The role of biological therapy in inflammatory bowel disease

Substantial evidence suggests a central role for TNF-alpha in the pathogene sis of IBD. This molecular observation has been supported by clinical trial s with anti-TNF therapies. The most extensively investigated among the vari ous anti-TNF agents is infliximab. Clinical trials to date have demonstrate d its efficacy in inducing remission in patients with moderately active, re fractory Crohn's disease (CD) and in managing patients with CD complicated by fistulas. One advantage of infliximab is its rapid onset of action. Howe ver, as expected with most medications used to treat patients with IBD, the effect of infliximab is of limited duration, with the response lasting 2-3 months in most patients. The efficacy of repeated infusions of infliximab in maintaining remission in patients with inflammatory CD has been demonstr ated in one trial to date. The results from the ACCENT I trial should soon be available. Many other important questions regarding the use of inflixima b remain unanswered. These include the optimal schedules of infusions, the effect of concomitant therapy with aminosalicylates, immunomodulators and a ntibiotics, and the timing and indication of using infliximab in the genera l management algorithm of a patient with CD. Certainly, the efficacy of inf liximab in the treatment of ulcerative colitis (UC) remains to be further e xplored in a controlled fashion, though preliminary uncontrolled data sugge sts efficacy. As experience with infliximab use accumulates, more data will become available regarding its safety with either short-term or long-term use. A large body of evidence exists regarding the shortterm safety of infl iximab. The concern of increased risk of hypersensitivity-like reactions wi th longer interval between treatments will also need to be addressed. The c urrently available data supports that infliximab is safe and well tolerated . Other anti-TNF therapies will also need to be investigated with the same rigor before widespread use can be advocated. In addition to these agents, advances in molecular engineering techniques have further expanded the arra y of biologic therapies available to treat IBD. These newer therapies hold promise in targeting specific pathways of the pathogenesis of IBD that may be different from all prior therapies. Certainly, the anti-TNF therapies an d others aforementioned have taken the field of IBD into a new and exciting generation, the biological era, (C) 2001 Prous Science. All rights reserve d.