Genentech Inc announced its Avastin (active ingredient: bevacizumab), a monoclonal antibody against vascular endothelial growth factor, showed encouraging results in patients with the most aggressive form of brain cancer. The announcement came after a successful Phase II trial in which bevacizumab showed clear improvements of the patients' survival rate.

The trial involved patients diagnosed with glioblastoma multiforme (GBM), the most common and aggressive type of brain cancer. The results were presented at the Society for Neuro- Oncology meeting today in Dallas. Genentech said that around 36 percent of the patients had their tumors remain stable for six months, compared to 15 percent for other competing drugs.

"Historical estimates suggest that only 15 percent of patients with this aggressive type of brain cancer live without their cancer progressing within six months," said Dr. Timothy Cloughesy, the lead investigator for the study. "The findings suggested that at 6 months, more patients had lived without their cancer advancing when Avastin was administered as a single agent or in combination with chemotherapy, than what we would normally expect," he said.

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

Bevacizumab was developed by Genentech and is marketed in the United States by Genentech and elsewhere by Roche, which is Genentech's parent company, under the brand name Avastin. Bevacizumab, approved by the Food and Drug Administration (FDA) in February 2004 for use in colorectal cancer, was the first commercially available angiogenesis inhibitor. This class of drugs stops tumor growth by preventing the formation of new blood vessels. The main side effects of the drug are hypertension and heightened risk of bleeding.

Avastin is the company's second-biggest seller with $1.75 billion in sales in 2006. According to the American Cancer Society (ACS), the five-year survival rate for patients with GBM is only 3 percent, and, more importantly, has not changed in more than 25 years as newer treatments proved ineffective. The ACS also estimates there will be 20,500 new cases of brain cancer and 12,740 brain cancer deaths in 2007.