Current understanding of safety and efficacy of stem cell therapy for discogenic pain—A systematic review of human studies

This study is a systematic review of human clinical studies of stem cell therapy for discogenic pain. To summarize the current human trials and feasibility studies involving mesenchymal stem cell (MSC) therapy for treatment of discogenic pain. A search of Ovid databases and Clinicaltrials.gov was conducted from inception through July 2016. We included human clinical trials and case reports that evaluated treatment with injected MSCs for patients with discogenic back pain. The outcomes of interest for published studies included pain score, Oswestry Disability Index, and T2-weighted magnetic resonance imaging signal intensity indicative of water content of the nucleus pulposus. The initial search in Ovid databases using the selected search terms identified 408 results, of which 11 were included in this review based on selection criteria. This includes 6 completed studies and 5 ongoing clinical trials, 4 of which were confirmed active at the time of retrieval. In the 6 completed studies involving intradiscal stem cell injections, improvement in pain score, Oswestry Disability Index, and T2-weighted magnetic resonance imaging signal intensity of nucleus pulposus were reported. Currently active clinical trials focus on establishing safety, tolerability, and efficacy with respect to injected MSCs for discogenic pain. Although pain and functional benefit have been reported in association with stem cell therapy, longer-term safety studies and more randomized controlled trials are needed to examine the safety and efficacy of stem cell therapy for discogenic pain.