TASP 0277308 is a potent and selective sphingosine 1-phosphate 1 (S1P1) receptor antagonist (IC50 = 7.8 nM). TASP 0277308 inhibits S1P-induced chemotaxis (IC50 = 1.1-1.6 nM), HUVEC cell proliferation (IC50 = 3-3.6 nM) and suppresses angiogenesisin vivo. TASP 0277308 also blocks VEGF-induced tube-formation of HUVECsin vitroand reverses or impairs the development of arthritis or mechano-allodynia.