By Will Dunham
WASHINGTON (Reuters) - Genentech Inc colon and lung cancer drug Avastin, along with standard chemotherapy, increases survival rates of patients with a very deadly type of brain tumor, U.S. researchers said on Thursday.
Researchers at Duke University in Durham, North Carolina, studied the use of Avastin, which works by cutting off a tumor's supply of blood, to treat patients with glioblastoma multiforme, or GBM, an aggressive type of brain tumor.
Doctors estimate patients with GBM generally have eight to 12 months to live after diagnosis and three to six months to live after a tumor returns following initial treatment.
In the small pilot study, the Duke researchers looked at 35 patients -- 22 men and 13 women, average age 48 -- whose tumors had returned after initial treatment with radiation and chemotherapy. The patients were given a combination of Avastin, also known as bevacizumab, and a standard chemotherapeutic agent called irinotecan.
Seventy-seven percent were still alive six months after the start of this treatment and 46 percent experienced no tumor growth in that period. The researchers said this represented improved outcomes for patients with this cancer.
"I feel comfortable saying that it's the first treatment for recurrent GBM that's really making a difference," Dr. James Vredenburgh, who led the study, said in a telephone interview.
"It's the hardest tumor on the patient because it destroys you physically, emotionally and cognitively. It's almost like having Alzheimer's disease and a horrible stroke," he said.
The study appeared in the Journal of Clinical Oncology.
Of people with recurrent GBM who get only standard treatment, less than half are alive after six months and about three quarters experience tumor growth in that time. Even when these tumors are treated with surgery or drugs, they come back in more than 90 percent of patients, the researchers said.
Avastin is in a class of drugs called anti-angiogenics that restrict the rapid growth of blood vessels that feed a tumor's growth and spread. The researchers said Avastin, used in these brain tumor patients, may be holding down the growth of blood vessels, making tumors more vulnerable to chemotherapy.
The researchers said using Avastin is not without risk, in that it may increase the chances of blood clots in the legs and lungs and inhibit normal wound-healing so patients cannot have surgery for anything else.
The current bleak survival rates point out the need for new types of treatment. Only about 30 percent of patients are alive a year after diagnosis and 3 percent are alive 5 years after diagnosis, the researchers said.
GBM is the most aggressive type of primary brain tumors, which are those originating in the brain itself rather than coming from another location in the body. These account for about half of primary brain tumors. In the United States alone, it kills about 10,000 people annually.
Swiss drug maker Roche Holding AG owns a majority stake in South San Francisco-based Genentech. The study was funded primarily by the U.S. National Institutes of Health, but Genentech also provided some financial backing.