Etanercept: new indication. For ankylosing spondylitis: another option

Abstract

(1) Nonsteroidal antiinflammatory drugs (NSAIDs) are the standard drug treatments in ankylosing spondylitis. Infliximab, a TNF-alpha antagonist immunosuppressant, is reserved for severely ill patients for whom standard treatment has failed. Infliximab is provided as an infusion and requires close monitoring. (2) Etanercept, another TNF-alpha antagonist immunosuppressant, was recently approved in Europe for the treatment of ankylosing spondylitis. (3) In three double-blind placebo-controlled trials (40 patients treated for 4 months, 277 patients treated for 6 months, 84 patients treated for 3 months), between 60% and 80% of patients on etanercept "responded" to treatment, with at least a 20% improvement in an endpoint combining various symptoms of ankylosing spondylitis. There are no direct comparisons to show whether this short-term effect differs tangibly from that of infliximab. (4) Etanercept has the same adverse effect profile as infliximab. In particular, both immunosuppressants increase the risk of tuberculosis and opportunistic infections. Risks associated with long-term immunosuppression, such as malignancy, are poorly understood: postmarketing follow-up data are only available for 6 years. (5) As of 7 December 2004, no detailed results had been published on randomised trials comparing etanercept with other recently approved immunosuppressants used to treat ankylosing spondylitis. (6) Etanercept is administered subcutaneously twice a week, on an outpatient basis, for the treatment of ankylosing spondylitis as well as psoriatic rheumatism. In contrast, infliximab is infused every 6 to 8 weeks and must be administered in hospital. (7) Etanercept is an alternative to infliximab as a treatment option for patients with ankylosing spondylitis who have failed to respond to standard treatments.