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
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
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
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.
"Both drugs have a very long history of clinical use,"
May says. "Exactly how they work is unclear, but we're trying to figure it
Although it's a long leap from the test tube to the human
brain, the drugs are relatively safe and the diseases are always fatal, so
Prusiner's group feels there's not much to lose.
Without doing extensive studies in animals, it is far too soon
to make predictions about how effective these drugs will work in humans,
Hermann Schätzl, MD, tells WebMD. He is a prion researcher at the Max von
Pettenkofer-Institute of the Gene Center in Munich, Germany.