Three recent research studies have shown that the unconventional application of an on-the-market cancer drug as a treatment for Alzheimer’s disease was unfortunately too good to be true.
Alzheimer’s disease is the most common type of dementia – a persistently degenerative loss of cognitive function. Memory, language, judgment, reasoning, planning, and behavior and personality are affected as vital sectors of the brain deteriorate.
Bexarotene, tradenamed Targretin, is an oral antineoplastic agent specifically designated – by the US Food and Drug Administration (FDA) – for cutaneous T-cell lymphoma, and used as an off-label treatment for lung cancer, breast cancer, and Kaposi’s sarcoma (KS).
In February 2012, scientists at Case Western University Medical Center reported, in a study published in the journal Science, that Targretin cured a form of Alzheimer’s in a mouse model – eliminating the hallmark plaque, clumps of protein known as beta-amyloid, associated with the disease. The mice seemed to recover some cognitive ability.
Targretin was being seen as a possible miracle drug. However, naysayers argued the effectiveness of the drug on humans, the potential side-effects, and the exorbitant expense of the medication likely not to be covered by insurance – projected to cost patients $14,000 a year.
Trials were quickly established to screen the off-label application of the medication for Alzheimer’s in humans, but based on the anecdotal report several individuals prematurely jumped ahead and began requesting a prescription.
Disappointingly, independent scientists have been unable to replicate the original Science mouse-model results.
Alzheimer’s experts, Sangram Sisodia, a professor of neuroscience at the University of Chicago, Dr. Rudolph Tanzi of Massachusetts General Hospital in Boston, and Dr. David Holtzman of Washington University School of Medicine attempted to repeat the work in their own labs without success. Amyloid levels in the brains of mice treated with this compound were unaffected.
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