A phase 3 clinical trial of tetrabenazine showed the drug to be effective in the treatment of chorea associated with Huntington's disease (HD). The results of the study presented at the 129th annual meeting of the American Neurological Association validated the treatment success that has been seen in Europe, Australia, and Canada. In a randomized, double-blind, placebo-controlled study of 84 patients with HD, patients received either tetrabenazine or a placebo for 12 weeks. The objective was to change baseline scores on the Unified Huntington's Disease Rating Scale, which is used to assess clinical elements.
After 12 weeks, the chorea score for the tetrabenazine group had decreased by 5 points, whereas the scores for the placebo group had decreased by only 1.5 points. Tetrabenazine also was proven to be superior to placebo on the Clinical Global Impression Scale, which assesses severity of illness and change in clinical condition. The drug's manufacturer, Prestwick Pharmaceuticals Inc, plans to file a New Drug Application with the FDA for tetrabenazine for use in the treatment of chorea in HD patients. If approved, tetrabenazine will be the first treatment of its kind in the United States.