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

BackgroundReal-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. ObjectivesTo report on IL-17i effectiveness, treatment modifications and C-t use in our clinic. MethodsData 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. ResultsA 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. ConclusionsThis 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.