Real-world duration of first-line maintenance niraparib monotherapy in patients with epithelial ovarian cancer in the United States: the CHAR1ZMA study.

Objective: The CHAR1ZMA study described real-world duration of first-line maintenance niraparib monotherapy among patients with epithelial ovarian cancer.

Methods: This retrospective study used a US nationwide, electronic-health-record-derived, de-identified database. Eligible patients were aged ≥18 years with epithelial ovarian cancer who initiated first-line maintenance niraparib monotherapy (January 2017-December 2022 [inclusive]) following first-line platinum-based chemotherapy. Niraparib monotherapy duration was measured as the time to treatment discontinuation, estimated using Kaplan-Meier methodology, overall and stratified by treatment duration (early discontinuers [≤90 days]; non-early discontinuers [>90 days or did not discontinue]). Analyses were repeated in a sub-group of patients with homologous recombination-deficient tumors.

Results: Toxicity was the most common reason for niraparib discontinuation among early discontinuers (67.7%) and was less frequent among non-early discontinuers (18.1%). Dose modifications were less frequent among early discontinuers (29.8%) than non-early discontinuers (53.6%). Disease progression was the most common reason for niraparib discontinuation among non-early discontinuers (74.8%) and was less frequent among early discontinuers (30.4%). The observed median treatment duration was 7.2 months (95% CI 6.0 to 8.1) overall (N = 560) and was 4.5 months longer among non-early discontinuers (11.7 months [95% CI 9.8 to 14.7]; n = 399). In the homologous recombination-deficient sub-group (n = 144), the observed median treatment duration was 11.6 months (95% CI 7.8. to 16.1) and was 5.1 months longer among non-early discontinuers (16.7 months [95% CI 12.0 to 22.8]; n = 114).

Conclusion: In this real-world study of patients with epithelial ovarian cancer receiving first-line maintenance niraparib monotherapy, drug toxicity was the most common reason for treatment discontinuation in early discontinuers. Effective and early clinical management of drug toxicity may help mitigate these adverse events, allowing patients to remain on niraparib maintenance treatment longer and experience the potential full therapeutic benefit.