Introduction/Background Niraparib, a poly(ADP-ribose) polymerase inhibitor (PARPi), was approved 29Apr2020 in the US for first-line maintenance (1LM) treatment of advanced epithelial ovarian cancer (EOC). To better understand how niraparib 1LM approval impacted who received niraparib in clinical practice, this study characterised real-world patients with EOC prescribed niraparib for 1LM before and after FDA approval using real-world data.

Methodology This retrospective cohort study used the nationwide Flatiron Health electronic health record-derived de-identified database and included patients diagnosed with EOC between 01Jan2011 and 30Nov2021, who were ≥18 years old at initial diagnosis and received first-line platinum-based treatment. The index date was defined as the initiation date of 1LM niraparib monotherapy, on or after 01Jan2017. Demographic and clinical characteristics of the study cohort were assessed from initial EOC diagnosis to index date. Patients were stratified by index date: before 29Apr2020 (niraparib preapproval cohort) or after 29Apr2020 (niraparib postapproval cohort).

Results A total of 374 patients initiated 1LM niraparib monotherapy. Most patients had stage III (50%) or IV (35%) disease and had BRCAwt (84%); 40% of patients had no visible residual disease (table 1). Demographic and clinical characteristics were mostly similar across the cohorts. However, the niraparib postapproval cohort (n=284) had fewer patients with stage IV disease (30% vs 49%) and more with BRCAwt (90% vs 63%) than the preapproval cohort (n=90). Furthermore, fewer patients in the niraparib postapproval cohort had unknown BRCA status (3% vs 16%), unknown HRD status (63% vs 84%), and no debulking surgery (13% vs 27%).

Conclusion This study is the first to describe characteristics of real-world patients who initiated 1LM niraparib monotherapy based on niraparib’s approval status. Study findings suggest that BRCA/HRD testing has increased over time. Moreover, understanding dosing patterns and associated treatment duration can help optimise disease management. These outcomes will be explored in the next study phase.