Immune Checkpoint Inhibition in Gastro-Oesophageal Cancer

Recently some progress has been made in the palliative treatment of gastric cancer. It was shown that second-line chemotherapy and VEGF-R2-directed treatment can prolong survival. Despite these advances most patients with metastatic gastric cancer live for less than 2 years. Immune-checkpoint blockade with anti-CTLA4, anti-PD-1 and anti-PD-L1 antibodies has revolutionised the treatment of many cancers. Significant benefit was also proven in gastric adenocarcinomas. Nivolumab improves overall survival as third-line treatment in Asian gastric cancer patients and is already registered in Japan. Pembrolizumab shows significant efficacy, especially in PD-L1-positive patients as third-line treatment and is FDA approved for this indication. Trials with avelumab are promising and studies with atezolizumab and durvalumab are also on the way. To extend the subgroup of benefitting patients combinations of PD-1/PD-L1 antibodies with CTLA4, or VEGF-R2 antibodies or combination with chemotherapy are investigated and show promising results. In this article, the existing evidence of PD1 and PD-L1 blockade as monotherapy or in combination with anti-CTLA4, anti-VEGF-R2 and chemotherapy in gastro-oesophageal adenocarcinoma is reviewed and put into perspective.