Efgartigimod for Myasthenia Gravis

Overseen By Alyssa Avilez, BS

Age: 18+

Sex: Any

Trial Phase: Phase 4

Sponsor: University of Colorado, Denver

Must be taking: Cholinesterase inhibitors

Must not be taking: C5-complement inhibitors

Disqualifiers: Active infection, Intubation, Pregnancy, 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

Compensation: Varies

Number of Visits: 5

Duration: 4 weeks

20 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores whether the drug efgartigimod can aid people with myasthenia gravis (MG) during sudden symptom worsening that requires hospital care. Efgartigimod is approved for regular use in adults with MG who have a specific antibody type, but it has not been studied for these acute episodes. The trial aims to determine if efgartigimod can improve symptoms and recovery during hospital stays. Suitable candidates include those with MG who have experienced severe weakness necessitating hospitalization. Participants will receive efgartigimod infusions over four weeks, followed by a follow-up visit. As a Phase 4 trial, this study focuses on understanding how this FDA-approved and effective treatment can benefit more patients during acute episodes.

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 excludes those who have used certain treatments like IVIG, plasma exchange, or efgartigimod recently. It also excludes those using specific medications like ravulizumab or eculizumab.

What is the safety track record for efgartigimod?

Research has shown that efgartigimod, approved by the FDA for treating generalized myasthenia gravis (MG), has been studied for its safety. Some studies suggest it might increase the risk of infections, based on data from patients who have used efgartigimod. However, these findings are part of ongoing research to better understand the drug's safety. It is important to note that many people with MG have safely used efgartigimod for long-term treatment. As researchers explore its use for sudden worsening of MG symptoms, they continue to monitor for any new safety information. ^{1 2 3 4 5}

Why are researchers enthusiastic about this study treatment?

Unlike the standard treatments for myasthenia gravis, which typically involve immunosuppressants and acetylcholinesterase inhibitors, efgartigimod offers a unique approach by targeting the neonatal Fc receptor (FcRn). This mechanism reduces the levels of pathogenic antibodies without broadly suppressing the immune system, potentially leading to fewer side effects. Researchers are excited about efgartigimod because it is administered through a series of intravenous infusions that may provide faster symptom relief compared to existing options.

What is the effectiveness track record for efgartigimod in treating myasthenia gravis exacerbations?

Research has shown that efgartigimod, which participants in this trial will receive, effectively treats generalized myasthenia gravis (MG). In earlier studies, participants experienced significant symptom improvements, measured using standard tools like the MG-ADL (Myasthenia Gravis Activities of Daily Living) and QMG (Quantitative Myasthenia Gravis score). These improvements were noticeable from weeks 2 to 4 of treatment and surpassed those seen with standard therapies. Efgartigimod is generally well-tolerated and has helped patients with hard-to-treat MG. The FDA has approved the drug for ongoing treatment of MG in adults with specific antibodies, confirming its effectiveness. ^{5 6 7 8 9}

Who Is on the Research Team?

Thomas Ragole, MD

Principal Investigator

University of Colorado, Denver

Are You a Good Fit for This Trial?

This trial is for hospitalized adults with myasthenia gravis (MG) experiencing a worsening of symptoms, known as an exacerbation. Participants must have MG that's confirmed by specific antibodies. Details on who can't join are not provided.

Inclusion Criteria

Abnormal single fiber EMG

Abnormal decrement on slow repetitive nerve stimulation testing

Quantitative Myasthenia Gravis (QMG) scale ≥ 11

Exclusion Criteria

I am currently using ravulizumab or eculizumab.

Intubation prior to ability to sign informed consent or intubation within 24 hours of hospitalization

I don't have health issues that could affect study assessments.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

1-2 weeks

Treatment

Participants receive 4 doses of efgartigimod via intravenous (IV) infusion on days 1, 4, 11, and 18

4 weeks

4 visits (in-person)

Follow-up

Participants are monitored for safety and effectiveness after treatment, with assessments at day 32

2 weeks

1 visit (in-person)

What Are the Treatments Tested in This Trial?

Interventions

• Efgartigimod

Trial Overview The study tests if efgartigimod, already approved for chronic MG treatment, is effective when given in the hospital to treat acute MG exacerbations. Patients will receive four doses over four weeks and be monitored using the QMG scale.

How Is the Trial Designed?

Group I: Efgartigimod Experimental Treatment 1 Intervention

Participants receive 4 doses of efgartigimod via intravenous (IV) infusion over the course of the study on days 1, 4, 11 and 18.

Who Is Running the Clinical Trial?

University of Colorado, Denver

Lead Sponsor

Trials

1,842

Recruited

3,028,000+

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 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 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]

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, 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]

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, 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]

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).