The present invention provides a method for the treatment of a tumor in a subject. The method comprises administering to the subject a composition comprising a therapeutically effective amount of a compound of Formula (I), wherein R1 is selected from H, substituted or unsubstituted, straight or branch chain alkyl, alkenyl, alkenylalkyl, cycloalkyl, cycloalkylalkyl, cycloalkenylalkyl, aryl, arylalkyl, -SR7, -SOR8, -SO2R9, -SCN, B(CH2)nBR10, -C(O)-R11 or -OR12, COOR13, -NO2, NR13aCOOR13b, isothiocyanato, or -CN where R7 to R13b are each independently selected from H, substituted or unsubstituted, straight or branch chain alkyl, alkenyl, alkenylalkyl, cycloalkyl, cycloalkylalkyl, cycloalkenylalkyl, aryl, arylalkyl, B and B are independently selected from O, S, S(O) or SO2 and n is 1 to 4 R2 is selected from H, or substituted or unsubstituted alkyl. R3 is selected from H, substituted or unsubstituted, straight or branch chain alkyl, alkenyl, alkenylalkyl, cycloalkyl, cycloalkylalkyl, cycloalkenylalkyl, aryl, arylalkyl, 5- or 6- membered heterocyclic ring the heteroatom(s) of which are selected from one of more of O, S and/or N, -SR14, -OR15, -SOR16, -SO2R17, -SCN, -C(O)-R18, -OR19, NR20COOR21, where R15 to R21 are each independently selected from H, substituted or unsubstituted, straight or branch chain alkyl, alkenyl, alkenylalkyl, cycloalkyl, cycloalkylalkyl, cycloalkenylalkyl, aryl or arylalkyl or an analogue or metabolite thereof.Linvention concerne une méthode permettant de traiter une tumeur chez un sujet, selon laquelle il est prévu dadministrer au sujet une composition comportant une quantité à effet thérapeutique dun composé de formule (I) dans laquelle R1 est sélectionné parmi H, alkyle substitué ou non substitué à chaîne linéaire ou ramifiée, alkényle, alkénylalkyle, cycloalkyle, cycloalkylalkyle, cycloalkénylalkyle, aryle, arylalkyle, -SR7, -SOR8, -SOR2R9, -SCN, B(CH2)nBR10, -C(O)-R11 ou OR12, COOR13, -NO2, NR13aCOOR13b, isothiocyanato, ou CN, R7 à R13b ét
