Latrepirdine, which failed in US clinical trials of Alzheimer’s disease, is showing new potential in an animal model.

The second of two studies on latrepirdine, recently published in Molecular Psychiatry, demonstrates new potential for the compound in the treatment of sleep disorders, Alzheimer’s disease, Parkinson’s disease, and other neurodegenerative conditions.

Latrepirdine was initially sold as an antihistamine in Russia, following its approval for use there in 1983. In the 1990s, the compound appeared effective in treating some of the earliest animal models of Alzheimer’s disease. In a high profile Phase II clinical trial in Russia, overseen by a panel of top US clinical trial experts, including Mount Sinai’s Mary Sano, PhD, professor of psychiatry and director of the Mount Sinai Alzheimer’s Disease Research Center, latrepirdine showed significant and sustained improvement in cognitive behavior in Alzheimer’s patients with minimal side effects. However, when the drug was tested in the United States in a Phase III trial, it did not demonstrate any improvement in people with the disease, causing the sponsors to halt further clinical study of the drug in Alzheimer’s disease.

Researchers are now testing whether latrepirdine might be beneficial in treating or preventing disorders associated with high levels of alpha-synuclein such as Parkinson’s disease, Lewy body dementia, and REM sleep disorder.