Pharmaceutical compound

1. A compound having the following formula, or a pharmaceutically acceptable salt thereof:

wherein:

X 1 is C;

X 3 and X 5 may be independently selected from C and O, wherein one of X3 and X5 is C and the other is O;

Y is N;

each bond represented by a dotted line may independently be a double bond or a single bond, provided that valencies at each ring atom are maintained and provided that the ring Q contains at least one double bond and provided that the atom N has a double bond;

R 3 and R 5 may be present or absent and may be the same or different and, when present, each is independently selected from H and C 1 -C 6 alkyl, provided that the number of R 3 groups present is such that the valency of X 3 is maintained, and the number of R 5 groups present is such that the valency of X 5 is maintained;

R 21 is selected from H, C 1 -C 6 alkyl,

wherein R 211 is a group selected from:

H;

C 1 -C 6 alkyl, unsubstituted or substituted with 1 to 3 substituents independently selected from —OH, C 3 -C 6 cycloalkyl, —NH 2 , —NH—C 1 -C 6 alkyl, —N(C 1 -C 6 alkyl)(C 1 -C 6 alkyl), —N(C 1 -C 6 alkyl)(SO 2 —C 1 -C 6 alkyl), —NH—SO 2 —C 1 -C 6 alkyl, —C(O)OH, —C(O)O—C 1 -C 6 alkyl, —C(O)—NH—C 1 -C 6 alkyl, phenyl, tetrahydropyranyl, piperidinyl, pyrrolidinyl and pyridinyl;

C 3 -C 6 cycloalkyl;

phenyl, unsubstituted or substituted with 1 to 3 substituents independently selected from C 1 -C 6 alkyl, halogen and —SO 2 —C 1 -C 6 alkyl; and

a heterocyclic ring selected from the group consisting of tetrahydropyranyl, piperidinyl, and pyrrolidinyl, each of which is unsubstituted or substituted with 1 to 3 substituents independently selected from C 1 -C 6 alkyl, —C(O)—C 1 -C 6 alkyl and —SO 2 —C 1 -C 6 alkyl;

R 22 is selected from the group consisting of H and C 1 -C 6 alkyl; and

Cy is a cyclic organic group selected from phenyl and pyridinyl, wherein each of the phenyl and pyridinyl is unsubstituted or substituted with 1 to 3 substituents independently selected from C 1 -C 6 alkyl, —CN, halogen, —OH, —NO 2 and —O—C 1 -C 6 alkyl.

2. The compound of claim 1 selected from the group consisting of:

or a pharmaceutically acceptable salt thereof.

3. The compound of claim 1 , wherein Cy is phenyl, unsubstituted or substituted with 1 to 3 substituents independently selected from C 1 -C 6 alkyl, —CN, halogen, —OH, —NO 2 and —O—C 1 -C 6 alkyl;

or a pharmaceutically acceptable salt thereof.

4. The compound of claim 1 , wherein, where present, R 3 and R 5 are each independently selected from H and a linear or branched C 1 -C 6 alkyl group; or a pharmaceutically acceptable salt thereof.

5. The compound of claim 1 , wherein R 21 is selected from:

wherein R 211 is a group selected from:

H;

C 1 -C 6 alkyl, unsubstituted or substituted with 1 to 3 substituents independently selected from —OH, C 3 -C 6 cycloalkyl, —NH 2 , —NH—C 1 -C 6 alkyl, —N(C 1 -C 6 alkyl)(C 1 -C 6 alkyl), —N(C 1 -C 6 alkyl)(SO 2 —C 1 -C 6 alkyl), —NH—SO 2 —C 1 -C 6 alkyl, —C(O)OH, —C(O)O-C 1 -C 6 alkyl, —C(O)—NH—C 1 -C 6 alkyl, phenyl and tetrahydropyranyl;

C 3 -C 6 cycloalkyl;

phenyl, unsubstituted or substituted with 1 to 3 substituents independently selected from C 1 -C 6 alkyl, halogen and —SO 2 —C 1 -C 6 alkyl; and

a heterocyclic ring selected from the group consisting of tetrahydropyranyl, piperidinyl, pyrrolidinyl, and pyridinyl, each of which is unsubstituted or substituted with 1 to 3 substituents independently selected from C 1 -C 6 alkyl, —C(O)—C 1 -C 6 alkyl and —SO 2 —C 1 -C 6 alkyl;

or a pharmaceutically acceptable salt thereof.

6. A compound selected from the group consisting of:

or a pharmaceutically acceptable salt thereof.

7. A pharmaceutical composition comprising a compound of claim 1 , or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable excipient.

8. The pharmaceutical composition of claim 7 for treating a cancer, further comprising a further agent for treating cancer; wherein the further agent for treating cancer is selected from anti-microtubule agents, platinum coordination complexes, alkylating agents, antibiotic agents, topoisomerase II inhibitors, antimetabolites, topoisomerase I inhibitors, hormones and hormone analogues, signal transduction pathway inhibitors, non-receptor tyrosine kinase angiogenesis inhibitors, immunotherapeutic agents (such as an anti-tumour vaccine, an oncolytic virus, an immune stimulatory antibody such as anti-CTLA4, anti-PD1, anti-PDL-1, anti-OX40, anti-41BB, anti-CD27, anti-CD40, anti-LAG3, anti-TIM3, and anti-GITR, a novel adjuvant, a peptide, a cytokine, a chimeric antigen receptor T cell therapy (CAR-T), a small molecule immune modulator, tumour microenvironment modulators, and anti-angiogenic agents), proapoptotic agents and cell cycle signalling inhibitors.

9. The pharmaceutical composition of claim 8 , wherein the further agent is selected from: an anti-tumour vaccine; a cancer immunotherapy treatment (such as an immune checkpoint modulator such as an anti-CTLA4, anti-PD1, anti PDL-1, anti-LAG3, or anti-TIM3 agent, and CD40, OX40, 41BB or GITR agonists); an immunomodulator; an immunosuppressant; a cytokine therapy; a tyrosine kinase inhibitor; and a chimeric antigen receptor T cell therapy (CAR-T).

10. A pharmaceutical kit for treating a cancer, which pharmaceutical kit comprises:

(a) a compound of claim 1 , or a pharmaceutically acceptable salt thereof; and

(b) a further agent for treating cancer; wherein the further agent for treating cancer is selected from anti-microtubule agents, platinum coordination complexes, alkylating agents, antibiotic agents, topoisomerase II inhibitors, antimetabolites, topoisomerase I inhibitors, hormones and hormone analogues, signal transduction pathway inhibitors, non-receptor tyrosine kinase angiogenesis inhibitors, immunotherapeutic agents (such as an anti-tumour vaccine, an oncolytic virus, an immune stimulatory antibody such as anti-CTLA4, anti-PD1, anti-PDL-1, anti-OX40, anti-41BB, anti-CD27, anti-CD40, anti-LAG3, anti-TIM3, and anti-GITR, a novel adjuvant, a peptide, a cytokine, a chimeric antigen receptor T cell therapy (CAR-T), a small molecule immune modulator, tumour microenvironment modulators, and anti-angiogenic agents), proapoptotic agents and cell cycle signalling inhibitors;

wherein the compound and the further agent are suitable for administration simultaneously, sequentially or separately.

11. A compound selected from the group consisting of:

or a pharmaceutically acceptable salt thereof.