Medivation has declared  top-line results of a Phase 2 study showing that its investigational drug Dimebon(TM) significantly improved cognitive function in patients with mild-to-moderate Huntington's disease (HD).

Medivation, Inc. is a biopharmaceutical company focused on the rapid development of novel small molecule drugs to treat serious diseases for which there are limited treatment options. 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 is an orally-available small molecule that has been shown to inhibit brain cell death in preclinical models relevant to Alzheimer's disease and Huntington's disease, making it a potential treatment for these and other neurodegenerative diseases.

Huntington's disease is a progressive, neurodegenerative disease. 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 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. Full results from the Phase 2 study will be submitted for presentation at an upcoming scientific meeting.

It is caused by the death of specific brain cells and is characterized by the gradual development of involuntary muscle movement, progressive deterioration of cognitive processes and memory (dementia) and severe behavioral disturbances. There are currently no drugs approved by the U.S. Food and Drug Administration to treat this uniformly fatal genetic disorder.

 The Company is currently enrolling patients in an international confirmatory Phase 3 clinical trial evaluating the efficacy and safety of Dimebon in patients with mild-to-moderate Alzheimer's disease. Preclinical data generated to date suggest that Dimebon operates through a novel mitochondrial mechanism of action.