Variations in outcome for advanced gastric cancer between Japanese and Western patients: a subgroup analysis of the RAINBOW trial

Two large, global phase 3 trials have confirmed the efficacy of the vascular endothelial growth factor receptor 2 monoclonal antibody ramucirumab in the second-line treatment of advanced gastric cancer (GC) and gastro-oesophageal junction cancer (GOJ) (1,2). The RAINBOW trial evaluated its use in conjunction with paclitaxel chemotherapy and reported significant improvements in overall survival (OS), progression free survival (PFS) and response rates (RR); however differentials in outcome based on geographical area were noted. For patients from the Asia geographical area (consisting of Japan, South Korea, Hong Kong, Singapore and Taiwan) addition of ramucirumab resulted in improvements in PFS and RR, but no significant improvement in OS (2). The majority of patients from the Asian geographical group were recruited from Japan (140 out of 223). This additional subgroup analysis gives further information about geographical differences in outcome between Japanese patients in comparison to ‘Western’ patients from Australia, Europe, Israel and the USA (3).