
New tricks: Loyal’s companion dog longevity study receives FDA protocol concurrence.
Loyal, a clinical-stage veterinary medicine company developing drugs intended to extend the healthspan and lifespan of dogs, has announced it has received protocol concurrence from the FDA for its companion dog longevity study.
Longevity.Technology: Loyal is on a mission is to help dogs everywhere live longer, healthier lives – and that means taking on the development of the first FDA-approved drugs explicitly intended to extend lifespan and healthspan. On the path to FDA approval, Loyal must run a clinical trial that objectively and robustly demonstrates that its drug extends dogs’ healthy lifespan – and does so safely. However, no-one has developed a dog – or human – longevity drug before, so Loyal is building the path to FDA approval largely from scratch.
Today, Loyal has announced that last week it learned from the FDA that the company has received protocol concurrence for its companion dog longevity study. This is good news for the longevity biotech sector, especially welcome as it comes on the same day that tech lender Silicon Valley Bank collapsed and was put under the control of the US Federal Deposit Insurance Corporation – news that left biotechs and VCs reeling.
Loyal’s protocol concurrence means the FDA has reviewed the scientific design of its study and determined that it meets their high quality standards, and will validate whether Loyal’s drug does indeed extend canine lifespan and healthspan.
In a nutshell, this means that if Loyal’s study demonstrates that its dog longevity drug extends healthy lifespan, those results will be sufficient to support bringing the drug to market for dogs across the US.
“Our concurrence means we fundamentally agree with your proposed design, execution, and analyses…” – FDA Center for Veterinary Medicine
Karen Greenwood, Loyal’s Senior Vice President, Regulatory & Strategy said: “This is a huge milestone for any drug company, but it’s especially significant because, to our knowledge, this is the first time the FDA has accepted a clinical study intending to show that a drug extends lifespan and healthspan, rather than only proving efficacy against a single, specific disease – which is the case with most drugs on the market today.
“Loyal was founded around the audacious idea that we should have drugs explicitly designed and FDA-approved to extend general healthy lifespan. With this milestone we take another big step in the direction of this vision.
“To achieve this milestone, we worked with scientists and statisticians at the Center for Veterinary Medicine (CVM) – the division of the FDA responsible for overseeing the medicines we give our pets – to interrogate and optimize our study design.
“We and the CVM have a shared interest in making sure our study is designed in a way that proves whether our products are effective and safe; both are paramount, scientifically and ethically.”
Of course, this concurrence is a milestone on the regulatory journey, and hard and careful work lies ahead. Clinical trials are complex, and although researchers strive to make scientific, evidence-based decisions in study design and treatments, the proof of the pudding is in the eating – how a drug will perform at scale in the real world won’t be known until the study is run.
“What looks promising and effective in a laboratory must in turn be proven in the field – the real world, where dogs live alongside us, and under the supervision of veterinarians in a clinical setting,” Greenwood explains.
“This is the purpose of clinical trials. If the study doesn’t deliver a positive outcome, we won’t – and shouldn’t – get approval.”

READ MORE: Loyal founder Celine Halioua talks about the inspiration behind her journey into aging science and why dog longevity has relevance in humans
Regardless of the subject, clinical studies are sometimes straightforward and sometimes complex, explains Greenwood, citing the example that a study to show whether a new flea and tick treatment works can take much less time to design and conduct, since there are many previous studies showing how to measure the efficacy of these drugs.
“Ours has been a much longer process – a total of 553 days, just over 18 months, from first discussion on the program to protocol concurrence,” explains Greenwood.
“We believe we’re the first to design and receive FDA concurrence for a clinical study that measures lifespan extension following treatment of the underlying causes of aging, rather than any specific disease.”
With myriad regulatory hurdles to jump, it might be wondered by Loyal is developing aging drugs, rather than dog aging supplements. After all, FDA approval is a rigorous, expensive, years-long process that sets a very high bar for both safety and efficacy, whereas supplements are under no such obligation, and their fine print often excludes the disclaimer that “These statements have not been evaluated by the FDA” whether the supplements are for dogs or humans.
Greenwood explains that the rigor and exacting standard applied to drug approval is exactly why Loyal is going down that route.
“While supplements may not hurt and might help your dog, there’s no process to regulate or validate the claims they make on their label, so you can’t be sure of a supplement’s safety or effectiveness,” she says.
“And for us, especially when our dogs are involved, that just isn’t good enough.”
Loyal is now actively recruiting veterinary practices across the country to run clinical trials later this year.