A compound of formula (I) or a pharmaceutically-acceptable salt, solvate or stereoisomer thereof wherein R1 is a group chosen from —CH2OH and —NHC(O)H; R2 is a hydrogen atom or R1 together with R2 form the group —NH—C(O)—CH═CH—, wherein the nitrogen atom is bound to the carbon atom in the phenyl ring holding R1 and the carbon atom is bound to the carbon atom in the phenyl ring holding R2; R3 is chosen from a hydrogen atom, a halogen atom and groups chosen from —SO—R5, —SO2—R5, —NH—CO—NH2, —CO—NH2, hydantoino, C1-4alkyl, C1-4alkoxy and —SO2NR5R6; R4 is chosen from a hydrogen atom, a halogen atom and a C1-4 alkyl group; R5 is chosen from a C1-4 alkyl group and a C3-8 cycloalkyl group; R6 is independently chosen from a hydrogen atom and a C1-4 alkyl group; n, p and q are independently 0, 1, 2, 3 or 4; m and s are independently 0, 1, 2 or 3; and r is 0, 1 or 2 with the provisos that at least one of m and r is not 0, the sum n+m+p+q+r+s is 7, 8, 9, 10, 11, 12 or 13, and the sum q+r+s is 2, 3, 4, 5 or 6.