LONDON - Shire Pharmaceuticals Group plc claimed a unique mode of action for galantamine (Reminyl), its treatment for Alzheimer's disease, when results of recently completed U.S. Phase III trials were presented to the Sixth International Conference on Alzheimer's Disease and Related Disorders.
Like Alzheimer's treatments already on the market, galantamine inhibits one of the enzymes that breaks down the neurotransmitter acetylcholine. Unlike other agents, however, it also appears to work on the brain's nicotinic receptors, which are believed to promote release of more acetylcholine.
If verified by further research, nicotinic modulation could present a series of new targets for drugs to treat Alzheimer's.
Data presented to the conference in Amsterdam indicated Reminyl significantly improved scores in standard learning and memory tests in patients with mild to moderate disease. In addition, cognitive scores were maintained at or above baseline throughout one year of treatment.
Shire, based in Andover, U.K., said these findings will be reinforced by results of a second, international multicenter trial involving 653 patients, which are due to be presented to the conference Thursday.
In the U.S. trial 423 patients received galantamine twice a day for six months, while 213 received a placebo. The cohort had a mean age of 75 years, and 62 percent were female. Patients were tested using the Alzheimer's Disease Assessment Scale to assess memory and learning skills such as word recall and recognition, ability to remember test instructions and accuracy in naming objects and figures.
Those who took galantamine had cognitive scores 3.7 to 3.8 points higher than those on placebo. While the performance of those on placebo declined by an average of two points over the length of the trial, those on galantamine showed an average improvement of 1.7 points over their baseline score.
The Phase III trials of galantamine are being conducted by Shire's partner, Janssen Research Foundation, of Beerse, Belgium, a wholly owned subsidiary of Johnson & Johnson, of New Brunswick, N.J. Wim Parys, associate director of clinical research, said Janssen intends to continue research into galantamine's possible effect on nicotinic receptors.
“Recent reports suggest that stimulation of nicotinic receptors may be associated with fewer of the amyloid plaques that are one of the hallmarks of Alzheimer's disease,“ he said. “However, while this data is intriguing, it needs replication.“ *