Resolves YES if, by December 31, 2029, Loyal (or the FDA, via a Freedom of Information summary or an approval announcement) publicly reports that the STAY study met its pre-specified primary effectiveness endpoint for LOY-002 (for example a statistically significant improvement in lifespan or the study's primary healthspan/lifespan measure versus placebo). A report of interim safety, enrollment, or regulatory section acceptance alone does not count. Resolves NO if the study reports a failed primary endpoint, or if no primary result has been reported by the deadline. Background: STAY is Loyal's pivotal, double-blinded, placebo-controlled effectiveness study of LOY-002, a daily pill intended to extend healthy lifespan in dogs aged 10 and older weighing at least 14 lb, in 1,300 dogs at 70 US veterinary practices, with participation up to four years; enrollment completed in July 2025. Under the FDA's expanded conditional approval pathway the drug may be marketed before the pivotal study completes, so conditional approval (see the companion question) can come before this result. Companion question: Will the FDA conditionally approve a drug to extend lifespan or healthspan in dogs before January 1, 2028? Sources: https://loyal.com/stay https://loyal.com/posts/loy-002-tas https://w0lph.github.io/k9/trials/loyal-stay-loy-002.html /w0lph/will-the-fda-conditionally-approve

One step closer to a dog longevity drug: What LOY-002’s safety milestone means to a practicing vet

The FDA recently accepted the Target Animal Safety (TAS) submission for LOY-002, our drug in development for senior dog lifespan extension. Our Director of Veterinary Medicine, Brennen McKenzie, explains what this milestone means for senior dogs and the people who care for them.