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Recruiting Phase 2, Phase 3 NCT04833894

NCT04833894 Evaluating the Pharmacokinetics, Pharmacodynamics, and Safety of Efgartigimod Administered Intravenously in Children With Generalized Myasthenia Gravis

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Clinical Trial Summary
NCT ID NCT04833894
Status Recruiting
Phase Phase 2, Phase 3
Sponsor argenx
Condition Generalized Myasthenia Gravis
Study Type INTERVENTIONAL
Enrollment 12 participants
Start Date 2021-10-26
Primary Completion 2027-03

Eligibility & Interventions

Sex All sexes
Min Age 2 Years
Max Age 18 Years
Study Type INTERVENTIONAL
Interventions
Efgartigimod IV

Eligibility Fast-Check

Enter your details for a quick preliminary check. This does not replace medical advice.

What to Expect as a Participant

You will actively receive the study intervention — which may be a drug, biologic, device, or procedure.

In Phase 2, researchers evaluate early signs of effectiveness. You may be randomized to receive the active treatment or a comparator. Monitoring continues closely.

This trial targets 12 participants in total. It began in 2021-10-26 with a primary completion date of 2027-03.

⚠ This information is for research awareness only. Always consult your physician before joining any clinical trial. Participation is voluntary and you may withdraw at any time.

Brief Summary

The purpose of this trial is to investigate the PK, PD, safety, and activity of efgartigimod IV in children and adolescents aged from 2 to less than 18 years of age with gMG. Trial details include: * The maximum trial duration for each individual participant will be approximately 28 weeks * The treatment duration will be 8 weeks for the dose-confirmatory part (Part A) and 18 weeks for the treatment response-confirmatory part (Part B)

Eligibility Criteria

Inclusion Criteria: 1. Ability of the participant and/or his/her legally authorized representative to understand the requirements of the trial and provide written informed consent/assent, if applicable (including consent/assent for the use and disclosure of research-related health information), willingness and ability to comply with the trial protocol procedures (including attending the required trial visits). 2. Male or female participants between 2 to less than 18 years of age at the time of providing informed consent/assent. Age groups are enrolled in a staggered fashion respectively: 6 participants in the 12 to less than 18 years of age group followed by 6 participants in the 2 to less than 12 years of age group at the time of providing informed consent/assent. 3. Diagnosed with Generalized Myasthenia Gravis (gMG) with confirmed documentation 4. Meeting the clinical criteria as defined by the Myasthenia Gravis Foundation of America (MGFA) class II, III, and IVa. 5. Eligible participants should have an unsatisfactory response (efficacy and/or safety) to immunosuppressants, steroids or acetylcholinesterase (AChE) inhibitors and should be on stable concomitant gMG therapy of adequate duration before screening. 6. Positive serologic test for acetylcholine receptor (anti-AChR) antibodies at screening (for younger participants (\<15kg) historical values can be used). 7. Contraceptive use should be consistent with local regulations regarding the methods of contraception for those participating in clinical trials. A subject is of childbearing potential if, in the opinion of the investigator, he/she is biologically capable of having children and is sexually active. 1. Male participants: Male participants must agree to not donate sperm from of providing informed consent/assent until they have completed the trial. 2. Female participants: Female adolescents of childbearing potential must have a negative serum pregnancy test at screening and a negative urine pregnancy test at baseline before investigational medicinal product (IMP) can be administered. Exclusion Criteria: 1. Participants with MGFA class I, IVb, and V. 2. Female adolescents of childbearing potential: Pregnancy or lactation, or the participant intends to become pregnant during the trial or within 90 days after the last dose of IMP. 3. Has any of the following medical conditions: 1. Clinically significant uncontrolled active or chronic bacterial, viral, or fungal infection at screening. 2. Any other known autoimmune disease that, in the opinion of the investigator, would interfere with an accurate assessment of clinical symptoms of myasthenia gravis or put the participant at undue risk. 3. History of malignancy unless deemed cured by adequate treatment with no evidence of recurrence for ≥3 years before the first administration of IMP. Participants with the following cancers can be included at any time: Adequately treated 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 4. Clinical evidence of other significant serious diseases, or have had a recent major surgery, or who have any other condition that, in the opinion of the investigator, could confound the results of the trial or put the participant at undue risk 4. Worsening muscle weakness secondary to concurrent infections or medications (aminoglycosides, fluoro-quinolones, beta-blockers, etc). 5. A documented lack of clinical response to plasma exchange (PLEX). 6. Received a live or live-attenuated vaccine fewer than 28 days before screening. Receiving an inactivated, subunit, polysaccharide, or conjugate vaccine any time before screening is not exclusionary. 7. Received a thymectomy \<3 months before screening or 1 is planned to be performed during the trial period. 8. The following results from these diagnostic assessments will be considered exclusionary: a. Positive serum test at screening for an active viral infection with any of the following conditions: Hepatitis B virus (HBV) that is indicative of an acute or chronic infection; Hepatitis C virus (HCV) based on HCV antibody assay; Positive HIV serology at screening; Positive nasopharyngeal swab polymerase chain reaction (PCR) test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) at screening. 9. Using the following prior or concomitant therapies: Use of an investigational product within 3 months or 5 half-lives (whichever is longer) before the first dose of IMP, Use of any monoclonal antibody within the 6 months before the first dose of IMP, Use of intravenous immunoglobulin (IVIg), administered subcutaneously or intramuscularly, or PLEX within 4 weeks before screening. 10. Total immunoglobulin (IgG) levels \<6 g/L below the lower limit of normal (LLN) according to the reference ranges of the central laboratory for participant by sex and age at screening. 11. A known hypersensitivity reaction to efgartigimod or any of its excipients. 12. Current participation in another interventional clinical trial or previous participation in an efgartigimod trial with at least 1 dose of IMP received. 13. History (within 12 months of screening) of current alcohol, drug, or medication abuse as assessed by the investigator.

Contact & Investigator

Central Contact

Sabine Coppieters, MD

✉ ClinicalTrials@argenx.com

📞 857-350-4834

Frequently Asked Questions

Who can join the NCT04833894 clinical trial?

This trial is open to participants of all sexes, aged 2 Years or older, up to 18 Years, studying Generalized Myasthenia Gravis. Full inclusion and exclusion criteria are listed in the Eligibility Criteria section. Always confirm your eligibility with the research team before applying.

What phase is the NCT04833894 trial and what does that mean for participants?

Phase 2 trials evaluate whether the treatment shows signs of effectiveness while continuing to monitor safety. More participants are enrolled than in Phase 1 to help refine the treatment protocol.

Is NCT04833894 currently recruiting?

Yes, NCT04833894 is actively recruiting participants. Contact the research team at ClinicalTrials@argenx.com for enrollment information.

Where is the NCT04833894 trial being conducted?

This trial is being conducted at Chicago, United States, Chapel Hill, United States, Charlottesville, United States, Vienna, Austria and 11 additional locations.

Who is sponsoring the NCT04833894 clinical trial?

NCT04833894 is sponsored by argenx. The trial plans to enroll 12 participants.

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ClinicalMetric — Independent clinical trial intelligence platform. Not affiliated with NIH, ClinicalTrials.gov, the U.S. FDA, or any pharmaceutical company, hospital, or clinical research organization. Trial data is sourced from ClinicalTrials.gov for informational purposes only and does not constitute medical advice. Do not make any treatment, enrollment, or health decisions based solely on information found here — always consult a qualified healthcare professional. Full Disclaimer  ·  Last Reviewed: September 2026  ·  Data Methodology