Bevacizumab (BEV)-based therapy in the treatment of recurrent glioblastoma (GBM) in patients (PTS) treated at a Brazilian cancer center

Abstract

Background: Temozolomide (TMZ) both concurrently and after radiation therapy constitutes the standard of care for newly diagnosed GBM PTS. BEV is FDA approved option for recurrent high-grade gliomas PTS based on the results phase II trials. Reports of the use of BEV in these setting have been limited to USA and European academic centers thus far. Methods: We conducted a cross sectional retrospective study of 39 consecutive PTS with histologically confirmed GBM that received BEV in the second or third line setting. The main objective of this analysis was to assess the efficacy and safety of BEV given "off protocol" in an unselected cohort of PTS treated at a Brazilian teaching hospital cancer center and to compare our results to those reported by North American and European academic centers. PTS received first-line treatment with TMZ plus radiotherapy and most received maintenance TMZ and received Bev-based therapy at the time of disease progression. Main endpoints were the evaluation of progression-free survival (PFS), overall survival (OS) and safety. Results: Between 2007 and 2011, 39 PTS with recurrent GBM that received BEV in second (92%) or third-line (8%) were identified. Seven PTS progressed during concomitant RT and TMZ, and 40 during or after TMZ maintenance. 72% were male; median age: 56 years (range 22-79). Most patients (89,7%) received BEV in combination with irinotecan, and the median number of cycles, regardless of combination, was 14. Reasons for BEV discontinuation were disease progression in 79,5% and toxicity in 4 patients. There was one treatment related death due to thrombocytopenia and bleeding. Twenty-four PTS (61,5%) achieved an objective response with BEV. Median PFS of the patients that received BEV in either second or third line was 7.5 months and median OS was 22.6 months. No bowel perforations or any unexpected toxicities occurred. Conclusions: This constitutes the first report of recurrent GBM PTS treated with Bev in the Southern Hemisphere. In this unselected "real life" cohort of PTS with recurrent GBM we have been able to reproduce and confirm the efficacy and safety of this agent used in the treatment of GBM in the second and third line setting.