Structures of the novel UT antagonists (A) GSK1440115 (4′-[(1R)-1-[[(6,7-dichloro-3-oxo-2,3-dihydro-4H-1,4-benzoxazin-4-yl)acetyl](methyl)amino]-2-(4-morpholinyl)ethyl]-4-biphenylcarboxylic acid, trifluoroacetate) and (B) GSK1562590 (4′-[(1R)-1-[[(6,7-dichloro-3-oxo-2,3-dihydro-4H-1,4-benzoxazin-4-yl)acetyl](methyl)amino]-2-(1-pyrrolidinyl)ethyl]-3-biphenylcarboxamide, hydrochloride).