A retrospective single institutional analysis of bevacizumab and chemotherapy versus non-bevacizumab treatments for recurrent glioblastoma

Abstract

2023 Background: Bevacizumab, a monoclonal antibody to vascular endothelial growth factor, has been shown to be effective in the treatment of recurrent glioblastoma in combination with chemotherapy compared to historical controls but not in randomized trials. Methods: We conducted a retrospective analysis of all patients treated at our institution for a recurrent glioblastoma to compare patients who received bevacizumab versus a control group of patients. We compared progression free survival (PFS) and overall survival (OS) between the two groups, and also compared these factors based on the age and performance status within each group. We also analyzed the impact of bevacizumab on quality of life by comparing change in performance status. Results: We identified 44 patients who received bevacizumab, and 79 patients who have not been treated with bevacizumab. There is a statistically significant improvement in PFS in the bevacizumab treated group, but only a trend toward better survival. Patients of older age (≥50) and poor performance status (KPS≤80) have significantly better PFS when treated with bevacizumab, and bevacizumab-treated older patients have significantly increase OS. Patients treated with bevacizumab also maintained their functional status longer than the control group. Conclusions: Bevacizumab in combination with chemotherapy can be a more effective treatment for recurrent glioblastoma and warrants further randomized prospective studies to determine its effect on survival. Bevacizumab also has more effect in those with older age and might reflect biological differences in glioblastoma in different age groups, and biological correlates should also be considered. Bev Control p value No 44 79 Age 54 55 0.86 KPS 82 82 0.8 Recurrence (%) 1st 50 100 2nd 32 0 3rd 18 0 PFS (mos) all (n) 4.25 (44) 1.82 (79) 0.01 age <50 (n) 4.01 (15) 2.01 (28) 0.85 age ≥50 (n) 4.60 (29) 1.87 (51) 0.0002 KPS >80 (n) 3.83 (24) 1.84 (36) 0.16 KPS ≤80 (n) 4.60 (20) 1.87 (43) 0.04 OS (mos) all 9.01 6.11 0.08 age <50 10.83 6.88 0.74 age ≥50 8.31 6.11 0.02 KPS >80 9.22 8.05 0.61 KPS ≤80 9.01 4.74 0.08 Time to KPS change (days) 252 120 0.006 Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Expert Testimony Other Remuneration Genentech™ BioOncology Genentech™ BioOncology