Olaparib as maintenance treatment in patients with chemosensitive small cell lung cancer (STOMP): A randomised, double-blind, placebo-controlled phase II trial

•SCLC is highly mutated and over expresses PARP.•We tested the efficacy of PARP inhibitor olaparib after first line therapy in SCLC.•220 patients were randomized to receive maintenance olaparib or placebo.•Olaparib did not significantly alter progression-free survival or overall survival.•Quality of life and performance status were unchanged with the addition of olaparib.