Purpose: To evaluate the long-term effects of once-daily valbenazine in elderly patients with tardive dyskinesia (TD), a persistent and potentially disabling movement disorder associated with exposure to antipsychotics and other dopamine-receptor blocking agents (DRBAs).
Rationale: Older patients have increased risk for TD, even with lower DRBA doses and shorter treatment durations. Identifying appropriate TD treatment options for this population is essential.
Conceptual/theoretical framework: Valbenazine is the only approved TD medication with enough clinical trial data to specifically indicate no required dose adjustment in elderly patients (≥65 years). These data can therefore be used to describe treatment effects in an elderly study population.
Methods: Data were pooled from two studies (KINECT 3-extension, KINECT 4) in which participants received valbenazine (40mg or 80mg) once-daily for up to 48 weeks. Analyses by age (≥65yrs, <65yrs) at Wk48 included: mean change from baseline in abnormal involuntary movement scale total score (AIMS-CFB); ≥50% improvement from baseline AIMS (AIMS-50%); and score ≤2 (“much improved” or better) for clinical global impression of change-tardive dyskinesia (CGI-TD≤2) and patient global impression of change (PGIC≤2). Treatment-emergent adverse events (TEAEs) were also monitored.
Results: Treatment outcomes were generally comparable between age subgroups. At Wk48, outcomes for once-daily valbenazine 40mg (≥65yrs [n=8]; <65yrs [n=46]) and 80mg (≥65yrs [n=20]; <65yrs [n=105]) were as follows: mean AIMS-CFB (≥65yrs, -6.4 and -9.8 [40mg and 80mg, respectively]; <65yrs, -5.5 and -8.3); AIMS-50% (≥65yrs, 75% and 85%; <65yrs, 50% and 70%); CGI-TD≤2 (≥65yrs, 88% and 95%; <65yrs, 62% and 83%); and PGIC≤2 (≥65yrs, 75% and 90%; <65yrs, 77% and 80%). Both age subgroups had similar incidences of any TEAEs (≥65yrs, 73%; <65yrs, 72%) and any serious TEAEs (≥65yrs, 18%; <65yrs, 17%), but discontinuations due to TEAEs were more common in elderly participants (≥65yrs, 26%; <65yrs, 13%; P<0.05). Applicability to APN practice: The analyses in this presentation indicate that long-term treatment with once-daily valbenazine is appropriate and beneficial for elderly patients (≥65 years), who had robust TD improvements that were comparable to those in the younger cohort (<65 years).
Learning outcome: Apply the treatment outcomes found in these analyses to the real-world management of TD in elderly patients.