Irrespective of their mechanism of action, all biologic drugs have demonstrated comparable efficacy in terms of articular manifestations; indeed, their use is prioritized based on SpA extraarticular manifestations such as uveitis and inflammatory bowel disease where monoclonal anti-TNF inhibitors are clearly superior versus etanercept as well as skin psoriasis where anti-IL-17 agents are recommended. This evidence concerns the gene IL17A and uveitis.