Update on the use of etanercept across a spectrum of rheumatoid disorders.

Etanercept is a soluble TNF receptor p75 fusion protein which is approved for subcutaneous use (50 mg weekly) in the treatment of patients with active rheumatoid arthritis (RA), juvenile RA, ankylosing spondylitis, and psoriatic arthritis. Etanercept binds to both TNFalpha and lymphotoxin and has quite a short mean half-life (70 hours). Numerous randomized clinical trials have demonstrated its efficacy to improve signs and symptoms in early and established RA and other inflammatory arthritis. Furthermore, etanercept has shown its ability to prevent radiographic progression and to improve health-related quality of life in patients with RA and psoriatic arthritis. A combination of etanercept plus methotrexate was more efficacious than etanercept monotherapy in RA patients but there is currently no evidence that such rheumatic combination is better than monotherapy in other disorders. Etanercept was generally well tolerated both in controlled trials with withdrawal rates being similar to the comparator groups and in large observational studies. Infections and injection-site reactions were the most frequently reported events. Serious infections were slightly increased but the occurrence of tuberculosis seemed less frequent than with anti-TNF monoclonal antibodies (infliximab and adalimumab). The benefit-risk ratio of etanercept appeared to be very positive, and this drug has now emerged as a major therapy in patients with active inflammatory arthritis. Furthermore, it is more frequently considered as an emerging and valuable option in patients with early disease.