Pyridyl inhibitors of hedgehog signalling

A method of inhibiting hedgehog pathway signaling in a cell comprising contacting said cell with an effective amount of a compound of formula I:

• wherein
• A is a carbocycle or heterocycle;
• X is alkylene, *NR4C(O), *NR4C(S), *N(C(O)R1)C(O), *NR4SO, *NR4SO2, *NR4C(O)NH, *NR4C(S)NH, *C(O)NR4, *C(S)NR4, *NR4PO or *NR4PO(OH), wherein * indicates the point of attachment to ring A;
• Y is absent, CHR4, O, S, SO, SO2 or NR4;
• R1 is selected from the group consisting of alkyl, a carbocycle or a heterocycle each of which is optionally substituted with hydroxyl, halogen, amino, carboxyl, amidino, guanidino, carbonyl, nitro, cyano, acyl, alkyl, haloalkyl, sulfonyl, sulfinyl, alkoxy, akylthio, carbamoyl, acylamino, sulfamoyl, sulfonamide, a carbocycle or a heterocycle;
• wherein said amino, amidino, alkyl, acyl, sulfonyl, sulfinyl, alkoxy, alkylthio, carbamoyl, acylamino, sulfamoyl, sulfonamide, carbocycle and heterocycle substituent is optionally substituted with, halogen, haloalkyl, hydroxyl, carboxyl, carbonyl, or an amino, alkyl, alkoxy, acyl, sulfonyl, sulfinyl, phosphinate, carbocycle or heterocycle that is optionally substituted with hydroxyl, carboxyl, carbonyl, amino, halogen, haloalkyl, alkyl, alkoxy, alkylthio, sulfonyl, sulfinyl, acyl, a carbocycle or a heterocycle;
• R2 is halogen, hydroxyl, alkyl, acyl or alkoxy, wherein each alkyl, acyl and alkoxy is optionally substituted with hydroxyl, halogen, amino, nitro, alkyl, acyl, alkylsulfonyl or alkoxy;
• R3 is halogen, hydroxyl, carboxyl, alkyl, acyl, alkoxy, alkoxycarbonyl, carbamoyl, alkylsulfide, sulfinyl, sulfonyl, a carbocycle or a heterocycle wherein each alkyl, acyl, alkoxy, alkoxycarbonyl, carbamoyl, alkylsulfide, sulfinyl, sulfonyl, carbocycle and heterocycle is optionally substituted with hydroxyl, halogen, amino, nitro, alkyl, acyl, sulfonyl or alkoxy;
• R4 is H or alkyl;
• m is 0-3;
• n is 0-3;
• or a salt or solvate thereof.