Bevacizumab plus irinotecan prolongs survival in recurrent glioblastoma

November 7, 2007

NEW YORK (Reuters Health) - Phase II trial results show that dual treatment with irinotecan and bevacizumab prolongs survival in cases of recurrent glioblastoma multiforme.

Response to current regimens for recurrent glioblastoma multiforme is usually less than 20%, investigators at Duke University in Durham, North Carolina note in the October 20th Journal of Clinical Oncology, and 6-month progression-free survival is less than 30%.

Bevacizumab is a monoclonal antibody active against vascular endothelial growth factor (VEGH), which is highly expressed in malignant gliomas, and irinotecan is a topoisomerase 1 inhibitor. Noting that irinotecan has some activity in recurrent glioblastoma multiforme, Dr. James J. Vredenburgh and associates theorized that adding bevacizumab would improve treatment.

In a two-part trial, a total of 35 patients with recurrent malignant glioma were treated with bevacizumab plus irinotecan.

The combination treatment was "strikingly active," the investigators report. Twenty patients had at least a partial response to combined treatment.

At 6 months, median progression-free survival was 46%, and overall survival was 77%. The median overall survival was 42 weeks. For six of the seven patients who were treated for a year, brain imaging revealed no residual high-grade tumor.

Toxicity was significant but acceptable, "given the extremely poor prognosis of recurrent glioblastoma multiforme," the investigators say. Four patients discontinued treatment because of thromboembolic complications, and another four because of fatigue.

Dr. Vredenburgh and associates suggest that including bevacizumab in the initial treatment of patients with glioblastoma multiforme "may have the greatest impact on survival."