Golimumab is a human anti-tumor necrosis factor (TNF) monoclonal antibody that acts principally by targeting and neutralizing TNF to prevent inflammation and destruction of cartilage and bone. Large, randomized, double-blind trials in patients with rheumatoid arthritis who were methotrexate-naïve (GO-BEFORE) or -experienced (GO-FORWARD) have shown that golimumab 50 or 100 mg every 4 weeks, in combination with methotrexate, was more effective than methotrexate alone for improving signs and symptoms of arthritis at weeks 14 and/or 24, according to American College of Rheumatology (ACR) criteria. In patients with active rheumatoid arthritis despite previous treatment with anti-TNF agents (GO-AFTER), golimumab 50 or 100 mg every 4 weeks was more effective than placebo for improving ACR responses at weeks 14 and 24; most patients in the study received concomitant methotrexate. In patients with psoriatic arthritis in the GO-REVEAL study, significantly more golimumab than placebo recipients achieved a >or=20% improvement in ACR criteria at week 14. Golimumab was also superior to placebo for improving the signs and symptoms of ankylosing spondylitis in the GO-RAISE study; significantly more golimumab than placebo recipients achieved a >or=20% improvement in the Assessment in Ankylosing Spondylitis (ASAS) criteria at week 14. In the five phase III trials in patients with rheumatoid arthritis, psoriatic arthritis, or ankylosing spondylitis, there was no clear evidence of improved ACR or ASAS responses with the 100 mg dosage compared with the 50 mg dosage of golimumab. The tolerability profile of golimumab was generally consistent with that of other anti-TNF agents.