Treatment of Myasthenia Gravis Exacerbation or Crisis With Efgartigimod

July 10, 2025 updated by: University of Colorado, Denver

Treatment of Myasthenia Gravis Exacerbation or Crisis With Efgartigimod: A Single Arm, Open Label Prospective Cohort Study

This study plans to learn more about if the drug efgartigimod can be used in the hospital to treat exacerbations in participants with myasthenia gravis (MG). Efgartigimod has been approved by the FDA for ongoing (chronic) treatment of generalized MG in adult patients who are anti-acetylcholine receptor (AChR) antibody positive but has not been studied in the treatment of worsening weakness requiring hospital admission (known as "exacerbation"). This investigation aims to see if using efgartigimod in this way improves symptoms and recovery from exacerbation, and how it affects certain MG markers in the blood. The main questions it aims to answer are:

  • Is efgartigimod effective as a hospital-administered acute therapy for participants with worsening MG (MG exacerbation) who require hospitalization?
  • Will efgartigimod lead to clinical improvement with a similar reduction in validated research scales, such as the Quantitative MG (QMG) scale, as standard of care therapies?

Participants will receive 4 doses of efgartigimod over the course of 4 weeks with an additional follow-up visit at the clinic.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Efgartigimod is thought to work by reducing circulating IgG antibodies, including the antibodies that cause MG. One of the currently used treatments for MG exacerbation, called plasma exchange (PLEX), is also thought to work by reducing antibody levels by filtering blood through a machine similar to those used in dialysis for kidney failure. Because of the similarities between how these two treatments work, there is reason to believe that efgartigimod may also be helpful in treating MG exacerbation.

Study Type

Interventional

Enrollment (Estimated)

20

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • United States
    • Colorado
      • Aurora, Colorado, United States, 80045
        • Recruiting
        • University of Colorado
        • Principal Investigator:
          • Thomas Ragole, MD
        • Contact:
        • Sub-Investigator:
          • Aaron Carlson, MD
        • Sub-Investigator:
          • Brian Sauer, MD, PhD
        • Sub-Investigator:
          • Elizabeth Matthews, MD

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Adults ≥ age 18 years with known generalized MG as identified by characteristic signs of generalized MG on clinical assessment and positive serology for AchR antibodies as well as one of the following:

    1. Documented positive response to cholinesterase inhibitors such as pyridostigmine or edrophonium
    2. Abnormal decrement on slow repetitive nerve stimulation testing
    3. Abnormal single fiber EMG

  • Evidence of worsening weakness requiring hospital admission for stabilization and change in therapy as determined by a neuromuscular expert including:

    1. Quantitative Myasthenia Gravis (QMG) scale ≥ 11
    2. MG-ADL score ≥ 6
    3. Worsening weakness that is unlikely to be ameliorated by adjustment of current medications including impaired respiratory status, dysarthria, dysphagia, difficulty chewing, limb weakness, diplopia, ptosis.
  • Ability to sign consent and be enrolled within 24 hours of hospital admission. For participants transferred to University of Colorado Hospital, the time of admission/presentation to the outside hospital is counted towards this 24-hour cap.

Exclusion Criteria:

  • MG worsening thought to be related to active infection or due to medications (e.g. fluoroquinolone or aminoglycoside antibiotics, magnesium, chloroquine derivatives)
  • Intubation prior to ability to sign informed consent or intubation within 24 hours of hospitalization
  • Use of IVIG within 2 weeks, or having undergone plasma exchange or received efgartigimod in the 4 weeks prior to admission
  • Current ongoing use of ravulizumab or eculizumab (monoclonal antibody C5-complement inhibitors).
  • Other medical conditions that, in the opinion of the investigator and treating clinicians, might interfere with the validity of assessment measures used in the study (e.g. steroid myopathy, CNS pathology, severe arthritis, fractures, etc.). This criterion is a standard exclusion in MG trials and relates solely to other conditions that reduce muscle power or range of motion and would thus worsen scores on assessment measures like the QMG due to non-MG conditions.
  • Known history of coagulopathy, blood clotting, recent severe bleeding (e.g. GI bleed).
  • Pregnancy or breastfeeding. Pregnancy must be excluded for all potential participants who are able to become pregnant prior to initiation of treatment.
  • IgG levels < 600mg/dL
  • Evidence of active or chronic Hepatitis B infection, untreated Hepatitis C infection, HIV with low CD4 (<200) count.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Efgartigimod
Participants receive 4 doses of efgartigimod via intravenous (IV) infusion over the course of the study on days 1, 4, 11 and 18.
Drug: Efgartigimod
Dose of 10 mg/kg for IV infusion on days 1, 4, 11 and 18
Other Names:
  • Vyvgart

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change from baseline in the Quantitative Myasthenia Gravis (QMG) score at day 11
Time Frame: Baseline, Day 11
The Quantitative Myasthenia Gravis (QMG) is a scoring system that quantifies disease severity by measuring ocular, bulbar, respiratory and limb strength. The total scores range from 0 to 39, with higher scores indicating greater disease severity.
Baseline, Day 11

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Percentage of participants requiring rescue therapy with Plasma Exchange (PLEX) or Intravenous Immunoglobulin (IVIG)
Time Frame: During hospitalization, approximately 7 days
Number of participants requiring rescue therapy with Plasma Exchange (PLEX) or Intravenous Immunoglobulin (IVIG) over number of total participants
During hospitalization, approximately 7 days
Change from baseline in Myasthenia Gravis Activities of Daily Life (MG-ADL) scale at day 18
Time Frame: Baseline, Day 18
The Myasthenia Gravis Activities of Daily Life (MG-ADL) is a questionnaire administered verbally that measures MG symptoms and functional activities related to activities of daily living. The summative total scores range from 0 to 24, with higher scores indicating greater disease severity.
Baseline, Day 18
Change from baseline in Myasthenia Gravis Activities of Daily Life (MG-ADL) scale at day 32
Time Frame: Baseline, Day 32
The Myasthenia Gravis Activities of Daily Life (MG-ADL) is a questionnaire administered verbally that measures MG symptoms and functional activities related to activities of daily living. The summative total scores range from 0 to 24, with higher scores indicating greater disease severity.
Baseline, Day 32
Change from baseline in Myasthenia Gravis Manual Muscle Test (MG-MMT) at day 11
Time Frame: Baseline, Day 11
The Myasthenia Gravis Manual Muscle Test (MG-MMT) is an assessment that assigns numerical values to the presence of mild, moderate or severe weakness for specific muscle groups that may be affected by MG. The summative total scores range from 0 to 120, with higher scores indicating greater disease severity.
Baseline, Day 11
Change from baseline in Myasthenia Gravis Manual Muscle Test (MG-MMT) at day 18
Time Frame: Baseline, Day 18
The Myasthenia Gravis Manual Muscle Test (MG-MMT) is an assessment that assigns numerical values to the presence of mild, moderate or severe weakness for specific muscle groups that may be affected by MG. The summative total scores range from 0 to 120, with higher scores indicating greater disease severity.
Baseline, Day 18
Change from baseline in Myasthenia Gravis Manual Muscle Test (MG-MMT) at day 32
Time Frame: Baseline, Day 32
The Myasthenia Gravis Manual Muscle Test (MG-MMT) is an assessment that assigns numerical values to the presence of mild, moderate or severe weakness for specific muscle groups that may be affected by MG. The summative total scores range from 0 to 120, with higher scores indicating greater disease severity.
Baseline, Day 32
Change from baseline in Myasthenia Gravis Quality of Life-15 Revised (MG-QOL15r) at day 18
Time Frame: Baseline, Day 18
The Myasthenia Gravis Quality of Life-15 Revised (MG-QOL15r) is a scale that measures perceived limitations to fifteen different activities due to MG. Individual items are score 0 (not at all) to 4 (quite a bit). The summative total scores range from 0 to 60, with higher scores representing worse quality of life.
Baseline, Day 18
Change from baseline in Myasthenia Gravis Quality of Life-15 Revised (MG-QOL15r) at day 32
Time Frame: Baseline, Day 32
The Myasthenia Gravis Quality of Life-15 Revised (MG-QOL15r) is a scale that measures perceived limitations to fifteen different activities due to MG. Individual items are score 0 (not at all) to 4 (quite a bit). The summative total scores range from 0 to 60, with higher scores representing worse quality of life.
Baseline, Day 32
Change from baseline in the Quantitative Myasthenia Gravis (QMG) score at day 4
Time Frame: Baseline, Day 4
The Quantitative Myasthenia Gravis (QMG) is a scoring system that quantifies disease severity by measuring ocular, bulbar, respiratory and limb strength. The total scores range from 0 to 39, with higher scores indicating greater disease severity.
Baseline, Day 4
Change from baseline in the Quantitative Myasthenia Gravis (QMG) score at day 32
Time Frame: Baseline, Day 32
The Quantitative Myasthenia Gravis (QMG) is a scoring system that quantifies disease severity by measuring ocular, bulbar, respiratory and limb strength. The total scores range from 0 to 39, with higher scores indicating greater disease severity.
Baseline, Day 32
Postinterventional status at day 11
Time Frame: Day 11
Postinterventional status is an assessment of whether a participant's MG symptoms/signs have remained unchanged, worsened, improved or reached minimal manifestations or minimal symptom expression.
Day 11
Postinterventional status at day 18
Time Frame: Day 18
Postinterventional status is an assessment of whether a participant's MG symptoms/signs have remained unchanged, worsened, improved or reached minimal manifestations or minimal symptom expression.
Day 18
Postinterventional status at day 32
Time Frame: Day 32
Postinterventional status is an assessment of whether a participants's MG symptoms/signs have remained unchanged, worsened, improved or reached minimal manifestations or minimal symptom expression.
Day 32
Length of hospital stay
Time Frame: Duration of hospitalization, approximately 7 days
Length of time between the participant being admitted to discharged. For participants transferred to University of Colorado Hospital, the time of admission/presentation to the outside hospital is counted.
Duration of hospitalization, approximately 7 days
Proportion of participants requiring mechanical ventilation
Time Frame: During hospitalization, approximately 7 days
Number of participants requiring mechanical ventilation against the total number of participants.
During hospitalization, approximately 7 days
Proportion of participants requiring enteral feeding
Time Frame: During hospitalization, approximately 7 days
Number of participants requiring enteral feeding (such as an NG tube or PEG tube) against the total number of participants.
During hospitalization, approximately 7 days
Time to freedom from respiratory support
Time Frame: During hospitalization, approximately 7 days
Length of time between the participant being put on respiratory support (e.g. ventilator, BiPAP) and respiratory support being discontinued.
During hospitalization, approximately 7 days
Change from baseline in Total Immunoglobin G (IgG) at day 32
Time Frame: Baseline, Day 32
Immunoglobin G (IgG) total level will be measured via blood collection.
Baseline, Day 32
Change from baseline in Acetylcholine Receptor (AchR) antibody titer at day 32
Time Frame: Baseline, Day 32
Acetylcholine Receptor (AchR) antibody titer will be measured via blood collection.
Baseline, Day 32

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Colorado, Denver

Collaborators

argenx

Investigators

  • Principal Investigator: Thomas Ragole, MD, University of Colorado, Denver

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

March 6, 2025

Primary Completion (Estimated)

December 31, 2026

Study Completion (Estimated)

December 31, 2026

Study Registration Dates

First Submitted

February 28, 2025

First Submitted That Met QC Criteria

February 28, 2025

First Posted (Actual)

March 6, 2025

Study Record Updates

Last Update Posted (Actual)

July 11, 2025

Last Update Submitted That Met QC Criteria

July 10, 2025

Last Verified

July 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 24-0158

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Individual participant data that underlie the results reported in this article, after deidentification (text, tables, figures, and appendices).

IPD Sharing Time Frame

Beginning 9 months and ending 36 months following article publication

IPD Sharing Access Criteria

Researchers who provide a methodologically sound proposal. Proposals should be directed to NeurologyResearch@cuanschutz.edu. To gain access, data requestors will need to sign a data access agreement.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Myasthenia Gravis Crisis

Clinical Trials on Efgartigimod

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in South Korea

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Subscribe