Sustained Treatment Response with Long-Term Valbenazine in Patients with Tardive Dyskinesia

Abstract: Background: Valbenazine is a once-daily VMAT2 inhibitor approved for the treatment of tardive dyskinesia (TD). Data from a 48-week, open-label study of valbenazine (KINECT 4 [NCT02405091]) were analyzed post hoc to assess treatment response patterns. Methods: Treatment completers (participants who reached the Wk48 visit) were included for analyses. Response was analyzed at Wk8 (first visit after dose-adjustment period) and Wk48 (end of treatment) using the following thresholds: ≥50% and ≥70% improvement from baseline in Abnormal Involuntary Movement Scale (AIMS) total score; rating of “much improved” or better (score ≤2) on the Clinical Global Impression of Change-Tardive Dyskinesia (CGI-TD) and Patient Global Impression of Change (PGIC). Results: 103 treatment completers were included for analysis. The proportion of these participants who met AIMS response thresholds at Wk8 and Wk48 were as follows: AIMS ≥50% improvement (39% and 86%); AIMS ≥70% improvement (17% and 52%). Of 40 participants with AIMS ≥50% response at Wk8, 95% also met this threshold at Wk48 (“sustained response”). Of 63 participants with < 50% AIMS improvement at Wk8, 81% achieved the ≥50% threshold by Wk48. The proportion of participants meeting thresholds for global response at Wk8 and Wk48 were as follows: CGI-TD (50% and 92%); PGIC (53% and 88%). Conclusions: These post hoc analyses showed that the proportion of participants meeting rigorous treatment response thresholds increased over time. By the end of once-daily valbenazine treatment at Wk48, >80% of participants demonstrated robust improvements in TD, as assessed using the AIMS (≥50% improvement), CGI-TD (score ≤2), and PGIC (score ≤2).Short Description: KINECT 4 study data were analyzed post hoc to assess treatment response in patients with tardive dyskinesia who received once-daily valbenazine (40 or 80 mg) for 48 weeks. The proportion of study participants who met rigorous thresholds for response increased over time. After 48 weeks of treatment, >80% of participants achieved ≥50% improvement from baseline in Abnormal Involuntary Movement Scale (AIMS) total score, along with clinician- and patient-reported ratings of “much improved” or better.Name of Sponsoring Organization(s): Neurocrine Biosciences, Inc.