Hypofractionated-intensity modulated radiotherapy (hypo-IMRT) and temozolomide (TMZ) with or without bevacizumab (BEV) for newly diagnosed glioblastoma multiforme (GBM): a comparison of two prospective phase II trials

To compare progression-free (PFS) and overall survival (OS) in patients treated in two consecutive phase II trials of hypofractionated-intensity modulated radiotherapy (hypo-IMRT) and temozolomide (TMZ) with or without bevacizumab (BEV). Patients with newly diagnosed glioblastoma multiforme (GBM) after biopsy or resection were enrolled on a clinical trial with hypo-IMRT and TMZ (hypo-IMRT/TMZ alone) from 2008 to 2010, or in the second protocol with the same hypo-IMRT and TMZ plus BEV (hypo-IMRT/TMZ/BEV) from 2010 to 2013. All patients received postoperative hypo-IMRT to the surgical cavity and residual tumor plus margin to a total dose of 60 Gy and to the T2 abnormality with margin to 30 Gy, both in ten fractions. Concurrent TMZ (75 mg/m(2)/day) was given to all patients for 28 consecutive days followed by adjuvant TMZ (150-200 mg/m(2)/day). Patients enrolled on the hypo-IMRT/TMZ/BEV trial received concurrent and adjuvant BEV (10 mg/kg) on days 1 and 15 of each 28-day cycle. Hazard ratios of PFS and OS were compared between trials in a Cox proportional hazards model. Twenty-six patients were enrolled on the hypo-IMRT/TMZ alone trial and 30 patients on the hypo-IMRT/TMZ/BEV trial. Median follow-up was 13.9 and 14.7 months, respectively. Median PFS was 3.4 months longer with hypo-IMRT/TMZ/BEV but the difference was not statistically significant (12.8 vs. 9.4 months, p = 0.58). Median (OS) was 16.3 months for both trials. The addition of BEV to TMZ and hypo-IMRT did not improve OS for patients with GBM in two phase II trials with small patient numbers; PFS was longer with BEV, but the difference was not statistically significant.