Introduction: Cell therapy is a promising approach to treating symptomatic degenerative disc disease, which currently has limited therapeutic options. We have developed a novel progenitor cell therapy derived from human disc tissue, which we term injectable discogenic cell therapy (IDCT). In this study, the human cell therapy was applied to rabbits and Gottingen minipigs to compare safety and efficacy outcomes over 6 weeks post-treatment.
Methods: This IACUC-approved study utilized 6 New Zealand white rabbits and 6 Gottingen minipigs. Three discs per animal were injured using needle puncture. Four weeks later, 2 animals/species received one injection/disc of human disc progenitor cells+vehicle, vehicle control, or sham (n=6/condition). Rabbits received 25 µl containing 30,000 human cells and pigs received 150 µl containing 100,000 human cells. Body weight and clinical observations were obtained. X-rays were taken at 0, 4, 6 and 10 weeks to assess disc height index. At 10 weeks (six weeks after treatment), all spines were prepared for histology (H&E, saO and Masson’s trichrome). Statistical analysis: 1-way ANOVAs with post hoc tests (p < 0.05).
Results: No safety concerns were noted in either animal model, despite the use of xenograft. Injury of discs in both models resulted in global changes. While the staining intensity for proteoglycan and collagen did not change in the nucleus pulposus, the morphology changed with injury in unique ways. Disc height index decreased with injury in both animal models and was significantly improved after treatment with human disc progenitor cells within 2 weeks (p < 0.05, Figure 1).
Conclusions: Human disc progenitor cell treatment was safe and efficacious in both animal models, leading to significantly improved disc height in rabbits and pigs. A human clinical trial is anticipated.
Patient Care: These studies directly contribute to regulatory approval for a human trial of a novel human disc progenitor cell treatment for degenerative disc disease.
Learning Objectives: By the conclusion of this session, participants should be able to: 1) Compare various animal models of degenerative disc disease, 2) Discuss outcome measures of the models, including findings related to treatment with human disc progenitor cells, and 3) Understand the type of preclinical data required by the FDA prior to allowing a human clinical trial of a cell therapy.