Delay in US approval of desloratadine hits Schering-Plough's stock price

Schering-Plough's positive news on the first approval of itsnew-generation antihistamine Aerius/NeoClarityn (desloratadine) in the European Union (Marketletter January 22) has been overshadowed by the prospect that its clearance in the important US market looks set to be delayed.

The US Food and Drug Administration has issued an approvable letter for the drug as a treatment for seasonal allergic rhinitis and chronic idiopathic urticaria in adults and children 12 years of age and older, but said that certain additional information is required before full approval can be given. S-P, which is well-known for playing its cards close to its chest, has not disclosed the agency's concerns or the conditions that must be met before it will give the go-ahead for marketing. The FDA has been reviewing S-P's New Drug Application for desloratadine since October 1999, so the application has already been delayed well beyond the Prescription Drug User Fee Act-mandated target of October 2000.

S-P is scheduled to lose its US marketing exclusivity for Claritin (loratadine), the forerunner to desloratadine which achieved sales of $3 billion in 2000 and is S-P's top product, in December 2002. Given the importance of desloratadine to the company, its shares dropped 4% on the day of the announcement (January 26) to close at $51.50.