Summary of Significant Accounting Policies	6 Months Ended
Jun. 30, 2026
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	3. Summary of Significant Accounting Policies The Company’s significant accounting policies, which are disclosed in the audited consolidated financial statements for the year ended December 31, 2025, and the notes thereto are included in the Company’s Annual Report on Form 10-K that was filed with the SEC on February 26, 2026. Since the date of filing, there have been no material changes to the Company’s significant accounting policies, except as noted below. Use of Estimates The preparation of the unaudited consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the unaudited consolidated financial statements and the reported amounts of costs and expenses during the reporting period. The Company bases estimates and assumptions on historical experience when available and on various factors that it believes to be reasonable under the circumstances. The Company evaluates its estimates and assumptions on an ongoing basis. Estimates and assumptions about future events and their effects cannot be determined with certainty and therefore require the exercise of judgment. As of the date of issuance of these unaudited consolidated financial statements, the Company is not aware of any specific event or circumstance that would require the Company to update its estimates, assumptions and judgments or revise the carrying value of its assets or liabilities. These estimates may change as new events occur and additional information is obtained and are recognized in the unaudited consolidated financial statements as soon as they become known. Actual results could differ from those estimates and any such differences may be material to the Company’s unaudited consolidated financial statements. Income taxes In accordance with Topic ASC 270, Interim Reporting, and Topic ASC 740, Income Taxes, the Company is required at the end of each interim period to determine the best estimate of its annual effective tax rate and then apply that rate in providing for income taxes on a current year-to-date (interim period) basis. For the six months ended June 30, 2026 and 2025, the Company recorded no tax expense or benefit due to the expected current year loss and its historical losses. As of June 30, 2026 and December 31, 2025, the Company concluded that a full valuation allowance would be necessary for all of its net deferred tax assets. The Company had no amounts recorded for uncertain tax positions, interest or penalties in the accompanying unaudited consolidated financial statements. On July 4, 2025, the One Big Beautiful Bill Act, or OBBBA, was enacted in the United States. The OBBBA includes significant changes to the Internal Revenue Code of 1986, such as the permanent extension of certain expiring provisions of the Tax Cuts and Jobs Act of 2017, modifications to certain aspects of the international tax framework and the restoration of favorable tax treatment for certain business expense provisions. The OBBBA introduced several U.S. tax law changes, including the ability to immediately expense domestic research and experimental, or R&E, expenditures starting in 2025, and an election to accelerate any unamortized domestic R&E expenditures over a one or two year period beginning with the 2025 tax year. In accordance with ASC 740, Accounting for Income Taxes, the impacts of the OBBBA did not affect the Company’s U.S. deferred tax assets or liabilities, as the Company continues to maintain a full valuation allowance against those balances. Other comprehensive income Comprehensive loss consists of two components, net loss and other comprehensive loss, net of tax. The Company’s other comprehensive loss, net of tax, consists of unrealized gains (losses) on the Company’s investments. Collaboration revenue, net In September 2021, the Company entered into the Incyte License and Collaboration Agreement, or the Incyte License, with Incyte, covering the worldwide development and commercialization of axatilimab. In August 2024, the U.S. Food and Drug Administration, or FDA, approved Niktimvo for the treatment of chronic graft-versus host disease, or cGVHD, after failure of at least two prior lines of systemic therapy in adult and pediatric patients weighing at least 40 kg (88.2 lbs). See Note 4 — Significant Collaborative Research and License Agreements — Incyte Collaboration for further details on the Incyte License and Collaboration Agreement. In accordance with Topic ASC 808, Collaboration Arrangements, Incyte has been identified as the principal in product sales, therefore, the Company will recognize its share of any profits or losses in the amount of net product sales less cost of goods sold and shared commercial costs, royalties and other expenses, in the period in which the underlying sales and costs are recognized. The Company’s share of net profits in connection with commercialization of products will be presented as “Collaboration revenue, net” and its share of net losses will be presented as “Collaboration loss, net” within operating expenses. The year to date “Collaboration revenue, net” or “Collaboration loss, net” will be presented as the net cumulative amount for all periods reported on in the financial statements. The Company will continue to recognize the costs associated with ongoing development services in the R&D operating expense line, including any cost-sharing components with Incyte. Recently Issued and Adopted Accounting Pronouncements From time to time, new accounting pronouncements are issued by the FASB or other accounting standard setting bodies that we adopt as of the specified effective date. Unless otherwise discussed below, we do not believe that the adoption of recently issued standards have or may have a material impact on our unaudited consolidated financial statements or disclosures. 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, or ASU 2024-03. Among other items, the requirements include expanded disclosures around employee compensation and selling expenses. ASU 2024-03 will be effective for the Company for the year ending December 31, 2027. The Company is still evaluating the impact of this new guidance on its unaudited consolidated financial statements but expects the adoption to result in disclosure changes only.

Summary of Significant Accounting Policies

6 Months Ended

Jun. 30, 2026

Summary of Significant Accounting Policies

3. Summary of Significant Accounting Policies

The Company’s significant accounting policies, which are disclosed in the audited consolidated financial statements for the year ended December 31, 2025, and the notes thereto are included in the Company’s Annual Report on Form 10-K that was filed with the SEC on February 26, 2026. Since the date of filing, there have been no material changes to the Company’s significant accounting policies, except as noted below.

Use of Estimates

The preparation of the unaudited consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the unaudited consolidated financial statements and the reported amounts of costs and expenses during the reporting period. The Company bases estimates and assumptions on historical experience when available and on various factors that it believes to be reasonable under the circumstances. The Company evaluates its estimates and assumptions on an ongoing basis.

Estimates and assumptions about future events and their effects cannot be determined with certainty and therefore require the exercise of judgment. As of the date of issuance of these unaudited consolidated financial statements, the Company is not aware of any specific event or circumstance that would require the Company to update its estimates, assumptions and judgments or revise the carrying value of its assets or liabilities. These estimates may change as new events occur and additional information is obtained and are recognized in the unaudited consolidated financial statements as soon as they become known. Actual results could differ from those estimates and any such differences may be material to the Company’s unaudited consolidated financial statements.

Income taxes

In accordance with Topic ASC 270, Interim Reporting, and Topic ASC 740, Income Taxes, the Company is required at the end of each interim period to determine the best estimate of its annual effective tax rate and then apply that rate in providing for income taxes on a current year-to-date (interim period) basis. For the six months ended June 30, 2026 and 2025, the Company

recorded no tax expense or benefit due to the expected current year loss and its historical losses. As of June 30, 2026 and December 31, 2025, the Company concluded that a full valuation allowance would be necessary for all of its net deferred tax assets. The Company had no amounts recorded for uncertain tax positions, interest or penalties in the accompanying unaudited consolidated financial statements.

On July 4, 2025, the One Big Beautiful Bill Act, or OBBBA, was enacted in the United States. The OBBBA includes significant changes to the Internal Revenue Code of 1986, such as the permanent extension of certain expiring provisions of the Tax Cuts and Jobs Act of 2017, modifications to certain aspects of the international tax framework and the restoration of favorable tax treatment for certain business expense provisions. The OBBBA introduced several U.S. tax law changes, including the ability to immediately expense domestic research and experimental, or R&E, expenditures starting in 2025, and an election to accelerate any unamortized domestic R&E expenditures over a one or two year period beginning with the 2025 tax year. In accordance with ASC 740, Accounting for Income Taxes, the impacts of the OBBBA did not affect the Company’s U.S. deferred tax assets or liabilities, as the Company continues to maintain a full valuation allowance against those balances.

Other comprehensive income

Comprehensive loss consists of two components, net loss and other comprehensive loss, net of tax. The Company’s other comprehensive loss, net of tax, consists of unrealized gains (losses) on the Company’s investments.

Collaboration revenue, net

In September 2021, the Company entered into the Incyte License and Collaboration Agreement, or the Incyte License, with Incyte, covering the worldwide development and commercialization of axatilimab. In August 2024, the U.S. Food and Drug Administration, or FDA, approved Niktimvo for the treatment of chronic graft-versus host disease, or cGVHD, after failure of at least two prior lines of systemic therapy in adult and pediatric patients weighing at least 40 kg (88.2 lbs). See Note 4 — Significant Collaborative Research and License Agreements — Incyte Collaboration for further details on the Incyte License and Collaboration Agreement.

In accordance with Topic ASC 808, Collaboration Arrangements, Incyte has been identified as the principal in product sales, therefore, the Company will recognize its share of any profits or losses in the amount of net product sales less cost of goods sold and shared commercial costs, royalties and other expenses, in the period in which the underlying sales and costs are recognized. The Company’s share of net profits in connection with commercialization of products will be presented as “Collaboration revenue, net” and its share of net losses will be presented as “Collaboration loss, net” within operating expenses. The year to date “Collaboration revenue, net” or “Collaboration loss, net” will be presented as the net cumulative amount for all periods reported on in the financial statements. The Company will continue to recognize the costs associated with ongoing development services in the R&D operating expense line, including any cost-sharing components with Incyte.

Recently Issued and Adopted Accounting Pronouncements

From time to time, new accounting pronouncements are issued by the FASB or other accounting standard setting bodies that we adopt as of the specified effective date. Unless otherwise discussed below, we do not believe that the adoption of recently issued standards have or may have a material impact on our unaudited consolidated financial statements or disclosures.

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, or ASU 2024-03. Among other items, the requirements include expanded disclosures around employee compensation and selling expenses. ASU 2024-03 will be effective for the Company for the year ending December 31, 2027. The Company is still evaluating the impact of this new guidance on its unaudited consolidated financial statements but expects the adoption to result in disclosure changes only.