It’s no secret that Alzheimer’s Disease (AD) is the most common cause of dementia among people age 65 and older.

Scientists estimate that 4.5 million Americans currently suffer from the disease and -- if current population trends continue and no cure is found -- that number will grow to13.2 million by 2050.

The 85-and-older age group is now the fastest growing segment of the population. Within the next 25 years, the number of Americans, age 65 and older, is expected to double in size to about 72 million, according to a 2005 U.S. Census Bureau report on aging. These facts are important because, beyond age 65, the number of people with AD doubles with every 5-year age interval. One study shows that nearly half of all people age 85 and older have AD.

All these factors combine to fuel researchers’ urgent need to find a cure. Committed and resolute, they spend their careers looking for clues, searching for answers and conducting studies with the hope that a cure for AD is near.

New Studies & Breakthroughs

Douglas Galasko, M.D., Professor of Neurology at UCSD, is directing a study to test R I, an experimental drug, that seeks to stop amyloid beta from binding to a receptor in the brain. The buildup of plaques can trigger inflammation in the brains of people with AD. Amyloid beta, a protein, builds up in plaque deposits and may promote damage to nerve cells. Current AD therapies focus on improving symptoms versus attacking the root of the disease progression. Galasko, along with other researchers, are currently testing this experimental medication to block nerve damage and inflammation in the brain with the goal to prevent progressive memory loss and behavioral changes in people with AD.

"The evidence from basic research studies is compelling and merits further evaluation in a rigorous human clinical trial," Galasko said. "While most current Alzheimer’s disease therapies focus on the various symptoms of cognitive impairment, this trial is testing whether we can modify actual progression of the disease itself by targeting the interaction between amyloid beta and an important receptor in the brain."

The industry-sponsored study is being conducted by the Alzheimer’s Disease Cooperative Study (ADCS), a consortium of leading researchers supported by the National Institute on Aging (NIA), part of National Institutes of Health (NIH). The ADCS at the University of California, San Diego (UCSD) is coordinating the 18-month, double blind, placebo-controlled clinical trial. The drug, which has been tested in animals and in preliminary human studies, is being studied in this Phase II clinical trial to determine if it will slow the progressive decline associated with Alzheimer’s disease.

"In addition to monitoring disease progression through cognitive tests, we will examine various biological markers of the disease," said Lon Schneider, M.D., local principal investigator at USC’s Keck School of Medicine. Those biological markers include: the degree of atrophy (or shrinkage) of the brain as measured by magnetic resonance imaging (MRI), the extent of amyloid buildup in the brain assessed by Positron Emission Topography (PET) imaging, and levels of amyloid beta and other proteins in blood and spinal fluid.

Other New Research

Researchers continue to examine how lifestyle factors, such as exercise and diet, play a role in the disease. Others are working to identify biomarkers of AD so that we may eventually be able to diagnose the disease with a simple blood test.