Congenital Myasthenic SyndromePhase 3CoMetSNCT07746089
A Study to Assess Efficacy and Safety of Adimanebart in Adult and Pediatric Participants With DOK7-,MUSK-, AGRN-, or LRP4- Congenital Myasthenic Syndromes (CMS)
A Phase 3 study testing Adimanebart IV in people with Congenital Myasthenic Syndrome and CMS, run by argenx.
Trial 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). Read more about this study
- Who is it for?
- Ages 12 years and older
- Conditions the study is for
- Congenital Myasthenic Syndrome, CMS
- What is being tested?
- Adimanebart IV
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 105 participants
- Where
- No sites listed yet
- Study dates
- Sep 2026to Oct 2030
- Phase
- Phase 3
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 12 years and older
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Who may be able to join
- 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.
Who cannot join
- 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.
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
Official title: Phase 3, Multicenter, Randomized, Double-Blinded, Placebo-Controlled Study With an Open-Label Extension to Evaluate the Efficacy and Safety of Intravenous Adimanebart in Adult and Pediatric Participants With DOK7-,MUSK-, AGRN-, or LRP4-CMS
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.
Read more
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
- Congenital Myasthenic Syndrome, CMS
- Being tested
- Adimanebart IV, Placebo IV
- Medical subject headings
- Myasthenic Syndromes, Congenital
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Adimanebart IVBiological
Intravenous infusion of Adimanebart
Placebo IVOther
Intravenous infusion of Placebo
| Study group | Role | What they receive |
|---|---|---|
| Double-blinded treatment period (DBTP) - Adimanebart IV | Experimental | Participants randomized to receive Adimanebart IV Receives: Biological: Adimanebart IV |
| Double-blinded treatment period (DBTP) - Placebo IV | Placebo comparator | Participants randomized to receive Placebo IV Receives: Other: Placebo IV |
| Open-label extension (OLE) - Adimanebart IV | Experimental | Participants receive Adimanebart IV Receives: Biological: Adimanebart IV |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change from baseline at week 24 in 6MWT distance
The 6-minute walk test (6MWT) measures the distance a participant walks in 6 minutes.
Measured: Up to 24 weeks
Incidence of AEs and SAEs
AE: adverse event; SAE: serious adverse event
Measured: up to 104 weeks
Secondary outcomes (18)
Change from baseline in 6MWT distance over time
The 6-minute walk test (6MWT) measures the distance a participant walks in 6 minutes.
Measured: up to 24 weeks (DBTP) + up to 104 weeks (OLE)
Change from baseline in PROMIS PF-10b T-score over time
The PROMIS PF-10b T-score (Patient-Reported Outcomes Measurement Information System Physical Function 10b) is a 10- item, participant-reported short-form questionnaire designed to assess physical function. The questionnaire asks the participant to rate the items on a 5-point Likert scale of 5 (without any difficulty) to 1 (unable to do)
Measured: up to 24 weeks (DBTP) + up to 104 weeks (OLE)
Change from baseline in QMG key component composite score over time
The Quantitative Myasthenia Gravis (QMG) scale is a standardized quantitative scoring system that was developed to assess disease severity based on impairment of body function and structures in patients with MG. Minimum value: 0 (no disease severity); Maximum value: 15 (highest disease severity).
Measured: up to 24 weeks (DBTP) + up to 104 weeks (OLE)
Change from baseline in 6MWT cadence over time
The 6-minute walk test (6MWT) measures the distance a participant walks in 6 minutes. Cadence is the number of steps taken per unit of time (steps/min) and is a measure of functional mobility.
Measured: up to 24 weeks (DBTP) + up to 104 weeks (OLE)
Change from baseline in the QMG key component raw values and scores over time
The Quantitative Myasthenia Gravis (QMG) scale is a standardized quantitative scoring system that was developed to assess disease severity based on impairment of body function and structures in patients with MG. Minimum value: 0 (no disease severity); Maximum value: 15 (highest disease severity).
Measured: up to 24 weeks (DBTP) + up to 104 weeks (OLE)
Change from baseline in PROMIS PF-WMA-SF T-score over time
The PROMIS PF-WMA-SF T-score (Patient-Reported Outcomes Measurement Information System Physical Function With Mobility Aid Short Form) is an 11-item, participant-completed questionnaire that assesses lower and upper extremity function and associated activities of daily living. The questionnaire asks the participant to rate the items on a 5-point scale of 5 (without any difficulty) to 1 (unable to do).
Measured: up to 24 weeks (DBTP) + up to 104 weeks (OLE)
Change from baseline in Neuro-QoL Short Form-Fatigue T-score over time
Neuro-QoL Short Form-Fatigue (Quality of Life in Neurological Disorders Short Form - Fatigue) is a participant-completed short-form questionnaire designed to provide a measurement of fatigue in patients with neurological conditions and the impact of their fatigue on their quality of life and daily activities.
Measured: up to 24 weeks (DBTP) + up to 104 weeks (OLE)
Change from baseline in FVC over time
FVC: forced vital capacity to assess pulmonary function
Measured: up to 24 weeks (DBTP) + up to 104 weeks (OLE)
Change from baseline in the Actigraphy measures over time
Participants will be asked to wear a wrist-worn actigraphy device to assess physical behaviour and mobility.
Measured: up to 24 weeks (DBTP) + up to 104 weeks (OLE)
Change from baseline in PGI-C over time
The Patient Global Impression of Change (PGI-C) is a patient-reported rating scale to assess the change in symptom severity and functional problems since the first IMP administration. Participants are asked to rate their change in symptom severity and functional problems on a 7- point Likert scale from 1 (much improved) to 7 (much worse).
Measured: up to 24 weeks (DBTP) + up to 104 weeks (OLE)
Change from baseline in PGI-S over time
The Patient Global Impression of Severity (PGI-S) scale is a patient-reported rating scale to assess symptom severity and functional problems. Participants are asked to rate their symptom severity and functional problems on a 7-point Likert scale from 1 (no problems) to 7 (unable to do).
Measured: up to 24 weeks (DBTP) + up to 104 weeks (OLE)
Change from baseline in CGI-C over time
The Clinical Global Impression of Change (CGI-C) scale is a clinician-reported rating scale to assess changes in a participant's symptom severity and functional problems since the first IMP administration. Clinicians are asked to rate the change in the participant's symptom severity and functional problems on a 7-point Likert scale from 1 (much improved) to 7 (much worse)
Measured: up to 24 weeks (DBTP) + up to 104 weeks (OLE)
Change from baseline in CGI-S over time
The Clinical Global Impression of Severity (CGI-S scale) is a clinician-reported rating scale to assess a participant's symptom severity and functional problems. The scale comprises a single item. Based on clinical judgment, clinicians rate the participant's symptom severity and functional problems on a 4-point Likert scale from 0 (no problems) to 4 (unable to do).
Measured: up to 24 weeks (DBTP) + up to 104 weeks (OLE)
Change from baseline in EQ-5D-5L over time
The participant-completed EQ-5D-5L questionnaire is a standardized test recognized by many health authorities as a generic measure of health status.
Measured: up to 24 weeks (DBTP) + up to 104 weeks (OLE)
Incidence of AEs and SAEs
AE: adverse event; SAE: serious adverse event
Measured: up to 24 weeks
Adimanebart serum concentrations over time
PK=pharmacokinetic(s)
Measured: up to 24 weeks (DBTP) + up to 104 weeks (OLE)
Incidence of ADA against adimanebart
ADA: Anti-drug antibodies
Measured: up to 24 weeks (DBTP) + up to 104 weeks (OLE)
Incidence of NAb against adimanebart
Nab: neutralizing antibody(ies)
Measured: up to 24 weeks (DBTP) + up to 104 weeks (OLE)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 Aug 2026
- Study startSep 2026 (estimated)
- Primary completionOct 2030 (estimated)
- Study completionOct 2030 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Congenital Myasthenic SyndromeStudies of the same condition, open and under way.
- More trials run by argenxThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 3
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 105 participants (estimated)
Sponsor and investigators
- Lead sponsor
- argenx
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07746089
- Sponsor's protocol ID
- ARGX-119-17-CMS-3001
- Other IDs
- 2025-524460-37-00, 2025
- Acronym
- CoMetS
- Status last verified
- Oct 2026
- First submitted
- 30 Jul 2026
- Last updated
- 19 Oct 2026
- Results posted
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No