An Open-label, Multicenter, Single-arm, Phase II Study of Fluzoparib in Patients with Germline BRCA1/2 Mutation and Platinum-sensitive Recurrent Ovarian Cancer

Purpose: Fluzoparib (PARP inhibitor) showed promising antitumor activity for advanced ovarian cancer in a phase I study. This study aimed to assess the efficacy and safety of fluzoparib in patients with germline BRCA1/2-mutated recurrent ovarian cancer. Patients and Methods: This open-label, multicenter, single-arm, phase II study enrolled patients with platinum-sensitive recurrent ovarian cancer and germline BRCA1/2 mutation who had previously received two to four lines of platinum-based chemotherapy. Fluzoparib 150 mg was administered orally twice daily. The primary endpoint was independent review committee (IRC)-assessed objective response rate per RECIST v1.1. Results: A total of 113 patients were enrolled and received at least one dose of fluzoparib. As of data cutoff on March 21, 2020, the median follow-up period was 15.9 months (interquartile range, 13.5-18.5). The IRC- and investigator-assessed objective response rates were 69.9% [95% confidence interval (CI), 60.6-78.2] and 70.8% (95% CI, 61.5- 79.0), respectively. The objective response rates were similar across all prespecified subgroups. The median IRC- and investigator-assessed progression-free survival was 12.0 months (95% CI, 9.3-13.9) and 10.3 months (95% CI, 9.212.0), respectively. The 12-month survival rate was 93.7% (95% CI, 87.2-96.9). Grade >= 3 adverse events occurred in 63.7% (72/113) of the patients, with the most common one being anemia/decreased hemoglobin. Adverse events that led to treatment interruption, dose reduction, and discontinuation occurred in 39.8%, 34.5%, and 0.9% of patients, respectively. One treatment-related death occurred. Conclusions: Fluzoparib demonstrated promising antitumor activity and acceptable safety profile in germline BRCA1/2-mutated, platinum-sensitive relapsed ovarian cancer. Thus, fluzoparib might be a novel treatment option for this population.