Nipocalimab, an immunoselective FcRn blocker that lowers IgG and has unique molecular properties
Year: 2025
Type: article
Abstract: Nipocalimab is a human immunoglobulin G (IgG)1 monoclonal antibody that binds to the neonatal Fc receptor (FcRn) with high specificity and high affinity at both neutral (extracellular) and acidic (intracellular) pH, resulting in the reduction of circulating IgG levels, including those of pathogenic IgG antibodies. Here, we present the molecular, cellular, and nonclinical characteristics of nipocalimab that support the reported clinical pharmacology and potential clinical application in IgG-driven, autoantibody- and alloantibody-mediated diseases. The crystal structure of the nipocalimab antigen binding fragment (Fab)/FcRn complex reveals its binding to a unique epitope on the IgG binding site of FcRn that supports the observed pH-independent high-binding affinity to FcRn. Cell-based and in vivo studies demonstrate concentration/dose- and time-dependent FcRn occupancy and IgG reduction. Nipocalimab selectively reduces circulating IgG levels without detectable effects on other adaptive and innate immune functions. In vitro experiments and in vivo studies in mice and cynomolgus monkeys generated data that align with observations from clinical studies of nipocalimab in IgG autoantibody- and alloantibody-mediated diseases.
Source: mAbs
Authors: Nilufer P. Seth, Rui Xu, Matthew DuPrie, Amit Choudhury, Samuel Sihapong, Steven Tyler, James Meador, William Avery, Edward Cochran, Thomas Daly, Julia Brown, Laura Rutitzky, Lynn Markowitz, Sujatha Kumar, Traymon Beavers, Sayak Bhattacharya, Hsin Chen, Viraj Parge, Karen Price, Yang Wang, Siddharth Sukumaran, Yvonne Pao, Katie Abouzahr, Fiona Elwood, Jay Duffner, Sucharita Roy, Pushpa Narayanaswami, Jonathan J. Hubbard, Leona E. Ling
Language: English
Subfield: Radiology, Nuclear Medicine and Imaging
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $3,575
Funder: Janssen Research and Development
OpenAlex ID: W4407412429