Successful short term treatment of patients with severe undifferentiated spondyloarthritis with the anti-tumor necrosis factor-alpha fusion receptor protein etanercept.

Objective: Anti-tumor necrosis factor-a (TNF-alpha) therapy has been successfully used in patients with active ankylosing spondylitis (AS) and other subtypes of spondyloarthritis (SpA). Treatment options for patients with severe forms of undifferentiated spondyloarthritis (uSpA), a rather frequent SpA subset, are limited. In this open study we examined the efficacy of the TNF-alpha receptor fusion protein etanercept in patients with uSpA.