Etanercept (Enbrel) in the treatment of juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) is a relatively common multidimensional and heterogeneous chronic disease of childhood. Children with JIA are at risk for significant morbidity in terms of joint damage, impairments in physical function and health-related quality of life. Outcomes for children with JIA have significantly improved with the use of biologic therapies in the past 15 years, with the most clinical experience being with etanercept .

Basic pharmacokinetic and pharmacodynamic data for etanercept will be highlighted. This article will review the clinical trials and open-label registry data for the efficacy and safety of etanercept for use in JIA.

Etanercept is very effective for the treatment of JIA. Data from clinical trials and open-label studies support its clinical efficacy in 80% of patients which appears to be sustained over several years for the majority of treated patients. The safety profile is also acceptable with a serious adverse event rate of 0.03 - 0.12 per patient-year. Further research is needed to evaluate any possible link between biologic therapy, JIA and malignancy, to obtain more long-term safety data, and to document improvements in quality of care and cost-benefit for associated with biologic therapies which may additionally assist in access to these medications. Further, identification of potential clinical or laboratory markers allowing for prediction of response and timing of starting and cessation of this biologic therapy are urgently required.