CHICAGO — For the first time, an experimental drug shows promise for halting the progression of Alzheimer's disease by taking a new approach: breaking up the protein tangles that clog victims' brains.
The encouraging results from the drug called Rember, reported yesterday at a medical conference in Chicago, electrified a field battered by recent setbacks. The drug was developed by Singapore-based TauRx Therapeutics.
Even if bigger, more rigorous studies show it works, Rember is still several years away from being available, and experts warned against overexuberance. But they were excited.
"These are the first very positive results I've seen" for stopping mental decline, the director of Alzheimer's research at the National Institute on Aging, Marcelle Morrison-Bogorad, said. "It's just fantastic."
The drug is in the second of three stages of development, and scientists are paying special attention to potential treatments because of the enormity of the illness, which afflicts more than 26 million people worldwide and is mushrooming as the population ages.
The four Alzheimer's drugs currently available just ease symptoms of the mind-robbing disease.
The chief of TauRx is Claude Wischik, a biologist at the University of Aberdeen in Scotland who has done key research on tau tangles and studies suggesting that Rember can dissolve them for many years.
In the study, 321 patients were given one of three doses of Rember or dummy capsules three times a day. The capsules containing the highest dose had a flaw in formulation that kept them from working, and the lowest dose was too weak to keep the disease from worsening, Mr. Wischik said.
However, the middle dose helped, as measured by a widely used score of mental performance.
"The people on placebo lost an average of 7% of their brain function over six months whereas those on treatment didn't decline at all," he said.
After about a year, the placebo group had continued to decline but those on the mid-level dose of Rember had not. At 19 months, the treated group still had not declined as Alzheimer's patients have been known to do.