, 2020 ft²	Dec. 31, 2016 ft²
Lessee Lease Description [Line Items]
Security deposit						$ 0.2
Rent expense			$ 2
Minimum
Lessee Lease Description [Line Items]
Finance lease term				3 years
Maximum
Lessee Lease Description [Line Items]
Finance lease term				5 years
Warehouse Space
Lessee Lease Description [Line Items]
Tenant improvements					$ 0.3
Office And Laboratory Space
Lessee Lease Description [Line Items]
Rentable area (in square feet) | ft²	22,000	84,321					20,000	4,000	18,748
Lease renewal options | Vote		2
Long-term line of credit				$ 0.9
Lessee operating sublease term	30 months
Lessee, operating lease, renewal term									3 years
Office And Laboratory Space | Laboratory, Manufacturing, Warehouse and Office Space
Lessee Lease Description [Line Items]
Lease renewal options | Vote		2
Operating lease term, option to extend		five-year
Office And Laboratory Space | Warehouse Space
Lessee Lease Description [Line Items]
Lessee, operating lease, renewal term							2 years

Leases - Summary of Lease Expen

Leases - Summary of Lease Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Leases [Abstract]
Operating lease expense	$ 8,293	$ 4,363
Finance lease expense:
Amortization of right-of-use assets	217	192
Interest on lease liabilities	27	32
Variable lease expense	2,260	947
Short-term lease expense	81	33
Sublease income	(2,446)	0
Total lease expense	$ 8,432	$ 5,567

Leases - Summary of Supplementa

Leases - Summary of Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash paid for amounts included in measurement of liabilities:
Operating cash outflows from operating leases	$ 6,876	$ 3,663
Operating cash outflows from finance leases	27	32
Financing cash outflows from finance leases	266	232	$ 90
Right-of-use assets obtained in exchange for lease liabilities:
Operating leases	1,384	35,554
Finance leases	$ 148	$ 0

Leases - Schedule of Future Min

Leases - Schedule of Future Minimum Payments under Noncancelable Leases (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Operating Leases
2023	$ 7,867
2024	7,577
2025	6,717
2026	6,898
2027	7,082
Thereafter	12,704
Total lease payments	48,845
Less: Interest or imputed interest	(12,978)
Total discounted lease liabilities	35,867
Less: Lease liabilities, current	(4,639)	$ (3,584)
Lease liabilities, non-current	31,228	35,785
Sublease Income
2023	(3,327)
2024	(2,898)
2025	(158)
2026	0
2027	0
Thereafter	0
Total lease payments	(6,383)
Finance Leases
2023	216
2024	45
2025	8
2026	0
2027	0
Thereafter	0
Total lease payments	269
Less: Interest or imputed interest	(15)
Total discounted lease liabilities	254
Less: Lease liabilities, current	(205)	(237)
Lease liabilities, non-current	$ 49	$ 167

Leases - Summary of Lease Terms

Leases - Summary of Lease Terms and Discount Rates (Details)	Dec. 31, 2022	Dec. 31, 2021
Leases [Abstract]
Operating lease, weighted average remaining lease term	6 years 3 months 18 days	6 years 9 months 18 days
Operating lease, weighted average discount rate, percent	10.40%	9.70%
Finance lease, weighted average remaining lease term	1 year 2 months 12 days	1 year 7 months 6 days
Finance lease, weighted average discount rate, percent	7.80%	5.90%

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details)			12 Months Ended				49 Months Ended
	Apr. 06, 2021 USD ($) $ / shares shares	Jun. 09, 2020 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) vote $ / shares shares	Dec. 31, 2021 USD ($) $ / shares shares	Dec. 31, 2020 USD ($) shares	Dec. 31, 2019 USD ($)	Dec. 31, 2020 USD ($)
Class Of Stock [Line Items]
Deferred offering costs			$ 876,000	$ 704,000	$ 3,948,000
Net proceeds from initial public offering			$ 0	$ 0	$ 164,703,000
Preferred stock, shares authorized (in shares) | shares			50,000,000	50,000,000
Preferred stock, par value (in dollars per share) | $ / shares			$ 0.0001	$ 0.0001
Preferred stock, shares outstanding (in shares) | shares			0	0
Common stock, shares authorized (in shares) | shares			450,000,000	450,000,000
Common stock, par value (in dollars per share) | $ / shares			$ 0.0001	$ 0.0001
Number of voting rights for each common stock held | vote			1
Common stock, dividends declared or paid							$ 0
Common Stock
Class Of Stock [Line Items]
Issuance of common stock upon initial public offering, net of underwriters’ commission and issuance costs (in shares) | shares				2,875,000	12,650,000
Conversion of convertible preferred stock into common stock, shares (in shares) | shares					13,966,292
Initial Public Offering | Common Stock
Class Of Stock [Line Items]
Issuance of common stock upon initial public offering, net of underwriters’ commission and issuance costs (in shares) | shares		12,650,000
Sale of stock, price per share (in dollars per share) | $ / shares		$ 14
Share issued with exercise by underwriters (in shares) | shares		1,650,000
Conversion of convertible preferred stock into common stock, shares (in shares) | shares		13,966,292
Aggregate offering price for shares sold		$ 177,100,000
Underwriting discounts and commissions		12,400,000
Deferred offering costs		4,100,000				$ 200,000
Net proceeds from initial public offering		$ 160,600,000
Follow-on Offering | Common Stock
Class Of Stock [Line Items]
Issuance of common stock upon initial public offering, net of underwriters’ commission and issuance costs (in shares) | shares	2,875,000
Sale of stock, price per share (in dollars per share) | $ / shares	$ 42
Share issued with exercise by underwriters (in shares) | shares	375,000
Aggregate offering price for shares sold	$ 120,800,000
Underwriting discounts and commissions	7,200,000
Deferred offering costs	800,000
Net proceeds from follow-on offering	$ 112,800,000

Stockholders' Equity - Schedule

Stockholders' Equity - Schedule of Common Stock Reserved for Future Issuance (Details) - shares	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Class Of Stock [Line Items]
Common stock reserved for future issuance (in shares)	11,428,888	8,673,536	7,189,851
Shares available for issuance under ESPP
Class Of Stock [Line Items]
Common stock reserved for future issuance (in shares)	872,792	636,962	314,006
Stock options outstanding
Class Of Stock [Line Items]
Common stock reserved for future issuance (in shares)	5,369,808	4,442,864	3,506,599
RSUs outstanding
Class Of Stock [Line Items]
Common stock reserved for future issuance (in shares)	531,366	717,440	0
Shares available for future grants under equity incentive plans
Class Of Stock [Line Items]
Common stock reserved for future issuance (in shares)	4,654,922	2,876,270	3,369,246

Stock-Based Compensation Expe_3

Stock-Based Compensation Expense - Additional Information (Details)		12 Months Ended
	May 31, 2020 shares	Dec. 31, 2022 USD ($) Employees $ / shares shares	Dec. 31, 2021 USD ($) $ / shares shares	Dec. 31, 2020 USD ($) $ / shares shares	Mar. 31, 2022 shares	Mar. 31, 2020 shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award granted (in shares)		2,625,018	2,026,976	2,598,319
Common stock reserved for future issuance (in shares)		11,428,888	8,673,536	7,189,851
Share expirations during period (in shares)				576,670
Stock-based compensation expense | $		$ 23,167,000	$ 16,698,000	$ 3,056,000
Number of employees with accelerated vesting | Employees		30
Reduction in stock-based compensation | $		$ 400,000
Weighted-average grant-date fair value of the options granted (in dollars per share) | $ / shares		$ 5.36	$ 32.05	$ 5.88
Intrinsic value of options exercised | $		$ 300,000	$ 20,800,000	$ 29,500,000
Total unrecognized stock-based compensation expense related to stock options granted | $		$ 31,500,000
Total unrecognized stock-based compensation expense related to nonvested awards weighted average period of recognition		2 years 6 months
Expected dividend yield		0%	0%	0%
Shares available for issuance under ESPP
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Purchase price of common stock percent	85%
Common stock reserved for future issuance (in shares)		872,792	636,962	314,006
Shares available for issuance (in shares)	314,006	872,792
Outstanding stock percent	1%
Stock-based compensation expense | $		$ 300,000	$ 300,000	$ 0
Sock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)		5,369,808	4,442,864	3,506,599
RSUs outstanding
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)		531,366	717,440	0
Accelerated vesting options (in shares)		43,711
Total unrecognized stock-based compensation expense related to nonvested awards weighted average period of recognition		2 years 2 months 12 days
Fair value of restricted stock units vested | $		$ 800,000
Share-based compensation arrangement by share-based payment award, equity instruments other than options, vested in period (in shares)		357,766	0	0
Total stock-based compensation expense related to unvested restricted stock units and awards | $		$ 5,000,000
Maximum | Shares available for issuance under ESPP
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Discount rate	15%
Minimum | Shares available for issuance under ESPP
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Increase in number of shares (in shares)	628,012
2015 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award granted (in shares)		0
2016 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period		4 years
Common stock reserved for future issuance (in shares)						1,250,000
2016 Plan | 10% Stockholder
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of voting power		10%
2016 Plan | Maximum
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%
Percentage of exercise price of stock option on estimated fair value of shares		110%
2020 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)		3,654,922		3,768,075
2020 Plan | Sock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period		4 years
2020 Plan | 10% Stockholder
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of voting power		10%
2020 Plan | Maximum
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%
Percentage of exercise price of stock option on estimated fair value of shares		110%
2022 Inducement Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)		1,000,000			1,000,000

Stock-Based Compensation Expe_4

Stock-Based Compensation Expense - Summary of Components of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 23,167	$ 16,698	$ 3,056
Research and development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	10,842	8,596	1,943
General and administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 12,325	$ 8,102	$ 1,113

Stock-Based Compensation Expe_5

Stock-Based Compensation Expense - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Options Outstanding Number of Shares
Options outstanding beginning balance (in shares)	4,442,864	3,506,599	2,143,368
Granted (in shares)	2,625,018	2,026,976	2,598,319
Exercised (in shares)	(53,709)	(595,339)	(1,144,330)
Forfeited (in shares)	(1,644,365)	(495,372)	(90,758)
Options outstanding ending balance (in shares)	5,369,808	4,442,864	3,506,599	2,143,368
Weighted- Average Exercise Price
Options outstanding, weighted-average exercise price, beginning balance (in dollars per share)	$ 24.63	$ 6.27	$ 1.22
Options granted, weighted-average exercise price (in dollars per share)	7.55	49.49	7.82
Options exercised, weighted-average exercise price (in dollars per share)	1.83	3.57	0.55
Options forfeited, weighted-average exercise price (in dollars per share)	22.12	21.69	3.43
Options outstanding, weighted-average exercise price, ending balance (in dollars per share)	$ 17.28	$ 24.63	$ 6.27	$ 1.22
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Additional Disclosures [Abstract]
Options exercisable as of December 31, 2022 (in shares)	2,557,181
Options exercisable, weighted-average exercise price (in dollars per share)	$ 17.08
Options outstanding, weighted-average remaining contractual life	7 years 7 months 6 days	8 years 4 months 24 days	8 years 9 months 18 days	7 years 3 months 18 days
Options exercisable, weighted-average remaining contractual life	6 years 4 months 24 days
Options outstanding, aggregate intrinsic value	$ 11	$ 22,850	$ 85,975	$ 10,555
Options exercisable, aggregate intrinsic value	$ 11

Stock-Based Compensation Expe_6

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, 2022	Dec. 31, 2021	Dec. 31, 2020
Share-Based Payment Arrangement [Abstract]
Expected term (years)	6 years	6 years 1 month 6 days	6 years 1 month 6 days
Expected volatility	83.30%	73.90%	75.60%
Expected dividend yield	0%	0%	0%
Risk-free interest rate	2.10%	1%	0.60%

Stock-Based Compensation Expe_7

Stock-Based Compensation Expense - Summary of Restricted Stock Unit Activity (Details) - RSUs outstanding - $ / shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Number of Shares
Unvested and outstanding beginning balance (in Shares)	717,440	0
Number of shares, granted (in shares)	465,372	717,440
Number of shares, vested (in shares)	(357,766)	0	0
Number of shares, forfeited (in shares)	(293,680)	0
Unvested and outstanding ending balance (in Shares)	531,366	717,440	0
Weighted-Average Grant Date Fair Value per Share
Outstanding, Weighted average grant date fair value at period start (in dollars per share)	$ 14.54	$ 0
Granted, Weighted average grant date fair value (in dollars per share)	7.21	14.54
Vested, Weighted average grant date fair value (in dollars per share)	13.10	0
Forfeited, Weighted average grant date fair value (in dollars per share)	12.67	0
Outstanding, Weighted average grant date fair value at period end (in dollars per share)	$ 10.12	$ 14.54	$ 0

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Tax [Line Items]
Provision for, or benefit from, income taxes	$ 0	$ 0	$ 0
Net increase in valuation allowance	26,300,000	26,600,000
Significant changes to unrecognized tax benefits over next 12 months	0
Tax impact related to unrecognized tax benefit in relation to valuation allowance positions	0	0
Interest or penalties recognized relating to unrecognized tax benefits	$ 0	$ 0	$ 0
Minimum
Income Tax [Line Items]
Cumulative ownership percentage change	50%
Federal
Income Tax [Line Items]
Net operating loss carryforwards	$ 278,800,000
Federal | General Business Credits
Income Tax [Line Items]
Tax credit carryforward	10,900,000
State
Income Tax [Line Items]
Net operating loss carryforwards	69,500,000
State | Research and Development Credits
Income Tax [Line Items]
Tax credit carryforward	7,500,000
Operating Losses Generated after December 31, 2017 | Federal
Income Tax [Line Items]
Net operating loss carryforwards	265,500,000
Operating Losses Generated before January 1, 2018 | Federal
Income Tax [Line Items]
Net operating loss carryforwards	$ 13,300,000

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, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Statutory income tax rate	21%	21%	21%
Stock-based compensation expense	(2.90%)	2.20%	8.20%
State income tax	1.20%	2.10%	1.20%
Tax credits	1.70%	2%	1.80%
Other	(0.10%)	(0.80%)	0%
Valuation allowance	(20.90%)	(26.50%)	(32.20%)
Total effective income tax rate	0%	0%	0%

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, 2022	Dec. 31, 2021
Deferred tax assets:
Federal and state net operating loss carryforwards	$ 63,653	$ 58,025
Tax credit carryforwards	13,403	9,874
Capitalized research expenditures	15,448	0
Lease liabilities	7,539	8,274
Stock-based compensation expense	3,312	2,129
Accrued expenses	903	728
Other	202	135
Total deferred tax assets	104,460	79,165
Deferred tax liabilities:
Right-of-use assets	(6,983)	(8,016)
Total deferred tax liabilities	(6,983)	(8,016)
Valuation allowance	(97,477)	(71,149)
Net deferred tax assets	$ 0	$ 0

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, 2022	Dec. 31, 2021	Dec. 31, 2020
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Gross unrecognized tax benefit as of January 1	$ 2,579	$ 1,499	$ 1,012
Additions for tax positions taken in the current year	927	1,080	626
Reductions for tax positions taken in the current year	0	0	(139)
Additions for tax positions taken in prior years	0	0	0
Gross unrecognized tax benefit as of December 31	$ 3,506	$ 2,579	$ 1,499

Net Loss Per Share - Schedule o

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, 2022	Dec. 31, 2021	Dec. 31, 2020
Numerator:
Net loss	$ (126,325)	$ (100,287)	$ (66,564)
Denominator:
Weighted-average shares of common stock outstanding, basic (in shares)	38,837,001	37,591,505	22,878,325
Weighted-average shares of common stock outstanding, diluted (in shares)	38,837,001	37,591,505	22,878,325
Net loss per share, basic (in dollars per share)	$ (3.25)	$ (2.67)	$ (2.91)
Net loss per share, diluted (in dollars per share)	$ (3.25)	$ (2.67)	$ (2.91)

Net Loss Per Share - Summary of

Net Loss Per Share - Summary of Potentially Dilutive Securities (Details) - shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of net loss per share	5,901,174	5,160,304	3,506,599
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	5,369,808	4,442,864	3,506,599
RSUs outstanding
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of net loss per share	531,366	717,440	0

Subsequent Event - Additional I

Subsequent Event - Additional Information (Details) - Subsequent Event - Reduction in Workforce Plan - Employee Severance $ in Millions	1 Months Ended
	Mar. 31, 2023 USD ($) employees
Subsequent Event [Line Items]
Reduction in workforce, percent	21%
Reduction in number of employees	16
Number of employees	61
Restructuring charges | $	$ 1.8