A compound of formula or a compound of formula or a pharmaceutically acceptable salt thereof; wherein A is selected from group and group: wherein #1 is attached to the carbon atom forming the oxime moiety and wherein group is optionally substituted by one or two R10 and group is optionally substituted by one R10; each R10 is independently halogen or - NH 2; X is -O-, -C(=O)-, -C(=CH 2)-, -CH 2 -, -NH- or -N(C1-C4alkyl)- and wherein X is a bond when R2 is halogen or -CN and wherein when X is -C(=O)-R2 is not hydrogen; or X-R2 is hydrogen; Ra and Rb together form a -CH 2 -CH 2 -CH 2 - or a -CH 2 -CH 2 -CH 2 -CH 2 -bridging moiety; R1 is -Y-R3; Y is a bond or C1-C6alkylene wherein one non-terminal -CH 2 - moiety may be replaced by -O-; R3 is hydrogen, -CN, -OH, C1-C4haloalkyl, C2-C4alkenylene-R4, C2-C4alkynylene-R4, -O-C1- C4alkylene-R4, -O-C1-C4haloalkyl, -NH 2, -NH(C1-C4alkylene-R4), -N(C1-C4alkylene-R4) 2, -C(=O)- OH, -C(=O)-O-C1-C4alkylene-R4, -C(=O)-NH 2, -C(=O)-NH(C1-C4alkylene-R4), -C(=O)-N(Cl- C4alkylene-R4) 2, Cycle P, Cycle Q, -O-Cycle P, -O-Cycle Q or -S(O 2)-C1-C4alkyl; R4 is hydrogen, -NH 2, -NH(C1-C2alkyl) or -N(C1-C2alkyl) 2; Cycle P is a 5-6-membered saturated or partially unsaturated carbocyclic ring optionally substituted by one to three R5 or is a 5-6-membered saturated or partially unsaturated heterocyclic ring containing one to two heteroatoms selected from N and O optionally substituted by one to three R5; each R5 is independently -NH 2, -OH, -CN, C1-C4alkyl, C1-C4alkylene-R11, -O-C1-C2alkyl or oxo; each R11 is independently halogen, -NH 2, -OH, -CN or -O-C1-C2alkyl; Cycle Q is phenyl optionally substituted by one to three R6, or is a 5-6-membered heteroaryl containing one to two heteroatoms selected from N, S and O optionally substituted by one to three R6; each R6 is independently -NH 2, -OH, -CN, C1-C2alkyl or -O-C1-C2alkyl; R2 is hydrogen, halogen, -CN, C1-C4alkyl optionally substituted by one or two R7, or is a 4- to 7- membered saturated carbocyclic ring optionally substituted by one or two R8, or is a 4- to 7-membered saturated heterocyclic ring containing one -N - moiety as ring member and otherwise containing only carbon atoms as ring members; each R7 is independently -OH, halogen, -NH 2, -NH(C1-C2alkyl), -N(C1-C2alkyl) 2 or -NH(-C(=O)-C1- C2alkyl); each R8 is independently -OH, halogen, -NH 2, -NH(C1-C2alkyl), -N(C1-C2alkyl) 2, -NH(-C(=O)-Cl- C2alkyl) or C1-C2alkyl; and R9 is hydrogen, C1-C4alkyl or -C(=O)-C1-C2alkyl. or a pharmaceutically acceptable salt thereof; wherein A is selected from group and group: wherein #1 is attached to the carbon atom forming the oxime moiety and wherein group is optionally substituted by one or two R10 and group is optionally substituted by one R10; each R10 is independently halogen or - NH 2; X is -O-, -C(=O)-, -C(=CH 2)-, -CH 2 -, -NH- or -N(C1-C4alkyl)- and wherein X is a bond when R2 is halogen or -CN and wherein when X is -C(=O)-R2 is not hydrogen; or X-R2 is hydrogen; Ra and Rb together form a -CH 2 -CH 2 -CH 2 - or a -CH 2 -CH 2 -CH 2 -CH 2 -bridging moiety; R1 is -Y-R3; Y is a bond or C1-C6alkylene wherein one non-terminal -CH 2 - moiety may be replaced by -O-; R3 is hydrogen, -CN, -OH, C1-C4haloalkyl, C2-C4alkenylene-R4, C2-C4alkynylene-R4, -O-C1- C4alkylene-R4, -O-C1-C4haloalkyl, -NH 2, -NH(C1-C4alkylene-R4), -N(C1-C4alkylene-R4) 2, -C(=O)- OH, -C(=O)-O-C1-C4alkylene-R4, -C(=O)-NH 2, -C(=O)-NH(C1-C4alkylene-R4), -C(=O)-N(Cl- C4alkylene-R4) 2, Cycle P, Cycle Q, -O-Cycle P, -O-Cycle Q or -S(O 2)-C1-C4alkyl; R4 is hydrogen, -NH 2, -NH(C1-C2alkyl) or -N(C1-C2alkyl) 2; Cycle P is a 5-6-membered saturated or partially unsaturated carbocyclic ring optionally substituted by one to three R5 or is a 5-6-membered saturated or partially unsaturated heterocyclic ring containing one to two heteroatoms selected from N and O optionally substituted by one to three R5; each R5 is independently -NH 2, -OH, -CN, C1-C4alkyl, C1-C4alkylene-R11, -O-C1-C2alkyl or oxo; each R11 is independently halogen, -NH 2, -OH, -CN or -O-C1-C2alkyl; Cycle Q is phenyl optionally substituted by one to three R6, or is a 5-6-membered heteroaryl containing one to two heteroatoms selected from N, S and O optionally substituted by one to three R6; each R6 is independently -NH 2, -OH, -CN, C1-C2alkyl or -O-C1-C2alkyl; R2 is hydrogen, halogen, -CN, C1-C4alkyl optionally substituted by one or two R7, or is a 4- to 7- membered saturated carbocyclic ring optionally substituted by one or two R8, or is a 4- to 7-membered saturated heterocyclic ring containing one -N - moiety as ring member and otherwise containing only carbon atoms as ring members; each R7 is independently -OH, halogen, -NH 2, -NH(C1-C2alkyl), -N(C1-C2alkyl) 2 or -NH(-C(=O)-C1- C2alkyl); each R8 is independently -OH, halogen, -NH 2, -NH(C1-C2alkyl), -N(C1-C2alkyl) 2, -NH(-C(=O)-Cl- C2alkyl) or C1-C2alkyl; and R9 is hydrogen, C1-C4alkyl or -C(=O)-C1-C2alkyl.