Icatibant for the Treatment of Hereditary Angioedema

Hereditary angioedema (HAE) is arare, potentially life-threatening au-tosomal dominant disease caused by C1 esterase inhibitor (CI-INH) deficiency.1-4 HAE is characterized by recurrent ede-ma of the skin (extremities, face, geni-tals); edema of the gastrointestinal track resulting in abdominal pain, nausea, vomiting, and diarrhea; and edema of the larynx. The prevalence of HAE is esti-mated to be between 1:10,000 and 1:50,000 in general populations.1-3 In contrast to acute allergic-anaphylactic angioedema, medications such as epinephrine, antihistamines, and corti-costeroids are ineffective in acute man-agement of HAE. Until recently, acute treatment in the US consisted of only supportive therapy (eg, intravenous flu-ids, airway management, analgesics, antiemetics) and administration of fresh frozen plasma. Long-term prophylactic therapy has included antifibrinolytics (tranexamic acid) and androgens (dana-zol), which resulted in significant ad-verse events including weight gain, viril-ization, and hepatotoxicity.1-5 Pharma-cotherapy development has focused on C1-INH protein concentrates, kallikrein inhibition, and bradykinin B2 receptor antagonism (Table 1). C1-INHs are ap-proved for the intravenous administra-tion in the prophylaxis (Cinryze) or acute treatment (Berinert) of HAE; however, the supply of these agents is limited and access is restricted.6,7 Ecallantide (Kalbitor), a kallikrein inhibitor, was approved in 2009 for the treatment of acute attacks and should be administered by a health care professional capable of treating hypersensitivity reac-tions.