Generalized Myasthenia GravisPhase 2/3ADAPT Jr +NCT05374590
Evaluating Long-term Safety of Efgartigimod Administered Intravenously and Efgartigimod PH20 Administered Subcutaneously in Children With Generalized Myasthenia Gravis
A Phase 2/3 study testing Efgartigimod IV or Efgartigimod PH20 SC in people with Generalized Myasthenia Gravis and gMG, run by argenx at 17 sites in 10 countries.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 2 to 18 years
- Conditions the study is for
- Generalized Myasthenia Gravis, gMG
- What is being tested?
- Efgartigimod IV or Efgartigimod PH20 SC
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 12 participants
- Where
- 17 sitesin 10 countries
- Study dates
- 18 Aug 2022to Sep 2029
- Phase
- Phase 2/3
- 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 2 to 18 years
- All sexes
- No healthy volunteers
- Child, Adult
Who may be able to join
- 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.
Who cannot join
- 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.
Trial locations and contacts
17 sites in 10 countries. Contact the study team or a site near you to ask about taking part.
17 sites in 10 countries
United States3 sites
Atrium Health Neurology Specialty Care
Charlotte, North Carolina, 28207
University of Virginia (UVA) Health - Developmental Pediatrics Clinic
Charlottesville, Virginia, 22903
Ann and Robert H Lurie Children's Hospital of Chicago - Main Hospital
Chicago, Illinois, 60611
Poland3 sites
Uniwersyteckie Centrum Kliniczne w Gdansku
Gdansk, 80-211
Wielospecjalistyczna Poradnia Lekarska Synapsis
Katowice, 40-123
Centralny Szpital Kliniczny - Uniwersyteckie Centrum Kliniczne WUM
Warsaw, 02-097
Belgium2 sites
Universitair Ziekenhuis Antwerpen
Edegem, 2650
UZ Gent
Ghent, 9000
Canada2 sites
Alberta Childrens Hospital
Calgary, Alberta, T3B 6A8
Childrens Hospital of Eastern Ontario
Ottawa, K1H 8L1
United Kingdom2 sites
Great Ormand Street Hospital for Children NHS Foundation Trust - Great Ormond Street Hospital - Pediatric Neurology
London, WC1N 3JH
Oxford University Hospitals NHS Foundation Trust - John Radcliffe Hospital Children's Hospital
Oxford, OX3 9DU
Spain1 site
Hospital Universitari i Politecnic La Fe de Valencia
Valencia, 46026
About this study
Official 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
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.
- Conditions
- Generalized Myasthenia Gravis, gMG
- Being tested
- Efgartigimod IV or Efgartigimod PH20 SC
- Medical subject headings
- Myasthenia Gravis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Efgartigimod IV or Efgartigimod PH20 SCBiological
Intravenous infusion of Efgartigimod or Subcutaneous injection of Efgartigimod PH20 SC
| Study group | Role | What they receive |
|---|---|---|
| Efgartigimod or Efgartigimod PH20 SC | Experimental | Patients receiving Efgartigimod IV treatment or Efgartigimod PH 20 SC treatment Receives: Biological: Efgartigimod IV or Efgartigimod PH20 SC |
What is being measured
The primary outcome is the main question the study is designed to answer.
Incidence of AEs, SAEs and AESIs
AE : adverse event; SAE : serious adverse event; AESI : adverse event of special interest
Measured: Up to 4 years
Secondary outcomes (2)
Incidence of ADAs against efgartigimod
ADA : anti-drug antibody
Measured: Up to 4 years
Incidence of antibodies against rHuPH20
rHuPH20: recombinant human hyaluronidase PH20
Measured: Up to 4 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 May 2022
- Study start18 Aug 2022
- Primary completionSep 2029 (estimated)
- Study completionSep 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Generalized Myasthenia GravisStudies 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 2/3
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 12 participants (estimated)
Sponsor and investigators
- Lead sponsor
- argenx
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05374590
- Sponsor's protocol ID
- ARGX-113-2008
- Other IDs
- 2023-507379-23-00, 2023
- Acronym
- ADAPT Jr +
- Status last verified
- Jan 2026
- First submitted
- 1 Apr 2022
- Last updated
- 3 Nov 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 3 Nov 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official 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
- ClinicalTrials.gov ID
- NCT05374590
- Acronym / sponsor ID
- ADAPT Jr + / ARGX-113-2008
- Conditions
- Generalized Myasthenia Gravis, gMG
- Phase
- Phase 2/3
- Study type
- Interventional
- Recruitment status
- Enrolling by invitation
- Enrolment
- 12 participants (estimated)
- Lead sponsor
- argenxIndustry (pharma, biotech, devices)
- Study start
- 18 Aug 2022 (actual)
- Primary completion
- Sep 2029 (estimated)
- Study completion
- Sep 2029 (estimated)
- First posted
- 16 May 2022 (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 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.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Efgartigimod or Efgartigimod PH20 SC | Experimental | Biological: Efgartigimod IV or Efgartigimod PH20 SCPatients receiving Efgartigimod IV treatment or Efgartigimod PH 20 SC treatment |
Who may qualify
- Ages
- 2 to 18 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult
Key inclusion criteria (5 listed)
- The participant completed ARGX-113-2006, defined as:
- 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.
Key exclusion criteria (3 listed)
- 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.
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 |
|---|---|---|
| Efgartigimod IV or Efgartigimod PH20 SCIntravenous infusion of Efgartigimod or Subcutaneous injection of Efgartigimod PH20 SC | Biological | Efgartigimod or Efgartigimod PH20 SC |
Primary outcome
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
2 secondary outcomes
Incidence of ADAs against efgartigimod
Time frame: Up to 4 years
Incidence of antibodies against rHuPH20
Time frame: Up to 4 years
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 3 Nov 2026.
- Individual participant dataSharing planned: Undecided
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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.
The record lists no contact. Use the official record to reach the sponsor.
17 sites in 10 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2/3 study testing Efgartigimod IV or Efgartigimod PH20 SC in people with Generalized Myasthenia Gravis and gMG, run by argenx at 17 sites in 10 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 5 inclusion and 3 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: enrolling by invitation, as of the sponsor's last update on 3 Nov 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 17 sites in United States, Poland, Belgium, Canada, United Kingdom and 5 more countries. 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. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this combined phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
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?
Incidence of AEs, SAEs and AESIs (time frame: Up to 4 years). 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 3 Nov 2026.