New Option for Rare Form of Hypertension
FDA has approved Letairis (ambrisentan) to treat pulmonary arterial hypertension, a rare, life-threatening condition characterized by continuous high blood pressure within the arteries of the lungs.
"Letairis represents a valuable addition to the treatment alternatives for this orphan disease," says John Jenkins, M.D., director of FDA's Office of New Drugs. "Letairis is similar to an existing drug, but offers the potential for fewer drug interactions."
FDA granted Letairis a priority review. This designation is intended for products that address unmet medical needs. The drug was granted orphan drug status because it treats a rare disease and meets other criteria. About 100,000 people in the United States have pulmonary arterial hypertension.
About Pulmonary Arterial Hypertension
In pulmonary arterial hypertension, the small arteries in the lungs become narrowed or blocked, and the heart must work harder to pump the blood through them. Over time, the overworked heart muscle may become weak and lose its ability to pump enough blood through the lungs. Symptoms include shortness of breath, fatigue, chest pain, dizzy spells and fainting.
Letairis will be available in 5-milligram and 10-milligram once-daily tablets. Safety and effectiveness were demonstrated in two international clinical trials involving 393 patients. Letairis significantly improved physical activity capacity compared with a placebo, as shown by a standard test of a six-minute walk. Letairis also delayed the worsening of the pulmonary hypertension.
The most common side effects included swelling of the legs and ankles, nasal congestion, sinusitis, and redness in the face (flushing). Letairis should not be used by women who are pregnant or may become pregnant because the drug may cause birth defects. Patients taking Letairis must have monthly blood tests to check for potential liver injury.
Letairis is manufactured by Gilead Sciences, Inc., Foster City , Calif. Gilead acquired the U.S. rights to ambrisentan when it acquired Myogen, Inc. in 2006. GlaxoSmithKline holds rights to ambrisentan outside of the United States .
For more information on pulmonary arterial hypertension, visit http://www.nhlbi.nih.gov/health/dci/Diseases/pah/pah_what.html
For more information on orphan drugs, visit http://www.fda.gov/FDAgov/ForConsumers/ConsumerUpdates/ucm124557.htm
This article appears on FDA's Consumer Updates page, which features the latest on all FDA-regulated products.
Date Posted: June 21, 2007