Immunotherapy in esophagogastric cancer

The uses of immune checkpoint inhibitors have now been advanced to include the first-line treatment of esophagogastric cancers. Initially approved for the treatment of chemotherapy-refractory programmed death ligand 1-positive or microsatellite instability (MSI)-high esophagogastric adenocarcinoma, these agents have been shown in earlier-line trials to have an additive benefit with first-line chemotherapy, and superiority to chemotherapy, in MSI-high cancers. Pembrolizumab and nivolumab have received approval for the second-line treatment of esophageal squamous cancer. The addition of nivolumab to first-line chemotherapy in gastric and gastroesophageal junction (GEJ) adenocarcinoma improved survival, progression-free survival, and response, findings that led to regulatory approval. The addition of pembrolizumab to first-line chemotherapy in esophageal and GEJ adenocarcinoma and squamous cancer also improved all outcomes, which led to the approval of pembrolizumab as part of first-line chemotherapy. The addition of pembrolizumab to first-line chemotherapy in human epidermal growth factor receptor 2-positive esophagogastric adenocarcinoma was also recently approved. In addition, the adjuvant use of nivolumab was recently approved in esophageal and GEJ cancer after chemoradiotherapy and surgery in patients with residual disease found at surgery. This article reviews recent advances in the use of immune checkpoint inhibitor therapy in esophagogastric cancers.