Crinetics Pharmaceuticals (CRNX) 10-K 30 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. 25, 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
Trading Symbol	CRNX
Entity Registrant Name	Crinetics Pharmaceuticals, Inc.
Entity Central Index Key	0001658247
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Non-accelerated Filer
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Common Stock, Shares Outstanding		47,784,611,000
Entity Public Float			$ 683
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common Stock, par value $0.001 per share
Security Exchange Name	NASDAQ
Entity File Number	001-38583
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	26-3744114
Entity Address, Address Line One	10222 Barnes Canyon Road
Entity Address, Address Line Two	Bldg. #2
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	450-6464
Document Annual Report	true
Document Transition Report	false
ICFR Auditor Attestation Flag	false
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 end of the fiscal year covered by this Form 10-K are incorporated by reference into Part III of this Form 10-K.
Auditor Firm ID	243
Auditor Name	BDO USA, LLP
Auditor Location	San Diego

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 200,695	$ 93,087
Investment securities	133,012	77,793
Prepaid expenses and other current assets	11,013	6,612
Total current assets	344,720	177,492
Property and equipment, net	2,825	3,181
Operating lease right-of-use asset	1,892	2,232
Derivative asset	68
Investment in Radionetics	1,010
Restricted cash	500	500
Other assets		40
Total assets	351,015	183,445
Current liabilities:
Accounts payable and accrued expenses	8,468	5,588
Accrued compensation and related expenses	6,588	4,066
Other current liabilities	939	835
Total current liabilities	15,995	10,489
Operating lease liability, non-current	3,074	4,014
Unvested stock liability	2	23
Total liabilities	19,071	14,526
Commitments and contingencies (Note 7)
Stockholders’ equity:
Preferred stock, $0.001 par; 10,000 shares authorized, no shares issued or outstanding at December 31, 2021 or 2020
Common stock and paid-in capital, $0.001 par; 200,000 shares authorized, 47,598 and 47,597 shares issued and outstanding at December 31, 2021; 33,017 and 33,001 shares issued and outstanding at December 31, 2020	607,581	336,508
Accumulated other comprehensive (loss) income	(382)	25
Accumulated deficit	(275,255)	(167,614)
Total stockholders’ equity	331,944	168,919
Total liabilities and stockholders’ equity	$ 351,015	$ 183,445

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2021	Dec. 31, 2020
Statement Of Financial Position [Abstract]
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock and paid-in capital, par value	$ 0.001	$ 0.001
Common stock and paid-in capital, shares authorized	200,000,000	200,000,000
Common stock and paid-in capital, shares issued	47,598,000	33,017,000
Common stock and paid-in capital, shares outstanding	47,597,000	33,001,000

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Statement [Abstract]
License revenues	$ 1,078	$ 0	$ 0
Grant revenues	0	71	1,193
Total revenues	$ 1,078	$ 71	$ 1,193
Type of Revenue [Extensible List]	us-gaap:GrantMember	us-gaap:GrantMember	us-gaap:GrantMember
Operating expenses:
Research and development	$ 84,255	$ 56,998	$ 41,506
General and administrative	24,525	18,026	13,519
Total operating expenses	108,780	75,024	55,025
Loss from operations	(107,702)	(74,953)	(53,832)
Other income (expense):
Interest income	157	991	3,460
Other income (expense), net	(96)	150	(50)
Total other income, net	61	1,141	3,410
Net loss	$ (107,641)	$ (73,812)	$ (50,422)
Net loss per share:
Net loss per share - basic and diluted	$ (2.80)	$ (2.42)	$ (2.09)
Weighted average shares - basic and diluted	38,436	30,448	24,175
Other comprehensive income (loss):
Unrealized gain (loss) on investment securities	$ (407)	$ (123)	$ 87
Comprehensive net loss	$ (108,048)	$ (73,935)	$ (50,335)

Consolidated Statements of Conv

Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Common Stock	Common stock and Paid-In Capital	Accumulated Other Comprehensive Income	Accumulated Deficit
Beginning Balance, Shares at Dec. 31, 2018		24,061,000
Beginning Balance at Dec. 31, 2018	$ 160,225		$ 203,544	$ 61	$ (43,380)
Vesting of shares subject to repurchase	94		94
Vesting of shares subject to repurchase, shares		63,000
Exercise of stock options	126		126
Exercise of stock options, shares		90,000
Stock issued under Stock Purchase Plan	735		735
Issuance of stock under Stock Purchase Plan, shares		49,000
Stock-based compensation	6,294		6,294
Comprehensive income (loss)	87			87
Net loss	(50,422)				(50,422)
Ending Balance at Dec. 31, 2019	117,139		210,793	148	(93,802)
Ending Balance, Shares at Dec. 31, 2019		24,263,000
Issuance of common stock, net of transaction costs	114,283		114,283
Issuance of common stock, net of transaction costs, shares		8,499,000
Vesting of shares subject to repurchase	26		26
Vesting of shares subject to repurchase, shares		17,000
Exercise of stock options	288		288
Exercise of stock options, shares		171,000
Stock issued under Stock Purchase Plan	691		691
Issuance of stock under Stock Purchase Plan, shares		51,000
Stock-based compensation	10,427		10,427
Comprehensive income (loss)	(123)			(123)
Net loss	(73,812)				(73,812)
Ending Balance at Dec. 31, 2020	168,919		336,508	25	(167,614)
Ending Balance, Shares at Dec. 31, 2020		33,001,000
Issuance of common stock, net of transaction costs	249,542		249,542
Issuance of common stock, net of transaction costs, shares		14,126,000
Vesting of shares subject to repurchase	21		21
Vesting of shares subject to repurchase, shares		15,000
Exercise of stock options	$ 3,137		3,137
Exercise of stock options, shares	364,273,000	364,000
Stock issued under Stock Purchase Plan	$ 1,021		1,021
Issuance of stock under Stock Purchase Plan, shares		91,000
Stock-based compensation	17,352		17,352
Comprehensive income (loss)	(407)			(407)
Net loss	(107,641)				(107,641)
Ending Balance at Dec. 31, 2021	$ 331,944		$ 607,581	$ (382)	$ (275,255)
Ending Balance, Shares at Dec. 31, 2021		47,597,000

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating activities:
Net loss	$ (107,641)	$ (73,812)	$ (50,422)
Reconciliation of net loss to net cash used in operating activities:
Stock-based compensation	17,352	10,427	6,294
Depreciation and amortization	922	948	887
Noncash lease expense	340	278	226
Accretion of purchase discounts and amortization of premiums on investment securities, net	422	(227)	(1,229)
Noncash license revenues	(1,078)
Other, net	(1)	(17)	(4)
Increase (decrease) in cash resulting from changes in:
Prepaid expenses and other assets	(4,361)	(1,623)	(2,221)
Accounts payable and accrued expenses, compensation and related expenses	6,293	2,723	696
Operating lease liability	(836)	(724)	(608)
Net cash used in operating activities	(88,588)	(62,027)	(46,381)
Investing activities:
Purchases of investment securities	(125,404)	(135,592)	(108,136)
Maturities of investment securities	69,357	135,995	150,295
Purchases of property and equipment	(436)	(186)	(492)
Net cash (used in) provided by investing activities	(56,483)	217	41,667
Financing activities:
Proceeds from issuance of common stock, net of $13.0 million (2021) and $7.5 million (2020) transaction costs	249,542	114,283
Proceeds from exercise of stock options	3,137	288	126
Repurchase of unvested shares			(59)
Net cash provided by financing activities	252,679	114,571	67
Net change in cash, cash equivalents and restricted cash	107,608	52,761	(4,647)
Cash, cash equivalents and restricted cash - beginning of period	93,587	40,826	45,473
Cash, cash equivalents and restricted cash - end of period	201,195	93,587	40,826
Components of cash, cash equivalents and restricted cash:
Cash and cash equivalents	200,695	93,087	40,326
Restricted cash	500	500	500
Cash, cash equivalents and restricted cash - end of period	201,195	93,587	40,826
Non-cash financing activity:
Investment in Radionetics	1,010
Derivative asset	68
Stock issued under Stock Purchase Plan	1,021	691	735
Amounts accrued for purchases of property and equipment	130	6	112
Change in unvested stock liability	$ 21	$ 26	$ 94

Consolidated Statements of Ca_2

Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Statement Of Cash Flows [Abstract]
Transaction costs	$ 13	$ 7.5

Organization and Basis of Prese

Organization and Basis of Presentation	12 Months Ended
	Dec. 31, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization and Basis of Presentation	1. ORGANIZATION AND BASIS OF PRESENTATION Description of Business Crinetics Pharmaceuticals, Inc. (the “Company”) is a clinical-stage pharmaceutical company incorporated in Delaware on November 18, 2008 and based in San Diego, California. The Company is focused on the discovery, development and commercialization of novel therapeutics for rare endocrine diseases and endocrine-related tumors. In January 2017, the Company established a wholly-owned Australian subsidiary, Crinetics Australia Pty Ltd (“CAPL”), in order to conduct various preclinical and clinical activities for its development candidates. Principles of Consolidation and Foreign Currency Transactions The consolidated financial statements include the accounts of the Company and CAPL. All intercompany accounts and transactions have been eliminated in consolidation. The functional currency of both the Company and CAPL is the U.S. dollar. Assets and liabilities that are not denominated in the functional currency are remeasured into U.S. dollars at foreign currency exchange rates in effect at the balance sheet date except for nonmonetary assets, which are remeasured at historical foreign currency exchange rates in effect at the date of transaction. Net realized and unrealized gains and losses from foreign currency transactions and remeasurement are reported in other income (expense), in the accompanying consolidated statements of operations and comprehensive loss and were not material for all periods presented. Segment Reporting Operating segments are identified as components of an enterprise about which discrete financial information is available for evaluation by the chief operating decision-maker in making decisions regarding resource allocation and assessing performance. The Company views its operations and manages its business in one operating segment. Liquidity From inception, the Company has devoted substantially all of its efforts to drug discovery and development and conducting preclinical studies and clinical trials. The Company has a limited operating history and the sales and income potential of the Company’s business and market are unproven. Successful transition to attaining profitable operations is dependent upon achieving a level of revenues adequate to support the Company’s cost structure. The Company has experienced net losses and negative cash flows from operating activities since its inception and has an accumulated deficit of $ 275.3 million as of December 31, 2021. As of December 31, 2021 , the Company had $ 333.7 million in unrestricted cash, cash equivalents and investment securities. To date, the Company has been funded primarily through equity offerings . On August 13, 2019, the Company entered into a sales agreement whereby the Company may offer and sell shares of its common stock from time to time up to $ 75.0 million through the sales agents (the “ATM Offering”). As of December 31, 2021, 275,764 shares had been sold through the ATM Offering, for net proceeds of $ 6.4 million, after deducting commissions of $ 0.2 million, (see Note 9). The Company expects to continue to incur net losses for the foreseeable future and believes it will need to raise substantial additional capital to accomplish its business plan over the next several years. The Company plans to continue to fund its losses from operations and capital funding needs through a combination of equity offerings, debt financings or other sources, including potential collaborations, licenses and other similar arrangements. If the Company is not able to secure adequate additional funding, the Company may be forced to make reductions in spending, extend payment terms with suppliers, liquidate assets, or suspend or curtail planned programs. Any of these actions could materially harm the Company’s business, results of operations and future prospects. There can be no assurance as to the availability or terms upon which such financing and capital might be available in the future. COVID-19 The COVID-19 pandemic has caused significant business disruption around the globe. The extent of the impact of COVID-19 on the Company's operational and financial performance will depend on certain developments, including the duration and spread of the pandemic and the impact on the Company's clinical trials, employees and vendors. To the extent possible, and consistent with applicable guidance from federal, state and local authorities, the Company is conducting business as usual, with necessary or advisable modifications to employee travel. The Company will continue to actively monitor the evolving situation related to COVID-19 and may take further actions that alter its operations, including those that may be required by federal, state or local authorities, or that the Company determines are in the best interests of its employees and other third parties with whom the Company does business. While the pandemic has not yet had a material effect on the Company’s financial results, the degree to which COVID-19, including the impact of new variants of the virus that causes COVID-19, may impact the Company's future financial condition or results of operations is uncertain. A prolonged outbreak could have a material adverse impact on financial results and business operations of the Company, including the timing and ability of Company to complete certain clinical trials and other efforts required to advance the development of its drug candidates and raise additional capital.

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 Use of Estimates The Company’s consolidated financial statements are prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”). The preparation of the Company’s consolidated financial statements requires it to make estimates and assumptions that impact the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities in the Company’s consolidated financial statements and accompanying notes. The most significant estimates in the Company’s consolidated financial statements relate to accrual of research and development expenses, valuation of stock-based awards, fair values of financial instruments, revenue recognition and equity method investment. Estimates are based on historical experiences or on forecasts, including information received from third parties and various other factors that the Company believes are reasonable under the circumstances. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Actual results could differ from those estimates . Equity Method Investment The Company first analyzes its investment in another entity to determine if the entity is a variable interest entity (“VIE”) and if so, whether the Company is the primary beneficiary requiring consolidation. An entity is considered a VIE if (1) the entity does not have enough equity to finance its own activities without additional support, (2) the entity’s at-risk equity holders lack the characteristics of a controlling financial interest, or (3) the entity is structured with non-substantive voting rights. VIEs are consolidated by the primary beneficiary, which is the entity that has both the power to direct the activities that most significantly impact the VIE’s economic performance and the obligation to absorb losses or the right to receive benefits from the VIE that potentially could be significant to the VIE. Variable interests in a VIE can be contractual, ownership, or other financial interests. The Company re-assesses its investment upon reconsideration events to determine whether the Company is the primary beneficiary of the VIE, in which case the Company would consolidate the VIE. If it has been determined that the Company is not the primary beneficiary or does not have control but does have the ability to exercise significant influence over the VIE, the Company accounts for the unconsolidated investment under the equity method of accounting. As discussed in Note 8, in October 2021, the Company, together with 5AM Ventures ("5AM") and Frazier Healthcare Partners ("Frazier"), announced the formation of Radionetics Oncology, Inc. ("Radionetics"). Radionetics aims to develop a deep pipeline of novel, targeted, nonpeptide radiopharmaceuticals for the treatment of a broad range of oncology indications. Radionetics is considered to be a VIE. The Company maintains an equity interest in Radionetics and accounts for its investment in Radionetics under the equity method of accounting. The Company records its share of Radionetics income (loss) outside of operations in the statements of operations and comprehensive loss on a quarterly lag. Since the Company’s investment in Radionetics was obtained on October 15, 2021, the Company will record its share of income (loss) beginning in the first quarter of 2022. Fair Value Measurements 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 non-recurring basis. Fair value is defined as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, the accounting guidance establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows: Level 1: Observable inputs such as quoted prices in active markets. Level 2: Inputs, other than the quoted prices in active markets, that are observable either directly or indirectly. Level 3: Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions about risk and the assumptions market participants would use in pricing the asset or liability developed based on the best information available in the circumstances. The carrying amounts of the Company’s current financial assets, restricted cash and current financial liabilities are considered to be representative of their respective fair values because of the short-term nature of those instruments. The Company recorded the derivative asset (see Note 8) and investment securities (see Note 3) at fair value. Cash, Cash Equivalents and Restricted Cash Cash and cash equivalents include cash held in readily available checking and money market accounts, as well as short-term debt securities with maturities of three months or less when purchased. Restricted cash represents cash held as collateral for the Company’s facility lease and is reported as a long-term asset in the accompanying consolidated balance sheets. Investment Securities All investments have been classified as “available-for-sale” and are carried at fair value as determined based upon quoted market prices or pricing models for similar securities at period end. Investments with contractual maturities less than 12 months at the balance sheet date are considered short-term investments. Investments with contractual maturities beyond one year are also classified as short-term due to the Company’s ability to liquidate the investment for use in operations within the next 12 months. Realized gains and losses on investment securities are derived using the specific identification method for determining the cost of securities sold and are included in other income (expenses), net in the accompanying consolidated statements of operations and comprehensive loss. The Company has not realized any significant gains or losses on sales of available-for-sale investment securities during any of the periods presented. As all the Company’s investment holdings are in the form of debt securities, unrealized gains and losses that are determined to be temporary in nature are reported as a component of accumulated other comprehensive income. Investment securities are evaluated periodically for impairment. A decline in the fair value of any security below cost that is deemed other than temporary results in a charge to earnings and the establishment of a new cost basis for the security. Interest income is recognized when earned and is included in interest income in the accompanying consolidated statements of operations and comprehensive loss, as are the amortization of purchase premiums and accretion of purchase discounts on investment securities. Derivative Asset Derivatives are recorded at fair value and changes in fair value are recorded through the statements of operations and comprehensive loss each period. The Company has a single derivative instrument, a warrant ("Radionetics Warrant") received on October 15, 2021, to purchase the greater of 3,407,285 additional shares of common stock or the number of additional shares of common stock that would all the Company to maintain an aggregate equity interest of 22 % of the fully diluted capitalization of Radionetics. The Company records the Radionetics Warrant as long-term on the balance sheets due to the lack of marketability, such that it is not expected to be available for current operations. Changes in fair value of the Radionetics Warrant are recognized in other income (expense) in the accompanying consolidated statements of operations and comprehensive loss. Concentrations of Credit Risk Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash, cash equivalents and investment securities. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. The Company has not experienced any losses in such accounts and believes it is not exposed to significant risk on its cash balances due to the financial position of the depository institution in which those deposits are held. Additionally, the Company has established guidelines regarding approved investments and maturities of investments, which are designed to maintain safety and liquidity. Leases The Company determines if an arrangement is a lease at the inception of the arrangement. Leases with a term longer than 12 months that are determined to be operating leases are included in operating lease right-of-use assets, other current liabilities and noncurrent operating lease liabilities in the consolidated balance sheets. The Company accounts for each separate lease and non-lease component as a single lease component. When the Company’s leases do not provide an implicit rate, an incremental borrowing rate is used based on the information available at commencement dates in determining the present value of lease payments. The incremental borrowing rate is the rate of interest that the Company would expect to pay to borrow over a similar term, and on a collateralized basis, an amount equal to the lease payments in a similar economic environment. The Company’s lease terms may include options to extend or terminate the lease when the Company is reasonably certain that it will exercise such options. Lease expense for lease payments is recognized on a straight-line basis over the lease term. Lease agreements may contain variable costs such as common area maintenance, insurance, taxes or other costs. Such variable lease costs are expensed as incurred. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term. Property and Equipment, Net Property and equipment consist of leasehold improvements, and lab and various other equipment. Such assets are stated at cost and depreciated on a straight-line basis over the estimated useful life of the related assets. The Company estimates its useful lives of its lab and other equipment as follows: lab equipment – three to five years ; office equipment - three to five years ; computer and software – three years . Leasehold improvements are amortized over the estimated useful life of the improvement or the remaining term of the associated lease. Repairs and maintenance costs are charged to expense as incurred and expenditures that materially extend the useful lives of assets are capitalized. Impairment of Long-Lived Assets The Company reviews long-lived assets for impairment whenever events or changes in business circumstances indicate that the carrying amount of the assets may not be fully recoverable. Factors considered in deciding when to perform an impairment review include significant underperformance of the business in relation to expectations, significant negative industry or economic trends, and significant changes or planned changes in the use of the assets. An impairment loss is recognized when estimated undiscounted future cash flows expected to result from the use of an asset are less than its carrying amount. If such assets are considered impaired, the impairment loss recognized is measured as the excess of the carrying value of the impaired asset over its fair value, determined based on future cash flows or appraised values, depending on the nature of the asset. The Company has no t recognized any impairment losses in any of the periods presented in these consolidated financial statements. Revenue Recognition The Company has generated revenue from a collaboration and license agreement with a partner, as well as from grants from government agencies. The Company recognizes revenues when, or as, the promised goods or services are transferred to customers in an amount that reflects the consideration to which it expects to be entitled in exchange for those services. To determine revenue recognition for arrangements, the Company performs the following five steps: (1) identify the contract(s) with a customer; (2) identify the performance obligation(s) in the contract; (3) determine the transaction price; (4) allocate the transaction price to the performance obligation(s) in the contract; and (5) recognize revenue when (or as) the performance obligation(s) are satisfied. At contract inception, the Company assesses the goods or services promised within each contract, assesses whether each promised good or service is distinct and identifies those that are performance obligations. The Company recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when, or as, the performance obligation is satisfied. The Company considers a variety of factors in determining the appropriate estimates and assumptions under the arrangements, such as whether the elements are distinct performance obligations, whether there are observable stand-alone prices, and whether the license is 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. Collaboration and License Agreement The Company has entered into a collaboration and license agreement ("CLA") with a partner that mainly includes the following: (i) upfront noncash considerations ; (ii) payments associated with achieving certain milestones; and (iii) royalties based on specified percentages of net product sales, if any. At the initiation of an agreement, the Company analyzes each unit of account within the contract to determine if the counterparty is a customer in the context of the unit of account. The Company's performance obligation under the CLA consisted of the license and know-how of the technology. The upfront noncash considerations are fixed considerations for functional intellectual property as it exists at a point in time, being the time that the CLA was executed. Revenues for sales-based royalties and milestones are recognized at the later of the subsequent sale or satisfaction of the performance obligation. Grant Revenue Recognition The Company’s grant revenues are derived from Small Business Innovation Research Grants (“SBIR Grants”) from the National Institutes of Health. The Company's performance obligation under SBIR Grants consists of research activities and the Company recognizes SBIR Grant revenue over time as reimbursable grant costs are incurred up to pre-approved award limits within the budget period. The costs associated with these reimbursements are reflected as a component of research and development expense in the accompanying consolidated statements of operations and comprehensive loss. Earnings in excess of billings are included as a component of prepaid expenses and other current assets in the accompanying consolidated balance sheets. Research and Development Expenses Research and development (“R&D”) expenses consist primarily of salaries, payroll taxes, employee benefits and stock-based compensation for individuals involved in R&D efforts, as well as consulting expenses, third-party R&D expenses, laboratory supplies, clinical materials and overhead, including facilities and depreciation costs, offset by the Australian Tax Incentive discussed below. R&D expenses are charged to expense as incurred. Payments made prior to the receipt of goods or services to be used in R&D are capitalized until the goods or services are received and are recorded as prepaid expenses and other current assets. Costs incurred under contracts with contract research organizations that conduct and manage the Company’s clinical trials are also included in research and development expenses. The financial terms and activities of these agreements vary from contract to contract and may result in uneven expense levels. Generally, these agreements set forth activities that drive the recording of expenses such as start-up and initiation activities, enrollment and treatment of patients, or the completion of other clinical trial activities. Expenses related to clinical trials are accrued based on estimates and/or representations from service providers regarding work performed, including actual level of patient enrollment, completion of patient studies and progress of the clinical trials. Other incidental costs related to patient enrollment or treatment are accrued when reasonably certain. If the amounts that the Company is obligated to pay under its clinical trial agreements are modified (for instance, as a result of changes in the clinical trial protocol or scope of work to be performed), the Company adjusts its accruals accordingly on a prospective basis. Revisions to contractual payment obligations are charged to expense in the period in which the facts that give rise to the revision become reasonably certain. Accrued R&D exp enses totaled $ 4.2 million and $ 2.1 million as of December 31, 2021 and 2020, respectively, and are a component of accounts payable and accrued expenses in the accompanying consolidated balance sheets. Australian Tax Incentive CAPL is eligible to obtain a cash refund from the Australian Taxation Office for eligible R&D expenditures under the Australian R&D Tax Incentive Program (the “Australian Tax Incentive”). The Australian Tax Incentive is recognized as a reduction to R&D expense when there is reasonable assurance that the relevant expenditure has been incurred, the amount can be reliably measured and that the Aust ralian Tax Incentive will be received. The Company recognized reductions to R&D expense of $ 0.3 million, $ 0.6 million and $ 1.0 million for the years ended December 31, 2021, 2020 and 2019 , respectively. Patent Costs All costs incurred for the filing of patent applications are recorded as general and administrative expenses in the accompanying consolidated statements of operations and comprehensive loss when incurred, as the recoverability of these expenses is uncertain. Stock-Based Compensati on Stock-based compensation expense represents the estimated grant date fair value of the Company’s equity awards, consisting of stock options and shares issued under the Company’s Employee Stock Purchase Plan, recognized over the requisite service period of such awards (usually the vesting period) on a straight-line basis. The Company estimates the fair value of equity awards using the Black-Scholes option pricing model on the date of grant and recognizes forfeitures as they occur. For stock awards for which vesting is subject to performance-based milestones, the expense is recorded over the remaining service period after the point when the achievement of the milestone is probable, or the performance condition has been achieved. 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 consolidated financial statements. Under this method, deferred tax assets and liabilities are determined based on the differences between the consolidated 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% 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, and any accrued interest and penalties would be included within the related tax liability. No such costs were recorded during the three years ended December 31, 2021 . Comprehensive Loss Comprehensive loss is comprised of the Company’s net loss and the unrealized gains or losses on the Company’s available for sale investment securities for all periods presented. The cumulative amount of unrealized gains and losses is reflected as a separate component of stockholders' equity in the accompanying consolidated balance sheets as accumulated other comprehensive income (loss). There are no tax effects for the years ended December 31, 2021, 2020 and 2019 . Net Loss Per Share Basic net loss per share is computed by dividing the net loss by the weighted-average number of common shares outstanding for the period, without consideration for potentially dilutive securities. Diluted net loss per share is computed by dividing the net loss by the weighted-average number of shares of common stock and dilutive common stock equivalents outstanding for the period determined using the treasury-stock. Dilutive common stock equivalents are comprised of common stock subject to repurchase, and options outstanding under the Company’s stock option plan. For all periods presented, there is no difference in the number of shares used to calculate basic and diluted shares outstanding as inclusion of the potentially dilutive securities on loss per share would be antidilutive. Potentially dilutive securities (in common stock equivalent shares) not included in the calculation of diluted net loss per share because to do so would be anti-dilutive are as follows ( in thousands ): Year ended December 31, 2021 2020 2019 Common stock options 6,554 4,422 3,127 Unvested common stock subject to repurchase 1 16 33 Total 6,555 4,438 3,160 Recently Adopted Accounting Pronouncements ASU 2020-01 In January 2020, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU") 2020-01, Investments-Equity Securities ("Topic 321"), Investments-Equity Method and Joint Ventures ("Topic 323"), and Derivatives and Hedging ("Topic 815"), - Clarifying the Interactions between Topic 321, Topic 323, and Topic 815 ("ASU 2020-01"), which addresses the accounting for the transition into and out of the equity method and provides clarification of the interaction of rules for equity securities, the equity method of accounting, and forward contracts and purchase options on certain types of securities. The amendments clarify that: (a) an entity should consider observable transactions that require it to either apply or discontinue the equity method of accounting for the purposes of applying the measurement alternative in accordance with Topic 321 immediately before applying or upon discontinuing the equity method; and (b) an entity should not consider whether, upon the settlement of the forward contract or exercise of the purchased option, individually or with existing investments, the underlying securities would be accounted for under the equity method in Topic 323 or the fair value option in accordance with the financial instruments guidance in Topic 825. The provisions of this guidance are to be applied prospectively upon their effective date. ASU 2020-01 was effective for fiscal years beginning after December 15, 2020, and interim periods within those years. Early adoption was permitted, but required simultaneous adoption of all provisions of this guidance. The Company adopted this guidance as of January 1, 2021, which did not result in a material impact on its consolidated financial statements and related disclosures. ASU 2020-06 In August 2020, the FASB issued ASU No. 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity (" ASU 2020-06") , which simplifies the accounting for certain financial instruments with characteristics of liabilities and equity, including convertible instruments and contracts on an entity’s own equity. Specifically, ASU 2020-06 simplifies accounting for the issuance of convertible instruments by removing major separation models required under current GAAP. In addition, the ASU removes certain settlement conditions that are required for equity contracts to qualify for the derivative scope exception and simplifies the diluted earnings per share (EPS) calculation in certain areas. The Company adopted ASU 2020-06 as of January 1, 2021 using the modified-retrospective approach, which did not have an impact on its consolidated financial statements. Recent Accounting Pronouncements ASU 2016-13 In June 2016, the FASB issued ASU No. 2016-13, “Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments ” (“Topic 326”). Topic 326 amends guidance on reporting credit losses for assets held at amortized cost basis and available for sale debt securities. For assets held at amortized cost basis, Topic 326 eliminates the probable initial recognition threshold in current GAAP and, instead, requires an entity to reflect its current estimate of all expected credit losses. The allowance for credit losses is a valuation account that is deducted from the amortized cost basis of the financial assets to present the net amount expected to be collected. For available for sale debt securities, credit losses should be measured in a manner similar to current GAAP, however Topic 326 will require that credit losses be presented as an allowance rather than as a write-down. This ASU update affects entities holding financial assets and net investment in leases that are not accounted for at fair value through net income. This update is effective for the Company for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. The Company is currently evaluating the impact of the pending adoption of this new standard on its consolidated financial statements. ASU 2021-04 In May 2021, the FASB issued ASU 2021-04, Earnings Per Share ("Topic 260"), Debt-Modifications and Extinguishments ("Subtopic 470-50"), Compensation-Stock Compensation ("Topic 718"), and Derivatives and Hedging-Contracts in Entity’s Own Equity ("Subtopic 815-40"): Issuer’s Accounting for Certain Modifications or Exchanges of Freestanding Equity-Classified Written Call Options , which intends to clarify and reduce diversity in an issuer’s accounting for modifications or exchanges of freestanding equity-classified written call options (for example, warrants) that remain equity classified after modification or exchange. The guidance is effective for fiscal years beginning after December 15, 2021, including interim periods therein, and early adoption is permitted. The Company is currently evaluating the potential impact that the adoption of ASU 2021-04 may have on its consolidated financial statements and related disclosures.

Investment Securities

Investment Securities	12 Months Ended
	Dec. 31, 2021
Investments Debt And Equity Securities [Abstract]
Investment Securities	3. INVESTMENT SECURITIES A vailable-for-sale investment securities consisted of the following as of December 31, 2021 and 2020 ( in thousands ): As of December 31, 2021 Amortized Gross Gross Fair Available-for-sale investment securities: U.S. government and agency obligations $ 54,637 $ — $ ( 180 ) $ 54,457 Certificates of deposit 5,735 1 ( 4 ) 5,732 Corporate debt securities 70,600 6 ( 204 ) 70,402 Asset-backed securities 2,421 — — 2,421 Total $ 133,393 $ 7 $ ( 388 ) $ 133,012 As of December 31, 2020 Amortized Gross Gross Fair Available-for-sale investment securities: U.S. government and agency obligations $ 74,222 $ 6 $ ( 5 ) 74,223 Certificates of deposit 2,161 14 — 2,175 Corporate debt securities 1,385 10 — 1,395 Total $ 77,768 $ 30 $ ( 5 ) $ 77,793 As of December 31, 2021 and 2020, available-for-sale investment securities by contractual maturity were as follows ( in thousands ): As of December 31, 2021 As of December 31, 2020 Amortized Fair Amortized Fair Available-for-sale investment securities: Due in one year or less $ 31,101 $ 31,078 $ 59,472 $ 59,487 Due after one year through five years 102,292 101,934 18,296 18,306 Total $ 133,393 $ 133,012 $ 77,768 $ 77,793 The Company reviewed its investment holdings as of December 31, 2021 and determined that its unrealized losses were not considered to be other-than-temporary based upon (i) the financial strength of the issuing institution and (ii) the fact that no securities have been in an unrealized loss position for twelve months or more. As such, the Company has not recognized any impairment in its financial statements related to its available-for-sale investment securities. During the years ended December 31, 2021, 2020, and 2019, the Company recognized $ 2,000 , $ 26,000 and $ 7,000 , respectively, of realized net gains in the accompanying statements of operations and comprehensive loss.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	4. FAIR VALUE MEASUREMENTS Investment Securities The Company holds investment securities that consist of highly liquid, investment grade debt securities. The Company determines the fair value of its investment securities based upon one or more valuations reported by its investment accounting and reporting service provider. The investment service provider values the securities using a hierarchical security pricing model that relies primarily on valuations provided by an industry-recognized valuation service. Such valuations may be based on trade prices in active markets for identical assets or liabilities (Level 1 inputs) or valuation models using inputs that are observable either directly or indirectly (Level 2 inputs), such as quoted prices for similar assets or liabilities, yield curves, volatility factors, credit spreads, default rates, loss severity, current market and contractual prices for the underlying instruments or debt, and broker and dealer quotes, as well as other relevant economic measures. Derivative Asset On October 15, 20 21, the Company received the Radionetics Warrant to purchase the greater of 3,407,285 additional shares of common stock or the number of additional shares of common stock that would all the Company to maintain an aggregate equity interest of 22 % of the fully diluted capitalization of Radionetics. The valuation method and primary inputs used in valuing the Radionetics Warrant are discussed in Note 8. Such valuation is based on valuations provided by a third-party valuation specialist using unobservable inputs due to little to no market data (Level 3 inputs). There were no material changes in the inputs or total the valuation of the Radionetics Warrant between October 15, 2021 and December 31, 2021. Financial assets measured at fair value on a recurring basis as of December 31, 2021 and 2020 were as follows (in thousands): As of December 31, 2021 Level 1 Level 2 Level 3 Total Investment securities: U.S. government and agency obligations $ 44,984 $ 9,473 $ — $ 54,457 Certificates of deposit — 5,732 — 5,732 Corporate debt securities — 70,402 — 70,402 Asset-backed securities — 2,421 2,421 Total Investment securities 44,984 88,028 — 133,012 Derivative Assets: Radionetics Warrant — — 68 68 Total assets measured at fair value $ 44,984 $ 88,028 $ 68 $ 133,080 As of December 31, 2020 Level 1 Level 2 Level 3 Total Investment securities: U.S. government and agency obligations $ 60,222 $ 14,001 $ — $ 74,223 Certificates of deposit — 2,175 — 2,175 Corporate debt securities — 1,395 — 1,395 Total assets measured at fair value $ 60,222 $ 17,571 $ — $ 77,793 The Company’s policy is to recognize transfers between levels of the fair value hierarchy on the date of the event or change in circumstances that caused the transfer. There were no transfers into or out of Level 3 during the years ended December 31, 2021 and 2020 .

Balance Sheet Details

Balance Sheet Details	12 Months Ended
	Dec. 31, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Balance Sheet Details	5. BALANCE SHEET DETAILS Prepaid expenses and other current assets consisted of the following ( in thousands ): December 31, December 31, Prepaid research and development costs $ 7,184 $ 3,062 Australian tax incentive receivable 977 1,720 Prepaid insurance 888 693 Interest receivable 499 113 Due from Radionetics (Note 8) 553 — Other 912 1,024 Total $ 11,013 $ 6,612 Property and equipment, net consisted of the following ( in thousands ): December 31, December 31, Leasehold improvements $ 3,516 $ 3,494 Lab equipment 1,889 1,551 Office equipment 859 653 Computers and software 41 41 Property and equipment at cost 6,305 5,739 Less accumulated depreciation and amortization 3,480 2,558 Total $ 2,825 $ 3,181 Depreciation and amortization expense was $ 0.9 million for each of the years ended December 31, 2021, 2020 and 2019 .

Operating Lease

Operating Lease	12 Months Ended
	Dec. 31, 2021
Leases [Abstract]
Operating Lease	6. OPERATING LEASE In February 2018, as amended in March 2018, the Company entered into a non-cancelable operating lease for a new facility in San Diego, California. The lease has an initial term of seven years which expires in August 2025 , and the Company has an option to extend the term of the lease for an additional five years and has a termination option subject to early termination fees. The lease is subject to base lease payments and additional charges for common area maintenance and other costs and includes certain lease incentives and tenant improvement allowances. The Company’s estimated incremental fully collateralized borrowing rate of 8.0 % was used in its present value calculation as the facility lease does not have a stated rate and the implicit rate was not readily determinable. Under the terms of the lease, the Company provided the lessor with an irrevocable letter of credit in the amount of $ 0.5 million. The lessor is entitled to draw on the letter of credit in the event of any default by the Company under the terms of the lease. As of December 31, 2021, future minimum payments under non-cancellable operating leases were as follows ( in thousands ): Year ending December 31, Minimum 2022 $ 1,208 2023 1,244 2024 1,280 2025 871 Total future minimum lease payments 4,603 Less imputed interest ( 590 ) Total operating lease liability 4,013 Less operating lease liability, current ( 939 ) Operating lease liability, non-current $ 3,074 Lease cost is recorded on a straight-line basis over the term of the Company’s facility lease. Rent expense was $ 1.0 million for each of the years ended December 31, 2021, 2020 and 2019 . As of December 31, 2021 and 2020, the Company’s operating lease weighted average remaining term was 3.6 and 4.6 years, respectively. As of December 31, 2021 and 2020, the Company’s weighted-average discount rate was 8 %. Cash paid for amounts included in the measurement of lease liabilities for operating cash flow from operating leases was $ 1.2 million, $ 1.1 million, and $ 1.1 million during each of the years ended years ended December 31, 2021, 2020 and 2019 .

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2021
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	7. COMMITMENTS AND CONTINGENCIES Litigation From time to time, the Company may be subject to various claims and suits arising in the ordinary course of business. The Company does not expect that the resolution of these matters will have a material adverse effect on its financial position or results of operations.

Radionetics Oncology, Inc.

Radionetics Oncology, Inc.	12 Months Ended
	Dec. 31, 2021
RADIONETICS ONCOLOGY, INC. [Abstract]
Radionetics Oncology, Inc.	8. RADIONETICS ONCOLOGY, INC. Formation In October 2021, the Company, together with 5AM and Frazier, announced the formation of Radionetics Oncology, Inc. Radionetics aims to develop a deep pipeline of novel, targeted, nonpeptide radiopharmaceuticals for the treatment of a broad range of oncology indications. Collaboration and License Agreement The Company and Radionetics entered into the CLA under which the Company granted to Radionetics an exclusive world-wide license to its radiotherapeutics technology platform and associated intellectual property for use in developing radiotherapeutics and related radio-imaging agents, including exclusive rights to the underlying intellectual property on certain preclinical drug candidates. Under the CLA, the Company will not be supporting or maintaining the intellectual property and does not plan on continuing to undertake those activities from which the utility of the intellectual property is derived. The collaborative provisions per the CLA are deemed to be protective measures for the advancement of the technology and not deemed to be a separate performance obligation. The performance obligation under the CLA consisted of the license and know-how of the technology that was transferred at the inception of the CLA. The CLA is effective until the earlier of the fifth anniversary of signing the CLA or a change in control of either the Company or Radionetics. In exchange, the C ompany received 50,500,000 shares of common stock of Radionetics, which represents an initial majority stake in Radionetics of 64 %, and the Radionetics Warrant to purchase the greater of 3,407,285 additional shares of common stock or the number of additional shares of commo n stock that would allow the Company to maintain an aggregate equity interest of 22 % of the fully diluted capitalization of Radionetics. The exercise price of the Radionetics Warrant is $ 0.00001 and it is exercisable at any time and has a term of 10 years . These upfront noncash considerations were valued at $ 1.1 million, which were comprised of $ 1.0 million for the Company's share of Radionetics common stock and $ 0.1 million for the Radionetics Warrant. The CLA is for functional intellectual property which was transferred at the inception of the CLA. The Company does not have an ongoing performance obligation to support or maintain the licensed intellectual property under the CLA. During the year ended December 31, 2021, the entire amount of the upfront noncash consideration of $ 1.1 million was recognized as license revenue in the accompanying consolidated statements of operations and comprehensive loss upon the Company's transfer of the license under the CLA. In addition, the Company may receive potential sales milestones in excess of $ 1.0 billion and single-digit royalties on net sales. The Company may also pay Radionetics potential royalties on certain net sales. Sales-based milestones and royalties are recognized at the later of when the subsequent sale or usage occurs or the performance obligation for which some or all of the sales-based milestones an d royalties have been allocated to has been satisfied or partially satisfied. As there have been no sales to date, no sales-based milestones or royalties were recognized during the year ended December 31, 2021. Valuation of Upfront Noncash Considerations The Company engaged a third-party valuation specialist to determine the estimated fair value of these upfront noncash considerations received. The valuation specialist utilized a cost approach to determine the implied value of Radionetics’ equity since it was newly formed with early development stage technology from the CLA for which there are not reliable long-term forecasts. Next, the total equity value was allocated to various share classes using the current value method and option pricing method. The current value method allocates the value of the business to the shareholders' given consideration of senior obligations such as debt, equity certificates and other preferred equity. The option pricing method entails allocating the total shareholders’ equity value to the various share classes based upon their respective claims on a series of call options with strike prices at various value levels depending upon the rights and preferences of each class. The primary inputs used in valuing the Radionetics common stock and the Radionetics Warrant, were as follows: Derivative Asset October 15, 2021 and December 31, 2021 Expected term 3.0 years Expected volatility 111.4 % Risk free interest rate 0.7 % Marketability discount 30.0 % The Company estimated the expected term based on the expected time to a liquidity event. The risk-free interest rate was based on the yields of zero-coupon U.S. treasury securities. Volatility was estimated based upon an analysis of historical equity and asset volatilities of companies deemed comparable to Radionetics. The valuation amounts were adjusted by a discount for lack of marketability to account for the lack of liquidity an owner of the interest would experience for common stock in an early-stage company. The estimated value for the common stock of Radionetics and the Radionetics Warrant was $ 0.02 per share as of October 15, 2021 and December 31, 2021. Investment in Radionetics The Company applied the VIE model to its variable interests in Radionetics and concluded Radionetics is a VIE due to its insufficient equity to finance its activities without additional subordinated financial support. The Company then evaluated whether it is the primary beneficiary of Radionetics by identifying Radionetics’ key activities: (1) research and development activities, (2) financing decisions, and (3) determining the strategic direction of Radionetics. Power over research and development activities are made by unanimous vote by members of the research and development committee, in which no party has power. Power for financing decisions and setting strategic direction rests with the Radionetics’ board of directors, and no party was determined to be in control since the Radionetics board of directors is comprised of 4 members for which Crinetics, 5AM and Frazier are entitled to appoint (and replace, as needed) their board designee while the fourth independent member must be mutually agreed to by all three investors. Radionetics’ management is entirely separate from the Company and is determined by Radionetics’ board of directors. As the Company does not control any of Radionetics' key activities, it is not the primary beneficiary of the VIE and does not consolidate Radionetics. The Company accounted for its investment in Radionetics under the equity method of accounting due to its ability to exercise significant influence through its board seat and involvement in R&D activities, among other factors. The Company’s initial investment in Radionetics was recorded at the fair value of common stock received in the amount of $ 1.0 million. The Company's maximum exposure to loss of Radionetics is limited to carrying value of its equity method investment in Radionetics and the Radionetics Warrant. The Company has no obligation to fund the operations of Radionetics and has not provided significant explicit or implicit support to Radionetics that was not contractually required. The financial statements of Radionetics are not received sufficiently timely for the Company to record its portion of earnings or loss in the current consolidated financial statements and therefore the Company reports its portion of earnings or loss on a one quarter lag. Other Radionetics Transactions During the year ended December 31, 2021, Radionetics completed a $ 30.0 million convertible notes financing with 5AM and Frazier as the sole participants. R. Scott Struthers, Ph.D. the Company’s President and Chief Executive Officer, serves as chairman of the Radionetics board of directors. As of December 31, 2021, The Company had approximately $ 0.6 million due from Radionetics for reimbursement of certain expenses paid on behalf of Radionetics. These amounts are recorded within prepaid expenses and other current assets in the accompanying balance sheets. The Company has evaluated these reimbursements and concluded that these reimbursements are not performance obligations for which the Company is acting as the principal and therefore these amounts have been included within operating expenses in the accompanying statements of operations and comprehensive income.

Stockholder's Equity

Stockholder's Equity	12 Months Ended
	Dec. 31, 2021
Stockholders Equity Note [Abstract]
Stockholders' Equity	9. STOCKHOLDERS’ EQUITY Stock Offerings On April 17, 2020, the Company completed a public offering of 8,222,500 shares of its common stock at a public offering price of $ 14.00 per share. Proceeds from the offering were approximately $ 107.9 million, net of underwriting discounts and commissions and offering costs of $ 7.3 million. The shares were registered pursuant to the Company’s Shelf Registration Statement discussed below. On April 12, 2021, the Company completed an underwritten follow-on offering of 4,562,044 shares of its common stock at a price to the public of $ 16.44 per share. Proceeds from the offering were approximately $ 72.6 million, net of underwriting discounts and commissions and offering costs of $ 2.4 million. The shares were registered pursuant to the Company’s Shelf Registration Statement discussed below. On July 28, 2021, the Company entered into a stock purchase agreement for the private placement of 851,306 shares of its common stock at a price of $ 17.62 per share (the “Private Placement”), which shares were issued on July 30, 2021. Proceeds from the offering were approximately $ 15.0 million. On October 21, 2021, the Company completed an underwritten follow-on offering of 8,712,400 shares of its common stock at a price to the public of $ 19.80 per share. Proceeds from the offering were approximately $ 162.0 million, net of underwriting discounts and commissions and offering costs of $ 10.5 million. The shares were registered pursuant to the Company’s 2021 Shelf Registration Statement discussed below. Shelf Registration Statements and ATM Offering On August 13, 2019, the Company filed a registration statement on Form S-3 (the “Shelf Registration Statement”), covering the offering of up to $ 300.0 million of common stock, preferred stock, debt securities, warrants and units. The Registration Statement became effective on August 29, 2019 . On August 13, 2019, the Company also entered into the Sales Agreement (the “Sales Agreement”) with SVB Leerink LLC and Cantor Fitzgerald & Co. (the “Sales Agents”), under which the Company may, from time to time, sell shares of its common stock having an aggregate offering price of up to $ 75.0 million. The Shelf Registration Statement included a prospectus covering the offering, issuance, and sale of up to $ 75.0 million of Company common stock from time to time through the ATM Offering. The shares to be sold under the Sales Agreement may be issued and sold pursuant to the Shelf Registration Statement. During the year ended December 31, 2020, the Company sold a total of 275,764 shares of common stock pursuant to its ATM Offering for net proceeds of $ 6.4 million, after deducting commissions of $ 0.2 million. The Company did not issue any additional shares of common stock in the ATM Offering during the year ended December 31, 2021. On August 10, 2021, the Company filed a registration statement on Form S-3 (the “2021 Shelf Registration Statement”), which became immediately effective upon filing, covering the offering of common stock, preferred stock, debt securities, warrants and units and the resale of up to 851,306 shares by the accredited investor who purchased shares in the Private Placement.

Equity Incentive Plans

Equity Incentive Plans	12 Months Ended
	Dec. 31, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Equity Incentive Plans	10. EQUITY INCENTIVE PLANS 2021 Employment Inducement Incentive Award Plan The Company adopted the 2021 Employment Inducement Incentive Award Plan (the "2021 Inducement Plan") in December 2021. The Company initially reserved 1,500,000 shares of the Company’s common stock for issuance pursuant to awards granted under the 2021 Inducement Plan. The terms of the 2021 Inducement Plan are substantially similar to the terms of the Company’s 2018 Incentive Award Plan with the exception that awards may only be made to an employee who has not previously been an employee or member of the board of directors of the Company if the award is in connection with commencement of employment. No awards were granted under the 2021 Inducement Plan during the year ended December 31, 2021. 2018 Incentive Award Plan The Company adopted the 2018 Incentive Award Plan (the “2018 Plan”) in July 2018. Under the 2018 Plan, which expires in July 2028 , the Company may grant equity-based awards to individuals who are employees, officers, directors or consultants of the Company. Options issued under the 2018 Plan will generally expire ten years from the date of grant and vest over a four-year period. As of December 31, 2021, an aggregate o f 1,121,703 shares of common stock were available for issuance under the 2018 Plan. The 2018 Plan contains a provision that allows annual increases in the number of shares available for issuance on the first day of each calendar year through January 1, 2028 in an amount equal to the lesser of: (i) 5 % of the aggregate number of shares of the Company’s common stock outstanding on December 31 of the immediately preceding calendar year, or (ii) such lesser amount determined by the Company. Under this evergreen provision, on January 1, 2022, an addition al 2,379,911 sh ares became available for future issuance under the 2018 Plan. 2015 Stock Incentive Plan In February 2015, the Company adopted the Crinetics Pharmaceuticals, Inc. 2015 Stock Incentive Plan (the “2015 Plan”), which provided for the issuance of equity awards to the Company’s employees, members of its board of directors and consultants. In general, options issued under this plan vest over four years and expire after 10 years. Subsequent to the adoption of the 2018 Plan, no additional equity awards can be made under the 2015 Plan. Certain awards issued under the 2015 Plan allowed for exercise prior to vesting. Shares issued under such early-exercise provisions are subject to repurchase by the Company until they become fully vested. As of December 31, 2021, 1,228 unvested shares issued under early-exercise provisions were subject to repurchase by the Company. The consolidated balance sheet reflects an unvested stock liability of $ 2,000 a nd $ 23,000 as of December 31, 2021 and 2020, respectively. 2018 Employee Stock Purchase Plan In July 2018, the Company adopted the 2018 Employee Stock Purchase Plan (the “ESPP”). The ESPP permits participants to purchase common stock through payroll deductions of up to 20 % of their eligible compensation. As of December 31, 2021 , an aggregate of 853,108 sh ares of common stock were available for issuance under the ESPP. The ESPP contains a provision that allows annual increases in the number of shares available for issuance on the first day of each calendar year through January 1, 2028 in an amount equal to the lesser of: (i) 1% of the aggregate number of shares of the Company’s common stock outstanding on December 31 of the immediately preceding calendar year, or (ii) such lesser amount determined by the Company. Under this evergreen provision, on January 1, 2022, an additional 475,982 shares became available for future issuance under the ESPP. Stock Option Activity Activity under the Company’s stock option plans during the yea r ended December 31, 2021 was as follows: Weighted- Weighted- Aggregate Average Average Intrinsic Options Exercise Remaining Value Outstanding Price Term (000’s) Balance at December 31, 2020 4,421,533 $ 14.42 Granted 2,889,000 $ 18.09 Exercised ( 364,273 ) $ 8.61 Forfeited and expired ( 392,666 ) $ 19.24 Balance at December 31, 2021 6,553,594 $ 16.07 8.1 $ 80,906 Vested and expected to vest at December 31, 2021 6,553,594 $ 16.07 8.1 $ 80,906 Exercisable at December 31, 2021 2,989,994 $ 13.28 7.1 $ 45,283 Aggregate intrinsic value is calculated as the difference between the closing price of the Company’s common stock at December 31, 2021 and the exercise price of stock options that had strike prices below the closing price. The total intrinsic value of options exercised during 2021, 2020 and 2019 was $ 5.1 million, $ 2.5 million and $ 2.0 million, respectively. Fair Value of Stock Awards The following table summarizes the weighted average assumptions used to estimate the fair value of stock options granted under the Company’s stock option plans and the shares purchasable under the ESPP d uring the periods presented: Year ended December 31, Stock Option Awards 2021 2020 2019 Expected term 6.0 years 6.0 years 5.9 years Expected volatility 86 % 78 % 78 % Risk free interest rate 1.0 % 0.8 % 2.3 % Expected dividend yield — % — % — % Year ended December 31, ESPP 2021 2020 2019 Expected term 1.6 years 1.4 years 1.8 years Expected volatility 91 % 84 % 65 % Risk free interest rate 0.3 % 0.2 % 2.2 % Expected dividend yield — % — % — % The key assumptions used in determining the fair value of equity awards, and the Company’s rationale, were as follows: (i) Expected term - the expected term for options represents the period that options are expected to be outstanding and has been estimated using the simplified method, which is an average of the contractual option term and its vesting period; the expected term for ESPP represents the term the awards are expected to be outstanding; (ii) Expected volatility - the expected volatility assumption is based on volatilities of a peer group of similar companies in the biotechnology industry whose share prices are publicly available; (iii) Risk-free interest rate - the risk-free interest rate is based on the U.S. Treasury yield in effect at the time of grant for zero coupon U.S. Treasury notes with maturities that approximate the expected terms of awards; and (iv) Expected dividend yield - the expected dividend yield assumption is zero as the Company has never paid dividends and has no present intention to do so in the futur e. The weighted-average fair value of stock options granted to employees during the years ended December 31, 2021, 2020 and 2019 was $ 13.02 , $ 12.83 and $ 16.35 per share, respectively. The weighted-average fair value of awards under the ESPP during the years ended December 31, 2021, 2020 and 2019 was $ 12.52 , $ 8.07 and $ 10.59 per share, respectively. Stock-Based Compensation Expense Stock-based compensation expense for the equity awards issued by the Company to employees and non-employees for the periods presented below was as follow s ( in thousands ): Year ended December 31, 2021 2020 2019 Included in research and development $ 9,654 $ 5,218 $ 3,190 Included in general and administrative 7,698 5,209 3,104 Total stock-based compensation expense $ 17,352 $ 10,427 $ 6,294 Unrecognized stock-based compensation cost related to option awards wa s $ 43.4 million as of December 31, 2021 , which is expected to be recognized over a remaining weighted-average period of approximately 2.0 years . Unrecognized stock-based compensation cost related to stock purchase rights under the Company ’s ESPP was $ 1.9 mil lion as of December 31, 2021, which is expected to be recognized over a remaining weighted-average period of a pproximately 1.5 ye ars.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	11. INCOME TAXES The Company is subject to taxation in the United States, various state jurisdictions and Australia; however, as it has operated at a loss since inception, it has not paid income taxes in any of the jurisdictions in which it has operated. At December 31, 2021 , the Company had federal, state, and foreign net operating loss (“NOL”) carryforwards of approximately $ 209.4 million, $ 216.0 million and $ 1.3 million, respectively. The federal loss carryforwards generated after 2017 of $ 203.1 million will carryforward indefinitely and can be used to offset up to 80 % of future annual taxable income, while those loss carryforwards generated prior to 2018 begin expiring in 2035, unless previously utilized. $ 0.2 million of the state loss carryforwards will carryforward indefinitely. The remaining state loss carryforwards begin expiring in 2035, unless previously utilized. The Company’s foreign loss carryforwards do not expire. The Company also has federal and California R&D credit carryforwards totaling $ 6.3 million and $ 4.1 million, respectively. The federal credits begin to expire in 2030 , unless previously utilized, while the state credits do not expire. The Company also has federal Orphan Drug credit carryforwards totaling $ 5.7 million which will begin to expire in 2041 unless previously utilized. The Company’s NOL and credit carryforwards to offset future taxable income may be subject to a substantial annual limitation upon future utilization as a result of ownership changes that could occur in the future pursuant to Internal Revenue Code Sections 382 and 383. These ownership changes may limit the amount of NOL and credit carryforwards that can be utilized to offset future taxable income and income tax, respectively. In general, an “ownership change” as defined by the tax code results from a transaction or series of transactions over a three-year period resulting in an ownership change of more than 50 percent of the outstanding stock of a company by certain stockholders or public groups. During 2020, the Company completed a study to assess whether an ownership change within the meaning of Section 382 had occurred for the time period prior to July 15, 2020 . The study identified several such ownership changes during the study period, which resulted in limitations on the annual utilization of the Company’s NOL and credit carryforwards, or the “Tax Attribute” carryforwards; however, the study findings also indicated that none of the Company’s Tax Attribute carryforwards generated during the study period would expire solely as a result of annual limitations on the utilization of such Tax Attribute carryforwards. Future ownership changes could still occur which might place further limits on the Company’s ability to utilize its Tax Attribute carryforwards. The Company’s federal income tax returns from 2018 forward, state income tax returns from 2017 forward, and its Australian tax returns beginning in 2019 are subject to examination by tax authorities; however, the Company’s Tax Attribute carryforwards generated in closed years are also subject to examination and remeasurement. No such audits are underway. Deferred tax assets and liabilities Net deferred tax assets are comprised of the following as of December 31, 2021 and 2020 ( in thousands ): December 31, 2021 2020 Deferred tax assets: Net operating loss carryforwards $ 59,453 $ 33,994 Capitalized research expenses 3,598 4,231 R&D and other tax credits 12,930 6,881 Stock-based compensation 5,899 3,233 Lease liability 1,125 1,358 Accrued expenses and other, net 3,309 1,932 Total deferred tax assets 86,314 51,629 Deferred tax liabilities: Right-of use asset ( 531 ) ( 625 ) Equity method investment ( 302 ) — Other deferred tax liabilities — ( 132 ) Net of deferred tax assets and liabilities 85,481 50,872 Less: valuation allowance ( 85,481 ) ( 50,872 ) Net deferred tax assets $ — $ — Realization of deferred tax assets is dependent upon future earnings, if any, the timing and amount of which are uncertain. Management assesses the available positive and negative evidence to estimate if sufficient future taxable income will be generated to use existing deferred tax assets. Based on the weight of available evidence, including the Company’s history of operating losses, management has determined that it is more likely than not that the Company’s net deferred tax assets will not be realized. Accordingly, a valuation allowance has been established by the Company to fully offset these net deferred tax assets. Income tax benefit For the three years in the period ended December 31, 2021, domestic and foreign pre-tax loss were ( in thousands ): Year ended December 31, 2021 2020 2019 Loss before income taxes - Domestic $ ( 107,723 ) $ ( 71,769 ) $ ( 48,643 ) Loss before income taxes - Foreign 82 ( 2,043 ) ( 1,779 ) Loss before income taxes - Consolidated $ ( 107,641 ) $ ( 73,812 ) $ ( 50,422 ) A reconciliation of income tax expense to the amount computed by applying the statutory federal income tax rate to the loss from operations for the three years in the period ended December 31, 2021 is as follows ( in thousands ): Year ended December 31, 2021 2020 2019 Expected income tax benefit at federal statutory rate $ ( 22,605 ) $ ( 15,417 ) $ ( 10,589 ) State income tax benefit, net of federal benefit ( 7,083 ) ( 4,886 ) ( 3,431 ) Tax effect of Change in valuation allowance 34,495 22,242 16,064 R&D credit ( 7,117 ) ( 2,597 ) ( 2,485 ) Stock-based compensation 1,196 539 226 Australian tax incentive 27 215 307 Other 1,087 ( 96 ) ( 92 ) Provision for income taxes $ — $ — $ — Changes to the Company’s unrecognized tax benefits are summarized in the following table ( in thousands ): Year ended December 31, 2021 2020 2019 Beginning balance $ 1,092 $ 886 $ 344 Increase (decrease) for prior year tax positions ( 34 ) ( 163 ) 70 Increase (decrease) for current year tax positions 495 369 472 Ending balance $ 1,553 $ 1,092 $ 886 Due to the existence of the valuation allowance, future changes in unrecognized tax benefits would not have any effect on the Company’s effective tax rate. The Company does not foresee any material changes to its unrecognized tax benefits within the next twelve months. There have been no decreases in unrecognized tax benefits due to settlements or expiration of statute of limitations for the assessment of taxes during the years ended December 31, 2021, 2020 and 2019. In response to the pandemic, the Coronavirus Aid, Relief and Economic Security Act (the “CARES Act”) was signed into law on March 27, 2020. The CARES Act, among other things, includes tax provisions relating to refundable payroll tax credits, deferment of employer’s social security payments, net operating loss utilization and carryback periods, modifications to the net interest deduction limitations and technical corrections to tax depreciation methods for qualified improvement property. The CARES Act did not have a material impact on our income tax provision for the year ended December 31, 2021 and 2020. Deferred income taxes have not been provided for undistributed earnings of the Company’s consolidated foreign subsidiary because the Parent entity would not be required to include the distribution into income as the amount would be tax free. The Tax Cuts and Jobs Act subjects a U.S. shareholder to tax on Global Intangible Low-Taxed Income ("GILTI") earned by certain foreign subsidiaries. The FASB Staff Q&A, Topic 740 No. 5. Accounting for Global Intangible Low-Taxed Income , states that an entity can make an accounting policy election to either recognize deferred taxes for temporary basis differences expected to reverse as GILTI in future years or to provide for the tax expense related to GILTI in the year the tax is incurred as a period expense only. We have elected to account for GILTI in the year the tax is incurred.

Employee Savings Plan

Employee Savings Plan	12 Months Ended
	Dec. 31, 2021
Retirement Benefits [Abstract]
Employee Savings Plan	12. EMPLOYEE SAVINGS PLAN The Company has a defined contribution 401(k) benefit plan (the “401(k) Plan”) for all eligible employees, effective May 1, 2016 . The plan permits participants to contribute up to the amount allowable under federal limits of annual pre-tax compensation to the 401(k) Plan. Effective in 2021, discretionary matching contributions to the 401(k) Plan are permitted in an amount equal to 50% of the first 6% of the employee’s taxable income up to a maximum of $ 3,000 per year . The Company accrued approximately $ 0.3 million for matching contributions for the year ended December 31, 2021.

Subsequent Event

Subsequent Event	12 Months Ended
	Dec. 31, 2021
Subsequent Events [Abstract]
Subsequent Event	13. SUBSEQUENT EVENTS On February 25, 2022, the Company and Sanwa Kagaku Kenkyusho Co., Ltd. ("Sanwa"), entered into a license agreement (the “Sanwa License Agreement”) whereby the Company granted Sanwa an exclusive license to develop and commercialize paltusotine in Japan. Under the terms of the Sanwa License Agreement, the Company received a $ 13.0 million nonrefundable, upfront payment and will be eligible to receive up to an additional $ 25.5 million in milestone payments related to the achievement of certain development, regulatory and commercial goals. In addition, upon market approval of paltusotine in Japan, the Company will be eligible to receive certain sales-based royalties. Sanwa will assume all costs associated with clinical trials and regulatory applications associated with these processes. Further, the Company retains all rights to develop and commercialize the product outside Japan.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Description of Business	Description of Business Crinetics Pharmaceuticals, Inc. (the “Company”) is a clinical-stage pharmaceutical company incorporated in Delaware on November 18, 2008 and based in San Diego, California. The Company is focused on the discovery, development and commercialization of novel therapeutics for rare endocrine diseases and endocrine-related tumors. In January 2017, the Company established a wholly-owned Australian subsidiary, Crinetics Australia Pty Ltd (“CAPL”), in order to conduct various preclinical and clinical activities for its development candidates.
Principles of Consolidation and Foreign Currency Transactions	Principles of Consolidation and Foreign Currency Transactions The consolidated financial statements include the accounts of the Company and CAPL. All intercompany accounts and transactions have been eliminated in consolidation. The functional currency of both the Company and CAPL is the U.S. dollar. Assets and liabilities that are not denominated in the functional currency are remeasured into U.S. dollars at foreign currency exchange rates in effect at the balance sheet date except for nonmonetary assets, which are remeasured at historical foreign currency exchange rates in effect at the date of transaction. Net realized and unrealized gains and losses from foreign currency transactions and remeasurement are reported in other income (expense), in the accompanying consolidated statements of operations and comprehensive loss and were not material for all periods presented.
Segment Reporting	Segment Reporting Operating segments are identified as components of an enterprise about which discrete financial information is available for evaluation by the chief operating decision-maker in making decisions regarding resource allocation and assessing performance. The Company views its operations and manages its business in one operating segment.
Liquidity	Liquidity From inception, the Company has devoted substantially all of its efforts to drug discovery and development and conducting preclinical studies and clinical trials. The Company has a limited operating history and the sales and income potential of the Company’s business and market are unproven. Successful transition to attaining profitable operations is dependent upon achieving a level of revenues adequate to support the Company’s cost structure. The Company has experienced net losses and negative cash flows from operating activities since its inception and has an accumulated deficit of $ 275.3 million as of December 31, 2021. As of December 31, 2021 , the Company had $ 333.7 million in unrestricted cash, cash equivalents and investment securities. To date, the Company has been funded primarily through equity offerings . On August 13, 2019, the Company entered into a sales agreement whereby the Company may offer and sell shares of its common stock from time to time up to $ 75.0 million through the sales agents (the “ATM Offering”). As of December 31, 2021, 275,764 shares had been sold through the ATM Offering, for net proceeds of $ 6.4 million, after deducting commissions of $ 0.2 million, (see Note 9). The Company expects to continue to incur net losses for the foreseeable future and believes it will need to raise substantial additional capital to accomplish its business plan over the next several years. The Company plans to continue to fund its losses from operations and capital funding needs through a combination of equity offerings, debt financings or other sources, including potential collaborations, licenses and other similar arrangements. If the Company is not able to secure adequate additional funding, the Company may be forced to make reductions in spending, extend payment terms with suppliers, liquidate assets, or suspend or curtail planned programs. Any of these actions could materially harm the Company’s business, results of operations and future prospects. There can be no assurance as to the availability or terms upon which such financing and capital might be available in the future.
COVID-19	COVID-19 The COVID-19 pandemic has caused significant business disruption around the globe. The extent of the impact of COVID-19 on the Company's operational and financial performance will depend on certain developments, including the duration and spread of the pandemic and the impact on the Company's clinical trials, employees and vendors. To the extent possible, and consistent with applicable guidance from federal, state and local authorities, the Company is conducting business as usual, with necessary or advisable modifications to employee travel. The Company will continue to actively monitor the evolving situation related to COVID-19 and may take further actions that alter its operations, including those that may be required by federal, state or local authorities, or that the Company determines are in the best interests of its employees and other third parties with whom the Company does business. While the pandemic has not yet had a material effect on the Company’s financial results, the degree to which COVID-19, including the impact of new variants of the virus that causes COVID-19, may impact the Company's future financial condition or results of operations is uncertain. A prolonged outbreak could have a material adverse impact on financial results and business operations of the Company, including the timing and ability of Company to complete certain clinical trials and other efforts required to advance the development of its drug candidates and raise additional capital.
Use of Estimates	Use of Estimates The Company’s consolidated financial statements are prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”). The preparation of the Company’s consolidated financial statements requires it to make estimates and assumptions that impact the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities in the Company’s consolidated financial statements and accompanying notes. The most significant estimates in the Company’s consolidated financial statements relate to accrual of research and development expenses, valuation of stock-based awards, fair values of financial instruments, revenue recognition and equity method investment. Estimates are based on historical experiences or on forecasts, including information received from third parties and various other factors that the Company believes are reasonable under the circumstances. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Actual results could differ from those estimates
Equity Method Investment	The Company first analyzes its investment in another entity to determine if the entity is a variable interest entity (“VIE”) and if so, whether the Company is the primary beneficiary requiring consolidation. An entity is considered a VIE if (1) the entity does not have enough equity to finance its own activities without additional support, (2) the entity’s at-risk equity holders lack the characteristics of a controlling financial interest, or (3) the entity is structured with non-substantive voting rights. VIEs are consolidated by the primary beneficiary, which is the entity that has both the power to direct the activities that most significantly impact the VIE’s economic performance and the obligation to absorb losses or the right to receive benefits from the VIE that potentially could be significant to the VIE. Variable interests in a VIE can be contractual, ownership, or other financial interests. The Company re-assesses its investment upon reconsideration events to determine whether the Company is the primary beneficiary of the VIE, in which case the Company would consolidate the VIE. If it has been determined that the Company is not the primary beneficiary or does not have control but does have the ability to exercise significant influence over the VIE, the Company accounts for the unconsolidated investment under the equity method of accounting. As discussed in Note 8, in October 2021, the Company, together with 5AM Ventures ("5AM") and Frazier Healthcare Partners ("Frazier"), announced the formation of Radionetics Oncology, Inc. ("Radionetics"). Radionetics aims to develop a deep pipeline of novel, targeted, nonpeptide radiopharmaceuticals for the treatment of a broad range of oncology indications. Radionetics is considered to be a VIE. The Company maintains an equity interest in Radionetics and accounts for its investment in Radionetics under the equity method of accounting. The Company records its share of Radionetics income (loss) outside of operations in the statements of operations and comprehensive loss on a quarterly lag. Since the Company’s investment in Radionetics was obtained on October 15, 2021, the Company will record its share of income (loss) beginning in the first quarter of 2022.
Fair Value Measurements	Fair Value Measurements 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 non-recurring basis. Fair value is defined as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, the accounting guidance establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows: Level 1: Observable inputs such as quoted prices in active markets. Level 2: Inputs, other than the quoted prices in active markets, that are observable either directly or indirectly. Level 3: Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions about risk and the assumptions market participants would use in pricing the asset or liability developed based on the best information available in the circumstances. The carrying amounts of the Company’s current financial assets, restricted cash and current financial liabilities are considered to be representative of their respective fair values because of the short-term nature of those instruments. The Company recorded the derivative asset (see Note 8) and investment securities (see Note 3) at fair value.
Cash, Cash Equivalents and Restricted Cash	Cash, Cash Equivalents and Restricted Cash Cash and cash equivalents include cash held in readily available checking and money market accounts, as well as short-term debt securities with maturities of three months or less when purchased. Restricted cash represents cash held as collateral for the Company’s facility lease and is reported as a long-term asset in the accompanying consolidated balance sheets.
Investment Securities	Investment Securities All investments have been classified as “available-for-sale” and are carried at fair value as determined based upon quoted market prices or pricing models for similar securities at period end. Investments with contractual maturities less than 12 months at the balance sheet date are considered short-term investments. Investments with contractual maturities beyond one year are also classified as short-term due to the Company’s ability to liquidate the investment for use in operations within the next 12 months. Realized gains and losses on investment securities are derived using the specific identification method for determining the cost of securities sold and are included in other income (expenses), net in the accompanying consolidated statements of operations and comprehensive loss. The Company has not realized any significant gains or losses on sales of available-for-sale investment securities during any of the periods presented. As all the Company’s investment holdings are in the form of debt securities, unrealized gains and losses that are determined to be temporary in nature are reported as a component of accumulated other comprehensive income. Investment securities are evaluated periodically for impairment. A decline in the fair value of any security below cost that is deemed other than temporary results in a charge to earnings and the establishment of a new cost basis for the security. Interest income is recognized when earned and is included in interest income in the accompanying consolidated statements of operations and comprehensive loss, as are the amortization of purchase premiums and accretion of purchase discounts on investment securities.
Derivative Asset	Derivative Asset Derivatives are recorded at fair value and changes in fair value are recorded through the statements of operations and comprehensive loss each period. The Company has a single derivative instrument, a warrant ("Radionetics Warrant") received on October 15, 2021, to purchase the greater of 3,407,285 additional shares of common stock or the number of additional shares of common stock that would all the Company to maintain an aggregate equity interest of 22 % of the fully diluted capitalization of Radionetics. The Company records the Radionetics Warrant as long-term on the balance sheets due to the lack of marketability, such that it is not expected to be available for current operations. Changes in fair value of the Radionetics Warrant are recognized in other income (expense) in the accompanying consolidated statements of operations and comprehensive loss.
Concentrations of Credit Risk	Concentrations of Credit Risk Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash, cash equivalents and investment securities. The Company maintains deposits in federally insured financial institutions in excess of federally insured limits. The Company has not experienced any losses in such accounts and believes it is not exposed to significant risk on its cash balances due to the financial position of the depository institution in which those deposits are held. Additionally, the Company has established guidelines regarding approved investments and maturities of investments, which are designed to maintain safety and liquidity.
Leases	Leases The Company determines if an arrangement is a lease at the inception of the arrangement. Leases with a term longer than 12 months that are determined to be operating leases are included in operating lease right-of-use assets, other current liabilities and noncurrent operating lease liabilities in the consolidated balance sheets. The Company accounts for each separate lease and non-lease component as a single lease component. When the Company’s leases do not provide an implicit rate, an incremental borrowing rate is used based on the information available at commencement dates in determining the present value of lease payments. The incremental borrowing rate is the rate of interest that the Company would expect to pay to borrow over a similar term, and on a collateralized basis, an amount equal to the lease payments in a similar economic environment. The Company’s lease terms may include options to extend or terminate the lease when the Company is reasonably certain that it will exercise such options. Lease expense for lease payments is recognized on a straight-line basis over the lease term. Lease agreements may contain variable costs such as common area maintenance, insurance, taxes or other costs. Such variable lease costs are expensed as incurred. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term.
Property and Equipment, Net	Property and Equipment, Net Property and equipment consist of leasehold improvements, and lab and various other equipment. Such assets are stated at cost and depreciated on a straight-line basis over the estimated useful life of the related assets. The Company estimates its useful lives of its lab and other equipment as follows: lab equipment – three to five years ; office equipment - three to five years ; computer and software – three years . Leasehold improvements are amortized over the estimated useful life of the improvement or the remaining term of the associated lease. Repairs and maintenance costs are charged to expense as incurred and expenditures that materially extend the useful lives of assets are capitalized.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets The Company reviews long-lived assets for impairment whenever events or changes in business circumstances indicate that the carrying amount of the assets may not be fully recoverable. Factors considered in deciding when to perform an impairment review include significant underperformance of the business in relation to expectations, significant negative industry or economic trends, and significant changes or planned changes in the use of the assets. An impairment loss is recognized when estimated undiscounted future cash flows expected to result from the use of an asset are less than its carrying amount. If such assets are considered impaired, the impairment loss recognized is measured as the excess of the carrying value of the impaired asset over its fair value, determined based on future cash flows or appraised values, depending on the nature of the asset. The Company has no t recognized any impairment losses in any of the periods presented in these consolidated financial statements.
Revenue Recognition	Revenue Recognition The Company has generated revenue from a collaboration and license agreement with a partner, as well as from grants from government agencies. The Company recognizes revenues when, or as, the promised goods or services are transferred to customers in an amount that reflects the consideration to which it expects to be entitled in exchange for those services. To determine revenue recognition for arrangements, the Company performs the following five steps: (1) identify the contract(s) with a customer; (2) identify the performance obligation(s) in the contract; (3) determine the transaction price; (4) allocate the transaction price to the performance obligation(s) in the contract; and (5) recognize revenue when (or as) the performance obligation(s) are satisfied. At contract inception, the Company assesses the goods or services promised within each contract, assesses whether each promised good or service is distinct and identifies those that are performance obligations. The Company recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when, or as, the performance obligation is satisfied. The Company considers a variety of factors in determining the appropriate estimates and assumptions under the arrangements, such as whether the elements are distinct performance obligations, whether there are observable stand-alone prices, and whether the license is 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. Collaboration and License Agreement The Company has entered into a collaboration and license agreement ("CLA") with a partner that mainly includes the following: (i) upfront noncash considerations ; (ii) payments associated with achieving certain milestones; and (iii) royalties based on specified percentages of net product sales, if any. At the initiation of an agreement, the Company analyzes each unit of account within the contract to determine if the counterparty is a customer in the context of the unit of account. The Company's performance obligation under the CLA consisted of the license and know-how of the technology. The upfront noncash considerations are fixed considerations for functional intellectual property as it exists at a point in time, being the time that the CLA was executed. Revenues for sales-based royalties and milestones are recognized at the later of the subsequent sale or satisfaction of the performance obligation.
Grant Revenue Recognition	Grant Revenue Recognition The Company’s grant revenues are derived from Small Business Innovation Research Grants (“SBIR Grants”) from the National Institutes of Health. The Company's performance obligation under SBIR Grants consists of research activities and the Company recognizes SBIR Grant revenue over time as reimbursable grant costs are incurred up to pre-approved award limits within the budget period. The costs associated with these reimbursements are reflected as a component of research and development expense in the accompanying consolidated statements of operations and comprehensive loss. Earnings in excess of billings are included as a component of prepaid expenses and other current assets in the accompanying consolidated balance sheets.
Research and Development Expense	Research and Development Expenses Research and development (“R&D”) expenses consist primarily of salaries, payroll taxes, employee benefits and stock-based compensation for individuals involved in R&D efforts, as well as consulting expenses, third-party R&D expenses, laboratory supplies, clinical materials and overhead, including facilities and depreciation costs, offset by the Australian Tax Incentive discussed below. R&D expenses are charged to expense as incurred. Payments made prior to the receipt of goods or services to be used in R&D are capitalized until the goods or services are received and are recorded as prepaid expenses and other current assets. Costs incurred under contracts with contract research organizations that conduct and manage the Company’s clinical trials are also included in research and development expenses. The financial terms and activities of these agreements vary from contract to contract and may result in uneven expense levels. Generally, these agreements set forth activities that drive the recording of expenses such as start-up and initiation activities, enrollment and treatment of patients, or the completion of other clinical trial activities. Expenses related to clinical trials are accrued based on estimates and/or representations from service providers regarding work performed, including actual level of patient enrollment, completion of patient studies and progress of the clinical trials. Other incidental costs related to patient enrollment or treatment are accrued when reasonably certain. If the amounts that the Company is obligated to pay under its clinical trial agreements are modified (for instance, as a result of changes in the clinical trial protocol or scope of work to be performed), the Company adjusts its accruals accordingly on a prospective basis. Revisions to contractual payment obligations are charged to expense in the period in which the facts that give rise to the revision become reasonably certain. Accrued R&D exp enses totaled $ 4.2 million and $ 2.1 million as of December 31, 2021 and 2020, respectively, and are a component of accounts payable and accrued expenses in the accompanying consolidated balance sheets.
Australian Tax Incentive	Australian Tax Incentive CAPL is eligible to obtain a cash refund from the Australian Taxation Office for eligible R&D expenditures under the Australian R&D Tax Incentive Program (the “Australian Tax Incentive”). The Australian Tax Incentive is recognized as a reduction to R&D expense when there is reasonable assurance that the relevant expenditure has been incurred, the amount can be reliably measured and that the Aust ralian Tax Incentive will be received. The Company recognized reductions to R&D expense of $ 0.3 million, $ 0.6 million and $ 1.0 million for the years ended December 31, 2021, 2020 and 2019 , respectively.
Patent Costs	Patent Costs All costs incurred for the filing of patent applications are recorded as general and administrative expenses in the accompanying consolidated statements of operations and comprehensive loss when incurred, as the recoverability of these expenses is uncertain.
Stock-Based Compensation	Stock-Based Compensati on Stock-based compensation expense represents the estimated grant date fair value of the Company’s equity awards, consisting of stock options and shares issued under the Company’s Employee Stock Purchase Plan, recognized over the requisite service period of such awards (usually the vesting period) on a straight-line basis. The Company estimates the fair value of equity awards using the Black-Scholes option pricing model on the date of grant and recognizes forfeitures as they occur. For stock awards for which vesting is subject to performance-based milestones, the expense is recorded over the remaining service period after the point when the achievement of the milestone is probable, or the performance condition has been achieved.
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 consolidated financial statements. Under this method, deferred tax assets and liabilities are determined based on the differences between the consolidated 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% 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, and any accrued interest and penalties would be included within the related tax liability. No such costs were recorded during the three years ended December 31, 2021 .
Comprehensive Loss	Comprehensive Loss Comprehensive loss is comprised of the Company’s net loss and the unrealized gains or losses on the Company’s available for sale investment securities for all periods presented. The cumulative amount of unrealized gains and losses is reflected as a separate component of stockholders' equity in the accompanying consolidated balance sheets as accumulated other comprehensive income (loss). There are no tax effects for the years ended December 31, 2021, 2020 and 2019 .
Net Loss Per Share	Net Loss Per Share Basic net loss per share is computed by dividing the net loss by the weighted-average number of common shares outstanding for the period, without consideration for potentially dilutive securities. Diluted net loss per share is computed by dividing the net loss by the weighted-average number of shares of common stock and dilutive common stock equivalents outstanding for the period determined using the treasury-stock. Dilutive common stock equivalents are comprised of common stock subject to repurchase, and options outstanding under the Company’s stock option plan. For all periods presented, there is no difference in the number of shares used to calculate basic and diluted shares outstanding as inclusion of the potentially dilutive securities on loss per share would be antidilutive. Potentially dilutive securities (in common stock equivalent shares) not included in the calculation of diluted net loss per share because to do so would be anti-dilutive are as follows ( in thousands ): Year ended December 31, 2021 2020 2019 Common stock options 6,554 4,422 3,127 Unvested common stock subject to repurchase 1 16 33 Total 6,555 4,438 3,160
Recent Accounting Pronouncements	Recently Adopted Accounting Pronouncements ASU 2020-01 In January 2020, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU") 2020-01, Investments-Equity Securities ("Topic 321"), Investments-Equity Method and Joint Ventures ("Topic 323"), and Derivatives and Hedging ("Topic 815"), - Clarifying the Interactions between Topic 321, Topic 323, and Topic 815 ("ASU 2020-01"), which addresses the accounting for the transition into and out of the equity method and provides clarification of the interaction of rules for equity securities, the equity method of accounting, and forward contracts and purchase options on certain types of securities. The amendments clarify that: (a) an entity should consider observable transactions that require it to either apply or discontinue the equity method of accounting for the purposes of applying the measurement alternative in accordance with Topic 321 immediately before applying or upon discontinuing the equity method; and (b) an entity should not consider whether, upon the settlement of the forward contract or exercise of the purchased option, individually or with existing investments, the underlying securities would be accounted for under the equity method in Topic 323 or the fair value option in accordance with the financial instruments guidance in Topic 825. The provisions of this guidance are to be applied prospectively upon their effective date. ASU 2020-01 was effective for fiscal years beginning after December 15, 2020, and interim periods within those years. Early adoption was permitted, but required simultaneous adoption of all provisions of this guidance. The Company adopted this guidance as of January 1, 2021, which did not result in a material impact on its consolidated financial statements and related disclosures. ASU 2020-06 In August 2020, the FASB issued ASU No. 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity (" ASU 2020-06") , which simplifies the accounting for certain financial instruments with characteristics of liabilities and equity, including convertible instruments and contracts on an entity’s own equity. Specifically, ASU 2020-06 simplifies accounting for the issuance of convertible instruments by removing major separation models required under current GAAP. In addition, the ASU removes certain settlement conditions that are required for equity contracts to qualify for the derivative scope exception and simplifies the diluted earnings per share (EPS) calculation in certain areas. The Company adopted ASU 2020-06 as of January 1, 2021 using the modified-retrospective approach, which did not have an impact on its consolidated financial statements. Recent Accounting Pronouncements ASU 2016-13 In June 2016, the FASB issued ASU No. 2016-13, “Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments ” (“Topic 326”). Topic 326 amends guidance on reporting credit losses for assets held at amortized cost basis and available for sale debt securities. For assets held at amortized cost basis, Topic 326 eliminates the probable initial recognition threshold in current GAAP and, instead, requires an entity to reflect its current estimate of all expected credit losses. The allowance for credit losses is a valuation account that is deducted from the amortized cost basis of the financial assets to present the net amount expected to be collected. For available for sale debt securities, credit losses should be measured in a manner similar to current GAAP, however Topic 326 will require that credit losses be presented as an allowance rather than as a write-down. This ASU update affects entities holding financial assets and net investment in leases that are not accounted for at fair value through net income. This update is effective for the Company for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. The Company is currently evaluating the impact of the pending adoption of this new standard on its consolidated financial statements. ASU 2021-04 In May 2021, the FASB issued ASU 2021-04, Earnings Per Share ("Topic 260"), Debt-Modifications and Extinguishments ("Subtopic 470-50"), Compensation-Stock Compensation ("Topic 718"), and Derivatives and Hedging-Contracts in Entity’s Own Equity ("Subtopic 815-40"): Issuer’s Accounting for Certain Modifications or Exchanges of Freestanding Equity-Classified Written Call Options , which intends to clarify and reduce diversity in an issuer’s accounting for modifications or exchanges of freestanding equity-classified written call options (for example, warrants) that remain equity classified after modification or exchange. The guidance is effective for fiscal years beginning after December 15, 2021, including interim periods therein, and early adoption is permitted. The Company is currently evaluating the potential impact that the adoption of ASU 2021-04 may have on its consolidated financial statements and related disclosures.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Schedule of Potentially Dilutive Securities not Included in Calculation of Diluted Net Loss Per Share	Potentially dilutive securities (in common stock equivalent shares) not included in the calculation of diluted net loss per share because to do so would be anti-dilutive are as follows ( in thousands ): Year ended December 31, 2021 2020 2019 Common stock options 6,554 4,422 3,127 Unvested common stock subject to repurchase 1 16 33 Total 6,555 4,438 3,160

Investment Securities (Tables)

Investment Securities (Tables)	12 Months Ended
	Dec. 31, 2021
Investments Debt And Equity Securities [Abstract]
Summary of Available-For-Sale Investment Securities Held by the Company	A vailable-for-sale investment securities consisted of the following as of December 31, 2021 and 2020 ( in thousands ): As of December 31, 2021 Amortized Gross Gross Fair Available-for-sale investment securities: U.S. government and agency obligations $ 54,637 $ — $ ( 180 ) $ 54,457 Certificates of deposit 5,735 1 ( 4 ) 5,732 Corporate debt securities 70,600 6 ( 204 ) 70,402 Asset-backed securities 2,421 — — 2,421 Total $ 133,393 $ 7 $ ( 388 ) $ 133,012 As of December 31, 2020 Amortized Gross Gross Fair Available-for-sale investment securities: U.S. government and agency obligations $ 74,222 $ 6 $ ( 5 ) 74,223 Certificates of deposit 2,161 14 — 2,175 Corporate debt securities 1,385 10 — 1,395 Total $ 77,768 $ 30 $ ( 5 ) $ 77,793
Summary of Available-For-Sale Investment Securities By Contractual Maturity	As of December 31, 2021 and 2020, available-for-sale investment securities by contractual maturity were as follows ( in thousands ): As of December 31, 2021 As of December 31, 2020 Amortized Fair Amortized Fair Available-for-sale investment securities: Due in one year or less $ 31,101 $ 31,078 $ 59,472 $ 59,487 Due after one year through five years 102,292 101,934 18,296 18,306 Total $ 133,393 $ 133,012 $ 77,768 $ 77,793

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Schedule of Financial Assets Measured at Fair Value on Recurring Basis	Financial assets measured at fair value on a recurring basis as of December 31, 2021 and 2020 were as follows (in thousands): As of December 31, 2021 Level 1 Level 2 Level 3 Total Investment securities: U.S. government and agency obligations $ 44,984 $ 9,473 $ — $ 54,457 Certificates of deposit — 5,732 — 5,732 Corporate debt securities — 70,402 — 70,402 Asset-backed securities — 2,421 2,421 Total Investment securities 44,984 88,028 — 133,012 Derivative Assets: Radionetics Warrant — — 68 68 Total assets measured at fair value $ 44,984 $ 88,028 $ 68 $ 133,080 As of December 31, 2020 Level 1 Level 2 Level 3 Total Investment securities: U.S. government and agency obligations $ 60,222 $ 14,001 $ — $ 74,223 Certificates of deposit — 2,175 — 2,175 Corporate debt securities — 1,395 — 1,395 Total assets measured at fair value $ 60,222 $ 17,571 $ — $ 77,793

Balance Sheet Details (Tables)

Balance Sheet Details (Tables)	12 Months Ended
	Dec. 31, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Components of Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consisted of the following ( in thousands ): December 31, December 31, Prepaid research and development costs $ 7,184 $ 3,062 Australian tax incentive receivable 977 1,720 Prepaid insurance 888 693 Interest receivable 499 113 Due from Radionetics (Note 8) 553 — Other 912 1,024 Total $ 11,013 $ 6,612
Components of Property and Equipment, Net	Property and equipment, net consisted of the following ( in thousands ): December 31, December 31, Leasehold improvements $ 3,516 $ 3,494 Lab equipment 1,889 1,551 Office equipment 859 653 Computers and software 41 41 Property and equipment at cost 6,305 5,739 Less accumulated depreciation and amortization 3,480 2,558 Total $ 2,825 $ 3,181

Radionetics Oncology, Inc. (Tab

Radionetics Oncology, Inc. (Tables)	12 Months Ended
	Dec. 31, 2021
RADIONETICS ONCOLOGY, INC. [Abstract]
Summary of primary inputs used in valuing the Radionetics common stock and the Radionetics Warrant	The primary inputs used in valuing the Radionetics common stock and the Radionetics Warrant, were as follows: Derivative Asset October 15, 2021 and December 31, 2021 Expected term 3.0 years Expected volatility 111.4 % Risk free interest rate 0.7 % Marketability discount 30.0 %

Operating Lease (Tables)

Operating Lease (Tables)	12 Months Ended
	Dec. 31, 2021
Leases [Abstract]
Schedule of Future Minimum Payments Under Non-cancellable Operating Leases	As of December 31, 2021, future minimum payments under non-cancellable operating leases were as follows ( in thousands ): Year ending December 31, Minimum 2022 $ 1,208 2023 1,244 2024 1,280 2025 871 Total future minimum lease payments 4,603 Less imputed interest ( 590 ) Total operating lease liability 4,013 Less operating lease liability, current ( 939 ) Operating lease liability, non-current $ 3,074

Equity Incentive Plans (Tables)

Equity Incentive Plans (Tables)	12 Months Ended
	Dec. 31, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Activity Under Stock Option Plans	Activity under the Company’s stock option plans during the yea r ended December 31, 2021 was as follows: Weighted- Weighted- Aggregate Average Average Intrinsic Options Exercise Remaining Value Outstanding Price Term (000’s) Balance at December 31, 2020 4,421,533 $ 14.42 Granted 2,889,000 $ 18.09 Exercised ( 364,273 ) $ 8.61 Forfeited and expired ( 392,666 ) $ 19.24 Balance at December 31, 2021 6,553,594 $ 16.07 8.1 $ 80,906 Vested and expected to vest at December 31, 2021 6,553,594 $ 16.07 8.1 $ 80,906 Exercisable at December 31, 2021 2,989,994 $ 13.28 7.1 $ 45,283
Weighted Average Assumptions Used to Estimate Fair Value of Stock Options Granted to Employees	The following table summarizes the weighted average assumptions used to estimate the fair value of stock options granted under the Company’s stock option plans and the shares purchasable under the ESPP d uring the periods presented: Year ended December 31, Stock Option Awards 2021 2020 2019 Expected term 6.0 years 6.0 years 5.9 years Expected volatility 86 % 78 % 78 % Risk free interest rate 1.0 % 0.8 % 2.3 % Expected dividend yield — % — % — % Year ended December 31, ESPP 2021 2020 2019 Expected term 1.6 years 1.4 years 1.8 years Expected volatility 91 % 84 % 65 % Risk free interest rate 0.3 % 0.2 % 2.2 % Expected dividend yield — % — % — %
Summary of Stock-based Compensation Expense for the Equity Awards Issued to Employees and Non-Employees	Stock-based compensation expense for the equity awards issued by the Company to employees and non-employees for the periods presented below was as follow s ( in thousands ): Year ended December 31, 2021 2020 2019 Included in research and development $ 9,654 $ 5,218 $ 3,190 Included in general and administrative 7,698 5,209 3,104 Total stock-based compensation expense $ 17,352 $ 10,427 $ 6,294

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Schedule of Deferred Tax Assets and Liabilities	Deferred tax assets and liabilities Net deferred tax assets are comprised of the following as of December 31, 2021 and 2020 ( in thousands ): December 31, 2021 2020 Deferred tax assets: Net operating loss carryforwards $ 59,453 $ 33,994 Capitalized research expenses 3,598 4,231 R&D and other tax credits 12,930 6,881 Stock-based compensation 5,899 3,233 Lease liability 1,125 1,358 Accrued expenses and other, net 3,309 1,932 Total deferred tax assets 86,314 51,629 Deferred tax liabilities: Right-of use asset ( 531 ) ( 625 ) Equity method investment ( 302 ) — Other deferred tax liabilities — ( 132 ) Net of deferred tax assets and liabilities 85,481 50,872 Less: valuation allowance ( 85,481 ) ( 50,872 ) Net deferred tax assets $ — $ —
Schedule of Domestic and Foreign Pre-Tax Loss	Income tax benefit For the three years in the period ended December 31, 2021, domestic and foreign pre-tax loss were ( in thousands ): Year ended December 31, 2021 2020 2019 Loss before income taxes - Domestic $ ( 107,723 ) $ ( 71,769 ) $ ( 48,643 ) Loss before income taxes - Foreign 82 ( 2,043 ) ( 1,779 ) Loss before income taxes - Consolidated $ ( 107,641 ) $ ( 73,812 ) $ ( 50,422 )
Schedule of Reconciliation of Income Tax Expense	A reconciliation of income tax expense to the amount computed by applying the statutory federal income tax rate to the loss from operations for the three years in the period ended December 31, 2021 is as follows ( in thousands ): Year ended December 31, 2021 2020 2019 Expected income tax benefit at federal statutory rate $ ( 22,605 ) $ ( 15,417 ) $ ( 10,589 ) State income tax benefit, net of federal benefit ( 7,083 ) ( 4,886 ) ( 3,431 ) Tax effect of Change in valuation allowance 34,495 22,242 16,064 R&D credit ( 7,117 ) ( 2,597 ) ( 2,485 ) Stock-based compensation 1,196 539 226 Australian tax incentive 27 215 307 Other 1,087 ( 96 ) ( 92 ) Provision for income taxes $ — $ — $ —
Schedule of Unrecognized Tax Benefits	Changes to the Company’s unrecognized tax benefits are summarized in the following table ( in thousands ): Year ended December 31, 2021 2020 2019 Beginning balance $ 1,092 $ 886 $ 344 Increase (decrease) for prior year tax positions ( 34 ) ( 163 ) 70 Increase (decrease) for current year tax positions 495 369 472 Ending balance $ 1,553 $ 1,092 $ 886

Organization and Basis of Pre_2

Organization and Basis of Presentation - Additional Information (Details) $ in Thousands	Aug. 13, 2019USD ($)	Dec. 31, 2021USD ($)Segmentshares	Dec. 31, 2020USD ($)shares
Organization And Basis Of Presentation [Line Items]
Number of operating segments | Segment		1
Unrestricted cash, cash equivalents and investments securities		$ 333,700
Common stock and paid-in capital, shares issued | shares		47,598,000	33,017,000
Proceeds from issuance of common stock, net	$ 75,000	$ 249,542	$ 114,283
Commissions			200
Accumulated deficit		$ 275,255	$ 167,614
ATM Offering
Organization And Basis Of Presentation [Line Items]
Common stock and paid-in capital, shares issued | shares		275,764	275,764
Proceeds from issuance of common stock, net		$ 6,400	$ 6,400
Commissions		$ 200
Common Stock | Maximum | ATM Offering
Organization And Basis Of Presentation [Line Items]
Proceeds from sale of common stock	$ 75,000

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Oct. 15, 2021
Summary Of Significant Accounting Policies [Line Items]
Impairment losses of long-lived assets	$ 0	$ 0	$ 0
Radionetics Warrant
Summary Of Significant Accounting Policies [Line Items]
Aggregate equity interest				22.00%
Additional common shares issued				3,407,285
Australian Research and Development Tax Incentive | Australian Taxation Office
Summary Of Significant Accounting Policies [Line Items]
Tax incentive receivable, reductions to research and development expense	300,000	600,000	$ 1,000,000
Accounts Payable And Accrued Expenses
Summary Of Significant Accounting Policies [Line Items]
Accrued R&D expenses	$ 4,200,000	$ 2,100,000
Computer and Software
Summary Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful life	3 years
Minimum [Member] | Lab Equipment
Summary Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful life	3 years
Minimum [Member] | Office Equipment
Summary Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful life	3 years
Maximum [Member] | Lab Equipment
Summary Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful life	5 years
Maximum [Member] | Office Equipment
Summary Of Significant Accounting Policies [Line Items]
Property and equipment, estimated useful life	5 years

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Schedule 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	Dec. 31, 2019
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from calculation of diluted net loss per share	6,555,000	4,438,000	3,160,000
Common Stock Option
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from calculation of diluted net loss per share	6,554,000	4,422,000	3,127,000
Unvested Common Stock Subject To Repurchase
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from calculation of diluted net loss per share	1,000	16,000	33,000

Investment Securities - Summary

Investment Securities - Summary of Available-For-Sale Investment Securities Held by the Company (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale investment securities, Amortized Cost	$ 133,393	$ 77,768
Available-for-sale investment securities, Gross Unrealized Gains	7	30
Available-for-sale investment securities, Gross Unrealized Losses	(388)	(5)
Available-for-sale investment securities, Fair Market Value	133,012	77,793
U.S. Government and Agency Obligations
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale investment securities, Amortized Cost	54,637	74,222
Available-for-sale investment securities, Gross Unrealized Gains		6
Available-for-sale investment securities, Gross Unrealized Losses	(180)	(5)
Available-for-sale investment securities, Fair Market Value	54,457	74,223
Certificates of Deposit
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale investment securities, Amortized Cost	5,735	2,161
Available-for-sale investment securities, Gross Unrealized Gains	1	14
Available-for-sale investment securities, Gross Unrealized Losses	(4)
Available-for-sale investment securities, Fair Market Value	5,732	2,175
Corporate Debt Securities
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale investment securities, Amortized Cost	70,600	1,385
Available-for-sale investment securities, Gross Unrealized Gains	6	10
Available-for-sale investment securities, Gross Unrealized Losses	(204)
Available-for-sale investment securities, Fair Market Value	70,402	$ 1,395
Asset-Backed Securities
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale investment securities, Amortized Cost	2,421
Available-for-sale investment securities, Gross Unrealized Gains
Available-for-sale investment securities, Gross Unrealized Losses
Available-for-sale investment securities, Fair Market Value	$ 2,421

Investment Securities - Summa_2

Investment Securities - Summary of Available-For-Sale Investment Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Fair Value [Abstract]
Available-for-sale investment securities, Fair market Value, Due in one year or less	$ 31,078	$ 59,487
Available-for-sale investment securities, Fair market Value, Due after one year through five years	101,934	18,306
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Fair Value, Total	133,012	77,793
Available-for-sale investment securities, Amortized Cost, Due in one year or less	31,101	59,472
Available-for-sale investment securities, Amortized Cost, Due after one year through five years	102,292	18,296
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Amortized Cost, Total	$ 133,393	$ 77,768

Investment Securities - Additio

Investment Securities - Additional Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021USD ($)Security	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Investments Debt And Equity Securities [Abstract]
Available-for-sale, unrealized loss position, twelve month or more | Security	0
Realized gains on securities | $	$ 2,000	$ 26,000	$ 7,000

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Financial Assets Measured at Fair Value on Recurring Basis (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Total assets measured at fair value	$ 133,080	$ 77,793
Total Investment securities	133,012
Level 1
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Total assets measured at fair value	44,984	60,222
Total Investment securities	44,984
Level 2
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Total assets measured at fair value	88,028	17,571
Total Investment securities	88,028
Level 3
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Total assets measured at fair value	68
Total Investment securities
U.S. Government and Agency Obligations
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Total assets measured at fair value		74,223
Total Investment securities	54,457
U.S. Government and Agency Obligations | Level 1
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Total assets measured at fair value		60,222
Total Investment securities	44,984
U.S. Government and Agency Obligations | Level 2
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Total assets measured at fair value		14,001
Total Investment securities	9,473
U.S. Government and Agency Obligations | Level 3
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Total assets measured at fair value
Total Investment securities
Certificates of Deposit
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Total assets measured at fair value		2,175
Total Investment securities	5,732
Certificates of Deposit | Level 1
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Total assets measured at fair value
Total Investment securities
Certificates of Deposit | Level 2
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Total assets measured at fair value		2,175
Total Investment securities	5,732
Certificates of Deposit | Level 3
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Total assets measured at fair value
Total Investment securities
Corporate Debt Securities
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Total assets measured at fair value		1,395
Total Investment securities	70,402
Corporate Debt Securities | Level 1
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Total assets measured at fair value
Total Investment securities
Corporate Debt Securities | Level 2
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Total assets measured at fair value		1,395
Total Investment securities	70,402
Corporate Debt Securities | Level 3
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Total assets measured at fair value
Total Investment securities
Asset-Backed Securities
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Total Investment securities	2,421
Asset-Backed Securities | Level 1
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Total Investment securities
Asset-Backed Securities | Level 2
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Total Investment securities	2,421
Radionetics Warrant
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Total assets measured at fair value	68
Radionetics Warrant | Level 1
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Total assets measured at fair value
Radionetics Warrant | Level 2
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Total assets measured at fair value
Radionetics Warrant | Level 3
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Total assets measured at fair value	$ 68

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) - USD ($)	Oct. 15, 2021	Dec. 31, 2021	Dec. 31, 2020
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value assets transferred into level 3		$ 0
Fair value assets transferred into level 3			$ 0
Radionetics Warrant
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Equity interest percentage	22.00%
Additional common shares issued	3,407,285

Balance Sheet Details - Compone

Balance Sheet Details - Components of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Prepaid research and development costs	$ 7,184	$ 3,062
Australian tax incentive receivable	977	1,720
Prepaid insurance	888	693
Interest receivable	499	113
Due from Radionetics (Note 8)	553
Other	912	1,024
Total	$ 11,013	$ 6,612

Balance Sheet Details - Compo_2

Balance Sheet Details - Components of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Property Plant And Equipment [Line Items]
Property and equipment at cost	$ 6,305	$ 5,739
Less accumulated depreciation and amortization	3,480	2,558
Total	2,825	3,181
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment at cost	3,516	3,494
Lab Equipment
Property Plant And Equipment [Line Items]
Property and equipment at cost	1,889	1,551
Office Equipment
Property Plant And Equipment [Line Items]
Property and equipment at cost	859	653
Computers and Software
Property Plant And Equipment [Line Items]
Property and equipment at cost	$ 41	$ 41

Balance Sheet Details - Additio

Balance Sheet Details - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Property Plant And Equipment [Abstract]
Depreciation expense	$ 0.9	$ 0.9	$ 0.9

Operating Lease - Additional In

Operating Lease - Additional Information (Details) - 2018 Operating Lease - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating Leased Assets [Line Items]
Operating lease, initial term	7 years
Operating lease expiration period	2025-08
Operating lease, option to extend term	five years
Lessee,operating lease, discount rate	8.00%
Irrevocable letter of credit	$ 0.5
Rent expense	1	$ 1	$ 1
Cash paid for operating lease liabilities	$ 1.2	$ 1.1	$ 1.1
Operating lease weighted average remaining term	3 years 7 months 6 days	4 years 7 months 6 days
Weighted-average discount rate	8.00%	8.00%

Operating Lease - Schedule of F

Operating Lease - Schedule of Future Minimum Payments Under Non-cancellable Operating Leases (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Leases [Abstract]
2022	$ 1,208
2023	1,244
2024	1,280
2025	871
Total future minimum lease payments	4,603
Less imputed interest	(590)
Total operating lease liability	$ 4,013
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Liabilities Current
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Operating lease liability, non-current
Less operating lease liability, current	$ (939)
Operating lease liability, non-current	3,074	$ 4,014
Total operating lease liabilities	$ 4,013

Convertible Preferred Stock - A

Convertible Preferred Stock - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Temporary Equity [Line Items]
Convertible preferred stock, issuance costs	$ 13	$ 7.5

Radionetics Oncology, Inc. - Ad

Radionetics Oncology, Inc. - Additional Information (Details) $ / shares in Units, $ in Thousands	Oct. 21, 2021$ / sharesshares	Apr. 12, 2021$ / sharesshares	Apr. 17, 2020$ / sharesshares	Oct. 31, 2021USD ($)shares	Dec. 31, 2021USD ($)$ / sharesshares	Dec. 31, 2020shares	Oct. 15, 2021$ / shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Due from Radionetics					$ 553
Radionetics Warrant
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Aggregate equity interest							22.00%
Common Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Issuance of common stock, net of transaction costs, shares | shares					14,126,000	8,499,000
Common Stock [Member] | I P O [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Issuance of common stock, net of transaction costs, shares | shares	8,712,400	4,562,044	8,222,500
Common stock price per share | $ / shares	$ 19.80	$ 16.44	$ 14
Radionetics Oncology Inc [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Investment in Company					$ 1,000
Due from Radionetics					$ 600
Radionetics Oncology Inc [Member] | Radionetics Warrant
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock price per share | $ / shares					$ 0.02
Radionetics Oncology Inc [Member] | Common Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock price per share | $ / shares							$ 0.02
Radionetics Oncology Inc [Member] | Five A M Ventures And Frazier Healthcare Partners [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Upfront noncash considerations				$ 1,100
Common stock value				$ 1,000
Warrant Price | shares				100,000
Noncash Upfront Fee as License Revenues					$ 1,100
Sales and royalties milestones				$ 1,000,000	0
Sales to Date					0
Convertible notes financing					$ 30,000
Exercise price of warrant | $ / shares					$ 0.00001
Warrant exercisable term					10 years
Radionetics Oncology Inc [Member] | Five A M Ventures And Frazier Healthcare Partners [Member] | Common Stock [Member] | I P O [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Issuance of common stock, net of transaction costs, shares | shares				50,500,000
Aggregate equity interest					64.00%
Common Stock Purchase | shares				3,407,285
Percentage of aggregate diluted capitalization					22

Radionetics Oncology, Inc. - Ra

Radionetics Oncology, Inc. - Radionetics Common Stock and Warrant (Details) - Radionetics Oncology, Inc.	Oct. 15, 2021	Dec. 31, 2021
Radionetics Warrant
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term		3 years
Expected volatility		111.40%
Risk free interest rate		0.70%
Marketability discount		30.00%
Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term	3 years
Expected volatility	111.40%
Risk free interest rate	0.70%
Marketability discount	30.00%

Stockholder's Equity - Addition

Stockholder's Equity - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	Oct. 21, 2021	Jul. 28, 2021	Apr. 12, 2021	Apr. 17, 2020	Aug. 13, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Aug. 10, 2021
Subsidiary Sale Of Stock [Line Items]
Common stock, shares authorized						200,000,000	200,000,000
Common stock and paid-in capital, par value						$ 0.001	$ 0.001
Preferred stock, par value						$ 0.001	$ 0.001
Offering discounts commissions and offering costs net							$ 200
Proceeds from issuance of common stock, net					$ 75,000	$ 249,542	$ 114,283
Maximum amount of common stock preferred stock debt securities warrants and units to be issued					300,000
Registration statement effective date						Aug. 29, 2019
Common stock and paid-in capital, shares issued						47,598,000	33,017,000
Maximum Share Of Common Stock Preferred Stock Debt Securities Warrants And Units To Be Issued									851,306
Stock-based compensation expenses						$ 17,352	$ 10,427	$ 6,294
SVB Leerink LLC and Cantor Fitzgerald & Co. | Maximum [Member]
Subsidiary Sale Of Stock [Line Items]
Sale of common stock at offering price					$ 75,000
Common Stock
Subsidiary Sale Of Stock [Line Items]
Sale of common stock						14,126,000	8,499,000
Issuance of common stock, net of transaction costs, shares						14,126,000	8,499,000
Initial Public Offering
Subsidiary Sale Of Stock [Line Items]
Offering discounts commissions and offering costs net			$ 2,400	$ 7,300
Proceeds from issuance of common stock, net			$ 72,600	$ 107,900
Initial Public Offering | Common Stock
Subsidiary Sale Of Stock [Line Items]
Sale of common stock	8,712,400		4,562,044	8,222,500
Common stock price per share	$ 19.80		$ 16.44	$ 14
Offering discounts commissions and offering costs net	$ 10,500
Issuance of common stock, net of transaction costs, shares	8,712,400		4,562,044	8,222,500
Common stock price per share	$ 19.80		$ 16.44	$ 14
Proceeds from issuance of common stock, net	$ 162,000
ATM Offering
Subsidiary Sale Of Stock [Line Items]
Offering discounts commissions and offering costs net						$ 200
Proceeds from issuance of common stock, net						$ 6,400	$ 6,400
Common stock and paid-in capital, shares issued						275,764	275,764
Private Placement [Member] | Common Stock
Subsidiary Sale Of Stock [Line Items]
Sale of common stock		851,306
Common stock price per share		$ 17.62
Issuance of common stock, net of transaction costs, shares		851,306
Common stock price per share		$ 17.62
Proceeds from issuance of common stock, net		$ 15,000

Equity Incentive Plans - Additi

Equity Incentive Plans - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	Jan. 01, 2022	Feb. 28, 2015	Jul. 31, 2018	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total intrinsic value of options exercised				$ 5,100	$ 2,500	$ 2,000
Dividend yield				0.00%
Unrecognized stock-based compensation cost				$ 43,400
Weighted-average period of unrecognized stock-based compensation cost expected to be recognized over remaining period				2 years
ESPP
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Maximum percentage of eligible compensation to purchase common stock through payroll deductions			20.00%
Dividend yield				0.00%	0.00%	0.00%
Weighted-average fair value of stock options granted to employees per share				$ 12.52	$ 8.07	$ 10.59
Unrecognized stock-based compensation cost				$ 1,900
Weighted-average period of unrecognized stock-based compensation cost expected to be recognized over remaining period				1 year 6 months
2018 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Plan expiration period			2028-07
Plan expiration term			10 years
Vesting period			4 years
Annual increase in the number of shares available for issuance				5.00%
Remaining shares available for issuance				1,121,703
2015 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Plan expiration term		10 years
Vesting period		4 years
Shares issued under early-exercise provisions subject to repurchase				1,228
Unvested stock liability				$ 2,000	$ 23,000
2021 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Remaining shares available for issuance				0
Additional shares available for future issuance				1,500,000
Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average fair value of stock options granted to employees per share				$ 13.02	$ 12.83	$ 16.35
Common Stock | ESPP
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Plan expiration date				Jan. 1, 2028
Shares reserved for issuance, authorized				853,108
Common Stock | Subsequent Event
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Additional shares available for future issuance	2,379,911
Common Stock | Subsequent Event | ESPP
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Additional shares available for future issuance	475,982

Equity Incentive Plans - Summar

Equity Incentive Plans - Summary of Activity Under Stock Option Plans (Details) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021USD ($)$ / sharesshares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Options Outstanding, Beginning balance | shares	4,421,533
Options Outstanding, Granted | shares	2,889,000
Options Outstanding, Exercised | shares	(364,273)
Options Outstanding, Forfeited and expired | shares	(392,666)
Options Outstanding, Ending balance | shares	6,553,594
Options Outstanding,Vested and expected to vest | shares	6,553,594
Options Exercisable, Ending balance | shares	2,989,994
Weighted-Average Exercise Price, Beginning balance | $ / shares	$ 14.42
Weighted-Average Exercise Price, Granted | $ / shares	18.09
Weighted Average Exercise Price, Exercised | $ / shares	8.61
Weighted Average Exercise Price, Forfeited and expired | $ / shares	19.24
Weighted-Average Exercise Price, Ending balance | $ / shares	16.07
Weighted-Average Exercise Price, Vested and expected to vest | $ / shares	16.07
Weighted-Average Exercise Price, Exercisable | $ / shares	$ 13.28
Weighted-Average Remaining Term, Ending balance	8 years 1 month 6 days
Weighted-Average Remaining Term, Vested and expected to vest	8 years 1 month 6 days
Weighted-Average Remaining Term, Exercisable	7 years 1 month 6 days
Aggregate Intrinsic Value, Ending balance | $	$ 80,906
Aggregate Intrinsic Value, Vested and expected to vest | $	80,906
Aggregate Intrinsic Value, Exercisable | $	$ 45,283

Equity Incentive Plans - Weight

Equity Incentive Plans - Weighted Average Assumptions Used to Estimate Fair Value of Stock Options Granted to Employees (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected dividend yield	0.00%
ESPP
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected option term	1 year 7 months 6 days	1 year 4 months 24 days	1 year 9 months 18 days
Expected volatility	91.00%	84.00%	65.00%
Risk free interest rate	0.30%	0.20%	2.20%
Expected dividend yield	0.00%	0.00%	0.00%
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected option term	6 years	6 years	5 years 10 months 24 days
Expected volatility	86.00%	78.00%	78.00%
Risk free interest rate	1.00%	0.80%	2.30%
Expected dividend yield	0.00%	0.00%	0.00%

Equity Incentive Plans - Stock-

Equity Incentive Plans - Stock-based Compensation Expense Recognized (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 17,352	$ 10,427	$ 6,294
Included in Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	9,654	5,218	3,190
Included in General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 7,698	$ 5,209	$ 3,104

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Operating Loss Carryforwards [Line Items]
Federal operating loss carryforwards	$ 209,400
State operating loss carryforwards	216,000
Foreign operating loss carryforwards	1,300
Federal loss carryforwards	203,100
Research and development credit carryforwards	12,930	$ 6,881
Research and development credit Carryforwards, Other	$ 5,700
Operating loss and research and development credit carryforwards, limitations on use	These ownership changes may limit the amount of NOL and credit carryforwards that can be utilized to offset future taxable income and income tax, respectively. In general, an “ownership change” as defined by the tax code results from a transaction or series of transactions over a three-year period resulting in an ownership change of more than 50 percent of the outstanding stock of a company by certain stockholders or public groups. During 2020, the Company completed a study to assess whether an ownership change within the meaning of Section 382 had occurred for the time period prior to July 15, 2020
Cumulative change in ownership percentage	50.00%
Period for cumulative change in ownership	3 years
California
Operating Loss Carryforwards [Line Items]
Research and development credit carryforwards	$ 4,100
Federal
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards, future taxable income, offset percentage	80.00%
Research and development credit carryforwards	$ 6,300
Research and development credit carryforwards, begin to expire	2030
State
Operating Loss Carryforwards [Line Items]
State operating loss carryforwards	$ 200

Income Taxes - Schedule of Defe

Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Net operating loss carryforwards	$ 59,453	$ 33,994
Capitalized research expenses	3,598	4,231
R&D and other tax credits	12,930	6,881
Stock-based compensation	5,899	3,233
Lease liability	1,125	1,358
Accrued expenses and other, net	3,309	1,932
Total deferred tax assets	86,314	51,629
Deferred tax liabilities:
Right-of use asset	(531)	(625)
Equity method investment	302	0
Other deferred tax liabilities	0	132
Net of deferred tax assets and liabilities	85,481	50,872
Less: valuation allowance	(85,481)	(50,872)
Net deferred tax assets	$ 0	$ 0

Income Taxes - Schedule of Dome

Income Taxes - Schedule of Domestic and Foreign Pre-Tax Loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Loss before income taxes - Domestic	$ (107,723)	$ (71,769)	$ (48,643)
Loss before income taxes - Foreign	82	(2,043)	(1,779)
Loss before income taxes - Consolidated	$ (107,641)	$ (73,812)	$ (50,422)

Income Taxes - Schedule of Reco

Income Taxes - Schedule of Reconciliation of Income Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Expected income tax benefit at federal statutory rate	$ (22,605)	$ (15,417)	$ (10,589)
State income tax benefit, net of federal benefit	(7,083)	(4,886)	(3,431)
Change in valuation allowance	34,495	22,242	16,064
R&D credit	(7,117)	(2,597)	(2,485)
Stock-based compensation	1,196	539	226
Australian tax incentive	27	215	307
Other	1,087	(96)	(92)
Provision for income taxes	$ 0	$ 0	$ 0

Income Taxes - Schedule of Unre

Income Taxes - Schedule of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Beginning balance	$ 1,092	$ 886	$ 344
Increase (decrease) for prior year tax positions	(34)	(163)	70
Increase (decrease) for current year tax positions	495	369	472
Ending balance	$ 1,553	$ 1,092	$ 886

Employee Savings Plan - Additio

Employee Savings Plan - Additional Information (Details)	12 Months Ended
	Dec. 31, 2021USD ($)
Retirement Benefits [Abstract]
Description of contributions to the plan	discretionary matching contributions to the 401(k) Plan are permitted in an amount equal to 50% of the first 6% of the employee’s taxable income up to a maximum of $3,000 per year
Employee's contributions to the plan	$ 3,000
Accrued matching contributions	$ 300,000
Defined contribution benefit plan, effective date	May 1, 2016

Subsequent Event - Additional I

Subsequent Event - Additional Information (Details) - Subsequent Event - Sanwa Kagaku Kenkyusho Co Ltd $ in Millions	Feb. 25, 2022USD ($)
Subsequent Event [Line Items]
Licensing Agreement Receivable	$ 13
Receivable additional milestone payments	$ 25.5