The company has filed its abbreviated new drug application (ANDA) containing a paragraph IV certification for a generic Xyzal product with the FDA in January 2008.
Following receipt of the notice from the FDA that its ANDA had been accepted for filing, the company notified the new drug application and patent holder.
On July 30, 2008, Sepracor, UCB SA, and UCB Inc filed suit in the US District Court of North Carolina to prevent the company from proceeding with the commercialization of its product. This action formally initiates the patent challenge process under the Hatch-Waxman Act.