A phase II study of feasibility and toxicity of bevacizumab in combination with temozolomide in patients with recurrent glioblastoma

The aim of this prospective and multicentric phase II study was to evaluate the efficacy and safety of temozolomide (TMZ) and bevacizumab (BV) in patients (pts) with recurrent glioblastoma (GB), previously treated with chemoradiotherapy and at least three cycles of adjuvant TMZ.

Patients with GB at first relapse received BV 10 mg/kg day every 2 weeks and TMZ 150 mg/m² days 1–7 and 15–21, every 28 days. Patients underwent brain magnetic resonance imaging every 8 weeks.

Thirty-two evaluable pts were recruited in 8 sites. Fourteen pts (44 %) had gross total resection. O⁶-methylguanine-DNA methyltransferase (MGMT) promoter was methylated in 12 pts, unmethylated in 6 pts, and missing in 14 pts. The estimated 6-month progression free survival (PFS) rate was 21.9 % (95 % CI 9.3–40.0 %). The median PFS and overall survival (OS) were 4.2 months (95 % CI 3.6–5.4 months) and 7.3 months (95 % CI 5.8–8.8 months), respectively. No significant association with MGMT status was found in terms of OS or PFS. Six of 32 pts (19 %; 95 % CI 7.2–36.4) were long-term survivors, with a median PFS and OS (50 % events) of 9.5 months (95 % CI 7.9–23.6) and 15.4 (95 % CI 8.9–NA), respectively: no differences in baseline characteristics were identified in comparison with total population. No unexpected toxicities or treatment-related deaths were observed.

This regimen showed to be feasible and well tolerated in pts with recurrent GB pretreated with TMZ. Further investigation is warranted to identify subpopulations that are more likely to benefit from addition of BV to GB therapy.