Minimal Clinically Important Difference in AIMS Score Based on Clinical and Patient Global Impression of Change in Patients With Tardive Dyskinesia Treated With Deutetrabenazine

Objective: To assess the Minimal Clinically Important Difference (MCID) in Abnormal Involuntary Movement Scale (AIMS) score in patients with tardive dyskinesia (TD) treated with deutetrabenazine. Background: Deutetrabenazine is FDA approved for TD based on two 12-week, randomized, double-blind, placebo-controlled studies evaluating safety and efficacy in patients with baseline AIMS score ≥6. Deutetrabenazine reduced overall AIMS scores compared with placebo in ARM-TD (−3.0 vs −1.6, P=0.019) and AIM-TD (24 mg/day, −3.2 vs −1.4, P=0.003; 36 mg/day, −3.3 vs −1.4, P=0.001). Design/Methods: MCID is the smallest change from baseline in AIMS score that is meaningful for patients. MCID analyses were performed based on Patient Global Impression of Change (PGIC) and Clinical Global Impression of Change (CGIC) as anchors as described by Hauser et al., where MCID is the difference between patients treated with deutetrabenazine who were minimally improved and patients treated with placebo who were unchanged. Additional MCID definitions were explored: difference between patients who demonstrated treatment improvement versus those who did not (Method 2); difference between patients who demonstrated treatment success versus those who did not (Method 3). Results: 295 patients were analyzed. Based on PGIC, the suggested MCID was −2.8. Results were similar for Method 2 (75% of patients had treatment improvement; MCID=−2.8) and Method 3 (38% of patients had treatment success; MCID=−2.6). Based on CGIC, the suggested MCID was −2.6. Results were similar for Method 2 (76% of patients had treatment improvement; MCID=−2.8) and Method 3 (41% of patients had treatment success; MCID=−3.0). Therefore, the suggested MCID for deutetrabenazine is −3. Conclusions: The MCID change in AIMS score based on PGIC and CGIC for deutetrabenazine was −3 regardless of the analytical method applied, suggesting that patients who experience an AIMS score reduction of ~3 could expect to experience clinically meaningful improvement in TD symptoms. Disclosure: Dr. Barkay has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Employee of Teva Pharmaceuticals, Israel. Dr. Wilhelm has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Employee of Teva Pharmaceuticals, USA.. Dr. Wieman has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Former employee of Teva Pharmaceuticals.. Dr. Gordon has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Teva Pharmaceuticals. Dr. Hauser has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Dr. Robert Hauser reports receiving fees from: AbbVie, Academy for Continued Healthcare Learning, Acadia Pharmaceuticals, Acorda Therapeutics, Adamas Pharmaceuticals, Affriris, Alliance for Aging Research, Alphasights, Amneal Pharmaceuticals Inc., ApoPhar. Dr. Hauser has received royalty, license fees, or contractual rights payments from Dr. Robert Hauser Received Receive licensing fees through the University of South Florida. Dr. Hauser has received research support from Dr. Hauser reports research support from: AbbVie Inc, Acorda Therapeutics, AstraZeneca, Axovant Sciences, Biogen Inc, Cavion, Convance, Enterin Inc, Global Kinetics Corp., Impax Laboratories LLC, Intec Pharma Ltd, Jazz Pharmaceuticals, NeuroDerm Ltd., Lun. Dr. Savola has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Former employee of Teva Pharmaceuticals International, GmbH, Basel, Switzerland..