Actelion shares leap on positive Ph III data with selexipag

Shares of Switzerland-based Actelion (SIX: ATLN), Europe’s largest biotech firm, gained 15.1% to 104.70 Swiss francs in early afternoon trading today, after the company revealed top-line results of the pivotal Phase III GRIPHON study in 1,156 patients with pulmonary arterial hypertension (PAH) with selexipag, the first selective oral prostacyclin IP receptor agonist.

Initial analysis shows that the event-driven outcome study has met its primary efficacy endpoint with high statistical significance. Selexipag decreased the risk of a morbidity/mortality event versus placebo by 39% (p<0.0001). Efficacy observed was consistent across the key subgroups; age, gender, WHO Functional Class, PAH etiology and background PAH therapy. Patients were treated for up to 4.3 years. The overall tolerability profile of selexipag in GRIPHON was consistent with prostacyclin therapies.

Selexipag is a third PAH treatment for Actelion, adding to Opsumit (macitentan), which has  already gained approval in Europe and the USA. They add to the firm’s mainstay drug Actelion Tracleer (bosentan), which accounts for about 80% of the group’s sales but loses patent protection in 2015. Actelion licensed the ex-Japan rights to the drug from Nippon Shinyaku (TYO: 4526).