59P Real-world Effectiveness of Niraparib in Recurrent Ovarian Cancer Patients in France: Impact of Starting Dose and Timing of the Maintenance Initiation

Niraparib is a PARP inhibitor first approved by EMA in 2017 as maintenance monotherapy in patients (pts) with platinum-sensitive relapsed high grade serous epithelial ovarian cancer (OC) who are in response to platinum-based chemotherapy (PBCT), based on the NOVA study. It is reimbursed in France since May 2019. This study aimed to retrospectively analyze the ESME French real-world dataset of OC pts to describe the clinical characteristics, treatment patterns and survival outcomes of pts who initiated niraparib in second-line or beyond (2L+) between May 2019 and Jul 2021. Subgroup analyses on pts eligible per the main criteria of the NOVA trial were explored. 389 pts were eligible (including 139 NOVA-like pts; 36%), with a median follow-up of 12 months. Mean age was 63 years, mean weight was 68kg. 93% of pts with available results were BRCAwt. Niraparib was mostly initiated in complete or partial PBCT responders (73%), at a dose of 200mg (72%), between 4-8 weeks after PBCT (57%) and in 2L (62%). Median exposure to niraparib was of 97 days and 76% of patients discontinued niraparib during the observational period. Among the 295 pts who discontinued niraparib, 56% discontinued for progression and 32% for toxicity. Median progression-free survival (mPFS) was estimated at 7.2 [95% CI 6.2-8.5] months (mo) in the main population. Unadjusted analyses in the NOVA like population showed comparable efficacy regardless the timing of initiation: median PFS of 8.7 [6.4-13.0] mo after 8 weeks (w) vs mPFS of 6.8 [6.0-8.5] mo before 8 w; as well as regardless of the dose, mPFS 8.7 [6.7–12.0] mo for patients who initiated niraparib at 300 mg vs mPFS of 6.8 [6.2-8.2] m for those who initiated niraparib at a lower dose. However, mPFS was higher for pts who initiated niraparib in 2L (8.7 [7.3-9.8] mo) compared to 3L+ (5.2 [4.0-6.2]). First study providing real-word data on the use of niraparib in French OC patients shows efficacy results (PFS) consistent with the randomized NOVA trial results. Niraparib can be introduced more than 8 w after end of PBCT without loss of efficacy; as well as initiated at the recommended dose depending on the pts features. The main reason for niraparib discontinuation was progression.