Response to Interleukin-17A Inhibitors According to Prior Biologic Exposures: A Danish Nationwide Study

Whether response to an interleukin (IL-17) inhibitor is different in patients with previous exposure to an IL-17 inhibitor compared with patients with exposure to biologics with other cytokine targets remains to be elucidated. Therefore, the aim of this study was to assess whether previous exposure to an IL-17A inhibitor was associated with worse response than exposure to (an)other biologic(s). All patients in the DERMBIO register treated with an IL-17A inhibitor (secukinumab or ixekizumab) were included. With an absolute Psoriasis Area and Severity Index (PASI) ≤ 2 as response, the proportion of responders treated with IL-17A inhibitors was assessed in patients previously treated with another IL-17A inhibitor and compared with patients with previous exposure to (an)other biologic(s), using a χ(2) test. In total, 100, 93 and 83 patients with previous exposure to an IL-17A inhibitor and 414, 372 and 314 patients with previous exposure to (an) other biologic(s) were assessed after 3, 6 and 12 months, respectively. No differences in the proportion of patients achieving PASI ≤ 2 were observed between the 2 groups after 3 months (54% vs 57%, p = 0.59), 6 months (70% vs 66%, p = 0.42) and 12 months (69% vs 60%, p = 0.14). In conclusion, when treating patients with IL-17A inhibitors the cytokine target of the previous biologic does not appear to affect the response. SIGNIFICANCE This study examined whether patients who were previously treated with an interleukin-17A inhibitor responded differently to another interleukin-17A inhibitor compared with those who had been treated with other biologics. The study included patients treated with secukinumab or ixekizumab. After 3, 6 and 12 months, no significant difference was found in the proportion of patients achieving a good response (Psoriasis Area and Severity Index ≤ 2) between those with prior exposure to interleukin-17A inhibitor and those with exposure to other biologics. In conclusion, prior exposure to an interleukin-17A inhibitor does not appear to affect the response when treating patients with interleukin-17A inhibitors.