CD274 and small cell lung carcinoma: CASPIAN is an open-label phase 3 trial in which untreated patients with ES-SCLC were randomly assigned (1:1:1 ratio) to receive durvalumab (anti-PD-L1 drug) plus platinum-etoposide or tremelimumab (anti-CTLA-4 antibody) and platinum-etoposide, or platinum-etoposide alone (5).