Medivation Announces Positive Top-Line Results From Phase 2 Dimebon Study in Huntington's Disease
News Jul 09, 2008
Medivation, Inc. announced top-line results of a Phase 2 study showing that its investigational drug Dimebon™ significantly improved cognitive function in patients with mild-to-moderate Huntington’s disease (HD).
Cognitive function was significantly improved over placebo (p=0.03) as measured by the Mini-Mental State Examination (MMSE), the cognition scale most widely used by clinicians to assess patients with neurodegenerative diseases.
Dimebon-treated patients also demonstrated favorable results on the behavioral component of the United Huntington’s Disease Rating Scale (UHDRS), a composite scale measuring several components of HD, but these results did not reach statistical significance.
Dimebon was very well tolerated in this trial. The overall incidence of adverse events was lower in the Dimebon group than in the placebo group, an unusual finding in a clinical study of any drug.
This result is consistent with a similar finding from the first pivotal Alzheimer’s disease trial in which Dimebon-treated patients had significantly fewer serious adverse events after one year of treatment.
Of particular note, Huntington’s disease patients treated with Dimebon had fewer falls (9%), a common problem in this patient population that often results in injury and associated health care costs, than did patients on placebo (16%).
The most common adverse event in the Dimebon group was headache, which occurred in 19% of treated patients compared to 7% of placebo patients. Headaches were generally mild in severity. Dry mouth and depressed mood were similar in both treated and placebo groups (4% and 7%, respectively).
The randomized, double-blinded, placebo-controlled Phase 2 trial was conducted at 16 centers in the United States and the United Kingdom in collaboration with the Huntington Study Group (HSG), a network of more than 250 experienced clinical trial investigators, coordinators and consultants from more than 60 academic and research institutions throughout the United States, Canada, Europe and Australia dedicated to clinical research of Huntington’s disease.
The trial enrolled 90 HD patients, with half randomized to Dimebon and the other half to placebo for a three-month dosing period. The primary endpoint of the trial was safety and tolerability.
The secondary endpoint was efficacy, as measured by the MMSE, the UHDRS and the Alzheimer’s Disease Assessment Scale-cognitive subscale (ADAS-cog), a cognition scale generally used in Alzheimer’s disease clinical trials.