A Natural History Study in Participants With Congenital Myasthenic Syndromes (CMS) Due to Mutations in DOK7, MUSK, AGRN, or LRP4

July 21, 2026 updated by: argenx

Multicenter, Multinational, Natural History Study in Participants With Congenital Myasthenic Syndromes Due to Mutations in DOK7, MUSK, AGRN, or LRP4

Participants will attend up to 4 study visits to collect clinical assessments. The assessments will evaluate participants' symptoms and quality of life to understand disease activity in patients with CMS due to mutations in DOK7, MUSK, AGRN, or LRP4.

More information can be found here: https://clinicaltrials.argenx.com/cms

Study Overview

Status

Recruiting

Conditions

Study Type

Observational

Enrollment (Estimated)

100

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • Austria
      • Vienna, Austria, 1090
        • Recruiting
        • Medical University of Vienna
        • Contact:
  • Belgium
    • Anderlecht
      • Brussels, Anderlecht, Belgium, 1070
        • Recruiting
        • Hopital Universitaire de Bruxelles/ Academisch Ziekenhuis Brussel
        • Contact:
  • Brazil
      • São Paulo, Brazil, 04038-002
        • Recruiting
        • Pseg Centro De Pesquisa ClinicaS.A
        • Contact:
      • São Paulo, Brazil, 05403-900
        • Recruiting
        • Universidade de Sao Paulo (USP) Hospital das Clinicas da Faculdade de Medicina (HCFMUSP)
        • Contact:
  • Canada
      • Ottawa, Canada, K1Y 4E9
        • Recruiting
        • The Ottawa Hospital - Civic Campus
        • Contact:
    • Ontario
      • Ottawa, Ontario, Canada, K1H8L1
        • Recruiting
        • The Children's Hospital of Eastern (CHEO), Ottawa
        • Contact:
  • France
      • Bordeaux, France, 33076
        • Recruiting
        • CHU Bordeaux - Groupe Hospitalier Pellegrin - Neurology
        • Contact:
      • Bron, France, 69500
        • Recruiting
        • Hospices Civils de Lyon (HCL) - Hopital Pierre Wertheimer - Neurology
        • Contact:
      • Lille, France, 59037
        • Recruiting
        • CHU Lille Hopital Salengro - Neurology
        • Contact:
      • Marseille, France, 13385
      • Paris, France, 75013
        • Recruiting
        • Assistance Publique Hopitaux de Paris - Hopital Pitie-Salpetriere
        • Contact:
      • Strasbourg, France, 67000
        • Recruiting
        • Centre Hospitalier Regional Universitaire de Strasbourg - Hopital de Hautepierre
        • Contact:
  • Germany
      • Berlin, Germany, 10117
      • Bochum, Germany, 44789
        • Recruiting
        • UKRUB - Berufsgenossenschaftliches Universitatsklinikum Bergmannsheil GmbH
        • Contact:
      • Essen, Germany, 45147
        • Recruiting
        • Universitaetsklinikum Essen (AoR)
        • Contact:
  • Italy
      • Milan, Italy, 20133
        • Recruiting
        • Fondazione IRCCS Istituto Neurologico Carlo Besta
        • Contact:
  • Japan
      • Kodaira, Japan, 187-8551
        • Recruiting
        • National Center Hospital, National Center of Neurology and Psychiatry
        • Contact:
      • Yurihonjō, Japan, 018-1393
        • Recruiting
        • National Hospital Organization Akita Hospital - Neurology
        • Contact:
  • Poland
      • Bydgoszcz, Poland, 85-065
        • Recruiting
        • Medicover Integrated Clinical Services (MICS) Centrum Medyczne Bydgoszcz
        • Contact:
      • Katowice, Poland, 40-689
        • Recruiting
        • Centrum Medyczne Neurologia Slaska - Neurology
        • Contact:
      • Warsaw, Poland, 02-097
        • Active, not recruiting
        • Uniwersyteckie Centrum Kliniczne Warszawskiego Uniwersytetu Medycznego
  • Spain
      • Esplugues de Llobregat, Spain, 08950
        • Recruiting
        • Hospital Sant Joan de Deu - Pediatric Neurology
        • Contact:
      • Madrid, Spain, 28041
        • Recruiting
        • Hospital Universitario 12 de Octubre
        • Contact:
      • Valencia, Spain, 46026
        • Recruiting
        • Hospital Universitari i Politècnic La Fe
        • Contact:
  • United Kingdom
      • Dundonald, United Kingdom, BT16 1RH
      • Oxford, United Kingdom, OX3 9DU
        • Recruiting
        • Oxford University Hospitals NHS Foundation Trust - John Radcliffe Hospital
        • Contact:
  • United States
    • California
      • Sacramento, California, United States, 95816
        • Recruiting
        • UC Davis Health - UC Davis Health Midtown Ambulatory Care Center
        • Contact:
    • Illinois
      • Chicago, Illinois, United States, 60611
        • Recruiting
        • Ann and Robert H Lurie Children's Hospital of Chicago - Main Hospital
        • Contact:
      • O'Fallon, Illinois, United States, 62269
        • Recruiting
        • Hospital Sisters Health System (HSHS) - St Elizabeth's Hospital
        • Contact:
    • Massachusetts
      • Boston, Massachusetts, United States, 02115
    • Ohio
    • Pennsylvania
      • Philadelphia, Pennsylvania, United States, 19104

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Participants with CMS due to mutations in DOK7, MUSK, AGRN, or LRP4 receiving standard of care at their treating physician

Description

Inclusion Criteria:

  • Can understand the requirements of the study and can provide written informed consent/assent, and willingness and ability to comply with the study protocol procedures
  • Is male or female and aged ≥2 years at the time of providing informed consent/assent
  • Has a diagnosis of CMS due to biallelic pathogenic mutations in DOK7 or any pathogenic mutations in MUSK, AGRN, or LRP4
  • Has a total Quantitative Myasthenia Gravis (QMG) score of ≥3 (applies only to participants aged ≥6 years)
  • For participants taking oral beta agonists (eg, albuterol, salbutamol, ephedrine), participant must have been receiving the medication for ≥3 months before screening/baseline

Exclusion Criteria:

  • Known medical condition that would interfere with an accurate assessment of CMS, in the investigator's opinion
  • Is currently participating in any interventional clinical study with a study drug at the time of providing informed consent/assent
  • Diagnosis of CMS due to mutation of any gene other than DOK7, MUSK, AGRN, or LRP4

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Summary statistics of retrospective and prospective collection of data on diagnosis.
Time Frame: Up to 12 months
Up to 12 months
Summary statistics of retrospective and prospective collection of data on health care utilization.
Time Frame: Up to 12 months
Up to 12 months
Summary statistics of retrospective and prospective collection of data on medications.
Time Frame: Up to 12 months
Up to 12 months
Summary statistics of retrospective and prospective collection of data on change in health status related to CMS
Time Frame: Up to 12 months
Up to 12 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change from baseline for QMG total score, each component score, and raw values
Time Frame: Up to 12 months
The Quantitative Myasthenia Gravis (QMG) consists of 13 items that assess ocular, bulbar, and limb function. Six of the 13 items are timed endurance tests measured in seconds. Each item has a possible score from 0 to 3, with 3 being the most severe. The total possible score is 39, with higher scores indicating more severe impairments.
Up to 12 months
Change from baseline for MG-ADL total score
Time Frame: Up to 12 months
The Myasthenia Gravis Activities of Daily Living (MG-ADL) is an 8-item scale that assesses MG symptoms and their effects on daily activities. The 8 items are rated by the participant on a scale of 0 to 3. The total score can range from 0 to 24, with higher total scores indicating more impairment.
Up to 12 months
Change from baseline for PROMIS-GHS
Time Frame: Up to 12 months
The Patient-Reported Outcomes Measurement Information System Global Health Scale (PROMIS-GHS) is a quality-of-life questionnaire that comprises questions on overall physical health, physical function, pain, and fatigue (GPH); and quality of life, mental health, satisfaction with social activities, and emotional problems (GMH). The participant marks their response on a 5-point Likert scale, with lower scores indicating poorer health
Up to 12 months
Change from baseline for PROMIS-DFL
Time Frame: Up to 12 months
The Patient-Reported Outcomes Measurement Information System Dyspnea Functional Limitations (PROMIS-DFL) is a questionnaire that evaluates the impact of dyspnea on the ability to perform daily activities within the last 7 days. The participant marks their response on a 4-point scale (0 to 3), with lower values indicating less functional impairment.
Up to 12 months
Change from baseline for EQ-5D-5L
Time Frame: Up to 12 months
The EQ-5D-5L questionnaire is a standardized test recognized by many health authorities as a generic measure of health status for clinical and economic appraisal. The descriptive system comprises 5 dimensions: mobility, self-care, usual activities, pain/discomfort, anxiety/depression. Participants mark their health status from 0 (the worst health you can imagine) to 100 (the best health you can imagine).
Up to 12 months
Change from baseline for 3TUG
Time Frame: Up to 12 months
The Triple Timed Up and Go (3TUG) is an objective measure of mobility requiring 3 repetitions (laps) to assess lower extremity weakness and fatigability.
Up to 12 months
Change from baseline for Neuro-QoL Fatigue score
Time Frame: Up to 12 months
The Quality of Life in Neurological Disorders (Neuro-QoL) Fatigue questionnaire will be completed by participants aged ≥18 years. The Neuro-QoL Pediatric Fatigue questionnaire will be completed by pediatric participants aged ≥12 to <18 years. Participants aged <8 years will be evaluated using the proxy version of the questionnaire.
Up to 12 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

argenx

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

February 13, 2024

Primary Completion (Estimated)

June 1, 2027

Study Completion (Estimated)

June 1, 2027

Study Registration Dates

First Submitted

September 8, 2023

First Submitted That Met QC Criteria

October 9, 2023

First Posted (Actual)

October 12, 2023

Study Record Updates

Last Update Posted (Actual)

July 22, 2026

Last Update Submitted That Met QC Criteria

July 21, 2026

Last Verified

July 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • ARGX-119-NIS-2301

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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