INTRODUCTION: Niraparib first-line maintenance (1LM) therapy has demonstrated clinical benefit for patients with ovarian cancer (OC) in clinical trial and real-world settings, but data on factors associated with real-world patient outcomes remain limited. This analysis identified patient characteristics associated with time to next treatment (TTNT), a proxy for real-world progression-free survival, in patients with OC treated with 1LM niraparib monotherapy. METHODS: This retrospective observational study used a USA nationwide electronic health record-derived deidentified database and included adult patients diagnosed with OC who initiated 1LM niraparib monotherapy after first-line platinum-based chemotherapy. Patients were followed until the earliest occurrence of last clinical activity, death, or end of study period. TTNT was measured from 1LM niraparib initiation to the start of second-line treatment or death. Cox proportional hazards models assessed univariable and multivariable associations between baseline characteristics and TTNT. RESULTS: Of 7872 patients diagnosed with OC, 526 met the eligibility criteria and were included in this analysis. Median (IQR) duration of follow-up was 14.1 (7.4-23.6) months. In univariable analyses, age, BRCA/homologous recombination deficiency (HRD) status, socioeconomic status, stage at initial diagnosis, cytoreductive surgery type, and residual disease status were significantly associated with observed TTNT and were introduced into the multivariable model with other clinically relevant variables. In the multivariable analysis, BRCA/HRD status, cytoreductive surgery type, and residual disease status were significantly associated with observed TTNT after covariate adjustment. Conversely, age, Eastern Cooperative Oncology Group performance status, disease stage, niraparib starting dose status, and first-line bevacizumab use were not associated with observed TTNT. CONCLUSION: This real-world, retrospective, observational analysis offers valuable insights on prognostic factors associated with TTNT in patients with OC treated with 1LM niraparib monotherapy after first-line platinum-based chemotherapy. Future studies are needed to examine how additional patient characteristics associated with clinical outcomes may guide treatment decisions and improve outcomes.