Trastuzumab was also FDA-approved in combination with pembrolizumab and chemotherapy for metastatic HER2-positive gastric or GEJ cancers after results from the phase III KEYNOTE-811 trial, in which a total of 434 patients with previously untreated metastatic HER2-positive gastric or GEJ adenocarcinoma were randomized to receive pembrolizumab or a placebo in combination with trastuzumab and chemotherapy (5FU and cisplatin or capecitabine and oxaliplatin). This evidence concerns the gene ERBB2 and gastroesophageal junction adenocarcinoma.