Tumour necrosis factor (TNF) has a central role in the pathogenesis of psoriatic arthritis (PsA). Adalimumab (Humira, Abbott Laboratories) is the first fully human, recombinant IgG1 monoclonal antibody that specifically targets human TNF. Adalimumab blocks the interaction of TNF with the p55 and p75 cell surface TNF receptors, thereby neutralising the activity of this cytokine. In clinical trials of patients with PsA, adalimumab significantly reduced both joint and skin symptoms. In addition, structural changes were inhibited, and statistically and clinically significant improvements in measures of disability and quality of life were observed. Adalimumab was generally safe and well tolerated.