Arizona researchers are part of a nationwide study involving a new drug that could halt the progression of Alzheimer's disease by preventing plaque from forming in the brain.
Scientists at Banner Alzheimer's Institute in Phoenix and Banner's newly acquired Sun Health Research Institute in Sun City are looking for volunteers with mild to moderate dementia to take part in a 18-month clinical trial.
The experimental drug has the potential to stop plaque formation - one of the hallmarks of the brain-withering disease - by preventing the abnormal proteins from binding to a receptor in the brain.
Unlike the medications commonly used to treat Alzheimer's disease, the drug is designed to attack the cause rather than its symptoms.
"This is something that actually goes to the pathology of the disease," said Dr. Roy Yaari of the Banner Alzheimer's Institute and a principal local investigator.
Deposits of abnormal proteins, or plaque, can build up in the brains of Alzheimer's patients, causing nerve damage and inflammation that interfere with brain function and cause symptoms, like memory loss and behavior change, associated with dementia.
In patients with Alzheimer's, certain proteins, called amyloid beta, are abnormally cleaved and float freely between the brain and bloodstream, looking to attach to other proteins and form the sticky plaque buildup.
Scientists discovered that the experimental drug has the potential to stop plaque formation by preventing it from binding to a receptor in the brain known as RAGE. Typically, the receptor would allow the protein to move back and forth between the brain and the bloodstream.
"If you block the enzyme, once (the protein) leaves, it can't get back in," Yaari said. "What this drug does is it blocks it from coming back into the brain."
About 400 people nationwide are needed for the second phase of clinical trials, sponsored by Pfizer and the National Institute on Aging.
"There's been a lot of interest in this. These slots are going quickly," said Dr. Sandra Jacobson, a neuropsychiatrist with Sun Health and a co-investigator in the study.
Earlier studies on animals and humans found few side effects, other than some gastrointestinal discomfort, Jacobson said, which is common when a new drug is introduced.
"Everything that we know so far about this molecule makes us think this is safe," she said.
Study volunteers must be 50 years or older and free of any serious diseases within the past three months. They will be randomly assigned to one of three groups, with two groups receiving different doses of the medication and the third group a placebo. Participants will be monitored during at least 12 clinic visits, including MRIs, cognitive testing and electrocardiograms.
"In addition to monitoring disease progression through cognitive tests, we will examine various biological markers of the disease," Yaari said.
Much of the preliminary research connecting RAGE to the plaque was done by scientists at Columbia University, the University of Perugia in Italy and the University of Magdeburg in Germany.
The study, led by the Alzheimer's Disease Cooperative Study at the University of California, San Diego, is under way at 40 sites nationwide.