Efgartigimod for Myasthenia Gravis

Overseen By François Jacques, Doctor

Age: 18+

Sex: Any

Trial Phase: Phase 3

Sponsor: Clinique Neuro-Outaouais

Must be taking: IVIG

Must not be taking: Rituxan, Eculizumab

Disqualifiers: Hepatitis, HIV, TB, Pregnancy, others

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

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

Compensation: Varies

Number of Visits: 26

Duration: 24 weeks

30 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests efgartigimod, a new treatment for people with myasthenia gravis, a condition that causes muscle weakness. The goal is to determine if efgartigimod can replace regular IVIG treatments while still managing symptoms effectively. Participants should have a stable form of myasthenia gravis, meaning their condition has not changed significantly recently, and they have received regular IVIG treatments for at least a year. As a Phase 3 trial, this is the final step before FDA approval, providing an opportunity to contribute to a potentially groundbreaking treatment.

Will I have to stop taking my current medications?

The trial does not specify if you need to stop taking your current medications, but it requires that your myasthenia gravis treatment has been stable for the past four months, with no changes in certain medications like corticosteroids for the past three months.

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

Research has shown that efgartigimod has been tested for safety in treating myasthenia gravis, a condition that leads to muscle weakness. Some studies have found that patients using efgartigimod might face a higher risk of infections because the treatment can impact the immune system. However, these risks are generally manageable.

One study examined the safety of efgartigimod using data from the FDA's reporting system. This study found that while some side effects occur, they are usually mild. Most people tolerate the treatment well.

Overall, efgartigimod is considered a promising option, but participants should discuss potential risks with their doctor. ^{1 2 3 4 5}

Why do researchers think this study treatment might be promising?

Efgartigimod is unique because it targets the neonatal Fc receptor (FcRn), which is a different approach from most current treatments for Myasthenia Gravis that primarily focus on suppressing the immune system or improving neuromuscular transmission. This new mechanism helps reduce harmful antibodies without broadly dampening the immune system, potentially leading to fewer side effects. Researchers are excited about efgartigimod because it offers a more targeted treatment option that could lead to faster and more effective symptom relief for patients.

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

Research has shown that efgartigimod, the treatment under study in this trial, effectively treats myasthenia gravis, a condition that weakens muscles. Studies have found that patients using efgartigimod experienced significant improvements in daily activities and muscle strength, noticeable as early as weeks 2 to 4. Efgartigimod is well-tolerated, with patients generally not experiencing severe side effects. Another study confirmed its effectiveness even for those unresponsive to other treatments. Overall, efgartigimod shows promise in helping people with this challenging condition. ^{5 6 7 8 9}

Who Is on the Research Team?

François Jacques, Doctor

Principal Investigator

Clinique Neuro-Outaouais

Are You a Good Fit for This Trial?

This trial is for patients with Myasthenia Gravis who rely on regular intravenous immunoglobulin (IVIG) therapy. Participants should be stable on their IVIG treatment before joining. Specific inclusion and exclusion criteria details are not provided, but typically these would outline health conditions and factors that qualify or disqualify someone from participating.

Inclusion Criteria

I have been getting IVIG treatments for myasthenia gravis for over a year.

No modification or addition of NSISTs in the past six months

I have Myasthenia Gravis confirmed by tests or improvement with specific medication.

Exclusion Criteria

I had my thymus gland removed within the last 3 months.

Patients that are pregnant or considering becoming pregnant in the next 6 months

I have not had rituxan, eculizumab, or plasma exchange in the last 6 months.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

1 week

Treatment

Efgartigimod is administered as a one-hour intravenous infusion every week for 4 infusions followed by a four-week break, repeated for a total of four treatment cycles

24 weeks

Weekly visits for infusions

Observation

Participants undergo a two-week observation period with an end of study visit

2 weeks

End of study visit at week 26

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 is testing efgartigimod as a replacement therapy for IVIG in Myasthenia Gravis patients over a period of 26 weeks. It's an open-label trial, meaning both the researchers and participants know what treatment is being given, at a single center with weekly evaluations using MG-ADL and MGQOL scales.

How Is the Trial Designed?

Group I: treatment Experimental Treatment 1 Intervention

Efgartigimod infusion

Who Is Running the Clinical Trial?

Clinique Neuro-Outaouais

Lead Sponsor

Trials

7

Recruited

240+

argenx

Industry 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 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]

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, 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 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 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]

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]

Citations

1.

argenx.com

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

argenx Presents New Data at AANEM and MGFA ...

Improvements in MG-ADL and QMG (Quantitative Myasthenia Gravis score) among patients treated with VYVGART were increasingly pronounced across ...

2.

pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC12366048/

The efficacy and safety of efgartigimod for refractory ...

Our study demonstrates that efgartigimod is highly effective and well-tolerated in patients with refractory MG. These findings suggest that ...

3.

sciencedirect.com

sciencedirect.com/science/article/pii/S1878747925002089

Efficacy and safety of efgartigimod versus intravenous ...

From weeks 2–4, the efgartigimod group showed significantly greater improvements in MG-ADL and QMG scores (both P ​< ​0.05), with a similar ...

4.

eurjmedres.biomedcentral.com

eurjmedres.biomedcentral.com/articles/10.1186/s40001-025-03057-6

The efficacy and safety of efgartigimod for refractory ...

Our study demonstrates that efgartigimod is highly effective and well-tolerated in patients with refractory MG. These findings suggest that ...

5.

neurology.org

neurology.org/doi/10.1212/WNL.0000000000208765

Outcomes for Patients with Generalized Myasthenia Gravis ...

Despite varying patient characteristics, results suggest both treatments improved patient outcomes and decreased OCS dosing.

6.

pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC12258281/

Postmarketing adverse events of efgartigimod alfa: a real- ...

Efgartigimod alfa is an important novel drug for the treatment of myasthenia gravis. However, postmarketing safety data for this drug is limited ...

7.

neurologylive.com

neurologylive.com/view/evaluating-risk-clarifying-safety-data-behind-efgartigimod

Clarifying the Safety Data Behind Efgartigimod

Josh Bryson, PhD, head of Medical Affairs at Argenx, discussed the safety profile of efgartigimod in light of recent FAERS-based infection data.

8.

neurology.org

neurology.org/doi/10.1212/WNL.0000000000211132

Infections-related Safety Profile of Efgartigimod Alpha and ...

This analysis identified a potential risk of infections in myasthenia gravis patients treated with efgartigimod alfa or immunoglobulins in clinical practice.

9.

frontiersin.org

frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2025.1510992/full

A real-world pharmacovigilance study of efgartigimod alfa ...

This study analyzed adverse events (AEs) linked to efgartigimod alfa using data from the FDA Adverse Event Reporting System (FAERS).