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

Inclusion Criteria: 1. 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) 2. Has confirmed diagnosis of HAE type I or II 3. 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 4. Has a documented congenital C1-INH functional activity \<50% with or without C1-INH deficiency and C4 ant…