Patient outcome in the Belgian medical need program on bevacizumab for recurrent glioblastoma

Bevacizumab (BEV) has demonstrated anti-tumor activity in patients with recurrent glioblastoma (rGB). Given the unmet need for active therapeutic options in rGB patients, a medical need program was initiated by the Belgian competent authorities. Between November 2010 and February 2013, a total of 313 patients with rGB initiated treatment with BEV administered at a dose of 10 mg/kg every 2 weeks. All patients had failed prior treatment with at least radiation therapy and temozolomide and the majority of patients (70 %) were treated with corticosteroids at baseline. Patients received a median of 6 BEV administrations (range 1-53). Overall, BEV was well tolerated. During BEV treatment the WHO-Performance Score (WHO-PS) improved in 59 patients (19 %) and stabilized for at least 6 weeks in an additional 139 (44 %) patients. Corticosteroid treatment could be stopped in 16 % or reduced in dose in 32 % of patients. The best objective tumor response rate using RANO criteria (investigator's assessment) was 3.5 % CR, 22 % PR, 38 % SD and 37 % PD. The median and 6-month PFS were 13 weeks (95 % CI 12.7-14) and 27.3 % (95 % CI 22.3-32.5), median and 6-month OS rates were 26 weeks (23-29) and 52 % (46.4-58.6), respectively. WHO-PS (0-1 vs. 2-3) and baseline steroid use were significantly correlated with PFS and OS. Our observations support the use of BEV as a monotherapy for patients with rGB who have no alternative treatment options. Optimal benefit from BEV treatment is likely to be obtained when treatment is initiated before the performance status deteriorates to two or less.