The U.S. Food and Drug Administration approved Kalbitor (ecallantide) on Dec. 1 to treat sudden and potentially life-threatening fluid buildup that can occur in people with a rare genetic condition known as hereditary angioedema (HAE).
Hereditary angioedema (HAE) is an autosomal dominant disease estimated to afflict between 1 in 10,000 to 1 in 50,000 people in the United States. Patients with HAE suffer from recurrent attacks of intense localized edema, abnormal accumulation of fluid beneath the skin or in one or more cavities of the body.
HAE is caused by a defect in the blood protein C1 esterase-inhibitor, which plays a role in regulating how certain immune system and blood clotting pathways function. Decreased function of this protein can lead to rapid
and serious swelling of the face or other parts of the body, which may result in permanent disfigurement, disability or death. Swelling of the digestive tract may cause excruciating abdominal pain, nausea, and vomiting, while airway swelling puts patients at risk of suffocation. About 10,000 people in the United States have HAE.
"Kalbitor offers another potentially life-saving option for those people with HAE," said John Jenkins, M.D., director, Office of New Drugs, in the FDA's Center for Drug Evaluation and Research. "FDA is committed to facilitating the development and approval of safe and effective therapies for patients with rare conditions."
This is the second drug marketed in the United States to treat HAE attacks. In October 2009 the FDA approved Berinert, a C1-inhibitor derived from blood plasma to treat facial and abdominal attacks of HAE.
Kalbitor is a liquid that is intended to be injected under the skin for patients age 16 and older who experience HAE attacks.
The medication's most serious side effect is anaphylaxis, a severe allergic reaction that can close a person's airways and stop them from breathing. Other side effects include headache, nausea, diarrhea, swelling in the nose and throat, fever, and skin irritations.
Kalbitor should only be administered by a healthcare professional with appropriate medical support to manage anaphylaxis.
The drug is marketed by Dyax Corp., Cambridge, Mass. The second HAE drug, Berinert, is marketed by CSL Behring Inc., Marburg, Germany.