Selective CCR1 receptor antagonist (Ki values are 0.04, > 10, > 10 and > 10 nM for CCR1, CCR5, CXCR2 and CXCR4 receptors respectively). Inhibits MIP-1α-induced intracellular calcium mobilization (IC50 = 2.5 μM). Also a full inverse agonist at US28, a HCMV-encoded chemokine receptor.