The fountain of youth is going to the dogs. At least that’s the case in Seattle, where biogerontologists Matt Kaeberlein and Daniel Promislow at the University of Washington have given local pet owners the chance to have their dogs test an experimental antiaging drug. Owners offered up more than 1,000 pooches, and the researchers selected 32 to participate in the study, set to begin this spring.
The drug they’ll be taking, rapamycin, wasn’t originally intended to extend canine longevity—it’s often used as an immunosuppressant, typically prescribed to people who have had an organ transplant. But rapamycin also blocks a gene called mTOR, which (among other things) causes cells to age and break down more rapidly. Several years ago, when scientists began feeding rapamycin to mice, they found that the rodents lived about 10 percent longer than control groups. That naturally evoked visions of (human) Florida retirees sipping rapamycin milk shakes, a scenario drug companies would already be fast-tracking toward reality if only rapamycin were still protected intellectual property. But the substance is off-patent, taking huge profits off the table. (You might still be able to patent the milk shake formulation, but you couldn’t stop competitors from making rapamycin lollipops.)
Call in the K9 squad! Millions of dog owners—including Kaeberlein and Promislow, who own a German shepherd, a keeshond, a Weimaraner, and a Chow mix between them, though none of their dogs are eligible for the study—are eager to give their pets an extra few years. Since most competent human masters can administer meds and provide some daily monitoring, researchers can crowdsource a lot of the data collection. Furthermore, the dog lifespan is so short (awww) that they can provide relatively rapid returns on research.
That’s a juicy bone for dogs and their best friends, but what’s really at stake is nothing less than a revolution in drug testing. Kaeberlein and Promislow have effectively unleashed a practical way to research new human uses for out-of-patent drugs. Pets can provide a cheap alternative to pricey and chancy human clinical tests, key when you’re dealing with a drug that might not be especially profitable in the first place. It’s easy to extend the idea beyond rapamycin. Testing experimental drugs on pets is a potential new template for human medical research: Such experiments on pets would be less expensive than testing drugs on lab animals but still statistically valid, since the greater number of test subjects would override the quirks of homestyle observation. And dogs are genetically diverse, another plus. It would also be more humane, since dogs are more frolicsome at home than in a kennel.
By making drug studies more affordable, this approach would allow pharmaceutical companies to profit from old or unpatentable drugs. Researchers could test other potential antiaging chemicals on dogs with the hope that they could one day invigorate people.
And researchers could enlist pets to investigate more targeted benefits of rapamycin as a treatment for specific human ailments. The drug can reverse cardiomyopathy in mice; as a step toward helping people, Doberman pinschers—a breed that’s naturally susceptible to a version of the disease—could serve as guinea pigs. (A study like this might require more veterinary participation, as the average pet owner isn’t going to have the wherewithal to administer a slate of cardiovascular tests.)
Dogs have other opportunities to give old drugs new tricks: Growing evidence suggests that the out-of-patent diabetes medicine metformin may have unexpected benefits for cancer patients. For example, diabetic men on metformin are less likely to die of prostate cancer than those taking other diabetes drugs. Those studies are retrospective, meaning that they analyze preexisting data. A metformin study on golden retrievers—a breed prone to cancer—could draw funding from golden retriever clubs and provide clinical data crucial to future human prescription.
Kaeberlein and Promislow are wary about treating people’s pet dogs as lab rats. Both insist that their motivation is to improve dogs’ lives; human benefits come second. Their respect for Fido’s well-being is laudable, but that’s nothing a clinical review board can’t handle. What would be irresponsible would be to lose the chance to help people.
Dogs share our lives. They live in the same environments as we do, and they’re exposed to many of the factors that most affect our health, from bad food to secondhand smoke. Testing drugs on them is a realistic way to try out pharmaceuticals that might otherwise get ignored. After all, if our dogs start living forever, we’re going to need to be around to walk them.