Valbenazine Effective for Long-Term Treatment of TD in Older Adults, Analysis Finds
A post hoc analysis found that valbenazine was safe and effective for the long-term treatment of tardive dyskinesia (TD) in adults aged 65 and older, according to results published in The Journal of Clinical Psychiatry.
“To date, the findings in this report are the first and only available analyses of clinical trial data for a vesicular monoamine transporter 2 (VMAT2) inhibitor in adults with TD who were aged 65 years and older,” wrote corresponding author Martha Sajatovic, MD, Case Western Reserve University School of Medicine, University Hospitals of Cleveland Medical Center, Cleveland, OH. “Given the projected rates of population aging in the US and globally, along with the increased risk of TD with older age and historic underrepresentation of adults aged ≥65 years in clinical trials, these results address an important gap in TD research.”
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Researchers pooled data from 2 previous studies examining the impact of valbenazine treatment in patients with TD: the KINECT 3 extension and KINECT 4 trials. The KINECT 3 trial involved a 6-week double-blind, placebo-controlled period followed by a 42-week period of double-blinded valbenazine dosing at 40 or 80 mg/day. In the KINECT 4 trial, participants received open-label valbenazine starting at 40 mg/day for 4 weeks, with escalation to to 80mg/day based on tolerability for 44 weeks.
Changes in TD symptoms were measured using the Abnormal Involuntary Movement Scale (AIMS), the Clinical Global Impression of Change-Tardive Dyskinesia (CGI-TD), and the Patient Clinical Global Impression of Change (PGIC), and safety was evaluated via the monitoring of treatment-emergent adverse events (TEAEs).
To assess the drug’s impact on older adults, researchers analyzed data from the 55 participants of the pooled population (N = 304) who were aged 65 years or older. Post hoc analyses found that the proportion of older patients who received either dose of valbenazine and saw a clinically significant improvement in total AIMS score increased from week 8 (58.0%) to week 24 (88.5%) and was maintained through week 48 (89.3%), indicating a sustained and substantial treatment effect. CGI-TD and PGIC outcomes showed similar sustained improvement, with 92.9% and 85.7% of participants achieving CGI-TD and PGIC scores ≤2 at week 48, respectively.
“This post hoc analysis of data from 2 clinical trials of valbenazine indicates that elderly participants who received up to 48 weeks of treatment experienced substantial and sustained improvements in TD,” the authors wrote. “Moreover, no new TEAEs of clinical concern were found in the elderly participants, and psychiatric stability was maintained through 48 weeks of treatment.”
The researchers noted several limitations of the study, including the small population size and the inclusion criteria of the pooled data group that may limit generalizability. “Nonetheless, findings from this post hoc analysis provide information about valbenazine treatment in adults with TD who are 65 years and older, a group in which clinical trial data are not publicly available for other TD medications,” they concluded.
