Prospective, multicenter, randomized, double-blind, parallel group, placebo- controlled, efficacy and safety phase 3 study of an intravenous human plasma- derived C1 esterase inhibitor (C1-INH) concentrate in participants with congenital C1-INH deficiency for the treatment and pre-procedure prevention of acute hereditary angioedema attacks
Is at least 18 years of age (applicable for 1st study phase) or is at least 2 years of age (applicable for 2nd study phase)
Has confirmed diagnosis of HAE type I or II
Has had at least 3 moderate or severe HAE attacks (excluding extremity attacks) in the last 3 months before the Screening Visit. For participants ≥2 and ≤12 years of age, has had at least 1 moderate or severe HAE attack (excluding extremity attacks) in the last 6 months before Screening Visit
Has a documented congenital C1-INH functional activity <50% with or without C1-INH deficiency and C4 antigen level below the laboratory reference range
Has a history of clinically relevant antibody development against C1-INH
Has a medical history consistent with Type 3 HAE (i.e., onset at age above 40 year, no family history, no known HAE mutation, low C1q level in plasma)
Has a history of allergic reaction to C1-INH or other blood/plasma product
Has a history of B-cell malignancy that was unresolved in the past 5 years