Current status of immunotherapy for advanced gastric cancer

Recently, immune checkpoint inhibitors such as anti-programmed cell death-1 (PD-1) or programmed cell death ligand-1 (PD-L1) monoclonal antibodies have improved the overall survival of various types of cancers including advanced gastric cancer (AGC). Until now, two ant-PD-1 inhibitors were approved for AGC in Japan: nivolumab as third- or later-line treatment for AGC and pembrolizumab for previously treated patients with microsatellite instability-high tumours. However, a limited number of patients achieved clinical benefit, highlighting the importance of the better selection of patients or additional treatment to overcome resistance to PD-1/PD-L1 blockade. This review focused on pivotal clinical trials, biomarkers and novel combination therapy of immune checkpoint inhibitors for AGC.