Eisai and US partner Pfizer yesterday unveiled plans to move into the field of severe Alzheimer’s disease after it filed an application with the US Food and Drug Administration for its market-leading drug Aricept (donepezil) in this indication.

Aricept is currently approved for the treatment of mild to moderate AD, and is the best-selling drug in its class, with sales recorded by Pfizer of $170 million dollars during the first six months of this year, up 18%. However, Eisai and Pfizer are hoping to significantly expand on this figure and have been exploring Aricept’s use not only in severe AD, but in patients with mild cognitive impairment [[20/07/04f]]. The companies have had to combat somenegative exposure, after an independent study published in The Lancet which said it was not cost effective and had little benefit in improving symptoms of the disease or in delaying institutionalisation [[20/07/04f]].

This latest submission was based on data from a six-month trial conducted in approximately 250 nursing home patients with severe AD. Results showed Aricept offered a significant improvement compared to those taking placebo on primary measures of cognition as well as patient function and ability to conduct activities of daily living.

AD affects 4.5 million Americans, including one in 10 persons over the age of 65, and nearly half of those over 85. Aricept is believed to work by inhibiting the breakdown of a neurotransmitter known as acetylcholine, thereby increasing available levels of this chemical in the brain.