Efgartigimod for Myasthenia Gravis

Overseen By Eduardo Ng

Age: 18+

Sex: Any

Trial Phase: Phase 3

Sponsor: University Health Network, Toronto

Must be taking: AChE inhibitors, steroids, NSISTs

Must not be taking: Rituximab, Eculizumab

Disqualifiers: Pregnancy, Hepatitis, HIV, 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

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

Compensation: Varies

Number of Visits: 24

30 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests a new treatment called efgartigimod (also known as Vyvgart) for individuals with seronegative generalized myasthenia gravis, a disorder causing muscle weakness. The trial aims to evaluate the treatment's effectiveness and safety. It is open-label, meaning all participants know the treatment being administered. Ideal participants have been diagnosed with this condition, have shown limited response to other treatments, and continue to experience moderate to severe symptoms despite current therapy. As a Phase 3 trial, this is the final step before FDA approval, offering participants the opportunity to contribute to a potentially groundbreaking treatment.

Will I have to stop taking my current medications?

The trial requires that you stay on a stable dose of your current myasthenia gravis medications, such as AChE inhibitors, steroids, and certain immunosuppressants, for at least one month before screening.

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

Research has shown that efgartigimod is generally well-tolerated by patients. Common side effects include colds, headaches, and bladder infections, which are typical and manageable. Importantly, long-term studies on efgartigimod's safety for patients with generalized myasthenia gravis (a condition causing muscle weakness) have confirmed its safety for extended use.

Additionally, tests on efgartigimod show no evidence of harmful effects on development, even at high doses, suggesting a strong safety profile for the treatment. Overall, while some mild side effects exist, the treatment is considered safe based on the available data. ^{1 2 3 4 5}

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

Unlike other treatments for myasthenia gravis, which typically focus on managing symptoms through immunosuppressants like prednisone or pyridostigmine, efgartigimod offers a novel approach. This treatment works by targeting and reducing antibodies that attack the body's own tissues, thanks to its action on the neonatal Fc receptor (FcRn). By doing this, efgartigimod has the potential to directly address the underlying cause of the disease, potentially providing more effective and rapid symptom relief. Researchers are excited about efgartigimod because it could offer a targeted therapy option with potentially fewer side effects compared to traditional treatments.

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, is a promising option for generalized myasthenia gravis (gMG). Studies have found it effective and generally well-tolerated by patients. In trials, participants using efgartigimod experienced significant improvements in daily activities. Importantly, the treatment proved effective for patients with a common marker in gMG called anti-AChR antibodies. These findings suggest that efgartigimod could offer meaningful benefits for those with myasthenia gravis. ^{1 2 6 7 8}

Who Is on the Research Team?

Vera Bril, MD

Principal Investigator

Toronto General Hospital

Are You a Good Fit for This Trial?

This trial is for individuals with seronegative generalized myasthenia gravis, a condition causing muscle weakness. Participants will be treated at the University Health Network Toronto General Hospital and must commit to a study duration of 43 weeks.

Inclusion Criteria

My myasthenia gravis is moderate to severe.

Evidence of signed and dated informed consent document(s) indicating willingness to comply with the protocol, complete study assessments, and return for follow-up visits

My myasthenia gravis is moderate to severe.

Exclusion Criteria

I have tested positive for HBV, HCV, or HIV.

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

I have not had immunoglobulin or plasma exchange in the last 4 weeks.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2 weeks

1 visit (in-person)

Run-in

Participants undergo a run-in period to stabilize conditions before baseline

3 weeks

1 visit (in-person)

Induction

Participants receive weekly induction treatment with efgartigimod

3 weeks

3 visits (in-person)

Maintenance

Participants receive maintenance treatment every 2 weeks

31 weeks

15 visits (in-person)

Observation

Participants are monitored with 4 visits during the observation period

4 weeks

4 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 trial is testing efgartigimod's effectiveness, safety, and tolerability in treating muscle weakness due to myasthenia gravis. It's an open-label study which means everyone knows they're getting efgartigimod; no placebos are used.

How Is the Trial Designed?

Group I: efgartigimod Experimental Treatment 1 Intervention

active treatment with efgartigimod.

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?

University Health Network, Toronto

Lead Sponsor

Trials

1,555

Recruited

526,000+

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]

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 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, 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, 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]

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. clinicaltrials.gov clinicaltrials.gov/study/NCT03669588

NCT03669588 | An Efficacy and Safety Study of ARGX-113 ... A randomized, double-blind, placebo controlled, multicenter Phase 3 trial to evaluate the efficacy, safety, tolerability, quality of life and impact on normal ...

5. uspharmacist.com uspharmacist.com/article/vyvgart-yields-significant-clinical-benefit-in-myasthenia-gravis-patients

Vyvgart Yields Significant Clinical Benefit in Myasthenia ... These positive results in the MG-ADL score indicate that patients experienced significant improvements in one or more of their abilities in ...

6. accessdata.fda.gov accessdata.fda.gov/drugsatfda_docs/nda/2024/761304Orig1s000OtherR.pdf

center for drug evaluation and research - accessdata.fda.gov There was no evidence of adverse developmental outcomes following the intravenous administration of efgartigimod alfa at up to 100 mg/kg/day in ...

7. vyvgarthcp.com vyvgarthcp.com/gmg/safety

Safety - VYVGART Hytrulo The most common adverse reactions for VYVGART-treated patients were respiratory tract infection, headache, and urinary tract infection.

8. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC10842202/

Long-term safety, tolerability, and efficacy of efgartigimod ... ADAPT+ assessed the long-term safety, tolerability, and efficacy of efgartigimod in adult participants with generalized myasthenia gravis (gMG).