Combination therapy in inflammatory bowel disease: Current evidence and perspectives

Inflammatory Bowel Diseases (IBD) are chronic nonspecific intestinal inflammatory diseases with a relapsing-remitting course, including Ulcerative Colitis (UC) and Crohn's Disease (CD). Combination therapy has been proposed as a strategy to enhance treatment efficacy in IBD. The aim of this study is to summarize current evidence and perspectives on combination therapies in IBD. Electronic databases such as PubMed, Ovid Embase, Medline, and Cochrane CENTRAL were searched to identify relevant studies. Current evidence supports that the combination of infliximab and thiopurines is more effective than monotherapy in inducing and maintaining remission in IBD. Data on the combination of other biological agents such as adalimumab, vedolizumab, ustekinumab, and immunosuppressors is lacking or showed conflicting results. Vedolizumab seems a potentially effective maintenance regimen after calcineurin inhibitors-based rescue therapy in acute severe ulcerative colitis (ASUC). Dual Targeted Therapy, which is the combination of two biological agents and/or small molecules, might be a reasonable choice in patients with concomitant IBD and extraintestinal manifestations, or in patients with medical-refractory IBD who lack valid alternatives. Some safety concerns such as adverse events (serious and opportunistic infections) and malignancies (lymphoma and nonmelanoma skin cancer) were raised in combination therapies. Combination therapies seem to be effective in some IBD patients such as refractory IBD patients or patients with extraintestinal manifestations, but it might be associated with an increased risk of adverse events and malignancies.