Anti-tumour necrosis factor alpha therapy for ankylosing spondylitis: international experience

The conventional approach to treatment of patients with spondyloarthritis (SpA), particularly ankylosing spondylitis (AS), has serious limitations, adding a sense of urgency to the evaluation of new treatments for these rheumatic disorders. Tumour necrosis factor alpha (TNFalpha) is a cytokine that has been shown to mediate inflammatory and regulatory activities in SpA and other immune mediated diseases, including other arthritides and inflammatory bowel disease. Positive results have been reported in several international open label and randomised controlled trials of infliximab and etanercept, the two main biological agents targeting TNFalpha, which have included approximately 300 patients with SpA. Specifically, TNFalpha-directed therapy resulted in significant improvements in disease activity, function, and quality of life in these patients, most of whom had AS and received infliximab. Preliminary evidence from open label, long term extension trials suggests clinical benefit with continued use. Serious side effects were rare and consistent with experience from patient groups receiving infliximab or etanercept treatment for inflammatory bowel disease or rheumatoid arthritis. Together, these findings herald an age of more effective treatment of patients with AS with anti-TNFalpha and other emerging biological agents.