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.