Inflammatory bowel disease therapy: blockade of cytokines and cytokine signaling pathways

PURPOSE OF REVIEW: Treatment of inflammatory bowel disease (IBD) patients can vary depending on the degree of response, lack of response or intolerance to conventional or biological agents aimed at blocking various cytokines or integrins. Recent therapies targeting several cytokines were reviewed to evaluate efficacy in IBD patients. RECENT FINDINGS: Ustekinumab is an interleukin inhibitor which blocks the p40 subunit of IL-12 and IL-23 axis and is already approved for the treatment of Crohn's disease patients, specially those who had inadequate response or intolerance to conventional treatment with anti-TNF-α agents. Several treatments have been developed that are focused on the blockade of specific cytokines such as IL-6, IL-12, IL-13, IL-17, IL-23 and a chemokine named IFN-γ-inducible protein-10 as well as some oral small-molecule inhibitors of intracellular cytoplasmic tyrosine kinases like tofacitinib, filgotinib and upadacitinib. SUMMARY: Several biologics blocking different and specific cytokines and oral small molecule agents have been and are being evaluated in IBD patients. A comprehensive understanding of the underlying immunological mechanisms will allow to develop effective and safe agents that inhibit one or more cytokines to improve the outcome in patients with IBD.