ES009 

ES009 is a high-affinity LILRB2 antagonist, with IC₅₀ values of 14.07 nM and 18.61 nM for inhibiting hLILRB2-huANGPTL3 and hLILRB2-huANGPTL4, respectively. ES009 specifically blocks the interactions between LILRB2 and MHC class I as well as non-MHC ligands, thereby effectively inhibiting receptor activation. ES009 can reprogram anti-inflammatory myeloid cells and induce their conversion to a pro-inflammatory phenotype, and also reverse the T cell suppression mediated by macrophages. When combined with anti-PD-1 blockade therapy, ES009 synergistically enhances T cell activation. ES009 can be used in research related to advanced solid tumors and ovarian cancer^[1][2][3].

Human IgG4 kappa

Human IgG4 (S228P) kappa, Isotype Control

Human

ES009 binds to human LILRB2 overexpressed on EL4-huLILRB2 cells, with an EC₅₀ of 0.49 nM^[1].
ES009 potently blocks the interactions between human LILRB2 and the MHC class I ligands HLA-G and HLA-A2 on EL4-huLILRB2 cells, with IC₅₀ values of 0.16 nM and 0.24 nM, respectively^[1].
ES009 induces a proinflammatory phenotype in human monocyte-derived dendritic cells by blocking LILRB2^[3].

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

ES009 (15-206 mg/kg; i.v.; single dose) exhibits an excellent safety profile in SD rats, with no detectable off-target toxic effects at doses up to 206 mg/kg and no impact on central nervous system or respiratory function at doses up to 135 mg/kg^[1].

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

10288  [NCBI]

Q8N423

LILRB2/ILT4

ELISA, FACS, Functional assay

Unconjugated

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

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

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

• [1]. Niu X, et al. LILRB2 inhibition by blocking antibody ES009 reprograms immunosuppressive myeloid cells and enhances T-cell-mediated tumor immunity. Hum Vaccin Immunother. 2026;22(1):2659499.  [Content Brief]

  [2]. Ganju V, et al. 596 A first-in-human study evaluating the safety, tolerability, pharmacokinetics, pharmacodynamics, and preliminary antitumor activity of the LILRB2 inhibitor ES009 in patients with advanced solid tumors[J]. 2025.

  [3]. Niu X, et al. 1062 ES009, a LILRB2-specific blocking antibody, reprograms myeloid cells into pro-inflammation phenotype and potentiates T cell activation[J]. J Immunother, 2022, 10(2): A1-A1595.