The objectives of the study are to:

1. Evaluate the safety and tolerability of CINRYZE administered by subcutaneous injection in subjects with hereditary angioedema
2. Characterize the pharmacokinetics and pharmacodynamics of CINRYZE administered by subcutaneous injection
3. Assess the immunogenicity of CINRYZE following subcutaneous administration

Inclusion Criteria:

To be eligible for this protocol, a subject must:

1. Have a confirmed diagnosis of HAE.
2. During the 3 consecutive months prior to screening, have a history of less than 1 HAE attack per month (average) treated with C1INH therapy or any other blood products, ecallantide (Kalbitor), icatibant (Firazyr), antifibrinolytics (e.g., tranexamic acid), IV fluids, or narcotic analgesics.
3. Agree to strictly adhere to the protocol-defined schedule of assessments and procedures.

Exclusion Criteria:

To be eligible for this protocol, a subject must not:

1. Have received C1INH therapy or any blood products for treatment or prevention of an HAE attack within 14 days prior to the first dose.
2. Have received any ecallantide (Kalbitor), icatibant (Firazyr), or antifibrinolytics (e.g., tranexamic acid) within 14 days prior to the first dose.
3. Have any change (start, stop, or change in dose) in androgen therapy (e.g., danazol, oxandrolone, stanozolol, testosterone) within 14 days prior to the first dose.
4. If female, have started taking or changed the dose of any hormonal contraceptive regimen or hormone replacement therapy (i.e., estrogen/progestin containing products) within 3 months prior to the first dose.
5. Have a history of abnormal blood clotting or other coagulopathy.
6. Have a history of allergic reaction to CINRYZE or other blood products.
7. Be pregnant or breastfeeding.
8. Have received an immunization within 30 days prior to the first dose.
9. Have participated in any other investigational drug study within 30 days prior to the first dose.