THE GRAVEYARD OF ALZHEIMER’S DRUG TRIALS
Can we prevent or slow the progression of Alzheimer’s disease? The short answer is no.
Many “observational” trials of drugs or supplements have had positive results, but all these compounds fail when subjected to rigorous clinical trials.
The list seems endless: nonsteroidal anti-inflammatory drugs, antihypertensives (although intuitively, treatment of hypertension should reduce the risk of Alzheimer’s), hormone replacement therapy, intensive control of blood sugar in diabetics. The following nutritional supplements have also been shown to be ineffective: vitamin B12, folic acid, and vitamin B6 with the hope that they lower homocysteine; fish oil or omega-3 fatty acids, which contain DHA; flavonoids; and high-dose vitamin E (2000 units a day).
Monoclonal antibodies against amyloid have generated the most buzz recently. All have failed in Class I trials, which are randomized, double blind, placebo-controlled, probably because patients are treated too late in the course of the disease. New trials are identifying patients who have normal cognition but are at risk for Alzheimer’s, specifically “healthy elderly” who have positive amyloid PET scans. In fact, a subanalysis of a recent large monoclonal antibody trial showed that the mildest group seemed to benefit. Results of these studies will not be available for several years.