Long-term efficacy and safety of intravenous injection of clonal mesenchymal stem cells derived from bone marrow in five adults with moderate to severe atopic dermatitis.

Background: Atopic dermatitis(AD) is a chronic and relapsing inflammatory skin disease that is treated with immunosuppressants. However, long-term use of immunosuppressants may cause toxicity and severe side effects. Objectives: This study aimed to confirm the long-term efficacy and safety of clonal mesenchymal stem cell therapy in adult patients with moderate to severe AD that was refractory to conventional treatments. Methods: A single-center, open-labeled investigator-initiated clinical trial for the therapeutic use of allogeneic bone marrow-derived clonal MSCs in five adults with moderate to severe AD was conducted intravenously. Eczema Area and Severity Index (EASI), Severity Scoring for AD and Investigator Global Assessment scale were used to evaluate the effectiveness of the therapy. Results: The clinical response assessment values such as EASI improved significantly at 16 weeks, and 80% (4/5) of the patients achieved EASI-50 after one or two treatment cycles. Patients were observed for long-term efficacy and safety for an average of 38 weeks and showed no serious side effects. Among the cytokines tested, CCL-17, IL-13 and IL-22 significantly decreased at the endpoint of the five participants, two patients who maintained good clinical response over 84 weeks showed increased IL-17 cytokine levels in the blood. Conclusion: This study suggests that clonal mesenchymal stem cell therapy could be safe and effective treatment option for chronic refractory AD.