Celavet Clinical Applications
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Pilot study to test the efficacy and safety of OK100 stem cells for the treatment of tendon injuries
The pilot and multicenter open label study that provided the support for our CVM (Center for Veterinary Medicine) submission was performed across 35 veterinarian centers and involved more than 400 horses with tendon and ligament injuries. Behaviorally, the horses demonstrated a return to normal function. Ultrasound examination showed reconstruction of lesions with anatomically correct fiber alignment and absence of scar tissue. Over 100 horses followed for three years post treatment showed no signs of tumors.
This study did not reveal any significant long term safety concerns associated with intra-lesional injections of OK100. There was some pain and swelling at the site of injection in 13.5% of cases that resolved within days. Two horses that received distal perfusion injections experienced transient anaphylactic reactions from which they recovered fully. No malignancies have been reported in any of the animals with 275 cases having been followed for longer than 1 year, and 113 cases for longer than 3 years.
Although the study was not controlled, it still allowed a tentative look at efficacy. The ultimate measure of efficacy for a treatment of a musculoskeletal injury is the level of functional improvement. Celavet addressed this by grading lameness, exercise level, pain, and swelling prior to injection and 90-120 days after the injection of stem cells. However, these endpoints do not give an indication of whether the improvement will be a lasting one. Scar tissue commonly may give an appearance of full recovery but fails in the long term. To address this issue, participating veterinarians performed a range of ultrasound measurements intended to reveal the structural changes to the lesions through the course of the follow up. The most important of these measures would be Echogenicity and Fiber Alignment. Echogenicity score reflects the degree to which the lesion has filled in, while fiber alignment score allows differentiation between scar tissue with its disorganized fiber pattern and healthy connective tissue with parallel fiber arrangement.
We observed statistically significant improvement compared to baseline values in most efficacy end measures. Echogenicity and fiber alignment scores are especially telling as improvement in these parameters suggests reconstruction of tendon/ligament tissue that is not achievable with simple scar formation.
It’s important to note that animals designated as “chronic” underwent other treatments and failed to improve prior to OK100 injections. Unlike the acute group, the baseline scores of the chronic animals can be viewed as the controls for the day 90-120 scores due to their prior failure to improve.
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