Valeant Pharmaceuticals International said yesterday that the US Food and Drug Administration has stamped the seal of approval on its application to market Zelapar orally disintegrating tablets for the treatment of Parkinson’s disease.

The group was given the go-ahead to market once-a-day Zelapar (selegiline HCl), the formulation of which has been designed to maximise delivery of the drug at a smaller dose, as an adjunct therapy to treatment with the Parkinson's drugs levodopa and carbidopa.

Approval was based on clinical data demonstrating that adding Zelapar to the treatment regimen helped cut down the "off" time experienced by Parkinson's patients by an average of 2.2 hours per day versus 0.6 hours per day in the placebo group.

"With more than 1.5 million Americans with Parkinson's disease, and 60,000 new cases diagnosed each year, having new treatment options available to help manage the symptoms associated with the disease are critical," commented Valeant’s President and Chief Executive Officer, Timothy Tyson.

The US nod follows an "approvable" letter it sent out for the drug in October this year, but news of final clearance failed to set investor enthusiasm alight; although it sparked heavy trading on the New York Stock Exchange yesterday, shares in the group closed up just $0.12 at $17.56.