Efgartigimod for Guillain-Barré Syndrome

Overseen By Kelsey Moulton

Age: 18+

Sex: Any

Trial Phase: Phase 2

Sponsor: Chafic Karam

Must not be taking: Investigational drugs

Disqualifiers: Pregnancy, Severe infections, IgG deficiency, 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 2 Jurisdictions This treatment is already approved in other countries

Compensation: Varies

Number of Visits: 9

Duration: 1 week

30 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial examines whether Efgartigimod, an immunotherapy, is safe and effective for individuals with Guillain-Barré Syndrome (GBS), a condition that can cause sudden muscle weakness or paralysis. Participants will receive either Efgartigimod or the commonly used treatment, Intravenous Immunoglobulin (IVIg), to determine which is more effective. Eligible participants should have been diagnosed with GBS and experienced weakness within the last 14 days. The trial includes blood tests and questionnaires to monitor health and any side effects. As a Phase 2 trial, the research focuses on measuring the treatment's effectiveness in an initial, smaller group of people.

Do I need to stop my current medications for the trial?

The trial information does not specify whether you need to stop taking your current medications. It's best to discuss this with the trial coordinators or your doctor.

Is there any evidence suggesting that this trial's treatments are likely to be safe?

Research shows that Efgartigimod is generally well-tolerated. It is already approved to treat myasthenia gravis, another autoimmune disease, indicating its safety is well understood. One study found Efgartigimod effective and safe in helping to shorten Guillain-Barré syndrome (GBS).

Patients reported few serious side effects. Common side effects include mild issues like headaches and tiredness, which are usually easy to manage. While some side effects might occur, they are not often severe. Overall, based on current data, this treatment appears to be a promising option for people with GBS. ^{1 2 3 4 5}

Why do researchers think this study treatment might be promising?

Unlike the standard treatment for Guillain-Barré Syndrome, which typically involves Intravenous Immunoglobulin (IVIg), efgartigimod Alfa-Fcab is a new and exciting option because it works differently. Most treatments focus on blocking the antibodies that attack the nerves, but efgartigimod targets the neonatal Fc receptor (FcRn), reducing all harmful antibodies more broadly. This unique mechanism could potentially lead to faster and more comprehensive symptom relief. Researchers are excited because this approach may improve recovery times and outcomes for patients with Guillain-Barré Syndrome.

What evidence suggests that Efgartigimod might be an effective treatment for Guillain-Barré syndrome?

Research has shown that Efgartigimod, which participants in this trial may receive, may help treat Guillain-Barré syndrome (GBS). One study found that all four patients who received Efgartigimod experienced positive results, suggesting potential benefits. Efgartigimod also lowers levels of certain antibodies linked to GBS. These findings indicate that Efgartigimod might improve outcomes for GBS patients. However, further research is needed to confirm these results in larger groups. ^{1 2 3 4 5}

Who Is on the Research Team?

Chafic Karam, MD

Principal Investigator

Staff Physician and Associate Professor of Clinical Neurology

Colin Quinn, MD

Principal Investigator

Staff Physician and Associate Professor of Clinical Neurology

Are You a Good Fit for This Trial?

This trial is for adults over 18 with Guillain-Barré Syndrome (GBS) who started experiencing weakness due to GBS within the last two weeks. Participants must be able to follow the study's procedures and agree to stay in the study for its duration. They should not have other health conditions that could interfere with the trial.

Inclusion Criteria

Stated willingness to comply with all study procedures and availability for the duration of the study

Provision of signed and dated informed consent form

I have been diagnosed with Guillain-Barré Syndrome.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive Efgartigimod or IVIg treatment. Efgartigimod is administered on days 1 and 5, with placebo on days 2-4. IVIg is administered daily for 5 days.

1 week

Daily visits for 5 days

Follow-up

Participants are monitored for safety and effectiveness after treatment, including assessments of GBS Disability Scale, NIS, and I-RODS.

48 weeks

4 follow-up visits

Long-term follow-up

Participants are monitored for adverse events and biomarker levels through study completion.

3 years

What Are the Treatments Tested in This Trial?

Interventions

• Efgartigimod Alfa-Fcab

Trial Overview The trial is testing Efgartigimod, a new potential treatment for GBS, against standard Intravenous Immunoglobulin (IVIg) therapy. It aims to determine if Efgartigimod is safe and can improve patient outcomes by monitoring protein levels indicative of nerve damage and assessing any changes in mental health status.

How Is the Trial Designed?

Group I: Efgartigimod Alfa-Fcab Experimental Treatment 1 Intervention

20mg/kg of Intravenous efgartigimod on days 1 and 5, with normal saline administered as placebo on days 2-4

Group II: Intravenous Immunoglobulin (IVIg) Active Control 1 Intervention

0.4g/kg of IVIg daily for 5 days

Efgartigimod Alfa-Fcab is already approved in United States, European Union for the following indications:

Approved in United States as Vyvgart for:

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

Approved in European Union as Vyvgart for:

• Generalized myasthenia gravis (gMG)

Who Is Running the Clinical Trial?

Chafic Karam

Lead Sponsor

Trials

1

Recruited

30+

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 new treatment that reduces pathogenic IgG autoantibodies, showed promising results in three patients with both stiff-person syndrome (SPS) and myasthenia gravis (MG) over a 12-week treatment period, leading to symptom improvement.

This study suggests that efgartigimod could be a potential therapy for SPS and other autoimmune neurological disorders, as it demonstrated efficacy in alleviating symptoms associated with both conditions.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Efgartigimod beyond myasthenia gravis: the role of FcRn-targeting therapies in stiff-person syndrome. Di Stefano, V., Alonge, P., Rini, N., 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 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]

Intravenous immunoglobulin (IVIg) therapy may help treat conditions like Guillain-Barré syndrome by inhibiting the binding of cholera toxin to GM1, which is linked to disease development in some patients.

The study suggests that the mechanism of IVIg involves its variable region binding to both anti-GM1 antibodies and cholera toxin, potentially neutralizing harmful effects of the autoantibody, indicating a specific action in the treatment of these neuropathies.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Possible mechanism of intravenous immunoglobulin treatment on anti-GM1 antibody-mediated neuropathies. Yuki, N., Miyagi, F.[2006]

Intravenous immunoglobulin (IVIG) treatment is effective in managing autoimmune disorders like myasthenia gravis (MG), but the specific components responsible for its action are not fully understood.

The study identified that a small, disease-specific fraction of immunoglobulin within IVIG is crucial for its immunosuppressive effects, highlighting the importance of this fraction in the treatment's efficacy.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A disease-specific fraction isolated from IVIG is essential for the immunosuppressive effect of IVIG in experimental autoimmune myasthenia gravis. Fuchs, S., Feferman, T., Meidler, R., et al.[2008]

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 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]

In a study of 38 patients with Guillain-Barré syndrome, high affinity anti-GM1 IgG antibodies were linked to a higher frequency of axonal degeneration, indicating a potential mechanism for nerve damage in these patients.

The predominant IgG subclass for high affinity anti-GM1 antibodies was IgG1, while the presence of anti-Campylobacter jejuni antibodies did not correlate with specific disease patterns, suggesting that not all antibodies play a role in the disease's progression.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Affinity of anti-GM1 antibodies in Guillain-Barré syndrome patients. Deisenhammer, F., Keir, G., Pfausler, B., et al.[2019]

Intravenous immunoglobulin (IVIg) treatment effectively prevented paralysis in a model of Guillain-Barré syndrome, demonstrating its potential as a therapeutic intervention.

The study found that intact-type IVIg was more effective than F(ab')2 fragments, suggesting that the Fc portion of IVIg plays a crucial role in modulating the immune response.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Fc portion of intravenous immunoglobulin suppresses the induction of experimental allergic neuritis. Miyagi, F., Horiuchi, H., Nagata, I., et al.[2019]

In a study of 121 patients with Guillain-Barré syndrome (GBS), 32 patients were found to have anti-GM1 IgG antibodies, and all of these also showed activity against a mixture of GM1 and phosphatidic acid (GM1/PA), suggesting a potential link to the disease's mechanism.

Notably, 78% of the patients with anti-GM1 IgG antibodies had stronger binding activity to GM1/PA than to GM1 alone, indicating that this binding may play a significant role in the pathogenesis of GBS and could influence diagnostic approaches.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Binding of immunoglobulin G antibodies in Guillain-Barré syndrome sera to a mixture of GM1 and a phospholipid: possible clinical implications. Kusunoki, S., Morita, D., Ohminami, S., et al.[2015]

Citations

1. clinicaltrials.gov clinicaltrials.gov/study/NCT05701189

Evaluating Efgartigimod in Patients with Guillain-Barré ... The goal of this clinical trial is to evaluate the safety and effectiveness of Efgartigimod in patients with Guillain-Barre syndrome (GBS).

2. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC12443784/

Efgartigimod in the treatment of Guillain-Barré syndrome Notably, all four patients achieved favorable clinical outcomes, highlighting the potential therapeutic benefits of efgartigimod in acute GBS ...

3. bmcneurol.biomedcentral.com bmcneurol.biomedcentral.com/articles/10.1186/s12883-025-04412-0

Efgartigimod for treating Guillain-Barré syndrome with poor ... The results of this study suggest that sequential efgartigimod treatment may be effective in reducing serum anti-ganglioside antibody titers, ...

4. clinicaltrials.gov clinicaltrials.gov/study/NCT06885762

Efgartigimod for the Treatment of Guillain-Barré Syndrome Study Overview. Brief Summary. The goal of this clinical trial is to evaluating the efficacy and safety of efgartigimod in the treatment of ...

5. reports.argenx.com reports.argenx.com/2024/argenx-group/our-products-and-product-candidates/efgartigimod-indications.html

efgartigimod Indications - Annual Report 2024 - Argenx In June 2024, we announced results from the Phase 2 ALPHA clinical trial of efgartigimod in PC-POTS. Based on the results, we decided not to move forward ...