Gilead gets FDA OK on Letairis
Patients typically complain of exhaustion, breathlessness, and inability to walk distances or perform activities of normal daily living. Often, no cause can be identified, although the condition can be triggered by diseases like scleroderma or advanced HIV, or by certain medicines like the diet drug combo Fen-Phen.
Letairis is in a class of drugs called ERAs, or endothelin receptor antagonists, compounds that relax the vessels, lowering blood pressure and lightening the load on the heart and lungs. However, such drugs can't be taken by pregnant women due to risk of major birth defects, and can cause liver damage. In studies, the drug improved patients exercise capacity, measured by a six-minute walking distance test.
Due to the risks of liver damage and birth defects, the label will carry strong cautionary language in a black box, as do other drugs of its class.