Many clinical trials for Alzheimer's Drug failed recently.  Dimebon (Latrepirdine) is one of them.

The drug latrepirdine, known as Dimebon, has been featured in two studies previously published in the journal Molecular Psychiatry.The second study showed that latrepirdine could serve as treatment for Alzheimer’s disease, Parkinson’s, as well as other neurodegenerative conditions.

Led by researchers from Mount Sinai School of Medicine, the drug was tested in three different systems (yeast cells, mice cells, and mammal cells), and each system had an accumulation of alpha-synuclein, a protein that causes neurodegeneration. In all three systems, latrepirdine was able to trigger autophagy, a homeostatic process by which the cells break down their own components. The autophagy decreased the amount of synuclein that built up in the mice’s brains.

In the first study, the researchers found that the drug, by activating autophagy, was able to stop the accumulation of beta-amyloid in the brains of mice with Alzheimer’s disease, and their memories also improved. In addition, it was found that the yeast cells were protected by latrepirdine from the toxicity of alpha-synuclein.

Latrepirdine was approved by Russia in 1983 to be sold as an antihistamine in the country. After being effective in treating animal models with Alzheimer’s disease in the 1990s, it underwent a large Phase II clinical trial in Russia with results showing that it significantly improved cognitive function in Alzheimer’s patients with minimal side effects and was able to maintain that improvement. A Phase III clinical trial was carried out in the United States, but there was so sign of improvement in the Alzheimer’s patients.  Scientists now believe that the trial failed “because of a lack of understanding of how latrepirdine works”.

Currently, the researchers are seeing if the drug can help treat or prevent Parkinson’s disease, Lewy body dementia, etc, all of which are disorders related to high levels of alpha-synuclein.

Sources: http://www.medicalnewstoday.com/articles/248956.php

http://scienceblog.com/56074/drug-reject-may-protect-against-alzheimers-parkinsons-diseases/

Keywords: drug; latrepiridine; alpha-synuclein; Alzheimer’s disease; Parkinson’s disease; research

Wendy Liu

August 14, 2012