WASHINGTON (Reuters) -- A cold virus genetically engineered to help it sneak into cancer cells can kill inoperable brain tumors in mice, U.S. scientists reported on Tuesday.
The effects were so stunning that the National Cancer Institute and the U.S. Food and Drug Administration are rushing to test the approach in people with brain tumors.
If it works, it will be the first treatment for malignant glioma, the deadliest form of brain cancer.
Brain tumors affect about 18,000 people in the United States every year, killing 13,000. Gliomas are responsible for about half of all the cases.
"The bottom line of gliomas is that they are bad. Everyone dies within a year," said Dr. Frederick Lang of the University of Texas M.D. Anderson Cancer Center in Houston.
Lang and colleagues used a genetically engineered form of a common cold virus known as an adenovirus. They weakened it so it could not affect healthy cells, then gave it an added genetic "key" to open the door into cancer cells.
When they tested it in mice injected with human brain tumor cells of a particularly nasty nature, called glioblastoma multiforme, it apparently cured 60 percent of them.
"The animals lived 140 days -- we took the brains out at that point and found no tumors there," Lang said in a telephone interview. Normally, mice injected with human brain tumor cells die within 20 days.
"We've never seen this kind of response before with any other treatment tested in either animals or humans," Dr. Juan Fueyo, who led the study, said in a statement.
Potential for humans
Writing in the May 7 issue of the Journal of the National Cancer Institute, the researchers said the institute will work to produce a drug-grade version of the therapy to test in humans, possibly by late next year.
The researchers, who included a team at the Institut Catala d'Oncologia in Barcelona, Spain and the University of Alabama at Birmingham, are also working with the FDA, which will have to approve any human trials of the new approach.
Scientists point out that it is often easy to cure lab mice of cancer, in part because they are injected with human cancer cells. Human cancer develops through complex processes.
But Lang thinks his team took this into account and said the tumors were not affected by any other treatments.
"We used radiation, we used standard chemotherapy and we even used a lot of novel chemotherapy," he said. "Sometimes we extended survival but eventually all the animals died. But with this particular agent, we actually had what we thought were cures."
Human adenoviruses are being studied for a range of medical uses, from cancer therapy to gene therapy, because they are very good at infecting human cells. One fear is that the immune system will recognize them and either overreact, causing illness, or kill the virus before it can do any good.
But Lang said because the viruses were injected directly into the brain tumor, this should not happen.
He also said the team wants to find out why only 60 percent of the mice were "cured." "It could just be in those cases the tumor grew faster than the virus could replicate," he said. Or it could be the injection was not done properly.
Well this sounds incredibly good to me! I sure hope this will lead to a cure for this awful illness.
But please, do not let this stip you supporting our fight against cancer (see my sig)