A skin cancer drug sold by Eisai Co. reversed signs and symptoms of Alzheimer’s disease in mice, a study found, setting the stage for tests to see if the treatment can do the same in humans.
The drug, Targretin, eased plaque buildup in the brains of mice with Alzheimer’s disease and improved their memory, according to the study published in the journal Science. The results were particularly promising because the drug worked quickly, as soluble amyloid fell by 25 percent and its buildup in the brain was halved in three days, the researchers said.
The reductions in amyloid, a hallmark of Alzheimer’s disease in humans, were accompanied by improvements in mental function, memory and smell, the researchers said. The most effective existing treatment for mice with the disease takes several months to reverse the plaque buildup in the brain, said Paige Cramer, a Ph.D candidate who led the research at Case Western Reserve School of Medicine in Cleveland, in a statement.
“The results of this study, showing the preservation of behaviors across a wide spectrum and accompanying brain function, are tremendously exciting and suggest great promise in the utility of this approach in treatment of Alzheimer’s disease,” said Daniel Wesson, an assistant professor of neurosciences at Case Western Reserve School of Medicine, in a statement.
While the results are exciting, they only stem from mouse models of the disease, said Gary Landreth, professor of neurosciences and the senior author of the paper. The researchers want to see if the medicine has similar benefits in humans next, though they are at an early stage in their planning, he said.
The medicine, known chemically as bexarotene, is thought to work by stimulating the production of a protein that helps remove amyloid beta from the body, the researchers said. Eisai, based in Tokyo, and New York-based Pfizer Inc., the world’s biggest drugmaker, sell Aricept, which was the most widely prescribed Alzheimer’s disease drug until cheaper generic copies of the medicine became available in the U.S. in 2010.
About 5.1 million Americans suffer from Alzheimer’s disease, the leading cause of dementia in the elderly, a number expected to double by 2050, according to the U.S. Department of Health and Human Services. Scientists have been unable to pinpoint the cause of the condition and there is no cure.
The Obama administration earlier this week said it would boost funding for Alzheimer’s research by $50 million to $500 million this year to investigate the genetic underpinnings of the disease and test drugs that may arrest its development.
The Case Western research released yesterday was funded by the Blanchette Hooker Rockefeller Foundation, the Thome Foundation and the U.S. National Institutes of Health.
Eisai acquired the rights to Targretin when it purchased Ligand Pharmaceuticals Inc. for $205 million in 2006. The drug treats patients with skin lesions caused by persistent or recurrent cutaneous T-cell lymphoma or AIDS-related Kaposi’s sarcoma.