FibroGen Announces Clinical Data from Dose Escalation Phase 1b Study of FG-3246 (FOR46) in Combination with Enzalutamide in Patients with Metastatic Castration Resistant Prostate Cancer will be Presented at the 2024 American Society of Clinical Oncology A

FibroGen, Inc. (NASDAQ: FGEN) today announced that clinical data from the dose escalation portion of the Phase 1b/2 study of FG-3246 in combination with enzalutamide in patients with metastatic castration resistant prostate cancer have been selected for a poster presentation at the 2024 American Society of Clinical Oncology (ASCO) Annual Meeting taking place May 31-June 4, 2024 in Chicago, Illinois.

Details for the poster presentation are as follows:Session: Poster Session – Genitourinary Cancer – Prostate, Testicular, and PenileTitle: A Phase 1b dose escalation study of FOR46, a novel antibody-drug conjugate targeting a tumor-specific epitope of CD46, in combination with enzalutamide (Enza) in patients with metastatic castration resistant prostate cancer (mCRPC).Presenter: Nonna Shakhnazaryan and Dr. Rahul Aggarwal, MD from the UCSF Helen Diller Family Comprehensive Cancer CenterAbstract number: 5066Poster number: 472Date and Time: June 2, 2024 at 9:00-12:00 AM CDT

About FG-3246FG-3246 (also known as FOR46) is a potential first-in-class fully human antibody-drug conjugate (ADC), exclusively in-licensed from Fortis Therapeutics, and is being developed by FibroGen for metastatic castration-resistant prostate cancer and other tumor types. FG-3246 binds to a tumor-specific epitope of CD46, a cell receptor target, that induces internalization upon antibody binding, is present at high levels in prostate cancer and other tumor types, and demonstrates limited expression in most normal tissues. FG-3246 is comprised of an anti-CD46 antibody, YS5, linked to the anti-mitotic agent, MMAE, which is a clinically and commercially validated ADC payload. FG-3246 has demonstrated anti-tumor activity in both preclinical and clinical studies. FG-3246 is currently in an ongoing investigator-initiated Phase 1b/2 study being conducted at UCSF to evaluate it in combination with enzalutamide with initial data expected in mid-2024, and a biomarker trial using a PET biomarker for CD46 using the same antibody backbone. We anticipate the initiation of a Phase 2 monotherapy dose optimization study of FG-3246 in metastatic castration-resistant prostate cancer in 2H 2024. FG-3246 is an investigational drug and not approved for marketing by any regulatory authority.

About FibroGen FibroGen, Inc. is a biopharmaceutical company focused on accelerating the development of novel therapies at the frontiers of cancer biology. Pamrevlumab, a fully human anti-CTGF monoclonal antibody, is in clinical development for the treatment of metastatic pancreatic cancer and locally advanced unresectable pancreatic cancer (LAPC). Roxadustat (爱瑞卓®, EVRENZOTM) is currently approved in China, Europe, Japan, and numerous other countries for the treatment of anemia in chronic kidney disease (CKD) patients on dialysis and not on dialysis. Roxadustat is in clinical development for chemotherapy-induced anemia (CIA) and a Supplemental New Drug Application (sNDA) has been accepted for review by the China Health Authority. FG-3246 (also known as FOR46), a first-in-class antibody-drug conjugate (ADC) targeting CD46 is in development for the treatment of metastatic castration-resistant prostate cancer. This program also includes the development of an associated CD46-targeted PET biomarker. In addition, FibroGen has expanded its research and development portfolio to include two immuno-oncology product candidates for the treatment of solid tumors. For more information, please visit www.fibrogen.com.

FibroGen, Inc.Investors:David DeLucia, CFAVice President of Corporate FP&A / Investor [e-mail]

Media:Meichiel KeenanDirector, Investor Relations and Corporate [e-mail]