"This study demonstrates that it is possible to alleviate some of the cognitive and functional losses associated with the later stages of Alzheimer's, providing a basis for greater optimism on the part of caregivers," says Barry Reisberg, M.D., Professor of Psychiatry at NYU School of Medicine, the lead investigator of the study, which is published in the January 2006 issue of the Archives of Neurology.
"Our study verifies that this medication continues to be beneficial and is safe with remarkably few side effects," said Dr. Reisberg, who is also Clinical Director of the Silberstein Aging and Dementia Research Center at NYU School of Medicine.
Namenda® was approved in October 2003 by the Food and Drug Administration for the treatment of moderate to severe Alzheimer's disease. The approval was based partly on a rigorous 28-week study of 252 people who were randomly chosen to receive the drug or a placebo. The results, published in the prestigious New England Journal of Medicine in the spring of 2003, showed that the drug could slow the downward spiral of the disease. Dr. Reisberg also was the principal investigator of this study.
The new study evaluated the effects of the medication in the same patients for an additional 24 weeks in what is called an "open label extension." All patients who received a placebo previously were given the drug. The study enrolled 175 patients, 80 of whom had received the placebo. The remaining patients continued to receive the drug. The study was paid for by the German company Merz Pharmaceutical GmbH, which markets the medicine in Germany and elsewhere. Forest Pharmaceuticals Inc sells Namenda® in the United States.
All patients were evaluated with a wide range of tests to assess cognitive and functional abilities, and behavior. Those who were switched from the placebo to Namenda® showed a significantly slower rate of decline in a test of their ability to perform daily activities and in a test designed to measure their cognition, compared with the rate of decline previously. They also showed a significant benefit on a test designed to evaluate overall abilities and behavior that includes input from caregivers.
In the patients who continued to receive Namenda®, the benefits of the treatment appeared to be maintained, according to the study.
Namenda® is the only approved treatment for slowing the later stages of the disease, when patients are in the most distress. In the moderate to severe stages, patients begin to lose the ability to care for themselves. They generally have trouble dressing and bathing; many can no longer make a cup or coffee or tea for themselves.
The authors of the study are: Dr. Reisberg and Steven Ferris, Ph.D., from NYU School of Medicine; Rachelle Doody, M.D. Ph.D., from Baylor College of Medicine; Frederick Schmitt, Ph.D., from the University of Kentucky; and Albrecht Stöffler, M.D., and Hans Jörg Möbius, M.D., Ph.D., from Merz Pharmaceuticals.