Cimzia is a prescription brand name drug belonging to the drug class TNF alfa inhibitors. TNF stands for Tumor Necrosis Factor. Cimzia is used in adult patients to reduce the signs and symptoms of moderate to severe Crohn's disease. However, Cimzia is given when all other medicines have failed. Cimzia is also used to treat moderate to severe arthritis, in many forms. Cimzia works to reduce inflammation in the body.