BI-33 * BEVACIZUMAB-INDUCED HYPERTENSION IS A PREDICTIVE MARKER FOR IMPROVED OUTCOMES IN RECURRENT GLIOBLASTOMA

Abstract

PURPOSE: Bevacizumab is a monoclonal antibody targeting vascular endothelial growth factor (VEGF) approved for treatment of recurrent glioblastoma (GBM). Previous studies have demonstrated differential outcomes for patients treated with this agent for other tumors based on whether hypertension developed as a side effect. We conducted a single-institutional retrospective study analyzing survival outcomes for patients with recurrent GBM treated with bevacizumab based on whether patients developed drug-induced hypertension. PATIENTS AND METHODS: All GBM patients treated within Emory Healthcare from 2007-2012 were reviewed. 82 patients were identified that received bevacizumab for recurrent GBM and were included on study. Patients were classified as normotensive or hypertensive depending on whether hypertension developed secondary to therapy. Progression free survival (PFS) and overall survival (OS) were graphed by the Kaplan-Meier method and normotensive versus hypertensive groups were compared by log rank tests. Univariate and multivariate analysis were performed using the Cox proportional hazard method assessing for potential patient, treatment and tumor factors that may predict outcome. RESULTS: Median followup time was 7 months. Of the 82 recurrent GBM patients treated with bevacizumab, 30 developed drug-induced hypertension. Median time to development of hypertension was 21 days. Median PFS for the normotensive and hypertensive groups was 2.5 months (95% CI: 1.6-3.0) and 6.7 months (95% CI: 4.6-10.0), respectively (p <0.001). Median OS for the normotensive and hypertensive groups was 4.9 (95% CI: 4.4-6.8) and 11.7 (95% CI: 9.0- 20.5), respectively (p <0.001). Drug-induced hypertension was the only factor found to be significant on univariate analysis when evaluated for both PFS (HR: 0.24, 95% CI: 0.14-41) and OS (HR: 0.32, 95% CI: 0.19-0.53) endpoints (p <0.001). CONCLUSION: Patients with recurrent GBM who developed bevacizumab-induced hypertension demonstrated significantly better PFS and OS. Bevicizumab-induced hypertension may be a physiologic marker of outcome in recurrent GBM patients.