A Phase 1b Study to Investigate Safety and Tolerability of ARGX-119 in Adult Participants With DOK7-Congenital Myasthenic Syndromes (CMS)

NCT06436742 | Recruiting Phase 1 FDA Drug

• 2 other identifiers: ARGX-119-23022023-509872-41-00
• Study Type: interventional
• Target: 16
• Locations: 6 countries
• Sites: 9

Brief 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 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

Outcome Measures

Primary Outcomes (2)

• Assessment of adverse events (AEs)

  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.

  Up to 72 weeks

Secondary Outcomes (15)

• Maximum observed serum concentration (Cmax) of ARGX-119

  Up to 42 weeks + 72 weeks

• Incidence of ADA against ARGX-119

  Up to 42 weeks + 72 weeks

• Change from baseline over time for key components of the QMG scale

  Up to 42 weeks + 72 weeks

• Change from baseline over time for MG-ADL

  Up to 42 weeks + 72 weeks

• Change from baseline over time for PROMIS-GH scale

  Up to 42 weeks

Study Arms (3)

Double-blinded treatment period - ARGX-119 IV

EXPERIMENTAL

Participants receive ARGX-119 during the double-blinded treatment period

Biological: ARGX-119

Double-blinded treatment period - Placebo IV

PLACEBO COMPARATOR

Participants receive placebo during the double-blinded treatment period

Other: Placebo

Active-treatment period - ARGX-119 IV

EXPERIMENTAL

Participants receive ARGX-119 during the active-treatment period

Biological: ARGX-119

Interventions

ARGX-119 BIOLOGICAL

Intravenous infusion of ARGX-119

Active-treatment period - ARGX-119 IV; Double-blinded treatment period - ARGX-119 IV

Placebo OTHER

Intravenous infusion of placebo

Double-blinded treatment period - Placebo IV

Eligibility Criteria

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

You may qualify if:

• 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.

You may not qualify if:

• 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.

Sponsors & Collaborators

• argenx: lead

Study Sites (9)

UC Davis Medical Center

Sacramento, California, 95817, United States

ACTIVE NOT RECRUITING

Ann and Robert H Lurie Childrens Hospital of Chicago

Chicago, Illinois, 60611, United States

RECRUITING

Ottawa Hospital Research Institute - Civic Campus

Ottawa, K1Y 4E9, Canada

RECRUITING

CHU - Hospital de la Timone

Marseille, 13385, France

COMPLETED

Group Hospitalier Pitie-Salpetriere

Paris, 75013, France

RECRUITING

Fondazione IRCCS Istituto Neurologico Carlo Besta

Milan, 20133, Italy

RECRUITING

Universitat de Valencia - Hospital Universitari i Politecnic La Fe de Valencia (Hospital La Fe Bulevar Sur)

Valencia, 46026, Spain

ACTIVE NOT RECRUITING

Clinical Trials Centre - South Eastern Health and Social Care Trust - The Ulster Hospital

Belfast, BT16 1RH, United Kingdom

RECRUITING

John Radcliffe Hospital - Oxford University Hospitals NHS Foundation Trust

Oxford, OX3 9DU, United Kingdom

ACTIVE NOT RECRUITING

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 1
• 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: May 21, 2024
• First Posted: May 31, 2024
• Study Start: September 24, 2024
• Primary Completion (Estimated): August 24, 2027
• Study Completion (Estimated): January 24, 2028
• Last Updated: April 23, 2026

Record last verified: 2026-02

Data Sharing

• IPD Sharing: Will not share

Locations

GB (2); IT (1); US (2); FR (2); ES (1); CA (1)