LONDON, July 20, 2011 /PRNewswire/ --

Eisai Europe Ltd and Pfizer Limited today announced the results from a new study conducted in France demonstrating Aricept(R) (donepezil hydrochloride) 10mg significantly reduced the rate of hippocampal atrophy (reduction in volume) in patients with an amnestic syndrome at an early phase of Alzheimer's disease.

The multi-centre, double-blind, randomised, placebo-controlled study was conducted to assess the effect of donepezil on the rate of hippocampal atrophy over one year in patients presenting an amnestic syndrome at a mild cognitive impairment (MCI) stage of the disease. A total of 216 patients were randomised to receive donepezil 10 mg daily or placebo.[1] The study was conducted outside the licensed indication for donepezil in the European Union. Aricept is licensed for the symptomatic treatment of mild to moderately severe Alzheimer's dementia in Europe.

The adverse events reported were consistent with the known safety profile of donepezil.[2] The most commonly reported adverse events in this study were headaches, nightmares, cramps, nausea and diarrhea.

Patients in the donepezil group exhibited a 45% lower rate of hippocampal atrophy than those in the placebo group after 1 year (-1.89% [SE=0.34] vs -3.74% [SE=0.32], p<0.001). There was no difference between the donepezil and placebo groups on any of the cognitive measures included in the study*. The full results of the study will be presented at the Alzheimer's Association International Conference 2011 (AAIC 2011) in Paris, France.

The hippocampus plays an important role in short-term and long-term memory and spatial navigation.[3] In Alzheimer's disease, the hippocampus is one of the first regions of the brain to suffer damage, with symptoms often presenting as memory problems and disorientation. Hippocampal atrophy has been identified as a common feature in Alzheimer's disease, and shrinkage in the hippocampal region has been shown to correlate with severity of the patient's decline.[4]

Commenting on this new study, Professor Bruno Dubois from the Neurological Institute of the Salpétrière University Hospital in Paris who led the study said: "These findings are important as the results show that subjects on donepezil 10mg displayed significantly less hippocampal atrophy after one year compared to subjects receiving placebo. This study also used the new diagnostic framework recently proposed by the International Working Group for New Research and Criteria for Diagnosis of Alzheimer's disease.[5]"

The hippocampus study is a result of a collaboration between the top centres in France, including Hôpital de la Pitié Salpêtriere.

Notes to Editors

*Cognitive measures for the study included:

- Mean change in the sum of items of the Alzheimer's Disease Assessment Scale - Cognitive - Mild Cognitive Impairment version (ADAS-Cog-MCI) from Baseline to 12 month visit - Mean change from Baseline to Endpoint in the sum of items of the MMSE from Baseline to 12 month visit - Mean change of Modified Isaacs test score from Baseline to Endpoint - Mean change of California Verbal Learning Test score from Baseline to 12 month visit - Mean change of time to perform the Trail Making Test A and B and number of errors from Baseline to 12 month visit - Mean change of Benton Visual Retention scorefrom Baseline to 12 month visit - Mean change of McNair scorefrom Baseline to 12 month visit