Multicenter phase 2 trial of perioperative chemotherapy plus immune checkpoint blockade for gastric and gastroesophageal junction adenocarcinoma

Combining immune checkpoint blockade (ICB) with chemotherapy improves outcomes of patients with metastatic gastric and gastroesophageal junction (G/GEJ) adenocarcinoma. Whether this combination has activity in the perioperative setting is unknown. A phase 2 trial at four centers in the USA evaluated chemotherapy (capecitabine-oxaliplatin) plus pembrolizumab before and after surgery followed by maintenance pembrolizumab for resectable G/GEJ adenocarcinoma. Among 34 evaluable patients, the pathologic complete response rate was 20.6%, and the two-year disease-free survival and overall survival rates were 67.8% and 80.6%, respectively. With the exception of diarrhea, this regimen did not result in increased treatment-related adverse events. The authors conclude that this regimen warrants further investigation.