An open-label, multi-center, prospective, exploratory clinical study evaluating niraparib monotherapy for maintenance of uterine serous carcinoma.

Objective: To evaluate the efficacy and safety of niraparib (a poly [ADP-ribose] polymerase [PARP] inhibitor) maintenance therapy among patients with uterine serous carcinoma (USC) who achieved complete remission (CR) or partial remission (PR) to the last line of platinum-based chemotherapy. Methods: In this open-label, multi-center, prospective, exploratory clinical study in China, the maintenance therapy cohort patients with USC (stage I-IV) with CR or PR to 1 line or first-time recurrent platinum-based therapy were received niraparib once-daily. A starting dose of 200 mg once daily (QD) was used, except in patients with a baseline body weight of =77 kg and platelet count =150,000/µL who received 300 mg QD. The primary endpoint was progression-free survival (PFS) rate at 12 months assessed by Investigator and analyzed using Kaplan-Meir method with corresponding 95% confidence intervals (CIs) (NCT04716686). Results: From August 24, 2021, to August 31, 2023, a total of 23 patients were enrolled at 5 clinical centers. median followup for PFS was 16.3 months (95% CI=11.2-21.5). At baseline, 78.2% (18/23) were International Federation of Gynecology and Obstetrics stage III or IV. The 95.6% (22/23) patients undergone cytoreductive surgery. The 39.1% (9/23) patients had undergone radiotherapy. Among patients who evaluated (n=21), the PFS rate at 12 months in niraparib maintenance therapy was 84.7% (95% CI=59.5%-94.8%). The safety profile of niraparib was consistent with previous studies. Conclusion: It was first time to investigate the efficacy and safety of niraparib monotherapy as maintenance therapy in Chinese patients with USC. PFS rates at 12 months (84.7%) showed a clinically meaningful improvement in patients receiving niraparib maintenance therapy. Niraparib was generally well tolerated. [ABSTRACT FROM AUTHOR]