PAH Market Snapshot: Actelion’s Tracleer Faces Stiffer U.S. Competition

United Therapeutics' recently approved pulmonary arterial hypertension drug Adcirca threatens to close in on the vast lead held by Actelion's Tracleer, though surpassing the market pioneer seems nearly impossible. Not to mention, the Swiss-based biotech has an ace up its sleeve with the expansive REVEAL patient registry