A compound of formula (I): A-L-B (I), or a pharmaceutically acceptable salt or stereoisomer thereof, wherein ** Formula ** A is X is (i) N or CR1； or (ii) O or NR2； each Y is independently N or CR3； each Z is independently N or C； and with the proviso that A contains 2, 3 or 4 nitrogen atoms in the ring； such that ** Formula ** B is ** Formula ** B1 is NR8； each R3 is independently hydrogen, halo, cyano, (C1-C6) alkyl, (C1-C6) alkoxy, (C1-C6) aminoalkyl, (C1-C6) heteroalkyl, aryl or heteroaryl； R4 and R5 together with the atoms to which they are attached form an aryl, heteroaryl, cycloalkyl or monocyclic or multicyclic heterocyclyl ring； R8 is hydrogen, alkyl, alkenyl, heteroalkyl, cycloalkyl, aryl, heteroaryl or heterocyclyl； R9 is hydrogen, halo, cyano, alkyl, alkenyl, alkoxy, aminoalkyl, heteroalkyl, cycloalkyl, aralkyl, heteroaralkyl, aryl, heteroaryl, heterocyclyl, amino, amido or thiol； each R10 is independently hydrogen, halo or alkyl； Ring C is a 5- or 6-membered heteroaryl ring or a 5- to 7-membered cycloalkyl or heterocyclyl ring； each R12 is independently hydrogen, halogen, cyano, -OR13, -NR13R14, -N (R13) C (O) R14, -C (O) NR13R14, - C (O) R13, -C (O) OR13, -OC (O) R13, -SR13, -S (O) R13, -S (O) 2R13, -S (O) 2NR13R14, alkyl, heteroalkyl, cycloalkyl, aralkyl, heteroaralkyl, aryl, heteroaryl or heterocyclyl； each R13 and R14 are independently hydrogen, alkyl, heteroalkyl, cycloalkyl, aralkyl, heteroaralkyl, aryl, heteroaryl or heterocyclyl； or, when R13 and R14 are both attached to a nitrogen atom, R13 and R14 together with the nitrogen atom to which they are attached form a 3- to 10-membered ring； the term "heteroalkyl" refers to a stable linear or branched chain, consisting of the indicated number of carbon atoms and one or more heteroatoms selected from the group consisting of O, N, Si and S, and in which the nitrogen and sulfur atoms are optionally oxidized and the nitrogen heteroatom may be optionally quaternized； alkyl, alkenyl, alkynyl, cycloalkyl,
