What is the difference between Humira and Cimzia?

Humira (adalimumab) and Cimzia (certolizumab) both belong to a class of drugs called tumor necrosis factor blockers. This is like comparing apples and oranges...while they are different drugs, they do the same thing. However, Humira is used to treat six different diseases (rheumatoid arthritis, juvenile idopathic arthritis, psoriatic arthritis, ankylosing spondylitis, Crohn's disease, and plaque psoriasis), Cimzia is used to treat rheumatoid arthritis and Crohn's disease only.