CTLA4 and gastroesophageal junction adenocarcinoma: Durvalumab is a mAb directed against PD-L1 and tremelimumab is a mAb against cytotoxic T-lymphocyte associated protein 4 (CTLA-4), and combining these 2 mAbs showed a manageable safety profile.16 A recently published phase 1b/2 trial with either durvalumab or tremelimumab alone, or in combination in patients with advanced gastric/GEJ adenocarcinoma demonstrated significant efficacy with a 6-month PFS of 20.0% and a 12-month OS of 38.8% in the durvalumab plus tremelimumab arm.17