Already approved cancer drugs reverse Alzheimer's? Maybe...

It's not unusual for a drug previously approved for treatment of one condition to be found to also treat something different.  Like many men my age, I take tamsulosin for my prostate, which was originally developed as a treatment for high blood pressure.  Tamsulosin is one of the α1‐blockers, most of which reduce blood pressure.  But that didn't work out in this case.  It was later found to treat benign prostatic hyperplasia (BHP), which makes older men get up a lot during the night.  So, in 1997, it was approved for BHP and not for hypertension.

So what about Alzheimer's?  Are there drugs already approved for some condition that would coincidentally treat Alzheimer's disease?  And treat it effectively?  Suppose we sifted through some massive data base of case histories and look for people who received this or that treatment and then showed improvement in Alzheimer's symptoms?

Well, someone did that, and the results were remarkable.  According to this research, published in the journal Cell, there are two drugs approved for the treatment of cancer that can reverse Alzheimer's symptoms.  The drugs were letrozole and irinotecan.  (Letrozole, like all drugs, has significant side effects, but it looks like irinotecan can be downright nasty.)

The drugs were first identified by analyzing an array of drugs for a "signature" on how they affected the generation of proteins in the brain.  The researchers then looked for correlations with Alzheimer's improvements in a database of case histories.  They then set about testing the drugs on mice.  (Yep, mice again.)  And, well, it checked out.  At least with the mice.

With the mice, the two drugs reversed multiple aspects of Alzheimer’s disease.  They undid the protein signatures in brain cells that are seen as the disease progresses.  They reduced both the formation of amyloid plaques and tau tangles seen with brain degeneration. And -- the most important thing -- they restored memory. 

So that's mice.  But where do we go from here?  Here's an article about the study.  They are, of course, quite excited about results with mice, but there's nothing about carrying this forward with people.  I sure hope something is going on with this.