Design Therapeutics (DSGN) 10-Q 9 Nov 21 2021 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2021	Nov. 05, 2021
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Trading Symbol	DSGN
Entity Registrant Name	Design Therapeutics, Inc.
Entity Central Index Key	0001807120
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Shell Company	false
Entity Small Business	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Common Stock, Shares Outstanding		55,662,501
Title of 12(b) Security	Common Stock, $0.0001 par value per share
Entity File Number	001-40288
Security Exchange Name	NASDAQ
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	82-3929248
Entity Address, Address Line One	6005 Hidden Valley Road
Entity Address, Address Line Two	Suite 110
Entity Address, City or Town	Carlsbad
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	92011
City Area Code	858
Local Phone Number	293-4900
Document Transition Report	false
Document Quarterly Report	true

Condensed Balance Sheets

Condensed Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 357,662	$ 2,379
Investment securities	36,056	33,712
Prepaid expense and other current assets (including related party amounts of $60 and $0, respectively)	1,572	142
Total current assets	395,290	36,233
Property and equipment, net	1,320	71
Right-of-use asset	3,743
Deferred offering costs		212
Total assets	400,353	36,516
Current liabilities:
Accounts payable (including related party amounts of $20 and $20, respectively)	2,216	1,399
Accrued expenses and other current liabilities (including related party amounts of $10 and $0, respectively)	3,289	931
Total current liabilities	5,505	2,330
Operating lease liability, net	3,273
Other long-term liabilities	11	145
Total liabilities	8,789	2,475
Commitments and contingencies (See Note 9)
Convertible preferred stock, $0.0001 par value; no shares and 22,500,000 shares authorized, no shares and 22,012,499 shares issued and outstanding at September 30, 2021 and December 31, 2020, respectively; liquidation preference of zero and $45,625 as of September 30, 2021 and December 31, 2020, respectively		45,356
Stockholders’ equity (deficit):
Common stock, $0.0001 par value; 200,000,000 and 60,000,000 shares authorized, 55,654,833 and 16,604,774 shares issued, 55,224,420 and 15,957,821 shares outstanding at September 30, 2021 and December 31, 2020, respectively	6	1
Additional paid-in capital	427,953	451
Accumulated deficit	(36,391)	(11,923)
Accumulated other comprehensive income	(4)	156
Total stockholders’ equity (deficit)	391,564	(11,315)
Total liabilities, convertible preferred stock and stockholders’ equity (deficit)	$ 400,353	$ 36,516

Condensed Balance Sheets (Paren

Condensed Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Statement Of Financial Position [Abstract]
Prepaid expense and other current assets, related party amounts	$ 60	$ 0
Accounts payable, related party amounts	20	20
Accrued expenses and other current liabilities, related party amounts	$ 10	$ 0
Convertible preferred stock, par value	$ 0.0001	$ 0.0001
Convertible preferred stock, authorized	0	22,500,000
Convertible preferred stock, issued	0	22,012,499
Convertible preferred stock, outstanding	0	22,012,499
Convertible preferred stock, liquidation preference	$ 0	$ 45,625
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	200,000,000	60,000,000
Common stock, shares issued	55,654,833	16,604,774
Common stock, shares outstanding	55,224,420	15,957,821

Condensed Statements of Operati

Condensed Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenue:
Grant revenue		$ 20		$ 193
Revenue, Product and Service [Extensible List]	us-gaap:ResearchAndDevelopmentArrangementContractToPerformForOthersCompensationEarned	us-gaap:ResearchAndDevelopmentArrangementContractToPerformForOthersCompensationEarned	us-gaap:ResearchAndDevelopmentArrangementContractToPerformForOthersCompensationEarned	us-gaap:ResearchAndDevelopmentArrangementContractToPerformForOthersCompensationEarned
Operating expenses:
Research and development (including related party amounts of $98, $0, $188 and $8, respectively)	$ 8,539	$ 1,914	$ 17,441	$ 3,352
General and administrative (including related party amounts of $82, $60, $202 and $232, respectively)	2,798	489	7,263	1,310
Total operating expenses	11,337	2,403	24,704	4,662
Loss from operations	(11,337)	(2,383)	(24,704)	(4,469)
Other income, net (including related party expense amounts of $0, $0, $0, and $30, respectively)	19	63	236	44
Net loss	$ (11,318)	$ (2,320)	$ (24,468)	$ (4,425)
Net loss per share, basic and diluted	$ (0.21)	$ (0.09)	$ (0.57)	$ (0.17)
Weighted-average shares of common stock outstanding, basic and diluted	55,155,030	25,701,737	42,759,656	25,606,779

Condensed Statements of Opera_2

Condensed Statements of Operations (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
Research and development expenses related party amount	$ 98	$ 0	$ 188	$ 8
General and administrative expenses related party amount	82	60	202	232
Other income, net related party expense amount	$ 0	$ 0	$ 0	$ 30

Condensed Statements of Compreh

Condensed Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (11,318)	$ (2,320)	$ (24,468)	$ (4,425)
Other comprehensive gain (loss):
Unrealized gain (loss) on available-for-sale securities	8	(42)	(160)	152
Comprehensive loss	$ (11,310)	$ (2,362)	$ (24,628)	$ (4,273)

Condensed Statements of Convert

Condensed Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Convertible Preferred Stock	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income	Accumulated Deficit
Beginning Balance at Dec. 31, 2019	$ (3,642)		$ 1			$ (3,643)
Beginning Balance, Shares at Dec. 31, 2019			15,640,133
Issuance of Series A and Series B convertible preferred stock, net of issuance costs		$ 44,731
Issuance of Series A and Series B convertible preferred stock, net of issuance costs, Shares		21,710,814
Conversion of convertible debt and interest to Series A convertible preferred stock		$ 500
Conversion of convertible debt and interest to Series A convertible preferred stock, Shares		301,685
Settlement of bifurcated conversion liability		$ 125
Exercises of stock options and vesting of restricted stock, Shares			247,213
Stock-based compensation	29			29
Unrealized gain (loss) on investments	152				152
Net loss	(4,425)					(4,425)
Ending Balance at Sep. 30, 2020	(7,886)		$ 1	29	152	(8,068)
Ending Balance, Shares at Sep. 30, 2020		22,012,499
Ending Balance at Sep. 30, 2020		$ 45,356
Ending Balance, Shares at Sep. 30, 2020			15,887,346
Beginning Balance at Jun. 30, 2020	(5,539)		$ 1	14	194	(5,748)
Beginning Balance, Shares at Jun. 30, 2020		22,012,499
Beginning Balance at Jun. 30, 2020		$ 45,356
Beginning Balance, Shares at Jun. 30, 2020			15,782,575
Exercises of stock options and vesting of restricted stock, Shares			104,771
Stock-based compensation	15			15
Unrealized gain (loss) on investments	(42)				(42)
Net loss	(2,320)					(2,320)
Ending Balance at Sep. 30, 2020	(7,886)		$ 1	29	152	(8,068)
Ending Balance, Shares at Sep. 30, 2020		22,012,499
Ending Balance at Sep. 30, 2020		$ 45,356
Ending Balance, Shares at Sep. 30, 2020			15,887,346
Beginning Balance at Dec. 31, 2020	$ (11,315)		$ 1	451	156	(11,923)
Beginning Balance, Shares at Dec. 31, 2020	22,012,499	22,012,499
Beginning Balance at Dec. 31, 2020	$ 45,356	$ 45,356
Beginning Balance, Shares at Dec. 31, 2020			15,957,821
Issuance of Series A and Series B convertible preferred stock, net of issuance costs		$ 124,712
Issuance of Series A and Series B convertible preferred stock, net of issuance costs, Shares		19,083,979
Preferred stock converted into shares of common stock	170,068		$ 4	170,064
Preferred stock converted into shares of common stock, Shares		(41,096,478)
Preferred stock converted into shares of common stock		$ (170,068)
Preferred stock converted into shares of common stock, Shares			25,212,548
Initial public offering of common shares, net of $21,728 of issuance costs	254,271		$ 1	254,270
Initial public offering of common shares, net of $21,728 of issuance costs, Shares			13,800,000
Exercises of stock options and vesting of restricted stock	35			35
Exercises of stock options and vesting of restricted stock, Shares			254,051
Stock-based compensation	3,133			3,133
Unrealized gain (loss) on investments	(160)				(160)
Net loss	(24,468)					(24,468)
Ending Balance at Sep. 30, 2021	$ 391,564		$ 6	427,953	(4)	(36,391)
Ending Balance, Shares at Sep. 30, 2021	0
Ending Balance, Shares at Sep. 30, 2021			55,224,420
Beginning Balance at Jun. 30, 2021	$ 401,601		$ 6	426,680	(12)	(25,073)
Beginning Balance, Shares at Jun. 30, 2021			55,114,729
Exercises of stock options and vesting of restricted stock	30			30
Exercises of stock options and vesting of restricted stock, Shares			109,691
Stock-based compensation	1,243			1,243
Unrealized gain (loss) on investments	8				8
Net loss	(11,318)					(11,318)
Ending Balance at Sep. 30, 2021	$ 391,564		$ 6	$ 427,953	$ (4)	$ (36,391)
Ending Balance, Shares at Sep. 30, 2021	0
Ending Balance, Shares at Sep. 30, 2021			55,224,420

Condensed Statements of Conve_2

Condensed Statements of Convertible Preferred stock and Stockholders' Equity (Deficit) (Parenthetical) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Series B Convertible Preferred Stock
Preferred stock issuance costs	$ 288
Series A Convertible Preferred Stock
Preferred stock issuance costs		$ 270
Initial Public Offering
Stock issuance costs	$ 21,728

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash flows from operating activities
Net loss	$ (24,468)	$ (4,425)
Reconciliation of net loss to net cash used in operating activities:
Depreciation	47	1
Stock-based compensation	3,133	29
Amortization of premiums on investment securities, net	(103)	(69)
Non-cash interest expense		12
Non-cash interest expense—related party		26
Non-cash lease expense	5
Change in operating assets and liabilities:
Prepaid expense and other assets	(1,158)	(71)
Prepaid expense and other assets—related party	(60)
Deferred revenue		(193)
Accounts payable and other liabilities	2,444	708
Accounts payable and other liabilities related-party	10	(1,843)
Net cash used in operating activities	(20,150)	(5,825)
Cash flows from investing activities
Purchases of investment securities	(36,356)	(55,589)
Proceeds from maturities of investment securities	33,955	20,092
Purchases of property and equipment	(1,184)	(62)
Net cash used in investing activities	(3,585)	(35,559)
Cash flows from financing activities
Proceeds from initial public offering, net of issuance costs	254,271
Proceeds from issuance of convertible preferred stock, net of issuance costs	124,712	44,731
Proceeds from the exercise of stock options and vesting of restricted stock	35
Proceeds from the issuance of notes payable, net of issuance costs—related party		200
Repayment of notes payable—related party		(400)
Net cash provided by financing activities	379,018	44,531
Net increase in cash and cash equivalents	355,283	3,147
Cash and cash equivalents at beginning of period	2,379	77
Cash and cash equivalents at end of period	357,662	3,224
Supplemental disclosures
Initial recognition of operating lease right-of-use asset and operating lease liability	3,786
Purchases of property and equipment included in accounts payable and accrued expenses	$ 112
Conversion of convertible notes to convertible preferred shares, including bifurcated conversion liability		271
Conversion of convertible notes to convertible preferred shares, including bifurcated conversion liability - related party		354
Interest paid		$ 18

Organization

Organization	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Organization	1. Organization Design Therapeutics, Inc. (the “Company”) was incorporated in Delaware in December 2017 and is based in Carlsbad, California. The Company is a biopharmaceutical company pioneering GeneTAC TM molecules, a novel class of disease-modifying small-molecule gene targeted chimera therapeutics that are designed to target the underlying cause of inherited nucleotide repeat expansion diseases. The Company’s lead product candidate is in Friedreich ataxia (“FA”), its second GeneTAC™ program is in myotonic dystrophy type-1 (“DM1”), and it is also advancing its GeneTAC TM portfolio to address other serious nucleotide repeat-driven monogenic diseases. The Company has experienced net losses and negative cash flows from operating activities since inception and expects to incur net losses for the foreseeable future as it advances its research and development programs, conducts clinical trials for any future product candidates and commercializes any such product candidates for which it receives regulatory approval. As the Company continues to incur losses, its transition to profitability will depend on the successful development, approval and commercialization of its future product candidates, and on the achievement of sufficient revenue to support its cost structure. The Company may never achieve profitability, and unless and until it does, it will need to continue to raise additional capital to fund its operations.

Basis of Presentation and Summa

Basis of Presentation and Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Basis of Presentation and Summary of Significant Accounting Policies	2. Basis of Presentation and Summary of Significant Accounting Policies Basis of Presentation and Use of Estimates The accompanying interim condensed financial statements are unaudited. These unaudited interim condensed financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP") and following the requirements of the United States Securities and Exchange Commission ("SEC") for interim reporting. The Company's financial statements include all adjustments, consisting of only normal recurring adjustments, which in the opinion of management are necessary to present fairly the Company’s financial position as of the reporting date and results of operations for the periods presented. The preparation of the Company’s financial statements requires it to make estimates and assumptions that impact the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities in the Company’s financial statements and accompanying notes. The most significant estimates in the Company’s financial statements relate to the recognition of grant revenue, accruals for research and development expenses and the valuation of equity-based awards. These estimates and assumptions are based on current facts, historical experience and various other factors believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities and the recording of revenue and expenses that are not readily apparent from other sources. Actual results may differ materially and adversely from these estimates. The full extent to which the novel coronavirus-2019 (“COVID-19”) pandemic will directly or indirectly impact the Company’s business, results of operations and financial condition, including research and development costs, will depend on future developments that are highly uncertain, including as a result of new information that may emerge concerning COVID-19 and the actions taken to contain or treat COVID-19, as well as the economic impact on local, regional, national and international markets. The Company has considered potential impacts arising from the COVID-19 pandemic and is not presently aware of any events or circumstances that would require the Company to update its estimates, judgments or revise the carrying value of its assets or liabilities. Stock Splits In February 2020, the Company effected a 5 -for-1 forward stock split of its issued and outstanding common stock. Further, in March 2021, the Company effected a 1-for- 1.63 reverse stock split of its issued and outstanding common stock. The par value and the authorized shares of the common stock were not adjusted as a result of these stock splits. The reverse stock split in March 2021 resulted in an adjustment to the convertible preferred stock conversion prices to reflect a proportional decrease in the number of shares of common stock to be issued upon conversion. The accompanying financial statements and notes to the financial statements give retroactive effect to the stock splits for all periods presented. Cash and Cash Equivalents The Company considers all highly liquid investments with maturities at the date of acquisition of three months or less to be cash equivalents. These investments may include money market accounts, money market funds, U.S. Government agency securities, corporate debt securities and commercial paper. The Company’s cash reserves are in a readily available checking account. Investment Securities Investments in securities with maturities at the date of acquisition of more than three months are considered marketable securities. The Company determines the appropriate classification of its investments at the time of acquisition and reevaluates such determination at each balance sheet date. The Company has classified its investment holdings as available-for-sale, as the sale of such securities may be required prior to maturity to implement management strategies. Further, the Company classifies its available-for-sale investment securities, including those with maturities beyond one year, as current assets on its balance sheets based on the highly liquid nature of the securities and because these investments are considered available for use in current operations. The Company’s investment policy sets minimum credit quality criteria and maximum maturity limits on its investments to provide for safety of principle, liquidity and a reasonable rate of return. Available-for-sale securities are recorded at fair value, based on current market valuations. Unrealized holding gains and losses on available-for-sale securities are excluded from earnings and are reported as a separate component of other comprehensive income (loss) until realized. Allowances for credit losses are reported on the balance sheet, if any. The cost of available-for-sale investment securities is adjusted for amortization of premiums and accretion of discounts until the securities mature. Such amortization and accretion is included in other income (expense) on the statements of operations. Realized gains and losses, if any, are also included in other income (expense) on the statement of operations and are derived using the specific identification method for determining the cost of the securities sold. During the periods presented, no realized gains or losses were recorded on the sale of investment securities and no impairments to reduce the value of any security was taken. See Note 5 for further discussion. Leases At lease commencement, the Company records a lease liability based on the present value of lease payments over the expected lease term. The expected lease term includes noncancelable lease periods and, when applicable, periods covered by an option to extend the lease if the Company is reasonably certain to exercise that option, as well as periods covered by an option to terminate the lease if the Company is reasonably certain not to exercise the option. The Company calculates the present value of lease payments using an incremental borrowing rate as the Company's leases do not provide an implicit interest rate. The Company's incremental borrowing rate for a lease is the rate of interest it would have to pay on a collateralized basis to borrow an amount equal to the lease payments under similar terms. At the lease commencement date, the Company records a corresponding right-of-use lease asset based on the lease liability, adjusted for any lease incentives received and any initial direct costs paid to the lessor prior to the lease commencement date. The Company may enter into leases with an initial term of 12 months or less ("Short-Term Leases"). For any Short-Term leases, the Company records the rent expense on a straight-line basis and does not record the leases on the condensed balance sheet. The Company had no Short-Term Leases as of September 30, 2021 or December 31, 2020. After lease commencement, the Company measures its leases as follows: (i) the lease liability based on the present value of the remaining lease payments using the discount rate determined at lease commencement and (ii) the right-of-use asset based on the remeasured lease liability, adjusted for any unamortized lease incentives received, any unamortized initial direct costs and the cumulative difference between rent expense and amounts paid under the lease agreement. Any lease incentives received and any initial direct costs are amortized on a straight-line basis over the expected lease term. Rent expense is recorded on a straight-line basis over the expected lease term. Revenue Recognition The Company has generated revenue from grants awarded to it by the National Science Foundation (“NSF”), the National Institutes of Health (“NIH”) and the Friedreich’s Ataxia Research Alliance (“FARA”). These grants provide the Company with funding for certain research and development activities on a best-efforts basis and do not require scientific achievement as a performance obligation. The Company has determined that the entities funding these grant awards do not meet the definition of a “customer”, as defined by Accounting Standards Codification (“ASC”) 606, Revenue from Contracts with Customers (Topic 606) , and does not consider there to be a transfer of control of goods or services to the entities funding the grant. As such, the Company recognizes revenue from these awards in the period during which the related qualifying services are rendered and costs are incurred in accordance with ASC 730, Research and Development . ASC 730 requires an assessment, at the inception of the grant, to determine whether the agreement is a liability or a contract to perform research and development services for others. Further, these grants are subject to the contribution’s guidance under ASC 958, Not-for-Profit Entities-Revenue Recognition , and as such, the Company determines whether it is obligated to repay the funds received to the grantor regardless of the outcome of the related research and development activities. If it determines there is such a liability, it estimates the obligation and recognize that liability. Alternatively, if the Company is not required to repay the funds, the grant agreement is accounted for as a contract to perform research and development services for others, in which case, the grant revenue is recorded as income in the statements of operations as the expenses are incurred. The Company’s current grant revenue is not deemed refundable, and therefore, no liability is recognized when income is recorded. Grant funding received prior to expenses being incurred are recorded as deferred revenue on the Company’s balance sheets. See Note 8 for further discussion. Research and Development Expenses Research and development expenses consist primarily of direct and indirect costs incurred in connection with its discovery efforts, and the preclinical and formulation development of its product candidates. In the future, the Company expects a substantial portion of its research and development expenses will relate to the clinical development of its product candidates. Direct costs include contracted research development and manufacturing, consulting fees, license fees, laboratory supplies and other expenses incurred to sustain research and development programs. Indirect costs include personnel-related expenses, consisting of employee salaries, related benefits, and stock-based compensation expense for employees engaged in research and development activities, facilities related expenses, and other indirect expenses. A significant portion of the Company’s research and development expenses have been direct costs, which the Company tracks by stage of development, preclinical or clinical. However, the Company does not track its internal research and development expenses on a program specific basis, unless specific to research grants, because these costs are deployed across multiple projects and, as such, are not separately classified. Research and development expenses are charged to operating expenses as incurred when these expenditures relate to the Company’s research and development efforts and have no alternative future uses. The Company has entered into various contracts with research and development organizations, vendors and consultants. Payments for these activities are based on the terms of the individual agreements, which may differ from the periods over which materials or services are provided. Payments made in advance of performance are reflected in the accompanying balance sheets as prepaid expenses. The Company records accruals for estimated costs incurred for ongoing research and development activities. The Company determines accrual estimates through review of the underlying contracts along with discussions with research and other key personnel as to the progress of the research and development activities, invoices received and contracted costs. During the course of a study or trial, the Company adjusts its rate of expense recognition if actual results differ from its estimates. Significant judgments and estimates may be made in determining the prepaid or accrued balances at the end of any reporting period. Actual results could differ from the Company’s estimates. Stock-Based Compensation Stock options issued pursuant to the Company’s 2021 Equity Incentive Plan (the “2021 Plan”) and 2018 Equity Incentive Plan (the “2018 Plan”) and option features associated with the rights to purchase shares pursuant to the Company’s 2021 Employee Stock Purchase Plan (the “ESPP”) are valued using the Black-Scholes option pricing model on the date of grant or subscription period. This option pricing model involves a number of estimates, including the expected lives of the stock options or subscription period, the Company’s anticipated stock volatility and interest rates. The Company recognizes the expense for equity awards on a straight-line basis over the requisite service periods of the awards or the number of shares estimated to be issued pursuant to the ESPP. Forfeitures are recognized as they occur. Stock-based compensation expense recognized in the Company’s statements of operations during the three and nine months ended September 30, 2021 and 2020, were as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Research and development $ 521 $ 12 $ 1,181 $ 22 General and administrative 722 3 1,952 7 Total $ 1,243 $ 15 $ 3,133 $ 29 Recent Accounting Pronouncements In May 2021, the Financial Accounting Standards Board (“FASB”) issued ASU 2021-04, Earnings Per Share (Topic 260), Debt—Modifications and Extinguishments (Subtopic 470-50), Compensation—Stock Compensation (Topic 718), and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40) . ASU 2021-04 clarifies and reduces diversity in an issuer’s accounting for modifications or exchanges of freestanding equity-classified written call options (for example, warrants) that remain equity classified after modification or exchange. The ASU provides guidance to clarify whether an issuer should account for a modification or an exchange of a freestanding equity-classified written call option that remains equity classified after modification or exchange as (1) an adjustment to equity and, if so, the related earnings per share effects, if any, or (2) an expense and, if so, the manner and pattern of recognition. ASU 2021-04 is effective for annual periods beginning after December 15, 2021, including interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period. The Company is currently evaluating the impact that this new guidance will have on its condensed consolidated financial statements and does not currently expect the adoption will have a material impact on its financial statements and related disclosures. In August 2020, the FASB issued ASU 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging— Contracts in Entity’s Own Equity . The guidance, among other items, clarifies that certain transactions between collaborative participants should be accounted for as revenue under Topic 606 when the collaborative arrangement participant is a customer in the context of a unit of account. The ASU’s amendments are effective for fiscal years beginning after December 15, 2021, and interim periods within those fiscal years, with early adoption permitted for periods beginning after December 15, 2020. The Company has not yet adopted this guidance and does not currently expect the adoption will have a material impact on its financial statements and related disclosures.

Net Loss Per Share

Net Loss Per Share	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Net Loss Per Share	3. Net Loss Per Share Basic net loss per share is computed by dividing the net loss by the weighted-average number of common shares outstanding for the period, without consideration for potentially dilutive securities. Diluted net loss per share is computed by dividing the net loss by the weighted average number of common shares and dilutive common stock equivalents outstanding for the period determined using the treasury-stock and if-converted methods. Dilutive common stock equivalents are comprised of convertible preferred stock, restricted common stock subject to repurchase, stock options outstanding under the Company’s equity incentive plans, employee stock purchase rights under the Company’s ESPP, and shares of common stock that are issuable under convertible debt, as applicable. For all periods presented, there is no difference in the number of shares used to calculate basic and diluted shares outstanding due to the Company's net loss position. The following table sets forth the outstanding, potentially dilutive securities that have been excluded in the calculation of diluted net loss per share because their inclusion would be anti-dilutive: September 30, September 30, Convertible preferred stock $ — $ 13,504,598 Stock options 2,124,238 389,565 Shares subject to repurchase 430,413 564,055 Employee stock purchase plan 15,335 — Total $ 2,569,986 $ 14,458,218

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	4. Fair Value Measurements Accounting guidance defines fair value, establishes a consistent framework for measuring fair value and expands disclosure for each major asset and liability category measured at fair value on either a recurring or non-recurring basis. Fair value is defined as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, the accounting guidance establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows: Level 1: Observable inputs such as quoted prices in active markets. Level 2: Inputs, other than the quoted prices in active markets that are observable either directly or indirectly. Level 3: Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions. The carrying value of the Company’s cash, accounts payable and accrued liabilities are considered to be representative of their respective fair values due to the short-term nature of those instruments. The Company’s investment securities, which may include money market accounts, money market funds, certificates of deposits, U.S. Treasury securities, and high quality, marketable debt instruments of corporations and government sponsored enterprises, are measured at fair value in accordance with the fair value hierarchy. None of the Company’s non-financial assets or liabilities are recorded at fair value on a non-recurring basis and no transfers between levels have occurred during the periods presented. The following table summarize the Company’s financial instruments measured at fair value on a recurring basis at September 30, 2021 and December 31, 2020 (in thousands): Fair Value Measurement at End of Period Using: Quoted Prices In Active Markets Significant For Other Significant Identical Observable Unobservable Assets Inputs Inputs Total (Level 1) (Level 2) (Level 3) As of September 30, 2021: Assets: Money market funds (1) $ 356,793 $ 356,793 $ — $ — Certificates of deposit 5,987 5,987 — — U.S. Treasury securities 30,068 30,068 — — Total $ 392,848 $ 392,848 $ — $ — As of December 31, 2020: Assets: Money market funds (1) $ 2,100 $ 2,100 $ — $ — Certificates of deposit 1,754 1,754 — — U.S. Treasury securities 31,958 31,958 — — Total $ 35,812 $ 35,812 $ — $ — (1) Included in cash and cash equivalents on the accompanying balance sheets. Interest bearing money market accounts and certificates of deposit are valued at amortized cost, which approximates fair value.

Investment Securities

Investment Securities	9 Months Ended
	Sep. 30, 2021
Investments Debt And Equity Securities [Abstract]
Investment Securities	5. Investment Securities The Company’s investment policy defines allowable investment securities and establishes guidelines relating to credit quality, diversification, and maturities of its investments to preserve principal and maintain liquidity. In accordance with the Company’s investment policy, it has invested funds in marketable securities. The cost, gross unrealized holding gains, gross unrealized holding losses, allowances for credit losses and fair value of available-for-sale investments by types, maturities and classes of securities at September 30, 2021 and December 31, 2020 consisted of the following (in thousands): As of September 30, 2021 Estimated Allowance Fair Amortized Unrealized Unrealized for Credit Market Maturity Cost Gains Losses Losses Value Certificates of deposits Within 1 year $ 2,853 $ — $ ( 1 ) $ — $ 2,852 U.S. Treasury securities Within 1 year 10,066 1 — — $ 10,067 Certificates of deposits 1 year to 2 years 3,137 — ( 2 ) — 3,135 U.S. Treasury securities 1 year to 2 years 20,004 — ( 2 ) — 20,002 Total $ 36,060 $ 1 $ ( 5 ) $ — $ 36,056 As of December 31, 2020 Estimated Allowance Fair Amortized Unrealized Unrealized for Credit Market Maturity Cost Gains Losses Losses Value Certificates of deposits Within 1 year $ 1,750 $ 4 $ — $ — $ 1,754 U.S. Treasury securities Within 1 year 31,806 152 — — 31,958 Total $ 33,556 $ 156 $ — $ — $ 33,712 The Company reviews its investments at each reporting date to identify and evaluate whether a decline in fair value below the amortized cost basis of available-for-sale securities is due to credit-related factors and determines if such unrealized losses are the result of credit losses that require impairment. Factors considered in determining whether an unrealized loss is the result of a credit loss or other factors include the extent to which the fair value is less than the cost basis, any changes to the rating of the security by a rating agency, the financial condition and near-term prospects of the issuer, any historical failure of the issuer to make scheduled interest or principal payments, any adverse legal or regulatory events affecting the issuer or issuer’s industry, any significant deterioration in economic condition and the Company’s intent and ability to hold the investment for a period of time sufficient to allow for any anticipated recovery in market value. At September 30, 2021 there were 19 securities in an unrealized loss position. The Company evaluated the securities individually for other-than-temporary impairment and considered the decline in market value to be primarily attributable to changes in interest rates. Each security remained at a high credit quality rating and the unrealized losses of each security was immaterial. Further, there had been no adverse conditions noted for any of the issuers and Company does not intend to sell any of the securities prior to maturity. As such, the Company has classified the losses as temporary in nature and the Company did not record a reserve for credit losses. At December 31, 2020, there were no securities in an unrealized loss position. As of September 30, 2021 , the Company held 25 domestic certificates of deposit with amortized costs below the Federal Deposit Insurance Corporation (“FDIC”) insured limit. Accrued interest receivable on available-for-sale investment securities, included in prepaids and other current assets on the Company’s balance sheets, was less than $ 0.1 million at September 30, 2021 and December 31, 2020.

Balance Sheet Details

Balance Sheet Details	9 Months Ended
	Sep. 30, 2021
Balance Sheet Component [Abstract]
Balance Sheet Details	6. Balance Sheet Details Prepaid expenses and other current assets consisted of the following (in thousands): September 30, December 31, Prepaid expenses $ 1,421 $ 60 Security deposits 104 47 Interest receivable 47 10 Other — 25 Total $ 1,572 $ 142 Property and equipment consisted of the following (in thousands): September 30, December 31, Laboratory equipment $ 1,058 $ 76 Computer equipment and software 77 — Leasehold improvements 91 — Construction in progress 146 — 1,372 76 Less accumulated depreciation ( 52 ) ( 5 ) Total $ 1,320 $ 71 Accrued liabilities consisted of the following (in thousands): September 30, December 31, Accrued personnel costs $ 1,411 $ 565 Accrued research and development costs 652 266 Current portion of operating lease liability 475 — Accrued other 751 100 Total $ 3,289 $ 931

Lease

Lease	9 Months Ended
	Sep. 30, 2021
Leases [Abstract]
Lease	7. Lease In May 2019 the Company entered into an agreement, as subsequently amended, to lease laboratory space pursuant to a three-month, automatically renewing lease. Due to the short-term nature of the lease, it was not included as an operating lease right of use asset nor as an operating lease liability on the Company’s balance sheets. The Company terminated the agreement in September 2021 . In February 2021, the Company entered into a lease agreement with Crossing Holdings, LLC to rent approximately 12,370 square feet of laboratory and office space (the “Lease”). The Company’s Executive Chairperson, co-founder and member of its board of directors, is the sole member and Manager of Crossing Holdings, LLC. The lease commenced in September 2021 with a term of 72 months and an option to extend the lease term for a period of three years ; however, it is not reasonably certain the Company will exercise the option to renew when the lease term ends in 2027 , and thus, the incremental term was excluded from the calculation of the right-of-use asset or lease liability. Lease payments are subject to annual increases of 3 % and the Company is responsible for its share of operating expenses and taxes, which are expensed as incurred. As of September 30, 2021 , the remaining lease term for the lease was 5.9 years and the discount rate used to determine the right-of-use asset and corresponding operating lease liability was 7.15 %. Maturities of operating lease liabilities as of September 30, 2021 are as follows (in thousands): 2021 (remaining three months) $ 181 2022 733 2023 755 2024 778 2025 801 Thereafter 1,386 Total future minimum lease payments 4,634 Less: Present value adjustment ( 886 ) Operating lease liabilities $ 3,748 Rent expense for the three months ended September 30, 2021 and 2020 was $ 0.2 million and less than $ 0.1 million, resp ectively. Rent expense for the nine months ended September 30, 2021 and 2020 was $ 0.4 million and $ 0.1 million, respectively.

Grant Revenue

Grant Revenue	9 Months Ended
	Sep. 30, 2021
Disaggregation Of Revenue [Abstract]
Grant Revenue	8. Grant Revenue The Company recognizes revenue pursuant to grants, as described further in Note 2, by measuring the progress of the applicable research and development services provided over time, based on the effort the Company expends and costs incurred, relative to the estimated total effort and costs to be incurred under the grant. This results in a percentage that the Company multiplies by the grant award amount to determine the amount of grant revenue to be recognized each period. This approach requires the Company to use judgement and make estimates of future expenditures. If the Company’s estimates or judgements change over the course of the term of the grant, it may affect the timing and amount of revenue that it recognizes in the current and future periods. During the three and nine months ended September 30, 2020, the Company recognized less t han $ 0.1 million and $ 0.2 million of grant revenue, respectively, from awards by the NSF, NIH and FARA, respectively. No grant revenue was recognized for the three and nine months ended September 30, 2021 .

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2021
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	9. Commitments and Contingencies Notes Payable-Related Party In January 2019, the Company issued an unsecured promissory note to borrow up to $ 0.5 million to a co-founder (the “January Note”) for working capital. The January Note bore interest at prime plus 4.5 %, was scheduled to mature on or before January 30, 2021 and included a final payment of 3 % on the amounts advanced at maturity. In February and March 2019, the Company borrowed an aggregate of $ 0.2 million under the January Note with interest payable at 10 % per annum. The Company recorded an immaterial amount of debt issuance costs associated with the January Note. The debt issuance costs and final payment for the advances were amortized to interest expense using the effective interest rate method over the loan term. The principal and interest payable on the January Note were repaid in full in 2020. In November 2019, the Company issued an unsecured promissory note to borrow up to $ 0.5 million to a co-founder (the “November Note”) for working capital. The November Note bore interest at prime plus 4.5 % and matured on or before January 1, 2022 and included a final payment of 3 % on the amounts advanced at maturity. In December 2019 and January 2020, the Company borrowed a total of $ 0.4 million under the November Note with interest payable at 9.25 % per annum. The final payment on the advances was amortized to interest expense using the effective interest rate method over the loan term. The principal and interest payable on the November Note were repaid in full in 2020. Convertible Notes In May and July 2018, the Company issued $ 0.3 million of convertible notes to a co-founder for cash with a maturity date on or after February 5, 2021, if not converted earlier . In February 2019, the Company issued an additional $ 0.2 million of convertible notes to consultants for services rendered with a maturity date on or after May 16, 2020, if not converted earlier . The convertible notes bore interest of 8 % per annum and were convertible into equity securities sold at the next financing at 80 % of the selling price per share of such equity financing. The conversion features of the convertible notes were recorded as a discount to the notes payable at issuance and amortized as interest expense over the loan term using the effective interest rate method. In February 2020, the outstanding principal and accrued interest of the convertible notes totaling $ 0.5 million were converted into 301,685 shares of the Company’s Series A convertible preferred stock at $ 1.65816 per share. See Note 11 for further discussion. Contingencies From time to time, the Company may become subject to claims or suits arising in the ordinary course of business. The Company accrues a liability for such matters when it is probable that the future expenditures will be made and such expenditures can be reasonably estimated. The Company had no such contingent liabilities as of September 30, 2021 or December 31, 2020.

License Agreement

License Agreement	9 Months Ended
	Sep. 30, 2021
License Agreement [Abstract]
License Agreement	10. License Agreement In February 2019, the Company entered into a Human Therapeutics Exclusive License Agreement (the “License Agreement”) with the Wisconsin Alumni Research Foundation (“WARF”). Under the License Agreement, the Company licensed the exclusive, worldwide, royalty-bearing, sublicensable rights to certain WARF patents and the nonexclusive worldwide rights to certain know-how to develop and commercialize products for the prevention, diagnosis and treatment of disease. As consideration for the license, the Company agreed to pay an upfront fee of $ 250,000 , which the Company immediately expensed as research and development expense in its statements of operations as there was no alternative future use for the license. The Company paid $ 25,000 of the upfront fee upon execution of the agreement and the remaining $ 225,000 was due upon the earlier of the first anniversary of the License Agreement or the Company receiving a certain level of gross proceeds from an equity financing. At December 31, 2019, the second payment of $ 225,000 was recorded as an accrued liability on the Company’s balance sheet. In February 2020, the Company paid the $ 225,000 balance upon the initial closing of its Series A preferred stock financing. Pursuant to the License Agreement, the Company is required to pay $ 125,000 upon the acceptance of an investigation new drug (“IND”) application in the U.S. and will be required to make further aggregate milestone payments of up to $ 17.5 million upon achievement of certain other regulatory and commercial milestones. The Company may also be required to pay royalties based on annual net product sales in the low single digits on its or its sublicensees’ net product sales on a country-by-country and product-by-product basis, and is subject to a minimum royalty of $ 0.1 million per calendar year upon first commercial product sale. Further, the Company may be required to pay sublicense fees in the mid-single digits percentage for fees, royalties or other payments earned from the granting of sublicenses to the WARF patents and know-how. The Company has paid no milestone or royalty payments as of September 30, 2021. The Company is responsible for reimbursing WARF for costs incurred in connection with prosecuting and maintaining patent rights that are specific to the License Agreement. Expenses recognized in connection with legal patent fees under this License Agreement were less th an $ 0.1 million for the three and nine months ended September 30, 2021 and 2020, respectively, which were recorded as general and administrative expenses in the statements of operations. The Company may terminate the License Agreement with 90 days written notice or for certain breaches of the agreement. WARF may terminate the License Agreement with 90 days written notice if first commercial sale does not occur before December 31, 2031. Unless terminated earlier by the parties, the term of the License Agreement will continue until the last licensed patent expires in all countries.

Convertible Preferred Stock and

Convertible Preferred Stock and Stockholders' Deficit	9 Months Ended
	Sep. 30, 2021
Equity [Abstract]
Convertible Preferred Stock and Stockholders' Deficit	11. Convertible Preferred Stock and Stockholders’ Deficit Authorized Shares In connection with the completion of the Company’s initial public offering (“IPO”) in March 2021, the Company amended its Certificate of Incorporation to authorize 200,000,000 shares of common stock, par value $ 0.0001 per share, and 10,000,000 shares of preferred stock, par value $ 0.0001 per share, respectively. Public Offering and Related Transaction In March 2021, the Company completed its IPO selling 13,800,000 shares its common stock at $ 20.00 per share. Proceeds from the Company’s IPO, net of underwriting discounts and commissions and other offering costs, were $ 254.3 million. In connection with the IPO, all 41,096,478 shares of convertible preferred stock outstanding at the time of the IPO converted into 25,212,548 shares of the Company’s common stock. Convertible Preferred Stock In February and March 2020, the Company issued 21,710,814 shares of Series A convertible preferred stock at $ 2.0727 per share for net cash proceeds of $ 44.7 million (the “Series A Financing”). In connection with the Series A Financing, the Company issued an additional 301,685 shares of its Series A convertible preferred stock at $ 1.65816 per share in February 2020 upon the conversion and extinguishment of its convertible notes, as discussed further in Note 8. In January 2021, the Company issued 19,083,979 shares of Series B convertible preferred stock at $ 6.55 per share for net cash proceeds of approximately $ 124.7 million. All shares of convertible preferred stock outstanding at the Company’s IPO were converted into shares of the Company’s common stock. Equity Incentive Award Plans In March 2021, the Company’s board of directors and stockholders adopted the 2021 Plan, which became effective on March 25, 2021, the date of the underwriting agreement related to the Company’s IPO. Commencing with the effectiveness of the 2021 Plan, no further grants can be made under the 2018 Plan. Under the 2021 Plan, the Company may grant stock options, stock appreciation rights, restricted stock, restricted stock units, performance stock awards, performance cash awards and other forms of stock awards to employees, directors and consultants, including employees and consultants of the Company’s affiliates. A total of 6,118,648 new shares of common stock were approved to be initially reserved for issuance under the 2021 Plan. The number of shares reserved under the 2021 Plan also include 881,352 shares of common stock that remained available for issuance under the 2018 Plan at the time the 2021 Plan became effective, and will be increased by the number of shares under the 2018 Plan that are repurchased, forfeited, expired or cancelled on or after the effective date of the 2021 Plan. In addition, the number of shares of common stock available for issuance under the 2021 Plan will automatically increase on January 1 of each calendar year, starting on January 1, 2022 through January 1, 2031, in an amount equal to 5 % of the total number of shares of the Company’s common stock on the last day of the calendar month before the date of each automatic increase, or a lesser number of shares determined by the Company’s board of directors. Shares subject to Repurchase Pursuant to the 2018 Plan, the Company has issued shares of restricted common stock to employees, consultants and members of its board of directors. Additionally, certain stock options granted pursuant to the 2018 Plan provide for the right to elect to exercise unvested options early in exchange for restricted shares of common stock. These restricted shares of common stock generally vest over a four-year period and are subject to repurchase by the Company at the original purchase price or, in certain instances the fair market value if such fair market value is lower than the purchase price, in the event the recipient’s service is terminated either voluntarily or involuntarily prior to vesting. A summary of the Company’s restricted shares of common stock and unvested stock liability, which is included in accrued expenses and other current liabilities and other long-term liabilities on the Company’s balance sheets, is as follows (in thousands, except share data): Shares Liability Balance at December 31, 2020 646,953 $ 145 Vested shares ( 216,540 ) ( 8 ) Balance at September 30, 2021 430,413 $ 137 2021 Employee Stock Purchase Plan In March 2021, the Company’s board of directors and stockholders adopted the 2021 Employee Stock Purchase Plan (the “ESPP”), which became effective on March 25, 2021, the date of the underwriting agreement related to the Company’s IPO. The ESPP permits eligible employees who elect to participate in an offering under the ESPP to have up to 15 % of their eligible earnings withheld, subject to certain limitations, to purchase shares of common stock pursuant to the ESPP. The price of common stock purchased under the ESPP is equal to 85 % of the lower of the fair market value of the common stock at the commencement date of each offering period or the relevant date of purchase. A total of 600,000 shares of common stock were approved to be initially reserved for issuance under the ESPP. In addition, the number of shares of common stock available for issuance under the ESPP will automatically increase on January 1 of each calendar year, starting on January 1, 2022 through January 1, 2031, in an amount equal to the lesser of (i) 1 % of the total number of shares of the Company’s common stock on the last day of the calendar month before the date of each automatic increase and (ii) 1,200,000 shares; provided that before the date of any such increase, the Company’s board of directors may determine that such increase will be less than the amount set forth in clauses (i) and (ii). As of September 30, 2021 , no shares of the Company’s common stock have been purchased under the ESPP.

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2021
Related Party Transactions [Abstract]
Related Party Transactions	12. Related Party Transactions Lease Agreement In February 2021, the Company entered into the Lease with Crossing Holdings, LLC to rent laboratory and office space. The Company's Executive Chairperson, co-founder and member of its board of directors, is the sole member and Manager of Crossing Holdings, LLC. Expenses recognized by the Company under the Lease during the periods presented were as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Research and development $ 53 $ — $ 53 $ — General and administrative 22 — 22 — Total expenses $ 75 $ — $ 75 $ — As of September 30, 2021 , and December 31, 2020, the Company had prepaid expenses of $ 0.1 million and zero , respectively, and accrued expenses and other current liabilities of less than $ 0.1 million and zero , respectively, pursuant to its related party lease agreement. Consulting Agreements In January 2019, the Company entered into an agreement with the Marlinspike Group, LLC (“Marlinspike Group”) for research support, management, and business consulting services (the “2019 Consulting Agreement”). Further, Marlinspike Group provides the use of approximately 2,120 square feet of its office space in Carlsbad, California to the Company on an as-available basis from time to time pursuant to the agreement. The Company’s Executive Chairperson, co-founder and member of its board of directors is an executive officer of Marlinspike Group and, the Company’s Chief Operating Officer was an executive officer of Marlinspike Group until February 2020. The term of the 2019 Consulting Agreement was for a one-year period, subject to automatic one-month renewals unless terminated upon 14 days’ written notice. In March 2020, the Consulting Agreement was terminated and replaced with an amended consulting agreement (the “2020 Consulting Agreement”), which provides for the similar services and use of office space for a monthly fee of $ 20,000 . Pursuant to the terms of the 2020 Consulting Agreement, it shall remain in effect until otherwise terminated. Termination may occur at any time upon mutual agreement or unilaterally upon 30 days’ written notice. If the Company unilaterally terminates the 2020 Consulting Agreement for any reason other than cause, it would be subject to a $ 240,000 termination fee. The Company cannot determine when, or if, such a termination will occur and hence has not recorded a liability for the fee. Expenses recognized by the Company under the 2020 Consulting Agreement during the periods presented were as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Research and development $ — $ — $ — $ 8 General and administrative 60 60 180 232 Total expenses $ 60 $ 60 $ 180 $ 240 In December 2017, the Company entered into a consulting agreement with Aseem Z. Ansari, Ph.D. Dr. Ansari, a co-founder, provides consulting services and advises on certain research and development activities (the “Research Consulting Agreement”). Pursuant to the Research Consulting Agreement, as amended, Dr. Ansari performs these services for a monthly fee of $ 15,000 . Expenses recognized by the Company under the Research Consulting Agreement during the periods presented were as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Research and development $ 45 $ — $ 135 $ — Total expenses $ 45 $ — $ 135 $ — As of September 30, 2021 and December 31, 2020, the Company had accounts payable of $ 20,000 pursuant to its related party consulting agreements. Convertible Notes and Notes Payable In May and July 2018, the Company issued a total of $ 0.3 million of convertible notes to a co-founder for cash with a maturity date on or after February 5, 2021, if not converted earlier . The notes bore interest of 8 % per annum and were convertible into equity securities sold at the next financing at 80 % of the selling price per share of such equity financing. In February 2020, these notes converted into 171,025 shares of the Company’s convertible preferred stock pursuant to the closing of the Series A preferred stock financing. Further, the Company has issued unsecured promissory notes to this co-founder for working capital. See Note 9 for further discussion.

Basis of Presentation and Sum_2

Basis of Presentation and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Basis of Presentation and Use of Estimates	Basis of Presentation and Use of Estimates The accompanying interim condensed financial statements are unaudited. These unaudited interim condensed financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP") and following the requirements of the United States Securities and Exchange Commission ("SEC") for interim reporting. The Company's financial statements include all adjustments, consisting of only normal recurring adjustments, which in the opinion of management are necessary to present fairly the Company’s financial position as of the reporting date and results of operations for the periods presented. The preparation of the Company’s financial statements requires it to make estimates and assumptions that impact the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities in the Company’s financial statements and accompanying notes. The most significant estimates in the Company’s financial statements relate to the recognition of grant revenue, accruals for research and development expenses and the valuation of equity-based awards. These estimates and assumptions are based on current facts, historical experience and various other factors believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities and the recording of revenue and expenses that are not readily apparent from other sources. Actual results may differ materially and adversely from these estimates. The full extent to which the novel coronavirus-2019 (“COVID-19”) pandemic will directly or indirectly impact the Company’s business, results of operations and financial condition, including research and development costs, will depend on future developments that are highly uncertain, including as a result of new information that may emerge concerning COVID-19 and the actions taken to contain or treat COVID-19, as well as the economic impact on local, regional, national and international markets. The Company has considered potential impacts arising from the COVID-19 pandemic and is not presently aware of any events or circumstances that would require the Company to update its estimates, judgments or revise the carrying value of its assets or liabilities.
Stock Splits	Stock Splits In February 2020, the Company effected a 5 -for-1 forward stock split of its issued and outstanding common stock. Further, in March 2021, the Company effected a 1-for- 1.63 reverse stock split of its issued and outstanding common stock. The par value and the authorized shares of the common stock were not adjusted as a result of these stock splits. The reverse stock split in March 2021 resulted in an adjustment to the convertible preferred stock conversion prices to reflect a proportional decrease in the number of shares of common stock to be issued upon conversion. The accompanying financial statements and notes to the financial statements give retroactive effect to the stock splits for all periods presented.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with maturities at the date of acquisition of three months or less to be cash equivalents. These investments may include money market accounts, money market funds, U.S. Government agency securities, corporate debt securities and commercial paper. The Company’s cash reserves are in a readily available checking account.
Investment Securities	Investment Securities Investments in securities with maturities at the date of acquisition of more than three months are considered marketable securities. The Company determines the appropriate classification of its investments at the time of acquisition and reevaluates such determination at each balance sheet date. The Company has classified its investment holdings as available-for-sale, as the sale of such securities may be required prior to maturity to implement management strategies. Further, the Company classifies its available-for-sale investment securities, including those with maturities beyond one year, as current assets on its balance sheets based on the highly liquid nature of the securities and because these investments are considered available for use in current operations. The Company’s investment policy sets minimum credit quality criteria and maximum maturity limits on its investments to provide for safety of principle, liquidity and a reasonable rate of return. Available-for-sale securities are recorded at fair value, based on current market valuations. Unrealized holding gains and losses on available-for-sale securities are excluded from earnings and are reported as a separate component of other comprehensive income (loss) until realized. Allowances for credit losses are reported on the balance sheet, if any. The cost of available-for-sale investment securities is adjusted for amortization of premiums and accretion of discounts until the securities mature. Such amortization and accretion is included in other income (expense) on the statements of operations. Realized gains and losses, if any, are also included in other income (expense) on the statement of operations and are derived using the specific identification method for determining the cost of the securities sold. During the periods presented, no realized gains or losses were recorded on the sale of investment securities and no impairments to reduce the value of any security was taken. See Note 5 for further discussion.
Leases	Leases At lease commencement, the Company records a lease liability based on the present value of lease payments over the expected lease term. The expected lease term includes noncancelable lease periods and, when applicable, periods covered by an option to extend the lease if the Company is reasonably certain to exercise that option, as well as periods covered by an option to terminate the lease if the Company is reasonably certain not to exercise the option. The Company calculates the present value of lease payments using an incremental borrowing rate as the Company's leases do not provide an implicit interest rate. The Company's incremental borrowing rate for a lease is the rate of interest it would have to pay on a collateralized basis to borrow an amount equal to the lease payments under similar terms. At the lease commencement date, the Company records a corresponding right-of-use lease asset based on the lease liability, adjusted for any lease incentives received and any initial direct costs paid to the lessor prior to the lease commencement date. The Company may enter into leases with an initial term of 12 months or less ("Short-Term Leases"). For any Short-Term leases, the Company records the rent expense on a straight-line basis and does not record the leases on the condensed balance sheet. The Company had no Short-Term Leases as of September 30, 2021 or December 31, 2020. After lease commencement, the Company measures its leases as follows: (i) the lease liability based on the present value of the remaining lease payments using the discount rate determined at lease commencement and (ii) the right-of-use asset based on the remeasured lease liability, adjusted for any unamortized lease incentives received, any unamortized initial direct costs and the cumulative difference between rent expense and amounts paid under the lease agreement. Any lease incentives received and any initial direct costs are amortized on a straight-line basis over the expected lease term. Rent expense is recorded on a straight-line basis over the expected lease term.
Revenue Recognition	Revenue Recognition The Company has generated revenue from grants awarded to it by the National Science Foundation (“NSF”), the National Institutes of Health (“NIH”) and the Friedreich’s Ataxia Research Alliance (“FARA”). These grants provide the Company with funding for certain research and development activities on a best-efforts basis and do not require scientific achievement as a performance obligation. The Company has determined that the entities funding these grant awards do not meet the definition of a “customer”, as defined by Accounting Standards Codification (“ASC”) 606, Revenue from Contracts with Customers (Topic 606) , and does not consider there to be a transfer of control of goods or services to the entities funding the grant. As such, the Company recognizes revenue from these awards in the period during which the related qualifying services are rendered and costs are incurred in accordance with ASC 730, Research and Development . ASC 730 requires an assessment, at the inception of the grant, to determine whether the agreement is a liability or a contract to perform research and development services for others. Further, these grants are subject to the contribution’s guidance under ASC 958, Not-for-Profit Entities-Revenue Recognition , and as such, the Company determines whether it is obligated to repay the funds received to the grantor regardless of the outcome of the related research and development activities. If it determines there is such a liability, it estimates the obligation and recognize that liability. Alternatively, if the Company is not required to repay the funds, the grant agreement is accounted for as a contract to perform research and development services for others, in which case, the grant revenue is recorded as income in the statements of operations as the expenses are incurred. The Company’s current grant revenue is not deemed refundable, and therefore, no liability is recognized when income is recorded. Grant funding received prior to expenses being incurred are recorded as deferred revenue on the Company’s balance sheets. See Note 8 for further discussion.
Research and Development Expenses	Research and Development Expenses Research and development expenses consist primarily of direct and indirect costs incurred in connection with its discovery efforts, and the preclinical and formulation development of its product candidates. In the future, the Company expects a substantial portion of its research and development expenses will relate to the clinical development of its product candidates. Direct costs include contracted research development and manufacturing, consulting fees, license fees, laboratory supplies and other expenses incurred to sustain research and development programs. Indirect costs include personnel-related expenses, consisting of employee salaries, related benefits, and stock-based compensation expense for employees engaged in research and development activities, facilities related expenses, and other indirect expenses. A significant portion of the Company’s research and development expenses have been direct costs, which the Company tracks by stage of development, preclinical or clinical. However, the Company does not track its internal research and development expenses on a program specific basis, unless specific to research grants, because these costs are deployed across multiple projects and, as such, are not separately classified. Research and development expenses are charged to operating expenses as incurred when these expenditures relate to the Company’s research and development efforts and have no alternative future uses. The Company has entered into various contracts with research and development organizations, vendors and consultants. Payments for these activities are based on the terms of the individual agreements, which may differ from the periods over which materials or services are provided. Payments made in advance of performance are reflected in the accompanying balance sheets as prepaid expenses. The Company records accruals for estimated costs incurred for ongoing research and development activities. The Company determines accrual estimates through review of the underlying contracts along with discussions with research and other key personnel as to the progress of the research and development activities, invoices received and contracted costs. During the course of a study or trial, the Company adjusts its rate of expense recognition if actual results differ from its estimates. Significant judgments and estimates may be made in determining the prepaid or accrued balances at the end of any reporting period. Actual results could differ from the Company’s estimates.
Stock-Based Compensation	Stock-Based Compensation Stock options issued pursuant to the Company’s 2021 Equity Incentive Plan (the “2021 Plan”) and 2018 Equity Incentive Plan (the “2018 Plan”) and option features associated with the rights to purchase shares pursuant to the Company’s 2021 Employee Stock Purchase Plan (the “ESPP”) are valued using the Black-Scholes option pricing model on the date of grant or subscription period. This option pricing model involves a number of estimates, including the expected lives of the stock options or subscription period, the Company’s anticipated stock volatility and interest rates. The Company recognizes the expense for equity awards on a straight-line basis over the requisite service periods of the awards or the number of shares estimated to be issued pursuant to the ESPP. Forfeitures are recognized as they occur. Stock-based compensation expense recognized in the Company’s statements of operations during the three and nine months ended September 30, 2021 and 2020, were as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Research and development $ 521 $ 12 $ 1,181 $ 22 General and administrative 722 3 1,952 7 Total $ 1,243 $ 15 $ 3,133 $ 29
Recent Accounting Pronouncements	Recent Accounting Pronouncements In May 2021, the Financial Accounting Standards Board (“FASB”) issued ASU 2021-04, Earnings Per Share (Topic 260), Debt—Modifications and Extinguishments (Subtopic 470-50), Compensation—Stock Compensation (Topic 718), and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40) . ASU 2021-04 clarifies and reduces diversity in an issuer’s accounting for modifications or exchanges of freestanding equity-classified written call options (for example, warrants) that remain equity classified after modification or exchange. The ASU provides guidance to clarify whether an issuer should account for a modification or an exchange of a freestanding equity-classified written call option that remains equity classified after modification or exchange as (1) an adjustment to equity and, if so, the related earnings per share effects, if any, or (2) an expense and, if so, the manner and pattern of recognition. ASU 2021-04 is effective for annual periods beginning after December 15, 2021, including interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period. The Company is currently evaluating the impact that this new guidance will have on its condensed consolidated financial statements and does not currently expect the adoption will have a material impact on its financial statements and related disclosures. In August 2020, the FASB issued ASU 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging— Contracts in Entity’s Own Equity . The guidance, among other items, clarifies that certain transactions between collaborative participants should be accounted for as revenue under Topic 606 when the collaborative arrangement participant is a customer in the context of a unit of account. The ASU’s amendments are effective for fiscal years beginning after December 15, 2021, and interim periods within those fiscal years, with early adoption permitted for periods beginning after December 15, 2020. The Company has not yet adopted this guidance and does not currently expect the adoption will have a material impact on its financial statements and related disclosures.

Basis of Presentation and Sum_3

Basis of Presentation and Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2021
Share Based Compensation Allocation And Classification In Financial Statements [Abstract]
Summary of Stock-based Compensation Expense	Stock-based compensation expense recognized in the Company’s statements of operations during the three and nine months ended September 30, 2021 and 2020, were as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Research and development $ 521 $ 12 $ 1,181 $ 22 General and administrative 722 3 1,952 7 Total $ 1,243 $ 15 $ 3,133 $ 29

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Schedule of Antidilutive Securities Excluded in Calculation of Diluted Net Loss Per Share	The following table sets forth the outstanding, potentially dilutive securities that have been excluded in the calculation of diluted net loss per share because their inclusion would be anti-dilutive: September 30, September 30, Convertible preferred stock $ — $ 13,504,598 Stock options 2,124,238 389,565 Shares subject to repurchase 430,413 564,055 Employee stock purchase plan 15,335 — Total $ 2,569,986 $ 14,458,218

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Summary of Company's Financial Instruments Measured at Fair Value on a Recurring Basis	The following table summarize the Company’s financial instruments measured at fair value on a recurring basis at September 30, 2021 and December 31, 2020 (in thousands): Fair Value Measurement at End of Period Using: Quoted Prices In Active Markets Significant For Other Significant Identical Observable Unobservable Assets Inputs Inputs Total (Level 1) (Level 2) (Level 3) As of September 30, 2021: Assets: Money market funds (1) $ 356,793 $ 356,793 $ — $ — Certificates of deposit 5,987 5,987 — — U.S. Treasury securities 30,068 30,068 — — Total $ 392,848 $ 392,848 $ — $ — As of December 31, 2020: Assets: Money market funds (1) $ 2,100 $ 2,100 $ — $ — Certificates of deposit 1,754 1,754 — — U.S. Treasury securities 31,958 31,958 — — Total $ 35,812 $ 35,812 $ — $ — (1) Included in cash and cash equivalents on the accompanying balance sheets.

Investment Securities (Tables)

Investment Securities (Tables)	9 Months Ended
	Sep. 30, 2021
Investments Debt And Equity Securities [Abstract]
Disclosure - Investment Securities - Summary of Cost, Gross Unrealized Holding Gains and Losses, Allowances for Credit Losses and Fair Value of Available-for-Sale Investments by Types, Maturities and Classes of Securities (Detail)	The cost, gross unrealized holding gains, gross unrealized holding losses, allowances for credit losses and fair value of available-for-sale investments by types, maturities and classes of securities at September 30, 2021 and December 31, 2020 consisted of the following (in thousands): As of September 30, 2021 Estimated Allowance Fair Amortized Unrealized Unrealized for Credit Market Maturity Cost Gains Losses Losses Value Certificates of deposits Within 1 year $ 2,853 $ — $ ( 1 ) $ — $ 2,852 U.S. Treasury securities Within 1 year 10,066 1 — — $ 10,067 Certificates of deposits 1 year to 2 years 3,137 — ( 2 ) — 3,135 U.S. Treasury securities 1 year to 2 years 20,004 — ( 2 ) — 20,002 Total $ 36,060 $ 1 $ ( 5 ) $ — $ 36,056 As of December 31, 2020 Estimated Allowance Fair Amortized Unrealized Unrealized for Credit Market Maturity Cost Gains Losses Losses Value Certificates of deposits Within 1 year $ 1,750 $ 4 $ — $ — $ 1,754 U.S. Treasury securities Within 1 year 31,806 152 — — 31,958 Total $ 33,556 $ 156 $ — $ — $ 33,712

Balance Sheet Details (Tables)

Balance Sheet Details (Tables)	9 Months Ended
	Sep. 30, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Summary of Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consisted of the following (in thousands): September 30, December 31, Prepaid expenses $ 1,421 $ 60 Security deposits 104 47 Interest receivable 47 10 Other — 25 Total $ 1,572 $ 142
Summary of Property and Equipment	Property and equipment consisted of the following (in thousands): September 30, December 31, Laboratory equipment $ 1,058 $ 76 Computer equipment and software 77 — Leasehold improvements 91 — Construction in progress 146 — 1,372 76 Less accumulated depreciation ( 52 ) ( 5 ) Total $ 1,320 $ 71
Summary of Accrued Liabilities	Accrued liabilities consisted of the following (in thousands): September 30, December 31, Accrued personnel costs $ 1,411 $ 565 Accrued research and development costs 652 266 Current portion of operating lease liability 475 — Accrued other 751 100 Total $ 3,289 $ 931

Lease (Tables)

Lease (Tables)	9 Months Ended
	Sep. 30, 2021
Leases [Abstract]
Summary of Maturities of Operating Lease Liabilities	Maturities of operating lease liabilities as of September 30, 2021 are as follows (in thousands): 2021 (remaining three months) $ 181 2022 733 2023 755 2024 778 2025 801 Thereafter 1,386 Total future minimum lease payments 4,634 Less: Present value adjustment ( 886 ) Operating lease liabilities $ 3,748

Convertible Preferred Stock a_2

Convertible Preferred Stock and Stockholders' Deficit (Tables)	9 Months Ended
	Sep. 30, 2021
Equity [Abstract]
Summary of Restricted Shares of Common Stock and Unvested Stock Liability	A summary of the Company’s restricted shares of common stock and unvested stock liability, which is included in accrued expenses and other current liabilities and other long-term liabilities on the Company’s balance sheets, is as follows (in thousands, except share data): Shares Liability Balance at December 31, 2020 646,953 $ 145 Vested shares ( 216,540 ) ( 8 ) Balance at September 30, 2021 430,413 $ 137

Related Party Transactions (Tab

Related Party Transactions (Tables)	9 Months Ended
	Sep. 30, 2021
Consulting Agreements
Related Party Transaction [Line Items]
Summary of Expenses Recognized under Various Agreements	Expenses recognized by the Company under the 2020 Consulting Agreement during the periods presented were as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Research and development $ — $ — $ — $ 8 General and administrative 60 60 180 232 Total expenses $ 60 $ 60 $ 180 $ 240
Research Consulting Agreements
Related Party Transaction [Line Items]
Summary of Expenses Recognized under Various Agreements	Expenses recognized by the Company under the Research Consulting Agreement during the periods presented were as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Research and development $ 45 $ — $ 135 $ — Total expenses $ 45 $ — $ 135 $ —
Lease Agreement
Related Party Transaction [Line Items]
Summary of Expenses Recognized under Various Agreements	Expenses recognized by the Company under the Lease during the periods presented were as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Research and development $ 53 $ — $ 53 $ — General and administrative 22 — 22 — Total expenses $ 75 $ — $ 75 $ —

Basis of Presentation and Sum_4

Basis of Presentation and Summary of Significant Accounting Policies - Additional Information (Details)	1 Months Ended		9 Months Ended
	Mar. 31, 2021	Feb. 29, 2020	Sep. 30, 2021USD ($)	Dec. 31, 2020USD ($)
Accounting Policies [Abstract]
Stock split of issued and outstanding common stock			5-for-1
Reverse stock split of issued and outstanding common stock			1-for-1.63
Conversion ratio of forward/reverse stock split	0.613497	5
Short-term leases			$ 0	$ 0

Basis of Presentation and Sum_5

Basis of Presentation and Summary of Significant Accounting Policies - Summary of Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 1,243	$ 15	$ 3,133	$ 29
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	521	12	1,181	22
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 722	$ 3	$ 1,952	$ 7

Net Loss Per Share - Schedule o

Net Loss Per Share - Schedule of Antidilutive Securities Excluded in Calculation of Diluted Net Loss Per Share (Details) - shares	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of diluted net loss per share	2,569,986	14,458,218
Convertible Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of diluted net loss per share		13,504,598
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of diluted net loss per share	2,124,238	389,565
Shares Subject to Repurchase
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of diluted net loss per share	430,413	564,055
Employee Stock Purchase Plan
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of diluted net loss per share	15,335

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Financial Instruments Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, fair value disclosure	$ 392,848	$ 35,812
Money market funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, fair value disclosure	356,793	2,100
Certificates of deposit
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, fair value disclosure	5,987	1,754
U.S. Treasury securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, fair value disclosure	30,068	31,958
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, fair value disclosure	392,848	35,812
Quoted Prices in Active Markets for Identical Assets (Level 1) | Money market funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, fair value disclosure	356,793	2,100
Quoted Prices in Active Markets for Identical Assets (Level 1) | Certificates of deposit
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, fair value disclosure	5,987	1,754
Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. Treasury securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, fair value disclosure	$ 30,068	$ 31,958

Investment Securities - Summary

Investment Securities - Summary of Cost, Gross Unrealized Holding Gains and Losses, Allowances for Credit Losses and Fair Value of Available-for-Sale Investments by Types, Maturities and Classes of Securities (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Schedule Of Available For Sale Securities [Line Items]
Debt securities, Amortized Cost	$ 36,060	$ 33,556
Debt securities, Unrealized Gains	1	156
Debt securities, Unrealized Losses	(5)
Debt securities, Estimated Fair Value	$ 36,056	$ 33,712
Certificates of deposit | Within 1 Year
Schedule Of Available For Sale Securities [Line Items]
Debt securities, Maturity	Within 1 year	Within 1 year
Debt securities, Amortized Cost	$ 2,853	$ 1,750
Debt securities, Unrealized Gains		4
Debt securities, Unrealized Losses	(1)
Debt securities, Estimated Fair Value	$ 2,852	$ 1,754
Certificates of deposit | 1 Year to 2 Years
Schedule Of Available For Sale Securities [Line Items]
Debt securities, Maturity	1 year to 2 years
Debt securities, Amortized Cost	$ 3,137
Debt securities, Unrealized Losses	(2)
Debt securities, Estimated Fair Value	$ 3,135
U.S. Treasury securities | Within 1 Year
Schedule Of Available For Sale Securities [Line Items]
Debt securities, Maturity	Within 1 year	Within 1 year
Debt securities, Amortized Cost	$ 10,066	$ 31,806
Debt securities, Unrealized Gains	1	152
Debt securities, Estimated Fair Value	$ 10,067	$ 31,958
U.S. Treasury securities | 1 Year to 2 Years
Schedule Of Available For Sale Securities [Line Items]
Debt securities, Maturity	1 year to 2 years
Debt securities, Amortized Cost	$ 20,004
Debt securities, Unrealized Losses	(2)
Debt securities, Estimated Fair Value	$ 20,002

Investment Securities - Additio

Investment Securities - Additional Information (Details)	Sep. 30, 2021USD ($)Security	Dec. 31, 2020USD ($)Security
Schedule Of Available For Sale Securities [Line Items]
Number of available-for-sale investment securities in continuous unrealized loss position, less than 12 months	19	0
Number of domestic certificates of deposit held	25
Maximum
Schedule Of Available For Sale Securities [Line Items]
Accrued interest receivable on available-for-sale investment securities | $	$ 100,000	$ 100,000

Balance Sheet Details - Summary

Balance Sheet Details - Summary of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Prepaid Expense And Other Assets Current [Abstract]
Prepaid expenses	$ 1,421	$ 60
Security deposits	104	47
Interest receivable	47	10
Other		25
Total	$ 1,572	$ 142

Balance Sheet Details - Summa_2

Balance Sheet Details - Summary of Property and Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Property Plant And Equipment [Line Items]
Property and equipment	$ 1,372	$ 76
Less accumulated depreciation	(52)	(5)
Total	1,320	71
Laboratory Equipment
Property Plant And Equipment [Line Items]
Property and equipment	1,058	$ 76
Computer Equipment and Software
Property Plant And Equipment [Line Items]
Property and equipment	77
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment	91
Construction in Progress
Property Plant And Equipment [Line Items]
Property and equipment	$ 146

Balance Sheet Details - Summa_3

Balance Sheet Details - Summary of Accrued Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Accrued Liabilities Current [Abstract]
Accrued personnel costs	$ 1,411	$ 565
Accrued research and development costs	652	266
Current portion of operating lease liability	475
Accrued other	751	100
Total	$ 3,289	$ 931

Lease - Additional Information

Lease - Additional Information (Details)	1 Months Ended		3 Months Ended		9 Months Ended
	Sep. 30, 2021	Feb. 28, 2021ft²	Sep. 30, 2021USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2021USD ($)	Sep. 30, 2020USD ($)
Lessee, Lease, Description [Line Items]
Lease agreement termination date	2021-09
Rent expense			$ 200,000		$ 400,000	$ 100,000
Maximum
Lessee, Lease, Description [Line Items]
Rent expense				$ 100,000
Crossing Holdings, LLC
Lessee, Lease, Description [Line Items]
Area of lease space | ft²		12,370
Lease commencement date					2021-09
Lease term		72 months
Option to renew lease term ends, year					2027
Lessee, Operating Lease, Existence of Option to Extend [true false]		true
Lease term, option to extend period					three years
Percentage of annual increase in lease payments		3.00%
Operating lease remaining lease term	5 years 10 months 24 days		5 years 10 months 24 days		5 years 10 months 24 days
Operating lease right-of-use asset discount rate	7.15%		7.15%		7.15%

Lease - Summary of Maturities o

Lease - Summary of Maturities of Operating Lease Liabilities (Details) $ in Thousands	Sep. 30, 2021USD ($)
Operating Lease Liabilities Payments Due [Abstract]
2021 (remaining three months)	$ 181
2022	733
2023	755
2024	778
2025	801
Thereafter	1,386
Total future minimum lease payments	4,634
Less: Present value adjustment	(886)
Operating lease liabilities	$ 3,748

Grant Revenue - Additional Info

Grant Revenue - Additional Information (Details) - Grant - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation Of Revenue [Line Items]
Recognized grant revenue	$ 0		$ 0	$ 200,000
Maximum
Disaggregation Of Revenue [Line Items]
Recognized grant revenue		$ 100,000

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended			9 Months Ended
	Feb. 29, 2020	Nov. 30, 2019	Jan. 31, 2019	Sep. 30, 2021	Jan. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Feb. 28, 2019
Commitments And Contingencies Disclosure [Line Items]
Debt instrument interest rate								8.00%
Convertible notes issued								$ 0.2
Percentage of selling price per share that can convertible into equity securities sold								80.00%
Converted amount	$ 0.5
Series A Convertible Preferred Stock
Commitments And Contingencies Disclosure [Line Items]
Converted shares	301,685
Share price	$ 1.65816
May 2018 Note
Commitments And Contingencies Disclosure [Line Items]
Maturity description				on or after February 5, 2021, if not converted earlier
July 2018 Note
Commitments And Contingencies Disclosure [Line Items]
Maturity description				on or after February 5, 2021, if not converted earlier
February 2019 Note
Commitments And Contingencies Disclosure [Line Items]
Maturity description				on or after May 16, 2020, if not converted earlier
Unsecured Promissory Note | January Note
Commitments And Contingencies Disclosure [Line Items]
Maturity description				on or before January 30, 2021
Percentage of final payment on advanced at maturity			3.00%
Debt instrument interest rate							10.00%	10.00%
Unsecured Promissory Note | January Note | Maximum
Commitments And Contingencies Disclosure [Line Items]
Notes issued			$ 0.5
Unsecured Promissory Note | January Note | Prime Plus
Commitments And Contingencies Disclosure [Line Items]
Debt instrument variable interest rate			4.50%
Unsecured Promissory Note | November Note
Commitments And Contingencies Disclosure [Line Items]
Maturity description				on or before January 1, 2022
Percentage of final payment on advanced at maturity		3.00%
Debt instrument interest rate					9.25%	9.25%
Unsecured Promissory Note | November Note | Maximum
Commitments And Contingencies Disclosure [Line Items]
Notes issued		$ 0.5
Unsecured Promissory Note | November Note | Prime Plus
Commitments And Contingencies Disclosure [Line Items]
Debt instrument variable interest rate		4.50%
Unsecured Promissory Note | February and March 2019 Draws | January Note
Commitments And Contingencies Disclosure [Line Items]
Borrowings				$ 0.2
Unsecured Promissory Note | Jan 2020 and Dec 2019 Draws | November Note
Commitments And Contingencies Disclosure [Line Items]
Borrowings				0.4
Convertible Notes Issued in May and July 2018
Commitments And Contingencies Disclosure [Line Items]
Convertible notes issued				$ 0.3

License Agreement - Additional

License Agreement - Additional Information (Details) - License Agreement - USD ($)	1 Months Ended		3 Months Ended		9 Months Ended		12 Months Ended
	Feb. 29, 2020	Feb. 28, 2019	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2019
Schedule Of License Agreement [Line Items]
Payment for upfront fee							$ 225,000
Upfront payment upon execution of agreement		$ 25,000
Upfront payment within first anniversary of license agreement		225,000
Written notice period for termination of agreement					90 days
Termination period Description					WARF may terminate the License Agreement with 90 days written notice if first commercial sale does not occur before December 31, 2031. Unless terminated earlier by the parties, the term of the License Agreement will continue until the last licensed patent expires in all countries.
Investigation New Drug (IND)
Schedule Of License Agreement [Line Items]
Expected milestone payment on achieving certain regulatory and commercial milestones			$ 125,000		$ 125,000
Milestone payment			0		0
Royalty payments					0
Investigation New Drug (IND) | Maximum
Schedule Of License Agreement [Line Items]
Expected milestone payment on achieving certain regulatory and commercial milestones			17,500,000		17,500,000
Investigation New Drug (IND) | Minimum [Member]
Schedule Of License Agreement [Line Items]
Expected royalty payments upon first commercial product sale			100,000		100,000
Initial Closing of Series A Preferred Stock
Schedule Of License Agreement [Line Items]
Payment for upfront fee	$ 225,000
Research and Development
Schedule Of License Agreement [Line Items]
Payment for upfront fee		$ 250,000
General and Administrative Expenses | Maximum
Schedule Of License Agreement [Line Items]
Legal patent fees			$ 100,000	$ 100,000	$ 100,000	$ 100,000

Convertible Preferred Stock a_3

Convertible Preferred Stock and Stockholders' Deficit - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	Mar. 25, 2021	Mar. 31, 2021	Jan. 31, 2021	Mar. 31, 2020	Feb. 29, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Convertible Preferred Stock And Stockholders Deficit [Line Items]
Common stock, shares authorized						200,000,000		60,000,000
Common stock, par value						$ 0.0001		$ 0.0001
Convertible preferred stock, issued						0		22,012,499
Convertible preferred stock, par value						$ 0.0001		$ 0.0001
Proceeds from issuance of convertible preferred stock, net of issuance costs						$ 124,712	$ 44,731
2021 Equity Incentive Award Plan
Convertible Preferred Stock And Stockholders Deficit [Line Items]
Common stock reserved for issuance	6,118,648
Common stock issuance, description and terms						the number of shares of common stock available for issuance under the 2021 Plan will automatically increase on January 1 of each calendar year, starting on January 1, 2022 through January 1, 2031, in an amount equal to 5% of the total number of shares of the Company’s common stock on the last day of the calendar month before the date of each automatic increase, or a lesser number of shares determined by the Company’s board of directors.
Percentage of number of shares that may be issued in accordance with plan	5.00%
2018 Equity Incentive Plan
Convertible Preferred Stock And Stockholders Deficit [Line Items]
Common stock remained available for issuance	881,352
2021 Employee Stock Purchase Plan
Convertible Preferred Stock And Stockholders Deficit [Line Items]
Common stock reserved for issuance	600,000
Common stock remained available for issuance	1,200,000
Common stock issuance, description and terms						the number of shares of common stock available for issuance under the ESPP will automatically increase on January 1 of each calendar year, starting on January 1, 2022 through January 1, 2031, in an amount equal to the lesser of (i) 1% of the total number of shares of the Company’s common stock on the last day of the calendar month before the date of each automatic increase and (ii) 1,200,000 shares; provided that before the date of any such increase, the Company’s board of directors may determine that such increase will be less than the amount set forth in clauses (i) and (ii). As of September 30, 2021, no shares of the Company’s common stock have been purchased under the ESPP.
Percentage of number of shares that may be issued in accordance with plan	1.00%
Maximum percentage of eligible earnings withheld to participate in offering	15.00%
Price of common stock purchased	85.00%
Number of common stock purchased						0
Series A Convertible Preferred Stock
Convertible Preferred Stock And Stockholders Deficit [Line Items]
Share price					$ 1.65816
Convertible preferred stock, issued				21,710,814	21,710,814
Convertible preferred stock, par value				$ 2.0727	$ 2.0727
Proceeds from issuance of convertible preferred stock, net of issuance costs				$ 44,700	$ 44,700
Converted shares					301,685
Series B Convertible Preferred Stock
Convertible Preferred Stock And Stockholders Deficit [Line Items]
Convertible preferred stock, issued			19,083,979
Convertible preferred stock, par value			$ 6.55
Proceeds from issuance of convertible preferred stock, net of issuance costs			$ 124,700
Common Stock
Convertible Preferred Stock And Stockholders Deficit [Line Items]
Initial public offering of common shares						13,800,000
Common Stock | 2018 Equity Incentive Plan | Restricted Shares
Convertible Preferred Stock And Stockholders Deficit [Line Items]
Vesting period						4 years
Initial Public Offering
Convertible Preferred Stock And Stockholders Deficit [Line Items]
Common stock, shares authorized		200,000,000
Common stock, par value		$ 0.0001
Preferred stock, authorized		10,000,000
Preferred stock, par value		$ 0.0001
Initial public offering of common shares		13,800,000
Share price		$ 20
Proceeds from sale of common stock		$ 254,300
Convertible preferred stock, shares issued upon conversion		41,096,478
Initial Public Offering | Common Stock
Convertible Preferred Stock And Stockholders Deficit [Line Items]
Convertible preferred stock, shares issued upon conversion		25,212,548

Convertible Preferred Stock a_4

Convertible Preferred Stock and Stockholders' Deficit - Summary of Restricted Shares of Common Stock and Unvested Stock Liability (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2021USD ($)shares
Liabilities And Stockholders Equity [Line Items]
Beginning Balance, Unvested stock liability | $	$ 145
Vested shares, Unvested stock liability | $	(8)
Ending Balance, Unvested stock liability | $	$ 137
Restricted Shares
Liabilities And Stockholders Equity [Line Items]
Beginning Balance | shares	646,953
Vested shares | shares	(216,540)
Ending Balance | shares	430,413

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details)	1 Months Ended				9 Months Ended
	Mar. 31, 2020USD ($)	Feb. 29, 2020shares	Jan. 31, 2019ft²	Dec. 31, 2017USD ($)	Sep. 30, 2021USD ($)	Dec. 31, 2020USD ($)	Feb. 28, 2019USD ($)	Jul. 31, 2018USD ($)	May 31, 2018USD ($)
Related Party Transaction [Line Items]
Accrued expenses and other current liabilities, related party amounts					$ 10,000	$ 0
Convertible notes issued							$ 200,000
Debt instrument interest rate							8.00%
Percentage of selling price per share that can convertible into equity securities sold							80.00%
Lease Agreement
Related Party Transaction [Line Items]
Prepaid expenses					100,000	0
Accrued expenses and other current liabilities, related party amounts						0
Lease Agreement | Maximum
Related Party Transaction [Line Items]
Accrued expenses and other current liabilities, related party amounts					100,000
Consulting Agreements
Related Party Transaction [Line Items]
Accounts payable					$ 20,000	$ 20,000
Marlinspike Group, LLC | 2020 Consulting Agreement
Related Party Transaction [Line Items]
Monthly fee for consultancy services	$ 20,000
Termination fee	$ 240,000
Marlinspike Group, LLC | Carlsbad, California | 2019 Consulting Agreement
Related Party Transaction [Line Items]
Area of office space | ft²			2,120
Aseem Z. Ansari, Ph.D. | Convertible Notes and Notes Payable
Related Party Transaction [Line Items]
Convertible notes issued								$ 300,000	$ 300,000
Debt instrument interest rate									8.00%
Percentage of selling price per share that can convertible into equity securities sold									80.00%
Aseem Z. Ansari, Ph.D. | Convertible Notes and Notes Payable | Series A Preferred Stock
Related Party Transaction [Line Items]
Convertible preferred stock converted | shares		171,025
Aseem Z. Ansari, Ph.D. | May Note
Related Party Transaction [Line Items]
Maturity description					on or after February 5, 2021, if not converted earlier
Aseem Z. Ansari, Ph.D. | July Note
Related Party Transaction [Line Items]
Maturity description					on or after February 5, 2021, if not converted earlier
Aseem Z. Ansari, Ph.D. | Consulting Agreements
Related Party Transaction [Line Items]
Monthly fee for services				$ 15,000

Related Party Transactions - Su

Related Party Transactions - Summary of Expenses Recognized under Consulting Agreement (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Related Party Transaction [Line Items]
Research and development (including related party amounts of $98, $0, $188 and $8, respectively)	$ 8,539	$ 1,914	$ 17,441	$ 3,352
General and administrative (including related party amounts of $82, $60, $202 and $232, respectively)	2,798	489	7,263	1,310
Lease Agreement
Related Party Transaction [Line Items]
Research and development (including related party amounts of $98, $0, $188 and $8, respectively)	53		53
General and administrative (including related party amounts of $82, $60, $202 and $232, respectively)	22		22
Total expenses	75		75
Research Consulting Agreements
Related Party Transaction [Line Items]
Research and development (including related party amounts of $98, $0, $188 and $8, respectively)	45		135
Total expenses	45		135
Marlinspike Group, LLC | Consulting Agreements
Related Party Transaction [Line Items]
Research and development (including related party amounts of $98, $0, $188 and $8, respectively)				8
General and administrative (including related party amounts of $82, $60, $202 and $232, respectively)	60	60	180	232
Total expenses	$ 60	$ 60	$ 180	$ 240