Applied Molecular Transport (AMTI) S-1 29 Mar 21 IPO registration Financial data

Document and Entity Information

Document and Entity Information	12 Months Ended
	Dec. 31, 2020
Cover [Abstract]
Document Type	S-1
Amendment Flag	false
Entity Registrant Name	Applied Molecular Transport Inc.
Entity Central Index Key	0001801777
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false

Balance Sheets

Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 5,843	$ 12,727
Short-term investments	124,026	19,676
Prepaid expenses	1,311	532
Deferred offering costs		366
Other current assets	321	152
Total current assets	131,501	33,453
Property and equipment, net	8,447	4,091
Long-term investments		249
Restricted cash	108	108
Other assets	127	632
Total assets	140,183	38,533
Current liabilities:
Accounts payable	3,174	2,666
Accrued expenses	4,173	1,315
Deferred rent, current	83	13
Capital lease obligations, current	232	42
Total current liabilities	7,662	4,036
Deferred rent	444	526
Capital lease obligations	404	58
Total liabilities	8,510	4,620
Commitments and contingencies (Note 6)
Convertible preferred stock		105,615
Stockholders’ equity (deficit):
Common stock, $0.0001 par value, 450,000,000 and 32,000,000 shares authorized as of December 31, 2020 and 2019, respectively; 35,121,360 and 7,360,738 shares issued and outstanding as of December 31, 2020 and 2019, respectively	4	1
Additional paid-in capital	271,000	1,078
Accumulated other comprehensive income	27	13
Accumulated deficit	(139,358)	(72,794)
Total stockholders’ equity (deficit)	131,673	(71,702)
Total liabilities, convertible preferred stock and stockholders’ equity (deficit)	$ 140,183	38,533
Series A Convertible Preferred Stock
Current liabilities:
Convertible preferred stock		32,826
Series B Convertible Preferred Stock
Current liabilities:
Convertible preferred stock		30,921
Series C Convertible Preferred Stock
Current liabilities:
Convertible preferred stock		$ 41,868

Balance Sheets (Parenthetical)

Balance Sheets (Parenthetical) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Convertible preferred stock, shares authorized		13,966,292
Convertible preferred stock, shares issued		13,966,292
Convertible preferred stock, shares outstanding	0	13,966,292
Convertible preferred stock, liquidation value		$ 105,974,000
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	450,000,000	32,000,000
Common stock, shares issued	35,121,360	7,360,738
Common stock, shares outstanding	35,121,360	7,360,738
Series A Convertible Preferred Stock
Convertible preferred stock, par value	$ 0.0001	$ 0.0001
Convertible preferred stock, shares authorized	0	5,157,213
Convertible preferred stock, shares issued	0	5,157,213
Convertible preferred stock, shares outstanding	0	5,157,213
Convertible preferred stock, liquidation value	$ 0	$ 33,000,000
Series B Convertible Preferred Stock
Convertible preferred stock, par value	$ 0.0001	$ 0.0001
Convertible preferred stock, shares authorized	0	3,992,919
Convertible preferred stock, shares issued	0	3,992,919
Convertible preferred stock, shares outstanding	0	3,992,919
Convertible preferred stock, liquidation value	$ 0	$ 31,025,000
Series C Convertible Preferred Stock
Convertible preferred stock, par value	$ 0.0001	$ 0.0001
Convertible preferred stock, shares authorized	0	4,816,160
Convertible preferred stock, shares issued	0	4,816,160
Convertible preferred stock, shares outstanding	0	4,816,160
Convertible preferred stock, liquidation value	$ 0	$ 41,949,000

Statements of Operations and Co

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

Statements of Convertible Prefe

Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Series A Convertible Preferred Stock	Series B Convertible Preferred Stock	Series C Convertible Preferred Stock	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income	Accumulated Deficit
Balance at Dec. 31, 2018	$ (44,140)				$ 1	$ 610		$ (44,751)
Convertible preferred stock balance, shares at Dec. 31, 2018		5,157,213	3,992,919
Convertible preferred stock balance at Dec. 31, 2018		$ 32,826	$ 30,921
Balance, shares at Dec. 31, 2018					7,360,738
Issuance of Series C convertible preferred stock, net of issuance costs of $81				$ 41,868
Issuance of Series C convertible preferred stock, net of issuance costs of $81, shares				4,816,160
Stock-based compensation expense	468					468
Unrealized gain on investments	13						$ 13
Net loss	(28,043)							(28,043)
Balance at Dec. 31, 2019	$ (71,702)				$ 1	1,078	13	(72,794)
Convertible preferred stock balance, shares at Dec. 31, 2019	13,966,292	5,157,213	3,992,919	4,816,160
Convertible preferred stock balance at Dec. 31, 2019	$ 105,615	$ 32,826	$ 30,921	$ 41,868
Balance, shares at Dec. 31, 2019	7,360,738				7,360,738
Conversion of convertible preferred stock into common stock	$ 105,615				$ 1	105,614
Conversion of convertible preferred stock into common stock, shares		(5,157,213)	(3,992,919)	(4,816,160)
Conversion of convertible preferred stock into common stock		$ (32,826)	$ (30,921)	$ (41,868)
Conversion of convertible preferred stock into common stock, shares					13,966,292
Issuance of common stock upon initial public offering, net of underwriters’ commission and issuance costs of $16,477	160,623				$ 1	160,622
Issuance of common stock upon initial public offering, net of underwriters' commission and issuance costs, shares					12,650,000
Exercise of common stock options	$ 631				$ 1	630
Exercise of common stock, shares	1,144,330				1,144,330
Stock-based compensation expense	$ 3,056					3,056
Unrealized gain on investments	33
Net unrealized gain(loss) on investments	14						14
Net loss	(66,564)							(66,564)
Balance at Dec. 31, 2020	$ 131,673				$ 4	$ 271,000	$ 27	$ (139,358)
Convertible preferred stock balance, shares at Dec. 31, 2020	0	0	0	0
Balance, shares at Dec. 31, 2020	35,121,360				35,121,360

Statements of Convertible Pre_2

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

Statements of Cash Flows

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

Organization and Principal Acti

Organization and Principal Activities	12 Months Ended
	Dec. 31, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization and Principal Activities	1. Organization and Principal Activities Business Description Applied Molecular Transport Inc. (the Company) is a clinical-stage biopharmaceutical company leveraging its proprietary technology platform to design and develop a pipeline of novel oral biologic product candidates to treat autoimmune, inflammatory, metabolic, and other diseases. The Company is building a portfolio of oral product candidates based on its technology platform including its most advanced product candidate, AMT-101, interleukin-10 (IL-10) AMT-101 AMT-126, GI-selective interleukin-22 (IL-22) Since the date of incorporation in Delaware on November 21, 2016, the Company has devoted substantially all of its resources to research and development activities, including research activities such as drug discovery, preclinical studies, and clinical trials as well as development activities such as the manufacturing of clinical and research material, establishing and maintaining an intellectual property portfolio, hiring personnel, raising capital, and providing general and administrative support for these operations. Initial Public Offering On June 4, 2020, the Company’s registration statement on Form S-1 No. 333-238464) Liquidity and Capital Resources Management believes that its existing cash, cash equivalents, and investments as of December 31, 2020 will be sufficient to allow the Company to fund its current operating plan through at least the next 12 months. The Company has incurred significant losses and negative cash flows from operations since its inception. As of December 31, 2020, the Company had an accumulated deficit of $139.4 million and does not expect positive cash flows from operations in the foreseeable future. The Company expects to incur significant and increasing losses until regulatory approval is granted and successful commercialization is achieved for any of its product candidates. Regulatory approval is not guaranteed and may never be obtained. The Company has historically financed its operations primarily through private placements of its convertible preferred stock and sale of common stock upon the completion of the IPO. The Company may seek to raise capital through debt financings, private or public equity financings, license agreements, collaborative agreements or other arrangements with other companies, or other sources of financing. There can be no assurance that such financing will be available or will be at terms acceptable to the Company. Risks and Uncertainties Since the COVID-19 COVID-19 COVID-19 th COVID-19 stay-at-home COVID-19

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation The financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP). Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. The Company bases its estimates on historical experience and market-specific or other relevant assumptions that it believes are reasonable under the circumstances. Assets and liabilities reported in the Company’s balance sheet and expenses and income reported are affected by estimates and assumptions, which are used for, but are not limited to, determining the fair value of assets and liabilities, including research and development expenses, common stock valuation, income tax uncertainties, and measurement of stock-based compensation expense. The Company assessed certain accounting matters that generally require consideration of forecasted financial information in context with the information reasonably available to the Company and the unknown future impacts of the COVID-19 Concentration of Credit Risk and Other Risks and Uncertainties Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash, cash equivalents, and investments. The Company invests in U.S. Treasury securities. The Company maintains bank deposits in federally insured financial institutions and these deposits may exceed federally insured limits. The Company is exposed to credit risk in the event of default by the financial institutions holding its cash, cash equivalents, and investments to the extent recorded in the balance sheet. The Company has not experienced any losses on its deposits of cash, cash equivalents, and investments. The Company is subject to a number of risks similar to other early-stage biopharmaceutical companies, including, but not limited to, the need to obtain adequate additional funding, possible failure of current or future preclinical studies or clinical trials, its reliance on third parties to conduct its clinical trials, the need to obtain regulatory and marketing approvals for its product candidates, competitors developing new technological innovations, the need to successfully commercialize and gain market acceptance of the Company’s product candidates, protection of its proprietary technology, and the need to secure and maintain adequate manufacturing arrangements with third parties. If the Company does not successfully commercialize or partner any of its product candidates, it will be unable to generate product revenue or achieve profitability. Operating Segment The Company operates and manages its business as one reportable and operating segment, which is the business of designing and developing a pipeline of novel oral biologic product candidates to treat autoimmune, inflammatory, metabolic, and other diseases. The Company’s chief executive officer, who is the chief operating decision maker, reviews financial information on an aggregate basis for allocating and evaluating financial performance. Cash and Cash Equivalents Cash and cash equivalents are held in accounts at financial institutions. Such deposits have and will continue to exceed federally insured limits in the foreseeable future. The Company considers all highly liquid investments purchased with original maturities of 90 days or less from the purchase date to be cash equivalents. Cash equivalents consist of amounts invested in money market funds exclusively composed of U.S. government obligations. Restricted Cash The Company has cash in a collateral account related to a letter of credit issued on behalf of the Company for the security deposit on the subleased property in South San Francisco. As of December 31, 2020, the collateralized cash in connection with the letter of credit was classified as restricted cash on the balance sheet based on the terms of the sublease agreement. The sublease term expires in May 2022 unless extended. Subsequent to December 31, 2020, the Company established a second collateral account related to a new lease it entered into. See Note 10, Subsequent Event. The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the statements of cash flows (in thousands): As of December 31, 2019 2020 Cash and cash equivalents $ 12,727 $ 5,843 Restricted cash 108 108 Total cash, cash equivalents and restricted cash $ 12,835 $ 5,951 Investments The Company’s investments have been classified and accounted for as available-for-sale 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 term Impairment of Long-Lived Assets The Company evaluates the carrying amount of its long-lived assets whenever events or changes in circumstances indicate that the assets may not be recoverable. An impairment loss is recognized when the remaining book value of an asset is not recoverable. There was no impairment of long-lived assets during the years ended December 31, 2020 and 2019. Leases The Company may enter into lease agreements that are classified as either operating or capital leases under Accounting Standards Codification (ASC) 840, Leases Research and Development Expenses Research and development expenses are charged to expense as incurred. Research and development expenses include personnel costs related to research and development activities, materials costs, external clinical drug product manufacturing costs, outside services costs, repair, maintenance and depreciation costs for research and development equipment, as well as facility costs for laboratory space used for research and development activities. Accrued Research and Development Expenses The Company records accruals for estimated costs of research, preclinical studies, clinical trials, and manufacturing development, 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, contract research organizations (CROs) and contract development and manufacturing organizations (CDMOs). The Company’s contracts 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, taxes, etc. The financial terms of these contracts are subject to negotiations, which vary from contract to contract and may result in payment flows 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 based on estimates of actual work completed in accordance with the respective agreements. The Company determines the estimated costs through discussions with internal personnel and external service providers as to the progress, stage of completion or actual timeline (start-date and end-date) of If the actual timing of the performance of services or the level of effort varies from the estimate, the Company adjusts accrued expenses or prepaid expenses accordingly, which impact research and development expenses. Although the Company does not expect its estimates to be materially different from amounts actually incurred, the Company’s understanding of the status and timing of services performed relative to the actual status and timing of services performed may vary and may result in reporting amounts that are too high or too low in any particular period. To date, there have not been any material adjustments to the Company’s prior estimates of research and development expenses. Stock-Based Compensation Expense The Company maintains an equity incentive plan as a long-term incentive for employees, consultants, and directors. The plan allows for the issuance of incentive stock options, non-statutory 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 The Company estimates the fair value of stock options granted to employees and non-employees Income Taxes The Company accounts for income taxes using the asset and liability method. The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements or tax returns subject to a determinable valuation allowance. Deferred tax assets and liabilities are determined based on the difference between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. In evaluating the ability to recover its deferred income tax assets, the Company considers all available positive and negative evidence, including its operating results, ongoing tax planning and forecasts of future taxable income on a jurisdiction-by-jurisdiction Tax benefits related to uncertain tax positions are recognized when it is more likely than not that a tax position will be sustained during an audit. It is the Company’s policy to classify interest and penalties related to unrecognized tax benefits as a component of income tax expense. Fair Value Measurement Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability, or an exit price, in the principal or most advantageous market for that asset or liability in an orderly transaction between market participants on the measurement date. Fair value measurement establishes a fair value hierarchy that requires an entity to maximize the use of observable inputs, where available, and minimize the use of unobservable inputs when measuring fair value. The Company determined the fair value of financial assets and liabilities using the fair value hierarchy that describes three levels of inputs that may be used to measure fair value, as follows: • Level 1—Quoted prices in active markets for identical assets and liabilities; • Level 2—Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities; and • Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. As of December 31, 2020 and 2019, fair value measurements consisted mainly of cash equivalents and investments. The carrying amounts of these instruments approximate their fair value. Comprehensive Loss Comprehensive loss includes net loss and other comprehensive income (loss) for the period. Other comprehensive income (loss) consists of unrealized gains on investments and amounts recognized for net realized gain included in net loss. Deferred Offering Costs Deferred offering costs, consisting of legal, accounting, and filing fees directly related to the IPO, were capitalized and offset against proceeds from the IPO upon the completion of the offering. For the year ended December 31, 2019, $0.4 million of deferred offering costs were incurred. Upon completion of the IPO in June 2020, approximately $4.1 million of deferred offering costs were offset against the IPO proceeds classified in additional paid-in Emerging Growth Company Status The Company is an emerging growth company (EGC) as defined in the JOBS Act and may take advantage of reduced reporting requirements that are otherwise applicable to public companies. Section 107 of the JOBS Act exempts EGCs from being required to comply with new or revised financial accounting standards until private companies are required to comply with those standards. The Company has elected to use the extended transition period for complying with new or revised accounting standards. 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. In February 2016, the FASB issued Accounting Standards Update (ASU) 2016-02, Leases (Topic 842) 2016-02), right-of-use 2018-10, Codification Improvements to Topic 842, Leases 2018-11, Leases (Topic 842): Targeted Improvements 2019-10, Financial Instruments — Credit Losses (Topic 326), Derivatives and Hedging (Topic 815), and Leases (Topic 842): Effective Dates 2016-02 non-public In October 2020, the FASB issued ASU 2020-10, 2020-10 Recently Adopted Accounting Pronouncements In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes 2019-12 2019-12 In August 2018, the FASB issued ASU 2018-13, Disclosure Framework (Topic 820)—Changes to the Disclosure Requirements for Fair Value Measurement In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments 2016-13 available-for-sale available-for-sale 2016-13 2016-13

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	3. Fair Value Measurements As of December 31, 2020 and 2019, the Company held $124.0 million and $19.9 million, respectively, of investment securities, comprised of U.S. Treasury securities. In determining fair value, the Company utilizes valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible as well as considers counterparty credit risk in its assessment of fair value. Financial instruments classified within Level 2 of the fair value hierarchy are valued based on other observable inputs. When quoted prices in active markets for identical assets or liabilities are not available, the Company relies on non-binding The carrying amounts of cash equivalents and marketable securities approximate their fair value based upon quoted market prices. Certain of the Company’s financial instruments are recorded at amounts that approximate their fair value, rather than at fair value on a recurring basis, due to their liquid or short-term nature, such as cash, accounts payable and accrued expenses. The unrealized losses on short-term investments as of December 31, 2020 were insignificant. The Company does not believe that these unrealized losses are credit related but are rather a reflection of current market yields and/or current marketplace bid/ask spreads. The Company has not recognized an allowance for credit losses as of December 31, 2020. The following tables summarize the Company’s financial assets measured at fair value on a recurring basis by level within the fair value hierarchy as of December 31, 2020 (in thousands): December 31, 2020 Fair Value Hierarchy Level Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash equivalents Money Market Funds Invested in U.S. government obligations (1) Level 1 $ 4,844 $ — $ — $ 4,844 Short-term and long-term investments U.S. Treasury securities Level 2 123,998 28 — 124,026 Total $ 128,842 $ 28 $ — $ 128,870 (1) Included in cash and cash equivalents on the balance sheet The following tables summarize the Company’s financial assets measured at fair value on a recurring basis by level within the fair value hierarchy as of December 31, 2019 (in thousands): December 31, 2019 Fair Value Amortized Gross Gross Fair Value Cash equivalents Money Market Funds Invested in U.S. government obligations (1) Level 1 $ 69 $ — $ — $ 69 Short-term and long-term investments U.S. Treasury securities Level 2 19,912 13 — 19,925 Total $ 19,981 $ 13 $ — $ 19,994 (1) Included in cash and cash equivalents on the balance sheet There were no transfers between Levels 1, 2, or 3 during the years ended December 31, 2020 and 2019, respectively.

Balance Sheet Components

Balance Sheet Components	12 Months Ended
	Dec. 31, 2020
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Components	4. Balance Sheet Components Property and Equipment, Net Property and equipment, net, consisted of the following (in thousands): December 31, 2019 2020 Laboratory and manufacturing equipment $ 3,062 $ 8,022 Leasehold improvements 242 2,550 Capital leases 188 959 Computer and office equipment 202 201 Construction in progress 2,080 162 5,774 11,894 Accumulated depreciation (1,683 ) (3,447 ) Total property and equipment, net $ 4,091 $ 8,447 Depreciation was $1.8 million and $0.7 million for the years ended December 31, 2020 and 2019, respectively. Capital leases consisted of laboratory and manufacturing equipment subject to capital leases. Depreciation on capital lease assets was insignificant for the years ended December 31, 2020 and 2019, respectively. Accumulated depreciation on capital lease assets was $0.1 million as of December 31, 2020 and insignificant as of December 31, 2019. There were insignificant disposals during the year ended December 31, 2020. Accrued Expenses Accrued expenses consisted of the following (in thousands): December 31, 2019 2020 Compensation expense $ 694 $ 2,389 Research and development expense 621 1,303 Professional services — 241 Property and equipment — 125 Other — 115 Total accrued expenses $ 1,315 $ 4,173 Accrued research and development expenses were primarily related to clinical trials, preclinical studies, contract manufacturing, and materials.

Capital Structure

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

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2020
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	6. 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, 2020 and 2019, and no material legal proceedings are subsequently outstanding or pending. Indemnification In the ordinary course of business, the Company enters into agreements that may include indemnification provisions. As permitted under Delaware law and in accordance with its bylaws, the Company indemnifies its officers and directors for certain events or occurrences while the officer or director is or was serving in such capacity. The Company is also party to indemnification agreements with its officers and directors. In some cases, the indemnification will continue after the termination of the agreement. The maximum potential amount of future payments that the Company could be required to make under these provisions is not determinable. The Company has never incurred material costs to defend lawsuits or settle claims related to these indemnification provisions. The Company is not currently aware of any indemnification claims. The Company also maintains director and officer insurance, which may cover certain liabilities arising from our obligation to indemnify our directors and officers. Accordingly, the Company has not recorded any liabilities for these indemnification rights and agreements as of December 31, 2020 and 2019. Operating Leases In December 2016, the Company entered into an operating lease agreement for its principal office in South San Francisco, California. The lease term expires in August 2024. Under the lease agreement, the Company has two three-year renewal options through August 2030. In October 2019, the Company entered into a sublease, as lessee, for office and laboratory space in South San Francisco, California. The sublease term expires in May 2022. Under the lease agreement, the Company has a five-year renewal option through May 2027. In September 2020, the Company entered into a lease agreement for warehouse space in South San Francisco, California. The lease term expires in September 2021. Under the lease agreement, the Company has two six-month In February 2021, the Company entered into a new lease agreement. See Note 10. Subsequent Event. Rent expense was $2.0 million and $1.5 million for the years ended December 31, 2020 and 2019, respectively. Capital Leases During 2020, the Company commenced a new capital lease for certain laboratory equipment. The Company entered the agreement for this lease during 2019. During 2019, the Company entered into two capital lease agreements for certain laboratory equipment. As of December 31, 2020, the Company’s future minimum payments under noncancelable leases were as follows (in thousands): Year Ended December 31, Operating Lease Commitments Capital Lease Commitments Total 2021 $ 2,123 $ 274 $ 2,397 2022 1,699 254 1,953 2023 1,457 171 1,628 2024 1,000 — 1,000 Thereafter — — — Total future minimum lease payments $ 6,279 $ 699 $ 6,978 COVID-19 The full extent of the impact of the COVID-19 COVID-19.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	7. Income Taxes No provision for, or benefit from, income taxes was recorded for the years ended December 31, 2020 and 2019. The Company has established a full valuation allowance against its net deferred tax assets due to the uncertainty regarding the realization of such assets. All losses to date have been incurred domestically. The effective income tax rate of the Company’s provision for income taxes differed from the federal statutory rate as follows: Year Ended December 31, 2019 2020 Statutory income tax rate 21.0 % 21.0 % Stock-based compensation expense (0.3 ) 8.2 Tax credits 4.7 1.8 State income tax 9.8 1.2 Other (0.1 ) — Valuation allowance (35.1 ) (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, 2019 2020 Deferred tax assets: Net operating losses $ 19,214 $ 37,785 Tax credits 3,545 5,805 Accrued expenses 345 617 Stock-based compensation expense 52 350 Other current assets 6 6 Total deferred tax assets 23,162 44,563 Deferred tax liabilities: Property and equipment, net (25 ) — Total deferred tax liabilities (25 ) — Valuation allowance (23,137 ) (44,563 ) Net deferred tax assets $ — $ — In March 2020, the Coronavirus Aid, Relief, and Economic Security Act (CARES Act) was enacted in response to the COVID-19 Realization of future tax benefits is dependent on the Company’s ability to generate sufficient taxable income within the carryforward period. Due to the Company’s history of operating losses and future sources of taxable income, the Company believes that the recognition of the deferred tax assets is currently not more likely than not to be realized and, accordingly, have provided a full valuation allowance against net deferred tax assets. For the years ended December 31, 2020 and 2019, the net increase in the valuation allowance was $21.4 million and $9.9 million, respectively. As of December 31, 2020, the Company had federal net operating loss carryforwards of $156.0 million, of which $13.3 million federal net operating losses generated before January 1, 2018 will begin to expire in 2036. Federal net operating losses of $142.7 million generated after December 31, 2017 will carryforward indefinitely. As of December 31, 2020, the Company had state net operating loss carryforwards of $69.0 million, which will begin to expire in 2036. As of December 31, 2020, the Company had federal general business credits from research and development expenses totaling $4.9 million, as well as state research and development credits of $3.1 million. The federal credits will begin to expire in 2037, if not utilized. The state research and development tax credits can be carried forward indefinitely. The amount of benefit from net operating loss and tax credit carryforwards may be impaired or limited in certain circumstances. Events which may cause a limitation in the amount of net operating losses and tax credits the Company can utilize include a cumulative ownership change of more than 50%, as defined by Internal Revenue Code Section 382, over a three-year testing period. The Company performed a Section 382 analysis through December 31, 2020. Although the Company has experienced an ownership change in the past, it did not result in a limitation that will materially reduce the total amount of net operating loss carryforwards and credits that can be utilized. Subsequent ownership changes may result in limitations on the Company’s ability to utilize the losses in future periods. The Company files U.S. federal and state tax returns with varying statutes of limitations. Due to net operating loss and credit carryforwards, all of the tax years since the date of incorporation through the 2020 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, 2020 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, 2020. A reconciliation of the beginning and ending amounts of unrecognized tax benefits was as follows (in thousands): Year Ended December 31, 2019 2020 Gross unrecognized tax benefit as of January 1 $ 390 $ 1,012 Additions for tax positions taken in the current year 407 626 Reductions for tax positions taken in the current year — (139 ) Additions for tax positions taken in prior years 215 — Gross unrecognized tax benefit as of December 31 $ 1,012 $ 1,499 None of the unrecognized tax benefits at December 31, 2020 or December 31, 2019 would affect the effective tax rate due to the Company’s valuation allowance position. During the years ended December 31, 2020 and 2019, no interest or penalties were required to be recognized relating to unrecognized tax benefits. In the event the Company should need to recognize interest and penalties related to unrecognized income tax liabilities, this amount will be recorded as an accrued expense and an increase to income tax expense.

Equity Incentive Plan and Stock

Equity Incentive Plan and Stock-Based Compensation Expense	12 Months Ended
	Dec. 31, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Equity Incentive Plan and Stock-Based Compensation Expense	8. Equity Incentive Plan and Stock-Based Compensation Expense 2015 Equity Incentive Plan In 2015, prior to the Company’s conversion to a C-corporation, In connection with its 2016 conversion to a C-corporation, 2016 Equity Incentive Plan The Company adopted the 2016 Plan, which provided for the granting of incentive stock options (ISO), non-statutory 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 adopted the 2020 Equity Incentive Plan (the 2020 Plan) effective on the day prior to the effectiveness of the registration statement on Form S-1 Since the date of incorporation and through December 31, 2020, the Company issued stock options to its employees and consultants. In most instances, the options vest over a four-year period, subject to continuing service. Options under the 2020 Plan may be granted for periods of up to 10 years and at prices no less than 100% of the estimated fair value of the underlying shares of common stock on the date of grant as determined by the Board of Directors provided that the exercise price of an ISO and NSO granted to a 10% stockholder shall not be less than 110% of the estimated fair value of the shares on the date of grant. The 2020 Plan requires that options be exercised no later than 10 years after the grant. Options granted to employees generally vest ratably on a monthly basis over four years, subject to cliff vesting restrictions. 2020 Employee Stock Purchase Plan The Company’s Board of Directors adopted and the Company’s stockholders approved, effective on the day prior to the effectiveness of the registration statement on Form S-1 Non-423 Subject to adjustment in the case of certain capitalization events, 314,006 shares of the Company’s common stock were available for purchase at adoption of the ESPP. Pursuant to the ESPP, the annual share increase pursuant to the evergreen provision is determined based on the least of (i) 628,012 shares, (ii) 1% of the Company’s common stock outstanding as of December 31 of the immediately preceding year, or (iii) such number of shares as determined by the Company’s Board of Directors. As of December 31, 2020, 314,006 shares of common stock remained available for issuance under the ESPP. During the years ended December 31, 2020 and 2019, the Company recognized no stock-based compensation expense related to the ESPP. The following summarizes stock option activity (in thousands, except share, per share and year amounts): Options Outstanding Shares Available for Grant Total Options Outstanding Weighted- Average Exercise Price Weighted- Average Remaining Contractual Life Aggregate Intrinsic Value Outstanding as of January 1, 2019 1,803,912 1,774,858 $ 0.84 $ 2,815 Granted (773,688 ) 773,688 2.38 Cancelled 405,178 (405,178 ) 1.81 Outstanding as of December 31, 2019 1,435,402 2,143,368 $ 1.22 7.30 $ 10,555 Additions 4,441,405 — $ — Granted (2,598,319 ) 2,598,319 7.82 Exercised — (1,144,330 ) 0.55 Cancelled 90,758 (90,758 ) 3.43 Outstanding as of December 31, 2020 3,369,246 3,506,599 $ 6.27 8.79 $ 85,975 Exercisable as of December 31, 2020 — 951,438 $ 3.06 8.02 $ 26,364 Weighted-average grant-date fair value of the options granted during the years ended December 31, 2020 and 2019 was $5.88 per share and $1.61 per share, respectively. The intrinsic value of the options exercised during the years ended December 31, 2020 and 2019 was $29.5 million and zero, respectively. As of December 31, 2020, the total stock-based compensation expense related to options granted but not yet amortized was $13.0 million and will be recognized over a weighted-average period of approximately 2.84 years. Fair Value Measurement The Company estimated the fair value of stock options using the Black-Scholes option pricing model. The fair value of employee and non-employee The fair value of the shares of common stock underlying stock options has historically been determined by the Board of Directors. Because there has been no public market for the Company’s common stock, the Board of Directors has determined the fair value of the common stock at the time of grant of the option by considering a number of objective and subjective factors including: external market conditions affecting the pharmaceutical and biotechnology industry and trends within the industry; the Company’s stage of development; the rights, preferences and privileges of the Company’s convertible preferred stock relative to those of the Company’s common stock; the prices at which the Company sold shares of its convertible preferred stock; the Company’s financial condition and operating results, including levels of available capital resources; the progress of the Company’s research and development efforts and business strategy; equity market conditions affecting comparable public companies; general U.S. market conditions; and the lack of marketability of the Company’s common stock. The Black-Scholes option-pricing model requires the use of highly subjective assumptions which determine the fair value of stock-based awards. These assumptions include: • Risk-free interest rate • Expected volatility • Expected term time-to-vesting • Expected dividend yield For options granted to non-employee The fair value of each employee stock option grant during the years ended December 31, 2020 and 2019 was estimated using the following weighted-average assumptions: Year Ended December 31, 2019 2020 Risk-free interest rate 2.3 % 0.6 % Expected volatility 70.0 % 75.6 % Expected term (years) 6.08 6.10 Expected dividend yield — — Stock-Based Compensation Expense In May 2020, the Board of Directors approved a one-time repricing of certain stock options granted to our service providers with a per share exercise price of $6.14 under our 2016 Plan. Pursuant to such approval, in May 2020, the exercise price of 1,998,677 stock options (including any cancelled stock options) were automatically repriced to $4.61 per share, which the Board of Directors determined represented the fair value of the Company’s common stock as of the date of the repricing. As a result of the repricing, the weighted-average exercise price for options granted during the six months ended June 30, 2020 decreased from $6.48 per share to $5.18 per share. The Company used the Black-Scholes option pricing model to estimate the fair value of the modified option grants immediately before and immediately after the modification in order to determine the increase in the fair value of $0.5 million for the modified option grants, which is recognized over the weighted-average remaining requisite service period of 3.3 years. The following table summarizes the components of stock-based compensation expense recognized in the Company’s statement of operations and comprehensive loss during 2020 and 2019 (in thousands): Year Ended December 31, 2019 2020 Research and development $ 338 $ 1,943 General and administrative 130 1,113 Total stock-based compensation expense $ 468 $ 3,056

Net Loss and Net Loss Per Share

Net Loss and Net Loss Per Share	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Net Loss, Net Loss Per Share and Unaudited Pro Forma Net Loss Per Share	9. Net Loss and Net Loss Per Share The following table sets forth the computation of the basic and diluted net loss per share (except share and per share amounts): Year Ended December 31, 2019 2020 Numerator: Net loss $ (28,043 ) $ (66,564 ) Denominator: Weighted-average shares of common stock outstanding used in the calculation of basic and diluted net loss per share 7,360,738 22,878,325 Net loss per share, basic and diluted $ (3.81 ) $ (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 all common stock equivalents outstanding would have been anti-dilutive. Potentially dilutive securities that were not included in the diluted per share calculations because they would be anti-dilutive were as follows: December 31, 2019 2020 Total stock options outstanding 2,143,368 3,506,599 Series A convertible preferred stock 5,157,213 — Series B convertible preferred stock 3,992,919 — Series C convertible preferred stock 4,816,160 — Total 16,109,660 3,506,599

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2020
Subsequent Events [Abstract]
Subsequent Events	10. Subsequent Event In February 2021, the Company entered into an agreement to lease approximately 84,321 square feet of laboratory, manufacturing, warehouse and office space in South San Francisco, California. Pursuant to the lease agreement, the lease term is estimated to commence in October 2021. The initial lease term is eight years from the commencement date and includes optional two five-year extensions. Annual lease payments during the first year are approximately $4.2 million. Annual lease payments during the second year are approximately $5.7 million with increases of approximately 3% each year. The Company has paid a security deposit of approximately $0.9 million and will classify the amount as restricted cash on the Company’s balance sheet.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP).
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. The Company bases its estimates on historical experience and market-specific or other relevant assumptions that it believes are reasonable under the circumstances. Assets and liabilities reported in the Company’s balance sheet and expenses and income reported are affected by estimates and assumptions, which are used for, but are not limited to, determining the fair value of assets and liabilities, including research and development expenses, common stock valuation, income tax uncertainties, and measurement of stock-based compensation expense. The Company assessed certain accounting matters that generally require consideration of forecasted financial information in context with the information reasonably available to the Company and the unknown future impacts of the COVID-19
Concentration of Credit Risk and Other Risks and Uncertainties	Concentration of Credit Risk and Other Risks and Uncertainties Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash, cash equivalents, and investments. The Company invests in U.S. Treasury securities. The Company maintains bank deposits in federally insured financial institutions and these deposits may exceed federally insured limits. The Company is exposed to credit risk in the event of default by the financial institutions holding its cash, cash equivalents, and investments to the extent recorded in the balance sheet. The Company has not experienced any losses on its deposits of cash, cash equivalents, and investments. The Company is subject to a number of risks similar to other early-stage biopharmaceutical companies, including, but not limited to, the need to obtain adequate additional funding, possible failure of current or future preclinical studies or clinical trials, its reliance on third parties to conduct its clinical trials, the need to obtain regulatory and marketing approvals for its product candidates, competitors developing new technological innovations, the need to successfully commercialize and gain market acceptance of the Company’s product candidates, protection of its proprietary technology, and the need to secure and maintain adequate manufacturing arrangements with third parties. If the Company does not successfully commercialize or partner any of its product candidates, it will be unable to generate product revenue or achieve profitability.
Operating Segment	Operating Segment The Company operates and manages its business as one reportable and operating segment, which is the business of designing and developing a pipeline of novel oral biologic product candidates to treat autoimmune, inflammatory, metabolic, and other diseases. The Company’s chief executive officer, who is the chief operating decision maker, reviews financial information on an aggregate basis for allocating and evaluating financial performance.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents are held in accounts at financial institutions. Such deposits have and will continue to exceed federally insured limits in the foreseeable future. The Company considers all highly liquid investments purchased with original maturities of 90 days or less from the purchase date to be cash equivalents. Cash equivalents consist of amounts invested in money market funds exclusively composed of U.S. government obligations.
Restricted Cash	Restricted Cash The Company has cash in a collateral account related to a letter of credit issued on behalf of the Company for the security deposit on the subleased property in South San Francisco. As of December 31, 2020, the collateralized cash in connection with the letter of credit was classified as restricted cash on the balance sheet based on the terms of the sublease agreement. The sublease term expires in May 2022 unless extended. Subsequent to December 31, 2020, the Company established a second collateral account related to a new lease it entered into. See Note 10, Subsequent Event. The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the statements of cash flows (in thousands): As of December 31, 2019 2020 Cash and cash equivalents $ 12,727 $ 5,843 Restricted cash 108 108 Total cash, cash equivalents and restricted cash $ 12,835 $ 5,951
Investments	Investments The Company’s investments have been classified and accounted for as available-for-sale
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 term
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets The Company evaluates the carrying amount of its long-lived assets whenever events or changes in circumstances indicate that the assets may not be recoverable. An impairment loss is recognized when the remaining book value of an asset is not recoverable. There was no impairment of long-lived assets during the years ended December 31, 2020 and 2019.
Leases	Leases The Company may enter into lease agreements that are classified as either operating or capital leases under Accounting Standards Codification (ASC) 840, Leases
Research and Development Expenses	Research and Development Expenses Research and development expenses are charged to expense as incurred. Research and development expenses include personnel costs related to research and development activities, materials costs, external clinical drug product manufacturing costs, outside services costs, repair, maintenance and depreciation costs for research and development equipment, as well as facility costs for laboratory space used for research and development activities.
Accrued Research and Development Expenses	Accrued Research and Development Expenses The Company records accruals for estimated costs of research, preclinical studies, clinical trials, and manufacturing development, 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, contract research organizations (CROs) and contract development and manufacturing organizations (CDMOs). The Company’s contracts 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, taxes, etc. The financial terms of these contracts are subject to negotiations, which vary from contract to contract and may result in payment flows 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 based on estimates of actual work completed in accordance with the respective agreements. The Company determines the estimated costs through discussions with internal personnel and external service providers as to the progress, stage of completion or actual timeline (start-date and end-date) of If the actual timing of the performance of services or the level of effort varies from the estimate, the Company adjusts accrued expenses or prepaid expenses accordingly, which impact research and development expenses. Although the Company does not expect its estimates to be materially different from amounts actually incurred, the Company’s understanding of the status and timing of services performed relative to the actual status and timing of services performed may vary and may result in reporting amounts that are too high or too low in any particular period. To date, there have not been any material adjustments to the Company’s prior estimates of research and development expenses.
Stock-Based Compensation Expense	Stock-Based Compensation Expense The Company maintains an equity incentive plan as a long-term incentive for employees, consultants, and directors. The plan allows for the issuance of incentive stock options, non-statutory 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 The Company estimates the fair value of stock options granted to employees and non-employees
Income Taxes	Income Taxes The Company accounts for income taxes using the asset and liability method. The Company recognizes deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements or tax returns subject to a determinable valuation allowance. Deferred tax assets and liabilities are determined based on the difference between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. In evaluating the ability to recover its deferred income tax assets, the Company considers all available positive and negative evidence, including its operating results, ongoing tax planning and forecasts of future taxable income on a jurisdiction-by-jurisdiction Tax benefits related to uncertain tax positions are recognized when it is more likely than not that a tax position will be sustained during an audit. It is the Company’s policy to classify interest and penalties related to unrecognized tax benefits as a component of income tax expense.
Fair Value Measurement	Fair Value Measurement Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability, or an exit price, in the principal or most advantageous market for that asset or liability in an orderly transaction between market participants on the measurement date. Fair value measurement establishes a fair value hierarchy that requires an entity to maximize the use of observable inputs, where available, and minimize the use of unobservable inputs when measuring fair value. The Company determined the fair value of financial assets and liabilities using the fair value hierarchy that describes three levels of inputs that may be used to measure fair value, as follows: • Level 1—Quoted prices in active markets for identical assets and liabilities; • Level 2—Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities; and • Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. As of December 31, 2020 and 2019, fair value measurements consisted mainly of cash equivalents and investments. The carrying amounts of these instruments approximate their fair value.
Comprehensive Loss	Comprehensive Loss Comprehensive loss includes net loss and other comprehensive income (loss) for the period. Other comprehensive income (loss) consists of unrealized gains on investments and amounts recognized for net realized gain included in net loss.
Deferred Offering Costs	Deferred Offering Costs Deferred offering costs, consisting of legal, accounting, and filing fees directly related to the IPO, were capitalized and offset against proceeds from the IPO upon the completion of the offering. For the year ended December 31, 2019, $0.4 million of deferred offering costs were incurred. Upon completion of the IPO in June 2020, approximately $4.1 million of deferred offering costs were offset against the IPO proceeds classified in additional paid-in
Emerging Growth Company Status	Emerging Growth Company Status The Company is an emerging growth company (EGC) as defined in the JOBS Act and may take advantage of reduced reporting requirements that are otherwise applicable to public companies. Section 107 of the JOBS Act exempts EGCs from being required to comply with new or revised financial accounting standards until private companies are required to comply with those standards. The Company has elected to use the extended transition period for complying with new or revised accounting standards.
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. In February 2016, the FASB issued Accounting Standards Update (ASU) 2016-02, Leases (Topic 842) 2016-02), right-of-use 2018-10, Codification Improvements to Topic 842, Leases 2018-11, Leases (Topic 842): Targeted Improvements 2019-10, Financial Instruments — Credit Losses (Topic 326), Derivatives and Hedging (Topic 815), and Leases (Topic 842): Effective Dates 2016-02 non-public In October 2020, the FASB issued ASU 2020-10, 2020-10 Recently Adopted Accounting Pronouncements In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes 2019-12 2019-12 In August 2018, the FASB issued ASU 2018-13, Disclosure Framework (Topic 820)—Changes to the Disclosure Requirements for Fair Value Measurement In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments 2016-13 available-for-sale available-for-sale 2016-13 2016-13

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Schedule of Reconciliation of Cash, Cash Equivalents and Restricted Cash	The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the statements of cash flows (in thousands): As of December 31, 2019 2020 Cash and cash equivalents $ 12,727 $ 5,843 Restricted cash 108 108 Total cash, cash equivalents and restricted cash $ 12,835 $ 5,951
Schedule of Estimated Useful Lives of Property and Equipment	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 term

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Summary of Financial Assets Measured at Fair Value on Recurring Basis	The following tables summarize the Company’s financial assets measured at fair value on a recurring basis by level within the fair value hierarchy as of December 31, 2020 (in thousands): December 31, 2020 Fair Value Hierarchy Level Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash equivalents Money Market Funds Invested in U.S. government obligations (1) Level 1 $ 4,844 $ — $ — $ 4,844 Short-term and long-term investments U.S. Treasury securities Level 2 123,998 28 — 124,026 Total $ 128,842 $ 28 $ — $ 128,870 (1) Included in cash and cash equivalents on the balance sheet The following tables summarize the Company’s financial assets measured at fair value on a recurring basis by level within the fair value hierarchy as of December 31, 2019 (in thousands): December 31, 2019 Fair Value Amortized Gross Gross Fair Value Cash equivalents Money Market Funds Invested in U.S. government obligations (1) Level 1 $ 69 $ — $ — $ 69 Short-term and long-term investments U.S. Treasury securities Level 2 19,912 13 — 19,925 Total $ 19,981 $ 13 $ — $ 19,994 (1) Included in cash and cash equivalents on the balance sheet

Balance Sheet Components (Table

Balance Sheet Components (Tables)	12 Months Ended
	Dec. 31, 2020
Balance Sheet Related Disclosures [Abstract]
Schedule of Property, Plant and Equipment, Net	Property and equipment, net, consisted of the following (in thousands): December 31, 2019 2020 Laboratory and manufacturing equipment $ 3,062 $ 8,022 Leasehold improvements 242 2,550 Capital leases 188 959 Computer and office equipment 202 201 Construction in progress 2,080 162 5,774 11,894 Accumulated depreciation (1,683 ) (3,447 ) Total property and equipment, net $ 4,091 $ 8,447
Schedule of Accrued Liabilities	Accrued expenses consisted of the following (in thousands): December 31, 2019 2020 Compensation expense $ 694 $ 2,389 Research and development expense 621 1,303 Professional services — 241 Property and equipment — 125 Other — 115 Total accrued expenses $ 1,315 $ 4,173

Capital Structure (Tables)

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

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2020
Commitments And Contingencies Disclosure [Abstract]
Schedule of Future Minimum Payments under Noncancelable Leases	As of December 31, 2020, the Company’s future minimum payments under noncancelable leases were as follows (in thousands): Year Ended December 31, Operating Lease Commitments Capital Lease Commitments Total 2021 $ 2,123 $ 274 $ 2,397 2022 1,699 254 1,953 2023 1,457 171 1,628 2024 1,000 — 1,000 Thereafter — — — Total future minimum lease payments $ 6,279 $ 699 $ 6,978

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
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, 2019 2020 Statutory income tax rate 21.0 % 21.0 % Stock-based compensation expense (0.3 ) 8.2 Tax credits 4.7 1.8 State income tax 9.8 1.2 Other (0.1 ) — Valuation allowance (35.1 ) (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, 2019 2020 Deferred tax assets: Net operating losses $ 19,214 $ 37,785 Tax credits 3,545 5,805 Accrued expenses 345 617 Stock-based compensation expense 52 350 Other current assets 6 6 Total deferred tax assets 23,162 44,563 Deferred tax liabilities: Property and equipment, net (25 ) — Total deferred tax liabilities (25 ) — Valuation allowance (23,137 ) (44,563 ) Net deferred tax assets $ — $ —
Schedule of Reconciliation of Beginning and Ending Amounts of Unrecognized Tax Benefits	A reconciliation of the beginning and ending amounts of unrecognized tax benefits was as follows (in thousands): Year Ended December 31, 2019 2020 Gross unrecognized tax benefit as of January 1 $ 390 $ 1,012 Additions for tax positions taken in the current year 407 626 Reductions for tax positions taken in the current year — (139 ) Additions for tax positions taken in prior years 215 — Gross unrecognized tax benefit as of December 31 $ 1,012 $ 1,499

Equity Incentive Plan and Sto_2

Equity Incentive Plan and Stock-Based Compensation Expense (Tables)	12 Months Ended
	Dec. 31, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Stock Option Activity	The following summarizes stock option activity (in thousands, except share, per share and year amounts): Options Outstanding Shares Available for Grant Total Options Outstanding Weighted- Average Exercise Price Weighted- Average Remaining Contractual Life Aggregate Intrinsic Value Outstanding as of January 1, 2019 1,803,912 1,774,858 $ 0.84 $ 2,815 Granted (773,688 ) 773,688 2.38 Cancelled 405,178 (405,178 ) 1.81 Outstanding as of December 31, 2019 1,435,402 2,143,368 $ 1.22 7.30 $ 10,555 Additions 4,441,405 — $ — Granted (2,598,319 ) 2,598,319 7.82 Exercised — (1,144,330 ) 0.55 Cancelled 90,758 (90,758 ) 3.43 Outstanding as of December 31, 2020 3,369,246 3,506,599 $ 6.27 8.79 $ 85,975 Exercisable as of December 31, 2020 — 951,438 $ 3.06 8.02 $ 26,364
Schedule of Weighted-Average Assumptions Used for Estimating Fair Value of Each Employee Stock Option	The fair value of each employee stock option grant during the years ended December 31, 2020 and 2019 was estimated using the following weighted-average assumptions: Year Ended December 31, 2019 2020 Risk-free interest rate 2.3 % 0.6 % Expected volatility 70.0 % 75.6 % Expected term (years) 6.08 6.10 Expected dividend yield — —
Summary of Components of Stock-Based Compensation Expense	The following table summarizes the components of stock-based compensation expense recognized in the Company’s statement of operations and comprehensive loss during 2020 and 2019 (in thousands): Year Ended December 31, 2019 2020 Research and development $ 338 $ 1,943 General and administrative 130 1,113 Total stock-based compensation expense $ 468 $ 3,056

Net Loss and Net Loss Per Sha_2

Net Loss and Net Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Schedule of Computation of Basic and Diluted Net Loss Per Share	The following table sets forth the computation of the basic and diluted net loss per share (except share and per share amounts): Year Ended December 31, 2019 2020 Numerator: Net loss $ (28,043 ) $ (66,564 ) Denominator: Weighted-average shares of common stock outstanding used in the calculation of basic and diluted net loss per share 7,360,738 22,878,325 Net loss per share, basic and diluted $ (3.81 ) $ (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 all common stock equivalents outstanding would have been anti-dilutive. Potentially dilutive securities that were not included in the diluted per share calculations because they would be anti-dilutive were as follows: December 31, 2019 2020 Total stock options outstanding 2,143,368 3,506,599 Series A convertible preferred stock 5,157,213 — Series B convertible preferred stock 3,992,919 — Series C convertible preferred stock 4,816,160 — Total 16,109,660 3,506,599

Organization and Principal Ac_2

Organization and Principal Activities - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	Jun. 09, 2020	Jun. 04, 2020	Dec. 31, 2020	Dec. 31, 2019
Organization And Principal Activities [Line Items]
Offering costs paid			$ 3,948
Net proceeds from offering			164,703
Accumulated deficit			$ 139,358	$ 72,794
Common Stock
Organization And Principal Activities [Line Items]
Share issued			12,650,000
Conversion of convertible preferred stock into common stock, shares			13,966,292
Common Stock | Initial Public Offering
Organization And Principal Activities [Line Items]
Share issued	12,650,000
Share price	$ 14
Share issued with exercise by underwriters	1,650,000
Conversion of convertible preferred stock into common stock, shares	13,966,292	13,966,292
Aggregate offering price for shares sold	$ 177,100
Underwriting discounts and commissions	12,400
Offering costs paid	4,100			$ 200
Net proceeds from offering	$ 160,600

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Details)	1 Months Ended	6 Months Ended	12 Months Ended
	Oct. 31, 2019	Jun. 30, 2020USD ($)	Dec. 31, 2020USD ($)Segmentshares	Dec. 31, 2019USD ($)shares
Summary Of Significant Accounting Policies [Line Items]
Number of reportable segment | Segment			1
Number of operating segment | Segment			1
Sublease, expiration period	2022-05		2022-05
Impairment of long-lived assets			$ 0	$ 0
Number of shares issued under share based compensation | shares			0	0
Deferred offering costs				$ 366,000
ASU 2019-12
Summary Of Significant Accounting Policies [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]			true
Change in Accounting Principle, Accounting Standards Update, Adoption Date			Jan. 1, 2020
Change in Accounting Principle, Accounting Standards Update, Immaterial Effect [true false]			true
ASU 2018-13
Summary Of Significant Accounting Policies [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]			true
Change in Accounting Principle, Accounting Standards Update, Adoption Date			Jan. 1, 2020
Change in Accounting Principle, Accounting Standards Update, Immaterial Effect [true false]			true
ASU 2016-13
Summary Of Significant Accounting Policies [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]			true
Change in Accounting Principle, Accounting Standards Update, Adoption Date			Jan. 1, 2020
Change in Accounting Principle, Accounting Standards Update, Immaterial Effect [true false]			true
Initial Public Offering
Summary Of Significant Accounting Policies [Line Items]
Deferred offering costs offset against IPO proceeds in additional paid-in capital		$ 4,100,000

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Schedule of Reconciliation of Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Accounting Policies [Abstract]
Cash and cash equivalents	$ 5,843	$ 12,727
Restricted cash	108	108
Total cash, cash equivalents and restricted cash	$ 5,951	$ 12,835

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, 2020
Laboratory and Manufacturing Equipment
Property Plant And Equipment [Line Items]
Estimated useful lives of property and equipment	5 years
Computer and Office Equipment
Property Plant And Equipment [Line Items]
Estimated useful lives of property and equipment	3 years
Leasehold Improvements
Property Plant And Equipment [Line Items]
Estimated useful lives of property and equipment	Shorter of remaining lease term or estimated useful life

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair value assets transfers from level 1 to level 2	$ 0	$ 0
Fair value assets transfers from level 2 to level 1	0	0
Fair value liabilities transfers from level 1 to level 2	0	0
Fair value liabilities transfers from level 2 to level 1	0	0
Fair value assets transfers into level 3	0	0
Fair value assets transfers out of level 3	0	0
Fair value liabilities transfers into level 3	0	0
Fair value liabilities transfers out of level 3	0	0
U.S. Treasury Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Investment securities	124,000,000	$ 19,900,000
Allowance for credit losses	$ 0

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Financial Assets Measured at Fair Value on Recurring Basis (Details) - Fair Value, Recurring - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	$ 128,842	$ 19,981
Gross Unrealized Gains	28	13
Fair Value	128,870	19,994
Level 1 | Money Market Funds Invested in U.S. Government Obligations
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	4,844	69
Fair Value	4,844	69
Level 2 | U.S. Treasury Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Amortized Cost	123,998	19,912
Gross Unrealized Gains	28	13
Fair Value	$ 124,026	$ 19,925

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Property, Plant and Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Property Plant And Equipment [Line Items]
Total property and equipment, gross	$ 11,894	$ 5,774
Accumulated depreciation	(3,447)	(1,683)
Total property and equipment, net	8,447	4,091
Laboratory and Manufacturing Equipment
Property Plant And Equipment [Line Items]
Total property and equipment, gross	8,022	3,062
Leasehold Improvements
Property Plant And Equipment [Line Items]
Total property and equipment, gross	2,550	242
Capital Leases
Property Plant And Equipment [Line Items]
Total property and equipment, gross	959	188
Computer and Office Equipment
Property Plant And Equipment [Line Items]
Total property and equipment, gross	201	202
Construction in Progress
Property Plant And Equipment [Line Items]
Total property and equipment, gross	$ 162	$ 2,080

Balance Sheet Components - Addi

Balance Sheet Components - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Balance Sheet Related Disclosures [Abstract]
Depreciation expense	$ 1,842	$ 706
Accumulated depreciation on capital lease assets	$ 100

Balance Sheet Components - Sc_2

Balance Sheet Components - Schedule of Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Balance Sheet Related Disclosures [Abstract]
Compensation expense	$ 2,389	$ 694
Research and development expense	1,303	621
Professional services	241
Property and equipment	125
Other	115
Total accrued expenses	$ 4,173	$ 1,315

Capital Structure - Additional

Capital Structure - Additional Information (Details)	Jun. 09, 2020shares	Jun. 04, 2020USD ($)$ / sharesshares	Dec. 31, 2020Vote$ / sharesshares	Dec. 31, 2020USD ($)Vote$ / sharesshares	Dec. 31, 2019$ / sharesshares	Dec. 31, 2018shares
Class Of Stock [Line Items]
Common stock, shares authorized			450,000,000	450,000,000	32,000,000
Common stock, par value | $ / shares			$ 0.0001	$ 0.0001	$ 0.0001
Common stock, voting rights			The holder of each share of common stock is entitled to one vote.
Number of voting rights for each common stock held | Vote			1	1
Common stock, dividends declared or paid | $				$ 0
Convertible preferred stock, shares outstanding			0	0	13,966,292
Series A Convertible Preferred Stock
Class Of Stock [Line Items]
Convertible preferred stock, shares outstanding			0	0	5,157,213	5,157,213
Non-cumulative dividend, convertible preferred stock | $ / shares			$ 0.5119
Series B Convertible Preferred Stock
Class Of Stock [Line Items]
Convertible preferred stock, shares outstanding			0	0	3,992,919	3,992,919
Non-cumulative dividend, convertible preferred stock | $ / shares			$ 0.6216
Series C Convertible Preferred Stock
Class Of Stock [Line Items]
Convertible preferred stock, shares outstanding			0	0	4,816,160
Non-cumulative dividend, convertible preferred stock | $ / shares			$ 0.6968
Common Stock
Class Of Stock [Line Items]
Conversion of convertible preferred stock into common stock, shares			13,966,292
Initial Public Offering
Class Of Stock [Line Items]
Preferred stock mandatory conversion into common stock offering price trigger | $ / shares		$ 13.065
Minimum proceeds from mandatory conversion triggers of preferred stock into common stock | $		$ 50,000,000
Initial Public Offering | Common Stock
Class Of Stock [Line Items]
Conversion of convertible preferred stock into common stock, shares	13,966,292	13,966,292

Capital Structure - Schedule of

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

Capital Structure - Schedule _2

Capital Structure - Schedule of Issued and Outstanding Convertible Preferred Stock and its Principal Terms (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Temporary Equity [Line Items]
Convertible preferred stock, shares authorized		13,966,292
Convertible preferred stock, shares issued		13,966,292
Convertible preferred stock, shares outstanding	0	13,966,292
Convertible preferred stock, liquidation value		$ 105,974,000
Convertible preferred stock		$ 105,615,000
Series A
Temporary Equity [Line Items]
Convertible preferred stock, shares authorized	0	5,157,213
Convertible preferred stock, shares issued	0	5,157,213
Convertible preferred stock, shares outstanding	0	5,157,213	5,157,213
Original Issue Price Per Share		$ 6.3988
Convertible preferred stock, liquidation value	$ 0	$ 33,000,000
Convertible preferred stock		$ 32,826,000	$ 32,826,000
Series B
Temporary Equity [Line Items]
Convertible preferred stock, shares authorized	0	3,992,919
Convertible preferred stock, shares issued	0	3,992,919
Convertible preferred stock, shares outstanding	0	3,992,919	3,992,919
Original Issue Price Per Share		$ 7.7700
Convertible preferred stock, liquidation value	$ 0	$ 31,025,000
Convertible preferred stock		$ 30,921,000	$ 30,921,000
Series C
Temporary Equity [Line Items]
Convertible preferred stock, shares authorized	0	4,816,160
Convertible preferred stock, shares issued	0	4,816,160
Convertible preferred stock, shares outstanding	0	4,816,160
Original Issue Price Per Share		$ 8.7100
Convertible preferred stock, liquidation value	$ 0	$ 41,949,000
Convertible preferred stock		$ 41,868,000

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) $ in Millions	1 Months Ended			12 Months Ended
	Sep. 30, 2020	Oct. 31, 2019	Dec. 31, 2016	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)Lease
Lessee Lease Description [Line Items]
Operating lease expiration period			2024-08
Sublease, expiration period		2022-05		2022-05
Sublease, renewal term		5 years
Sublease expiration period including possible renewal options		2027-05
Rent expense | $				$ 2	$ 1.5
Number of capital lease agreements for laboratory equipment | Lease					2
Warehouse Space
Lessee Lease Description [Line Items]
Operating lease expiration period	2021-09
Operating lease term, option to extend				two six-month renewal options through September 2022.
Operating lease, existence of option to extend	true
Operating lease expiration period including possible renewal options	2022-09
Lessee, operating lease, description				In September 2020, the Company entered into a lease agreement for warehouse space in South San Francisco, California. The lease term expires in September 2021. Under the lease agreement, the Company has two six-month renewal options through September 2022. In February 2021, the Company entered into a new lease agreement. See Note 10. Subsequent Event.
Lease Agreement
Lessee Lease Description [Line Items]
Operating lease term, option to extend				two three-year renewal options through August 2030
Operating lease, existence of option to extend			true
Operating lease expiration period including possible renewal options			2030-08
Lessee, operating lease, description				In December 2016, the Company entered into an operating lease agreement for its principal office in South San Francisco, California. The lease term expires in August 2024. Under the lease agreement, the Company has two three-year renewal options through August 2030.

Commitments and Contingencies_2

Commitments and Contingencies - Schedule of Future Minimum Payments under Noncancelable Leases (Details) $ in Thousands	Dec. 31, 2020USD ($)
Commitments And Contingencies Disclosure [Abstract]
Operating Lease Commitments, 2021	$ 2,123
Operating Lease Commitments, 2022	1,699
Operating Lease Commitments, 2023	1,457
Operating Lease Commitments, 2024	1,000
Operating Lease Commitments, Total future minimum lease payments	6,279
Capital Lease Commitments, 2021	274
Capital Lease Commitments, 2022	254
Capital Lease Commitments, 2023	171
Capital Lease Commitments, Total future minimum lease payments	699
Operating and Capital Lease Commitments, 2021	2,397
Operating and Capital Lease Commitments, 2022	1,953
Operating and Capital Lease Commitments, 2023	1,628
Operating and Capital Lease Commitments, 2024	1,000
Operating and Capital Lease Commitments, Total future minimum lease payments	$ 6,978

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	1 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Income Tax [Line Items]
Provision for, or benefit from, income taxes		$ 0	$ 0
Net increase in valuation allowance		$ 21,400,000	9,900,000
Income tax examination description		Due to net operating loss and credit carryforwards, all of the tax years since the date of incorporation through the 2020 tax year remain subject to examination by the U.S. federal and some state authorities.
Significant changes to unrecognized tax benefits over next 12 months		$ 0
Interest or penalties recognized relating to unrecognized tax benefits		0	0
Tax impact related to unrecognized tax benefit in relation to valuation allowance positions		$ 0	$ 0
Minimum
Income Tax [Line Items]
Cumulative ownership percentage change		50.00%
Federal
Income Tax [Line Items]
Net operating loss carryforwards		$ 156,000,000
Federal | General Business Credits
Income Tax [Line Items]
Tax credit carryforward		$ 4,900,000
Tax credit carryforward expiration year		2037
State
Income Tax [Line Items]
Net operating loss carryforwards		$ 69,000,000
Operating loss carryforwards expiration year		2036
State | Research and Development Credits
Income Tax [Line Items]
Tax credit carryforward		$ 3,100,000
Operating Losses Generated after December 31, 2017
Income Tax [Line Items]
Operating loss carryforwards percentage of taxable income limitation	80.00%
Operating Losses Generated after December 31, 2017 | Federal
Income Tax [Line Items]
Net operating loss carryforwards		142,700,000
Operating Losses Generated before January 1, 2018 | Federal
Income Tax [Line Items]
Net operating loss carryforwards		$ 13,300,000
Operating loss carryforwards expiration year		2036

Income Taxes - Schedule of Effe

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

Income Taxes - Schedule of Sign

Income Taxes - Schedule of Significant Components of Deferred Tax Assets for Federal and State Income Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Net operating losses	$ 37,785	$ 19,214
Tax credits	5,805	3,545
Accrued expenses	617	345
Stock-based compensation expense	350	52
Other current assets	6	6
Total deferred tax assets	44,563	23,162
Deferred tax liabilities:
Property and equipment, net		(25)
Total deferred tax liabilities		(25)
Valuation allowance	$ (44,563)	$ (23,137)

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, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Gross unrecognized tax benefit as of January 1	$ 1,012	$ 390
Additions for tax positions taken in the current year	626	407
Reductions for tax positions taken in the current year	(139)
Additions for tax positions taken in prior years		215
Gross unrecognized tax benefit as of December 31	$ 1,499	$ 1,012

Equity Incentive Plan and Sto_3

Equity Incentive Plan and Stock-Based Compensation Expense - Additional Information (Details) - USD ($)	May 31, 2020	May 14, 2020	May 31, 2020	Mar. 31, 2020	Jun. 30, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award granted						2,598,319	773,688
Common stock reserved for future issuance						7,189,851	17,545,062
Share expirations during period						576,670
Shares available for issuance						3,369,246	1,435,402	1,803,912
Stock-based compensation expense						$ 3,056,000	$ 468,000
Weighted-average grant-date fair value of the options granted						$ 5.88	$ 1.61
Intrinsic value of options exercised						$ 29,500,000	$ 0
Total stock-based compensation expense related to options granted but not yet amortized						$ 13,000,000
Total stock-based compensation expense related to options weighted average period of recognition						2 years 10 months 2 days
Options granted in period weighted average exercise price						$ 7.82	$ 2.38
Increase in fair value of modified option grants		$ 500,000
Remaining requisite service period		3 years 3 months 18 days
Employee Stock Purchase Plan, Available for Future Grants
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Purchase price of common stock percent	85.00%
Common stock reserved for future issuance						314,006
Shares available for issuance	314,006		314,006			314,006
Outstanding stock percent	1.00%
Stock-based compensation expense						$ 0	$ 0
Maximum | Employee Stock Purchase Plan, Available for Future Grants
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Discount rate	15.00%
Minimum | Employee Stock Purchase Plan, Available for Future Grants
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Increase in number of shares	628,012		628,012
2015 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award granted						0
Equity Incentive plan term						In connection with its 2016 conversion to a C-corporation, each outstanding stock option agreement under the 2015 Plan was assumed by it and converted into stock options covering shares of its common stock rather than Class B common stock of its predecessor entity. Except with respect to the shares underlying such options, no other terms were amended with respect to such stock option agreements.
2016 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period						4 years
Common stock reserved for future issuance				1,250,000
Number of stock option approved for one-time repricing			1,998,677
Options granted in period weighted average exercise price			$ 6.48	$ 6.14	$ 5.18
Stock options exercise price at the repricing date			$ 4.61
2016 Plan | 10% Stockholder
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of voting power						10.00%
2016 Plan | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Term of options						10 years
2016 Plan | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Purchase price of common stock percent						100.00%
Percentage of exercise price of stock option on estimated fair value of shares						110.00%
2020 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity Incentive plan term						Shares subject to awards granted under the 2015 Plan or 2016 Plan were added to the available shares in the 2020 Plan. Shares subject to awards granted under the 2015 Plan and 2016 Plan that are repurchased by, or forfeited to, the Company will also be reserved for issuance under the 2020 Plan
Vesting period						4 years
Common stock reserved for future issuance						3,768,075
2020 Plan | 10% Stockholder
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of voting power						10.00%
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						100.00%
Percentage of exercise price of stock option on estimated fair value of shares						110.00%

Equity Incentive Plan and Sto_4

Equity Incentive Plan and Stock-Based Compensation Expense - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Options Outstanding, Shares Available for Grant, Beginning Balance	1,435,402	1,803,912
Options Outstanding, Shares Available for Grant, Granted	(2,598,319)	(773,688)
Options Outstanding, Shares Available for Grant, Cancelled	90,758	405,178
Options Outstanding, Shares Available for Grant, Ending Balance	3,369,246	1,435,402
Options Outstanding, Shares Available for Grant, Additions	4,441,405
Options Outstanding, Total Options Outstanding, Beginning Balance	2,143,368	1,774,858
Options Outstanding, Total Options Outstanding, Granted	2,598,319	773,688
Options Outstanding, Total Options Outstanding, Cancelled	(90,758)	(405,178)
Options Outstanding, Total Options Outstanding, Ending Balance	3,506,599	2,143,368
Options Outstanding, Total Options Outstanding, Exercised	(1,144,330)
Options Outstanding, Total Options Outstanding, Exercisable as of December 31, 2020	951,438
Options Outstanding, Weighted-Average Exercise Price, Beginning Balance	$ 1.22	$ 0.84
Options Outstanding, Weighted-Average Exercise Price, Granted	7.82	2.38
Options Outstanding, Weighted-Average Exercise Price, Cancelled	3.43	1.81
Options Outstanding, Weighted-Average Exercise Price, Ending Balance	6.27	$ 1.22
Options Outstanding, Weighted-Average Exercise Price, Exercised	0.55
Options Outstanding, Weighted-Average Exercise Price, Exercisable as of December 31, 2020	$ 3.06
Options Outstanding, Weighted-Average Remaining Contractual Life (in years)	8 years 9 months 14 days	7 years 3 months 18 days
Options Outstanding, Weighted-Average Remaining Contractual Life (in years), Exercisable	8 years 7 days
Options Outstanding, Aggregate Intrinsic Value	$ 85,975	$ 10,555	$ 2,815
Options Outstanding, Aggregate Intrinsic Value, Exercisable	$ 26,364

Equity Incentive Plan and Sto_5

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

Equity Incentive Plan and Sto_6

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

Net Loss and Net Loss Per Sha_3

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

Net Loss and Net Loss Per Sha_4

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

Subsequent Events - Additional

Subsequent Events - Additional Information (Details) - Lease Agreement $ in Millions	1 Months Ended		12 Months Ended
	Feb. 28, 2021USD ($)ft²	Dec. 31, 2016	Dec. 31, 2020
Subsequent Event [Line Items]
Lessee operating lease existence of option to extend		true
Lessee operating lease option to extend			two three-year renewal options through August 2030
Subsequent Event
Subsequent Event [Line Items]
Area of land subjected to lease | ft²	84,321
Initial lease term	8 years
Lessee operating lease existence of option to extend	true
Lessee operating lease option to extend	optional two five-year extensions
Annual lease payments during the first year	$ 4.2
Annual lease payments during the second year	$ 5.7
Percentage increase in annual lease payments each year	3.00%
Security deposit	$ 0.9