In a study appearing in the July 5 issue of JAMA, Samuel Frank, M.D., of Harvard Medical School, Boston, and the Huntington Study Group, and colleagues evaluated the efficacy and safety of the drug deutetrabenazine to control a prominent symptom of Huntington’s disease, chorea, which is an involuntary, sudden movement that can affect any muscle and flow randomly across body regions. Chorea can interfere with daily functioning and increase the risk of injury.
The drug tetrabenazine is the only U.S. Food and Drug Administration-approved therapy for treating chorea associated with Huntington’s disease. Despite established efficacy, tetrabenazine often requires 3-times-a-day dosing, and there may be some peak concentration-related neuropsychiatric symptoms, such as sedation, fatigue, anxiety or nausea. For this study, 90 adults diagnosed with Huntington’s disease and a certain level of chorea were randomly assigned to receive deutetrabenazine (n = 45) or placebo (n = 45). Deutetrabenazine or placebo was titrated to optimal dose level over 8 weeks and maintained for 4 weeks.
The researchers found that deutetrabenazine treatment significantly improved chorea control as measured by a chorea score. Significant improvement was also observed on measures of impression of change and physical functioning, although no improvement was observed on a balance test. Adverse event rates were similar for deutetrabenazine and placebo, including depression, anxiety and akathisia (a movement disorder).
The authors note that the difference in total maximal chorea score associated with deutetrabenazine treatment that was observed in this study is notable given the progressive decline in total maximal chorea score and total motor score that has been previously described as part of the natural history of Huntington’s disease.
“Further research is needed to assess the clinical importance of the effect size and to determine longer-term efficacy and safety.”