C1 Esterase Inhibitor (C1INH-nf) for the Prevention of Acute Hereditary Angioedema (HAE) Attacks

Subjects were given diary cards and instructed to document all HAE attacks on a daily basis. Subjects evaluated their symptoms over the previous 24 hours, noting the severity and duration of swelling at each of 5 locations (abdominal, genitourinary, facial, respiratory \[including laryngeal\], and/or extremity). The study design also allowed for administration of open-label C1INH-nf (1,000 U of C1INH-nf administered IV \[repeated after 60 minutes, if necessary\] for treatment of laryngeal angioedema or if deemed necessary by the investigator; 1,000 U of C1INH-nf administered IV \[single dose\] prior to emergency surgical procedures). A total of 26 subjects were enrolled in the study. One subject received open-label C1INH-nf but withdrew prior to randomization. Another subject was randomized but withdrew prior to receiving study drug. Twenty-four (24) subjects were randomized and treated with blinded study drug. In total, 25 subjects received at least 1 dose of study drug and were analyzed for safety; all 25 subjects were exposed to C1INH-nf and 23 subjects were exposed to placebo.