In the phase II trial RTOG1205, Reirradiation (re-RT) with concurrent bevacizumab (BEV) demonstrated a clinically meaningful improvement in PFS in patients with recurrent Glioblastoma Multiforme and tumor progression ≥ 6 months from completion of prior chemo-RT.

In this randomized trial, median PFS for BEV + RT was 7.1 vs 3.8 months for BEV, HR= 0.73, P = 0.05. The 6-month PFS rate was significantly improved from 29.1% for BEV to 54.3% for BEV + RT (P =0 .001). However, there was no improvement in OS, the median OS was 10.1 versus 9.7 months for BEV + RT versus BEV alone, (HR= 0.98; P = .46). The treatment was generally well tolerated. There were a 5% rate of acute grade 3+ treatment-related AEs and no delayed high-grade AEs. Most patients died of recurrent GBM.