Certain viruses cause disease, so we have created vaccines as a preventative measure against them. Similarly, it is clear that aging causes disease. But while pharmacy shelves are packed with supplements and lotions promising eternal youth, there are no approved drugs being sold in the US to delay the onset of aging and the inevitable diseases that come with it.
That paradox is at the heart of a debate raging between scientists—who believe they have anti-aging drugs that work in animals and could work in humans—and the US Food and Drug Administration (FDA), which regulates the sale of such drugs. On June 24, the FDA will hear the case for a clinical trial of a drug that can slow down the process of aging. If approved, it could set precedent for a swathe of drugs waiting to be trialled and brought to market.
The trial is called Targeting Aging with Metformin (TAME), where metformin is a drug that is already widely used to treat diabetes. But based on research in animals, Nir Barzilai of the Albert Einstein College of Medicine contends that metformin could also help delay the onset of cancer, heart disease, and cognitive impairment. (Its off-label use for this purpose is already common.)
And there are many other drugs that are probably even more promising than metformin sitting on labs’ shelves. Take rapamycin for instance. This naturally occurring chemical was found in the early 1970s, and it has since been used for treating fungal infections and suppressing the immune system for those receiving organ transplants, to prevent the body rejecting the organ. But in recent years it has been found to extend life in mice by slowing down aging, and is now considered the most promising candidate for an anti-aging pill.
But metformin has the upper hand because of its wide use and relatively fewer serious side-effects. The TAME trial aims to enroll 3,000 people aged between 70 and 80. It will last five to seven years and cost about $50 million. Despite all the promise of such an anti-aging drug, however, Barzilai doesn’t have the funding. And therein lies another paradox.
Drug repurposing—where an already approved drug for one disease could be approved to treat something else—looks attractive, but it is something that big pharmaceutical industries rarely invest in. That’s because most of the repurposed drugs have outlasted their patent protection. The company that makes the investment in the new trials does not get an exclusivity period in which to recoup the costs of the trial, and therefore can’t monopolize the profits from it for that time. This removes the incentive for a company to make the considerable initial investment required.
As the world gets older on average, there may come a point where pharmaceutical companies will see enough of a profit incentive to test and produce completely new, patentable, anti-aging drugs that target this aging population. Still, it would be sad if existing and possibly effective drugs, such as metformin and rapamycin, just remained on lab shelves, when they could have been extending people’s lives.