In this single-arm open-label extension study (Alternatives for Reducing Chorea in Huntington Disease [ARC-HD]), the safety and efficacy of deutetrabenazine were evaluated for the treatment of chorea associated with Huntington disease; compared to the pivotal double-blind study, no new safety concerns arose.

Conclusions related to efficacy were limited because of the study design, but there appeared to be continued chorea control throughout the study with an average daily end-of-study dose of 45.7 mg.

Overall, the use of twice-daily deutetrabenazine maintained and improved chorea control in patients with Huntington disease with favorable safety and tolerability.