FDA Accepts Efficacy for Loyal's LOY-002, Paving Way for Canine Longevity Pill by 2026

San Francisco, CA – Loyal, a biotech company focused on extending canine healthy lifespans, is on track to introduce a pill designed to make dogs live longer, potentially hitting the market by 2026. This development follows the U.S. Food and Drug Administration's (FDA) Center for Veterinary Medicine accepting the "Reasonable Expectation of Effectiveness" (RXE) for Loyal's LOY-002, a drug targeting senior dogs. Ashlee Vance, in a recent social media post, highlighted this as a "big deal for many reasons," noting the involvement of Loyal and CEO Celine Halioua.

LOY-002, a daily pill, is specifically developed for senior dogs aged 10 years or older and weighing at least 14 pounds. It aims to extend healthy lifespan by addressing age-associated metabolic dysfunction, a core driver of unhealthy aging. Loyal announced in February 2025 that LOY-002 completed its preliminary efficacy package, a critical step towards conditional FDA approval anticipated in 2026.

Loyal, founded by Celine Halioua, is also advancing two other longevity therapies. LOY-001, an injectable, and LOY-003, a daily pill, are designed for large and giant dog breeds (7+ years, 40+ lbs for LOY-001; 5+ years, 60+ lbs for LOY-003). These drugs target the overexpression of IGF-1, a growth hormone linked to the shorter lifespans observed in larger dogs. LOY-001 received its RXE acceptance in November 2023, with conditional approvals for both LOY-001 and LOY-003 anticipated in 2027.

The FDA's acceptance of the RXE for these drugs marks a historic milestone, signifying the agency's formal acknowledgement that a drug can be developed and approved to extend lifespan. Loyal is currently conducting the "STAY" clinical study for LOY-002, a large-scale trial involving 1,300 senior dogs across 70 veterinary clinics nationwide, to gather further efficacy and safety data. The company has secured over $150 million in funding, including a recent $22 million Series B-2 round, to support its mission.

"In 2026, it's quite likely that a pill will hit the market which makes dogs live longer," Ashlee Vance stated in the tweet, emphasizing the significance of Loyal's work. "This is a big deal for many reasons."

The company's approach focuses on preventive care, aiming to address the underlying causes of age-associated diseases before their onset, ensuring not just longer lives but healthier ones. The Core Memory podcast, featuring Celine Halioua, delves into the science of aging, FDA trials, and the ethical considerations of longevity drugs, sponsored by finance firms Brex and E1 Ventures.