Positioning biologic therapy for Crohn's disease and ulcerative colitis.

Over the past decade, the introduction of biologic agents such as tumor necrosis factor-alpha and alpha4 integrin leukocyte adhesion molecule inhibitors has provided new and effective treatment options for patients with inflammatory bowel disease (IBD). Recent debates have centered on where biologics should be positioned within the current treatment strategy so as to maximize efficacy while balancing risk. This review highlights the current position biologics hold relative to conventional therapies within the current "step-up" treatment strategy. It also critically appraises emerging data, testing the hypothesis that positioning biologics early in the IBD treatment algorithm ("top-down" strategy) results in superior outcomes compared with the current step-up strategy, in which biologics are used only in patients failing conventional therapies or who are steroid dependent.