Real-World Long-Term Effectiveness and Safety of Secukinumab in Psoriasis: Up to 7 Years of Evidence from the Italian Landscape Psoriasis (IL PSO) Multicenter Retrospective Study

Introduction: Secukinumab, approved in 2015 for the treatment of moderate-to-severe psoriasis, has demonstrated sustained efficacy and safety in pivotal randomized controlled trials. However, real-world data on its long-term effectiveness and safety are limited. We conducted a multicenter retrospective study involving 15 Italian dermatology units to assess the long-term effectiveness and safety of secukinumab in routine clinical practice over a period of up to 7 years. Methods: A total of 769 adult patients with moderate-to-severe psoriasis who received continuous secukinumab treatment for at least 4 years were included. We assessed effectiveness in terms of the Psoriasis Area and Severity Index (PASI) 90 and 100 (complete skin clearance) and an absolute PASI score of ≤ 2 at various time points from week 16 to 7 years. We performed subgroup analyses to evaluate the impact of different comorbidities. Safety was assessed by recording all adverse events (AEs) reported during follow-up visits. Results: PASI 90 was achieved by 36.0% of patients at week 16, increasing to 71.0% at year 1, 84.1% at year 4, 87.0% at year 5, and 90.0% at year 6. PASI 100 rates rose from 27.4% at week 16 to 67.1% at year 4 and 80.2% at year 7. Patients with concomitant psoriatic arthritis (PsA) showed significantly higher PASI 100 rates at years 5 and 6 (p ≤ 0.05). The overall incidence of AEs was low, with serious AEs occurring in a small number of patients. Treatment was permanently discontinued due to adverse drug reactions in five patients (three due to de novo malignancies, one due to eosinophilic pneumonia, and one due to massive pulmonary embolism). Conclusions: In this selected cohort of long-term responders, secukinumab demonstrated sustained and progressively increasing effectiveness with a favorable safety profile over up to 7 years of treatment.