Currently utilized clinician-rated symptom scales for tardive dyskinesia (TD) have not kept up with the expanding spectrum of TD phenomenology. The objective of this study was to develop and test the reliability of a new instrument, the CTI.

A movement disorder neurologist devised the outline of the scale. A steering committee (four neurologists and two psychiatrists) provided revisions until consensus was reached. The resulting instrument assesses frequency of abnormal movements of the eye/eyelid/face, tongue/mouth, jaw, limb/trunk, complex movements (e.g., handwringing, self-caressing), and vocalizations. The CTI rates symptoms from 0–3 with 0 = absent, 1 = infrequent/intermittent or only present with activating maneuvers, 2 = frequent intermittent, brief periods without movements, 3 = constant or nearly constant. Functional impairments including activities of daily living (ADL), social impairment, symptom bother, and harm are rated 0–3 with 0 = patient is unaware or unaffected, 1 = symptoms mildly impact patient, 2 = symptoms moderately impact patient, 3 = symptoms severely impact patient. Following institutional review board approval, the CTI underwent inter-rater and test-retest reliability testing. Videos of patient TD examinations were obtained and reviewed by two movement disorder specialists to confirm the diagnosis of TD by consensus and the adequacy to demonstrate a TD-consistent movement. Vignettes were created to include patients’ symptom descriptions and functional, social, or occupational impairments/limitations. Four clinicians rated each video/vignette. Selected videos/vignettes were also subject to an intra-rater retest. Interrater agreement was analyzed via 2-way random-effects interclass correlation (ICC) and test-retest agreement assessment utilizing Kendall’s tau-b.

45 video/vignettes were assessed for interrater reliability, and 16 for test-retest reliability. ICCs for movement frequency were as follows: abnormal eye movement .89; abnormal tongue/mouth movement .91; abnormal jaw movement .89; abnormal limb movement .76; complex movement .87; abnormal vocalization .77; and functional impairments including harm .82; social embarrassment .88; ADLs .83; and symptom bother .92. Retests were conducted on mean (SD) 15 (3) days later with scores ranging from .66–.87.

The CTI is a new instrument with good reliability in assessing TD symptoms and functional impacts. Future validation study is warranted.

Neurocrine Biosciences

Tardive dyskinesia (TD), a persistent and potentially disabling movement disorder, is associated with prolonged exposure to antipsychotics and other dopamine receptor blocking agents. Valbenazine (VBZ) is a novel and highly selective vesicular monoamine transporter 2 (VMAT2) inhibitor approved for the treatment of TD in adults. Using data from two long-term phase 3 studies (KINECT 3 [K3], NCT02274558; KINECT 4 [K4], NCT02405091) and a rollover study (1506, NCT02736955), the long-term outcomes of once-daily VBZ on TD were examined in participants who received 40mg or had a dose reduction from 80 to 40mg.

The effects of VBZ 40mg (as well as VBZ 80mg) were evaluated in the following studies: the pivotal K3 study (6 weeks double-blind, placebo controlled), the extension phase of K3 (42 additional weeks of VBZ, 4 week discontinuation), and the open-label K4 study (48 weeks of VBZ, 4 week discontinuation). Completers from K3 extension and K4 were invited to participate in 1506 (up to 72 additional weeks of VBZ or until commercial availability of VBZ). Few participants reached Week 60 (n=4) or Week 72 (n=0) in the 1506 study before termination. Analyses focused on VBZ 40mg in two populations: pooled K3/K4 (participants who received VBZ 40mg throughout K3 or K4 or who had a dose reduction [80/40mg] during K3 or K4); and 1506 (participants who received VBZ 40mg from beginning of K3 or K4 to last visit in 1506 or who had a dose reduction [80/40mg] at any time). Outcomes for the K3/K4 population included mean change from baseline (CFB) in Abnormal Involuntary Movement Scale (AIMS) total score (sum of items 1-7) and AIMS response (≥50% total score improvement from baseline) at Week 48 of K3 or K4. Outcomes for the 1506 population included a Clinical Global Impression of Severity-Tardive Dyskinesia (CGIS-TD) score ≤2 (“normal, not at all ill” or “borderline ill”).

In the K3/K4 population, AIMS CFB to Week 48 indicated mean TD improvements in participants who received 40mg continuously (40mg, -5.7 [n=54]) and in those who had a dose reduction to 40mg (80/40mg, -6.2 [n=13]). In addition, a majority of these participants had an AIMS response after 48 weeks of treatment (40mg, 53.7%; 80/40mg, 53.8%). In the 1506 population, the percentage of participants who had a CGIS-TD score ≤2 (rating of “normal, not at all ill” or “borderline ill”) at Week 12 was 63.6% (7/11) in the 40mg group and 30.8% (4/13) in the 80/40mg group. Data from Weeks 24 to 60 of 1506 were limited by the small sample sizes (<10 participants each in 40mg or 80/40mg group at each of these visits).

Based on these analyses and results from published studies, VBZ 40mg may be an effective long-term option for some TD patients. Dose reductions from 80 to 40mg, if necessary, did not appear to compromise long-term benefit.

This study was sponsored by Neurocrine Biosciences, Inc.

Valbenazine (VBZ) is a highly selective vesicular monoamine transporter 2 (VMAT2) inhibitor approved for the treatment of tardive dyskinesia (TD), a persistent and potentially disabling movement disorder associated with prolonged antipsychotic exposure. Post hoc response and shift analyses were conducted using Abnormal Involuntary Movement Scale (AIMS) data from KINECT 4 (NCT02405091), a long-term open-label study in which participants received up to 48 weeks of open-label treatment with once-daily VBZ (40 or 80 mg).

KINECT 4 included participants who met the following criteria: ages 18 to 85 years; DSM-IV diagnosis of schizophrenia, schizoaffective disorder, or mood disorder; neuroleptic-induced TD for ≥3 months prior to screening; stable psychiatric status (Brief Psychiatric Rating Scale score <50); no high risk of active suicidal ideation or behavior. Stable doses of concomitant medications to treat psychiatric and medical disorders were allowed. VBZ dosing was initiated at 40 mg, with escalation to 80 mg at Week 4 based on clinical assessment of TD and tolerability; a dose reduction to 40 mg was allowed if 80 mg was not tolerated. AIMS responses, ranging from ≥10% to 100% improvement from baseline in AIMS total score (sum of items 1-7), were analyzed at Week 48 based on scoring by site investigators. AIMS shift, conducted for each item (representing 7 different body regions), was defined as an improvement from a score ≥3 (moderate/severe) at baseline to a score ≤2 (none/minimal/mild) at Week 48.

103 participants had an available AIMS assessment at Week 48 (40 mg, n=20; 80 mg, n=83 [including 9 with a dose reduction]). At Week 48, 94.2% of participants had ≥30% total AIMS score improvement (40 mg, 90.0%; 80 mg, 95.2%) and 86.4% had ≥50% improvement (40 mg, 90.0%; 80 mg, 85.5%). The percentage of participants meeting the remaining AIMS response thresholds ranged from 9.7% (for 100% response) to 97.1% (for ≥10% response). In participants who had an AIMS item score ≥3 at baseline, shifts to a score ≤2 at Week 48 were as follows: 100% for lips, upper extremities, and lower extremities (VBZ 40 mg and 80 mg). Shift rates for the remaining regions were as follows (40 mg, 80 mg): face (100% [9/9], 96.9% [31/32]), jaw (100% [10/10], 97.6% [40/41]), tongue (100% [11/11], 97.9% [47/48]), trunk (87.5% [7/8], 88.9% [16/18]).

After 48 weeks of treatment with once-daily VBZ (40 or 80 mg), >85% of KINECT 4 participants had a clinically meaningful AIMS response (≥30% total score improvement), a robust AIMS response (≥50% total score improvement), or an AIMS shift (from item score ≥3 at baseline to score ≤2 at Week 48). These results suggest that VBZ is an appropriate long-term treatment for many adults with TD.

This study was sponsored by Neurocrine Biosciences, Inc.