The drug, memantine, could become the nation's first treatment for late stages of the mind-stealing disease, if a panel of advisers to the Food and Drug Administration recommend its approval on Wednesday.
The agency will consider that advice before making a final decision on memantine, expected by year's end. It's a decision anxiously awaited by families out of options, some of whom now try buying overseas supplies of memantine via the Internet.
"This is not a miracle cure. The effects overall are relatively modest," cautioned New York University psychiatry professor Steven Ferris, who co-directed one of the drug's U.S. studies. "But it's an important step forward in terms of treating this really important portion of the Alzheimer's population."
About 4 million Americans have Alzheimer's. It afflicts mainly the elderly, robbing them of memory and the ability to care for themselves. There is no known cure or prevention. The only four medications available temporarily slow the inevitable worsening when used in early stages of the disease.
If approved, memantine would be the first option designated to slow deterioration during advanced Alzheimer's. It works on a different brain chemical than other Alzheimer's medicines, meaning doctors for the first time could prescribe drug combinations in hopes of better results.
A six-month study of patients with moderate to severe Alzheimer's symptoms found those given memantine worsened at half the pace of those given a dummy drug, said NYU's Dr. Barry Reisberg.
Some patients reported actual improvements in memory and thinking skills, Reisberg said, but for the most part, the drug simply slowed deterioration.
The effect was measured largely by tracking how well patients could perform some basic functions, such as getting dressed or bathing without assistance. Maintaining such skills even a little longer could help delay the need for a nursing home, proponents say.
Today's Alzheimer's drugs — Aricept, Exelon, Reminyl and Cognex — delay the breakdown of a brain chemical called acetylcholine that is vital for nerve cells to communicate. Memantine works differently. It blocks excess amounts of another brain chemical, called glutamate, that can damage or kill nerve cells.
Memantine has been sold in Germany for two decades to treat various forms of dementia, with few, mild side effects, researchers say.
It wasn't until 1999 that the first good research suggesting memantine truly helped late-stage Alzheimer's was done, prompting Reisberg's U.S. study, he said. German drug-maker Merz Pharmaceuticals last year won Europe-wide approval of memantine, and the U.S. marketer, Forest Laboratories, filed for FDA approval in January.
No one yet knows if memantine might help in earlier stages of Alzheimer's. Studies of that are continuing, although Forest recently announced that one trial found no apparent benefit.