Material Agreement, Corporate Action (Form 8-K)

Item 1.01 Entry into a Material Definitive Agreement.

On January 3, 2026, Agenus Inc. (the "Company"), Agenus Royalty Fund, LLC and Agenus Holdings 2024, LLC entered into an amendment and release agreement (the "Amendment Agreement") with Ligand Pharmaceuticals Incorporated ("Ligand") related to a Purchase and Sale Agreement and related Warrant each previously disclosed in the Company's Current Report on Form 8-K filed with the SEC on May 7, 2024. The Amendment Agreement provides for a release by Ligand of liens it has on certain of the Company's assets in exchange for a modification of the exercise price under the warrant from $17.30 per share to $7.50 per share.

The foregoing descriptions of the Amendment Agreement does not purport to be complete and is qualified in its entirety by reference to the full text of the Amendment Agreement, a copy of which will be filed, with confidential terms redacted, as an exhibit to the Company's next period report, which will be its Annual Report on Form 10-K.

Item 3.03 Material Modification to Rights of Security Holders.

The information contained in Item 1.01 of this Current Report on Form 8-K is incorporated by reference into this Item 3.03.