The U.S. Food and Drug Administration (FDA) granted Breakthrough Therapy designation to bemarituzumab as first-line treatment for patients with fibroblast growth factor receptor 2b (FGFR2b)-overexpressing and HER2-negative metastatic and locally advanced gastric and gastroesophageal adenocarcinoma in combination with modified FOLFOX6 (fluoropyrimidine, leucovorin, and oxaliplatin), based on an FDA-approved companion diagnostic assay showing at least 10% of tumor cells overexpressing FGFR2b.
Approximately 80% to 85% of patients with advanced gastric and gastroesophageal junction cancers are HER2-negative, and approximately 30% of these patients present with FGFR2b overexpression. Bemarituzumab (anti-FGFR2b) is a potential first-in-class investigational targeted antibody that is designed to block fibroblast growth factors from binding and activating FGFR2b, inhibiting several downstream pro-tumor signaling pathways and potentially slowing cancer progression.
FIGHT Trial
The FIGHT trial (ClinicalTrials.gov identifier NCT03694522) evaluated bemarituzumab plus chemotherapy (modified FOLFOX6) vs chemotherapy alone in patients with FGFR2b-positive, HER2-negative front-line advanced gastric or gastroesophageal cancer. In the study, treatment with bemarituzumab plus chemotherapy demonstrated clinically significant and substantial improvements in the primary endpoint of progression-free survival and secondary endpoint of overall survival in the patient population in which at least 10% of tumor cells overexpressed FGFR2b.
Additional analysis showed a positive correlation between benefit and the prevalence of FGFR2b-positive tumor cells, affirming both the importance of the FGFR2b target and the activity of bemarituzumab against this target. The Breakthrough Therapy designation was granted based upon this subset of patients who showed at least 10% of tumor cells overexpressing FGFR2b.
