U.S. biotechnology company Genentech Inc. revealed on Sunday that its cancer drug, Avastin, seems to have positive results in treating patients suffering from the most aggressive form of brain cancer.

Relapsed glioblastoma multiforme is the most common type of brain cancer. The study showed that 36 percent of patients given Avastin and 51 percent treated with a combination of the drug and chemotherapy lived progression free from relapsed GBM for six month.

"Historical estimates suggest that only 15 percent of patients with this aggressive type of brain cancer live without their cancer progressing within six months," Timothy Cloughesy, the lead investigator for the study, said in a statement, according to Reuters.

GBM has proven notoriously hard to treat. People, who are diagnosed with the disease, usually get chemotherapy and after they relapse, they are given from three to six months to live.

The study is ongoing and final analyses for safety and other efficacy endpoints will be available in 2008. The first results were presented at the 12^th Annual Scientific Meeting of the Society for Neuro-Oncology.

One hundred and sixty seven cancer patients who relapsed after previous treatment were involved in this study.

Avastin, which was approved for colon and lung tumors, in the first place, is Genentech’s second-biggest seller. The drug earned $1.75 billion in sales in 2006. According to the company’s release, it is being tested in 300 clinical trials worldwide against 20 different types of cancer. If approved for treating brain cancer, Avastin will help 12,740 patients expected to die of the disease in 2007, according to the American Cancer Society.

"These findings exceeded our expectations," said Hal Barron, Genentech's senior vice president of development, in a statement.

According to the American Cancer Society, the five-year survival rate for patients with GBM has been steady at 3 percent for more than 25 years

The company plans to discuss next steps with the Food and Drug Administration