A Study to Assess Efficacy and Safety of Adimanebart in Adult and Pediatric Participants With DOK7-,MUSK-, AGRN-, or LRP4- Congenital Myasthenic Syndromes (CMS)

NCT07746089 | Not Yet Recruiting Phase 3 FDA Drug

• 2 other identifiers: ARGX-119-17-CMS-30012025-524460-37-00
• Study Type: interventional
• Target: 105
• Locations: 0 countries
• Sites: N/A

Brief Summary

The purpose of this study is to assess efficacy and safety of adimanebart in participants at least 12 years of age with DOK7-, MUSK-, AGRN-, or LRP4- Congenital Myasthenic Syndromes (CMS). The study aims to determine whether adimanebart is safe and can help people with CMS feel better and perform daily activities more easily. The study includes a double-blinded treatment period (DBTP) and an Open- label extension period (OLE). In the DBTP, all participants will be randomized in a 1:1 ratio to adimanebart or placebo. Participants who complete the DBTP will continue to the OLE. Additionally, participants who complete part of the active-treatment period of ARGX-119-2302 study are eligible to enroll in the OLE of this study. In the OLE, all participants will receive open-label adimanebart. After final IMP dose, the participants will enter a follow-up period and their health will be monitored. The total duration of the study is up to approximately 152 weeks (2 years and 11 months). More information can be found here: clinicaltrials.argenx.com/Comets

Conditions

CMS; Congenital Myasthenic Syndrome

Outcome Measures

Primary Outcomes (2)

• Change from baseline at week 24 in 6MWT distance

  The 6-minute walk test (6MWT) measures the distance a participant walks in 6 minutes.

  Up to 24 weeks

• Incidence of AEs and SAEs

  AE: adverse event; SAE: serious adverse event

  up to 104 weeks

Secondary Outcomes (18)

• Change from baseline in 6MWT distance over time

  up to 24 weeks (DBTP) + up to 104 weeks (OLE)

• Change from baseline in PROMIS PF-10b T-score over time

  up to 24 weeks (DBTP) + up to 104 weeks (OLE)

• Change from baseline in QMG key component composite score over time

  up to 24 weeks (DBTP) + up to 104 weeks (OLE)

• Change from baseline in 6MWT cadence over time

  up to 24 weeks (DBTP) + up to 104 weeks (OLE)

• Change from baseline in the QMG key component raw values and scores over time

  up to 24 weeks (DBTP) + up to 104 weeks (OLE)

Study Arms (3)

Double-blinded treatment period (DBTP) - Adimanebart IV

EXPERIMENTAL

Participants randomized to receive Adimanebart IV

Biological: Adimanebart IV

Double-blinded treatment period (DBTP) - Placebo IV

PLACEBO COMPARATOR

Participants randomized to receive Placebo IV

Other: Placebo IV

Open-label extension (OLE) - Adimanebart IV

EXPERIMENTAL

Participants receive Adimanebart IV

Biological: Adimanebart IV

Interventions

Adimanebart IV BIOLOGICAL

Intravenous infusion of Adimanebart

Double-blinded treatment period (DBTP) - Adimanebart IV; Open-label extension (OLE) - Adimanebart IV

Placebo IV OTHER

Intravenous infusion of Placebo

Double-blinded treatment period (DBTP) - Placebo IV

Eligibility Criteria

• Age: 12 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

• DBTP:
• At least 12 years of age.
• Has a diagnosis of DOK7-, MUSK-, AGRN-, or LRP4-CMS with documented mutations.
• Participants taking oral beta agonists (eg, albuterol, salbutamol, ephedrine) or other CMS medication must have been receiving the medication for at least 6 months and agree to remain on a same stable dosing regimen of the same medication unless directed to change their CMS medication(s) by their treating physician.
• OLE:
• Completed part of the active-treatment period of ARGX-119-2302.

You may not qualify if:

• DBTP:
• Known medical condition that would interfere with an accurate assessment of CMS, confound the results of the study, or put the patient at undue risk, as assessed by the investigator.
• OLE:
• Investigational study drug discontinuation in ARGX-119-2302.

Sponsors & Collaborators

• argenx: lead

MeSH Terms

Conditions

Myasthenic Syndromes, Congenital

Condition Hierarchy (Ancestors)

Neuromuscular Junction Diseases; Neuromuscular Diseases; Nervous System Diseases; Genetic Diseases, Inborn; Congenital, Hereditary, and Neonatal Diseases and Abnormalities

Central Study Contacts

Sabine Coppieters, MD

CONTACT

857-350-4834; clinicaltrials@argenx.com

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: July 30, 2026
• First Posted: August 4, 2026
• Study Start: September 1, 2026
• Primary Completion (Estimated): October 1, 2030
• Study Completion (Estimated): October 1, 2030
• Last Updated: August 4, 2026

Record last verified: 2026-07

Data Sharing

• IPD Sharing: Will not share