Treatment sequences in moderate-to-severe psoriasis: a hospital-based retrospective analysis

Background: For moderate-to-severe psoriasis, clinical guidelines recommend biologic treatments after failure of at least one traditional systemic therapy. Biologics target different pathways, but a common challenge is loss of efficacy, often requiring a switch. This study explores real-world therapeutic management of moderate-to-severe psoriasis, focusing on biologic treatments. Methods: A retrospective study was conducted using health records of adult patients currently receiving biologics at Sant’Orsola Hospital in Bologna. Therapeutic sequences were investigated using state sequence analysis. Within-sequence Shannon entropy was calculated and used as the outcome in linear regression models. A directed acyclic graph informed the hierarchical regression models to identify factors influencing treatment duration. Results: The cohort included 364 patients. Adalimumab was the most common first-line biologic (27%), followed by secukinumab (18%) and etanercept (16%). Nearly half of patients (48%) switched treatments. Increasing age was associated with lower sequence heterogeneity (β = -0.001, p = 0.002). Ustekinumab demonstrated the longest median treatment duration (1,841 days), while etanercept had the shortest (639 days). After adjusting for confounding variables, ustekinumab maintained its positive effect on treatment duration (β = 0.285, p = 0.009). Conclusion: The treatment duration for ustekinumab was encouraging, supporting its potential role as a durable option in these patients.