Summary of Significant Accounting Policies	9 Months Ended
Sep. 30, 2025
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Allowance for Credit Losses For available-for-sale securities in an unrealized loss position, we first assess whether we intend to sell, or if it is more likely than not that we will be required to sell, the security before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the security’s amortized cost basis is written down to fair value through earnings. For available-for-sale securities that do not meet the aforementioned criteria, we evaluate whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, we consider the severity of the impairment, any changes in interest rates, market conditions, changes to the underlying credit ratings and forecasted recovery, among other factors. The credit-related portion of unrealized losses, and any subsequent improvements, are recorded in interest and other income, net on the unaudited condensed statements of operations and comprehensive loss through an allowance account. Any impairment that has not been recorded through an allowance for credit losses is included in other comprehensive income on the unaudited condensed statements of operations and comprehensive loss. We elected the practical expedient to exclude the applicable accrued interest from both the fair value and amortized costs basis of our available-for-sale securities for purposes of identifying and measuring an impairment. Accrued interest receivable on available-for-sale securities is recorded in prepaid expenses and other current assets on our unaudited condensed balance sheets. Our accounting policy is to not measure an allowance for credit loss for accrued interest receivable and to write-off any uncollectible accrued interest receivable as a reversal of interest income in a timely manner, which we consider to be in the period in which we determine the accrued interest will not be collected by us. Concentration of Credit Risk Financial instruments that potentially subject us to significant concentrations of credit risk consist primarily of cash, cash equivalents and short-term investments. We maintain deposits in federally insured financial institutions in excess of federally insured limits. We have established guidelines to limit our exposure to credit risk by placing investments with high credit quality financial institutions, diversifying our investment portfolio and placing investments with maturities that maintain safety and liquidity. We periodically review and modify these guidelines to maximize trends in yields and interest rates without compromising safety and liquidity. Our accounts receivable is derived from contracts with our collaborators. We do not typically require collateral from our collaborators. We continuously monitor payments from collaborators and consider various factors including historical experience, age of the receivable balances, and other current economic conditions or other factors that may affect our collaborators’ ability to pay. Property and Equipment Property and equipment are stated at cost and depreciated using the straight-line method over the estimated useful lives of the assets. Computer software and equipment are depreciated over their estimated useful lives of three to five years. Laboratory equipment is depreciated over its estimated useful life of five years. Furniture and fixtures are depreciated over their estimated useful lives of five years. Leasehold improvements are depreciated over the lesser of the term of the related lease or the useful life of the asset. Leases We determine if an arrangement is a lease or contains lease components at inception. Short-term leases with an initial term of 12 months or less are not recorded on the unaudited condensed balance sheets. For operating leases with an initial term greater than 12 months, we recognize operating lease right-of-use, or ROU, assets and operating lease liabilities based on the present value of lease payments over the lease term at commencement date. Operating lease ROU assets are comprised of the lease liability plus any lease payments made and exclude lease incentives. Lease terms may include options to extend or terminate when we are reasonably certain that the options will be exercised. We do not separate lease components from non-lease components. For our operating leases, we generally cannot determine the interest rate implicit in the lease, in which case we use our incremental borrowing rate as the discount rate for the lease. We estimate our incremental borrowing rate for our operating leases based on what we would normally pay to borrow on a collateralized basis over a similar term for an amount equal to the lease payments. Operating lease expense is recognized on a straight-line basis over the lease term. If a lease is modified, the modified contract is evaluated to determine whether it is or contains a lease. If a lease continues to exist, the lease modification is determined to be a separate contract when the modification grants the lessee an additional ROU that is not included in the original lease and the lease payments increase commensurate with the standalone price for the additional ROU. A lease modification that results in a separate contract will be accounted for in the same manner as a new lease. For a modification that is not a separate contract, we reassess the lease classification using the modified terms and conditions and the facts and circumstances as of the effective date of the modification and recognize the amount of the remeasurement of the lease liability for the modified lease as an adjustment to the corresponding operating lease ROU asset. Collaboration Arrangements We assess whether our licensing and other agreements are collaborative arrangements within the scope of Accounting Standards Codification, or ASC, Topic 808, Collaborative Arrangements, or Topic 808, based on whether they involve joint operating activities wherein both parties actively participate in the arrangement and are exposed to significant risks and rewards of the arrangement. For arrangements that we determine are collaborations under the Scope of Topic 808, we identify each unit of account by determining which promised goods or services are distinct in accordance with ASC Topic 606, Revenue from Contracts with Customers, or Topic 606, and then determine whether a customer relationship exists for that unit of account. If we determine a unit of account within the collaborative arrangement to be with a customer, we apply our revenue recognition accounting policy as further described below. For units of account within the collaborative arrangement under Topic 808 that are not with a customer in its entirety and are not within the scope of other relevant accounting topics, we apply recognition and measurement principles based on an analogy to authoritative accounting literature or, if there is no appropriate analogy, a reasonable, rational and consistently applied accounting policy election. See Note 7, Kyowa Kirin Collaboration and License Agreement, for more details. Revenue from Collaborations and Licenses We recognize revenue when control of the promised goods or services is transferred to our customers, in an amount that reflects the consideration we expect to be entitled to in exchange for those goods or services. To determine revenue recognition for arrangements that are within the scope of Topic 606, we perform the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation. For enforceable contracts with our customers, we evaluate the promises in the contract that are based on goods and services that will be transferred to the customer and determine whether those promises are both (i) capable of being distinct and (ii) distinct in the context of the contract. Arrangements that include rights to additional goods or services that are exercisable at the customer’s discretion are generally considered customer options. We assess if these customer options provide a material right to the customer and, if so, these customer options are considered performance obligations. The transaction price may comprise of payments received under our commercial arrangements, such as licensing technology rights, and may include non-refundable fees at the inception of the arrangements, cost reimbursements, milestone payments for specific achievements designated in the agreements, and royalties on the sale of products. Profit-sharing payments to our customers are generally not for a distinct good or service and, as such, are included as a reduction of the transaction price. At the inception of arrangements that include variable consideration, we may be required to exercise significant judgment to estimate the amount of variable consideration to include in the transaction price. In making such estimates, we generally use the most likely amount method for milestone payments and the expected value method for other forms of variable consideration and take into account relevant development, regulatory, and other factors that can impact the level of uncertainty associated with these estimates. The amount of variable consideration that is included in the transaction price may be constrained and is included in the transaction price only to the extent that it is probable that a significant reversal in the amount of the cumulative revenue recognized will not occur in a future period. Milestone payments that are not within our or the licensee’s control, such as regulatory approvals, are not included in the transaction price until those approvals are received. At the end of each reporting period, we re-evaluate estimated variable consideration included in the transaction price and any related constraint and, as necessary, we adjust our estimate of the overall transaction price. Any adjustments are recorded on a cumulative catch-up basis, which affects revenues and earnings in the period of adjustment. We develop estimates of the stand-alone selling price for each distinct performance obligation, which involve assumptions that may require significant judgment. Our estimates of the stand-alone selling price for license-related performance obligations may include forecasted revenues and expenses, development timelines, reimbursement rates for personnel costs, discount rates and probabilities of technical, regulatory and commercial success. Our estimates of the stand-alone selling price for research and development or other service-related performance obligations generally include forecasting the expected costs of satisfying a performance obligation at market rates. We allocate the transaction price, including any unconstrained variable consideration, to the performance obligations within the arrangement based on the relative stand-alone selling prices. When the variable consideration relates specifically to our efforts to satisfy one or more, but not all, performance obligations and allocating the consideration specifically to those performance obligations is consistent with the overall allocation objectives within Topic 606, we allocate the consideration entirely to those performance obligations. We use judgment to assess the nature of the performance obligation to determine whether the performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue related to the performance obligation. If the performance obligation is satisfied over time, we evaluate the measure of progress each reporting period and, if necessary, adjust the measure of performance and related revenue recognition. The selection of the method to measure progress towards completion of over-time performance obligations is based on the nature of the products or services to be provided. Our over-time performance obligations generally involve research and development or other services provided to the customer, and we generally use a cost-to-cost measure of progress because it best depicts the transfer of control to the customer. Under a cost-to-cost measure of progress, the extent of progress towards completion is measured based on the ratio of costs incurred to date compared to the total estimated costs at completion of the performance obligation (an “input method” under Topic 606). We use judgment to estimate the total cost expected to complete the research and development or other service-related performance obligations, which include subcontractors’ costs, labor, materials, other direct costs and an allocation of indirect costs. We evaluate these cost estimates and the progress each reporting period and, as necessary, we adjust the measure of progress and related revenue recognition. For arrangements that include sales-based or usage-based royalties, we recognize revenue at the later of (i) when the related sales occur or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied or partially satisfied. Consideration received or invoices issued as stipulated in contracts prior to revenue recognition are recorded as contract liabilities in the accompanying unaudited condensed balance sheets, classified as either current or long-term contract liabilities based on our best estimate of when such amounts will be recognized. Amounts recognized as revenue, but not yet invoiced are generally recognized as contract assets in other current assets in the accompanying unaudited condensed balance sheets. Net Loss per Share Basic net loss per common share is calculated by dividing the net loss by the weighted-average number of common shares outstanding for the period, which includes the shares related to outstanding pre-funded warrants, but excludes other potential common stock equivalents. Pre-funded warrants are considered outstanding for the purposes of computing basic and diluted net loss per share because shares may be issued for little additional consideration, and are fully vested and exercisable. Diluted net loss per share is calculated by dividing net loss by the weighted-average number of common shares and common stock equivalents outstanding for the period. As we have reported net loss for the three and nine months ended September 30, 2025 and 2024, dilutive net loss per common share is the same as basic net loss per common share for those periods. Common stock equivalents outstanding are comprised of stock options, restricted stock units, or RSUs, performance-based restricted stock units, or PSUs, warrants and employee stock purchase plan rights and are only included in the calculation of diluted earnings per common share when net income is reported and their effect is dilutive. Common stock equivalents outstanding at September 30, 2025 and 2024 totaling approximately 18,559,000 and 15,136,000, respectively, were excluded from the computation of dilutive weighted-average shares outstanding because their effect would be anti-dilutive. Segment Reporting Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision-maker in making decisions regarding resource allocation and assessing performance. We operate in a single industry segment which is the discovery and development of precision medicines for the treatment of cancer. Troy E. Wilson, Ph.D., J.D., our president and chief executive officer, who serves as the Chief Operating Decision-Maker, or CODM, reviews the operating results on an aggregate basis and manages the operations as a single operating segment in the United States. Recent Accounting Pronouncements Improvements to Income Tax Disclosures In December 2023, the Financial Accounting Standards Board, or FASB, issued ASU 2023-09 – Improvements to Income Tax Disclosures (Topic 740), which improves the transparency of income tax disclosures by requiring disaggregated information about our effective tax rate reconciliation as well as information on income taxes paid. For each annual period, we will be required to disclose specific categories in the rate reconciliation and provide additional information for reconciling items that meet a quantitative threshold (if the effect of those reconciling items is equal to or greater than 5% of the amount computed by multiplying pretax income or loss by the applicable statutory income tax rate). ASU 2023-09 is effective for annual periods beginning after December 15, 2024. Early adoption is permitted for annual financial statements that have not yet been issued. We plan to adopt the standard on December 31, 2025, and are currently evaluating the effect of the standard on our financial statements. Disaggregation of Income Statement Expenses In November 2024, the FASB issued ASU 2024-03 Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses, which requires disaggregated disclosure of certain costs and expenses on an interim and annual basis. ASU No. 2024-03 is effective for fiscal years beginning after December 15, 2026, and interim periods within fiscal years beginning after December 15, 2027, with early adoption permitted. The disclosure updates are required to be applied prospectively with the option for retrospective application. We are currently evaluating the impact of adopting ASU 2024-03.

Allowance for Credit Losses

For available-for-sale securities in an unrealized loss position, we first assess whether we intend to sell, or if it is more likely than not that we will be required to sell, the security before recovery of its amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the security’s amortized cost basis is written down to fair value through earnings. For available-for-sale securities that do not meet the aforementioned criteria, we evaluate whether the decline in fair value has resulted from credit losses or other factors. In making this assessment, we consider the severity of the impairment, any changes in interest rates, market conditions, changes to the underlying credit ratings and forecasted recovery, among other factors. The credit-related portion of unrealized losses, and any subsequent improvements, are recorded in interest and other income, net on the unaudited condensed statements of operations and comprehensive loss through an allowance account. Any impairment that has not been recorded through an allowance for credit losses is included in other comprehensive income on the unaudited condensed statements of operations and comprehensive loss.

We elected the practical expedient to exclude the applicable accrued interest from both the fair value and amortized costs basis of our available-for-sale securities for purposes of identifying and measuring an impairment. Accrued interest receivable on available-for-sale securities is recorded in prepaid expenses and other current assets on our unaudited condensed balance sheets. Our accounting policy is to not measure an allowance for credit loss for accrued interest receivable and to write-off any uncollectible accrued interest receivable as a reversal of interest income in a timely manner, which we consider to be in the period in which we determine the accrued interest will not be collected by us.

Leases

We determine if an arrangement is a lease or contains lease components at inception. Short-term leases with an initial term of 12 months or less are not recorded on the unaudited condensed balance sheets. For operating leases with an initial term greater than 12 months, we recognize operating lease right-of-use, or ROU, assets and operating lease liabilities based on the present value of lease payments over the lease term at commencement date. Operating lease ROU assets are comprised of the lease liability plus any lease payments made and exclude lease incentives. Lease terms may include options to extend or terminate when we are reasonably certain that the options will be exercised. We do not separate lease components from non-lease components. For our operating leases, we generally cannot determine the interest rate implicit in the lease, in which case we use our incremental borrowing rate as the discount rate for the lease. We estimate our incremental borrowing rate for our operating leases based on what we would normally pay to borrow on a collateralized basis over a similar term for an amount equal to the lease payments. Operating lease expense is recognized on a straight-line basis over the lease term.

If a lease is modified, the modified contract is evaluated to determine whether it is or contains a lease. If a lease continues to exist, the lease modification is determined to be a separate contract when the modification grants the lessee an additional ROU that is not included in the original lease and the lease payments increase commensurate with the standalone price for the additional ROU. A lease modification that results in a separate contract will be accounted for in the same manner as a new lease. For a modification that is not a separate contract, we reassess the lease classification using the modified terms and conditions and the facts and circumstances as of the effective date of the modification and recognize the amount of the remeasurement of the lease liability for the modified lease as an adjustment to the corresponding operating lease ROU asset.

Collaboration Arrangements

We assess whether our licensing and other agreements are collaborative arrangements within the scope of Accounting Standards Codification, or ASC, Topic 808, Collaborative Arrangements, or Topic 808, based on whether they involve joint operating activities wherein both parties actively participate in the arrangement and are exposed to significant risks and rewards of the arrangement. For arrangements that we determine are collaborations under the Scope of Topic 808, we identify each unit of account by determining which promised goods or services are distinct in accordance with ASC Topic 606, Revenue from Contracts with Customers, or Topic 606, and then determine whether a customer relationship exists for that unit of account. If we determine a unit of account within the collaborative arrangement to be with a customer, we apply our revenue recognition accounting policy as further described below. For units of account within the collaborative arrangement under Topic 808 that are not with a customer in its entirety and are not within the scope of other relevant accounting topics, we apply recognition and measurement principles based on an analogy to authoritative accounting literature or, if there is no appropriate analogy, a reasonable, rational and consistently applied accounting policy election. See Note 7, Kyowa Kirin Collaboration and License Agreement, for more details.

Revenue from Collaborations and Licenses

We recognize revenue when control of the promised goods or services is transferred to our customers, in an amount that reflects the consideration we expect to be entitled to in exchange for those goods or services. To determine revenue recognition for arrangements that are within the scope of Topic 606, we perform the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation.

For enforceable contracts with our customers, we evaluate the promises in the contract that are based on goods and services that will be transferred to the customer and determine whether those promises are both (i) capable of being distinct and (ii) distinct in the context of the contract. Arrangements that include rights to additional goods or services that are exercisable at the customer’s discretion are generally considered customer options. We assess if these customer options provide a material right to the customer and, if so, these customer options are considered performance obligations.

The transaction price may comprise of payments received under our commercial arrangements, such as licensing technology rights, and may include non-refundable fees at the inception of the arrangements, cost reimbursements, milestone payments for specific achievements designated in the agreements, and royalties on the sale of products. Profit-sharing payments to our customers are generally not for a distinct good or service and, as such, are included as a reduction of the transaction price. At the inception of arrangements that include variable consideration, we may be required to exercise significant judgment to estimate the amount of variable consideration to include in the transaction price. In making such estimates, we generally use the most likely amount method for milestone payments and the expected value method for other forms of variable consideration and take into account relevant development, regulatory, and other factors that can impact the level of uncertainty associated with these estimates. The amount of variable consideration that is included in the transaction price may be constrained and is included in the transaction price only to the extent that it is probable that a significant reversal in the amount of the cumulative revenue recognized will not occur in a future period. Milestone payments that are not within our or the licensee’s control, such as regulatory approvals, are not included in the transaction price until those approvals are received. At the end of each reporting period, we re-evaluate estimated variable consideration included in the transaction price and any related constraint and, as necessary, we adjust our estimate of the overall transaction price. Any adjustments are recorded on a cumulative catch-up basis, which affects revenues and earnings in the period of adjustment.

We develop estimates of the stand-alone selling price for each distinct performance obligation, which involve assumptions that may require significant judgment. Our estimates of the stand-alone selling price for license-related performance obligations may include forecasted revenues and expenses, development timelines, reimbursement rates for personnel costs, discount rates and probabilities of technical, regulatory and commercial success. Our estimates of the stand-alone selling price for research and development or other service-related performance obligations generally include forecasting the expected costs of satisfying a performance obligation at market rates. We allocate the transaction price, including any unconstrained variable consideration, to the performance obligations within the arrangement based on the relative stand-alone selling prices. When the variable consideration relates specifically to our efforts to satisfy one or more, but not all, performance obligations and allocating the consideration specifically to those performance obligations is consistent with the overall allocation objectives within Topic 606, we allocate the consideration entirely to those performance obligations.

We use judgment to assess the nature of the performance obligation to determine whether the performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue related to the performance obligation. If the performance obligation is satisfied over time, we evaluate the measure of progress each reporting period and, if necessary, adjust the measure of performance and related revenue recognition.

The selection of the method to measure progress towards completion of over-time performance obligations is based on the nature of the products or services to be provided. Our over-time performance obligations generally involve research and development or other services provided to the customer, and we generally use a cost-to-cost measure of progress because it best depicts the transfer of control to the customer. Under a cost-to-cost measure of progress, the extent of progress towards completion is measured based on the ratio of costs incurred to date compared to the total estimated costs at completion of the performance obligation (an “input method” under Topic 606). We use judgment to estimate the total cost expected to complete the research and development or other service-related performance obligations, which include subcontractors’ costs, labor, materials, other direct costs and an allocation of indirect costs. We evaluate these cost estimates and the progress each reporting period and, as necessary, we adjust the measure of progress and related revenue recognition.

Net Loss per Share

Basic net loss per common share is calculated by dividing the net loss by the weighted-average number of common shares outstanding for the period, which includes the shares related to outstanding pre-funded warrants, but excludes other potential common stock equivalents. Pre-funded warrants are considered outstanding for the purposes of computing basic and diluted net loss per share because shares may be issued for little additional consideration, and are fully vested and exercisable. Diluted net loss per share is calculated by dividing net loss by the weighted-average number of common shares and common stock equivalents outstanding for the period. As we have reported net loss for the three and nine months ended September 30, 2025 and 2024, dilutive net loss per common share is the same as basic net loss per common share for those periods. Common stock equivalents outstanding are comprised of stock options, restricted stock units, or RSUs, performance-based restricted stock units, or PSUs, warrants and employee stock purchase plan rights and are only included in the calculation of diluted earnings per common share when net income is reported and their effect is dilutive. Common stock equivalents outstanding at September 30, 2025 and 2024 totaling approximately 18,559,000 and 15,136,000, respectively, were excluded from the computation of dilutive weighted-average shares outstanding because their effect would be anti-dilutive.

Recent Accounting Pronouncements

Improvements to Income Tax Disclosures

In December 2023, the Financial Accounting Standards Board, or FASB, issued ASU 2023-09 – Improvements to Income Tax Disclosures (Topic 740), which improves the transparency of income tax disclosures by requiring disaggregated information about our effective tax rate reconciliation as well as information on income taxes paid. For each annual period, we will be required to disclose specific categories in the rate reconciliation and provide additional information for reconciling items that meet a quantitative threshold (if the effect of those reconciling items is equal to or greater than 5% of the amount computed by multiplying pretax income or loss by the applicable statutory income tax rate). ASU 2023-09 is effective for annual periods beginning after December 15, 2024. Early adoption is permitted for annual financial statements that have not yet been issued. We plan to adopt the standard on December 31, 2025, and are currently evaluating the effect of the standard on our financial statements.

Disaggregation of Income Statement Expenses

In November 2024, the FASB issued ASU 2024-03 Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses, which requires disaggregated disclosure of certain costs and expenses on an interim and annual basis. ASU No. 2024-03 is effective for fiscal years beginning after December 15, 2026, and interim periods within fiscal years beginning after December 15, 2027, with early adoption permitted. The disclosure updates are required to be applied prospectively with the option for retrospective application. We are currently evaluating the impact of adopting ASU 2024-03.