Oct. 22 (HealthDay News) -- A combination of the drug bevacizumab (brand name Avastin) and the standard chemotherapy agent irinotecan may benefit patients with a type of deadly brain tumor called glioblastoma multiforme (GBM), says a Duke University pilot study.

This treatment approach may extend the length of time GBM patients can survive without tumor growth and may improve overall survival, according to researchers at Duke's Preston Robert Tisch Brain Tumor Center.

The study included 35 patients whose GBMs returned after they'd had standard therapy, possibly including surgery, radiation and chemotherapy. After the patients received the combination bevacizumab/irinotecan therapy, almost half had no tumor progression after six months, and 80 percent were still alive six months after diagnosis.

The findings are published in the Oct. 20 issue of the Journal of Clinical Oncology.

"These results represent tremendous hope for these patient and their families," lead investigator Dr. James J. Vredenburgh, a neuro-oncologist, said in a prepared statement.

He noted that 75 percent of patients with recurrent GBM treated with standard therapy, such as chemotherapy alone, have tumor progression at six months, and fewer than 50 percent are alive after six months.

"We speculate that bevacizumab and irinotecan each attack a particular characteristic of the tumor independently, or they work together, with bevacizumab suppressing the growth of blood vessels which makes the tumor more susceptible to the chemotherapy," Vredenburgh said.

"Further studies will tease out the exact mechanism of the therapy's success, and we also hope to study the effectiveness of this treatment in patients with newly diagnosed GBM," he added.

SOURCE: Duke University, news release, Oct. 18, 2007