Congenital Myasthenic SyndromePhase 1NCT06436742
A Phase 1b Study to Investigate Safety and Tolerability of ARGX-119 in Adult Participants With DOK7-Congenital Myasthenic Syndromes (CMS)
A Phase 1 study testing ARGX-119 in people with Congenital Myasthenic Syndrome and CMS, run by argenx at 9 sites in 6 countries.
Trial summary
The purpose of this study is to assess the safety and tolerability of ARGX-119 in adult participants with DOK7- Congenital Myasthenic Syndromes. The study will also assess how ARGX-119 is processed by the body (pharmacokinetics), how the immune system reacts to it (immunogenicity), and how it may improve the way… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Congenital Myasthenic Syndrome, CMS
- What is being tested?
- ARGX-119
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 15 participants
- Where
- 9 sitesin 6 countries
- Study dates
- 24 Sep 2024to 24 Jan 2028
- Phase
- Phase 1
- Are there results?
- Not yet: the study is under way
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 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- At least 18 years of age.
- Has genetically confirmed congenital myasthenic syndromes due to mutation of downstream of kinase 7 (DOK7-CMS).
- Participants taking oral beta agonists (eg, albuterol, salbutamol, ephedrine) must have been receiving the medication for more than 3 months and agree to remain on a same stable dosing regimen of the same medication until the end of the study.
Who cannot join
- Diagnosis of CMS due to mutation of any gene other than DOK7.
- 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.
- History of malignancy, cancer, unless considered cured by adequate treatment with no evidence of recurrence for more than 5 years. Adequately treated participants with the following cancers can be included at any time: Basal cell or squamous cell skin cancer, Carcinoma in situ of the cervix, Carcinoma in situ of the breast, Incidental histological findings of prostate cancer.
- Pregnant or lactating state or intention to become pregnant during the study.
Trial locations and contacts
9 sites in 6 countries.
9 sites in 6 countries
United States2 sites
Ann and Robert H Lurie Childrens Hospital of Chicago
Chicago, Illinois, 60611
UC Davis Medical Center
Sacramento, California, 95817
France2 sites
CHU - Hospital de la Timone
Marseille, 13385
Group Hospitalier Pitie-Salpetriere
Paris, 75013
United Kingdom2 sites
Clinical Trials Centre - South Eastern Health and Social Care Trust - The Ulster Hospital
Belfast, BT16 1RH
John Radcliffe Hospital - Oxford University Hospitals NHS Foundation Trust
Oxford, OX3 9DU
Spain1 site
Universitat de Valencia - Hospital Universitari i Politecnic La Fe de Valencia (Hospital La Fe Bulevar Sur)
Valencia, 46026
About this study
Official title: A Phase 1b, Double-Blinded, Randomized, Placebo-Controlled Study to Assess the Safety, Tolerability, Pharmacokinetics, Immunogenicity, and Efficacy of ARGX-119 in Adult Participants With DOK7-Congenital Myasthenic Syndromes
The purpose of this study is to assess the safety and tolerability of ARGX-119 in adult participants with DOK7- Congenital Myasthenic Syndromes. The study will also assess how ARGX-119 is processed by the body (pharmacokinetics), how the immune system reacts to it (immunogenicity), and how it may improve the way patients feel and function.
After the screening period, eligible participants will be randomized in a 4:1 ratio to receive intravenous infusions of ARGX-119 or placebo during the double-blinded treatment period. Participants will then enter the follow-up period. After the follow-up period, participants may enrol in the active-treatment period, where they will receive open-label ARGX-119.
The full duration of the study is approximately 38 months.
- Conditions
- Congenital Myasthenic Syndrome, CMS
- Being tested
- ARGX-119, Placebo
- 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.
ARGX-119Biological
Intravenous infusion of ARGX-119
PlaceboOther
Intravenous infusion of placebo
| Study group | Role | What they receive |
|---|---|---|
| Double-blinded treatment period - ARGX-119 IV | Experimental | Participants receive ARGX-119 during the double-blinded treatment period Receives: Biological: ARGX-119 |
| Double-blinded treatment period - Placebo IV | Placebo comparator | Participants receive placebo during the double-blinded treatment period Receives: Other: Placebo |
| Active-treatment period - ARGX-119 IV | Experimental | Participants receive ARGX-119 during the active-treatment period Receives: Biological: ARGX-119 |
What is being measured
The primary outcome is the main question the study is designed to answer.
Assessment of adverse events (AEs)
Measured: Up to week 42
Change from active-treatment baseline over time for 6MWT distance
The 6-minute walk test (6MWT) measures the distance a participant walks in 6 minutes. Before and after the 6MWT assessment, the participant's blood pressure, heart rate, and SPO2 will be recorded, and the participant's perception of fatigue and dyspnea will be measured.
Measured: Up to 72 weeks
Secondary outcomes (15)
Maximum observed serum concentration (Cmax) of ARGX-119
Measured: Up to 42 weeks + 72 weeks
Incidence of ADA against ARGX-119
ADA : anti-drug antibodies
Measured: Up to 42 weeks + 72 weeks
Change from baseline over time for key components of the QMG scale
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: 39 (highest disease severity). The change from active-treatment baseline will be used for the 72 week timepoint.
Measured: Up to 42 weeks + 72 weeks
Change from baseline over time for MG-ADL
The Myasthenia Gravis Activities of Daily Living (MG-ADL) is an 8-item scale that assesses MG symptoms and their effects on daily activities. Minimum value: 0 (normal symptoms); Maximum value: 24 (most severe symptoms). The change from active-treatment baseline will be used for the 72 week timepoint.
Measured: Up to 42 weeks + 72 weeks
Change from baseline over time for PROMIS-GH scale
The Patient-Reported Outcomes Measurement Information System Global Health (PROMIS-GH) is a 10-item participant completed quality of life questionnaire that measures global physical health and mental health. The participant records their response to each question on a 5-point Likert scale, with lower scores indicating poorer health (Minimum value: 0, Maximum value: 20)
Measured: Up to 42 weeks
Change from active-treatment baseline over time for 6MWT cadence
The 6-minute walk test (6MWT) measures the distance a participant walks in 6 minutes. Before and after the 6MWT assessment, the participant's blood pressure, heart rate, and SPO2 will be recorded, and the participant's perception of fatigue and dyspnea will be measured.
Measured: Up to 72 weeks
Change from active-treatment baseline over time for PROMIS PF-WMA-SF
The PROMIS PF-WMA-SF 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 0 (unable to do).
Measured: Up to 72 weeks
Change from active-treatment baseline over time for Neuro-QoL fatigue
Measured: Up to 72 weeks
Change from active-treatment baseline over time for FVC
Measured: Up to 72 weeks
Change from active-treatment baseline over time for PGI-C
Measured: Up to 72 weeks
Change from active-treatment baseline over time for PGI-S
Measured: Up to 72 weeks
Change from active-treatment baseline over time for CGI-C
Measured: Up to 72 weeks
Change from active-treatment baseline over time for CGI-S
Measured: Up to 72 weeks
Change from active-treatment baseline over time for EQ-5D-5L
Measured: Up to 72 weeks
Incidence of AEs and SAEs
AE : Adverse events ; SAE : Serious Adverse events
Measured: Up to 72 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted31 May 2024
- Study start24 Sep 2024
- Primary completion24 Aug 2027 (estimated)
- Study completion24 Jan 2028 (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 1
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 15 participants (actual)
Sponsor and investigators
- Lead sponsor
- argenx
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06436742
- Sponsor's protocol ID
- ARGX-119-2302
- Other IDs
- 2023-509872-41-00, 2023
- Status last verified
- Jul 2026
- First submitted
- 21 May 2024
- Last updated
- 24 Jul 2026
- Results posted
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 24 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 1b, Double-Blinded, Randomized, Placebo-Controlled Study to Assess the Safety, Tolerability, Pharmacokinetics, Immunogenicity, and Efficacy of ARGX-119 in Adult Participants With DOK7-Congenital Myasthenic Syndromes
- ClinicalTrials.gov ID
- NCT06436742
- Acronym / sponsor ID
- ARGX-119-2302
- Conditions
- Congenital Myasthenic Syndrome, CMS
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 15 participants (actual)
- Lead sponsor
- argenxIndustry (pharma, biotech, devices)
- Study start
- 24 Sep 2024 (actual)
- Primary completion
- 24 Aug 2027 (estimated)
- Study completion
- 24 Jan 2028 (estimated)
- First posted
- 31 May 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this study is to assess the safety and tolerability of ARGX-119 in adult participants with DOK7- Congenital Myasthenic Syndromes. The study will also assess how ARGX-119 is processed by the body (pharmacokinetics), how the immune system reacts to it (immunogenicity), and how it may improve the way patients feel and function.
After the screening period, eligible participants will be randomized in a 4:1 ratio to receive intravenous infusions of ARGX-119 or placebo during the double-blinded treatment period. Participants will then enter the follow-up period. After the follow-up period, participants may enrol in the active-treatment period, where they will receive open-label ARGX-119.
The full duration of the study is approximately 38 months.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Double-blinded treatment period - ARGX-119 IV | Experimental | Biological: ARGX-119Participants receive ARGX-119 during the double-blinded treatment period |
| Double-blinded treatment period - Placebo IV | Placebo comparator | Other: PlaceboParticipants receive placebo during the double-blinded treatment period |
| Active-treatment period - ARGX-119 IV | Experimental | Biological: ARGX-119Participants receive ARGX-119 during the active-treatment period |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- At least 18 years of age.
- Has genetically confirmed congenital myasthenic syndromes due to mutation of downstream of kinase 7 (DOK7-CMS).
- Participants taking oral beta agonists (eg, albuterol, salbutamol, ephedrine) must have been receiving the medication for more than 3 months and agree to remain on a same stable dosing regimen of the same medication until the end of the study.
Key exclusion criteria (4 listed)
- Diagnosis of CMS due to mutation of any gene other than DOK7.
- 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.
- History of malignancy, cancer, unless considered cured by adequate treatment with no evidence of recurrence for more than 5 years. Adequately treated participants with the following cancers can be included at any time: Basal cell or squamous cell skin cancer, Carcinoma in situ of the cervix, Carcinoma in situ of the breast, Incidental histological findings of prostate cancer.
- Pregnant or lactating state or intention to become pregnant during the study.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| ARGX-119Intravenous infusion of ARGX-119 | Biological | Active-treatment period - ARGX-119 IV, Double-blinded treatment period - ARGX-119 IV |
| PlaceboIntravenous infusion of placebo | Other | Double-blinded treatment period - Placebo IV |
Primary outcome
Assessment of adverse events (AEs)
Time frame: Up to week 42
Change from active-treatment baseline over time for 6MWT distance
Time frame: Up to 72 weeks
The 6-minute walk test (6MWT) measures the distance a participant walks in 6 minutes. Before and after the 6MWT assessment, the participant's blood pressure, heart rate, and SPO2 will be recorded, and the participant's perception of fatigue and dyspnea will be measured.
15 secondary outcomes
Maximum observed serum concentration (Cmax) of ARGX-119
Time frame: Up to 42 weeks + 72 weeks
Incidence of ADA against ARGX-119
Time frame: Up to 42 weeks + 72 weeks
Change from baseline over time for key components of the QMG scale
Time frame: Up to 42 weeks + 72 weeks
Change from baseline over time for MG-ADL
Time frame: Up to 42 weeks + 72 weeks
Change from baseline over time for PROMIS-GH scale
Time frame: Up to 42 weeks
Change from active-treatment baseline over time for 6MWT cadence
Time frame: Up to 72 weeks
Change from active-treatment baseline over time for PROMIS PF-WMA-SF
Time frame: Up to 72 weeks
Change from active-treatment baseline over time for Neuro-QoL fatigue
Time frame: Up to 72 weeks
Change from active-treatment baseline over time for FVC
Time frame: Up to 72 weeks
Change from active-treatment baseline over time for PGI-C
Time frame: Up to 72 weeks
Change from active-treatment baseline over time for PGI-S
Time frame: Up to 72 weeks
Change from active-treatment baseline over time for CGI-C
Time frame: Up to 72 weeks
Change from active-treatment baseline over time for CGI-S
Time frame: Up to 72 weeks
Change from active-treatment baseline over time for EQ-5D-5L
Time frame: Up to 72 weeks
Incidence of AEs and SAEs
Time frame: Up to 72 weeks
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 24 Jul 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
9 sites in 6 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing ARGX-119 in people with Congenital Myasthenic Syndrome and CMS, run by argenx at 9 sites in 6 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 24 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 9 sites in United States, France, United Kingdom, Canada, Italy and 1 more country. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Assessment of adverse events (AEs) (time frame: Up to week 42). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 24 Jul 2026.