Prana Biotechnology Limited has announced that a potential treatment for Alzheimer's Disease was presented at the annual meeting of the Society for Neuroscience in New Orleans.

Dr. Bush said the drug, called Clioquinol, was approved for human use decades ago. Clioquinol is now being tested on 36 Alzheimer's patients. The patients are all moderately affected by Alzheimer's disease, but still live independently and are able to give informed consent. The results of the test will not be known for at least another 12 months. Patients are being carefully monitored for any possible side effects.

Clioquinol was last used during the 1970s, when it was linked to a rare neurological disorder that was found only in Japan, Dr. Bush said at the neuroscience meeting. "The syndrome appears due to rapid B12 depletion," Dr. Bush added. "Now that we know what causes that side-effect, we believe that we can prevent it, and rehabilitate the drug for safe use once more"

Mice used in the initial experiment were genetically manipulated to over-produce beta-amyloid, which creates the sticky plaques that are a major feature of Alzheimer's. Copper and zinc "decorate" those plaques -- and mice given Clioquinol, which strips away those metals, showed a 51 percent reduction in the plaques compared with untreated mice of the same strain.

"The drug was effective in the mice experiments not because it kills germs but because it binds two metals," Dr. Bush pointed out. "In a third of the younger animals, it eliminated the plaques, even though the animals continued to overproduce beta-amyloid."

Dr. Bush believes that "the brain may heal and repair the damage -- depending on how advanced the disease is -- if you get the plaque out of the way."

Dr. Bush and his colleagues are investigating ways to optimize the effect of the drug, and determine the minimum and maximum safe dosages. Currently, clinical trials have begun at the University of Melbourne in Australia, headed by Colin Masters, MD, and sponsored by Prana Biotechnology, Ltd. Professor Masters is a Director of Prana Biotechnology and chair of the Company's Scientific Advisory Board.

Dr. Bush is the Director of the Laboratory for Oxidation Biology in the Genetics and Aging Unit at Massachusetts General Hospital, Associate Professor of Psychiatry at Harvard Medical School, and Visiting Professor at the University of Melbourne. His discoveries relating to the role of metals and oxidative stress in neurological disorders have opened a new field of research of neuroscience that forms the basis of the Company's platform technology in the arena of age-related diseases.

Dr. Bush is a consultant on the scientific advisory board and shareholder in Prana Biotechnology, which had sponsored the research at MGH until September 1999.