Abstract
Background: Inflammatory bowel diseases (IBD) are a group of heterogeneous conditions, characterized by immune-mediated inflammation of the gastrointestinal tract. Traditionally, medical management of these disorders has been based on use of systemic immunosuppressives. The development of new drugs that selectively inhibit leukocyte trafficking to the gut has the potential to reduce inflammation and minimize systemic toxicities. Key Messages: In this article, we review the immunology of the gut and the mechanism of action these emerging therapies for IBD. Natalizumab, a monoclonal antibody to the alpha 4 integrin, was approved for the treatment of multiple sclerosis and showed promise in Crohn's disease (CD), however it is encumbered by the risk of progressive multifocal leukoencephalopathy. Vedolizumab inhibits the alpha 4 beta 7 integrin to induce clinical remission in patients with both ulcerative colitis and CD. Long-term safety data on this agent is not yet available. We also review agents in the pipeline. Finally, we discuss the positioning of therapies and potential alterations to therapeutic algorithms as new medications emerge. Conclusions: New therapies are emerging for IBD; however, long-term data are pending. The positioning of these agents in algorithms will evolve. (C) 2016 S. Karger AG, Basel