Platinum rechallenge treatment using gemcitabine plus carboplatin with or without bevacizumab for platinum-resistant ovarian cancer

Purpose Platinum-resistant ovarian cancer (PROC) is usually treated with single-agent chemotherapy. A synergistic effect of gemcitabine and platinum has been reported in PROC. We evaluated the efficacy and safety of gemcitabine and carboplatin with or without bevacizumab (GC ± B) in patients with PROC. Methods From April 2014 to April 2018, patients with PROC received gemcitabine on days 1 and 8, and carboplatin on day 1, with or without bevacizumab (Bev) on day 1 every 3 weeks. The primary endpoint was objective response rate (ORR). The secondary endpoints were disease control rate (DCR), progression-free survival (PFS), overall survival (OS), and rate of adverse events. Results In total, 215 cycles were administered to 31 patients, of whom 21 received Bev and the median number of cycle for each patient was 6 (range, 2–19). The median platinum-free interval (PFI) was 4 months. The ORR and DCR were 51.9% and 92.6%, respectively. Median PFS and OS were 7.9 months and 16.1 months, respectively. PFS and OS of patients with 3–6 months PFI were significantly longer than those with PFI < 3 months (median PFS, 9.7 vs. 5.8 months; p < 0.01; median OS, 20.0 vs. 12.1 months; p = 0.03). Grade 3 or 4 hematological toxicities observed included neutropenia (71.0%), leukopenia (54.8%), anemia (51.6%), and thrombocytopenia (25.8%). No other grade 2–4 nonhematological toxicity was observed except for hypertension in one and CBDCA hypersensitivity reaction in two. Conclusion GC ± B may be effective and safe treatment alternative for PROC, especially with PFI of 3–6 months, despite hematological toxicity.