0000950170-24-020212 | 10-K | XBRL Viewer | DAY ONE Biopharmaceuticals INC

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Stock-Based Compensation - Summary of Fair Value of The Incentive Shares Estimated Using An Option Pricing Model (Detail) - Incentive Share Plan Member [Member]	12 Months Ended
	Dec. 31, 2021 $ / shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk free rate	0.14%
Volatility	72.90%
Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common share fair value	$ 6.36
Participating threshold	$ 6.36
Time to liquidity (in years)	2 months 12 days
Grant date fair value	$ 4.24
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common share fair value	8.89
Participating threshold	$ 7.51
Time to liquidity (in years)	1 year 9 months 18 days
Grant date fair value	$ 4.52

Summary of Significant Accounting Policies	12 Months Ended
Summary of Significant Accounting Policies	Dec. 31, 2023
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation The accompanying consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States of America, or U.S. GAAP, and include the accounts of the Company’s subsidiaries. All intercompany transactions and balances have been eliminated in consolidation. Prior to December 31, 2021, the Company consolidated its Subsidiaries. Effective December 31, 2021, the Company's board of directors approved the Merger of the Subsidiaries with and into the Company, with the Company being the surviving corporation (refer to the section “Organization and Business”). Because the Merger did not constitute a change in the reporting entity, as defined in Accounting Standard Codification, or ASC, 250, Accounting changes and error corrections, the Company has reported the assets and liabilities transferred from its Subsidiaries at historical carrying value, prospectively from December 31, 2021. Subsequent to December 31, 2021, amounts presented in the financial statements are unconsolidated as the Company had no subsidiaries. Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in ASC and Accounting Standards Updates, or ASU, of the Financial Accounting Standards Board, or FASB. Going Concern The Company assesses and determines its ability to continue as a going concern in accordance with the provisions of ASC Topic 205-40, Presentation of Financial Statements—Going Concern, which requires the Company to evaluate whether there are conditions or events that raise substantial doubt about its ability to continue as a going concern within one year after the date that its annual and interim financial statements are issued. Certain additional financial statement disclosures are required if such conditions or events are identified. Determining the extent, if any, to which conditions or events raise substantial doubt about the Company’s ability to continue as a going concern, or the extent to which mitigating plans sufficiently alleviate any such substantial doubt, as well as whether or not liquidation is imminent, requires significant judgment by management. Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements, and the reported amounts of expenses during the reporting period. Estimates and assumptions made in the accompanying consolidated financial statements include, but are not limited to, the valuation of share-based awards, the valuation of deferred tax assets and income tax uncertainties, and accruals for research and development activities. The Company bases its estimates on historical experience and on various other assumptions that are believed to be reasonable. Actual results may differ from those estimates or assumptions. Segments The Company has determined that its chief executive officer is the chief operating decision maker, or CODM. The Company operates and manages the business as one reporting and one operating segment, which is the business of identifying and advancing targeted therapies for people of all ages with genomically defined cancers. The Company’s CODM reviews financial information on an aggregate basis for purposes of allocating resources and evaluating financial performance. All of the Company’s assets are located in the United States. Concentration of credit risk and other risks and uncertainties Financial instruments that subject the Company to significant concentrations of credit risk consist primarily of cash, cash equivalents and short-term investments. Amounts on deposit may at times exceed federally insured limits. The Company is exposed to credit risk in the event of default by the financial institutions holding its cash, cash equivalents and short-term investments that are recorded on its balance sheet. Per policy, the Company mitigates its risk by investing in high-grade instruments and limiting the concentration in any one issuer, which limits its exposure. The Company has not experienced any losses on its cash, cash equivalents and short-term investments. The Company is subject to certain risks and uncertainties and believes that changes in any of the following areas could have a material adverse effect on the Company's future financial position or results of its operations: ability to obtain future financing; regulatory requirements for approval and market acceptance of, and reimbursement for, product candidates; performance of third-party clinical research organizations and manufacturers upon which the Company relies; development of sales channels; protection of the Company’s intellectual property; litigation or claims against the Company based on intellectual property, patent, product, regulatory or other factors; changes to the market landscape; and the Company’s ability to attract and retain employees necessary to support its growth. The Company is dependent on third-party manufacturers to supply products for research and development activities in its programs. In particular, the Company relies and expects to continue to rely on a small number of manufacturers to supply it with its requirements for the active pharmaceutical ingredients and formulated drugs related to these programs. These programs could be adversely affected by a significant interruption in the supply of active pharmaceutical ingredients and formulated drugs. Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity of three months or less at the time of purchase to be cash equivalents. The Company’s cash equivalents consist of investments in money market funds, U.S. government agency securities, and U.S. treasury securities. Cash equivalents are recognized at amortized cost, which approximates fair value. Investments The Company’s investments are comprised of U.S. treasury securities and U.S. government agency securities. Investments are classified at the time of purchase, based on management’s intent, as held-to-maturity, available-for-sale, or trading. All of the Company’s investments are classified as available-for-sale. Available-for-sale securities are carried at estimated fair value with unrealized holdings gains and losses (net of tax effects) on such investments reported in other comprehensive income as a separate component on the consolidated statements of comprehensive loss. Fair value is determined based on quoted market rates when observable or by utilizing data points that are observable, such as quoted prices, interest rates, and yield curves. For available-for-sale securities, the Company determines if any impairment is related to credit loss or non-credit loss. In making the assessment of whether a loss is from credit or other factors, management considers the extent to which fair value is less than amortized cost, any changes to the rating of the security by a rating agency and adverse conditions related to the security, among other factors. If this assessment indicates that a credit loss exists, the present value of cash flows expected to be collected from the security are compared to the amortized cost basis of the security. If the present value of cash flows is less than the amortized cost basis, a credit loss exists and an allowance is created, limited by the amount that the fair value is less than amortized cost basis. Subsequent activity related to the credit loss component in the form of write-offs or recoveries is recognized as part of the allowance for credit losses on available-for-sale securities. Fair Value of Financial Instruments Assets and liabilities recorded at fair value on a recurring basis in the consolidated balance sheets are categorized based upon the level of judgment associated with the inputs used to measure their fair values. Fair value is defined as the exchange price that would be received for an asset or an exit price that would be paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The authoritative guidance on fair value measurements establishes a three-tier fair value hierarchy for disclosure of fair value measurements as follows: Level 1—Observable inputs such as unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date; Level 2—Inputs (other than quoted prices included in Level 1) are either directly or indirectly observable for the asset or liability. These include quoted prices for similar assets or liabilities in active markets and quoted prices for identical or similar assets or liabilities in markets that are not active; and Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The carrying amounts reflected in the accompanying consolidated balance sheets for cash equivalents, prepaid expenses, other current assets, accounts payable, accrued expenses and other current liabilities approximate their fair values, due to their short-term nature. Property and Equipment, Net Property and equipment are recorded at cost, less accumulated depreciation and amortization. Depreciation is recognized using the straight-line method over the estimated useful lives of the related assets ranging from three to five years, and leasehold improvements are amortized over the shorter of the lease term or the estimated useful life of the asset. As of December 31, 2023 and 2022, property and equipment, net was not material. Depreciation expense for each of the years ended December 31, 2023, 2022, and 2021 was immaterial. Leases Contractual arrangements that meet the definition of a lease are classified as operating or finance leases and are recorded on the consolidated balance sheets as both a right-of-use asset, or ROU asset, and lease liability, calculated by discounting fixed lease payments over the lease term at the rate implicit in the lease or the Company’s incremental borrowing rate, or IBR. Lease ROU assets and lease obligations are recognized based on the present value of the future minimum lease payments over the lease term at commencement date. The Company currently does not have any finance leases. Operating lease ROU assets are adjusted for (i) payments made at or before the commencement date, (ii) initial direct costs incurred, and (iii) tenant incentives under the lease. As the implicit rate for the operating leases are not determinable, the Company determines its IBR based on the information available at the applicable lease commencement date. The IBR is determined by using the rate of interest that the Company would pay to borrow on a collateralized basis an amount equal to the lease payments for a similar term and in a similar economic environment where the asset is located. The Company considers a lease term to be the noncancelable period that it has the right to use the underlying asset, including any periods where it is reasonably certain the Company will exercise any option to extend the contract. Lease costs for minimum lease payments for operating leases are recognized on a straight-line basis over the lease term. Lease liabilities are increased by interest and reduced by payments each period, and the ROU asset is amortized over the lease term. Variable lease costs are recorded when incurred. In measuring the ROU assets and lease liabilities, the Company has elected to combine lease and non-lease components. The Company excludes short-term leases, if any, having initial terms of 12 months or less at lease commencement as an accounting policy election, and recognizes rent expense on a straight-line basis over the lease term for these types of leases. Impairment of Long-Lived Assets The Company evaluates its long-lived asset group, which consist of property and equipment and right-of-use assets, for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to the future undiscounted net cash flows expected to be generated by the asset. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the carrying amount of the asset exceeds the fair value of the asset. To date, no impairments have been recognized in the consolidated financial statements. Research and Development Expenses Research and development expenses consist of costs associated with acquiring technology and intellectual property licenses that have no alternative future uses; costs incurred under agreements with third-party contract research organizations, contract manufacturing organizations and other third parties that conduct clinical trials on the Company’s behalf; other costs associated with research and development programs, including laboratory materials and supplies; employee-related costs, including salaries, benefits and share-based compensation expense, for the Company’s research and development personnel; and facilities and other overhead expenses, including expenses for rent and facilities maintenance, and amortization. The Company expenses research and development costs as incurred. The Company is obligated to make upfront payments upon execution of certain research and development agreements. Advance payments, including nonrefundable amounts, for goods or services that will be used or rendered for future research and development activities are deferred. Such amounts are recognized as expense as the related goods are delivered or the related services are performed, or such time when the Company does not expect the goods to be delivered or services to be performed. Accrued Research and Development Expenses The Company records accrued liabilities for estimated costs of our clinical trials conducted by third-party service providers. The Company records the estimated costs of the clinical trials as research and development expense based upon the estimated amount of services provided but not yet invoiced. The Company accrues for these costs based on factors such as estimates of the work completed and in accordance with terms established with third-party service providers under the service agreements. The Company makes judgments and estimates in determining the accrued liabilities balance in each reporting period. As actual costs become known, the Company adjusts its accrued liabilities. The Company has not experienced any material differences between accrued costs and actual costs incurred. The Company makes payments in connection with the clinical trials under contracts with contract research organizations who conduct and manage our clinical trials. The financial terms of these contracts are subject to negotiation, which vary by contract and may result in payments that do not match the periods over which materials or services are provided. Generally, these agreements set forth the scope of work to be performed at a fixed fee, unit price or on a time and materials basis. In the event the Company makes advance payments for goods or services that will be used or rendered for future research and development activities, the payments are deferred and capitalized as a prepaid expense and recognized as expense as the goods are received or the related services are rendered. Such payments are evaluated for current or long-term classification based on when they are expected to be realized. Patent Costs All patent-related costs incurred in connection with filing and prosecuting patent applications are expensed as incurred due to the uncertainty of the recovery of the expenditure. Amounts incurred are classified as general and administrative expenses in the consolidated statements of operations. Redeemable Convertible Preferred Shares The Company recorded redeemable convertible preferred shares at their respective fair values on the dates of issuance, net of issuance costs. The redeemable convertible preferred shares were recorded outside of members’ deficit because while they were not mandatorily redeemable, in the event of a deemed liquidation event, which was outside of the Company’s control, the proceeds were distributed first to the redeemable convertible preferred stockholders in accordance with their liquidation preferences. The Company had not adjusted the carrying values of the redeemable convertible preferred shares to their liquidation preferences because it is uncertain whether or when a deemed liquidation event would occur that would obligate it to pay the liquidation preferences to holders of redeemable convertible preferred shares. Redeemable convertible preferred shares were all converted to common stock shares upon the closing of the IPO in May 2021. Redeemable Noncontrolling Interest Redeemable noncontrolling interest represented the portion of equity (net assets) in DOT-1 that was neither directly nor indirectly attributable to the Company. Redeemable noncontrolling interest is classified as temporary equity because preferred shares issued to a holder contained certain redemption features that were not solely within the control of the Company. Redeemable noncontrolling interest was extinguished as part of the Exchange in May 2021. Share-Based Compensation Prior to the IPO, the Company recognized share-based compensation expense based on the estimated fair value of all share-based awards, incentive shares and restricted share awards, on the date of grant using the option-pricing model. The option-pricing model requires the input of subjective assumptions, including the fair value of the underlying common shares, the expected term of the award, the expected volatility, risk-free interest rates, and the dividend yield. In determining the fair value of common shares, the methodologies used to estimate the enterprise value were performed using methodologies, approaches, and assumptions consistent with the American Institute of Certified Public Accountants Accounting and Valuation Guide, Valuation of Privately-Held-Company Equity Securities Issued as Compensation. The participation threshold amounts for the profit interest in the LLC were determined by the board of directors, at the time of grant. The expected life of the awards granted during the period was determined based on an expected time to the liquidation event. The Company applied the risk-free interest rate based on the U.S. Treasury yield in effect at the time of the grant consistent with the life of the award. The expected volatility was based on a peer group in the industry in which the Company did business consistent with the expected time to liquidity. The dividend yield was set at zero as the underlying security did not and was not expected to pay a dividend. Subsequent to closing of the IPO, the Company uses the Black-Scholes valuation model to estimate the fair value of options granted to employees and non-employees, intrinsic value to estimate the fair value of restricted stock award, and fair value of the Company’s common stock at the grant date for restricted stock units. The Black-Scholes option-pricing model, used to estimate fair value of stock options awards, requires the use of the following assumptions: • Fair Value of Common Stock—The Company’s closing price on the Nasdaq market at the grant date. • Expected Term—The expected term represents the period that the share-based awards are expected to be outstanding. The expected term for stock options is calculated using the simplified method, as the weighted-average vesting term of the award and the award’s contract period (generally 10 years). The Company utilizes this method due to lack of historical exercise data and the plain-vanilla nature of the Company’s service condition share-based awards. For the Company's performance condition stock option awards, the Company calculated the expected term by taking into consideration the options' contractual life, the timing of when milestones are expected to be achieved, and the expected exercise period by a holder from the vesting date until the contractual term (generally 10 years). • Expected Volatility—Since the Company does not have sufficient trading history for its common stock, the expected volatility is estimated based on the average historical volatilities of common stock of comparable publicly traded biopharmaceutical companies over a period equal to the expected term of the stock option grants. The comparable biopharmaceutical companies are chosen based on their size, stage in the life cycle or area of specialty. The Company will continue to apply this process until sufficient historical information regarding the volatility of the common stock price becomes available. • 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 approximately equal to the expected term of the awards. • Expected Dividend Yield—The Company has never paid dividends on the common stock and has no plans to pay dividends on its common stock. Therefore, the expected dividend yield use is zero. The Company uses the straight-line attribution method for recognizing share-based compensation expense for awards with service condition. The Company recognizes share-based compensation expense for awards with performance conditions when it is probable that the condition will be met, and the award will vest. The Company recognizes forfeitures by reducing the expense in the same period the forfeitures occur. The Company classifies share-based compensation expense in the consolidated statements of operations in the same manner in which the award recipients’ payroll costs are classified or in which the award recipients’ service payments are classified. Income Taxes Prior to the IPO, the Company was treated as a partnership for tax purposes under the Internal Revenue Code with two corporate subsidiaries. Prior to the Conversion, the members of the Company, formerly Day One Biopharmaceuticals Holding Company, LLC, were taxed directly on their respective ownership interests and activity in Day One Biopharmaceuticals Holding Company, LLC. The Company’s consolidated corporate subsidiaries accounted for income taxes under the asset and liability method, as discussed below. Upon the closing of the IPO and the Conversion, the Company’s income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax base and net operating loss and tax credit carryforwards. Deferred tax assets and liabilities are determined based upon the difference between the consolidated financial statement carrying amounts and the tax basis of assets and liabilities and are measured using the enacted tax rate expected to apply to taxable income in the years in which the differences are expected to be reversed. Deferred tax assets are reduced by a valuation allowance if it is more likely than not that some portion or all of the deferred tax asset will not be realized. The uncertain income tax positions are recognized at the largest amount that is more likely than not to be sustained upon audit by the relevant taxing authority. Changes in recognition or measurement are reflected in the period in which judgment occurs. The Company’s policy is to recognize interest and penalties related to the underpayment of income taxes as a component of the provision for income taxes. To date, there have been no interest or penalties recorded in relation to unrecognized tax benefits. Net Loss per Share The Company calculates basic and diluted net loss per share in conformity with the two-class method required for participating securities. Under the two-class method, basic net loss per share is computed by dividing the net loss by the weighted average number of common shares outstanding during the period, without consideration of potential dilutive securities. Diluted net loss per share is computed by dividing the net loss, after adjusting it for loss attributable to redeemable noncontrolling interest, in any, by the sum of the weighted average number of common stock shares outstanding during the period plus the dilutive effects of potentially dilutive securities outstanding during the period. Potentially dilutive securities include incentive shares, unvested restricted common shares and redeemable convertible preferred shares, prior to the IPO. Potentially dilutive securities include unvested restricted stock awards, unvested restricted stock units and stock options, after the IPO. For all periods presented, diluted net loss per share is the same as basic net loss per share since the effect of including potential common stock shares is anti-dilutive and incentive shares participation thresholds were not met. Comprehensive Loss Comprehensive loss represents all changes in stockholders' equity except those resulting from and distributions to stockholders. The Company’s unrealized gains and losses on available-for-sale securities represent the only component of other comprehensive loss that are excluded from the reported net loss and that are presented in the consolidated statements of comprehensive loss. Recently Issued Accounting Pronouncements In November 2023, the FASB issued ASU No. 2023-07, Segment Reporting (Topic 280) – Improvements to Reportable Segment Disclosures, which requires incremental disclosure of segment information on an interim and annual basis. This ASU is effective for public entities for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024. Retrospective application to all prior periods presented in the financial statements is required for public entities. The Company is currently evaluating the effect of this update on its financial statement disclosures. In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740) – Improvements to Income Tax Disclosures, which enhances the transparency and decision usefulness of income tax disclosures by requiring disclosure of disaggregated income taxes paid, prescribes standard categories for the components of the effective tax rate reconciliation, and modifies other income tax-related disclosures. The ASU is effective for fiscal years beginning after December 15, 2024 and allows for adoption on a prospective basis, with a retrospective option. The Company is currently evaluating the effect of this update on its financial statement disclosures.

Stock-Based Compensation - Summary of Share/Stock-based Compensation Expense Recorded in The Accompanying Condensed Consolidated Statements of Operations and Comprehensive Loss (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Share-based compensation expense	$ 39,341	$ 27,242	$ 13,321
2021 Employee Stock Purchase Plan [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Share-based compensation expense	800	500	200
Research and Development Expense [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Share-based compensation expense	14,381	8,486	3,840
General and Administrative Expense
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Share-based compensation expense	$ 24,960	$ 18,756	$ 9,481

Stock-Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	May 31, 2021	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Oct. 31, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common Stock, capital shares purchase an additional for future issuance		15,567,663
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested, Number of Shares		4,719,605
Share-based compensation expense		$ 39,341	$ 27,242	$ 13,321
Weighted-average grant date fair value of options granted			$ 15.08
Weighted-average vesting contractual term of the award		10 years
Unvested Restricted Stock And Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average vesting contractual term of the award		2 years 10 months 24 days
Unamortized stock-based compensation for stock options		$ 700
Unvested PSOs and PSUs [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation by share based payment arrangement unrecognized compensation		$ 600
Performance Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested, Number of Shares		71,750
Total fair value of options		$ 500
Weighted-average grant date fair value of options granted			$ 7.78
Weighted average remaining contractual term		8 years 6 months
Weighted-average vesting contractual term of the award		8 years 6 months
Unvested Performance Stock Units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation by share based payment arrangement unrecognized compensation		$ 700
Incentive Share Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation by share based payment arrangement unrecognized compensation remaining period for recognition		2 years 9 months 18 days
Unamortized stock-based compensation for stock options		$ 3,300
Incentive Share Plan [Member] \| Day One Holding LLC [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation by share based payment arrangment number of shares authorized		8,924,177
2021 Equity Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected dividend yield		0.00%	0.00%	0.00%
Common Stock, capital shares purchase an additional for future issuance	6,369,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested, Number of Shares		9,759,258
Conversion of Stock, Shares Issued	4,719,605
Granted		2,653,000
Total intrinsic value of the options outstanding		$ 3,260
Total fair value of options		$ 27,300	$ 23,100	$ 1,100
Weighted average remaining contractual term		8 years 2 months 12 days
Weighted-average vesting contractual term of the award		8 years 2 months 12 days
2021 Equity Incentive Plan [Member] \| Performance Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average grant date fair value of options granted		$ 13.14	$ 9.61	$ 9.91
Weighted-average vesting contractual term of the award		2 years 4 months 24 days
Unamortized stock-based compensation for stock options		$ 54,700
2021 Equity Incentive Plan [Member] \| Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average vesting contractual term of the award		2 years 10 months 24 days
Unamortized stock-based compensation for stock options		$ 16,100
2021 Equity Incentive Plan [Member] \| Incremental Shares Reserved For Future Issuance
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Percentage of Outstanding Stock Maximum	5.00%
2021 Employee Stock Purchase Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected dividend yield		0.00%	0.00%	0.00%
Common Stock, capital shares purchase an additional for future issuance	603,000
Share-based Compensation Arrangement by Share-based Payment Award, Percentage of Outstanding Stock Maximum	1.00%
Stock Issued During Period, Shares, Employee Stock Ownership Plan		236,187
Share-based compensation expense		$ 800	$ 500	$ 200
2021 Employee Stock Purchase Plan [Member] \| Unvested Restricted Stock And Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation by share based payment arrangement unrecognized compensation		$ 78,900
Share based compensation by share based payment arrangement unrecognized compensation remaining period for recognition		2 years 6 months
2021 Employee Stock Purchase Plan [Member] \| Unvested PSOs and PSUs [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation by share based payment arrangement unrecognized compensation		$ 1,300
2022 Equity Inducement Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common Stock, capital shares purchase an additional for future issuance					1,000,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested, Number of Shares		309,000
Granted		0
Total intrinsic value of the options outstanding		$ 0
Total fair value of options		$ 1,400	$ 0	$ 0
Weighted-average grant date fair value of options granted			$ 0	$ 0
Weighted average remaining contractual term		8 years 9 months 18 days
Weighted-average vesting contractual term of the award		8 years 9 months 18 days

Recurring Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2023

Fair Value Disclosures [Abstract]

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis

The following table sets forth the Company’s financial instruments as of December 31, 2023 and 2022, which are measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands):


	December 31, 2023
	Level 1		Level 2		Level 3		Total
Financial assets:
Money market funds	$	47,003	$	—	$	—	$	47,003
U.S. treasury securities		—		246,208		—		246,208
U.S. government agency securities		—		63,202		—		63,202
Total assets measured at fair value	$	47,003	$	309,410	$	—	$	356,413


	December 31, 2022
	Level 1		Level 2		Level 3		Total
Financial assets:
Money market funds	$	18,765	$	—	$	—	$	18,765
U.S. treasury securities		—		145,785		—		145,785
U.S. government agency securities		—		136,022		—		136,022
Total assets measured at fair value	$	18,765	$	281,807	$	—	$	300,572

Schedule of cash equivalents, marketable securities, and unrealized gains and losses

The following tables summarize the estimated fair value of the Company's cash equivalents, available-for-sale securities classified as short-term investments, and associated unrealized gains and losses (in thousands):


	December 31, 2023
	Amortized Cost		Unrealized Gains		Unrealized Losses		Estimated Fair Value
Cash equivalents:
Money market funds	$	47,003	$	—	$	—	$	47,003
U.S. government agency securities		63,202		—		—		63,202
U.S. treasury securities		110,645		—		—		110,645
Total cash equivalents		220,850		—		—		220,850

Short-term investments
U.S. treasury securities		135,554		9		—		135,563
Total short-term investments	$	135,554	$	9	$	—	$	135,563


	December 31, 2022
	Amortized Cost		Unrealized Gains		Unrealized Losses			Estimated Fair Value
Cash equivalents:
Money market funds	$	18,765	$	—	$	—		$	18,765
U.S. government agency securities		24,800		—		—			24,800
Total cash equivalents		43,565		—		—			43,565

Short-term investments
U.S. treasury securities		145,880		1		(96	)		145,785
U.S. government agency securities		111,197		37		(12	)		111,222
Total short-term investments	$	257,077	$	38	$	(108	)	$	257,007

Schedule of maturities of our available-for-sale marketable securities table text block

The following table summarizes the maturities of our cash equivalents and available-for-sale securities (in thousands):


	December 31, 2023
	Amortized Cost		Fair Value
Mature in one year or less	$	356,404	$	356,413
Total	$	356,404	$	356,413


	December 31, 2022
	Amortized Cost		Fair Value
Mature in one year or less	$	300,642	$	300,572
Total	$	300,642	$	300,572

Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets
Federal and state net operating loss carryforwards	$ 38,973	$ 25,884
Capitalized R&D Section 174 Expense	34,938	14,908
Credits	10,338	6,653
Intangible asset basis	4,034	2,562
Share-based compensation	4,775	2,133
Other	1,397	1,803
Total deferred tax assets	94,455	53,943
Total deferred tax liabilities	(75)	(149)
Less: valuation allowance	(94,380)	(53,794)	$ (23,778)	$ (8,601)
Net deferred tax assets	$ 0	$ 0

Stock-Based Compensation - Summary of Restricted Stock Units Activity (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
2021 Stock Incentive Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vested	(953,665)
Forfeited	(21,400)
Unvested restricted stock as of December 31, 2022	$ 16	$ 16
Vested	16
Forfeited	16
Unvested restricted stock Grant fair value at December 31, 2022	$ 16	$ 16
2021 Stock Incentive Plan [Member] \| Restricted Stock Units (RSUs) [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Unvested restricted stock at December 31, 2022		485,351
Granted	777,010
Vested	(258,770)
Forfeited	(54,221)
Unvested restricted stock units at December 31, 2023	949,370
Unvested restricted stock as of December 31, 2022	$ 18.31	$ 16.83
Grant date fair value	19.73
Vested	19.44
Forfeited	20.09
Unvested restricted stock Grant fair value at December 31, 2022	$ 18.31	$ 16.83
2021 Stock Incentive Plan [Member] \| Performance Stock Options
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Unvested restricted stock at December 31, 2022		95,500
Vested	(46,625)
Forfeited	(2,250)
Unvested restricted stock units at December 31, 2023	46,625
Unvested restricted stock as of December 31, 2022	$ 15.25	$ 15.25
Vested	15.25
Forfeited	15.25
Unvested restricted stock Grant fair value at December 31, 2022	$ 15.25	$ 15.25
2022 Equity Inducement Plan [Member] \| Restricted Stock Units (RSUs) [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Unvested restricted stock at December 31, 2022		47,400
Granted	0
Vested	(11,850)
Forfeited	0
Unvested restricted stock units at December 31, 2023	35,550
Unvested restricted stock as of December 31, 2022	$ 21.14	$ 21.14
Grant date fair value	0
Vested	21.14
Forfeited	0
Unvested restricted stock Grant fair value at December 31, 2022	$ 21.14	$ 21.14

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 230,784	$ 85,262
Short-term investments	135,563	257,007
Prepaid expenses and other current assets	8,927	5,605
Total current assets	375,274	347,874
Property and equipment, net	208	20
Operating lease right-of-use asset	352	699
Deposits and other long-term assets	214	469
Total assets	376,048	349,062
Current liabilities:
Accounts payable	2,576	260
Accrued expenses and other current liabilities	26,524	15,950
Current portion of operating lease liabilities	408	405
Total current liabilities	29,508	16,615
Long-term portion of lease liabilities	0	408
Total liabilities	29,508	17,023
Commitments and contingencies (Note 6)
Stockholders' equity
Common stock, $0.001 par value; 500,000,000 shares authorized as of December 31, 2023 and December 31, 2022; 87,227,132 and 73,458,176 shares issued and outstanding as of December 31, 2023 and December 31, 2022, respectively	9	7
Additional paid-in-capital	805,107	601,771
Accumulated other comprehensive loss	9	(71)
Accumulated deficit	(458,585)	(269,668)
Total stockholders' equity	346,540	332,039
Total liabilities and stockholders' equity	$ 376,048	$ 349,062

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating Loss Carryforwards [Line Items]
Change in deferred tax assets valuation allowance	$ 40,600	$ 30,000	$ 15,200
Operating Loss Carryforwards	$ 177,700
Net Operating Loss, Carryback period	12 months
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	$ 0	0	$ 0
Tax Credit Carryforward, Expiration Year
Domestic Tax Authority
Operating Loss Carryforwards [Line Items]
Tax Credit Carryforward, Expiration Year	2038
Research and experimental expenses amortization period	5 years
Foreign Tax Authority
Operating Loss Carryforwards [Line Items]
Research and experimental expenses amortization period	15 years
State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
State tax credits		$ 1,600
Gross state NOL	$ 19,200
Tax Credit Carryforward, Expiration Year	2038
Tax Credit Carryforward, Expiration Year

Balance Sheet Items - Summary of Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Property Plant And Equipment [Line Items]
Property and equipment, net	$ 208	$ 20

Net Loss Per Share - Summary of Basic and Diluted Net Loss Per Share Attributable to Common Shareholders/Stockholders (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Earnings Per Share [Abstract]
Net loss	$ (188,917)	$ (142,181)	$ (72,754)
Net loss attributable to redeemable convertible noncontrolling interests	0	0	(2,109)
Exchange of redeemable noncontrolling interest shares - deemed dividend	0	0	(99,994)
Net loss attributable to common stockholders/members	$ (188,917)	$ (142,181)	$ (170,639)
Net loss per share, diluted	$ (2.37)	$ (2.17)	$ (4.62)
Net loss per share, basic	$ (2.37)	$ (2.17)	$ (4.62)
Weighted-average number of common shares used in computing net loss per share, diluted	79,773,004	65,466,773	36,960,569
Weighted-average number of common shares used in computing net loss per share, basic	79,773,004	65,466,773	36,960,569

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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Amount of Net Income (Loss) attributable to noncontrolling interest.

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The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

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-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B

Reference 27: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 30
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-30

Reference 28: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
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-Section 50
-Paragraph 32
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-32

Reference 29: http://www.xbrl.org/2003/role/exampleRef
-Topic 280
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-Name Accounting Standards Codification
-Section 50
-Paragraph 31
-Publisher FASB
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Reference 30: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-32

Reference 31: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 235
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-05(b)(2))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479557/942-235-S99-1

Reference 32: http://www.xbrl.org/2003/role/disclosureRef
-Topic 205
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483499/205-20-50-7

Reference 33: http://www.xbrl.org/2003/role/exampleRef
-Topic 810
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 4J
-Publisher FASB
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Reference 34: http://www.xbrl.org/2003/role/exampleRef
-Topic 810
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-Publisher FASB
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Reference 35: http://www.xbrl.org/2003/role/disclosureRef
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-SubTopic 10
-Name Accounting Standards Codification
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-Paragraph 1A
-Subparagraph (a)
-Publisher FASB
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Reference 36: http://www.xbrl.org/2003/role/disclosureRef
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-Subparagraph (a)
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Reference 37: http://www.xbrl.org/2003/role/disclosureRef
-Topic 230
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-Section 45
-Paragraph 2
-Publisher FASB
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Reference 38: http://www.xbrl.org/2003/role/disclosureRef
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-Subparagraph (a)(1)
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Reference 39: http://www.xbrl.org/2003/role/disclosureRef
-Topic 810
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-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481203/810-10-50-1A

+ Details

Recurring Fair Value Measurements - Schedule of cash equivalent, marketable securities and unrealized gains and losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$ 230,784	$ 85,262
Marketable Securities [Member]
Cash and Cash Equivalents [Line Items]
Debt Securities, Available-for-Sale, Amortized Cost	135,554	257,077
Debt Securities, Available-for-Sale, Unrealized Gain	9	38
Debt Securities, Available-for-Sale, Unrealized Loss	0	(108)
Debt Securities, Available-for-Sale	135,563	257,007
Cash Equivalents [Member]
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	220,850	43,565
Cash Equivalents Unrealized Gains		0
Cash Equivalents Unrealized Losses	0	0
Cash and Cash Equivalents, Fair Value Disclosure	220,850	43,565
Money Market Funds [Member]
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	47,003	18,765
Cash Equivalents Unrealized Gains	0	0
Cash Equivalents Unrealized Losses	0	0
Cash and Cash Equivalents, Fair Value Disclosure	47,003	18,765
U.S. government agency securities [Member]
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	63,202	24,800
Cash Equivalents Unrealized Gains	0	0
Cash Equivalents Unrealized Losses	0	0
Cash and Cash Equivalents, Fair Value Disclosure	63,202	24,800
Debt Securities, Available-for-Sale, Amortized Cost		111,197
Debt Securities, Available-for-Sale, Unrealized Gain		37
Debt Securities, Available-for-Sale, Unrealized Loss		(12)
Debt Securities, Available-for-Sale		111,222
US Treasury Securities [Member]
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	110,645
Cash Equivalents Unrealized Gains	0
Cash Equivalents Unrealized Losses	0
Cash and Cash Equivalents, Fair Value Disclosure	110,645
Debt Securities, Available-for-Sale, Amortized Cost	135,554	145,880
Debt Securities, Available-for-Sale, Unrealized Gain	9	1
Debt Securities, Available-for-Sale, Unrealized Loss	0	(96)
Debt Securities, Available-for-Sale	$ 135,563	$ 145,785

Stock-Based Compensation - Summary of Stock Option Activity (Detail) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vested and expected to vest at December 31, 2023	4,719,605
Granted \| $ / shares	$ 18.83
Vested and expected to vest at December 31, 2023	10 years
Performance Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares, Beginning Balance	146,950
Forfeiture	(3,450)
Number of Shares, Ending Balance	143,500
Vested and expected to vest at December 31, 2023	71,750
Exercisable at December 31, 2023	71,750
Forfeiture \| $ / shares	$ 15.25
Weighted Average Exercise Price, Ending Balance \| $ / shares	15.25
Vested and expected to vest at December 31, 2023 \| $ / shares	15.25
Exercisable at December 31, 2023 \| $ / shares	$ 15.25
Weighted-Average Remaining Contractual Term, Outstanding at December 31, 2021	8 years 6 months
Vested and expected to vest at December 31, 2023	8 years 6 months
Weighted-Average Remaining Contractual Term, Exercisable at December 31, 2021	8 years 6 months
2021 Equity Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares, Beginning Balance	7,634,167
Granted	2,653,000
Exercised	(88,459)
Forfeiture	(439,450)
Number of Shares, Ending Balance	9,759,258
Vested and expected to vest at December 31, 2023	9,759,258
Exercisable at December 31, 2023	4,602,684
Weighted Average Exercise Price, Begining Balance \| $ / shares	$ 16.42
Exercised \| $ / shares	15.12
Forfeiture \| $ / shares	18.3
Weighted Average Exercise Price, Ending Balance \| $ / shares	17
Vested and expected to vest at December 31, 2023 \| $ / shares	17
Exercisable at December 31, 2023 \| $ / shares	$ 16.74
Weighted-Average Remaining Contractual Term, Outstanding at December 31, 2021	8 years 2 months 12 days
Vested and expected to vest at December 31, 2023	8 years 2 months 12 days
Weighted-Average Remaining Contractual Term, Exercisable at December 31, 2021	7 years 9 months 18 days
Exercised \| $	$ 643
Outstanding at December 31, 2022, Aggregiate Intrinsic Value \| $	3,260
Vested and expected to vest at December 31, 2023 \| $	3,260
Exercisable at December 31, 2023, Aggregiate Intrinsic Value \| $	$ 904
2021 Equity Incentive Plan [Member] \| Performance Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vested and expected to vest at December 31, 2023	2 years 4 months 24 days
2022 Equity Inducement Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares, Beginning Balance	309,000
Granted	0
Number of Shares, Ending Balance	309,000
Vested and expected to vest at December 31, 2023	309,000
Exercisable at December 31, 2023	90,124
Weighted Average Exercise Price, Begining Balance \| $ / shares	$ 21.14
Granted \| $ / shares	0
Weighted Average Exercise Price, Ending Balance \| $ / shares	21.14
Vested and expected to vest at December 31, 2023 \| $ / shares	21.14
Exercisable at December 31, 2023 \| $ / shares	$ 21.14
Weighted-Average Remaining Contractual Term, Outstanding at December 31, 2021	8 years 9 months 18 days
Vested and expected to vest at December 31, 2023	8 years 9 months 18 days
Weighted-Average Remaining Contractual Term, Exercisable at December 31, 2021	8 years 9 months 18 days
Outstanding at December 31, 2022, Aggregiate Intrinsic Value \| $	$ 0
Vested and expected to vest at December 31, 2023 \| $	0
Exercisable at December 31, 2023, Aggregiate Intrinsic Value \| $	$ 0

Consolidated Statements of Redeemable Convertible Preferred Shares, Redeemable Noncontrolling Interest and Stockholders Equity/ Members (Deficit) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Series B Redeemable Convertible Preferred Shares
Stock issuance costs			$ 243
Common Stock [Member]
Stock issuance costs	$ 10,827	$ 10,864	$ 16,995

Common Stock - Additional Information (Detail) $ / shares in Units, $ in Thousands	1 Months Ended		6 Months Ended	12 Months Ended
	Jun. 30, 2023 USD ($) $ / shares shares	Nov. 30, 2018 USD ($) shares	Jun. 30, 2023 USD ($) $ / shares shares	Dec. 31, 2023 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2021 USD ($)	Jun. 30, 2022 $ / shares shares
Class Of Stock [Line Items]
Common Stock, Shares Authorized				500,000,000	500,000,000
Common Stock, Par or Stated Value Per Share \| $ / shares				$ 0.0001	$ 0.0001
Common Stock, Shares, Issued				87,227,132	73,458,176
Common Stock, Shares, Outstanding				87,227,132	73,458,176
Number Of Directors Entitled To Be Elected By The Holders Of Common Stock		200
Common Stock, capital shares purchase an additional for future issuance				15,567,663
Proceeds from issuance of common stock, net \| $				$ 161,409	$ 161,610	$ 167,045
Common Stock, Capital Shares Reserved for Future Issuance				15,567,663
Proceeds from Issuance of Common Stock \| $				$ 161,409	$ 161,610	$ 167,045
Common Shares Purchase Agreement
Class Of Stock [Line Items]
Common Stock, Shares Authorized				500,000,000
Common Stock, Par or Stated Value Per Share \| $ / shares				$ 0.0001
Common Shares Purchase Agreement \| Founder
Class Of Stock [Line Items]
Stock Issued During Period, Shares, New Issues		2,790,000
Proceeds from issuance of common stock, net \| $		$ 300
Proceeds from Issuance of Common Stock \| $		$ 300
Sales agreement [Member]
Class Of Stock [Line Items]
Common Stock, Par or Stated Value Per Share \| $ / shares	$ 13		$ 13				$ 15
Common Stock, Shares, Issued	13,269,231		13,269,231				11,500,000
Common Stock, capital shares purchase an additional for future issuance	1,730,769		1,730,769				1,500,000
Gross Proceeds \| $				$ 250,000
Proceeds from issuance of common stock, net \| $	$ 161,600		$ 161,400
Gross Proceeds \| $				$ 250,000
Common Stock, Capital Shares Reserved for Future Issuance	1,730,769		1,730,769				1,500,000
Proceeds from Issuance of Common Stock \| $	$ 161,600		$ 161,400

Prepaid Expenses and Other Current Assets (Tables)

12 Months Ended

Dec. 31, 2023

Prepaid Expense and Other Assets, Current [Abstract]

Schedule Of Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consisted of the following (in thousands):


	December 31, 2023		December 31, 2022
Prepaid research and development expenses	$	5,657	$	3,007
Prepaid insurance		918		1,592
Other prepaid expenses and other assets		2,352		1,006
Total prepaid expenses and other current assets	$	8,927	$	5,605

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash flows from operating activities
Net loss	$ (188,917)	$ (142,181)	$ (72,754)
Adjustments to reconcile net loss to net cash used in operating activities:
Acquired in-process research and development assets	3,000	0	8,000
Share-based compensation expense	39,341	27,242	13,321
Depreciation expense	36	63	20
Accretion of discounts on short-term investments, net	(10,078)	(2,030)	0
Amortization of operating right-of-use assets	347	468	179
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(3,322)	(546)	(3,717)
Deposits and other long-term assets	255	(300)	(62)
Accounts payable	2,316	(1,484)	1,542
Accrued expenses and other current liabilities	10,574	9,241	5,114
Operating lease liabilities	(405)	(347)	(182)
Net cash used in operating activities	(146,853)	(109,874)	(48,539)
Cash flows from investing activities
Cash paid for purchase of short-term investments	(443,838)	(394,206)	0
Proceeds from maturity of short-term investment	575,440	139,158	0
Cash paid for purchase of property and equipment	(224)	(26)	0
Cash paid for acquired in-process research and development assets	(3,000)	0	(8,000)
Net cash used in investing activities	128,378	(255,074)	(8,000)
Cash flows from financing activities
Proceeds from issuance of common stock, net	161,409	161,610	167,045
Proceeds from issuance of common stock upon stock option exercises	1,338	3,649	0
Proceeds from issuance of common stock upon ESPP purchase	1,250	642	318
Net cash provided by financing activities	163,997	165,901	297,120
Net increase (decrease) in cash and cash equivalents	145,522	(199,047)	240,581
Cash and cash equivalents, beginning of period	85,262	284,309	43,728
Cash and cash equivalents, end of period	230,784	85,262	284,309
Supplemental disclosures of noncash activities
Lease liability obtained in exchange for right-of-use asset	0	940	0
Exchange of 45,331,483 preferred, common, and incentive shares in connection with the Conversion (Note 1)	0	0	224,892
Exchange of redeemable convertible noncontrolling interest to 6,470,382 shares of common stock (Note 11)	0	0	3,592
Series B Preferred Stock [Member]
Cash flows from financing activities
Proceeds from issuance of redeemable convertible preferred shares, net of issuance costs	$ 0	$ 0	$ 129,757

Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating expenses:
Research And Development Expense	$ 130,521	$ 85,618	$ 43,584
General and administrative	75,543	61,291	29,159
Total operating expenses	206,064	146,909	72,743
Loss from operations	(206,064)	(146,909)	(72,743)
Investment Income, Net	17,187	4,746	4
Other expense, net	(40)	(18)	(15)
Net loss	(188,917)	(142,181)	(72,754)
Net loss attributable to redeemable convertible noncontrolling interests	0	0	(2,109)
Exchange of redeemable noncontrolling interest shares-deemed dividend	0	0	(99,994)
Net loss attributable to common stockholders/members	$ (188,917)	$ (142,181)	$ (170,639)
Net loss per share, basic	$ (2.37)	$ (2.17)	$ (4.62)
Net loss per share, diluted	$ (2.37)	$ (2.17)	$ (4.62)
Weighted-average number of common shares used in computing net loss per share, basic	79,773,004	65,466,773	36,960,569
Weighted-average number of common shares used in computing net loss per share, diluted	79,773,004	65,466,773	36,960,569

Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2023

Commitments and Contingencies Disclosure [Abstract]

Summary of Future Lease Obligations

As of December 31, 2023, the future lease obligations were as follows (in thousands):


	December 31, 2023
2024	$	424
Total future minimum lease payments		424
Less: Imputed interest		(16	)
Present value of operating lease liabilities		408
Less: current portion of operating lease liabilities		(408	)
Operating lease liabilities	$	-

Insider Trading Arrangements	3 Months Ended
Insider Trading Arrangements	Dec. 31, 2023 shares
Trading Arrangements, by Individual
Material Terms of Trading Arrangement	Insider Trading Policies and Arrangements The Company’s directors and Section 16 officers (as defined in Rule 16a-1(f) under the Exchange Act) are only permitted to trade in the Company’s securities pursuant to a prearranged trading plan intended to satisfy the affirmative defense of Rule 10b5-1(c) under the Exchange Act (a “Rule 10b5-1 Plan”). During the three months ended December 31, 2023, three of the Company’s Section 16 officers, including the Company’s Chief Executive Officer, who also serves as a member of the Company’s board of directors, adopted new Rule 10b5-1 Plans. The Plans (as defined below) were entered into during an open trading window in accordance with the Company’s Insider Trading Policy and Trading Plan Policy. On October 3, 2023, Jeremy Bender, our Chief Executive Officer and a member of our board of directors, entered into a pre-arranged written stock sale plan in accordance with Rule 10b5-1 (the “Bender Rule 10b5-1 Plan”) under the Exchange Act for the sale of shares of our common stock. The Bender Rule 10b5-1 Plan was entered into during an open trading window in accordance with our policies regarding transactions in our securities and is intended to satisfy the affirmative defense of Rule 10b5-1(c) under the Exchange Act. The Bender Rule 10b5-1 Plan provides for the potential sale of shares of our common stock, including upon the vesting and settlement of restricted stock units/vesting and exercise of stock options, so long as the market price of our common stock is higher than certain minimum threshold prices specified in the Bender Rule 10b5-1 Plan, between January 2, 2024 and October 5, 2024. The aggregate number of shares of common stock that will be available for sale under the Bender Rule 10b5-1 Plan is not yet determinable because the shares available will be net of shares sold to satisfy tax withholding obligations that arise in connection with the vesting and settlement of such restricted stock unit awards. As such, for purposes of this disclosure, the aggregate number of shares of common stock available for sale is approximately 496,250, which reflects the aggregate maximum number of shares underlying Jeremy Bender’s restricted stock units which may be sold, without excluding the shares that will be sold to satisfy the tax withholding obligations. The Bender Rule 10b5-1 Plan expires on October 5, 2024. On October 10, 2023, Samuel Blackman, our Head of Research and Development, entered into a pre-arranged written stock sale plan in accordance with Rule 10b5-1 (the “Blackman Rule 10b5-1 Plan”) under the Exchange Act for the sale of shares of our common stock. The Blackman Rule 10b5-1 Plan was entered into during an open trading window in accordance with our policies regarding transactions in our securities and is intended to satisfy the affirmative defense of Rule 10b5-1(c) under the Exchange Act. The Blackman Rule 10b5-1 Plan provides for the potential sale of shares of our common stock, including upon the vesting and settlement of restricted stock units, so long as the market price of our common stock is higher than certain minimum threshold prices specified in the Blackman Rule 10b5-1 Plan, between January 9, 2024 and December 31, 2024. As such, for purposes of this disclosure, the aggregate number of shares of common stock available for sale is approximately 360,000. The Blackman Rule 10b5-1 Plan expires on December 31, 2024. On October 6, 2023, Charles York, our Chief Financial Officer, entered into a pre-arranged written stock sale plan in accordance with Rule 10b5-1 (the “York Rule 10b5-1 Plan” and collectively with the Bender Rule 10b5-1 Plan and Blackman Rule 10b5-1 Plan, the “Plans”) under the Exchange Act for the sale of shares of our common stock. The York Rule 10b5-1 Plan was entered into during an open trading window in accordance with our policies regarding transactions in our securities and is intended to satisfy the affirmative defense of Rule 10b5-1(c) under the Exchange Act. The York Rule 10b5-1 Plan provides for the potential sale of shares of our common stock, including upon the vesting and settlement of restricted stock units/vesting and exercise of stock options, so long as the market price of our common stock is higher than certain minimum threshold prices specified in the York Rule 10b5-1 Plan, between January 5, 2024 and October 10, 2024. The aggregate number of shares of common stock that will be available for sale under the York Rule 10b5-1 Plan is not yet determinable because the shares available will be net of shares sold to satisfy tax withholding obligations that arise in connection with the vesting and settlement of such restricted stock unit awards. As such, for purposes of this disclosure, the aggregate number of shares of common stock available for sale is approximately 228,743, which reflects the aggregate maximum number of shares underlying Charles York’s restricted stock units which may be sold, without excluding the shares that will be sold to satisfy the tax withholding obligations. The York Rule 10b5-1 Plan expires on October 10, 2024.
Jeremy Bender [Member]
Trading Arrangements, by Individual
Name	Jeremy Bender
Title	Chief Executive Officer and a member of our board of directors
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	October 3, 2023
Rule 10b5-1 Arrangement Terminated	false
Arrangement Duration	277 days
Aggregate Available	496,250
Expration Date	October 5, 2024
Samuel Blackman [Member]
Trading Arrangements, by Individual
Name	Samuel Blackman
Title	Head of Research and Development
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	October 10, 2023
Rule 10b5-1 Arrangement Terminated	false
Arrangement Duration	357 days
Aggregate Available	360,000
Expration Date	December 31, 2024
Charles York [Member]
Trading Arrangements, by Individual
Name	Charles York
Title	Chief Financial Officer
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	October 6, 2023
Rule 10b5-1 Arrangement Terminated	false
Arrangement Duration	279 days
Aggregate Available	228,743
Expration Date	October 10, 2024

Income Taxes - Summary of Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Balance at beginning of year	$ 2,535	$ 1,141	$ 188
Additions based on tax positions related to prior year	29	726	0
Additions based on tax positions related to current year	872	916	953
Reductions based on tax positions related to prior year	(802)	(248)	0
Reductions based on tax positions related to current year	0	0	0
Balance at end of year	$ 2,634	$ 2,535	$ 1,141

Commitments and Contingencies

12 Months Ended

Dec. 31, 2023

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

Leases

The Company entered into a lease agreement for its corporate office facility in South San Francisco, California in March 2020. Such agreement was determined to be a lease, since the right to control the use of the identified asset was conveyed to the Company for a period of time in exchange for consideration. The Company can extend the lease term for an additional three years at market rates upon the notice of extension. The Company is obligated to pay monthly rent expense and its pro rata share of utilities, common area maintenance expenses, and property taxes. The landlord also provided an allowance of $10,000 for tenant improvements. The Company concluded that it is an operating lease. Common area expenses are a non-lease component and a variable consideration and included in operating expenses as incurred. The extension period has not been included in the determination of the Right of Use, or ROU, asset or the lease liability for operating leases as the Company concluded that it is not reasonably certain that it would exercise this option. In October 2022, the Company terminated this lease agreement prior to its scheduled expiration in January 2023.

In April 2022, the Company entered into a lease agreement for approximately 12,000 square feet of general use office space in Brisbane, California. Such agreement was determined to be a lease since the right to control the use of the identified asset was conveyed to the Company for a period of time in exchange for consideration. The term of the lease is 31 months and commenced in May 2022. There is no option to extend the lease term nor is there an option to terminate the lease term prior to its expiration. The Company is obligated to pay monthly rent expense and its pro rata share of the landlord's operating expenses which include utilities, common area maintenance expenses, and property taxes. Such expenses are a non-lease component and a variable consideration and included in the Company's operating expenses as incurred. The Company concluded that this lease is also an operating lease. The total payments for base rent over the term of the lease is approximately $1.1 million. Upon execution of the agreement, the Company paid a security deposit of approximately $40,000 classified as deposits and other long-term assets on the consolidated balance sheet.

The Company determined the lease incremental borrowing rate, or IBR, based on the information available at the applicable lease commencement date as the Company’s leases do not provide an implicit rate. The IBR is determined by using the rate of interest that the Company would pay to borrow on a collateralized basis an amount equal to the lease payments for a similar term and in a similar economic environment where the asset is located. As of December 31, 2023, the weighted-average remaining lease term and weighted-average discount rate were 0.9 years and 9.0%, respectively.

The Company’s lease does not require any contingent rental payments, impose financial restrictions, or contain any residual value guarantees.

Lease expense of right-of-use assets is recognized on a straight-line basis over the applicable lease term. Lease expense was $0.4 million, $0.5 million and $0.2 million for the years ended December 31, 2023, 2022 and 2021,

respectively. Cash paid for amounts included in the measurement of operating lease liabilities was $0.5 million, $0.4 million and $0.2 million for the years ended December 31, 2023, 2022 and 2021, respectively. Variable payments expensed during the years ended December 31, 2023, 2022, and 2021 were immaterial.

As of December 31, 2023, the future lease obligations were as follows (in thousands):


	December 31, 2023
2024	$	424
Total future minimum lease payments		424
Less: Imputed interest		(16	)
Present value of operating lease liabilities		408
Less: current portion of operating lease liabilities		(408	)
Operating lease liabilities	$	-

Research and Development Agreements

The Company enters into contracts in the normal course of business with clinical research organizations, contract manufacturing organizations, and other third-party vendors for clinical trial, manufacturing, testing, and other research and development activities. These contracts generally provide for termination on notice, with the exception of one vendor where certain costs are non-cancellable after the approval of the project. As of December 31, 2023 and 2022, there were no amounts accrued related to termination and cancellation charges as these are not probable.

License Agreements

The Company entered into the license agreements, as disclosed in Note 5, pursuant to which the Company is required to pay milestones contingent upon meeting specific events. The first milestone of $3.0 million, related to the Viracta License Agreement, was achieved and recorded to research and development expense during the year ended December 31, 2021. The first milestone of $2.5 million, related to the MRKDG License Agreement, was achieved and recorded to research and development during the year ended December 31, 2022. The second milestone of $5.0 million, related to the Viracta License Agreement, was achieved and recorded to research and development expense during the year ended December 31, 2023. The Company may be required to pay royalties on sales of products developed under these agreements. All products are in development as of December 31, 2023 and no such royalties were due.

Purchase Commitments

To support product needs for tovorafenib, the Company has entered into a manufacturing and supply agreement with Quotient Sciences - Philadelphia, LLC in July 2023 that requires the Company to meet minimum purchase obligations on an annual basis. The amount of future minimum purchase obligations under the manufacturing and supply agreement over the next five years is approximately $17.2 million, in aggregate, as of December 31, 2023. For the year ended December 31, 2023, the Company has not yet made any purchases under the purchase obligation.

Legal Proceedings

The Company, from time to time, may be party to litigation, claims and assessments arising in the ordinary course of business. The Company accrues liabilities for such matters when it is probable that future expenditures will be made and such expenditures can be reasonably estimated. The Company is not subject to any material legal proceedings, and to the best of its knowledge, no material legal proceedings are currently pending or threatened.

Indemnification Agreements

In the normal course of business, the Company enters into contracts and agreements that contain a variety of representations and warranties and provide for indemnification for certain liabilities. The exposure under these agreements is unknown because it involves claims that may be made against it in the future but have not yet been made. To date, the Company has not paid any claims or been required to defend any action related to its indemnification obligations. However, the Company may record charges in the future as a result of these indemnification obligations. The Company also has indemnification obligations to its directors and executive officers for specified events or occurrences, subject to some limits, while they are serving at its request in such

capacities. There have been no claims to date, and the Company believes the fair value of these indemnification agreements is minimal. Accordingly, the Company had not recorded any liabilities for these agreements as of December 31, 2023 and 2022.

Common Stock (Tables)

12 Months Ended

Dec. 31, 2023

Stockholders' Equity Note [Abstract]

Schedule of Common Stock Shares Reserved for Future Issuance

The Company has reserved shares of common stock for future issuances as follows:


	December 31, 2023
Common stock options issued and outstanding		10,211,758
Common stock available for future grants		2,603,444
Common stock available for ESPP		1,720,916
Restricted stock units issued and outstanding		1,031,545
Total		15,567,663

Share-Based Compensation

12 Months Ended

Dec. 31, 2023

Share-Based Payment Arrangement [Abstract]

Share-based Compensation

9. Share-based Compensation

Share-based compensation expense recorded in the accompanying consolidated statements of operations is as follows (in thousands):


	Year Ended December 31,
	2023		2022		2021
Research and development expense	$	14,381	$	8,486	$	3,840
General and administrative expense		24,960		18,756		9,481
Total share-based compensation expense	$	39,341	$	27,242	$	13,321

As of December 31, 2023, there was $78.9 million of unrecognized compensation cost related to unvested restricted stock, unvested restricted stock units, unvested stock options, and shares subject to purchase under the ESPP that is expected to be recognized over a weighted-average period of approximately 2.5 years.

As of December 31, 2023, there was $1.3 million of unrecognized compensation cost related to unvested performance stock options, or PSOs, and performance stock units, or PSUs. The Company will recognize the PSO and PSU expense through the expected vesting dates when the achievement of the performance-based metrics is probable.

2022 Equity Inducement Plan

In October 2022, the Company's board of directors approved the 2022 Equity Inducement Plan, or the 2022 Plan. The 2022 Plan provides for the grant of non-statutory stock options and restricted stock units. The number of shares of common stock reserved for issuance under the 2022 Plan is 1,000,000 shares.

The following table provides a summary of stock option activity under the 2022 Plan during the year ended December 31, 2023.


	Options		Weighted-Average Exercise Price Per Share		Weighted-Average Remaining Contractual Term		Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2022		309,000	$	21.14
Granted		—	$	—
Exercised		—	$	—			$	—
Forfeiture		—	$	—
Outstanding at December 31, 2023		309,000	$	21.14		8.8	$	—
Vested and expected to vest at December 31, 2023		309,000	$	21.14		8.8	$	—
Exercisable at December 31, 2023		90,124	$	21.14		8.8	$	—

Aggregate intrinsic value represents the difference between the estimated fair value of the underlying common stock and the exercise price of outstanding, in-the-money options.

The total fair value of options that vested during the year ended December 31, 2023 was $1.4 million. There were no options vested during the years ended December 31, 2022 and 2021. There were no options granted during the years ended December 31, 2023 and 2021. The weighted-average grant date fair value of options granted during the year ended December 31, 2022 was $15.08 per share.

Unrecognized share-based compensation for stock options as of December 31, 2023 was $3.3 million, which is expected to be recognized over a weighted-average period of 2.8 years.

The Company used the Black-Scholes option pricing model to estimate the fair value of stock options awards granted with the following assumptions:


	Year Ended December 31,
	2023	2022	2021
Expected term (in years)	—	6.08	—
Expected volatility	—	79.53%	—
Risk-free interest rate	—	4.18%	—
Expected dividend yield	—	—	—

The following table provides a summary of restricted stock units activity under the 2022 Plan during the year ended December 31, 2023:


	Number of Shares			Weighted Average Grant Date Fair Value Per Share
Unvested restricted stock units at December 31, 2022		47,400		$	21.14
Granted		—		$	—
Vested		(11,850	)	$	21.14
Forfeiture		—		$	—
Unvested restricted stock units at December 31, 2023		35,550		$	21.14

Unrecognized share-based compensation for restricted stock units as of December 31, 2023 was $0.7 million, which is expected to be recognized over a weighted-average period of 2.9 years.

2021 Equity Incentive Plan

Immediately prior to consummation of the IPO, all the outstanding incentive shares were converted into common stock awards. The following table provides a summary of the unvested common stock awards activity during the year ended December 31, 2023.


	Number of Shares			Weighted Average Grant Date Fair Value Per Share
Unvested common stock as of December 31, 2022		1,722,744		$	16.00
Vested		(953,665	)	$	16.00
Forfeiture		(21,400	)	$	16.00
Unvested common stock as of December 31, 2023		747,679		$	16.00

In May 2021, in connection with the IPO, the board of directors and stockholders approved the 2021 Equity Incentive Plan, or the 2021 Plan, which became effective on the day before the date of the effectiveness of the IPO. The 2021 Plan provides for the grant of incentive stock options, non-statutory stock options, stock appreciation rights, awards of restricted stock, restricted stock units and other share-based awards. The number of shares of common stock reserved for issuance under the 2021 Plan is equal to the sum of: (x) 6,369,000 shares of common stock; plus (y) 4,719,605 shares of common stock issued in respect of the Conversion of incentive shares that were subject to vesting immediately prior to the effectiveness of the registration statement for the IPO that expire, terminate or are otherwise surrendered, canceled, forfeited or repurchased by us at their original issuance price pursuant to a contractual repurchase right. The number of shares available for grant and issuance under the 2021 Plan will be automatically increased on the first day of each fiscal year, beginning with the fiscal year commencing on January 1, 2021 and continuing for each fiscal year until, and including, the fiscal year commencing on January 1, 2031, by the lesser of (a) 5% of the number of shares of all classes of the Company’s common stock, plus the total number of shares of Company common stock issuable upon conversion of any preferred stock or exercise of any warrants to acquire shares of Company common stock for a nominal exercise price issued and outstanding on each December 31 immediately prior to the date of increase or (b) such number of shares determined by the board of directors.

The following table provides a summary of stock option activity under the 2021 Plan during the year ended December 31, 2023.


	Options			Weighted-Average Exercise Price Per Share		Weighted-Average Remaining Contractual Term		Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2022		7,634,167		$	16.42
Granted		2,653,000		$	18.83
Exercised		(88,459	)	$	15.12			$	643
Forfeiture		(439,450	)	$	18.30
Outstanding at December 31, 2023		9,759,258		$	17.00		8.2	$	3,260
Vested and expected to vest at December 31, 2023		9,759,258		$	17.00		8.2	$	3,260
Exercisable at December 31, 2023		4,602,684		$	16.74		7.8	$	904

Aggregate intrinsic value represents the difference between the estimated fair value of the underlying common stock and the exercise price of outstanding, in-the-money options.

The total fair value of options that vested during the years ended December 31, 2023, 2022, and 2021 were $27.3 million, $23.1 million and $1.1 million, respectively. The weighted-average grant date fair value of options granted during the years ended December 31, 2023, 2022, and 2021 were $13.14 per share, $9.61 per share, and $9.91 per share, respectively.

Unrecognized share-based compensation for stock options as of December 31, 2023 was $54.7 million, which is expected to be recognized over a weighted-average period of 2.4 years.

The Company used the Black-Scholes option pricing model to estimate the fair value of stock options awards granted with the following assumptions:


	Year Ended December 31,
	2023	2022	2021
Expected term (in years)	5.27 - 6.25	5.27 - 6.33	5.31 - 6.08
Expected volatility	68.74% - 81.98%	65.20% - 81.68	61.25% - 66.53%
Risk-free interest rate	3.47% - 4.67%	1.47% - 4.37%	0.82% - 1.39%
Expected dividend yield	—	—	—

The following table provides a summary of restricted stock units activity under the 2021 Plan during the year ended December 31, 2023:


	Number of Shares			Weighted Average Grant Date Fair Value Per Share
Unvested restricted stock units at December 31, 2022		485,351		$	16.83
Granted		777,010		$	19.73
Vested		(258,770	)	$	19.44
Forfeiture		(54,221	)	$	20.09
Unvested restricted stock units at December 31, 2023		949,370		$	18.31

Unrecognized share-based compensation for restricted stock units as of December 31, 2023 was $16.1 million, which is expected to be recognized over a weighted-average period of 2.9 years.

Performance Awards

In June 2022, the Company granted performance awards, consisting of PSOs and PSUs to non-executive employees pursuant to the 2021 Plan. Each performance award is earned through the achievement of a performance-based metric over a defined performance period determined by the compensation committee of the Company's board of directors. The estimated fair value of the equity awards that contain a performance condition is recognized if and when the Company concludes that it is probable that the performance condition will be achieved.

The following table provides a summary of PSO activity under the 2021 Plan during the year ended December 31, 2023.


	Options			Weighted-Average Exercise Price Per Share		Weighted-Average Remaining Contractual Term		Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2022		146,950		$	15.25
Granted		—		$	—
Exercised		—		$	—			$	—
Forfeiture		(3,450	)	$	15.25
Outstanding at December 31, 2023		143,500		$	15.25		8.5	$	—
Vested and expected to vest at December 31, 2023		71,750		$	15.25		8.5	$	—
Exercisable at December 31, 2023		71,750		$	15.25		8.5	$	—

Aggregate intrinsic value represents the difference between the estimated fair value of the underlying common stock and the exercise price of outstanding, in-the-money PSOs.

The total fair value of PSOs that vested during the year ended December 31, 2023 was $0.5 million. There was no fair value of PSOs that vested during each of the years ended December 31, 2022 and 2021.There was no weighted-average grant date fair value of PSOs granted since there were no PSOs granted during the years ended December 31, 2023 and 2021. The weighted-average grant date fair value of PSOs granted during the year ended December 31, 2022 was $7.78 per share.

As of December 31, 2023, there was $0.6 million of unrecognized compensation cost related to unvested PSOs. The Company will recognize the PSO expense through the expected vesting dates when the achievement of the performance-based metrics is probable.

The Company used the Black-Scholes option pricing model to estimate the fair value of the PSO awards granted with the following assumptions:


	Year Ended December 31,
	2023	2022	2021
Expected term (in years)	—	2.92 - 3.42	—
Expected volatility	—	72.72% - 72.98%	—
Risk-free interest rate	—	3.37%	—
Expected dividend yield	—	—	—

The following table provides a summary of PSU activity under the 2021 Plan during the year ended December 31, 2023:


	Number of Shares			Weighted Average Grant Date Fair Value Per Share
Unvested restricted stock units at December 31, 2022		95,500		$	15.25
Granted		—		$	—
Vested		(46,625	)	$	15.25
Forfeiture		(2,250	)	$	15.25
Unvested restricted stock units at December 31, 2023		46,625		$	15.25

As of December 31, 2023, there was $0.7 million of unrecognized compensation cost related to unvested PSUs. The Company will recognize the PSU expense through the expected vesting dates when the achievement of the performance-based metrics is probable.

2021 Employee Stock Purchase Plan

In May 2021, the board of directors adopted and the stockholders approved the 2021 Employee Stock Purchase Plan, or the ESPP, which became effective on May 26, 2021. A total of 603,000 shares of common stock were initially reserved for issuance under the ESPP. The number of shares of the common stock reserved for issuance under the ESPP will automatically increase on the first day of each fiscal year, beginning with the fiscal year commencing on January 1, 2021 and continuing for each fiscal year until, and including, the fiscal year commencing on January 1, 2031, by the lesser of: (a) 1% of the total number of outstanding shares of common stock of the Company (on an as converted basis outstanding on the immediately preceding December 31 (rounded down to the nearest whole share) and (b) an amount determined by the board of directors. 236,187 shares have been issued under the ESPP as of December 31, 2023. The Company recognized $0.8 million, $0.5 million, and $0.2 million of compensation expense related to the ESPP plan for the years ended December 31, 2023, 2022, and 2021, respectively.

The fair value of our common stock to be issued under the ESPP is estimated at the date of grant using a Black-Scholes option-pricing model with the following assumptions:


	Year Ended December 31,
	2023	2022	2021
Expected term (in years)	0.5	0.5	0.25 - 0.50
Expected volatility	55.91%	128.95%	42.5% - 48.4%
Risk-free interest rate	5.41%	4.54%	0.05% - 0.06%
Expected dividend yield	—	—	—

Incentive Share Plan

Prior to the Conversion, Day One Holding LLC granted incentive shares under the Incentive Share Plan and was authorized to issue 8,924,177 incentive shares. Incentive shares were a separate non-voting class of shares that participated in distributions only after incentive shares vested, unless it was approved by the board of directors and included at least two of the preferred members, and a participation threshold was met. The incentive shares represented profits interests in Day One Holding LLC, which was an interest in the increase in the Company’s value over the participation threshold, as defined in its operating agreement and as determined at the time of grant. A holder of incentive shares had the right to participate in distributions of profits only in excess of the participation threshold. The participation threshold was based on the valuation of the Company’s common shares on or around the grant date.

The fair value of the incentive shares was estimated using an option pricing model with the following assumptions:


		Year Ended December 31,
		2021
Common share fair value		$6.36 - $8.89
Participating threshold		$6.36 - $7.51
Risk free rate		0.14%
Volatility		72.90%
Time to liquidity (in years)		0.20 - 1.80
Grant date fair value		$4.24 - $4.52

During the Conversion, the Company converted all incentive shares to vested and unvested shares of common stock. As such, there was no incentive shares activity for the year ended December 31, 2023.

The Company used the option pricing model to estimate the fair value of each incentive shares award on the date of grant. The members’ equity value was based on a recent enterprise valuation analysis performed and common share fair value. The participation threshold amounts were determined by the board of directors at the time of grant. The expected life of the awards granted during the period was determined based on an expected time to the

liquidation event. The Company applied the risk-free interest rate based on the U.S. Treasury yield in effect at the time of the grant.

Fair Value of Common Share

Prior to the IPO, management’s approach to estimate the fair value of the common share was consistent with the methods outlined in the American Institute of Certified Public Accountants’ Practice Aid, Valuation of Privately-Held-Company Equity Securities Issued as Compensation, or the Practice Aid, considering a number of objective and subjective factors including: valuations of common shares performed with the assistance of independent third-party valuation specialists; the Company’s stage of development and business strategy, including the status of research and development efforts, and the material risks related to the business and industry; the Company’s results of operations and financial position, including levels of available capital resources; the valuation of publicly traded companies in the life sciences and biotechnology sectors, as well as recently completed mergers and acquisitions of peer companies; the lack of marketability of the common shares; the prices of redeemable convertible preferred shares sold to investors in arm’s length transactions and the rights, preferences, and privileges of the Company’s redeemable convertible preferred shares relative to those of common shares; the likelihood of achieving a liquidity event for the holders of the common and redeemable convertible preferred shares, such as an initial public offering or a sale, given prevailing market conditions. The fair value of the common shares was approved by the board of directors until such time as the Company shares were listed on an established stock exchange or national market system.

The incentive shares were classified as equity awards and share-based compensation expense was based on the grant date fair value of the award.

The following table provides a summary of the incentive shares activity:


	Number of Shares			Weighted Average Grant Date Fair Value
Outstanding as of December 31, 2020		4,112,017		$	1.26
Granted		2,959,795		$	4.32
Forfeited		(265,596	)	$	1.67
Converted to unvested common stock		(6,806,216	)	$	2.58
Outstanding as of December 31, 2021		—		$	—

Accrued Expenses and Other Current Liabilities (Tables)

12 Months Ended

Dec. 31, 2023

Disclosure Text Block [Abstract]

Schedule of Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consisted of the following (in thousands):


	December 31, 2023		December 31, 2022
Accrued research and development expenses	$	12,643	$	7,554
Accrued payroll related expenses		9,165		6,129
Accrued professional service expenses		3,675		2,088
Other		1,041		179
Total accrued expenses and other current liabilities	$	26,524	$	15,950

Summary of Significant Accounting Policies (Policies)	12 Months Ended
Summary of Significant Accounting Policies (Policies)	Dec. 31, 2023
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States of America, or U.S. GAAP, and include the accounts of the Company’s subsidiaries. All intercompany transactions and balances have been eliminated in consolidation. Prior to December 31, 2021, the Company consolidated its Subsidiaries. Effective December 31, 2021, the Company's board of directors approved the Merger of the Subsidiaries with and into the Company, with the Company being the surviving corporation (refer to the section “Organization and Business”). Because the Merger did not constitute a change in the reporting entity, as defined in Accounting Standard Codification, or ASC, 250, Accounting changes and error corrections, the Company has reported the assets and liabilities transferred from its Subsidiaries at historical carrying value, prospectively from December 31, 2021. Subsequent to December 31, 2021, amounts presented in the financial statements are unconsolidated as the Company had no subsidiaries. Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in ASC and Accounting Standards Updates, or ASU, of the Financial Accounting Standards Board, or FASB.
Going Concern	Going Concern The Company assesses and determines its ability to continue as a going concern in accordance with the provisions of ASC Topic 205-40, Presentation of Financial Statements—Going Concern, which requires the Company to evaluate whether there are conditions or events that raise substantial doubt about its ability to continue as a going concern within one year after the date that its annual and interim financial statements are issued. Certain additional financial statement disclosures are required if such conditions or events are identified. Determining the extent, if any, to which conditions or events raise substantial doubt about the Company’s ability to continue as a going concern, or the extent to which mitigating plans sufficiently alleviate any such substantial doubt, as well as whether or not liquidation is imminent, requires significant judgment by management.
Use of Estimates	Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements, and the reported amounts of expenses during the reporting period. Estimates and assumptions made in the accompanying consolidated financial statements include, but are not limited to, the valuation of share-based awards, the valuation of deferred tax assets and income tax uncertainties, and accruals for research and development activities. The Company bases its estimates on historical experience and on various other assumptions that are believed to be reasonable. Actual results may differ from those estimates or assumptions.
Segments	Segments The Company has determined that its chief executive officer is the chief operating decision maker, or CODM. The Company operates and manages the business as one reporting and one operating segment, which is the business of identifying and advancing targeted therapies for people of all ages with genomically defined cancers. The Company’s CODM reviews financial information on an aggregate basis for purposes of allocating resources and evaluating financial performance. All of the Company’s assets are located in the United States.
Concentration of credit risk and other risks and uncertainties	Concentration of credit risk and other risks and uncertainties Financial instruments that subject the Company to significant concentrations of credit risk consist primarily of cash, cash equivalents and short-term investments. Amounts on deposit may at times exceed federally insured limits. The Company is exposed to credit risk in the event of default by the financial institutions holding its cash, cash equivalents and short-term investments that are recorded on its balance sheet. Per policy, the Company mitigates its risk by investing in high-grade instruments and limiting the concentration in any one issuer, which limits its exposure. The Company has not experienced any losses on its cash, cash equivalents and short-term investments. The Company is subject to certain risks and uncertainties and believes that changes in any of the following areas could have a material adverse effect on the Company's future financial position or results of its operations: ability to obtain future financing; regulatory requirements for approval and market acceptance of, and reimbursement for, product candidates; performance of third-party clinical research organizations and manufacturers upon which the Company relies; development of sales channels; protection of the Company’s intellectual property; litigation or claims against the Company based on intellectual property, patent, product, regulatory or other factors; changes to the market landscape; and the Company’s ability to attract and retain employees necessary to support its growth. The Company is dependent on third-party manufacturers to supply products for research and development activities in its programs. In particular, the Company relies and expects to continue to rely on a small number of manufacturers to supply it with its requirements for the active pharmaceutical ingredients and formulated drugs related to these programs. These programs could be adversely affected by a significant interruption in the supply of active pharmaceutical ingredients and formulated drugs.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity of three months or less at the time of purchase to be cash equivalents. The Company’s cash equivalents consist of investments in money market funds, U.S. government agency securities, and U.S. treasury securities. Cash equivalents are recognized at amortized cost, which approximates fair value.
Investments	Investments The Company’s investments are comprised of U.S. treasury securities and U.S. government agency securities. Investments are classified at the time of purchase, based on management’s intent, as held-to-maturity, available-for-sale, or trading. All of the Company’s investments are classified as available-for-sale. Available-for-sale securities are carried at estimated fair value with unrealized holdings gains and losses (net of tax effects) on such investments reported in other comprehensive income as a separate component on the consolidated statements of comprehensive loss. Fair value is determined based on quoted market rates when observable or by utilizing data points that are observable, such as quoted prices, interest rates, and yield curves. For available-for-sale securities, the Company determines if any impairment is related to credit loss or non-credit loss. In making the assessment of whether a loss is from credit or other factors, management considers the extent to which fair value is less than amortized cost, any changes to the rating of the security by a rating agency and adverse conditions related to the security, among other factors. If this assessment indicates that a credit loss exists, the present value of cash flows expected to be collected from the security are compared to the amortized cost basis of the security. If the present value of cash flows is less than the amortized cost basis, a credit loss exists and an allowance is created, limited by the amount that the fair value is less than amortized cost basis. Subsequent activity related to the credit loss component in the form of write-offs or recoveries is recognized as part of the allowance for credit losses on available-for-sale securities.
Fair Value of Financial Instruments	Fair Value of Financial Instruments Assets and liabilities recorded at fair value on a recurring basis in the consolidated balance sheets are categorized based upon the level of judgment associated with the inputs used to measure their fair values. Fair value is defined as the exchange price that would be received for an asset or an exit price that would be paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The authoritative guidance on fair value measurements establishes a three-tier fair value hierarchy for disclosure of fair value measurements as follows: Level 1—Observable inputs such as unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date; Level 2—Inputs (other than quoted prices included in Level 1) are either directly or indirectly observable for the asset or liability. These include quoted prices for similar assets or liabilities in active markets and quoted prices for identical or similar assets or liabilities in markets that are not active; and Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The carrying amounts reflected in the accompanying consolidated balance sheets for cash equivalents, prepaid expenses, other current assets, accounts payable, accrued expenses and other current liabilities approximate their fair values, due to their short-term nature.
Property and Equipment, Net	Property and Equipment, Net Property and equipment are recorded at cost, less accumulated depreciation and amortization. Depreciation is recognized using the straight-line method over the estimated useful lives of the related assets ranging from three to five years, and leasehold improvements are amortized over the shorter of the lease term or the estimated useful life of the asset. As of December 31, 2023 and 2022, property and equipment, net was not material. Depreciation expense for each of the years ended December 31, 2023, 2022, and 2021 was immaterial.
Leases	Leases Contractual arrangements that meet the definition of a lease are classified as operating or finance leases and are recorded on the consolidated balance sheets as both a right-of-use asset, or ROU asset, and lease liability, calculated by discounting fixed lease payments over the lease term at the rate implicit in the lease or the Company’s incremental borrowing rate, or IBR. Lease ROU assets and lease obligations are recognized based on the present value of the future minimum lease payments over the lease term at commencement date. The Company currently does not have any finance leases. Operating lease ROU assets are adjusted for (i) payments made at or before the commencement date, (ii) initial direct costs incurred, and (iii) tenant incentives under the lease. As the implicit rate for the operating leases are not determinable, the Company determines its IBR based on the information available at the applicable lease commencement date. The IBR is determined by using the rate of interest that the Company would pay to borrow on a collateralized basis an amount equal to the lease payments for a similar term and in a similar economic environment where the asset is located. The Company considers a lease term to be the noncancelable period that it has the right to use the underlying asset, including any periods where it is reasonably certain the Company will exercise any option to extend the contract. Lease costs for minimum lease payments for operating leases are recognized on a straight-line basis over the lease term. Lease liabilities are increased by interest and reduced by payments each period, and the ROU asset is amortized over the lease term. Variable lease costs are recorded when incurred. In measuring the ROU assets and lease liabilities, the Company has elected to combine lease and non-lease components. The Company excludes short-term leases, if any, having initial terms of 12 months or less at lease commencement as an accounting policy election, and recognizes rent expense on a straight-line basis over the lease term for these types of leases.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets The Company evaluates its long-lived asset group, which consist of property and equipment and right-of-use assets, for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to the future undiscounted net cash flows expected to be generated by the asset. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the carrying amount of the asset exceeds the fair value of the asset. To date, no impairments have been recognized in the consolidated financial statements.
Research and Development Expenses	Research and Development Expenses Research and development expenses consist of costs associated with acquiring technology and intellectual property licenses that have no alternative future uses; costs incurred under agreements with third-party contract research organizations, contract manufacturing organizations and other third parties that conduct clinical trials on the Company’s behalf; other costs associated with research and development programs, including laboratory materials and supplies; employee-related costs, including salaries, benefits and share-based compensation expense, for the Company’s research and development personnel; and facilities and other overhead expenses, including expenses for rent and facilities maintenance, and amortization. The Company expenses research and development costs as incurred. The Company is obligated to make upfront payments upon execution of certain research and development agreements. Advance payments, including nonrefundable amounts, for goods or services that will be used or rendered for future research and development activities are deferred. Such amounts are recognized as expense as the related goods are delivered or the related services are performed, or such time when the Company does not expect the goods to be delivered or services to be performed.
Accrued Research and Development Expenses	Accrued Research and Development Expenses The Company records accrued liabilities for estimated costs of our clinical trials conducted by third-party service providers. The Company records the estimated costs of the clinical trials as research and development expense based upon the estimated amount of services provided but not yet invoiced. The Company accrues for these costs based on factors such as estimates of the work completed and in accordance with terms established with third-party service providers under the service agreements. The Company makes judgments and estimates in determining the accrued liabilities balance in each reporting period. As actual costs become known, the Company adjusts its accrued liabilities. The Company has not experienced any material differences between accrued costs and actual costs incurred. The Company makes payments in connection with the clinical trials under contracts with contract research organizations who conduct and manage our clinical trials. The financial terms of these contracts are subject to negotiation, which vary by contract and may result in payments that do not match the periods over which materials or services are provided. Generally, these agreements set forth the scope of work to be performed at a fixed fee, unit price or on a time and materials basis. In the event the Company makes advance payments for goods or services that will be used or rendered for future research and development activities, the payments are deferred and capitalized as a prepaid expense and recognized as expense as the goods are received or the related services are rendered. Such payments are evaluated for current or long-term classification based on when they are expected to be realized.
Patent Costs	Patent Costs All patent-related costs incurred in connection with filing and prosecuting patent applications are expensed as incurred due to the uncertainty of the recovery of the expenditure. Amounts incurred are classified as general and administrative expenses in the consolidated statements of operations.
Redeemable Convertible Preferred Shares	Redeemable Convertible Preferred Shares The Company recorded redeemable convertible preferred shares at their respective fair values on the dates of issuance, net of issuance costs. The redeemable convertible preferred shares were recorded outside of members’ deficit because while they were not mandatorily redeemable, in the event of a deemed liquidation event, which was outside of the Company’s control, the proceeds were distributed first to the redeemable convertible preferred stockholders in accordance with their liquidation preferences. The Company had not adjusted the carrying values of the redeemable convertible preferred shares to their liquidation preferences because it is uncertain whether or when a deemed liquidation event would occur that would obligate it to pay the liquidation preferences to holders of redeemable convertible preferred shares. Redeemable convertible preferred shares were all converted to common stock shares upon the closing of the IPO in May 2021.
Redeemable Noncontrolling Interest	Redeemable Noncontrolling Interest Redeemable noncontrolling interest represented the portion of equity (net assets) in DOT-1 that was neither directly nor indirectly attributable to the Company. Redeemable noncontrolling interest is classified as temporary equity because preferred shares issued to a holder contained certain redemption features that were not solely within the control of the Company. Redeemable noncontrolling interest was extinguished as part of the Exchange in May 2021.
Share-Based Compensation	Share-Based Compensation Prior to the IPO, the Company recognized share-based compensation expense based on the estimated fair value of all share-based awards, incentive shares and restricted share awards, on the date of grant using the option-pricing model. The option-pricing model requires the input of subjective assumptions, including the fair value of the underlying common shares, the expected term of the award, the expected volatility, risk-free interest rates, and the dividend yield. In determining the fair value of common shares, the methodologies used to estimate the enterprise value were performed using methodologies, approaches, and assumptions consistent with the American Institute of Certified Public Accountants Accounting and Valuation Guide, Valuation of Privately-Held-Company Equity Securities Issued as Compensation. The participation threshold amounts for the profit interest in the LLC were determined by the board of directors, at the time of grant. The expected life of the awards granted during the period was determined based on an expected time to the liquidation event. The Company applied the risk-free interest rate based on the U.S. Treasury yield in effect at the time of the grant consistent with the life of the award. The expected volatility was based on a peer group in the industry in which the Company did business consistent with the expected time to liquidity. The dividend yield was set at zero as the underlying security did not and was not expected to pay a dividend. Subsequent to closing of the IPO, the Company uses the Black-Scholes valuation model to estimate the fair value of options granted to employees and non-employees, intrinsic value to estimate the fair value of restricted stock award, and fair value of the Company’s common stock at the grant date for restricted stock units. The Black-Scholes option-pricing model, used to estimate fair value of stock options awards, requires the use of the following assumptions: • Fair Value of Common Stock—The Company’s closing price on the Nasdaq market at the grant date. • Expected Term—The expected term represents the period that the share-based awards are expected to be outstanding. The expected term for stock options is calculated using the simplified method, as the weighted-average vesting term of the award and the award’s contract period (generally 10 years). The Company utilizes this method due to lack of historical exercise data and the plain-vanilla nature of the Company’s service condition share-based awards. For the Company's performance condition stock option awards, the Company calculated the expected term by taking into consideration the options' contractual life, the timing of when milestones are expected to be achieved, and the expected exercise period by a holder from the vesting date until the contractual term (generally 10 years). • Expected Volatility—Since the Company does not have sufficient trading history for its common stock, the expected volatility is estimated based on the average historical volatilities of common stock of comparable publicly traded biopharmaceutical companies over a period equal to the expected term of the stock option grants. The comparable biopharmaceutical companies are chosen based on their size, stage in the life cycle or area of specialty. The Company will continue to apply this process until sufficient historical information regarding the volatility of the common stock price becomes available. • 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 approximately equal to the expected term of the awards. • Expected Dividend Yield—The Company has never paid dividends on the common stock and has no plans to pay dividends on its common stock. Therefore, the expected dividend yield use is zero. The Company uses the straight-line attribution method for recognizing share-based compensation expense for awards with service condition. The Company recognizes share-based compensation expense for awards with performance conditions when it is probable that the condition will be met, and the award will vest. The Company recognizes forfeitures by reducing the expense in the same period the forfeitures occur. The Company classifies share-based compensation expense in the consolidated statements of operations in the same manner in which the award recipients’ payroll costs are classified or in which the award recipients’ service payments are classified.
Income Taxes	Income Taxes Prior to the IPO, the Company was treated as a partnership for tax purposes under the Internal Revenue Code with two corporate subsidiaries. Prior to the Conversion, the members of the Company, formerly Day One Biopharmaceuticals Holding Company, LLC, were taxed directly on their respective ownership interests and activity in Day One Biopharmaceuticals Holding Company, LLC. The Company’s consolidated corporate subsidiaries accounted for income taxes under the asset and liability method, as discussed below. Upon the closing of the IPO and the Conversion, the Company’s income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax base and net operating loss and tax credit carryforwards. Deferred tax assets and liabilities are determined based upon the difference between the consolidated financial statement carrying amounts and the tax basis of assets and liabilities and are measured using the enacted tax rate expected to apply to taxable income in the years in which the differences are expected to be reversed. Deferred tax assets are reduced by a valuation allowance if it is more likely than not that some portion or all of the deferred tax asset will not be realized. The uncertain income tax positions are recognized at the largest amount that is more likely than not to be sustained upon audit by the relevant taxing authority. Changes in recognition or measurement are reflected in the period in which judgment occurs. The Company’s policy is to recognize interest and penalties related to the underpayment of income taxes as a component of the provision for income taxes. To date, there have been no interest or penalties recorded in relation to unrecognized tax benefits.
Net Loss per Share	Net Loss per Share The Company calculates basic and diluted net loss per share in conformity with the two-class method required for participating securities. Under the two-class method, basic net loss per share is computed by dividing the net loss by the weighted average number of common shares outstanding during the period, without consideration of potential dilutive securities. Diluted net loss per share is computed by dividing the net loss, after adjusting it for loss attributable to redeemable noncontrolling interest, in any, by the sum of the weighted average number of common stock shares outstanding during the period plus the dilutive effects of potentially dilutive securities outstanding during the period. Potentially dilutive securities include incentive shares, unvested restricted common shares and redeemable convertible preferred shares, prior to the IPO. Potentially dilutive securities include unvested restricted stock awards, unvested restricted stock units and stock options, after the IPO. For all periods presented, diluted net loss per share is the same as basic net loss per share since the effect of including potential common stock shares is anti-dilutive and incentive shares participation thresholds were not met.
Comprehensive Loss	Comprehensive Loss Comprehensive loss represents all changes in stockholders' equity except those resulting from and distributions to stockholders. The Company’s unrealized gains and losses on available-for-sale securities represent the only component of other comprehensive loss that are excluded from the reported net loss and that are presented in the consolidated statements of comprehensive loss.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In November 2023, the FASB issued ASU No. 2023-07, Segment Reporting (Topic 280) – Improvements to Reportable Segment Disclosures, which requires incremental disclosure of segment information on an interim and annual basis. This ASU is effective for public entities for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024. Retrospective application to all prior periods presented in the financial statements is required for public entities. The Company is currently evaluating the effect of this update on its financial statement disclosures. In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740) – Improvements to Income Tax Disclosures, which enhances the transparency and decision usefulness of income tax disclosures by requiring disclosure of disaggregated income taxes paid, prescribes standard categories for the components of the effective tax rate reconciliation, and modifies other income tax-related disclosures. The ASU is effective for fiscal years beginning after December 15, 2024 and allows for adoption on a prospective basis, with a retrospective option. The Company is currently evaluating the effect of this update on its financial statement disclosures.

Redeemable Convertible Preferred Shares

12 Months Ended

Dec. 31, 2023

Temporary Equity Disclosure [Abstract]

Redeemable Convertible Preferred Shares

7. Redeemable Convertible Preferred Shares

On June 1, 2021, the Company completed its IPO, selling an aggregate of 11,500,000 shares of common stock. All outstanding redeemable convertible preferred shares were converted into 32,489,398 shares of common stock upon the completion of the IPO. As of December 31, 2023, the Company did not have any outstanding shares of redeemable convertible preferred shares.

In February 2021, the Company issued 9,638,141 Series B redeemable convertible preferred shares at a price of $13.488 per share for gross cash proceeds of $130.0 million. The Company incurred issuance costs of $243,000.

Balance Sheet Items - Summary of Accrued Expenses and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Payables and Accruals [Abstract]
Accrued research and development expenses	$ 12,643	$ 7,554
Accrued payroll related expenses	9,165	6,129
Accrued professional service expenses	3,675	2,088
Other	1,041	179
Total accrued expenses and other current liabilities	$ 26,524	$ 15,950

Consolidated Statements of Redeemable Convertible Preferred Shares, Redeemable Noncontrolling Interest and Stockholders Equity/ Members (Deficit) - USD ($) $ in Thousands	Total	Preferred Stock [Member] Redeemable Convertible Preferred Stock [Member]	Redeemable Noncontrolling [Member]	Common Stock [Member]	Common Shares [Member]	Incentive Shares [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Loss [Member]	Accumulated Deficit [Member]
Beginning Balance at Dec. 31, 2020	$ (54,205)	$ 91,964	$ 5,702		$ 2,000	$ 637			$ (56,842)
Beginning Balance (In shares) at Dec. 31, 2020		22,851,257			6,035,869	4,112,017
Issuance of Series B redeemable convertible preferred shares for cash, net of issuance costs of $243, Value		$ 129,757
Issuance of Series B redeemable convertible preferred shares for cash, net of issuance costs of $243, Shares		9,638,141
Issuance of incentive shares, shares						2,959,795
Cancellations of incentive, shares						(265,596)
Conversion of redeemable convertible preferred, common, and incentive shares into common stock	221,721	$ (221,721)		$ 4	$ (2,000)	$ (1,175)	$ 224,892
Conversion of redeemable convertible preferred, common, and incentive shares into common stock, Shares		(32,489,398)		43,958,557	(6,035,869)	(6,806,216)
Conversion of redeemable noncontrolling interest to common stock	3,593		(3,593)	$ 1			3,592
Conversion of redeemable noncontrolling interest to common stock (In shares)				6,470,382
Common stock issued in IPO, net of issuance costs	167,045			$ 1			167,044
Common stock issued in IPO, net of issuance costs of $16,995, shares				11,500,000
Issuance of shares pursuant to Employee Stock Purchase Plan	318						318
Issuance of shares pursuant to Employee Stock Purchase Plan, Shares				23,353
Share-based compensation expense	13,321					$ 538	12,783
Net loss attributable to redeemable convertible noncontrolling interests	(2,109)		(2,109)
Net loss attributable to common stockholders/members	(70,645)								(70,645)
Unrealized loss on available-for-sale securities	0
Ending Balance at Dec. 31, 2021	281,148			$ 6			408,629		(127,487)
Ending Balance (In shares) at Dec. 31, 2021				61,952,292
Issuance of shares pursuant to Employee Stock Purchase Plan	642						642
Issuance of shares pursuant to Employee Stock Purchase Plan, Shares				97,413
Share-based compensation expense	27,242						27,242
Net loss attributable to redeemable convertible noncontrolling interests	0
Net loss attributable to common stockholders/members	(142,181)								(142,181)
Issuance of common stock pursuant to follow-on offering, net of issuance costs				11,500,000
Issuance of common stock pursuant to follow-on offering, net of issuance costs	161,610			$ 1			161,609
Issuance of common stock upon exercise of stock options, shares				235,474
Issuance of common stock upon exercise of stock options, Amount	3,649						3,649
Issuance of common stock upon release of restricted stock units, shares				79,441
Unvested common stock forfeiture, shares				(406,444)
Unrealized loss on available-for-sale securities	(71)							$ (71)
Ending Balance at Dec. 31, 2022	332,039	$ 0	0	$ 7	$ 0	$ 0	601,771	(71)	(269,668)
Ending Balance (In shares) at Dec. 31, 2022		0		73,458,176	0	0
Issuance of shares pursuant to Employee Stock Purchase Plan	1,250						1,250
Issuance of shares pursuant to Employee Stock Purchase Plan, Shares				115,421
Share-based compensation expense	39,341						39,341
Net loss attributable to redeemable convertible noncontrolling interests	0
Net loss attributable to common stockholders/members	(188,917)								(188,917)
Issuance of common stock pursuant to follow-on offering, net of issuance costs				13,269,231
Issuance of common stock pursuant to follow-on offering, net of issuance costs	161,409			$ 2			161,407
Issuance of common stock upon exercise of stock options, shares				88,459
Issuance of common stock upon exercise of stock options, Amount	1,338						1,338
Issuance of common stock upon release of restricted stock units, shares				317,245
Unvested common stock forfeiture, shares				(21,400)
Unrealized loss on available-for-sale securities	80							80
Ending Balance at Dec. 31, 2023	$ 346,540	$ 0	$ 0	$ 9	$ 0	$ 0	$ 805,107	$ 9	$ (458,585)
Ending Balance (In shares) at Dec. 31, 2023		0		87,227,132	0	0

Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Statement [Abstract]
Net loss	$ (188,917)	$ (142,181)	$ (72,754)
Other comprehensive loss:
Unrealized loss on available-for-sale securities	80	(71)	0
Comprehensive Income (Loss), Net of Tax, Attributable to Parent, Total	$ (188,837)	$ (142,252)	$ (72,754)

- Definition

The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

+ References

+ Details

Stock-Based Compensation - Summary of The Incentive Shares Activity (Detail) - Incentive Shares [Member]	12 Months Ended
	Dec. 31, 2021 $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Share Outstanding, Beginning balance \| shares	4,112,017
Granted \| shares	2,959,795
Forfeited \| shares	(265,596)
Converted to unvested common stock \| shares	(6,806,216)
Number of Share Outstanding, Ending balance \| shares	0
Weighted Average Grant Date Fair Value, Beginning Balance \| $ / shares	$ 1.26
Grant date fair value \| $ / shares	4.32
Forfeited \| $ / shares	1.67
Converted to unvested common stock \| $ / shares	2.58
Weighted Average Grant Date Fair Value, Ending Balance \| $ / shares	$ 0

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Common Stock, Par or Stated Value Per Share	$ 0.0001	$ 0.0001
Common Stock, Shares Authorized	500,000,000	500,000,000
Common Stock, Shares, Issued	87,227,132	73,458,176
Common Stock, Shares, Outstanding	87,227,132	73,458,176

Balance Sheet Items

12 Months Ended

Dec. 31, 2023

Balance Sheet Related Disclosures [Abstract]

Balance Sheet Items

4. Balance Sheet Items

Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consisted of the following (in thousands):


	December 31, 2023		December 31, 2022
Prepaid research and development expenses	$	5,657	$	3,007
Prepaid insurance		918		1,592
Other prepaid expenses and other assets		2,352		1,006
Total prepaid expenses and other current assets	$	8,927	$	5,605

Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consisted of the following (in thousands):


	December 31, 2023		December 31, 2022
Accrued research and development expenses	$	12,643	$	7,554
Accrued payroll related expenses		9,165		6,129
Accrued professional service expenses		3,675		2,088
Other		1,041		179
Total accrued expenses and other current liabilities	$	26,524	$	15,950

Income Taxes

12 Months Ended

Dec. 31, 2023

Income Tax Disclosure [Abstract]

Income Taxes

12. Income Taxes

Prior to the IPO and conversion, the Company was treated as a partnership for tax purposes, and thus, not subject to income taxes. It was the responsibility of the LLC members to report their proportion share of any taxable income or loss generated by Day One Biopharmaceuticals Holdings Company, LLC to the appropriate taxing authorities and pay the associated taxes, if any. Prior to the Conversion, the Company’s consolidated subsidiaries were treated as corporations for tax purposes and were subject to income taxes, which have been included in the consolidated financial statements. Subsequent to the Conversion, the Company and its subsidiaries were treated as a consolidated corporate group for income tax purposes through December 31, 2021. On December 31, 2021, the Company liquidated its subsidiaries into the Company in a tax-free Internal Revenue Code Section 332 liquidation. As such, a single entity provision has been calculated for the years ended December 31, 2023 and 2022. All pre-tax losses have been incurred in the United States.

The effective tax rate of the Company’s provision (benefit) for income taxes differs from the federal statutory rate as follows:


	Year Ended December 31,
	2023			2022			2021
Statutory rate		21.0	%		21.0	%		21.0	%
State tax		0.5	%		0.6	%		(0.8	)%
Permanent differences		(0.3	)%		—			0.6	%
Credits		2.0	%		1.7	%		3.8	%
Change in valuation allowance		(21.5	)%		(22.6	)%		(21.5	)%
Share-based compensation		(1.7	)%		(0.7	)%		(3.1	)%
Total		—			—			—

Deferred income taxes reflect the net effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. The principal components of the Company’s deferred tax assets and liabilities consisted of the following (in thousands):


	As of December 31,
	2023			2022
Deferred tax assets
Federal and state net operating loss carryforwards	$	38,973		$	25,884
Capitalized R&D Section 174 Expense		34,938			14,908
Credits		10,338			6,653
Intangible asset basis		4,034			2,562
Share-based compensation		4,775			2,133
Other		1,397			1,803
Total deferred tax assets		94,455			53,943
Total deferred tax liabilities		(75	)		(149	)
Less: valuation allowance		(94,380	)		(53,794	)
Net deferred tax assets	$	—		$	—

Changes in the valuation allowance for deferred tax assets during the years ended December 31, 2023, 2022 and 2021 were as follows (in thousands):


	Year Ended December 31,
	2023		2022		2021
Valuation allowance as of beginning of year	$	53,794	$	23,778	$	8,601
Increases recorded to income tax provision		40,586		30,016		15,177
Valuation allowance as of end of year	$	94,380	$	53,794	$	23,778

The Company has incurred net operating losses in each year since inception. The Company has not reflected the benefit of any such net operating loss carryforwards in the consolidated financial statements. Due to its history of losses, and lack of other positive evidence, the Company determined that it is more likely than not that its net deferred tax assets will not be realized, and therefore, the net deferred tax assets are fully offset by a valuation allowance at December 31, 2023, 2022, and 2021. The Company increased the valuation allowance by $40.6 million, $30.0 million and $15.2 million for the years ended December 31, 2023, 2022, and 2021, respectively.

As of December 31, 2023, the Company had federal net operating loss carryforwards, or NOLs, of $177.7 million that do not expire and federal tax credits of $11.6 million available to offset tax liabilities that begin to expire in 2038. The Company also has gross state NOLs of $19.2 million and state tax credits of $1.6 million which are available to offset state tax liabilities. The state NOLs begin to expire in 2038 and the state tax credits do not expire.

The Company has not completed a study as of December 31, 2023 to determine whether an ownership change per the provisions of Section 382 of the Internal Revenue Code, as well as similar state provisions, has occurred. Utilization of its net operating loss and income tax credit carryforwards may be subject to an annual limitation due to ownership changes that may have occurred or that could occur in the future. These ownership changes may limit the amount of the net operating loss and income tax credit carryover that can be utilized annually to offset future taxable income. In general, an “ownership change” as defined by Section 382 of the Internal Revenue Code results from a transaction or series of transactions over a three-year period resulting in an ownership change of more than 50 percentage points of the outstanding shares of a company by certain stockholders.

In accordance with the Tax Cuts and Jobs Act of 2017, Research and Experimental, or R&E, expenses under Internal Revenue Code Section 174 are required to be capitalized beginning in 2022. R&E expenses are required to be amortized over a period of 5 years for domestic expenses and 15 years for foreign expenses.

Uncertain Tax Positions

In accordance with authoritative guidance, the impact of an uncertain income tax position on the income tax return must be recognized at the largest amount that is more-likely-than-not to be sustained upon audit by the relevant taxing authority. An uncertain income tax position will not be recognized if it has less than a 50% likelihood of being sustained.

The following table reconciles the beginning and ending amount of unrecognized tax benefits (in thousands):


	Year Ended December 31,
	2023			2022			2021
Balance at beginning of year	$	2,535		$	1,141		$	188
Additions based on tax positions related to prior year		29			726			—
Additions based on tax positions related to current year		872			916			953
Reductions based on tax positions related to prior year		(802	)		(248	)		—
Reductions based on tax positions related to current year		—			—			—
Balance at end of year	$	2,634		$	2,535		$	1,141

The entire amount of the unrecognized tax benefits would not impact the Company’s effective tax rate if recognized. The Company has elected to include interest and penalties as a component of tax expense. During the years ended December 31, 2023, 2022 and 2021, the Company did not recognize accrued interest and penalties related to unrecognized tax benefits. The Company does not anticipate that the amount of existing unrecognized tax benefits will significantly increase or decrease during the next 12 months.

The Company files income tax returns in the U.S. federal, California and other state tax jurisdictions. The federal and state income tax returns from December 31, 2018 to December 31, 2022 remain subject to examination.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480990/946-20-50-13

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(h)(2))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//740/tableOfContent

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-14

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
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+ Details

Cover Page - USD ($) $ in Millions	12 Months Ended
Cover Page - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Feb. 21, 2024	Jun. 30, 2023
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Annual Report	true
Document Transition Report	false
Document Period End Date	Dec. 31, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	FY
Entity Registrant Name	DAY ONE BIOPHARMACEUTICALS, INC.
Entity Central Index Key	0001845337
Entity File Number	001-40431
Entity Tax Identification Number	83-2415215
Entity Incorporation, State or Country Code	DE
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Shell Company	false
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Address, Address Line One	2000 Sierra Point Parkway
Entity Address, Address Line Two	Suite 501
Entity Address, City or Town	Brisbane
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94005
City Area Code	650
Local Phone Number	484-0899
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Trading Symbol	DAWN
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding			87,384,856
Document Financial Statement Error Correction [Flag]	false
Entity Public Float				$ 758.5
Documents Incorporated by Reference [Text Block]	Portions of the registrant’s Definitive Proxy Statement relating to the 2023 Annual Meeting of Shareholders are incorporated by reference into Part III of this Annual Report on Form 10-K to the extent stated herein. The Definitive Proxy Statement will be filed within 120 days of the Registrant’s fiscal year ended December 31, 2022. Except with respect to information specifically incorporated by reference in this Form 10-K, the Proxy Statement is not deemed to be filed as part of this Form 10-K.
Auditor Name	PricewaterhouseCoopers LLP	Ernst & Young LLP
Auditor Firm ID	238	42
Auditor Location	Dallas, Texas	San Mateo, California

Income Taxes - Schedule of Changes in the Valuation Allowance for Deferred Tax Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Valuation allowance as of beginning of year	$ 53,794	$ 23,778	$ 8,601
Increases recorded to income tax provision	40,586	30,016	15,177
Valuation allowance as of end of year	$ 94,380	$ 53,794	$ 23,778

Commitments and Contingencies - Additional Information (Detail)	1 Months Ended	12 Months Ended
	Apr. 30, 2022 USD ($) ft²	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Lessee Lease Description [Line Items]
Operating lease term	31 months
Weighted-average remaining lease term		10 months 24 days
Weighted-average discount rate		9.00%
Amortization of operating right-of-use assets		$ 347,000	$ 468,000	$ 179,000
Operating lease payments	$ 1,100,000
Research And Development Expense		130,521,000	85,618,000	43,584,000
Research And Development Agreements [Member]
Lessee Lease Description [Line Items]
Termination and cancellation charges payable		0	0
Viracta License Agreement [Member]
Lessee Lease Description [Line Items]
Research And Development Expense		5,000,000		3,000,000
Royalty fee payable		0
MRKDG License Agreement [Member]
Lessee Lease Description [Line Items]
Research And Development Expense			2,500,000
Indemnification Agreement [Member]
Lessee Lease Description [Line Items]
Termination and cancellation charges payable		0	0
Brisbane California
Lessee Lease Description [Line Items]
Area of land \| ft²	12,000
Security deposit	$ 40,000
Lease For Corporate Office Facility
Lessee Lease Description [Line Items]
Amortization of operating right-of-use assets		400,000	500,000	200,000
Operating lease payments		500,000	$ 400,000	$ 200,000
Lease For Corporate Office Facility \| Central America
Lessee Lease Description [Line Items]
Tenant improvement allowances receivable		$ 10,000
Lessee operating lease renewal lease term		3 years
Purchase Commitment
Lessee Lease Description [Line Items]
Purchase Commitment, Remaining Minimum Amount Committed		$ 17,200,000
Purchase Commitment, Remaining Minimum Amount Committed		$ 0

Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2023

Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]

Summary of Fair Value of The Incentive Shares Estimated Using An Option Pricing Model

The fair value of the incentive shares was estimated using an option pricing model with the following assumptions:


		Year Ended December 31,
		2021
Common share fair value		$6.36 - $8.89
Participating threshold		$6.36 - $7.51
Risk free rate		0.14%
Volatility		72.90%
Time to liquidity (in years)		0.20 - 1.80
Grant date fair value		$4.24 - $4.52

Summary of The Incentive Shares Activity

The following table provides a summary of the incentive shares activity:


	Number of Shares			Weighted Average Grant Date Fair Value
Outstanding as of December 31, 2020		4,112,017		$	1.26
Granted		2,959,795		$	4.32
Forfeited		(265,596	)	$	1.67
Converted to unvested common stock		(6,806,216	)	$	2.58
Outstanding as of December 31, 2021		—		$	—

Schedule of Stock Options Assumptions

The Company used the Black-Scholes option pricing model to estimate the fair value of stock options awards granted with the following assumptions:


	Year Ended December 31,
	2023	2022	2021
Expected term (in years)	—	6.08	—
Expected volatility	—	79.53%	—
Risk-free interest rate	—	4.18%	—
Expected dividend yield	—	—	—

Schedule of Performance Stock Options Assumptions

The Company used the Black-Scholes option pricing model to estimate the fair value of the PSO awards granted with the following assumptions:


	Year Ended December 31,
	2023	2022	2021
Expected term (in years)	—	2.92 - 3.42	—
Expected volatility	—	72.72% - 72.98%	—
Risk-free interest rate	—	3.37%	—
Expected dividend yield	—	—	—

Summary of Performance Stock Units activity

The following table provides a summary of PSU activity under the 2021 Plan during the year ended December 31, 2023:


	Number of Shares			Weighted Average Grant Date Fair Value Per Share
Unvested restricted stock units at December 31, 2022		95,500		$	15.25
Granted		—		$	—
Vested		(46,625	)	$	15.25
Forfeiture		(2,250	)	$	15.25
Unvested restricted stock units at December 31, 2023		46,625		$	15.25

Summary of Performance Stock Options

The following table provides a summary of PSO activity under the 2021 Plan during the year ended December 31, 2023.


	Options			Weighted-Average Exercise Price Per Share		Weighted-Average Remaining Contractual Term		Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2022		146,950		$	15.25
Granted		—		$	—
Exercised		—		$	—			$	—
Forfeiture		(3,450	)	$	15.25
Outstanding at December 31, 2023		143,500		$	15.25		8.5	$	—
Vested and expected to vest at December 31, 2023		71,750		$	15.25		8.5	$	—
Exercisable at December 31, 2023		71,750		$	15.25		8.5	$	—

Schedule of Stock Options Assumptions

The Company used the Black-Scholes option pricing model to estimate the fair value of stock options awards granted with the following assumptions:


	Year Ended December 31,
	2023	2022	2021
Expected term (in years)	—	6.08	—
Expected volatility	—	79.53%	—
Risk-free interest rate	—	4.18%	—
Expected dividend yield	—	—	—

Common stock to be issued under the ESPP Table text block

The fair value of our common stock to be issued under the ESPP is estimated at the date of grant using a Black-Scholes option-pricing model with the following assumptions:


	Year Ended December 31,
	2023	2022	2021
Expected term (in years)	0.5	0.5	0.25 - 0.50
Expected volatility	55.91%	128.95%	42.5% - 48.4%
Risk-free interest rate	5.41%	4.54%	0.05% - 0.06%
Expected dividend yield	—	—	—

Schedule of Performance Stock Options Assumptions

The Company used the Black-Scholes option pricing model to estimate the fair value of the PSO awards granted with the following assumptions:


	Year Ended December 31,
	2023	2022	2021
Expected term (in years)	—	2.92 - 3.42	—
Expected volatility	—	72.72% - 72.98%	—
Risk-free interest rate	—	3.37%	—
Expected dividend yield	—	—	—

Summary of Share-based Compensation Expense Recorded in The Accompanying Condensed Consolidated Statements of Operations and Comprehensive Loss

Share-based compensation expense recorded in the accompanying consolidated statements of operations is as follows (in thousands):


	Year Ended December 31,
	2023		2022		2021
Research and development expense	$	14,381	$	8,486	$	3,840
General and administrative expense		24,960		18,756		9,481
Total share-based compensation expense	$	39,341	$	27,242	$	13,321

2022 Equity Inducement Plan [Member]

Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]

Summary of Stock Option Activity

The following table provides a summary of stock option activity under the 2022 Plan during the year ended December 31, 2023.


	Options		Weighted-Average Exercise Price Per Share		Weighted-Average Remaining Contractual Term		Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2022		309,000	$	21.14
Granted		—	$	—
Exercised		—	$	—			$	—
Forfeiture		—	$	—
Outstanding at December 31, 2023		309,000	$	21.14		8.8	$	—
Vested and expected to vest at December 31, 2023		309,000	$	21.14		8.8	$	—
Exercisable at December 31, 2023		90,124	$	21.14		8.8	$	—

Summary of Restricted Stock Units Activity

The following table provides a summary of restricted stock units activity under the 2022 Plan during the year ended December 31, 2023:


	Number of Shares			Weighted Average Grant Date Fair Value Per Share
Unvested restricted stock units at December 31, 2022		47,400		$	21.14
Granted		—		$	—
Vested		(11,850	)	$	21.14
Forfeiture		—		$	—
Unvested restricted stock units at December 31, 2023		35,550		$	21.14

2021 Equity Incentive Plan [Member]

Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]

Summary of Stock Option Activity

The following table provides a summary of stock option activity under the 2021 Plan during the year ended December 31, 2023.


	Options			Weighted-Average Exercise Price Per Share		Weighted-Average Remaining Contractual Term		Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2022		7,634,167		$	16.42
Granted		2,653,000		$	18.83
Exercised		(88,459	)	$	15.12			$	643
Forfeiture		(439,450	)	$	18.30
Outstanding at December 31, 2023		9,759,258		$	17.00		8.2	$	3,260
Vested and expected to vest at December 31, 2023		9,759,258		$	17.00		8.2	$	3,260
Exercisable at December 31, 2023		4,602,684		$	16.74		7.8	$	904

Schedule of Stock Options Assumptions

The Company used the Black-Scholes option pricing model to estimate the fair value of stock options awards granted with the following assumptions:


	Year Ended December 31,
	2023	2022	2021
Expected term (in years)	5.27 - 6.25	5.27 - 6.33	5.31 - 6.08
Expected volatility	68.74% - 81.98%	65.20% - 81.68	61.25% - 66.53%
Risk-free interest rate	3.47% - 4.67%	1.47% - 4.37%	0.82% - 1.39%
Expected dividend yield	—	—	—

Schedule of Stock Options Assumptions

The Company used the Black-Scholes option pricing model to estimate the fair value of stock options awards granted with the following assumptions:


	Year Ended December 31,
	2023	2022	2021
Expected term (in years)	5.27 - 6.25	5.27 - 6.33	5.31 - 6.08
Expected volatility	68.74% - 81.98%	65.20% - 81.68	61.25% - 66.53%
Risk-free interest rate	3.47% - 4.67%	1.47% - 4.37%	0.82% - 1.39%
Expected dividend yield	—	—	—

Schedule of Nonvested Share Activity

The following table provides a summary of the unvested common stock awards activity during the year ended December 31, 2023.


	Number of Shares			Weighted Average Grant Date Fair Value Per Share
Unvested common stock as of December 31, 2022		1,722,744		$	16.00
Vested		(953,665	)	$	16.00
Forfeiture		(21,400	)	$	16.00
Unvested common stock as of December 31, 2023		747,679		$	16.00

Summary of Restricted Stock Units Activity

The following table provides a summary of restricted stock units activity under the 2021 Plan during the year ended December 31, 2023:


	Number of Shares			Weighted Average Grant Date Fair Value Per Share
Unvested restricted stock units at December 31, 2022		485,351		$	16.83
Granted		777,010		$	19.73
Vested		(258,770	)	$	19.44
Forfeiture		(54,221	)	$	20.09
Unvested restricted stock units at December 31, 2023		949,370		$	18.31

Balance Sheet Items - Schedule of Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Prepaid Expense and Other Assets, Current [Abstract]
Prepaid research and development expenses	$ 5,657	$ 3,007
Prepaid insurance	918	1,592
Other prepaid expenses and other assets	2,352	1,006
Total prepaid expenses and other current assets	$ 8,927	$ 5,605

Redeemable Convertible Preferred Shares - Additional Information (Detail) - USD ($)		1 Months Ended
	Jun. 01, 2021	Jun. 30, 2021	Feb. 28, 2021	Dec. 31, 2023
Temporary Equity [Line Items]
Payments of Stock Issuance Costs	$ 17,000,000
Redeemable Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Common Stock Shares Issued As A Result Of Conversion Of Temporary Equity Into Permanent Equity		32,489,398
Temporary Equity, Shares Outstanding				0
Series B Redeemable Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Temporary Equity Stock Issued During The Period Shares New Issues			9,638,141
Temporary Equity Issue Price Per Share			$ 13.488
Payments of Stock Issuance Costs			$ 243,000
Series B Redeemable Convertible Preferred Stock [Member] \| Gross Proceeds [Member]
Temporary Equity [Line Items]
Proceeds from redeemable convertible preferred stock			$ 130,000,000
IPO [Member]
Temporary Equity [Line Items]
Stock Issued During Period, Shares, New Issues	11,500,000	11,500,000

Summary of Significant Accounting Policies - Additional Information (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($)
Class of Stock [Line Items]
Share-based compensation arrangement by share-based payment award, fair value assumptions, expected dividend payments	$ 0
Weighted-average vesting contractual term of the award	10 years
Weighted-average vesting term of the award	10 years

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
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-Paragraph 13
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-Publisher FASB
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Reference 2: http://www.xbrl.org/2003/role/recommendedDisclosureRef
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-URI https://asc.fasb.org//1943274/2147483014/272-10-45-3

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 18: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Common Stock - Schedule of Common Stock Shares Reserved for Future Issuance (Detail)	Dec. 31, 2023 shares
Class Of Stock [Line Items]
Common Stock, capital shares purchase an additional for future issuance	15,567,663
Common Stock [Member]
Class Of Stock [Line Items]
Common Stock, capital shares purchase an additional for future issuance	10,211,758
Restricted Stock Units (RSUs) [Member]
Class Of Stock [Line Items]
Common Stock, capital shares purchase an additional for future issuance	1,031,545
Employee Stock Option
Class Of Stock [Line Items]
Common Stock, capital shares purchase an additional for future issuance	2,603,444
Employee Stock Purchase Plan [Member]
Class Of Stock [Line Items]
Common Stock, capital shares purchase an additional for future issuance	1,720,916

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

+ Details

Redeemable Noncontrolling Interest - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended	5 Months Ended	12 Months Ended
	May 26, 2021	May 26, 2021	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Redeemable Noncontrolling Interest [Line Items]
Net loss attributable to redeemable convertible noncontrolling interests			$ 0	$ 0	$ (2,109)
Adjustment To Additional Paid In Capital Loss On Conversion Of Temporary Equity Into Permanent Equity		$ 100,000
DOT One [Member]
Redeemable Noncontrolling Interest [Line Items]
Temporary Equity Shares Converted Into Permanent Equity	9,857,143
Common Stock Shares Issued As A Result Of Conversion Of Temporary Equity Into Permanent Equity	6,470,382
DOT One [Member] \| Takeda [Member]
Redeemable Noncontrolling Interest [Line Items]
Net loss attributable to redeemable convertible noncontrolling interests		$ 2,100

Common Stock

12 Months Ended

Dec. 31, 2023

Stockholders' Equity Note [Abstract]

Common Stock

8. Common Stock

Pursuant to its certificate of incorporation, the Company is authorized to issue 500.0 million shares of common stock at a par value of $0.0001 per share. As of December 31, 2023, 87,227,132 shares of common stock were issued and outstanding.

In November 2018, the Company entered into common shares purchase agreements with two founders of the Company. The individuals purchased a total of 2,790,000 common shares for a total purchase price of $300. Shares vested monthly for two and four years, respectively. Vesting for a certain number of shares was accelerated upon the Company’s closing of its Series A redeemable convertible preferred share financing. The Company also had an option for a period of ninety days after the individual’s employment is terminated either voluntarily or involuntarily to repurchase the unvested common shares at a price that is the lower of the original price per share paid by the founder for such stock or the fair value as of the date of such repurchase. The founders’ shares were converted to common stock in the Conversion. As of December 31, 2023, all founders’ common stock were vested.

The Company has reserved shares of common stock for future issuances as follows:


	December 31, 2023
Common stock options issued and outstanding		10,211,758
Common stock available for future grants		2,603,444
Common stock available for ESPP		1,720,916
Restricted stock units issued and outstanding		1,031,545
Total		15,567,663

June 2023 Follow-On Offering

In June 2023, the Company completed a follow-on offering and issued and sold 13,269,231 shares of common stock (including the exercise by the underwriters of their option to purchase an additional 1,730,769 shares of common stock) at a price to the public of $13.00 per share for net proceeds of approximately $161.4 million, after deducting underwriting discounts, commissions, and offering costs.

At-The-Market Offering

The Company has entered into an equity distribution agreement, or the Equity Distribution Agreement, with Piper Sandler & Co. and JonesTrading Institutional Services LLC, as sales agents, relating to the issuance and sale of shares of the Company’s common stock for an aggregate offering price of up to $250.0 million under an at-the-market offering program, or the ATM. The Company has no obligation to sell any shares and could at any time suspend solicitations and offers under the ATM. No shares of the Company’s common stock have been sold under the ATM as of December 31, 2023.

June 2022 Follow-On Offering

In June 2022, the Company completed a follow-on offering and issued and sold 11,500,000 shares of common stock (including the exercise by the underwriters of their option to purchase an additional 1,500,000 shares of

common stock) at a price to the public of $15.00 per share for net proceeds of approximately $161.6 million, after deducting underwriting discounts, commissions, and offering costs.

- Definition

The entire disclosure for equity.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Name Accounting Standards Codification
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Net Loss Per Share (Tables)

12 Months Ended

Dec. 31, 2023

Earnings Per Share [Abstract]

Summary of Basic and Diluted Net Loss Per Share Attributable to Common Shareholders/Stockholders

Basic and diluted net loss per share attributable to common stockholders after the Conversion is calculated as follows (in thousands except share and per share amounts):


	Year Ended December 31,
	2023			2022			2021
Net loss	$	(188,917	)	$	(142,181	)	$	(72,754	)
Net loss attributable to redeemable convertible noncontrolling interests		—			—			(2,109	)
Exchange of redeemable noncontrolling interest shares – deemed dividend		—			—			(99,994	)
Net loss attributable to common stockholders/members	$	(188,917	)	$	(142,181	)	$	(170,639	)
Net loss per share, basic and diluted	$	(2.37	)	$	(2.17	)	$	(4.62	)
Weighted-average number of common shares used in computing net loss per share, basic and diluted		79,773,004			65,466,773			36,960,569

Summary of Outstanding Potentially Dilutive Securities Have Been Excluded From Calculation of Diluted Net Loss Per Share

The following outstanding potentially dilutive securities have been excluded from the calculation of diluted net loss per share, as their effect is anti-dilutive:


	As of December 31,
	2023		2022
Stock options		10,068,258		7,943,167
Unvested common shares		747,679		1,722,744
Restricted stock units		984,920		532,751
Shares committed under ESPP		104,700		44,672
Total		11,905,557		10,243,334

Stock-Based Compensation - Summary of The Unvested Common Stock (Detail) - Two Thousand And Twenty One Stock Incentive Plan	12 Months Ended
	Dec. 31, 2023 $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares, Unvasted Restricted Stock, Beginning balance \| shares	1,722,744
Vested \| shares	(953,665)
Forfeited \| shares	(21,400)
Number of Shares, Unvasted Restricted Stock, Ending balance \| shares	747,679
Weighted Average Grant Date Fair Value, Beginning Balance \| $ / shares	$ 16
Vested \| $ / shares	16
Forfeited \| $ / shares	(16)
Weighted Average Grant Date Fair Value, Ending Balance \| $ / shares	$ 16

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

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+ Details

Significant Agreements

12 Months Ended

Dec. 31, 2023

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Significant Agreements

5. Significant Agreements

Takeda asset agreement

On December 16, 2019, DOT Therapeutics-1, Inc., or DOT-1, the Company's subsidiary, entered into an asset purchase agreement, or the Takeda Asset Agreement, with Millennium Pharmaceuticals, Inc., a related party and an affiliate of Takeda Pharmaceutical Company Limited, or Takeda. Pursuant to the Takeda Asset Agreement, DOT-1 purchased certain technology rights and know-how related to TAK-580 (which is now tovorafenib) that provides a new approach for treating patients with primary brain tumors or brain metastases of solid tumors. DOT-1 also received clinical inventory supplies to use in the Company's research and development activities of such RAF-inhibitor and an assigned investigator clinical trial agreement. Takeda also assigned to DOT-1 its exclusive license agreement, or the Viracta License Agreement, with Viracta Therapeutics, Inc. (f/k/a Sunesis Pharmaceuticals, Inc.), or Viracta. Takeda also granted DOT-1 a worldwide, sublicensable exclusive license under specified patents and know-how and non-exclusive license under other patents and know-how generated by Takeda under the Takeda Asset Agreement. The Company also granted Takeda a grant back license, as defined in the Takeda Asset Agreement, which is terminable either automatically or by DOT-1 in the event Takeda does not achieve specified development milestones within the applicable timeframes set forth under the Takeda Asset Agreement. This grant back license to Takeda was terminated at the time of Conversion in connection with the Millennium Stock Exchange Agreement.

In consideration for the sale and assignment of assets and the grant of the license under the Takeda Asset Agreement, DOT-1 made an upfront payment of $1.0 million in cash and issued 9,857,143 shares of Series A redeemable convertible preferred stock in DOT-1 in December 2019. The fair value of issued shares was estimated as $9.9 million, based on the price paid by other investors for issued shares in the Series A financing of DOT-1. Based on the terms of the Millennium Stock Exchange Agreement, Takeda exchanged the 9,857,143 shares of Series A redeemable convertible preferred stock of DOT-1 for 6,470,382 shares of the Company's common stock upon the effectiveness of the Conversion, on May 26, 2021.

The term of the Takeda Asset Agreement will expire on a country-by-country basis upon expiration of all assigned patent rights and all licensed patent rights in such country. Takeda may terminate the Takeda Asset Agreement prior to the Company's first commercial sale of a product if the Company ceases conducting any development activities for a continuous and specified period of time and such cessation is not agreed upon by the parties and is not done in response to guidance from a regulatory authority. Additionally, Takeda can terminate the Takeda Asset Agreement in the event of the Company's bankruptcy. In the event of termination of the Takeda Asset Agreement by Takeda as a result of the Company's cessation of development or bankruptcy, all assigned patents, know-how and contracts (other than the Viracta License Agreement) will be assigned back to Takeda and Takeda will obtain a reversion license under patents and know-how generated to exploit all such terminated products.

Effective December 31, 2021, DOT-1 was merged with and into the Company, with the Company being the surviving corporation and assuming DOT-1’s obligations under the Takeda Assets Purchase Agreement.

Viracta license agreement

On December 16, 2019, DOT-1 amended and restated the Viracta License Agreement that was assigned pursuant to the Takeda Asset Agreement. Under the Viracta License Agreement, DOT-1 received a worldwide exclusive license under specified patent rights and know-how to develop, use, manufacture, and commercialize products containing compounds binding the RAF protein family.

DOT-1 paid $2.0 million upfront in cash to Viracta, which was recorded as research and development expenses as the technology does not have an alternative future use. As of December 31, 2023, the Company could be required to make additional milestone payments of up to $49.0 million upon achievement of specified development and regulatory milestones for each licensed product in two indications, with milestones payable for the second indication to achieve a specified milestone event being lower than milestones payable for the first indication. Additionally, if DOT-1 obtains a priority review voucher with respect to a licensed product and sells such priority review voucher to a third party or uses such priority review voucher, DOT-1 is obligated to pay Viracta a specified percentage in the mid-teen digits of all net consideration received from any such sale or of the value of such used priority review voucher, as applicable. Commencing on the first commercial sale of a licensed product in a country, DOT-1 is obligated to pay tiered royalties ranging in the mid-single-digit percentages on net sales of licensed products, if any. The obligation to pay royalties will end on a country-by-country and licensed product-by-licensed product basis commencing on the first commercial sale in a country and continuing until the later of: (i) the expiration of the last valid claim of the Viracta licensed patents, jointly owned collaboration patents or specified patents owned by the Company covering the use or sale of such product in such country, (ii) the expiration of the last statutory exclusivity pertaining to such product in such country or (iii) the tenth anniversary of the first commercial sale of such product in such country.

The term of the Viracta License Agreement will expire on a licensed product-by-licensed product and country-by-country basis upon the expiration of the Company’s obligation to pay royalties to Viracta with respect to such product in such country. DOT-1 has the right to terminate the Viracta License Agreement with respect to any or all of the licensed products at will upon a specified notice period.

Effective December 31, 2021, DOT-1 was merged with and into the Company, with the Company being the surviving corporation and assuming DOT-1’s obligations under Viracta License Agreement.

License agreement with Merck KGaA, Darmstadt, Germany

On February 10, 2021, DOT Therapeutics-2, Inc., or DOT-2, the Company's subsidiary, entered into a license agreement, or the MRKDG License Agreement, with Merck KGaA, Darmstadt, Germany, a pharmaceutical corporation located in Darmstadt, Germany. Under the MRKDG License Agreement, Merck KGaA, Darmstadt, Germany granted to the Company an exclusive worldwide license, with the right to grant sublicenses through multiple tiers, under specified patent rights and know-how for the Company to research, develop, manufacture and commercialize products containing and comprising the pimasertib and MSC2015103B compounds. The Company also received clinical inventory supplies to use in its research and development activities. The Company's exclusive license grant is subject to a non-exclusive license granted by Merck KGaA, Darmstadt, Germany’s affiliate to a cancer research organization and Merck KGaA, Darmstadt, Germany retains the right to conduct, directly or indirectly, certain ongoing clinical studies relating to pimasertib.

Under the MRKDG License Agreement, the Company has obligations to use commercially reasonable efforts to develop and commercialize at least two licensed products in at least two specified major market countries by the year 2029.

In consideration for the rights granted under the MRKDG License Agreement and clinical supplies, the Company made an upfront payment of $8.0 million, which was recorded as research and development expenses, as the technology does not have an alternative future use and supplies are used for research activities. As of December 31, 2023, the Company could be required to make additional payments of up to $364.5 million based upon the achievement of specified development, regulatory, and commercial milestones, as well a high, single-digit royalty percentage on future net sales of licensed products, if any. Milestones and royalties are contingent upon future events and will be recorded when the milestones are achieved and when payments are due.

The term of the MRKDG License Agreement will expire on a licensed product-by-licensed product and country-by-country basis upon the expiration of the Company's obligation to pay royalties to the licensor with respect to such licensed product in such country and will expire in its entirety upon the expiration of all of the Company's payment obligations with respect to all licensed products and all countries under the MRKDG License Agreement.

Effective December 31, 2021, DOT-2 was merged with and into the Company, with the Company being the surviving corporation and assuming DOT-2’s obligations under the MRKDG License Agreement.

Research Collaboration and License Agreement with Sprint Bioscience AB

On August 15, 2023, the Company entered into a research collaboration and license agreement, or the Sprint License Agreement, with Sprint Bioscience AB, or Sprint, a Swedish corporation located in Huddinge, Sweden. Under the Sprint License Agreement, Sprint granted to the Company an exclusive, worldwide license, with the right to grant sublicenses through multiple tiers, to research, develop, and commercialize pharmaceutical products and to engage in research aimed at discovery, optimization and development of Vaccinia Related Kinase 1, or VRK1.

The Company paid $3.0 million upfront in cash to Sprint, which was recorded as research and development expenses as the technology does not have an alternative future use. As of December 31, 2023, the Company could be required to make milestone payments of up to $309.0 million based upon achievement of specified development, regulatory, and commercial milestones for each licensed product, as well as tiered royalties ranging in the single-digit percentages on future net sales of licensed products, if any. Milestones and royalties are contingent upon future events and will be recorded when the milestones are achieved and when payments are due.

The term of the Sprint License Agreement will expire on a licensed product and country basis upon the expiration of the royalty term with respect to such licensed product and such country, unless terminated earlier. The Company has the right to terminate the Sprint License Agreement in its entirety, or on a licensed product-by-licensed product basis, at will upon a specified notice period.

Balance Sheet Items (Tables)

12 Months Ended

Dec. 31, 2023

Balance Sheet Related Disclosures [Abstract]

Schedule of Prepaid and Other Current Assets

Prepaid expenses and other current assets consisted of the following (in thousands):


	December 31, 2023		December 31, 2022
Prepaid research and development expenses	$	5,657	$	3,007
Prepaid insurance		918		1,592
Other prepaid expenses and other assets		2,352		1,006
Total prepaid expenses and other current assets	$	8,927	$	5,605

Schedule of Accrued Expenses and Other Current Liabilities

Accrued expenses and other current liabilities consisted of the following (in thousands):


	December 31, 2023		December 31, 2022
Accrued research and development expenses	$	12,643	$	7,554
Accrued payroll related expenses		9,165		6,129
Accrued professional service expenses		3,675		2,088
Other		1,041		179
Total accrued expenses and other current liabilities	$	26,524	$	15,950

Net Loss Per Share - Summary of Outstanding Potentially Dilutive Securities Have Been Excluded From Calculation of Diluted Net Loss Per Share (Detail) - shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Stock options	11,905,557	10,243,334
Employee Stock Option
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Stock options	10,068,258	7,943,167
Unvested common shares
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Stock options	747,679	1,722,744
Restricted Stock Units (RSUs) [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Stock options	984,920	532,751
Shares committed under ESPP
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Stock options	104,700	44,672

Recurring Fair Value Measurements - Schedule of maturities of our available-for-sale marketable securities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Amortized cost, Mature in one year or less	$ 356,404	$ 300,642
Amortized Cost, Total	356,404	300,642
Fair Value, Mature in one year or less	356,413	300,572
Fair Value, Total	$ 356,413	$ 300,572

Commitments and Contingencies - Summary of Future Lease Obligations (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Lessee Lease Description [Line Items]
2024	$ 424
Total future minimum lease payments	424
Less: Imputed interest	(16)
Present value of operating lease liabilities	408
Current portion of operating lease liabilities	(408)	$ (405)
Operating lease liabilities	$ 0

Recurring Fair Value Measurements - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net	$ 0	$ 0
Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ 0	$ 0

Defined Contribution Plan (Additional Information) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Retirement Benefits [Abstract]
Matching Contribution	$ 1,300	$ 800	$ 0

Recurring Fair Value Measurements

12 Months Ended

Dec. 31, 2023

Fair Value Disclosures [Abstract]

Fair Value Measurements

3. Recurring Fair Value Measurements


	December 31, 2023
	Level 1		Level 2		Level 3		Total
Financial assets:
Money market funds	$	47,003	$	—	$	—	$	47,003
U.S. treasury securities		—		246,208		—		246,208
U.S. government agency securities		—		63,202		—		63,202
Total assets measured at fair value	$	47,003	$	309,410	$	—	$	356,413


	December 31, 2022
	Level 1		Level 2		Level 3		Total
Financial assets:
Money market funds	$	18,765	$	—	$	—	$	18,765
U.S. treasury securities		—		145,785		—		145,785
U.S. government agency securities		—		136,022		—		136,022
Total assets measured at fair value	$	18,765	$	281,807	$	—	$	300,572

The Company's money market funds are classified as Level 1 because they are measured using observable inputs from active markets for identical assets.

The Company's U.S. treasury securities and U.S. government agency securities are classified as Level 2 because they are measured with inputs that are either directly or indirectly observable for the asset which include quoted prices for similar assets in active markets and quoted prices for identical or similar assets in markets that are not active.

There were no assets or liabilities classified as Level 3 as of December 31, 2023 and 2022.

There were no transfers between Level 1, Level 2 or Level 3 categories during the periods presented.


	December 31, 2023
	Amortized Cost		Unrealized Gains		Unrealized Losses		Estimated Fair Value
Cash equivalents:
Money market funds	$	47,003	$	—	$	—	$	47,003
U.S. government agency securities		63,202		—		—		63,202
U.S. treasury securities		110,645		—		—		110,645
Total cash equivalents		220,850		—		—		220,850

Short-term investments
U.S. treasury securities		135,554		9		—		135,563
Total short-term investments	$	135,554	$	9	$	—	$	135,563


	December 31, 2022
	Amortized Cost		Unrealized Gains		Unrealized Losses			Estimated Fair Value
Cash equivalents:
Money market funds	$	18,765	$	—	$	—		$	18,765
U.S. government agency securities		24,800		—		—			24,800
Total cash equivalents		43,565		—		—			43,565

Short-term investments
U.S. treasury securities		145,880		1		(96	)		145,785
U.S. government agency securities		111,197		37		(12	)		111,222
Total short-term investments	$	257,077	$	38	$	(108	)	$	257,007

The following table summarizes the maturities of our cash equivalents and available-for-sale securities (in thousands):


	December 31, 2023
	Amortized Cost		Fair Value
Mature in one year or less	$	356,404	$	356,413
Total	$	356,404	$	356,413


	December 31, 2022
	Amortized Cost		Fair Value
Mature in one year or less	$	300,642	$	300,572
Total	$	300,642	$	300,572

The Company regularly reviews the changes to the rating of its securities and monitors the surrounding economic conditions to assess the risk of expected credit losses. As of December 31, 2023 and 2022, there were no securities that were in an unrealized loss position for more than 12 months. As of December 31, 2023 and 2022, the unrealized losses, if any, on the Company’s investments in U.S. treasury securities and U.S. government agency securities were primarily caused by interest rate increases. The Company does not expect the issuers to settle any security at a price less than the amortized cost basis of the investment with the contractual cash flows of these investments guaranteed by the issuer. No allowance for credit losses has been recorded since it is not more-likely-than-not that the Company will be required to sell the investments before recovery of their amortized cost basis.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Redeemable Noncontrolling Interest

12 Months Ended

Dec. 31, 2023

Temporary Equity Disclosure [Abstract]

Redeemable Noncontrolling Interest

11. Redeemable Noncontrolling Interest

Prior to the Merger, DOT-1, the Company’s subsidiary, issued Series A redeemable convertible preferred shares to Takeda in accordance with the Takeda Asset Agreement (Note 5). The Company concluded that it represented a redeemable noncontrolling interest.

The Company adjusted the carrying value of redeemable noncontrolling interest to allocate net losses of the subsidiary to Takeda. Transfers to and from the redeemable noncontrolling interest represented changes in ownership and the allocation of Series A redeemable convertible preferred shares issuance costs issued by the subsidiary.

On May 26, 2021, pursuant to the terms of the Millennium Stock Exchange Agreement, Takeda exchanged 9,857,143 shares of Series A redeemable convertible preferred stock in DOT-1 for 6,470,382 shares of common stock of the Company. Prior to the Exchange, the Company accounted for the redeemable noncontrolling interest as discussed in the paragraph above and allocated $2.1 million of net losses to Takeda for the period from January 1, 2021 to May 26, 2021. The Exchange resulted in DOT-1 becoming a wholly owned subsidiary of the Company and was recorded for accounting purposes as an extinguishment of the redeemable noncontrolling interest. As such, the Company also recognized an extinguishment loss of $100.0 million to additional paid-in-capital, which was calculated as a difference between the fair value of common stock issued to Takeda in the conversion and the carrying value of redeemable noncontrolling interest at the conversion date. The all-stock exchange was treated as a deemed dividend in the calculation of net loss attributable to common stockholders/members and net loss per share.

Defined Contribution Plan

12 Months Ended

Dec. 31, 2023

Retirement Benefits [Abstract]

Defined Contribution Plan

13. Defined Contribution Plan

The Company maintains an employee savings plan pursuant to Section 401(k) of the Internal Revenue Code. All employees are eligible to participate provided that they meet the requirements of the plan. For the year ended December 31, 2023 and 2022, the Company made matching contributions of $1.3 million and $0.8 million, respectively. The Company did not make matching contributions for the year ended December 31, 2021.

Significant Agreements - Additional Information (Detail) - USD ($)				12 Months Ended
	May 26, 2021	Feb. 10, 2021	Dec. 16, 2019	Dec. 31, 2023	Dec. 31, 2021
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Common stock issued in IPO, net of issuance costs					$ 167,045,000
Common Stock [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Stock Issued During Period, Shares, New Issues					11,500,000
Common stock issued in IPO, net of issuance costs					$ 1,000
Takeda Asset Agreement [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront of cash payment			$ 1,000,000
Takeda Asset Agreement [Member] \| Common Stock [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Issuance of Series B redeemable convertible preferred shares for cash, net of issuance costs of $243, Shares	6,470,382
Takeda Asset Agreement [Member] \| Series A Redeemable Convertible Preferred Stock [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Stock Issued During Period, Shares, New Issues			9,857,143
Common stock issued in IPO, net of issuance costs			$ 9,900,000
Issuance of Series B redeemable convertible preferred shares for cash, net of issuance costs of $243, Shares	9,857,143
Takeda Asset Agreement [Member] \| Research and Development Expense [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront payment		$ 8,000,000
Merck License Agreement [Member] \| Research and Development Expense [Member] \| Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone payments not yet paid				$ 364,500,000
Viracta License Agreement [Member] \| Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone payments not yet paid				49,000,000
Viracta License Agreement [Member] \| Research and Development Expense [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront of cash payment			$ 2,000,000
Sprint Bioscience Agreement [Member] \| Research and Development Expense [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront payment				3,000,000
Payment of Milestones				$ 309,000

Description of Business, Organization and Liquidity

12 Months Ended

Dec. 31, 2023

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Description of Business, Organization and Liquidity

1. Description of Business and Organization

Organization and Business

Day One Biopharmaceuticals, Inc., or the Company, is a clinical-stage biopharmaceutical company dedicated to developing and commercializing targeted therapies for people of all ages with life-threatening diseases. The Company was formed as a limited liability company under the laws of the State of Delaware in November 2018, under the name Hero Therapeutics Holding Company, LLC. Subsequently, the Company changed its name to Day One Therapeutics Holding Company, LLC in December 2018 and to Day One Biopharmaceuticals Holding Company, LLC, or Day One Holding LLC, in March 2020.

On May 26, 2021, the Company completed a conversion by filing a certificate of conversion with the Secretary of State of the State of Delaware and changed its name to Day One Biopharmaceuticals, Inc. Prior to December 31, 2021, the Company had two subsidiaries: DOT Therapeutics-2, Inc. (formerly Hero Therapeutics Inc. and Day One Biopharmaceuticals, Inc.), or DOT-2, incorporated in Delaware in November 2018, and DOT Therapeutics-1, Inc., or DOT-1, incorporated in Delaware in December 2019. DOT-2 and DOT-1 are collectively referred to herein as the Subsidiaries.

In December 2021, the Company’s board of directors approved the merger, or the Merger, of the Subsidiaries with and into the Company, with the Company being the surviving corporation, effective December 31, 2021. For more information on the financial statement impact of the Merger, refer to the section titled “Basis of Presentation.”

Initial Public Offering, Corporate Conversion and Exchange of Takeda’s shares

On June 1, 2021, the Company closed its initial public offering, or the IPO, in which it sold an aggregate of 11,500,000 shares of common stock at a price to the public of $16.00 per share, which included 1,500,000 shares issued upon the full exercise by the underwriters of their option to purchase additional shares of common stock. The Company received aggregate net proceeds from the IPO of $167.0 million, after deducting underwriting discounts and commissions and offering costs, of $17.0 million. The common stock began trading on the Nasdaq Global Select Market on May 27, 2021 under the symbol “DAWN.”

In contemplation of the IPO, on May 26, 2021, the Company completed a legal entity conversion, or the Conversion, which included the following: Day One Holding LLC (i) converted from a Delaware limited liability company to a Delaware corporation by filing a certificate of conversion with the Secretary of State of the State of Delaware and (ii) changed its name to Day One Biopharmaceuticals, Inc.

As part of the Conversion:

•

holders of Series A redeemable convertible preferred shares of Day One Holding LLC received one share of Series A redeemable convertible preferred stock of the Company for each Series A redeemable convertible preferred share held immediately prior to the Conversion;

•

holders of Series B redeemable convertible preferred shares of Day One Holding LLC received one share of Series B redeemable convertible preferred stock of the Company for each Series B redeemable convertible preferred share held immediately prior to the Conversion;

•

holders of common shares of Day One Holding LLC received one share of common stock of the Company for each common share held immediately prior to the Conversion;

•

each outstanding incentive share in Day One Holding LLC converted into a number of shares of common stock of the Company based upon a conversion price determined by the board of directors. The conversion price was determined as a difference between the IPO price of $16.00 per share and the participating threshold for each incentive share. The Company issued 5,433,290 common stock shares upon the conversion of incentive shares of Day One Holding LLC, of which 4,719,605 common stock shares continue to vest as per the original vesting terms of the incentive shares awards.

In connection with the IPO and the Conversion, pursuant to the terms of the Millennium Stock Exchange Agreement and the Conversion, Millennium Pharmaceuticals, Inc. exchanged 9,857,143 shares of Series A redeemable convertible preferred stock of DOT-1, a subsidiary of Day One Holding LLC, for 6,470,382 shares of common stock of the Company, or the Exchange.

The Company holds all property and assets of Day One Holding LLC and assumed all of the debts and obligations of Day One Holding LLC. Effective on the date of the Conversion, each member of the board of directors and each officer of Day One Holding LLC became a member of the board of directors and an officer of the Company. The Conversion was a tax-free reorganization, that included authorization to issue capital stock consisting of 500,000,000 shares of common stock, $0.0001 par value per share, and 10,000,000 shares of undesignated preferred stock, $0.0001 par value per share.

Upon the closing of the IPO, 32,489,398 shares of redeemable convertible preferred stock issued by the Company in the Conversion converted into an equal number of shares of common stock. The Company also granted options for 4,418,874 shares of common stock at an exercise price of $16.00 per share upon the IPO date.

Shares Split

On May 23, 2021, the board of directors of Day One Holding LLC approved an amendment to its operating agreement to effect a forward split of the Company’s shares at a 2.325-for-1 ratio, or the Stock Split. The Stock Split became effective on May 23, 2021, upon approval by the members and execution of the amended LLC operating agreement. All issued and outstanding common shares, redeemable convertible preferred shares, incentive shares and per share amounts contained in these consolidated financial statements have been retroactively adjusted to reflect this Stock Split for all periods presented.

Risks and Uncertainties

The Company is subject to risks common to early-stage companies in the biopharmaceutical industry including, but not limited to, uncertainties related to clinical effectiveness of the product, commercialization of products, regulatory approvals, dependence on key products, key personnel and third-party service providers such as contract research organizations (“CROs”), protection of intellectual property rights and the ability to make milestone, royalty or other payments due under any license, collaboration or supply agreements.

Stock-Based Compensation - Summary of The Black-Scholes Option Pricing Model to Estimate The Fair Value of Stock Option Granted (Detail)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
2021 Equity Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)		6 years 29 days
Expected volatility	0.00%	79.53%	0.00%
Risk-free interest rate	0.00%	4.18%	0.00%
Expected dividend yield	0.00%	0.00%	0.00%
2021 Equity Incentive Plan [Member] \| Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	5 years 3 months 7 days	5 years 3 months 7 days	5 years 3 months 21 days
Expected volatility	68.74%	65.20%	61.25%
Risk-free interest rate	3.47%	1.47%	0.82%
2021 Equity Incentive Plan [Member] \| Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	6 years 3 months	6 years 3 months 29 days	6 years 29 days
Expected volatility	81.98%	81.68%	66.53%
Risk-free interest rate	4.67%	4.37%	1.39%
2021 Employee Stock Purchase Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	6 months	6 months
Expected volatility	55.91%	128.95%
Risk-free interest rate	5.41%	4.54%
Expected dividend yield	0.00%	0.00%	0.00%
2021 Employee Stock Purchase Plan [Member] \| Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)			3 months
Expected volatility			42.50%
Risk-free interest rate			0.05%
2021 Employee Stock Purchase Plan [Member] \| Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)			6 months
Expected volatility			48.40%
Risk-free interest rate			0.06%
Performance Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate		3.37%
Performance Stock Options \| Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)		2 years 11 months 1 day
Expected volatility		72.72%
Performance Stock Options \| Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)		3 years 5 months 1 day
Expected volatility		72.98%

Description of Business, Organization and Liquidity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands			1 Months Ended	12 Months Ended
	Jun. 01, 2021	May 23, 2021	Jun. 30, 2021	Dec. 31, 2023	Dec. 31, 2022
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Proceeds from issuance of initial public offering	$ 167,000
Payments of stock issuance costs	$ 17,000
Share-based compensation arrangement by share-based payment award, options, vested, number of shares				4,719,605
Common stock shares authorized				500,000,000	500,000,000
Preferred stock shares authorized				10,000,000
Common stock par or stated value per share				$ 0.0001	$ 0.0001
Preferred stock par or stated value per share				$ 0.0001
Stockholders' equity note, stock split		2.325-for-1
Retained Earnings (Accumulated Deficit)				$ (458,585)	$ (269,668)
Cash and cash equivalents				$ 230,784	$ 85,262
IPO [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Common stock issued in IPO, net of issuance costs of $16,995, shares	11,500,000		11,500,000
Shares issued, price per share	$ 16			$ 16
Conversion Of Stock Shares Issued1				5,433,290
Stock issued during period, shares, conversion of units				32,489,398
Share-based compensation arrangement by share-based payment award, options, grants in period, net of forfeitures				4,418,874
Over-Allotment Option [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Stock issued during period, shares, issued for services	1,500,000
Series A Redeemable Convertible Preferred Stock [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Common stock par or stated value per share				$ 0.0001
Series A Redeemable Convertible Preferred Stock [Member] \| Millennium Pharmaceuticals, Inc. [Member] \| The Millennium Stock Exchange Agreement [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Conversion of stock, shares converted				9,857,143
Convertible preferred stock, shares issued upon conversion				6,470,382

Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Detail)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Statutory rate	21.00%	21.00%	21.00%
State tax	0.50%	0.60%	(0.80%)
Permanent differences	(0.30%)	0.00%	0.60%
Credits	2.00%	1.70%	3.80%
Change in valuation allowance	(21.50%)	(22.60%)	(21.50%)
Share-based compensation	(1.70%)	(0.70%)	(3.10%)

Net Loss Per Share

12 Months Ended

Dec. 31, 2023

Earnings Per Share [Abstract]

Net Loss Per Share

10. Net Loss Per Share

Basic and diluted net loss per share attributable to common stockholders after the Conversion is calculated as follows (in thousands except share and per share amounts):


	Year Ended December 31,
	2023			2022			2021
Net loss	$	(188,917	)	$	(142,181	)	$	(72,754	)
Net loss attributable to redeemable convertible noncontrolling interests		—			—			(2,109	)
Exchange of redeemable noncontrolling interest shares – deemed dividend		—			—			(99,994	)
Net loss attributable to common stockholders/members	$	(188,917	)	$	(142,181	)	$	(170,639	)
Net loss per share, basic and diluted	$	(2.37	)	$	(2.17	)	$	(4.62	)
Weighted-average number of common shares used in computing net loss per share, basic and diluted		79,773,004			65,466,773			36,960,569

The following outstanding potentially dilutive securities have been excluded from the calculation of diluted net loss per share, as their effect is anti-dilutive:


	As of December 31,
	2023		2022
Stock options		10,068,258		7,943,167
Unvested common shares		747,679		1,722,744
Restricted stock units		984,920		532,751
Shares committed under ESPP		104,700		44,672
Total		11,905,557		10,243,334

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2023

Income Tax Disclosure [Abstract]

Schedule of Effective Income Tax Rate Reconciliation

The effective tax rate of the Company’s provision (benefit) for income taxes differs from the federal statutory rate as follows:


	Year Ended December 31,
	2023			2022			2021
Statutory rate		21.0	%		21.0	%		21.0	%
State tax		0.5	%		0.6	%		(0.8	)%
Permanent differences		(0.3	)%		—			0.6	%
Credits		2.0	%		1.7	%		3.8	%
Change in valuation allowance		(21.5	)%		(22.6	)%		(21.5	)%
Share-based compensation		(1.7	)%		(0.7	)%		(3.1	)%
Total		—			—			—

Schedule of Deferred Tax Assets and Liabilities


	As of December 31,
	2023			2022
Deferred tax assets
Federal and state net operating loss carryforwards	$	38,973		$	25,884
Capitalized R&D Section 174 Expense		34,938			14,908
Credits		10,338			6,653
Intangible asset basis		4,034			2,562
Share-based compensation		4,775			2,133
Other		1,397			1,803
Total deferred tax assets		94,455			53,943
Total deferred tax liabilities		(75	)		(149	)
Less: valuation allowance		(94,380	)		(53,794	)
Net deferred tax assets	$	—		$	—

Schedule of Changes in the Valuation Allowance for Deferred Tax Assets

Changes in the valuation allowance for deferred tax assets during the years ended December 31, 2023, 2022 and 2021 were as follows (in thousands):


	Year Ended December 31,
	2023		2022		2021
Valuation allowance as of beginning of year	$	53,794	$	23,778	$	8,601
Increases recorded to income tax provision		40,586		30,016		15,177
Valuation allowance as of end of year	$	94,380	$	53,794	$	23,778

Summary of Unrecognized Tax Benefits

The following table reconciles the beginning and ending amount of unrecognized tax benefits (in thousands):


	Year Ended December 31,
	2023			2022			2021
Balance at beginning of year	$	2,535		$	1,141		$	188
Additions based on tax positions related to prior year		29			726			—
Additions based on tax positions related to current year		872			916			953
Reductions based on tax positions related to prior year		(802	)		(248	)		—
Reductions based on tax positions related to current year		—			—			—
Balance at end of year	$	2,634		$	2,535		$	1,141

Recurring Fair Value Measurements - Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Fair Value, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value disclosure	$ 356,413	$ 300,572
Fair Value, Inputs, Level 1 \| Fair Value, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value disclosure	47,003	18,765
Fair Value, Inputs, Level 2 \| Fair Value, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value disclosure	309,410	281,807
Fair Value, Inputs, Level 3 \| Fair Value, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value disclosure	0	0
Money Market Funds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value disclosure	47,003	18,765
Money Market Funds [Member] \| Fair Value, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value disclosure	47,003	18,765
Money Market Funds [Member] \| Fair Value, Inputs, Level 1 \| Fair Value, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value disclosure	47,003	18,765
Money Market Funds [Member] \| Fair Value, Inputs, Level 2 \| Fair Value, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value disclosure	0	0
Money Market Funds [Member] \| Fair Value, Inputs, Level 3 \| Fair Value, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value disclosure	0	0
US Treasury Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value disclosure	110,645
US Treasury Securities [Member] \| Fair Value, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value disclosure	246,208	145,785
US Treasury Securities [Member] \| Fair Value, Inputs, Level 1 \| Fair Value, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value disclosure	0	0
US Treasury Securities [Member] \| Fair Value, Inputs, Level 2 \| Fair Value, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value disclosure	246,208	145,785
US Treasury Securities [Member] \| Fair Value, Inputs, Level 3 \| Fair Value, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value disclosure	0	0
U.S. government agency securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value disclosure	63,202	24,800
U.S. government agency securities [Member] \| Fair Value, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value disclosure	63,202	136,022
U.S. government agency securities [Member] \| Fair Value, Inputs, Level 1 \| Fair Value, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value disclosure	0	0
U.S. government agency securities [Member] \| Fair Value, Inputs, Level 2 \| Fair Value, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value disclosure	63,202	136,022
U.S. government agency securities [Member] \| Fair Value, Inputs, Level 3 \| Fair Value, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value disclosure	0	0
Cash Equivalents [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash and cash equivalents, fair value disclosure	$ 220,850	$ 43,565