Rugocrixan

AZD8797 (KAND567) is an allosteric non-competitive and orally active antagonist of the human CX3CR1 receptor; antagonizes CX3CR1 and CXCR2 with K_is of 3.9 and 2800 nM, respectively^[1]. IC50 & Target:Ki: 3.9 nM (CX3CL1); 2800 (CXCL2)^[3] In Vitro: In a flow adhesion assay, AZD8797 antagonizes the natural ligand, fractalkine (CX3CL1), in both human whole blood (hWB) and in a B-lymphocyte cell line with IC₅₀ values of 300 and 6 nM respectively. AZD8797 also prevents G-protein activation in a [³⁵S]GTPγS accumulation assay. AZD8797 positively modulates the CX3CL1 response at sub-micromolar concentrations in a β-arrestin recruitment assay. In equilibrium saturation binding experiments, AZD8797 reduces the maximal binding of 125I-CX3CL1 without affecting K_d^[1]. AZD8797 binds selectively with high affinity to human and rat CX3CR1 (K_i of hCX3CR1, 4 nM; K_i of rCX3CR1, 7 nM, respectively). The equilibrium dissociation constant, K_B, demonstrates that AZD8797 is a very potent inhibitor for human CX3CR1 (10 nM). The potency is threefold lower for rat CX3CR1 (29 nM) and decreases even further at mouse CX3CR1 (54 nM)^[2]. In Vivo: AZD8797 treatment in Dark Agouti rats with myelin oligodendrocyte glycoprotein-induced EAE results in reduced paralysis, CNS pathology, and incidence of relapses. The compound is effective when starting treatment before onset, as well as after the acute phase^[2].