Poster Presentations

Session Title: Novel Pharmacological Compounds
Presentation Date: Thursday, March 12 – Friday, March 13 ,2009

THE SAFETY AND EFFICACY OF DIMEBON IN MILD-TO-MODERATE HUNTINGTON'S DISEASE: A MULTICENTER, PHASE 2, RANDOMIZED, PLACEBO-CONTROLLED TRIAL (DIMOND)

K. Kieburtz
University of Rochester, Neurology, Rochester, United States

Background: Dimebon is an investigational drug previously shown to improve cognition, behavior, and function in Alzheimer's disease. The most potent activity identified for Dimebon to date is the enhancement of mitochondrial function in the setting of neuronal stress, with a corresponding increase in cell viability and neurite outgrowth. This study evaluated the safety and tolerability of Dimebon in Huntington's disease (HD) and explored its effects on cognitive, motor, and behavioral symptoms.
Methods: Ninety-one patients with mild-to-moderate HD (TFC ≥ 5) enrolled at 16 centers in the US and UK were randomized to Dimebon 20 mg TID or placebo for a 90-day treatment period. The primary endpoint was safety/tolerability and secondary endpoints assessed change from baseline to Day 90 in UHDRS, ADAS-cog, and MMSE scores.
Results: A greater percentage of Dimebon patients completed the treatment period (87% vs. 82%) and a smaller percentage of Dimebon patients experienced adverse events (70% vs. 80%) compared to placebo. Treatment with Dimebon led to a significant improvement in cognition on the MMSE (1 point treatment difference, p = 0.03) and favorable trends on the UHDRS behavior component (p = NS). Dimebon did not affect other UHDRS components or the ADAS-cog. Subgroup analyses revealed a stronger treatment effect in more moderate (TFC < 10) and cognitively impaired (MMSE < 27) patients.
Conclusion: Dimebon was safe and well-tolerated in HD patients and may have a beneficial effect on cognition. Further study of the potential of Dimebon as a novel treatment for HD is warranted.