Abstract
The optimal combination of bevacizumab with cytotoxic or cytostatic drugs in recurrent glioblastoma is unknown. We performed a phase 2 trial of combined bevacizumab and fotemustine for patients with glioblastoma at first relapse after radiotherapy and temozolomide. The primary endpoint was 6-month progression-free survival (PFS), while secondary endpoints were overall survival (OS), response rate based on RANO criteria and toxicity. Fifty-four patients with recurrent GBM were enrolled. The authors observed a 6-month PFS rate of 42.6% (95% CI 29.3-55.2) and a median PFS of 5.2 months (95% CI 3.8-6.6). The median OS was 9.1 months (95% CI 7.3-10.3). Twenty-eight patients (52%) had a radiographic response, and a significant neurological improvement with steroid reduction was observed in 25/42 symptomatic patients (60%). MGMT promoter methylation was significantly associated with improved PFS in univariate analysis. Most unifocal tumors at baseline had a focal enhancing progression (76%), while the diffuse non-enhancing progression accounted for 9.5%. Response or survival were not associated with any pattern of progression. Survival after failure of treatment was short. Twelve out of 54 patients (22%) discontinued fotemustine for grade 3/4 myelotoxicity, while 4/54 (7.4%) discontinued bevacizumab. This study failed to demonstrate a superiority of the combination of bevacizumab and fotemustine over either bevacizumab or fotemustine alone as historical controls. Future studies should explore alternative regimens of combination of the two drugs.