P97 Drug survival rates and predictors of switching in psoriasis: a study of biologics and small molecules in the argentine population

Abstract Several real-world drug survival studies of biologics and small molecules (B&SM) have been published, but not in Argentina. The objectives of this study were to estimate the proportion of patients requiring switching B&SM, identify factors associated with switching, and evaluate the drug survival rate by class of the first B&SM. A retrospective cohort study was conducted on patients with psoriasis disease who consecutively attended the psoriasis clinic from 1 March 2022, to 29 February 2024. Patients treated with B&SM were selected. The start date of the first B&SM was considered the index date, with the end date being the switching date, death, or last visit. Drug survival rates were analysed using a Kaplan–Meier graph and log-rank test. Switching associated factors were examined through a Cox proportional hazards model, adjusting for age, sex, psoriasis onset time, obesity, diabetes, joint involvement, and worst psoriasis area and severity index (PASI) score.A total of 893 patients were evaluated, with 18.9% (169) receiving B&SM; 64% (108) were men, with a mean age of 55 [standard deviation (SD) 16.3]. 74.6% (126) had psoriasis that started before age 40, and the mean worst PASI score was 18.8 (SD 11.2). Joint involvement was present in 30.8% (52), and among them, 17.3% (9) were diagnosed with psoriatic arthritis after biologic treatment initiation. Anti-TNF agents were prescribed in 50.3% of cases and antiIL-17 in 22.5% as the first biologic. Anti-TNF agents had a higher survival rate when used as the first biological (P = 0.0016). Switching B&SM was needed in 37.9% (64) of cases, with 39% of failures occurring within the initial treatment year. The most common reason for change was secondary failure, with inter-class change accounting for 86% (55) of cases. The Cox proportional hazard model showed that joint involvement was linked to an increased risk of switching B&SM [hazard ratio (HR) 2.12, 95% confidence interval (CI) 1.14–3.97; P = 0.017]. Additionally, each unit increase in PASI score raised the HR of switching by 1.03 (95% CI 1.00–1.05; P = 0.034). Finally, diabetes was associated with a heightened risk of switching (HR 1.49, 95% CI 1.09–2.06; P = 0.012). In our setting, joint involvement, high PASI score, and diabetes are predictors of switching B&SM.