Two-Year Treatment Persistence and Effectiveness of Ixekizumab in Psoriatic Arthritis in Italian Clinical Practice: Results from the ROUTE-IXE Study

Randomised controlled trials have demonstrated the efficacy and safety of ixekizumab as a treatment for active psoriatic arthritis (PsA), and real-world evidence on long-term persistence and effectiveness is emerging. This study aimed to characterise ixekizumab use in the Italian routine clinical setting and provide insights into its persistence and effectiveness, complementing real-world evidence from single-country cohorts and multinational studies. This descriptive, multicentre, retrospective study was conducted in Italy in adult patients with PsA who received a first prescription of ixekizumab after January 2021 and had a minimum of three subsequent evaluations. The primary objective was to describe treatment persistence at week 104. Secondary objectives aimed to describe patients’ demographic and clinical characteristics and evaluate treatment persistence and effectiveness at weeks 12, 24, 52 and 104. A total of 204 patients, of whom 88 (43.1%) were male and 116 (56.9%) were female, were eligible for inclusion in the study. The mean (standard deviation) age was 55.8 (11.0) years. Comorbidities were present in 66.7% ( n = 136) of patients, with the majority being cardiometabolic disorders. The median (interquartile range) disease duration was 5.3 (2.4–12.2) years. Peripheral joint involvement was the most common PsA manifestation (66.7%, n = 136), followed by mixed symptoms (28.4%, n = 58) and axial-only symptoms (4.9%, n = 10). Most patients (74.5%, n = 152) had prior exposure to biologic therapy; most also presented with high or moderate disease activity (84.6%, n = 132). Treatment persistence at week 104 was 78.6% ( n = 158), and the Kaplan–Meier estimate was 0.800 (95% confidence interval 0.736–0.850). Disease activity progressively improved. At week 104, 45.3% ( n = 72) of patients had low disease activity, and 25.2% ( n = 40) were in remission; 34.1% ( n = 31) achieved very low disease activity, and, among patients with axial involvement, 61.9% ( n = 26) had inactive or mild disease. Ixekizumab showed high 2-year treatment persistence and effectiveness in the treatment of patients with PsA and complex disease profiles, supporting its value in informing treatment decisions and optimising patient outcomes.