Etanercept: a review of its use in the management of ankylosing spondylitis and psoriatic arthritis.

Etanercept (Enbrel), a recombinant, dimeric, soluble tumour necrosis factor (TNF) receptor protein, is approved in various countries for the treatment of adult patients with ankylosing spondylitis or psoriatic arthritis. Monotherapy with subcutaneous etanercept 25mg twice weekly or 50mg once weekly was effective and generally well tolerated in patients with ankylosing spondylitis or psoriatic arthritis participating in several large, well designed clinical studies. Treatment with etanercept was more effective than placebo in reducing disease activity and improving health-related quality of life (HR-QOL) in both patient populations, and in delaying structural disease progression in patients with psoriatic arthritis. The beneficial response to etanercept achieved with shorter-term treatment was sustained in studies of up to 4 years' total duration. Randomised, well designed, head-to-head comparisons, including pharmacoeconomic analyses, with other anti-TNF biological modulators are required to accurately position etanercept and fully establish its cost effectiveness. In the meantime, etanercept is a valuable treatment option for patients with ankylosing spondylitis or psoriatic arthritis who are suitable candidates for therapy.