Current Status of Medical Therapy for Inflammatory Bowel Disease: The Wealth of Medications.

Previously, the natural history of Crohn's disease and ulcerative colitis included significant morbidity due to limited treatment options that were not without serious side effects. Early treatment options included corticosteroids as well as mesalamine, thiopurines, and methotrexate. In 1998, monoclonal antibodies to a key inflammatory cytokine, TNFα, became available. Over the next 22 years, the field of gastroenterology has seen multiple new treatments emerging for inflammatory bowel disease (IBD) that target different aspects of the inflammatory cascade, significantly changing the therapeutic landscape. Additional monoclonal antibodies are available that target the integrins, which are adhesion proteins that traffic inflammatory leukocytes. Small molecule inhibitors block the inflammatory signals of several cytokines. New therapies that modulate lymphocyte escape from lymphoid tissue are promising. Lastly, stem cell technology has emerged as a platform to successfully treat perianal fistulizing disease. Our aim is to summarize the currently available therapies for IBD beyond steroids, mesalamine, and immune modulators. We highlight the most important clinical trials that have brought these treatments to clinical practice, and we discuss the ongoing clinical trials of novel therapies that have a high probability of eventual regulatory approval.