New Alzheimer’s Disease Prevention Trial about to Start

Have you ever experienced a “senior moment” when you cannot remember someone’s name or a word when you need it and wonder if this could be an early symptom of Alzheimer’s disease? Well, if so, you are not alone. Recalling names or words, occasionally misplacing items and having more difficulty learning new information are common mild problems as we get older. By and large, these symptoms are not progressive, and people can learn and recall new information and carry out their normal daily activities. It is a worrisome sign when the problems start occurring more frequently; the person becomes repetitive – they fail to recall whole events and not just details and lack awareness of these cognitive problems.

People are often confused about the difference between Alzheimer’s disease and dementia. Dementia is a general term that means there is cognitive impairment that significantly interferes with day-to-day functioning. Alzheimer’s is a disease that is the most common cause of dementia. Alzheimer’s disease is associated with the build-up of plaques in the brain composed of amyloid protein and neurofibrillary tangles made up of tau protein. Amyloid and tau are proteins normally found in the brain but they become twisted and deposit clumps as Alzheimer’s disease progresses. The amyloid deposits stimulate the development of tau tangles, which eventually lead to the breakdown of connections or synapses between nerve cells.

The major risk factor for Alzheimer’s disease is advancing age followed by a history of dementia in first-degree relatives. There is growing evidence that Alzheimer’s takes place over many years in the brain. The first stage begins with a silent build-up of amyloid plaques in the brain 10-15 years before the onset of cognitive symptoms. The next stage referred to as mild cognitive impairment is associated with mild memory loss but fairly normal activities of daily living. Dementia occurs in later stages and can be mild, moderate, or severe. The medications currently available for dementia provide a modest benefit but do not slow down the disease process. Early intervention with disease-modifying medications that decrease amyloid and tau deposits may help delay memory loss and other cognitive symptoms. Early intervention has been successful in other major diseases such as cancer and heart disease.

Fortunately, a new FDA-approved brain scan is now available to safely determine who is building up amyloid plaques in the brain and is, thus, at greater risk for developing Alzheimer’s disease. Soon, we will also be testing a new tau PET tracer to detect the build-up of tau tangles. These are major advances, because, previously, we had to wait until an autopsy to see the amyloid plaques and tau tangles under a microscope.

We will be using the amyloid PET scan in a new study to prevent Alzheimer’s disease. The study is called the anti-amyloid in asymptomatic Alzheimer’s disease (A4) trial and is funded by the National Institute of Health, Lilly Pharm aceuticals and private foundations. The study will enroll people age 65-85 without significant cognitive impairment. Participants will have an amyloid PET scan to see who is building up amyloid plaques (approximately 33% of normal people in this age range). Those with a positive amyloid scan will receive a vaccine that binds to amyloid or a placebo infusion each month for 39 months to try and delay the onset of cognitive symptoms. Those who do not meet the amyloid cut-off may be followed in an observational group, but will not receive medication. The vaccine was selected by a panel of dementia experts based on the safety profile and potential benefit seen in in more than two thousand people with Alzheimer’s disease.

These studies are being conducted at the Butler Hospital Memory and Aging Program. There is no charge for any of the procedures or medications involved in this study. For more information about this study contact Diane Monast, RN, MSN at Butler Hospital at 455-6403.

STEPHEN SALLOWAY, M.D., M.S. is Director of Neurology and the Memory and Aging Program at Butler Hospital and Professor of Neurology and Psychiatry at the Warren Alpert Medical School of Brown University. He is an internationally recognized expert on Alzheimer’s disease and the first author of a large phase 3 trial of an anti-amyloid vaccine for Alzheimer’s disease in a recent issue of the New England Journal of Medicine.