328 RENI-1: a prospective, multicenter real-world study of niraparib as first-line maintenance therapy in newly diagnosed advanced ovarian cancer

Introduction/Background Niraparib is the first PARP inhibitor to be approved for the first-line maintenance (1LM) treatment of all patients with newly diagnosed advanced ovarian cancer. The RENI-1 study (NCT04986371) was designed to evaluate the maintenance treatment patterns, efficacy and safety in ovarian cancer patients who received niraparib as 1LM therapy in the real world. Methodology The study prospectively enrolled patients eligible for niraparib 1LM therapy. The primary endpoint was the maintenance treatment patterns, including initiation time of maintenance, starting dose of niraparib and maintenance regimens. Secondary endpoints included progression-free survival (PFS), chemotherapy-free interval, time to first subsequent treatment, overall survival, safety and quality of life. Results From September 2021 to September 2022, 227 per-protocol patients were enrolled in 22 hospitals in China. Of the 227 patients, 210 (92.5%) had III-IV disease, 97 (42.7%) received neoadjuvant chemotherapy, 160 (70.5%) had a complete response to platinum-based chemotherapy, 47 (20.7%) carried BRCA mutations (BRCAm), and 116 (51.1%) had homologous recombination deficiency (HRD). The median initiation time of maintenance was 7.6 weeks (range, 0.9–40 weeks), with 215 (94.7%) patients starting with 200 mg of niraparib and 218 (96.0%) patients receiving niraparib monotherapy. After a median follow-up of 16.8 months, median PFS (mPFS) was 24.2 months and 12-month PFS rate was 70.0% in the overall population. PFS benefit was observed regardless of BRCAm status and HRD status (table 1). Adverse events (AEs) of any grade were reported in 67.4% of patients, including 13.7% grade 3 or higher. AEs led to treatment interruption, dose reduction and discontinuation were 24.2%, 20.3% and 4.0%, respectively. Conclusion Treatment patterns of niraparib 1LM are diverse in the real world, with BRCAm and HRD patients benefiting the most. The results of this prospective real-world study provide reassuring evidence of the activity and tolerability of niraparib maintenance therapy in newly diagnosed advanced ovarian cancer. Disclosures All authors have declared no conflicts of interest.