Bemarituzumab is an afucosylated monoclonal antibody against FGFR2b (a FGF receptor) with demonstrated monotherapy clinical activity in patients with late-line gastric cancer whose tumors overexpress FGFR2b (NCT02318329). We describe the rationale and design of the FIGHT trial (NCT03343301), a global, randomized, double-blind, placebo-controlled Phase III study evaluating the role of bemarituzumab in patients with previously untreated, FGFR2b-overexpressing advanced gastroesophageal cancer. Patients are randomized in a blinded fashion to the combination of mFOLFOX6 and bemarituzumab or mFOLFOX6 and placebo. Eligible patients are selected based on the presence of either FGFR2b protein overexpression determined by immunohistochemistry or FGFR2 gene amplification determined by circulating tumor DNA. The primary end point is overall survival, and secondary end points include progression-free survival, objective response rate and safety.