By the Blouin News Science & Health staff

Pharmaceutical treatment for Alzheimer’s disease is elusive

by in Medicine, Research.

An Alzheimer's patient has her hair done inside the Alzheimer foundation in Mexico City, Mexico

An Alzheimer’s patient has her hair done inside the Alzheimer foundation in Mexico City, Mexico (REUTERS/Edgard Garrido)

Last month, Blouin News reported on research indicating that the rate of Alzheimer’s disease among older adults in the U.S. will triple by 2050.  There are currently five medications used to treat the symptoms of Alzheimer’s, but none fundamentally alter the progression of the disease. As the cost of care rises, researchers are racing to find a cure — here is a sampling of some pharmaceutical treatments in the works.

A drug known as ORM-12741 just completed Phase IIa clinical trials to establish the proper dosage in treating people with Alzheimer’s.  Researchers gave 100 people with moderate Alzheimer’s either 30-60 milligrams of the drug, 100-200 milligrams of the drug or a placebo.  According to the study, which was sponsored by Orion Pharma, the memory of people who took ORM-12741 improved by four percent after three months, while the memory of people who took the placebo worsened by 33 percent. The results will be presented at the American Academy of Neurology’s annual meeting on March 16, and if convincing, the 100-200 milligram dose should elicit a greater response than the 30-60 milligram dose.

Researchers from the University of British Columbia recently published a study supporting the use of drugs that inhibit the proliferation of blood vessels in the brain for treating Alzheimer’s. In their earlier work from 2011, lead researcher Wilfred Jefferies proposed that Alzheimer’s might be related to a high density of capillaries in the brain, which could contribute to the break down of the barrier that prevents harmful substances like amyloid proteins from infiltrating and accumulating.  The new study, published last month in the Nature journal Scientific Reports, indicated that the amount of capillaries in the brain decreased in mice immunized with amyloid beta protein, which also corresponded with a decrease in protein plaque build-up.  There is some evidence that drugs like Targretin, which decreases the amount of blood vessels, have improved memory in mice with Alzheimer’s.

In a study out on March 1, researchers from the University of Washington tested 1,120 existing drugs for their ability to decrease tau, another protein thought to be excessive in the brains of people with Alzheimer’s. The researchers found that the antipsychotic Azaperone alleviated tau build-up in C. elegans, a small transparent worm, as well as in human cell cultures. Previous studies have determined that high doses of antipsychotics may actually increase the aggressiveness of tau buildup in the brain, however, and University of Washington researcher Brian Kraemer cautioned that more work needs to be done to establish if low doses of Azaperone are effective in treating Alzheimer’s.

For now, the state of the research on drug treatments for Alzheimer’s is still very preliminary.  There is an abundance of studies that offer encouraging results from animal models, but few will progress to replicating the effects in humans. And considering the growing market for Alzheimer’s medications, those that are eventually approved for use in humans should be approached with a healthy amount of skepticism.