In April, 2017, valbenazine (Ingrezza™), developed by Neurocrine Biosciences, received its first global approval in the US for use in adults with tardive dyskinesia (TD). 
Valbenazine, dispensed as oral capsules, is a vesicular monoamine transporter 2 (VMAT2) inhibitor. It is believed to work by regulating dopamine release in the area of the brain associated with movement and motor function. The condition is commonly, but not exclusively iatrogenic, caused by chronic use of antipsychotic and antidepressant medications for the treatment of mental illness. According to one source TD is estimated to affect at least 500,000 people in the US.
Valbenazine was granted Fast Track, Priority Review and Breakthrough Therapy designations and is the first and only available treatment for TD, a condition resulting in uncontrollable, repetitive movements particularly in the face, trunk and extremities.
Mitchell Mathis, M.D., director of the Division of Psychiatry Products in the FDA’s Center for Drug Evaluation and Research said that TD was “…disabling and can further stigmatize patients with mental illness.” However, “approving the first drug for the treatment of tardive dyskinesia is an important advance for patients suffering with this condition.”
“Until now, one of the few options for physicians, when managing TD, was to stop, change or lower the dose of antipsychotic medication, potentially jeopardizing patients’ psychiatric stability,” said Christoph U. Correll, MD, Professor, Psychiatry and Molecular Medicine, Hofstra Northwell School of Medicine. He went on to describe the combination of effective performance in clinical trials and the convenient once-daily dosing as “a tremendous breakthrough for patients suffering from TD.”
Valbenazine is also under phase 3 investigation for TD in Canada, and under phase 2 investigation in the US for Tourette syndrome.
The labelling information for valbenazine carries warnings and precautions relating to somnolence, and QT prolongation. For the latter, advice is a dose reduction in patients who are poor CYP2D6 metabolisers and in those taking strong inhibitors of either CYP2D6 or CYP3A4, plus the complete avoidance of the agent in patients with congenital long QT syndrome or with arrhythmias associated with a prolonged QT interval.
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