AZD8797 (KAND567) is an orally available, selective and potent human CX3CR1-converting antagonist with inhibitory effects on CX3CR1 and CXCR2, and potentially protects against SARS-CoV-2-induced neuronal damage, preventing worsening of nociceptive sensitization and microglial activation in a migraine model of rats following seizures.

B-lymphocyte cell lines:6 nM, CX3CR1 (human):4 nM (Ki), CX3CR1 (rat):7 nM (Ki), WB (human):300 nM, CX3CR1:54 nM (mouse), CX3CR1:10 nM (human), CX3CR1:29 nM (Rat), [125I]-IL8-CXCR2:2800 nM (Ki, HEK293S cells), [125I]-CX3CL1-CX3CR1:3.9 nM (Ki, HEK293S cells)

In a flow adhesion assay, AZD8797, with IC50 values of 300 nM in human whole blood (hWB) and 6 nM in a B-lymphocyte cell line, antagonizes the natural ligand fractalkine (CX3CL1). AZD8797 also prevents G-protein activation in a [35S]GTPγS accumulation assay. In a β-arrestin recruitment assay, AZD8797 positively modulates the CX3CL1 response at sub-micromolar concentrations. In equilibrium saturation binding experiments, AZD8797 reduces the maximal binding of 125I-CX3CL1 without affecting Kd[1]. AZD8797 selectively and with high affinity binds to human and rat CX3CR1 (Ki of hCX3CR1, 4 nM; Ki of rCX3CR1, 7 nM, respectively). The equilibrium dissociation constant, KB, 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)[3].

Treatment with AZD8797 in Dark Agouti rats with myelin oligodendrocyte glycoprotein-induced EAE results in reduced paralysis, CNS pathology, and incidence of relapses. The compound is effective both when starting treatment before onset and after the acute phase[3].