WO2023033742A1 - Compounds useful in modulation of ahr signalling - Google Patents

Abstract

Compounds of the general formula (I) as described and defined herein, methods for preparing said compounds, pharmaceutical compositions and combinations comprising said compounds and the use of said compounds and pharmaceutical compositions for the treatment or prevention of diseases, in particular cancer or conditions with dysregulated immune functions, or other conditions associated with aberrant AhR signalling, as a sole agent or in combination with other active ingredients.

Description

Compounds Useful in Modulation of AhR Signalling

The present, invention relates to compounds of toe genera] formula (I) and sub-formulas thereof as described and defined herein, methods for preparing said compounds, pharmaceutical compositions and combinations comprising said compounds and the use of said compounds and pharmaceutical compositions for the treatment or prevention of diseases, in particular cancer or conditions with dysregulated immune functions, or other conditions associated with aberrant AhR signalling, as a sole agent or in combination with other active ingredients. Such compounds may also be of utility in the expansion of hematopoietic stem cells (HSCs) and the use of HSCs in autologous or allogenic transplantation for the treatment of patients with inherited immunological and autoimmune diseases and diverse hematopoietic disorders.

BACKGROUND

The aryl hydrocarbon receptor (AhR) is a ligand-activated factor that belongs to toe family of toe basic helix-loop-helix-Per/ARNT/Sim family. Following ligand binding in the cytoplasm, AhR dissociates from its complex with Hsp90 and the AhR-interacting protein, XAP2, allowing ligated AhR to translocate to toe nucleus. There, AhR dimerizes with the AhR nuclear translocator (ARNT), that then binds to xenobiotic response elements (XREs) promoting the up- or downregulation of a multitude of target genes in many different tissues. The AhR is best known for binding to environmental toxins and inducing various members of the cytochrome P450 family including CYP1A1, CYP1A2 and CYP1B1 required for their elimination. Activation of AhR by xenobiotics has demonstrated that this receptor plays a role In a range of physiological processes including embryogenesis, tumourigenesis and inflammation (Esser & Rannug, Pharmacol Rev, 2015, 67:259; Roman et al., Pharmacol Ther, 2018, 185:50).

AhR is expressed in many immune cell types including dendritic cells, macrophages, T ceils, NR ceils and B cells and plays an important role in immuno regulation (Quintana & Sherr, Pharmacol Rev, 2013, 65:1148; Nguyen et al, Front Immunol, 2014, 5:551). The toxic/adverse effects of classical exogenous AhR agonists, such as 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) are well known and include profound immunosuppression and initiation of malignancy (Esser et aL, Trends Immunol, 2009, 30:447; Feng et at, Biochimica et Biophysica Acta, 2013, 1836:197), Physiological effects of AhR agonists on immune cells include promotion of regulatory T cell (Treg) generation (Pot, Swiss Med Wkly, 2012, 142:wl3592), modulation of'Thl? ceil differentiation and activation (Baricza et al., Cell Mol Life Sci, 2016, 73:95) and stimulation of interleukin-22 (IL-22) expression and/or release from human activated peripheral blood mononuclear cells and T cells (Ramirez et aL, Eur J Immunol, 2010, 40:2450: Effner et aL, Sci Rep, 2017, 7:44005). AhR also modulates the function of antigen presenting ceils, such as dendritic cells and macrophages. AhR activation decreases the expression of class 11 major histocompatibility complex and costimulatory molecules and also the production of Thl and Thl7 polarizing cytokines by dendritic cells (Mezrich et aL, J Immunol, 2010, 185:3190; Nguyen et aL, Proc Natl Acad Sci USA, 2010, 107:19961; Quintana et al, 2010 Proc Natl Acad Sci USA, 107:20768). Indeed, AhR activation boosts the ability of DCs to promote the differentiation of Tregs (Jurado-Manzano et aL, 2017, Immunol Lett, 190:84).

In addition to xenobiotics, the AhR can also bind metabolic products of tryptophan degradation including kynurenine (KYN) and kynurenic acid (KYNA). Indoleamine 2,3 dioxygenase 1 and 2 (ID01/ID02) and tryptophan 2,3 -dioxygenase 2 (TDO2) catalyse the commitment step of the KYN metabolic pathway and are expressed in immune ceils (IDO1) and a range of cancer cells (IDO1 and TD02)(PiIotte et al., Proc Nat Acad Sei, 2012, 109:2497). Inhibitors of IDO1 have- attracted much interest as potential new treatments to stimulate the immune system to recognize and eliminate cancer cells (Cheong &. Sun, Trends Pharmacol Sei, 2018, 39:307), Traditionally the immunosuppressive effect of IDO1 has been attributed mainly to reduced levels of tryptophan, which activates the kinase GCN2 (general control non-derepressible 2) and inhibits T cell proliferation/activation both in tumour draining lymph nodes lymph nodes and in the tumour micro-environment More recently it has become apparent that some of the efficacy of IDO inhibitors may be the result of decreased production of AhR agonists. These endogenously generated AhR agonists have been showm to elicit a range of effects on immune cells including upregulation of IDO1 in dendritic cells (Julhard el: al,, Front Immunol, 2014, 3:458), inhibition of human T cell proliferation (Frumento et al., J Exp Med, 2002; 196:459; Terness et al., J Exp Med, 2002; 196: 447; Opitz et al., Nature, 2011, 478:197) and up-regulation of PD-1 expression in cytotoxic T lymphocytes (Liu et al, Cancer Cell, 2018; 33:480). As highlighted above, IDO 1 is not. the only source of endogenous AhR agonists. TDO2 is predominately expressed in the liver but it is also constitutively expressed in some cancers, notably malignant glioma, hepatocellular carcinoma, melanoma, bladder, breast, lung and colorectal cancer (Opitz el: al., Nature, 2011, 478: 197: Pilotte etal., Proc Nat Acad Sci, 2012, 109:2497; D'Amato et al, Cancer Res, 2015, 75(21):4651; Hsu et al., Oncotarget, 2016, 7(19): 27584; Chen et al., Dis Markers, 2016, 2016:8169724). Such data suggests that AhR antagonists may have broader efficacy than selective IDO-1 inhibitors, as they will attenuate endogenous AhR agonist signalling regardless of its source. This assertion was given more weight by the recent discovery of another enzyme, Interleukin-4 induced 1 (IL411), capable of generating endogenous AhR agonists (Sadik et al,. Cell, 2020, 182:10).

In addition to their effects on immune ceils, such endogenous agonists have also been implicated in cancer progression via direct effects on the tumour. For example, KYN increases human glioblastoma ceil survival and migration (Opitz et al., Nature, 2011, 478:197). Several other studies also implicate the AhR in cancer progression in the absence of environmental ligands. The AhR-repressor (Al-IRR) protein acts as a tumour suppressor gene in several human cancers (Zudaire et al., J Clin Invest, 2008, 118:640). AhR expression and “constitutive” (endogenous ligand-driven) activity in breast cancer cells correlate with tumour aggressiveness (Schiezmger et al., Biol Chem, 2006, 387: 1175; Yang et al., 1 Cell Biochem, 2008, 104:402) and control expression of genes associated with tumour invasion (Yang et al., Oncogene, 2005, 24:7869). Ectopic AhR expression in non-malignant human mammary epithelial cells induces an epitheiiai-to- mesenchymal transition and a > 50% increase in cell growth rates (Brooks & Eltom, Curr Cancer Drug Targets, 2011, 11:654) and AhR knockdown induced gene changes in human breast cancer cell lines consistent with a mesenchymal to epithelial cell reversion to a less aggressive phenotype (Narasimhan et at, Int j Mol Sci, 2018, 19:1388). AhR antagonists or AhR knockdown has been shown to reduce proliferation, survival, invasiveness and migration of human breast cancer cells in culture (Parks et al., Mol Pharmacol, 2014, 86:593; D’Amato et al., Cancer Res, 2015, 75(21):4651; Narasimhan et at, int J Mol Sci, 2018, 19:1388) and to reduce survival of glioblastoma cells (Grarnatzki et al., Oncogene, 2009, 28:2593; Opitz et al., Nature, 2011, 478:197; Guastella et al., J Neuro-oncol, 2018, in press). Finally, AhR antagonists block the formation of tumourspheres (Stanford et al., Mol Cancer Res, 2016, 14:696) which are formed by cancer stem ceils (CSCs), a subset of tumour ceils that drive the initiation, progression and metastasis of tumours.

Thus, AhR agonists released from immune cells and from tumour cells act in an autocrine and paracrine fashion to promote tumour growth. Agents that, reduce or block these effects may therefore find utility in the treatment of cancer and/or conditions with dysreguiated immune functions. Thus such agents may also have utility in a range of other diseases/ conditions including but not limited to, obesity (Rojas et al, Jnt J Obesity, 2020, 44:948) and various viral infections (Giovannoni etaL, NatNeurosci. 2020, 23:939; Giovannoni et al,, Res Sq. 2020, rs.3.rs-25639).

WO2017/202816 relates to compounds and compositions for the treatment or prophylaxis of cancer or conditions with dysreguiated immune responses or other disorders associated with aberrant. AhR signalling. In particular, W02017/202816 W02018/146010 and W02019/101642 relate inter alia to heterocyclic compounds capable of inhibiting AhR function. W02020/081840 relates to aryl hydrocarbon receptor antagonists, such as substituted imidazopyridines and imidazopyrazines, as well as methods of expanding hematopoietic stem cells by culturing hematopoietic stem or progenitor cells In the presence of these agents. W02020/039093 relates to compositions and methods for using tetrahydropyridopyrirnicllne derivatives as AhR modulators, WO2018/153893 relates to 6-amido-lH-indol-2-yl compounds which can act as aryl hydrocarbon receptor (AhR) modulators and, in particular, as AhR antagonists. The invention further relates to the use of the compounds for the treatment and/or prophylaxis of diseases and/or conditions through binding of said aryl hydrocarbon receptor by said compounds. W02020/021024 relates to bicyclic compounds which can act as aryl hydrocarbon receptor (AhR) modulators and, in particular, as AhR antagonists. The invention further relates to the use of the compounds for the treatment and/or prophylaxis of diseases and/or conditions through binding of said aryl hydrocarbon receptor by said compounds. W02020/043880 relates to heterocyclic compounds which are ARH inhibitors, for prevention of diseases, in particular cancer or conditions with dysreguiated immune functions, or other conditions associated with aberrant AHR signalling, as a sole agent of in combination with other active ingredients. WO 2020/018848 relates to methods for expanding stem cells and/or lineage committed progenitor cells, such as hematopoietic stems cells and/or lineage committed progenitor cells, at least in part, by using compounds that antagonize AhR. W02020/050409 relates to novel heterocyclic compound having an aryl hydrocarbon receptor antagonist activity and useful for the promotion of platelet production. WO 2019/236766 relates to methods for expanding stem cells and/or lineage committed progenitor cells, at least in part, by using lactam compounds that antagonize AhR. WO2019/018562 relates to compositions and methods of using het.eroaryl amides as AhR modulator compounds, for the treatment of diseases modulated, as least in part, by AhR. WO 2018/195397 relates to compositions and methods for indole AhR inhibitors. WO 2018/146010 relates to the preparation of 2-heteroaryi-3-oxo-2,3-dihydropyridazine-4-carboxamides for the treatment or prophylaxis of diseases, in particular cancer or conditions with dysreguiated immune responses, as a sole agent or in combination with other active ingredients.

W02010/059401 relates to compounds and compositions for expanding the number of CD34+ cells for transplantation. In particular, WO 2010/059401 relates inter alia to heterocyclic compounds capable of down regulating the activity and/or expression of AhR. W02012/015914 relates to compositions and methods for modulating AhR activity. In particular, W02012/01.3914 relates inter alia to heterocyclic compounds that modulate AhR activity for use in therapeutic compositions to inhibit cancer cell proliferation and tumour ceil invasion and metastasis. W02020/0.31207 relates to AhR antagonists as well as methods of modulating AhR activity and expanding hematopoietic stem cells by culturing hematopoietic stem or progenitor ceils in the presence of these agents. Additionally, this disclosure provides methods of treating various pathologies, such as cancer, by administration of these AhR antagonists US2018/327411 Al relates to compounds and compositions useful as inhibitors of AhR to treat a variety of diseases, disorders and conditions associated with AhR. US2019/389857 Al relates to compounds which can act as AhR modulators, and in particular, as AhR antagonists. W02020/039093 discloses certain AhR modulators.

The present compounds are potent modulators, particularly inhibitors of AhR.

SUMMARY OF THE PRESENT DISCLOSURE

1. A compound of formula (I)

wherein:

Y is phenyl or a 3 to 6 membered ring optionally comprising 1, 2, or 3 heteroatoms selected from N, 0 and S, said phenyl or ring substituted with R⁵ and R⁶:

PJ is H, Ci ₃ alkyl, (-CH_z)pCN, -COCi 3 alkyl, -C0(CH_z)qNR⁷R⁸, -SO_zCi-₃ alkyl, -S0_zNR⁷R⁸, -(CH₂)qPh, -C(O)Z, C3-5 cycloalkyl, C1.3 alkyl bearing 1 to 6 halogen groups,

C , .3 alkyl bearing one or more independently selected from OR⁷ and -NR⁷R¹⁵ (such as one OR^yand optionally 1 -NR⁷R⁸), -(CH_z)p’ OCs.?, alkyl substituted with 1 to 6 halogen groups (such as -(CH_z)p’ OCF3I, -Co-3alkyleneC(0)Co-3 alkyl wherein the alkyl bears at least one group selected from OR^Y and -NR⁷R⁸ tsuch as one OR^¥ and optionally 1 -NR⁷R⁸), Z, -C(O)(CH₂]qZ, -C(O)O(CH_z)qZ, -C(O)O(CH₂)pPh, -C(O)(CH₂)qZ', -C(O)O(Cl-I₂)qZ'

R² is H or C1.3 alkyl, C3.5 cycloalkyl;

R²' is H or Ci-3 alkyl; wherein R² & R²‘ together can form an alkylene bridge -CH_ZCH_Z- between two carbons in the ring;

R³ is H or C : : alkyl:

R⁴ is a 9 to 13 membered heterocycle with at least one heteroatom selected from N, 0 and S (for an aromatic or partially saturated), with substituentsR⁷', R’^;" and R^K1; Rs is H, hydroxy, halogen (such as F, Cl), CN, C1.3 alkyl, C1.3 alkoxy (such as OMe), Ci-2 haloalkyl (i.e. alkyl bearing 1 to 6 halogen groups, such as CF3), C1.3 alkyl bearing one or more OH groups, -C(O)(CH2)qNR⁷R⁸, -SO2C1.3 alkyl, -SO2 NR⁷R⁸,

R6 is H, hydroxy, halogen (such as F, Cl), CN, C1.3 alkyl, -C(O)(CH2)qNR⁷R⁸, -SO2C 1 3 alkyl, -SO₂NR⁷R«

R⁷ is H or C1.3 alkyl, such as -CH3;

R⁸ is H or C1-3 alkyl, such as -CH3;

R⁹ is H, hydroxy, halogen (such as F, Cl), CN, C1.3 alkyl, C1.3 alkoxy (such as OMe), C1.3 alkyl bearing 1 to 6 halogen groups (such as CF3), C1.3 alkyl bearing one or more OR^Y groups, Cs-scycloalkyl, -(CfojqOCi-salkyl substituted with 1 to 6 halogen groups (such as -(CH₂)qOCF₃), -CO(CH₂)q NR⁷R⁸, -SO2C1.3 alkyl, or -SO₂ NR⁷R⁸;

_R9- is H, OH, halogen (such as F, Cl), CN, C1.3 alkyl, C1.3 alkoxy (such as OMe), C1.3 alkyl bearing 1 to 6 halo groups (such as CF3), C1.3 alkyl bearing one or more OH groups, -CO(CH2)q NR⁷R⁸, - SO2C1.3 alkyl, or -SO₂ NR⁷R⁸, in particular H;

Rio is H, hydroxy, halogen (such as F, Cl), CN, C1.3 alkyl, -C(O)(CH2)q NR⁷R⁸;

-SO2C 1.3 alkyl, or -SO2 NR⁷R⁸;

R‘i is H or C1.3 alkyl (such as -CH3);

RY is H or C1.3 alkyl(such as H or -CH3);

X is CHa, S, -SO2, NR¹¹ or 0;

Z is a 5 or 6 membered heteroaryl with at least one heteroatom selected from N, 0 and S, for example 1 or 2 nitrogens, wherein said heteroaiyl optionally bears one, two or three substituents selected from hydroxy, halogen (such as F, Cl), CN, C1.3 alkyl;

Z* is a 5 or 6 membered cycloalkyl or heterocycle comprising at least heteroatom selected from N, 0 and S optionally bears one, two or three substituents selected from hydroxy, halogen (such as F, Cl), CN, C1.3 alkyl (such as bearing no substitu tents), b is 0, 1 or 2; n is 1 or 2; m is 1 or 2;

P is an integer 1, 2 or 3 (such as 1); P' is an integer 2 or 3 (such as ); q is 0, 1, 2 or 3 (such as 0 or 1), or a pharmaceutically acceptable salt thereof, with the proviso that only when wherein R² & R²' together can form an alkylene bridge -CH2CH2- between two carbons in the ring can R¹ represent H, C1.3 alkyl, ( CH₂)pCN, COC1.3 alkyl, -CO(CH₂)qNR⁷R⁸, SO2C1.3 alkyl, -SO₂NR⁷R⁸, -(CH₂)qPh, -C(O)Z.

2. A compound of formula (II)

wherein X, Rfi RR R²'. R³, R⁴, R³. R⁶, b, n and m are defined above for compounds of formula fl) or a pharmaceutically acceptable salt thereof.

A compound of formula fill):

or a pharmaceutically acceptable salt thereof, wherein X, R¹, R², R²’, R³, R⁴, R⁵, R⁶, b, n and m are defined above for compounds of formula (I).

A compound according to any one of paragraphs 1 to 3 wherein n is 2.

A compound according to any one of paragraphs 1 to 3, wherein n is 1.

A compound according to any one of paragraphs 1 to 5, wherein m is 2.

A compound according to any one of paragraphs 1 to 5, wherein m is 1.

A compound according to any one of paragraphs 1 to 3, of formula (IV):

or a pharmaceutically acceptable salt thereof, wherein X, R^!, R², R²'>R³, R⁴, R⁵, R⁶, and b are defined above for compounds of formula (1). A compound according to any one of paragraphs 1 to 3, of formula (V):

or a pharmaceutically acceptable salt thereof, wherein X, R⁴, R², R²', R³, R⁴, R³, R⁶, and b are defined above for compounds of formula (I). A compound according to any one of paragraphs 1 to 3, of formula (VI):

or a pharmaceutically acceptable salt thereof wherein X, R’, R², R²’, R³, R⁴, R³, R⁶, and b are defined above for compounds of formula (I), , A compound according to any one of paragraphs 1 to 3, of formula (VII) :

or a pharmaceutically acceptable salt thereof, wherein X, R¹, R², R²', R³, R⁴, R⁵, R⁶, and b are defined above for compounds of formula (I). A compound according to any one of paragraphs 1 to 11, wherein R^! is independently selected from:

■ C(O)OC(CH₃)₃

Pyridine, Pyrimidine, -C(O)OCH₂Ph, -C(O)OCH?5-6 membered saturated heterocycle, in particular -CH(CH₃)CH₂OH, A compound according to paragraph 12, wherein R? is selected from - C(0)OCH₂pyrrolldinyl, -C(0)0CH₂morpholinyt A compound according to any one of paragraphs 1 to 13, wherein R² is H or -CH₃, particularly H. A compound according to any one of paragraphs 1 to 14, wherein R²' is H or -CH?, particularly H. A compound according to paragraph 15, wherein R² is H. A compound according to any one of paragraphs 1 to 16, wherein R³ is H or -CH?„ particularly H. A compound according to any one of paragraphs 1 to 17, wherein R⁴ is selected from indolyl (such as indol-3-yl) and benzimidazolyl (such as benzimidazole-2-yl). A compound according to any one of paragraphs 1 to 18, wherein R⁵ is selected from H, Fl, Cl, CM and -CH?. A compound according to any one of paragraphs 1 to 19, wherein R⁶ is H, Fl, Ci, CN or -CH?,. A compound according to any one of paragraphs 1 to 20, wherein R⁷ is selected from H and

-CH?. A compound according to paragraph 21, wherein R⁷ is -CH?, A compound according to any one of claims 1 to 22, wherein R⁸ is selected from H and

-CH?.

A compound according to paragraph 23, wherein R⁸ is H.

A compound according to any one of paragraphs 1 to 24, wherein R'¹'¹ is H.

A compound according to paragraph 1, selected from:

and a pharmaceutical acceptable saltof any one of the same. A compound according to parrygraph 1, wherein R² and R²‘ represent an alkylene bridge ■ CH2CH2 ■ between two carbons in the ring. A compound according to paragraph 27, selected from:

A pharmaceutical composition comprising a compound according to any one of paragraphs 1 to 28, and a pharmaceutically acceptable diluent or carrier. A compound according to any one of claims 1 to 28 or a composition according to paragraph 29, for use in treatment, in particular the treatment of cancer. A compound according to any one of claims 1 to 28 or a composition according to paragraph 29, for use in the manufacture of a medicament for the treatment of cancer. 32. A method of treatment comprising administering a therapeutically effective amount of a compound according to any one of paragraphs 1 to 28 or a composition according to claim 29 to a patient in need thereof, for example for the treatment of cancer.

33. A compound for use or a method according to any one of paragraphs 30 to 32, further comprising one or more checkpoint inhibitors, for example selected from the group comprising: PD- 1 inhibitor, PD-L1 inhibitor, PD-L2 inhibitor, CTLA-4 inhibitor, checkpoint kinase inhibitor 1 (CHEK1/CHK1), checkpoint kinase inhibitor 2 (CHEK2/ CHK2), Ataxia telangiectasia and Rad3 related [AYR] inhibitor, ataxia-telangiectasia mutated (ATM) inhibitor, Weel dual specificity protein kinase (Weel) inhibitor, Poly ADP Ribose polymerase (PARP) inhibitor and Mytl inhibitor, in particular a PD-1 inhibitor, a PD-L1 inhibitor and/or a CTLA-4 inhibitor.

34. A combination therapy comprising a compound according to any one of paragraphs 1 to 28 or a composition according to paragraph 29, and one or more checkpoint inhibitors, for example selected from the group comprising; PD-1 inhibitor, PD-L1 inhibitor, PD-L2 inhibitor, CTLA-4 inhibitor, 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, in particular a PD-1 inhibitor, a PD-L1 inhibitor and/or a CTLA-4 inhibitor.

35. A process of preparing a compound of formula (1) according to any one of paragraphs 1 to 28 by reacting a compound of formula (VIII):

(VW) and Y’-R* wherein R¹, R², R ■. R⁴, X. m and n are defined for compounds of formula (I) and Y' is an activated derivative of Y also defined in formula (I) and R^x is the activating group. In one embodiment R² is not H. In one embodiment R²' is not H. In one embodiment R² is not H. In one embodiment R² and R²' are not H. In one embodiment R² and R³ are not H. In one embodiment R²' and R³ are not H. In one embodiment R², R²’ and R² are not H. In one embodiment when m is 1 and n is 1 or 2, and Y is pyridine one or both of R³ and R^& are not H. In one embodiment when Y' is pyridine one or both of R^s and R⁶ are not H, in one embodiment R^s is not H.

In one embodiment R⁶ is not H. In one embodiment R^:? is not H. In one embodiment R⁹' is not H. In one embodiment R¹⁰ is not H.

In one embodiment R¹ is selected from pyridine, pyrimidine,. -CH2CH2OH, -CHfCHafCHzOH, -

R² is independently selected from H, methyl, -CH2OCH3, -CH2OH, CF3, -CHzNfCHsX such as H or methyl,

R² is methyl or H, such as H.

In one embodiment Y is a 3 to 6 membered ring optionally comprising 1, 2, or 3 heteroatoms selected from N, 0 and S, each substituted with R^s and R^:\ for example a .3 to 6 membered ring comprising 1, 2, or 3 heteroatoms selected from N, 0 and S, each substituted with R⁵ and R⁶-, in particular a 5 or 6 membered ring, especially a nitrogen containing ring.

In one embodiment R⁴ is a 9 or 13 membered partially saturated or aromatic heterocycle (for example a 9 to 13 membered heteroaryl) for example selected from indole, tetrahydrobenzoindole, tetrahydrocarbazole and tetrahydropyridoindole.In one embodiment R⁴ is a 9 membered heterocycle, for example a heteroaromatic, such as tryptophan.

In one embodiment R⁴ is a 13 membered heterocycle, for example a partially saturated heterocycle, such as tetrahydrocarbazole.

In one embodiment R⁵ is independently selected from the group comprising oxo, methyl, ethyl, -CF3, -OCF3, -OCH3 and halogen, such as halogen, for example fluoro.

R⁶ is independently selected from methyl, ethyl, -OCH3, and H, such as H.

In one embodiment R⁷ is

R⁹ is independently selected from R^s is H, methyl, OCF3 and - Cj scydoalkyl, such asH, methyl, or - C^scycloalkyl, alternatively H, methyl or OCF3.

In one embodiment R⁹' is independently selected from H, F and methyl such as H or F.

In one embodiment R¹⁰ is Independently selected from H, F and methyl such as H or F, in particular H.

In one embodiment X is NR”. In one embodiment Y is independently selected from pyrimidine, pyridine, pyridone, triazole and thiazole, in particular pyrimidine and or pyridine.

In one embodiment Y is aromatic, in one embodiment Y is partially saturated. In one embodiment compounds of the disclosure have an activity of in an assay of human PBMC Inhibition of CD3/CD28 induced IL- 22 release.

In one embodiment the compounds of the disclosure have activity in an U937 assay, for example as disclosure herein.

The compounds of the present invention effectively inhibit AhR. Said compounds are useful for the treatment or prophylaxis of conditions where exogenous and endogenous AhR ligands induce dysreguiated immune responses, for example: uncontrolled cell growth, proliferation and/or survival of tumour ceils, immunosuppression. This dysregulation may be observed in the context of cancer, inappropriate cellular immune responses, and inappropriate cellular inflammatory responses.

In one embodiment the compounds of the present disclosure are useful in the treatment of cancer for example, liquid and/or solid tumours, and/or metastases thereof. Examples of cancers include head and neck cancer (such as brain tumours and brain metastases), cancer of the thorax including non-smail cell and small ceil lung cancer, gastrointestinal cancer (including stomach, oesophageal, colon, and colorectal), biliary tract cancer, pancreatic cancer, liver cancer, endocrine cancer, breast cancer, ovarian cancer, bladder cancer, kidney cancer, prostate cancer, bone cancer and skin cancer. In one embodiment the cancer is an epithelia! cancer, In one embodiment the cancer is a sarcoma. In one embodiment the cancer is metastatic.

DETAILED DISCLOSURE

Generally, substituents employed in molecules of the present disclosure will be suitable for use in therapeutic molecules. Reactive molecules, such as epoxides etc will usually one be employed in intermediates.

Ci-3 alkyl as employed herein refers to straight or branched chain alkyl, for example methyl, ethyl, propyl or isopropyl. Where the alkyl is optionally substituted as defined herein will generally provide a straight or branched chain alkylene.

Ci _xa!kylene as employed herein refers to strait or branched chain alkyl of 1 to X carbons in length bearing terminal substituent, such as an alcohol, for example -CHzCHaCHz-substiiitesit is a Cs straight chain alkylene. When the alkylene is branched then a branch may terminate in an alkyl group to the satisfy the valency of the atoms, for example -CHaCHfCHaj-substituent is a C -. branched chain alkylene.

Ci-3 alkoxy as employed here refers to a branched or straight chain alkyl chain with an oxygen atom located in the chain, for example so the oxygen connects the alkoxy group to the remainder of the molecule (such as -OCHs) or a carbon links the alkoxy group to the rest of the molecule and the oxygen is located internally within the alkoxy chain (such as -CH2OCH3).

Halogen as employed herein includes fluoro, chloro, bromo or iodo.

Examples of alkyl bearing up to 6 halogen groups include --CH2F, -CH2CL, -CHF?, -CHCL2, -CF₃, -CCL₂, -CH2CF3, -CF₂CF₃, -CH₂CHCL₂, -CHCCL₃.

C(Oj represents carbonyl.

C3.5 cycloalkyl includes cyclopropyl, cyclobutyl and cyclopentyl.

A 3 to 6 membered ring optionally comprising 1, 2 or 3 heteroatoms selected from nitrogen, oxygen and sulfur, refers to a saturated, partially saturated or aromatic ring containing 3 or 6 atoms, for example as defined below.

In one embodiment the 3 to 6 membered ring contains no heteroatoms.

In one embodiment the 3 to 6 membered ring comprises 1, 2 or 3 heteroatoms selected from nitrogen, oxygen and sulfur.

In one embodiment the ring is saturated. Examples of saturated rings include cyclopropane, cyclobutane, cydopentane, cyclohexane, azetidine, oxetane, thietane, tetrahydrofuran, tetrahydrothiophene, oxathiolane, 1,3-dioxolane, pyrazolidine, pyrrolidine, thiolane, imidazoline, piperidine, tetrahydropyran, dioxane, morpholine, thiane, dithiane, piperazine and thiomorpholine.

In one embodiment there is provided a 5 or 6 membered ring as optionally comprising 1, 2 or 3 heteroatoms selected from nitrogen, oxygen and sulfur, refers to a saturated, partially saturated or aromatic ring containing 5 or 6 atoms, including wherein all the atoms are carbon or where there are 1, 2 or 3 heteroatoms independently selected from nitrogen, oxygen and sulfur, for example including: cyclopentadiene, phenyl, thiophene, furan, pyrroline, pyrrole, pyrazoline, pyrazole, Imidazoline, Imidazole, oxazole, isoxazole, thiazole, isothiazole, oxadiazoie, thiadiazole, triazole, tetrazole, pyridine, pyrimidine, pyrazine, triazine, thiazine, oxazine, thiopyran, 2H pyran, 4H pyran, dioxine, 2H thiopyran, 4H thiopyran, 4H-l,2-oxazine, 2H-l,2-oxazine, 6H-l,2-oxazine, 4H-l,3-oxazine, 6H- 1,3-oxazine, 4H-l,4-oxazine, 4H- 1,4- thiazine, 2H-l,2-thiazine, 6H-l,2-thiazine. hi one embodiment there is provided a 5 or 6 membered ring comprising 1, 2 or 3 heteroatoms selected from nitrogen, oxygen and sulfur, refers to a saturated, partially saturated or aromatic ring containing 5 or 6 atoms, where there are 1, 2 or 3 heteroatoms independently selected from nitrogen, oxygen and sulfur, for example as defined above, such as thiophene, furan, pyrroline, pyrrole, pyrazole, imidazole, oxazole, isoxazole, thiazole, isothiazole, triazoie, pyridine, pyrimidine, pyrazine, triazine, thiazine, oxazine, pyrroline, 4-H pyran, thiopyran, .

In one embodiment the ring is saturated. hi one embodiment the ring is a saturated carbocyclic ring, hi one embodiment the ring in a saturated heterocyclic ring. In one embodiment the ring is partially saturated or aromatic, in one embodiment the ring is partially saturated or aromatic carbocycle, in one embodiment the ring is partially saturated or aromatic heterocycle. In one embodiment the ring is 5 membered. In one embodiment the ring is 6 membered, in one embodiment the 5 or 6 membered ring is unsaturated or aromatic.

In one embodiment the 5 or 6 membered ring is selected from cyclopentadiene, phenyl, pyridine and pyrazine, such as phenyl and pyridine.

5 or 6 membered heteroaryl as employed herein is a ring containing 5 or 6 atoms wherein at least one atom is a heteroatom (for example 1, 2, 3 or 4 heteroatoms independently selected from 0, N and S) and generally the ring is aromatic or at least partially unsatured (such as aromatic), for example selected from nitrogen, oxygen or sulphur, such as pyrrole, pyrazole, imidazole, thiophene, oxazole, isothiazole, thiazole, pyridine, pyridazine, pyrimidine, pyrazine, triazine, thiopyran, oxazine and thiazine, such as pyrrole, pyrazole and pyridine and pyrimidine.

Unless the context indicates otherwise 5 to 6 membered heterocycle as employed herein generally refers to a non-aromatic ring containing 5 or 6 atoms wherein at least one atom is a heteroatom (for example 1, 2, 3 or 4 heteroatoms independently selected from 0, N and S), for example pyrrolidine, imidazohdine, pyrazolidine, oxathiolane, tetrahydrofuran, morpholine, piperidine, piperazine, tetrahydropyran, thiane, dithiane, thiomorpholine and the like.

9 to 13 membered heterocycle as employed herein refers to a bicyclic or tricyclic system containing 9 to 13 atoms, for example containing 1, 2, 3, or 4 heteroatoms independently selected from nitrogen, oxygen and sulfur, which is saturated, partially unsaturated or aromatic.

9 to 13 membered heteroaryl as employed herein refers to a bicyclic or tricyclic system containing 9 to 13 atoms, wherein at least one ring is aromatic and at least one ring contains a heteroatom, for example containing 1, 2, 3, or 4 heteroatoms independently selected from nitrogen, oxygen and sulfur such as indoline, indole, isoindole, indolizine, indazole, benzimidazole, azaindole, pyrazolopyrimidine, purine, benzofuran, isobenzofuran, benzothiophene, benzoisooxazoie, benzoisothiazoie, benzoxazole, benzothiadlazoie, adenine, guanine, tetrahydroquinoline, dihydroisoquinoline, quinoline, isoquinoline, quinolizine, quinoxaline, phthalazine, cinnoiine, napthrhyridme, pyridopyrimidme, pyridopyrazine, pyridopyrazine, pteridine, chromene, isochromene, chromenone, benzoxazine, quinolinone, isoquinolinone, dibenzofuran, carbazole, acridine, phenothiazine, 2,3,4,9-tetrahydro-lH-carbazoie.

In one embodiment R⁴ is a 9 or 10 membered heteroaryl. 9 to 10 membered heteroaryl as employed herein refers to a bicyclic ring system containing 9 or 10 atoms, wherein at. least one ring is aromatic and at least one ring contains a heteroatom, for example containing 1, 2, 3, or 4 heteroatoms independently selected from nitrogen, oxygen and sulfur, such as indoline, indole, isoindole, indolizine, indazole, benzimidazole, azaindole, pyrazolopyrimidine, purine, benzofuran, isobenzofuran, benzothiophene, benzoisooxazole, benzoisothiazoJe, benzoxazole, benzothiadiazole, adenine, guanine, tetrahydroquinoiine, dihydroisoquinoiine, quinoline, isoquinoiine, quinolizine, quinoxaline, phthalazine, cirmoline, napt.hrhyridine, pyridopyrimidine, pyridopyrazine, pyridopyrazine, pteridine, chromene, isochromene, chromenone, benzoxazine, quinolinone, and isoquinolinone. in one embodiment the 9 or 10 membered heteroaryl is selected from indolylyi and benzimidazolyl, such as indol-3-yl or benzimidazoIe-2-yl.

Ph as employed herein refers to phenyl.

The compounds of the present disclosure can be prepared by methods described herein.

In one embodiment there is provided a process of preparing a compound of formula (I) by reacting a compound of formula wherein R¹, R², R³, R⁴, X, m and n are defined for

compounds of formula fl) and Y' is an activated derivative of Y also defined in formula (I) and R^x is the activating group.

In one embodiment the reaction is a condensation reaction.

substitution

Reduction Boc-pratection Dieckmann condensation

su s u on

ceavage

Protecting groups may be required to protect chemically sensitive groups during one or more of the reactions described above, to ensure that, the process is efficient. Thus, if desired or necessary, intermediate compounds may be protected by the use of conventional protecting groups. Protecting groups and means for their removal are described in "Protective Groups in Organic Synthesis”, by Theodora W, Greene and Peter G.M. Wuts, published by John Wiley & Sons Inc; 4^f;; Rev Ed„ 2006, ISBN-10: 0471697540.

Examples of salts of compound of the present disclosure include ail pharmaceutically acceptable salts, such as, without limitation, 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.

The present disclosure extends to solvates of the compounds disclosed herein. Examples of solvates include hydrates.

Novel intermediates are an aspect of the invention.

A further aspect of the present disclosure is methods of making the compounds disclosed herein,

Also provided herein a pharmaceutically composition comprising a compound according to the present disclosure and an excipient, diluent or carrier. A thorough discussion of pharmaceutically acceptable carriers is available in Remington's Pharmaceutical Sciences (Mack Publishing Company, NJ. 1991],

The pharmaceutical compositions of this disclosure may be administered by any number of routes including, but not limited to, oral, Intravenous, Intramuscular, intra-arterial, intramedullary, intrathecal, intraventricular, transdermal, transcutaneous (for example, see WO98/20734), subcutaneous, intraperitoneal, intranasal, enteral, topical, sublingual, intravaginal or rectal routes. Hyposprays may also be used to administer the pharmaceutical compositions of the invention.

In one embodiment the therapeutic compositions may be prepared as injectables, either as liquid solutions or suspensions. Solid forms suitable for solution in, or suspension in, liquid vehicles prior to injection may also be prepared. Suitable liquids for reconstitution of such solid forms (Including lyophilised solids) may be selected from aqueous solutions, for example saline, dextrose or water for injection and the like. In one embodiment the reconstituted liquid formulation is isotonic.

In one embodiment the pharmaceutical composition according to the present disclosure is provided as a tablet or a capsule for oral administration.

TREATMENT

The present disclosure also extends to methods of treating a patient comprising administering a therapeutically effective amount of a compound of the present disclosure (or a pharmaceutical composition comprising the same), for example for the treatment of cancer.

Also provide is a compound according to the present disclosure (or a pharmaceutical composition comprising the same) for use in treatment, for example for use in the treatment of cancer.

In a further aspect there is provided a compound of the present disclosure (or a pharmaceutical composition comprising the same) for use in the manufacture of a medicament for the treatment of cancer. In one embodiment the cancer is an epithelial cancer, for example selected from example is selected from liver cancer (such as hepatocellular carcinoma], biliary tract cancer, breast cancer (such as none ER+ breast cancer], prostate cancer, colorectal cancer, ovarian 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.

In one embodiment the cancer is selected from selected from the group comprising hepatocellular carcinoma, choiangiocarclnoma, breast cancer, prostate cancer, colorecetal cancer, ovarian cancer, lung cancer, gastric cancer, pancreatic and oesophagus cancer.

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. In one embodiment the epithelial cancer is a carcinoma. in one embodiment the treatment according to the disclosure is adjuvant therapy, for example after surgery.

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

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.

In one embodiment the treatment according to the present disclosure is suitable for the treatment of cancerous cells in a lymph node. 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, 3 A, 3B, 3C, 4A or 4B. in one embodiment the gastric cancer is stage 0, 1, II, HI or IV.

The precise therapeutically effective amount for a human subject will depend upon the severity of the disease state, the general health of the subject, the age, weight and gender of the subject, diet, time and frequency of administration, drug combinatlonfs], reaction sensitivities and toierance/response to therapy. This amount can be determined by routine experimentation and is within the judgement of the clinician. Generally, a therapeutically effective amount will be from 0.01 mg/kg to 1000 mg/kg, for example 0.1 mg/kg to 500 mg/kg. Pharmaceutical compositions may be conveniently presented in unit dose forms containing a predetermined amount of an active agent of the invention per dose. Combination Therapy

In one embodiment, the compound of the present disclosure is employed in combination therapy, for example wherein the further therapy is an anticancer therapy.

In one embodiment the anticancer therapy is a chemotherapy.

Chemotherapeutic agent, and chemotherapy or cytotoxic agent are employed interchangeably herein unless the context indicates otherwise.

Chemotherapy as employed herein is intended to refer to specific antineopiastic chemical agents or drugs that are "selectively” destructive to malignant cells and tissues, for example alkylating agents, antimetabohtes including thymidylate synthase inhibitors, anthracyclines, antimicrotubule 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.

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

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

Platinum containing chemotherapeutic agent (also referred to as platins] includes, for example cisplatin, carboplatin, oxaliplatin, satraplatin, picoplatin, nedaplatin, triplatin and ilpoplatin (a liposomal version of cisplatin), in particular cisplatin, carboplatin and oxaliplatin.

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.

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

Nitrosoureas include N-Nitroso-N-methylurea (MNU), carmustine (BCNU), lomustine (CCNU) and semustine (MeCCNU), fotemustine and streptozotocin. Tetrazines include dacarbazine, mitozoiomide and temozolomide.

Aziridines include thiotepa, mytomycin and diaziquone (AZQ).

Examples of antimetabohtes, 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 dadribine], pyrimidine analogues (for example fluoropyrimidines, such as 5-fluorouracil and prodrugs thereof such as capecitabine [Xeioda®]), floxuridine, gemcitabine, cytarabine, decitabine, raititrexed(tomudex) hydrochloride, dadribine and 6-azauradl.

Examples of anthracyclines, which may be employed in the method of the present disclosure, include dauuorubicin (Daunomycin), daunorubicln (liposomal), doxorubicin (Adriamycm), doxorubicin (liposomal), epirubicin, idarubicin, valrubicin (currently used only to treat bladder cancer) and mitoxantrone an anthracycline analog, in particular doxorubicin.

Examples of anti-microtubule agents, which may be employed in the method of the present disclosure, include include vinca alkaloids and taxanes. Vinca alkaloids include completely natural chemicals, for example vincristine and vinblastine and also semi-synthetic vinca alkaloids, for example vinorelbine, vindesine, and vinflunine

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 micellar formulations, derivatives also include chemical derivatives wherein synthetic chemistry is employed to modify a starting material which is a taxane.

Topoisomerase inhibitors, which may be employed in a method of foe 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 include genistein and 1CRF 193 which has the following structure:

Type 11 poisons include amsacrine, etoposide, etoposide phosphate, teniposide and doxorubicin and fluoroquinolones.

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.

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

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

In one embodiment the chemotherapy combination in capecitabine and oxaliplatin (Xeloxj.

In one embodiment foe chemotherapy is a combination of folinic acid and 5-FU, optionally in combination with oxaliplatin. in one embodiment the chemotherapy is a combination of folinic acid, 5-FU and irinotecan (FOLFIRJ), optionally in combination with oxaliplatin (FOLFIRINOX), The regimen consists of: irinotecan (ISO mg/m² IV over 90 minutes) concurrently with folinic acid ('400 mg/m² [or 2 x 250 mg/ni²] 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.

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

In one embodiment the chemotherapy combination comprises an antimetabolite such as capecitabine (xeloda), fludarabine phosphate, fludarabine (iludara), decitabine, raltitrexed (tomudex), gemcitabine hydrochloride and cladribine. In one embodiment the anticancer therapy combination employs an mTor inhibitor. Examples of mTor inhibitors include: everolirous (RAD001), WYE-354, KU-0063794, papamycm (Sirohmus), Temsirolimus, Deforoiimus(MK-8669), AZD8055 and BEZ235(NVP-BEZ235).

In one embodiment the anticancer therapy combination employs a MEK inhibitor. Examples of MEK inhibitors include: AS703026, Cl-1040 (PD 184352), AZD6244 (Selumetinib), PD318088, PD0325901, AZD8330, PD98059, U0126-EIOH, BIX 02189 or BIX 02188.

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

In one embodiment the anticancer therapy 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.

In one embodiment the chemotherapy combination employs a p38 inhibitor, for example as disclosed in W02010/038086, such as N-[4-({4-[3-(3-tert-Butyl-l-p-tolyl-l//-pyrazol-5- yI)ureido]naphthaIen-l-yloxy}methyl]pyridin-2-yI]-2-methoxyacetamide.

In one embodiment the combination employs a Bel -2 Inhibitor. Examples of Bcl-2 inhibitors include: obatoclax mesylate, ABT-737, ABT-263 (navi tociax) and TW-37.

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

In one embodiment the anticancer therapy includes a PARE inhibitor.

In one embodiment the anticancer therapy includes an inhibitor of cancer metabolism with specific inhibition of the activity of the DHODH enzyme.

In one embodiment the compound of the present disclosure is employed in combination (for example in a combination therapy] with a checkpoint inhibitor. Thus, the present disclosure provides a combination therapy comprising a compound or pharmaceutical composition of the present disclosure, and a checkpoint inhibitor or a combination of checkpoint inhibitors.

In one embodiment the checkpoint inhibitor is selected from the group comprising; PD-1 inhibitor, PD-L1/L2 inhibitor, CTLA-4 inhibitor, 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 (PARE) inhibitor and Mytl inhibitor. in one embodiment the checkpoint inhibitor is selected from the group comprising: a PD-1 inhibitor, a ED-LI /L2 inhibitor, a CTLA-4 inhibitor: and a combination thereof. In one embodiment a combination of a PD-1 inhibitor and a PD-L1 inhibitor is employed. In one embodiment a combination of a PD-1 and a CTA-4 inhibitor is employed. In one embodiment, a combination of a ED-LI and CTA-4 inhibitor is employed. In one embodiment, a combination of a PD-1, ED-LI and a CTA-4 inhibitor is employed.

In one embodiment, the checkpoint inhibitor is a PD-1 inhibitor, in one embodiment, the PD-1 inhibitor is selected from the group comprising: nivolumab (also known as OPDIVO®, 5C4, BMS-936558, MDX-1106, and ONO-4538), pembrolizuraab (Merck; also known as KEYTRUDA®, lambroiizumab, and MK-3475), PDR001 (Novartis; also known as spartaiizumab), MED1- 0680 (AstraZeneca; also known as AMP-514), cemiplimab (Regeneron; also known as REGN-2810), JS001 or “toripahmab” (TAIZHOU JUNSHI PHARMA), BGB-A317 ("Tislelizumab.:" Beigene), INCSHR1210 (Jiangsu Hengrui Medicine; also known as "camrelizumab,", SHR- 1210), TSR-042 or "dostarlimab” (Tesaro Biopharmaceutical; also known as ANB011), GLS- 010 (Wuxi/Harbin Gloria Pharmaceuticals; also known as WBP3055), STI-1110 (Sorrento Therapeutics), AGEN2034 or “balstilimab" (Agenus), MGA012 or “retifanlimab" (Macrogenics), 1B1308 or “sinitilimab" (Innovent), BCD-100 or "bevacizurnab” (Biocad), and JTX-4014 (jounce Therapeutics).

In one embodiment, the checkpoint inhibitor is pembrolizumab, In one embodiment the checkpoint inhibitor is nivoiumab. In one embodiment the checkpoint inhibitor is cemiplimab. In one embodiment the checkpoint inhibitor is dostarlimab.

In one embodiment the checkpoint inhibitor is a PD-L1 inhibitor. In one embodiment the PD -L1 inhibitor is selected from the group comprising: atezolizuniab (Tecentriq), avelumab (Bavencio), durvalumab (Imfinzi), KN035, CK-301 (Checkpoint Therapeutics), AUNP12 (Aurigene), CA-170 (Aurigen/Curis) and BMS-986189 (BMS).

In one embodiment, the checkpoint inhibitor is atezolizumab. In one embodiment, the checkpoint inhibitor is avelumab. In one embodiment, the checkpoint inhibitor is durvalumab.

In one embodiment; the checkpoint inhibitor is a CTLA-4 inhibitor. In one embodiment t.be CTLA-4 inhibitor is selected from the group comprising: ipihmumab (Yervoy), tremelimumab

In one embodiment the checkpoint inhibitor is an antibody or binding fragment specific to a checkpoint protein, in particular one disclosed herein, such as PD-1, PD-L1 or CTLA-4.

In one embodimentthe checkpoint kinase inhibitor is independently selected from:

3- 4(Amlnocarbonyi)ammo]-5 -(3-fiuorophenyl)-N-(3S)-3-piperidlnyl-2-thiopheRecarboxamide hydrochloride; (3R,4S]-4-fi2-(5-Fhioro-2-hydroxyphenyl)-6,7-dimethoxy-4-quinazolmyl]amino]- a,a-dimet.hyl-3-pyrroIidinemethanol dihydrochloride; 4,4'-diacetyldiphenyIurea bis(guanylhydrazone) ditosylate; 9-Hydroxy-4-phenyl-pyrrolo[3,4-c]carbazoie-l,3(2H,6H)-dione; (R)-a-Amino-N-[5,6-dihydro-2-(l-metiiyl-lH-pyrazol-4-yl)-6-oxo-lH-pyrroloJ4,3,2- efj[2,3]benzodiazepin-8-yl]-cyclohexaneacetamide; 9,10,11,12 -Tetrahydro- 9,12-epoxy-lH- diindolo[l,2,?3-fg:3',2',i'-kI]pyrroIo[?3,4-i][l,6]benzodiazocine-i,3(2H)-dfone; 4'-[5-[[3- fiCyclopropylamino)methyl]phenyi]amlno]-lH-pyrazoi-3-yl]-[l,l'-biphenyI]-2,4-dioi; and (R)-5-((4-((Morpholin-2-ylmethyI)amino)-5-(trifluoromethyl)pyridin-2-yl)amino)pyrazine-2- carboni trile (C CT245737] .

In one embodiment, the checkpoint inhibitor is a PARP inhibitor, for example one of the followmg:

AZD-2281 (Olaparib) a PARP- 1 & -2

AG-014699 (Rucaparib) a PARP-1 inhibitor inhibitor (which is the first PARP (currently in Phase 111 trials for ovarian and inhibitor to gain US FDA approval) pancreatic cancer)

trials for ovarian, breast, cancer and BMN-673 (Talazoparib) a PARP-1 and PAR- 2 Ewing sarcoma) inhibitor (which is currently in Phase III trials for ovarian, breast and other solid cancers)

ABT-888 (Veliparib) a PARP-1 and PARE- CEP-9722 a PARP-1 and P ARP-2 inhibitor; 2 inhibitor (which is currently being evaluated in Phase III studies for breast, pancreatic, non-small cell lung cancer, lymphoma and multiple myeloma)

BGP-15 a PARP inhibitor (which has been E7016 (previously known as GPI-21016) shown to protect against ischemiaa PARP inhibitor (undergoing Phase I trials reperfusion injury) in combination with temozolomide for advanced solid tumours and gliomas).

IM01001 (3-ammobenzamide) a potent inhibitor of

PARP (with 1C50 of <50 nM in CHO cells and a mediator of oxidant-induced myocyte dysfunction during reperfusion)

BGB-290 a PARP-1 and P ARP-2 inhibitor (structure not shown); or a pharmaceutically acceptable salt thereof.

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.

In one embodiment, there is provided the use of multiple cycles of treatment ('such as chemotherapy) for example 2, 3, 4, 5, 6, 7 or 8.

Comprising" in the context of the present specification is intended to mean "including". Where technically appropriate, embodiments of the invention may be combined.

Embodiments are described herein as comprising certain features/elements. The disclosure also extends to separate embodiments consisting or consisting essentially of said fea tu res/elem e n ts.

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.

The invention will now be described with reference to the following examples, which are merely illustrative and should not be construed as limiting the scope of the present invention. EXAMPLES

The present compounds can be made by methods analogous to those described in W02020/039093 and PCT/SG2021/050095 both incorporated herein by reference.

General method A (tryptamine)

A suitable round bottom flask or reacti-vial was charged with aryl halide (1 equiv.), tryptamine (1.1 equiv.), IPA (TOmL/mmoI) and triethyiamine (2 equiv.) and heated at 100°C for 3 h (reaction monitored by UPLC analysis). On cooling the reaction mixture was evaporated to dryness and the resultant residue partitioned between ethyl acetate and water. The organic phase was separated and sequentially washed with saturated bicarbonate solution, water, brine, then dried over sodium sulfate, filtered and evaporated. Purification, if required was performed by chromatography or trituration.

General method B (Suzuki)

A suitable round bottom flask or reacti-vial was charged with aryl halide (lequiv.), aryl boronic acid (1.5-2.0 equiv.), potassium carbonate fl.5-2.0 equiv.), dioxane/water ([5: 1] about 60 vol). Head space was flushed with nitrogen gas, then [l,l'-Bis(diphenylphosphino) ferrocene]clichloropailadium(H) dichioride (0.2-0.3 equiv.) was added. The reaction mixture was heated under nitrogen at 100°C for 2-24 h until complete as determined by UPLC analysis. The reaction mixture was evaporated to dryness and applied to a silica column as a slurry in DCM; or preabsorbed onto celite, which was loaded in to a dry load unit and placed in series with a silica cartridge. The desired product was eluted with a gradient of ethyl acetate in hexane, sometimes more polar eluent of methanol (0-10%) in ethyl acetate may be required. Further chromatography on silica eluting with 7M ammonia in methanol (0-10%) in DCM may be required. Trituration with diethyl ether and subsequent filtration afforded the desired product.

General method C (TEA deBOC)

TFA (0.2-0.5 mL) was added to a solution of DOC compound (20-200 mg] in DCM (3-10 mb). Once complete as judged by UPLC, the reaction mixture was loaded on to an SCX resin cartridge (0.5 g or 1.0 g). The cartridge was washed through with methanol (10 mL). The product was eluted as the free base, eluting with 7M ammonia in methanol (10 mb). The free based material was evaporated, triturated with ether and collected by filtration. Dried in a desiccator <10mbar.

Example 1

2₎4-dichlos-O”5,6₎7_J8-tetrahydropyrido[3_>4~d]pydmidine tnfhmroacetate

Trifluoroacetic acid (40 mb) was added in a dropwise manner to a stirred solution of tert-butyl 2,4-dichloro-5H,6H,7H,8H-pyrido[3,4-d]pyrimidine-7-carboxylate (5.0 g, 0.016 mol, 1.0 eq) in dichloromethane (100 mb) at ambient temperature, and the resulting mixture was stirred for 2 h. The solution was evaporated to dryness in vacuo before being co-evaporated with toluene (3 x 50 mL) to afford the desired product as a solid (3.97 g, 0,012 mol, 75.9%).

UPLC-MS (2 min basic): rt ~ 0.86 min (M+H+ ~ 204.1/206.1)

^!H NMR (400 MHz, DMSO) 6 9.46 (s, 2H), 4.41 (s, 2H), 3.47 ft, J = 6.2 Hz, 2H), 2.96 (t, J = 6.2 Hz, 2H).

7-(2-((tert-butyldimethyIsiIyI)oxy)ethyl)-2,4~dichloro-5,6,7,8-tetrahydropyrido[3,4~ d]pyrimidme

Triethylamine (0,87 mL, 6,29 mmol, 2.0 eq) was added to a stirred solution of 2,4-dichloro- 5H,6H,7H,8H-pyrido[3,4-d]pyrimidine trifin oroacetate (1.0 g, 3.14 mmol, 1.0 eq) in dichloromethane (2.0 mL), and the resulting solution was stirred for 10 min. Acetic acid (0.54 mL, 9.43 mmol, 3.0 eq) and 2-[(tert-butyIdimethylsiIyl)oxy]acetaldehyde (1,8 mL, 9.43 mmol, 3,0 eq) were added sequentially to the reaction, and the resulting mixture was stirred for 10 min. Sodium triacetoxyborohydride (1.1 g, 5.03 mmol, 1.60 eq) was added to the reaction m a single portion, and the resulting mixture was stirred for 16 h at ambient temperature. The reaction mixture was partitioned between DCM (10 mb] and a saturated solution of aqueous sodium bicarbonate (10 mL). The organic phase was collected and washed with a saturated solution of aqueous sodium bicarbonate [10 mL), dried (NajSOi), filtered and evaporated to dryness in vacuo to afford the crude product as a residue. Purification by automated column chromatography over silica (40 g cartridge), eluting with a gradient of EtOAc in iso-hexane (0-100%) afforded the desired product as an oil (730 mg, 1.712 mmol, 54.5%). UPLC-MS (2 min basic): rt ~ 1.45 min (M+H+ ~ 362.3/364.3). NMR (400 MHz, DMSO) 6 3.78 (t, J = 5.9 Hz, 2H), 3.74 (d, J = 1.1 Hz, 2H), 2.87 (t, J - 5.8 Hz, 2H), 2.74 (t, J - 5.5 Hz, 2H), 2.69 (t, J - 5.9 Hz, 2H), 0.88 fs, 9H), 0.06 (s, 6H).

N"(2-(lH-indoI"3-yI)ethyl)"7-(2"((tert-butyldimethylsiIyl)oxy)ethyl)-2"ChiorO"5,6,7,8- tetrahydropyrido [3,4-d] pyrimidm-4-amine

A 50 ml. round bottom flask was charged with R1 (500.0 mg, 1.380 mmol, 1.000 eq, 7-{2-[(tert- buty’ldimethyIsiiyI)oxy]ethyI}-2,4-dichioro-5H,6H,7H,8H-pyrido[3,4-cl]pyrimidine) and R3 (243.4 mg, 1.519 mmol, 1.101 eq) in SI (4.2 mL, propan-2-oi). The solution was treated with R2 (0.384 mb, 2.760 mmol, 2.000 eq, triethylamine) and heated at 100°C for "-2h. UPLC-MS showed the complete conversion of the potential desired product (rt - 1.23, [M+H]+ - 426.3/428.3, basic 2 min). On cooling the reaction mixture was evaporated to dryness and the resultant residue partitioned between ethyl acetate and water. The organic phase was separated and sequentially washed with saturated bicarbonate solution, water, brine, then dried over Na2SO4, filtered and evaporated. The resultant solid was triturated with MTBE (10 mb) and filtered off to afford Pl (507.0 mg, 0.991 mmol, 71.8%, 7-{2-[(tert-buty^?ldimethylsiiyl)oxy']ethyl}-2-chioro-N-[2-(lH-indoi- 3-yl)ethyi]-5H,6H,7H,8H-pyrfdo[3,4-d]pyrjmidfn-4-amine) as an off-white solid.

UPLC-MS (2 min basic): rt = 1.53 min (M+H+ = 486.3/488.3) iH NMR (400 MHz, DMSO) 6 10.78 (s, IH), 7.60 (dp, j = 7.9, 0.7 Hz, IH], 7.37 (t, j = 5.7 Hz, TH], 7.28 (dt, J - 8.1, 0.9 Hz, 1 H], 7.12 (d, .] - 2.3 Hz, IH), 7.01 ftd, J = 8.2, 7.0, 1.2 Hz, IH), 6.93 (tri, J = 7.9, 7.0, 1.1 Hz, IH), 3.70 ft, J - 5.9 Hz, 2H), 3.54 (dd, J - 14.6, 6.2 Hz, 2H), 3.36 (s, 2H], 2.95 - 2.86 (m, 2H), 2.70 (t, J = 5.8 Hz, 2H), 2.55 (t, J = 6.0 Hz, 2H), 2.28 (t, J = 5.8 Hz, 2H), 0.82 (s, 9H), -0.00 (s, 6H).

N-(2-(1.H-wdoI-3-yI)etbyl)-7-(2-((tert-butyldiniethyIsiIyl)oxy)etbyl)-2-(5-fiuoropyndm-3- yl)-5,6,7_>8-tetrahydropyrido[3,4-d]pyrimidin"4-amine

A reacti-vial was charged with 7-{2-[(tert-butyldimethylsi]yl)oxy]ethyl}-2-chloro-N-[2-(lH-indol- 3-yl)ediyl]-5H,6H,7H,8H-pyrido[3,4-d]pyrimidin-4-aniine) (507 mg, 1.04 mmol, 1.0 eq), (5- fiuoropyridin-3-yl)boronic acid (220 mg, 1.56 mmol, 1.5 eq), potassium carbonate (216 mg, 1.56 mmol, 1.5 eq), 1,4-dioxane (6.7 mb) and water (1,3 ml,), and the resulting mixture was purged with a gentle stream of nitrogen gas. [l,l^/-Bis(diphenylphosphino)ferrocene]dichloropalladium(II), (47 mg, 0.064 mmol, 0.061 eq) was added, and the vial was sealed and heated under nitrogen at 100 °C for 24 h. The reaction was cooled to ambient temperature and partitioned between water (10 ml,) and EtOAc (10 mL), The organic phase was collected and the aqueous was extracted with EtOAc (2 x 10 mb). The combined organics were washed with water (1 10 mL), dried (NajSCU), filtered and evaporated to dryness in vacuo to give the crude product as a residue. Purification by automated column chromatography over silica (12 g cartridge), eluting with a gradient of EtOAc in hexanes (0-100%) afforded the desired product as a solid (407 mg, 0.744 mmol, 71.4%).

UPLC-MS (2 min basic): it = 1.49

10.75 (s, 1H), 9.24 (t, ( - 1.7 Hz, 1H), 8.59 (d, j - 2.9 Hz, 1H), 8,23 (ddd, J - 10,1., 2.9, 1.6 Hz, 1H), 7,53 (d, j - 7.8 Hz, 1H), 7.27 (dt, J = 8.1, 1.0 Hz, 1H), 7.13 (d, J = 2.3 Hz, 1H), 7.09 (t, J = 5.8 Hz, 1H), 7.00 (ddd, J = 8.2, 7.0, 1.2 Hz, 1H), 6.90 (ddd, J = 8.0, 6.9, 1.0 Hz, 1H), 3.78 - 3.65 (m, 4H), 3.49 (d, J = 8.4 Hz, 2H), 2.97 (t, ( - 7,5 Hz, 2H), 2.74 (t, f - 5,8 Hz, 2H), 2.58 (t, f - 6,0 Hz, 2H), 2.36 (t, j - 5,8 Hz, 2H), 0.82 (s, 9H), -0.00 (s, 6H). ¹⁹F NMR (376 MHz, DMSO) 6 -127.77.

2-(4-((2-(lII-indol-3-yl)ethyI)amin0)~2-(5~fluoropyridiii-3-yl)-5₍8-dihydropyrido[3,4- -oI

Tetrabutylammonium fluoride solution (1.0 M in THF; 0.82 mL, 0.82 mmol, 1.0 eq) was added to a stirred solution of 7-{2-[(tert-but.yldimethylsi]yl)oxy]ethyl}-2-(5-f]uoropyridin-3-yl)-N-[2-(lH- indoI-3-ynethyI]“5H,6H,7H,8H~pyrido[3,4-d]pyrimidin--4--amine) (449 mg, 0.82 mmol, 1.0 eq) in dioxane (40 mL) at 0 °C, and the resulting mixture was stirred at room temperature for 16 h. The reaction mixture was evaporated to dryness in vacuo, and the resulting residue was dissolved in a 9:1 (v/v) mixture of DCM and MeOH (20 mb), before being washed sequentially with water (1 x 10 mL) and brine (1 x 10 mL). The organic phase was then dried (NazSCL), filtered and evaporated to dryness in vacuo to afford the desired product as a solid (190 mg, 0.43 mmol, 51.9%).

UPLC-MS (4 min basic): rt - 1,59 min (M + H+ - 433.4). ’H NMR (400 MHz, DMSO) 8 10.75 (d, J - 2.4 Hz, 1H), 9.24 (I. J - 1.7 Hz. 1 H), 8.59 (d, J - 2.9 Hz, 1H), 8.24 (ddd, J - 10.1, 2.9, 1.6 Hz, 1H), 7.54 (d, J = 7,8 Hz, IH), 7,27 (dd, J = 8,0, 1,0 Hz, 1HJ, 7.13 (d, J = 2.3 Hz, IH), 7,09 (t, J = 5.7 Hz, IH), 7.00 (Id, J - 8.1, 6.9, 1.2 Hz, IH), 6.91 (td, .] = 8.0, 7,0, 1.1 Hz, IH), 4.43 (t, J - 5.4 Hz, IH), 3.72 (q, J - 6.5 Hz, 2H), 3.54 (q, J = 5.9 Hz, 2H), 3.46 (s, 2H), 2,97 (t, J = 7.6 Hz, 2H), 2,71 (t, J = 5.8 Hz, 2H), 2.54 (t, J = 6.1 Hz, 2H 2.37 (t, J = 5.8 Hz, 2H). «F NMR (376 MHz, DMSO) 6 -127.77.

Example 2 2-(4“((2“(lH"indob3-yl)ethyl)aminG)-2-(5-fluoropyridin-3-yl)-5,8- dihydropynd0[3,4-d]pyrimidin-7(6H)-yl)propan-l-ol

Prepared in an analogous manner to Example 1, affording the desired product as a solid (66 mg, 0.15 mmol, 70.2%)- UPLC-MS (4 min basic): rt ~ 1.71 mins (M+H+ ~ 447.4). HI NMR (400 MHz, DMSO) S 10.83 (s, IHj, 9.32 (t, j = 1.7 Hz, IHj, 8.66 (d, J = 2.9 Hz, IH), 8.32 (ddd, J = 10.1, 2,9, 1.6 Hz, IH), 7,61 (d, J - 7,8 Hz, IH), 7.35 (dt. J = 8,1, 0.9 Hz, IH), 7.21 (d, J = 2.3 Hz, IH), 7.14 ft. J - 5.8 Hz, 1 H j, 7,08 (td, J - 8.2, 7.0, 1.2 Hz, 1 H), 6,98 (td, ( - 7.9, 7.0, 1.0 Hz, 1 H), 4.40 (dd, J - 6.2, 4.6 Hz, IHj, 3.79 (q, J = 6.6 Hz, 2H), 3.63 (s, 2H), 3.61 - 3.52 (m, 1 H ), 3.39 (dt, J = 10.8, 6.2 Hz, IH), 3.08 - 3.00 (m, 2H), 2.82 (tq, J = 11.2, 5.7 Hz, 3H j, 2,43 (d, J = 5.8 Hz, 2H), 1.03 (d, J = 6,7 Hz, 3H).

¹⁹F NMR (376 MHz, DMSO) 6 -127,79,

Example 3 2-(4-(2-(lH~indol-3~yl)ethoxy)-2-(5-fluoropyridhi-3-yl)-5₍8- dihydropyrido[3,4-d)pyTimidta-7(6H)-yl)ethan-l-oi

Prepared in an analogous manner to Example 1, affording the desired product as a solid [11 mg, 0.024 mmol, 17.2%). UPLC-MS (4 min basic): rt = 1.79 min (M+H+ = 434.5)

*H NMR (400 MHz, DMSO-d6] 6 10.87 (s, IH), 9.32 (t. J - 1.7 Hz, IH), 8.71 (d, J = 2,8 Hz, IH), 8.35 (ddd, J - 9,9, 2,9, 1.6 Hz, IH), 7.62 (d, J - 7.7 Hz, I H), 7,34 (dt, J - 8.1, 1.0 Hz, IH), 7.26 (d, J - 2.3 Hz, IH), 7.07 (td, J = 8.2, 7.0, 1.2 Hz, IH), 6.99 (td, J = 8.0, 7.0, 1.1 Hz, IH), 4.77 (t, J = 6,9 Hz, 2H), 4.52 ft, J - 5.4 Hz, IH), 3.67 (s, 2H), 3.61 (q, J = 5,8 Hz, 2H), 3.22 (t, J - 6.9 Hz, 2H), 2.77 (t, .] = 5.9 Hz, 2H], 2.63 (t, J - 6.1 Hz, 4H)

^{! 9}F NMR (376 MHz, DMSO-d6) 6 -127.31.

Example 4 ethyl (E)-5"(3-ethoxy-3"OX0prop"l-en-l-yl)"lH-pyrrole-2-carboxylate

A cooled suspension of sodium hydride (1.56 g, 38.89 mmol, 1.3 eq) in 1,4-dioxane (35.8 mb] was treated with ethyl 2-(diethoxyphosphoryl)acet.ate (8.3 mL, 41.9 mmol, 1.4 eq], and the resulting mixture was stirred at 0 °C for 3 h. Ethyl 5- formyl- lH-pyi'role-2-carboxylate (5.0 g, 29.9 mmol, 1.0 eq) was added, and the resulting mixture was stirred at ambient temperature for 18 h. The reaction mixture was quenched by the additional of a saturated solution of aqueous ammonium chloride (50 mb) and extracted into diethy] ether (5 *• 50 mb). The combined organics were washed with brine (50 mb), dried (NajSOi), filtered and concentrated under reduced pressure. The crude material was triturated in a 9:1 (v/v) mixture of n-heptane and EtOAc (70 mL], filtered and dried under vacuum to afford the desired product as a solid (6.280 g, 26.469 mmol, 88.5%).

UPLC-MS (2 min basic): rt = 1.07 min (M-H- = 236.1)

A mixture of ethyl 5 -[(lE)-3-ethoxy-3-oxoprop-l-en-l-yl]-lH-pyrroie-2-carboxylate (1.0 g, 4.22 mmol, 1.0 eq) and rhodium on alumina ((0.70 g), corresponding to 0.34 mmol Rh (0.08 eq)], was suspended in acetic acid (4.0 mb) under nitrogen at ambient temperature. The flask was vacuum purged with hydrogen gas, and the resulting mixture was stirred at ambient temperature under hydrogen for 12 h. The crude reaction mixture was passed through a pad of Celite, washing with DCM (2 x 10 mb). The combined filtrate and washings were washed with aq. NaHCO3, brine, dried (Na2SO4), filtered and concentrated under reduced pressure to afford the desired product as an oil (0.99 g, 4.09 mmol, 96.9%). The product was used without any purification.

*H NMR (400 MHz, DMSO) 6 4.12 - 4,00 (m, 4H), 3.64 (dd, | = 8.9, 5.4 Hz, 1H), 2.97 (p, j = 6.9 Hz, 1H), 2.85 (s, 1H), 2.42 - 2.33 (m, 1H), 2.33 - 2.24 (m, 1 H), 2.00 - 1.86 (m, 1H), 1.85 - 1.71 (m, 2H), 1.62 (q, J = 7.4 Hz, 2H), 1.33 ■■ 1.23 (m, 1H), 1.23 ■■ 1.12 (rn, 6H).

1- (tert- butyl) 2-ethyl 5-(3-ethoxy-3-oxopropyI)pyrroIidine-l,2-dicarboxylate (JR_VC_278)

A solution of ethyl 5-(3-ethoxy-3 -oxopropyI)pyrrohdine-2-carboxyiate (1.85 g, 7.60 mmol, 1.0 eq) and di-tert-butyl dicarbonate (1.83 g, 8.36 mmol, 1.10 eq) in dichloromethane (15.2 mb) was slowly charged with triethylamme (2.1 mb, 15,21 mmol, 2,0 eq). The resulting reaction mixture was stirred at ambient temperature overnight.

The reaction mixture was diluted with DCM (10 mb) and washed with water, brine, dried over Na2SO4, filtered and concentrated to afford the desired product as an oil (2.72 g, 7.524 mmol, 99.0%). UPLC-MS/ELSD (2 min basic): rt ~ 1.19 min (M+H+ ~ 344.2, M-Boc+H+ ~ 244.1) 1H NMR (400 MHz, DMSO) 8 4.25 - 3.98 (m, 5H), 3.91 - 3.75 (m, 1H), 2.42 - 2.27 (m, 2H), 2.25 - 2.13 (m, 1H), 2.01 - 1.77 (m, 3H), 1.75 - 1.59 (m, 2H), 1.44 - 1.24 (m, 9H), 1.25 - 1.14 (m, 6H).

8-(tert-but}4) 3~ethyl 2-oxo-8-azabicydo[3.2.1]octane-3,8-dicarboxylate (VC-0046-10)

A stirring solution of l-(tert-butyi) 2-ethyl 5-(3-ethoxy-3-oxopropyl)pyrro]idine-l,2-dicarboxylate (1.00 eq. 1.35 g, 3.73 mmol) in THF (29.9 mL) and Potassium tert-butoxide (1.20 eq, 0.50 g, 4.48 mmol) was heated at 60° C for 2h. The reaction was cooled and concentrated under reduced pressure. The residue was resuspended in DCM (20 mL] and washed with sat. NH4CI. The aqueous layer was re-extracted with EtOAc (20 mL x 3). The combined organic layers were washed with brine, dried (NaaSOj), filtered and concentrated under reduced pressure to afford the desired product as an oil (0.99 g, 3,16 mmol, 84.7%). UPLC-MS (2 min acidic): rt - 1.26 min (M-Boc+H+ - 198.1). ^!H NMR (400 MHz, DMSO) 6 11.78 (s, 1H), 4.25 (s, 2H), 4.20 - 4.01 (m, 6H), 3.87 (dd, J - 11.1, 7.8 Hz, 1H), 2.64 (s, 1H), 2.22 - 2.02 (m, 4H), 2.02 ■■ 1.82 (m, 4H), 1.70 - 1.55 (m, 2H), 1.38 (s, 18H), 1.25 - 1.15 (m, 6H). tert-butyl 2-(5-fluoropyridin-3-yl)-4-hydroxy-6,7,8,9"tetrahydro-5H-6,9 epiminocydohepta[d] pyrimidine- 10-carbnxyIate

To a stirring solution of 8- (tert- butyl) 3-ethyl 2-oxo-8-azabicyclo|3.2.1]octane--3,8-dicarboxylate (1.00 eq, 0.99 g, 3.16 mmol) in Ethanol (25.3 mb), 5-fluoropyridine-3-carboxamidine hydrochloride (1.0 eq, 555 mg, 3.16 mmol] and potassium tert-butoxide (3,0 eq, 1.06 g, 9.49 mmol) were added and the resulting mixture was stirred at ambient temperature for 18 h. The reaction mixture was evaporated under reduced pressure, Water (20 mL) was added to the residue to obtain a solution which was acidified with citric acid added portion wise to pH —3, The resulting suspension was filtered. The solid precipitate was washed with the minimum amount of water and vacuum dried at 45 °C to afford the desired product as a solid (0.77 g, 1.84 mmol, 58.2%).

UPLC-MS (2 min acidic): rt = 1.00 mins (M+H+ = 373.2, M-H- = 371,2)

’H NMR (400 MHz, DMSO) 0 9.14 (s, 1H), 8.74 (d, J - 2.8 Hz, 1H), 8.36 - 8.26 (m, i ll), 4.63 (d, J - 5.5 Hz, 1H), 4.42 (s, 1 H ), 2.84 (dd, J = 17.7, 4.8 Hz, 1H), 2.39 - 2.09 (m, 3H), 2.00 - 1.87 (m, 1H), 1.62 (s, 1HJ, 1.38 (s, 9H), =% NMR (376 MHz, DMSO] 6 -127.02. tert-butyl 4-chlGro-2-(5-fluoropyridin-3-yI)-6,7,8₎9-tetrahydro-5H-6,9- epiminocydohepta(d]pyrimidme-10-carboxylate

A suspension of tert-butyl 2-(5-fluoropyridin-3-yr)-4-hydroj^-6,7,8,9-tetrahydro-5H-6,9 epiminocyclohepta[d]pyrimidine-10-carboxylat.e (1.0 eq, 0.72 g, 1.72 mmol) and triphenylphosphine (3.0 eq. 1.35 g, 5.16 mmol) in 1,2-dichforoethane (17.2 mb] was treated with carbon tetrachloride (4.0 eq, 0.66 mb, 6.88 mmol), and the resulting mixture was stirred at 70 °C for 1 h. The solvent was evaporated to afford a residue, which was purified by automated column chromatography (24 g column), eluting with 25% EtOAc in iso-hexane to afford the desired product as a solid (0.57 g, 1.44 mmol, 83.9%).

UPLC-MS (2 min basic): rt - 1.32 mins (M+H+ - 391.3/393.3) iH NMR (400 MHz, DMSO) 8 9.31 ft, J - 1.7 Hz, IH), 8.79 (d, f - 2.8 Hz, IH), 8.50 - 8.31 ( m, IH), 4.94 fd, J = 6.4 Hz, IH), 4.56 (s, IH), 3.14 (dd, J = 17.8, 5.1 Hz, IH), 2.69 (cl, J = 17.6 Hz, IH), 2.33 - 2.13 (m, 2H), 2.02 - 1.91 (m, IH], 1.83 - 1.69 (m, IH], 1.27 (s, 9H).

A suspension tert-butyl 4-chloro-2-(5-fluoropyrfdin-3-yl)-6,7,8,9-tetrahydro-5H-6,9-epfmino cydohepta[d]pyrimidine-10-carboxylate (0.18 g, 0.46 mmol, 1,0 eq), 2-(lH-indol-3-yl)ethan-l- amine (97 mg, 0.61 mmol, 1.32 eq] and triethylamine (0.13 mL, 0.92 mmol, 2.0 eq) in propan-2-ol (3.1 mb) was reacted at 120 °C under microwave irradiation for 2 h. The reaction was concentrated under reduced pressure and the resulting residue was treated with water (15 mb) under vigorous stirring. The resulting suspension was sonicated and filtered to give a whitish solid crude which was thoroughly washed with water followed by a 5:1 (v/v) mixture of iso-hexane and diethyl ether fl mb), before being dried under vacuum to afford the desired product as a solid

(0.21 g, 0.41 mmol, 88.6%). UPLC-MS (2 min basic): rt~ 1.27 mins (M+H+ ~ 515.3, M-H- ~ 513.3] ^! H NMR (400 MHz, DMSO] 5 10.83 (s, IH], 9.33 (t, j = 1.7 Hz, IH), 8.68 fd, J = 2.9 Hz, IH), 8.40 - 8.29 (m, IH), 7.58 (d, J - 7.9 Hz, IH), 7.37 - 7.30 (m, IH), 7.20 fd, .] - 2.3 Hz, IH), 7.15 (1; J = 5.7 Hz, IH), 7.10 - 7.04 (m, IH), 7.00 - 6.94 fin, IH), 4.68 fd, J - 5.9 Hz, I H), 4.49 (s, IH), 3.85 - 3.68 (m, 2H), 3.03 ft, J = 7.5 Hz, 2H), 2.88 (d, J = 15.6 Hz, IH), 2.30 - 2.04 fm, 3H), 1.94 - 1.84 (m, IH), 1.70 ■ 1.58 (m, IH), 1.36 (s, 9H). W NMR (376 MHz, DMSO) 6 -127.65.

Example 5 N-(2-(lH-indoI-3-yI)ethyl)-2-(5-fluoropyridiu-3-yl)-6,7,8,9-tetrahydro-5H-

6,9-epiminocydohepta[d]pyrimidin-4-amine hydrochloride

A 4M solution of hydrogen chloride (2.0 mL, 7.97 mmol, 20.0 eq] in 1,4-dioxane was added to a suspension of tert-butyl 4-{[2-(2-ethyl-lH-indol-3-yl)ethyI]amino}-2-(5-f]uoropyridin-3-yl)- 5H,6H,7H,8H-pyrido[3,4-d]pyrlmidine-7-carbc»qdate) (0.205 g, 0.398 mmol, 1.0 eq) in dichloromethane (2.4 mL). The reaction mixture was stirred at ambient temperature for 1 h. The reaction mixture was evaporated to dryness to obtain an orange residue which was triturated with 9:1 (v/v) mixture of diethyl ether and MeOH (10 mL), filtered, washed with diethyl ether (10 mL) and dried under vacuum at 45 °C to afford the desired product as a solid (0.18 g, 0.39 mmol, 100%). UPLC-MS (4 min basic): rt - 1.66 mins (M<H+ - 415,3, M-H- - 413.3) iH NMR (400 MHz, DMSO) 8 10.87 (s, 1H), 9.72 (s, 1 H), 9.48 (d, J - 10.1 Hz, 1H), 9.34 (t, J = 1.7 Hz, 1H), 8.73 (cl, J = 2.9 Hz, 1H), 8.42 ■■ 8.34 (m, 1 H), 7.67 - 7.51 (m, 2H), 7.39 - 7.30 (m, 1H), 7.23 i d, J = 2.2 Hz, 1H), 7.13 - 7.04 (m, 1H), 7.03 - 6.95 (m, 1H), 4.64 (d, J = 5.2 Hz, 1H), 4.46 (s, 1H), 3.89 - 3.76 (m, 2H), 3.09 - 2.94 (m, 3H], 2.44 (d, J - 17.3 Hz, 1H), 2.37 - 2.22 (m, 2H), 2.16 (t, J = 10.4 Hz, 1H), 1.86 - 1.74 (m, 1 H ). ^:% NMR (376 MHz, DMSO) 5 -127.32.

Example 6 l-(4-((2-(lH-indoI-3-yI)ethyI)ammo)-2-(5-fluoropyridin-3-yI)-6,7,8,9- ] pyrimidm - 10-yl) -2 - (tert-bu toxy) e than- 1 -one

To a solution of N-(2-(LH-indoI-3-yl)ethyl)-2-(5-lluoropyridin-3-yl)-6,7,8,9-tetrahydro-5H-6,9- epiminocydobepta[d]pyrimidin-4-amine hydrochloride (60 mg, 0.13 mmol, 1.0 eq) and triethylamine (0.093 mL, 0.67 mmol, 5.0 eq) in N,N- dimethylformamide (1.3 mL) was added 2- (tert-butoxy)acetic acid (53 mg, 0.39 mmol, 3.0 eq), followed by 1- [bis(dimethylamino)methylene]-lH-l,2,3-triazolo[4,5-b]pyridinium 3-oxid hexafluorophosphate (101 mg, 0.27 mmol, 2.0 eq), and the resulting solution was stirred at ambient temperature for 20 min. The mixture was poured into water (10 mL), and the resulting suspension was filtered to give a solid, which was washed with water (10 mb) and dried by suction to afford the desired product as a solid (48 mg, 0.087 mmol, 65.5%). UPLC-MS (2 min basic): rt ~ 1.17 mins (M+H+ ~ 529.3) iH NMR (400 MHz, DMSO) 8 10.83 (s, 1H), 9.34 (s, 1H), 8.68 (d, J = 2.9 Hz, 1H), 8.33 (d, J = 8.4 Hz, 1H), 7.56 (d, J - 7.4 Hz, 1H), 7.34 (d, ] - 8.1 Hz, 1 H), 7.28 - 7.09 (m, 2H), 7.07 (t, j - 7.4 Hz, 1H), 6.96 (t, J = 7.4 Hz, 1H), 5.08 (d, J - 6.2 Hz, 1H), 4.86 (s, 1H), 4.10 - 3.84 (m, 2H), 3.76 (s, 2H), 3.03 (t. J = 7.6 Hz, 3H), 2.87 - 2.74 (m, 1H), 2.39 ■■ 1.85 (m, 4H), 1.75 ■■ 1.56 (m, 1H), 1.19 (s, 4H), 1.05 (s, 5H). ^,9F NMR (376 MHz, DMSO) 6 -127.64 (d, J = 11.7 Hz).

Example 7 l"(4-((2-(lH-indoI"3-yI)ethyl)ammo)“2-(5“fluoropyridin"3-yI)-6,7,8,9- tetrahydro-5H~6,9~epimmocydohepta(djpyrimidin-10-yl)-2-hydroxyethan-l-one To a solution of l-(4-((2 ■(lH-indoi-3-yi)ethyi)an'iino)-2-(5-fiuoropyridin-3-yI)- 6, 7, 8, 9- tetrahydro- 5H-6,9-epiminoe}⁷clohepta(d]pyrimidin-10-yl)-2-(tert-butoxy)ethan-l-one (45 mg, 0.085 mmol, 1.0 eq) in dichloromethane (1.7 ml.) was added a 4 M solution of hydrogen chloride in 1,4-dioxane

> (0.43 mL, 1.70 mmol, 20 eq), and the resulting solution was stirred at ambient temperature for 1 h.

The mixture was evaporated to dryness, and the resulting residue was purified by reversed-phase chromatography (CIS; 12 g column] under basic conditions (water r 0.1% NH.4OH / acetonitrile 0.1% NH4OH) to afford the desired product as a solid (26 mg, 0.055 mmoi, 64.6%].

UPLC-MS (4 mm basic): rt = 1.63 mln (M+H+ = 473.3). ^: H NMR (400 MHz, DMSO) 6 10.83 ( s, IH), 9.34 (d, J = 7.2 Hz, IH], 8.68 (d, J = 2.9 Hz, 1H), 8.35 (t, J = 8.8 Hz, IH), 7.57 (d, | = 7.9 Hz, 1H), 7.34

(d, J - 8.1 Hz, IH), 7.25 - 7.10 (m, 2H), 7.11 - 7.03 (m, IH), 7.01 - 6.94 (m, IH], 5.14 - 4.70 (m, 3H), 4.32 - 3.66 (m, 4H), 3.03 (t, J = 7.7 Hz, 2H), 2.94 - 2.79 (m, IH), 2.32 - 1.89 (m, 4H), 1.79 - 1.54 (m, IH). NMR (376 MHz, DMSO] S -127.67 (d, ] = 11.9 Hz).

The following Examoles were repared by methods analogous to Examples 1 to 7,

EG Structure rnman PBMC mhmition 11937 Antagonist

No:

22 release DICSO average uICSO

5 7.89 7.45

8.4 8.32

to vitro assay 1: AAR Antagonism in U937 cells (Promega P450-Glo™ Assay)

AhR antagonism was assessed in U937 ceils (myeloid lineage ceil line derived from a human histiocytic lymphoma). ). Ligand binds the AhR in the cytoplasm, and the AhR-Iigand complex translocates to the nucleus and forms a heterodimer with AhR nuclear translocator (Arnt). This complex binds the xenobiotic response element (XRE) in the 5' upstream region of the CYP1A1 promoter, enhancing CYP1A1 expression. CYP1A1 activity is subsequently determined by assessing the conversion of Luciferin-CEE to luciferin, which in turn reacts with luciferase to produce light, The amount of light produced is directly proportional to cytochrome P450 activity.

U937 cells in Ultraculture serum free media (Lonza) were plated at 100,000 ceils per well in a round bottom 96 well tissue culture plate. Seven concentrations of test compound (final [DMSO] 1%) were added and incubated for 10 minutes before the addition of 300pM KYNA, The plates were then placed in an incubator at 37°C, > 85% humidity, 5% CO? for 24hrs. After aspiration of the supernatant the CYP1A1 substrate Luciferin-CEE ([Final) 83 pM) was added and incubated for 3 hrs before the reaction was stopped by adding luciferin detection reagent and luminescence was read after 20 minutes. hi vitro assay 2: CYP1A1 inhibition assay

The direct CYP1A1 inhibitory activity of test compounds was also assessed using the Promega P450-G1O™ assay system. Seven concentrations of test compound were added to a % area white 96 well plate. Cypex CYP1A1 bactosomes ([final] 0.5pmoi) and CYP1A1 substrate Luciferin-CEE ([final] 30uM) were prepared in 0.1M potassium phosphate buffer and incubated with test

Claims

1. A compound of formula (I)

R⁴ b

Y

(i) wherein:

Y is phenyl or a 3 to 6 membered ring optionally comprising 1, 2, or 3 heteroatoms selected from N, 0 and S, said phenyl or ring substituted with R⁵ and R⁶;

R¹ is H, C1.3 alkyl, (-CHJpCN, -COC1.3 alkyl, -CO(CH₂)qNR⁷R⁸, -SO2C1.3 alkyl, -SO₂NR⁷R⁸, -(CHz)qPh, C3.5 cycloalkyl, C1.3 alkyl bearing 1 to 6 halogen groups, C1.3 alkyl bearing one or more independently selected from OR^Y and -NR⁷R³ (such as one OR^Y and optionally 1 - NR⁷R⁸), -(CH₂)p' OCi-salkyl substituted with 1 to 6 halogen groups (such as -(CH₂)p' OCF3), -Co-3alkyleneC(0)Co-3 alkyl wherein the alkyl is or bears at least one group selected from OR^Y and -NR⁷R³ (such as one OR^Y and optionally 1 -NR⁷R³), Z,-C(O)(CH₂)qZ; -C(O)O(CH₂)qZ -C(O)O(CH_z)pPh, -C(O)(CH₂)qZ', -C(O)O(CH₂)qZ’;

R² is H or C1.3 alkyl, C3-5 cycloalkyl halogen and C1.3 alkyl optionally bearing one or more groups independently selected from OR^Y, halogen -NR⁷R⁶-such as OR^Y and halogen (e.g. F) in particular only one group [in one embodiment is H or Ci .3 alkyl, C3.5 cycloallyl];

R²’ is H, C1.3 alkyl or halogen (such as F or Cl), such as H or C1-3 alkyl; wherein R² & R²' together can form an alkylene bridge -CH₂CH₂-, CH2- or -NR⁸- between two carbons in the ring, such as -CH_ZCH_Z-;

R³ is H or C1.3 alkyl;

R» is a 9 to 13 membered heterocycle with at least one heteroatom selected from N, 0 and S (for an aromatic or partially saturated), with substituentsR⁹, R⁹' and R¹⁰;

R? is H, hydroxy, halogen (such as F, Cl), CN, C1.3 alkyl, C1.3 alkoxy (such as OMe),

Ci-2 haloalkyl (i,e, alkyl bearing 1 to 6 halogen groups, such as CF3), C1.3 alkyl bearing one or more OH groups, -C(0)(CH₂)qNR⁷R⁸, -SO₂Ci.₃ alkyl, -SO₂ NR⁷R⁸,

R» is H, hydroxy, halogen (such as F, Cl), CN, C1.3 alkyl, -C(0)(CH_z)qNR⁷R⁸, -SO₂Ci« alkyl, -SO₂ NR⁷R«

R⁷ is H, C1.3 alkyl or -C(O)OR^Y, for example H or C1.3 alkyl, such as -CH3;

Rs is H or C1.3 alkyl, such as -CH3;

R? is H, hydroxy, halogen (such as F, Cl), CN, C1.3 alkyl, C1.3 alkoxy (such as OMe), C1.3 alkyl bearing 1 to 6 halogen groups (such as CF₃), Cj.3 alkyl bearing one or more OR^Y groups, Cs-scycloalkyl, -(CH_z)qOCi-3alkyl substituted with 1 to 6 halogen groups (such as - (CH_z)qOCF₃), -CO(CH₂)q NR⁷R⁸, -SO_zCi-₃ alkyl, or -SO₂ NR⁷R⁸;