GSK and Actelion drop insomnia treatment

Actelion and GlaxoSmithKline are to abandon development of phase III insomnia drug almorexant because of problems with side-effects.

Almorexant a dual orexin receptor antagonist,has been discontinued following a review of data from additional clinical studies which were conducted to gather further data on its clinical profile, "including the tolerability profile".

The companies nevertheless say they "remain committed to conducting further research to better understand the potential of orexin receptor antagonism in sleep disorders and other indications". 

Actelion has grown very rapidly over the last few years thanks to its pulmonary arterial hypertension blockbuster Tracleer (bosentan), but is needs other drugs to maintain and expand its revenues.

Tracleer brings in the vast majority of the company’s revenues, but faces patent expiry from 2015.