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 of patients with tardive dyskinesia (TD), the percentage of patients achieving ≥50% and ≥70% responses (i.e. reductions from baseline in Abnormal Involuntary Movement Scale (AIMS) scores) was higher in the deutetrabenazine-treated group compared to placebo, with low rates of overall adverse events (AEs) and discontinuations associated with deutetrabenazine. We evaluated the long-term efficacy of deutetrabenazine by examining response rates. Updated results of the responder analysis are reported here.

DESIGN/METHODS: Patients completing ARM-TD or AIM-TD were included in this open-label, single-arm extension study, in which all patients underwent response-driven titration of deutetrabenazine from 12 mg/day up to a maximum total dose of 48 mg/day. The study comprised a 6-week titration and a long-term maintenance phase. The cumulative proportion of AIMS responders from baseline was assessed; response rates for ≥50% and ≥70% improvement from baseline for each patient were evaluated.

RESULTS: 343 patients enrolled in the extension study. At Week 106 (n=169; total daily dose (mean±standard error): 39.6±0.77 mg), 55% of patients achieved ≥50% response and 30% achieved ≥70% response. At Week 132 (n=108; total daily dose: 39.7±0.97 mg), 61% of patients achieved ≥50% response and 40% achieved ≥70% response. Treatment was generally well tolerated. Exposure-adjusted incidence rates of AEs of interest were somnolence and sedation (0.07), depression (0.05), parkinsonism (0.04), suicidality (0.02), and akathisia/restlessness (0.01).

CONCLUSIONS: Patients who received long-term treatment with deutetrabenazine achieved response rates that indicated clinically meaningful sustained improvement in the severity of TD symptoms. Responder rates increased over time.

This poster was presented at the 32nd annual Psych Congress, held Oct. 3-6, 2019, in San Diego, California.