The present invention provides a compound of formula (I) wherein: R1 is a group selected from —CH2OH, —NHC(O)H and R7 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 is atom in the phenyl ring holding R2; R3 is selected from hydrogen and halogen atoms or groups selected from —SO—R5, —SO2—R5, —NH—CO—NH2, —CO—NH2, hydantoino, C1-4alkyl, C1-4alkoxy and —SO2NR5R6; R4 is selected from hydrogen atoms, halogen atoms and C1-4alkyl groups; R5 is a C1-4alkyl group or C3-5 cycloalkyl; R6 is independently selected from hydrogen atoms and C1-4alkyl groups; n, p and q are independently 0, 1, 2, 3 or 4: m and s are independently 0, 1, 2 or 3; 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: the sum q+r+s is 2, 3, 4, 5 or 6 or a pharmaceutically-acceptable salt, solvate or stereoisomer thereof.