Safety and Efficacy of Oral BCX4161 as a Prophylactic Treatment for HAE

Key Inclusion Criteria: * Written informed consent * Clinical and laboratory diagnosis of Hereditary Angioedema Type I or II * An average angioedema attack frequency of 1/week * Acceptable birth control measures Key Exclusion Criteria: * Concurrent use of defined treatments for prophylaxis * Pregnancy or breast-feeding * Clinically significant medical condition, laboratory abnormality or medical history