CD274 and small cell lung carcinoma: Two phase 3 trials evaluated the addition of programmed cell death-ligand 1 (PD-L1) inhibitor atezolizumab (IMpower133) (5, 6) or durvalumab (CASPIAN) (7, 8) to first-line chemotherapy (etoposide and cisplatin [EP]) followed by maintenance PD-L1 inhibitor in patients with ES-SCLC, and showed a significant improvement in overall survival (OS).