CAY10734 is an agonist of sphingosine-1-phosphate receptor 1 (S1P1; IC50 = 0.6 nM). It selectively binds S1P1 over S1P2, S1P3, and S1P4 receptors (IC50s = >10,000, 12,000, and 70 nM, respectively) but does also bind S1P5 receptors (IC50 = 1 nM) in radioligand binding assays. CAY10734 reduces the number of peripheral blood lymphocytes in mice, rats, and dogs, with the maximal response achieved when administered at doses of 10, 0.5, and 0.5 mg/kg, respectively. It increases graft survival in a rat skin allograft model when administered at a dose of 5 mg/kg per day in combination with cyclosporin A (CsA; ).
