AUTHOR=Lindemann Aylin , Roth Dominik , Koop Kristina , Neufert Clemens , Zundler Sebastian , Atreya Raja , Neurath Markus F. , Leppkes Moritz TITLE=Protective effect of the novel calcineurin inhibitor voclosporin in experimental colitis JOURNAL=Frontiers in Medicine VOLUME=Volume 10 - 2023 YEAR=2023 URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2023.1177450 DOI=10.3389/fmed.2023.1177450 ISSN=2296-858X ABSTRACT=Background and Aims: Acute severe steroid-refractory ulcerative colitis remains a medically challenging condition with frequent need of surgery. It can be treated with the calcineurin inhibitor cyclosporine A with the need for therapeutic drug monitoring and significant toxicity. Recently, a novel calcineurin inhibitor, voclosporin, has been approved for the treatment of lupus nephritis with no need for therapeutic drug monitoring and an improved long-term safety profile. We aimed to assess the therapeutic potential of voclosporin to ameliorate inflammation in an experimental model of colitis. Methods: We used the dextran sodium sulfate-induced model of colitis in C57BL/6J wildtype mice treated with either cyclosporine A, voclosporin or solvent control. We employed endoscopy, histochemistry, immunofluorescence, bead-based multiplex immunoassays and flow cytometry to study the therapeutic effect of calcineurin inhibitors in a preventive setting. Results: Acute colitis was induced by dextran sodium sulfate characterized by weight loss, diarrhea, mucosal erosions and rectal bleeding. Both cyclosporine A and voclosporin strongly ameliorated the course of disease and reduced colitis severity in a similar manner. Conclusions: Voclosporin was identified as biologically effective in a preclinical model of colitis and may be successfully developed in clinical studies of patients with acute severe steroid-refractory ulcerative colitis.