The Clinical Significance of Simultaneous IL-17A and IL-17F Blockade in Psoriasis Non-Responding to Anti-IL17A Therapy

The better understanding of the immunopathogenesis of psoriasis has led to the development of highly efficacious targeted therapies with favorable safety profiles. Among them, the class of Interleukin (IL)-17 antibodies are well established for the treatment of psoriasis, psoriatic arthritis and axial spondyloarthritis. Bimekizumab is a new antibody that simultaneously neutralizes IL-17A and IL-17F. We present two patients with psoriasis, who lost response to several biologics, among them IL-17 antagonists such as secukinumab, ixekizumab or brodalumab. Besides plaque-type psoriasis, patients also had psoriasis in hard-to-treat areas such as scalp and groins or psoriatic arthritis. Remarkably, both patients already responded to the therapy with bimekizumab 4 weeks after the first injection and, one year thereafter, both patients sustained PASI100. No side effects were observed. The fast response to bimekizumab emphasizes the crucial role of IL-17F in the pathogenesis of psoriasis. Besides, due to the new mechanism of action, non-responders to other anti-IL-17 therapies could benefit when switched to bimekizumab.