New research finds canine osteoarthritis treatment may have disease-modifying effect

New research suggests that the use of tin-117m (Sn-117m) homogeneous microparticles (HTM) delivered via radiosynoviorthesis—a procedure where radioactive particles are injected directly into a joint—may slow the progression of osteoarthritis.¹ The study, Evidence of osteoarthritis disease modification with a Sn-117m microparticle device: a review and validation in mammalian models, found that this treatment (Synovetin OA; Exubrion Therapeutics) reduced synovial inflammation, cartilage degradation, and osteophyte formation in preclinical rat models with surgically induced osteoarthritis.²

According to Exubrion Therapeutics, veterinarian have used Synovetin OA to treat thousands of canine patients with arthritis since it was launched in 2021.¹ The therapy consists of one outpatient injection into the patient’s joint, which provides relief from inflammation and pain related to arthritis for up to a year.

Bennett, a patient who received Synovetin OA. (Image courtesy of Exubrion Therapeutics)

“Until now, treatments for arthritis in dogs have focused primarily on managing symptoms, without much ability to address the underlying inflammation that causes pain, reduced mobility and disease progression,” Bob Menardi, DVM, chief veterinary officer at Exubrion Therapeutics, said in a company release.¹ “Synovetin OA is a breakthrough in treatment that specifically interrupts the vicious inflammatory cycle. This newly published research in rodents provides hope for slowing the course of the disease.”

In dogs, arthritis is caused by joint inflammation, which leads to pain, cartilage breakdown, lameness, limited mobility, and a reduced quality of life.¹ The disease affects up to 80% of senior dogs and at least 1 in 4 adult dogs.¹

According to the study, which was published in Frontiers in Veterinary Science, 4 clinical trials in in dogs with mild to severe elbow osteoarthritis were conducted to assess the safety and effectiveness of HTM over a 1-year post-treatment period.² The trials found that most participants continued to experience pain relief and joint improvement for up to 1 year, even after there was no active HTM remaining in the joint.^1,2

In a reinjection study, 50% of dogs showed no progression of osteoarthritis on imaging, “suggesting HTM’s capacity to slow disease advancement,” noted the authors of the study Evidence of osteoarthritis disease modification.²

“Unlike [nonsteroidal anti-inflammatory drugs], which relieve pain without addressing etiology, Sn-117m targets the source of inflammation. Corticosteroids are effective anti-inflammatories when delivered into the joint, but can cause thinning of cartilage, bone loss, and joint instability,” they continued.²

In the preclinical research in rats, the therapy also showed a disease-modifying effect. Specifically, the treatment led to a 73% reduction in inflammation and a 65% reduction in cartilage degeneration.

“This review substantiates Sn-117m [radiosynoviorthesis] as a transformative veterinary therapy, bridging preclinical insights with clinical outcomes that strongly support a positive disease-modifying mechanism,” wrote the authors of the study.¹

References

1. Newly published research shows groundbreaking joint treatment changes the course of dog arthritis management. News release. Exubrion Therapeutics. July 22, 2025.
2. Bendele A, Doerr CA, Gonzales GR, Menardi R, Schreiber E, Stevenson NR. Evidence of osteoarthritis disease modification with a Sn‑117m microparticle device: a review and validation in mammalian models. Front Vet Sci. 2025;12:1621296. doi:10.3389/fvets.2025.1621296