Allogeneic expanded adipose‐derived mesenchymal stem cell therapy for perianal fistulas in Crohn’s disease: A case series

Abstract

Background Even with optimal medical and surgical therapy, perianal fistulas in patients with Crohn's disease (CD) have low closure rates. As a new therapeutic option, local mesenchymal stem cell (MSC) administration proved to be an innovative option after failure of treatment with immunosuppressive or immunomodulatory agents. Methods A total of 11 CD patients with complex perianal fistulas with non‐ or mildly active luminal disease were treated with local injection of 120 million allogeneic adipose‐derived stem cells at a tertiary hospital between February 2019 and June 2020. Results The mean age of the 11 patients was 38.3 years, 72.7% were male and 27.2% smokers. The mean duration of fistula manifestation was 7.8 years and except one patient (therapy with tacrolimus) all other patients were treated with an anti‐TNF agent without fistula healing in the last 6 months. After a mean follow‐up time of 41.5 weeks, 72.7% (8/11) patients had complete closure of the fistulas and three patient failed MSC treatment. Complete fistula healing could be observed 4‐6 weeks postoperatively in half of patients. 36.5% (4/11) patients developed a perianal abscess which had to be drained. One patient experienced a CMV viremia 2 weeks after MSC administration and one patient developed a testicular carcinoma 16 weeks after treatment. Conclusion This case series demonstrates that the efficacy and safety of Darvadstrocel in the ADMIRE trial can be replicated outside a clinical trial. This new modality in the treatment of perianal complex fistula appears to be a promising therapeutic option for a challenging patient population.