Did Pfizer "Hide" a Potential Treatment for Alzheimer's Disease?

Contributed by: Dennis Fortier, President, Medical Care Corporation _______________________________________________
Despite the provocative title, this post is largely a summary of a non-story. However, it is worth discussing because this "non-story" has been widely covered in the general media, often in a manner that leans strongly toward the sensational end of the news spectrum.

The facts are fairly non-controversial. Pfizer, a major pharmaceutical drug developer and marketer, performed an analysis of medical insurance data comprised of approximately 254,000 patients with rheumatoid arthritis or another inflammatory disease. The analysis revealed that, among those patients whose inflammatory disease was being treated with Enbrel, a drug marketed by Pfizer in the US, a slightly smaller percentage also had an Alzheimer's diagnosis compared to those who were not treated with Enbrel. Despite the seeming potential for Enbrel to prevent Alzheiemr's disease, Pfizer conducted further internal review and opted not to initiate a clinical trial for the purpose of measuring the efficacy of Enbrel in preventing Alzheimer's disease.

As far as I can tell, no one is disputing those facts. However, how those facts are interpreted has become a matter of creative reporting. One angle that has created a fair amount of reporting (initially in the Washington Post) suggests that, because Enbrel is nearly off patent, after which the drug will be far less profitable, Pfizer made a greedy decision and opted not to pursue a potentially promising Alzheimer's treatment. Most drug development experts disagree with that suggestion.

The noted statistical evidence of a preventative effect of Enbrel against Alzheimer's disease was far smaller than what the drug development industry would generally require before initiating a trial. Furthermore, the effects of anti-inflammatory drugs in the Alzheimer's space have been thoroughly investigated in other studies to no avail. Given that Enbrel does not cross the blood-brain barrier, it is fairly unlikely that a long and expensive trial (see previous summary here of FDA drug approval process) would yield a favorable outcome. In fact, another major marketer of pharmaceutical drugs (Amgen), who holds the rights to Enbrel outside of the US,  reviewed the same data and also concluded that further investigation was not warranted.

Overall, small statistical patterns are commonly present in large data sets like the one discussed here. However, such patterns are not necessarily indicative of an underlying treatment with a clinically meaningful effect. In the opinion of most knowledgeable scientists (as summarized here by Derek Lowe), Pfizer made a prudent decision not to further evaluate Enbrel as a potential treatment for Alzheimer's disease.

A better understanding and more awareness of Alzheimer's related issues can impact personal health decisions and generate significant impact across a population of aging individuals. Please use the share button below to spread this educational message as widely as possible. ____________________________________________________________

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