In patients with platinum-sensitive relapsed (PSR) ovarian cancer (OC), olaparib maintenance monotherapy significantly improves progression-free survival (PFS) versus placebo. However, evidence in the Asian population is lacking. This is the first study to evaluate olaparib efficacy and tolerability exclusively in Asian patients with PSR OC.Considering the limited placebo effect and significant clinical benefit of olaparib in previous trials, and the rapid approval of olaparib in China, this phase III study was designed as an open-label, single-arm trial. Patients with high-grade epithelial PSR OC were enrolled from country-wide clinical centers across China and Malaysia. Patients received oral olaparib (300 mg) twice daily until disease progression or unacceptable toxicity. Primary endpoint was median PFS (mPFS). Primary analysis of PFS using the Kaplan-Meier method was performed when data reached 60% maturity (clinicaltrials.gov NCT03534453).Between 2018 and 2020, 225 patients were enrolled, and 224 received olaparib; 35.7% had received {greater than or equal to}3 lines of chemotherapy, 35.3% had achieved complete response to their last line of platinum-based chemotherapy, and 41.1% had a platinum-free interval {less than or equal to}12 months. At primary data cutoff (December 25, 2020), overall mPFS was 16.1 months; mPFS was 21.2 and 11.0 months in BRCA-mutated and wild-type BRCA subgroups, respectively. Adverse events occurred in 99.1% of patients (grade {greater than or equal to}3: 48.7%); 9.4% discontinued therapy due to treatment-related adverse events.Olaparib maintenance therapy was highly effective and well tolerated in Asian patients with PSR OC, regardless of BRCA status. This study highlights the promising efficacy of olaparib in this Asian population.