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
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: ARGX-119 IV, Placebo IV.
- Who it may be relevant to
- Registry conditions: Spinal Muscular Atrophy (SMA). Basic parameters: 5 years — 17 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- United States
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
Unsure about the terms? Read our patient guide →
Official 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
Overview
This study aims to find the correct dose of ARGX-119 for children with SMA. The study will also look at how safe the study drug is, how well it works, how it moves through the body, and how the immune system responds to it. The study consists of a double-blinded treatment period (DBTP) where participants will either receive ARGX-119 IV or placebo IV, in addition to disease-modifying therapy (DMT) for 24 weeks. Participants who complete the DBTP will enter the open-label active-treatment extension period (ATEP) during which all participants will receive ARGX-119 IV up to 100 weeks (approximately 2 years).
Detailed description
This phase 2 study aims to establish proof of concept with the age-appropriate dose of ARGX-119 in ambulant pediatric patients with spinal muscular atrophy (SMA). Despite available treatments, there remains an unmet medical need for patients with SMA. Neuromuscular junction (NMJ) dysfunction contributes to the pathophysiology of SMA, including muscle weakness and fatigability. Activation of muscle-specific kinase (MuSK) by ARGX-119 may stabilize and improve NMJ function in patients with SMA, reducing muscle weakness and fatigability, and improving quality of life.
Interventions
- Biological ARGX-119 IV
Intravenous infusion of ARGX-119 - Other Placebo IV
Intravenous infusion of placebo
Primary outcome measures
- Incidence of AEs [Time frame: Up to 124 weeks]
- Incidence of SAEs [Time frame: Up to 124 weeks]
- Change in RHS total score from baseline to week 24 of the double blinded treatment period (DBTP) [Time frame: Up to 24 weeks]
Secondary outcome measures (3)
- Change from baseline over time for the 6MWT - distance and fatigue index [Time frame: Up to 124 weeks]
- ARGX-119 serum concentrations over time [Time frame: Up to 124 weeks]
- Incidence of antidrug antibodies (ADA) against ARGX-119 [Time frame: Up to 124 weeks]
Eligibility criteria
Inclusion criteria
- Is aged ≥5 to <18 years when completing the informed consent process, defined as providing informed assent according to local regulations and having a parent or guardian sign the ICF, and can comply with protocol
- requirements.
- Has documented historical genetic diagnosis of 5q-SMA.
- Currently receiving a stable SMA treatment regimen (nusinersen or risdiplam) and/or have a history of onasemnogene abeparvovec treatment
- Must be able to walk at least 50 meters without walking aids in the 6MWT at screening
Exclusion criteria
- Known medical condition that would interfere with an accurate assessment of SMA, confound the results of the study, or put the participant at undue risk, as assessed by the investigator
- Recent major surgery, except spinal fusion, within 3 months of screening or intends to have major surgery during the study
- Current or previous administration of antimyostatin therapies in the past 6 months
- Severe scoliosis (defined as curvature >40°) and/or contractures at screening. o History of spinal fusion within 6 months before screening or planned during the study
- Respiratory insufficiency, defined by the medical necessity for invasive or noninvasive ventilation for daytime treatment while awake. Ventilation used overnight or during daytime naps is acceptable.
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Allocation
- Randomized
- Model
- Parallel assignment
- Masking
- Double blind
- Primary purpose
- Treatment
Study locations
United States · 17 centers
- Arkansas Children's Hospital — Little Rock
- Rady Childrens Hospital — San Diego
- Stanford University Medical Center — Stanford
- Connecticut Children's Medical Center — Hartford
- Rare Disease Research FL LLC — Kissimmee
- Ann & Robert H. Lurie Children's Hospital of Chicago — Chicago
- University of Iowa Stead Family Children's Hospital — Iowa City
- The Johns Hopkins Hospital — Baltimore
- … and 9 more centers
Identifiers
NCT: NCT07287982 · ARGX-119-24-SMA-2001 · 2025-523496-32-00