TEAEs were defined as adverse events (AEs) with onset at the time of or following the first exposure to lanadelumab in this study, or medical conditions present prior to the start of treatment but increasing in severity or relationship at the time of or following the start of treatment. Serious TEAEs were defined as any untoward clinical manifestation of signs, symptoms, outcomes (related to IP or not) that at any dose: resulted in death, was life-threatening, required inpatient/prolongation of hospitalization, resulted in persistent/significant disability/incapacity, congenital abnormality/birth defect, important medical event. AESI were defined as investigator-reported hypersensitivity reactions, events of disordered coagulation as bleeding/hypercoagulable. Relatedness to study drug was based on Investigator's discretion. TEAEs were classified and reported as Hereditary Angioedema (HAE) attack and non-HAE attack AEs in this outcome measure.

Clinical laboratory testing included clinical serum chemistry, hematology, coagulation and urinalysis. Any change in clinical laboratory abnormalities which were deemed clinically significant by the investigator were recorded as TEAEs.

Vital signs parameters included blood pressure, heart rate, body temperature and respiratory rate. Any change in vital sign abnormalities which were deemed clinically significant by the investigator were recorded as TEAEs.