Neurocrine Biosciences, Inc. announced that the U.S. Food and Drug Administration (FDA) has accepted its supplemental New Drug Application (sNDA) for valbenazine as a treatment for chorea associated with Huntington disease (HD). The agency set a Prescription Drug User Fee Act (PDUFA) target action date of August 20, 2023. The sNDA filing included data from the KINECT™-HD Phase 3 study and the on-going KINECT™-HD2 open-label study of valbenazine in adults with chorea associated with Huntington disease.

Huntington disease is a hereditary, progressive neurodegenerative disorder. Approximately 90% of adults with HD experience chorea, an abnormal involuntary movement disorder. The sNDA for valbenazine for the treatment of chorea associated with Huntington disease is supported by data from two clinical studies, including the Phase 3 KINECT-HD study and the on-going KINECT-HD2 open-label rollover study, with more than 150 patients with Huntington disease.

The KINECT-HD study was a Phase 3, randomized, double-blind placebo-controlled study to evaluate the efficacy, safety, and tolerability of valbenazine as a treatment for chorea associated with Huntington disease. Approximately 128 adults 18 to 75 years of age who had been diagnosed with manifest HD and who had chorea symptoms were enrolled in the study and received once daily valbenazine or placebo for 12 weeks. KINECT-HD2 is an open-label study of approximately 150 patients for continuing valbenazine administration for the treatment of chorea associated with Huntington disease for up to 156 weeks.

The primary endpoint in both studies was the change from baseline to maintenance in the Unified Huntington's Disease Rating Scale (UHDRS) Total Maximal Chorea (TMC) Score. Data from these studies along with the results from a PK study were included in the sNDA submission. Enrollment continues in the KINECT-HD2 open-label study to evaluate the long-term safety and tolerability of valbenazine for the treatment of chorea in Huntington disease.