Phase 2 Study of ARGX-119 IV for Children Aged 5 to Under 18 Years With Spinal Muscular Atrophy Evaluating Safety, Effectiveness, and Immune Response

What this Trial Is About

This research aims to find the right dose of ARGX-119 for children aged 5 to less than 18 years with spinal muscular atrophy SMA. It evaluates the safety, tolerability, effectiveness, how the drug moves through the body, and immune response to ARGX-119. SMA causes muscle weakness due to neuromuscular junction dysfunction, and ARGX-119 may improve muscle function and quality of life by targeting this mechanism. Participants will be randomly assigned in a double-blinded treatment period DBTP lasting 24 weeks, receiving either intravenous ARGX-119 or placebo alongside their current SMA disease-modifying therapy. After completing this period, all participants enter an open-label extension ATEP where they receive ARGX-119 intravenously for up to 100 weeks, continuing treatment for about two years. During the study, participants will have regular evaluations including muscle function tests like the Revised Hammersmith Scale and the 6-Minute Walk Test, blood tests to measure ARGX-119 levels and immune response, and monitoring for side effects. Safety and effectiveness will be assessed throughout the 124 weeks, with ongoing follow-up to track adverse events and treatment impact.

A Study to Assess the Safety, Tolerability, Efficacy, Pharmacokinetics, and Immunogenicity of Intravenous Administration of ARGX-119 in Pediatric Participants Aged 5 to Less Than 18 Years With Spinal Muscular Atrophy