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.