Safety and Efficacy Study of Repeated Doses of DX-88 (Ecallantide) to Treat Attacks of Hereditary Angioedema (HAE)

This is an open label trial.

The study is designed to assess the efficacy and safety of 30 mg subcutaneous ecallantide in
the treatment of acute attacks of hereditary angioedema. This study is designed to provide
efficacy and safety data on repeated use of 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.

Inclusion Criteria:

- 10 years of age or older

- Documented diagnosis of HAE (Type I or II)

- Willing and able to give informed consent

- Acute HAE attack at time of presentation

Exclusion Criteria:

- Receipt of an investigational drug or device, within 30 days prior to study treatment,
other than DX-88 (ecallantide)

- Pregnancy or breastfeeding

- Receipt of non-investigational C1-INH or DX-88 within 72 hours of treatment

- Patients eligible for current, ongoing clinical trial in which DX 88 (ecallantide) is
offered