Bemarituzumab is a humanized monoclonal antibody specific to the human fibroblast growth factor receptor 2b (FGFR2b) in clinical development as a targeted therapy for tumors that overexpress FGFR2b, including gastric and gastroesophageal junction cancers. We have an exclusive license for bemarituzumab in mainland China, Hong Kong (China), Macau (China) and Taiwan region from Five Prime Therapeutics, Inc. (Five Prime). We are collaborating with Five Prime to conduct the randomized, controlled Phase III clinical trial FIGHT to evaluate bemarituzumab in combination with modified FOLFOX6 chemotherapy as a front-line therapy for the treatment of gastric and gastro-esophageal junction cancers. In a Phase I trial, bemarituzumab demonstrated monotherapy activity in heavily pre-treated patients with FGFR2b-positive gastric cancer and did not cause some of the toxicities that had been seen with less selective small molecule FGFR2 inhibitors. FGFR2b is a splice variant of a receptor for some members of the fibroblast growth factor (FGF) family. An estimated 10% of patients with gastric cancer have tumors that overexpress FGFR2b or have FGFR2 gene amplification, which is associated with poor prognosis.
Mechanism of Action
Bemarituzumab has been engineered for enhanced antibody-dependentcell-mediated cytotoxicity (ADCC) to increase direct tumor cell killing byrecruiting natural killer (NK) cells.