Management of lack and loss of response to anti-tumor necrosis factor therapy

The introduction of biologics has proven a significant breakthrough in the treatment of Crohn's disease. At the present time, three anti-tumor necrosis factor (anti-TNF) agents are approved by the US Food and Drug Administration for the treatment of Crohn's disease: infliximab, adalimumab, and certolizumab. Although anti-TNF therapy has been widely studied in clinical trials and found to be effective in Crohn's disease, approximately one-third of patients do not respond to induction therapy, and around one-third of initial responders lose their response after several months of treatment. In this review, factors associated with lack of response (primary non-responders) and loss of response (secondary non-responders) are discussed. Identifying factors associated with lack and/or loss of response could be helpful in the selection of patients who are likely to benefit from anti-TNF therapy. This could attenuate morbidity and side effects, and reduce costs.