Blocking interleukin‐17 in psoriasis: Real‐world experience from the PsoPlus cohort

Abstract Background Real‐world studies on the use of biologics in psoriasis (Pso) are increasing, but still scarce. Trough concentrations ( C t s) of interleukin‐17 inhibitors (IL‐17i) seem promising for clinical decision‐making, but their value in daily practice has yet to be proven. Objectives To report on IL‐17i effectiveness, treatment modifications and C t use in our clinic. Methods Data were collected from IL‐17i‐treated Pso patients followed up in the PsoPlus clinic at the Dermatology department, Ghent University Hospital, Belgium. Descriptive statistics and Kaplan–Meier analysis were performed. Results A total of 111 patients were included, counting for 134 IL‐17i courses (secukinumab, ixekizumab, and brodalumab). Fifty‐five per cent of the patients were bio‐naive prior to IL‐17i initiation. During maintenance, merely 97.0% and 77% achieved near‐complete and complete skin clearance, respectively. Major reasons for treatment modification were suboptimal response (63.0%) and safety issues (9.3%). Reported modifications were switch (25.4%), dose escalation (11.9%), dose de‐escalation (6.7%), treatment association (6.0%) and IL‐17i stop (3.0%). Overall drug survival was 69.0 months, without difference between the different IL‐17i ( p = 0.078). Ixekizumab tended to have the highest survival. Drug survival was higher in bio‐naive subjects compared to bio‐experienced subjects ( p = 0.011). C t was measured in 20 patients and interpreted post hoc. In 85%, the clinical decision was in accordance with the C t (e.g. substantiated need for dose escalation). For the other cases, the C t would have led to another clinical decision if known at that time. Conclusions This real‐world study showed that IL‐17i are very effective drugs for Pso, with ixekizumab as leading biologic. Prior bio‐experience seemed to impact IL‐17i drug survival. Treatment modifications were mainly performed in case of insufficient response, primarily via switch and dose escalation, and least frequently in ixekizumab patients. C t might rationalize clinical decision‐making; however, there is need for standardized algorithms to corroborate its use.