Background:

INCB3344 is a novel potent and selective antagonist of CCR2 receptor, which possesses an IC 50 of 10 nM for CCL2. [1]

CCR2 is a chemokine receptor mainly expressed on monocytes which acts as the key receptor in mediating their tissue influx in the context of immune-based inflammation. CCR2 is a G protein-coupled receptor (GPCR), whose ligands include the chemokines MCP family, including CCL2, CCL7, CCL8. These ligands bind CCR2 receptor with high affinity and elicit a chemotactic signal which leads to directed migration of the receptor-bearing cells. CCL2 has been shown to be relevant in high concentrations in various inflammatory lesions, implicating this chemokine as a physiologically important chemotactic signal for monocytes. [1]

Characterization of the pharmacological activity of INCB3344 was first evaluated by testing its ability to inhibit CCL2 binding to CCR2 in a whole cell binding assay using a murine monocyte cell line, WEHI-274.1 and 125I-labeled mCCL2 as a tracer. The binding IC 50 of INCB3344 in this assay was determined to be 10±5 nM, and inhibition greater than 90% binding was observed at a concentration of 90nM . The chemotaxis inhibitory activity of different concentrations of INCB3344 was evaluated using 30nM mCCL2 as the agonist. The result showed a similar potency to the binding assay. Selectivity of INCB3344 was evaluated against a panel of GPCRs including several human chemokine receptors using radioligand binding assays. Results from these studies demonstrate at least 100-fold selectivity of INCB3344 against all of the receptors tested. [1]

INCB3344 treatment results in a dose-dependent inhibition of macrophage influx in a mouse delayed-type hypersensitivity model. The histopathological analysis of tissues from the delayed-type hypersensitivity model illustrates that inhibitory activity of CCR2 leads to a substantial reduction in tissue inflammation. [1]

Reference:
[1].  Brodmerkel C M, Huber R, Covington M, et al. Discovery and pharmacological characterization of a novel rodent-active CCR2 antagonist, INCB3344[J]. The Journal of Immunology, 2005, 175(8): 5370-5378.