An Investigational Treatment for Chorea Associated with Huntington Disease

Valbenazine, a selective vesicular monoamine transporter 2 (VMAT2) inhibitor, is thought to work by reducing the amount of dopamine released in a region of the brain that controls movement and motor function. VMAT2 is a protein in the brain that packages neurotransmitters, such as dopamine, for transport and release in presynaptic neurons. Valbenazine is novel in that it selectively inhibits VMAT2 with no appreciable binding affinity for VMAT1, dopaminergic (including D2), serotonergic, adrenergic, histaminergic or muscarinic receptors. Valbenazine is currently FDA-approved for the treatment of adults with tardive dyskinesia, an irreversible involuntary movement disorder, and may show similar benefits in addressing the motor symptoms associated with chorea in patients with Huntington disease.