WO2018136009A1 - Combination therapy - Google Patents

Abstract

A method of treating cancer with a combination therapy comprising administering a DHODH inhibitor and a checkpoint inhibitor. Also provided is a combination therapy for use in the treatment of cancer.

Description

COMBINATION THERAPY

[001] The present disclosure relates to a method of treating cancer with a combination therapy, and a combination therapy for use in the treatment of cancer, in particular a cancer disclosed herein.

BACKGROUND

[002] Cellular sensing of DNA damage, along with concomitant cell cycle arrest, is mediated by a great many proteins and enzymes. One focus of pharmaceutical development has been the inhibition of DNA damage signaling, and checkpoint kinases (CHKs]. There have been a number of clinical trial of checkpoint kinase inhibition alone or as a combination therapy for example, as a means to sensitize proliferating tumor cells to chemotherapies that damage DNA. The development of checkpoint kinase inhibitors for treatment of cancer was a major objective in drug discovery. However, in clinical trials for the checkpoint inhibitors have failed to show a high level of clinical activity expected even when combined with chemotherapeutic agents. Thus as a class, checkpoint inhibitors have failed to deliver their predicted therapeutic benefits in the clinic.

[003] In the fight against cancer we need as many ways as possible of undermining and attacking cancer to ensure patients have options for alternative therapies, for example once first line therapy has failed and the patient's disease progresses.

[004] The present disclosure provides a novel, therapeutic combination with checkpoint inhibitors for the treatment of cancer, for example that will induce synthetic lethality specifically in cancer cells, in particular cancer cells that have mutations that effect the function of the p53 pathway. This combination therapy may fight cancer employing at least two distinct mechanisms but may also employ complementary mechanisms. Thus, the presently disclosed therapy may increase the repertoire of cancer treatments available to patients and, in particular may give options and hope to patients who have, for example already failed on one or more standard of care therapies.

SUMMARY OF THE DISCLOSURE

[005] Thus there is provided a combination therapy comprising an inhibitor of human enzyme dihydroorotate dehydrogenase (OMIM 126064, HUGO 2867, ENTREZ 1723, Uniprot Q02127] also referred to as a DHODH inhibitor, administered in combination with an inhibitor of a protein involved in control of the human cell cycle and DNA damage response (DDR], commonly referred to as a checkpoint inhibitor, for example selected from: checkpoint kinase inhibitor 1 (CHEK1/CHK1, Uniprot 014757], checkpoint kinase inhibitor 2 (CHEK2/ CHK2], Ataxia telangiectasia and Rad3 related (ATR] inhibitor, ataxia-telangiectasia mutated (ATM] inhibitor, Weel dual specificity protein kinase (Weel] inhibitor and Poly ADP Ribose polymerase (PARP] inhibitor, Mytl inhibitor for use in treatment, especially for the treatment of cancer, such as cancers that have modulated or inhibited the expression, function or cell signalling capability of the p53 pathway. In one embodiment the checkpoint inhibitor targets a molecule within the cancer cells (as opposed to a molecule expressed on the surface of the cancer cell]. The pathway and chemotherapy damage of DNA is shown schematically in Figure 1. The DHODH inhibitor may be provided in a pharmaceutical formulation comprising one or more diluents, carriers and/or excipients. The checkpoint inhibitor may also be provided in a pharmaceutical formulation comprising one or more diluents, carriers and/or excipients.

[006] The present inventors have demonstrated that the results of the combined therapies are at least additive and may be synergistic, for example, by increasing the therapeutic effect of one or both components (in particular the checkpoint inhibitor] by 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15-fold or more. The data generated demonstrates that the combination of a DHODH inhibitor and a check point inhibition, in particular CHK1 (CHEK1], synergistically kills tumours cells and synergistically induces mitotic catastrophe in tumour cells. In addition, this combination may allow use of up to a 10-fold lower therapeutic dose of a checkpoint inhibitor, such as a checkpoint kinase inhibitor, in particular CHK1 (CHEK1], in the clinic. Second generation checkpoint inhibitors are better tolerated than first generation checkpoint inhibitors. However, the ability to employ a smaller dose of the checkpoint inhibitor will greatly reduce the toxicity of the checkpoint inhibitor in the cancer patient and significantly improve the tolerability of this class of human cell cycle/DDR checkpoint inhibitor therapy.

Thus, the invention provides the following aspects described from paragraph 007 below:

[007] A method of treating a cancer patient comprising administering a therapeutically effect amount of a DHODH inhibitor and a therapeutically effective amount of a checkpoint inhibitor, for example selected from: checkpoint kinase inhibitor 1 (CHEK1/CHK1], checkpoint kinase inhibitor 2 (CHEK2/ CHK2], Ataxia telangiectasia and Rad3 related (ATR] inhibitor, ataxia-telangiectasia mutated (ATM] inhibitor, Weel dual specificity protein kinase (Weel] inhibitor, Poly ADP Ribose polymerase (PARP] inhibitor and Mytl inhibitor, such as a checkpoint kinase inhibitor, in particular a CHK1 inhibitor.

[008] A combination therapy comprising a checkpoint inhibitor (for example selected from: checkpoint kinase inhibitor 1, checkpoint kinase inhibitor 2 (CHEK2/ CHK2], Ataxia telangiectasia and Rad3 related (ATR] inhibitor, ataxia-telangiectasia mutated (ATM] inhibitor, Weel dual specificity protein kinase (Weel] inhibitor, Poly ADP Ribose polymerase (PARP] inhibitor and Mytl inhibitor, such as checkpoint kinase inhibitor, in particular as disclosed herein] and a DHODH inhibitor for use in the treatment, in particular for use in treatment, for example for use in the treatment of cancer, such as a cancer disclosed herein.

[009] Use of a checkpoint inhibitor (for example selected from: checkpoint kinase inhibitor 1, checkpoint kinase inhibitor 2 (CHEK2/ CHK2], Ataxia telangiectasia and Rad3 related (ATR] inhibitor, ataxia-telangiectasia mutated (ATM] inhibitor, Weel dual specificity protein kinase (Weel] inhibitor, Poly ADP Ribose polymerase (PARP] inhibitor and Mytl inhibitor, such as checkpoint kinase inhibitor, in particular as disclosed herein] and a DHODH inhibitor in the manufacture of a combination therapy for the treatment of cancer, in particular a cancer disclosed herein.

[010] Also provided is a DHODH inhibitor for use in a combination therapy further comprising a checkpoint inhibitor (for example selected from: checkpoint kinase inhibitor 1, checkpoint kinase inhibitor 2 (CHEK2/ CHK2], Ataxia telangiectasia and Rad3 related (ATR] inhibitor, ataxia- telangiectasia mutated (ATM] inhibitor, Weel dual specificity protein kinase (Weel] inhibitor, Poly ADP Ribose polymerase (PARP] inhibitor and Mytl inhibitor, such as a checkpoint kinase 1 inhibitor (CHK1/CHEK1], in particular as disclosed herein] for the treatment of cancer, such as a cancer disclosed herein.

[Oil] Also provided is a checkpoint inhibitor (for example selected from: checkpoint kinase inhibitor 1, checkpoint kinase inhibitor 2 (CHEK2/ CHK2], Ataxia telangiectasia and Rad3 related (ATR] inhibitor, ataxia-telangiectasia mutated (ATM] inhibitor, Weel dual specificity protein kinase (Weel] inhibitor, Poly ADP Ribose polymerase (PARP] inhibitor and Mytl inhibitor, such as a checkpoint kinase inhibitor 1 (CHK1/CHEK1]] for use in a combination therapy further comprising a DHODH inhibitor (in particular a DHODH inhibitor disclosed herein], in particular for use in the treatment of cancer, such as a cancer disclosed herein.

[012] Also provide is a co-formulated combination therapy of a DHODH inhibitor and checkpoint inhibitor, (for example selected from: checkpoint kinase inhibitor 1, checkpoint kinase inhibitor 2 (CHEK2/ CHK2], Ataxia telangiectasia and Rad3 related (ATR] inhibitor, ataxia-telangiectasia mutated (ATM] inhibitor, Weel dual specificity protein kinase (Weel] inhibitor, Poly ADP Ribose polymerase (PARP] inhibitor and Mytl inhibitor, such as a checkpoint kinase inhibitor, in particular CHK1/CHEK1).

[013] In one embodiment according to the present disclosure, for example according to paragraph 007 to 012, the cancer has a mutation or mutations that result in modulate of p53 signalling or p53 function or p53 regulation, for example where p53 is deleted or has reduced function.

[014] In one embodiment according to the present disclosure, for example according to paragraphs 007 to 013 the cancer is a solid tumour.

[015] In one embodiment according to the present disclosure, for example according to paragraphs 007 to 014 the cancer is a liquid tumour.

[016] In one embodiment according to the present disclosure, for example according to paragraphs 007 to 015, the cancer is metastatic.

[017] In one embodiment according to the present disclosure, for example according to any one of paragraphs 007 to 016, the cancer is selected from liver cancer (such as hepatocellular carcinoma], biliary tract cancer, breast cancer (such as non-ER+ breast cancer, in particular double negative breast cancer or triple negative breast cancer], prostate cancer, colorectal cancer, ovarian cancer, endometrial cancer, cervical cancer, lung cancer, gastric cancer, pancreatic cancer, bone cancer, bladder cancer, head and neck cancer, thyroid cancer, skin cancer, renal cancer, oesophageal cancer, nasopharangeal cancer, leukaemia, acute myeloid leukaemia (AML], T-cell lymphoma, B-cell lymphoma, Hodgkins lymphoma, Non-Hodgkins lymphoma, acute lymphocytic leukaemia (ALL], chronic myelogenous leukemia(CML], acute monocytic leukaemia (AMoL], chronic lymphocytic leukaemia (CLL]; any cancer that has results from uncontrolled proliferation of lymphoid, myeloid or haematopoietic cell lineage and combination of two or more of the same.

[018] In one embodiment according to the present disclosure, for example according to paragraph 017, the cancer is an epithelial cancer for example selected from liver cancer (such as hepatocellular carcinoma], biliary tract cancer, breast cancer (such as non-ER+ breast cancer, in particular double negative breast cancer and/or BRCA1 positive breast cancer], prostate cancer, colorectal cancer, ovarian cancer, endometrial cancer, cervical cancer, lung cancer (for example non-small cell lung cancer], gastric cancer, pancreatic cancer, bone cancer, bladder cancer, head and neck cancer, thyroid cancer, skin cancer, renal cancer, oesophageal cancer, nasopharyngeal cancer and combinations of two or more of the same.

[019] In one embodiment according to the present disclosure, for example according to paragraph 018, the cancer is selected from liver cancer (such as hepatocellular carcinoma], biliary tract cancer, breast cancer (such as non-ER+ breast cancer, in particular double negative or triple negative breast cancer and/or BRAC1 positive breast cancer], prostate cancer, colorectal cancer, ovarian cancer, endometrial cancer, cervical cancer, lung cancer (for example non-small cell lung cancer], gastric cancer, pancreatic cancer, bone cancer, bladder cancer, head and neck cancer, thyroid cancer, skin cancer, renal cancer, oesophageal cancer, and combinations of two or more of the same.

[020] In one embodiment according to the present disclosure, for example according to paragraph 018 or 019, the cancer is selected from the group comprising liver cancer (such as hepatocellular carcinoma], biliary duct cancer, breast cancer (such as non-ER+ breast cancer, in particular double negative breast cancer and/or BRCA1 positive breast cancer], prostate cancer, colorectal cancer, bladder cancer, ovarian cancer, endometrial cancer, lung cancer (for example non-small cell lung cancer], gastric cancer, oesophageal cancer, kidney cancer, head and neck cancers and a combination of two or more of the same.

[021] In one embodiment according to the presenting disclosure, for example according to paragraphs 007 to 020, wherein the cancer is selected from hepatocellular carcinoma, biliary duct cancer (for example cholangiocarcinoma], breast cancer (such as non-ER+ breast cancer, in particular double negative breast cancer and/or BRCA1 positive breast cancer], lung cancer (for example non-small cell lung cancer], ovarian cancer, pancreatic cancer, gastric cancer and combinations of two or more of the same.

[022] In one embodiment according to the present disclosure, for example according to any one of paragraphs 007 to 021, wherein the DHODH inhibitor is selected from the group comprising a compound of formula (I]:

wherein:

one of the groups G¹ represents a nitrogen atom or a group CR^C and the other group represents CR^C;

G² represents a nitrogen atom or a group CR^d;

R¹ represents a group selected from hydrogen, halogen, C1- alkyl which may be optionally substituted with 1, 2 or 3 substituents selected from the group comprising halogen, hydroxy, and C3-8 cycloalkyl which may be optionally substituted with 1, 2 or 3 substituents selected from halogen and hydroxyl;

R² represents a group selected from hydrogen, halogen, hydroxyl, C1-4 alkyl which may be optionally substituted by 1, 2 or 3 substituents selected from the group comprising halogen, hydroxy, C3-8 alkyl which may be optionally substituted with 1, 2, or 3 substituents selected from halogen and hydroxyl;

R^a, R^b and R^c independently represent a radical selected from the group comprising hydrogen, halogen, C1-4 alkyl optionally substituted by 1, 2 or 3 substituents selected from the group comprising halogen, hydroxy and C1.4 alkoxy;

R^d represents a group selected from hydrogen, halogen, hydroxyl, C1-4 alkyl which may be substituted by 1, 2 or 3 substituents selected from the group comprising halogen, hydroxyl, C1-4 alkoxy which may be optionally substituted with 1, 2 or 3 substituent selected from the group comprising halogen, hydroxy, and C3.8 cycloalkoxy which may be optionally substituted with 1, 2 or 3 substitutents selected from halogen and hydroxyl;

G³ & G⁴ one is a nitrogen atom and the other is a CH;

M is hydrogen or a pharmaceutically acceptable cation;

teriflunomide, leflunomide, brequinar, atovaquone;

Or a compound of formula (II):

wherein

R3 is CF2CF3, CF₃, OCH2CH3 or CH₂CH₃;

R4 is F, CH₃, CF₃, SF₃ or CL, or

a pharmaceutically acceptable salt of any one of the same.

[023] In one embodiment according to the present disclosure, for example according to paragraph 022, the DHODH inhibitor is 2-(3,5-difluoro-3'-methoxybiphenyl-4-ylamino]nicotinic acid or a pharmaceutically acceptable salt thereof, for example a salt disclosed in WO2010/102826 (incorporate herein by reference], such as the meglumine salt.

[024] In one embodiment according to the present disclosure, for example according to paragraph 022 or 023, wherein the DHODH inhibitor is 2-(3,5-difluoro-3'-methoxybiphenyl-4- ylamino]nicotinic acid (i.e. provided as the acid].

[025] In one embodiment according to the present disclosure, for example according to any one of paragraphs 007 to 024 wherein the DHODH inhibitor is provided as a pro-drug.

[026] In one embodiment according to the present disclosure, for example according to any one of paragraphs 007 to 024, the checkpoint inhibitor, is a checkpoint kinase inhibitor, for example the checkpoint kinase inhibitor, is an inhibitor of at a least checkpoint kinase 1 (CHK1/ CHEK1].

[027] In one embodiment according to the present disclosure, for example according to any one of paragraphs 007 to 026, the checkpoint kinase inhibitor is an inhibitor of at least checkpoint kinase 2.

[028] In one embodiment according to the present disclosure, for example according to any one of paragraphs 007 to 027, the checkpoint kinase is an inhibitor of: Ataxia telangiectasia and Rad3 related (ATR] inhibitor; ataxia-telangiectasia mutated (ATM]; Weel dual specificity protein kinase (Weel]; and Mytl inhibitor or a combination thereof.

[029] In one embodiment according to the present disclosure, for example according to any one of paragraphs 007 to 028, the checkpoint kinase inhibitor is an inhibitor that induces DNA synthesis catastrophe in a cancer cell.

[030] In one embodiment according to the present disclosure, for example according to any one of paragraphs 007 to 029, the checkpoint kinase inhibitor is an inhibitor that induces mitotic catastrophe in a cancer cell.

[031] In one embodiment according to the present disclosure, for example according to any one of paragraphs 007 to 030, the checkpoint inhibitor is independently selected from:

GDC-0575 (structure not given];

KU55933 is a potent and selective ATM inhibitor (vis-a-vie DNA-PK, Pi3K/Pi4K, ATR and mTOR] with an IC50 of 13 nM and KI of 2.2 mM;

is an ATM inhibitor

KU60019 is an ATM inhibitor

N

U6027 is a potent ATR inhibitor

VE-821 is a potent and selective ATP competitive inhibitor of ATR with a ¾ of 13 nM and an IC50 of 26 nM

BGB-290 a PARP-1 and PARP-2 inhibitor (structure not shown); MP-124 a PARP-1 inhibitor (structure not shown);

or a pharmaceutically acceptable salt or solvate of any one of the same. The following articles disclose certain checkpoint inhibitors: Drugs Fut 2003, 28(9): 881 Cell cycle inhibitors for the treatment of cancer Kong, N., Fotouhi, N., Wovkulich, P.M., Roberts, J; Novel pyrrole derivatives as selective CHK1 inhibitors: design, regioselective synthesis and molecular modelling Med. Chem. Commun, 2015,6, 852-859; PLoS One 2010; 5 (8] : el2214. Binding of protein kinase inhibitors to synapsin I inferred from pair-wise binding site similarity measurements. In one embodiment the checkpoint inhibitor is a PARP inhibitor. Examples of PARP inhibitors are disclosed in US7449464 and US8071623. The compounds disclosed in this paragraph are incorporated herein by reference. In one embodiment the checkpoint inhibitor is an antibody or binding fragment specific to a checkpoint protein, in particular one disclosed herein.

[032] In one embodiment of the disclosure, for example according to any one of paragraphs 007 to 031, wherein the checkpoint kinase inhibitor is independently selected from:

3- [(Aminocarbonyl]amino]-5-(3-fluorophenyl]-N- (3S]-3-piperidinyl-2-thiophenecarboxamide hydrochloride; (3R,4S]-4- [[2-(5-Fluoro-2-hydroxyphenyl]-6,7-dimethoxy-4-quinazolinyl]amino]- a,a-dimethyl-3-pyrrolidinemethanol dihydrochloride; 4,4'-diacetyldiphenylurea

bis(guanylhydrazone] ditosylate; 9-Hydroxy-4-phenyl-pyrrolo[3,4-c]carbazole-l,3 (2H,6H]-dione; (R]-a-Amino-N- [5,6-dihydro-2-(l-methyl-lH-pyrazol-4-yl]-6-oxo-lH-pyrrolo[4,3,2- efj [2,3]benzodiazepin-8-yl]-cyclohexaneacetamide; 9,10,11,12-Tetrahydro- 9,12-epoxy-lH- diindolo [l,2,3-fg:3',2',l '-kl]pyrrolo[3,4-i] [l,6]benzodiazocine-l,3 (2H]-dione; 4'- [5- [[3- [(Cyclopropylamino]methyl]phenyl]amino]- lH-pyrazol-3-yl]- [l,l '-biphenyl]-2,4-diol; and

(R]-5-((4-((Morpholin-2-ylmethyl]amino]-5-(trifluoromethyl]pyridin-2-yl]amino]pyrazine-2- carbonitrile (CCT245737).

[033] In one embodiment of the disclosure, for example according to any one of paragraphs 007 to 032, the checkpoint inhibitor is a PARP inhibitor, for example one of the following:

BGB-290 a PARP-1 and PARP-2 inhibitor (structure not shown); or a pharmaceutically acceptable salt thereof. In one embodiment the check point inhibitor employed is prexasertib (LY2606368] or a pharamaceutically acceptable salt thereof.

[034] In one embodiment of the disclosure, for example according to any one of paragraphs 007 to 033, the target patient population has a mutated p53 gene or mutations in the p53 pathway that modulate or inhibit the pathways signalling or cellular function in the tumour cells.

[035] In one embodiment of the disclosure, for example according to any one of paragraphs 007 to 034, wherein the DHODH inhibitor provides anti-cancer efficacy via induction of p53 mediated apoptosis.

[036] In one embodiment of the disclosure, for example according to any one of paragraphs 007 to 035, wherein the DHODH inhibitor is administered orally, for example once or twice daily.

[037] In one embodiment of the disclosure, for example according to paragraph 036, wherein each dose of the DHODH inhibitor is in the range of lOmg to lOOOmg, for example 50mg to 500mg, such as QD or BID, in particular BID.

[038] In one embodiment of the disclosure, for example according to any one of claims 007 to 037, wherein the checkpoint inhibitor is administered orally. In one embodiment the checkpoint inhibitor is administered one or twice daily, for example twice daily.

[039] In one embodiment of the method according to any one of paragraphs 007 to 038 the combination therapy continues for 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60 months or more.

DETAILED DISCLOSURE

[040] DHODH is a key enzyme in the de novo synthesis of pyrimidine nucleotides in human cells, which are central building blocks in the manufacture of DNA and RNA in a human cell. DHODH is the only enzyme in the synthetic pathway for the de novo biosynthesis of pyrimidines whose cellular location is in the inner mitochondrial membrane. In comparison to DHODH the other members of this pyrimidine biosynthetic synthetic pathway are all in the cellular cytoplasm. Recently data has been published demonstrating that DHODH is a key stress sensor in the cell. This is partly by virtue of its position in the inner mitochondrial membrane where DHODH couples the de novo biosynthesis of pyrimindines with the mitochondrial respiratory chain and the manufacture of adenosine triphosphate (ATP].

[041] DHODH controls the rate-limiting step in the manufacture of pyrmidines by converting dihydroorotate to orotate. However, this enzymatic process uses an electron to reduce ubiquinone to ubiquinol in Complex III of the human electron transport chain and thereby contributes to the cellular manufacture of ATP.

[042] Whilst not wishing to be bound by theory, in human cells with a functional p53 pathway it may be that the DHODH inhibitor is able to upregulate p53 mediated cellular apoptosis. Inhibition of DHODH in human cells may lead to cell cycle arrest and at higher levels of prolonged inhibition may lead to p53 mediated apoptosis.

[043] Inhibition of DHODH in human cells leads to depleted levels of pyrimidine nucleotides and a lowering of the cellular ATP levels, which together result in greatly increased mitochondrial stress. This in turn leads to increased levels of mitochondrially derived reactive oxygen species (ROS] that non-specifically damage human DNA, thereby inducing single and double stranded breaks in the DNA chain. This results in activation of the cellular DNA Damage Response (DDR] pathway, which activates checkpoint inhibitor to control the progression through Gl to Synthesis (S phase] checkpoint and the G2 to mitosis checkpoint (M phase].

[044] The activated checkpoint kinases stall checkpoints, e.g. Chkl stalls the G2 /M checkpoint and the progression into mitosis so that DNA damage can be repaired ensuring that chromosomes are replicated and the mitochondrial spindle is correctly formed before progression into mitosis. Failure to control progression into and out of DNA synthesis and progression into mitosis results in improperly replicated DNA and improperly replicated human chromosomes. Cellular death induced by this mechanism is called replication and mitotic catastrophe and results in cellular apoptosis.

[045] The human protein E4F1 is a transcription factor and an atypical ubiquitin ligase. Conditional knockout of this gene in human cells results in; depressed levels of cellular pyrimidines, increased reactive oxygen species (ROS] and reduced protein and mRNA levels of CHK1 kinase.

[046] In p53 wildtype tumour cells E4F1 knock-out leads to cell cycle arrest mediated by p53 in order to allow the tumour cells sufficient time to repair DNA that has been damaged by reactive oxygen species before they progress into mitosis. However, in tumour cells that have inactivated the p53 gene via mutation of the gene sequence p53, or in tumour cells that have blocked p53 signalling via mutations that effect other members of the p53 pathway, knocking out the E4F1 gene leads to cell death via apoptosis. This results in cellular death via apoptosis as tumour cells are forced into mitosis before they can repair ROS damaged DNA.

[047] E4F1 knockout in tumour cells with p53 mutation results in synthetic and mitotic catastrophe and is a lethal phenotype. The present application contains new and surprising data showing that the E4F1 knockout lethal phenotype in p53 mutated tumours can be recapitulated synthetically by combining an inhibitor of dihydroorotate dehydrogenase (DHODH] and checkpoint kinase 1 (CHK1/ CHEK1] in a p53 mutated tumour. The synthetic lethality of the DHODH and CHK1 combination, for example in p53 mutated tumours, allows a 10 fold reduction in the therapeutic dose of the CHK1 inhibitor therefore reducing the extensive toxicity associated with this therapeutic modality. In addition, the combination of DHODH/ CHK1 inhibitor efficiently kill tumour cells that mutate p53. It is estimated that at least 50% of all solid and liquid tumours mutate p53.

[048] As discussed above a target patient population for the therapy according to the present disclosure is cancer patients with a mutated p53 gene. A mutated p53 gene as employed herein refers to non-native/non-natural/non-wild-type p53 gene. For example, inactivation of the p53 tumor suppressor is a frequent event in tumorigenesis. In many cases, the p53 gene is mutated, giving rise to a stable mutant protein whose accumulation is regarded as a hallmark of cancer cells. Mutant p53 proteins may not only lose their tumor suppressive activities but may gain additional oncogenic functions that endow cells with growth and survival advantages. Interestingly, mutations in the p53 gene have been shown to occur at different phases of the multistep process of malignant transformation, thus contributing differentially to tumor initiation, promotion, aggressiveness, and metastasis. [049] Checkpoint kinase inhibitor as employed herein refers to an inhibitor that reduces or eliminates the biological activity of a cell regulatory checkpoint kinase 1 and/or 2. Cells that suffer DNA damage activate the checkpoint kinases CHK1 and CHK2, which signal to initiate the DNA repair processes, limit cell-cycle progression and prevent cell replication, until the damaged DNA is repaired.

[050] Surprisingly a combination therapy of a DHODH and a checkpoint inhibitor provides effective treatment, in particular an effective cancer treatment The data generated by the inventors suggests the combination therapy is highly effective in treating cancer.

[051] In one embodiment a therapeutically effective amount of the DHODH inhibitor is administered. In one embodiment a therapeutically effective amount which is administered is approximately the same dose as employed in monotherapy of said DHODH inhibitor. In one embodiment a therapeutically effective amount is a dose which is less than a monotherapy of said DHODH inhibitor, for example 5, 10, 15, 20, 25, 30, 35, 40, 45 or 50% less than the dose for monotherapy. In one embodiment a therapeutically effective amount is a dose which is more than the dose employed for monotherapy, for example a dose which is 5, 10, 15, 20, 25, 30, 35, 40, 45 or 50% more than the dose for monotherapy. In particular at least the dose for monotherapy is employed for the DHODH inhibitor.

[052] A DHODH as employed herein refers to a compound which inhibits the activity of dihydroorotate dehydrogenase, in particular in vivo. Compounds disclosed herein in particular of formula (II] described above are examples of DHODH inhibitors. The latter compounds are disclosed in WO2008/077639, incorporated herein by reference.

[053] Other examples of DHODH inhibitor, which may be employed in the present disclosure include:

• teriflunomide which has the following structure:

and the compounds disclosed in WO97/34600 incorporated herein by reference;

• leflunomide which has the following structure:

the DHODH inhibitors of formula (1] disclosed in W099/45926 incorporated herein reference;

compounds of formula (I] disclosed in WO2003/006425 incorporated herein reference; • the DHODH inhibitors of formula (I] disclosed in W02004/056746 incorporated herein by reference;

• compounds of formula (I] disclosed in WO2006/022442 incorporated herein by reference;

• ML390;

• DHODH inhibitors disclosed in WO2015/155680 incorporated herein by reference; and

• DHODH inhibitors disclosed in WO2009/021696 incorporated herein by reference.

[054] Suitable salts of DHODH inhibitors include those disclosed in WO2010/102826, WO2010/10225 and WO2010/102824 each incorporated herein by reference.

[055] The following articles disclose various DHODH inhibitors and the compounds disclosed therein are incorporated herein by reference: European Journal of Medicinal Chemistry Volume 82, 23 July 2014, Pages 385-393 Design, synthesis and pharmacological evaluation of novel substituted quinoline-2-carboxamide derivatives as human dihydroorotate dehydrogenase (hDHODH] inhibitors and anticancer agents; November 1, 2002 The Journal of Biological Chemistry 277, 1827-41834; J. Med. Chem., 2013, 56 (8], pp 3148-3167.

[056] In one embodiment the DHODH inhibitor is selected from the group comprising teriflunomide, leflunomide a compound of formula (I] as defined above and as disclosed in WO2008/077639:

wherein the variables are defined above, or a pharmaceutically acceptable salt or a prodrug thereof. A prodrug is converted to an active form in vivo.

[057] In one embodiment there is a provided a compound of formula (I] with the proviso that, when at least one of the groups R^a and R^b represents a hydrogen atom and G² is a group CR^d, then R^d represents a group selected from C1- alkoxy which may be optionally substituted with 1, 2 or 3 substituents selected from halogen, hydroxy, C3.8 cycloalkoxy which may be optionally substituted with 1, 2 or 3 substituents selected from halogen and hydroxyl.

[058] In one embodiment the DHODH inhibitor is 2- (3, 5-difluoro-3'-methoxybiphenyl-4- ylamino] nicotinic acid (referred to herein as ASLAN003] or a pharmaceutically acceptable salt thereof, in particular:

[059] In one embodiment the DHODH inhibitor is not 2-(3, 5-difluoro-3'-methoxybiphenyl-4- ylamino] nicotinic acid (referred to herein as ASLAN003] or a pharmaceutically acceptable salt thereof, such as the meglumine salt thereof.

[060] In one embodiment the DHODH inhibitor is administered daily, for example once or twice daily, in particular twice daily.

[061] In one embodiment the DHODH inhibitor is administered orally.

[062] In one embodiment the checkpoint inhibitor (such as a checkpoint kinase inhibitor] is administered orally.

[063] In one embodiment the checkpoint inhibitor (such as a checkpoint kinase inhibitor] is administered intravenously.

[064] In one embodiment the checkpoint inhibitor (such as a checkpoint kinase inhibitor] is administered orally and the DHODH inhibitor is administered orally, for example co-formulated or provided as separate formulations.

[065] In one embodiment the checkpoint kinase inhibitor is administered intravenously and the DHODH inhibitor is administered orally.

[066] In one embodiment the DHODH inhibitor and checkpoint inhibitor (such as a checkpoint kinase inhibitor] are administered sequentially in a treatment regimen, for example are administered on the same day, for example within 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, or 24 hours of each other.

[067] In one embodiment the DHODH inhibitor and the checkpoint kinase inhibitors (are administered simultaneously, at approximately the same time.

[068] In one embodiment the DHODH inhibitor and checkpoint inhibitor (such as a checkpoint kinase inhibitor] are administered sequentially in a treatment regimen, for example are administered on different days, for example wherein both therapies are administered within the same 7 day period.

[069] In one embodiment the DHODH inhibitor is administered in a continuous treatment regimen.

[070] In one embodiment the DHODH inhibitor is administered in an intermittent treatment regimen, for example in treatment cycles, such as where each cycle in the range of 7 to 28 days.

[071] In one embodiment the checkpoint inhibitor (such as a checkpoint kinase inhibitor] is administered in a continuous treatment regimen. [072] In one embodiment the checkpoint inhibitor (such as a checkpoint kinase inhibitor] is administered in an intermittent treatment regimen, for example in treatment cycles, such as where each cycle in the range of 7 to 28 days.

[073] In one embodiment the DHODH inhibitor is administered in regimen that is daily or weekly for a continuous period of time, for example 1 to 60 months or more, and the checkpoint inhibitor (such as a checkpoint kinase inhibitor] is administered in regimen that is daily or weekly for a continuous period of time, for example 1 to 60 months or more.

[074] In one embodiment the DHODH inhibitor is administered in regimen that is daily or weekly for intermittent periods over, for example 1 to 60 months or more, and the checkpoint inhibitor (such as the checkpoint kinase inhibitor] is administered concomitantly with the DHODH inhibitor in a regimen that is daily or weekly for intermittent periods over, for example 1 to 60 months or more.

[075] Administered intermittently as employed herein refers to a period wherein the therapy is administered and then stopped with the option of starting the therapy again at some point in the future, for example 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 weeks of non-treatment may be between treatment cycles.

[076] In one embodiment the cancer is selected from liver cancer, biliary tract cancer, breast cancer (such as ER+ or non-ER+ breast cancer], prostate cancer, colorectal cancer, ovarian cancer, endometrial cancer, cervical cancer, lung cancer, gastric cancer, pancreatic, bone cancer, bladder cancer, head and neck cancer, thyroid cancer, skin cancer, renal cancer, oesophagus cancer, for example gastric cancer, hepatocellular carcinoma and cholangiocarcinoma, and cancers of the blood, such as sarcoma myeloma, leukemia, lymphoma and mixed liquid tumour phenotypes.

[080] In one embodiment the cancer is selected from and epithelial cancer, for example selected from the group comprising hepatocellular carcinoma, cholangiocarcinoma, breast cancer, prostate cancer, colorectal cancer, ovarian cancer, lung cancer, stomach cancer, pancreatic and oesophagus cancer.

[081] In one embodiment the cancer is selected from other than cancer forms where HER inhibition is effective.

[082] In one embodiment the patient is a human, for example an adult or a child.

[083] In one embodiment the combination therapy of the present disclosure is efficacious and, for example beneficial in that it provides augmented therapeutic activity in comparison to monotherapy comprising one of the components i.e. a checkpoint inhibitor.

[084] Augmented activity may be any beneficial therapeutic effect of employing the combination of the present disclosure, for example an increase in anti-tumor activity and/or a reduced propensity for the cancer to become resistant Other benefits may be therapeutic effect in patients who have failed one or more lines of therapy. Thus in one embodiment the patient population has a cancer that is resistant or refractory to known therapies, such as cytotoxic chemotherapy.

[085] Unless the context indicated otherwise refractory and resistant are used to interchangeably herein to refer to where the cancer does not respond to therapy or does not responds poorly to therapy.

[086] Combination therapy as employed herein refers to two or more modes of therapy being employing over the same treatment period, i.e. the opposite of sequential therapy. Combination therapy thus refers to where a medicament according to the present disclosure is administered in a treatment regimen along with at least one further therapeutic agent. The regime may be separate formulations administered at the same time or different times or co-formulations of the two or more therapeutic agents. The "first" medicament employed in the combination therapy according to the present disclosure may be administered; prior to the further therapeutic agent or agents, concomitant with the further therapeutic agent or agents, or after the further therapeutic agent or agents. More specifically combination therapy as employed herein, unless the context indicates otherwise, refers to a treatment regimen for a DHODH inhibitor and a checkpoint inhibitor (such as a CHK1, CHK2, ATR, ATM, Weel or PARP] which overlap, for example in time, in particular such that the pathological effects of each therapy in the combination have an opportunity to augment each other and be at least additive, and allowing the possibility for them to be synergistic.

[087] Thus to obtain the benefits of the combination therapy of the present disclosure the checkpoint inhibitor (such as a checkpoint kinase inhibitor] and the DHODH inhibitor have to be administered in a time frame, where the pharmacological effects of a checkpoint inhibitor (such as a checkpoint kinase inhibitor] and the DHODH inhibitor overlap, i.e. the treatment regimens for the said therapies partly coincide in time. A skilled person will understand in practice what this means.

[088] Two or more modes of therapy as employed herein refers to at least two therapies which have different modes of action and/or different activities and/or different routes of administration.

[089] In one embodiment further therapeutic agent or agents, such as an anti-cancer therapy are employed in combination with the therapy of the present disclosure.

[090] In one embodiment the combination therapy according to the present disclosure further comprises a RON inhibitor, for example as disclosed WO2008/058229, incorporated herein by reference. In one embodiment the combination therapy of the present disclosure comprises a checkpoint inhibitor, such as a CTLA4 inhibitor, a PD-1 inhibitor or a PD-L1 inhibitor, in particular an antibody or binding fragment thereof. Molecules such as PD-1 and PD-L1 are expressed on cell surfaces and are involve in signalling that downregulates immune responses to the cancer cell.

[091] In one embodiment the further therapeutic agent is a chemotherapeutic agent. Chemotherapeutic agent as employed herein is intended to refer to specific antineoplastic chemical agents or drugs that are destructive to malignant cells and tissues, including alkylating agents, antimetabolites, anthracyclines, plant alkaloids, topoisomerase inhibitors, and other antitumour agents. Specific examples of chemotherapy include doxorubicin, 5-fluorouracil (5-FU], gemcitabine, paclitaxel (for example abraxane or docetaxel], capecitabine, TSl, irinotecan, and platins, such as cisplatin and oxaliplatin or a combination thereof. A suitable dose may be chosen by the practitioner based on the nature of the cancer being treated and the patient. Chemotherapeutic agents are discussed in more detail below.

[092] Inhibitor as employed refers to the reduction of a relevant biological activity, for example by 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95 or 100%, such as when measured in a relevant in vitro assay.

[093] In one embodiment the DHODH inhibitor is a direct inhibitor. [094] In one embodiment the DHODH inhibitor is an indirect inhibitor.

[095] In one embodiment the checkpoint inhibitor (such as a checkpoint kinase inhibitor] is a direct inhibitor.

[096] In one embodiment the checkpoint inhibitor (such as a checkpoint kinase inhibitor] is a direct inhibitor.

[097] Direct inhibition is where the inhibitor binds directly to or physically blocks a binding interaction to inhibit a biological activity (including where the binding causes a conformational change in the polypeptide structure and reduces and eliminates binding of a ligand] or when the inhibitor inhibits the activation through phosphorylation of the target molecule, or the like.

[098] Indirect inhibition as employed herein refers to where the biological activity in question is inhibited as a result of directly inhibiting a target that is other than the entity that is indirectly inhibited, for example inhibiting a receptor by blocking a binding site in the ligand for said receptor.

[099] Dihydroorotate dehydrogenase (DHODH] is the enzyme that catalyzes the fourth step in the pyrimidine biosynthetic pathway namely the conversion of dihydroorotate to orotate concomitantly with an electron transfer to ubiquinone (cofactor Q] via a flavin mononucleotide intermediate (Loffler Mol Cell Biochem, 1997]. In contrast to parasites [Plasmodium falciparum) (McRobert et al Mol Biochem Parasitol 2002] and bacteria [E.coli) which exclusively have this de novo pathway as the source of pyrimidines, mammal cells have an additional salvage pathway.

[100] During homeostatic proliferation, the salvage pathway which is independent of DHODH seems sufficient for the cellular supply with pyrimidine bases. However in cells with a high turnover and particularly T and B lymphocytes the de novo pathway is required to proliferate. In these cells, DHODH inhibition stops the cell cycle progression by suppressing DNA synthesis and ultimately cell proliferation (Breedveld F.C. Ann Rheum Dis 2000].

[101] There are some suggestions that inhibition of mitochondrial cytochrome bcl, a component of the electron transport chain complex III, leads to activation of tumor suppressor p53, followed by apoptosis induction. The mitochondrial respiratory chain is coupled to the de novo pyrimidine biosynthesis pathway via the mitochondrial enzyme dihydroorotate dehydrogenase (DHODH]. The p53 activation has been shown to be triggered by the impairment of the de novo pyrimidine biosynthesis due to the suppression of DHODH.

[102] A checkpoint inhibitor as employed herein refers to an inhibitor of biological molecule or pathway in place to reduce the likelihood of a damaged cells (in particular a cell with damaged DNA] replicating. An inhibitor of at least checkpoint kinase 1 as employed herein refers to therapeutic agent, for example biological therapy or a "drug", which inhibits at least checkpoint kinase 1 but may also inhibit other entities, such as checkpoint kinase 2.

[103] A biological therapeutic is one based on a protein, for example an antibody or binding fragment thereof, including fusion proteins and biological molecules conjugated to a polymer, toxin or similar payload.

[104] A "drug" as employed herein refers to a chemical entity, organic chemistry molecule with pharmacological activity.

[105] Examples of pharmaceutically acceptable salts include but are not limited to acid addition salts of strong mineral acids such as HC1 and HBr salts and addition salts of strong organic acids, such as a methansulfonic acid salt, tosylates, furoates and the like, including di, tri salts thereof, such as ditosylates.

[106] In one embodiment the treatment of the present disclosure is administered for epithelial cancer, for example is selected from liver cancer (such as hepatocellular carcinoma], biliary tract cancer, breast cancer (such as ER+ or none ER+ breast cancer], prostate cancer, colorectal cancer, ovarian cancer, endometrial cancer, cervical cancer, lung cancer, gastric cancer, pancreatic cancer, bladder cancer, head and neck cancer, thyroid cancer, skin cancer, renal cancer, oesophagus cancer, or a cancer of the blood, such as sarcoma myeloma, leukemia, lymphoma, or bone cancer, and/or mixed liquid tumour phenotypes.

[107] In one embodiment the cancer is selected from the group comprising hepatocellular carcinoma, cholangiocarcinoma, breast cancer, prostate cancer, colorectal cancer, ovarian cancer, lung cancer, gastric cancer, pancreatic and oesophagus cancer.

[108] In one embodiment the cancer, such as the epithelial cancer is a carcinoma.

[109] In one embodiment the combination treatment according to the disclosure is adjuvant therapy, for example after surgery.

[110] In one embodiment the combination therapy according to the disclosure is neoadjuvant treatment, for example to shrink a tumour before surgery.

[Ill] In one embodiment the tumour is a solid tumour. In one embodiment the cancer is a primary cancer, secondary cancer, metastasis or combination thereof. In one embodiment the treatment according to the present disclosure is suitable for the treatment of secondary tumours. In one embodiment the cancer is metastatic cancer. In one embodiment the treatment according to the present disclosure is suitable for the treatment of primary cancer and metastases. In one embodiment the treatment according to the present disclosure is suitable for the treatment of secondary cancer and metastases. In one embodiment the treatment according to the present disclosure is suitable for the treatment of primary cancer, secondary cancer and metastases.

[112] In one embodiment the treatment according to the present disclosure is suitable for the treatment of cancerous cells in a lymph node, for example a cancer of the disclosed herein.

[113] In one embodiment the biliary duct cancer is in a location selected from intrahepatic bile ducts, left hepatic duct, right hepatic duct, common hepatic duct, cystic duct, common bile duct, Ampulla of Vater and combinations thereof. In one embodiment the biliary duct cancer is in an intrahepatic bile duct In one embodiment the biliary duct cancer is in a left hepatic duct. In one embodiment the biliary duct cancer is in a right hepatic duct. In one embodiment the biliary duct cancer is in a common hepatic duct. In one embodiment the biliary duct cancer is in a cystic duct In one embodiment the biliary duct cancer is in a common bile duct. In one embodiment the biliary duct cancer is in an Ampulla of Vater.

[114] In one embodiment the liver cancer is primary liver cancer. In one embodiment the liver cancer is secondary liver cancer. In one embodiment the liver cancer is stage 1, 2, 3A, 3B, 3C, 4A or 4B.

[115] In one embodiment the gastric cancer is stage 0, 1, II, III or IV. Cancer Types In more Detail

[116] In one embodiment the gastric cancer is selected from the group comprising adenocarcinoma of the stomach, squamous cell carcinomas, lymphoma of the stomach, gastric stromal tumor, and neuroendocrine tumors.

[117] In one embodiment the liver cancer is, for example selected from the group hepatocellular carcinoma, cholangiocarcinoma, angiosarcoma, and hepatoblastoma, in particular hepatocellular carcinoma. In one embodiment the primary liver cancer is stage 1, 2, 3 or 4. In one embodiment the liver cancer is secondary or metastasized liver cancer. In one embodiment liver cancer does not include cholangiocarcinoma.

[118] Prostate cancer as employed herein refers to cancer of the prostate, for example ductal adenocarcinoma, transitional cell (urothelial cancer], squamous cell cancer, carcinoid of the prostate, small cell cancer or sarcoma and sarcomatoid cancer.

[119] Pancreatic cancer as employed herein includes exocrine cancers (including rare forms thereof such as cystitic tumours, and cancer of the acinar cells], endocrine pancreatic tumours (including gastrinomas, insulinomas, somatostatinomas, VIPomas, glucagonomas], pancreatoblastoma, sarcomas of the pancreas and lymphoma.

[120] Biliary tract cancer as employed herein refers to cholangiocarcinoma (intrahepatic, extrahepatic], gall bladder cancer and ampullary carcinoma.

[121] Colorectal cancer as employed herein refers to cancer or the colon and/or rectum and includes squamous cell cancers, carcinoid tumours, sarcomas and lymphomas.

[122] Breast cancer as employed herein refers to cancer of the breast and includes ductal carcinoma in situ, lobular carcinoma in situ, invasive ductal breast cancer, invasive lobular breast cancer, invasive breast cancer, Paget's disease, angiosarcoma of the breast and rare types of breast cancer such as medullary breast cancer, mucinous breast cancer, tubular breast cancer, adenoid cystic carcinoma of the breast metaplastic breast cancer, basal type breast cancer and papillary breast cancer.

[123] Lung cancers are classified according to histological type and are categorized by the size and appearance of the malignant cells seen by a histopathologist under a microscope. For therapeutic purpose, two broad classes are distinguished: non-small cell lung carcinoma and small cell lung carcinoma.

[124] In one embodiment the epithelial cancer is lung cancer, for example small-cell lung cancer (SCLC] and non-small-cell lung cancer (NSCLC].

[125] Non-small-cell lung carcinoma-The three main subtypes of NSCLC are adenocarcinoma, squamous-cell carcinoma and large-cell carcinoma.

[126] Nearly 40% of lung cancers are adenocarcinoma, which usually originates in peripheral lung tissue. A subtype of adenocarcinoma, the bronchioloalveolar carcinoma, is more common in female never-smokers, and may have a better long term survival.

[127] Squamous-cell carcinoma accounts for about 30% of lung cancers. They typically occur close to large airways. A hollow cavity and associated cell death are commonly found at the center of the tumor. About 9% of lung cancers are large-cell carcinoma. These are so named because the cancer cells are large, with excess cytoplasm, large nuclei and conspicuous nucleoli. [128] Small-cell lung carcinoma-In small-cell lung carcinoma (SCLC], the cells contain dense neurosecretory granules (vesicles containing neuroendocrine hormones], which give this tumor an endocrine/paraneoplastic syndrome association. Most cases arise in the larger airways (primary and secondary bronchi]. These cancers grow quickly and spread early in the course of the disease. Sixty to seventy percent have metastatic disease at presentation. In one embodiment the cancer is non-small lung carcinoma.

[129] In one embodiment the cancer is liver cancer, for example a liver metastasis from a primary cancer, for example colon cancer, which has spread to the liver. In one embodiment the liver cancer is HCC (hepatocellular carcinoma].

[130] In one embodiment there is provided treatment of renal cancer, for example renal cell carcinoma and/or urothelial cell carcinoma. Other examples of renal cancer include squamous cell carcinoma, juxtaglomerular cell tumor (reninoma], angiomyolipoma, renal oncocytoma, Bellini duct carcinoma, clear-cell sarcoma of the kidney, mesoblastic nephroma, Wilms' tumor, mixed epithelial stromal tumor, clear cell adenocarcinoma, transitional cell carcinoma, inverted papilloma, renal lymphoma, teratoma, carcinosarcoma, and carcinoid tumor of the renal pelvis.

[131] In one embodiment the cancer is bladder cancer, for example is any of several types of malignancy arising from the epithelial lining (i.e., the urothelium] of the urinary bladder. About 90% of bladder cancers are transitional cell carcinoma. The other 10% are squamous cell carcinoma, adenocarcinoma, sarcoma, small cell carcinoma, and secondary deposits from cancers elsewhere in the body. The staging of is given below.

[132] T (Primary tumour) TX Primary tumour cannot be assessed; TO No evidence of primary tumour; Ta Non-invasive papillary carcinoma; Tis Carcinoma in situ ('flat tumour']; Tl Tumour invades subepithelial connective tissue; T2a Tumour invades superficial muscle (inner half); T2b Tumour invades deep muscle (outer half); T3 Tumour invades perivesical tissue; T3a Microscopically; T3b Macroscopically (extravesical mass]; T4a Tumour invades prostate, uterus or vagina; T4b Tumour invades pelvic wall or abdominal wall.

[133] N (Lymph nodes) NX Regional lymph nodes cannot be assessed; NO No regional lymph node metastasis; Nl Metastasis in a single lymph node 2 cm or less in greatest dimension; N2 Metastasis in a single lymph node more than 2 cm but not more than 5 cm in greatest dimension, or multiple lymph nodes, none more than 5 cm in greatest dimension; N3 Metastasis in a lymph node more than 5 cm in greatest dimension.

[134] M (Distant metastasis) MX Distant metastasis cannot be assessed; MO No distant metastasis; Ml Distant metastasis.

[135] The current disclosure extends to any stage of bladder cancer.

[136] There are more than 30 different types of ovarian cancer which are classified according to the type of cell from which they start Cancerous ovarian tumors can start from three common cell types: Surface Epithelium - cells covering the lining of the ovaries; Germ Cells - cells that are destined to form eggs; and Stromal Cells - Cells that release hormones and connect the different structures of the ovaries

[137] The present disclosure relates to treatment of ovarian cancer from any source, for example as described herein, in particular epithelium cells. Epithelial ovarian carcinomas (EOCs] account for 85 to 90 percent of all cancers of the ovaries. [138] Common Epithelial Tumors - Epithelial ovarian tumors develop from the cells that cover the outer surface of the ovary. Most epithelial ovarian tumors are benign (noncancerous]. There are several types of benign epithelial tumors, including serous adenomas, mucinous adenomas, and Brenner tumors. Cancerous epithelial tumors are carcinomas - meaning they begin in the tissue that lines the ovaries. These are the most common and most dangerous of all types of ovarian cancers. Unfortunately, almost 70 percent of women with the common epithelial ovarian cancer are not diagnosed until the disease is advanced in stage.

[139] There are some ovarian epithelial tumors whose appearance under the microscope does not clearly identify them as cancerous. These are called borderline tumors or tumors of low malignant potential (LMP tumors]. The method of the present disclosure includes treatment of the latter.

[140] Germ Cell Tumors - Ovarian germ cell tumors develop from the cells that produce the ova or eggs. Most germ cell tumors are benign (non-cancerous], although some are cancerous and may be life threatening. The most common germ cell malignancies are maturing teratomas, dysgerminomas, and endodermal sinus tumors. Germ cell malignancies occur most often in teenagers and women in their twenties. Today, 90 percent of patients with ovarian germ cell malignancies can be cured and their fertility preserved.

[141] Stromal Tumors - Ovarian stromal tumors are a rare class of tumors that develop from connective tissue cells that hold the ovary together and those that produce the female hormones, estrogen and progesterone. The most common types are granulosa-theca tumors and Sertoli- Leydig cell tumors. These tumors are quite rare and are usually considered low-grade cancers, with approximately 70 percent presenting as Stage I disease (cancer is limited to one or both ovaries].

[142] Primary Peritoneal Carcinoma-The removal of one's ovaries eliminates the risk for ovarian cancer, but not the risk for a less common cancer called Primary Peritoneal Carcinoma. Primary Peritoneal Carcinoma is closely rated to epithelial ovarian cancer (most common type]. It develops in cells from the peritoneum (abdominal lining] and looks the same under a microscope. It is similar in symptoms, spread and treatment.

Stages of Ovarian Cancer

[143] Once diagnosed with ovarian cancer, the stage of a tumor can be determined during surgery, when the doctor can tell if the cancer has spread outside the ovaries. There are four stages of ovarian cancer - Stage I (early disease] to Stage IV (advanced disease]. The treatment plan and prognosis (the probable course and outcome of your disease] will be determined by the stage of cancer.

[144] Following is a description of the various stages of ovarian cancer:

Stage I - Growth of the cancer is limited to the ovary or ovaries.

Stage IA - Growth is limited to one ovary and the tumor is confined to the inside of the ovary.

There is no cancer on the outer surface of the ovary. There are no ascites present containing malignant cells. The capsule is intact

Stage IB - Growth is limited to both ovaries without any tumor on their outer surfaces. There are no ascites present containing malignant cells. The capsule is intact. Stage IC - The tumor is classified as either Stage IA or IB and one or more of the following are present: (1] tumor is present on the outer surface of one or both ovaries; (2] the capsule has ruptured; and (3] there are ascites containing malignant cells or with positive peritoneal washings.

Stage II - Growth of the cancer involves one or both ovaries with pelvic extension.

Stage IIA - The cancer has extended to and/or involves the uterus or the fallopian tubes, or both.

Stage IIB - The cancer has extended to other pelvic organs.

Stage IIC - The tumor is classified as either Stage IIA or IIB and one or more of the following are present: (1] tumor is present on the outer surface of one or both ovaries; (2] the capsule has ruptured; and (3] there are ascites containing malignant cells or with positive peritoneal washings.

Stage III - Growth of the cancer involves one or both ovaries, and one or both of the following are present: (1] the cancer has spread beyond the pelvis to the lining of the abdomen; and (2] the cancer has spread to lymph nodes. The tumor is limited to the true pelvis but with histologically proven malignant extension to the small bowel or omentum.

Stage IIIA - During the staging operation, the practitioner can see cancer involving one or both of the ovaries, but no cancer is grossly visible in the abdomen and it has not spread to lymph nodes. However, when biopsies are checked under a microscope, very small deposits of cancer are found in the abdominal peritoneal surfaces.

Stage IIIB - The tumor is in one or both ovaries, and deposits of cancer are present in the abdomen that are large enough for the surgeon to see but not exceeding 2 cm in diameter. The cancer has not spread to the lymph nodes.

Stage IIIC - The tumor is in one or both ovaries, and one or both of the following is present: (1] the cancer has spread to lymph nodes; and/or (2] the deposits of cancer exceed 2 cm in diameter and are found in the abdomen.

Stage IV - This is the most advanced stage of ovarian cancer. Growth of the cancer involves one or both ovaries and distant metastases (spread of the cancer to organs located outside of the peritoneal cavity] have occurred. Finding ovarian cancer cells in pleural fluid (from the cavity which surrounds the lungs] is also evidence of stage IV disease.

[145] In one embodiment the ovarian cancer is: type I, for example IA, IB or IC; type II, for example IIA, IIB or IIC; type III, for example IIIA, IIIB or IIIC; or type IV.

[146] In one embodiment the breast cancer is one selected from the group comprising ductal carcinoma in situ, lobular carcinoma in situ, invasive breast cancer, invasive lobular breast cancer, Paget's disease, angiosarcoma of the breast, medulllary breast cancer, mucinous breast cancer, tubular breast cancer, adenoid cystic carcinoma of the breast, metaplastic breast cancer, lymphoma of the breast, basal type breast cancer, phyllodes or cystosarcoma phyllodes, papillary breast cancer and a combination of two or more of the same.

[147] In one embodiment the prostate cancer is selected from the group comprising ductal adenocarcinoma, transitional cell (urothelial] cancer, squamous cell cancer, carcinoid, small cell cancer, sarcomas and sarcomatoid cancers and a combination of two or more of the same.

[148] Thyroid cancer as employed herein refers to cancer of the thyroid originating from follicular or parafollicular thyroid cells and includes papillary thyroid cancer (75% to 85% of cases]; follicular thyroid cancer (10% to 20% of cases]; medullary thyroid cancer (5% to 8% of cases]- cancer of the parafollicular cells, often part of multiple endocrine neoplasia type 2; poorly differentiated thyroid cancer; anaplastic thyroid cancer (less than 5% of cases] is not responsive to treatment and can cause pressure symptoms, thyroid lymphoma, squamous cell thyroid carcinoma, sarcoma of thyroid.

[149] Esophageal cancer as employed herein refers to cancer of the oesphagus including esophageal squamous-cell carcinomas, esophageal adenocarcinomas, and variants of squamous- cell carcinoma, and non-epithelial tumors, such as leiomyosarcoma, malignant melanoma, rhabdomyosarcoma, lymphoma, among others and a combination of two or more of the same.

[150] Head and neck cancer as employed herein refers to cancer of the neck and/or head, including mouth cancer, nasopharyngeal cancer, oropharyngeal cancer, paranasal sinus cancer, salivary gland cancer and a combination of two or more of the same.

Chemotherapeutic Agents

[151] The combination therapy of the present disclosure may be employed in combination with a further cancer therapy, for example chemotherapy. Chemotherapeutic agent and chemotherapy or cytotoxic agent are employed interchangeably herein unless the context indicates otherwise.

[152] Chemotherapy as employed herein is intended to refer to specific antineoplastic chemical agents or drugs that are "selectively" destructive to malignant cells and tissues, for example alkylating agents, antimetabolites including thymidylate synthase inhibitors, anthracyclines, anti- microtubule agents including plant alkaloids, topoisomerase inhibitors, parp inhibitors and other antitumour agents. Selectively in this context is used loosely because of course many of these agents have serious side effects.

[153] The preferred dose may be chosen by the practitioner, based on the nature of the cancer being treated.

[154] Examples of alkylating agents, which may be employed in the method of the present disclosure include an alkylating agent nitrogen mustards, nitrosoureas, tetrazines, aziridines, platins and derivatives, and non-classical alkylating agents.

[155] Examples of a platinum containing chemotherapeutic agent (also referred to as platins], include cisplatin, carboplatin, oxaliplatin, satraplatin, picoplatin, nedaplatin, triplatin and lipoplatin (a liposomal version of cisplatin], in particular cisplatin, carboplatin and oxaliplatin.

[156] The dose for cisplatin ranges from about 20 to about 270 mg/m² depending on the exact cancer. Often the dose is in the range about 70 to about 100mg/m².

[157] Nitrogen mustards include mechlorethamine, cyclophosphamide, melphalan, chlorambucil, ifosfamide and busulfan.

[158] Nitrosoureas include N-Nitroso-N-methylurea (MNU], carmustine (BCNU], lomustine (CCNU] and semustine (MeCCNU], fotemustine and streptozotocin. Tetrazines include dacarbazine, mitozolomide and temozolomide.

[159] Aziridines include thiotepa, mytomycin and diaziquone (AZQ].

[160] Examples of antimetabolites, which may be employed in the method of the present disclosure, include anti-folates (for example methotrexate and pemetrexed], purine analogues (for example thiopurines, such as azathiopurine, mercaptopurine, thiopurine, fludarabine (including the phosphate form], pentostatin and cladribine], pyrimidine analogues (for example fluoropyrimidines, such as 5-fluorouracil and prodrugs thereof such as capecitabine [Xeloda®]], floxuridine, gemcitabine, cytarabine, decitabine, raltitrexed(tomudex] hydrochloride, cladribine and 6-azauracil, in particular capecitabine.

[161] Examples of anthracyclines, which may be employed in the method of the present disclosure, include daunorubicin (Daunomycin], daunorubicin (liposomal], doxorubicin (Adriamycin], doxorubicin (liposomal], epirubicin, idarubicin, valrubicin currenlly used only to treat bladder cancer and mitoxantrone an anthracycline analog, in particular doxorubicin.

[162] Examples of anti-microtubule agents, which may be employed in the method of the present disclosure, include include vinca alkaloids and taxanes.

[163] Vinca alkaloids include completely natural chemicals for example vincristine and vinblastine and also semi-synthetic vinca alkaloids, for example vinorelbine, vindesine, and vinflunine.

[164] Taxanes include paclitaxel, docetaxel, abraxane, carbazitaxel and derivatives of thereof. Derivatives of taxanes as employed herein includes reformulations of taxanes like taxol, for example in a micelluar formulations, derivatives also include chemical derivatives wherein synthetic chemistry is employed to modify a starting material which is a taxane.

[165] Topoisomerase inhibitors, which may be employed in a method of the present disclosure include type I topoisomerase inhibitors, type II topoisomerase inhibitors and type II topoisomerase poisons. Type I inhibitors include topotecan, irinotecan, indotecan and indimitecan. Type II inhibitors i ich has the following structure:

[166] Type II poisons include amsacrine, etoposide, etoposide phosphate, teniposide and doxorubicin and fluoroquinolones.

[167] In one embodiment a combination of chemotherapeutic agents employed is, for example a platin and 5-FU or a prodrug thereof, for example cisplatin or oxaplatin and capecitabine or gemcitabine, such as FOLFOX.

[168] In one embodiment the chemotherapy comprises a combination of chemotherapy agents, in particular cytotoxic chemotherapeutic agents.

[169] In one embodiment the chemotherapy combination comprises a platin, such as cisplatin and fluorouracil or capecitabine.

[170] In one embodiment the chemotherapy combination in capecitabine and oxaliplatin (Xelox].

[171] In one embodiment the chemotherapy is a combination of folinic acid and 5-FU, optionally in combination with oxaliplatin.

[172] In one embodiment the chemotherapy is a combination of folinic acid, 5-FU and irinotecan (FOLFIRI], optionally in combination with oxaliplatin (FOLFIRINOX]. The regimen consists of: irinotecan (180 mg/m² IV over 90 minutes] concurrently with folinic acid (400 mg/m² [or 2 x 250 mg/m²] IV over 120 minutes]; followed by fluorouracil (400-500 mg/m² IV bolus] then fluorouracil (2400-3000 mg/m² intravenous infusion over 46 hours]. This cycle is typically repeated every two weeks. The dosages shown above may vary from cycle to cycle.

[173] In one embodiment the combination employs a microtubule inhibitor, for example vincristine sulphate, epothilone A, N- [2-[(4-Hydroxyphenyl]amino]-3-pyridinyl]-4- methoxybenzenesulfonamide (ABT-751], a taxol derived chemotherapeutic agent, for example paclitaxel, abraxane, or docetaxel or a combination thereof.

[174] In one embodiment the combination employs an mTor inhibitor. Examples of mTor inhibitors include: everolimus (RAD001], WYE-354, KU-0063794, papamycin (Sirolimus], Temsirolimus, Deforolimus (MK-8669), AZD8055 and BEZ235(NVP-BEZ235).

[175] In one embodiment the combination employs a MEK inhibitor. Examples of MEK inhibitors include: AS703026, CI-1040 (PD184352), AZD6244 (Selumetinib], PD318088, PD0325901, AZD8330, PD98059, U0126-EtOH, BIX 02189 or BIX 02188.

[176] In one embodiment the combination employs an AKT inhibitor. Examples of AKT inhibitors include: MK-2206 and AT7867.

[177] In one embodiment the combination employs an aurora kinase inhibitor. Examples of aurora kinase inhibitors include: Aurora A Inhibitor I, VX-680, AZD1152-HQPA (Barasertib], SNS- 314 Mesylate, PHA-680632, ZM-447439, CCT129202 and Hesperadin.

[178] In one embodiment combination employs a p38 inhibitor, for example as disclosed in WO2010/038086, such as N [4-({4-[3-(3-tert-Butyl-l-p-tolyl-lH-pyrazol-5-yl]ureido]naphthalen- l-yloxy}methyl]pyridin-2-yl]-2-methoxyacetamide.

[179] In one embodiment the combination employs a pi3K inhibitor, for example selected from dactolisib, pictilisib, LY294002, idelalsib, buparlisib, autophinib, serabelisib, IP1-549, SF2534, GDC-0326, SAR405, TGR-1202, VPS34, GSK2269557, 740 Y-P, PI-103, NU7441, TGX-221, IC- 87114, wormannin, XL147 analogue, ZSTK474, alpelisib, AS-605240, PIK-75, 3-methyladenine, A66, voxtalisib, PIK-93, AZD6482, PF-04691502, apitolisib, GSK105965, duvelisib, TG100-115, AS- 252424, BGT226, CUDU-907, PIK-294, AS-604850, GSK2636771, copanlisib, YM201636, CH5132799, CAY10505, PIK-293, TG100713, VS-5584, taselisib, CZC24832, AMG319, GSK2292767, GDC-0084, HS-173, quercetin, voxtalisib, GNE-317, LY3023414, VPS34-IN1, PIK-III, PI-3065, pilaralisib, AZD8835, PF-4989216 and AZD8186.

[180] In one embodiment the combination employs a Bcl-2 inhibitor. Examples of Bcl-2 inhibitors include: obatoclax mesylate, ABT-737, ABT-263(navitoclax] and TW-37.

[181] In one embodiment the chemotherapy combination comprises an antimetabolite such as capecitabine (xeloda], fludarabine phosphate, fludarabine (fludara], decitabine, raltitrexed (tomudex], gemcitabine hydrochloride and cladribine.

[182] In one embodiment the chemotherapy combination comprises ganciclovir, which may assist in controlling immune responses and/or tumour vasculation.

[183] In one embodiment the chemotherapy is combined with a PARP inhibitor.

[184] In one embodiment one or more therapies employed in the method herein are metronomic, that is a continuous or frequent treatment with low doses of anticancer drugs, often given concomitant with other methods of therapy. [185] In one embodiment, there is provided the use of multiple cycles of treatment (such as chemotherapy] for example 2, 3, 4, 5, 6, 7, 8.

[186] In one embodiment the combination of the present disclosure is employed after chemotherapy.

[187] In one embodiment the combination therapy of the present disclosure is employed before chemotherapy.

[188] In one embodiment the dose of chemotherapy employed in the combination therapy of the present disclosure is lower than the dose of chemotherapy employed in "monotherapy" (where monotherapy may include the dose of chemotherapy employed when combinations of chemotherapy agents are employed].

[189] In one embodiment the medicament is administered in combination with therapy complimentary to the cancer therapy, for example a treatment for cachexia, such as cancer cachexia, for example S-pindolol, S-mepindolol or S-bopindolol. Suitable doses may be in the range of 2.5mg to lOOmg, such as 2.5mg to 50mg per day provided a single dose or multiple doses given as multiple doses administered during the day.

Treatment

[190] Treatment as employed herein refers to where the patient has a disease or disorder, for example cancer and the medicament according to the present disclosure is administered to stabilise the disease, delay the disease, amelorate the disease, send the disease into remission, maintain the disease in remission or cure the disease. Treating as employed herein includes administration of a medicament according to the present disclosure for treatment or prophylaxis.

[191] The present disclosure is explained in the context of a method of treating a patients. However, the disclosure extends to use of the combination therapy as described herein for use in treatment, in particular for the treatment of cancer, such as a cancer described herein. Also provided is use of the combination of compounds as described herein for the manufacture of a medicament for the treatment of cancer, in particular a cancer described herein.

[192] In one embodiment the combination therapy according to the present disclosure is employed as cancer adjuvant therapy, for example after surgery to remove some or all of the cancerous cells.

[193] In one embodiment the combination according to the present disclosure is employed as neoadjuvant therapy, for example before surgery to remove some or all of the cancerous cells.

[194] In one embodiment a therapeutically effective dose (such as a daily dose] of a DHODH inhibitor is in the range lOmg to lOOOmg, for example 50 to 500mg, such as 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 150, 200, 250, 300, 350, 400, 450, 500 mg, in particular administered once or twice a day, such as twice daily.

[195] In the context of this specification "comprising" is to be interpreted as "including". Embodiments of the invention comprising certain features/elements are also intended to extend to alternative embodiments "consisting" or "consisting essentially" of the relevant elements/features. Where technically appropriate, embodiments of the invention may be combined. Technical references such as patents and applications are incorporated herein by reference. Any embodiments specifically and explicitly recited herein may form the basis of a disclaimer either alone or in combination with one or more further embodiments. Headings herein are employed to divide the document into sections and are not intended to be used to construe the meaning of the disclosure provided herein.

The present invention is further described by way of illustration only in the following examples.

BRIEF SUMMARY OF THE FIGURES

Figure 1 Schematic showing DNA damage response pathway. Extract from Array

BioPharma presentation entitled Preclinical Characterisation of ARRY-575 Figure 2 Flow diagram showing effect of E4F1 knockout in (A) p53 wild type cells and

(B) p53 mutant cells (i.e. tumour cells)

Figure 3 Schematic showing proposed strategy for inducing E4Fl-like synthetic lethality in cancer cells

Figures 4A to I show body weight of animals treated. (A) Combination treatment of ASLAN003

(100 mg/kg BID] and AZD7762 (25 mg/kg Q2D] or LY2606368 (Prexasertib] (10 mg/kg BID], (B) Combination treatment of ASLAN003 (100 mg/kg BID] and AZD7762 (25 mg/kg Q2D), (C) Combination treatment of ASLAN003 (100 mg/kg BID] and Prexasertib (10 mg/kg BID), (D) Monotherapy treatment with Prexasertib at different dosages, (E) Combination treatment of ASLAN003 (100 mg/kg QD) or ASLAN003 (10 mg/kg QD) and Prexasertib (10 mg/kg BID), (F) Combination treatment of ASLAN003 (100 mg/kg BID) and Prexasertib (3 mg/kg BID), (G) Combination treatment of ASLAN003 (100 mg/kg BID) and Prexasertib (1 mg/kg BID), (H) Consolidated data, (I) a different plot of body weight of same mice treated over time. .

Figures 5A to I show tumor volumes (mm³) of tumors excised from treated mice. (A)

Combination treatment of ASLAN003 (100 mg/kg BID) and AZD7762 (25 mg/kg Q2D) or Prexasertib (10 mg/kg BID), (B) Combination treatment of ASLAN003 (100 mg/kg BID) and AZD7762 (25 mg/kg Q2D), (C) Combination treatment of ASLAN003 (100 mg/kg BID) and Prexasertib (10 mg/kg BID), (D) Monotherapy treatment with Prexasertib at different dosages, (E) Combination treatment of ASLAN003 (100 mg/kg QD) or ASLAN003 (10 mg/kg QD) and Prexasertib (10 mg/kg BID), (F) Combination treatment of ASLAN003 (100 mg/kg BID) and Prexasertib (3 mg/kg BID), (G) Combination treatment of ASLAN003 (100 mg/kg BID) and Prexasertib (1 mg/kg BID), (H) Combination treatment of ASLAN003 100 mg/kg BID) and Prexasertib (0.3 mg/kg BID) (I) Consolidated data

Figures 6A to H show images of tumors excised from treated mice. (A) Combination treatment of ASLAN003 (100 mg/kg BID) and AZD7762 (25 mg/kg Q2D) or Prexasertib (10 mg/kg BID), (B) Combination treatment of ASLAN003 (100 mg/kg BID) and AZD7762 (25 mg/kg Q2D), (C) Combination treatment of ASLAN003 (100 mg/kg BID) and Prexasertib (10 mg/kg BID), (D) Monotherapy treatment with Prexasertib at different dosages, (E) Combination treatment of ASLAN003 (100 mg/kg QD) or ASLAN003 (10 mg/kg QD) and Prexasertib (10 mg/kg BID), (F) Combination treatment of ASLAN003 (100 mg/kg BID) and Prexasertib (3 mg/kg BID), (G) Combination treatment of ASLAN003 (100 mg/kg BID) and Prexasertib (1 mg/kg BID), (H) Consolidated data

Figures 7 A to I show tumor weight in mg of tumors excised from treated mice. (A) Combination treatment of ASLAN003 (100 mg/kg BID) and AZD7762 (25 mg/kg Q2D) or Prexasertib (10 mg/kg BID), (B) Combination treatment of ASLAN003 (100 mg/kg BID) and AZD7762 (25 mg/kg Q2D), (C) Combination treatment of ASLAN003 (100 mg/kg BID) and Prexasertib (10 mg/kg BID), (D) Monotherapy treatment with Prexasertib at different dosages, (E) Combination treatment of ASLAN003 (100 mg/kg QD) or ASLAN003 (10 mg/kg QD) and Prexasertib (10 mg/kg BID), (F) Combination treatment of ASLAN003 (100 mg/kg BID) and Prexasertib (3 mg/kg BID), (G) Combination treatment of ASLAN003 (100 mg/kg BID) and Prexasertib (1 mg/kg BID), (H) Combination treatment of ASLAN003 100 mg/kg BID) and Prexasertib (0.3 mg/kg BID) (I) Consolidated data

Figure 8 (A) Microscopy images of p-H3 stained HCC tumours showing mitotic catastrophe induced with combination treatment of ASLAN003 (lOOmg/kg BID) and Prexasertib (10 mg/kg BID). (B) Graph showing percentage of cells among 500 cells per region staining positive for p-H3 in tumours treated with ASLAN003 lOOmg/kg BID and Prexasertib 10 mg/kg BID (C) Graph showing percentage of cells among 500 cells per region staining positive for p-H3 in tumours treated with ASLAN003 and Prexasertib at different doses

ABBREVIATIONS

BID Dose is administered twice a day

QD Dose is administered once a day

Q2D Dose is administered once every 2 days.

Example 1 - Animal model studies

A murine HCC xenograft model [Cancer Res August 1, 2015; 752674 (AACR Abstract 2674): Activity of BAY1082439, a balanced PI3Ka/b inhibitor, in gastric cancer Huynh T. Hung, Richard Ong, Katja Haike, Elissaveta Petrova, Mei Ling Chong, Marie Loh, Bhaskar Bhattacharya, Richie Soong and Ningshu Liu.] was used (as opposed to a gastric cancer cell line) to evaluate the combination therapy of the DHODH inhibitor is 2-(3,5-difluoro-3'-methoxybiphenyl-4- ylamino)nicotinic acid (ASLAN003) and a checkpoint kinase (CHK1) inhibitor selected from AZD7762 and LY2606368 (Prexasertib).

The dose of ASLAN003 was either 10 mg/kg BID, 30 mg/kg BID or lOOmg/Kg BID, 10 mg/kg QD or 100 mg/kg QD(oral gavage administration).

The dose of AZD7762 was 25mg/Kg Q2D (intravenous administration).

The dose of LY2606368 (Prexasertib) was either 0.3 mg/kg BID, 1 mg/kg BID, 3 mg/kg BID or lOmg/Kg BID for three days, followed by four days of rest (subcutaneous administration).

The following treatment combinations were tested in 2 separate experiments: Ex eriment 1

Group 1 in each experiment was a negative control wherein the mice were treated with a vehicle alone. Each group consists of 5 mice (n=10 or 5 mice with 2 flanks]. For both experiments, treatments commenced when the tumours reached a size of approximately 100-150 mm³. Bi- dimensional measurements were performed twice a week and tumor volumes were calculated based on the following formula: Tumor volume = [(Length] x (Width²] x (π/6]]. The data was plotted as means and standard errors for each treatment group versus time. Mice body weight was also monitored throughout the treatment process. At the end of the study, the mice were sacrificed and tumor samples were collected.

The results are shown in Figures 4 to 7. In all of the groups tested, tumour volume and tumour weight was decreased more significantly when a combination of ASLAN003 and a CHKl inhibitor was used, compared to the same dosage of either ASLAN003 alone or CHKl inhibitor alone.

EXAMPLE 2 - Mitotic Catastrophe studies

6 tumour slides per treatment group (3 tumors from 3 independent mice per treatment and 2 slides per tumor] were stained with phosphohistone-H3 (SerlO]. Figure 8A shows phosphohistone-H3 (p-H3] staining images from the p53 mutant HCC tumours treated with ASLAN003 alone, CHKl inhibitor (Prexasertib] alone and when ASLAN003 and CHKl inhibitor are administered in combination. p-H3 stains mitotic figures from early prophase through metaphase, anaphase and telophase. As can be seen, there is a significantly increased staining in the sample treated with the ASLAN003 and CHKl inhibitor combination compared to the other samples. For the quantitation of mitotic catastrophe, the number of p-H3 positive cells among at least 500 cells per region was counted and expressed as percentage values. Figure 8B shows the quantitative data of Figure 8A, whilst Figure 8C shows the quantitative data from experiments conducted on tumors excised from mice that were treated with other treatment combinations. The raw data is also shown below in Table 1.

Table 1 - % of mitotic catastrophic positive cells following various treatments

The results above provide evidence that a greater number of the tumour cells treated with the ASLAN003 and CHKl inhibitor combination were forced into mitosis, i.e. mitotic catastrophe, than when either ASLAN003 or CHKl inhibitor were used alone.

In conclusion, the above results demonstrate conclusively that the combination of ASLAN003 and CHKl inhibitors can act synergistically to induce synthetic lethality in p53 mutant HCC. The combination of ASLAN003/CHK1 in the clinical setting would allow a 10-fold reduction in the dose of the CHKl drug whilst giving enhanced induction of mitotic catastrophe and tumour killing. This in effect means that enhanced tumour killing can be achieved with a lower dosage of CHKl inhibitor, reducing treatment costs and side effects typically associated with high dosages.

Claims

Claims

1. A method of treating a cancer patient comprising administering a therapeutically effect

amount of a DHODH inhibitor and a therapeutically effective amount of a checkpoint inhibitor, such as a checkpoint kinase inhibitor.

2. A method according to claim 1, wherein the cancer is an epithelial cancer.

3. A method according to claim 2, wherein the epithelial cancer is selected from liver cancer (such as hepatocellular carcinoma], biliary tract cancer, breast cancer (such as non-ER+ breast cancer, in particular double negative breast cancer ], prostate cancer, colorectal cancer, ovarian cancer, endometrial cancer, cervical cancer, lung cancer, gastric cancer, pancreatic, bone cancer, bladder cancer, head and neck cancer, thyroid cancer, skin cancer, renal cancer, and oesophagus cancer, for example gastric cancer

4. A method according to claim 3, wherein the cancer is selected from the group comprising liver cancer (such as hepatocellular carcinoma], breast cancer, biliary duct cancer prostate cancer, colorectal cancer, bladder cancer, ovarian cancer, endometrial cancer, lung cancer, gastric cancer, oesophageal cancer, kidney cancer, head and neck cancers and combinations thereof.

5. A method according to claim 4, wherein the cancer is selected from hepatocellular carcinoma, breast cancer, biliary duct cancer and gastric cancer.

6. A method according to any one of claims 1 to 5, wherein the DHODH inhibitor is selected from the group comprisinga compound of formula (I]:

wherein:

one of the groups G¹ represents a nitrogen atom or a group CR^C and the other group represents CR^C;

G² represents a nitrogen atom or a group CR^d;

R¹ represents a group selected from hydrogen, halogen, C1.4 alkyl which may be optionally substituted with 1, 2 or 3 substituents selected from the group comprising halogen, hydroxy, and C3-8 cycloalkyl which may be optionally substituted with 1, 2 or 3 substituents selected from halogen and hydroxyl;

R² represents a group selected from hydrogen, halogen, hydroxyl, C1-4 alkyl which may be optionally substituted by 1, 2 or 3 substituents selected from the group comprising halogen, hydroxy, C3-8 alkyl which may be optionally substituted with 1, 2, or 3 substituents selected from halogen and hydroxyl;

R^a, R^b and R^c independently represent a radical selected from the group comprising hydrogen, halogen, C1-4 alkyl optionally substituted by 1, 2 or 3 substituents selected from the group comprising halogen, hydroxy and C1-4 alkoxy;

R^d represents a group selected from hydrogen, halogen, hydroxyl, C1-4 alkyl which may be substituted by 1, 2 or 3 substituents selected from the group comprising halogen, hydroxyl, C1-4 alkoxy which may be optionally substituted with 1, 2 or 3 substituent selected from the group comprising halogen, hydroxy, and C3.8 cycloalkoxy which may be optionally substituted with 1, 2 or 3 substitutents selected from halogen and hydroxyl;

G³ & G⁴ one is a nitrogen atom and the other is a CH;

M is hydrogen or a pharmaceutically acceptable cation;

teriflunomide, leflunomide, brequinar, atovaquone;

wherein

R3 is CF2CF3, CF₃, OCH2CH3 or CH₂CH₃;

R4 is F, CH¾ CF¾ SF₃ or CL, or

a pharmaceutically acceptable salt of any one of the same.

7. A method according to claim 6, wherein the DHODH inhibitor is 2-(3,5-difluoro-3'- methoxybiphenyl-4-ylamino]nicotinic acid or a pharmaceutically acceptable salt thereof.

8. A method according to claim 7, wherein the DHODH inhibitor is 2-(3,5-difluoro-3'- methoxybiphenyl-4-ylamino]nicotinic acid or a pharmaceutically acceptable salt thereof a

9. A method according to any one of claims 1 to 8, wherein checkpoint kinase inhibitor is an inhibitor of at a least checkpoint kinase 1.

10. A method according to any one of claims 1 to 9, wherein the checkpoint kinase inhibitor is an inhibitor of at least checkpoint kinase 2.

11. A method according to any one of claims 1 to 10, wherein the checkpoint kinase is an

inhibitor of protein kinase C

12. A method according to any one of claims 1 to 10, wherein the checkpoint kinase inhibitor is an inhibitor of G2 DNA damage.

13. A method according to any one of claims 1 to 10, wherein the checkpoint kinase inhibitor is independently selected from:



or a pharmaceutically acceptable salt or solvate of any one of the same.

1 . A method according to any one of claims 1 to 13, wherein the checkpoint kinase inhibitor is independently selected from:

3-[(Aminocarbonyl]amino]-5-(3-fluorophenyl]-N-(3S]-3-piperidinyl-2- thiophenecarboxamide hydrochloride;

(3R,4S]-4-[[2-(5-Fluoro-2-hydroxyphenyl]-6,7-dimethoxy-4-quinazolinyl]amino]-a,a- dimethyl-3-pyrrolidinemethanol dihydrochloride;

4,4'-diacetyldiphenylurea bis(guanylhydrazone] ditosylate;

9-Hydroxy-4-phenyl-pyrrolo[3,4-c]carbazole-l,3(2H,6H]-dione;

(R]-a-Amino-N-[5,6-dihydro-2-(l-methyl-lH-pyrazol-4-yl]-6-oxo-lH-pyrrolo[4,3,2- efj [2,3]benzodiazepin-8-yl]-cyclohexaneacetamide;

9,10,11,12-Tetrahydro- 9,12-epoxy-lH-diindolo[l,2,3-fg:3',2',l'-kl]pyrrolo[3,4- i] [l,6]benzodiazocine-l,3(2H]-dione;

4'-[5-[[3-[(Cyclopropylamino]methyl]phenyl]amino]-lH-pyrazol-3-yl]-[l,l'-biphenyl]-2,4- diol; and

(R]-5-((4-((Morpholin-2-ylmethyl]amino]-5-(trifluoromethyl]pyridin-2-yl]amino]pyrazine- 2-carbonitrile (CCT245737).

15. A method according to any one of claims 1 to 14, wherein the patient population has a mutated p53 gene

16. A method according to any one of claims 1 to 15, wherein the DHODH inhibitor provides anticancer efficacy via induction of p53 apoptosis.

17. A method according to any one of claims 1 to 16, wherein the DHODH inhibitor is

administered orally, for example once or twice daily, such as twice daily.

18. A method according to claim 17, wherein each dose is in the range 10 to 500mg, such as 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 150, 200, 250, 300, 350, 400, 450 or 500 mg.

19. A method according to any one of claims 1 to 18, wherein the checkpoint inhibitor is

administered orally, for example one or twice daily, such as twice daily.

20. A combination therapy comprising a checkpoint inhibitor and a DHODH inhibitor for use in the treatment of cancer, in particular a cancer disclosed herein.

21. Use of a checkpoint inhibitor and a DHODH inhibitor in the manufacture of a combination therapy for the treatment of cancer.