Effectiveness of first-line niraparib maintenance in Korean patients with advanced ovarian cancer: a multicenter retrospective cohort study.

OBJECTIVE: To evaluate the real-world effectiveness of first-line niraparib maintenance therapy in Korean patients with advanced epithelial ovarian cancer (EOC) and assess outcomes across clinical and molecular subgroups. METHODS: This multicenter retrospective study included patients with newly diagnosed International Federation of Gynecology and Obstetrics stage III-IV EOC who completed first-line platinum-based chemotherapy between December 2019 and October 2022 at nine tertiary institutions in South Korea. Patients were classified according to receipt of niraparib maintenance or no maintenance therapy. Propensity score matching was performed based on age, neoadjuvant chemotherapy, and BRCA mutation status. Progression-free survival (PFS) and overall survival (OS) were evaluated using Kaplan-Meier analysis and Cox proportional hazards models. RESULTS: A total of 554 patients were included (niraparib, n=248; no maintenance, n=306). In the unmatched cohort, niraparib was associated with significantly longer PFS (p<0.001) and OS (p=0.001). After 1:1 matching, 189 pairs were analyzed. The 3-year PFS rate was higher in the niraparib group (43.1% vs 25.7%; p<0.001), as was the 3-year OS rate (86.3% vs 74.7%; p=0.005). PFS benefit was observed in both BRCA-mutated and BRCA wild-type subgroups. OS improvement was evident in the BRCA wild-type subgroup, with minimal post-progression crossover. CONCLUSION: First-line niraparib maintenance was associated with improved PFS regardless of BRCA status and with improved OS, particularly in BRCA wild-type patients. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT06086665.