We present data from the second interim analysis of overall survival and a retrospective , preplanned analysis of data by BRCA mutation status from our randomised , double-blind , phase 2 study that assessed maintenance treatment with olaparib 400 mg twice daily ( capsules ) versus placebo in patients with platinum-sensitive recurrent serous ovarian cancer who had received two or more platinum-based regimens and who had a partial or complete response to their most recent platinum-based regimen .