Inflammatory bowel diseases (IBD) are chronic relapsing and remitting disorders 
that have varying degrees of severity. However multiple studies have confirmed 
that a large proportion of patients on maintenance treatment lose response to 
anti-TNF therapy. This has led to increasing interest in the concept of 
'switching therapy out-of-class' i.e. a nonanti- TNF antibody when patients 
either fail to respond (primary non-response, develop secondary non-response) or 
do not tolerate anti-TNF therapies. The most widely known and studied 
alternative class of antibodies therapies at present are the selective adhesion 
molecule inhibitors. Several antibodies exist which constitute selection 
adhesion molecule inhibitors, including Natalizumab, MLN-0002 (Vedolizumab) and 
ISIS 2302 (Alicaforsen) will be discussed in this review.