Cancer Drug Shows Promise in Alzheimer's Mice

U.S. researchers said Tuesday a cancer drug has shown promise toward improving memory when given to older mice with Alzheimer's disease.

The drug, epothilone or EpoD, had previously been shown by the same team of scientists at the University of Pennsylvania to prevent cognitive decline in young mice who were bred to show Alzheimer's-like symptoms later in life.

But their latest study showed that benefits in learning and memory extended to older mice who showed signs of Alzheimer's, offering one more step toward someday trying the treatment in humans with the incurable form of dementia.

The drug appears to work by stabilizing nutrient-transporting structures in nerve cells known as microtubules, which break down when clumps of a protein called tau build up in the brain, causing what are known as "tangles" in the nerve cells.

EpoD functions like a well-known chemotherapy drug, paclitaxel, but is different in that it crosses the blood-brain barrier, said lead author Kurt Brunden, whose study appears in the Journal of Neuroscience.

"EpoD readily enters the brain, where it appears to persist for a much longer time than in the blood. This may explain why low doses were both effective and safe in the mouse model of Alzheimer's disease."

Mice were treated for only three months, however. Humans likely would have to treated for much longer because Alzheimer's is a chronic, deteriorating condition, so more research is needed to see if lengthier treatment would be harmful.

A separate team of researchers last month reported that another widely available cancer drug, bexarotene, showed remarkable success in reversing Alzheimer's disease in mice.

Mice treated with the drug became rapidly smarter and the plaque in their brains that was causing Alzheimer's started to disappear within hours, said the research in the US journal Science.

But experts caution that mice models do not always translate to success in human trials, and significant hurdles remain before it will be known whether such approaches could work in humans.