Experts Optimistic About Solving Puzzle of Alzheimer's

Research into Alzheimer's disease has reached a point of significant potential, even as the disease's looming impact on society grows more and more dire, experts say.

Some leading scientists, in fact, worry that we may not be doing enough to press forward with key advances and new insights into Alzheimer's, the most common type of dementia among older people.

Scientists researching early detection and treatment for the disease, say they are on the verge of substantial advances.

Despite some disappointments, a large slate of Alzheimer's drugs are undergoing human trials, says John C. Morris, MD, a professor and director of the Alzheimer's Disease Research Center at the Washington University School of Medicine in St. Louis and a spokesman for the American Academy of Neurology.

"There has never been a period in which we had more potential drugs to alter the disease course of Alzheimer's," Morris says. "We have lots of highly promising drug candidates."

The drugs focus mostly on amyloid, a protein that clumps in the brains of people with Alzheimer's.

"Many scientists believe eliminating that accumulation will eliminate Alzheimer's," says William H. Thies, PhD, chief medical and science officer for the Alzheimer's Association. "We've seen amyloid accumulation as one of the key markers in the development of Alzheimer's. It's really the first step in taking the basic science of Alzheimer's and using it to develop therapeutics."

However, three of the first antiamyloid drugs to be tested on people all failed to produce results. Treatment with AN-1792, Flurizan, and tramiprosate did not significantly improve the symptoms of people with Alzheimer's.

Part of the problem could have been that the drugs were tested on people with advanced Alzheimer's, Morris says, adding that they might be more effective if given to people in earlier stages of the disease.

But that requires a means to detect Alzheimer's disease early in its development or even to flag people who are at risk for developing the disease. The only way doctors have been able to diagnose Alzheimer's is when symptoms appear, and by then the damage has already been done, Morris and Thies say.

That might be about to change. Work is being done on scans and tests that could lead to the early detection of Alzheimer's.

Researchers are identifying substances that bind with amyloid deposits and make them visible to imaging scans, such as the PET scan. Previously, amyloid clumps have been invisible to scanning technology, and the only way doctors have been able to detect their presence in a human brain was during an autopsy, Morris says.

Researchers also are identifying genetic and biological markers that could indicate that a person is at increased risk for developing Alzheimer's.

"The excitement in the field is, yes, new imaging technology, and studies of amyloid beta in the spinal fluid of elderly and middle-age people do seem to identify people who, if they continue to live, will develop dementia," Morris says. "This will set the stage for targeting people at high risk of developing dementia if they live long enough."

Thies sees these two areas of research—detection and treatment—spurring each other along as progress is made.

Source: Brigham and Women's Hospital