Drug survival of systemic treatments for severe paediatric psoriasis: An international retrospective study

Background: Three conventional systemic treatments, acitretin, methotrexate and cyclosporine, are used for severe childhood psoriasis. In many countries, they are the only treatments available. There are limited data and no comparative evaluations of these treatments. Objectives: The international, multicentre, retrospective, real-world ACMe cohort was developed to assess the comparative 2-year drug survival of acitretin, methotrexate and cyclosporine in paediatric psoriasis. Methods: Thirty dermatology centres in France, Italy, Portugal, Canada and the United Kingdom participated in the study. Demographic and clinical data were collected using a standardized form for patients receiving treatment from 2014 to 2024. Results: A total of 506 patients received 683 treatments: acitretin (n = 316), methotrexate (n = 245) and cyclosporine (n = 122). Median drug survival at 2 years was similar for acitretin (10.8 months) and methotrexate (10.9 months), but lower for cyclosporine (3.9 months; p < 0.0001). The most common reasons for discontinuation were inefficacy for cyclosporine (43.0%), and loss of effectiveness for acitretin (27.2%) and methotrexate (31.8%). No demographic, clinical or therapeutic characteristics were associated with higher rates of treatment maintenance at 6 months. Drug survival was higher for acitretin when used as a first-line therapy (median drug survival: 11.3 months for first-line vs. 5.5 months for second- or subsequent-line therapy; p < 0.001), but there were no differences for methotrexate and cyclosporine. Adverse events (AEs) were the reason for stopping treatment in 13.8% of patients on acitretin, 23.1% on methotrexate and 14.0% on cyclosporine (p = 0.02). Only one serious AE was reported: hepatitis in the methotrexate group. Conclusions: This cohort study showed that acitretin and methotrexate had comparable 2-year drug survival rates, which were superior to cyclosporine. We did not find any predictive factors for increased treatment maintenance except for first-line use of acitretin. AEs were a frequent reason for discontinuing treatments. These results may help develop treatment algorithms for systemic therapy in paediatric psoriasis.