A compound of formula (I), or a pharmaceutically acceptable salt, solvate or polymorph thereof, including all tautomers and stereoisomers thereof wherein: R1 represents where Y represents a C2-5 alkylene chain, which may be optionally substituted with one or two methyl groups or it may be optionally substituted with two alkylene substituents in the same position where the two alkylene substituents join together to form a C3-5 and R2 spirocycloalkyl group independently represent H or alkyl of C1-2, but where R2, R3 and R4 do not all represent H； and each of X1, X2, X3 and X4 independently represent C, N, O or S； or X4 can represent a link； and X1, X2, X3 and X4 together with the ring to which they are attached form a C6-12 aryl or C5-12 heteroaryl ring system； provided that no more than two of X1, X2, X3 and X4 represent a heteroatom； and the C6-12 aryl or C5-12 heteroaryl ring consisting of X1, X2, X3 and X4 may be optionally substituted by one or more substituents selected from C1-6 alkyl, halogen, C1-6 alkoxy, carbocyclyl C3-12, phenyl, monocyclic C5-12 heteroaryl, -C 1-4 alkyl-phenyl, -C 1-4 alkyl- (monocyclic C5-12 heteroaryl) and / or one or more substituents selected from C2 alkenyl- 6, C2-6 alkynyl, C1-6 haloalkyl, C1-6 thioalkyl, -SO2-C1-4 alkyl, -O3-8 cycloalkyl, C3-8 cycloalkyl, -SO2-C3 cycloalkyl - 8, C3-6 alkenyloxy, C3-6 alkynyloxy, -C (O) -C 1-6 alkyl, -C (O) O-C1-6 alkyl, C1-6 alkoxy-C1-alkyl 6, nitro, cyano, hydroxyl, -C (O) OH, -NH2, -NH-C1-4 alkyl (for example, -NHmethyl), -N (C1-4 alkyl) (C1-4 alkyl) , -C (O) N (C1-4 alkyl) (C1-4 alkyl), C (O) NH2, -C (O) NH (C1-4 alkyl), -SO C1-4 alkyl and - C3-6 cycloalkyl.Un compuesto de fórmula (I), o una sal, solvato o polimorfo farmacéuticamente aceptable del mismo, incluyendo todos los tautómeros y estereoisómeros del mismo en donde: R1 representa en donde Y representa una cadena alquileno de C2-5, que puede estar opcionalmente sustituida con uno o dos grupos metilo o puede estar opcionalmente sustituida co
