Sparkle
Research type
Research Study
Full title
A Phase 2 Double-Blinded, Randomized, Placebo-Controlled 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
IRAS ID
1013117
Contact name
Sabine Coppieters
Contact email
Sponsor organisation
argenx BV
Eudract number
2025-523496-32
Clinicaltrials.gov Identifier
Research summary
The purpose of this study is to find the correct dose of the study drug for children ≥5 and <18 years of age with spinal muscular atrophy (SMA). The study will also look at how safe the drug is, how well it works, how it moves through the body, and how the immune system responds to it. Despite available treatments, there remains an unmet medical need for patients with SMA. This study drug is made to attach to a protein called muscle-specific kinase (MuSK). It is important for communication at the junction between nerves and muscles: the neuromuscular junction (NMJ). Good communication is important for muscles to move and function normally.
We know from previous work that the NMJ does not work as it should in SMA. This may contribute to the weakness in muscles and the fatigue. The study drug is designed to help improve the communication between muscles and nerves and could help muscle function. Approximately 60 participants will be randomized to receive ARGX-119 intravenously (IV) or placebo IV in this study.
The study will be up to 148 weeks (approximately 3 years) and will include the following periods:
•Screening period: up to 4 weeks
•double-blinded treatment period: 24 weeks
•Active-treatment extension period (ATEP): up to 104 weeks (approximately 2 years)
•Safety follow-up period: 20-week period after the last dose of investigational medicinal product (IMP)
Participant will be assigned to 1 of 3 study groups by chance:
Group 1: usual treatment for SMA + high dose of the study drug based on participant age
Group 2: usual treatment for SMA + low dose of the study drug based on participant age
Group 3: usual treatment for SMA + placebo.
Participant has an equal chance of being in any of the groups. There is a 2 in 3 (or 67%) chance of receiving the study drug, and 1 in 3 (or 33%) chance of receiving the placebo. Participant and the study team will not know which study group they are in. However, the study doctor can find out in case of an emergency.REC name
London - Central Research Ethics Committee
REC reference
26/LO/0089
Date of REC Opinion
26 Mar 2026
REC opinion
Further Information Favourable Opinion