Neurocrine Reports Positive Phase 3 Data for Study of Valbenazine for Huntington’s Chorea

Neurocrine Biosciences reported positive top-line data from its phase 3 study evaluating the efficacy, safety and tolerability of valbenazine, a selective vesicular monoamine transporter 2 inhibitor being investigated as a once-daily treatment in adults with chorea associated with Huntington disease.

Photo: Eiry Roberts, chief medical officer at Neurocrine Biosciences

The study met the primary endpoint of reduction in severity of chorea, the cardinal motor feature in Huntington disease, as measured by change in the Unified Huntington’s Disease Rating Scale (UHDRS) Total Maximal Chorea (TMC) score from baseline to the average score at weeks 10 and 12.

Huntington disease (HD) is a hereditary progressive, ultimately fatal neurodegenerative disorder in which neurons within the brain break down, resulting in motor, cognitive and psychiatric symptoms. Symptoms generally appear between the ages of 30 to 50 and worsen over a 10- to 25-year period. Many people with HD experience chorea, a troublesome involuntary movement disorder, characterized by irregular and unpredictable movements affecting roughly 90 percent of those diagnosed with HD over the course of disease progression. Chorea can affect various body parts and interfere with motor coordination, gait, posture, swallowing, and speech. HD is estimated to affect approximately 30,000 adults in the United States, with more than 200,000 at risk of inheriting the disease.

In the randomized, double-blind, placebo-controlled KINECT-HD study, treatment with valbenazine resulted in a placebo-adjusted mean reduction in the TMC score of 3.2 units, indicating a highly statistically significant improvement in chorea. The TMC score is part of the motor assessment of the UHDRS and measures chorea in seven different body parts, including the face, oral-buccal-lingual region, trunk and each limb independently. The TMC score is the sum of the individual scores and ranges from 0 to 28. The secondary endpoints of Clinical Global Impression of Change (CGI-C) Response Status and Patient Global Impression of Change (PGI-C) Response Status were also statistically significant in favor of valbenazine treatment.

The treatment emergent adverse events observed in this trial were consistent with the known safety profile of valbenazine. No suicidal behavior or worsening of suicidal ideation was observed in the valbenazine-treated subjects in this study. Data from the phase 3 KINECT-HD study will be presented at a medical conference in 2022.

“The positive results of the KINECT-HD study move us closer to bringing valbenazine as a potential treatment option to patients in the U.S. living with chorea, one of the most common symptoms of Huntington disease,” said Eiry Roberts, chief medical officer at Neurocrine Biosciences. “We are immensely grateful to our partners at the Huntington Study Group and the Clinical Trials Coordination Center at the University of Rochester, New York, who were instrumental in completing this study, as well as the study participants and the families and caregivers who supported them.”

Neurocrine will review the complete data and begin preparing a supplemental new drug application (sNDA) for submission to the U.S. Food and Drug Administration in 2022. In the meantime, the company said it will continue dosing in the KINECT-HD2 study, which is evaluating the long-term safety and tolerability of valbenazine in this same patient population.

Author: Rare Daily Staff