Gallant Reports Positive Pilot Data for Feline Osteoarthritis Stem Cell Therapy; Receives FDA Eligibility for Expanded Conditional Approval Pathway

Randomized, placebo-controlled study shows over 76% of treated cats demonstrated improved quality of life

SAN DIEGO, April 15, 2026 /PRNewswire/ -- Gallant, an animal health biotechnology company pioneering off-the-shelf stem cell therapies for pets, today announced positive results from a pilot clinical study evaluating intravenous (IV) uterine-derived mesenchymal stromal cell (UMSC) therapy in cats with naturally occurring osteoarthritis (OA). Additionally, the U.S. Food and Drug Administration's Center for Veterinary Medicine (FDA-CVM) granted eligibility for the expanded conditional approval pathway for Gallant's feline OA therapy, allowing a faster pathway to market for a product that addresses a significant unmet medical need, ensuring target animal safety and cGMP-quality manufacturing while full effectiveness is being confirmed.

OA affects 90% of older cats, resulting in increased pain and decreased mobility, which negatively impacts physical appearance, energy and vitality, mood, sociability and physical and mental wellbeing. Caregivers report that the burden of medically managing feline OA surpasses that of other chronic debilitating feline diseases including cancer, heart disease, and diabetes mellitus. Medications currently on the market only target the symptoms of OA by blocking inflammatory and pain pathways; however, the immunomodulatory properties of MSCs allow them to target the root cause of disease, potentially offering a disease-modifying therapy.

In a randomized, masked, placebo-controlled study across six U.S. veterinary clinics, 35 client-owned cats with radiographically confirmed OA received two IV injections of either low-dose (5 million cells), high-dose (20 million cells), or saline placebo, administered 14 days apart. The cats were evaluated over 90 days by veterinarians and cat parents.

Overall, the pilot study findings support that IV UMSC therapy is well tolerated in cats with naturally occurring OA. Results showed statistically significant and clinically relevant improvement across both cat parent-reported and veterinarian-assessed outcomes.

Three months following treatment:

• Cat's quality of life as assessed by the cat parent using a validated tool (client-specific outcome measure; CSOM): 76.2% of treated cats improved vs. 36.4% placebo
• Cat's overall quality of life as assessed by the cat parent: 81% of treated cats improved vs. 36.4% placebo
• Cat's pain scores assessed by the veterinarian: 81% of treated cats improved vs. 45.5% placebo
• Cat's overall quality of life as assessed by the veterinarian: 60% of treated cats improved vs. 20% placebo

The results of the 90-day study have been submitted for publication. A continuation study evaluating safety and efficacy of the low-dose therapy out to one year is ongoing.

"This data marks additional meaningful progress toward a new category of care, where regenerative medicine targets disease at its source," said Dr. Linda Black, DVM, Ph.D., CEO of Gallant. "Osteoarthritis remains a significant burden for cats and their families, and current treatments largely manage symptoms rather than addressing the underlying joint pathology. As we continue to study duration of effect for feline OA, we're encouraged about the potential to deliver long-lasting relief - particularly given results from our refractory feline chronic gingivostomatitis program, where two-thirds of cats showed a positive response one year post-treatment."

A Focus on Felines
Gallant's pipeline reflects a deliberate focus on feline medicine - a historically underserved area of veterinary therapeutics.

"Felines have long been overlooked in medical research and therapeutic development, leaving a significant gap in care for a population that deserves far more attention," said Dr. Rebecca Windsor, vice president of Veterinary Affairs at Gallant. "Our mission at Gallant is to change that. By advancing cutting-edge regenerative therapies specifically for cats, we aim to lead a new era of innovation that brings meaningful, feline-specific solutions to this underserved community."

The feline OA therapy represents the company's second stem cell therapy for cats, building on momentum toward anticipated conditional approval of the potential first-ever FDA-approved, off-the-shelf IV stem cell therapy — sonruvetcel injectable suspension for cats with refractory Feline Chronic Gingivostomatitis (rFCGS) — expected later this year. Together, these programs underscore Gallant's commitment to expanding the spectrum of care for cats.

The company's pipeline also includes programs in canine osteoarthritis, feline chronic kidney disease, and canine atopic dermatitis, as well as others.
For information on Gallant's Feline OA pilot study data, go to: https://bit.ly/481sItp

About Gallant
Gallant is an animal health biotechnology company creating a new category of veterinary care with a pipeline of off-the-shelf, ready-to-use stem cell therapies targeting the root cause of disease in pets. Led by pioneers in veterinary regenerative medicine with deep expertise in development, manufacturing, and commercialization, Gallant is making regenerative medicine accessible - moving beyond symptom management to restoring health at the source. Learn more at www.gallant.com.

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Gallant's uterine-derived mesenchymal stromal cell therapy for feline osteoarthritis is an investigational new animal drug and has not received FDA approval or conditional approval. Availability is pending regulatory review.

SOURCE Gallant