BYON4228

BYON4228 is a humanized immunoglobulin G1 (IgG1) monoclonal antibody that targets signal-regulatory protein alpha (SIRPα; CD172a), an immune checkpoint receptor expressed on myeloid cells such as monocytes, macrophages, and neutrophils[3][4][5]. It is designed to block the interaction between SIRPα and its ligand CD47, which transmits a "don't eat me" signal that protects tumor cells from phagocytosis by the innate immune system[1][2][5]. By inhibiting this axis, BYON4228 stimulates macrophage- and neutrophil-mediated killing of both hematologic and solid cancer cells in the presence of tumor-targeting antibodies. Unlike some other anti-SIRPα agents, BYON4228 recognizes all major human SIRPα variants (pan-allelic) but does not bind to SIRPγ on T cells, thus preserving T cell function[1][2][6]. Its Fc region is silenced to avoid depletion of healthy myeloid cells. Developed by Byondis, it is being investigated for use in combination with other antibodies for enhanced antitumor activity in cancers such as relapsed/refractory B-cell Non-Hodgkin's lymphoma[6][7].

Other names

anti-SIRPalpha monoclonal antibody BYON4228