RS-1748 is a highly potent, selective, orallu active CCR4 antagonist, inhibits [125I]CCL17 binding to human CCR4 with IC50 of 59.9 nM.
RS-1748 displays no competitive displacement in the binding of [125I]CCL3 (MIP-1α) to CCR1 and [125I]CCL2 (MCP-1) to CCR2b. dose-dependently inhibited 50 nM CCL22-induced [Ca2+]i mobilization with IC50 of 28.3 nM, inhibited the binding of [35S]GTPgS to human CCR4-expressing CHO cells with IC50 of 18.4 nM.
Orally administered RS-1748 (30 mg/kg) significantly lowered the total cell numbers and the eosinophils numbers in ovalbumin-sensitized guinea pigs.
