Recruiting

Phase 2

ARGX-119A 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

Sponsor:

argenx

Code:

NCT07287982

Conditions

Spinal Muscular Atrophy (SMA)

Eligibility Criteria

Sex: All

Age: 5 - 17

Healthy Volunteers: Not accepted

Interventions

ARGX-119 IV

Placebo IV

Study Details

Brief summary:

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).

Conditions

Spinal Muscular Atrophy (SMA)

Study ID

NCT07287982

Start date

Dec 19, 2025

Status verified date

Sep, 2026

Completion date

May 28, 2029

Anticipated

Primary completion date

May 28, 2029

Anticipated

Eligibility Criteria

Sex: All

Age: 5 - 17

Healthy Volunteers: Not accepted

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.

Study Design

Enrollment

60 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: DBTP - ARGX-119 IV

Participants receive ARGX-119 IV during the DBTP

placebo comparator: DBTP - Placebo IV

Participants receive placebo IV during the DBTP

placebo comparator: ATEP - ARGX-119 IV

Participants receive ARGX-119 IV during the ATEP. Participants from ARGX-119 IV arm in the DBTP will receive placebo once to maintain the DBTP blinding

Interventions

ARGX-119 IV

Intravenous infusion of ARGX-119

Placebo IV

Intravenous infusion of placebo

Primary outcome measure

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 ]

Central Contacts and Locations

Central contacts

Sabine Coppieters, MD

857-350-4834 Clinicaltrials@argenx.com

Locations

Arkansas Children's Hospital

Recruiting

Little Rock, Arkansas, United States, 72202

Contacts

Steven Giompoletti

(501) 364-1430 giompolettis@archildrens.org

Principal Investigator:

Kapil Arya, Dr.

Stanford University Medical Center

Recruiting

Stanford, California, United States, 94305

Contacts

Lidia Choniawko

(650) 304-8094 lidiacho@stanford.edu

Principal Investigator:

Carolina Tesi Rocha, Dr.

Connecticut Children's Medical Center

Recruiting

Hartford, Connecticut, United States, 06106

Contacts

Gyula Acsadi

(860) 545-9460 gacsadi@connecticutchildrens.org

Principal Investigator:

Gyula Acsadi, Dr.

Rare Disease Research FL LLC

Recruiting

Kissimmee, Florida, United States, 34746

Contacts

Maria Cordero

(407) 545-7610 maria.cordero@rarediseaseresearch.com

Principal Investigator:

Renata Shih, Dr.

Ann & Robert H. Lurie Children's Hospital of Chicago

Recruiting

Chicago, Illinois, United States, 60611

Contacts

Alka Maheshwari

(815) 444-6362 amaheshwari@luriechildrens.org

Principal Investigator:

Nancy Kuntz, Dr.

University of Iowa Stead Family Children's Hospital

Recruiting

Iowa City, Iowa, United States, 52242

Contacts

Katherine Mathews

(319) 356-1851 katherine-mathews@uiowa.edu

Principal Investigator:

Katherine Mathews, Dr.

Boston Children's Hospital

Recruiting

Boston, Massachusetts, United States, 02115

Contacts

Samantha Remis

(617) 355-2752 samantha.remis@childrens.harvard.edu

Principal Investigator:

Basil Darras, Dr.

Rare Disease Research NC, LLC

Recruiting

Hillsborough, North Carolina, United States, 27278

Contacts

Norma Davis

(470) 665-3051 norma.davis@rarediseaseresearch.com

Principal Investigator:

Edward Smith, Dr.

Neurology Rare Disease Center

Recruiting

Flower Mound, Texas, United States, 75028

Contacts

Natalie Gomez

(972) 999-1011 Natalie.Gomez@Neuromdcenter.com

Principal Investigator:

Diana Castro, Dr.

Texas Children's Hospital

Recruiting

Houston, Texas, United States, 77030

Contacts

Timothy Lotze

(832) 822-1779 tlotze@bcm.edu

Principal Investigator:

Timothy Lotze, Dr.

More Information

Sponsor

argenx

Last update posted

Sep 14, 2026

Last verified

Sep, 2026

Keywords

Spinal Muscular Atrophy
Pediatric
Muscle Function
Fatigability
SMA
ambulant

Trial information was received from ClinicalTrials.gov and was last updated on 2026-10-08. This information was provided to ClinicalTrials.gov by argenx on 2026-09-14. Recruitment status is synced daily from ClinicalTrials.gov and may not reflect the sponsor's current status. Confirm during your call.