Commitments and Contingencies	6 Months Ended
Jun. 30, 2026
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	10. Commitments and Contingencies Leases There have been no material changes to the Company’s lease agreements during the three or six months ended June 30, 2026. For additional information on the Company's operating leases, see Note 8, Leases, of the Notes to the Consolidated Financial Statements in the Company’s Annual Report on Form 10-K for the year ended December 31, 2025. Legal Proceedings and Other Contingencies In connection with the merger, two actions were filed against the Company and its board of directors in the Supreme Court for the State of New York, County of New York, captioned Smith v. Ikena Oncology, Inc., et al., No. 653576/2025 (filed June 12, 2025) and Kent v. Ikena Oncology, Inc., et al., No. 653588/2025 (filed June 13, 2025) (collectively, the “Complaints”). The Complaints allege that the defendants filed or caused to be filed a materially incomplete and misleading registration statement with the SEC and asserts claims under New York common law for negligent misrepresentation and concealment and negligence. In addition, the Company and its board of directors have received five additional demands from purported stockholders seeking additional disclosures in the registration statement (collectively, the “Demands”). On February 27, 2026, the Complaints were voluntarily dismissed and the Company has received no additional outreach from the purported stockholders who sent the Demands. Liabilities for loss contingencies arising from claims, assessments, litigation, fines and penalties and other sources are recorded when it is probable that a liability has been incurred and the amount can be reasonably estimated. Regardless of outcome, litigation can have an adverse impact on our business, financial condition, results of operations and prospects because of defense and settlement costs, diversion of management resources and other factors. Indemnification In the ordinary course of business, the Company enters into agreements that may include indemnification provisions. Pursuant to such agreements, the Company may indemnify, hold harmless, and defend an indemnified party for losses suffered or incurred by the indemnified party. Some of the provisions will limit losses to those arising from third-party actions. In some cases, the indemnification will continue after the termination of the agreement. The maximum potential amount of future payments the Company could be required to make under these provisions is not determinable. In addition, the Company has entered into indemnification agreements with members of its board of directors and executive officers that will require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers. To date, the Company has not incurred any material costs as a result of such indemnification provisions. The Company is not currently aware of any indemnification claims and has not accrued any liabilities related to such obligations in its condensed consolidated financial statements as of June 30, 2026. Licensing Agreements with HUTCHMED Limited Upon consummation of the Merger in July 2025, the Company became the successor of the Collaboration, Option and License Agreement, as amended (the “Hutchmed Agreement”) between Legacy Inmagene and HUTCHMED Limited (formerly known as Hutchinson Medipharma Limited) (“Hutchmed”). Under the terms of the Hutchmed Agreement, Legacy Inmagene received an exclusive, royalty-free, worldwide license to perform research and development and for use in regulatory filings related to the licensed compounds (the “Licensed Compounds”). Further, on a Licensed Compound-by-Licensed Compound basis, Hutchmed granted Legacy Inmagene the exclusive option to the worldwide license with the right to sublicense to develop, manufacture and commercialize the licensed compound, with Hutchmed retaining first right to co-commercialization in mainland China (each a “License Option”). In April 2023, Legacy Inmagene entered into an amendment to the Hutchmed Agreement which terminated portions of the Hutchmed Agreement related to one of the compounds, and extended Legacy Inmagene’s deadline for License Option exercise by an additional year to allow time for additional research to be performed on two of the remaining targets. On October 16, 2023, Legacy Inmagene exercised the License Option for (a) anti-OX40 mAb, and (b) the BTK (Bruton tyrosine kinase) inhibitor. Upon exercise of the License Option, Legacy Inmagene acquired an exclusive, worldwide, royalty-bearing license with the right to sublicense through multiple tiers, under certain patents and know-how controlled by Hutchmed and Hutchmed’s right, title and interest in the joint intellectual property to develop, manufacture and commercialize any product that contains, incorporates, or otherwise includes the Licensed Compound (the “Licensed Products”). Hutchmed is eligible to receive up to $92.5 million for each Licensed Product upon the achievement of various development and regulatory milestones. Additionally, Hutchmed is eligible to receive up to $135.0 million for each Licensed Compound upon the achievement of various worldwide aggregate cumulative net sales milestones for the Licensed Products that contain such Licensed Compound and tiered royalty rates in the high-single-digit to low-tens percentages on a Licensed Compound-by-Licensed Compound basis for net sales of such Licensed Compounds worldwide, subject to reduction in certain circumstances. None of the payments under the Hutchmed Agreement are refundable. As of June 30, 2026, the Company has not met any of the milestones. In connection with the Non-OX40 Divestiture (see Note 1), the BTK inhibitor program was initially sublicensed to BuyCo. Thereafter, pursuant to a novation agreement, BuyCo became the direct licensee of the BTK inhibitor program from Hutchmed. The Company continues to actively develop the anti-OX40 mAb program. Legacy Collaborative Arrangements Other collaboration agreements and programs that Legacy Inmagene was a party to were divested in connection with the Non-OX40 Divestiture as described in Note 1 and the Company has no further obligations under such agreements.

Commitments and Contingencies

6 Months Ended

Jun. 30, 2026

Commitments and Contingencies Disclosure [Abstract]

10. Commitments and Contingencies

Leases

There have been no material changes to the Company’s lease agreements during the three or six months ended June 30, 2026. For additional information on the Company's operating leases, see Note 8, Leases, of the Notes to the Consolidated Financial Statements in the Company’s Annual Report on Form 10-K for the year ended December 31, 2025.

Legal Proceedings and Other Contingencies

In connection with the merger, two actions were filed against the Company and its board of directors in the Supreme Court for the State of New York, County of New York, captioned Smith v. Ikena Oncology, Inc., et al., No. 653576/2025 (filed June 12, 2025) and Kent v. Ikena Oncology, Inc., et al., No. 653588/2025 (filed June 13, 2025) (collectively, the “Complaints”). The Complaints allege that the defendants filed or caused to be filed a materially incomplete and misleading registration statement with the SEC and asserts claims under New York common law for negligent misrepresentation and concealment and negligence. In addition, the Company and its board of directors have received five additional demands from purported stockholders seeking additional disclosures in the registration statement (collectively, the “Demands”). On February 27, 2026, the Complaints were voluntarily dismissed and the Company has received no additional outreach from the purported stockholders who sent the Demands.

Liabilities for loss contingencies arising from claims, assessments, litigation, fines and penalties and other sources are recorded when it is probable that a liability has been incurred and the amount can be reasonably estimated. Regardless of outcome, litigation can have an adverse impact on our business, financial condition, results of operations and prospects because of defense and settlement costs, diversion of management resources and other factors.

Indemnification

In the ordinary course of business, the Company enters into agreements that may include indemnification provisions. Pursuant to such agreements, the Company may indemnify, hold harmless, and defend an indemnified party for losses suffered or incurred by the indemnified party. Some of the provisions will limit losses to those arising from third-party actions. In some cases, the indemnification will continue after the termination of the agreement. The maximum potential amount of future payments the Company could be required to make under these provisions is not determinable. In addition, the Company has entered into indemnification agreements with members of its board of directors and executive officers that will require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers. To date, the Company has not incurred any material costs as a result of such indemnification provisions. The Company is not currently aware of any indemnification claims and has not accrued any liabilities related to such obligations in its condensed consolidated financial statements as of June 30, 2026.

Licensing Agreements with HUTCHMED Limited

Upon consummation of the Merger in July 2025, the Company became the successor of the Collaboration, Option and License Agreement, as amended (the “Hutchmed Agreement”) between Legacy Inmagene and HUTCHMED Limited (formerly known as Hutchinson Medipharma Limited) (“Hutchmed”). Under the terms of the Hutchmed Agreement, Legacy Inmagene received an exclusive, royalty-free, worldwide license to perform research and development and for use in regulatory filings related to the licensed compounds (the “Licensed Compounds”). Further, on a Licensed Compound-by-Licensed Compound basis, Hutchmed granted Legacy Inmagene the exclusive option to the worldwide license with the right to sublicense to develop, manufacture and commercialize the licensed compound, with Hutchmed retaining first right to co-commercialization in mainland China (each a “License Option”). In April 2023, Legacy Inmagene entered into an amendment to the Hutchmed Agreement which terminated portions of the Hutchmed Agreement related to one of the compounds, and extended Legacy Inmagene’s deadline for License Option

exercise by an additional year to allow time for additional research to be performed on two of the remaining targets. On October 16, 2023, Legacy Inmagene exercised the License Option for (a) anti-OX40 mAb, and (b) the BTK (Bruton tyrosine kinase) inhibitor. Upon exercise of the License Option, Legacy Inmagene acquired an exclusive, worldwide, royalty-bearing license with the right to sublicense through multiple tiers, under certain patents and know-how controlled by Hutchmed and Hutchmed’s right, title and interest in the joint intellectual property to develop, manufacture and commercialize any product that contains, incorporates, or otherwise includes the Licensed Compound (the “Licensed Products”).

Hutchmed is eligible to receive up to $92.5 million for each Licensed Product upon the achievement of various development and regulatory milestones. Additionally, Hutchmed is eligible to receive up to $135.0 million for each Licensed Compound upon the achievement of various worldwide aggregate cumulative net sales milestones for the Licensed Products that contain such Licensed Compound and tiered royalty rates in the high-single-digit to low-tens percentages on a Licensed Compound-by-Licensed Compound basis for net sales of such Licensed Compounds worldwide, subject to reduction in certain circumstances. None of the payments under the Hutchmed Agreement are refundable. As of June 30, 2026, the Company has not met any of the milestones.

In connection with the Non-OX40 Divestiture (see Note 1), the BTK inhibitor program was initially sublicensed to BuyCo. Thereafter, pursuant to a novation agreement, BuyCo became the direct licensee of the BTK inhibitor program from Hutchmed. The Company continues to actively develop the anti-OX40 mAb program.

Legacy Collaborative Arrangements

Other collaboration agreements and programs that Legacy Inmagene was a party to were divested in connection with the Non-OX40 Divestiture as described in Note 1 and the Company has no further obligations under such agreements.