Dihydroorotate dehydrogenase (DHODH) is involved in pyrimidine nucleoside biosynthesis. DHODH inhibitors have value in autoimmune diseases as well as cancer and certain infections. Vidofludimus is an immunosuppressive drug that inhibits DHODH (IC50s = 0.134, 1.29, and 10.6 μM for human, rat, and mouse isoforms, respectively). Through this action, it inhibits the proliferation of T cells and B cells and the secretion of IL-17 (IC50s = 12.9, 3.7, and 6.0 μM, respectively, in human cells). Oral administration of vidofludimus improves both chronic dextran sodium sulfate-induced and acute TNBS-induced colitis in mice.