Efficacy and Safety of Valbenazine in Japanese Patients With Tardive Dyskinesia and Schizophrenia/Schizoaffective Disorder or Bipolar Disorder/Depressive Disorder: Primary Results and Post Hoc Analyses of the J-KINECT Study.

PURPOSE: This post hoc analysis investigated whether a patient's underlying psychiatric disease (schizophrenia/schizoaffective disorder [SCHZ] or bipolar disorder/depressive disorder [MOOD]) influenced the efficacy or safety of valbenazine for tardive dyskinesia (TD) in an Asian population.

METHODS: We analyzed data from J-KINECT, a multicenter, phase II/III, randomized, double-blind study, which consisted of a 6-week placebo-controlled period followed by a 42-week extension where Japanese patients with TD received once-daily 40- or 80-mg valbenazine. We compared the change from baseline in Abnormal Involuntary Movement Scale total score and Clinical Global Impression of TD score between patients with SCHZ and those with MOOD, and incidence of treatment-emergent adverse events.

RESULTS: Of 256 patients included in the placebo-controlled period, 211 continued to the long-term extension. The mean change from baseline in Abnormal Involuntary Movement Scale total score at week 6 (95% confidence interval) was -1.8 (-3.2 to -0.5) and -3.3 (-4.7 to -1.9) in the valbenazine 40- and 80-mg groups, respectively (SCHZ group), and -2.4 (-3.9 to -0.9) and -3.5 (-5.1 to -1.9) in the valbenazine 40- and 80-mg groups, respectively (MOOD group), demonstrating improvement at either dose level over placebo, regardless of the underlying disease. These results were maintained to week 48, and improvements of Clinical Global Impression of TD scores were similar. There were no notable differences in the incidence of serious or fatal treatment-emergent adverse events by underlying disease; differences in the incidence of worsening schizophrenia and depression were attributed to underlying disease progression.

CONCLUSIONS: Safety and efficacy of long-term valbenazine therapy for TD did not vary according to underlying psychiatric disease.