SAN DIEGO (TheStreet) -- An experimental drug from Auspex Pharmaceuticals (ASPX) significantly reduced the incidence of uncontrolled movements in patients with Huntington's disease compared to a placebo, according to results from a phase III study announced Tuesday.
The Auspex drug, SD-809, is a chemically modified version of an older drug, tetrabenazine, currently approved to treat chorea (abnormal involuntary movements) associated with Huntington's disease, a genetic and fatal neuro-degenerative disease. Auspex designed SD-809's effect to last longer in a patient's body and to be better tolerated than tetrabenazine, which sees limited use in Huntington's patients because of the need for frequent dosing and relatively high side effects.
Auspex is expected to seek U.S. approval for SD-809 in the middle of next year based on the positive results from the placebo-controlled phase III study plus results from a separate study in which Huntington's patients were switched successfully from tetrabenazine to SD-809.
The phase III study enrolled 90 patients suffering from involuntary movements related to their Huntington's. None of the patients had been treated with tetrabenazine previously. The patients were randomized to receive 12 weeks of treatment with SD-809 once or twice daily or a placebo. The primary endpoint measures Total Maximum Chorea Score to assess the comparable reduction in involuntary movements between SD-809 and placebo.
As reported Tuesday, patients treated with SD-809 showed a 4.4-point improvement in Total Maximum Chorea Score compared to a 1.9-point improvement for patients treated with placebo. The 2.5-point benefit favoring SD-809 was statistically significant. Key secondary efficacy endpoints measuring quality of life and physical functioning also showed a statistically significant benefit for SD-809, Auspex said.