Switzerland’s Actelion has seen its stock rise on the news that the firm has begun late-stage trials on two of its most promising experimental compounds.

First up is a Phase III study, called RESTORA, which will evaluate the safety and efficacy of almorexant, its first-in-class orexin receptor antagonist for people suffering from sleep disorders. The study is looking to enrol 670 patients diagnosed with primary insomnia at 70 sites and the Allschwil-based firm is hoping it will confirm the effects of almorexant on sleep induction and maintenance that have been previously observed.

Another Phase III trial will begin next year which will focus on longer treatment exposure and different populations such as elderly patients. Goran Hajak, professor of psychiatry at the University of Regensburg in Germany and member of the RESTORA steering committee, noted that earlier studies suggest that almorexant may be effective “without the side effects associated with currently available sleep agents that target the benzodiazepine receptor”.

Chief executive Jean-Paul Clozel added that given its novel mode of action, “and the substantial body of pre-clinical and clinical data available today, I strongly believe that almorexant has the potential to transform our approach to treating sleep disorders.” He will also be hoping that it will help transform the firm’s future earnings and a search to select “the optimal commercial partner” for the drug is underway.

The firm also announced the initiation of a 500-patient Phase III trial called SERAPHIN for its endothelin receptor antagonist Actelion-1 (ACT-064992), which is designed to see if the drug delays disease progression and mortality in patients with pulmonary arterial hypertension.

Isaac Kobrin, head of clinical development, said that with Actelion-1, the firm has used its “20 years of experience in the field of endothelin science to take ERA therapy to the next level.” The firm’s lead drug is Tracleer (bosentan) a PAH treatment that is responsible for pretty much all of Actelion’s revenues. Nine-month 2007 sales of the drug were up 30% to 846.5 million Swiss francs.