Summary of Significant Accounting Policies (Policies)	3 Months Ended
Mar. 31, 2026
Accounting Policies [Abstract]
Basis of Presentation and Principles of Consolidation	Basis of Presentation and Principles of Consolidation The Company’s unaudited condensed consolidated 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 interim financial reporting. All intercompany balances and transactions have been eliminated upon consolidation. The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the annual consolidated financial statements and reflect, in the opinion of management, all adjustments of a normal and recurring nature that are necessary for the fair presentation of the Company’s financial information. The unaudited condensed consolidated results of operations for the three months ended March 31, 2026 are not necessarily indicative of the results to be expected for the year ending December 31, 2026, or for any other future annual or interim period. Certain information and footnote disclosures typically included in the Company’s annual consolidated financial statements have been condensed or omitted. As such, these unaudited interim condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and related notes included in the Annual Report on Form 10-K for the year ended December 31, 2025.
Use of Estimates	Use of Estimates The preparation of the unaudited condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent liabilities at the date of the unaudited condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting periods. The Company evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors and adjusts those estimates and assumptions when facts and circumstances dictate. Actual results could materially differ from those estimates.
Segments	Segments Operating segments are defined as components of an entity about which separate discrete information is available for evaluation by the chief operating decision maker (CODM) in deciding how to allocate resources and in assessing performance. The Company manages the business activities on a consolidated basis and operates as one reportable segment that constitutes all of the consolidated entity, which is the business of powering the immune system to transform lives by discovering and developing medicines for serious infectious diseases and cancer. Factors used in determining the reportable segment include the nature of the Company’s operating activities, the organizational and reporting structure, and the type of information regularly provided to the CODM to allocate resources and evaluate financial performance. The Company’s CODM is its Chief Executive Officer.
Cash Equivalents	Cash Equivalents The Company considers all highly liquid investments with original maturities of three months or less at the date of purchase to be cash equivalents, which consist of amounts invested primarily in money market funds and are stated at fair value.
Investments	Investments Investments include available-for-sale debt securities and equity investments, which are carried at fair value. Available-for-Sale Debt Securities The Company’s valuations of marketable securities are generally derived from independent pricing services based on quoted prices in active markets for similar securities at period end. Generally, investments with original maturities beyond three months at the date of purchase and that mature at, or less than 12 months from, the unaudited condensed consolidated balance sheet date are considered short-term investments, with all others considered to be long-term investments. Unrealized gains and losses deemed temporary in nature are reported as a component of accumulated other comprehensive loss. The amortized cost of debt securities is adjusted for amortization of premiums and accretion of discounts to maturity, which is included in interest income on the unaudited condensed consolidated statements of operations. The cost of securities sold is based on the specific identification method.
Restricted Cash and Cash Equivalents	Restricted Cash and Cash Equivalents Restricted cash and cash equivalents primarily includes funds to secure standby letters of credit and security deposits with financial institutions under lease agreements and funds restricted as to withdrawal or usage under grant agreements and collaboration agreements.
Research and Development Expenses	Research and Development Expenses To date, research and development expenses have related primarily to discovery efforts and preclinical and clinical development of product candidates. Research and development expenses are recognized as incurred, and payments made prior to the receipt of goods or services to be used in research and development are capitalized until the goods or services are received. Research and development expenses include expenses related to license and collaboration agreements; contingent consideration from business acquisitions; personnel-related expenses, including salaries, benefits, and stock-based compensation for personnel contributing to research and development activities; expenses incurred under agreements with third-party contract development and manufacturing organizations (CDMOs), contract research organizations, and consultants; clinical costs, including laboratory supplies and costs related to compliance with regulatory requirements; and other allocated expenses, including expenses for rent, facilities maintenance, and depreciation and amortization. The Company has acquired and may continue to acquire the rights to develop and commercialize new product candidates from third parties. Upfront payments and research and development milestone payments made in connection with acquired licenses or product rights are expensed as incurred, provided that they do not relate to a regulatory approval milestone or assets acquired in a business combination. The Company’s expense accruals for clinical trials and manufacturing are based on estimates of contracted services provided by third-party vendors not yet billed. When billing terms under these contracts do not coincide with the timing of when the work is performed, the Company is required to make estimates of its outstanding obligations to those third parties as of the period end. The accrual estimates are based on a number of factors, including the Company’s knowledge of the research and development programs and clinical manufacturing activities, the status of the programs and activities, invoicing to date, and the provisions in the contracts. The Company obtains information regarding unbilled services directly from these service providers and performs procedures to support its estimates based on its internal understanding of the services provided to date. However, the Company may also be required to estimate these services based on information available to its internal clinical and manufacturing administrative staff if such information is not able to be obtained timely from its service providers.
New Accounting Pronouncement Not Yet Adopted	New Accounting Pronouncement Not Yet Adopted In November 2024, the FASB issued ASU No. 2024-03, Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (ASU 2024-03), which requires entities to disclose specific information on the types of expenses included in the expense captions presented on the face of the income statement as well as disclosures about selling expenses. The guidance is effective for annual periods beginning after December 15, 2026 and interim periods within annual reporting periods beginning after December 15, 2027. Early adoption is permitted. ASU 2024-03 should be applied on a prospective basis, but retrospective application is permitted. The Company is currently evaluating the impact the adoption of ASU 2024-03 may have on its consolidated financial statements and related disclosures. In September 2025, the FASB issued ASU No. 2025-06, Targeted Improvements to the Accounting for Internal-Use Software (ASU 2025-06), which clarifies and modernizes the accounting for costs related to internal-use software in Accounting Standards Codification Topic 350-40, Intangibles —Goodwill and Other — Internal-Use Software (ASC 350-40). ASU 2025-06 removed all references to project stages throughout ASC 350-40, and requires entities to begin capitalizing software costs when both of the following occur: (1) management, with the relevant authority, implicitly or explicitly authorizes and commits to funding a computer software project; and (2) it is probable that the project will be completed and the software will be used to perform the function intended (referred to as the probable-to-complete recognition threshold). The guidance is effective for annual periods beginning after December 15, 2027 and interim periods within those annual reporting periods. Early adoption is permitted. ASU 2025-06 should be either applied on a prospective basis, retrospective or modified prospective basis based on the status of the project and whether software costs were capitalized before the date of adoption. The Company is currently evaluating the impact the adoption of ASU 2025-06 may have on its consolidated financial statements and related disclosures. In December 2025, the FASB issued ASU 2025-11 Interim Reporting (Topic 270): Narrow-Scope Improvements. The update provides clarifications intended to improve the consistency and usability of interim disclosure requirements, including a comprehensive listing of required interim disclosures and a new disclosure principle for reporting material events occurring after the most recent annual period. The amendments do not change the underlying objectives of interim reporting but are designed to enhance clarity in application. The guidance is effective for fiscal years beginning after December 15, 2027, including interim periods within those fiscal years. The Company is currently evaluating the impact of this guidance on its consolidated financial statements and related disclosures. In December 2025, the FASB issued ASU 2025-12 Codification Improvements, which addresses suggestions received from stakeholders on the Accounting Standards Codification ("the Codification") and to make other incremental improvements to U.S. GAAP. The update represents changes to the Codification that (i) clarify, (ii) correct errors, or (iii) make minor improvements. The amendments make the Codification easier to understand and apply. The guidance is effective for fiscal years beginning after December 15, 2026, including interim periods within those fiscal years. The Company is currently evaluating the impact of this guidance on its consolidated financial statements and related disclosures.
Reclassification	Reclassification Certain reclassifications have been made to prior period amounts on the Company’s consolidated statement of operations to conform to the current period presentation and enhance comparability. As a result, the Company changed its presentation of collaboration revenue to license and collaboration revenue and its presentation of contract revenue to other revenue. In conjunction with these changes, certain license revenue, primarily related the Company’s collaboration with Glaxo Wellcome UK Limited and GlaxoSmithKline Biologicals S.A. (GSK), which were presented as part of contract revenue in prior years, are now presented as part of license and collaboration revenue. Certain reclassifications have been made to prior period amounts on the Company’s condensed consolidated statements of cash flows to conform to the current period presentation and enhance comparability. As a result, certain amounts related to deferred revenue, previously reflected in changes in operating assets and liabilities – deferred revenue, were reclassified to changes in operating assets and liabilities – accrued liabilities and other long-term liabilities.

Summary of Significant Accounting Policies (Policies)

3 Months Ended

Mar. 31, 2026

Basis of Presentation and Principles of Consolidation

The Company’s unaudited condensed consolidated 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 interim financial reporting. All intercompany balances and transactions have been eliminated upon consolidation. The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the annual consolidated financial statements and reflect, in the opinion of management, all adjustments of a normal and recurring nature that are necessary for the fair presentation of the Company’s financial information. The unaudited condensed consolidated results of operations for the three months ended March 31, 2026 are not necessarily indicative of the results to be expected for the year ending December 31, 2026, or for any other future annual or interim period.

Certain information and footnote disclosures typically included in the Company’s annual consolidated financial statements have been condensed or omitted. As such, these unaudited interim condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and related notes included in the Annual Report on Form 10-K for the year ended December 31, 2025.

Use of Estimates

The preparation of the unaudited condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent liabilities at the date of the unaudited condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting periods. The Company evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors and adjusts those estimates and assumptions when facts and circumstances dictate. Actual results could materially differ from those estimates.

Segments

Operating segments are defined as components of an entity about which separate discrete information is available for evaluation by the chief operating decision maker (CODM) in deciding how to allocate resources and in assessing performance. The Company manages the business activities on a consolidated basis and operates as one reportable segment that constitutes all of the consolidated entity, which is the business of powering the immune system to transform lives by discovering and developing medicines for serious infectious diseases and cancer. Factors used in determining the reportable segment include the nature of the Company’s operating activities, the organizational and reporting structure, and the type of information regularly provided to the CODM to allocate resources and evaluate financial performance. The Company’s CODM is its Chief Executive Officer.

Cash Equivalents

The Company considers all highly liquid investments with original maturities of three months or less at the date of purchase to be cash equivalents, which consist of amounts invested primarily in money market funds and are stated at fair value.

Investments

Investments include available-for-sale debt securities and equity investments, which are carried at fair value.

Available-for-Sale Debt Securities

The Company’s valuations of marketable securities are generally derived from independent pricing services based on quoted prices in active markets for similar securities at period end. Generally, investments with original maturities beyond three months at the date of purchase and that mature at, or less than 12 months from, the unaudited condensed consolidated balance sheet date are considered short-term investments, with all others considered to be long-term investments. Unrealized gains and losses deemed temporary in nature are reported as a component of accumulated other comprehensive loss. The amortized cost of debt securities is adjusted for amortization of premiums and accretion of discounts to maturity, which is included in interest income on the unaudited condensed consolidated statements of operations. The cost of securities sold is based on the specific identification method.

Restricted Cash and Cash Equivalents

Restricted cash and cash equivalents primarily includes funds to secure standby letters of credit and security deposits with financial institutions under lease agreements and funds restricted as to withdrawal or usage under grant agreements and collaboration agreements.

Research and Development Expenses

To date, research and development expenses have related primarily to discovery efforts and preclinical and clinical development of product candidates. Research and development expenses are recognized as incurred, and payments made prior to the receipt of goods or services to be used in research and development are capitalized until the goods or services are received. Research and development expenses include expenses related to license and collaboration agreements; contingent consideration from business acquisitions; personnel-related expenses, including salaries, benefits, and stock-based compensation for personnel contributing to research and development activities; expenses incurred under agreements with third-party contract development and manufacturing organizations (CDMOs), contract research organizations, and consultants; clinical costs, including laboratory supplies and costs related to compliance with regulatory requirements; and other allocated expenses, including expenses for rent, facilities maintenance, and depreciation and amortization.

The Company has acquired and may continue to acquire the rights to develop and commercialize new product candidates from third parties. Upfront payments and research and development milestone payments made in connection with acquired licenses or product rights are expensed as incurred, provided that they do not relate to a regulatory approval milestone or assets acquired in a business combination.

The Company’s expense accruals for clinical trials and manufacturing are based on estimates of contracted services provided by third-party vendors not yet billed. When billing terms under these contracts do not coincide with the timing of when the work is performed, the Company is required to make estimates of its outstanding obligations to those third parties as of the period end. The accrual estimates are based on a number of factors, including the Company’s knowledge of the research and development programs and clinical manufacturing activities, the status of the programs and activities, invoicing to date, and the provisions in the contracts. The Company obtains information regarding unbilled services directly from these service providers and performs procedures to support its estimates based on its internal understanding of the services provided to date. However, the Company may also be required to estimate these services based on information available to its internal clinical and manufacturing administrative staff if such information is not able to be obtained timely from its service providers.

New Accounting Pronouncement Not Yet Adopted

In November 2024, the FASB issued ASU No. 2024-03, Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (ASU 2024-03), which requires entities to disclose specific information on the types of expenses included in the expense captions presented on the face of the income statement as well as disclosures about selling expenses. The guidance is effective for annual periods beginning after December 15, 2026 and interim periods within annual reporting periods beginning after December 15, 2027. Early adoption is permitted. ASU 2024-03 should be applied on a prospective basis, but retrospective application is permitted. The Company is currently evaluating the impact the adoption of ASU 2024-03 may have on its consolidated financial statements and related disclosures.

In September 2025, the FASB issued ASU No. 2025-06, Targeted Improvements to the Accounting for Internal-Use Software (ASU 2025-06), which clarifies and modernizes the accounting for costs related to internal-use software in Accounting Standards Codification Topic 350-40, Intangibles —Goodwill and Other — Internal-Use Software (ASC 350-40). ASU 2025-06 removed all references to project stages throughout ASC 350-40, and requires entities to begin capitalizing software costs when both of the following occur: (1) management, with the relevant authority, implicitly or explicitly authorizes and commits to funding a computer software project; and (2) it is probable that the project will be completed and the software will be used to perform the function intended (referred to as the probable-to-complete recognition threshold). The guidance is effective for annual periods beginning after December 15, 2027 and interim periods within those annual reporting periods. Early adoption is permitted. ASU 2025-06 should be either applied on a prospective basis, retrospective or modified prospective basis based on the status of the project and whether software costs were capitalized before the date of adoption. The Company is currently evaluating the impact the adoption of ASU 2025-06 may have on its consolidated financial statements and related disclosures.

In December 2025, the FASB issued ASU 2025-11 Interim Reporting (Topic 270): Narrow-Scope Improvements. The update provides clarifications intended to improve the consistency and usability of interim disclosure requirements, including a comprehensive listing of required interim disclosures and a new disclosure principle for reporting material events occurring after the most recent annual period. The amendments do not change the underlying objectives of interim reporting but are designed to enhance clarity in application. The guidance is effective for fiscal years beginning after December 15, 2027, including interim periods within those fiscal years. The Company is currently evaluating the impact of this guidance on its consolidated financial statements and related disclosures.

In December 2025, the FASB issued ASU 2025-12 Codification Improvements, which addresses suggestions received from stakeholders on the Accounting Standards Codification ("the Codification") and to make other incremental improvements to U.S. GAAP. The update represents changes to the Codification that (i) clarify, (ii) correct errors, or (iii) make minor improvements. The amendments make the Codification easier to understand and apply. The guidance is effective for fiscal years beginning after December 15, 2026, including interim periods within those fiscal years. The Company is currently evaluating the impact of this guidance on its consolidated financial statements and related disclosures.

Reclassification

Certain reclassifications have been made to prior period amounts on the Company’s consolidated statement of operations to conform to the current period presentation and enhance comparability. As a result, the Company changed its presentation of collaboration revenue to license and collaboration revenue and its presentation of contract revenue to other revenue. In conjunction with these changes, certain license revenue, primarily related the Company’s collaboration with Glaxo Wellcome UK Limited and GlaxoSmithKline Biologicals S.A. (GSK), which were presented as part of contract revenue in prior years, are now presented as part of license and collaboration revenue.

Certain reclassifications have been made to prior period amounts on the Company’s condensed consolidated statements of cash flows to conform to the current period presentation and enhance comparability. As a result, certain amounts related to deferred revenue, previously reflected in changes in operating assets and liabilities – deferred revenue, were reclassified to changes in operating assets and liabilities – accrued liabilities and other long-term liabilities.