Prometheus Biosciences (RXDX) 10-K 9 Mar 22 2021 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Mar. 01, 2022	Jun. 30, 2021
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
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 Voluntary Filers	No
Entity Well-known Seasoned Issuer	No
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 Public Float			$ 738
Entity Common Stock, Shares Outstanding		39,073,802
Entity File Number	001-40187
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	81-4282653
Entity Address, Address Line One	9410 Carroll Park Drive
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	684-1300
ICFR Auditor Attestation Flag	false
Title of 12(b) Security	Common Stock, $0.0001 par value per share
Trading Symbol	RXDX
Security Exchange Name	NASDAQ
Document Annual Report	true
Document Transition Report	false
Auditor Name	BDO USA, LLP
Auditor Location	San Diego, CA
Auditor Firm ID	243
Documents Incorporated by Reference	DOCUMENTS INCORPORATED BY REFERENCE Certain sections of the registrant’s definitive proxy statement for the 2022 annual meeting of stockholders to be filed with the Securities and Exchange Commission pursuant to Regulation 14A not later than 120 days after the end of the fiscal year covered by this Form 10-K are incorporated by reference into Part III of this Form 10-K.

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets
Cash and cash equivalents	$ 257,254	$ 54,201
Accounts receivable	1,079	1,086
Prepaid expenses and other current assets	7,050	2,169
Total current assets	265,383	57,456
Equipment, net	1,447	447
Deferred financing costs		1,730
Other assets	971
Total assets	267,801	59,633
Current liabilities
Accounts payable	1,153	958
Accrued compensation	5,378	2,722
Accrued expenses and other current liabilities	6,050	2,894
Amounts due to Nestlé, current—related party		5,675
Payable to PLI	193	1,130
Deferred revenue	3,668	1,876
Total current liabilities	16,442	15,255
Long-term debt, net		7,399
Deferred revenue, non-current	16,204	4,597
Preferred stock purchase right liability		3,900
Total liabilities	32,646	31,151
Commitments and contingencies (Note 9)
Convertible preferred stock—$0.0001 par value; no shares and 254,983,985 shares authorized at December 31, 2021 and 2020, respectively; no shares and 160,864,434 shares issued and outstanding at December 31, 2021 and 2020, respectively; liquidation preferences of $0 and $130,487 at December 31, 2021 and 2020, respectively.		126,023
Stockholders’ equity (deficit):
Preferred stock—$0.0001 par value; 40,000,000 shares and no shares authorized at December 31, 2021 and 2020, respectively; no shares issued and outstanding at December 31, 2021 and 2020.
Common stock—$0.0001 par value; 400,000,000 shares and 325,000,000 shares authorized as of December 31, 2021 and 2020, respectively; 38,960,716 shares and 1,768,325 shares issued at December 31, 2021 and 2020, respectively; 38,943,110 shares and 1,713,622 shares outstanding at December 31, 2021 and 2020, respectively.	4
Additional paid-in capital	424,492	1,605
Accumulated deficit	(189,341)	(99,146)
Total stockholders’ equity (deficit)	235,155	(97,541)
Total liabilities, convertible preferred stock and stockholders’ equity (deficit)	$ 267,801	$ 59,633

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Statement Of Financial Position [Abstract]
Convertible preferred stock, par value	$ 0.0001	$ 0.0001
Convertible preferred stock, shares authorized	0	254,983,985
Convertible preferred stock, shares issued	0	160,864,434
Convertible preferred stock, shares outstanding	0	160,864,434
Convertible preferred stock, liquidation preference	$ 0	$ 130,487,000
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	40,000,000	0
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	325,000,000
Common stock, shares issued	38,960,716	1,768,325
Common stock, shares outstanding	38,943,110	1,713,622

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Income Statement [Abstract]
Collaboration revenue	$ 3,129	$ 1,229
Operating expenses:
Research and development	62,427	19,147
General and administrative	28,505	11,089
Total operating expense	90,932	30,236
Loss from operations	(87,803)	(29,007)
Other income (expense), net:
Interest income	108	13
Interest expense	(861)	(2,130)
Loss on early extinguishment of debt	(554)
Change in fair value of preferred stock purchase right liability	(980)
Change in fair value of preferred stock warrant liability	(105)	(15)
Total other income (expense), net	(2,392)	(2,132)
Loss from continuing operations	(90,195)	(31,139)
Loss from discontinued operations		(5,999)
Net loss	$ (90,195)	$ (37,138)
Net loss per share, basic and diluted:
Continuing operations	$ (2.88)	$ (20.78)
Discontinued operations		(4)
Net loss per share, basic and diluted	$ (2.88)	$ (24.78)
Weighted average shares outstanding, basic and diluted	31,334,154	1,498,973

Consolidated Statements of Conv

Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Convertible Preferred Stock	Series C Convertible Preferred Stock	Series D Convertible Preferred Stock	Series D-2 Convertible Preferred Stock	Common Stock	Additional Paid-in Capital	Accumulated Deficit
Beginning Balance at Dec. 31, 2019	$ (36,968)						$ 483	$ (37,451)
Temporary Equity, Balance, shares at Dec. 31, 2019	58,145,867	58,145,867
Temporary Equity, Balance at Dec. 31, 2019	$ 43,740	$ 43,740
Balance, shares at Dec. 31, 2019						1,351,380
Issuance of convertible preferred stock for cash, net of issuance costs			$ 27,989	$ 41,948
Issuance of convertible preferred stock for cash, net of issuance costs, shares			28,063,500	61,066,216
Convertible preferred stock issuance costs			$ (74)	$ (305)
Issuance of Series C convertible preferred stock upon release of escrow of acquisition-related contingent consideration			$ 3,500
Issuance of Series C convertible preferred stock upon release of escrow of acquisition-related contingent consideration, shares			3,500,000
Issuance of convertible preferred stock for deferred purchase price			$ 5,000	$ 3,846
Issuance of convertible preferred stock for deferred purchase price, shares			5,000,000	5,088,851
Issuance of common stock in exchange for services	112						112
Issuance of common stock in exchange for services, shares						36,200
Vesting of common shares issued to founders	1						1
Vesting of common shares issued to founders, shares						48,750
Vesting of common shares issued for licensing rights	1						1
Vesting of common shares issued for licensing rights, shares						111,667
Issuance of common stock upon exercise of stock options	156						156
Issuance of common stock upon exercise of stock options, shares						131,002
Vesting of early exercised stock options	12						12
Vesting of early exercised stock options, shares						34,623
Impact of spinoff of diagnostic services business	(24,557)							(24,557)
Stock-based compensation	840						840
Net loss	(37,138)							(37,138)
Ending Balance at Dec. 31, 2020	$ (97,541)						1,605	(99,146)
Temporary Equity, Balance, shares at Dec. 31, 2020	160,864,434	160,864,434
Temporary Equity, Balance at Dec. 31, 2020	$ 126,023	$ 126,023
Balance, shares at Dec. 31, 2020	1,713,622					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
Convertible preferred stock issuance costs					$ (94)
Issuance of Series D-2 convertible preferred stock for settlement of deferred purchase price					$ 6,144
Issuance of Series D-2 convertible preferred stock for settlement of deferred purchase price, shares					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	199,792					$ 1	199,791
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	725						725
Issuance of common stock in exchange for services, shares						28,850
Issuance costs related to initial public offering						$ 18,709
Issuance of common stock upon exercise of stock options	$ 237						237
Issuance of common stock upon exercise of stock options, shares	151,436					151,436
Issuance of common stock under employee stock purchase plan	$ 428						428
Issuance of common stock under employee stock purchase plan, shares						26,150
Vesting of early exercised stock options	32						32
Vesting of early exercised stock options, shares						37,097
Stock-based compensation	10,698						10,698
Net loss	(90,195)							(90,195)
Ending Balance at Dec. 31, 2021	$ 235,155					$ 4	$ 424,492	$ (189,341)
Temporary Equity, Balance, shares at Dec. 31, 2021	0
Balance, shares at Dec. 31, 2021	38,943,110					38,943,110

Consolidated Statements of Co_2

Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Series D-2 Convertible Preferred Stock
Temporary stock, issuance costs	$ 94
Series D Convertible Preferred Stock
Temporary stock, issuance costs		$ 305
Series C Convertible Preferred Stock
Temporary stock, issuance costs		$ 74
Common Stock
Stock issuance costs	$ 18,709

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities
Net loss	$ (90,195)	$ (37,138)
Loss from continuing operations	(90,195)	(31,139)
Loss from discontinued operations		(5,999)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	258	109
Stock-based compensation expenses	10,698	739
Loss on early extinguishment of debt	554
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	725	113
Noncash interest expense	553	1,589
Other		(15)
Changes in operating assets and liabilities:
Accounts receivable	7	(1,086)
Prepaid expenses and other current assets	(4,881)	(1,802)
Other assets	(971)
Accounts payable	103	(480)
Accrued compensation	2,655	1,738
Accrued expenses and other current liabilities	3,443	1,108
Payments made to PLI		(6,866)
Payable to PLI	(937)	1,130
Deferred revenue	13,398	4,931
Net cash used in operating activities – continuing operations	(63,505)	(29,931)
Net cash used in operating activities – discontinued operations		1,913
Net cash used in operating activities	(63,505)	(28,018)
Cash flows from investing activities
Purchase of property and equipment	(1,136)	(204)
Net cash used in investing activities – continuing operations	(1,136)	(204)
Net cash used in investing activities – discontinued operations		(859)
Net cash used in investing activities	(1,136)	(1,063)
Cash flows from financing activities
Proceeds from issuance of convertible preferred stock, net of issuance costs	73,749	73,826
Proceeds from issuance of long-term debt, net of issuance costs		7,338
Payments of stock issuance costs		(23)
Repayment of debt	(7,963)
Proceeds from sale of common stock in initial public offering	218,500
Payment of financing costs	(17,257)	(1,452)
Proceeds from issuance of common stock under employee stock purchase plan	428
Proceeds from issuance of common stock upon stock option exercises	237	197
Net cash provided by financing activities	267,694	79,886
Net increase in cash and cash equivalents	203,053	50,805
Cash and cash equivalents at beginning of period – continuing operations	54,201	4,450
Cash and cash equivalents at beginning of period – discontinued operations	4,975	3,921
Cash and cash equivalents cash at end of period	257,254	59,176
Cash and cash equivalents at end of period – discontinued operations		4,975
Cash and cash equivalents at end of period – continuing operations	257,254	54,201
Supplemental disclosures
Cash paid for income taxes	15	7
Cash paid for interest expense on Oxford debt	315	571
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
Acquisition-related consideration held in escrow		(3,500)
Issuance of Series C convertible preferred stock for deferred purchase price		5,000
Vesting of unvested issued common stock	32	38
Costs incurred, but not paid, in connection with capital expenditures included in accounts payable	153	181
Preferred stock purchase right liability	$ (4,880)	$ 3,900

Organization

Organization	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Organization	1. 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 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) (see Note 6). PLI marketed and conducted 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 (see Note 6). 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 December 31, 2021, has an accumulated deficit of $189.3 million. The Company has historically financed its operations primarily through private placements of convertible preferred stock. The Company expects operating losses and negative cash flows from operations to continue for the foreseeable future. The Company believes its current capital resources will be sufficient for the Company to continue as a going concern for at least one year from the issuance date of these consolidated financial statements. 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	12 Months Ended
	Dec. 31, 2021
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 consolidated 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 December 31, 2020, the Company completed the spinoff of PLI. The results of operations for all periods presented have been presented as discontinued operations in the accompanying consolidated financial statements in accordance with ASC 205-20, Presentation of Financial Statements—Discontinued Operations On an ongoing basis, management evaluates its estimates, primarily related to revenue recognition, stock-based compensation, fair value of common stock, fair value of the convertible preferred stock, fair value of the preferred stock purchase right liability, and accrued research and development costs. 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. Principles of Consolidation The consolidated financial statements include the accounts of the Company and until December 31, 2020, the date at which the spinoff was completed, its wholly-owned subsidiary, PLI and have been prepared in conformity with GAAP. All intercompany accounts and transactions have been eliminated in consolidation. Segment Reporting The Company’s Chief Executive Officer, who is considered to be the chief operating decision maker (CODM), reviews financial information presented on a consolidated basis, accompanied by information about operating segments for purposes of making operating decisions and assessing financial performance. Operating segments are defined as components of an enterprise about which separate financial information is available that is evaluated regularly by the CODM in deciding how to allocate resources and in assessing performance. Prior to the spinoff of PLI in December 2020, the Company determined its operating segments to be the therapeutics and diagnostic services businesses. The therapeutics business derives substantially all of its revenue from collaboration agreements and devotes all of its efforts to development of product candidates and companion diagnostics in the IBD space. The diagnostic services business, which is recorded as a discontinued operations, derives its revenue from diagnostic services in the IBD space generated from the conduct of laboratory developed tests. Subsequent to the spinoff, the Company operates in one segment. The Company operates solely in the United States. 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 December 31, 2021 and 2020 represents cash in readily available checking and money market accounts. Concentration of Credit Risk Financial instruments, which potentially subject the Company to concentration of credit risk, consist primarily of cash, cash equivalents, 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 clinical trial costs subject to reimbursement under the Company’s collaboration agreements. The Company did not record any allowance for doubtful accounts as of December 31, 2021 and 2020. Equipment, Net 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 three to five 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 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. Deferred Financing Costs At December 31, 2020, $1.7 million of deferred financing costs were recorded in the accompanying consolidated balance sheets. Upon completion of the IPO in March 2021, all of these costs were offset against the proceeds from the IPO and there were no deferred financing costs recorded as of December 31, 2021. Revenue Recognition The Company recognizes revenue in accordance with ASC Topic 606, Revenue from Contracts with Customers 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 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, 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. Patent Costs Costs related to filing and pursuing patent applications are recorded as general and administrative expense in the accompanying consolidated statements of operations and are expensed as incurred since recoverability of such expenditures is uncertain. 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 over the requisite service period (usually the vesting period) on a straight-line basis, net of actual forfeitures during the period, based on the estimated grant-date fair value of the awards. The Company estimates the fair value of stock option grants 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. For restricted stock awards, the fair value of the award is the estimated fair value of the Company’s common stock on the grant date, as determined by the Company’s board of directors. Valuation of Common Stock Prior to the IPO, given the absence of a public trading market for the Company’s common stock, its 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 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 were 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 Income Taxes The Company accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, deferred tax assets and liabilities are determined on the basis of the differences between the financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. The Company recognizes net deferred tax assets to the extent that the Company believes these assets are more likely than not to be realized. In making such a determination, management considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies, and results of recent operations. If management determines that the Company would be able to realize its deferred tax assets in the future in excess of their net recorded amount, management would make an adjustment to the deferred tax asset valuation allowance, which would reduce the provision for income taxes. The Company records uncertain tax positions on the basis of a two-step process whereby (1) management determines whether it is more likely than not that the tax positions will be sustained on the basis of the technical merits of the position and (2) for those tax positions that meet the more-likely-than-not recognition threshold, management recognizes the largest amount of tax benefit that is more than 50 percent likely to be realized upon ultimate settlement with the related tax authority. The Company recognizes interest and penalties related to unrecognized tax benefits within income tax expense. Any accrued interest and penalties are included within the related tax liability. 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 32,381 and 145,046 weighted-average shares subject to repurchase or forfeiture from the weighted-average number of common shares outstanding for the years ended December 31, 2021 and 2020, respectively. Dilutive common stock equivalents are comprised of convertible preferred stock, options outstanding under the Company’s stock option plan, warrants to purchase common or convertible preferred stock and ESPP shares pending issuance. 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 years ended December 31, 2021 and 2020, 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): December 31, 2021 2020 Convertible preferred stock outstanding — 16,086,426 Common stock options issued and outstanding 6,474,039 2,930,248 Warrants to purchase common stock outstanding 14,884 — Warrants to purchase convertible preferred stock outstanding — 11,250 ESPP shares pending issuance 7,187 — Total 6,496,110 19,027,924 Comprehensive Loss Net loss and comprehensive loss were the same for the periods presented; therefore, a separate statement of comprehensive loss is not included in the accompanying consolidated financial statements. 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. Adoption of New Accounting Standards In February 2016, the FASB issued Accounting Standards Update (ASU) 2016-02, Leases (Topic 842) Leases (Topic 840) The Company made accounting policy elections to exclude leases with terms of 12 months or less from the recognition requirements and to not separate lease and non-lease components. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses: Measurement of credit Losses on Financial Instruments (ASU 2016-13) determined there was no cumulative-effect transition adjustment required to the opening balance of accumulated deficit for the recognition of additional credit losses upon adoption of this standard based on its outstanding accounts receivable, the composition and credit quality of its short-term investments, and current economic conditions as of that date. In August 2020, the FASB issued ASU No. 2020-06, Debt – Debt with Conversion and Other options (Subtopic 470-20) and Derivative and Hedging – Contracts in Entity’s Own Equity (Subtopic 815-40). In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes (ASU 2019-12) December 15, 2020. The Company adopted this standard o n January 1, 2021 and it did no t have a material impact on its consolidated financial statements . New Accounting Pronouncements Not Yet Adopted 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, which are the dates included above.

Fair Value Measurements and Fai

Fair Value Measurements and Fair Value of Financial Instruments	12 Months Ended
	Dec. 31, 2021
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 cash equivalents, prepaid and other assets, accounts payable and accrued liabilities are representative of their respective fair values because of the short-term nature of those instruments. Based on the borrowing rates currently available to the Company for loans with similar terms, which is considered a Level 2 input, the Company believes that the fair value of long-term debt approximates its carrying value. The Company’s financial instruments that are carried at fair value consist of Level 3 liabilities. There were no transfers within the hierarchy during the years ended December 31, 2021 and 2020. 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 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 Series C 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 Series C convertible preferred stock warrant liability at the date of the IPO and December 31, 2020 were as follows: IPO Date December 31, 2020 Fair value of underlying preferred stock $ 1.90 $ 0.83 Risk-free interest rate 1.70 % 1.70 % Expected volatility 70.00 % 70.00 % Expected term (in years) 9.0 9.2 Expected dividend yield —% —% Preferred Stock Purchase Right Liability The preferred stock purchase right liability was determined 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. Upon the issuance of the shares of Series D-2 convertible preferred stock in January 2021, the liability was remeasured and as a result of closing the sale of shares of Series D-2 convertible preferred stock, a charge of $1.0 million was recorded in the statement of operations for the year ended December 31, 2021. 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): Acquisition-related Consideration Held in Escrow Convertible Preferred Stock Warrant Liability Series D Convertible Preferred Stock Purchase Right Liability Balance at December 31, 2019 $ 3,500 $ — $ — Acquisition-related consideration released from escrow (3,500 ) — — Issuance of Series C convertible preferred stock warrants — 79 — Issuance of Series D convertible preferred stock purchase right liability — — 3,900 Change in fair value — (15 ) — Balance at December 31, 2020 — 64 3,900 Change in fair value — 105 980 Reclassification of warrant liability to equity due to conversion from preferred stock warrant to common stock warrant upon completion of initial public offering — (169 ) — Settlement of Series D convertible preferred stock purchase right liability (4,880 ) Balance at December 31, 2021 $ — $ — $ —

Balance Sheet Details

Balance Sheet Details	12 Months Ended
	Dec. 31, 2021
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Details	4. Balance Sheet Details Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consist of the following (in thousands): December 31, 2021 December 31, 2020 Prepaid contract manufacturing expenses $ 3,808 $ 121 Prepaid clinical trial expenses 1,397 998 Prepaid research and development expenses 627 775 Other prepaid expenses 1,218 275 Total $ 7,050 $ 2,169 Equipment, Net Equipment, net, consist of the following (in thousands): December 31, 2021 December 31, 2020 Laboratory equipment $ 1,830 $ 572 Office equipment and furniture 24 24 1,854 596 Less accumulated depreciation (407 ) (149 ) Total $ 1,447 $ 447 Depreciation expense related to property and equipment was $0.3 million and $0.1 million for the years ended December 31, 2021 and 2020, respectively. Accrued Compensation Accrued compensation consist of the following (in thousands). December 31, 2021 December 31, 2020 Accrued salaries and payroll taxes $ 64 $ 402 Accrued vacation — 102 Accrued employee stock purchase plan contributions 129 — Accrued bonuses 5,024 1,556 Accrued severance 161 662 Total $ 5,378 $ 2,722 Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consist of the following (in thousands): December 31, 2021 December 31, 2020 Accrued research and development expenses $ 2,123 $ 216 Accrued clinical trial expenses 1,999 109 Accrued contract manufacturing expenses 906 1,343 Accrued legal expenses 531 490 Unvested early exercise liability 35 67 Accrued other 456 669 Total $ 6,050 $ 2,894

Collaboration and License Agree

Collaboration and License Agreements	12 Months Ended
	Dec. 31, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Collaboration and License Agreements	5. 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 Agreement over a three-year In 2017, the Company and Cedars-Sinai also entered into research agreements, under which the parties can provide research services to each other at pricing specified in individual statements of work. During the years ended December 31, 2021 and 2020, no services were provided under the agreements. 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 PR600 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 PR600 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 eight-year Millennium Pharmaceuticals, Inc., a subsidiary of Takeda Pharmaceutical Company Limited 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, pursuant to which the Company agreed to develop a companion diagnostic product for drug target s selected by Takeda, and Takeda agreed to develop and commercialize any therapeutic clinical candidates that it develops directed against any selected drug targets for the treatment of IBD (Takeda Drugs) . Under the Takeda Agreement, Takeda agreed to reimburse us for certain research and development expenses and i n the event the parties agree on any drug targets to advance under the agreement we would be eligible to receive various payments, including future development and regulatory milestone payments , commercial milestone payments , sales milestone payments , and royalties on net sales of Takeda Drugs, subject to the terms and conditions set forth in the Takeda Agreement. The Company has identified one performance obligation per target for all the deliverables under the agreement since the delivered elements are not distinct within the context of the contract. Accordingly, the Company will recognize revenue for the transaction price in an amount proportional to the collaboration expenses incurred and the total estimated collaboration expenses over the four-year A reconciliation of deferred revenue related to the Falk and Takeda agreements for the years ended December 31, 2021 and 2020 is as follows (in thousands): Takeda Agreement Falk Agreement Total Balance at December 31, 2019 $ 1,542 $ — $ 1,542 Amounts received 960 5,200 6,160 Revenue recognized (792 ) (437 ) (1,229 ) Balance at December 31, 2020 1,710 4,763 6,473 Amounts received/credited (150 ) 16,678 16,528 Revenue recognized (379 ) (2,750 ) (3,129 ) Balance at December 31, 2021 $ 1,181 $ 18,691 $ 19,872 The Company expects to recognize $3.7 million of the deferred revenue balance in 2022.

Discontinued Operations

Discontinued Operations	12 Months Ended
	Dec. 31, 2021
Discontinued Operations And Disposal Groups [Abstract]
Discontinued Operations	6. On June 30, 2019, the Company acquired 100% of the common stock of PLI and the related intangible assets used by PLI for total consideration of approximately $31.7 million, consisting of the issuance of 16.5 million shares of the Company’s Series C convertible preferred stock with a fair value of $16.5 million, the present value of $15.0 million in deferred cash payments due as follows: $5.0 million due on June 30, 2020 and $10.0 million due on June 30, 2021, and acquisition-related contingent consideration consisting of 3,500,000 shares of the of the Company’s Series C convertible preferred stock with a fair value of $3.5 million. The deferred cash payments totaling $15.0 million were not contingent upon any event and to reflect the interest component were discounted at 12%. In June 2020, $5.0 million of deferred cash payments were converted to 5,000,000 shares of Series C convertible preferred stock and in October 2020, $3.8 million of deferred cash payments were converted to 5,088,851 shares of Series D convertible preferred stock. In addition, in January 2021, $6.1 million of deferred cash payments were converted to 7,219,560 shares of Series D-2 convertible preferred stock. As of December 31, 2021 and 2020, a total of $0 and $5.7 million, respectively, is recorded as Amounts due to Nestlé, current—related party in the accompanying consolidated balance sheets. The acquisition-related contingent consideration stipulated certain revenue thresholds for the Anser® test during the first calendar year following the acquisition. The shares were released from escrow on June 30, 2020. In December 2020, in order to achieve the Company’s strategic objectives, the Company’s board of directors approved 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. In connection with the spinoff, which was effected on December 31, 2020, the Company assigned PLI specific intellectual property to PLI; entered into a transition services agreement whereby the Company agreed to provide PLI with certain transition services including general and administrative, finance and clinical operations support; and entered into a sublease agreement under which the Company occupied approximately 40,000 square feet in the PLI facility for a term of one year, which was subsequently extended for six months through June 2022. Post spinoff, the Company retained obligations under the Oxford Loan (see Note 7) and for the deferred cash payments to Nestlé The major line items constituting the loss of PLI for the year ended December 31, 2020, which are reflected in the accompanying consolidated statements of operations as discontinued operations, are as follows: Year Ended December 31, 2020 Diagnostic services revenue $ 36,593 Operating expenses: Cost of diagnostic services revenue 12,625 Research and development 4,956 Sales and marketing 10,993 General and administrative 9,885 Restructuring 2,260 Amortization of intangible assets 1,179 Goodwill impairment charge 724 Total operating expenses 42,622 Income (loss) from discontinued operations (6,029 ) Interest income 30 Loss from discontinued operations, net of taxes $ (5,999 ) Commitments and Contingencies At the acquisition date, PLI was involved with several legal proceedings and claims against it. All claims against PLI remained obligations of PLI and effective upon the spinoff, the Company has no remaining obligations with respect to these claims.

Long Term Debt

Long Term Debt	12 Months Ended
	Dec. 31, 2021
Debt Disclosure [Abstract]
Long Term Debt	7. In January 2020, the Company entered into a Loan and Security Agreement with Oxford Finance LLC and its affiliates (Oxford) (the Oxford Loan) which provides for total borrowings of up to $25.0 million, of which $7.5 million was drawn upon execution of the agreement. Interest accrues 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 is required to make interest only payments. Beginning March 1, 2023, in addition to interest payments, the monthly payments will include an amount equal to the outstanding principal divided by 24 months. At maturity (or earlier prepayment), the Company is 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 Oxford Loan was collateralized by a first priority security interest in substantially all of the Company’s current and future assets, other than its intellectual property, and contains customary conditions of borrowing, events of default and covenants, including covenants that restricted the Company’s ability to dispose of assets, merge with or acquire other entities, incur indebtedness and make distributions to holders of the Company’s capital stock. Should an event of default occur, including the occurrence of a material adverse change, the Company could have been liable for immediate repayment of all obligations under the Oxford Loan. In December 2020, the Oxford Loan Agreement was amended to allow the PLI spinoff and to release PLI from all obligations pursuant to the Oxford Loan. In addition, warrants to purchase 112,500 shares of Series C convertible preferred stock were issued to Oxford in conjunction with the execution of the agreement at an exercise price of $1.00 per share. The warrants have a ten-year 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 consolidated statements of operations for the year ended December 31, 2021.

Stockholders' Equity (Deficit)

Stockholders' Equity (Deficit)	12 Months Ended
	Dec. 31, 2021
Equity [Abstract]
Stockholders' Equity (Deficit)	8. Amended Articles 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. As of December 31, 2020, the Company’s convertible preferred stock was classified as temporary equity on the accompanying balance sheet in accordance with authoritative guidance for the classification and measurement of potentially redeemable securities whose redemption is based upon certain change in control events outside of the Company’s control. Series C Convertible Preferred Stock In March 2020, the Company sold 28,063,500 shares of Series C convertible preferred stock and received net cash proceeds totaling $28.0 million. 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 year ended December 31, 2021. The liability was then reclassified to stockholders’ equity. The authorized, issued and outstanding shares of convertible preferred stock as of December 31, 2020 consist of the following (in thousands, except share and per share amounts): Shares Authorized Shares Issued and Outstanding Per Share Original Issue Price Liquidation Value Carrying Value Series A 14,979,200 14,979,200 $ 0.50 $ 7,490 $ 7,391 Series B 26,666,667 26,666,667 0.75 20,000 19,901 Series C 53,176,000 53,063,500 1.00 53,064 52,937 Series D-1 66,155,067 66,155,067 0.76 49,933 45,794 Series D-2 94,007,051 — — — — Total 254,983,985 160,864,434 $ 130,487 $ 126,023 The rights, preferences and privileges of the convertible preferred stock as of December 31, 2020 were as follows: Dividends The Company shall not declare, pay or set aside any dividends on shares of any other class or series of capital stock unless the holders of Series A , B, C, and D convertible preferred stock (collectively referred to as Preferred Stock) shall first receive, or simultaneously receive, a dividend on each outstanding share of Preferred Stock in an amount equal to (on an as-if-converted to Common Stock basis) the amount paid or set aside for each share of Common Stock. There have been no dividends declared by the board as of December 31, 2020. Liquidation In the event of any voluntary or involuntary liquidation, dissolution or winding up of the Company or Deemed Liquidation Event, as defined, each holder Series D Preferred Stock is entitled to receive, prior and in preference to any distributions to the holders of Series A preferred stock, Series B preferred stock, Series C preferred stock and common stock, an amount equal to the greater of (i) the Original Issue Price per share, plus any declared but unpaid dividends thereon or (ii) the amount such holder would have received if such holder had converted its shares into common stock immediately prior to such liquidation event. Subject to the prior payment of all amounts due to holders of Series D preferred stock, each holder of Series C Preferred Stock is entitled to receive, prior and in preference to any distributions to the holders of Series A preferred stock, Series B preferred stock and common stock, an amount equal to the greater of (i) the Original Issue Price per share, plus any declared but unpaid dividends thereon or (ii) the amount such holder would have received if such holder had converted its shares into common stock immediately prior to such liquidation event. Subject to the prior payment of all amounts due to holders of Series C preferred stock, each holder of Series A and Series B preferred stock is entitled to receive, prior and in preference to any distributions to the common stockholders, an amount equal to the greater of (i) the Original Issue Price per share, plus any declared but unpaid dividends thereon or (ii) the amount such holder would have received if such holder had converted its shares into common stock immediately prior to such liquidation event. In the event that the assets available for distribution to the holders of preferred stock are insufficient to pay such holders the full amounts to which they are entitled, the assets available for distribution will be distributed on a pro rata basis among the holders of the preferred stock in proportion to the respective amounts that would otherwise be payable in respect of such stock. After all preferential payments have been made to the holders of preferred stock, the remaining amounts would be distributed among the holders of the Preferred Stock and common stock, pro rata based on the number of shares held by each holder. The maximum aggregate amount the holders of Series A, B, C, D-1, and D-2 preferred stock are entitled to receive is $1.50, $2.25, $3.00, $2.2674, and $2.553 per share, respectively. Conversion The shares of Preferred Stock are convertible into an equal number of shares of common stock, at the option of the holder, subject to certain anti-dilution adjustments. Each share of preferred stock is automatically converted into common stock, (A) at any time upon the affirmative election of the holders of at least a majority of the outstanding shares of the Preferred Stock, or (B) immediately upon the closing of a firmly underwritten public offering pursuant to an effective registration statement under the Securities Act of 1933, as amended, covering the offer and sale of common stock for the account of the Company in which the pre-money valuation of the Company is at least $330.0 million and the aggregate gross proceeds, net of underwriting discount and commissions, to the Company is at least $75.0 million. Voting The holders of Preferred stock are entitled to one vote for each share of common stock into which it would convert and to vote as one class with the common stockholders on all matters. Also, the preferred stockholders have been granted certain rights with regard to the election of members of the Company’s Board of Directors. Presentation of Convertible Preferred Stock The Company’s Preferred Stock have been classified as temporary equity in the accompanying balance sheets in accordance with authoritative guidance for the classification and measurement of potentially redeemable securities whose redemption is based upon certain change in control events outside of the Company’s control, including liquidation, sale or transfer of control of the Company. The Company has determined not to adjust the carrying values of the convertible preferred stock to the liquidation preferences of such shares because the occurrence of any such change of control event is not probable. Common Stock Founder Stock During 2016 and 2017, in connection with the founding of the Company, shares of common stock were sold to certain founders (the Founder Stock) at a price of $0.01 per share and which are subject to vesting, generally over a period of four years. The repurchase liability for the Founder Stock was nominal for all periods presented. For accounting purposes, the unvested shares are not considered to be outstanding. During the year ended December 31, 2020, 48,750 shares vested and there were no remaining unvested shares as of December 31, 2020. Restricted Shares Issued to Cedars-Sinai As previously described in Note 5, in 2017, as consideration for a license agreement, the Company granted 335,000 shares of restricted common stock to Cedars-Sinai that vest on the anniversary date of the grant date over a three-year 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 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 The maximum term of the options granted under both the 2017 Plan and 2021 Plan is ten years. 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 year ended December 31, 2021 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, 2020 2,930,248 $ 2.90 9.3 $ 2,290 Granted 3,943,984 $ 18.23 Exercised (151,436 ) $ 1.57 Cancelled/forfeited (248,757 ) $ 5.44 Outstanding at December 31, 2021 6,474,039 $ 12.18 8.5 $ 177,130 Vested or expected to vest at December 31, 2021 6,474,039 $ 12.18 8.5 $ 177,130 Exercisable at December 31, 2021 1,505,832 $ 3.51 6.1 $ 54,256 The weighted-average grant date fair value of options granted during the year ended December 31, 2021 and 2020 was $12.15, and $5.93, respectively. The total intrinsic value of options exercised during the years ended December 31, 2021 and 2020 was $2.5 million and $0.3 million, respectively. The total fair value of options vested during the years ended December 31, 2021 and 2020 was $21.9 million and $0.9 million, respectively. The grant date fair value of stock options was determined using the Black-Scholes option pricing model with the following assumptions: Year Ended December 31, 2021 2020 Risk-free interest rate 0.2 – 1.4% 0.2 – 1.4% Expected volatility 73.0 – 95.2% 61.5 – 71.8% Expected term (in years) 5.3 – 6.1 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. 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: Year Ended December 31, 2021 2020 Unvested at beginning of year 54,703 70,266 Early exercised stock options during the period — 23,540 Early exercised stock options repurchased during the period — (4,480 ) Vested during the period (37,097 ) (34,623 ) Unvested at end of year 17,606 54,703 Employee Stock Purchase Plan In February 2021, the Company’s board of directors approved the 2021 Employee Stock Purchase Plan, 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. Stock compensation expense for the year ended December 31, 2021 related to the ESPP was $0.5 million. As of December 31, 2021, the Company has issued 26,150 shares under the ESPP. The Company had an outstanding liability of $0.1 million at December 31, 2021, which is included in accrued compensation on the consolidated balance sheet, for employee contributions to the ESPP for shares pending issuance at the end of the offering period. At December 31, 2021, 333,850 shares remain available for issuance under the 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: Year Ended December 31, 2021 Risk-free interest rate 0.03– 0.33% Expected volatility 71.6 – 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): Year Ended December 31, 2021 2020 Research and development $ 1,755 $ 144 General and administrative 8,943 595 Discontinued operations — 101 Total stock-based compensation $ 10,698 $ 840 The total unrecognized compensation cost related to unvested stock-based awards as of December 31, 2021 was $45.4 million and is expected to be recognized over a weighted average period of 3.6 years. Stock Option Modification In August 2021, in connection with the passing of the Company’s former Chairman of the board of directors, the Company fully accelerated all of the former Chairman’s outstanding equity awards, which resulted in a charge of $4.6 million to stock-based compensation expense for the year ended December 31, 2021. Common Stock Reserved for Future Issuance Common stock reserved for future issuance consists of the following: December 31, 2021 December 31, 2020 Conversion of convertible preferred stock issued — 16,086,426 Conversion of convertible preferred stock in future issuance (D-2) — 9,400,705 Common stock options issued and outstanding 6,474,039 2,930,248 Warrants to purchase convertible preferred stock outstanding — 11,250 Warrants to purchase common stock outstanding 14,884 — Shares available for issuance under equity incentive plan 1,856,063 373,789 Shares available for issuance under the ESPP 333,850 — Total 8,678,836 28,802,418

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2021
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	9. Commitments and Contingencies Leases As a result of the PLI spinoff on December 31, 2020, the Company entered into a sublease agreement with PLI for approximately 40,000 square feet currently occupied in the PLI facility. The sublease agreement is for one year with an option to renew for an additional year. The sublease agreement was extended during the year ended December 31, 2021 through June 2022. The monthly payment is $80,000 and the total remaining payment obligation at December 31, 2021 is $0.5 million. In March 2021, the Company executed a non-cancellable lease agreement for office and laboratory space in San Diego, California. The lease has an initial term of ten years, following the commencement date 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. 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 At December 31, 2021, as the Company had not taken control of the space and the lease term had not yet commenced, no operating lease right-of-use assets or operating lease liabilities for the space has been recorded. The Company expects the lease to commence in 2022. The total future minimum lease payments under the amended lease are $47.1 million as of December 31, 2021. 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 December 31, 2021, no claims exist under indemnification arrangements and accordingly, no amounts have been accrued in its consolidated financial statements as of December 31, 2021.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	10. For the year ended December 31, 2021 and 2020, the income tax expense from continuing operations was zero and $7,000 and is recorded in general and administrative expense in the accompanying statements of operations. A reconciliation of the Company’s effective tax rate and federal statutory tax rate related to continuing operations is summarized as follows (in thousands): Years Ended December 31, 2021 2020 Income tax expense (benefit) at statutory rates $ (18,938 ) $ (6,538 ) State income tax, net of federal benefit (5,865 ) (586 ) Permanent items 255 (14 ) Change in valuation allowance 28,219 7,373 Forfeiture of state operating losses 42 521 Stock-based compensation 751 82 Purchase price accretion 101 311 Return to provision adjustment (84 ) 293 Research and development tax credits (4,481 ) (1,442 ) $ — $ — Deferred income taxes reflect the net tax effects of loss and credit carryforwards and temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Significant components of the Company’s deferred tax assets and liabilities related to continuing operations for federal and state income taxes are follows (in thousands): December 31, 2021 2020 Deferred tax assets: Net operating loss carryforward $ 32,373 $ 11,333 Research tax credits 7,012 2,509 Accrued and other 1,980 543 Stock-based compensation 1,390 121 Total deferred tax assets 42,755 14,506 Less valuation allowance (42,688 ) (14,477 ) Net deferred tax assets 67 29 Deferred tax liabilities: Property and equipment (67 ) (29 ) Total deferred tax liabilities (67 ) (29 ) Net deferred tax assets $ — $ — A valuation allowance is required to be established when it is more likely than not that all or a portion of a deferred tax asset will not be realized. Realization of deferred tax assets is dependent upon future earnings, the timing and amount of which are uncertain. A full review of all positive and negative evidence needs to be considered. The Company has established a full valuation allowance against the net deferred tax assets as of December 31, 2021 due to the uncertainty surrounding the realization of such assets. Management determined it more likely than not that the deferred tax assets are not realizable due to our historical loss position. The valuation allowance increased by $28.2 million and $7.4 million between December 31, 2020 and December 31, 2021 and between December 31, 2019 and December 31, 2020, respectively, due primarily to the generation of current year operating losses. As of December 31, 2021, the Company has net operating loss carryforwards for federal and state income tax purposes of $126.1 million and $85.0 million, respectively. The federal and state NOLs will begin to expire in 2036, unless previously utilized. The federal net operating loss carryover include $125.2 million of net operating losses generated in 2018 and after. Federal net operating losses generated in 2018 and after carryover indefinitely and may generally be used to offset up to 80% of future taxable income. The Company has research credit carryforwards for federal and state income tax purposes of approximately $5.1 million and $4.7 million, respectively, as of December 31, 2021. The federal credits begin to expire in 2037 and the state credits can be carried forward indefinitely. Pursuant to the Internal Revenue Code (IRC) Sections 382 and 383, annual use of the Company's NOL and research and development credit carryforwards may be limited in the event a cumulative change in ownership of more than 50% occurs within a three-year The Company recognizes a tax benefit from uncertain tax positions when it is more likely than not that the position will be sustained upon examination, including resolutions of any related appeals or litigation processes, based on the technical merits. Income tax positions must meet a more likely than not recognition at the effective date to be recognized. Due to the existence of the full valuation allowance, future changes in unrecognized tax benefits will not impact the Company’s effective tax rate. The Company does not foresee material changes to its liability for uncertain tax benefits within the next 12 months. The following table summarizes the activity in the Company’s gross unrecognized tax benefits (in thousands): December 31, 2021 2020 Balance at beginning of period $ 697 $ 300 Increase (decrease) related to prior year positions (186 ) — Increase related to current year positions 1,438 397 Balance at the end of the year $ 1,949 $ 697 The Company’s policy is to recognize interest and penalties related to income tax matters in the provision. During the years ended December 31, 2021 and 2020, no interest or penalties were required to be recognized relating for unrecognized tax benefits. The Company files tax returns in the United States and California. The Company is not currently under examination in any of these jurisdictions and all of the Company’s tax years remain effectively open to examination due to net operating loss carryforwards. On March 27, 2020, the United States enacted the Coronavirus Aid, Relief and Economic Security Act (CARES Act). The Cares Act is an emergency economic stimulus package that includes spending and tax breaks to strengthen the United States economy and fund a nationwide effort to curtail the effect of COVID-19. While the CARES Act provides sweeping tax changes in response to the COVID-19 pandemic, some of the more significant provisions which are expected to impact the Company’s financial statements include removal of certain limitations on utilization of net operating losses, increasing the loss carryback period for certain losses to five years, and increasing the ability to deduct interest expense, as well as amending certain provisions of the previously enacted Tax Cuts and Jobs Act. Due to the loss position of the U.S. entities, many provisions of the CARES Act do not impact the Company and the CARES Act did not have an impact on the Company’s income tax provision for the years ended December 31, 2021 or 2020.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2021
Related Party Transactions [Abstract]
Related Party Transactions	11. 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 their percentage of common stock ownership and their 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 years ended December 31, 2021 and 2020, no services were provided under the research agreements. During the year ended December 31, 2021, the Company incurred compensation related expenses for one employee who is an immediate family member of a former member of the Company’s board of directors. These expenses totaled $0.8 million for the year ended December 31, 2021, which is included in in research and development expenses in the accompanying consolidated statement of operations. During the year ended December 31, 2020, the Company incurred compensation related expenses for two employees, each of whom is an immediate family member of a different former member of the Company’s board of directors. These expenses totaled $ million for the year ended December 31, 2020 , respectively, of which $ 0.2 million is included in general and administrative expenses in the accompanying consolidated statement of operations and $ million is included in research and development expenses, respectively. As of December 31, 2020, the Company has a $5.7 million liability recorded within Amounts due to Nestlé, current—related party in the consolidated balance sheet. As disclosed in Notes 6 and 8, this amount relates to deferred consideration for the acquisition of PLI and was satisfied with the issuance of shares of Series D-2 convertible preferred stock in January 2021. The Company has an ongoing collaboration with Regents of the University of California, where a former member of its board of directors was employed until April 2021. During the year ended December 31, 2021, the Company incurred $0.5 million in expense related to this collaboration that was recorded in research and development expenses in the accompanying consolidated statement of operations for the year ended December 31, 2021. During the year ended December 31, 2020, the Company incurred $0.3 million in expense related to this collaboration that was recorded in Loss from discontinued operations in the accompanying consolidated statements of operations for the year ended December 31, 2020. As a result of the PLI spinoff on December 31, 2020, the Company entered into a transition services agreement under which it assumed a $1.1 million liability related to the payout of PLI employee bonuses for the year ended December 31, 2020. This amount is included in the amount payable to PLI in the accompanying consolidated balance sheets. Additionally, pursuant to this agreement, the Company is providing PLI certain transitional services, including general and administrative, finance and clinical operations support, and PLI is providing 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 initial term of the agreement is for one year, subject to earlier termination and extension thereafter. During the year ended December 31, 2021, the Company paid PLI $3.8 million in accordance with the terms of this agreement. The transition services agreement was extended during the year ended December 31, 2021 and includes providing for the use of facilities under a sublease through June 2022.

401(K) Plan

401(K) Plan	12 Months Ended
	Dec. 31, 2021
Compensation And Retirement Disclosure [Abstract]
401(K) Plan	12. 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 each of the years ended December 31, 2021 and 2020 were $0.3 million and $45,000, respectively.

COVID-19 Outbreak

COVID-19 Outbreak	12 Months Ended
	Dec. 31, 2021
Extraordinary And Unusual Items [Abstract]
COVID-19 Outbreak	13. The current COVID-19 worldwide pandemic has presented substantial public health and economic challenges and is affecting 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.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation and Use of Estimate	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 consolidated 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 December 31, 2020, the Company completed the spinoff of PLI. The results of operations for all periods presented have been presented as discontinued operations in the accompanying consolidated financial statements in accordance with ASC 205-20, Presentation of Financial Statements—Discontinued Operations On an ongoing basis, management evaluates its estimates, primarily related to revenue recognition, stock-based compensation, fair value of common stock, fair value of the convertible preferred stock, fair value of the preferred stock purchase right liability, and accrued research and development costs. 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.
Principles of Consolidation	Principles of Consolidation The consolidated financial statements include the accounts of the Company and until December 31, 2020, the date at which the spinoff was completed, its wholly-owned subsidiary, PLI and have been prepared in conformity with GAAP. All intercompany accounts and transactions have been eliminated in consolidation.
Segment Reporting	Segment Reporting The Company’s Chief Executive Officer, who is considered to be the chief operating decision maker (CODM), reviews financial information presented on a consolidated basis, accompanied by information about operating segments for purposes of making operating decisions and assessing financial performance. Operating segments are defined as components of an enterprise about which separate financial information is available that is evaluated regularly by the CODM in deciding how to allocate resources and in assessing performance. Prior to the spinoff of PLI in December 2020, the Company determined its operating segments to be the therapeutics and diagnostic services businesses. The therapeutics business derives substantially all of its revenue from collaboration agreements and devotes all of its efforts to development of product candidates and companion diagnostics in the IBD space. The diagnostic services business, which is recorded as a discontinued operations, derives its revenue from diagnostic services in the IBD space generated from the conduct of laboratory developed tests. Subsequent to the spinoff, the Company operates in one segment. The Company operates solely in the United States.
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 December 31, 2021 and 2020 represents cash in readily available checking and money market accounts.
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, 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 clinical trial costs subject to reimbursement under the Company’s collaboration agreements. The Company did not record any allowance for doubtful accounts as of December 31, 2021 and 2020.
Equipment, Net	Equipment, Net 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 three to five 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 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.
Deferred Financing Costs	Deferred Financing Costs At December 31, 2020, $1.7 million of deferred financing costs were recorded in the accompanying consolidated balance sheets. Upon completion of the IPO in March 2021, all of these costs were offset against the proceeds from the IPO and there were no deferred financing costs recorded as of December 31, 2021.
Revenue Recognition	Revenue Recognition The Company recognizes revenue in accordance with ASC Topic 606, Revenue from Contracts with Customers 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 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, 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.
Patent Costs	Patent Costs Costs related to filing and pursuing patent applications are recorded as general and administrative expense in the accompanying consolidated statements of operations and are expensed as incurred since recoverability of such expenditures is uncertain.
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 over the requisite service period (usually the vesting period) on a straight-line basis, net of actual forfeitures during the period, based on the estimated grant-date fair value of the awards. The Company estimates the fair value of stock option grants 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. For restricted stock awards, the fair value of the award is the estimated fair value of the Company’s common stock on the grant date, as determined by the Company’s board of directors.
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, its 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 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 were 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
Income Taxes	Income Taxes The Company accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, deferred tax assets and liabilities are determined on the basis of the differences between the financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. The Company recognizes net deferred tax assets to the extent that the Company believes these assets are more likely than not to be realized. In making such a determination, management considers all available positive and negative evidence, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies, and results of recent operations. If management determines that the Company would be able to realize its deferred tax assets in the future in excess of their net recorded amount, management would make an adjustment to the deferred tax asset valuation allowance, which would reduce the provision for income taxes. The Company records uncertain tax positions on the basis of a two-step process whereby (1) management determines whether it is more likely than not that the tax positions will be sustained on the basis of the technical merits of the position and (2) for those tax positions that meet the more-likely-than-not recognition threshold, management recognizes the largest amount of tax benefit that is more than 50 percent likely to be realized upon ultimate settlement with the related tax authority. The Company recognizes interest and penalties related to unrecognized tax benefits within income tax expense. Any accrued interest and penalties are included within the related tax liability.
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 32,381 and 145,046 weighted-average shares subject to repurchase or forfeiture from the weighted-average number of common shares outstanding for the years ended December 31, 2021 and 2020, respectively. Dilutive common stock equivalents are comprised of convertible preferred stock, options outstanding under the Company’s stock option plan, warrants to purchase common or convertible preferred stock and ESPP shares pending issuance. 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 years ended December 31, 2021 and 2020, 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): December 31, 2021 2020 Convertible preferred stock outstanding — 16,086,426 Common stock options issued and outstanding 6,474,039 2,930,248 Warrants to purchase common stock outstanding 14,884 — Warrants to purchase convertible preferred stock outstanding — 11,250 ESPP shares pending issuance 7,187 — Total 6,496,110 19,027,924
Comprehensive Loss	Comprehensive Loss Net loss and comprehensive loss were the same for the periods presented; therefore, a separate statement of comprehensive loss is not included in the accompanying consolidated financial statements.
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. Adoption of New Accounting Standards In February 2016, the FASB issued Accounting Standards Update (ASU) 2016-02, Leases (Topic 842) Leases (Topic 840) The Company made accounting policy elections to exclude leases with terms of 12 months or less from the recognition requirements and to not separate lease and non-lease components. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses: Measurement of credit Losses on Financial Instruments (ASU 2016-13) determined there was no cumulative-effect transition adjustment required to the opening balance of accumulated deficit for the recognition of additional credit losses upon adoption of this standard based on its outstanding accounts receivable, the composition and credit quality of its short-term investments, and current economic conditions as of that date. In August 2020, the FASB issued ASU No. 2020-06, Debt – Debt with Conversion and Other options (Subtopic 470-20) and Derivative and Hedging – Contracts in Entity’s Own Equity (Subtopic 815-40). In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes (ASU 2019-12) December 15, 2020. The Company adopted this standard o n January 1, 2021 and it did no t have a material impact on its consolidated financial statements . New Accounting Pronouncements Not Yet Adopted 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, which are the dates included above.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2021
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): December 31, 2021 2020 Convertible preferred stock outstanding — 16,086,426 Common stock options issued and outstanding 6,474,039 2,930,248 Warrants to purchase common stock outstanding 14,884 — Warrants to purchase convertible preferred stock outstanding — 11,250 ESPP shares pending issuance 7,187 — Total 6,496,110 19,027,924

Fair Value Measurements and F_2

Fair Value Measurements and Fair Value of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
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 Series C convertible preferred stock warrant liability at the date of the IPO and December 31, 2020 were as follows: IPO Date December 31, 2020 Fair value of underlying preferred stock $ 1.90 $ 0.83 Risk-free interest rate 1.70 % 1.70 % Expected volatility 70.00 % 70.00 % Expected term (in years) 9.0 9.2 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): Acquisition-related Consideration Held in Escrow Convertible Preferred Stock Warrant Liability Series D Convertible Preferred Stock Purchase Right Liability Balance at December 31, 2019 $ 3,500 $ — $ — Acquisition-related consideration released from escrow (3,500 ) — — Issuance of Series C convertible preferred stock warrants — 79 — Issuance of Series D convertible preferred stock purchase right liability — — 3,900 Change in fair value — (15 ) — Balance at December 31, 2020 — 64 3,900 Change in fair value — 105 980 Reclassification of warrant liability to equity due to conversion from preferred stock warrant to common stock warrant upon completion of initial public offering — (169 ) — Settlement of Series D convertible preferred stock purchase right liability (4,880 ) Balance at December 31, 2021 $ — $ — $ —

Balance Sheet Details (Tables)

Balance Sheet Details (Tables)	12 Months Ended
	Dec. 31, 2021
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): December 31, 2021 December 31, 2020 Prepaid contract manufacturing expenses $ 3,808 $ 121 Prepaid clinical trial expenses 1,397 998 Prepaid research and development expenses 627 775 Other prepaid expenses 1,218 275 Total $ 7,050 $ 2,169
Schedule of Equipment, Net	Equipment, net, consist of the following (in thousands): December 31, 2021 December 31, 2020 Laboratory equipment $ 1,830 $ 572 Office equipment and furniture 24 24 1,854 596 Less accumulated depreciation (407 ) (149 ) Total $ 1,447 $ 447
Schedule of Accrued Compensation	Accrued compensation consist of the following (in thousands). December 31, 2021 December 31, 2020 Accrued salaries and payroll taxes $ 64 $ 402 Accrued vacation — 102 Accrued employee stock purchase plan contributions 129 — Accrued bonuses 5,024 1,556 Accrued severance 161 662 Total $ 5,378 $ 2,722
Schedule of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities consist of the following (in thousands): December 31, 2021 December 31, 2020 Accrued research and development expenses $ 2,123 $ 216 Accrued clinical trial expenses 1,999 109 Accrued contract manufacturing expenses 906 1,343 Accrued legal expenses 531 490 Unvested early exercise liability 35 67 Accrued other 456 669 Total $ 6,050 $ 2,894

Collaboration and License Agr_2

Collaboration and License Agreements (Tables)	12 Months Ended
	Dec. 31, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Schedule of Reconciliation of Deferred Revenue	A reconciliation of deferred revenue related to the Falk and Takeda agreements for the years ended December 31, 2021 and 2020 is as follows (in thousands): Takeda Agreement Falk Agreement Total Balance at December 31, 2019 $ 1,542 $ — $ 1,542 Amounts received 960 5,200 6,160 Revenue recognized (792 ) (437 ) (1,229 ) Balance at December 31, 2020 1,710 4,763 6,473 Amounts received/credited (150 ) 16,678 16,528 Revenue recognized (379 ) (2,750 ) (3,129 ) Balance at December 31, 2021 $ 1,181 $ 18,691 $ 19,872

Discontinued Operations (Tables

Discontinued Operations (Tables)	12 Months Ended
	Dec. 31, 2021
Discontinued Operations And Disposal Groups [Abstract]
Schedule of Major Line Items Constituting the Loss reflected in Accompanying Consolidated Statements of Operations	The major line items constituting the loss of PLI for the year ended December 31, 2020, which are reflected in the accompanying consolidated statements of operations as discontinued operations, are as follows: Year Ended December 31, 2020 Diagnostic services revenue $ 36,593 Operating expenses: Cost of diagnostic services revenue 12,625 Research and development 4,956 Sales and marketing 10,993 General and administrative 9,885 Restructuring 2,260 Amortization of intangible assets 1,179 Goodwill impairment charge 724 Total operating expenses 42,622 Income (loss) from discontinued operations (6,029 ) Interest income 30 Loss from discontinued operations, net of taxes $ (5,999 )

Stockholders' Equity (Deficit)

Stockholders' Equity (Deficit) (Tables)	12 Months Ended
	Dec. 31, 2021
Equity [Abstract]
Summary of the Authorized, Issued and Outstanding Shares of Convertible Preferred Stock	The authorized, issued and outstanding shares of convertible preferred stock as of December 31, 2020 consist of the following (in thousands, except share and per share amounts): Shares Authorized Shares Issued and Outstanding Per Share Original Issue Price Liquidation Value Carrying Value Series A 14,979,200 14,979,200 $ 0.50 $ 7,490 $ 7,391 Series B 26,666,667 26,666,667 0.75 20,000 19,901 Series C 53,176,000 53,063,500 1.00 53,064 52,937 Series D-1 66,155,067 66,155,067 0.76 49,933 45,794 Series D-2 94,007,051 — — — — Total 254,983,985 160,864,434 $ 130,487 $ 126,023
Summary of Stock Option Activity	The Company’s stock option activity for the year ended December 31, 2021 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, 2020 2,930,248 $ 2.90 9.3 $ 2,290 Granted 3,943,984 $ 18.23 Exercised (151,436 ) $ 1.57 Cancelled/forfeited (248,757 ) $ 5.44 Outstanding at December 31, 2021 6,474,039 $ 12.18 8.5 $ 177,130 Vested or expected to vest at December 31, 2021 6,474,039 $ 12.18 8.5 $ 177,130 Exercisable at December 31, 2021 1,505,832 $ 3.51 6.1 $ 54,256
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: Year Ended December 31, 2021 2020 Risk-free interest rate 0.2 – 1.4% 0.2 – 1.4% Expected volatility 73.0 – 95.2% 61.5 – 71.8% Expected term (in years) 5.3 – 6.1 6.1 Expected dividend yield —% —%
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: Year Ended December 31, 2021 2020 Unvested at beginning of year 54,703 70,266 Early exercised stock options during the period — 23,540 Early exercised stock options repurchased during the period — (4,480 ) Vested during the period (37,097 ) (34,623 ) Unvested at end of year 17,606 54,703
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: Year Ended December 31, 2021 Risk-free interest rate 0.03– 0.33% Expected volatility 71.6 – 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): Year Ended December 31, 2021 2020 Research and development $ 1,755 $ 144 General and administrative 8,943 595 Discontinued operations — 101 Total stock-based compensation $ 10,698 $ 840
Summary of Common Stock Reserved for Future Issuance	Common stock reserved for future issuance consists of the following: December 31, 2021 December 31, 2020 Conversion of convertible preferred stock issued — 16,086,426 Conversion of convertible preferred stock in future issuance (D-2) — 9,400,705 Common stock options issued and outstanding 6,474,039 2,930,248 Warrants to purchase convertible preferred stock outstanding — 11,250 Warrants to purchase common stock outstanding 14,884 — Shares available for issuance under equity incentive plan 1,856,063 373,789 Shares available for issuance under the ESPP 333,850 — Total 8,678,836 28,802,418

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Reconciliation of Effective Tax Rate and Federal Statutory Tax Rate	A reconciliation of the Company’s effective tax rate and federal statutory tax rate related to continuing operations is summarized as follows (in thousands): Years Ended December 31, 2021 2020 Income tax expense (benefit) at statutory rates $ (18,938 ) $ (6,538 ) State income tax, net of federal benefit (5,865 ) (586 ) Permanent items 255 (14 ) Change in valuation allowance 28,219 7,373 Forfeiture of state operating losses 42 521 Stock-based compensation 751 82 Purchase price accretion 101 311 Return to provision adjustment (84 ) 293 Research and development tax credits (4,481 ) (1,442 ) $ — $ —
Components of Deferred Tax Assets and Liabilities	Significant components of the Company’s deferred tax assets and liabilities related to continuing operations for federal and state income taxes are follows (in thousands): December 31, 2021 2020 Deferred tax assets: Net operating loss carryforward $ 32,373 $ 11,333 Research tax credits 7,012 2,509 Accrued and other 1,980 543 Stock-based compensation 1,390 121 Total deferred tax assets 42,755 14,506 Less valuation allowance (42,688 ) (14,477 ) Net deferred tax assets 67 29 Deferred tax liabilities: Property and equipment (67 ) (29 ) Total deferred tax liabilities (67 ) (29 ) Net deferred tax assets $ — $ —
Summary of Gross Unrecognized Tax Benefits	The following table summarizes the activity in the Company’s gross unrecognized tax benefits (in thousands): December 31, 2021 2020 Balance at beginning of period $ 697 $ 300 Increase (decrease) related to prior year positions (186 ) — Increase related to current year positions 1,438 397 Balance at the end of the year $ 1,949 $ 697

Organization - Additional Infor

Organization - Additional Information (Details) $ / shares in Units, $ in Thousands	Mar. 16, 2021USD ($)$ / sharesshares	Mar. 05, 2021	Dec. 31, 2021USD ($)shares	Dec. 31, 2020USD ($)shares
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Date of incorporation			Oct. 26, 2016
Percentage of spinoff in kind distribution				100.00%
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
Offering-related transaction costs | $				$ 23
Common stock, shares authorized	400,000,000		400,000,000	325,000,000
Preferred stock, shares authorized	40,000,000		40,000,000	0
Accumulated deficit | $			$ 189,341	$ 99,146
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			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)	12 Months Ended
	Dec. 31, 2021USD ($)Segmentshares	Dec. 31, 2020USD ($)shares
Summary Of Significant Accounting Policies [Line Items]
Number of operating segments | Segment	1
Allowance for doubtful accounts	$ 0	$ 0
Deferred financing costs	$ 0	$ 1,700,000
Weighted-average shares subject to repurchase or forfeiture | shares	32,381	145,046
ASU 2020-06
Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted	true
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2021
Change in accounting principle, accounting standards update, immaterial effect	true
ASU 2016-02
Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted	true
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2021
Change in accounting principle, accounting standards update, immaterial effect	true
ASU 2016-13
Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted	true
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2021
Change in accounting principle, accounting standards update, immaterial effect	true
ASU 2019-12
Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted	true
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2021
Change in accounting principle, accounting standards update, immaterial effect	true
Series D-2 Convertible Preferred Stock
Summary Of Significant Accounting Policies [Line Items]
Change in fair value into other income (expense)	$ 1,000,000
Minimum
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful lives	3 years
Maximum
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful lives	5 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	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total	6,496,110	19,027,924
Convertible Preferred Stock Outstanding
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total		16,086,426
Common Stock Options Issued and Outstanding
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total	6,474,039	2,930,248
Warrants to Purchase Common Stock Outstanding
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total	14,884
Warrants to Purchase Convertible Preferred Stock Outstanding
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total		11,250
ESPP Shares Pending Issuance
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total	7,187

Fair Value Measurements and F_3

Fair Value Measurements and Fair Value of Financial Instruments - Additional Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021USD ($)	Dec. 31, 2020USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Transfers within Level 3 hierarchy	$ 0	$ 0
Level 3 liabilities	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)	Dec. 31, 2021	Mar. 16, 2021$ / shares	Dec. 31, 2020$ / shares
Series C 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	$ 0.83
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 | Series C Convertible Preferred Stock Warrant Liability
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Measurement input		0.0170	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 | Series C Convertible Preferred Stock Warrant Liability
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Measurement input		0.7000	0.7000
Expected Term | Series C 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	9 years 2 months 12 days

Fair Value Measurements and F_5

Fair Value Measurements and Fair Value of Financial Instruments - Summary of Activity of Financial Instruments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Change in fair value	$ 1,000
Ending Balance	0
Acquisition Related Consideration Held in Escrow
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning Balance		$ 3,500
Acquisition-related consideration released from escrow		(3,500)
Convertible Preferred Stock Warrant Liability
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning Balance	64
Issuance of Series C convertible preferred stock warrants		79
Change in fair value	105	(15)
Reclassification of warrant liability to equity due to conversion from preferred stock warrant to common stock warrant upon completion of initial public offering	(169)
Ending Balance		64
Series D Convertible Preferred Stock Warrant Liability
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning Balance	3,900
Issuance of Series D convertible preferred stock purchase right liability		3,900
Change in fair value	980
Settlement of Series D convertible preferred stock purchase right liability	$ (4,880)
Ending Balance		$ 3,900

Balance Sheet Details - Schedul

Balance Sheet Details - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Prepaid Expense And Other Assets Current [Abstract]
Prepaid contract manufacturing expenses	$ 3,808	$ 121
Prepaid clinical trial expenses	1,397	998
Prepaid research and development expenses	627	775
Other prepaid expenses	1,218	275
Total	$ 7,050	$ 2,169

Balance Sheet Details - Sched_2

Balance Sheet Details - Schedule of Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Property Plant And Equipment [Line Items]
Equipment, gross	$ 1,854	$ 596
Less accumulated depreciation	(407)	(149)
Total	1,447	447
Laboratory Equipment
Property Plant And Equipment [Line Items]
Equipment, gross	1,830	572
Office Equipment and Furniture
Property Plant And Equipment [Line Items]
Equipment, gross	$ 24	$ 24

Balance Sheet Details - Additio

Balance Sheet Details - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Balance Sheet Related Disclosures [Abstract]
Depreciation expense	$ 0.3	$ 0.1

Balance Sheet Details - Sched_3

Balance Sheet Details - Schedule of Accrued Compensation (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Balance Sheet Related Disclosures [Abstract]
Accrued salaries and payroll taxes	$ 64	$ 402
Accrued vacation		102
Accrued employee stock purchase plan contributions	129
Accrued bonuses	5,024	1,556
Accrued severance	161	662
Total	$ 5,378	$ 2,722

Balance Sheet Details - Sched_4

Balance Sheet Details - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Balance Sheet Related Disclosures [Abstract]
Accrued research and development expenses	$ 2,123	$ 216
Accrued clinical trial expenses	1,999	109
Accrued contract manufacturing expenses	906	1,343
Accrued legal expenses	531	490
Unvested early exercise liability	35	67
Accrued other	456	669
Total	$ 6,050	$ 2,894

Collaboration and License Agr_3

Collaboration and License Agreements - Additional Information (Details) - USD ($)	1 Months Ended		12 Months Ended
	Jul. 31, 2020	Sep. 30, 2017	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Common stock, shares issued			38,960,716	1,768,325
Revenue recognized			$ 3,129,000	$ 1,229,000
Deferred revenue			19,872,000	6,473,000	$ 1,542,000
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 | Falk
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Funding percentage third-party development costs set forth in development plan	25.00%
Collaboration agreement, upfront payment received upon agreement execution	$ 2,500
Collaboration agreement, pre-clinical development milestone payment received upon finalization of development plan			2,500
Collaboration agreement, pre-clinical development milestone payment received upon clinical candidate selected	10,000
Collaboration agreement additional pre-clinical development milestone payment eligible to receive	$ 5,000
Revenue recognized			2,750,000	437,000
Deferred revenue			18,691,000	4,763,000
Takeda Collaboration Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue recognized			379,000	792,000
Deferred revenue			1,181,000	1,710,000	$ 1,542,000
Takeda Collaboration Agreement | Takeda Pharmaceutical Company Limited
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue recognized			400,000	800,000
Deferred revenue			$ 1,200,000	$ 1,700,000

Collaboration and License Agr_4

Collaboration and License Agreements - Additional Information (Details1) - Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2022-01-01	Dec. 31, 2021USD ($)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	8 years
Falk Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, remaining performance obligation expected to be recognized amount	$ 3,700
Falk Agreement | Falk
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	8 years
Takeda Collaboration Agreement | Takeda Pharmaceutical Company Limited
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	4 years

Collaboration and License Agr_5

Collaboration and License Agreements - Schedule of Reconciliation of Deferred Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Disaggregation Of Revenue [Line Items]
Beginning Balance	$ 6,473	$ 1,542
Amounts received/credited	16,528	6,160
Revenue recognized	(3,129)	(1,229)
Ending Balance	19,872	6,473
Takeda Collaboration Agreement
Disaggregation Of Revenue [Line Items]
Beginning Balance	1,710	1,542
Amounts received/credited	(150)	960
Revenue recognized	(379)	(792)
Ending Balance	1,181	1,710
Falk Agreement | Falk
Disaggregation Of Revenue [Line Items]
Beginning Balance	4,763
Amounts received/credited	16,678	5,200
Revenue recognized	(2,750)	(437)
Ending Balance	$ 18,691	$ 4,763

Discontinued Operations - Addit

Discontinued Operations - Additional Information (Details) $ in Thousands	Jun. 30, 2019USD ($)shares	Jan. 31, 2021USD ($)shares	Oct. 31, 2020USD ($)shares	Jun. 30, 2020USD ($)shares	Dec. 31, 2020USD ($)ft²
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Amounts due to Nestlé, current—related party					$ 5,675
PLI | Discontinued Operations, Disposed of by Means Other than Sale, Spinoff
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Discontinued operation distribution of interest, percentage					100.00%
Area of Space Leased | ft²					40,000
Term of sublease					1 year
PLI
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Percentage of voting interest acquired	100.00%
Total consideration	$ 31,700
Business acquisition, deferred cash payment	15,000		$ 3,800	$ 5,000
Business acquisition, deferred cash payment due on June 30, 2020	5,000
Business acquisition, deferred cash payment due on June 30, 2021	10,000
Acquisition-related contingent consideration	$ 3,500
Percentage of discount rate on interest component	12.00%
Amounts due to Nestlé, current—related party					$ 5,700
PLI | Series C Convertible Preferred Stock
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Business acquisition, number of shares issued | shares	16,500,000
Business acquisition, number of shares issued with fair value	$ 16,500
Acquisition-related contingent consideration shares | shares	3,500,000
Business acquisition deferred cash payment converted to shares of convertible preferred stock | shares				5,000,000
PLI | Series D Convertible Preferred Stock
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Business acquisition deferred cash payment converted to shares of convertible preferred stock | shares			5,088,851
PLI | Series D-2 Convertible Preferred Stock
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Business acquisition, number of shares issued | shares		7,219,560
Business acquisition, deferred cash payment		$ 6,100
Business acquisition deferred cash payment converted to shares of convertible preferred stock | shares		7,219,560

Discontinued Operations - Sched

Discontinued Operations - Schedule of Consolidated Statements of Operations as Discontinued Operations (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)
Operating expenses:
Loss from discontinued operations, net of taxes	$ (5,999)
PLI
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Diagnostic services revenue	36,593
Operating expenses:
Cost of diagnostic services revenue	12,625
Research and development	4,956
Sales and marketing	10,993
General and administrative	9,885
Restructuring	2,260
Amortization of intangible assets	1,179
Goodwill impairment charge	724
Total operating expenses	42,622
Income (loss) from discontinued operations	(6,029)
Interest income	30
Loss from discontinued operations, net of taxes	$ (5,999)

Long Term Debt - Additional Inf

Long Term Debt - Additional Information (Details) - USD ($)	1 Months Ended		12 Months Ended
	Jul. 31, 2021	Jan. 31, 2020	Dec. 31, 2021
Debt Instrument [Line Items]
Loss on early extinguishment of debt			$ (554,000)
Oxford Finance LLC
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		4.00%
Percentage of future amount to be funded		3.00%
Prepayment of outstanding principal balance	$ 7,500,000
Prepayment penalty, accrued interest and final payment	$ 500,000
Loss on early extinguishment of debt			$ (600,000)
Oxford Finance LLC | Series C Convertible Preferred Stock
Debt Instrument [Line Items]
Warrant to purchase of convertible preferred stock		112,500
Exercise price of warrants		$ 1
Expected term (in years)		10 years
Fair value of warrant, debt issuance cost and final payment		$ 600,000

Stockholders' Equity (Deficit_2

Stockholders' Equity (Deficit) - Additional Information (Details) - USD ($)	Mar. 16, 2021	Feb. 28, 2021	Jan. 31, 2021	Oct. 31, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2019
Class Of Stock [Line Items]
Common stock, shares authorized	400,000,000					400,000,000	325,000,000
Preferred stock, shares authorized	40,000,000					40,000,000	0
Net cash proceeds from sale of convertible preferred stock						$ 73,749,000	$ 73,826,000
Dividends declared							$ 0
Minimum pre-money valuation						$ 330,000,000
Number of shares vested						(37,097)	(34,623)
Remaining unvested shares						17,606	54,703			70,266
Common stock reserved for issuance						8,678,836	28,802,418
Weighted average grant date fair value of options granted						$ 12.15	$ 5.93
Total intrinsic value of options exercised						$ 2,500,000	$ 300,000
Total intrinsic value of options vested						$ 21,900,000	900,000
Unvested shares early exercised option right to repurchase shares vesting period						4 years
Early exercise liability						$ 35,000	100,000
Stock compensation expense						10,698,000	$ 840,000
Unrecognized compensation cost related to unvested stock-based awards						$ 45,400,000
Unrecognized compensation cost is expected to be recognized over a weighted average period						3 years 7 months 6 days
2021 Employee Stock Purchase Plan
Class Of Stock [Line Items]
Common stock reserved for issuance		360,000
Common stock, shares available for grant						333,850
Annually increase amount equal to lessor of percentage of shares of common stock outstanding on the final day of the immediately preceding calendar year		1.00%
Participants to purchase common stock through payroll deductions maximum percentage of eligible compensation		20.00%
Stock compensation expense		$ 500,000
Issuance of common stock under employee stock purchase plan, shares						26,150
Outstanding liability related to employee contributions for shares pending issuance						$ 100,000
Stock Option Modification
Class Of Stock [Line Items]
Stock compensation expense						$ 4,600,000
2017 Equity Incentive Plan
Class Of Stock [Line Items]
Common stock reserved for issuance								5,524,354
2021 Incentive Award Plan
Class Of Stock [Line Items]
Common stock, shares available for grant		3,600,000				1,856,063
Annually increase amount equal to lessor of percentage of shares of common stock outstanding on the final day of the immediately preceding calendar year		5.00%
2017 Plan and 2021 Plan
Class Of Stock [Line Items]
Maximum options granted period						10 years
Award subject to continuous service						36 months
2017 Plan and 2021 Plan | Tranche One
Class Of Stock [Line Items]
Award vesting period						1 year
Percentage of award vested						25.00%
Cedars-Sinai | Restricted Common Stock
Class Of Stock [Line Items]
Award vesting period								3 years
Number of shares vested							111,667
Remaining unvested shares							0
Number of shares granted								335,000
Minimum
Class Of Stock [Line Items]
Threshold proceeds for conversion						$ 75,000,000
Convertible Preferred Stock
Class Of Stock [Line Items]
Warrant to purchase of convertible preferred stock	148,848
Common stock reserved for issuance							16,086,426
Series C Convertible Preferred Stock
Class Of Stock [Line Items]
Issuance of convertible preferred stock for cash, net of issuance costs, shares					28,063,500
Net cash proceeds from sale of convertible preferred stock					$ 28,000,000
Maximum aggregate amount convertible preferred shares holders entitled to receive price per share						$ 3
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
Net cash proceeds from sale of convertible preferred stock				$ 46,200,000
Shares issued, price per share				$ 0.7558
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
Maximum aggregate amount convertible preferred shares holders entitled to receive price per share						$ 2.2674
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				$ 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
Maximum aggregate amount convertible preferred shares holders entitled to receive price per share						$ 2.553
Series D Convertible Preferred Stock
Class Of Stock [Line Items]
Issuance of convertible preferred stock for cash, net of issuance costs, shares							61,066,216
Fair value of preferred stock purchase right liability				$ 3,900,000
Series A Convertible Preferred Stock
Class Of Stock [Line Items]
Maximum aggregate amount convertible preferred shares holders entitled to receive price per share						1.50
Series B Convertible Preferred Stock
Class Of Stock [Line Items]
Maximum aggregate amount convertible preferred shares holders entitled to receive price per share						$ 2.25
Founder Stock
Class Of Stock [Line Items]
Shares issued, price per share								$ 0.01	$ 0.01
Award vesting period								4 years	4 years
Number of shares vested							48,750
Remaining unvested shares							0
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 common stock under employee stock purchase plan, shares						26,150
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 the Authorized, Issued and Outstanding Shares of Convertible Preferred Stock (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Temporary Equity [Line Items]
Shares Authorized	0	254,983,985
Shares Issued and Outstanding		160,864,434
Per Share Original Issue Price	$ 0.0001	$ 0.0001
Liquidation Value	$ 0	$ 130,487,000
Carrying Value		$ 126,023,000	$ 43,740,000
Series A
Temporary Equity [Line Items]
Shares Authorized		14,979,200
Shares Issued and Outstanding		14,979,200
Per Share Original Issue Price		$ 0.50
Liquidation Value		$ 7,490,000
Carrying Value		$ 7,391,000
Series B
Temporary Equity [Line Items]
Shares Authorized		26,666,667
Shares Issued and Outstanding		26,666,667
Per Share Original Issue Price		$ 0.75
Liquidation Value		$ 20,000,000
Carrying Value		$ 19,901,000
Series C Convertible Preferred Stock Warrant Liability
Temporary Equity [Line Items]
Shares Authorized		53,176,000
Shares Issued and Outstanding		53,063,500
Per Share Original Issue Price		$ 1
Liquidation Value		$ 53,064,000
Carrying Value		$ 52,937,000
Series D-1
Temporary Equity [Line Items]
Shares Authorized		66,155,067
Shares Issued and Outstanding		66,155,067
Per Share Original Issue Price		$ 0.76
Liquidation Value		$ 49,933,000
Carrying Value		$ 45,794,000
Series D-2
Temporary Equity [Line Items]
Shares Authorized		94,007,051

Stockholders' Equity (Deficit_4

Stockholders' Equity (Deficit) - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Equity [Abstract]
Number of shares, Outstanding at December 31, 2020	2,930,248
Number of shares, Granted	3,943,984
Number of shares, Exercised	(151,436)
Number of shares, Cancelled/forfeited	(248,757)
Number of shares, Outstanding at December 31, 2021	6,474,039	2,930,248
Number of shares, Vested or expected to vest at December 31, 2021	6,474,039
Number of shares, Exercisable at December 31, 2021	1,505,832
Weighted Average Exercise Price, Outstanding at December 31, 2020	$ 2.90
Weighted Average Exercise Price, Granted	18.23
Weighted Average Exercise Price, Exercised	1.57
Weighted Average Exercise Price, Cancelled/forfeited	5.44
Weighted Average Exercise Price, Outstanding at December 31, 2021	12.18	$ 2.90
Weighted Average Exercise Price, Vested or expected to vest at December 31, 2021	12.18
Weighted Average Exercise Price, Exercisable at December 31, 2021	$ 3.51
Weighted Average Remaining Contractual Terms (in Years), Outstanding	8 years 6 months	9 years 3 months 18 days
Weighted Average Remaining Contractual Terms (in Years), Vested or excepted to vest at December 31, 2021	8 years 6 months
Weighted Average Remaining Contractual Terms (in Years), Exercisable at December 31, 2021	6 years 1 month 6 days
Aggregate Intrinsic Value, Outstanding	$ 177,130	$ 2,290
Aggregate Intrinsic Value, Vested or excepted to vest at December 31, 2021	177,130
Aggregate Intrinsic Value, Exercisable at December 31, 2021	$ 54,256

Stockholders' Equity (Deficit_5

Stockholders' Equity (Deficit) - Summary of Grant Date Fair Value of Stock Options (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate, Minimum	0.20%	0.20%
Risk-free interest rate, Minimum	1.40%	1.40%
Expected volatility, Minimum	73.00%	61.50%
Expected volatility, Maximum	95.20%	68.10%
Expected term (in years)		6 years 1 month 6 days
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	5 years 3 months 18 days
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	6 years 1 month 6 days

Stockholders' Equity (Deficit_6

Stockholders' Equity (Deficit) - Summary of Activity Unvested Common Stock Issued Pursuant Early Exercise of Stock Options Awards (Details) - shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Equity [Abstract]
Unvested at beginning of year	54,703	70,266
Early exercised stock options during the period		23,540
Early exercised stock options repurchased during the period		(4,480)
Number of shares vested	(37,097)	(34,623)
Unvested at end of year	17,606	54,703

Stockholders' Equity (Deficit_7

Stockholders' Equity (Deficit) - Summary of Fair Value of Stock of the Stock Purchase Right Under ESPP (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate, Minimum	0.20%	0.20%
Risk-free interest rate, Minimum	1.40%	1.40%
Expected volatility, Minimum	73.00%	61.50%
Expected volatility, Maximum	95.20%	68.10%
Expected term (in years)		6 years 1 month 6 days
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, Minimum	0.33%
Expected volatility, Minimum	71.60%
Expected volatility, Maximum	83.90%
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	5 years 3 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 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	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	$ 10,698	$ 840
Discontinued Operations
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation		101
Research and Development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	1,755	144
General and Administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	$ 8,943	$ 595

Stockholders' Equity (Deficit_9

Stockholders' Equity (Deficit) - Summary of Common Stock Reserved for Future Issuance (Details) - shares	Dec. 31, 2021	Dec. 31, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for issuance	8,678,836	28,802,418
Convertible Preferred Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for issuance		16,086,426
Common Stock Options Issued and Outstanding
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for issuance	6,474,039	2,930,248
Warrants to Purchase Convertible Preferred Stock Outstanding
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for issuance		11,250
Warrants to Purchase Common Stock Outstanding
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for issuance	14,884
Conversion of Convertible Preferred Stock in Future Issuance (D-2)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for issuance		9,400,705
Shares Available for Issuance Under Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for issuance	1,856,063	373,789
ESPP Shares Pending Issuance
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for issuance	333,850

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details)	1 Months Ended		12 Months Ended
	Oct. 31, 2021USD ($)	Mar. 31, 2021USD ($)	Dec. 31, 2021USD ($)	Dec. 31, 2020ft²
Commitments And Contingencies [Line Items]
Indemnification Claims			$ 0
Accrued Indemnification			0
Office and Laboratory Space, San Diego
Commitments And Contingencies [Line Items]
Initial lease term	127 months	10 years
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
Future minimum lease payments			$ 47,100,000
Office and Laboratory Space, San Diego | Maximum
Commitments And Contingencies [Line Items]
Tenant improvement allowance	$ 6,300,000	$ 6,300,000
PLI
Commitments And Contingencies [Line Items]
Area of land | ft²				40,000
Sublease agreement term				1 year
Sublease option to extend			true
Sublease option to extend, description			The sublease agreement was extended during the year ended December 31, 2021 through June 2022.
Sublease term expiration date			2022-06
Monthly payment			$ 80,000
Remaining payment obligations			$ 500,000

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	Mar. 27, 2020	Dec. 31, 2021	Dec. 31, 2020
Income Tax [Line Items]
Increase in valuation allowance		$ 7,400,000	$ 28,200,000
Federal and state carry forward expiration beginning year		2036
Percentage of future taxable income		80.00%
Research tax credits		$ 7,012,000	2,509,000
Federal credits expiration beginning year		2037
Unrecognized tax benefits interest or penalties		$ 0	0
Loss carryback period	5 years
Internal Revenue Code 382 and 383
Income Tax [Line Items]
Annual usage of net operating loss and research and development credit carryforwards limited in event of cumulative change in minimum ownership in percentage within three year		50.00%
NOLs and tax credit carryforwards utilization period		3 years
Cumulative changes in ownership percentage, description		The Company had an ownership change analysis completed through June 30, 2021 and determined that ownership changes there were ownership changes on May 31, 2017, September 1, 2017, September 26, 2017, May 29, 2019, March 27, 2020 and January 29, 2021.
Tax Year 2018
Income Tax [Line Items]
Net operating loss carryforwards		$ 125,200
Federal
Income Tax [Line Items]
Net operating loss carryforwards		126,100,000
Research tax credits		5,100,000
Federal | Internal Revenue Code 382 and 383
Income Tax [Line Items]
Research tax credits		968,000
Research tax credits valuation allowance		968,000
State
Income Tax [Line Items]
Net operating loss carryforwards		85,000,000
Research tax credits		4,700,000
State | Internal Revenue Code 382 and 383
Income Tax [Line Items]
Net operating loss carryforwards		562,000
Net operating loss carryforwards valuation allowance		562,000
General and Administrative
Income Tax [Line Items]
Income tax expense (Benefit)		$ 0	$ 7,000

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Effective Tax Rate and Federal Statutory Tax Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income tax expense (benefit) at statutory rates	$ (18,938)	$ (6,538)
State income tax, net of federal benefit	(5,865)	(586)
Permanent items	255	(14)
Change in valuation allowance	28,219	7,373
Forfeiture of state operating losses	42	521
Stock-based compensation	751	82
Purchase price accretion	101	311
Return to provision adjustment	(84)	293
Research and development tax credits	$ (4,481)	$ (1,442)

Income Taxes - Components of De

Income Taxes - Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Net operating loss carryforward	$ 32,373	$ 11,333
Research tax credits	7,012	2,509
Accrued and other	1,980	543
Stock-based compensation	1,390	121
Total deferred tax assets	42,755	14,506
Less valuation allowance	(42,688)	(14,477)
Net deferred tax assets	67	29
Deferred tax liabilities:
Property and equipment	(67)	(29)
Total deferred tax liabilities	$ (67)	$ (29)

Income Taxes - Summary of Gross

Income Taxes - Summary of Gross Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Balance at beginning of period	$ 697	$ 300
Increase (decrease) related to prior year positions	(186)
Increase related to current year positions	1,438	397
Balance at the end of the year	$ 1,949	$ 697

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details)	1 Months Ended	12 Months Ended
	Jan. 31, 2021shares	Dec. 31, 2021USD ($)Employee$ / sharesshares	Dec. 31, 2020USD ($)Employee$ / sharesshares	Sep. 30, 2017$ / sharesshares
Related Party Transaction [Line Items]
Common stock, shares issued | shares		38,960,716	1,768,325
Common stock, par value | $ / shares		$ 0.0001	$ 0.0001
Number of employees | Employee		1	2
Compensation related expense			$ 800,000
Amounts due to Nestlé, current—related party			5,675,000
Discontinued Operations
Related Party Transaction [Line Items]
Payment for collaboration expense			300,000
PLI
Related Party Transaction [Line Items]
Amounts due to Nestlé, current—related party			5,700,000
PLI | Series D-2 Convertible Preferred Stock
Related Party Transaction [Line Items]
Business acquisition, number of shares issued | shares	7,219,560
Nestle
Related Party Transaction [Line Items]
Amounts due to Nestlé, current—related party			5,700,000
Research and Development
Related Party Transaction [Line Items]
Compensation related expense		$ 800,000	600,000
Payment for collaboration expense		500,000
General and Administrative
Related Party Transaction [Line Items]
Compensation related expense			200,000
Cedars-Sinai Agreement | Vested Common Stock | Cedars-Sinai
Related Party Transaction [Line Items]
Common stock, shares issued | shares				257,500
Common stock, par value | $ / shares				$ 0.0001
Cedars-Sinai Agreement | Unvested Restricted Common Stock | Cedars-Sinai
Related Party Transaction [Line Items]
Common stock, shares issued | shares				335,000
Common stock, par value | $ / shares				$ 0.0001
Transition Services Agreement
Related Party Transaction [Line Items]
Payment for terms of agreement		$ 3,800,000
Transition Services Agreement | PLI Spinoff
Related Party Transaction [Line Items]
Payout bonus liability			$ 1,100,000
Initial term of agreement			1 year

401(K) Plan - Additional Inform

401(K) Plan - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Compensation And Retirement Disclosure [Abstract]
Company contribution to 401(k) plan	$ 300,000	$ 45,000