Epix Pharmaceuticals (nasdaq: EPIX) announced that its Phase II clinical trial of experimental drug PRX-03140 showed “compelling” results. Alzheimer’s patients who received 150 mg doses of PRX-03140 orally once per day for two weeks achieved an average improvement of 5.7 points on the Alzheimer’s Disease Assessment Scale cognitive subscale (ADAS-cog).
The natural history of Alzheimer’s disease is one of progressive decline; cognitive, physical, and social functions gradually deteriorate. Thus, “improvement” from an intervention for Alzheimer’s disease means slowing the rate of decline. The rate of decline in Alzheimer’s disease is not linear, however.67 People with mild dementia experience an average rate of decline of 5 or fewer ADAS-Cog points (2 or fewer MMSE points) per year. Thus, for people with mild dementia, a slowing of decline by 2 to 3ADAS-Cog points over a year could mean a delay of up to 7 months in the progress of the disease.
Therefore, an almost 6 ADAS-cog point improvement is equal to about 14 months of delay in the disease.