Prometheus Biosciences (RXDX) 10-Q 11 Aug 22 2022 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2022	Aug. 08, 2022
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2022
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q2
Current Fiscal Year End Date	--12-31
Entity Registrant Name	PROMETHEUS BIOSCIENCES, INC.
Entity Central Index Key	0001718852
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		40,904,098
Entity File Number	001-40187
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	81-4282653
Entity Address, Address Line One	3050 Science Park Road
Entity Address, City or Town	San Diego
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	92121
City Area Code	858
Local Phone Number	422-4300
Title of 12(b) Security	Common Stock, $0.0001 par value per share
Trading Symbol	RXDX
Security Exchange Name	NASDAQ
Document Quarterly Report	true
Document Transition Report	false

Unaudited Condensed Balance She

Unaudited Condensed Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Current assets
Cash and cash equivalents	$ 95,959	$ 257,254
Short term investments	115,823
Accounts receivable	1,865	1,079
Prepaid expenses and other current assets	5,703	7,050
Total current assets	219,350	265,383
Property and equipment, net	2,891	1,447
Right-of-use asset	14,377
Other assets	971	971
Total assets	237,589	267,801
Current liabilities
Accounts payable	462	1,153
Accrued compensation	2,854	5,378
Accrued expenses and other current liabilities	10,058	6,050
Payable to PLI	110	193
Deferred revenue	1,781	3,668
Lease liabilities, current portion	1,202
Total current liabilities	16,467	16,442
Deferred revenue, non-current	15,733	16,204
Lease liabilities, net of current portion	13,558
Total liabilities	45,758	32,646
Commitments and contingencies (Note 9)
Stockholders’ equity:
Preferred stock—$0.0001 par value; 40,000,000 shares authorized at June 30, 2022 and December 31, 2021; No shares issued and outstanding at June 30, 2022 and December 31, 2021
Common stock—$0.0001 par value; 400,000,000 shares authorized as of June 30, 2022 and December 31, 2021; 39,699,667 shares and 38,960,716 shares issued at June 30, 2022 and December 31, 2021, respectively; 39,690,686 shares and 38,943,110 shares outstanding at June 30, 2022 and December 31, 2021, respectively;	4	4
Additional paid-in capital	447,191	424,492
Accumulated other comprehensive loss	(310)
Accumulated deficit	(255,054)	(189,341)
Total stockholders’ equity	191,831	235,155
Total liabilities and stockholders’ equity	$ 237,589	$ 267,801

Unaudited Condensed Balance S_2

Unaudited Condensed Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2022	Dec. 31, 2021
Statement Of Financial Position [Abstract]
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	40,000,000	40,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	400,000,000	400,000,000
Common stock, shares issued	39,699,667	38,960,716
Common stock, shares outstanding	39,690,686	38,943,110

Unaudited Condensed Statements

Unaudited Condensed Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Income Statement [Abstract]
Collaboration revenue	$ 1,269	$ 326	$ 5,188	$ 1,086
Operating expenses:
Research and development	25,918	13,554	53,848	21,312
General and administrative	9,319	5,618	17,405	10,840
Total operating expense	35,237	19,172	71,253	32,152
Loss from operations	(33,968)	(18,846)	(66,065)	(31,066)
Other income (expense), net:
Interest income	321	37	352	55
Interest expense		(190)		(848)
Change in fair value of preferred stock purchase right liability				(980)
Change in fair value of preferred stock warrant liability				(105)
Total other income (expense), net	321	(153)	352	(1,878)
Net loss	(33,647)	(18,999)	(65,713)	(32,944)
Other comprehensive loss:
Unrealized loss on available-for-sale securities, net	(310)		(310)
Comprehensive loss	$ (33,957)	$ (18,999)	$ (66,023)	$ (32,944)
Net loss per share, basic	$ (0.86)	$ (0.49)	$ (1.68)	$ (1.39)
Net loss per share, diluted	$ (0.86)	$ (0.49)	$ (1.68)	$ (1.39)
Weighted average shares outstanding, basic	39,242,839	38,813,865	39,125,850	23,660,559
Weighted average shares outstanding, diluted	39,242,839	38,813,865	39,125,850	23,660,559

Unaudited Condensed Statement_2

Unaudited Condensed Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Convertible Preferred Stock	Series D-2 Convertible Preferred Stock	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit
Beginning Balance at Dec. 31, 2020	$ (97,541)				$ 1,605		$ (99,146)
Temporary Equity, Balance, shares at Dec. 31, 2020		160,864,434
Temporary Equity, Balance at Dec. 31, 2020		$ 126,023
Balance, shares at Dec. 31, 2020				1,713,622
Issuance of convertible preferred stock for cash, net of issuance costs			$ 73,763
Issuance of convertible preferred stock for cash, net of issuance costs, shares			86,775,740
Issuance of convertible preferred stock for settlement of deferred purchase price			$ 6,144
Issuance of convertible preferred stock for settlement of deferred purchase price			7,219,560
Reclassification of convertible preferred stock purchase right liability		$ 4,880
Conversion of convertible preferred stock into common stock at initial public offering	210,810			$ 3	210,807
Temporary Equity, Conversion of convertible preferred stock into common stock at initial public offering, shares		(254,859,734)
Temporary Equity, Conversion of convertible preferred stock into common stock at initial public offering		$ (210,810)
Conversion of convertible preferred stock into common stock at initial public offering, shares				25,485,955
Issuance of shares of common stock in initial public offering for cash, net of issuance costs	199,838			$ 1	199,837
Issuance of shares of common stock in initial public offering for cash, net of issuance costs, shares				11,500,000
Reclassification of convertible preferred stock warrants	169				169
Issuance of common stock in exchange for services	3				3
Issuance of common stock in exchange for services, shares				500
Issuance costs related to initial public offering				$ 18,662
Issuance of common stock upon exercise of stock options	64				64
Issuance of common stock upon exercise of stock options, shares				56,645
Vesting of early exercised stock options	9				9
Vesting of early exercised stock options, shares				12,981
Stock-based compensation	792				792
Net loss	(13,945)						(13,945)
Ending Balance at Mar. 31, 2021	300,199			$ 4	413,286		(113,091)
Balance, shares at Mar. 31, 2021				38,769,703
Beginning Balance at Dec. 31, 2020	(97,541)				1,605		(99,146)
Temporary Equity, Balance, shares at Dec. 31, 2020		160,864,434
Temporary Equity, Balance at Dec. 31, 2020		$ 126,023
Balance, shares at Dec. 31, 2020				1,713,622
Vesting of early exercised stock options	18
Net loss	(32,944)
Ending Balance at Jun. 30, 2021	282,428			$ 4	414,514		(132,090)
Balance, shares at Jun. 30, 2021				38,835,067
Beginning Balance at Mar. 31, 2021	300,199			$ 4	413,286		(113,091)
Balance, shares at Mar. 31, 2021				38,769,703
Issuance costs related to initial public offering	(46)				(46)
Issuance of common stock upon exercise of stock options	62				62
Issuance of common stock upon exercise of stock options, shares				54,561
Vesting of early exercised stock options	9				9
Vesting of early exercised stock options, shares				10,803
Stock-based compensation	1,203				1,203
Net loss	(18,999)						(18,999)
Ending Balance at Jun. 30, 2021	282,428			$ 4	414,514		(132,090)
Balance, shares at Jun. 30, 2021				38,835,067
Beginning Balance at Dec. 31, 2021	$ 235,155			$ 4	424,492		(189,341)
Balance, shares at Dec. 31, 2021	38,943,110			38,943,110
Issuance of common stock upon exercise of stock options	$ 349				349
Issuance of common stock upon exercise of stock options, shares				142,391
Vesting of early exercised stock options	6				6
Vesting of early exercised stock options, shares				4,311
Stock-based compensation	3,279				3,279
Net loss	(32,066)						(32,066)
Ending Balance at Mar. 31, 2022	206,723			$ 4	428,126		(221,407)
Balance, shares at Mar. 31, 2022				39,089,812
Beginning Balance at Dec. 31, 2021	$ 235,155			$ 4	424,492		(189,341)
Balance, shares at Dec. 31, 2021	38,943,110			38,943,110
Issuance of common stock upon exercise of stock options, shares	163,675
Vesting of early exercised stock options	$ 12
Vesting of early exercised stock options, shares	8,625
Net loss	$ (65,713)
Ending Balance at Jun. 30, 2022	$ 191,831			$ 4	447,191	$ (310)	(255,054)
Balance, shares at Jun. 30, 2022	39,690,686			39,690,686
Beginning Balance at Mar. 31, 2022	$ 206,723			$ 4	428,126		(221,407)
Balance, shares at Mar. 31, 2022				39,089,812
Issuance of shares of common stock in initial public offering for cash, net of issuance costs	13,979				13,979
Issuance of shares of common stock in initial public offering for cash, net of issuance costs, shares				555,297
Issuance of common stock upon exercise of stock options	98				98
Issuance of common stock upon exercise of stock options, shares				21,284
Issuance of common stock under employee stock purchase plan	346				346
Issuance of common stock under employee stock purchase plan, shares				19,979
Vesting of early exercised stock options	6				6
Vesting of early exercised stock options, shares				4,314
Stock-based compensation	4,636				4,636
Unrealized loss on marketable securities	(310)					(310)
Net loss	(33,647)						(33,647)
Ending Balance at Jun. 30, 2022	$ 191,831			$ 4	$ 447,191	$ (310)	$ (255,054)
Balance, shares at Jun. 30, 2022	39,690,686			39,690,686

Unaudited Condensed Statement_3

Unaudited Condensed Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2022	Mar. 31, 2021
Series D-2 Convertible Preferred Stock
Temporary stock, issuance costs		$ 94
Common Stock
Financing costs, net	$ 1,184
Stock issuance costs		$ 18,662

Unaudited Condensed Statement_4

Unaudited Condensed Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Cash flows from operating activities
Net loss	$ (65,713)	$ (32,944)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	248	95
Stock-based compensation expenses	7,915	1,995
Amortization of premiums and discounts on marketable securities, net	(158)
Noncash lease expense	220
Change in fair value of preferred stock purchase right liability		980
Change in fair value of preferred stock warrant liability		105
Common stock issued in exchange for services		3
Noncash interest expense		540
Changes in operating assets and liabilities:
Accounts receivable	(786)	869
Prepaid expenses and other current assets	1,395	(4,815)
Other assets		(468)
Accounts payable	(539)	1,143
Accrued compensation	(2,524)	(325)
Accrued expenses and other current liabilities	3,985	114
Payable to PLI	(83)	(897)
Deferred revenue	(2,357)	9,254
Operating lease liabilities	162
Net cash used in operating activities	(58,235)	(24,351)
Cash flows from investing activities
Purchases of property and equipment	(1,843)	(580)
Purchases of marketable securities	(115,975)
Net cash used in investing activities	(117,818)	(580)
Cash flows from financing activities
Proceeds from issuance of convertible preferred stock, net of issuance costs		73,749
Proceeds from sale of common stock in initial public offering		218,500
Proceeds from sale of common stock in public offerings, gross	15,163
Payment of financing costs	(1,172)	(17,256)
Proceeds from issuance of common stock upon stock option exercises	421	126
Proceeds from issuance of common stock under employee stock purchase plan	346
Net cash provided by financing activities	14,758	275,119
Net (decrease) increase in cash and cash equivalents	(161,295)	250,188
Cash and cash equivalents at beginning of period	257,254	54,201
Cash and cash equivalents cash at end of period	95,959	304,389
Supplemental schedule of non-cash investing and financing activities
Conversion of convertible preferred stock into common stock upon completion of initial public offering		210,810
Reclassification of preferred stock purchase right liability to equity due to issuance of Series D convertible preferred stock		4,880
Reclassification of warrant liability to equity due to conversion from preferred stock warrant to common stock warrant upon completion of initial public offering		169
Issuance of Series D-2 convertible preferred stock for the settlement of deferred purchase price		6,144
Financing costs incurred, but not paid, included in accrued expenses and accounts payable	12
Vesting of early exercised stock options	12	18
Costs incurred, but not paid, in connection with capital expenditures included in accounts payable	$ 25	$ 208

Organization

Organization	6 Months Ended
	Jun. 30, 2022
Accounting Policies [Abstract]
Organization	1. Organization Prometheus Biosciences, Inc. (the Company) was incorporated in the state of Delaware on October 26, 2016 under the name Precision IBD, Inc. and is headquartered in San Diego, California. The Company changed its name to Prometheus Biosciences, Inc. on October 1, 2019. The Company’s business is focused on the discovery, development and commercialization of novel therapeutic and companion diagnostic products for the treatment of immune-mediated diseases, starting first with inflammatory bowel disease (IBD). In June 2019, the Company acquired Prometheus Laboratories, Inc. (PLI) and the related intangible assets used by PLI. PLI was wholly owned by Nestlé Health Science US Holdings, Inc. and the related intangible assets were owned by Societé Des Produits Nestlé S.A (together, Nestlé). PLI markets and conducts several laboratory developed tests useful to gastroenterologists in monitoring their IBD patients’ disease state and informing their therapeutic decisions. On December 31, 2020, the Company completed the spinoff of PLI by making an in-kind distribution of 100% of its interest in PLI to the Company’s stockholders of record on December 30, 2020. Reverse Stock Split On March 5, 2021, the Company effected a one-for-ten Initial Public Offering On March 16, 2021, the Company completed its initial public offering (IPO) with the sale of 11,500,000 shares of common stock, which included the exercise in full by the underwriters of their option to purchase 1,500,000 additional shares, at an initial public offering price of $19.00 per share and received gross proceeds of $218.5 million, which resulted in net proceeds to the Company of approximately $199.8 million, after deducting underwriting discounts and commissions of approximately $15.3 million and offering-related transaction costs of approximately $3.4 million. In addition, in connection with the completion of the IPO, all outstanding shares of convertible preferred stock were converted into 25,485,955 shares of the Company’s common stock; outstanding warrants to purchase 148,848 shares of convertible preferred stock were converted into warrants to purchase 14,884 shares of the Company’s common stock; and the Company’s certificate of incorporation was amended and restated to authorize 400,000,000 shares of common stock and 40,000,000 shares of undesignated preferred stock. Liquidity The Company has incurred net losses since inception, experienced negative cash flows from operations, and as of June 30, 2022, has an accumulated deficit of $255.1 million The Company will be required to raise additional capital, however, there can be no assurance as to whether additional financing will be available on terms acceptable to the Company, if at all. If sufficient funds on acceptable terms are not available when needed, it would have a negative impact on the Company’s financial condition and could force the Company to delay, limit, reduce, or terminate product development or future commercialization efforts or grant rights to develop and market product candidates or testing products that the Company would otherwise plan to develop.

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2022
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation and Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States (GAAP) requires management to make estimates and assumptions that impact the reported amounts of assets, liabilities, and expenses and the disclosure of contingent assets and liabilities in the Company’s condensed financial statements and accompanying notes. Although these estimates are based on the Company’s knowledge of current events and actions it may undertake in the future, actual results may materially differ from these estimates and assumptions. On an ongoing basis, management evaluates its estimates, primarily related to revenue recognition, stock-based compensation, marketable securities, accrued research and development costs, and the incremental borrowing rate for lease liabilities. These estimates are based on historical data and experience, as well as various other factors that management believes to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying value of assets and liabilities that are not readily apparent from other sources. Estimates relating to the valuation of stock require the selection of appropriate valuation methodologies and models, and significant judgment in evaluating ranges of assumptions and financial inputs. Unaudited Interim Financial Information The unaudited financial statements at June 30, 2022, and for the three and six months ended June 30, 2022 and 2021, have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission (SEC), and with GAAP applicable to interim financial statements. These unaudited financial statements have been prepared on the same basis as the audited financial statements and include all adjustments, consisting of only normal recurring accruals, which in the opinion of management are necessary to present fairly the Company’s financial position as of the interim date and results of operations for the interim periods presented. Interim results are not necessarily indicative of results for a full year or future periods. The preparation of financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period. Actual results could differ materially from those estimates. These unaudited financial statements should be read in conjunction with the Company’s audited financial statements for the year ended December 31, 2021, included in the Annual Report on Form 10-K filed with the SEC on March 9, 2022. Segment Reporting Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by management in making decisions regarding resource allocation and assessing performance. The Company manages its operations as a single operating segment in the United States for the purposes of assessing performance and making operating decisions. Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity of three months or less when purchased to be cash equivalents. The cash and cash equivalents balance at June 30, 2022 represents cash in readily available checking and money market accounts, and commercial paper. The cash and cash equivalents balance at December 31, 2021 represents cash in readily available checking and money market accounts. Marketable Securities The Company’s marketable securities primarily consist of commercial paper and U.S. government and agency securities classified within cash and cash equivalents and short term investments depending on their maturity date at the time of purchase. The Company classifies its marketable securities as available-for-sale and records such assets at estimated fair value in the condensed balance sheets, with unrealized gains and losses, if any, reported as a component of other comprehensive income (loss) within the condensed statements of operations and comprehensive loss and as a separate component of stockholders’ equity. The Company classifies marketable securities with remaining maturities greater than one year as current assets because such marketable securities are available to fund the Company’s current operations. Realized gains and losses are calculated on the specific identification method and recorded as interest income (loss). There were no realized gains and losses during any of the periods presented. At each balance sheet date, the Company assesses available-for-sale securities in an unrealized loss position to determine whether the unrealized loss is other-than-temporary. When the Company determines that a decline in the fair value below its cost basis is other-than-temporary, the Company recognizes an impairment loss in the period in which the other-than-temporary decline occurred. There have been no other-than-temporary impairments recognized during any of the periods presented. Concentration of Credit Risk Financial instruments, which potentially subject the Company to concentration of credit risk, consist primarily of cash, cash equivalents, short term investments, and accounts receivable. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. Management believes that the Company is not exposed to significant credit risk due to the financial position of the depository institutions in which those deposits are held. Accounts Receivable Accounts receivable is stated at the original invoice amount and consists of certain research and development and contract manufacturing costs subject to reimbursement under the Company’s collaboration agreements. The Company did not record any credit losses as of June 30, 2022 and December 31, 2021. Property and Equipment, Net Property and equipment is stated at cost less accumulated depreciation. Depreciation is recorded using the straight-line method over the estimated useful lives of the related assets, which ranges from two to ten years. Repairs and maintenance charges that do not increase the useful life of the assets are charged to operating expenses as incurred. Long-Lived Assets The Company’s long-lived assets are comprised principally of its property and equipment. If the Company identifies a change in the circumstances related to its long-lived assets that indicates the carrying value of any such asset may not be recoverable, the Company will perform an impairment analysis. A long-lived asset is not recoverable when the undiscounted cash flows expected to be generated by the asset (or asset group) are less than the asset’s carrying amount. Any required impairment loss would be measured as the amount by which the asset’s carrying value exceeds its fair value, and would be recorded as a reduction in the carrying value of the related asset and a charge to operating expense. Revenue Recognition The Company recognizes revenue in accordance with ASC Topic 606, Revenue from Contracts with Customers (ASC 606). In accordance with ASC 606, the Company performs the following steps in determining the appropriate amount of revenue to be recognized as it fulfills its obligations under each of these agreements: (i) identification of the promised goods or services in the contract; (ii) determination of whether the promised goods or services are performance obligations including whether they are distinct in the context of the contract; (iii) measurement of the transaction price, including the constraint on variable consideration; (iv) allocation of the transaction price to the performance obligations; and (v) recognition of revenue when, or as, the Company satisfies each performance obligation. At contract inception, once the contract is determined to be within the scope of ASC 606, the Company assesses the goods or services promised within each contract and determines those that are performance obligations and assesses whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. To date, all of the Company’s collaboration revenue has been derived from its collaboration agreement with Dr. Falk Pharma GmbH and its collaboration agreement with Millennium Pharmaceuticals, Inc., a subsidiary of Takeda Pharmaceutical Company Limited (collectively, Takeda) as described in Note 5. The terms of these arrangements include the following types of payments to the Company: non-refundable, up-front license fees; development, regulatory and commercial milestone payments; payments for research and development services provided by the Company; and royalties on net sales of licensed products. At the initiation of an agreement, the Company analyzes whether each unit of account results in a contract with a customer under ASC 606 or in an arrangement with a collaborator subject to guidance under ASC 808, Collaborative Arrangements (ASC 808). The Company considers a variety of factors in determining the appropriate estimates and assumptions under these arrangements, such as whether the elements are distinct performance obligations, whether there are observable stand-alone prices, and whether any licenses are functional or symbolic. The Company evaluates each performance obligation to determine if it can be satisfied and recognized as revenue at a point in time or over time. Typically, license fees, non-refundable upfront fees, and funding of research activities are considered fixed, while milestone payments are identified as variable consideration which must be evaluated to determine if it is constrained and, therefore, excluded from the transaction price. The Company estimates the amount of variable consideration using the most likely amount, as milestone payments typically only have two possible outcomes. The Company recognizes revenue for sales-based royalty promised in exchange for the license of intellectual property only when the subsequent sale occurs. The Company may allocate transaction price using a number of methods including estimating standalone selling price of performance obligations and using the residual approach when the standalone selling price of the license is highly variable or uncertain, and observable standalone selling prices exist for the other goods or services promised in the contract. The Company receives payments from its collaborators based on terms established in each contract. Upfront payments and other payments may require deferral of revenue recognition to a future period until the Company is unconditional. The Company does not assess whether a contract has a significant financing component if the expectation at contract inception is such that the payment by the customer is akin to a deposit for research and development services. Research and Development and Clinical Trial Accruals Research and development costs are charged to expense as incurred. Research and development expenses include certain payroll and personnel expenses, laboratory supplies, consulting costs, external contract research and development expenses, and allocated overhead, including rent, information technology, property and equipment depreciation and utilities. Advance payments for goods or services for future research and development activities are deferred and expensed as the goods are delivered or the related services are performed. The Company estimates preclinical studies and clinical trial expenses based on the services performed pursuant to contracts with research institutions and clinical research organizations that conduct and manage preclinical studies and clinical trials on the Company’s behalf. In addition, clinical study and trial materials are manufactured by contract manufacturing organizations. In accruing for these services, the Company estimates the time period over which services will be performed and the level of effort to be expended in each period. These estimates are based on communications with the third-party service providers and the Company’s estimates of accrued expenses and on information available at each balance sheet date. If the actual timing of the performance of services or the level of effort varies from the estimate, the Company will adjust the accrual accordingly. Fair Value Measurements Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. 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. Stock-Based Compensation The Company expenses stock-based compensation to employees and non-employees related to stock options, restricted stock units, and shares granted under the Company’s 2021 Employee Stock Purchase Plan (the ESPP). Stock-based compensation expense represents the cost of the grant date fair value of applicable awards recognized over the requisite service period (usually the vesting period) on a straight-line basis, net of actual forfeitures during the period. The Company estimates the fair value of stock options and shares purchased under the ESPP using the Black-Scholes option pricing model, and the assumptions used in calculating the fair value of stock-based awards represent management’s best estimates and involve inherent uncertainties and the application of management’s judgment. Valuation of Common Stock Prior to the IPO, given the absence of a public trading market for the Company’s common stock, the Company’s board of directors exercised their judgment and considered a number of objective and subjective factors to determine the best estimate of the fair value of the Company’s common stock, such as: contemporaneous valuations performed by independent third-party specialists, its stage of development, including the status of its research and development efforts of its product candidates, the material risks related to its businesses and industry, its results of operations before discontinued operations and financial position, including its levels of capital resources, the prices at which its sold shares of its convertible preferred stock, the rights, preferences and privileges of its convertible preferred stock relative to those of its common stock, the conditions in the biotechnology industry and the economy in general, the stock price performance and volatility of comparable life sciences public companies, as well as recently completed mergers and acquisitions of peer companies, the likelihood of achieving a liquidity event for the holders of its common stock or convertible preferred stock, such as an IPO or a sale of the Company given prevailing market conditions, trends and developments in its industry, external market conditions affecting the life sciences and biotechnology sectors, and the lack of liquidity of its common stock, among other factors. After the completion of the IPO, the fair value of each share of common stock is based on the closing price of the Company’s common stock as reported by the Nasdaq Global Select Market. Preferred Stock Purchase Right Liabilities From time to time, the Company entered into convertible preferred stock financings where, in addition to the initial closing, investors agreed to buy, and the Company agreed to sell, additional shares of that convertible preferred stock at a fixed price in the event that certain conditions are met, or agreed upon milestones are achieved. The Company evaluated this purchase right and assessed whether it met the definition of a freestanding instrument and, if so, determined the fair value of the purchase right liability and recorded it on the balance sheet with the remainder of the proceeds raised allocated to convertible preferred stock. The preferred stock purchase right liability was revalued at each reporting period with changes in the fair value of the liability recorded as change in fair value of preferred stock purchase right liability in the statements of operations. Upon the issuance of the shares of Series D-2 convertible preferred stock in January 2021, the no longer required liability accounting and the then fair value of the was reclassified into stockholders’ equity. The Company performed the final remeasurement of the preferred stock purchase right liability Comprehensive Loss Comprehensive loss is defined as the change in equity during a period from transactions and other events and circumstances from non-owner sources, including unrealized gains and losses on marketable securities. Comprehensive gains (losses) have been reflected in the statements of operations and comprehensive loss for all periods presented Net Loss Per Share Basic net loss per share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted average number of common shares outstanding during the period. Diluted net loss per share attributable to common stockholders is computed by dividing the net loss attributable to common stockholders by the weighted average number of common stock equivalents outstanding for the period determined using the treasury-stock method. The Company has excluded 11,084 and 13,231 weighted average shares subject to repurchase or forfeiture from the weighted average number of common shares outstanding for the three and six months ended June 30, 2022, respectively, and 35,369 and 41,654 weighted average shares subject to repurchase or forfeiture from the weighted average number of common shares outstanding for the three and six months ended June 30, 2021, respectively Basic and diluted net loss attributable to common holders per share is presented in conformity with the two- class method required for participating securities as the convertible preferred stock are considered participating securities. The Company’s participating securities do not have a contractual obligation to share in the Company’s losses. As such, the net loss was attributed entirely to common stockholders. Accordingly, for the three and six months ended June 30, 2022 and 2021, there is no difference in the number of shares used to calculate basic and diluted shares outstanding. Potentially dilutive securities not included in the calculation of diluted net loss per share because to do so would be anti-dilutive are as follows (in common stock equivalent shares): June 30, 2022 2021 Common stock options issued and outstanding 7,544,646 5,190,989 Warrants to purchase common stock 14,884 14,884 ESPP shares pending issuance 9,072 12,536 Total 7,568,602 5,218,409 Recent Accounting Standards From time to time, new accounting standards are issued by the Financial Accounting Standards Board (FASB) or other standard setting bodies and adopted by the Company as of the specified effective date. Unless otherwise discussed, the impact of recently issued standards that are not yet effective will not have a material impact on the Company’s financial position or results of operations upon adoption. In April 2012, the Jump-Start Our Business Startups Act (the JOBS Act) was signed into law. The JOBS Act contains provisions that, among other things, reduce certain reporting requirements for an emerging growth company. As an emerging growth company, the Company may elect to adopt new or revised accounting standards when they become effective for non-public companies, which typically is later than when public companies must adopt the standards. The Company has elected to take advantage of the extended transition period afforded by the JOBS Act and, as a result, will comply with new or revised accounting standards on the relevant dates on which adoption of such standards is required for emerging growth companies .

Fair Value Measurements and Fai

Fair Value Measurements and Fair Value of Financial Instruments	6 Months Ended
	Jun. 30, 2022
Fair Value Disclosures [Abstract]
Fair Value Measurements and Fair Value of Financial Instruments	3. The 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 nonrecurring 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 — Quoted prices in active markets for identical assets or liabilities. Level 2 — Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3 — Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. Assets and liabilities measured at fair value are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires management to make judgments and consider factors specific to the asset or liability. The carrying amounts of prepaid and other assets, accounts payable and accrued liabilities are considered to be representative of their respective fair values because of the short term nature of those instruments. The following tables summarize the Company’s financial instruments measured at fair value on a recurring basis (in thousands): Fair Value Measurements At Reporting Date Using Total Quoted Prices in Active Markets For Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) As of June 30, 2022 Assets: Cash and cash equivalents: Money market funds $ 755 $ 755 $ — $ — Commercial paper 33,323 — 33,323 — Total cash and cash equivalents 34,078 755 33,323 — Short term investments: Commercial paper $ 99,911 $ — $ 99,911 $ — U.S. government and agency securities 15,912 15,912 — — 115,823 15,912 99,911 — Total assets measured at fair value $ 149,901 $ 16,667 $ 133,234 $ — The Company had no financial instruments measured at fair value as of December 31, 2021. The Company determines the fair value of its marketable securities based on one or more valuations from its investment accounting and reporting service provider. The investment service provider values the securities using a hierarchical security pricing model that relies primarily on valuations provided by an industry-recognized valuation service. Such valuations may be based on trade prices in active markets for identical assets (Level 1 inputs) or valuation models using inputs that are observable either directly or indirectly (Level 2 inputs), such as quoted prices for similar assets, yield curves, volatility factors, credit spreads, default rates, loss severity, current market and contractual prices for the underlying instruments or debt, and broker and dealer quotes, as well as other relevant economic measures. There were no transfers within the hierarchy during the three and six months ended June 30, 2022 and 2021. At December 31, 2020, Level 3 liabilities that were measured at fair value on a recurring basis consisted of warrants to purchase shares of convertible preferred stock and a preferred stock purchase right liability. The Company had no Level 3 liabilities at June 30, 2022 and December 31, 2021 as the liabilities for the warrants to purchase shares of convertible preferred stock and the preferred stock purchase right was remeasured and reclassified to stockholders’ equity upon the closing of the Company’s IPO in March 2021 and the issuance of shares of Series D-2 convertible preferred stock in January 2021, respectively. Convertible Preferred Stock Warrant Liability The convertible preferred stock warrant liability was recorded at fair value utilizing the Black-Scholes option pricing model using significant unobservable inputs consistent with the inputs used for the Company’s stock-based compensation expense adjusted for the preferred stock warrants’ expected term and the fair value of the underlying preferred stock. The assumptions used in the Black-Scholes option pricing model to determine the fair value of the convertible preferred stock warrant liability at the date of the IPO were as follows: IPO Date Fair value of underlying preferred stock $ 1.90 Risk-free interest rate 1.70 % Expected volatility 70.00 % Expected term (in years) 9.0 Expected dividend yield —% Preferred Stock Purchase Right Liability Upon the issuance of the shares of Series D-2 convertible preferred stock in January 2021, the liability was remeasured using a valuation model that considered: (i) the risk-free rate commensurate with the expected milestone timing of 0.09%; (ii) the probability of the Series D-2 tranche of 80.0%; (iii) volatility of 80.0%; (iv) consideration received for the Series D-1 preferred stock; (v) the number of shares to be issued to satisfy the preferred stock purchase right and at what price; and (vi) certain implied and provided assumptions needed to calibrate the Series D-1 value and the Series D-2 purchase right, and as Activity of Liabilities Using Fair Value Level 3 Measurements The following table summarizes the activity of the financial instruments valued using Level 3 inputs (in thousands): Convertible Preferred Stock Warrant Liability Series D Convertible Preferred Stock Purchase Right Liability Balance at December 31, 2020 $ 64 $ 3,900 Change in fair value 105 980 Conversion/Settlement during 2021 (169 ) (4,880 ) Balance at June 30, 2021 $ — $ —

Marketable Securities

Marketable Securities	6 Months Ended
	Jun. 30, 2022
Investments Debt And Equity Securities [Abstract]
Marketable Securities	4 . . The following tables summarize marketable securities (in thousands): As of June 30, 2022 Unrealized Maturity (in years) Amortized Cost Unrealized Gains Unrealized Losses Estimated Fair Value Cash and cash equivalents: Money market funds $ 755 $ — $ — $ 755 Commercial paper one or less 33,351 (28 ) 33,323 Total cash and cash equivalents $ 34,106 $ — $ (28 ) $ 34,078 Short term investments: Commercial paper one or less $ 100,170 $ — $ (259 ) $ 99,911 U.S. government and agency securities one or less 15,935 — (23 ) 15,912 Total short term investments $ 116,105 $ — $ (282 ) $ 115,823 Total marketable securities $ 150,211 $ — $ (310 ) $ 149,901 As of June 30, 2022, none of the marketable securities held have been in an unrealized loss position for greater than 12 months. The Company does not intend to sell these investments and it is not likely that the Company will be required to sell these investments before recovery of their amortized cost basis. Accordingly, no allowance for credit losses was recorded. There were no marketable securities as of December 31, 2021.

Balance Sheet Details

Balance Sheet Details	6 Months Ended
	Jun. 30, 2022
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Details	5 . Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consist of the following (in thousands): June 30, 2022 December 31, 2021 Prepaid contract manufacturing expenses $ 930 $ 3,808 Prepaid clinical trial expenses 2,069 1,397 Prepaid research and development expenses 503 627 Other prepaid expenses 2,201 1,218 Total $ 5,703 $ 7,050 Property and equipment, Net Property and equipment, net, consist of the following (in thousands): June 30, 2022 December 31, 2021 Laboratory equipment $ 2,579 $ 1,830 Computer equipment 493 24 Office equipment and furniture 474 — 3,546 1,854 Less accumulated depreciation (655 ) (407 ) Total $ 2,891 $ 1,447 Depreciation expense related to property and equipment was $0.2 million and $0.1 million for the three months ended June 30, 2022 and 2021, respectively, and $0.2 million and $0.1 million for the six months ended June 30, 2022 and 2021, respectively. Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consist of the following (in thousands): June 30, 2022 December 31, 2021 Accrued research and development $ 2,841 $ 2,123 Accrued clinical trial expenses 3,635 1,999 Accrued contract manufacturing expenses 2,689 906 Accrued legal expenses 433 531 Unvested early exercise liability 22 35 Accrued other 438 456 Total $ 10,058 $ 6,050

Collaboration and License Agree

Collaboration and License Agreements	6 Months Ended
	Jun. 30, 2022
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Collaboration and License Agreements	6. Collaboration and License Agreements Exclusive License Agreement with Cedars-Sinai Medical Center In September 2017, the Company entered into an Exclusive License Agreement with Cedars-Sinai Medical Center (Cedars-Sinai), a related party, as amended and restated (the Cedars-Sinai Agreement). Under the terms of the Cedars-Sinai Agreement, Cedars-Sinai granted the Company an exclusive, worldwide, royalty bearing license with respect to certain patent rights, information and materials related to therapeutic targets and companion diagnostic products, in each case to conduct research, develop, and commercialize therapeutic and diagnostic products for human use. The licensed technology includes information and materials arising out of Cedars-Sinai’s database and biobank, as well as exclusive access to this database and biobank, which is an integral part of the Company’s Prometheus360 platform. In August 2021, the Company and Cedars-Sinai amended and restated the Cedars-Sinai Agreement to, among other things, add a joint steering committee and cover new intellectual property. As consideration for the license rights, in September 2017 the Company issued (i) 257,500 shares of fully vested common stock, and (ii) 335,000 shares of unvested restricted common stock, all of which is vested as of December 31, 2020. The fair value of all of the shares were measured at the date of issuance. The shares of unvested restricted common stock had vesting conditions tied to continuing services required of certain Cedars-Sinai employees pursuant to consulting agreements with the Company. One third of the restricted shares were released from restriction annually on the anniversary of the Cedars-Sinai Agreement over a three-year Co-Development and Manufacturing Agreement with Dr. Falk Pharma GmbH In July 2020, the Company entered into a Co-Development and Manufacturing Agreement (the Falk Agreement) with Dr. Falk Pharma GMBH (Falk), pursuant to which the parties will co-develop and commercialize, exclusively in their respective territories, therapeutic product candidates targeting members of the TNF super family for the treatment of UC and CD under the Company’s PRA052 program. Under the Falk Agreement, the Company is obligated to use commercially reasonable efforts to conduct development activities under an agreed development plan and the Company is responsible for regulatory approvals and commercialization of any products in the United States and the rest of the world, other than the Falk territory. Falk is responsible for regulatory approvals and commercialization of any products in the European Union, United Kingdom, Switzerland, the countries of the European Economic Area (excluding Malta and the Republic of Cyprus), Australia and New Zealand (Falk territory). Falk agreed to fund 25% of the Company’s third-party development costs set forth in the development plan. Under the agreement, Falk paid the Company an upfront payment of $2.5 million and made a second payment of $2.5 million following the parties’ mutual agreement on the development plan. In addition, in June 2021, Falk made a milestone payment to the Company of $10 million upon the selection of a clinical candidate for the PRA052 program and, in December 2021, Falk made the final milestone payment of $5 million, based on the Company’s . The Company has identified one performance obligation for all the deliverables under the Falk Agreement. Accordingly, the Company is recognizing revenue for the transaction price allocated to the performance obligation in an amount proportional to the collaboration expenses incurred and the total estimated collaboration expenses over the eight-year The Company included the upfront payment and all milestone payments in the transaction price as it was deemed not probable of significant reversal at the inception of the agreement. In connection with the Falk Agreement, the Company recognized revenue of $1.3 million and $0.3 million for the three months ended June 30, 2022 and 2021, respectively, and $4.0 million and $0.3 million for the six months ended June 30, 2022 and 2021 , respectively eight-year . Companion Diagnostics Development Agreement with Millennium Pharmaceuticals, Inc. In March 2019, the Company entered into a Companion Diagnostics Development and Collaboration Agreement (the Takeda Agreement) with Millennium Pharmaceuticals, Inc., a wholly-owned subsidiary of Takeda. , respectively A reconciliation of deferred revenue related to the Falk Agreement and the Takeda Agreement for the six months ended June 30, 2022 is as follows (in thousands): Falk Agreement Takeda Agreement Total Balance at December 31, 2021 $ 18,691 $ 1,181 $ 19,872 Amounts received in 2022 2,830 — $ 2,830 Revenue recognized in 2022 (4,007 ) (1,181 ) $ (5,188 ) Balance at June 30, 2022 $ 17,514 $ — $ 17,514

Long Term Debt

Long Term Debt	6 Months Ended
	Jun. 30, 2022
Debt Disclosure [Abstract]
Long Term Debt	7 . Long Term Debt In January 2020, the Company entered into a Loan and Security Agreement (the Loan Agreement) with Oxford Finance LLC and its affiliates (Oxford) (the Oxford Loan) which provided up to $25.0 million, of which $7.5 million was drawn upon execution of the agreement. Interest accrued at an annual rate at the greater of (a) the 30-day U.S. LIBOR rate reported the last business day of the month that immediately precedes the month in which the interest will accrue, or (b) 2.01%, plus 5.98%, with a minimum annual rate of 7.99%. From March 1, 2020 through February 28, 2023, the Company was required to make interest only payments. Beginning March 1, 2023, in addition to interest payments, the monthly payments were to include an amount equal to the outstanding principal divided by 24 months. At maturity (or earlier prepayment), the Company was also required to make a final payment equal to 4.0% of the original principal amount borrowed and 3% of the future amount to be funded. The Loan Agreement was collateralized by substantially all the Company’s assets, excluding intellectual property, which was subject to a negative pledge. In connection with execution of the Loan Agreement, the Company issued Oxford a warrant to purchase 112,500 shares of the Company’s Series C convertible preferred stock at an exercise price of $1.00 per share, exercisable at any time following issuance. The preferred stock warrant has a term of ten years. The warrant became exercisable for an aggregate of 14,884 shares of the Company’s common stock at an exercise price of $7.558 per share upon the completion of the Company’s IPO. In July 2021, the Company voluntarily prepaid the aggregate outstanding principal balance of $7.5 million plus an additional $0.5 million consisting of the prepayment penalty, accrued interest, and final payment due under the terms of the Oxford Loan, and the Loan Agreement was terminated in accordance with its terms. All liens and security interests securing the Oxford Loan were released upon termination. The Company recognized a $0.6 million loss on extinguishment on the Company’s condensed statements of operations for the year ended December 31, 2021.

Stockholders' Equity (Deficit)

Stockholders' Equity (Deficit)	6 Months Ended
	Jun. 30, 2022
Equity [Abstract]
Stockholders' Equity (Deficit)	8 . Amended Certificate of Incorporation In March 2021, the Company amended its Certificate of Incorporation to authorize 400,000,000 shares of common stock and 40,000,000 shares of preferred stock. Convertible Preferred Stock In connection with the completion of the Company’s IPO on March 16, 2021, all outstanding shares of convertible preferred stock were converted into 25,485,955 shares of the Company’s common stock and outstanding warrants to purchase 148,848 shares of convertible preferred stock were converted into warrants to purchase 14,884 shares of the Company’s common stock. Series D Convertible Preferred Stock In October 2020, the Company entered into a Series D convertible preferred stock purchase agreement (Series D SPA) under which it issued 61,066,216 shares of Series D-1 convertible preferred stock, for cash, at a price of $0.7558 per share, for net proceeds of $46.2 million (the Initial Series D Closing). In addition, 5,088,851 shares of Series D-1 convertible preferred stock were issued to Nestlé in satisfaction of a deferred purchase price obligation of $3.8 million. The Series D SPA contained provisions that potentially obligated the Company to issue an additional 94,007,051 shares of Series D-2 convertible preferred stock at $0.8510 per share in an additional closing, 7,231,311 of which was issuable to Nestlé for satisfaction of deferred purchase price obligations of $6.2 million, upon the approval by the Company’s board of directors, or at the option of the investors who participated in the Initial Series D Closing, or upon the achievement of certain milestones as defined in the Series D SPA, which purchase right terminates upon certain specified events, including an initial public offering of the Company, if any. The Company determined its obligation to issue additional shares of the Company’s Series D-2 convertible preferred stock in the Initial Series D Closing represented a freestanding financial instrument that required liability accounting. This freestanding preferred stock purchase right liability for the additional closing was recorded at fair value, with changes in fair value recognized in the statements of operations. As of the Initial Series D Closing, the estimated fair value of the preferred stock purchase right liability was $3.9 million. In January 2021, preferred stock purchase right liability was remeasured to fair value and the change in fair value of $1.0 million was recorded in the statement of operations for the six months ended June 30, 2021. The liability was then reclassified to stockholders’ equity. Sale Agreement On April 1, 2022, the Company entered into an Open Market Sale Agreement (the “Sale Agreement”) with Jefferies LLC (the “Agent”), pursuant to which the Company may, from time to time, offer and sell shares of the Company’s common stock having an aggregate offering price of up to $150.0 million in “at the market” offerings through the Agent. Sales of the shares of common stock, if any, will be made at prevailing market prices at the time of sale, or as otherwise agreed with the Agent. The Agent will receive a commission from the Company of 3.0% of the gross proceeds of any shares of common stock sold under the Sale Agreement. The Company is not obligated to sell, and the Agent is not obligated to buy or sell, any shares of common stock under the Sale Agreement. No assurance can be given that the Company will sell any shares of common stock under the Sale Agreement, or, if it does, as to the price or amount of shares of common stock that it sells or the dates when such sales will take place. The Company and the Agent may each terminate the Sale Agreement at any time upon specified prior written notice. As of June 30, 2022, the Company has sold 555,297 shares of its common stock under the Sale Agreement at a weighted average price of $27.31 resulting in net proceeds of approximately $14.0 million. Equity Incentive Plan In 2017, the Company adopted the 2017 Equity Incentive Plan (the 2017 Plan), which as amended, had 5,524,354 shares of common stock reserved for issuance. Under the 2017 Plan, the Company could grant stock options, stock appreciation rights, restricted stock, restricted stock units and other awards to individuals who are employees, non-employee directors or consultants of the Company or its subsidiaries. The maximum term of the options granted under the 2017 Plan was no more than ten years. The 2017 Plan allowed for the early exercise of all stock options granted if authorized by the board of directors at the time of grant. In February 2021, the board of directors adopted, and the Company’s stockholders approved, the 2021 Incentive Award Plan (the 2021 Plan), which became effective in connection with the IPO. Pursuant to the 2021 Plan, the Company ceased granting awards under the 2017 Plan. Under the 2021 Plan, the Company may grant stock options, restricted stock, dividend equivalents, restricted stock units, stock appreciation rights, and other stock or cash-based awards to individuals who are then employees, officers, non-employee directors or consultants of the Company. The number of shares initially available for issuance under awards granted pursuant to the 2021 Plan is the sum of (1) 3,600,000 shares of common stock, plus (2) any shares subject to outstanding awards under the 2017 Plan as of the effective date of the 2021 Plan that become available for issuance under the 2021 Plan thereafter in accordance with its terms Grants generally vest at 25% one year from the vesting commencement date and ratably each month thereafter for a period of 36 months, subject to continuous service. The Company’s stock option activity for the six months ended June 30, 2022 is summarized in the following table: Number Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (in Years) Aggregate Intrinsic Value (in thousands) Outstanding at December 31, 2021 6,474,039 $ 12.18 8.5 $ 177,130 Granted 1,325,947 $ 30.34 Exercised (163,675 ) $ 2.73 Cancelled/forfeited (91,665 ) $ 20.54 Outstanding at June 30, 2022 7,544,646 $ 15.47 8.3 $ 108,623 Vested or expected to vest at June 30, 2022 7,544,646 $ 15.47 8.3 $ 108,623 Exercisable at June 30, 2022 2,299,870 $ 4.98 6.6 $ 53,483 The weighted average grant date fair value of options granted during the six months ended June 30, 2022 and 2021 was $20.52 and $5.93, respectively. The total intrinsic value of options exercised during the three months ended June 30, 2022 and 2021 was $0.5 million and $1.2 million, respectively. The total intrinsic value of options exercised during the six months ended June 30, 2022 and 2021 was $6.3 million and $1.3 million, respectively. The grant date fair value of stock options was determined using the Black-Scholes option pricing model with the following assumptions: Three Months Ended June 30, Six Months Ended June 30, 2022 2021 2022 2021 Risk-free interest rate 2.7 – 3.0% 1.0 – 1.1% 1.5 – 3.0% 0.6 – 1.1% Expected volatility 73.8 – 74.4% 73.0 – 74.2% 73.2 – 74.6% 73.0 – 95.2% Expected term (in years) 5.5 – 6.5 5.8 – 6.1 5.5 – 6.5 5.8 – 6.1 Expected dividend yield —% —% —% —% Expected Term —The expected term of options granted represents the period of time that the options are expected to be outstanding. Due to the lack of historical exercise history, the expected term of the Company’s employee stock options has been determined utilizing the simplified method for awards that qualify as plain-vanilla options. Expected Volatility —The estimated volatility was based on the historical volatility of the common stock of a group of publicly traded companies deemed comparable to the Company. Risk-Free Interest Rate —The risk-free interest rate is the implied yield in effect at the time of the option grant based on U.S. Treasury securities with contract maturities similar to the expected term of the Company’s stock options. Dividend Rate —The Company has not paid any cash dividends on common stock since inception and does not anticipate paying any dividends in the foreseeable future. Consequently, an expected dividend yield of zero was used. Restricted Stock Units A summary of the Company’s restricted stock units activity is as follows (in thousands, except share and per share amounts): Number of Outstanding Awards Weighted Average Grant Date Fair Value Aggregate Intrinsic Value Balance at December 31, 2021 — Granted 112,886 $ 29.56 Cancelled — Balance at June 30, 2022 112,886 $ — Vested or expected to vest at June 30, 2022 112,886 $ — The Company’s current restricted stock units vest 100% three years from the grant date, subject to continued service. The fair-value of each restricted stock unit is determined on the grant date using the closing price of the Company’s common stock on the grant date. Early Exercise Liability The unvested shares of the early-exercised options are held in escrow until the stock option becomes fully vested or until the employee’s termination, whichever occurs first. The right to repurchase these shares lapses over the four-year The following table summarizes the activity of the unvested common stock issued pursuant to an early exercise of stock option awards for the six months ended June 30, 2022: Unvested at beginning of period 17,606 Vested or cancelled during the period (8,625 ) Unvested at end of period 8,981 Employee Stock Purchase Plan In February 2021, the Company’s board of directors approved the 2021 Employee Stock Purchase Plan (the ESPP), which became effective upon the pricing of the Company’s IPO on March 16, 2021. The ESPP permits participants to purchase common stock through payroll deductions of up to 20% of their eligible compensation. Initially, a total of 360,000 shares of common stock were reserved for issuance under the ESPP. In addition, the number of shares of common stock available for issuance under the ESPP will be annually increased on the first day of each fiscal year during the term of the ESPP, beginning with the 2022 fiscal year, by an amount equal to the lessor of: (i) 1% of the total number of shares of common stock outstanding on December 31st of the preceding calendar year; or (ii) such other amount as the Company’s board of directors may determine. The number of shares of common stock available for issuance under the ESPP increased by 1% at January 1, 2022. Stock-based compensation expense for the three and six months ended June 30, 2022 related to the ESPP was $0.1 million. As of June 30, 2022, the Company has The fair value of stock of the stock purchase right under the ESPP was determined using the Black-Scholes option pricing model with the following assumptions: Six Months Ended June 30, 2022 Risk-free interest rate 0.03– 2.4% Expected volatility 69.4 – 83.9% Expected term (in years) 0.5 – 1.64 Expected dividend yield —% Stock-Based Compensation Expense The following table summarizes the components of stock-based compensation expense recognized in the accompanying statements of operations (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2022 2021 2022 2021 Research and development $ 1,644 $ 267 $ 2,780 $ 438 General and administrative 2,992 936 5,135 1,557 Total stock-based compensation $ 4,636 $ 1,203 $ 7,915 $ 1,995 As of June 30, 2022, approximately $70.1 million of total unrecognized compensation expense related to unvested stock options and restricted stock units is expected to be recognized over a weighted average period of 3.0 years. Common Stock Reserved for Future Issuance Common stock reserved for future issuance consists of the following: June 30, 2022 December 31, 2021 Common stock options issued and outstanding 7,544,646 6,474,039 Warrants to purchase common stock 14,884 14,884 Shares available for issuance under equity incentive plan 2,456,930 1,856,063 Shares available for issuance under the ESPP 703,478 333,850 Total 10,719,938 8,678,836

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2022
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	9 . Commitments and Contingencies Leases In March 2021, the Company executed a non-cancellable lease agreement for office and laboratory space in San Diego, California (“Second Floor Lease”). The Second Floor Lease and related monthly payments commenced in March 2022, and has an initial term of ten years with an option to extend the lease for an additional five-year In October 2021, the Company executed an amendment to the lease agreement to expand the leased premises (“First Floor Lease”). The amended lease extends the initial term of the original lease to 127 months following the commencement date of the expansion premises, with an option to extend the lease term for an additional five-year In connection with the PLI spinoff on December 31, 2020, the Company entered into a sublease agreement for approximately 40,000 square feet currently occupied in the PLI facility. The sublease agreement was for one year with an option to renew for an additional year. The sublease agreement was extended through June 2022 during the year ended December 31, 2021 and expired on June 30, 2022 in accordance with its terms. No further payment obligations exist at June 30, 2022. Information related to the Company’s operating lease is as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2022 2021 2022 2021 Operating lease expense (including variable costs of $0.1 million and zero during the three and six months ended June 30, 2022 and 2021, respectively) $ 893 $ 247 $ 1,227 $ 492 Cash paid for amounts included in the measurement of lease liabilities $ 228 $ — $ 228 $ — As of June 30, 2022 the remaining lease term of the Company’s operating lease was 129 months and the discount rate on the Company’s operating lease was 8.0%. Future minimum operating lease payments for the Second Floor Lease and information related to the lease liability as of June 30, 2022 are as follows (in thousands): Remainder of 2022 $ 312 2023 1,912 2024 1,970 2025 2,029 2026 2,090 Thereafter 14,552 Total lease payments 22,865 Imputed interest (8,105 ) Lease liability 14,760 Less current portion of lease liability 1,202 Lease liability, net of current portion $ 13,558 Litigation From time to time, the Company may become involved in legal proceedings or be subject to claims arising in the ordinary course of its business. Regardless of outcome, legal proceedings or claims can have an adverse impact on the company because of defense and settlement costs, diversion of resources and other factors, and there can be no assurances that favorable outcomes will be obtained. Indemnification Agreements In the ordinary course of business, the Company may provide indemnification of varying scope and terms to vendors, lessors, business partners and other parties with respect to certain matters including, but not limited to, losses arising out of breech of such agreements or from intellectual property infringement claims made by third parties. In addition, the Company has entered into indemnification agreements with officers and members of its board of directors that will require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is, in many cases, unlimited. To date, the Company has not incurred any material costs as a result of such indemnifications. At June 30, 2022, no claims exist under indemnification arrangements and accordingly, no amounts have been accrued in its condensed financial statements as of June 30, 2022.

Related Party Transactions

Related Party Transactions	6 Months Ended
	Jun. 30, 2022
Related Party Transactions [Abstract]
Related Party Transactions	10. Related Party Transactions As discussed in Note 5, in September 2017, the Company entered into the Cedars-Sinai Agreement. A related-party relationship exists with Cedars-Sinai due to its percentage of common stock ownership and representation on the Company’s board of directors. As consideration for the license rights, the Company issued (i) 257,500 common stock shares at par value of $0.0001 per share, and (ii) 335,000 unvested restricted common stock shares at par value of $0.0001 per share. The parties also entered into additional license agreements as well as research agreements, under which the parties can provide research services to each other at pricing specified in the individual statements of work. During the three and six months ended June 30, 2022 and 2021, no services were provided under the research agreements. As disclosed in Note 8, in January 2021, deferred purchase price obligations of $6.1 million due to was satisfied with the issuance of 7,219,560 shares of Series D-2 convertible preferred stock in January 2021. As a result of the PLI spinoff on December 31, 2020, the Company entered into a transition services agreement with PLI, pursuant to which the Company provided PLI certain transitional services, including general and administrative, finance and clinical operations support, and PLI provided the Company with certain transitional services, including providing for the use of facilities under a sublease, in each case for specified monthly service fees. The transition services agreement was terminated in June 2022. During the three and six months ended June 30, 2022, the Company paid PLI $1.0 million and $1.9 million, respectively, and during the three and six months ended June 30, 2021 the Company paid PLI $0.7 million and $2.2 million, respectively, in accordance with the terms of this agreement.

401(K) Plan

401(K) Plan	6 Months Ended
	Jun. 30, 2022
Compensation And Retirement Disclosure [Abstract]
401(K) Plan	1 1 . Effective January 1, 2018, the Company maintains a defined contribution 401(k) plan available to eligible employees. Employee contributions are voluntary and are determined on an individual basis, limited to the maximum amount allowable under federal tax regulations. The Company, at its discretion, may make certain contributions to the 401(k) plan. Company contributions made during the three months ended June 30, 2022 and 2021 were $ 0.2 million and $ 0.1 million, respectively. Company contributions made during the six months ended June 30, 2022 and 2021 were $ million and $ 0.1 million , re s pectively.

COVID-19 Pandemic

COVID-19 Pandemic	6 Months Ended
	Jun. 30, 2022
Extraordinary And Unusual Items [Abstract]
COVID-19 Pandemic	1 2 . The COVID-19 worldwide pandemic has presented substantial public health and economic challenges and has affected, and may continue to affect the Company’s employees, patients, physicians and other healthcare providers, communities and business operations, as well as the U.S. and global economies and financial markets. International and U.S. governmental authorities in impacted regions have taken, and are continuing to take, actions in an effort to slow the spread of COVID-19 and variants of the virus. The COVID-19 pandemic continues to rapidly evolve. The extent to which the COVID-19 pandemic may impact the Company’s business, including its preclinical studies, planned and ongoing clinical trials, and financial condition will depend on future developments, which are highly uncertain and cannot be predicted with confidence, such as the continued geographic spread of variants, the duration of the pandemic, the timing and effectiveness of vaccine distribution, travel restrictions and social distancing in the United States and other countries, business closures or business disruptions and the effectiveness of actions taken in the United States and other countries to contain and treat the disease.

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2022
Subsequent Events [Abstract]
Subsequent Events	1 3 . From July 1, 2022 through the date of this filing, the Company sold 1,581,583 shares of its common stock under the Sale Agreement at a weighted average price of $ resulting in net proceeds of approximately $ million.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2022
Accounting Policies [Abstract]
Basis of Presentation and Use of Estimates	Basis of Presentation and Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States (GAAP) requires management to make estimates and assumptions that impact the reported amounts of assets, liabilities, and expenses and the disclosure of contingent assets and liabilities in the Company’s condensed financial statements and accompanying notes. Although these estimates are based on the Company’s knowledge of current events and actions it may undertake in the future, actual results may materially differ from these estimates and assumptions. On an ongoing basis, management evaluates its estimates, primarily related to revenue recognition, stock-based compensation, marketable securities, accrued research and development costs, and the incremental borrowing rate for lease liabilities. These estimates are based on historical data and experience, as well as various other factors that management believes to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying value of assets and liabilities that are not readily apparent from other sources. Estimates relating to the valuation of stock require the selection of appropriate valuation methodologies and models, and significant judgment in evaluating ranges of assumptions and financial inputs.
Unaudited Interim Financial Information	Unaudited Interim Financial Information The unaudited financial statements at June 30, 2022, and for the three and six months ended June 30, 2022 and 2021, have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission (SEC), and with GAAP applicable to interim financial statements. These unaudited financial statements have been prepared on the same basis as the audited financial statements and include all adjustments, consisting of only normal recurring accruals, which in the opinion of management are necessary to present fairly the Company’s financial position as of the interim date and results of operations for the interim periods presented. Interim results are not necessarily indicative of results for a full year or future periods. The preparation of financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period. Actual results could differ materially from those estimates. These unaudited financial statements should be read in conjunction with the Company’s audited financial statements for the year ended December 31, 2021, included in the Annual Report on Form 10-K filed with the SEC on March 9, 2022.
Segment Reporting	Segment Reporting Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by management in making decisions regarding resource allocation and assessing performance. The Company manages its operations as a single operating segment in the United States for the purposes of assessing performance and making operating decisions.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity of three months or less when purchased to be cash equivalents. The cash and cash equivalents balance at June 30, 2022 represents cash in readily available checking and money market accounts, and commercial paper. The cash and cash equivalents balance at December 31, 2021 represents cash in readily available checking and money market accounts.
Marketable Securities	Marketable Securities The Company’s marketable securities primarily consist of commercial paper and U.S. government and agency securities classified within cash and cash equivalents and short term investments depending on their maturity date at the time of purchase. The Company classifies its marketable securities as available-for-sale and records such assets at estimated fair value in the condensed balance sheets, with unrealized gains and losses, if any, reported as a component of other comprehensive income (loss) within the condensed statements of operations and comprehensive loss and as a separate component of stockholders’ equity. The Company classifies marketable securities with remaining maturities greater than one year as current assets because such marketable securities are available to fund the Company’s current operations. Realized gains and losses are calculated on the specific identification method and recorded as interest income (loss). There were no realized gains and losses during any of the periods presented. At each balance sheet date, the Company assesses available-for-sale securities in an unrealized loss position to determine whether the unrealized loss is other-than-temporary. When the Company determines that a decline in the fair value below its cost basis is other-than-temporary, the Company recognizes an impairment loss in the period in which the other-than-temporary decline occurred. There have been no other-than-temporary impairments recognized during any of the periods presented.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments, which potentially subject the Company to concentration of credit risk, consist primarily of cash, cash equivalents, short term investments, and accounts receivable. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. Management believes that the Company is not exposed to significant credit risk due to the financial position of the depository institutions in which those deposits are held.
Accounts Receivable	Accounts Receivable Accounts receivable is stated at the original invoice amount and consists of certain research and development and contract manufacturing costs subject to reimbursement under the Company’s collaboration agreements. The Company did not record any credit losses as of June 30, 2022 and December 31, 2021.
Property and Equipment, Net	Property and Equipment, Net Property and equipment is stated at cost less accumulated depreciation. Depreciation is recorded using the straight-line method over the estimated useful lives of the related assets, which ranges from two to ten years. Repairs and maintenance charges that do not increase the useful life of the assets are charged to operating expenses as incurred.
Long-Lived Assets	Long-Lived Assets The Company’s long-lived assets are comprised principally of its property and equipment. If the Company identifies a change in the circumstances related to its long-lived assets that indicates the carrying value of any such asset may not be recoverable, the Company will perform an impairment analysis. A long-lived asset is not recoverable when the undiscounted cash flows expected to be generated by the asset (or asset group) are less than the asset’s carrying amount. Any required impairment loss would be measured as the amount by which the asset’s carrying value exceeds its fair value, and would be recorded as a reduction in the carrying value of the related asset and a charge to operating expense.
Revenue Recognition	Revenue Recognition The Company recognizes revenue in accordance with ASC Topic 606, Revenue from Contracts with Customers (ASC 606). In accordance with ASC 606, the Company performs the following steps in determining the appropriate amount of revenue to be recognized as it fulfills its obligations under each of these agreements: (i) identification of the promised goods or services in the contract; (ii) determination of whether the promised goods or services are performance obligations including whether they are distinct in the context of the contract; (iii) measurement of the transaction price, including the constraint on variable consideration; (iv) allocation of the transaction price to the performance obligations; and (v) recognition of revenue when, or as, the Company satisfies each performance obligation. At contract inception, once the contract is determined to be within the scope of ASC 606, the Company assesses the goods or services promised within each contract and determines those that are performance obligations and assesses whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. To date, all of the Company’s collaboration revenue has been derived from its collaboration agreement with Dr. Falk Pharma GmbH and its collaboration agreement with Millennium Pharmaceuticals, Inc., a subsidiary of Takeda Pharmaceutical Company Limited (collectively, Takeda) as described in Note 5. The terms of these arrangements include the following types of payments to the Company: non-refundable, up-front license fees; development, regulatory and commercial milestone payments; payments for research and development services provided by the Company; and royalties on net sales of licensed products. At the initiation of an agreement, the Company analyzes whether each unit of account results in a contract with a customer under ASC 606 or in an arrangement with a collaborator subject to guidance under ASC 808, Collaborative Arrangements (ASC 808). The Company considers a variety of factors in determining the appropriate estimates and assumptions under these arrangements, such as whether the elements are distinct performance obligations, whether there are observable stand-alone prices, and whether any licenses are functional or symbolic. The Company evaluates each performance obligation to determine if it can be satisfied and recognized as revenue at a point in time or over time. Typically, license fees, non-refundable upfront fees, and funding of research activities are considered fixed, while milestone payments are identified as variable consideration which must be evaluated to determine if it is constrained and, therefore, excluded from the transaction price. The Company estimates the amount of variable consideration using the most likely amount, as milestone payments typically only have two possible outcomes. The Company recognizes revenue for sales-based royalty promised in exchange for the license of intellectual property only when the subsequent sale occurs. The Company may allocate transaction price using a number of methods including estimating standalone selling price of performance obligations and using the residual approach when the standalone selling price of the license is highly variable or uncertain, and observable standalone selling prices exist for the other goods or services promised in the contract. The Company receives payments from its collaborators based on terms established in each contract. Upfront payments and other payments may require deferral of revenue recognition to a future period until the Company is unconditional. The Company does not assess whether a contract has a significant financing component if the expectation at contract inception is such that the payment by the customer is akin to a deposit for research and development services.
Research and Development and Clinical Trial Accruals	Research and Development and Clinical Trial Accruals Research and development costs are charged to expense as incurred. Research and development expenses include certain payroll and personnel expenses, laboratory supplies, consulting costs, external contract research and development expenses, and allocated overhead, including rent, information technology, property and equipment depreciation and utilities. Advance payments for goods or services for future research and development activities are deferred and expensed as the goods are delivered or the related services are performed. The Company estimates preclinical studies and clinical trial expenses based on the services performed pursuant to contracts with research institutions and clinical research organizations that conduct and manage preclinical studies and clinical trials on the Company’s behalf. In addition, clinical study and trial materials are manufactured by contract manufacturing organizations. In accruing for these services, the Company estimates the time period over which services will be performed and the level of effort to be expended in each period. These estimates are based on communications with the third-party service providers and the Company’s estimates of accrued expenses and on information available at each balance sheet date. If the actual timing of the performance of services or the level of effort varies from the estimate, the Company will adjust the accrual accordingly.
Fair Value Measurements	Fair Value Measurements Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. 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.
Stock-Based Compensation	Stock-Based Compensation The Company expenses stock-based compensation to employees and non-employees related to stock options, restricted stock units, and shares granted under the Company’s 2021 Employee Stock Purchase Plan (the ESPP). Stock-based compensation expense represents the cost of the grant date fair value of applicable awards recognized over the requisite service period (usually the vesting period) on a straight-line basis, net of actual forfeitures during the period. The Company estimates the fair value of stock options and shares purchased under the ESPP using the Black-Scholes option pricing model, and the assumptions used in calculating the fair value of stock-based awards represent management’s best estimates and involve inherent uncertainties and the application of management’s judgment.
Valuation of Common Stock	Valuation of Common Stock Prior to the IPO, given the absence of a public trading market for the Company’s common stock, the Company’s board of directors exercised their judgment and considered a number of objective and subjective factors to determine the best estimate of the fair value of the Company’s common stock, such as: contemporaneous valuations performed by independent third-party specialists, its stage of development, including the status of its research and development efforts of its product candidates, the material risks related to its businesses and industry, its results of operations before discontinued operations and financial position, including its levels of capital resources, the prices at which its sold shares of its convertible preferred stock, the rights, preferences and privileges of its convertible preferred stock relative to those of its common stock, the conditions in the biotechnology industry and the economy in general, the stock price performance and volatility of comparable life sciences public companies, as well as recently completed mergers and acquisitions of peer companies, the likelihood of achieving a liquidity event for the holders of its common stock or convertible preferred stock, such as an IPO or a sale of the Company given prevailing market conditions, trends and developments in its industry, external market conditions affecting the life sciences and biotechnology sectors, and the lack of liquidity of its common stock, among other factors. After the completion of the IPO, the fair value of each share of common stock is based on the closing price of the Company’s common stock as reported by the Nasdaq Global Select Market.
Preferred Stock Purchase Right Liabilities	Preferred Stock Purchase Right Liabilities From time to time, the Company entered into convertible preferred stock financings where, in addition to the initial closing, investors agreed to buy, and the Company agreed to sell, additional shares of that convertible preferred stock at a fixed price in the event that certain conditions are met, or agreed upon milestones are achieved. The Company evaluated this purchase right and assessed whether it met the definition of a freestanding instrument and, if so, determined the fair value of the purchase right liability and recorded it on the balance sheet with the remainder of the proceeds raised allocated to convertible preferred stock. The preferred stock purchase right liability was revalued at each reporting period with changes in the fair value of the liability recorded as change in fair value of preferred stock purchase right liability in the statements of operations. Upon the issuance of the shares of Series D-2 convertible preferred stock in January 2021, the no longer required liability accounting and the then fair value of the was reclassified into stockholders’ equity. The Company performed the final remeasurement of the preferred stock purchase right liability
Comprehensive Loss	Comprehensive Loss Comprehensive loss is defined as the change in equity during a period from transactions and other events and circumstances from non-owner sources, including unrealized gains and losses on marketable securities. Comprehensive gains (losses) have been reflected in the statements of operations and comprehensive loss for all periods presented
Net Loss Per Share	Net Loss Per Share Basic net loss per share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted average number of common shares outstanding during the period. Diluted net loss per share attributable to common stockholders is computed by dividing the net loss attributable to common stockholders by the weighted average number of common stock equivalents outstanding for the period determined using the treasury-stock method. The Company has excluded 11,084 and 13,231 weighted average shares subject to repurchase or forfeiture from the weighted average number of common shares outstanding for the three and six months ended June 30, 2022, respectively, and 35,369 and 41,654 weighted average shares subject to repurchase or forfeiture from the weighted average number of common shares outstanding for the three and six months ended June 30, 2021, respectively Basic and diluted net loss attributable to common holders per share is presented in conformity with the two- class method required for participating securities as the convertible preferred stock are considered participating securities. The Company’s participating securities do not have a contractual obligation to share in the Company’s losses. As such, the net loss was attributed entirely to common stockholders. Accordingly, for the three and six months ended June 30, 2022 and 2021, there is no difference in the number of shares used to calculate basic and diluted shares outstanding. Potentially dilutive securities not included in the calculation of diluted net loss per share because to do so would be anti-dilutive are as follows (in common stock equivalent shares): June 30, 2022 2021 Common stock options issued and outstanding 7,544,646 5,190,989 Warrants to purchase common stock 14,884 14,884 ESPP shares pending issuance 9,072 12,536 Total 7,568,602 5,218,409
Recent Accounting Standards	Recent Accounting Standards From time to time, new accounting standards are issued by the Financial Accounting Standards Board (FASB) or other standard setting bodies and adopted by the Company as of the specified effective date. Unless otherwise discussed, the impact of recently issued standards that are not yet effective will not have a material impact on the Company’s financial position or results of operations upon adoption. In April 2012, the Jump-Start Our Business Startups Act (the JOBS Act) was signed into law. The JOBS Act contains provisions that, among other things, reduce certain reporting requirements for an emerging growth company. As an emerging growth company, the Company may elect to adopt new or revised accounting standards when they become effective for non-public companies, which typically is later than when public companies must adopt the standards. The Company has elected to take advantage of the extended transition period afforded by the JOBS Act and, as a result, will comply with new or revised accounting standards on the relevant dates on which adoption of such standards is required for emerging growth companies .

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	6 Months Ended
	Jun. 30, 2022
Accounting Policies [Abstract]
Summary of Potentially Dilutive Securities Not Included in Calculation of Diluted Net Loss Per Share	Potentially dilutive securities not included in the calculation of diluted net loss per share because to do so would be anti-dilutive are as follows (in common stock equivalent shares): June 30, 2022 2021 Common stock options issued and outstanding 7,544,646 5,190,989 Warrants to purchase common stock 14,884 14,884 ESPP shares pending issuance 9,072 12,536 Total 7,568,602 5,218,409

Fair Value Measurements and F_2

Fair Value Measurements and Fair Value of Financial Instruments (Tables)	6 Months Ended
	Jun. 30, 2022
Fair Value Disclosures [Abstract]
Summary of Financial Instruments Measured at Fair Value on Recurring Basis	The following tables summarize the Company’s financial instruments measured at fair value on a recurring basis (in thousands): Fair Value Measurements At Reporting Date Using Total Quoted Prices in Active Markets For Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) As of June 30, 2022 Assets: Cash and cash equivalents: Money market funds $ 755 $ 755 $ — $ — Commercial paper 33,323 — 33,323 — Total cash and cash equivalents 34,078 755 33,323 — Short term investments: Commercial paper $ 99,911 $ — $ 99,911 $ — U.S. government and agency securities 15,912 15,912 — — 115,823 15,912 99,911 — Total assets measured at fair value $ 149,901 $ 16,667 $ 133,234 $ —
Summary of Assumptions Used in Black-Scholes Option Pricing Model	The assumptions used in the Black-Scholes option pricing model to determine the fair value of the convertible preferred stock warrant liability at the date of the IPO were as follows: IPO Date Fair value of underlying preferred stock $ 1.90 Risk-free interest rate 1.70 % Expected volatility 70.00 % Expected term (in years) 9.0 Expected dividend yield —%
Summary of Activity of Financial Instruments	The following table summarizes the activity of the financial instruments valued using Level 3 inputs (in thousands): Convertible Preferred Stock Warrant Liability Series D Convertible Preferred Stock Purchase Right Liability Balance at December 31, 2020 $ 64 $ 3,900 Change in fair value 105 980 Conversion/Settlement during 2021 (169 ) (4,880 ) Balance at June 30, 2021 $ — $ —

Marketable Securities (Tables)

Marketable Securities (Tables)	6 Months Ended
	Jun. 30, 2022
Investments Debt And Equity Securities [Abstract]
Summarize Marketable Securities	The following tables summarize marketable securities (in thousands): As of June 30, 2022 Unrealized Maturity (in years) Amortized Cost Unrealized Gains Unrealized Losses Estimated Fair Value Cash and cash equivalents: Money market funds $ 755 $ — $ — $ 755 Commercial paper one or less 33,351 (28 ) 33,323 Total cash and cash equivalents $ 34,106 $ — $ (28 ) $ 34,078 Short term investments: Commercial paper one or less $ 100,170 $ — $ (259 ) $ 99,911 U.S. government and agency securities one or less 15,935 — (23 ) 15,912 Total short term investments $ 116,105 $ — $ (282 ) $ 115,823 Total marketable securities $ 150,211 $ — $ (310 ) $ 149,901

Balance Sheet Details (Tables)

Balance Sheet Details (Tables)	6 Months Ended
	Jun. 30, 2022
Balance Sheet Related Disclosures [Abstract]
Schedule of Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consist of the following (in thousands): June 30, 2022 December 31, 2021 Prepaid contract manufacturing expenses $ 930 $ 3,808 Prepaid clinical trial expenses 2,069 1,397 Prepaid research and development expenses 503 627 Other prepaid expenses 2,201 1,218 Total $ 5,703 $ 7,050
Schedule of Equipment, Net	Property and equipment, net, consist of the following (in thousands): June 30, 2022 December 31, 2021 Laboratory equipment $ 2,579 $ 1,830 Computer equipment 493 24 Office equipment and furniture 474 — 3,546 1,854 Less accumulated depreciation (655 ) (407 ) Total $ 2,891 $ 1,447
Schedule of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities consist of the following (in thousands): June 30, 2022 December 31, 2021 Accrued research and development $ 2,841 $ 2,123 Accrued clinical trial expenses 3,635 1,999 Accrued contract manufacturing expenses 2,689 906 Accrued legal expenses 433 531 Unvested early exercise liability 22 35 Accrued other 438 456 Total $ 10,058 $ 6,050

Collaboration and License Agr_2

Collaboration and License Agreements (Tables)	6 Months Ended
	Jun. 30, 2022
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Schedule of Reconciliation of Deferred Revenue	A reconciliation of deferred revenue related to the Falk Agreement and the Takeda Agreement for the six months ended June 30, 2022 is as follows (in thousands): Falk Agreement Takeda Agreement Total Balance at December 31, 2021 $ 18,691 $ 1,181 $ 19,872 Amounts received in 2022 2,830 — $ 2,830 Revenue recognized in 2022 (4,007 ) (1,181 ) $ (5,188 ) Balance at June 30, 2022 $ 17,514 $ — $ 17,514

Stockholders' Equity (Deficit)

Stockholders' Equity (Deficit) (Tables)	6 Months Ended
	Jun. 30, 2022
Equity [Abstract]
Summary of Stock Option Activity	The Company’s stock option activity for the six months ended June 30, 2022 is summarized in the following table: Number Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (in Years) Aggregate Intrinsic Value (in thousands) Outstanding at December 31, 2021 6,474,039 $ 12.18 8.5 $ 177,130 Granted 1,325,947 $ 30.34 Exercised (163,675 ) $ 2.73 Cancelled/forfeited (91,665 ) $ 20.54 Outstanding at June 30, 2022 7,544,646 $ 15.47 8.3 $ 108,623 Vested or expected to vest at June 30, 2022 7,544,646 $ 15.47 8.3 $ 108,623 Exercisable at June 30, 2022 2,299,870 $ 4.98 6.6 $ 53,483
Summary of Grant Date Fair Value of Stock Options	The grant date fair value of stock options was determined using the Black-Scholes option pricing model with the following assumptions: Three Months Ended June 30, Six Months Ended June 30, 2022 2021 2022 2021 Risk-free interest rate 2.7 – 3.0% 1.0 – 1.1% 1.5 – 3.0% 0.6 – 1.1% Expected volatility 73.8 – 74.4% 73.0 – 74.2% 73.2 – 74.6% 73.0 – 95.2% Expected term (in years) 5.5 – 6.5 5.8 – 6.1 5.5 – 6.5 5.8 – 6.1 Expected dividend yield —% —% —% —%
Summary of Restricted Stock Units Activity	A summary of the Company’s restricted stock units activity is as follows (in thousands, except share and per share amounts): Number of Outstanding Awards Weighted Average Grant Date Fair Value Aggregate Intrinsic Value Balance at December 31, 2021 — Granted 112,886 $ 29.56 Cancelled — Balance at June 30, 2022 112,886 $ — Vested or expected to vest at June 30, 2022 112,886 $ —
Summary of Activity Unvested Common Stock Issued Pursuant Early Exercise of Stock Options Awards	The following table summarizes the activity of the unvested common stock issued pursuant to an early exercise of stock option awards for the six months ended June 30, 2022: Unvested at beginning of period 17,606 Vested or cancelled during the period (8,625 ) Unvested at end of period 8,981
Summary of Fair Value of Stock of the Stock Purchase Right Under ESPP	The fair value of stock of the stock purchase right under the ESPP was determined using the Black-Scholes option pricing model with the following assumptions: Six Months Ended June 30, 2022 Risk-free interest rate 0.03– 2.4% Expected volatility 69.4 – 83.9% Expected term (in years) 0.5 – 1.64 Expected dividend yield —%
Summary of Stock-based Compensation Expense	The following table summarizes the components of stock-based compensation expense recognized in the accompanying statements of operations (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2022 2021 2022 2021 Research and development $ 1,644 $ 267 $ 2,780 $ 438 General and administrative 2,992 936 5,135 1,557 Total stock-based compensation $ 4,636 $ 1,203 $ 7,915 $ 1,995
Summary of Common Stock Reserved for Future Issuance	Common stock reserved for future issuance consists of the following: June 30, 2022 December 31, 2021 Common stock options issued and outstanding 7,544,646 6,474,039 Warrants to purchase common stock 14,884 14,884 Shares available for issuance under equity incentive plan 2,456,930 1,856,063 Shares available for issuance under the ESPP 703,478 333,850 Total 10,719,938 8,678,836

Commitments and Contingencies (

Commitments and Contingencies (Tables)	6 Months Ended
	Jun. 30, 2022
Leases [Abstract]
Schedule of Information Related to Operating Lease	Information related to the Company’s operating lease is as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2022 2021 2022 2021 Operating lease expense (including variable costs of $0.1 million and zero during the three and six months ended June 30, 2022 and 2021, respectively) $ 893 $ 247 $ 1,227 $ 492 Cash paid for amounts included in the measurement of lease liabilities $ 228 $ — $ 228 $ —
Future Minimum Operating Lease Payments for the Second Floor Lease and Information Related to Lease Liability	Future minimum operating lease payments for the Second Floor Lease and information related to the lease liability as of June 30, 2022 are as follows (in thousands): Remainder of 2022 $ 312 2023 1,912 2024 1,970 2025 2,029 2026 2,090 Thereafter 14,552 Total lease payments 22,865 Imputed interest (8,105 ) Lease liability 14,760 Less current portion of lease liability 1,202 Lease liability, net of current portion $ 13,558

Organization - Additional Infor

Organization - Additional Information (Details) $ / shares in Units, $ in Thousands			3 Months Ended		6 Months Ended		12 Months Ended
	Mar. 16, 2021 USD ($) $ / shares shares	Mar. 05, 2021	Jun. 30, 2022 USD ($) shares	Mar. 31, 2021 shares	Jun. 30, 2022 USD ($) shares	Jun. 30, 2021 USD ($)	Dec. 31, 2020	Dec. 31, 2021 USD ($) shares
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Date of incorporation					Oct. 26, 2016
Percentage of spinoff in kind distribution							100%
Description of reverse stock split					Company effected a one-for-ten reverse stock split of the Company’s common stock
Reverse stock split, conversion ratio		0.1
Proceeds from sale of common stock in initial public offering | $						$ 218,500
Common stock, shares authorized	400,000,000		400,000,000	400,000,000	400,000,000			400,000,000
Preferred stock, shares authorized	40,000,000		40,000,000	40,000,000	40,000,000			40,000,000
Accumulated deficit | $			$ 255,054		$ 255,054			$ 189,341
Convertible Preferred Stock
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Warrant to purchase of convertible preferred stock	148,848
Common Stock
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Issuance of common stock, shares			555,297	11,500,000
Conversion of convertible preferred stock into common stock at initial public offering, shares				25,485,955
Common Stock | Convertible Preferred Stock
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Conversion of convertible preferred stock into common stock at initial public offering, shares	25,485,955
Common Stock | Convertible Preferred Stock Warrant Liability
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Conversion of convertible preferred stock into common stock at initial public offering, shares	14,884
IPO
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Issuance of common stock, shares	11,500,000
Common stock price per share | $ / shares	$ 19
Gross proceeds from issuance initial public offering | $	$ 218,500
Proceeds from sale of common stock in initial public offering | $	199,800
Payments of underwriting discounts and commissions | $	15,300
Offering-related transaction costs | $	$ 3,400
Underwriters
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Issuance of common stock, shares	1,500,000

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Summary Of Significant Accounting Policies [Line Items]
Realized gains and losses			$ 0		$ 0
Other-than-temporary impairments			0		0
Credit losses	$ 0		$ 0		$ 0
Weighted-average shares subject to repurchase or forfeiture	11,084	35,369	13,231	41,654
Series D-2 Convertible Preferred Stock
Summary Of Significant Accounting Policies [Line Items]
Change in fair value into other income (expense)				$ 1,000
Minimum
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful lives			2 years
Maximum
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful lives			10 years

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Summary of Potentially Dilutive Securities Not Included in Calculation of Diluted Net Loss Per Share (Details) - shares	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total	7,568,602	5,218,409
Common Stock Options Issued and Outstanding
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total	7,544,646	5,190,989
Warrants to Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total	14,884	14,884
ESPP Shares Pending Issuance
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total	9,072	12,536

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Financial Instruments Measured at Fair Value on Recurring Basis (Details) - Fair Value, Recurring $ in Thousands	Jun. 30, 2022 USD ($)
Cash and cash equivalents:
Total cash and cash equivalents	$ 34,078
Short term investments:
Total short term investments	115,823
Total assets measured at fair value	149,901
Quoted Prices in Active Markets For Identical Assets (Level 1)
Cash and cash equivalents:
Total cash and cash equivalents	755
Short term investments:
Total short term investments	15,912
Total assets measured at fair value	16,667
Significant Other Observable Inputs (Level 2)
Cash and cash equivalents:
Total cash and cash equivalents	33,323
Short term investments:
Total short term investments	99,911
Total assets measured at fair value	133,234
Commercial paper
Cash and cash equivalents:
Total cash and cash equivalents	33,323
Short term investments:
Total short term investments	99,911
Commercial paper | Significant Other Observable Inputs (Level 2)
Cash and cash equivalents:
Total cash and cash equivalents	33,323
Short term investments:
Total short term investments	99,911
Money market funds
Cash and cash equivalents:
Total cash and cash equivalents	755
Money market funds | Quoted Prices in Active Markets For Identical Assets (Level 1)
Cash and cash equivalents:
Total cash and cash equivalents	755
U.S. government and agency securities
Short term investments:
Total short term investments	15,912
U.S. government and agency securities | Quoted Prices in Active Markets For Identical Assets (Level 1)
Short term investments:
Total short term investments	$ 15,912

Fair Value Measurements and F_3

Fair Value Measurements and Fair Value of Financial Instruments - Additional Information (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2022 USD ($)	Mar. 31, 2021 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)	Jan. 31, 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Financial instruments, measured, at fair value					$ 0
Transfers within Level 3 hierarchy	$ 0	$ 0	$ 0	$ 0
Transfers within Level 3 hierarchy			$ 0		$ 0
Change in fair value				$ 1,000
Expected Risk-Free Rate
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Measurement input						0.0009
Probability of Tranche
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Measurement input						0.800
Expected Volatility
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Measurement input						0.800

Fair Value Measurements and F_4

Fair Value Measurements and Fair Value of Financial Instruments - Summary of Assumptions Used in Black-Scholes Option Pricing Model (Details)	Mar. 16, 2021 $ / shares	Jan. 31, 2021
Convertible Preferred Stock Warrant Liability
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair value of underlying preferred stock	$ 1.90
Expected Risk-Free Rate
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Measurement input		0.0009
Expected Risk-Free Rate | Convertible Preferred Stock Warrant Liability
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Measurement input	0.0170
Expected Volatility
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Measurement input		0.800
Expected Volatility | Convertible Preferred Stock Warrant Liability
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Measurement input	0.7000
Expected Term | Convertible Preferred Stock Warrant Liability
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Expected term (in years)	9 years

Fair Value Measurements and F_5

Fair Value Measurements and Fair Value of Financial Instruments - Summary of Activity of Financial Instruments (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2021 USD ($)
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Change in fair value	$ 1,000
Convertible Preferred Stock Warrant Liability
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance at December 31, 2020	64
Change in fair value	105
Conversion/Settlement during 2021	(169)
Balance at June 30, 2021	0
Series D Convertible Preferred Stock Warrant Liability
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance at December 31, 2020	3,900
Change in fair value	980
Conversion/Settlement during 2021	(4,880)
Balance at June 30, 2021	$ 0

Marketable Securities - Summari

Marketable Securities - Summarize Marketable Securities (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2022 USD ($)
Marketable Securities [Line Items]
Marketable securities, Amortized Cost	$ 150,211
Marketable securities, Gross Unrealized Losses	(310)
Marketable securities, Estimated Fair Value	149,901
Cash And Cash Equivalents
Marketable Securities [Line Items]
Marketable securities, Amortized Cost	34,106
Marketable securities, Gross Unrealized Losses	(28)
Marketable securities, Estimated Fair Value	34,078
Short Term Investments
Marketable Securities [Line Items]
Marketable securities, Amortized Cost	116,105
Marketable securities, Gross Unrealized Losses	(282)
Marketable securities, Estimated Fair Value	$ 115,823
Commercial paper | Cash And Cash Equivalents
Marketable Securities [Line Items]
Marketable securities, Maturity (in years)	one or less
Marketable securities, Amortized Cost	$ 33,351
Marketable securities, Gross Unrealized Losses	(28)
Marketable securities, Estimated Fair Value	$ 33,323
Commercial paper | Short Term Investments
Marketable Securities [Line Items]
Marketable securities, Maturity (in years)	one or less
Marketable securities, Amortized Cost	$ 100,170
Marketable securities, Gross Unrealized Losses	(259)
Marketable securities, Estimated Fair Value	99,911
Money market funds | Cash And Cash Equivalents
Marketable Securities [Line Items]
Marketable securities, Amortized Cost	755
Marketable securities, Estimated Fair Value	$ 755
U.S. government and agency securities | Short Term Investments
Marketable Securities [Line Items]
Marketable securities, Maturity (in years)	one or less
Marketable securities, Amortized Cost	$ 15,935
Marketable securities, Gross Unrealized Losses	(23)
Marketable securities, Estimated Fair Value	$ 15,912

Marketable Securities - Additio

Marketable Securities - Additional Information (Details) - USD ($)	Jun. 30, 2022	Dec. 31, 2021
Investments Debt And Equity Securities [Abstract]
Marketable securities held in unrealized loss position for greater than 12 months	$ 0
Marketable securities allowance for credit losses	$ 0
Marketable securities		$ 0

Balance Sheet Details - Schedul

Balance Sheet Details - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Prepaid Expense And Other Assets Current [Abstract]
Prepaid contract manufacturing expenses	$ 930	$ 3,808
Prepaid clinical trial expenses	2,069	1,397
Prepaid research and development expenses	503	627
Other prepaid expenses	2,201	1,218
Total	$ 5,703	$ 7,050

Balance Sheet Details - Sched_2

Balance Sheet Details - Schedule of Equipment, Net (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Property Plant And Equipment [Line Items]
Equipment, gross	$ 3,546	$ 1,854
Less accumulated depreciation	(655)	(407)
Total	2,891	1,447
Laboratory Equipment
Property Plant And Equipment [Line Items]
Equipment, gross	2,579	1,830
Computer Equipment
Property Plant And Equipment [Line Items]
Equipment, gross	493	$ 24
Office Equipment and Furniture
Property Plant And Equipment [Line Items]
Equipment, gross	$ 474

Balance Sheet Details - Additio

Balance Sheet Details - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Balance Sheet Related Disclosures [Abstract]
Depreciation expense	$ 0.2	$ 0.1	$ 0.2	$ 0.1

Balance Sheet Details - Sched_3

Balance Sheet Details - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Balance Sheet Related Disclosures [Abstract]
Accrued research and development	$ 2,841	$ 2,123
Accrued clinical trial expenses	3,635	1,999
Accrued contract manufacturing expenses	2,689	906
Accrued legal expenses	433	531
Unvested early exercise liability	22	35
Accrued other	438	456
Total	$ 10,058	$ 6,050

Collaboration and License Agr_3

Collaboration and License Agreements - Additional Information (Details) - USD ($)	1 Months Ended		3 Months Ended		6 Months Ended		12 Months Ended
	Jul. 31, 2020	Sep. 30, 2017	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Common stock, shares issued			39,699,667		39,699,667		38,960,716
Revenue recognized					$ 5,188,000
Deferred revenue			$ 17,514,000		17,514,000		$ 19,872,000
Cedars-Sinai Agreement | Cedars-Sinai
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
License agreement expiration term		3 years
Cedars-Sinai Agreement | Cedars-Sinai | Vested Common Stock
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Common stock, shares issued		257,500
Cedars-Sinai Agreement | Cedars-Sinai | Unvested Restricted Common Stock
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Common stock, shares issued		335,000
License Agreement | Cedars-Sinai
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
License agreement expiration term		10 years
Falk Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue recognized					4,007,000
Deferred revenue			17,514,000		17,514,000		18,691,000
Falk Agreement | Falk
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Funding percentage third-party development costs set forth in development plan	25%
Collaboration agreement, upfront payment received upon agreement execution	$ 2,500,000
Collaboration agreement, pre-clinical development milestone payment received upon finalization of development plan							2,500,000
Collaboration agreement, pre-clinical development milestone payment received upon clinical candidate selected	10,000,000
Collaboration agreement additional pre-clinical development milestone payment eligible to receive	$ 5,000,000
Revenue recognized			1,300,000	$ 300,000	4,000,000	$ 300,000
Deferred revenue			17,500,000		17,500,000		18,700,000
Takeda Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue recognized					1,181,000
Deferred revenue							1,181,000
Takeda Agreement | Takeda Pharmaceutical Company Limited
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue recognized			0	$ 100,000	1,200,000	$ 300,000
Deferred revenue			$ 0		$ 0		$ 1,200,000

Collaboration and License Agr_4

Collaboration and License Agreements - Additional Information (Details1) - Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2022-04-01	Jun. 30, 2022
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	8 years
Falk Agreement | Falk
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	8 years

Collaboration and License Agr_5

Collaboration and License Agreements - Schedule of Reconciliation of Deferred Revenue (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2022 USD ($)
Disaggregation Of Revenue [Line Items]
Balance at December 31, 2021	$ 19,872
Amounts received in 2022	2,830
Revenue recognized in 2022	(5,188)
Balance at June 30, 2022	17,514
Falk Agreement
Disaggregation Of Revenue [Line Items]
Balance at December 31, 2021	18,691
Amounts received in 2022	2,830
Revenue recognized in 2022	(4,007)
Balance at June 30, 2022	17,514
Takeda Agreement
Disaggregation Of Revenue [Line Items]
Balance at December 31, 2021	1,181
Revenue recognized in 2022	$ (1,181)

Long Term Debt - Additional Inf

Long Term Debt - Additional Information (Details) - Oxford Finance LLC - USD ($)		1 Months Ended		12 Months Ended
	Mar. 16, 2021	Jul. 31, 2021	Jan. 31, 2020	Dec. 31, 2021
Debt Instrument [Line Items]
Long term debt, maximum borrowing amount			$ 25,000,000
Long term debt, amount drawn upon execution of agreement			$ 7,500,000
Interest rate			2.01%
Additional interest rate			5.98%
Debt instrument minimum annual interest rate			7.99%
Percentage of final payment equal to original principal amount borrowed			4%
Percentage of future amount to be funded			3%
Prepayment of outstanding principal balance		$ 7,500,000
Prepayment penalty, accrued interest and final payment		$ 500,000
Loss on extinguishment of debt				$ (600,000)
Series C Convertible Preferred Stock
Debt Instrument [Line Items]
Warrant to purchase of convertible preferred stock			112,500
Exercise price of warrants	$ 7.558		$ 1
Expected term (in years)			10 years
Conversion of convertible preferred stock into common stock at initial public offering, shares	14,884

Stockholders' Equity (Deficit_2

Stockholders' Equity (Deficit) - Additional Information (Details)				1 Months Ended			3 Months Ended			6 Months Ended		12 Months Ended
	Apr. 01, 2022 USD ($)	Jan. 01, 2022 shares	Mar. 16, 2021 shares	Feb. 28, 2021 shares	Jan. 31, 2021 USD ($) shares	Oct. 31, 2020 USD ($) $ / shares shares	Jun. 30, 2022 USD ($) $ / shares shares	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($) shares	Jun. 30, 2022 USD ($) $ / shares shares	Jun. 30, 2021 USD ($) $ / shares	Dec. 31, 2017 shares	Dec. 31, 2021 USD ($) shares
Class Of Stock [Line Items]
Common stock, shares authorized			400,000,000				400,000,000		400,000,000	400,000,000			400,000,000
Preferred stock, shares authorized			40,000,000				40,000,000		40,000,000	40,000,000			40,000,000
Net cash proceeds from sale of convertible preferred stock | $											$ 73,749,000
Common stock, value | $							$ 4,000			$ 4,000			$ 4,000
Gross proceeds | $										$ 15,163,000
Common stock reserved for issuance							10,719,938			10,719,938			8,678,836
Weighted average grant date fair value of options granted | $ / shares										$ 20.52	$ 5.93
Total intrinsic value of options exercised | $							$ 500,000	$ 1,200,000		$ 6,300,000	$ 1,300,000
Unvested shares early exercised option right to repurchase shares vesting period										4 years
Unvested early exercise liability | $							23,000			$ 23,000			$ 35,000
Stock compensation expense | $							4,636,000	$ 1,203,000		7,915,000	1,995,000
Unrecognized compensation cost related to unvested stock-based awards | $							$ 70,100,000			$ 70,100,000
Unrecognized compensation cost is expected to be recognized over a weighted average period										3 years
2021 Employee Stock Purchase Plan
Class Of Stock [Line Items]
Common stock reserved for issuance				360,000
Common stock, shares available for grant							703,478			703,478
Annually increase amount equal to lessor of percentage of shares of common stock outstanding on the final day of the immediately preceding calendar year		1%		1%
Issuance of shares including automatic increase		389,607
Participants to purchase common stock through payroll deductions maximum percentage of eligible compensation				20%
Stock compensation expense | $										$ 100,000
Issuance of common stock under employee stock purchase plan, shares										46,129
Outstanding liability related to employee contributions for shares pending issuance | $							$ 200,000			$ 200,000
Restricted Stock Units
Class Of Stock [Line Items]
Percentage of award vested										100%
Award vesting period										3 years
2017 Equity Incentive Plan
Class Of Stock [Line Items]
Common stock reserved for issuance												5,524,354
Maximum options granted period												10 years
Award subject to continuous service										36 months
2017 Equity Incentive Plan | Tranche One
Class Of Stock [Line Items]
Percentage of award vested										25%
Award vesting period										1 year
2021 Incentive Award Plan
Class Of Stock [Line Items]
Common stock, shares available for grant				3,600,000			2,456,930			2,456,930
Annually increase amount equal to lessor of percentage of shares of common stock outstanding on the final day of the immediately preceding calendar year				5%
Issuance of shares including automatic increase		1,948,035
Sale Agreement
Class Of Stock [Line Items]
Issuance of shares of common stock in initial public offering for cash, net of issuance costs, shares										555,297
Common stock price per share | $ / shares							$ 27.31			$ 27.31
Gross proceeds | $										$ 14,000,000
PLI | Sale Agreement | Agent
Class Of Stock [Line Items]
Percentage of commission from sale of common stock	3
PLI | Maximum | Sale Agreement | Agent
Class Of Stock [Line Items]
Common stock, value | $	$ 150,000,000
Convertible Preferred Stock
Class Of Stock [Line Items]
Warrant to purchase of convertible preferred stock			148,848
Series D-1 Convertible Preferred Stock
Class Of Stock [Line Items]
Issuance of convertible preferred stock for cash, net of issuance costs, shares						61,066,216
Shares issued, price per share | $ / shares						$ 0.7558
Net cash proceeds from sale of convertible preferred stock | $						$ 46,200,000
Convertible preferred stock issued for deferred purchase price obligation, shares						5,088,851
Convertible preferred stock, shares issued for deferred purchase price obligation, value | $						$ 3,800,000
Series D-2 Convertible Preferred Stock
Class Of Stock [Line Items]
Issuance of convertible preferred stock for cash, net of issuance costs, shares					93,995,300	94,007,051			86,775,740
Shares issued, price per share | $ / shares						$ 0.8510
Convertible preferred stock issued for deferred purchase price obligation, shares					7,219,560	7,231,311			7,219,560
Convertible preferred stock, shares issued for deferred purchase price obligation, value | $					$ 6,100,000	$ 6,200,000			$ 6,144,000
Change in fair value of preferred stock purchase right liability | $											$ 1,000,000
Series D Convertible Preferred Stock
Class Of Stock [Line Items]
Fair value of preferred stock purchase right liability | $						$ 3,900,000
Common Stock
Class Of Stock [Line Items]
Conversion of convertible preferred stock into common stock at initial public offering, shares									25,485,955
Issuance of shares of common stock in initial public offering for cash, net of issuance costs, shares							555,297		11,500,000
Issuance of common stock under employee stock purchase plan, shares							19,979
Common Stock | Convertible Preferred Stock
Class Of Stock [Line Items]
Conversion of convertible preferred stock into common stock at initial public offering, shares			25,485,955
Common Stock | Convertible Preferred Stock Warrant Liability
Class Of Stock [Line Items]
Conversion of convertible preferred stock into common stock at initial public offering, shares			14,884

Stockholders' Equity (Deficit_3

Stockholders' Equity (Deficit) - Summary of Stock Option Activity (Details) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2022 USD ($) $ / shares shares	Dec. 31, 2021 USD ($) $ / shares shares
Equity [Abstract]
Number of shares, Outstanding at December 31, 2021 | shares	6,474,039
Number of shares, Granted | shares	1,325,947
Number of shares, Exercised | shares	(163,675)
Number of shares, Cancelled/forfeited | shares	(91,665)
Number of shares, Outstanding at June 30, 2022 | shares	7,544,646	6,474,039
Number of shares, Vested or expected to vest at June 30, 2022 | shares	7,544,646
Number of shares, Exercisable at June 30, 2022 | shares	2,299,870
Weighted Average Exercise Price, Outstanding at December 31, 2021 | $ / shares	$ 12.18
Weighted Average Exercise Price, Granted | $ / shares	30.34
Weighted Average Exercise Price, Exercised | $ / shares	2.73
Weighted Average Exercise Price, Cancelled/forfeited | $ / shares	20.54
Weighted Average Exercise Price, Outstanding at June 30, 2022 | $ / shares	15.47	$ 12.18
Weighted Average Exercise Price, Vested or expected to vest at June 30, 2022 | $ / shares	15.47
Weighted Average Exercise Price, Exercisable at June 30, 2022 | $ / shares	$ 4.98
Weighted Average Remaining Contractual Terms (in Years), Outstanding at December 31, 2021	8 years 3 months 18 days	8 years 6 months
Weighted Average Remaining Contractual Terms (in Years), Vested or excepted to vest at June 30, 2022	8 years 3 months 18 days
Weighted Average Remaining Contractual Terms (in Years), Exercisable at June 30, 2022	6 years 7 months 6 days
Aggregate Intrinsic Value, Outstanding at December 31, 2021 | $	$ 108,623	$ 177,130
Aggregate Intrinsic Value, Vested or excepted to vest at June 30, 2022 | $	108,623
Aggregate Intrinsic Value, Exercisable at June 30, 2022 | $	$ 53,483

Stockholders' Equity (Deficit_4

Stockholders' Equity (Deficit) - Summary of Grant Date Fair Value of Stock Options (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate, Minimum	2.70%	1%	1.50%	0.60%
Risk-free interest rate, Maximum	3%	1.10%	3%	1.10%
Expected volatility, Minimum	73.80%	73%	73.20%	73%
Expected volatility, Maximum	74.40%	74.20%	74.60%	95.20%
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	5 years 6 months	5 years 9 months 18 days	5 years 6 months	5 years 9 months 18 days
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	6 years 6 months	6 years 1 month 6 days	6 years 6 months	6 years 1 month 6 days

Stockholders' Equity (Deficit_5

Stockholders' Equity (Deficit) - Summary of Restricted Stock Units Activity (Details) - Restricted Stock Units	6 Months Ended
	Jun. 30, 2022 $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Outstanding Awards, Granted	112,886
Number of Outstanding Awards, Balance at June 30, 2022	112,886
Vested or expected to vest at June 30, 2022	112,886
Weighted Average Grant Date Fair Value, Granted | $ / shares	$ 29.56

Stockholders' Equity (Deficit_6

Stockholders' Equity (Deficit) - Summary of Activity Unvested Common Stock Issued Pursuant Early Exercise of Stock Options Awards (Details)	6 Months Ended
	Jun. 30, 2022 shares
Equity [Abstract]
Unvested at beginning of period	17,606
Vested or cancelled during the period	(8,625)
Unvested at end of period	8,981

Stockholders' Equity (Deficit_7

Stockholders' Equity (Deficit) - Summary of Fair Value of Stock of the Stock Purchase Right Under ESPP (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate, Minimum	2.70%	1%	1.50%	0.60%
Risk-free interest rate, Maximum	3%	1.10%	3%	1.10%
Expected volatility, Minimum	73.80%	73%	73.20%	73%
Expected volatility, Maximum	74.40%	74.20%	74.60%	95.20%
2021 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate, Minimum			0.03%
Risk-free interest rate, Maximum			2.40%
Expected volatility, Minimum			69.40%
Expected volatility, Maximum			83.90%
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	5 years 6 months	5 years 9 months 18 days	5 years 6 months	5 years 9 months 18 days
Minimum | 2021 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)			6 months
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	6 years 6 months	6 years 1 month 6 days	6 years 6 months	6 years 1 month 6 days
Maximum | 2021 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)			1 year 7 months 20 days

Stockholders' Equity (Deficit_8

Stockholders' Equity (Deficit) - Summary of Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	$ 4,636	$ 1,203	$ 7,915	$ 1,995
Research and Development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	1,644	267	2,780	438
General and Administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	$ 2,992	$ 936	$ 5,135	$ 1,557

Stockholders' Equity (Deficit_9

Stockholders' Equity (Deficit) - Summary of Common Stock Reserved for Future Issuance (Details) - shares	Jun. 30, 2022	Dec. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for issuance	10,719,938	8,678,836
Common Stock Options Issued and Outstanding
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for issuance	7,544,646	6,474,039
Warrants to Purchase Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for issuance	14,884	14,884
Shares Available for Issuance Under Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for issuance	2,456,930	1,856,063
ESPP Shares Pending Issuance
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for issuance	703,478	333,850

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details)	1 Months Ended	6 Months Ended	12 Months Ended
	Mar. 31, 2022 USD ($)	Jun. 30, 2022 USD ($)	Dec. 31, 2020 ft²	Oct. 31, 2021
Commitments And Contingencies [Line Items]
Operating lease right-of-use asset and liabilities	$ 14,600,000
Operating lease, weighted average remaining lease term		129 months
Operating lease, weighted average discount rate, percent		8%
Indemnification claims		$ 0
Accrued indemnification		$ 0
PLI
Commitments And Contingencies [Line Items]
Number of square feet of the building leased | ft²			40,000
Sublease agreement term			1 year
Sublease option to extend		true
Sublease option to extend, description		The sublease agreement was extended through June 2022 during the year ended December 31, 2021 and expired on June 30, 2022 in accordance with its terms. No further
Sublease term expiration date		2022-06
Office and Laboratory Space, San Diego
Commitments And Contingencies [Line Items]
Initial lease term	10 years			127 months
Option to extend additional lease term	5 years			5 years
Approximate monthly rental payment proceeds from lease	$ 200,000	$ 200,000
Option to extend lease	true	true
Lessee operating lease lease expect to commence year		2022-09
Office and Laboratory Space, San Diego | Maximum
Commitments And Contingencies [Line Items]
Tenant improvement allowance	$ 6,300,000	$ 6,300,000

Commitments and Contingencies_2

Commitments and Contingencies - Schedule of Information Related to Operating Lease (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Commitments And Contingencies Disclosure [Abstract]
Operating lease expense (including variable costs of $0.1 million and zero during the three and six months ended June 30, 2022 and 2021, respectively)	$ 893	$ 247	$ 1,227	$ 492
Cash paid for amounts included in the measurement of lease liabilities	$ 228		$ 228

Commitments and Contingencies_3

Commitments and Contingencies - Schedule of Information Related to Operating Lease (Parenthetical) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Commitments And Contingencies Disclosure [Abstract]
Variable lease, costs	$ 0.1	$ 0.1	$ 0	$ 0

Commitments and Contingencies_4

Commitments and Contingencies - Future Minimum Operating Lease Payments for the Second Floor Lease and Information Related to Lease Liability (Details) $ in Thousands	Jun. 30, 2022 USD ($)
Commitments And Contingencies Disclosure [Abstract]
Remainder of 2022	$ 312
2023	1,912
2024	1,970
2025	2,029
2026	2,090
Thereafter	14,552
Total lease payments	22,865
Imputed interest	(8,105)
Lease liability	14,760
Less current portion of lease liability	1,202
Lease liability, net of current portion	$ 13,558

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended		3 Months Ended			6 Months Ended
	Jan. 31, 2021	Oct. 31, 2020	Jun. 30, 2022	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021	Sep. 30, 2017
Related Party Transaction [Line Items]
Common stock, shares issued			39,699,667			39,699,667		38,960,716
Common stock, par value			$ 0.0001			$ 0.0001		$ 0.0001
Series D-2 Convertible Preferred Stock
Related Party Transaction [Line Items]
Issuance of convertible preferred stock for settlement of deferred purchase price	$ 6,100	$ 6,200			$ 6,144
PLI | Series D-2 Convertible Preferred Stock
Related Party Transaction [Line Items]
Number of convertible preferred stock issued as deferred consideration for acquisition	7,219,560
Cedars-Sinai Agreement | Vested Common Stock | Cedars-Sinai
Related Party Transaction [Line Items]
Common stock, shares issued									257,500
Common stock, par value									$ 0.0001
Cedars-Sinai Agreement | Unvested Restricted Common Stock | Cedars-Sinai
Related Party Transaction [Line Items]
Common stock, shares issued									335,000
Unvested restricted common stock shares par value									$ 0.0001
Transition Services Agreement
Related Party Transaction [Line Items]
Payment for terms of agreement			$ 1,000	$ 1,900		$ 700	$ 2,200

401(K) Plan - Additional Inform

401(K) Plan - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Compensation And Retirement Disclosure [Abstract]
Company contribution to 401(k) plan	$ 0.2	$ 0.1	$ 0.6	$ 0.1

Subsequent Events - Additional

Subsequent Events - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	6 Months Ended
	Aug. 11, 2022	Jun. 30, 2022
Subsequent Event [Line Items]
Net proceeds		$ 15,163
Sale Agreement
Subsequent Event [Line Items]
Sale of common stock		555,297
Weighted average price		$ 27.31
Net proceeds		$ 14,000
Subsequent Event | Sale Agreement
Subsequent Event [Line Items]
Sale of common stock	1,581,583
Weighted average price	$ 33.54
Net proceeds	$ 51,500