To assess real-world progression-free survival (rwPFS) and time to next treatment (rwTTNT) among patients with epithelial ovarian cancer (EOC) who received first-line maintenance (1LM) niraparib monotherapy. In this US-nationwide, electronic health record-derived, deidentified database study, eligible patients with EOC initiated 1LM niraparib monotherapy (1 January 2017-1 December 2022) following first-line platinum-based chemotherapy. Median rwPFS and rwTTNT were estimated with Kaplan-Meier methodology overall and in a homologous recombination-deficient (HRd) subgroup (further stratified as Observed median rwPFS was 11.4 (95% CI, 10.1-12.7) months overall ( The real-world observed median rwPFS and rwTTNT were longer for patients with EOC who received 1LM niraparib monotherapy in the HRd subgroup (specifically for the