Huntington's disease: Latrepirdine appears well-tolerated and beneficial

A medication previously studied in patients with Alzheimer's disease (latrepirdine) appears well tolerated and may improve thinking, learning and memory skills among individuals with Huntington's disease, according to a report in the February issue of Archives of Neurology, one of the JAMA/Archives journals.

"Huntington's disease is a hereditary neurodegenerative disorder that affects movement, behavior and cognition and leads to death within 20 years of disease onset," the authors write as background information in the article. "Cognitive [thinking, learning and memory] impairment occurs early in the disease and deteriorates as Huntington's disease progresses, contributing to loss of ability to work and perform activities of daily living." The only approved therapy for Huntington's disease, tetrabenazine, treats only motor symptoms and does not alter the course of the disease or prevent cognitive decline.

Abnormalities in mitochondria, parts of cells that help convert food into energy, have been implicated in the development of Huntington's disease. The synthetic molecule latrepirdine stabilizes and improves mitochondrial function, and has been studied as a way to improve cognitive, behavioral and functional outcomes in patients with Alzheimer's disease. Karl Kieburtz, M.D., M.P.H., of the School of Medicine and Dentistry, University of Rochester, N.Y., and colleagues assessed the safety and tolerability of latrepirdine among 91 participants with mild to moderate Huntington's disease at enrollment (2007 to 2008).

For 90 days, 46 patients were randomly assigned to take 20 milligrams of latrepirdine three times daily and the other 45 took a matching placebo. The medication was well tolerated (87 percent of the patients given latrepirdine completed the study, compared with 82 percent in the control group) and adverse event rates were similar between the two groups (70 percent in the treatment group vs. 80 percent in the placebo group).

In addition, the treatment resulting in improved average scores on an evaluation measuring overall cognitive function. Scores of individuals in the placebo group remained steady over the study period.

"Taken together, our data suggest that latrepirdine, at a dosage of 20 milligrams three times daily, is well tolerated for 90 days in patients with Huntington's disease and may have a beneficial effect on cognition," the authors conclude. "Future studies of latrepirdine are planned to further evaluate the effect of latrepirdine on the cognitive and behavioral symptoms of Huntington's disease."