Efgartigimod for Myasthenia Gravis

(ADAPT Jr SC Trial)

Recruiting at 17 trial locations

Overseen By Sabine s Coppieters, MD

Age: < 18

Sex: Any

Trial Phase: Phase 2 & 3

Sponsor: argenx

Must be taking: Corticosteroids, Immunosuppressants

Disqualifiers: Pregnancy, Infection, Autoimmune disease, Cancer, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Prior Safety Data This treatment has passed at least one previous human trial

Approved in 4 Jurisdictions This treatment is already approved in other countries

Compensation: Varies

Number of Visits: Unknown

Duration: 12 weeks

12 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial examines how efgartigimod PH20 SC, an experimental drug, works in children and teens with generalized Myasthenia Gravis, a condition that causes muscle weakness. Researchers aim to determine the right dose for children by assessing how the body absorbs and responds to the treatment. Participants will receive injections and be monitored for safety over 14 weeks, with an opportunity to continue in another study afterward. Eligible participants have Myasthenia Gravis, have tried other treatments without sufficient success, and are currently on stable medication. As a Phase 2, Phase 3 trial, this study evaluates the treatment's effectiveness in a smaller group and represents the final step before FDA approval, offering a chance to advance treatment options.

Will I have to stop taking my current medications?

The trial does not specify if you must stop taking your current medications, but it mentions that participants should be on a stable dose of their current MG therapy for at least one month before screening. It's best to discuss your specific medications with the study team.

Is there any evidence suggesting that efgartigimod PH20 SC is likely to be safe for pediatric patients?

Previous studies have tested the safety of efgartigimod PH20 SC for treating generalized myasthenia gravis (gMG). Research has shown that this treatment is generally well-tolerated. Over 10% of participants reported common side effects, such as mild reactions at the injection site. Other studies found that efgartigimod PH20 SC has a safety profile similar to its intravenous form, efgartigimod IV. This similarity in side effects and overall safety offers reassurance about its use. ^{1 2 3 4 5}

Why do researchers think this study treatment might be promising?

Unlike the standard treatments for myasthenia gravis, which often include medications like acetylcholinesterase inhibitors or immunosuppressants, efgartigimod PH20 SC offers a novel approach. This treatment works by targeting and reducing specific antibodies that attack the neuromuscular junction, potentially alleviating symptoms more effectively. Additionally, it's administered subcutaneously, which could make it more convenient compared to traditional intravenous options. Researchers are excited about this treatment because it promises a new mechanism of action that could provide relief for patients who don't respond well to existing therapies.

What evidence suggests that efgartigimod PH20 SC might be an effective treatment for myasthenia gravis?

Research has shown that efgartigimod PH20 SC, the treatment under study in this trial, may help treat generalized myasthenia gravis (gMG). Studies have found that patients experienced improvements in their condition, as reflected in MG-ADL scores, which measure daily muscle weakness. These improvements persisted through several treatment cycles, providing consistent benefits. Efgartigimod PH20 SC is as effective as the intravenous version, efgartigimod IV, for treating gMG, and it is also safe and well-tolerated by patients. This suggests that efgartigimod PH20 SC could be a good option for managing gMG symptoms. ^{2 3 4 5 6}

Are You a Good Fit for This Trial?

This trial is for children aged 2 to less than 18 with generalized Myasthenia Gravis (gMG), confirmed by tests. They should understand the study and follow its rules, have tried other gMG treatments without enough improvement, and be on a stable dose of current medications for at least a month. Participants must use birth control if applicable.

Inclusion Criteria

I understand the study requirements and can consent to participate.

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

I've tried certain medications for my condition without much success but am on a stable treatment plan now.

Exclusion Criteria

I had cancer but have been free of it for over 3 years or was treated successfully for certain cancers.

I don't have any health issues that would risk my safety in the study.

Positive PCR test for SARS-CoV-2 at screening

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive injections of efgartigimod PH20 SC and are monitored for safety, pharmacokinetics, and pharmacodynamics

12 weeks

Follow-up

Participants are monitored for safety and effectiveness after treatment

2 weeks

Open-label extension (optional)

Eligible participants may roll over to an open-label extension study for continued treatment

What Are the Treatments Tested in This Trial?

Interventions

• Efgartigimod PH20 SC

Trial Overview The study tests Efgartigimod PH20 SC in kids with gMG to find the right dose based on how their body absorbs and responds to it. It involves injections of this drug, monitoring over up to 14 weeks, followed by an optional extension phase for further observation.

How Is the Trial Designed?

Group I: Efgartigimod PH20 SC Experimental Treatment 1 Intervention

Participants aged 12 to \<18 years receiving efgartigimod PH20 SC treatment

Efgartigimod PH20 SC is already approved in European Union, United States, Japan, China for the following indications:

Approved in European Union as VYVGART for:

• Generalized myasthenia gravis in adults who are anti-acetylcholine receptor antibody positive

Approved in United States as VYVGART Hytrulo for:

• Generalized myasthenia gravis in adults who are anti-acetylcholine receptor antibody positive
• Chronic inflammatory demyelinating polyneuropathy (CIDP)

Approved in Japan as VYVDURA for:

• Generalized myasthenia gravis in adults who are anti-acetylcholine receptor antibody positive

Approved in China as Efgartigimod alfa injection (subcutaneous injection) for:

• Generalized myasthenia gravis in adults who are anti-acetylcholine receptor antibody positive

Who Is Running the Clinical Trial?

argenx

Lead Sponsor

Trials

76

Recruited

11,500+

Tim Van Hauwermeiren

argenx

Chief Executive Officer since 2008

B.Sc. and M.Sc. in Bioengineering from Ghent University, Executive MBA from The Vlerick School of Management

Dr. Peter Ulrichts

argenx

Chief Medical Officer since 2023

MD from Maastricht University, PhD in Molecular Immunology from Maastricht University

Published Research Related to This Trial

Efgartigimod, a human IgG1 antibody, significantly improved symptoms in patients with generalized myasthenia gravis, with 68% of treated patients showing a meaningful response compared to only 30% in the placebo group, indicating strong efficacy.

The treatment was well tolerated, with similar rates of adverse events between efgartigimod and placebo groups, suggesting it is a safe option for patients, with no deaths reported during the trial.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Safety, efficacy, and tolerability of efgartigimod in patients with generalised myasthenia gravis (ADAPT): a multicentre, randomised, placebo-controlled, phase 3 trial. Howard, JF., Bril, V., Vu, T., et al.[2022]

NVA237 (glycopyrronium bromide) demonstrated consistent pharmacokinetics in mild-to-moderate COPD patients, with a steady-state reached within one week of treatment and limited systemic accumulation after repeated once-daily inhalation.

The study showed that plasma exposure to NVA237 was dose-proportional within the 50-200 μg range, indicating its potential for effective dosing without significant safety concerns.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Pharmacokinetics of multiple inhaled NVA237 doses in patients with chronic obstructive pulmonary disease (COPD). Sechaud, R., Renard, D., Zhang-Auberson, L., et al.[2019]

Efgartigimod, an FcRn antagonist, has been shown in clinical trials to effectively improve clinical status and reduce autoantibody levels in patients with myasthenia gravis, with no significant safety concerns reported.

This treatment has received regulatory approvals in the United States, Japan, and Europe, suggesting its potential effectiveness across various subgroups and severities of myasthenia gravis.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Clinical efficacy and safety of efgartigimod for treatment of myasthenia gravis. Sivadasan, A., Bril, V.[2023]

Efgartigimod was found to be safe and well-tolerated in a phase 2 study involving 24 patients with generalized myasthenia gravis, with no serious adverse events reported.

The treatment led to a significant reduction in pathogenic IgG autoantibodies and resulted in a rapid and long-lasting improvement in disease symptoms for 75% of patients, suggesting its potential as an effective therapy for myasthenia gravis.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Randomized phase 2 study of FcRn antagonist efgartigimod in generalized myasthenia gravis. Howard, JF., Bril, V., Burns, TM., et al.[2020]

In a study of 37 patients with acetylcholine receptor antibody-positive generalized myasthenia gravis, 72% experienced a significant improvement in daily living activities after one cycle of efgartigimod, indicating its efficacy in managing symptoms.

Efgartigimod treatment resulted in a substantial reduction in IgG levels and was generally well-tolerated, with only mild side effects reported, although one patient had to discontinue due to a Clostridium difficile infection.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Safety and outcomes with efgartigimod use for acetylcholine receptor-positive generalized myasthenia gravis in clinical practice. Katyal, N., Halldorsdottir, K., Govindarajan, R., et al.[2023]

In a 52-week study involving 1,066 patients with moderate-to-severe COPD, NVA237 (glycopyrronium bromide) significantly improved lung function, with a 97 mL increase in trough FEV(1) at 12 weeks compared to placebo.

NVA237 also reduced the risk of moderate-to-severe COPD exacerbations by 34% and improved patients' dyspnoea and health status, showing comparable efficacy to the standard treatment tiotropium, while maintaining a similar safety profile.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Efficacy and safety of NVA237 versus placebo and tiotropium in patients with COPD: the GLOW2 study. Kerwin, E., Hébert, J., Gallagher, N., et al.[2022]

In a thorough QT study involving 70 healthy volunteers, the GFF metered dose inhaler (MDI) demonstrated no potential for QT prolongation, indicating cardiovascular safety at therapeutic doses.

In a separate study with 237 patients suffering from moderate-to-severe COPD, GFF MDI did not cause significant changes in heart rate or other cardiovascular measures, confirming its safety profile compared to standard treatments.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Cardiovascular safety profile of a fixed-dose combination of glycopyrrolate and formoterol fumarate delivered via metered dose inhaler using co-suspension delivery technology. Ferguson, GT., Reisner, C., Pearle, J., et al.[2019]

Efgartigimod alfa is the first neonatal Fc receptor antagonist approved for treating generalized myasthenia gravis (gMG), showing significant and rapid improvements in muscle strength and quality of life in a phase 3 trial with a placebo group.

The treatment was generally well tolerated, with most side effects being mild to moderate, indicating a favorable safety profile for patients with gMG.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Efgartigimod Alfa in Generalised Myasthenia Gravis: A Profile of Its Use. Heo, YA.[2023]

Efgartigimod, a first-in-class neonatal Fc receptor antagonist, received its first approval in the USA in December 2021 for treating generalized myasthenia gravis in adults who are positive for anti-acetylcholine receptor antibodies.

The drug is also being evaluated for other autoimmune diseases and has been approved in Japan for generalized myasthenia gravis patients regardless of antibody status, indicating its potential broad application in autoimmune conditions.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Efgartigimod: First Approval. Heo, YA.[2022]

The fixed-dose combination of glycopyrrolate and formoterol (GFF MDI) significantly improved lung function in patients with moderate-to-very severe COPD after 7 days of treatment, outperforming monocomponent inhalers and placebo.

Both doses of GFF MDI (72/9.6 μg and 36/9.6 μg) were well tolerated, indicating a favorable safety profile for this combination therapy in managing COPD.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A randomized, seven-day study to assess the efficacy and safety of a glycopyrrolate/formoterol fumarate fixed-dose combination metered dose inhaler using novel Co-Suspension™ Delivery Technology in patients with moderate-to-very severe chronic obstructive pulmonary disease. Reisner, C., Fabbri, LM., Kerwin, EM., et al.[2022]

Glycopyrronium, a long-acting muscarinic antagonist (LAMA), delivered a significantly higher fine particle fraction (42.6%) compared to tiotropium (9.8%), indicating better potential for effective lung deposition in COPD patients.

The study found that glycopyrronium also achieved greater intrathoracic drug deposition (39%) than tiotropium (22%), suggesting it may be more effective for a broader range of COPD severities.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Delivery characteristics of a low-resistance dry-powder inhaler used to deliver the long-acting muscarinic antagonist glycopyrronium. Colthorpe, P., Voshaar, T., Kieckbusch, T., et al.[2023]

Citations

1. argenx.com argenx.com/news/2025/press-release-3176635

argenx Presents New Data at AANEM and MGFA ... What is VYVGART® (efgartigimod alfa-fcab)? VYVGART is a prescription medicine used to treat a condition called generalized myasthenia gravis ...

2. clinicaltrials.gov clinicaltrials.gov/study/NCT06909214

NCT06909214 | A Study to Evaluate the ... A Study to Evaluate the Clinical Outcomes of Efgartigimod PH20 SC in Adults With New-onset Generalized Myasthenia Gravis (gMG) (ADAPT-EARLY) · Study Overview.

3. argenxmedical.com argenxmedical.com/content/dam/medical-affairs/congress-posters/nuerology/aan-2025/Long-Term-Safety-and-Efficacy-of-Subcutaneous-Efgartigimod-PH20-in-Adult-Participants-With-Generalized-Myasthenia-Gravis-Interim-Results-of-the-ADAPT-S.pdf

Interim Results of the ADAPT-SC+ Study aData presented represents mean change in MG-ADL score from study baseline maintained as patients move through multiple cycles of efgartigimod ...

4. pubmed.ncbi.nlm.nih.gov pubmed.ncbi.nlm.nih.gov/39227284/

A phase 3 randomized noninferiority study (ADAPT-SC) ... These findings support noninferiority between efgartigimod PH20 SC 1000 mg and efgartigimod IV 10 mg/kg, as well as long-term safety, tolerability, and ...

5. neurology.org neurology.org/doi/10.1212/WNL.0000000000210678

Interim Results of the ADAPT-SC+ Study (P1-11.005) Objective: To evaluate long-term safety and efficacy of efgartigimod PH20 SC in participants with generalized myasthenia gravis (gMG) enrolled ...

6. argenxmedical.com argenxmedical.com/content/dam/medical-affairs/congress-posters/nuerology/mgfa/Long-Term%20Safety%20and%20Efficacy%20of%20Subcutaneous%20Efgartigimod%20PH20%20in%20Adult%20Participants%20With%20Generalized%20Myasthenia%20Gravis_%20Interim%20Results%20of%20the%20ADAPT-SC%2B%20Study.pdf

Interim Results of the ADAPT-SC+ Study AEs occurring in >10% of participants receiving efgartigimod PH20 SC in either data cut. ▫ Participants experiencing injection site reaction events ...