A compound of formula: wherein: X represents -CONH-, -NHCO- or -CH 2 NH-. R 1 represents phenyl substituted by two groups independently selected from halogen. R 2 represents hydrogen, -C 1-6 alkyl or -C 1-3 alkylOC 1-3 alkyl; R 3 represents: -C 5-9 heteroaryl optionally substituted by one, two or three groups independently selected from: -C 1-3 alkyl, -C 1-6 alkoxy, -CO 2 R 4, -C(=O)NR 5 R 6, -C(=O)NHC 1-3 alkylNR 7 R 8, -C(=O)NHC 1-3 alkylOC 1-3 alkyl, -C(=O)NHC 1-3 alkylOH, -C(=O)R 9, -C 1-6 alkylOH, -CHO, -C 1-3 alkylCO 2 C 1-3 alkyl, -C 1-3 alkylOC 1-3 alkyl, -C 1-6 haloalkyl, -OC 1-6 haloalkyl, -OC 3-6 cycloalkyl, -C 3-6 cycloalkyl or halogen wherein C 5-9 heteroaryl means an aromatic cyclic group containing 5 to 9 ring-atoms 1, 2, 3 or 4 of which are hetero-atoms independently selected from nitrogen, oxygen and sulphur and the remaining ring-atoms are carbon; R 4 represents -H or -C 1-3 alkyl; R 5 represents -H or -C 1-3 alkyl; R 6 represents -H or -C 1-6 alkyl; R 7 represents -H or -C 1-3 alkyl; R 8 represents -H or -C 1-3 alkyl; and R 9 represents -C 8 heterocycle which is optionally substituted by a group independently selected from: -C 1-6 alkyl wherein C 6 heterocyclyl refers to a cyclic group containing 6 ring-atoms 1,2 or 3 of which are hetero-atoms independently selected from nitrogen, oxygen and sulphur and the remaining ring-atoms are carbon.; or a pharmaceutically acceptable salt thereof. X represents -CONH-, -NHCO- or -CH 2 NH-. R 1 represents phenyl substituted by two groups independently selected from halogen. R 2 represents hydrogen, -C 1-6 alkyl or -C 1-3 alkylOC 1-3 alkyl; R 3 represents: -C 5-9 heteroaryl optionally substituted by one, two or three groups independently selected from: -C 1-3 alkyl, -C 1-6 alkoxy, -CO 2 R 4, -C(=O)NR 5 R 6, -C(=O)NHC 1-3 alkylNR 7 R 8, -C(=O)NHC 1-3 alkylOC 1-3 alkyl, -C(=O)NHC 1-3 alkylOH, -C(=O)R 9, -C 1-6 alkylOH, -CHO, -C 1-3 alkylCO 2 C 1-3 alkyl, -C 1-3 alkylOC 1-3 alkyl, -C 1-6 haloalkyl, -OC 1-6 haloalkyl, -OC 3-6 cycloalkyl, -C 3-6 cycloalkyl or halogen wherein C 5-9 heteroaryl means an aromatic cyclic group containing 5 to 9 ring-atoms 1, 2, 3 or 4 of which are hetero-atoms independently selected from nitrogen, oxygen and sulphur and the remaining ring-atoms are carbon; -C 5-9 heteroaryl optionally substituted by one, two or three groups independently selected from: -C 1-3 alkyl, -C 1-6 alkoxy, -CO 2 R 4, -C(=O)NR 5 R 6, -C(=O)NHC 1-3 alkylNR 7 R 8, -C(=O)NHC 1-3 alkylOC 1-3 alkyl, -C(=O)NHC 1-3 alkylOH, -C(=O)R 9, -C 1-6 alkylOH, -CHO, -C 1-3 alkylCO 2 C 1-3 alkyl, -C 1-3 alkylOC 1-3 alkyl, -C 1-6 haloalkyl, -OC 1-6 haloalkyl, -OC 3-6 cycloalkyl, -C 3-6 cycloalkyl or halogen wherein C 5-9 heteroaryl means an aromatic cyclic group containing 5 to 9 ring-atoms 1, 2, 3 or 4 of which are hetero-atoms independently selected from nitrogen, oxygen and sulphur and the remaining ring-atoms are carbon; R 4 represents -H or -C 1-3 alkyl; R 5 represents -H or -C 1-3 alkyl; R 6 represents -H or -C 1-6 alkyl; R 7 represents -H or -C 1-3 alkyl; R 8 represents -H or -C 1-3 alkyl; and R 9 represents -C 8 heterocycle which is optionally substituted by a group independently selected from: -C 1-6 alkyl wherein C 6 heterocyclyl refers to a cyclic group containing 6 ring-atoms 1,2 or 3 of which are hetero-atoms independently selected from nitrogen, oxygen and sulphur and the remaining ring-atoms are carbon.;