Ixekizumab: an anti-IL-17A monoclonal antibody for the treatment of psoriatic arthritis

Introduction: Psoriatic arthritis (PsA) is an inflammatory rheumatic disease that manifests itself with synovitis, dactylitis, enthesitis and also axial involvement. Interleukin-17A has been identified as a master cytokine in the inflammatory response and pathogenesis of PsA and spondyloarthritis in general. Ixekizumab is a new humanized monoclonal antibody that blocks the biological activity of IL-17A. This biological agent has previously demonstrated a high level of efficacy in psoriasis. Areas covered: This review discusses the basic immunology of the IL-17 cytokine family, the contribution of IL-17A to the immunopathogenesis of PsA, the clinical trials that evaluated ixekizumab in patients with PsA (SPIRIT program) and the safety of this agent. Expert opinion: Ixekizumab demonstrated its efficacy in different aspects of PsA including peripheral joint involvement, dactylitis, skin symptoms and patient reported outcomes in the 2 phase III trials from the SPIRIT program. Its safety profile was consistent with previous observations in patients with psoriasis. The role of IL-17A in the management of patients with PsA needs further clarification. According to EULAR recommendations for the management of PsA, IL-17A inhibitors may be used as second line biological DMARDs after TNF inhibitors.