Researchers at Case Western Reserve University School of Medicine have demonstrated that bexarotene, an FDA-approved drug for the treatment of skin cancer, dramatically and rapidly clears amyloid plaques from the brains of mice bred with Alzheimer’s disease. Led by Gary Landreth, Ph.D., the study just published on line in Science Express, found that bexarotene not only enhanced clearance of beta amyloid, an abnormal protein associated with Alzheimer’s disease, but also improved some cognitive and behavioral functions. After discovering that Apolipoprotein E (ApoE), the main cholesterol carrier in the brain, facilitates clearance of beta amyloid, Landreth and his colleagues decided to explore the effectiveness of bexarotene for increasing ApoE expression and, thereby, facilitating reduction beta amyloid. Small soluble forms of beta amyloid are presently believed by the scientific community to cause the memory and other impairments seen in animal models of Alzheimer’s disease and in humans. Soluble amyloid levels fell by 25% within six hours of administering bexarotene, and by more than 50% at 72 hours.
Bexarotene appears to have the potential to help the 5.4 million Americans currently affected by Alzheimer’s disease, however, caution is warranted, as the study is very preliminary. As noted by Professor Landreth, “This is a particularly exciting and rewarding study because of the new science we have discovered and the potential promise of a therapy for Alzheimer’s disease. We need to be clear; the drug works quite well in mouse models of the disease. Our next objective is to ascertain if it acts similarly in humans. We are at an early stage in translating this basic science discovery into a treatment.”