Bevacizumab in recurrent glioblastoma: does dose matter? Our monocentric and comparative experience.

Purpose: Bevacizumab is an anti-angiogenetic treatment that can be used in patients with recurrent glioblastoma, but there are limited and controversial data on the optimal dose and schedule, associated toxicities and survival benefits of different doses.

Methods: A retrospective analysis of patients with recurrent IDHwt glioblastoma treated with bevacizumab at the Veneto Institute of Oncology was performed. Patients received bevacizumab in 2 different schedules (5 mg/kg or 10 mg/kg q2w), as monotherapy or in combination with chemotherapy.

Results: 81 patients were analyzed, 33 received bevacizumab 5 mg/Kg, 48 received bevacizumab 10 mg/Kg. Median PFS was 4 months in both patients treated with 5 mg/kg and those treated with 10 mg/kg (p-value=0.08), median OS was 5 months in patients treated with 5 mg/kg and 7 months in those treated with 10 mg/kg (p-value=0.10). There was no difference in the use of steroid therapy between the two groups. The incidence of adverse events was not statistically different.

Conclusions: There was no statistically significant difference in survival, PFS, response, toxicity and steroid reduction between the two different doses. These results may support the use of lower doses of the drug with comparable benefit for patients and with additional advantage in terms of health care costs.