Investigational new drugs in the treatment of inflammatory bowel disease: a review

The unraveling of the immuno-pathobiology of inflammatory bowel disease (IBD) in the past three decades has ushered in a new era of translational medicine. The biotechnology revolution has resulted in a paradigm shift in how clinicians view and treat IBD. Anti-tumor necrosis factor (TNF)-α strategies using infliximab and adalimumab currently dominate the therapeutic arena. Better understanding of how these biologicals work is driving the quest for loftier therapeutic goals of achieving mucosal healing, sustaining deep remission, and even modifying the natural history of IBD. However, not all patients respond to anti-TNF drugs. Immune-mediated adverse reactions and loss of efficacy with time also limit their use. There are many investigational drugs undergoing active clinical trials. Many have not fulfilled their early promises but some are potentially making the transition from bench to trial and to the bedside in the near future. Clinicians and investigators need to underpin our excitement with caution for the unknown long-term consequences of modulating cytokines and selective adhesion molecules in human. Here we provide an overview of investigational new drugs and other therapeutic strategies currently undergoing clinical trials in IBD.