Efficacy and safety of oral and parenteral methotrexate therapy in children with juvenile idiopathic arthritis: An observational study with patients from the German Methotrexate Registry

Objective The German Methotrexate Registry has been collecting data concerning the efficacy and safety of methotrexate (MTX) treatment since 2005. The aim of this retrospective analysis is to compare oral and parenteral MTX treatment regarding efficacy and safety. Methods Inclusion criteria were diagnosis of juvenile idiopathic arthritis, MTX treatment for at least 6 months, a consistent route of administration of MTX, and no previous or concomitant treatment with biologic agents. Efficacy was measured by the American College of Rheumatology (ACR) pediatric (Pedi) criteria. Primary outcome was efficacy defined as the number of patients reaching ACR Pedi 30 improvement criteria after 6 months of treatment. Secondary outcome criteria were the ACR Pedi 50 and Pedi 70 criteria at 6 and 12 months, respectively. Analyses were performed with the intent‐to‐treat population. Results Of the 411 eligible patients, 259 (63%) received oral MTX and 152 (37%) received subcutaneous MTX. In both patient groups, a comparable weekly dose of MTX (0.4 mg/kg versus 0.42 mg/kg) was used, and a comparable number of patients received concomitant steroids. The primary outcome in both treatment groups was that a comparably high number of patients showed a clinical response according to the ACR Pedi 30 score after 6 months of treatment (73% versus 72%; P = 0.87). Twenty‐two percent of patients with oral therapy and 27% with subcutaneous therapy had at least 1 documented adverse event. Discontinuation of treatment was observed in both groups with equal frequency, while significantly more patients with subcutaneous application discontinued MTX because of adverse events (11% versus 5%; P = 0.02). Conclusion In this retrospective analysis, parenteral MTX was not superior to oral administration regarding efficacy and tolerability.