A compound of Formula I, or a pharmaceutically acceptable salt, or solvate thereof: wherein: R is selected from H, C 1-2 alkyl and C 1-2 fluoroalkyl; R 1 is (CR 5 R 5')PO(OR 6) 2, wherein R 5 is selected from PO(OR 6') 2, CO 2 R 6', C NHR 7, SO 3 R 7, and SO 2 NHR 7; R 5' is selected from H, OH and halo; R 6 and R 6' are independently selected from H and C 1-6 alkyl; and R 7 is selected from H, OH and C 1-6 alkyl; X is selected from O, CH 2, NH and N(C 1-4 alkyl); Z and Y are independently selected from S, O, NR 3 and CR 3 R 3'; Cy 1 is selected from C 6-10 aryl, C 5-10 heteroaryl, C 3-10 cycloalkyl and C 3-10 heterocycloalkyl, each of which are unsubstituted or substituted with one or two substituents independently selected from halo, cyano, hydroxyl, NH 2, NHC 1-6 alkyl, NHC 3-6 cycloalkyl, N(C 1-6 alkyl)(C 1-6 alkyl), C 1-6 fluoroalkyl, C 1-6 alkyl, C 3-6 cycloalkyl, C 1-6 fluoroalkoxy, C 3-6 cycloalkoxy and C 1-6 alkoxy; Cy 2 is selected from C 3-10 cycloalkyl, C 3-10 heterocycloalkyl, C 6-10 aryl and C 5-10 heteroaryl, each of which is unsubstituted or substituted with one to three substituents independently selected from halo, cyano, hydroxyl, NH 2, NHC 1-6 alkyl, NHC 3-6 cycloalkyl, N(C 1-6 alkyl)(C 1-6 alkyl), C 1-6 fluoroalkyl, C 1-6 alkyl, C 3-6 cycloalkyl, C 1-6 fluoroalkoxy, C 3-6 cycloalkoxy, phenyl, C 3-6 heterocycloalkyl, C 5-6 heteroaryl and C 1-6 alkoxy; L is selected from a direct bond, C, O, AC (CR 4 R 4') m (A') p, ASO 2 (CR 4 R 4') m (A') p, C A(CR 4 R 4') m (A') p and SO 2 A(CR 4 R 4') m (A') p; R 3 and R 3' are independently selected from H, C 3-6 cycloalkyl and C 1-4 alkyl, or when the atom to which R 3 is attached is sp 2 hybridized, R 3 is not present; R 4 and R 4' are independently selected from H, halo, C 1-4 fluoroalkyl, C 1-4 alkyl, C 3-6 cycloalkyl, C 1-4 fluoroalkoxy, C 3-6 cycloalkoxy and C 1-4 alkoxy; m is selected from 0, 1 and 2; p is selected from 0 and 1; A is selected from NH and N(C 1-4 alkyl); A' is selected from O, NH and N(C 1-4 alkyl) when m is 1 or 2 and A' is selected from NH and N(C 1-4 alkyl) when m is 0; and represents a single or double bond, provided that two double bonds are not adjacent to each other. R is selected from H, C 1-2 alkyl and C 1-2 fluoroalkyl; R 1 is (CR 5 R 5')PO(OR 6) 2, wherein R 5 is selected from PO(OR 6') 2, CO 2 R 6', C NHR 7, SO 3 R 7, and SO 2 NHR 7; R 5' is selected from H, OH and halo; R 6 and R 6' are independently selected from H and C 1-6 alkyl; and R 7 is selected from H, OH and C 1-6 alkyl; X is selected from O, CH 2, NH and N(C 1-4 alkyl); Z and Y are independently selected from S, O, NR 3 and CR 3 R 3'; Cy 1 is selected from C 6-10 aryl, C 5-10 heteroaryl, C 3-10 cycloalkyl and C 3-10 heterocycloalkyl, each of which are unsubstituted or substituted with one or two substituents independently selected from halo, cyano, hydroxyl, NH 2, NHC 1-6 alkyl, NHC 3-6 cycloalkyl, N(C 1-6 alkyl)(C 1-6 alkyl), C 1-6 fluoroalkyl, C 1-6 alkyl, C 3-6 cycloalkyl, C 1-6 fluoroalkoxy, C 3-6 cycloalkoxy and C 1-6 alkoxy; Cy 2 is selected from C 3-10 cycloalkyl, C 3-10 heterocycloalkyl, C 6-10 aryl and C 5-10 heteroaryl, each of which is unsubstituted or substituted with one to three substituents independently selected from halo, cyano, hydroxyl, NH 2, NHC 1-6 alkyl, NHC 3-6 cycloalkyl, N(C 1-6 alkyl)(C 1-6 alkyl), C 1-6 fluoroalkyl, C 1-6 alkyl, C 3-6 cycloalkyl, C 1-6 fluoroalkoxy, C 3-6 cycloalkoxy, phenyl, C 3-6 heterocycloalkyl, C 5-6 heteroaryl and C 1-6 alkoxy; L is selected from a direct bond, C, O, AC (CR 4 R 4') m (A') p, ASO 2 (CR 4 R 4') m (A') p, C A(CR 4 R 4') m (A') p and SO 2 A(CR 4 R 4') m (A') p; R 3 and R 3' are independently selected from H, C 3-6 cycloalkyl and C 1-4 alkyl, or when the atom to which R 3 is attached is sp 2 hybridized, R 3 is not present; R 4 and R 4' are independently selected from H, halo, C 1-4 fluoroalkyl, C 1-4 alkyl, C 3-6 cycloalkyl, C 1-4 fluoroalkoxy, C 3-6 cycloalkoxy and C 1-4 alkoxy; m is selected from 0, 1 and 2; p is selected from 0 and 1; A is selected from NH and N(C 1-4 alkyl); A' is selected from O, NH and N(C 1-4 alkyl) when m is 1 or 2 and A' is selected from NH and N(C 1-4 alkyl) when m is 0; and represents a single or double bond, provided that two double bonds are not adjacent to each other.