A compound of formula: wherein each of X 1 to X 12 are independently N or CR 3, wherein 0, 1, 2 or 3 of X 1 to X 12 are N; R 1 is selected from the group consisting of hydrogen, C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl, C R 4 and C R 4; R 2 is selected from the group consisting of hydrogen, OH, SH, halo, OR 5, SR 5, C R 4, C R 4, NOz, CN, N(R 6) 2, OS n N(R 6) 2 and OS n R 4; each R 3 is independently selected from the group consisting of hydrogen, halo, C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl, C 1-10 haloalkyl, (C(R 7) 2) m C 3-10 cycloalkyl, (C(R 7) 2) m C 5-10 cycloalkenyl, (C(R 7) 2) m aryl, (C(R 7) 2) m heterocyclyl, (C(R 7) 2) m heteroaryl, (C(R 7) 2) m OH, (C(R 7) 2) m SH, (C(R 7) 2) m OR 5, (C(R 7) 2) m SR 5, (C(R 7) 2) m C R 4, (C(R 7) 2) m C R 4, (C(R 7) 2) m OC R 4, (C(R 7) 2) m SC R 4, (C(R 7) 2) m OC R 4, (C(R 7) 2) m SC R 4, (C(R 7) 2) m CN, (C(R 7) 2) m NO 2, (C(R 7) 2) m N(R 6) 2, (C(R 7) 2) m S n R 4, (C(R 7) 2) m N(R 6)C N(R 6) 2 and (C(R 7) 2) m N(R 6)C N(R 6) 2; R 4 is selected from the group consisting of hydrogen, C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl, C 1-10 haloalkyl, C 3-10 cycloalkyl, C 5-10 cycloalkenyl, aryl, heterocyclyl, heteroaryl, OR 5, SR 5 and N(R 6) 2; R 5 is selected from the group consisting of hydrogen, C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl, C 1-10 haloalkyl, C 3-10 cycloalkyl, C 5-10 cycloalkenyl, aryl, heterocyclyl, heteroaryl C C 1-10 alkyl, C C 2-10 alkenyl, C C 2-10 alkynyl, S n R 4 and S n N(R 6) 2; R 6 is selected from the group consisting of hydrogen, C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl, C 1-10 haloalkyl, C 3-10 cycloalkyl, C 5-10 cycloalkenyl, aryl, heterocyclyl and heteroaryl; each R 7 is selected from the group consisting of hydrogen, C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl and C 1-10 haloalkyl; m is 0 or an integer from 1 to 6; n is 1 or 2; wherein each C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl, C 3-10 cycloalkyl, C 5-10 cycloalkenyl, aryl, heterocyclyl and heteroaryl is optionally substituted with one or more substituents selected from the group consisting of C 1-6 alkyl, C 2-6 alkenyl, C 3-6 cycloalkyl, oxo (=O), -OH, -SH, C 1-6 alkylO-, C 2-6 alkenylO-, C 3-6 cycloalkylO-, C 1-6 alkylS-, C 2-6 alkenylS-, C 3-6 cycloalkylS-, -CO 2 H, -CO 2 C 1-6 alkyl, -NH 2, -NH(C 1-6 alkyl), -N(C 1-6 alkyl) 2, -NH(phenyl), -N(phenyl) 2, oxo, - CN, -NO 2, -halogen, -CF 3, -OCF 3, -SCF 3, -CHF 2, -OCHF 2, -SCHF 2, -phenyl, - heterocyclyl, -heteroaryl, -Oheteroaryl, -Oheterocyclyl, -Ophenyl, -C(=O)phenyl, -C(=O)C 1-6 alkyl; or a pharmaceutically acceptable salt or solvate thereof with the proviso that when R 1 is methyl, X 1, X 2, X 3, X 4, X 5, X 6, X 8, X 9, X 10, X 11 and X 12 are each CR 3 where R 3 is hydrogen and X 7 is CR 3 where R 3 is OCH 3, R 2 is not hydrogen. each of X 1 to X 12 are independently N or CR 3, wherein 0, 1, 2 or 3 of X 1 to X 12 are N; R 1 is selected from the group consisting of hydrogen, C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl, C R 4 and C R 4; R 2 is selected from the group consisting of hydrogen, OH, SH, halo, OR 5, SR 5, C R 4, C R 4, NOz, CN, N(R 6) 2, OS n N(R 6) 2 and OS n R 4; each R 3 is independently selected from the group consisting of hydrogen, halo, C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl, C 1-10 haloalkyl, (C(R 7) 2) m C 3-10 cycloalkyl, (C(R 7) 2) m C 5-10 cycloalkenyl, (C(R 7) 2) m aryl, (C(R 7) 2) m heterocyclyl, (C(R 7) 2) m heteroaryl, (C(R 7) 2) m OH, (C(R 7) 2) m SH, (C(R 7) 2) m OR 5, (C(R 7) 2) m SR 5, (C(R 7) 2) m C R 4, (C(R 7) 2) m C R 4, (C(R 7) 2) m OC R 4, (C(R 7) 2) m SC R 4, (C(R 7) 2) m OC R 4, (C(R 7) 2) m SC R 4, (C(R 7) 2) m CN, (C(R 7) 2) m NO 2, (C(R 7) 2) m N(R 6) 2, (C(R 7) 2) m S n R 4, (C(R 7) 2) m N(R 6)C N(R 6) 2 and (C(R 7) 2) m N(R 6)C N(R 6) 2; R 4 is selected from the group consisting of hydrogen, C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl, C 1-10 haloalkyl, C 3-10 cycloalkyl, C 5-10 cycloalkenyl, aryl, heterocyclyl, heteroaryl, OR 5, SR 5 and N(R 6) 2; R 5 is selected from the group consisting of hydrogen, C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl, C 1-10 haloalkyl, C 3-10 cycloalkyl, C 5-10 cycloalkenyl, aryl, heterocyclyl, heteroaryl C C 1-10 alkyl, C C 2-10 alkenyl, C C 2-10 alkynyl, S n R 4 and S n N(R 6) 2; R 6 is selected from the group consisting of hydrogen, C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl, C 1-10 haloalkyl, C 3-10 cycloalkyl, C 5-10 cycloalkenyl, aryl, heterocyclyl and heteroaryl; each R 7 is selected from the group consisting of hydrogen, C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl and C 1-10 haloalkyl; m is 0 or an integer from 1 to 6; n is 1 or 2; wherein each C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl, C 3-10 cycloalkyl, C 5-10 cycloalkenyl, aryl, heterocyclyl and heteroaryl is optionally substituted with one or more substituents selected from the group consisting of C 1-6 alkyl, C 2-6 alkenyl, C 3-6 cycloalkyl, oxo (=O), -OH, -SH, C 1-6 alkylO-, C 2-6 alkenylO-, C 3-6 cycloalkylO-, C 1-6 alkylS-, C 2-6 alkenylS-, C 3-6 cycloalkylS-, -CO 2 H, -CO 2 C 1-6 alkyl, -NH 2, -NH(C 1-6 alkyl), -N(C 1-6 alkyl) 2, -NH(phenyl), -N(phenyl) 2, oxo, - CN, -NO 2, -halogen, -CF 3, -OCF 3, -SCF 3, -CHF 2, -OCHF 2, -SCHF 2, -phenyl, - heterocyclyl, -heteroaryl, -Oheteroaryl, -Oheterocyclyl, -Ophenyl, -C(=O)phenyl, -C(=O)C 1-6 alkyl; or a pharmaceutically acceptable salt or solvate thereof with the proviso that when R 1 is methyl, X 1, X 2, X 3, X 4, X 5, X 6, X 8, X 9, X 10, X 11 and X 12 are each CR 3 where R 3 is hydrogen and X 7 is CR 3 where R 3 is OCH 3, R 2 is not hydrogen.