Reply to comments on: “Efficacy of cx601 (darvadstrocel) for the treatment of perianal fistulizing Crohn’s disease—A prospective nationwide multicenter cohort study”

Excerpt

Thank you for reading our manuscript carefully, we also appreciate your comments on this important topic [1, 2]. The authors addressed two interesting questions: firstly, it was stated that the effect of anti-TNFα agents carries the risk of reducing the inflammatory process in the microenvironment of mesenchymal stem cells, thus potentially decreasing their immunomodulatory efficacy [3]. As Crohn’s disease represents a systemic disease, we believe that a combined treatment strategy is mandatory to achieve an optimal clinical outcome. Addressing Crohn’s disease solely locally might reduce the overall healing rate, especially in those patients with systemic signs of disease activity; however, we agree that it is essential to choose the correct medication in order not to mitigate the effect of mesenchymal stem cells (MSCs). Further studies are needed to clarify the best management in this complex group of affected patients. Our study is definitely too small to assess relations between immunosuppressive drugs and efficacy of MSCs. Notably, in the phase III randomized, double-blind controlled trial evaluating the effect of MSCs (Cx601) by Panés et al. patients receiving concomitant immunomodulator or anti-TNF treatment or both had a better effect in both treatment cohorts [4]. …