Long-Term Safety and Efficacy of Valbenazine for Patients With Tardive Dyskinesia
Long-term results for valbenazine (Ingrezza; Neurocrine Biosciences, San Diego, CA), a treatment for patients with tardive dyskinesia (TD), are being presented at the 2018 World Congress on Parkinson's Disease and Related Disorders (IAPRD) in Lyon, France, Aug. 19-22, 2018.
In the KINECT 3 (NCT02274558) and KINECT 4 (NCT02405091) studies, patients with TD were given valbenzaine for 48 weeks followed by a 4-week washout period. Some patients reported a loss of improvement during the washout period, suggesting that patients may require ongoing therapy with valbenazine to maintain the effect on TD. During the study, patients treated with valbenazine had greater improvements in TD than those given placebo. Now in 2 open-label long-term extension studies, patients received 40 mg per day of valbenazine for 4 weeks, which was then increased to 80 mg per day in patients who could tolerate the higher dose. All patients on both doses (n = 160) were treated for 72 weeks. Mean clinical global impressions of severity-TD (CGIS-TD) were measured every 12 weeks, as were safety assessments. After 48 weeks of treatment, 74.4% of patients taking 80 mg per day of valbenazine and 41.7% of patients taking 40 mg per day had a CGIS-TD score £2, and these results were sustained through week 72 of treatment. Of patients who had no suicidal ideation at baseline, 98.1 % continued to have no suicidal ideation at any time during treatment. Valbenazine was well tolerated and no new safety signals were observed.
Valbenazine is a selective vesicular monoamine transporter 2 (VMAT2) inhibitor and the first FDA-approved treatment for adults with tardive dyskinesia that is thought to work by reducing dopamine available in presynaptic regions. Valbenazine can be taken as 1capsule, once-daily, with other medications (eg, antipsychotics, antidepressants).