Loyal Receives FDA Acceptance of Safety Package for Senior Dog Lifespan Extension Drug

Loyal, a clinical-stage animal health company developing lifespan extension drugs for dogs, has announced that the FDA’s Center for Veterinary Medicine (CVM) has accepted the Target Animal Safety (TAS) technical section of its conditional approval application for LOY-002, the company’s lead drug program to extend the healthy lifespan of senior dogs.

With the Reasonable Expectation of Effectiveness (RXE) and TAS sections now complete, LOY-002 has earned FDA-acceptance for two of three major technical sections required for market launch.

“Since founding Loyal six years ago, my goal has always been to get the first drug FDA approved for lifespan extension. This safety acceptance brings us very close to achieving that vision,” said Loyal Founder and CEO Celine Halioua. “We are well on our way to bringing the first dog longevity drugs to market.”

The First Longevity Drug for Dogs

LOY-002, a prescription daily pill, aims to extend the healthy lifespan of senior dogs and maintain their quality of life as they age by proactively targeting the underlying metabolic drivers of aging and delaying the onset of disease. If approved, LOY-002 stands to be the first FDA-approved drug for lifespan extension itself in any species.

Acceptance of both TAS and RXE are strong advances in Loyal’s pursuit of FDA Expanded Conditional Approval (XCA), a new regulatory pathway that allows innovative therapies that fill unmet medical needs to come to market sooner. The FDA’s acceptance of LOY-002’s TAS submission represents the first known safety acceptance for a lifespan extension drug from the FDA.

As part of the TAS package, Loyal submitted scientific evidence from multiple studies to support LOY-002’s safety profile. This included a standard safety study as well as additional field safety data from over 400 dogs on LOY-002 from the program’s pivotal effectiveness trial, the STAY study. The FDA has agreed that LOY-002’s data supports its safety for the proposed conditions of use.

“As a veterinarian, what I care about most, especially when it involves preventive care, is safety,” said Dr. Ellen Ratcliff, Loyal’s VP of Clinical and Veterinary Medicine. “The FDA’s sign off on this submission is an important vote of confidence in our mission to develop safe and effective lifespan extension drugs for dogs.”

TAS completion follows on several milestones for LOY-002 in the past year, including the FDA’s acceptance of RXE in February 2025. Loyal also completed enrollment for LOY-002’s pivotal efficacy trial, the STAY study, in July 2025. At 1,300 dogs across 70 veterinary clinics, it’s the largest clinical trial in the history of veterinary medicine. Loyal expects to complete the final major technical section and apply for XCA next year.