Pyridyl substituted triazoles of formula (I) wherein R1 is naphthyl or phenyl optionally substituted with one or more substituents selected from the group consisting of halo, —O—C1-6alkyl, —S—C1-6alkyl, C1-6alkyl, C1-6haloalkyl, —O—(CH2)n-Ph, —S—(CH2)n-Ph, cyano, phenyl, and CO2R, wherein R is hydrogen or C1-6alkyl, and n is 0, 1, 2 or 3; or R1 is phenyl fused with an aromatic or non-aromatic cyclic ring of 5-7 members wherein said cyclic ring optionally contains up to three heteroatoms, independently selected from N, O and S, and N may be further optionally substituted by C1-6 alkyl; R2 is H, C1-6alkyl, C1-6alkoxy, phenyl, NH(CH2)n-Ph, NH—C1-6alkyl, halo, CN, NO2, CONHR and SO2NHR; two of X1, X2 and X3 are N and the other is NR3 wherein R3 is hydrogen, C1-6alkyl, C3-7cycloalkyl, —(CH2)p—CN, —(CH2)p—CO2H, —(CH2)p—CONHR4R5, —(CH2)pCOR4, —(CH2)q(OR6)2, —(CH2)pOR4, —(CH2)q—CH═CH—CN, —(CH2)q—CH═CH—CO2H, —(CH2)p—CH═CH—CONHR4R5, (CH2)pNHCOR7 or (CH2)pNR8R9; R4 and R5 are independently hydrogen or C1-6alkyl; R6 is C1-6alkyl; R7 is C1-7alkyl, or optionally substituted aryl, heteroaryl, arylC1-6alkyl or heteroarylC1-6alkyl; R8 and R9 are independently selected from hydrogen, C1-6alkyl, aryl and arylC1-6alkyl; p is 04; and q is 1-4. and salts and solvates thereof, are disclosed, as are methods for their preparation, pharmaceutical compositions containing them and their use in medicine.