Excitement has greeted the publication of data from a study which shows that patients with mild-to-moderate Alzheimer's disease who were treated with Medivation’s Dimebon experienced significant improvements in memory and thinking.

The trial, the results from which were published in The Lancet, involved 183 patients with mild-to-moderate Alzheimer’s disease who were randomised to receive Dimebon (dimebolin), an antihistamine formerly sold in Russia, or placebo for six months. 134 of them continued treatment for another six months and for both time periods, patients on the antihistamine experienced statistically significant improvements “in all the key aspects of the disease”, Medivation said. These include memory and thinking, activities of daily living, behaviour and overall function.

Lead author Rachelle Doody said Dimebon improved the clinical course of Alzheimer's, “which is important given that the natural course is progressive deterioration over time". She added that "there is a clear need for new treatments that can add value and enduring benefit” and the results of the trial suggest that, “if the findings are replicated, Dimebon could advance Alzheimer's treatment."

Medivation chief executive David Hung noted that currently available therapies treat the symptoms of Alzheimer's with only modest effect but the Dimebon study is the first “in which a drug has achieved statistically significant benefits of this breadth, size and duration in a one year, well-controlled trial”.

The response to the data was one of cautious optimism. Susanne Sorensen, head of research at the UK’s Alzheimer's Society, said “these initial findings imply that Dimebon could be more effective than treatments currently licensed for people with Alzheimer's, however this was a modest-sized study”.

She went on to say that more substantial research is now needed, which studies more people over a longer period of time, “to investigate the true value of this drug and whether it treats Alzheimer's disease itself or just the symptoms”.