Etanercept: an introduction.

Etanercept is a member of a new generation of therapeutic agents referred to as biologics or targeted therapies, which have caused some enthusiasm in the field of autoimmune disorders in recent years. Most of these agents are inhibitors of tumor necrosis factor, a key cytokine in the chronic inflammatory process. Etanercept is a tumor necrosis factor recombinant fusion protein consisting of two molecules of the tumor necrosis factor p75 receptor, which binds to the cytokine and thus antagonizes its effect. This review provides an introduction to the compound and describes its clinical efficacy in the main indications, rheumatoid arthritis, ankylosing spondylitis, psoriasis, psoriatic arthritis and juvenile rheumatoid arthritis. Focus has been placed on the newest data on long-term efficacy and radiologic outcome parameters. Reports on the use of the drug in other indications are reviewed as well as the actual data on safety issues. The authors will provide their opinion on the current status of the drug and speculate on its rank in the future.