Infliximab is a chimeric monoclonal antibody biologic drug that works against tumor necrosis factor alpha (TNF-α) and is used to treat autoimmune diseases. Infliximab was approved by the U.S. Food and Drug Administration (FDA) for the treatment of Crohn's disease, ulcerative colitis, psoriasis, psoriatic arthritis, ankylosing spondylitis, and rheumatoid arthritis.It is used off-label outside its FDA approval for Behçet's disease and other conditions. Infliximab is administered by intravenous infusion, typically at six- to eight-week intervals. It cannot be given by mouth because the digestive system would destroy the drug.