Efficacy and Safety of Bevacizumab-Combined Single-Agent Chemotherapy for Platinum-Resistant Ovarian Cancer that Recurred During PARP Inhibitor Treatment

Background Currently, there are no reports on the subsequent treatment of patients with ovarian cancer who exhibited platinum-resistant recurrence during treatment with poly(ADP-ribose) polymerase (PARP) inhibitors. This retrospective study was aimed at evaluating the efficacy and safety of single-agent chemotherapy combined with bevacizumab (BEV) in such patients. Patients and Methods The efficacy and safety of the treatment were evaluated in 16 patients with ovarian cancer, fallopian tube cancer, or primary peritoneal cancer diagnosed with platinum-resistant recurrence during PARP inhibitor treatment between April 2019 and June 2025. Chemotherapy was administered with paclitaxel alone or nogitecan alone in combination with BEV and generally continued until the disease progressed. Results The median number of single-agent chemotherapy cycles with BEV was 6 (range: 1–20). The objective response and disease control rates were 31.3% and 75.0%, respectively. The median progression-free survival and overall survival were 5.5 months [95% confidence interval (CI) = 4.0–6.0) and 17 months (95%CI = 10.0–29.0), respectively. Grade 3 or higher hematological toxicities were observed, including leukopenia, neutropenia, anemia, and thrombocytopenia in 7, 9, 1, and 3 patients, respectively. Non-hematological toxicities included hypertension in three patients and nausea, vomiting, fatigue, proteinuria, thrombosis, ileus, and heart failure in one patient each. None of the patients discontinued chemotherapy because of adverse events or treatment-related deaths. Conclusion BEV-combined single-agent chemotherapy has potential efficacy even in the challenging setting of platinum-resistant recurrence during PARP inhibitor treatment of ovarian cancer.