(Abstracted from Lancet Oncol2021;22:620–631)The poly (ADP-ribose) polymerase (PARP) inhibitor olaparib is approved as maintenance therapy in newly diagnosed ovarian cancer or in patients with platinum-sensitive, relapsed ovarian cancer regardless of BRCA1/2mutation status. The primary analysis of the SOLO2/ENGOT-Ov21 phase 3 trial found a significant improvement in median progression-free survival associated with olaparib treatment compared with placebo in patients with platinum-sensitive, relapsed ovarian cancer and a BRCA1/2mutation.