This is a randomized placebo-controlled trial.~The study is designed to assess the efficacy and safety of 30 mg subcutaneous ecallantide versus placebo in the treatment of moderate to severe acute attacks of hereditary angioedema. This study is conducted under Special Protocol Assessment with the FDA and is designed to provide pivotal efficacy data on ecallantide. These data are intended to support the marketing authorization of ecallantide in the treatment of acute attacks of hereditary angioedema. Efficacy and safety of ecallantide will be evaluated in this study.
The purpose of this study is to evaluate the efficacy and safety of DX-88 (ecallantide) versus placebo in the treatment of moderate to severe acute attacks of hereditary angioedema.