Bevacizumab and irinotecan for recurrent oligodendroglial tumors

Abstract

Background: Treatment with a regimen of bevacizumab–irinotecan has been shown to be effective in recurrent grade 3 and 4 gliomas, but the effect of this regimen against recurrent oligodendroglial tumors has not been specifically studied.

Methods: The bevacizumab–irinotecan regimen was retrospectively evaluated in a consecutive series of 25 patients with recurrent oligodendroglial tumors. All patients had not responded to previous treatment with radiation therapy and at least one line of temozolomide chemotherapy. Bevacizumab (10 mg/kg) and irinotecan (125 or 340 mg/m² according to the antiepileptic regimen) were administered every 14 days. Response was measured clinically and on monthly MRI.

Results: The objective response rate was 72% (20% complete response, 52% partial response). After a median follow up of 202 days, the median progression-free survival was 140 days (95% confidence interval [CI] 116–∞), and overall survival had not been reached. The 6-month progression-free survival was 42% (95% CI 26%–67%). Among the 17 patients in whom the status of the main molecular alterations of gliomas could be evaluated (search for deletions of chromosomes 1p, 19q, 9p, and 10q and amplification of epidermal growth factor receptor, mouse double-minute gene, and cyclin-dependent kinase 4 gene), no relation could be found between the response rate and the type of genetic change (including 1p-19q codeletion). The profile of tolerance was fair, with treatment discontinuation in 20% of patients. Intratumoral hemorrhages occurred in 6 patients (24%), but the treatment had to be discontinued because of symptomatic bleeding in only 1 patient (4%).

Conclusions: This regimen is effective in recurrent oligodendrogliomas, and the overall tolerance is acceptable.