Efgartigimod alfa  (Synonyms: ARGX-113)

Efgartigimod alfa (ARGX-113) is a reversibility, humanized ^Fc receptor antagonist . Efgartigimod alfa is a anti FcRn monoclonal immunoglobulin G (IgG1) Fc fragment. Efgartigimod reduces serum levels of total IgG, including pathogenic autoantibodies, by blocking FcRn function without permanent impairment. Efgartigimod alfa can be used for generalised myasthenia gravis (gMG) and primary immune thrombocytopenia research^[1][2][3].

Human

FCGRT

Efgartigimod alfa rapidly reduces serum IgG levels, and improves muscle weakness and fatigability in a mouse model for muscle-specific kinase myasthenia gravis^[2].
Efgartigimod alfa (i.v.) rapidly and specifically reduces serum IgG levels in cynomolgus monkeys^[2].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

2217  [NCBI]

P55899

ELISA, FACS, Functional assay

Unconjugated

The product can be reconstituted/diluted with sterile PBS or saline.

51.28 kDa

1821402-21-4

Liquid

Colorless to light yellow

[Efgartigimod alfa]

Shipping with dry ice.

Please refer to the lot-specific COA for specific buffer information.

Please store the product under the recommended conditions in the Certificate of Analysis.

• 
  FC-GAMMA-1

• 
  Immobilized FCGRT Protein, Human (GST, HY-P72192) can bind Efgartigimod alfa. The EC₅₀ for this effect is 535.9 ng/mL.
• 
  Flow cytometric analysis of 1X10⁶ THP-1 cells with Efgartigimod alfa (HY-147305, red). Cells were fixed with 4% paraformaldehyde. Then stained with the primary antibody at 1/200 dilution for an hour at 4℃. Alexa Fluor 488-conjugated AffiniPure Goat Anti-Human IgG H&L (AF488) (HY-P83776) was used as the secondary antibody at 1/1,000 dilution for 30 minutes at 4℃. cells without incubation with primary antibody were used as the unlabeled control (black).

• [1]. Heo YA. Efgartigimod: First Approval. Drugs. 2022 Feb;82(3):341-348.  [Content Brief]

  [2]. Heo YA. Efgartigimod Alfa in Generalised Myasthenia Gravis: A Profile of Its Use. CNS Drugs. 2023 May;37(5):467-473.  [Content Brief]

  [3]. Mansour GK, et al. Efgartigimod for Generalized Myasthenia Gravis and Beyond: A Narrative Review of Its Pharmacological Profile, Clinical Utility, and Expanding Applications. Biomedicines. 2025 Dec 4;13(12):2975.  [Content Brief]

  [4]. Peter Ulrichts, et al. Argx-113, a Novel Fc-Based Approach for Antibody-Induced Pathologies Such As Primary Immune Thrombocytopenia. Blood (2016) 128 (22): 4919.