A Study to Assess the Clinical Efficacy of Donidalorsen (Also Known as IONIS-PKK-LRx and ISIS 721744) in Participants With Hereditary Angioedema

This was a randomized, double-blind, placebo-controlled study in 23 participants conducted concurrently in 2 parts (Part A and Part B); participants were allocated into Part A or Part B according to type of HAE (i.e., either HAE-1/HAE-2 in Part A or HAE-nC1-INH in Part B). Part A was randomized, double-blind, and placebo-controlled; and Part B was open-label. The length of participation in the study was approximately 8 months, which included an up to 8-week screening period, a 12-week treatment period, and a 13-week post-treatment period.