Efgartigimod for Myasthenia Gravis

(ADAPT SERON Trial)

Not currently recruiting at 112 trial locations

Overseen By Sabine s Coppieters, MD

Age: 18+

Sex: Any

Trial Phase: Phase 3

Sponsor: argenx

Must be taking: Acetylcholinesterase inhibitors, Steroids

Disqualifiers: Autoimmune disease, Cancer, HIV, others

Pivotal Trial (Near Approval) This treatment is in the last trial phase before FDA approval

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

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests a new treatment called efgartigimod for individuals with Generalized Myasthenia Gravis (gMG), a condition that causes muscle weakness. The trial aims to determine if efgartigimod is safe and effective compared to a placebo (inactive substance). In the first part, participants will randomly receive either efgartigimod or a placebo, while in the second part, all participants will receive efgartigimod. Individuals with gMG who experience muscle weakness that worsens with activity but improves with rest, and who are currently on a stable MG treatment, might be suitable for this trial. Participants will be involved in the study for about 2.5 years. As a Phase 3 trial, this study represents the final step before FDA approval, offering participants a chance to contribute to a potentially groundbreaking treatment.

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 Myasthenia Gravis therapy before screening. It's best to discuss your specific medications with the trial team.

Is there any evidence suggesting that efgartigimod is likely to be safe for humans?

Research has shown that efgartigimod is usually well-tolerated for treating generalized Myasthenia Gravis (gMG). Some studies found it might slightly increase the risk of infections and cause allergic reactions or reactions during infusions. However, these side effects are uncommon, and most patients do not experience serious problems. The treatment has been tested in other studies and approved for some gMG patients, indicating it is safe for many people. Those with concerns should discuss with their doctor how these findings might apply to them. ^{1 2 3 4 5}

Why do researchers think this study treatment might be promising for myasthenia gravis?

Unlike the standard treatments for Myasthenia Gravis, which primarily focus on symptom relief and immune suppression, efgartigimod works by specifically targeting and reducing pathogenic antibodies. This action is achieved through a unique mechanism that modulates the neonatal Fc receptor, leading to decreased levels of harmful IgG antibodies in the bloodstream. Researchers are excited about efgartigimod because it not only offers a targeted approach but also has the potential to provide rapid and possibly more effective relief compared to current options.

What evidence suggests that efgartigimod might be an effective treatment for Myasthenia Gravis?

Research has shown that efgartigimod effectively treats generalized myasthenia gravis (gMG). Studies have found that it can reduce symptoms in patients with anti-AChR antibodies. Specifically, efgartigimod has improved muscle strength and reduced tiredness in these patients. In this trial, participants will receive either efgartigimod IV or a placebo in part A, with all participants receiving efgartigimod IV in part B. Although this trial focuses on individuals without these antibodies, the treatment lowers antibodies that attack muscle receptors, which might also benefit those without the antibodies. The treatment is generally well-tolerated, making it a promising option for managing gMG symptoms. ^{1 2 4 6 7}

Are You a Good Fit for This Trial?

This trial is for adults with seronegative Generalized Myasthenia Gravis (gMG), who can consent and follow the study plan. They must use birth control if applicable, have a negative pregnancy test if female, and show signs of MG that improve with certain treatments or tests.

Inclusion Criteria

I can sign the consent form and follow the study rules.

The participant agrees to use contraceptive measures consistent with local regulations and the women of child-bearing potential (WOCBP) must have a negative serum pregnancy test result at screening and a negative urine pregnancy test result at baseline before receiving the study drug

I am of legal age to consent to join a study.

Exclusion Criteria

I had cancer but have been free of it for over 3 years, or I had specific non-aggressive cancers treated successfully.

I have used certain medications as outlined in the trial protocol.

Known hypersensitivity to study drug or one of its excipients (inactive ingredients)

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Part A: Treatment

Participants are randomized to receive either efgartigimod IV or placebo

4 weeks

Weekly visits (in-person)

Part B: Open-label Treatment

Participants completing Part A will receive open-label efgartigimod IV

4 weeks

Weekly visits (in-person)

Follow-up

Participants are monitored for safety and effectiveness after treatment

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Efgartigimod

Trial Overview The study compares Efgartigimod IV to a placebo in treating gMG. Participants are randomly chosen to receive either the drug or placebo. Those completing this part will later all receive Efgartigimod in an open-label extension.

How Is the Trial Designed?

Group I: Efgartigimod IV Experimental Treatment 1 Intervention

Patients receiving efgartigimod IV in both part A and part B

Group II: Placebo Placebo Group 2 Interventions

Patients receiving placebo during part A and receiving efgartigimod IV during part B

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

Approved in European Union as Vyvgart for:

• Generalized Myasthenia Gravis (gMG)

Approved in United States as Vyvgart for:

• Generalized Myasthenia Gravis (gMG)
• Chronic Inflammatory Demyelinating Polyneuropathy (CIDP)

Approved in Canada as Vyvgart for:

• Generalized Myasthenia Gravis (gMG)

Approved in Japan as Vyvgart for:

• Generalized Myasthenia Gravis (gMG)

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 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, 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]

Efgartigimod, an engineered antibody, significantly improves muscle function and strength in patients with generalized myasthenia gravis (gMG), as shown by notable enhancements in Myasthenia Gravis Activities of Daily Living (MG-ADL) and Quantitative Myasthenia Gravis (QMG) scores over a 10-week period.

Improvements were observed across all muscle function subdomains (bulbar, ocular, limb/gross motor, and respiratory) within 1 to 2 weeks after the first infusion, correlating with reduced levels of pathogenic IgG, indicating its mechanism of action in decreasing autoantibody levels.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effect of efgartigimod on muscle group subdomains in participants with generalized myasthenia gravis: post hoc analyses of the phase 3 pivotal ADAPT study. Bril, V., Howard, JF., Karam, C., et al.[2023]

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]

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]

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]

Citations

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

argenx Presents New Data at AANEM and MGFA ... The study's primary objectives were to assess the long-term safety and sustained clinical effectiveness of VYVGART Hytrulo in a real-world, ...

2. vyvgarthcp.com vyvgarthcp.com/gmg/clinical-data

Clinical Trial Data - VYVGART Hytrulo The ADAPT trial established the effectiveness of VYVGART for IV infusion in the treatment of gMG in adults who are anti-AChR antibody positive.

3. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC10212825/

Efgartigimod Alfa in Generalised Myasthenia Gravis Efgartigimod alfa is a novel, effective and generally well-tolerated treatment option for patients with gMG.

4. uspharmacist.com uspharmacist.com/article/study-vyvgart-yields-positive-results-in-myasthenia-gravis-patients

Vyvgart Yields Positive Results in Myasthenia Gravis Patients Study: Vyvgart Yields Positive Results in Myasthenia Gravis Patients. Recently, argenx announced positive topline data from the pivotal phase ...

5. aetna.com aetna.com/cpb/medical/data/1000_1099/1002.html

Efgartigimod Alfa-fcab (Vyvgart) and ... Vyvgart is indicated for the treatment of generalized myasthenia gravis (gMG) in adult patients who are anti-acetylcholine receptor (AChR) antibody positive.

6. vyvgart.com vyvgart.com/gmg

VYVGART (efgartigimod alfa-fcab) for IV infusion and ... VYVGART and VYVGART Hytrulo may increase the risk of infection and can cause allergic, infusion or injection-related reactions. The most common side effects ...

7. clinicaltrials.gov clinicaltrials.gov/study/NCT03770403

A Safety and Tolerability Study of ARGX-113 in Patients ... This is a Long-Term, Single-Arm, Open-Label, Multicenter Phase 3 follow-on trial of the ARGX-113-1704 study to evaluate the safety and tolerability of ...