A Study to Evaluate the Clinical Outcomes of Efgartigimod PH20 SC in Adults With New-onset Generalized Myasthenia Gravis (gMG)

Recruitment Status
RECRUITING
(See Contacts and Locations)Verified February 2026 by argenx
Sponsor
argenx
Information Provided by (Responsible Party)
argenx
Clinicaltrials.gov Identifier
NCT06909214
Other Study ID Numbers:
ARGX-113-2407
First Submitted
March 26, 2025
First Posted
April 2, 2025
Last Update Posted
March 9, 2026
Last Verified
February 2026

ClinicalTrials.gov processed this data on March 2026. Link to the current ClinicalTrials.gov record .

History of Changes

Study Details

Study Description

Condition or DiseaseIntervention/Treatment
New Onset Generalized Myasthenia Gravis (gMG)
Biological: Efgartigimod PH20 SC

Study Design

Study TypeInterventional
Actual Enrollment30 participants
Design AllocationN/A
Interventional ModelSingle Group Assignment
MaskingNone (Open Label)
Primary PurposeTreatment
Official TitleA Phase 4, Open-Label, Prospective, Single-Group, Multicenter Study to Evaluate the Clinical Outcomes of Efgartigimod PH20 SC in Adult Participants With New-Onset Generalized Myasthenia Gravis
Study Start DateApril 16, 2025
Actual Primary Completion Date2w 3d from now
Actual Study Completion Date9mos 2w from now

Groups and Cohorts

Group/CohortIntervention/Treatment
Efgartigimod PH20 SC
Participants receiving efgartigimod PH20 SC
Biological: Efgartigimod PH20 SC
Subcutaneous injection of efgartigimod PH20 SC

Outcome Measures

Primary Outcome Measures
  1. Proportion of participants who achieve MSE of MG at any time within the first 16 weeks of treatment with efgartigimod PH20 SC
    MSE (minimal symptom expression) is defined as an MG-ADL (Myasthenia Gravis Activities of Daily Living) total score of 0 or 1. The MG-ADL scale assesses MG symptoms and their effects on daily activities. The score varies between 0 and 24 (with 24 the most severe).
Secondary Outcome Measures
  1. Changes from baseline in MG-ADL total scores over time
    The MG-ADL (Myasthenia Gravis Activities of Daily Living) scale assesses MG symptoms and their effects on daily activities. The score varies between 0 and 24 (with 24 the most severe).
  2. Changes from baseline in MG-QOL-15r total scores over time
    The MG-QoL15r (Myasthenia Gravis Quality of Life 15-item scale revised) questionnaire is a patient-reported instrument that measures the impact of MG symptoms on Quality of Life. The score varies between 0 and 30 (with 30 the lowest quality of life).
  3. Proportion of participants who are administered systemic corticosteroid therapy as background add-on therapy throughout the study
  4. Incidence of adverse events, serious adverse events and adverse events leading to study drug discontinuation

Eligibility Criteria

Ages Eligible for Study(Adult, Older Adult)
Sexes Eligible for StudyAll
Accepts Healthy VolunteersNo
Inclusion Criteria
Is at least 18 years when signing the ICF
Has been diagnosed with gMG of MGFA class II, III, or IV
Is seropositive for AChR-Ab
Is treatment-naive for gMG or has been administered AChEI for the treatment of gMG
Had onset of generalized MG signs and/or symptoms within 12 months before screening; candidates who also had onset of ocular MG signs and/or symptoms within 24 months before screening may be enrolled in the study
Has an MG-ADL score ≥5
Exclusion Criteria
gMG diagnosis of MGFA class I or V
Underwent a thymectomy prior to screening, except thymectomy for treatment of nonmalignant thymoma prior to the gMG diagnosis
Prior or current use of any of any systemic corticosteroid therapy or nonsteroidal immunosuppressive therapy for the treatment of gMG

Contacts and Locations

Sponsors and Collaboratorsargenx
Locations
University of California, San Diego - Altman Clinical and Translational Research Institute (ACTRI) | La Jolla California, United States, 92037Samir Macwan, M.D., Inc. (S corporation) | Rancho Mirage California, United States, 92270EZR Research | Boca Raton Florida, United States, 33486University of Florida Jacksonville | Jacksonville Florida, United States, 32209Visionary Investigators Network | Miami Florida, United States, 33133University of California Irvine | Orange Florida, United States, 92868Medsol Clinical Research Center Inc | Port Charlotte Florida, United States, 33952Baycare Medical Group | St. Petersburg Florida, United States, 33705Emory Brain Health Center | Atlanta Georgia, United States, 30329The Queen's Medical Center - West Oahu | Honolulu Hawaii, United States, 96813Hawaii Pacific Neuroscience | Honolulu Hawaii, United States, 96817HSHS Medical Group | O'Fallon Illinois, United States, 62269UMass Memorial Medical Center | Worcester Massachusetts, United States, 01655Henry Ford Health System | Detroit Michigan, United States, 48202Cleveland Clinic | Cleveland Ohio, United States, 44195Erlanger Neuroscience Institute | Chattanooga Tennessee, United States, 37403Central Texas Neurology Consultants - Elligo | Round Rock Texas, United States, 78681Center for Neurological Disorders - Greenfield | Greenfield Wisconsin, United States, 53228-1321