To describe baseline characteristics and treatment patterns in Huntington Disease-associated chorea by chorea severity.

Though multiple treatment options exist for HD-associated chorea, there are little real-world data on treatment patterns, especially across disease trajectory and variation by severity of chorea.

Participants were adults from “Enroll-HD”, a global observational registry for patients with HD and their families (data cut 2013 – 31 October, 2020). Data on age, sex, Total Maximal Chorea (TMC) score, vesicular monoamine transporter 2 (VMAT2) inhibitors, and antipsychotic agents (APs; typical, atypical, and other [lithium]) were collected at the baseline visit. Participants were grouped by chorea severity (TMC score categories) recorded at baseline (0–7, 8–14, 15–21, 22–28).

There were 10,903 participants (TMC 0–‍7, n=5055; TMC 8–‍14, n=4374; TMC 15–‍21, n=1310; TMC 22–‍28, n=164). 51% were female (51.2%, 51.5%, 51.4%, and 53.1%, respectively) and the mean age at baseline was 53.0 years (50.8, 54.5, 55.9, 54.4, respectively). Overall, VMAT2i use at baseline was 14.9% and increased with chorea severity (10.8%, 16.4%, 23.9%, 29.3%, respectively). The proportion of patients using APs at baseline was 34.5% overall and increased with chorea severity (29.9%, 35.1%, 47.8%, 57.3%, respectively). Overall, 5.8% of patients used VMAT2 inhibitors combined with APs, and combined use increased with chorea severity (3.9%, 5.8%, 11.5%, 15.9%, respectively).

Use of medications to treat chorea was low across the spectrum of chorea severities but increased incrementally in patients with greater chorea severity. Use of a combination of VMAT2 inhibitors and APs at baseline was low but increased as chorea severity increased. These data suggest that HD-associated chorea may be undertreated globally. More data are needed to understand chorea treatment considerations and the utility of VMAT2 inhibitors and APs for treating HD-associated chorea and comorbidities.