TNF and ankylosing spondylitis: An open-label trial reported data from 20 patients with active ankylosing spondylitis (AS) (10 of whom were anti-TNF naïve) treated with rituximab (1000 mg × 2, 2 weeks apart) with an efficacy of 90% in the group naïve to anti-TNF and 30% in the group with prior anti-TNF failure (effectiveness defined by a 20% reduction in the Bath Ankylosing Spondylitis Disease Activity Index).