A company in San Diego says a stem cell treatment helped many dogs and cats with arthritis in small pilot studies, and it hopes to bring the treatment to US vets within about two years1. The company, Gallant, reported that most treated dogs with mild or moderate arthritis improved after three months, and that a majority of treated cats had a better quality of life1. The results have not yet been published, and the company itself said more data are needed1.
What happened
Gallant described results from two pilot studies, one in dogs and one in cats, all of them pets brought in by their owners rather than lab animals1. The treatment uses what the company calls mesenchymal stromal cells, or MSCs, a type of stem cell therapy1. The animals all had osteoarthritis, the common form of arthritis in which joints slowly break down over time1.
The company said the treated animals showed significant improvements compared with animals given a placebo (a dummy treatment)1. It now hopes to win backing from the US Food and Drug Administration (FDA) for arthritis treatments in 20281. It said it is also in contact with regulators outside the FDA about the technique1.
Rebecca Windsor, Gallant’s vice-president of veterinary affairs, explained the idea behind the approach:
“By targeting the systemic and local immune dysregulation that precedes the progressive, degenerative changes of OA, MSC therapy has the potential to not only control clinical signs, but also impact the course of disease.”1
In plain words, the company thinks the cells may calm immune changes in the body and in the joint that come before the joint damage, which it hopes could do more than ease symptoms. That is a hope stated by the company, not something the pilot studies have shown.
The evidence so far
Dogs
The dog study enrolled 88 pet dogs1. Among dogs with mild or moderate arthritis, 73.7% showed improvement 90 days after treatment, measured with the Liverpool Osteoarthritis in Dogs (LOAD) assessment, a standard scoring tool for arthritis in dogs1.
On safety, the company said no serious side effects were seen in the dog study1. Minor side effects were reported in 53.8% of dogs that got the stem cells and in nearly 70% of dogs in the comparison group1. Only four cases, or 6.5%, were judged to be caused by the treatment1.
Cats
The cat study was smaller, with 35 cats1. Three months after treatment, 60% of treated cats had a better quality of life according to a vet’s assessment1. When owners rated their own cats using a validated questionnaire, the share rose to 76.2%1. No side-effect figures were shared for the cats1.
The cat results have been submitted for publication in a journal, the company said1.
What it does not show yet
These are pilot studies, which are small early tests meant to check whether a treatment looks worth testing in bigger trials. Windsor acknowledged that more arthritis data are needed and said the pilot results would help design later trials on the way to FDA approval1.
Several things are still unknown from what has been reported:
- How large the difference was. The company said the treated animals did significantly better than those on placebo, but the reported figures give the share of treated animals that improved, not the matching figures for the placebo group1.
- How long any benefit lasts. The reported results cover about three months. Longer work looking at the effects over a year is still under way1.
- Independent review. None of the results have yet been published or checked by outside scientists. The cat data are only at the submission stage1.
- Use with other medicines. Company leaders believe the treatment could work alongside current arthritis medicines or even replace them1. How far stem cells can be used with or instead of other treatments is likely to be a key question in future work, and the pilot studies were not designed to answer it1.
Owner ratings also deserve care. In the cat study, owners saw improvement more often than vets did (76.2% against 60%)1. The reports do not say whether owners knew if their cat got the real treatment or the dummy one.
Who is behind it
All of the results come from Gallant, the company developing the treatment, and were reported through the company1. Its chief executive, Linda Black, said:
“This data marks additional meaningful progress toward a new category of care, where regenerative medicine targets disease at its source.”1
The company has a commercial interest in the outcome. The sources do not say who paid for the studies beyond the company itself, or how the trials were run.
Arthritis is not Gallant’s first target. In May, the company said it was on course to win FDA approval later this year for its first stem cell therapy, for a hard-to-treat inflammatory mouth disease in cats called feline chronic gingivostomatitis1. Windsor pointed to long-term signs from that work as encouraging. Speaking about cats in that program, she said:
“These cats were dependent on medications for pain and inflammation, and the majority did not need to re-add medications back in in that one year follow-up time.”1
That observation is about the mouth disease, not arthritis, and the company has not shared figures from it in the reported coverage1.
How it fits the field
Stem cell treatments for pets are not new. As early as 2009, the company VetStem was writing on its blog that dogs, horses and cats were being treated for arthritis and tendon injuries with stem cells taken from the animal’s own fat2. That post noted that pets were getting such treatments ahead of people2.
The same mouth disease Gallant is targeting has also been studied at university vet schools. In 2016, UC Davis described a veterinary clinical trial in which researchers used stem cells taken from cats to try to reduce inflammation in cats with chronic gingivostomatitis3. The university said that work might also matter for a similar mouth disease in people, oral lichen planus3.
What Gallant is aiming for is different from offering a treatment informally: a full FDA approval for arthritis, backed by comparison studies against a placebo1. If it reaches that step, it would give vets and owners a reviewed set of results to judge the treatment by, rather than individual stories.
What to watch next
- Publication of the cat study. The results have been submitted to a journal, which would let outside scientists see the full data1.
- One-year results. Longer-term work on how the treatment holds up over a year is still running1.
- Larger trials. The company said the pilot data will shape the design of the next trials toward approval1.
- The mouth-disease decision. Whether the FDA approves Gallant’s first stem cell therapy for cats will show how regulators view this type of treatment1.
- The 2028 target. The company hopes for FDA backing for arthritis that year, and is talking with other regulators too1.
For now, the picture is of early, company-reported results in about 120 pets, measured over three months. Biohack will follow this thread as published data and larger trials appear.
