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Enrolling by Invitation

NCT Number: NCT05374590

Evaluating Long-term Safety of Efgartigimod Administered Intravenously and Efgartigimod PH20 Administered Subcutaneously in Children With Generalized Myasthenia Gravis

The purpose of this trial is to evaluate the long-term safety of efgartigimod IV and efgartigimod PH20 SC administered to participants with gMG in the antecedent studies, ARGX-113-2006 and ARGX-113-2207, respectively.

Participants will receive efgartigimod IV or efgartigimod PH20 SC, using the dose administered in the antecedent studies. Participants who have not reached the age of 18 can remain in the study until efgartigimod becomes commercially available in the respective country or available through another continued access program for gMG. Participants who have reached the age of 18 can remain in the study for a maximum of 2 years, until efgartigimod becomes commercially available in the respective country or available through another continued access program for gMG, whichever comes first.

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Key information

Conditions

Generalized Myasthenia Gravis Autoimmune Diseases Autoimmune Diseases of the Nervous System Immune System Diseases Myasthenia Gravis Neoplasms Neoplasms by Site Nervous System Diseases Nervous System Neoplasms Neurodegenerative Diseases Neuromuscular Diseases Neuromuscular Junction Diseases Paraneoplastic Syndromes Paraneoplastic Syndromes, Nervous System gMG

Age range

2 year–18 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 2 / Phase 3

Primary location

Universitair Ziekenhuis Antwerpen, Edegem, Belgium

Loading trial locations.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • The participant completed ARGX-113-2006, defined as:
  • The participant reached End of Trial in trial ARGX-113-2006 or End of Study in ARGX-113-2207 and agreed to participate in the ARGX-113-2008 trial.
  • The participant qualifies for retreatment in trial ARGX-113-2006, but cannot complete a Treatment Period (TP) and the required Intertreatment Period (IP) visits within the ARGX-113-2006 trial's timeframe.
  • Either the participant or the participant's legally authorized representative can understand the requirements of the trial and provide written informed consent/assent, and willingness and ability to comply with the trial protocol procedures.
  • Contraceptive use for sexually active participants should be consistent with local regulations for those participating in clinical studies.

Exclusion criteria

  • Female adolescents of childbearing potential (FAOCBP): Pregnancy or lactation, or the participant intends to become pregnant during their participation in the study.
  • Discontinued early from ARGX-113-2006 or ARGX-113-2207 treatment.
  • Clinically significant uncontrolled chronic bacterial, viral, or fungal infection at study entry not sufficiently resolved in the investigator's opinion or known autoimmune disease or any medical condition that would interfere with an accurate assessment of clinical symptoms of gMG or put the participant at undue risk.

Treatment and study plan

Efgartigimod IV or Efgartigimod PH20 SC

Biological

Intravenous infusion of Efgartigimod or Subcutaneous injection of Efgartigimod PH20 SC

Primary outcomes

  1. Incidence of AEs, SAEs and AESIs

    Time frame: Up to 4 years

    AE : adverse event; SAE : serious adverse event; AESI : adverse event of special interest

Secondary outcomes

  1. Incidence of ADAs against efgartigimod

    Time frame: Up to 4 years

    ADA : anti-drug antibody

  2. Incidence of antibodies against rHuPH20

    Time frame: Up to 4 years

    rHuPH20: recombinant human hyaluronidase PH20

Sponsors and collaborators

Lead sponsor

argenx

Industry

Registry information

Official study title

A Long-term, Single-Arm, Open-label, Multicenter Trial to Evaluate Safety of Efgartigimod Administered Intravenously and Efgartigimod PH20 Administered Subcutaneously in Children With Generalized Myasthenia Gravis

Acronym: ADAPT Jr +

Important dates

Study start
2022
Primary completion
2029
Study completion
2029
First posted
May 16, 2022
Registry last updated
Apr 23, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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