Swiss biopharmaceutical firm Actelion Ltd. gained FDA orphan status for its lead treatment, bosentan in pulmonary hypertension, which is currently undergoing an NDA filing. It has also sought a similar designation under the new European Union rules.

Bosentan, an orally active endothelin receptor antagonist, also is in Phase III trials for congestive heart failure, which affects about 10 million people in the U.S. and Europe. Pulmonary hypertension is a life-threatening condition in which the blood pressure between the heart and lungs becomes abnormally elevated, leading to shortness of breath, fainting, and, ultimately, reduced life expectancy. The disease, which presents primarily in young women, but also in children, affects just 100,000 people in the U.S. and Europe, according to Allschwil-based Actelion. The FDA's threshold for orphan status is twice that figure in the U.S. alone.

Actelion has no current plans to pursue any of the financial incentives available under the FDA's orphan drug program, company spokeswoman Jennifer Schweizer told BioWorld International. The main benefit of the designation is that it demonstrates official support for bosentan, she said. "It's shown that the product, from the study results, is on the right track in the review process. The [seven-year] exclusivity that it provides is an added benefit."

Actelion expects to complete its rolling NDA filing for bosentan in pulmonary hypertension by November and to launch the product by the fourth quarter next year. United Therapeutics Corp., of Silver Spring, Md., is developing an alternative pulmonary hypertension treatment, based on a prostacyclin analogue called UT-15, or Uniprost, which is delivered by subcutaneous injection. Earlier this week, it said it completed its NDA filing for the drug and that its synthesis and manufacturing subsidiary, SynQuest Inc., had successfully completed its FDA pre-approval inspection.