First COMT Inhibitor For Parkinson's Reaches Market

Roche has launched its catechol-O-methyl transferase inhibitor Tasmar(tolcapone) in the UK and Germany for the adjunctive treatment of Parkinson's disease with levodopa. These are the first world launches for the product, and indeed the first introductions ever of a selective COMT inhibitor.

The drug has also been approved in Switzerland (back in February), and a launch in that country will occur after pricing negotiations have concluded. Roche has also received an approvable letter for tolcapone in the USA.

Tolcapone inhibits the enzyme responsible for the metabolism of levodopa to a breakdown product, 3-O-methyldopa. The drug therefore increases the amount of levodopa reaching the brain and smoothes its delivery, improving its clinical effect. Trials have suggested that patients receiving tolcapone plus levodopa can increase the "on" time (when their symptoms are controlled) by between 25% and 50% compared to levodopa plus placebo. Periods of severe symptoms - the "off" time - were significantly reduced (Marketletter March 31).