ICH5433 is a research-grade biosimilar of cepeprubart, an unconjugated non-therapeutic analog of the originator antibody supplied for research use only. It is built to reproduce the binding architecture of the originator, which is directed against human SELPLG (P-selectin glycoprotein ligand-1, PSGL-1 / CD162; UniProt Q14242). The molecule is a human IgG2, kappa immunoglobulin and is provided as a full-length antibody without conjugation or reporter modification. As a biosimilar reagent it carries no therapeutic claim and is not a clinical drug; it is intended to give investigators a consistent, well-characterized tool for interrogating the PSGL-1 axis in vitro. Ichor supplies this format at research grade with low endotoxin (typically less than 1 EU/mg), and material is available in bulk milligram-to-gram quantities suitable for assay development, larger screening campaigns, and standardization across experiments. It is well suited to comparability work, epitope and binding studies, and as a defined reference analog of the originator for functional characterization. Ichor should confirm lot-specific isotype, endotoxin, and formulation details before publication or distribution.
SELPLG encodes P-selectin glycoprotein ligand-1 (PSGL-1, CD162), a homodimeric mucin-type cell-surface glycoprotein expressed on essentially all leukocytes. Its extended, heavily O-glycosylated extracellular domain presents an N-terminal region bearing tyrosine sulfation and a sialyl-Lewis-x motif that together confer high-affinity binding to P-selectin, and lower-affinity binding to E- and L-selectin. Through these interactions PSGL-1 mediates the initial tethering and rolling of leukocytes on activated endothelium and platelets, a rate-limiting early step in the inflammatory cascade and in leukocyte recruitment to sites of injury. PSGL-1 also contributes to leukocyte aggregation, signaling, and, in T cells, to immune regulation and exhaustion. Its central role in adhesion makes it a target of interest in inflammatory, thrombotic, and immuno-oncology research contexts.