Impact of niraparib maintenance on progression-free survival and overall survival: An updated meta-analysis.

5591 Background: Niraparib is an oral poly(ADP-ribose) polymerase (PARP) inhibitor used as maintenance therapy in advanced ovarian cancer after platinum response. Mature OS data were lacking, so we performed an updated meta-analysis. Methods: PubMed, Embase, and CENTRAL were searched from January 2023 to January 2026 for randomized controlled trials (RCTs) of niraparib maintenance in advanced ovarian cancer. Hazard ratios with 95% confidence intervals were pooled using random-effects models for TFST, OS, overall PFS, and subgroup PFS by BRCA, HRD status, and newly diagnosed patients. The study is registered in PROSPERO with ID CRD420261294461. Results: Four RCTs (PRIMA, NOVA, NORA, and PRIME) including 1935 patients were analysed, of whom 1,291 received niraparib, and 644 received placebo. Niraparib significantly prolonged the TFST (HR 0.54, 95% CI 0.42-0.69; I²=77.6%; p<0.0001). No statistically significant improvement in OS was observed (HR 0.94, 95% CI 0.82-1.08; I²=10.0%; p=0.398). Niraparib significantly improved overall PFS (HR 0.42, 95% CI 0.31-0.58; I²=83.8%). PFS in BRCA-mutated patients (HR 0.33, 95% CI 0.24-0.45; I²=46.0%), HRD-positive patients (HR 0.41, 95% CI 0.30-0.56; I²=58.6%) (all p<0.0001). HRD-negative patients (HR 0.56, 95% CI 0.35-0.89; I²=52.4%), and newly diagnosed (HR 0.55 95% CI 0.39-0.80, I²=79.1%) (all p≤0.015). Conclusions: Niraparib provides durable disease-control benefits across molecular subgroups and significantly delays the need for subsequent therapy, however, mature data does not demonstrate a corresponding overall survival advantage. These findings refine patient selection and highlight the need for strategies that translate PFS gains into survival benefit. Updated meta-analysis of niraparib efficacy outcomes in advanced ovarian cancer. Study TFST (HR) Overall Survival (HR) Overall PFS (HR) PFS in BRCA mutation (HR) HRD+ PFS (HR) HRD− PFS (HR) Newly Diagnosed (HR) PRIMA 0.74 (0.62–0.89) * 1.01 (0.84–1.23) * 0.66 (0.55–0.78) * 0.43 (0.31–0.59) * 0.51 (0.40–0.66) * 0.67 (0.50–0.89) * 0.66 (0.55–0.78) * PRIME 0.45 (0.34–0.59) 0.63 (0.38–1.03) * 0.45 (0.34–0.60) 0.40 (0.23–0.68) 0.48 (0.34–0.68) 0.41 (0.22–0.75) 0.45 (0.34–0.60) NOVA (gBRCA) 0.57 (0.41–0.78) * 0.85 (0.61–1.20) * - 0.27 (0.17–0.41) 0.38 (0.24–0.60) - - NOVA (non-gBRCA) 0.58 (0.45–0.74) * 1.06 (0.81–1.37) * - - - - - NORA 0.39 (0.29–0.52) * 0.86 (0.60–1.23) * 0.32 (0.23–0.45) 0.22 (0.12–0.40) 0.22 (0.12–0.40) - - Total Result (95% CI) 0.54 (0.42 – 0.69) 0.94 (0.82–1.08) 0.42 (0.31–0.58) 0.33 (0.24–0.45) 0.41 (0.30–0.56) 0.56 (0.35–0.89) 0.55 (0.39–0.80) I² (%) 77.6 10 83.8 46 58.6 51.4 79.1 p value <0.0001 0.3979 <0.0001 <0.0001 <0.0001 0.0146 0.0014 *Indicate updated values.