Ellen Ratcliff, DVM

Welcome to the latest update on the STAY study! I’m Dr. Ellen, veterinarian and VP of Clinical and Veterinary Medicine at Loyal. 

I came to Loyal over 4 years ago with a background in the Army Veterinary Corps and mixed animal clinical practice. I traded in days full of treating creatures of all shapes and sizes – from pigs and cats to tigers and beavers — for the ambitious goal of helping our beloved furry canine family members live longer and healthier lives through the development of safe and effective medications. 

I could never have imagined the mission-motivated excitement that would fill the years to come working on FDA approval for lifespan-extending drugs. Lucky me, I had the privilege of problem-solving with the Loyal team to design a clinical trial for lifespan extension – the STAY study. Spoiler alert, it’s not simple (and I reckon that’s why not everybody does it). ;)

How it started — the design of LOY-002 and the STAY study

Our team of scientists, veterinarians, and dog lovers (omg, do these folks love dogs!) researched the very best ways to lengthen the period of time that dogs are healthy — also known as healthspan. Tapping into that knowledge, they then worked to identify a pharmaceutical solution that targets the metabolic dysfunction that occurs in dogs as they age with the goal of making senior dogs live longer, healthier lives.

We now know that product as LOY-002, which we’re testing in the STAY study. LOY-002 aims to mimic the positive effects of 

, which is one of the only proven mechanisms in scientific literature to increase lifespan in dogs. We believe that increasing insulin sensitivity and changing the adipose tissue dysfunction and redistribution that happens in aging dogs will also keep them healthier longer and, therefore, help them live longer and feel better. 

The STAY study is the culmination of many years of research and commitment by everyone at Loyal. But when it comes to actually running this clinical trial? I have to give mad props to the team near and dear to my heart who work so tirelessly to make this study come to life. Sincere shout out to our small, but mighty, clinical operations team. No, running a lifespan extension study is not easy. But they are doing it and doing it well, y’all!

The STAY study is different from most clinical studies

Part of what has been so exciting for us about the STAY study is how different it is. Yes, it’s the first-ever longevity trial of its kind, but it also represents something newer, bigger, and better in clinical veterinary medicine. For example, the average clinical trial in veterinary medicine has a fraction of the number of animals and study sites. They tend to be much smaller, target a specific disease process, and are significantly shorter. 

At Loyal, however, we like to do things differently. While most vet clinics expect clinical studies to be a few months long and enroll less than a hundred dogs, we’re looking to enroll over 1,000 dogs at approximately 70 sites nationwide and study them for approximately four years. We believe it’s the largest study seeking FDA approval in animal health history. Many logistical and operational hurdles associated with the scope and duration of this study make it really unique, and I’m pretty proud we found a pathway forward to accomplish this. 

Baylor, Dog #565, is a 10-year-old Boxer mix enrolled by Dr. Sam Geller at Quakertown Veterinary Clinic.

As a bit of background, the STAY study is the pivotal effectiveness study for the medication we call LOY-002. Pivotal studies are the final step required to get a drug approved by the FDA’s Center for Veterinary Medicine, and they are meant to fully demonstrate that the drug is safe and effective in the target population. 

These studies are scientifically rigorous, which means the study is double-blinded and placebo-controlled. Because of the blinding, nobody knows if enrolled dogs are in the group getting the LOY-002 drug or the placebo. At the end of the study, statisticians will compare lifespan (as well as frailty and quality of life) between the two groups of dogs.

The study has been enrolling dogs for over 10 months now, starting with Boo, the 10-year-old whippet, back in December of 2023. (You can read more about Boo 

!) The study is currently making strong progress, being brought to life in over 60 veterinary clinics across the US. We consider our Principal Investigators (or as we call them, PIs) to be our friends and allies in the execution of the STAY study. We depend on them and their veterinary clinics to be the boots-on-ground movers and shakers. So what are they saying about partnering with us to make sure the STAY study is a success? 

Dr. Samuel Geller from Quakertown Veterinary Clinic is one of the OG PIs to enroll his practice in the clinical trial. He said, “When you look at the topic that STAY is addressing, ‘how can we get our pets and our loved ones to live longer, happier lives?’ That’s a pretty easy decision.

How have we found ways to manage the complexity of such a large and long study? We looked for opportunities to make enrolling dogs easier for both the PIs and the dog owners. The STAY study is using some novel approaches to overcome the hurdles of running a clinical trial in veterinary medicine, like directly shipping the study drug to the dog owner's home. 

Dr. Alex Cardascio from Northgate Pet Clinic said, “STAY is different because of the ease of having people who live far away. Our clinic is in Central Illinois, and so we have a few people from Missouri and our Chicagoland area [participating]. Being able to distribute the meds in the mail and making that as easy as possible has been great for this study.” 

And I love seeing the impact that this is having across the country and how excited the dog owners participating in the study are. We  are constantly in awe of the commitment to the scientific process that study participants share with us. Wagner, a 13-year-old (and very social) Cavapoo enrolled at Country Oaks Veterinary Clinic in Florida, joined the trial back in February. His mom said, “[We joined] because I believe in advancing medicine and helping where I can… and it wouldn’t hurt to keep Wagner around longer!”

Wagner, Dog #32, is a 13-year-old Cavapoo enrolled in the STAY study at Country Oaks Veterinary Clinic.

You can help give dogs longer, healthier lives!

The good news is that while we are well on our way to achieving our enrollment goals, the study is still recruiting dogs, and we would love your help! Dogs 10 years old or older that weigh at least 14 pounds may be eligible to participate. 

If you’re a veterinarian interested in getting involved in clinical trials - I’m your gal. Reach out to me and my team at 

, and let me tell you what it means to be a PI in such a landmark study (or see this 

I wrote that explains why I think general practitioner veterinarians should get in on this kind of research). If you have a best friend dog that meets the study requirements and you’re interested in getting involved in the study, give our 

 a look and see if there’s a clinic near you. 

How’s the STAY study going? Here’s an update from the vet who designed it.