Fusion protein · Antagonist of neonatal Fc receptor (FCGRT) · developed by Argenx Us
Efgartigimod is a human IgG1-derived Fc fragment that binds the neonatal Fc receptor (FcRn) and blocks it, preventing IgG recycling and thereby reducing circulating IgG, including pathogenic autoantibodies. It is studied in myasthenia gravis, autoimmune encephalitis, immune thrombocytopenia and myositis. A subcutaneous coformulation with hyaluronidase is also described.
Summary written with AI from the sources listed at the end of this page.
From the indications section of the FDA label (version of May 13, 2026). Read the full label for the exact wording, limitations and safety information.
| Trial | Phase | Condition | Status | Sponsor |
|---|---|---|---|---|
| NCT06637072 | Phase 4 | Chronic Inflammatory Demyelinating Polyneuropathy | Completed | ARGX |
| NCT06544499 | Phase 3 | Primary Immune Thrombocytopenia (ITP) | Recruiting | ARGX |
| NCT05523167 | Phase 2/3 | Active Idiopathic Inflammatory Myopathy | Completed | ARGX |
| NCT04225156 | Phase 3 | Primary Immune Thrombocytopenia | Completed | ARGX |
| NCT07583641 | Phase 2 | Autoimmune Encephalitis (AE) | Not yet recruiting | ARGX |
| NCT05701189 | Phase 2 | Guillain-Barre Syndrome | Withdrawn | ARGX |
| NCT06203457 | Phase 2 | Primary Sjögren's Syndrome | Completed | IQV |
| NCT07782775 | Phase 1 | Healthy Volunteer | Recruiting | ARGX |
| NCT07294170 | N/A | Myasthenia Gravis | Recruiting | ARGX |
Trials of the companies BioRadar tracks, from ClinicalTrials.gov, most advanced phase first.
AChR-Ab Seropositive Generalized Myasthenia GravisAutoimmune Encephalitis (AE)Generalized Myasthenia GravisGeneralized Myasthenia Gravis (gMG)gMGHealthy Adult ParticipantsHealthy VolunteerMGMyasthenia GravisPrimary Immune Thrombocytopenia (ITP)Active Idiopathic Inflammatory MyopathyAntisynthetase SyndromeChronic Inflammatory Demyelinating PolyneuropathyDermatomyositis
Updated Oct 11, 2026. Something wrong or missing? Report it on the ARGX page.
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