Real-World First-Line Maintenance Niraparib Monotherapy Use Following Chemotherapy Plus Bevacizumab: The SW1TCH Study.

Introduction: Clinical trials have demonstrated prolonged survival associated with niraparib first-line maintenance (1LM) therapy, compared with placebo, for patients with ovarian cancer (OC). However, data are limited on real-world 1LM niraparib monotherapy use, particularly as switch 1LM, following first-line (1L) combination chemotherapy plus bevacizumab. This real-world study aimed to describe patient demographics, clinical characteristics, and clinical outcomes of patients with OC receiving 1LM niraparib monotherapy following 1L combination chemotherapy plus bevacizumab.

Methods: This retrospective observational study used data from a US-based nationwide database of deidentified, electronic health record-derived data. Patients diagnosed with OC during the study period (1 January 2011-30 November 2022, inclusive) were eligible if they received 1L chemotherapy plus bevacizumab treatment followed by 1LM niraparib monotherapy, initiated between 1 January 2017 (inclusive) and 2 September 2022. Patients were followed from index date (initiation of niraparib 1LM) until the first occurrence of death, end of follow-up, or end of study. Clinical outcomes were time to treatment discontinuation (TTD) and time to next treatment (TTNT). Kaplan-Meier curves were used to estimate TTD, TTNT, and 95% confidence intervals (CIs).

Results: Among 93 patients selected, median age at index was 67 years (interquartile range [IQR] 60-72 years). Most patients had BRCA wild-type/homologous recombination (HR)-proficient or BRCA wild-type/HR unknown disease (75.3%). In all, 18 (19.4%) patients had HR-deficient disease. Five (5.4%) patients had unknown test results for both BRCA and HR deficiency status. Median follow-up time was 16.3 months (IQR 8.7-25.4 months), and median time from end of 1L therapy to 1LM initiation was 35.0 days (IQR 25.0-53.9 days). Median TTD was 9.3 months (95% CI 6.1-11.3 months). Median TTNT was 12.9 months (95% CI 11.5-19.0 months).

Conclusions: This real-world study provided insights into switch maintenance with 1LM niraparib monotherapy, which may be a viable treatment option for patients with advanced OC.