Medical treatment of inflammatory bowel diseases

Despite the advent of the anti-TNF agent, infliximab, an important unmet medical need characterizes the medical treatment of inflammatory bowel diseases. This review aims to summarize recent progress in the field.

For Crohn's disease, the fully human IgG1 anti-TNF monoclonal antibody, adalimumab and the humanized anti-alpha4 integrin IgG4 antibody, natalizumab have yielded the most promising results in controlled trials, but agents inhibiting the crucial IL12/interferon-gamma feedback loop also suggest therapeutic potential. Maintenance treatment with azathioprine, although efficacious, is not tolerated by up to 25% of individuals, but 6-thioguanine, an active metabolite, is associated with liver toxicity and is no longer recommended. For severe ulcerative colitis, low intravenous cyclosporine doses have been demonstrated to be efficacious, and may serve to limit the toxicity with this agent. Biologic treatment is being developed to target severe ulcerative colitis. Efficacy of infliximab to stop fistula draining as a maintenance agent for fistulizing Crohn's disease has been demonstrated in a large controlled trial, but MRI imaging indicates that the improvement of inflammation in fistula tracks is delayed.

In conclusion, medical therapy of inflammatory bowel diseases is a constantly moving field and recent evolutions will undoubtedly change clinical practice in the years to come.