Etanercept
Etanercept (Enbrel®, co-marketed by Amgen and Wyeth) is a synthetic soluble receptor for Tumor necrosis factor-alpha (TNFα). It is a small protein (p75, i.e., its molecular weight is 75 KD) that binds TNFα and decreases its role in inflammatory diseases such as rheumatoid arthritis, Crohn's disease, psoriasis, psoriatic arthritis, and ankylosing spondylitis. It was released briefly after infliximab, a monoclonal antibody with anti-TNFα activity, but etanercept is generally tolerated better and does not seem to cause reactivation of tuberculosis.
