Rapamycin, its derivatives such as everolimus, and the cellular biology directly affected by this class of drug continue to be of interest to that part of the aging research community focused on modestly slowing the progression of aging. The regulatory situation in the US makes it far from straightforward to move matters towards clinic applications for aging, however, even putting aside the usual technical challenges and side-effect issues inherent in this sort of drug development. This is illustrated in the following popular science article:
Can a pill make you younger? One of the few drug studies ever carried out in an attempt to address this question was reported by Novartis on Christmas Eve 2014. The company had sought to see whether giving low doses of a drug called everolimus to people over 65 increased their response to flu vaccines. It did, by about 20 percent. Yet behind the test was a bigger question about whether any drug can slow or reverse the symptoms of old age. Novartis's study on everolimus, which looked at whether the immune system of elderly people could be made to act younger, has been called the "first human aging trial."
Last week a Boston company, licensing two drug molecules, and the right to use them against aging-related disease, from Novartis and making the research the basis of a startup company, resTORbio. The company says it will further test whether such drugs can rejuvenate aged immune cells. The drug Novartis tested is a derivative of rapamycin, a compound first discovered oozing from a bacterium native to Easter Island, or Rapa Nui, and named after it. Thanks to its broad effects on the immune system, rapamycin has already been used in transplant medicine as an immune suppressant.
What's even more interesting about rapamycin, however, is its reputation as the most consistent way to postpone death, at least in laboratory species. It lengthens the lives of flies, worms, and rodents, too. Feed the compound to mice and they live 25 percent longer, on average. A study is under way in Seattle to see if rapamycin extends the lives of pet dogs. What we don't have yet are formal studies of whether rapamycin or any other drug can lengthen people's life spans. For many reasons, companies haven't been keen to pursue potential anti-aging treatments. Scientifically, longevity pills remain an outré idea, the domain of cranks and quacks. Clinically, it's difficult to prove a drug extends life, as it would take too long. Regulation-wise, there's no clear path forward, as aging hasn't generally been recognized as a disease you can treat. But recently, venture capitalists who used to run from such ideas have begun investing.
Brian Kennedy, who researches aging at the Buck Institute, says the Novartis study was "groundbreaking" because of how it found a way to address the drug's impact on the effects of age. "No one has the stomach to do longevity studies. Or you can do what Novartis did, which is to choose a property of aging and see if you can slow it down." Novartis says it will soon be reporting more results from its studies in the elderly. But the company also decided that the research did not fit its priorities. "We will stop developing it for aging-related disorders. It's outside of our current strategy." The resTORbio startup will try to use the Novartis drugs to reverse what it calls "immunosenescence," or detrimental changes to the immune system that occur with age. In part, that might include trying to restore certain types of T cells, which become exhausted and don't remain vigilant against cancer and infections.