You can only learn so much from laboratory mice. Trials of stem cells conducted in our four-legged friends may serve as a bridge to human studies.
A staple in labs across the world, laboratory rodents are genetically homogenous, closely monitored, and are kept in standard, controllable environments -- and that's a problem. In the human real world, people are genetically different, have various diets and habits, and live in diverse environments. What's more, many times disease is induced in these animals, whereas in humans diseases are rarely planned and may have more than one cause. It's not very surprising that so many promising preclinical experiments do not pan out in human clinical trials. The cost of these failures is sky high, for companies, patients, and society.
What if we instead turned to our own pets, who tend to be closer to us in size, develop spontaneous disease like we do, and also vary in how and where they live? That's the perspective of a recent article that envisions that veterinary clinical trials have a place in the development of human drugs.
Dogs, for example, commonly get cancer, and unlike in lab mice, where tumors are implanted by experimenters, the malignancies occur spontaneously. The larger size of dogs means that tumor dimensions more closely approximate those of humans. In fact, the popular new mantle cell lymphoma drug ibrutinib, was first tested in dogs who had developed naturally occurring lymphoma. The lessons gained from this trial accelerated progression through human clinical trials.
Stem cell therapies, as well, may benefit from our companion animals. The authors propose that a disease in cats called feline chronic gingivostomatitis is a model for human chronic oral inflammatory diseases. A clinical trial using mesenchymal stem cells is showing promise. Mesenchymal stem cells may also be useful for regenerating tissue in arthritis patients. Pets get arthritis, too, and dogs, rabbits, and horses can be used as models of chronic osteoarthritis that developed spontaneously.
To be sure, some limitations exist in using data from clinical trials of companion animals. As they differ from us in genetic makeup and in the ways they metabolite drugs, a compound that is safe and effective in a pet may be neither for its owner. Still, researchers may leverage the significant similarities between us and the critters that live with us to learn insights from animal trials and apply the lessons learned to human health.
We at HemaCare follow with great interest novel ideas in improving the successes of clinical trials. We provide (human) stem cells for your own research and invite you to call at (877) 397-3087 for more information.
- Kol, A. et al. Companion animals: Translational scientist's new best friends. Sci Transl Med 2015; 7(308):308ps21.