Isoxazolyl substituted imidazopyridines

A compound which is an isoxazolyl imidazopyridine of formula (I): wherein: R0 and R, which are the same or different, are each H or C alkyl; R9' and R9", which are the same or different, are each H or F; X is -(alk)n-, -alk-C(=O)-NR-, -alk-NR-C(=O)- or -alk-C(=O)-; R1 is selected from -S(=O)2R' and a 4- to 7-membered heterocyclic group which is unsubstituted or substituted; R2 and R2', which are the same or different, are each H or C1-6 alkyl; or R2 and R2' form, together with the C atom to which they are attached, a C3-6 cycloalkyl group; R3 and R3', which are the same or different, are each H, C1-6 alkyl, OH or F; R4 is phenyl or a 5- to 12-membered N-containing heteroaryl group and is unsubstituted or substituted; alk is C1-6 alkylene; R' is C1-6 alkyl; and n is 0 or 1; or a pharmaceutically acceptable salt thereof. The compound has activity in modulating the activity of p300 and/or CBP and is used to treat cancer.