Summary of Significant Accounting Policies (Policies)	12 Months Ended
Dec. 31, 2023
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (GAAP) and applicable rules and regulations of the SEC regarding financial reporting. The U.S. dollar is the Company’s functional and reporting currency.
Emerging Growth Company Status	Emerging Growth Company Status The Company is an emerging growth company as defined in the Jumpstart Our Business Startups Act of 2012 (JOBS Act). Under the JOBS Act, emerging growth companies can delay adopting new or revised accounting standards issued subsequent to the enactment of the JOBS Act until such time as those standards apply to private companies. The Company has elected to use this extended transition period for complying with certain new or revised accounting standards that have different effective dates for public and private companies until the earlier of the date that it (1) is no longer an emerging growth company or (2) affirmatively and irrevocably opts out of the extended transition period provided in the JOBS Act. As a result, these financial statements may not be comparable to companies that comply with the new or revised accounting pronouncements as of public company effective dates.
Use of Estimates	Use of Estimates The preparation of the Company’s financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period. Management estimates that affect the reported amounts of assets and liabilities include the research contract costs and accruals, stock-based compensation expense, and the valuation allowance for deferred tax assets. The Company evaluates and adjusts its estimates and assumptions on an ongoing basis using historical experience and other factors. Actual results could differ materially from those estimates.
Concentrations of Credit Risk and Other Risks and Uncertainties	Concentrations of Credit Risk and Other Risks and Uncertainties Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash, cash equivalents and marketable securities. The Company maintains bank deposits in a federally insured financial institution and these deposits may exceed federally insured limits. The Company is exposed to credit risk in the event of default by the financial institution holding its cash, cash equivalents, and marketable securities to the extent recorded in the balance sheet. The Company has not experienced any losses to date related to these concentrations. The Company’s future results of operations involve a number of other risks and uncertainties. Factors that could affect the Company’s future operating results and cause actual results to vary materially from expectations include, but are not limited to, uncertainty of results of clinical trials and reaching milestones, uncertainty of regulatory approval of the Company’s current and potential future product candidates, uncertainty of market acceptance of the Company’s product candidates, competition from substitute products and larger companies, securing and protecting proprietary technology, strategic relationships and dependence on key individuals or sole-source suppliers. The Company relies on one supply chain for each of its product candidates. If any of the single source suppliers in any of the supply chains fails to satisfy the Company’s requirements on a timely basis, it could suffer delays in its clinical development programs and activities, which could adversely affect operating results. The Company’s product candidates require approvals from the U.S. Food and Drug Administration and comparable foreign regulatory authorities prior to commercial sales in their respective jurisdictions. There can be no assurance that any product candidates will receive the necessary approvals. If the Company was denied approval, approval was delayed, or the Company was unable to maintain approval for any product candidate, it could have a materially adverse impact on the Company.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with an original maturity of three months or less when purchased to be cash equivalents. Cash equivalents consist of money market funds and are stated at fair value.
Restricted Cash	Restricted Cash Restricted cash represents cash held by a financial institution as collateral for a letter of credit securing its operating lease for office and laboratory space, which is classified as a non-current asset on the balance sheets based on the maturity of the lease.
Marketable Securities	Marketable Securities The Company holds investments in marketable securities, consisting of U.S. government securities. Marketable debt securities with stated maturities of three months or less from the date of purchase are classified as cash equivalents and those with stated maturities of greater than three months as marketable securities on the balance sheet. The Company determines the appropriate classification of marketable debt securities at the time of purchase. The Company has the ability, if necessary, to liquidate its investments to meet its liquidity needs in the next 12 months, without significant penalty. Accordingly, those investments with contractual maturities greater than one year from the date of purchase are classified as current assets on the accompanying balance sheets. All marketable debt securities are classified as available-for-sale and are reported at estimated fair value, with unrealized gains and losses recorded in accumulated other comprehensive loss within stockholders’ equity. Interest, amortization and accretion of purchase premiums and discounts on marketable debt securities are included in other income (expense), net, in the statements of operations and comprehensive loss. The cost of available-for-sale marketable securities sold is based on the specific identification method. Realized gains and losses on the sale of available-for-sale marketable securities are recorded in other income, net in the statements of operations and comprehensive loss. The Company regularly reviews all of the marketable securities for decline in fair value to determine whether unrealized losses have resulted from credit loss or other factors. The review includes considerations for the cause of the impairment but is not limited to (i) the consideration of the cause of the decline, (ii) any currently recorded expected credit losses and (iii) the creditworthiness of the respective security issuers. A decline of fair value below cost basis is considered an other-than-temporary impairment if the Company has the intent to sell the security or it is more likely than not that the company will be required to sell the security before recovery of the entire cost basis. Regardless of the Company’s intent or requirement to sell the security, an impairment is considered other-than-temporary if the Company does not expect to recover the entire cost basis. In those instances, an impairment charge equal to the difference between fair value and the cost basis is recorded in other income (expense), on the statements of operations and comprehensive loss. No impairment loss was recognized for the fiscal years ended December 31, 2023 and 2022. The amortized or accreted cost basis of the marketable securities approximates its fair value.
Deferred Offering Costs	Deferred Offering Costs Deferred offering costs consisting of legal, accounting and filing fees relating to equity offerings. Deferred offering costs are included in other long-term assets on the Company’s balance sheets. Upon completion of the offering, these amounts are offset against the proceeds of the offering.
Leases	Leases The Company leases office space under operating leases and determines if the arrangement is a lease at inception. These leases contain lease and non-lease components. Non-lease components include payments for maintenance, utilities, real estate taxes, and management fees. The lease and non-lease components are combined and accounted as a single lease component. Payments made under operating leases (net of any incentive received from the lessors) are recorded on a straight-line basis over the term of the lease. These leases do not provide an implicit rate, the Company uses an incremental borrowing rate based on information available at commencement date in determining the present value of lease payments. The incremental borrowing rate is a hypothetical rate based on the Company’s understanding of what the credit rating would be in a similar economic environment. Operating leases are included in operating lease right-of-use assets and operating lease liabilities, current and non-current, on the balance sheets. Leases may include one or more options to renew. The Company does not assume renewals in determination of the lease term unless the renewals are deemed to be reasonably assured. The lease agreements generally do not contain any material residual value guarantees or material restrictive covenants.
Foreign Currency Translations	Foreign Currency Translations Transactions denominated in foreign currencies are initially measured in U.S. dollars using the exchange rate on the date of the transaction. Foreign currency denominated monetary assets and liabilities are subsequently re-measured at the end of each reporting period using the exchange rate at that date, with the corresponding foreign currency transaction gain or loss recorded in the statements of operations and statements of cash flows. Nonmonetary assets and liabilities are not subsequently re-measured.
Fair Value Measurements	Fair Value Measurements Fair value is defined as the exchange price to sell an asset or transfer a liability (exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants at the measurement date. Fair value should be based on the assumptions market participants would use when pricing the asset or liability. The valuation hierarchy is based upon the transparency of inputs to the valuation of an asset or liability as of the measurement date. Fair value measurements are classified and disclosed in one of the following three categories: Level 1 – Quoted unadjusted prices for identical instruments in active markets. Level 2 – Quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-derived valuations in which all observable inputs and significant value drivers are observable in active markets. Level 3 – Model derived valuations in which one or more significant inputs or significant value drivers are unobservable, including assumptions developed by the Company. Fair value accounting is applied to all financial assets and liabilities that are recognized or disclosed in the financial statements on a recurring basis. The Company’s financial instruments consist of cash and cash equivalents, restricted cash, marketable securities, prepaid expenses and other current assets, non-marketable equity securities, accounts payable and accrued expenses and long-term debt. Cash, restricted cash, and marketable securities and non-marketable securities are reported at their respective fair values on the Company’s balance sheets. The remaining financial instruments are reported on the Company’s balance sheets at cost, which approximate their fair value due to their short-term nature. Money market funds are highly liquid investments that are actively traded. The pricing information for the Company’s money market funds are readily available and can be independently validated as of the measurement date. This approach results in the classification of these securities as Level 2 of the fair value hierarchy. The Company’s non-marketable equity securities (see Note 5) are measured at fair value using an option pricing valuation methodology. The option pricing methodology relies on risk-neutral valuation which calculates the value of an asset by discounting the expected value of its future payoffs at the risk-free rate of return. The fair value of the non-marketable equity securities is derived from quoted prices for similar instruments and observable inputs in active markets. This approach results in the classification of these securities as Level 2 of the fair value hierarchy. There were no transfers between Levels 1, 2, or 3 for any of the periods presented. As of December 31, 2023, and December 31, 2022, the Company held $44.7 million and $42.5 million, respectively, in money market funds.
Comprehensive Loss	Comprehensive Loss Comprehensive loss consists of two components: net loss and other comprehensive loss. Other comprehensive loss refers to unrealized gains and losses that are recorded as an element of stockholders’ equity and are excluded from net loss. For the year ended December 31, 2023, other comprehensive loss consists of unrealized gains and losses on marketable securities.
Research and Development Costs	Research and Development Costs Research and development costs are expensed as incurred and consist primarily of employees’ salaries and related benefits, including stock-based compensation and termination expenses for employees engaged in research and development efforts, allocated overhead including rent, depreciation, information technology and utilities, contracted services, license fees, and external expenses to conduct and support the Company’s operations that are directly attributable to the Company’s research and development efforts. Payments made to third parties under these arrangements in advance of the performance of the related services by the third parties are recorded as prepaid expenses until the services are rendered. Costs incurred in obtaining technology licenses including upfront and milestone payments incurred under the Company’s licensing agreements are recorded as expense in the period in which they are incurred, provided that the licensed technology, method or process has no alternative future uses other than for the Company’s research and development activities. Where contingent milestone payments are due to third parties under license or other agreements, the milestone payment obligations are recognized as expense when achievement of the contingent milestone is probable, which is generally upon achievement of the milestone.
Research Contract Costs And Accruals	Research Contract Costs and Accruals The Company enters into various research and development and other agreements with commercial firms, researchers, and others for provisions of goods and services from time to time. These agreements are generally cancellable, and the related costs are recorded as research and development expenses as incurred. The Company records accruals for estimated ongoing research and development costs. When evaluating the adequacy of the accrued liabilities, the Company analyzes progress of the studies or clinical trials, including the phase or completion of events, invoices received and contracted costs. Significant judgments and estimates are made in determining the accrued balances at the end of any reporting period. Actual results could differ materially from the Company’s estimates.
Stock-Based Compensation	Stock-Based Compensation The Company recognizes compensation expense based on estimated fair values for all stock-based payment awards made to the Company’s employees, nonemployee directors and consultants that are expected to vest. The valuation of stock option awards is determined at the date of grant using the Black-Scholes option pricing model. The Black-Scholes option pricing model requires the Company to make assumptions and judgments about the inputs used in the calculations, such as the fair value of the common stock, expected term, expected volatility of the Company’s common stock, risk-free interest rate and expected dividend yield. The valuation of restricted stock awards is measured by the fair value of the Company’s Class A common stock on the date of the grant. For all stock options granted, the Company calculated the expected term using the simplified method (derived from the average midpoint between the weighted average vesting period and the contractual term of the award) for “plain vanilla” stock option awards, as the Company has limited historical information to develop expectations about future exercise patterns and post vesting employment termination behavior. The estimate of expected volatility is based on comparative companies’ volatility. The risk-free rate is based on the yield available on United States Treasury zero-coupon issues corresponding to the expected term of the award. The Company records forfeitures when they occur. The Company determines the fair value of its Class A common stock using the market closing price on the date of grant. The Company records compensation expense for service-based awards on a straight-line basis over the requisite service period, which is generally the vesting period of the award. The amount of stock-based compensation expense recognized during a period is based on the value of the portion of the awards that are ultimately expected to vest.
Income Taxes	Income Taxes Income taxes are accounted for under the asset and liability method. Deferred income taxes are recorded for temporary differences between financial statement carrying amounts and the tax basis of assets and liabilities. Deferred tax assets and liabilities reflect tax rates expected to be in effect for the years in which the differences are expected to be reversed. A valuation allowance is provided if it is more likely than not that some or all of the deferred tax assets will not be realized.
Net Loss Per Share Attributable to Common Stockholders	Net Loss Per Share Attributable to Common Stockholders Net loss per share of common stock is computed using the two-class method required for multiple classes of common stock and participating securities based upon their respective rights to receive dividends as if all income for the period has been distributed. The rights, including the liquidation and dividend rights and sharing of losses, of the Class A and Class B common stock are identical, other than voting rights. As the liquidation and dividend rights and sharing of losses are identical, the undistributed earnings are allocated on a proportionate basis and the resulting net loss per share attributed to common stockholders is therefore the same for Class A and Class B common stock on an individual or combined basis. Basic net loss per share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding during the period, adjusted for outstanding shares that are subject to repurchase. Diluted net loss per share is computed by giving effect to all potentially dilutive securities outstanding for the period using the treasury stock method or the if-converted method based on the nature of such securities. For periods in which the Company reports net losses, diluted net loss per share attributable to common stockholders is the same as basic net loss per share attributable to common stockholders, because potentially dilutive shares are not assumed to have been issued if their effect is anti-dilutive.
Recently Issued Accounting Pronouncements Not Yet Adopted	Recently Issued Accounting Pronouncements Not Yet Adopted In June 2022, the FASB issued ASU 2022-03, Fair Value Measurement (Topic 820): Fair Value Measurement of Equity Securities Subject to Contractual Sale Restrictions. This standard clarifies the guidance in Topic 210, when measuring the fair value of an equity security subject to contractual restrictions that prohibit the sale of an equity security and introduces new disclosure requirements for equity securities subject to contractual sale restrictions that are measured at fair value in accordance with Topic 820. The guidance is effective for annual periods beginning after December 15, 2023, with early adoption permitted. The Company does not expect that the adoption of this standard will have a material impact on its financial statements and related disclosures. In December 2023, the FASB issued ASU 2023-09, Improvements to Income Tax Disclosures (Topic 740). The ASU requires disaggregated information about a reporting entity’s effective tax rate reconciliation as well as additional information on income taxes paid. The ASU is effective on a prospective basis for annual periods beginning after December 15, 2024. Early adoption is also permitted for annual financial statements that have not yet been issued or made available for issuance. This ASU will result in the required additional disclosures being included in the Company’s financial statements upon adoption.

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2023

The accompanying financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (GAAP) and applicable rules and regulations of the SEC regarding financial reporting. The U.S. dollar is the Company’s functional and reporting currency.

Emerging Growth Company Status

The Company is an emerging growth company as defined in the Jumpstart Our Business Startups Act of 2012 (JOBS Act). Under the JOBS Act, emerging growth companies can delay adopting new or revised accounting standards issued subsequent to the enactment of the JOBS Act until such time as those standards apply to private companies. The Company has elected to use this extended transition period for complying with certain new or revised accounting standards that have different effective dates for public and private companies until the earlier of the date that it (1) is no longer an emerging growth company or (2) affirmatively and irrevocably opts out of the extended transition period provided in the JOBS Act. As a result, these financial statements may not be comparable to companies that comply with the new or revised accounting pronouncements as of public company effective dates.

Use of Estimates

The preparation of the Company’s financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period. Management estimates that affect the reported amounts of assets and liabilities include the research contract costs and accruals, stock-based compensation expense, and the valuation allowance for deferred

tax assets. The Company evaluates and adjusts its estimates and assumptions on an ongoing basis using historical experience and other factors. Actual results could differ materially from those estimates.

Concentrations of Credit Risk and Other Risks and Uncertainties

Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash, cash equivalents and marketable securities. The Company maintains bank deposits in a federally insured financial institution and these deposits may exceed federally insured limits. The Company is exposed to credit risk in the event of default by the financial institution holding its cash, cash equivalents, and marketable securities to the extent recorded in the balance sheet. The Company has not experienced any losses to date related to these concentrations.

The Company’s future results of operations involve a number of other risks and uncertainties. Factors that could affect the Company’s future operating results and cause actual results to vary materially from expectations include, but are not limited to, uncertainty of results of clinical trials and reaching milestones, uncertainty of regulatory approval of the Company’s current and potential future product candidates, uncertainty of market acceptance of the Company’s product candidates, competition from substitute products and larger companies, securing and protecting proprietary technology, strategic relationships and dependence on key individuals or sole-source suppliers. The Company relies on one supply chain for each of its product candidates. If any of the single source suppliers in any of the supply chains fails to satisfy the Company’s requirements on a timely basis, it could suffer delays in its clinical development programs and activities, which could adversely affect operating results.

The Company’s product candidates require approvals from the U.S. Food and Drug Administration and comparable foreign regulatory authorities prior to commercial sales in their respective jurisdictions. There can be no assurance that any product candidates will receive the necessary approvals. If the Company was denied approval, approval was delayed, or the Company was unable to maintain approval for any product candidate, it could have a materially adverse impact on the Company.

Cash and Cash Equivalents

The Company considers all highly liquid investments with an original maturity of three months or less when purchased to be cash equivalents. Cash equivalents consist of money market funds and are stated at fair value.

Restricted Cash

Restricted cash represents cash held by a financial institution as collateral for a letter of credit securing its operating lease for office and laboratory space, which is classified as a non-current asset on the balance sheets based on the maturity of the lease.

Marketable Securities

The Company holds investments in marketable securities, consisting of U.S. government securities. Marketable debt securities with stated maturities of three months or less from the date of purchase are classified as cash equivalents and those with stated maturities of greater than three months as marketable securities on the balance sheet. The Company determines the appropriate classification of marketable debt securities at the time of purchase. The Company has the ability, if necessary, to liquidate its investments to meet its liquidity needs in the next 12 months, without significant penalty. Accordingly, those investments with contractual maturities greater than one year from the date of purchase are classified as current assets on the accompanying balance sheets. All marketable debt securities are classified as available-for-sale and are reported at estimated fair value, with unrealized gains and losses recorded in accumulated other comprehensive loss within stockholders’ equity. Interest, amortization and accretion of purchase premiums and discounts on marketable debt securities are included in other income (expense), net, in the statements of operations and comprehensive loss.

The cost of available-for-sale marketable securities sold is based on the specific identification method. Realized gains and losses on the sale of available-for-sale marketable securities are recorded in other income, net in the statements of operations and comprehensive loss.

The Company regularly reviews all of the marketable securities for decline in fair value to determine whether unrealized losses have resulted from credit loss or other factors. The review includes considerations for the cause of the impairment but is not limited to (i) the consideration of the cause of the decline, (ii) any currently recorded expected credit losses and (iii) the creditworthiness of the respective security issuers. A decline of fair value below cost basis is considered an other-than-temporary impairment if the Company has the intent to sell the security or it is more likely than not that the company will be required to sell the security before recovery of the entire cost basis. Regardless of the Company’s intent or requirement to sell the security, an impairment is considered other-than-temporary if the Company does not expect to recover the entire cost basis. In those instances, an impairment charge equal to the

difference between fair value and the cost basis is recorded in other income (expense), on the statements of operations and comprehensive loss. No impairment loss was recognized for the fiscal years ended December 31, 2023 and 2022.

The amortized or accreted cost basis of the marketable securities approximates its fair value.

Deferred Offering Costs

Deferred offering costs consisting of legal, accounting and filing fees relating to equity offerings. Deferred offering costs are included in other long-term assets on the Company’s balance sheets. Upon completion of the offering, these amounts are offset against the proceeds of the offering.

Leases

The Company leases office space under operating leases and determines if the arrangement is a lease at inception. These leases contain lease and non-lease components. Non-lease components include payments for maintenance, utilities, real estate taxes, and management fees. The lease and non-lease components are combined and accounted as a single lease component. Payments made under operating leases (net of any incentive received from the lessors) are recorded on a straight-line basis over the term of the lease.

These leases do not provide an implicit rate, the Company uses an incremental borrowing rate based on information available at commencement date in determining the present value of lease payments. The incremental borrowing rate is a hypothetical rate based on the Company’s understanding of what the credit rating would be in a similar economic environment. Operating leases are included in operating lease right-of-use assets and operating lease liabilities, current and non-current, on the balance sheets.

Leases may include one or more options to renew. The Company does not assume renewals in determination of the lease term unless the renewals are deemed to be reasonably assured. The lease agreements generally do not contain any material residual value guarantees or material restrictive covenants.

Foreign Currency Translations

Transactions denominated in foreign currencies are initially measured in U.S. dollars using the exchange rate on the date of the transaction. Foreign currency denominated monetary assets and liabilities are subsequently re-measured at the end of each reporting period using the exchange rate at that date, with the corresponding foreign currency transaction gain or loss recorded in the statements of operations and statements of cash flows. Nonmonetary assets and liabilities are not subsequently re-measured.

Fair Value Measurements

Fair value is defined as the exchange price to sell an asset or transfer a liability (exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants at the measurement date. Fair value should be based on the assumptions market participants would use when pricing the asset or liability. The valuation hierarchy is based upon the transparency of inputs to the valuation of an asset or liability as of the measurement date.

Fair value measurements are classified and disclosed in one of the following three categories:

Level 1 – Quoted unadjusted prices for identical instruments in active markets.

Level 2 – Quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-derived valuations in which all observable inputs and significant value drivers are observable in active markets.

Level 3 – Model derived valuations in which one or more significant inputs or significant value drivers are unobservable, including assumptions developed by the Company.

Fair value accounting is applied to all financial assets and liabilities that are recognized or disclosed in the financial statements on a recurring basis. The Company’s financial instruments consist of cash and cash equivalents, restricted cash, marketable securities, prepaid expenses and other current assets, non-marketable equity securities, accounts payable and accrued expenses and long-term debt. Cash, restricted cash, and marketable securities and non-marketable securities are reported at their respective fair values on the Company’s balance sheets. The remaining financial instruments are reported on the Company’s balance sheets at cost, which approximate their fair value due to their short-term nature.

Money market funds are highly liquid investments that are actively traded. The pricing information for the Company’s money market funds are readily available and can be independently validated as of the measurement date. This approach results in the classification of these securities as Level 2 of the fair value hierarchy.

The Company’s non-marketable equity securities (see Note 5) are measured at fair value using an option pricing valuation methodology. The option pricing methodology relies on risk-neutral valuation which calculates the value of an asset by discounting the expected value of its future payoffs at the risk-free rate of return. The fair value of the non-marketable equity securities is derived from quoted prices for similar instruments and observable inputs in active markets. This approach results in the classification of these securities as Level 2 of the fair value hierarchy.

There were no transfers between Levels 1, 2, or 3 for any of the periods presented. As of December 31, 2023, and December 31, 2022, the Company held $44.7 million and $42.5 million, respectively, in money market funds.

Comprehensive Loss

Comprehensive loss consists of two components: net loss and other comprehensive loss. Other comprehensive loss refers to unrealized gains and losses that are recorded as an element of stockholders’ equity and are excluded from net loss. For the year ended December 31, 2023, other comprehensive loss consists of unrealized gains and losses on marketable securities.

Research and Development Costs

Research and development costs are expensed as incurred and consist primarily of employees’ salaries and related benefits, including stock-based compensation and termination expenses for employees engaged in research and development efforts, allocated overhead including rent, depreciation, information technology and utilities, contracted services, license fees, and external expenses to conduct and support the Company’s operations that are directly attributable to the Company’s research and development efforts. Payments made to third parties under these arrangements in advance of the performance of the related services by the third parties are recorded as prepaid expenses until the services are rendered.

Costs incurred in obtaining technology licenses including upfront and milestone payments incurred under the Company’s licensing agreements are recorded as expense in the period in which they are incurred, provided that the licensed technology, method or process has no alternative future uses other than for the Company’s research and development activities. Where contingent milestone payments are due to third parties under license or other agreements, the milestone payment obligations are recognized as expense when achievement of the contingent milestone is probable, which is generally upon achievement of the milestone.

Research Contract Costs And Accruals

Research Contract Costs and Accruals

The Company enters into various research and development and other agreements with commercial firms, researchers, and others for provisions of goods and services from time to time. These agreements are generally cancellable, and the related costs are recorded as research and development expenses as incurred. The Company records accruals for estimated ongoing research and development costs. When evaluating the adequacy of the accrued liabilities, the Company analyzes progress of the studies or clinical trials, including the phase or completion of events, invoices received and contracted costs. Significant judgments and estimates are made in determining the accrued balances at the end of any reporting period. Actual results could differ materially from the Company’s estimates.

Stock-Based Compensation

The Company recognizes compensation expense based on estimated fair values for all stock-based payment awards made to the Company’s employees, nonemployee directors and consultants that are expected to vest. The valuation of stock option awards is determined at the date of grant using the Black-Scholes option pricing model. The Black-Scholes option pricing model requires the Company to make assumptions and judgments about the inputs used in the calculations, such as the fair value of the common stock, expected term, expected volatility of the Company’s common stock, risk-free interest rate and expected dividend yield. The valuation of restricted stock awards is measured by the fair value of the Company’s Class A common stock on the date of the grant.

For all stock options granted, the Company calculated the expected term using the simplified method (derived from the average midpoint between the weighted average vesting period and the contractual term of the award) for “plain vanilla” stock option awards, as the Company has limited historical information to develop expectations about future exercise patterns and post vesting employment termination behavior. The estimate of expected volatility is based on comparative companies’ volatility. The risk-free rate is based on the yield available on United States Treasury zero-coupon issues corresponding to the expected term of the award. The Company records forfeitures when they occur. The Company determines the fair value of its Class A common stock using the market closing price on the date of grant.

The Company records compensation expense for service-based awards on a straight-line basis over the requisite service period, which is generally the vesting period of the award. The amount of stock-based compensation expense recognized during a period is based on the value of the portion of the awards that are ultimately expected to vest.

Income Taxes

Income taxes are accounted for under the asset and liability method. Deferred income taxes are recorded for temporary differences between financial statement carrying amounts and the tax basis of assets and liabilities. Deferred tax assets and liabilities reflect tax rates expected to be in effect for the years in which the differences are expected to be reversed. A valuation allowance is provided if it is more likely than not that some or all of the deferred tax assets will not be realized.

Net Loss Per Share Attributable to Common Stockholders

Net loss per share of common stock is computed using the two-class method required for multiple classes of common stock and participating securities based upon their respective rights to receive dividends as if all income for the period has been distributed. The rights, including the liquidation and dividend rights and sharing of losses, of the Class A and Class B common stock are identical, other than voting rights. As the liquidation and dividend rights and sharing of losses are identical, the undistributed earnings are allocated on a proportionate basis and the resulting net loss per share attributed to common stockholders is therefore the same for Class A and Class B common stock on an individual or combined basis.

Basic net loss per share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding during the period, adjusted for outstanding shares that are subject to repurchase.

Diluted net loss per share is computed by giving effect to all potentially dilutive securities outstanding for the period using the treasury stock method or the if-converted method based on the nature of such securities. For periods in which the Company reports net losses, diluted net loss per share attributable to common stockholders is the same as basic net loss per share attributable to common stockholders, because potentially dilutive shares are not assumed to have been issued if their effect is anti-dilutive.

Recently Issued Accounting Pronouncements Not Yet Adopted

In June 2022, the FASB issued ASU 2022-03, Fair Value Measurement (Topic 820): Fair Value Measurement of Equity Securities Subject to Contractual Sale Restrictions. This standard clarifies the guidance in Topic 210, when measuring the fair value of an equity security subject to contractual restrictions that prohibit the sale of an equity security and introduces new disclosure requirements for equity securities subject to contractual sale restrictions that are measured at fair value in accordance with Topic 820. The guidance is effective for annual periods beginning after December 15, 2023, with early adoption permitted. The Company does not expect that the adoption of this standard will have a material impact on its financial statements and related disclosures.

In December 2023, the FASB issued ASU 2023-09, Improvements to Income Tax Disclosures (Topic 740). The ASU requires disaggregated information about a reporting entity’s effective tax rate reconciliation as well as additional information on income taxes paid. The ASU is effective on a prospective basis for annual periods beginning after December 15, 2024. Early adoption is also permitted for annual financial statements that have not yet been issued or made available for issuance. This ASU will result in the required additional disclosures being included in the Company’s financial statements upon adoption.