Etanercept, a fusion protein of the soluble TNF receptor 2 and a Fc fragment (human IgG1 isotype). Etanercept can be used to treat autoimmune diseases by interfering with tumor necrosis factor (TNF), a soluble inflammatory cytokine, by acting as a TNF inhibitor. TNF alpha is the "master regulator" of the inflammatory (immune) response in many organ systems. Autoimmune diseases are caused by an overactive immune response. Etanercept has the potential to treat these diseases by inhibiting TNF alpha. Etanercept binds to TNF alpha and decreases its role in disorders involving excess inflammation in humans and other animals, including autoimmune diseases such as ankylosing spondylitis, juvenile rheumatoid arthritis, psoriasis, psoriatic arthritis, rheumatoid arthritis, and, potentially, in a variety of other disorders mediated by excess TNF alpha.
