Hope for Mad Cow Disease
Aug. 13, 2001 -- Old drugs for malaria and psychiatric disease might get a new twist in treating the human form of mad cow disease, known as new variant Creutzfeldt-Jakob disease.
Like mad cow disease, this devastating brain condition is thought to be caused by infectious proteins called prions, discovered by Nobel Prize winner Stanley Prusiner. Only 1% of prion diseases are contracted by infection, which new variant Creutzfeldt-Jakob disease would fall under, about 5%-15% are inherited, and the rest have no known cause. Though prion diseases are relatively rare in humans, more than 100 young Europeans may have contracted new variant Creutzfeldt-Jakob disease by eating beef from so-called mad cows.
Now, a new study has found that the antimalarial drug quinacrine and the antipsychotic drug chlorpromazine can effectively treat mouse cells infected with prions, according to research described in the Aug. 14 issue of Proceedings of the National Academy of Science.
"This is one of the most exciting developments in prion research, as there is nothing else available to treat these terrifying diseases," researcher Barnaby C.H. May, PhD, a visiting postdoctoral fellow in cellular and molecular pharmacology at University of California, San Francisco, tells WebMD. "These very promising compounds are very potent against prion protein."
The researchers say they are beginning to test the treatment in humans on a compassionate-use basis. Carsten Korth, MD, tells WebMD that because of patient confidentiality concerns, he cannot provide more details about the results the research team are seeing in people now. But formal clinical trials for the treatment should start soon, he says. Korth is one of the authors of the cell study and a postdoctoral scholar in Prusiner's lab at UCSF.
In addition, the Associated Press reports that the FDA has approved human testing. A British woman who is believed to have developed the human form of the disease began to walk and talk again after receiving the therapy.
Rather than developing new drugs from scratch, which is time-consuming, expensive, and often futile, Prusiner's group tested about 50 existing drugs that reach the brain before finding one that worked against prions. The winner was chlorpromazine, used to treat hallucinations, among other things. Next they tested quinacrine, a drug for malaria, because its chemical structure resembles chlorpromazine. Their hunch paid off.