Sepracor currently commercializes two proprietary products, LUNESTA(TM) (eszopiclone) for the treatment of insomnia and XOPENEX(R)(levalbuterol HCI) Inhalation Solution for the treatment or prevention of bronchospasm. Sepracor received U.S. Food and Drug Administration (FDA) approval for the XOPENEX HFA™ (levalbuterol tartrate) Inhalation Aerosol, a hydrofluoroalkane (HFA) metered-dose inhaler (MDI) and anticipates launching the product around year-end 2005. In addition, Sepracor anticipates filing a New Drug Application with the FDA for arformoterol inhalation solution as a maintenance treatment for chronic obstructive pulmonary disease.

Sepracor’s out-licensing agreements include: Schering-Plough for CLARINEX(®) (desloratadine); sanofi-aventis for ALLEGRA(®) (fexofenadine HCl); and UCB Pharma for XYZAL(®)/XUSAL(TM) (levocetirizine). Additionally, Sepracor established a research and development collaboration with ACADIA Pharmaceuticals in early 2005 to investigate potential clinical candidates targeted towards the treatment of central nervous system disorders.

Sepracor's corporate headquarters are located in Marlborough, Massachusetts.