Treatment Retention and Safety of Ixekizumab in Psoriatic Arthritis: A Real Life Single-Center Experience

Background and objectives: Information on the performance of ixekizumab (IXE) in patients with psoriatic arthritis (PsA) in clinical practice is scarce. We aimed to analyze the retention rate and safety of IXE in patients with PsA in routine clinical practice. Methods: A retrospective longitudinal observational single-center study of all patients with PsA who had received at least one dose of IXE. Adverse events (AEs) and drug retention rate were the main study focus. Survival was analyzed using Kaplan-Meier curves and predictive factors using multivariate Cox regression analysis. The hazard ratio (HR) was used as a measure of the association. Results: Seventy-two patients were included (52 women and 20 men). Median disease duration was 5 years (IQR 3-9). More than 90% received >= 2 biologic and/or targeted synthetic disease-modifying anti-rheumatic drugs (DMARDs) prior to IXE. Ixekizumab showed a 1-year retention rate of 65% and a 2-year retention rate of 57%. Regarding discontinuation due to AEs, 0.18 AEs per person-year were identified. The number of previous biologics did not influence drug survival but prior use of methotrexate (HR 2.31 (95% CI 1.05-5.10), p < 0.05) and depression (HR 2.40 (95% CI 1.07-5.41), p < 0.05) increased the risk of IXE discontinuation. Conclusions: Ixekizumab showed a good retention rate in a PsA population mostly refractory to biologic and targeted synthetic DMARDs. Drug survival was consistently good regardless of age, gender, metabolic comorbidities, smoking status, or prior number of biologic therapies. This information may be of interest to better position this drug in the PsA treatment algorithms.