M16. Valbenazine (NBI-98854) for the Treatment of Tardive Dyskinesia: Analysis by Underlying Psychiatric Diagnosis in Phase III KINECT 3 Study

Abstract

Background: Valbenazine is a novel and highly selective vesicular mono‐amine transporter 2 (VMAT2) inhibitor that is being evaluated for the treatment of tardive dyskinesia (TD), a persistent movement disorder resulting from exposure to antipsychotics or other dopamine receptor blocking agents (DRBAs). The effcacy of valbenazine in treating TD was demonstrated in a Phase 3 clinical trial (KINECT 3; NCT02274558), which included subjects with underlying schizophrenia/schizoaffective disorder or mood disorder. Further analyses of data from that trial were conducted to explore the effcacy of valbenazine across diagnostic subgroups. Methods: Subjects in this 6‐week, double‐blind, placebo‐controlled trial were randomized 1:1:1 to once‐daily valbenazine 80 mg, valbenazine 40 mg, or placebo. The primary endpoint was change from baseline to Week 6 on the Abnormal Involuntary Movement Scale (AIMS) total score (items 1‐7) for valbenazine 80 mg vs placebo in the intent‐to‐treat (ITT) population. AIMs were videotaped and ratings were conducted by central raters blind to study visit and group. Additional outcomes included AIMS total score change (40 mg vs placebo) and Clinical Global Impression of Change‐Tardive Dyskinesia (CGI TD) score (80 and 40 mg vs placebo) at Week 6. In addition to being evaluated in the ITT population, these outcomes were analyzed in subgroups categorized by underlying psychiatric diagnosis (schizophrenia/schizoaffective disorder or mood disorder). Results: At Week 6 in the ITT population (N = 225), AIMS score improvement was signifcantly greater with valbenazine 80 mg than placebo (least squares [LS] mean change from baseline: 80 mg, 3.2; placebo,‐0.1; P