Genentech Inc said on Sunday its blockbuster cancer drug, Avastin, showed encouraging results for patients with the most aggressive form of brain cancer. (file photo from Xinhua)

Genentech, the largest U.S. maker of cancer drugs, said 36 percent of patients treated with Avastin alone and 51 percent treated with a combination of the drug and chemotherapy lived without the disease advancing within six months.     

The announcement came after a successful Phase II trial in which bevacizumab showed clear improvements of the patients' survival rate.

In the Phase II trial, the drug, administered alone or with chemotherapy, demonstrated an encouraging six-month survival rate for patients with glioblastoma multiforme (GBM), the most common and aggressive type of brain cancer.

"The findings suggested that at six 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," Timothy Cloughesy, the lead investigator for the study, said in a statement.

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

Bevacizumab was developed by Genentech and is marketed in the United States by Genentech and elsewhere by Swiss drug maker 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.

According to the American Cancer Society (ACS), the five-year survival rate for patients with GBM is only three 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.

(Agencies via Xinhua November 19, 2007)