Rapamycin, a drug that suppresses the immune system and helps prevent organ rejection, is fast becoming the hottest chemical in medicine. (The drug also goes by the name sirolimus.)
New research into Alzheimer's is going to make it hotter, and spark new debate.
Veronica Galvin at the Texas Health Science Center in San Antonio says she successfully curbed symptoms of Alzheimer's in mice using the drug. A second group, working at the same center, did the same thing using another mouse model for Alzheimer's.
Sounds great. But wait, there's more. This comes a year after Nature published a study showing mice fed rapamycin late in life actually lived longer.
Back then The Wall Street Journal ran an interesting piece noting that the compound was first found on Easter Island, secreted by bacteria seeking to fend off rivals. It said the compound was closely related to some cancer drugs then going through testing. (It's also being looked at in Huntington's Disease.)
There is enormous speculation about how this can be true. One theory published in Time is that it actually mimics the calorie-restricted diet some now advertise as a life-extender, increasing cellular efficiency.
Now before the old druggie in you starts looking for a connection to fix you up with some of this stuff, wait.
- This stuff has some nasty side effects. Like a low platelet count, which means your blood may have trouble clotting. It can raise cholesterol and other blood fats, resulting in arterial disease.
- The work is being done through a government testing program that is looking at all sorts of substances -- green tea, aspirin, resveratrol, and statins among them -- as life extenders. Some of the results may be wishful thinking.
Rapamycin is one of a class of drugs called mTOR inhibitors, which drug companies have long pushed for late stage cancers. Its maker, Pfizer, trails rivals Novartis and Roche in testing these drugs on cancer, which may have led to its testing for other things. (Pfizer's brand name for it is Rapamune.)
This sort of thing happens with drugs. Much of the time, initial excitement turns to disappointment, sometimes when studies on rodents don't play out on people, sometimes when side-effects are found, sometimes not until the drug is on the market and it gets its real test.
This is a drug that was originally thought to be an anti-fungal agent, then used on drug-coated stents. Now it's supposed to cure cancer, prevent Alzheimer's and extend your life by as much as 15 years?
Extraordinary claims. Wait for extraordinary proof.