VMAT2 is a protein concentrated in the human brain that is primarily responsible for re-packaging and transporting monoamines (dopamine, norepinephrine, serotonin, and histamine) among nerve cells. NBI-98854, developed in the Neurocrine laboratories, is a novel highly selective VMAT2 inhibitor that is effective in regulating the levels of dopamine release during nerve communication, while at the same time having minimal impact on the other monoamines thereby reducing the likelihood of "off target" side effects. NBI-98854 is designed to provide low, sustained, plasma and brain concentrations of the active drug to minimize side effects associated with excessive dopamine depletion.

The next step for this VMAT2 development program is to complete a multiple, repeated dose Phase 1 study in healthy male volunteers after approval of the Canadian CTA submission. Once complete, Neurocrine will approach the FDA regarding the filing of an Investigational New Drug application in the United States with the express purpose of initiating the proof-of-concept study in patients with Tardive Dyskinesia late in 2010. In addition, NBI-98854 may well be useful in other disorders, such as Huntington's chorea, schizophrenia, Tourette's syndrome, and tardive dystonia.