Dimeric fusion protein including the extracellular ligand-binding portion of the human seventy five kilodalton (p75) tumor necrosis factor receptor (TNFR) linked to the Fc part of human IgG1. The Fc factor of etanercept consists of the CH2 area, the CH3 area and hinge region, however now not the CH1 domain of IgG1. Etanercept is produced by means of recombinant DNA technology in a chinese hamster ovary (CHO) mammalian mobile expression gadget. It includes 934 amino acids.
Etanercept binds specifically to tumor necrosis factor (TNF) and thereby modulates biological processes that are induced or regulated by TNF. Such processes or molecules affected include the level of adhesion molecules expressed, as well as serum levels of cytokines and matrix metalloproteinase-3, also known as stromelysin. In animal models, etanarcept has been demonstrated to affect inflammation, such as in murine collagen-induced arthritis.
Etanercept is indicated for the treatment of moderately to severely active rheumatoid arthritis in adults and chronic moderate to severe plaque psoriasis in adults. It is also used to manage signs and symptoms of polyarticular idiopathic arthritis in those aged 4 to 17 after insufficient response to one or more disease-modifying anti-rheumatic drugs. Etanercept is also used to improve psoriatic arthritis and ankylosing spondylitis.
There are two distinct receptors for TNF (TNFRs), a 55 kilodalton protein (p55) and a 75 kilodalton protein (p75). The biological activity of TNF is dependent upon binding to either cell surface receptor (p75 or p55). Etanercept is a dimeric soluble form of the p75 TNF receptor that can bind to two TNF molecules, thereby effectively removing them from circulation. TNF is a naturally occurring cytokine that is involved in normal inflammatory and immune responses. Increased levels of TNF are found in tissues and fluids of those with rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis (AS), and plaque psoriasis.