Subcutaneous kallikrein inhibitor ecallantide (Kalbitor) approved for treatment of hereditary angioedema (HAE)
What is HAE?
Plasma kallikrein plays a major role in the kallikrein-kinin cascade producing bradykinin. Bradykinin is a vasodilator, which increases vascular permeability, activates inflammation and produces pain.
Ecallantide (DX-88, Kalbitor)
Ecallantide (DX-88, Kalbitor) is a subcutaneous kallikrein inhibitor which was approved for treatment of hereditary angioedema (HAE) in patients 16 years of age and older on December 2, 2009.
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New therapies for hereditary angioedema (HAE) (click to enlarge the image).
The drug is to be launched in the first quarter of 2010 and see an ex-U.S. partnership in the first half of next year. Kalbitor is the only approved treatment for life-threatening laryngeal attacks.
The drug's short half-life is the main reason for its suitability as a treatment for acute attacks only and not as a preventive therapy.
Kalbitor has a half-life of about two hours, while Cinryze has a half-life of about 56 hours and Berinert has about 22 hours.
Black-box warning
The labelling of the drug includes a black-box warning for possible allergic reactions which usually occur within 10 minutes of the injection. This means that the injections will typically be administered in a supervised setting (doctor's office) rather than by the patient at home.
As a condition of the FDA approval, Dyax is required to set up a risk management program to warn patients that Kalbitor can cause severe allergic reactions.
Other treatments of HAE
Cinryze is only approved as a preventive therapy.
Berinert was approved by the FDA in October 2009 for only acute abdominal and facial attacks of the disease. HAE patients can self-administer Berinert C1-INH by IV infusion - FDA, 2012.
References:
Virtually No Relapses After Ecallantide for Acute HAE attacks, despite short half-life. Medscape, 2011.