Safety of pembrolizumab in combination with bevacizumab in recurrent glioblastoma (rGBM)
2010Background: Inhibition of vascular endothelial growth factor (VEGF) may enhance immunotherapies and decrease cerebral edema among GBM patients (pts) This multicenter, randomized phase 2 study determined safety and anti tumor activity of pembrolizumab (P) a PD 1 blocking monoclonal antibody (Mab) with and without bevacizumab (Bev) a humanized anti VEGF Mab among rGBM pts. Herein, we report the safety lead in of this study. Methods: Pts in dose level 1 received P 200 mg Q3W and Bev 10 mg/kg Q2W. Dose de escalation levels 1 and 2 increased the P interval to 4 and 6 weeks, respectively if dose level 1 exceeded maximum tolerated dose (MTD) based on standard 3+3 criteria. Eligible pts were 18 years, had 1or 2 recurrences, no prior anti VEGF treatment, and KPS 70. The primary endpoint was MTD/recommended phase 2 dose (RP2D) determination based on dose limiting toxicity (DLT) during cycle 1. MRI scans were obtained after each 6 week cycle. Results: 6 pts were treated (4 male, 2 female) at1st (n 2)