Submitted:
10 March 2026
Posted:
11 March 2026
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Abstract
Objective: Bevacizumab (BEV) and Olaparib (OLA) have demonstrated clinical efficacy as maintenance therapies for first platinum-sensitive recurrent ovarian cancer. However, direct comparisons between these agents independent of homologous recombination deficiency (HRD) and BRCA status, remain limited and the clinical validity of OLA dose reduction has not yet been confirmed. This study aimed to compare the efficacy and safety of BEV, standard-dose OLA, and dose-reduced OLA as maintenance therapy and to evaluate the clinical utility of OLA dose reduction. Methods: This retrospective multicenter study included 101 patients with first platinum-sensitive recurrent ovarian, fallopian tube, or primary peritoneal cancer who received maintenance therapy after achieving a response to chemotherapy. Patients were classified into three groups: BEV (n = 34), standard-dose OLA (n = 31), and dose-reduced OLA (n = 36). The primary endpoint was progression-free survival (PFS), and secondary endpoints included overall survival (OS) and adverse events. Survival outcomes were evaluated using Kaplan–Meier analysis and Cox proportional hazards models. Results: Median PFS was 16 months in the BEV group, 16 months in the standard-dose OLA group, and 24 months in the dose-reduced OLA group, with significantly longer PFS in the dose-reduced OLA group (p < 0.001). In the multivariate Cox analysis, treatment remained an independent prognostic factor for PFS (HR 0.67, 95% CI 0.46–0.96, p = 0.030). Median OS was 44, 45, and 64 months, respectively, with no significant differences among groups; PFI ≥12 months was the only independent prognostic factor for OS. Grade ≥3 hematologic toxicities were more frequent in the OLA groups but were manageable. Conclusions: Dose-reduced OLA was associated with prolonged PFS while maintaining manageable toxicity, supporting its clinical validity as a maintenance option independent of HRD and BRCA status.