Exploring Outcomes and Characteristics of Myasthenia Gravis 2 (EXPLORE-MG2)

The goal of this prospective observational study is to create a network repository of clinical data and biological samples to help researchers learn more about myasthenia gravis.

Study Overview

• Status: Completed
• Conditions: Myasthenia Gravis
• Intervention / Treatment: Other: Blood sample

Detailed Description

The EXPLORE-MG2 (EXPLoring Outcomes and chaRactEristics of Myasthenia Gravis 2) study is a multi-center natural history study of myasthenia gravis (MG), a rare autoimmune disease characterized by weakness of the voluntary muscles. MG has a prevalence of approximately 14-40 per 100,000 people in the United States. There is no cure for MG, however, understanding the disease is crucial to pave the way for development of new therapies and a deeper mechanistic understanding to improve patient outcomes. Thus, EXPLORE-MG2 aims to accomplish comprehensive clinical phenotyping linked to bio-specimen collection in an effort to better understand disease characteristics and identify treatment predictive and responsive biomarkers. The primary purpose of this project is to create a network repository of data and biological samples to help researchers learn more about myasthenia gravis.

• Study Type: Observational
• Enrollment (Actual): 311

Contacts and Locations

Study Locations

• United States
  • California
    • Irvine, California, United States, 92697
      • University of California-Irvine
    • Los Angeles, California, United States, 90048
      • Cedars Sinai Medical Center
  • Connecticut
    • New Haven, Connecticut, United States, 06519
      • Yale University
  • District of Columbia
    • Washington D.C., District of Columbia, United States, 20037
      • George Washington University
  • Illinois
    • Chicago, Illinois, United States, 60637
      • University Of Chicago
  • Massachusetts
    • Boston, Massachusetts, United States, 02114
      • Massachusetts General Hospital
  • North Carolina
    • Chapel Hill, North Carolina, United States, 27599
      • University of North Carolina
    • Durham, North Carolina, United States, 27710
      • Duke University Medical Center
    • Winston-Salem, North Carolina, United States, 27157
      • Wake Forest University
  • South Carolina
    • Charleston, South Carolina, United States, 29425
      • Medical University of South Carolina

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Subjects will be 18 years of age or older with a clinical diagnosis of a Myasthenia Gravis.

Description

Inclusion Criteria:

• Diagnosed with MG based on clinical presentation and seropositivity for MG associated autoantibodies (AChR binding, MuSK, or LRP4 antibodies), and/or a decremental response on repetitive nerve stimulation, positive single fiber electromyography (EMG) or positive edrophonium test. Signs and symptoms should not be better explained by another disease process.
• A) Diagnosed with MG within 2 years of study enrollment and with adequate records to document MG history (e.g., onset, MG meds) prior to enrollment at the discretion of the investigator.

or B) MuSK antibody, LRP4 antibody, or thymoma-associated MG at any point in the disease course. Patients with a diagnosis of MG more than 2 years prior to the first study visit who are expected to undergo a thymectomy may also be enrolled.

• Participant has the capacity to understand and sign a written informed consent form.
• Participant must be willing to complete the study and return for follow-up visits.

Exclusion Criteria:

• A history of chronic degenerative, psychiatric, or neurologic disorder other than MG that can produce weakness or fatigue that would confound outcome measure assessments or any disorder that interferes with participation in this protocol.
• Participant is unable or unwilling to comply with the study procedures.

• Treatment with any investigational agent within 4 weeks of the baseline visit or 5 half-lives of the investigational drug (whichever is longer).

  1. Participation in other observational studies is not exclusionary
  2. It is anticipated that some participants enrolled in EXPLORE-MG2 may be enrolled in future interventional trials while active in EXPLORE-MG2. This is acceptable. The exclusion only applies to starting EXPLORE-MG2 when participation in an interventional trial is imminent or active.
  3. If an EXPLORE-MG2 participant is later enrolled in an interventional trial, it will be at the investigator's discretion whether to continue collecting biosamples while the patient is participating in the interventional trial. Collection of natural history data should continue.
• Known active malignancy at enrollment other than skin cancer, low grade prostate cancer, or cervical cancer in situ. Thymoma is not included in this exclusion criteria.
• Any other disease, metabolic dysfunction, physical examination finding, or clinical laboratory finding giving reasonable suspicion of a disease or condition that contraindicates or that may affect the interpretation of the results or render the participant not an appropriate study participant.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Neurological Outpatients; Participants in this group will be recruited from the outpatient clinical population at MGNet participating sites. Treating physicians will make the initial determination of patients' potential eligibility to participate in the study.	Other: Blood sample; Each blood draw will involve removing approximately 75 mL (5 tablespoons) of blood

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
The number of participants enrolled and serial blood reported at the conclusion of the enrollment period.	5 years

Collaborators and Investigators

• Sponsor: Yale University
• Collaborators: National Institute of Neurological Disorders and Stroke (NINDS); National Center for Advancing Translational Sciences (NCATS)
• Investigators: Principal Investigator: Richard Nowak, MD, Yale University; Principal Investigator: Vern Juel, MD, Duke University

Study record dates

Study Major Dates

• Study Start (Actual): January 12, 2021
• Primary Completion (Actual): May 31, 2025
• Study Completion (Actual): May 31, 2025

Study Registration Dates

• First Submitted: August 14, 2023
• First Submitted That Met QC Criteria: August 14, 2023
• First Posted (Actual): August 21, 2023

Study Record Updates

• Last Update Posted (Actual): June 11, 2026
• Last Update Submitted That Met QC Criteria: June 9, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: Immune System Diseases; Nervous System Diseases; Autoimmune Diseases; Neuromuscular; Muscle weakness; Autoimmune Diseases of the Nervous System
• Additional Relevant MeSH Terms: Neurologic Manifestations; Musculoskeletal Diseases; Muscular Diseases; Neuromuscular Manifestations; Pathologic Processes; Neoplasms by Site; Neoplasms; Neuromuscular Diseases; Neurodegenerative Diseases; Paraneoplastic Syndromes, Nervous System; Nervous System Neoplasms; Paraneoplastic Syndromes; Neuromuscular Junction Diseases; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Muscle Weakness; Myasthenia Gravis; Autoimmune Diseases; Nervous System Diseases; Immune System Diseases; Autoimmune Diseases of the Nervous System; Investigative Techniques; Specimen Handling; Clinical Laboratory Techniques; Diagnostic Techniques and Procedures; Diagnosis; Punctures; Surgical Procedures, Operative; Blood Specimen Collection
• Other Study ID Numbers: 2000026920; 1U54NS115054-01 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No