Infliximab: a novel chimeric monoclonal antibody for the treatment of Crohn's disease.

Crohn's disease (CD) is characterized by transmural inflammatory disease involving any portion of the gastrointestinal tract. Patients with CD have increased mucosal concentrations of the cytokine tumor necrosis factor-alpha (TNF-alpha), a key mediator of mucosal inflammation. In addition, TNF-alpha has multiple biologic activities involved in apoptosis, metabolism, and activation of granulocytes, lymphocytes, eosinophils, fibroblasts, chondrocytes, and endothelial cells. Recently, infliximab has emerged as a novel chimeric monoclonal antibody that inhibits TNF-alpha. Infliximab is indicated for the treatment of moderately to severely active CD in patients having an inadequate response to conventional therapy. To date, a small number of clinical trials with infliximab have demonstrated efficacy and tolerability when the agent is initiated as a 5-mg/kg single intravenous infusion. In patients with fistulizing CD, administration of 2 subsequent 5-mg/kg doses 2 and 6 weeks after the initial dose appears to be efficacious. Infliximab seems to be a promising therapeutic strategy for patients with refractory CD.