Long-Term Treatment With Deutetrabenazine is Associated With Continued Improvement in Tardive Dyskinesia (TD): Results From an Open-Label Extension Study

Background: In the 12-week ARM-TD and AIM-TD studies, the odds of response to deutetrabenazine treatment were higher than the odds of response to placebo at all response levels. Deutetrabenazine was associated with low rates of overall adverse events and discontinuation.
Objective: To evaluate long-term efficacy of deutetrabenazine in patients with tardive dyskinesia (TD) by examining response rates using Abnormal Involuntary Movement Scale (AIMS) scores.  

Methods: Patients who completed ARM-TD or AIM-TD were included in this open-label, single-arm extension study that comprised a 6-week titration and long-term maintenance phase. All patients restarted/started deutetrabenazine 12 mg/day, titrating up to a maximum total daily dose of 48 mg/day based on dyskinesia control and tolerability. The cumulative proportion of AIMS responders was assessed. Response was defined as a percent improvement from baseline for each patient from 10% to 90% in 10% increments. AlMS score was assessed by local site ratings for this analysis.

Results: A total of 343 patients from the parent studies were included (111 placebo, 232 deutetrabenazine). At Week 54 (n=145; total daily dose [mean±standard error]: 38.1±0.9 mg), 63% of patients receiving deutetrabenazine achieved ≥30% response, 48% of patients achieved ≥50% response, and 26% achieved ≥70% response. At Week 80 (n=66; total daily dose: 38.6±1.1 mg), 76% of patients achieved ≥30% response, 59% of patients achieved ≥50% response, and 36% achieved ≥70% response. Treatment was generally well tolerated.

Conclusions: Patients who received long-term deutetrabenazine achieved response rates higher than those observed in positive short-term studies, indicating clinically meaningful long-term treatment benefit.