IL17A and dermatomyositis: Interestingly, Secukinumab, an IL-17 inhibitor, causes a disease flare of dermatomyositis.[8] This difference may be related to the different pathogeneses of dermatomyositis and polymyositis, as well as the fact that Secukinumab is an IgG1 mAb targeting IL-17A, while Ixekizumab is an IgG4 mAb targeting IL-17A.