Combining Biologics in Inflammatory Bowel Disease and Other Immune Mediated Inflammatory Disorders

Current therapies used in the treatment of inflammatory bowel disease (IBD) are not effective in all patients. Biologic agents result in approximately 40% remission rates at 1 year in selected populations, prompting a growing interest in combining biologic therapy to improve outcomes. There are limited published data regarding the efficacy and safety of combination targeted therapy in IBD specifically, which include only 1 exploratory randomized control trial and 3 case reports or series. This review evaluates the published literature regarding this therapeutic paradigm in IBD and its extensive utilization in the treatment of other immune-mediated inflammatory disorders. The combination of biologic therapies demonstrates variable degrees of efficacy and highlights some safety concerns, depending upon the agents used and the disease state treated. A trial (Clinical Trials.gov Identifier: NCT02764762) combining vedolizumab and adalimumab is currently underway evaluating the effectiveness and safety of this approach in patients with Crohn's disease, which should provide further insight into this treatment concept. While combination biologic therapy is an attractive strategy, the lack of consistent superior efficacy as well as safety concerns militates the need for further trials prior to its general application in IBD.