$7M grant rescues dog study investigating rapamycin for canine aging

Ted Katauskas’ 13-year-old wire-haired Labradoodle Halo, who was bred to be a service dog, has spent his entire life as a search-and-rescue dog in the mountains of Colorado.

So, it is fitting, his owner says, that Halo in his retirement is participating in the Dog Aging Project (DAP) helping researchers investigate rapamycin’s effects on canine health and aging.

The community science project, touted as a first-of-its-kind large-scale initiative, is back on track after a funding lapse in 2024 and speeding up enrollment with a new grant.

The longitudinal project, launched in 2019 with a five-year, $29 million grant from the National Institutes of Health’s National Institute on Aging (NIA), was in jeopardy in 2024 when funding was not renewed, said Dr. Kate Creevy, the project’s chief veterinary officer, in an interview with AVMA News.

So rather than continuing to rely on a single grant for the entire project, investigators pursued multiple funding avenues. This included a smaller, standalone grant for an expanded clinical trial researchers say could shed light on not just how to help dogs live longer and healthier but also holds implications for human aging as well.

Now armed with a five-year, $7 million grant from the NIA, DAP researchers are evaluating rapamycin—commonly used as an immunosuppressant in people after organ transplants—in the randomized, double-blind “Test of Rapamycin in Aging Dogs” (TRIAD) clinical trial, which first launched in 2021.

“We all want our dogs to live longer, healthier lives,” said Dr. Creevy, the study’s co-principal investigator and a professor at Texas A&M University College of Veterinary Medicine & Biomedical Sciences. “But the other thing that’s really important about TRIAD is that it’s another terrific example of how relevant veterinary medicine is to human health, and to the basic biology and science that we can learn about in diverse species.”

Clinical trial

TRIAD marks “the first rigorous test of a pharmacologic intervention against biological aging with lifespan and healthspan metrics as endpoints to be performed outside of the laboratory in any species,” according to the researchers’ methodology review, published February 14 in GeroScience, which details the study rationale, design, and goals.

The multicenter trial is still enrolling eligible, normally aging dogs at least 7 years old to receive oral rapamycin or a placebo for one year, followed by a two-year observation period.

Of its target enrollment of 580, the study has enrolled over 180 dogs so far, including a few like Halo that have already completed the three-year trial period since it first launched. With the latest funding, Dr. Creevy said they hope to speed up the process to finish enrolling by the end of the year to initiate medication by spring 2026.

The researchers hypothesized that a once-weekly, weight-adjusted low dose of rapamycin will extend the lifespan of mature or senior dogs—the study’s primary endpoint. A secondary endpoint includes improvements in physiologic health and age-related disease markers such as arthritis and kidney function.

If the study findings support their hypothesis, Dr. Creevy said it will shed light on the mechanisms of rapamycin at a molecular level. “We will be in a position to say why rapamycin improves healthy aging, not just that it did,” she said, adding that would be directly relevant to people because “all molecular pathways are the same.”

Drug mechanism

Long called the “universal anti-aging drug,” rapamycin is hailed as “one of the most promising geroprotective agents identified to date.”

Dr. Creevy said rapamycin helps suppress the immune system at high doses and modifies cellular energy processing at the low doses used in their study, which appeared to be well tolerated in previous DAP studies, with a limited side-effect profile.

Rapamycin, also known as sirolimus and sold under the brand name Rapamune, works by inhibiting the mTOR pathway, which is responsible for regulating metabolism and growth.

Dr. Creevy explained the mTOR inhibitor has a number of similar effects as the popular diet method, intermittent fasting, that causes cells to activate energy-preservation mode, improving cellular efficiency.

Translational potential

The TRIAD study is slated to conclude in November 2029, though Dr. Creevy noted they have only received the first-year portion of the multi-year grant.

As subsequent federal grant funding remains in limbo under the Trump administration, Dr. Creevy noted the study’s importance and potential translational significance.

“Given the translational relevance imparted by companion dog morphologic and genetic variability, risk for age-related disease, and diverse environmental exposures, the TRIAD randomized clinical trial will provide insight into the feasibility and utility of future studies designed to evaluate potential lifespan-prolonging interventions in human beings,” DAP investigators wrote in their methodology review. “It is our hope that the … trial will be a foundation for future pseudo-pragmatic clinical trial design, recruitment strategies, logistic implementation, and data analytic and integrative approaches. We anticipate that results will provide avenues for other geroscience interventions in animals and human beings, including non-pharmacologic, environmental, pharmacologic, nutritional, biologic, and gene- and cell-based therapies.”

Katauskas does not know if his Labradoodle received rapamycin or a placebo in 2023, but he knows Halo’s participation in the ongoing prospective study was “no question” to help fellow dogs, other pet owners, and veterinary research. “It really is kind of a full circle of life of service for this dog,” he said.