GlaxoSmithKline (GSK) and Actelion Ltd announced that clinical development of the phase III investigational dual orexin receptor antagonist, almorexant, has been discontinued. This decision follows a review of data from additional clinical studies, which were conducted to further establish the clinical profile of almorexant, including the tolerability profile.

GSK and Actelion remain committed to conducting further research to better understand the potential of orexin receptor antagonism in sleep disorders and other indications. Both companies will continue to work on the discovery and development of new orexin receptor antagonist therapies, based on the orexin alliance formed in July 2008.

GlaxoSmithKline – one of the world’s leading research-based pharmaceutical and healthcare companies – is committed to improving the quality of human life by enabling people to do more, feel better and live longer.

Actelion Ltd’s first drug Tracleer, an orally available dual endothelin receptor antagonist, has been approved as a therapy for pulmonary arterial hypertension. It is a leading player in innovative science related to the endothelium - the single layer of cells separating every blood vessel from the blood stream.