Generalized Myasthenia GravisPhase 3ADAPT NXTNCT04980495
An Open-label Study to Investigate the Clinical Efficacy of Different Dosing Regimens of Efgartigimod IV in Patients With Generalized Myasthenia Gravis
A Phase 3 study testing Efgartigimod IV in people with Generalized Myasthenia Gravis and MG - Myasthenia Gravis, run by argenx at 39 sites in 11 countries.
Trial summary
The purpose of this open-label study is to investigate the efficacy, safety, and tolerability of a continuous regimen of efgartigimod compared with a cyclic regimen in participants with Generalized Myasthenia Gravis (gMG). Participants will receive efgartigimod throughout the study. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Generalized Myasthenia Gravis, MG - Myasthenia Gravis, gMG
- What is being tested?
- Efgartigimod IV
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 69 participants
- Where
- 39 sitesin 11 countries
- Study dates
- 16 Dec 2021to 6 Oct 2025
- Phase
- Phase 3
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
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 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- At least 18 years of age, at the time of signing the informed consent.
- Diagnosed with Generalized Myasthenia Gravis (gMG) with confirmed documentation and supported by a physical exam and confirmed seropositivity for anti-acetylcholine receptor antibodies (AChR-Abs).
- Meets the clinical criteria as defined by the Myasthenia Gravis Foundation of America (MGFA) class II, III, or IV
Who cannot join
- Any other condition that, in the opinion of the investigator, would interfere with an accurate assessment of the clinical symptoms of gMG and/or put the participant at undue risk
- A thymectomy within 3 months of screening
- Use of the following prior or concomitant therapies:
- intravenous immunoglobulin (IVIg) or subcutaneous immunoglobulin (SCIg) within 14 days of day 1
- Rituximab within 6 months of day 1
- Eculizumab within 1 month of day 1
- Other monoclonal antibodies (eg, adalimumab, tocilizumab, ixekizumab)
Trial locations and contacts
39 sites in 11 countries.
39 sites in 11 countries
United States12 sites
Investigator Site 16 - US0010009
Augusta, Georgia, 30910
Investigator Site 11 - US0010011
Austin, Texas, 78756
Investigator Site 9 - 0010006
Boca Raton, Florida, 33487
Investigator Site 10 - US0010007
Carlsbad, California, 92011
Investigator Site 8 - US0010003
Chicago, Illinois, 60611
Investigator Site 15 - US0010014
Coral Springs, Florida, 33067
Investigator Site 12 - US0010004
Kansas City, Kansas, 66160
Investigator Site 6 - US0010008
Meadows, Illinois, 60008
Investigator Site 7 - US0010001
Orange, California, 92868
Investigator Site 17 - US0010012
Philadelphia, Pennsylvania, 19104
Investigator Site 13 - US0010013
Portland, Oregon, 97239
Investigator Site 14 - US0010010
Richmond, Virginia, 23219
France5 sites
Investigator Site 23 - FR0330005
Bordeaux, 33604
Investigator Site 24 - FR0330004
Lille, 59000
Investigator Site 20 - FR0330001
Marseille, 13385
Investigator Site 25 - FR0330003
Nice, 06001
Investigator site 38 - FR0330002
Paris, 75013
Italy5 sites
Investigator Site 31 - IT0390005
Bologna, 40139
Investigator Site 30 - IT0390004
Genova, 16132
Investigator Site 21 - IT0390002
Milan, 20133
Investigator site 39 - IT0390006
Pisa, 56126
Investigator Site 22 - IT0390001
Roma, 00168
Germany4 sites
Investigator Site 33 - DE0490004
Berlin, 10117
Investigator Site 36 - DE0490002
Bochum, 44791
Investigator Site 32 - DE0490001
Essen, 45147
Investigator Site 34 - DE0490005
Hanover, 30625
Georgia3 sites
Investigator Site 2 - GEO9950002
Tbilisi, 0112
Investigator Site 1 - GEO9950001
Tbilisi, 0114
Investigator Site 3 - GEO9950003
Tbilisi, 0114
Austria2 sites
Investigator Site 26 - AT0430002
Innsbruck, 6020
Investigator Site 27 - AT0430001
Vienna, 1090
Canada2 sites
Investigator Site 29 - CA0019003
London, N6A 5A5
Investigator site 37 - CA0019002
Québec, H3A 2B4
Poland2 sites
Investigator Site 5 - PL0480002
Krakow, 31-426
Investigator Site 4 - PL0480001
Lubin, 20-093
Spain2 sites
Investigator Site 19 - ES0340001
Barcelona, 08041
Investigator Site 18 - ES0340002
Santiago de Compostela, A Coruña, 15706
About this study
Official title: A Phase 3b, Randomized, Open-label, Parallel-Group Study to Evaluate Different Dosing Regimens of Intravenous Efgartigimod to Maximize and Maintain Clinical Benefit in Patients With Generalized Myasthenia Gravis
The purpose of this open-label study is to investigate the efficacy, safety, and tolerability of a continuous regimen of efgartigimod compared with a cyclic regimen in participants with Generalized Myasthenia Gravis (gMG).
Participants will receive efgartigimod throughout the study. The participants will be randomized to the continuous regimen arm or to the cyclic regimen arm. The study consists of a part A (regimen comparison period) where participants will continue the treatment based on the treatment regimen arm they were assigned at randomization. Following part A, participants will enter part B (extension period) where all participants will receive efgartigimod in the continuous regimen. The study duration for participants is up to 138 weeks.
- Conditions
- Generalized Myasthenia Gravis, MG - Myasthenia Gravis, gMG
- Being tested
- Efgartigimod IV
- 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 IVBiological
Intravenous infusions of efgartigimod
| Study group | Role | What they receive |
|---|---|---|
| Efgartigimod IV - continuous regimen | Experimental | Participants receiving efgartigimod IV on a continuous regimen Receives: Biological: Efgartigimod IV |
| Efgartigimod IV - cyclic regimen | Experimental | Participants receiving efgartigimod IV on a cyclic regimen Receives: Biological: Efgartigimod IV |
What is being measured
The primary outcome is the main question the study is designed to answer.
Mean of the Average MG-ADL Total Score Change From Baseline During the Visit of Week 1 Through Week 21 by Regimen Arm
The MG-ADL (Myasthenia Gravis Activities of Daily Living) scale assesses MG symptoms and their effects on daily activities. The total score varies between 0 and 24, with higher total scores indicating more impairment.
Measured: Up to 21 weeks
Secondary outcomes (7)
Incidence of AEs, SAEs and AESIs
AE : adverse event; SAE: serious adverse event; AESI: adverse event of special interest
Measured: Up to 135 weeks
Change From Baseline in the MG-ADL Total Score Over Time
The MG-ADL (Myasthenia Gravis Activities of Daily Living) scale assesses MG symptoms and their effects on daily activities. The total score varies between 0 and 24, with higher total scores indicating more impairment.
Measured: Up to 126 weeks
Normalized Area Under the Effect Curve (AUEC) of MG-ADL Total Score Improvement From Baseline
The MG-ADL (Myasthenia Gravis Activities of Daily Living) scale assesses MG symptoms and their effects on daily activities. The total score varies between 0 and 24, with higher total scores indicating more impairment.
Measured: Up to 21 weeks
Characterization of MG-ADL Total Score Change From Baseline
The MG-ADL (Myasthenia Gravis Activities of Daily Living) scale assesses MG symptoms and their effects on daily activities. The total score varies between 0 and 24, with higher total scores indicating more impairment.
Measured: Up to 21 weeks
Percentage of Participants Who Have a ≥ 2, 3, 4, or 5 Points Improvement in MG-ADL Total Score From Baseline
The MG-ADL (Myasthenia Gravis Activities of Daily Living) scale assesses MG symptoms and their effects on daily activities. The total score varies between 0 and 24, with higher total scores indicating more impairment.
Measured: Up to 21 weeks
Percentage of Time Participants Have a Change in MG-ADL Total Score of at Least 2 Points From Baseline During Week 4 Through Week 21
The MG-ADL (Myasthenia Gravis Activities of Daily Living) scale assesses MG symptoms and their effects on daily activities. The total score varies between 0 and 24, with higher total scores indicating more impairment.
Measured: From week 4 to week 21
Percentage of Participants Who Achieve MSE, Defined as a MG-ADL Total Score of 0 or 1
MSE = minimal symptom expression; The MG-ADL (Myasthenia Gravis Activities of Daily Living) scale assesses MG symptoms and their effects on daily activities. The total score varies between 0 and 24, with higher total scores indicating more impairment.
Measured: Up to 21 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Jul 2021
- Study start16 Dec 2021
- Primary completion24 Aug 2023
- Study completion6 Oct 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- 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 3
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 69 participants (actual)
Sponsor and investigators
- Lead sponsor
- argenx
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04980495
- Sponsor's protocol ID
- ARGX-113-2003
- Other IDs
- 2024-510932-36-00
- Acronym
- ADAPT NXT
- Status last verified
- Nov 2025
- First submitted
- 19 Jul 2021
- Last updated
- 27 May 2026
- Results posted
- Yes, on ClinicalTrials.gov
- 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 27 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 3b, Randomized, Open-label, Parallel-Group Study to Evaluate Different Dosing Regimens of Intravenous Efgartigimod to Maximize and Maintain Clinical Benefit in Patients With Generalized Myasthenia Gravis
- ClinicalTrials.gov ID
- NCT04980495
- Acronym / sponsor ID
- ADAPT NXT / ARGX-113-2003
- Conditions
- Generalized Myasthenia Gravis, MG - Myasthenia Gravis, gMG
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 69 participants (actual)
- Lead sponsor
- argenxIndustry (pharma, biotech, devices)
- Study start
- 16 Dec 2021 (actual)
- Primary completion
- 24 Aug 2023 (actual)
- Study completion
- 6 Oct 2025 (actual)
- First posted
- 28 Jul 2021 (actual)
- Results
- Posted 27 May 2026
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 open-label study is to investigate the efficacy, safety, and tolerability of a continuous regimen of efgartigimod compared with a cyclic regimen in participants with Generalized Myasthenia Gravis (gMG).
Participants will receive efgartigimod throughout the study. The participants will be randomized to the continuous regimen arm or to the cyclic regimen arm. The study consists of a part A (regimen comparison period) where participants will continue the treatment based on the treatment regimen arm they were assigned at randomization. Following part A, participants will enter part B (extension period) where all participants will receive efgartigimod in the continuous regimen. The study duration for participants is up to 138 weeks.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Efgartigimod IV - continuous regimen | Experimental | Biological: Efgartigimod IVParticipants receiving efgartigimod IV on a continuous regimen |
| Efgartigimod IV - cyclic regimen | Experimental | Biological: Efgartigimod IVParticipants receiving efgartigimod IV on a cyclic regimen |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- At least 18 years of age, at the time of signing the informed consent.
- Diagnosed with Generalized Myasthenia Gravis (gMG) with confirmed documentation and supported by a physical exam and confirmed seropositivity for anti-acetylcholine receptor antibodies (AChR-Abs).
- Meets the clinical criteria as defined by the Myasthenia Gravis Foundation of America (MGFA) class II, III, or IV
Key exclusion criteria (7 listed)
- Any other condition that, in the opinion of the investigator, would interfere with an accurate assessment of the clinical symptoms of gMG and/or put the participant at undue risk
- A thymectomy within 3 months of screening
- Use of the following prior or concomitant therapies:
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 IVIntravenous infusions of efgartigimod | Biological | Efgartigimod IV - continuous regimen, Efgartigimod IV - cyclic regimen |
Primary outcome
Mean of the Average MG-ADL Total Score Change From Baseline During the Visit of Week 1 Through Week 21 by Regimen Arm
Time frame: Up to 21 weeks
The MG-ADL (Myasthenia Gravis Activities of Daily Living) scale assesses MG symptoms and their effects on daily activities. The total score varies between 0 and 24, with higher total scores indicating more impairment.
7 secondary outcomes
Incidence of AEs, SAEs and AESIs
Time frame: Up to 135 weeks
Change From Baseline in the MG-ADL Total Score Over Time
Time frame: Up to 126 weeks
Normalized Area Under the Effect Curve (AUEC) of MG-ADL Total Score Improvement From Baseline
Time frame: Up to 21 weeks
Characterization of MG-ADL Total Score Change From Baseline
Time frame: Up to 21 weeks
Percentage of Participants Who Have a ≥ 2, 3, 4, or 5 Points Improvement in MG-ADL Total Score From Baseline
Time frame: Up to 21 weeks
Percentage of Time Participants Have a Change in MG-ADL Total Score of at Least 2 Points From Baseline During Week 4 Through Week 21
Time frame: From week 4 to week 21
Percentage of Participants Who Achieve MSE, Defined as a MG-ADL Total Score of 0 or 1
Time frame: Up to 21 weeks
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 27 May 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- 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. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
39 sites in 11 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing Efgartigimod IV in people with Generalized Myasthenia Gravis and MG - Myasthenia Gravis, run by argenx at 39 sites in 11 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 3 inclusion and 7 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: finished, as of the sponsor's last update on 27 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 39 sites in United States, France, Italy, Germany, Georgia and 6 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 phase mean?
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?
Yes. Results are posted in the registry (first posted 27 May 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
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?
Mean of the Average MG-ADL Total Score Change From Baseline During the Visit of Week 1 Through Week 21 by Regimen Arm (time frame: Up to 21 weeks). 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 27 May 2026.