Schering-Plough sues Copley over Claritin

The Schering Corp unit of Schering-Plough has sued Copley Pharmaceuticalin an attempt to prevent it from marketing a generic version of S-P's blockbuster antihistamine Claritin (loratadine). The suit claims that the generic syrup for which Copley has filed an Abbreviated New Drug Application with the US Food and Drug Administration infringes S-P's patent rights to the metabolized form of the compound. There are five forms of Claritin; the only one at issue in the litigation is the syrup.

For its part, Copley says that it does not intend to market a generic syrup until S-P's patent on loratadine runs out in 2002. However, a company spokesman claimed that S-P's patent for the metabolite desloratadine, which expires in 2004, is invalid. The lawsuit will lead to a 20-month stay, even if Copley's ANDA were to be approved, though the company expects to be first to market with a generic once the loratadine patent expires and hopefully have 180 days' exclusivity.