This was an open-label extension study of donidalorsen in 20 participants with HAE. The length of participation in the study was approximately 68 weeks, which included an up to 4-week qualification period, a 52-week treatment period, and a 12-week post-treatment period. Following the Week 53 treatment period visit, participants received donidalorsen in an extended treatment period for up to an additional 156 weeks. Participants taking part in the extended treatment period entered the 12-week post-treatment period after completion of, or early termination from, the extended treatment period.
