SA17. Response to Treatment With Valbenazine (NBI-98854) in Subjects With Tardive Dyskinesia

Abstract

Background: Tardive dyskinesia (TD) is a persistent and potentially disabling movement disorder resulting from exposure to dopamine receptor-blocking agents (DRBAs), such as antipsychotics. Valbenazine is a novel and highly selective vesicular monoamine transporter 2 (VMAT2) inhibitor that is being evaluated for the treatment of TD and other movement disorders. Clinical studies include a Phase 3 trial of valbenazine in adults who had TD and underlying schizophrenia/schizoaffective disorder or mood disorder (KINECT 3; NCT02274558). The primary end point of this trial was met as demonstrated by a signifcant difference between valbenazine 80 mg/day and placebo for the Abnormal Involuntary Movement Scale (AIMS) dyskinesia total score (Items 1-7) change from baseline. Additional analyses of AIMS data from this trial were conducted to assess treatment response in subjects with TD. Methods: In this 6-week, double-blind, placebo-controlled trial, subjects were randomized 1:1:1 to once-daily treatment with valbenazine 80 mg, valbenazine 40 mg, or placebo. Treatment response was defned as ≥50% reduction in the AIMS total score. AIMS responders were analyzed by study visit (Weeks 2, 4, and 6) in the intent-to-treat (ITT) population and in subgroups categorized by underlying psychiatric diagnosis (schizophre-nia/schizoaffective disorder or mood disorder). Numbers needed to treat (NNTs) were calculated for AIMS responders (valbenazine vs placebo) at Week 6. Signifcance testing was not conducted in the subgroups. Results: At Week 6 in the ITT population (N = 225), AIMS responder rates were signifcantly higher with valbenazine than with placebo: 80 mg, 40.0% (P