Early Response With Valbenazine and Long-Term Symptom Reduction in Patients With Tardive Dyskinesia: Post Hoc Analysis of the KINECT 3 Study

Background: Valbenazine is approved for the treatment of tardive dyskinesia (TD), a persistent and disabling movement disorder associated with prolonged antipsychotic exposure. Data from KINECT 3 were analyzed post hoc to evaluate changes in TD (based on Abnormal Involuntary Movement Scale [AIMS]) in participants with early treatment response (based on subjective global measures).

Methods: KINECT 3 included 48 weeks of treatment (6-week double-blind, placebo-controlled; 42-week blinded extension). AIMS outcomes at Wk48 included: mean change from baseline (CFB) in the total score (sum of items 1-7) and response (≥50% improvement). These outcomes were assessed in participants with “early improvement”, defined as Patient Global Impression of Change (PGIC) or Clinician Impression of Change (CGI-TD) score ≤3 (“minimally improved” or better) at Wk2.

Results: In valbenazine-treated participants with available Wk2 assessments, 50% had early PGIC improvement and 43% had early CGI-TD improvement. Baseline characteristics were generally similar between participants who had Wk2 improvements and those who did not meet that threshold. AIMS outcomes at Wk48 were also generally similar between early improvers and those who did not meet that threshold: CFB in early PGIC improvers (-4.1 vs -3.5); CFB in early CGI-TD improvers (-4.2 vs -3.5); response in early PGIC improvers (40% vs 39%); response in early CGI-TD improvers (42% vs 38%).

Conclusions: Many KINECT 3 participants achieved at least minimal global improvements at Wk2. AIMS outcomes at Wk48 demonstrated long-term reductions in TD severity regardless of early response. Early non-improvement based on subjective measures may not be predictive of long-term treatment failure.

This poster was presented at the 32nd annual Psych Congress, held Oct. 3-6, 2019, in San Diego, California.