Toward a Treat‐to‐Target Strategy in Juvenile Dermatomyositis: What Are the Suitable Targets and Optimal Timing of Their Achievement?

Objective: Juvenile dermatomyositis (JDM) is a rare autoimmune condition. The treat-to-target strategy has garnered interest in pediatric rheumatology. It is based on defining clear therapeutic targets, with frequent disease activity monitoring, and adjustment of the treatments if targets are not met within a defined time frame. Recently, an international task force of experts launched an initiative aimed at the development of recommendations for the adoption of treat-to-target strategy in JDM. This study was done to support those recommendations. We aimed to determine the time-to-treatment response in patients with JDM, to better inform the development of a treat-to-target strategy in JDM. Methods: This is a retrospective review of patients with a physician-confirmed diagnosis of JDM, observed at two tertiary care centers—the Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Istituto Giannina Gaslini (Gaslini), and The Hospital for Sick Children (SickKids). Demographic and clinical data were obtained on all patients with JDM during the first two years following diagnosis. Kaplan-Meier survival curves were used to determine time to outcome definitions. Results: A total of 187 patients were identified across two sites; the mean age of diagnosis was 8 years. On average, patients with JDM achieved normalization of muscle enzymes and muscle remission three months and six months after treatment initiation, respectively. Skin remission occurred within 12 months after starting treatment. Time to reach inactive disease varied between the sites, with median time being 10.3 months (Gaslini) and 8.8 months (SickKids). Conclusion: This study provides real-world data for potential timelines to target with a treat-to-target strategy for JDM.