Swiss biotechnology company Actelion sells a drug in the same class called Tracleer, a twice-a-day pill. Actelion receies nearly 95 percent of its reenue from Tracleer sales.

• 这种新研制出的药物是内皮素受体拮抗剂家族的一员，他们可以阻断内皮素，从而阻断了其引起血管收缩和升高血压的作用。