Background: Valbenazine, a novel and highly selective VMAT2 inhibitor, is approved for the treatment of TD in adults. Data from two long-term studies (KINECT 3 [K3], KINECT 4 [K4]) and a roll-over study (1506) were analyzed to better understand the effectiveness of valbenazine in patients who received the lower dose (40 mg) or required a dose reduction (80 to 40 mg).
Methods: Participants who completed K3 (6-week double-blind, placebo-controlled; 42-week blinded extension) or K4 (48-week open-label) were invited to participate in 1506 (72-week or until commercial availability open-label of valbenazine). Focusing on participants who received valbenazine 40 mg or had a dose reduction (80/40 mg), analyses were conducted as follows: mean change from baseline (CFB) to Wk48 in Abnormal Involuntary Movement Scale (AIMS) total score (pooled K3/K4 population); AIMS response, defined as ≥50% total score improvement at Wk48 (pooled K3/K4 population); and Clinical Global Impression of Severity (CGIS-TD) score ≤2 (“borderline ill” or better) (1506 population).
Results: AIMS CFB indicated mean improvements in the pooled K3/K4 population (40 mg, -5.7; 80/40 mg, -6.2), with a majority experiencing an AIMS response at Wk48 (40 mg, 53.7%; 80/40 mg, 53.8%). At Wk12 in 1506, 63.6% of participants taking valbenazine 40 mg had a CGIS-TD score ≤2. Data from subsequent visits were limited by small sizes due to study termination when valbenazine became commercially available.
Conclusions: Valbenazine 40 mg may be an effective long-term option for some TD patients. Dose reductions (from 80 to 40 mg) did not appear to compromise long-term benefit.
This poster was presented at the 32nd annual Psych Congress, held Oct. 3-6, 2019, in San Diego, California.