US regulators approved a new indication for Novartis’ Alzheimer’s disease drug Exelon yesterday, after concluding that it is effective in the treatment of dementia associated with Parkinson's disease.

The move follows a positive recommendation by a US Food and Drug Administration advisory panel earlier this year, which was based on results of the Express study - the first large-scale trial to assess an AD medicine in the treatment of PD.

The trial included 541 patients with the mild-to-moderate form of the disease who received varying daily doses of Exelon (rivastigmine), or placebo for 24 weeks. Novartis notes that those receiving the branded drug showed significant improvements in cognition versus those given placebo - at week 24, 41% of Exelon-treated patients showed improvements on a recognised disease measurement scale, versus 30% of those in the placebo group. Furthermore, they also performed better across a range of specific tests to assess a range of symptoms, such as loss of memory and concentration.

Exelon, a cholinesterase inhibitor, has been on the US for mild-to-moderate dementia caused by AD since 2000. At the moment there is no drug approved to treat dementia associated with Parkinson's and, seeing as up to 40% of people with PD suffer from dementia, this new indication could add some significant momentum to Exelon sales, which came in at $467 million last year but slipped 1% to $116 million in the first quarter of 2006, with US sales down 13% to $42 million.

European regulators opened the door to Exelon for this indication in March, and it has also gained clearance in this setting in several other countries accross the globe.