Optimal dose of bevacizumab in recurrent glioma: A retrospective study

Background: Recurrent gliomas have a dismal prognosis. They can be treated with re-surgery and re-irradiation. Bevacizumab as a single agent or in combination with chemotherapy is an alternative treatment option. However, in our country, a considerable proportion of patients cannot afford the approved 10 mg/kg dose. Objective: This study was aimed at evaluating the efficacy of low-dose bevacizumab in recurrent gliomas. Methods: Patients with recurrent gliomas presenting to our Neuro-Medical Oncology unit between July 1, 2015, and November 30, 2018, were retrospectively analyzed. The patients were divided into two groups, those treated with ≤5 mg/kg of bevacizumab (low dose) and those treated with >5–10 mg/kg (standard dose) of bevacizumab. The status of isocitrate dehydrogenase (IDH) and O[6]-methylguanine-DNA methyltransferase was recorded. The primary endpoint of the study was overall survival (OS), and the secondary endpoints were progression-free survival (PFS) and adverse events. Results: A total of 68 patients were treated with bevacizumab, of which 23 (33.8%) received the low-dose regimen. At a median follow-up of 26.2 months, there was no difference in the median PFS (low-dose group: 3.60 months; 95% confidence interval [CI], 2.5–7.47 vs. standard-dose group: 3.67 months; 95% CI, 2.17–4.53) (P = 0.18) and median OS (low-dose group: 7.33 months; 95% CI, 3.97–9.10 vs. standard-dose group: 5.47 months; 95% CI, 4.67–6.2) (P = 0.27). In addition, the adverse events were not significantly different between the two groups. Conclusion: Low-dose bevacizumab may be effective in the treatment of recurrent gliomas and should be compared with standard dose in prospective randomized studies.