Neurocrine Reports Phase 3 Data Evaluating Valbenazine for Huntington’s Chorea

Rare Daily Staff

Neurocrine Biosciences reported results from the phase 3 KINECT-HD study, which demonstrated once-daily administration of valbenazine was associated with significant improvement in chorea associated with Huntington disease compared with placebo.

These data will be shared as an oral presentation during the Emerging Science Session at the American Academy of Neurology (AAN) 2022 “Great Neuro Reunion” annual meeting in Seattle, Washington.

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. Chorea can affect various body parts and interfere with motor coordination, gait, posture, swallowing, and speech. HD is estimated to affect approximately 40,000 adults in the United States, with more than 200,000 at risk of inheriting the disease.

“Presentation of these positive data of valbenazine for chorea in Huntington disease represent a major step forward in our commitment to offering the community a potential new treatment option,” said Eiry Roberts, chief medical officer at Neurocrine Biosciences. “Data from the KINECT-HD and the ongoing KINECT-HD2 study will form the basis of our supplemental new drug application (sNDA) for submission to the U.S. Food and Drug Administration later this year.”

KINECT-HD is a phase 3, randomized, double-blind, placebo-controlled study designed to: evaluate the efficacy of valbenazine as a once-daily treatment to reduce chorea associated with Huntington disease (HD) and evaluate the safety and tolerability of valbenazine in patients with HD. The study enrolled 128 adults 18 to 75 years of age who have been diagnosed with motor manifest HD and who have sufficient chorea symptoms to meet study protocol criteria.

The study met its primary endpoint of change in chorea severity using the TMC score of the Unified Huntington’s Disease Rating Scale (UHDRS) from screening period baseline to maintenance period. Improvement in the TMC score was significantly greater with valbenazine versus placebo, with a placebo-adjusted mean reduction of 3.2 units vs placebo. Improvements in the TMC score with valbenazine were seen as early as Week 2, and TMC scores continued to improve versus placebo throughout the dose adjustment and maintenance periods.

The secondary endpoints of Clinical Global Impression of Change (CGI-C) Response Status and Patient Global Impression of Change (PGI-C) Response Status also significantly favored valbenazine treatment. Patients achieving “much improved” or “very much improved” status were classified as responders. Using this classification, at Week 12, the response rate in the valbenazine group was 42.9 percent for CGI-C compared to 13.2 percent in the placebo group. The response rate at Week 12 for PGI-C was 52.7 percent in the valbenazine group and 26.4 percent in the placebo group. Response rates favoring valbenazine were seen as early as Week 4 for CGI-C and Week 2 for PGI-C. The secondary endpoints of Neuro-QoL upper and lower extremity physical function endpoints at Week 12 were not significantly different between the treatment groups.

Treatment emergent adverse events, including somnolence, fatigue, fall, and akathisia, were mild to moderate and 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.

“We are pleased with this data readout and are grateful to the patients and collaborators who have helped to advance this potential treatment,” said Andrew Feigin, M.D., Chief Medical Officer of the Huntington Study Group (HSG) Clinical Research, Inc., former chair of HSG, and Professor, Department of Neurology at NYU Grossman School of Medicine. “We remain committed to this patient community as we look to further our scientific understanding of the efficacy and safety of valbenazine for chorea associated with Huntington disease in the long-term trial.”

The full data results from the KINECT-HD study will be submitted to a peer-reviewed journal later this year. The safety and tolerability of valbenazine in chorea associated with Huntington disease continues to be evaluated in KINECT-HD2, an open-label long-term safety and tolerability study.

Photo: Eiry Roberts, chief medical officer at Neurocrine Biosciences