Half-dose bevacizumab experience in relapsed ovarian cancer patients in Turkey due to formal regulations: similar effectiveness with lower rate of hypertension

Abstract

Purpose: Ovarian cancer is the fifth leading cause of cancer related death in women. Platin-based doublet regimens plus bevacizumab is standard treatment in relapse. Due to formal regulation of Turkish Ministry of Health, adjuvant bevacizumab has not been reimbursed and clinicians can use bevacizumab at a dose of 7.5 mg/kg/3wk in platin-resistant and sensitive relapse settings. The primary aim of this study was to evaluate 7.5 mg/kg/3wk bevacizumab dosing in platin-resistant and sensitive relapse ovarian cancer and compare these findings with the current literature.

Methods: A total of 106 patients with relapsed ovarian cancer and treated with bevacizumab (bevacizumab is not reimbursed as a part of adjuvant treatment in Turkey) on their first relapse were included.

Results: At a median follow-up of 32.1 months (5.3-110.8), 56 (52.8%) patients died. Progression-free survival (PFS) and overall survival (OS) were estimated at 18.8 months (14.4-23.3) vs 29.7 months (24.3-35.1) of the whole group overall survival. We observed that 78.4% of patients treated with primary surgery without neoadjuvant treatment and 59 (57.8%) out of the 102 patients with debulking surgery relapsed. A significant number of patients (81%) treated with primary surgery without neoadjuvant treatment and 59 (76.6 %) had secondary debulking surgery at relapse. In relapse, 38 patients were treated with single agent liposomal doxorubicin (LPD) plus bevacizumab. On the other hand, 68 patients were treated with carboplatin and LPD plus bevacizumab. Multivariate analysis failed to show any clinicopathological characteristics with significant effect on PFS. However, cytoreductive surgery at relapse showed significant effect on OS. Bevacizumab-related toxicities were detected in 23 (21.7%) patients; hypertension, pulmonary embolism, perforation, and other toxicities (nephrotic syndrome in 2, osteonecrosis in 2, cerebrovascular and cardiac ischemia in 3 patients) were seen in 12 (11.3%), 3 (2.8%), 1 (0.9%) and 7 (6.6%) patients, respectively.

Conclusions: In conclusion, our findings showed that 7.5 mg/ kg/3week dosing of bevacizumab in relapsed ovarian cancer could have similar effectiveness compared to standard 15 mg/ kg/3week dosing. Increase of OS and PFS in patients treated with primary and secondary debulking surgery with no-visible disease was more pronounced. No new safety information was observed but lower rate of grade 3 or above hypertension with similar rate of severe vascular and intestinal complications were detected.