Material Agreement (Form 8-K)

Item 1.01 Entry into a Material Definitive Agreement

On March 28, 2025, FibroGen, Inc. and Fortis Therapeutics, Inc. (collectively, the "Parties") entered into Amendment No.1 to the First Amended and Restated Evaluation Agreement, dated June 6, 2024, which amended and restated the original agreement dated May 5, 2023. On March 28, 2025, the Parties entered into Amendment No.1 to the First Amended and Restated Option Agreement and Plan of Merger, dated June 6, 2024, which amended and restated the original agreement dated May 5, 2023. Both amendments modified the option exercise deadline under such agreements to December 31, 2027.

The foregoing descriptions of Amendment No.1 to the First Amended and Restated Evaluation Agreement and Amendment No.1 to the First Amended and Restated Option Agreement and Plan of Merger are qualified in their entirety by reference to the full texts of Amendment No.1 to the First Amended and Restated Evaluation Agreement and Amendment No.1 to the First Amended and Restated Option Agreement and Plan of Merger, which will be filed with the Securities and Exchange Commission as an exhibit to FibroGen's Quarterly Report on Form 10-Q for the quarter ending March 31, 2025.