Minimal clinically important change in Abnormal Involuntary Movement Scale score in tardive dyskinesia as assessed in pivotal trials of deutetrabenazine

• Published in: Parkinsonism & related disorders Vol. 97; pp. 47 - 51
• Main Authors: Hauser, Robert A., Barkay, Hadas, Wilhelm, Amanda, Wieman, Maria, Savola, Juha-Matti, Gordon, Mark Forrest
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.04.2022
• Subjects: Abnormal Involuntary Movement Scale; Antipsychotic Agents - therapeutic use; Deutetrabenazine; Humans; Minimal clinically important change; Movement disorders; Tardive dyskinesia; Tardive Dyskinesia - chemically induced; Tardive Dyskinesia - drug therapy; Tetrabenazine - analogs & derivatives; Tetrabenazine - pharmacology; Tetrabenazine - therapeutic use; Deutetrabenazine; Tardive dyskinesia; Minimal clinically important change; Movement disorders
• ISSN: 1353-8020; 1873-5126
• DOI: 10.1016/j.parkreldis.2022.02.017

Deutetrabenazine is approved by the US Food and Drug Administration to treat tardive dyskinesia (TD) based on 2 pivotal, 12-week, placebo-controlled studies (ARM-TD and AIM-TD) evaluating safety and efficacy in patients with baseline total motor Abnormal Involuntary Movement Scale (AIMS) score ≥6. This analysis estimated the minimal clinically important change (MCIC) in total motor AIMS score in TD patients treated with deutetrabenazine. The pooled analysis population included all patients in ARM-TD and AIM-TD who received study drug and had ≥1 postbaseline AIMS assessment. MCIC analyses were performed using Patient Global Impression of Change (PGIC) and Clinical Global Impression of Change (CGIC) as anchors. MCIC was defined as the mean change from baseline in total motor AIMS score in patients treated with deutetrabenazine who were rated minimally improved on PGIC or CGIC at Week 12. This analysis included 295 patients (deutetrabenazine, n = 197; placebo, n = 98). At Week 12, the MCIC in deutetrabenazine-treated patients was −2.4 based on the PGIC and −2.1 based on the CGIC. Mean change from baseline in total motor AIMS score for placebo-treated patients rated minimally improved was −1.4 based on the PGIC and −1.5 based on the CGIC. The proportion of deutetrabenazine-treated patients who achieved improvement in total motor AIMS score by ≥2 and ≥3 points was 66% and 55%, respectively. Using anchor-based methodology, the MCIC on the AIMS for deutetrabenazine in patients with TD was approximately −2, suggesting that a reduction in total motor AIMS score of ∼2 is associated with clinically meaningful improvement in TD symptoms. •Deutetrabenazine is approved for the treatment of tardive dyskinesia (TD).•Abnormal Involuntary Movement Scale score assesses severity of abnormal movements.•Minimal clinically important change (MCIC) describes a threshold of clinical benefit to patients.•We calculated an MCIC of about −2 for the Abnormal Involuntary Movement Scale in TD.•Deutetrabenazine provides clinically meaningful reductions in abnormal movements.