A drug that did $1.2 billion in sales in 2010, has been reanalyzed and determined to be ineffective against Alzheimer’s compared with a dummy pill regiment in patients.
The drug, Namenda by Forest Laboratories Inc and Germany’s Merz Pharma, is also sold under the generic name mematine.
There are not many drugs approved for Alzheimer’s, but this is one of them. The disease affects over 26 million persons around the world. Memantine is intended to treat moderate to severe Alzheimer’s, but it is frequently used in mild Alzheimer’s patients “off-label,” for uses other than those approved by the FDA, either alone or in combination with a drug known as a cholinesterase inhibitor.
Dr. Lon Schneider of the University of Southern California wrote:
“There were no significant differences between memantine and placebo on any outcome for patients with mild AD, either within any trial or when data were combined. Despite its frequent off-label use, evidence is lacking for a benefit of memantine in mild Alzheimer’s disease, and there is meager evidence for its efficacy in moderate Alzheimer’s disease.”
Cholinesterase inhibitors increase levels of the brain chemical acetylcholine, which may slow mental decline in Alzheimer’s patients.
Previously, memantine has been associated with a moderate decrease in clinical deterioration in Alzheimer’s disease. A systematic review of randomized controlled trials found that memantine has a small positive effect on cognition, mood, behavior and the ability to perform daily activities in moderate to severe Alzheimer’s disease.
The team identified three studies that included 431 patients with mild Alzheimer’s and 697 patients with moderate levels of the disease. Among patients with moderate Alzheimer’s, there was no significant difference between memantine and the placebo in any individual trial, but there was a significant effect when the three trials were combined.
They said more scientifically rigorous studies are needed to show the drug works.
Bill Thies, chief medical and scientific officer of the Alzheimer’s Association states:
“All the drugs we have for Alzheimer’s disease have modest effects and they are transient because the underlying disease is continuing to get worse while these drugs are being given. Eventually, that overcomes any benefit you get from the drug.”
Memantine was first synthesized and patented by Eli Lilly and Company in 1968 (as cited in the Merck Index), and then developed by Merz in collaboration with Neurobiological Technologies, Inc. and licensed to Forest for the U.S. and Lundbeck for selected European and international markets.
Memantine is marketed under the brands Axura and Akatinol by Merz, Namenda by Forest, Ebixa and Abixa by Lundbeck and Memox by Unipharm.
In treating any disease, one of the most difficult parts of designing a new drug is finding ways to maximize its beneficial effect while minimizing harmful side effects. Memantine was thought to be a particularly safe treatment for Alzheimer’s disease because it dampens excessive glutamate signaling that occurs away from synapses without blocking glutamate activity at the synapses. This is important because interfering with synaptic glutamate signaling would disrupt normal brain activity.
