Rotation or change of biotherapy after TNF blocker treatment failure for axial spondyloarthritis: the ROC-SpA study, a randomised controlled study protocol

Axial spondyloarthritis (axSpA) is a chronic inflammatory disease characterised by inflammatory low back pain. Non-steroidal anti-inflammatory drugs (NSAIDs) are recommended as a first treatment in axSpA. In case of inadequate response to NSAIDs, biological disease-modifying antirheumatic drugs (bDMARDs) should be introduced according to the recommendations of the European League Against Rheumatism (EULAR) and the American College of Rheumatology. Until 2015, only bDMARD was recommended for axSpA in case of failure to anti-tumour necrosis factor (TNF). The 2022 Assessment of SpondyloArthritis International Society (ASAS)-EULAR recommendation proposed to start an alternative bDMARD but without advocating a switch in mode of action as proposed in rheumatoid arthritis. Since 2015, the inhibition of interleukin (IL)-17 has demonstrated efficacy in axSpA. Then, we designed a randomised multicentre clinical trial to identify the more effective treatment after a first anti-TNF failure in axSpA, comparing an anti-IL-17 to a second anti-TNF.