Vedolizumab: A New Opponent in the Battle Against Crohn's Disease and Ulcerative Colitis.

Inflammatory bowel diseases (IBDs) are chronic inflammatory disorders affecting the gastrointestinal (GI) tract that encompass Crohn's disease (CD) and ulcerative colitis (UC). In these disease states, epithelial damage of the intestinal mucosa is evident due to increased lymphocyte trafficking to the area, which affects the normal intestinal barrier function. Currently available pharmacotherapy can be limited in terms of efficacy and associated toxicities. Newer agents have emerged, including the monoclonal antibody natalizumab, which antagonizes integrin, an important component within the inflammation cascade. Natalizumab works by modulating both the GI and brain biologic responses and as a result there is risk of the opportunistic infection known as progressive multifocal leukoencephalopathy (PML), putting patients at risk for severe disability and death. Vedolizumab, another integrin inhibitor, is selective for modulating the gut biologic response but not the brain, consequently decreasing the risk for PML. To generate information regarding the role of vedolizumab in the treatment of IBD, a literature search was conducted, yielding 7 phase I to III clinical trials. This article serves as a summary of efficacy, safety, and other relevant information from clinical studies to explore the role of vedolizumab in the treatment of CD and UC.