Long-Term Effects of Once-Daily Valbenazine in Older and Younger Adults with Tardive Dyskinesia

Introduction. Older patients taking a dopamine receptor blocking agent (eg, firstor second-generation antipsychotic) have an increased risk for tardive dyskinesia (TD), a persistent and potentially disabling movement disorder. Valbenazine, a selective and potent vesicular monoamine transporter 2 inhibitor, is approved for once-daily treatment of TD with no dosing adjustments required for older patients. This analysis of valbenazine clinical trial data, which is the first to evaluate an approved TD medication in a population ≥65 years, was conducted to better understand treatment outcomes in older patients. Methods. Data from two 48-week long-term studies (KINECT 3-extension, KINECT 4) were pooled and analyzed in older (≥65 years) and younger (<65 years) participants. Analyses based on theAbnormal InvoluntaryMovement Scale (AIMS) total score included: mean change from baseline (BL); clinically meaningful response (≥30% improvement from BL [AIMS-30%]); and protocol-defined response (≥50% improvement from BL [AIMS50%]). Additional analyses included response thresholds for Clinical Global Improvement-Tardive Dyskinesia and Patient Global Impression of Change as follows: rating of “minimally improved” or better (score≤3) at week 48 (CGI-TD≤3, PGIC≤3); rating of “much improved” or “very much improved” (score ≤2) at week 48 (CGI-TD≤2, PGIC≤2). Results. AIMS outcomes in the older subgroup were generally comparable to (or better than) outcomes in the younger subgroup and overall study populations. In participants ≥65 years, pooled AIMS results indicated substantial improvements in TD movements with valbenazine 40 mg (n = 8) and 80 mg (n = 20): mean change from BL ( 6.4 and 9.8 [for 40 and 80mg, respectively]); AIMS-30% (75% and 95%); AIMS-50% (75% and 85%). CGI-TD and PGIC response rates indicated that clinicianand patientreported global improvements were also substantial in the older subgroup: CGI-TD = 3 (88% and 100% [for 40 and 80 mg, respectively]); CGI-TD = 2 (88% and 95%); PGIC = 3 (88% and 100%); PGIC = 2 (75% and 90%). Conclusions. These analyses, which are the first to evaluate longterm valbenazine effects in patients ≥65 years, indicate that older study participants had clinically meaningful and substantial improvements in TD that were comparable to (or better than) those in younger participants. Funding. Neurocrine Biosciences, Inc. Rhabdomyolysis in Young Adult Male Stabilized on Mirtazapine and with History of COVID-19 Infection Christine Philippe, MD, Douglas Misquitta, MD and Julie Niedermier, MD The Ohio State University, Columbus, OH, USA