Clinical field study evaluating the safety and efficacy of allogeneic uterine-derived mesenchymal stem cells for refractory feline chronic gingivostomatitis.

ObjectivesThe present study evaluated the safety and efficacy of intravenous, allogeneic uterine-derived mesenchymal stem cells (UMSCs) for client-owned cats with refractory feline chronic gingivostomatitis (FCGS).MethodsThis was a 90-day prospective, multi-site, baseline-controlled, clinical trial involving 46 cats with refractory FCGS after partial- or full-mouth extractions. Cats received two doses of 20 million UMSCs, 14 days apart. Effectiveness was evaluated at days 14, 28, 60 and 90 using owner-reported assessment of overall response (ORA), client-specific outcome measures (CSOM) of quality-of-life improvement and veterinarian-assessed global oral lesion score (GOLS) tissue healing. Safety assessments included clinical observations and clinical pathology.ResultsTreatment success rates at days 28, 60 and 90 were 61.4% (27/44), 76.3% (29/38) and 78.8% (26/33) for CSOM; 65.9% (29/44), 73.7% (28/38) and 75.8% (25/33) for ORA; and 31.8% (13/44), 47.5% (18/38) and 45.5% (15/33) for GOLS. CSOM and GOLS on day 14 after a single dose were 52.3% (23/44) and 25.0% (11/44), respectively. Cats treated within 6 months of tooth extraction had greater improvement in GOLS. There were no statistically significant differences in outcomes between cats with partial- or full-mouth extractions. Adverse events were generally mild and transient, with most related to underlying disease. All six serious adverse events were either unlikely to be due to, or in one case inconclusively attributed to, UMSC therapy.Conclusions and relevanceRepeated intravenous UMSC therapy was well tolerated and demonstrated clinically meaningful improvement in quality of life in cats with refractory FCGS within 2 weeks of treatment. In addition, oral lesions continued to improve over time. These results support the safe and effective use of UMSCs for this life-threatening condition.