NCT06392386 · argenx
A Study of Efgartigimod PH20 SC in Children Between 2 and Less Than 18 Years of Age With Generalized Myasthenia Gravis
(ADAPT Jr SC)
What this study is about
The purpose of this study is to measure the how the drug moves through the body (PK), how the drug affects the body (PD), safety, tolerability, and immunogenicity of efgartigimod PH20 SC in pediatric participants with gMG aged 2 to \<18 years. The primary goal is to confirm an appropriate dose of efgartigimod PH20 SC for pediatric patients using PK and PD results from this study.
View original scientific description
The purpose of this study is to measure the pharmacokinetics (PK), pharmacodynamics (PD), safety, tolerability, and immunogenicity of efgartigimod PH20 SC in pediatric participants with gMG aged 2 to \<18 years. The primary goal is to confirm an appropriate dose of efgartigimod PH20 SC for pediatric patients using PK and PD results from this study. Participants will receive injections of efgartigimod PH20 SC and will be monitored for safety until the end of the study.
Interventions
BIOLOGICAL
Efgartigimod PH20 SC
Subcutaneous injections
Primary outcome measures
Efgartigimod serum concentrations as input for compartmental, model-driven analysis to determine age and size dependency of Clearance (CL)
Time frame: Up to 12 weeks
Efgartigimod serum concentrations as input for compartmental, model-driven analysis to determine age and size dependency of Volume Distribution (Vd)
Time frame: Up to 12 weeks
Total G immunoglobulins (IgG) levels as input for pharmacokinetics (PK)/pharmacodynamics (PD) modelling analysis
Time frame: Up to 12 weeks
Anti-acetylcholine receptors antibodies (AChR-Ab) as input for pharmacokinetics (PK)/ pharmacodynamics (PD) modelling analysis
Time frame: Up to 12 weeks
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- The participant (and/or their legally authorized representative) understands the requirements of the study and is capable of providing written informed consent/assent and complying with protocol requirements
- The participant is aged 2 to \<18 years at the time of informed consent/assent
- The participant has been diagnosed with generalised Myasthenia Gravis that is supported by a physical examination and confirmed seropositivity for anti-acetylcholine receptor antibodies
- The participant has had an unsatisfactory response to immunosuppressants, corticosteroids, or acetylcholinesterase inhibitors but is on stable concomitant MG therapy. If receiving corticosteroids and/or immunosuppressants, must be on a stable dose for ≥1 month before screening
- The participant agrees to use birth control consistent with local regulations and people of child-bearing potential must have a negative blood pregnancy test at screening and a negative urine pregnancy test before receiving the study drug
Exclusion criteria
- Is a female adolescent of child-bearing potential who is pregnant and/or lactating or intends to become pregnant during their participation in the study
- Has worsening muscle weakness secondary to a concurrent infection or as a result of a medication
- Has a documented lack of clinical response to plasma exchange (PLEX)
- Received a live or live-attenuated vaccine within \<4 weeks before screening
- Received a thymectomy within 3 months before screening or is planning to get a thymectomy during their participation in the study
- Has a known autoimmune disease or any medical condition that would interfere with an accurate assessment of clinical symptoms of generalised Myasthenia Gravis or puts the participant at undue risk
- History of malignancy, cancer, unless considered cured by adequate treatment with no evidence of recurrence for ≥3 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
- Clinically significant active infection that is not sufficiently resolved in the investigator's opinion or positive serum test at screening for active infection with any of the following: Hepatitis B virus (HBV), Hepatitis C virus (HCV), HIV
- Has a positive PCR test for SARS-CoV-2 at screening
- Has/had a clinically significant disease, had recent major surgery (within 3 months of screening) or intends to have major surgery during the study, or has/had any other medical condition that, in the investigator's opinion, would confound the results of the study or put the participant at undue risk
- Has received a different study drug in another clinical study within \<12 before screening
- Is currently participating in another interventional clinical study
- Has previously participated in an efgartigimod clinical study and received at least one dose of study drug
- Has a known hypersensitivity to study drug or any of its excipients
- Has a history of or current episode of alcohol, drug, or medication abuse as assessed by the investigator
- Use of some medications before screening (more information is found in the protocol) The complete list of exclusion criteria can be found in the protocol.
Where
- Charlotte, North Carolina
- Denton, Texas
- Charlottesville, Virginia
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Sep 28, 2026 · Source of record for eligibility and locations