Neurocrine Biosciences (NASDAQ:NBIX) announced on January 26, 2026, the initiation of its Phase 2 clinical study for NBI-1065890, an investigational compound targeting tardive dyskinesia (TD).
The study marks a strategic push to evolve the company's leadership in the VMAT2 (vesicular monoamine transporter 2) space, where it already holds a dominant market share with its blockbuster drug, Ingrezza (valbenazine).
NBI-1065890 is described as a highly selective VMAT2 inhibitor with distinct chemical and physical properties.
While existing treatments like Ingrezza have revolutionized the field, Neurocrine's goal with this new candidate is to offer a "potentially differentiated profile," including the possibility of longer-acting dosing options.
By inhibiting VMAT2, these drugs reduce the amount of dopamine that is packaged into vesicles and released into the synaptic cleft.
In conditions like tardive dyskinesia—which is caused by long-term use of dopamine-blocking antipsychotics—this reduction in synaptic dopamine helps calm the uncontrollable, repetitive muscle movements characteristic of the disorder.
The newly initiated study is a randomized, double-blind, placebo-controlled trial expected to enroll approximately 100 adults with TD.