The duration of treatment with fitusiran was 9 months. The estimated total time on study, inclusive of screening, for each participant was up to 11 months for all participants who enroll in the extension study and participants in the on-demand arm who did not enroll in the extension study. The estimated total time on study was up to 17 months in fitusiran treatment arm participants who did not enroll in the extension study due to the requirement for up to an additional 6 months of follow-up monitoring for antithrombin levels.
