Biologic switching in psoriatic arthritis: Insights from real-world data and key risk factors

Background: Psoriatic arthritis (PsA) is a chronic, heterogeneous inflammatory condition requiring personalized treatment strategies. Biologic therapy switching reflects the disease's dynamic nature and aims to optimize disease control while balancing efficacy, safety, and patient-specific factors. Objective: To analyze real-world switching patterns of biologic disease-modifying antirheumatic drugs (bDMARDs) in PsA patients, identify associated risk factors, and provide insights into predictors of mode-of-action switching. Methods: This retrospective cohort study utilized the Clalit Health Services database (2005–2023), encompassing 9607 PsA patients in Israel. Patients initiating bDMARDs were tracked for therapy switches. Clinical, demographic, and socioeconomic variables were extracted, and statistical analyses compared characteristics between switchers and non-switchers. Patterns of switching were stratified by the number of switches and study periods (2005–2014, 2015–2023). Results: Among 3851 patients initiating bDMARDs, 1848 (48 %) switched therapy at least once. Anti-TNF therapy was the dominant first-line choice, but switching to anti-IL17 therapy became prevalent as the first switch in both single-switch and multi-switch scenarios. Subsequent switches often involved cycling back to anti-TNF or transitioning to other modes of action, such as anti-IL23 or JAK inhibitors. Switching patterns remained consistent across study periods. Switchers were more likely to be female (56.5 vs. 50.6 %, p < 0.001), obese (28.1 vs. 22.6 %, p < 0.001), smokers (41.6 vs. 37.1 %, p = 0.005), and from lower socioeconomic backgrounds (34.1 vs 31.4 %, p = 0.04). These factors were all independently associated with switching in mechanism of action on multivariate analysis. Conclusion: Cross class biologic switching is common in PsA management (48 %) and influenced by patient demographics and comorbidities. Switching patterns were consistent across time periods despite expanding therapeutic options.