Valbenazine is a highly selective vesicular monoamine transporter 2 inhibitor indicated for tardive dyskinesia (TD), a persistent and potentially debilitating movement disorder associated with prolonged antipsychotic exposure. Given the paucity of data regarding the course of TD in patients no longer taking antipsychotics, a meta-analysis of 3 long-term valbenazine studies was conducted in subgroups with and without concomitant antipsychotic use at baseline.

KINECTTM-3 (NCT02274558), KINECTTM-4 (NCT02405091), and JKINECT (NCT03176771) data were analyzed in study completers taking antipsychotics at baseline (AP+) and those who were not (AP-). The Abnormal Involuntary Movement Scale (AIMS) total score was used to measure TD severity at baseline, Wk48 (end of valbenazine treatment), and Wk52 (4 weeks after valbenazine withdrawal). The meta-analysis implemented a random-effects model that weighted each study based on inverse variance, adjusted for between-study variance.

Of 576 enrolled patients, 336 (58.3%) were study completers and included for analysis: AP+ (n=269); AP- (n=67). Mean baseline AIMS scores ranged from 7.9–14.9 (AP+) and 10.9–14.5 (AP-). Mean changes from baseline in AIMS scores indicated substantial TD improvements with valbenazine at Wk48 (AP+, 6.1; AP-, -6.5) and return towards baseline severity at Wk52 (AP+, -2.1; AP-, -1.4).

Once-daily valbenazine treatment resulted in substantial and sustained TD improvement through Wk48, with no meaningful differences between AP+ and AP- subgroups. The return towards baseline severity after valbenazine withdrawal shows TD is chronic and often irreversible, even in patients no longer taking antipsychotics. Continuous treatment with valbenazine may be warranted irrespective of antipsychotic therapy.

Neurocrine Biosciences, Inc.

Valbenazine is a once-daily VMAT2 inhibitor approved for the treatment of tardive dyskinesia (TD), a persistent and potentially disabling movement disorder associated with prolonged exposure to antipsychotics, antiemetics, and other dopamine receptor blocking agents. The efficacy, safety, and tolerability of valbenazine has been established in several phase 3 trials, including a long-term study (KINECT 4 [NCT02405091]) in which participants received open-label valbenazine (40 or 80 mg) for 48 weeks. Post hoc analyses of KINECT 4 data were conducted to assess patterns of treatment response.

Data from KINECT 4 treatment completers (participants who reached the Week 48 visit and had the longest duration of treatment) were analyzed post hoc. TD was assessed using the Abnormal Involuntary Movement Scale (AIMS) total score (sum of items 1–7, as rated by the study investigator), the Clinical Global Impression of Change-Tardive Dyskinesia (CGI-TD), and the Patient Global Impression of Change (PGIC). Analyses were conducted at Week 8 (first study visit after the valbenazine dose-optimization period) and Week 48 using the following definitions of response: ≥50% and ≥70% improvement from baseline in AIMS total score; rating of “much improved” or “very much improved” (score ≤2) on the CGI-TD and PGIC.

Of the 167 participants who entered KINECT 4, 103 (62%) were treatment completers and included for analysis. Of these 103 participants, 39% and 86% met the ≥50% AIMS response threshold at Weeks 8 and 48, respectively. The percentages of participants who met the highly rigorous AIMS ≥70% response threshold at Weeks 8 and 48 were 17% and 52%, respectively. Of the 40 participants with AIMS ≥50% total score improvement at Week 8, 95% also met this threshold at Week 48 (“sustained response”). Of the 63 participants with <50% AIMS improvement at Week 8, 81% achieved the ≥50% response threshold by end of treatment at Week 48. The proportion of participants meeting the threshold for CGI-TD response also increased over time, from 50% at Week 8 to 92% at Week 48. PGIC results were similar, with response rates of 53% and 88% at Weeks 8 and 48, respectively.

Post hoc analyses of data from a 48-week, open-label study of once-daily valbenazine showed that the proportion of participants meeting rigorous treatment response thresholds increased over time. By the end of treatment at Week 48, >80% of participants demonstrated robust improvements in TD, as assessed using the AIMS (≥50% improvement), CGI-TD (score ≤2), and PGIC (score ≤2).

Neurocrine Biosciences, Inc.