efgartigimod alfa   

GtoPdb Ligand ID: 9777

Synonyms: ARGX-113
Compound class: Antibody
Comment: Efgartigimod alfa (ARGX-113) is a first-in-class antibody fragment designed for the treatment of patients with severe autoimmune diseases associated with high levels of pathogenic immunoglobulin G (IgG) autoantibodies [6]. It binds to the IgG receptor, major histocompatibility complex class I-like Fc receptor (FcRn, the protein product of the FCGRT gene). Efgartigimod alfa inactivates FcRn's IgG binding ability (the FcRn-IgG interaction normally protects IgG from degradation) thus facilitating accelerated catabolism of native pathogenic autoantibodies [3,5]. The mechanism of this drug action is discussed more comprehensively in Roopenian and Akilesh (2007) [4] and Vaccaro et al. (2005) [7].
References
1. FDA. 
human anti-neonatal Fc receptor IgG1 Fc fragment.
Accessed on 25/01/2018. Modified on 25/01/2018. www.accessdata.fda.gov, https://www.accessdata.fda.gov/scripts/opdlisting/oopd/detailedIndex.cfm?cfgridkey=527316
2. Liu L, Garcia AM, Santoro H, Zhang Y, McDonnell K, Dumont J, Bitonti A. (2007)
Amelioration of experimental autoimmune myasthenia gravis in rats by neonatal FcR blockade.
J. Immunol., 178 (8): 5390-8. [PMID:17404325]
3. Petkova SB, Akilesh S, Sproule TJ, Christianson GJ, Al Khabbaz H, Brown AC, Presta LG, Meng YG, Roopenian DC. (2006)
Enhanced half-life of genetically engineered human IgG1 antibodies in a humanized FcRn mouse model: potential application in humorally mediated autoimmune disease.
Int. Immunol., 18 (12): 1759-69. [PMID:17077181]
4. Roopenian DC, Akilesh S. (2007)
FcRn: the neonatal Fc receptor comes of age.
Nat. Rev. Immunol., 7 (9): 715-25. [PMID:17703228]
5. Ulrichts P, Blanchetot C, de Haard J, Ward OES, Ongenae NGH. (2015)
Fcrn antagonists and methods of use.
Patent number: WO2015100299. Assignee: Argen-X N.V, The Board Of Regents Of The University Of Texas System. Priority date: 24/12/2013. Publication date: 02/07/2015.
6. Ulrichts P, Cousin T, Dreier T, de Haard H, Leupin N. (2016)
Argx-113, a Novel Fc-Based Approach for Antibody-Induced Pathologies Such As Primary Immune Thrombocytopenia.
Blood, 128: 4919.
7. Vaccaro C, Zhou J, Ober RJ, Ward ES. (2005)
Engineering the Fc region of immunoglobulin G to modulate in vivo antibody levels.
Nat. Biotechnol., 23 (10): 1283-8. [PMID:16186811]