Summary of Significant Accounting Policies	6 Months Ended
Jun. 30, 2026
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 (loss) 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 cost 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 receivable from contracts with collaborators, included within accounts receivable, net, 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. 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. 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 months ended June 30, 2026 and 2025, 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 June 30, 2026 and 2025 totaling approximately 21,667,000 and 18,213,000, respectively, were excluded from the computation of dilutive weighted-average shares outstanding because their effect would be anti-dilutive. Recent Accounting Pronouncements Disaggregation of Income Statement Expenses In November 2024, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or 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 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. Intangibles – Goodwill and Other – Internal-Use Software (Subtopic 350-40) In September 2025, the FASB issued ASU 2025-06, Intangibles – Goodwill and Other – Internal-Use Software (Subtopic 350-40): Targeted Improvements to the Accounting for Internal-Use Software. Under this guidance, software capitalization will begin when management authorizes and commits to funding the software project and it is probable that the project will be completed and the software will be used for its intended purpose. ASU 2025-06 is effective for annual reporting periods beginning after December 15, 2027, and interim reporting periods within those periods, with early adoption permitted. We are currently evaluating the impact of adopting ASU 2025-06.

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 (loss) 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 cost 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 receivable from contracts with collaborators, included within accounts receivable, net, 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.

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.

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 months ended June 30, 2026 and 2025, 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 June 30, 2026 and 2025 totaling approximately 21,667,000 and 18,213,000, respectively, were excluded from the computation of dilutive weighted-average shares outstanding because their effect would be anti-dilutive.

Recent Accounting Pronouncements

Disaggregation of Income Statement Expenses

In November 2024, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or 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 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.

Intangibles – Goodwill and Other – Internal-Use Software (Subtopic 350-40)

In September 2025, the FASB issued ASU 2025-06, Intangibles – Goodwill and Other – Internal-Use Software (Subtopic 350-40): Targeted Improvements to the Accounting for Internal-Use Software. Under this guidance, software capitalization

will begin when management authorizes and commits to funding the software project and it is probable that the project will be completed and the software will be used for its intended purpose. ASU 2025-06 is effective for annual reporting periods beginning after December 15, 2027, and interim reporting periods within those periods, with early adoption permitted. We are currently evaluating the impact of adopting ASU 2025-06.