Safety of infliximab for the treatment of inflammatory bowel disease: current understanding of the potential for serious adverse events

Introduction: Infliximab, a chimeric monoclonal antibody directed towards TNF-alpha, has revolutionized the treatment of inflammatory bowel disease (IBD). Since this therapy suppresses the immune system by neutralizing the immunological activity of TNF, concerns exist regarding the potential for infection, malignancy and immune disorders. Areas covered: Comprehensive data from randomized controlled trials, meta-analyses and cohort studies have defined the risk of infection and malignancy with infliximab. Additional data regarding associations with immune disorders, such as drug-induced lupus, demyelinating syndromes and psoriaform skin disease have emerged, primarily from case reports. We report evidence from the most robust data sources that have examined these adverse events. Expert opinion: A modest increase in the incidence of serious infection with infliximab and TNF-antagonists has been observed in methodologically rigorous studies. Combination therapy with an immunosuppressant does not confer a higher risk of serious infection than infliximab monotherapy. TNF-antagonist therapy alone with an immunosuppressant is not associated with higher rates of malignancy. Additional data are required to define causality, the magnitude and determinants of risk for other immune-related complications. Available data suggest the therapeutic index of infliximab is favorable for treatment of moderate-to-severe IBD.