Bexarotene: Alzheimer’s Research is Called ‘Stunning’

A skin-cancer drug could offer hope for the millions of patients coping with the debilitating effects of Alzheimer’s disease. Scientists at Case Western Reserve University led a study of the drug Bexarotene (Brand name: Targretin) on mice and found that it helped wipe out a protein linked to Alzheimer’s. Their study, published yesterday in the journal Science, showed that the drug reduced the amount of amyloid beta by as much as 75 percent. The protein damages nerve cells.

The mice returned to normal behaviors three days after treatment with bexarotene, which is marketed as Targretin.

“No one, ourselves included, would have ever imagined that any drug would have worked with this speed,” said Gary Landreth, a Case neuroscientist and lead researcher. “It’s stunning.”

There are an estimated 5.4 million people with Alzheimer’s in the United States.

Amyloid beta is a common substance in human brains, but Alzheimer’s patients lose the ability to clear it from synapses. The researchers suspected that bexarotene’s effect on brain activity might help with Alzheimer’s.

If not cleared, the protein builds up as plaque and blocks synapses, ultimately killing nerve cells, said Dr. Doug Scharre, director of cognitive neurology at the Ohio State University Medical Center.

“The fact that this agent gets rid of the amyloid is very positive,” said Scharre, who was not involved in the study.

Scharre said many researchers speculate that by the time drugs are used in human trials of Alzheimer’s patients, it’s too late to halt serious problems.

“We can’t revive a dead nerve cell,” Scharre said. “If we could attack this at the very early stages of memory loss, we could have much better results.”

Other studies of drugs that showed promise in mice produced little change in human patients, said Maria Carrillo of the Alzheimer’s Association, which has helped fund some of Landreth’s research.

“We’re not sure that this is going to actually show the desired clinical benefits,” Carrillo said. “We owe it to ourselves and our constituents to follow every lead that we have.”

Landreth said he hopes to begin human trials soon. “I want to be in the clinic within the next few months,” he said.

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