Phase II randomized placebo-controlled study of olaparib (AZD2281) in patients with platinum-sensitive relapsed serous ovarian cancer (PSR SOC)

5003 Background: Olaparib (AZD2281) is an oral PARP inhibitor that has shown antitumor activity in patients (pts) with high-grade serous ovarian cancer (SOC) with and without BRCA1 or BRCA2 mutations. This randomized, double-blind, multicenter, placebo-controlled Phase II study evaluated maintenance treatment with olaparib in pts with high-grade PSR SOC (clinicaltrials.gov; NCT00753545). Methods: Pts with PSR SOC who had received ≥2 previous platinum regimens and were in a maintained partial or complete response following their last platinum-containing regimen were randomized to oral olaparib 400 mg bid or placebo. The primary endpoint was progression-free survival (PFS) by RECIST. Secondary endpoints included time to progression (TTP) by CA-125 (GCIG criteria) or RECIST, overall survival (OS) and safety. Results: 265 pts were randomized (136 to olaparib and 129 to placebo). Demographics and baseline characteristics were generally well balanced. At data cut-off there were 153 (58%) progression events. PFS...