Amgen’s FGFR2b drug shows survival boost in phase 3 gastric cancer trial

Amgen’s monoclonal antibody bemarituzumab, paired with chemotherapy, significantly improved overall survival in a global phase 3 trial for advanced gastric cancer, meeting its primary endpoint.

Why it matters: The results signal progress in treating FGFR2b-overexpressing gastric cancers, which affect 38% of advanced-stage patients, a group with few effective options and historically poor outcomes.

Backstory: Bemarituzumab targets FGFR2b, a receptor overexpressed in a subset of gastric and gastroesophageal cancers. Amgen acquired the drug in 2021 via its $1.9B buyout of Five Prime Therapeutics, while Chinese biotech Zai Lab retains rights in Greater China.

Big picture: If approved, bemarituzumab would become the first FGFR2b-targeted therapy for gastric cancer. The therapy may also pave the way for combination strategies, including ongoing trials with immunotherapy (nivolumab).

Trial details: The study enrolled 547 patients across 37 countries; all were HER2-negative with FGFR2b overexpression. Top-line results show a survival benefit, but full data is pending presentation. Prior phase 2 data showed overall survival nearly doubled (24.7 vs. 11.1 months).

Next steps: Zai Lab plans a regulatory filing in China. A second phase 3 trial combining bemarituzumab with nivolumab is underway, with data expected later this year.