Efficacy was noticeable 4 to 8 weeks after injection.[18,19] Nocturne et al reported data from 8 patients treated with rituximab (3 with ankylosing spondylitis, 2 with undifferentiated spondyloarthritis and 3 with psoriatic arthritis) of whom 7 had failed anti-TNF treatment. Here, TNF is linked to ankylosing spondylitis.