Nanofiltered C1 Inhibitor Concentrate for Treatment of Hereditary Angioedema

A recently developed preparation of C1 inhibitor concentrate was evaluated in patients with hereditary angioedema in two trials. In the acute-attack treatment trial, the time to relief of an acute attack of angioedema was significantly shorter with the C1 inhibitor than with placebo. In the prophylaxis trial, the attack rate over a 12-week period was significantly lower with the C1 inhibitor than with placebo. Hereditary angioedema due to C1 inhibitor deficiency is an autosomal dominant disorder characterized by recurrent episodes of angioedema that typically involve the extremities, abdomen, external genitalia, face, or oropharynx. 1 Abdominal attacks of angioedema, which are caused by local mucosal swelling, are often associated with severe abdominal pain, nausea, and vomiting. Such attacks frequently lead to hospitalization and occasionally to unnecessary exploratory surgery. 2 Laryngeal attacks are associated with a substantial risk of death. 2 Two forms of hereditary angioedema have been defined: type I (accounting for 85% of cases) is characterized by low antigenic and functional levels of C1 inhibitor, whereas type . . .