Scoping review of the use of mesenchymal stem and stromal cell products in cats, Part 1: current logistics and safety.

Despite a pressing need for new therapies to address unmet veterinary medical need, no approved stem cell products are available for use in cats in the US. To evaluate the current state of mesenchymal stem or stromal cell (MSC) research in cats, a scoping review of published literature was performed, which identified 108 publications related to feline MSCs. Twenty-six of the articles described administration of MSC products to a total of 215 cats. Twelve of the studies included a control group. These experimental and clinical trials used 7 cell sources, 9 administration routes, 12 delivery vehicles, and a 300-fold range in dosages for initial studies in healthy cats and cats with 12 naturally occurring and induced diseases. The majority of studies administered 2 doses of allogeneic, adipose-derived MSC IV and monitored a median of 6.5 treated cats for a median of 90 days. The majority (150/215 [69.8%]) of cats had no reported adverse events associated with treatment. Although an increase in feline MSC publications in the past 10 years indicates progress, the wide variety and small number of studies using MSCs and MSC products in cats demonstrates that current evaluations are mostly still in the discovery phase, and several issues remain related to larger scale trials using MSC products in cats. The current available publications provide information to direct further clinical study development and informed owner consent for study enrollment.