Biological response modifiers for the treatment of Crohn's disease

Although standard medical therapy in Crohn's disease is efficient in most patients, a substantial proportion of patients suffering from chronic active disease do not adequately respond to standard therapy. In these patients, alternative regimens have to be considered. Due to the major advances in understanding the pathogenesis of this complex disease involving genetic, environmental, microbial and immunological factors, various new biological therapies targeting key mechanisms have emerged. In this review, a critical appraisal of modern therapeutical concepts will be presented, focusing on antibody and small inhibitory molecule therapies, including inhibition of TNF-α and other pro-inflammatory cytokines, adhesion molecules and T cell activation, as well as hormonal therapies.