title: Strategies that target leukocyte traffic in inflammatory bowel diseases: recent developments.
abstract: OBJECTIVE
  We review the most recent developments regarding the targeting of molecules involved in the traffic of leukocytes for the treatment of inflammatory bowel diseases (IBD).
  
  
  RESULTS
  We discuss the most important findings of one published phase II trial that targeted the β7 integrin (etrolizumab), two phase II trials that targeted the α4β7 integrin ligand: mucosal addressin cell adhesion molecule 1 (MAdCAM-1, PF-00547659), a phase II trial targeting the chemokine IP-10 (CXCL10) in Crohn's, and a phase II trial that targeted the sphingosine-1-phosphate receptor-1: ozanimod in patients with ulcerative colitis.
  
  
  CONCLUSIONS
  Targeting molecules involved in leukocyte traffic has recently become an effective and well tolerated strategy for the treatment of IBD. Novel approaches now not only target the integrins on the lymphocyte surface, but also its endothelial ligand: MAdCAM-1. As with vedolizumab, antibodies against MAdCAM-1 appear most effective in ulcerative colitis rather than in Crohn's. Targeting chemokines or their receptors does not appear to have the same efficacy as those that target the most stable integrin: immunoglobulin superfamily interactions between the lymphocyte and endothelium. Preliminary results also suggest that the sphingosine-1-phosphate pathway might also be targeted therapeutically in IBD, no longer with parenterally administered antibodies but with orally administered small molecules.
authors.affiliation: aInflammatory Bowel Disease Center, University of California San Diego bSan Diego Veterans Administration Medical Center cLa Jolla Institute for Allergy and Immunology, San Diego, California, USA.
authors.forename: Jesús
authors.initials: J
authors.lastname: Rivera-Nieves
mesh_terms: D061067:Antibodies, Monoclonal, Humanized / Q000494:pharmacology / Q000627:therapeutic use; D005765:Gastrointestinal Agents / Q000494:pharmacology / Q000627:therapeutic use*; D006801:Humans; D007189:Indans / Q000494:pharmacology / Q000627:therapeutic use; D015212:Inflammatory Bowel Diseases / Q000188:drug therapy* / Q000276:immunology; D007962:Leukocytes / Q000187:drug effects*; D058990:Molecular Targeted Therapy / Q000379:methods*; D000069442:Natalizumab / Q000494:pharmacology / Q000627:therapeutic use; D010069:Oxadiazoles / Q000494:pharmacology / Q000627:therapeutic use
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D005765:Gastrointestinal Agents; D007189:Indans; D000069442:Natalizumab; D010069:Oxadiazoles; C543529:vedolizumab; C000607776:ozanimod