Cimzia (certolizumab) is a prescription drug used to treat plaque psoriasis, Crohn’s disease, and some types of arthritis, including rheumatoid arthritis. It’s given as an injection under the skin.

Each of these conditions causes your immune system (the body’s defense against disease) to mistakenly attack healthy cells. Cimzia and Humira help prevent the immune system from doing this. The drugs ...