Study Design:~This is a multi-center, randomized, double-blind, placebo-controlled, 3-period crossover study of rhC1INH in prophylaxis of angioedema attacks in patients with HAE.~Medical screening (clinical and laboratory parameters) will be performed and patient medical history specific to HAE attacks will be collected to assess eligibility. Each patient will receive three 4 week periods of treatment twice weekly.
Primary Objective:~To evaluate the efficacy of recombinant human C1 inhibitor (rhC1INH) in the prophylaxis of angioedema attacks in patients with HAE~Secondary Objective:~To evaluate the safety and immunogenicity of recombinant human C1 inhibitor (rhC1INH) in the prophylaxis of angioedema attacks in patients with HAE