Biologics in spondyloarthritis: TNFα inhibitors and other agents.

TNFα inhibitors are currently the only class of biological agent that has proven to be effective in the treatment of patients with ankylosing spondylitis and/or spondyloarthritis (SpA). These agents have been shown to control inflammatory pain of the axial skeleton, peripheral clinical manifestations, certain extra-articular manifestations as well as systemic and spinal MRI inflammation. Conversely, they are unable to slow radiographic progression in the spine. Since around 20-30% of patients with SpA are considered as nonmajor responders to TNFα inhibitors, there is a need for alternative therapies. Biological agents that target IL-1, IL-6, B cells and costimulatory pathways are not effective in SpA. Conversely, novel biological agents blocking IL-23 or IL-17 are promising in SpA, especially secukinumab, an anti-IL-17A monoclonal antibody.