WASHINGTON — A huge international medical trial could be a gamechanger for millions of people at risk of getting Alzheimer’s disease.
Researchers at 60 sites in the United States, Canada and Australia are getting ready to test an antibody that they believe could break-up a dangerous form of plaque that builds in the brain.
It is called amyloid plaque and this abnormal protein has the ability to kill nerve cells, triggering the dementia of Alzheimer’s.
The theory goes, detect the plaque early, destroy it, and the disease will never take hold.
For many years that was an illusive goal because the only way to find the plaque was through an autopsy. But a new form of imaging – the PET scan — is giving doctors the ability to find amyloid plaque years before the first symptoms of Alzheimer’s appear.
“This was the breakthrough that really allowed this prevention study to happen because now we can identify the patients that are at high risk of getting Alzheimer’s disease,” says Dr. Scott Turner, director of the memory disorders program at Georgetown University Medical Center.
Georgetown and the other trial sites are now recruiting 10,000 volunteers for PET screening — all of them healthy seniors between the ages 65 and 85. They need so many because most of the volunteers are likely to test negative for amyloid plaque. Their goal is to find 1,000 with positive test results who are willing to take part in the 39-month trial.
So far, the response to the call for volunteers has been slow. Georgetown, for example only has one person in the screening process, and several more signed up.
“I think it will take longer than planned because almost all our studies take longer than planned,” says Turner, who believes the original recruiting target will eventually be met.
Of equal concern to this Georgetown professor of neurology is getting a volunteer pool that is representative of the diversity of the Alzheimer patient population. “The people that tend to join our studies are very educated and overwhelmingly Caucasian and yet we know that Alzheimer’s affects everyone,” he says.
Traditionally, African-Americans and Hispanics have accounted for only only a tiny fraction of the participants in clinical trials. This time, the researchers have set an ambitious target, insisting that 20 percent of those taking part in the study must come from these groups.
Some research sites say they are having problems with recruitment because so many seniors are scared to find out if they are high risk of Alzheimer’s. Turner says that isn’t really an issue, and that most of the volunteers are likely to be people with a family history, who have seen first hand the devastating affect of the disease.
It will be what is called a “blind trial.” Half the participants will be randomly chosen to get the treatment and half will take a placebo. Neither patients nor their health care providers will know which is being administered until the end of the study.
The stakes for the researchers are huge. Five million Americans have Alzheimer’s, and there are about 15 million caregivers. Turner says if this trial works, the medical community will finally be able to move forward and, hopefully, prevent the disease.
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