Deutetrabenazine Reduces Severe Tardive Dyskinesia Movements in a 3-year Open-Label Extension Trial

Background There are no established treatment guidelines for tardive dyskinesia (TD) based on movement severity. The 12-week ARM-TD and AIM-TD studies in TD patients with baseline Abnormal Involuntary Movement Scale (AIMS) total score (items 1–7) ≥6 showed clinically significant improvements in AIMS score with deutetrabenazine versus placebo. Patients who completed these studies were eligible for the open-label extension (OLE) trial. This post-hoc analysis evaluated deutetrabenazine in TD patients with severe movements. Methods Subgroups were defined by upper quartile of baseline total AIMS score (local rating). Endpoints were: change and percent change from baseline in AIMS score, and percent of patients achieving ≥50% AIMS reduction from baseline. Results 337 patients were analyzed. The upper quartile of baseline total AIMS score was 14. Subgroups were defined as >14 and ≤14 at baseline, respectively (n=64 vs 273); data are presented at Week 145 (n=40 vs 120). Mean treatment duration was 880.5 and 760.8 days. Mean±SE daily doses were 41.1±1.6mg and 38.9±1.0mg. Mean±SE change from baseline in AIMS score was –11.0±0.8 versus –5.1±0.3; percent change from baseline was –60.1%±3.6% versus –55.9%±3.0%. More patients with AIMS score >14 had ≥50% AIMS reduction (73% vs 65%). Less patients discontinued (38% vs 51%); reasons included withdrawal by subject (16% vs 25%), adverse event (3% vs 11%), and lost to follow-up (6% vs 7%). Withdrawal due to lack of efficacy was uncommon (5% vs 2%). Conclusions Patients with baseline total AIMS score >14 had clinically meaningful reductions in AIMS score, suggesting deutetrabenazine has long-term benefit in these patients. Funding Teva Pharmaceutical Industries Ltd., Petach Tikva, Israel