Inflammatory Bowel Disease: From Conventional Immunosuppression to Biologic Therapy

<b><i>Background:</i></b> Inflammatory bowel diseases (IBDs) are chronic, recurrent inflammatory diseases with partly understood etiology and pathogenesis. The course of IBD, both ulcerative colitis and Crohn’s disease, is characterized by periods of relapse and remission with the possible occurrence of extraintestinal manifestations. <b><i>Summary:</i></b> During the last decades, therapeutic goals in IBD evolved toward endoscopic remission and mucosal healing creating the need for early administration of disease-modifying agents (DMAs). DMAs include conventional immunosuppressants (thiopurines, methotrexate), biologic drugs (anti-TNF, anti-integrin, and anti-IL-12/23 monoclonal antibodies), and small molecules (JAK inhibitors, S1P receptor modulators). Patients with aggressive course of disease and risk factors for poor prognosis should be treated with biologic therapy early, while conventional immunomodulators should be used in those with milder course of disease in the absence of risk factors. <b><i>Key Messages:</i></b> Challenges in the treatment of IBD patients include the choice of effective yet safe drug and prevention or overcoming loss of response.