CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No. 17/119,512 filed Dec. 11, 2020, which claims priority to U.S. Provisional Patent Application No. 62/946,876 filed Dec. 11, 2019, the disclosures of which are incorporated herein by reference in their entireties.

FIELD OF THE INVENTION

The invention relates to combinations of Ataxia-telangiectasia and RAD-3-related protein (ATR) kinase inhibitors, pharmaceutically acceptable salts thereof, or pharmaceutical composition containing the same, and Poly (ADP ribose) polymerase (PARP) inhibitors, pharmaceutically acceptable salts thereof, or pharmaceutical composition containing the same, and their use in the treatment of a disease or condition, such as cancer.

BACKGROUND

DNA damage occurs continually in cells as a result of environmental insults including ultraviolet radiation, X-rays and endogenous stress factors, such as reactive oxygen and hydrolysis of bases. Cancer cells are subject to a higher rate of DNA damage inherently induced by higher rates of DNA replication in these cells. Several DNA damage response (DDR) pathways have evolved in a highly coordinated manner to help repair DNA damage and to act as a cellular checkpoint to stop the replication of cells with damaged DNA, allowing for repair functions to occur before the damaged DNA is passed on to daughter cells. Each of the identified DNA repair pathways sense and repair distinct but overlapping types of DNA damage.

One major DDR protein that acts as a key cell cycle checkpoint is the ataxia telangiectasia mutated and rad3-related (ATR) kinase, related to the family of phosphoinositide 3-kinase-related protein kinases (PIKKs). ATR is activated by single stranded (ss) DNA lesions caused by stalled replication forks or during nucleotide excision repair but is also activated by double strand breaks following DNA end resection during homologous recombination. ATR is recruited to sites of DNA damage by binding to the RPA protein that coats ssDNA along with an accessory factor called ATR-interacting protein (ATRIP). The ATR/ATRIP complex is then activated by recruitment of additional factors in the 9-1-1 complex (RAD 9, RAD1, and HUS1) which subsequently recruits the TOPBP1 protein and represents critical steps for activation of the downstream phosphorylation cascade that results in cell cycle arrest. The primary target for ATR kinase is CHK1, which when phosphorylated, targets both cdc25 proteins and Wee1 resulting in inhibition of cyclin-dependent kinase activity and cell cycle arrest in S-phase or in G2/M.

ATR has been identified as an important cancer target since it is essential for dividing cells. ATR deficient mice are embryonic lethal, however, adult mice with conditional ATR knocked out are viable with effects on rapidly proliferating tissues and stem cell populations. Mouse embryonic stem cells lacking ATR will only divide for 1-2 doublings and then die, suggesting that ATR is required for the maintenance of dividing cells. Interestingly, mice harboring hypomorphic ATR mutations that reduce expression of ATR to 10% of normal levels showed reduced H-rasG12D-induced tumor growth with minimal effects on proliferating normal cells, e.g., the bone marrow or intestinal epithelial cells. Cancer cells that have high levels of replication stress due to oncogenic mutations, dysfunctional GUS checkpoint control (e.g., loss of p53 function), defects in other DNA repair pathways (e.g., ATM) or that are subject to the effects of DNA damaging agents, e.g., radiation therapy or chemotherapeutic agents, are therefore more dependent on ATR for DNA repair and survival. Together, these results highlight a rationale for the selective sensitivity of proliferating tumor cells to ATR inhibition and the potential for a therapeutic window over healthy proliferating cells.

Inhibitors of poly(ADP-ribose) polymerases (PARP inhibitors) target the DNA repair enzyme poly(ADP-ribose) polymerase 1 (PARP1) and closely related paralogs. Several PARP inhibitors (olaparib, niraparib, rucaparib, talazoparib) have been approved for treatment of various cancers (e.g., ovarian cancer, breast cancer, fallopian tube cancer, and primary peritoneal cancer).

There is a need for new anti-cancer therapies and, in particular, effective combinations of known inhibitors with different mechanisms of action that can synergize to increase overall efficacy and treat a broader spectrum of cancers than either inhibitor alone.

SUMMARY OF THE INVENTION

In general, the invention provides a combination of an ATR inhibitor, or a pharmaceutically acceptable salt thereof, and a PARP inhibitor, or a pharmaceutically acceptable salt thereof for the treatment of cancers or for inducing cell death in cancer cells. The cancers included herein may be, e.g., cancers having a loss of function of ATM, BRCA2, RNAse H2A, RNAse H2B, CDK12, or a combination thereof. The cancer may be, e.g., an ALT+ cancer.

In one aspect, the invention provides a method of treating a cancer in a subject, the method comprising administering to the subject in need thereof a therapeutically effective amount of an ATR inhibitor and PARP inhibitor, where the cancer has been previously identified as a cancer having a loss of function of ATM, BRCA2, RNAse H2A, RNAse H2B, CDK12, or a combination thereof, or the cancer has been previously identified as an ALT+ cancer.

In another aspect, the invention provides a method of treating a cancer in a subject, the method comprising administering to the subject in need thereof a therapeutically effective amount of an ATR inhibitor and PARP inhibitor, where the cancer has a loss of function of ATM serine/threonine kinase, BRCA2, RNAse H2A, RNAse H2B, CDK12, or a combination thereof, or the cancer is an ALT+ cancer.

In yet another aspect, the invention provides a method of treating a cancer in a subject, the method comprising:

- (i) identifying the cancer as having a loss of function of ATM, BRCA2, RNAse H2A, RNAse H2B, CDK12, or a combination thereof, or as an ALT+ cancer; and
- (ii) administering to the subject in need thereof a therapeutically effective amount of an ATR inhibitor and PARP inhibitor.

In some embodiments, the ATR inhibitor is administered before the PARP inhibitor (e.g., within 1 week, within 6 days, within 5 days, within 4 days, within 3 days, within 2 days, within 1 day, or within 12 hours). In some embodiments, the ATR inhibitor is administered after the PARP inhibitor (e.g., within 1 week, within 6 days, within 5 days, within 4 days, within 3 days, within 2 days, within 1 day, or within 12 hours). In some embodiments, the ATR inhibitor is co-administered with the PARP inhibitor. In some embodiments, the ATR inhibitor is administered intermittently (e.g., 1 day/week, 2 days/week, or 3 days/week). In some embodiments, the PARP inhibitor is administered on a continuous daily basis.

In some embodiments, the therapeutically effective amount is a subtherapeutic regimen of the ATR inhibitor. In some embodiments, the therapeutically effective amount is a subtherapeutic regimen of the PARP inhibitor. In some embodiments, the subtherapeutic regimen comprises a starting dosage that is at least 50% less than the lowest standard starting dosage that is used for a monotherapy. In some embodiments, the subtherapeutic regimen comprises a maintenance dosage that is at least 50% less than the lowest standard maintenance dosage that is used for a monotherapy. In some embodiments, the maintenance dosage comprises a first reduced dosage. In some embodiments, the maintenance dosage comprises a second reduced dosage. In some embodiments, the maintenance dosage comprises a third reduced dosage. In some embodiments, the route of administration is an oral administration.

In still another aspect, the invention provides a method of inducing cell death in an aberrant cancer cell having a loss of function of ATM, BRCA2, RNAse H2A, RNAse H2B, CDK12, or a combination thereof, or in an ALT+ cancer cell, the method comprising contacting the cell with an effective amount of an ATR inhibitor and an effective amount of a PARP inhibitor, the effective amounts being sufficient to induce cell death in the aberrant cancer cell.

In some embodiments, the loss of function is a loss of function of ATM. In some embodiments, the loss of function is a loss of function of RNAse H2A. In some embodiments, the loss of function is a loss of function of RNAse H2B. In some embodiments, the loss of function is a loss of function of CDK12. In some embodiments, the loss of function is a loss of function of BRCA2. In some embodiments, the cancer is an ALT+ cancer.

In some embodiments, the ATR inhibitor is a compound of formula (I):

[Image Omitted]

- or a pharmaceutically acceptable salt thereof,
  
  wherein
- is a double bond, and each Y is independently N or CR⁴; or is a single bond, and each Y is independently NR^Y, carbonyl, or C(R^Y)₂; wherein each R^Yis independently H or optionally substituted C_1-6alkyl;
- R¹is optionally substituted C_1-6alkyl or H;
- R²is optionally substituted C_2-9heterocyclyl, optionally substituted C_1-6alkyl, optionally substituted C_3-8cycloalkyl, optionally substituted C_2-9heterocyclyl C_1-6alkyl, optionally substituted C_6-10aryl, optionally substituted C_1-9heteroaryl, optionally substituted C_1-9heteroaryl C_1-6alkyl, halogen, —N(R⁵)₂, —OR⁵, —CON(R⁶)₂, —SO₂N(R⁶)₂, —SO₂R^5A, or -Q-R^5B;
- R³is optionally substituted C_1-9heteroaryl or optionally substituted C_1-9heteroaryl C_1-6alkyl;
- each R⁴is independently hydrogen, halogen, optionally substituted C_1-6alkyl, optionally substituted C_2-6alkenyl, or optionally substituted C_2-6alkynyl;
- each R⁵is independently hydrogen, optionally substituted C_1-6alkyl, optionally substituted C_6-10aryl C_1-6alkyl, optionally substituted C_6-10aryl, optionally substituted C_1-9heteroaryl, or —SO₂R^5A; or both R⁵, together with the atom to which they are attached, combine to form an optionally substituted C_2-9heterocyclyl;
- each R^5Ais independently optionally substituted C_1-6alkyl, optionally substituted C_3-8cycloalkyl, or optionally substituted C_6-10aryl;
- R^5Bis hydroxyl, optionally substituted C_1-6alkyl, optionally substituted C_6-10aryl, optionally substituted C_1-9heteroaryl, —N(R⁵)₂, —CON(R⁶)₂, —SO₂N(R⁶)₂, —SO₂R^5A, or optionally substituted alkoxy;
- each R⁶is independently hydrogen, optionally substituted C_1-6alkyl, optionally substituted C_2-6alkoxyalkyl, optionally substituted C_6-10aryl C_1-6alkyl, optionally substituted C_6-10aryl, optionally substituted C_3-8cycloalkyl, or optionally substituted C_1-9heteroaryl; or both R⁶, together with the atom to which they are attached, combine to form an optionally substituted C_2-9heterocyclyl;
- Q is optionally substituted C_2-9heterocyclylene, optionally substituted C_3-8cycloalkylene, optionally substituted C_1-9heteroarylene, or optionally substituted C_6-10arylene; and
- X is hydrogen or halogen.

In some embodiments, the ATR inhibitor is a compound of formula (II):

[Image Omitted]

- or a pharmaceutically acceptable salt thereof,
  
  wherein
- each Y is independently N or CR⁴;
- R¹is optionally substituted C_1-6alkyl or H;
- R²is optionally substituted C_2-9heterocyclyl, optionally substituted C_1-6alkyl, optionally substituted C_3-8cycloalkyl, optionally substituted C_2-9heterocyclyl C_1-6alkyl, optionally substituted C_6-10aryl, optionally substituted C_1-9heteroaryl, optionally substituted C_1-9heteroaryl C_1-6alkyl, halogen, —N(R⁵)₂, —OR⁵, —CON(R⁶)₂, —SO₂N(R⁶)₂, —SO₂R^5A, or -Q-R^5B;
- R³is optionally substituted C_1-9heteroaryl or optionally substituted C_1-9heteroaryl C_1-6alkyl;
- each R⁴is independently hydrogen, halogen, optionally substituted C_1-6alkyl, optionally substituted C_2-6alkenyl, or optionally substituted C_2-6alkynyl;
- each R⁵is independently hydrogen, optionally substituted C_1-6alkyl, optionally substituted C_6-10aryl C_1-6alkyl, optionally substituted C_6-10aryl, optionally substituted C_1-9heteroaryl, or —SO₂R^5A; or both R⁵, together with the atom to which they are attached, combine to form an optionally substituted C_2-9heterocyclyl;
- each R^5Ais independently optionally substituted C_1-6alkyl, optionally substituted C_3-8cycloalkyl, or optionally substituted C_6-10aryl;
- R^5Bis hydroxyl, optionally substituted C_1-6alkyl, optionally substituted C_6-10aryl, optionally substituted C_1-9heteroaryl, —N(R⁵)₂, —CON(R⁶)₂, —SO₂N(R⁶)₂, —SO₂R^5A, or optionally substituted alkoxy;
- each R⁶is independently hydrogen, optionally substituted C_1-6alkyl, optionally substituted C_2-6alkoxyalkyl, optionally substituted C_6-10aryl C_1-6alkyl, optionally substituted C_6-10aryl, optionally substituted C_3-8cycloalkyl, or optionally substituted C_1-9heteroaryl; or both R⁶, together with the atom to which they are attached, combine to form an optionally substituted C_2-9heterocyclyl;
- Q is optionally substituted C_2-9heterocyclylene, optionally substituted C_3-8cycloalkylene, optionally substituted C_1-9heteroarylene, or optionally substituted C_6-10arylene; and X is hydrogen or halogen.

In some embodiments, the ATR inhibitor is selected from the group consisting of compounds 43, 57, 62, 87, 93, 94, 95, 99, 100, 106, 107, 108, 109, 111, 112, 113, 114, 115, 116, 118, 119, 120, 121, 122, 123, 135, 147, 148, and pharmaceutically acceptable salts thereof.

In some embodiments, the ATR inhibitor is compound 43 or a pharmaceutically acceptable salt thereof. In some embodiments, the ATR inhibitor is compound 121 or a pharmaceutically acceptable salt thereof. In some embodiments, the ATR inhibitor is compound 122 or a pharmaceutically acceptable salt thereof. In some embodiments, the PARP inhibitor is talazoparib or a pharmaceutically acceptable salt thereof. In some embodiments, the PARP inhibitor is niraparib or a pharmaceutically acceptable salt thereof. In some embodiments, the PARP inhibitor is rucaparib or a pharmaceutically acceptable salt thereof. In some embodiments, the PARP inhibitor is olaparib or a pharmaceutically acceptable salt thereof. In some embodiments, the cancer is renal cell carcinoma, mature B-cell neoplasms, endometrial cancer, ovarian cancer, fallopian tube cancer, primary peritoneal cancer, colorectal cancer, skin cancer, small bowel cancer, non-small cell lung cancer, melanoma, bladder cancer, pancreatic cancer, head and neck cancer, mesothelioma, glioma, prostate cancer, breast cancer, or esophagogastric cancer.

Definitions

The term “aberrant,” as used herein, refers to different from normal. When used to describe enzymatic activity, aberrant refers to activity that is greater or less than a normal control or the average of normal non-diseased control samples. Aberrant activity may refer to an amount of activity that results in a disease, where returning the aberrant activity to a normal or non-disease-associated amount (e.g. by administering a compound or using a method as described herein), results in reduction of the disease or one or more disease symptoms. The aberrant activity can be measured by measuring the modification of a substrate of the enzyme in question; a difference of greater or equal to a 2-fold change in activity could be considered as aberrant. Aberrant activity could also refer to an increased dependence on a particular signaling pathway as a result of a deficiency in a separate complementary pathway

The term “acyl,” as used herein, represents a group —C(═O)—R, where R is alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, cycloalkynyl, aryl, heteroaryl, or heterocyclyl. Acyl may be optionally substituted as described herein for each respective R group.

The term “adenocarcinoma,” as used herein, represents a malignancy of the arising from the glandular cells that line organs within an organism. Non-limiting examples of adenocarcinomas include non-small cell lung cancer, prostate cancer, pancreatic cancer, esophageal cancer, and colorectal cancer.

The term “alkanoyl,” as used herein, represents a hydrogen or an alkyl group that is attached to the parent molecular group through a carbonyl group and is exemplified by formyl (i.e., a carboxyaldehyde group), acetyl, propionyl, butyryl, and iso-butyryl. Unsubstituted alkanoyl groups contain from 1 to 7 carbons. The alkanoyl group may be unsubstituted of substituted (e.g., optionally substituted C1-7 alkanoyl) as described herein for alkyl group. The ending “-oyl” may be added to another group defined herein, e.g., aryl, cycloalkyl, and heterocyclyl, to define “aryloyl,” “cycloalkanoyl,” and “(heterocyclyl)oyl.” These groups represent a carbonyl group substituted by aryl, cycloalkyl, or heterocyclyl, respectively. Each of “aryloyl,” “cycloalkanoyl,” and “(heterocyclyl)oyl” may be optionally substituted as defined for “aryl,” “cycloalkyl,” or “heterocyclyl,” respectively.

The term “alkenyl,” as used herein, represents acyclic monovalent straight or branched chain hydrocarbon groups of containing one, two, or three carbon-carbon double bonds. Non-limiting examples of the alkenyl groups include ethenyl, prop-1-enyl, prop-2-enyl, 1-methylethenyl, but-1-enyl, but-2-enyl, but-3-enyl, 1-methylprop-1-enyl, 2-methylprop-1-enyl, and 1-methylprop-2-enyl. Alkenyl groups may be optionally substituted as defined herein for alkyl.

The term “alkoxy,” as used herein, represents a chemical substituent of formula —OR, where R is a C_1-6alkyl group, unless otherwise specified. In some embodiments, the alkyl group can be further substituted as defined herein. The term “alkoxy” can be combined with other terms defined herein, e.g., aryl, cycloalkyl, or heterocyclyl, to define an “aryl alkoxy,” “cycloalkyl alkoxy,” and “(heterocyclyl)alkoxy” groups. These groups represent an alkoxy that is substituted by aryl, cycloalkyl, or heterocyclyl, respectively. Each of “aryl alkoxy,” “cycloalkyl alkoxy,” and “(heterocyclyl)alkoxy” may optionally substituted as defined herein for each individual portion.

The term “alkoxyalkyl,” as used herein, represents a chemical substituent of formula -L-O—R, where L is C_1-6alkylene, and R is C_1-6alkyl. An optionally substituted alkoxyalkyl is an alkoxyalkyl that is optionally substituted as described herein for alkyl.

The term “alkyl,” as used herein, refers to an acyclic straight or branched chain saturated hydrocarbon group, which, when unsubstituted, has from 1 to 12 carbons, unless otherwise specified. In certain preferred embodiments, unsubstituted alkyl has from 1 to 6 carbons. Alkyl groups are exemplified by methyl; ethyl; n- and iso-propyl; n-, sec-, iso- and tert-butyl; neopentyl, and the like, and may be optionally substituted, valency permitting, with one, two, three, or, in the case of alkyl groups of two carbons or more, four or more substituents independently selected from the group consisting of: amino; aryl; aryloxy; azido; cycloalkyl; cycloalkoxy; cycloalkenyl; cycloalkynyl; halo; heterocyclyl; (heterocyclyl)oxy; heteroaryl; hydroxy; nitro; thiol; silyl; cyano; alkylsulfonyl; alkylsulfinyl; alkylsulfenyl; =O; ═S; —SO₂R, where R is amino or cycloalkyl; =NR′, where R′ is H, alkyl, aryl, or heterocyclyl. Each of the substituents may itself be unsubstituted or, valency permitting, substituted with unsubstituted substituent(s) defined herein for each respective group.

The term “alkylene,” as used herein, refers to a divalent alkyl group. An optionally substituted alkylene is an alkylene that is optionally substituted as described herein for alkyl.

The term “alkylamino,” as used herein, refers to a group having the formula —N(R^N1)₂or —NHR^N1, in which R^N1is alkyl, as defined herein. The alkyl portion of alkylamino can be optionally substituted as defined for alkyl. Each optional substituent on the substituted alkylamino may itself be unsubstituted or, valency permitting, substituted with unsubstituted substituent(s) defined herein for each respective group.

The term “alkylsulfenyl,” as used herein, represents a group of formula —S-(alkyl). Alkylsulfenyl may be optionally substituted as defined for alkyl.

The term “alkylsulfinyl,” as used herein, represents a group of formula —S(O)-(alkyl). Alkylsulfinyl may be optionally substituted as defined for alkyl.

The term “alkylsulfonyl,” as used herein, represents a group of formula —S(O)₂-(alkyl). Alkylsulfonyl may be optionally substituted as defined for alkyl.

The term “alkynyl,” as used herein, represents monovalent straight or branched chain hydrocarbon groups of from two to six carbon atoms containing at least one carbon-carbon triple bond and is exemplified by ethynyl, 1-propynyl, and the like. The alkynyl groups may be unsubstituted or substituted (e.g., optionally substituted alkynyl) as defined for alkyl.

The term “ALT+ cancer,” as used herein, refers to cancers utilizing homologous recombination-based pathway called alternative lengthening of telomeres (ALT) to extend and maintain telomeres. ALT+ cells may be identified using techniques known in the art. For example, ALT+ cells exhibit one or more of ALT-associated PML bodies, heterogeneous telomere length, abundant extrachromosomal telomere repeat (ECTR), and high levels of telomere sister chromatid exchange (T-SCE). See Bryan et al., EMBO J., 14:4240-4248, 1995; Dunham et al., Nat Genet., 26:447-450, 2000; Muntoni et al., Hum. Mol. Genet., 18:1017-1027, 2009; Yeager et al., Cancer Res., 59:4175-4179, 1999; and Cesare et al., Mol. Cell. Biol., 247:765-772, 2004. ALT+ cancer (e.g., ALT+ cancer cell) may be an ALT+ mesenchymal cancer (e.g., an ALT+ mesenchymal cancer cell). Non-limiting examples of ALT+ cancers include leiomyosarcoma, liposarcoma, glioblastoma, and neuroendocrine pancreatic cancer.

The term “amino,” as used herein, represents —N(R^N1)₂, where, if amino is unsubstituted, both R^N1are H; or, if amino is substituted, each R^N1is independently H, —OH, —NO₂, —N(R^N2)₂, —SO₂OR^N2, —SO₂R^N2, —SOR^N2, —COOR^N2, an N-protecting group, alkyl, alkenyl, alkynyl, alkoxy, aryl, arylalkyl, aryloxy, cycloalkyl, cycloalkenyl, heteroalkyl, or heterocyclyl, provided that at least one R^N1is not H, and where each R^N2is independently H, alkyl, or aryl. Each of the substituents may itself be unsubstituted or substituted with unsubstituted substituent(s) defined herein for each respective group. In some embodiments, amino is unsubstituted amino (i.e., —NH₂) or substituted amino (e.g., NHR^N1), where R^N1is independently —OH, SO₂OR^N2, —SO₂R^N2, —SOR^N2, —COOR^N2, optionally substituted alkyl, or optionally substituted aryl, and each R^N2can be optionally substituted alkyl or optionally substituted aryl. In some embodiments, substituted amino may be alkylamino, in which the alkyl groups are optionally substituted as described herein for alkyl. In some embodiments, an amino group is NHR^N1, in which R^N1is optionally substituted alkyl.

The term “aryl,” as used herein, represents a mono-, bicyclic, or multicyclic carbocyclic ring system having one or two aromatic rings. Aryl group may include from 6 to 10 carbon atoms. All atoms within an unsubstituted carbocyclic aryl group are carbon atoms. Non-limiting examples of carbocyclic aryl groups include phenyl, naphthyl, 1,2-dihydronaphthyl, 1,2,3,4-tetrahydronaphthyl, fluorenyl, indanyl, indenyl, etc. The aryl group may be unsubstituted or substituted with one, two, three, four, or five substituents independently selected from the group consisting of: alkyl; alkenyl; alkynyl; alkoxy; alkylsulfinyl; alkylsulfenyl; alkylsulfonyl; amino; aryl; aryloxy; azido; cycloalkyl; cycloalkoxy; cycloalkenyl; cycloalkynyl; halo; heteroalkyl; heterocyclyl; (heterocyclyl)oxy; hydroxy; nitro; thiol; silyl; and cyano. Each of the substituents may itself be unsubstituted or substituted with unsubstituted substituent(s) defined herein for each respective group.

The term “aryl alkyl,” as used herein, represents an alkyl group substituted with an aryl group. The aryl and alkyl portions may be optionally substituted as the individual groups as described herein.

The term “arylene,” as used herein, refers to a divalent aryl group. An optionally substituted arylene is an arylene that is optionally substituted as described herein for aryl.

The term “aryloxy,” as used herein, represents a chemical substituent of formula —OR, where R is an aryl group, unless otherwise specified. In optionally substituted aryloxy, the aryl group is optionally substituted as described herein for aryl.

The term “ATM,” as used herein, represents ATM serine/threonine kinase.

The term “ATR inhibitor,” as used herein, represents a compound that upon contacting the enzyme ATR kinase, whether in vitro, in cell culture, or in an animal, reduces the activity of ATR kinase, such that the measured ATR kinase IC₅₀is 10 μM or less (e.g., 5 μM or less or 1 μM or less). For certain ATR inhibitors, the ATR kinase IC₅₀may be 100 nM or less (e.g., 10 nM or less, or 1 nM or less) and could be as low as 100 μM or 10 μM. Preferably, the ATR kinase IC₅₀is 0.1 nM to 1 μM (e.g., 0.1 nM to 750 nM, 0.1 nM to 500 nM, or 0.1 nM to 250 nM).

The term “ATR kinase,” as used herein, refers to Ataxia-telangiectasia and RAD-3-related protein kinase.

The term “azido,” as used herein, represents an —N₃group.

The term “BRCA2,” as used herein, represents a breast cancer type 2 susceptibility gene or protein.

The term “cancer,” as used herein, refers to all types of cancer, neoplasm or malignant tumors found in mammals (e.g. humans), including leukemia, carcinomas and sarcomas. Non-limiting examples of cancers that may be treated with a compound or method provided herein include prostate cancer, thyroid cancer, endocrine system cancer, brain cancer, breast cancer, cervix cancer, colon cancer, head & neck cancer, liver cancer, kidney cancer, lung cancer, non-small cell lung cancer, melanoma, mesothelioma, ovarian cancer, sarcoma, stomach cancer, uterus cancer, medulloblastoma, ampullary cancer, colorectal cancer, and pancreatic cancer. Additional non-limiting examples may include, Hodgkin's disease, Non-Hodgkin's lymphoma, multiple myeloma, neuroblastoma, glioma, glioblastoma multiforme, ovarian cancer, rhabdomyosarcoma, primary thrombocytosis, primary macroglobulinemia, primary brain tumors, cancer, malignant pancreatic insulinoma, malignant carcinoid, urinary bladder cancer, premalignant skin lesions, testicular cancer, lymphoma, thyroid cancer, neuroblastoma, esophageal cancer, genitourinary tract cancer, malignant hypercalcemia, endometrial cancer, adrenal cortical cancer, neoplasms of the endocrine or exocrine pancreas, medullary thyroid cancer, medullary thyroid carcinoma, melanoma, colorectal cancer, papillary thyroid cancer, hepatocellular carcinoma, and prostate cancer.

The term “carbocyclic,” as used herein, represents an optionally substituted C3-16 monocyclic, bicyclic, or tricyclic structure in which the rings, which may be aromatic or non-aromatic, are formed by carbon atoms. Carbocyclic structures include cycloalkyl, cycloalkenyl, cycloalkynyl, and certain aryl groups.

The term “carbonyl,” as used herein, represents a —C(O)— group.

The term “carcinoma,” as used herein, refers to a malignant new growth made up of epithelial cells tending to infiltrate the surrounding tissues and give rise to metastases. Non-limiting examples of carcinomas that may be treated with a compound or method provided herein include, e.g., medullary thyroid carcinoma, familial medullary thyroid carcinoma, acinar carcinoma, acinous carcinoma, adenocystic carcinoma, adenoid cystic carcinoma, carcinoma adenomatosum, carcinoma of adrenal cortex, alveolar carcinoma, alveolar cell carcinoma, basal cell carcinoma, carcinoma basocellulare, basaloid carcinoma, basosquamous cell carcinoma, bronchioalveolar carcinoma, bronchiolar carcinoma, bronchogenic carcinoma, cerebriform carcinoma, cholangiocellular carcinoma, chorionic carcinoma, colloid carcinoma, comedo carcinoma, corpus carcinoma, cribriform carcinoma, carcinoma en cuirasse, carcinoma cutaneum, cylindrical carcinoma, cylindrical cell carcinoma, duct carcinoma, carcinoma durum, embryonal carcinoma, encephaloid carcinoma, epiermoid carcinoma, carcinoma epitheliale adenoides, exophytic carcinoma, carcinoma ex ulcere, carcinoma fibrosum, gelatiniforni carcinoma, gelatinous carcinoma, giant cell carcinoma, carcinoma gigantocellulare, glandular carcinoma, granulosa cell carcinoma, hair-matrix carcinoma, hematoid carcinoma, hepatocellular carcinoma, Hurthle cell carcinoma, hyaline carcinoma, hypernephroid carcinoma, infantile embryonal carcinoma, carcinoma in situ, intraepidermal carcinoma, intraepithelial carcinoma, Krompecher's carcinoma, Kulchitzky-cell carcinoma, large-cell carcinoma, lenticular carcinoma, carcinoma lenticulare, lipomatous carcinoma, lymphoepithelial carcinoma, carcinoma medullare, medullary carcinoma, melanotic carcinoma, carcinoma molle, mucinous carcinoma, carcinoma muciparum, carcinoma mucocellulare, mucoepidermoid carcinoma, carcinoma mucosum, mucous carcinoma, carcinoma myxomatodes, nasopharyngeal carcinoma, oat cell carcinoma, carcinoma ossificans, osteoid carcinoma, papillary carcinoma, periportal carcinoma, preinvasive carcinoma, prickle cell carcinoma, pultaceous carcinoma, renal cell carcinoma of kidney, reserve cell carcinoma, carcinoma sarcomatodes, schneiderian carcinoma, scirrhous carcinoma, carcinoma scroti, signet-ring cell carcinoma, carcinoma simplex, small-cell carcinoma, solanoid carcinoma, spheroidal cell carcinoma, spindle cell carcinoma, carcinoma spongiosum, squamous carcinoma, squamous cell carcinoma, string carcinoma, carcinoma telangiectaticum, carcinoma telangiectodes, transitional cell carcinoma, carcinoma tuberosum, tuberous carcinoma, verrucous carcinoma, and carcinoma villosum.

The term “cyano,” as used herein, represents —CN group.

The term “cycloalkenyl,” as used herein, refers to a non-aromatic carbocyclic group having at least one double bond in the ring and from three to ten carbons (e.g., a C_3-10cycloalkenyl), unless otherwise specified. Non-limiting examples of cycloalkenyl include cycloprop-1-enyl, cycloprop-2-enyl, cyclobut-1-enyl, cyclobut-1-enyl, cyclobut-2-enyl, cyclopent-1-enyl, cyclopent-2-enyl, cyclopent-3-enyl, norbornen-1-yl, norbornen-2-yl, norbornen-5-yl, and norbornen-7-yl. The cycloalkenyl group may be unsubstituted or substituted (e.g., optionally substituted cycloalkenyl) as described for cycloalkyl.

The term “cycloalkenyl alkyl,” as used herein, represents an alkyl group substituted with a cycloalkenyl group, each as defined herein. The cycloalkenyl and alkyl portions may be substituted as the individual groups defined herein.

The term “cycloalkoxy,” as used herein, represents a chemical substituent of formula —OR, where R is cycloalkyl group, unless otherwise specified. In some embodiments, the cycloalkyl group can be further substituted as defined herein.

The term “cycloalkyl,” as used herein, refers to a cyclic alkyl group having from three to ten carbons (e.g., a C₃-C₁₀cycloalkyl), unless otherwise specified. Cycloalkyl groups may be monocyclic or bicyclic. Bicyclic cycloalkyl groups may be of bicyclo[p.q.0]alkyl type, in which each of p and q is, independently, 1, 2, 3, 4, 5, 6, or 7, provided that the sum of p and q is 2, 3, 4, 5, 6, 7, or 8. Alternatively, bicyclic cycloalkyl groups may include bridged cycloalkyl structures, e.g., bicyclo[p.q.r]alkyl, in which r is 1, 2, or 3, each of p and q is, independently, 1, 2, 3, 4, 5, or 6, provided that the sum of p, q, and r is 3, 4, 5, 6, 7, or 8. The cycloalkyl group may be a spirocyclic group, e.g., spiro[p.q]alkyl, in which each of p and q is, independently, 2, 3, 4, 5, 6, or 7, provided that the sum of p and q is 4, 5, 6, 7, 8, or 9. Non-limiting examples of cycloalkyl include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, 1-bicyclo[2.2.1.]heptyl, 2-bicyclo[2.2.1.]heptyl, 5-bicyclo[2.2.1.]heptyl, 7-bicyclo[2.2.1.]heptyl, and decalinyl. The cycloalkyl group may be unsubstituted or substituted (e.g., optionally substituted cycloalkyl) with one, two, three, four, or five substituents independently selected from the group consisting of: alkyl; alkenyl; alkynyl; alkoxy; alkylsulfinyl; alkylsulfenyl; alkylsulfonyl; amino; aryl; aryloxy; azido; cycloalkyl; cycloalkoxy; cycloalkenyl; cycloalkynyl; halo; heteroalkyl; heterocyclyl; (heterocyclyl)oxy; heteroaryl; hydroxy; nitro; thiol; silyl; cyano; =O; ═S; —SO₂R, where R is amino or cycloalkyl; =NR′, where R′ is H, alkyl, aryl, or heterocyclyl; or —CON(R^A)₂, where each R^Ais independently H or alkyl, or both R^A, together with the atom to which they are attached, combine to form heterocyclyl. Each of the substituents may itself be unsubstituted or substituted with unsubstituted substituent(s) defined herein for each respective group.

The term “cycloalkyl alkyl,” as used herein, represents an alkyl group substituted with a cycloalkyl group, each as defined herein. The cycloalkyl and alkyl portions may be optionally substituted as the individual groups described herein.

The term “cycloalkylene,” as used herein, represents a divalent cycloalkyl group. An optionally substituted cycloalkylene is a cycloalkylene that is optionally substituted as described herein for cycloalkyl.

The term “cycloalkynyl,” as used herein, refers to a monovalent carbocyclic group having one or two carbon-carbon triple bonds and having from eight to twelve carbons, unless otherwise specified. Cycloalkynyl may include one transannular bond or bridge. Non-limiting examples of cycloalkynyl include cyclooctynyl, cyclononynyl, cyclodecynyl, and cyclodecadiynyl. The cycloalkynyl group may be unsubstituted or substituted (e.g., optionally substituted cycloalkynyl) as defined for cycloalkyl.

“Disease” or “condition” refer to a state of being or health status of a patient or subject capable of being treated with the compounds or methods provided herein.

The term “halo,” as used herein, represents a halogen selected from bromine, chlorine, iodine, and fluorine.

The term “heteroalkyl,” as used herein refers to an alkyl, alkenyl, or alkynyl group interrupted once by one or two heteroatoms; twice, each time, independently, by one or two heteroatoms; three times, each time, independently, by one or two heteroatoms; or four times, each time, independently, by one or two heteroatoms. Each heteroatom is, independently, O, N, or S.

In some embodiments, the heteroatom is 0 or N. None of the heteroalkyl groups includes two contiguous oxygen or sulfur atoms. The heteroalkyl group may be unsubstituted or substituted (e.g., optionally substituted heteroalkyl). When heteroalkyl is substituted and the substituent is bonded to the heteroatom, the substituent is selected according to the nature and valency of the heteratom. Thus, the substituent bonded to the heteroatom, valency permitting, is selected from the group consisting of ═O, —N(R^N2)₂, —SO₂OR^N3, —SO₂R^N2, —SOR^N3, —COOR^N3, an N protecting group, alkyl, alkenyl, alkynyl, aryl, cycloalkyl, cycloalkenyl, cycloalkynyl, heterocyclyl, or cyano, where each R^N2is independently H, alkyl, cycloalkyl, cycloalkenyl, cycloalkynyl, aryl, or heterocyclyl, and each R^N3is independently alkyl, cycloalkyl, cycloalkenyl, cycloalkynyl, aryl, or heterocyclyl. Each of these substituents may itself be unsubstituted or substituted with unsubstituted substituent(s) defined herein for each respective group. When heteroalkyl is substituted and the substituent is bonded to carbon, the substituent is selected from those described for alkyl, provided that the substituent on the carbon atom bonded to the heteroatom is not Cl, Br, or I. It is understood that carbon atoms are found at the termini of a heteroalkyl group.

The term “heteroaryl alkyl,” as used herein, represents an alkyl group substituted with a heteroaryl group, each as defined herein. The heteroaryl and alkyl portions may be optionally substituted as the individual groups described herein.

The term “heteroarylene,” as used herein, represents a divalent heteroaryl. An optionally substituted heteroarylene is a heteroarylene that is optionally substituted as described herein for heteroaryl.

The term “heteroaryloxy,” as used herein, refers to a structure —OR, in which R is heteroaryl. Heteroaryloxy can be optionally substituted as defined for heterocyclyl.

The term “heterocyclyl,” as used herein, represents a monocyclic, bicyclic, tricyclic, or tetracyclic ring system having fused, bridging, and/or spiro 3-, 4-, 5-, 6-, 7-, or 8-membered rings, unless otherwise specified, containing one, two, three, or four heteroatoms independently selected from the group consisting of nitrogen, oxygen, and sulfur. In some embodiments, “heterocyclyl” is a monocyclic, bicyclic, tricyclic, or tetracyclic ring system having fused or bridging 5-, 6-, 7-, or 8-membered rings, unless otherwise specified, containing one, two, three, or four heteroatoms independently selected from the group consisting of nitrogen, oxygen, and sulfur. Heterocyclyl can be aromatic or non-aromatic. Non-aromatic 5-membered heterocyclyl has zero or one double bonds, non-aromatic 6- and 7-membered heterocyclyl groups have zero to two double bonds, and non-aromatic 8-membered heterocyclyl groups have zero to two double bonds and/or zero or one carbon-carbon triple bond. Heterocyclyl groups include from 1 to 16 carbon atoms unless otherwise specified. Certain heterocyclyl groups may include up to 9 carbon atoms. Non-aromatic heterocyclyl groups include pyrrolinyl, pyrrolidinyl, pyrazolinyl, pyrazolidinyl, imidazolinyl, imidazolidinyl, piperidinyl, homopiperidinyl, piperazinyl, pyridazinyl, oxazolidinyl, isoxazolidiniyl, morpholinyl, thiomorpholinyl, thiazolidinyl, isothiazolidinyl, thiazolidinyl, tetrahydrofuranyl, dihydrofuranyl, tetrahydrothienyl, dihydrothienyl, dihydroindolyl, tetrahydroquinolyl, tetrahydroisoquinolyl, pyranyl, dihydropyranyl, dithiazolyl, etc. If the heterocyclic ring system has at least one aromatic resonance structure or at least one aromatic tautomer, such structure is an aromatic heterocyclyl (i.e., heteroaryl). Non-limiting examples of heteroaryl groups include benzimidazolyl, benzofuryl, benzothiazolyl, benzothienyl, benzoxazolyl, furyl, imidazolyl, indolyl, isoindazolyl, isoquinolinyl, isothiazolyl, isothiazolyl, isoxazolyl, oxadiazolyl, oxazolyl, purinyl, pyrrolyl, pyridinyl, pyrazinyl, pyrimidinyl, qunazolinyl, quinolinyl, thiadiazolyl (e.g., 1,3,4-thiadiazole), thiazolyl, thienyl, triazolyl, tetrazolyl, etc. The term “heterocyclyl” also represents a heterocyclic compound having a bridged multicyclic structure in which one or more carbons and/or heteroatoms bridges two non-adjacent members of a monocyclic ring, e.g., quinuclidine, tropanes, or diaza-bicyclo[2.2.2]octane. The term “heterocyclyl” includes bicyclic, tricyclic, and tetracyclic groups in which any of the above heterocyclic rings is fused to one, two, or three carbocyclic rings, e.g., an aryl ring, a cyclohexane ring, a cyclohexene ring, a cyclopentane ring, a cyclopentene ring, or another monocyclic heterocyclic ring. Examples of fused heterocyclyls include 1,2,3,5,8,8a-hexahydroindolizine; 2,3-dihydrobenzofuran; 2,3-dihydroindole; and 2,3-dihydrobenzothiophene. The heterocyclyl group may be unsubstituted or substituted with one, two, three, four, five, or six substituents independently selected from the group consisting of: alkyl; alkenyl; alkynyl; alkoxy; alkylsulfinyl; alkylsulfenyl; alkylsulfonyl; amino; aryl; aryloxy; azido; cycloalkyl; cycloalkoxy; cycloalkenyl; cycloalkynyl; halo; heteroalkyl; heterocyclyl; (heterocyclyl)oxy; hydroxy; nitro; thiol; silyl; cyano; ═O; ═S; =NR′, where R′ is H, alkyl, aryl, or heterocyclyl. Each of the substituents may itself be unsubstituted or substituted with unsubstituted substituent(s) defined herein for each respective group.

The term “heterocyclyl alkyl,” as used herein, represents an alkyl group substituted with a heterocyclyl group, each as defined herein. The heterocyclyl and alkyl portions may be optionally substituted as the individual groups described herein.

The term “heterocyclylene,” as used herein, represents a divalent heterocyclyl. An optionally substituted heterocyclylene is a heterocyclylene that is optionally substituted as described herein for heterocyclyl.

The term “(heterocyclyl)oxy,” as used herein, represents a chemical substituent of formula —OR, where R is a heterocyclyl group, unless otherwise specified. (Heterocyclyl)oxy can be optionally substituted in a manner described for heterocyclyl.

The terms “hydroxyl” and “hydroxy,” as used interchangeably herein, represent an —OH group.

The term “isotopically enriched,” as used herein, refers to the pharmaceutically active agent with the isotopic content for one isotope at a predetermined position within a molecule that is at least 100 times greater than the natural abundance of this isotope. For example, a composition that is isotopically enriched for deuterium includes an active agent with at least one hydrogen atom position having at least 100 times greater abundance of deuterium than the natural abundance of deuterium. Preferably, an isotopic enrichment for deuterium is at least 1000 times greater than the natural abundance of deuterium. More preferably, an isotopic enrichment for deuterium is at least 4000 times greater (e.g., at least 4750 times greater, e.g., up to 5000 times greater) than the natural abundance of deuterium.

The term “leukemia,” as used herein, refers broadly to progressive, malignant diseases of the blood-forming organs and is generally characterized by a distorted proliferation and development of leukocytes and their precursors in the blood and bone marrow. Leukemia is generally clinically classified on the basis of (1) the duration and character of the disease-acute or chronic; (2) the type of cell involved; myeloid (myelogenous), lymphoid (lymphogenous), or monocytic; and (3) the increase or non-increase in the number abnormal cells in the blood-leukemic or aleukemic (subleukemic). Exemplary leukemias that may be treated with a compound or method provided herein include, e.g., acute nonlymphocytic leukemia, chronic lymphocytic leukemia, acute granulocytic leukemia, chronic granulocytic leukemia, acute promyelocytic leukemia, adult T-cell leukemia, aleukemic leukemia, a leukocythemic leukemia, basophylic leukemia, blast cell leukemia, bovine leukemia, chronic myelocytic leukemia, leukemia cutis, embryonal leukemia, eosinophilic leukemia, Gross' leukemia, hairy-cell leukemia, hemoblastic leukemia, hemocytoblastic leukemia, histiocytic leukemia, stem cell leukemia, acute monocytic leukemia, leukopenic leukemia, lymphatic leukemia, lymphoblastic leukemia, lymphocytic leukemia, lymphogenous leukemia, lymphoid leukemia, lymphosarcoma cell leukemia, mast cell leukemia, megakaryocytic leukemia, micromyeloblastic leukemia, monocytic leukemia, myeloblastic leukemia, myelocytic leukemia, myeloid granulocytic leukemia, myelomonocytic leukemia, Naegeli leukemia, plasma cell leukemia, multiple myeloma, plasmacytic leukemia, promyelocytic leukemia, Rieder cell leukemia, Schilling's leukemia, stem cell leukemia, subleukemic leukemia, and undifferentiated cell leukemia.

The term “lymphoma,” as used herein, refers to a cancer arising from cells of immune origin. Non-limiting examples of T and B cell lymphomas include non-Hodgkin lymphoma and Hodgkin disease, diffuse large B-cell lymphoma, follicular lymphoma, mucosa-associated lymphatic tissue (MALT) lymphoma, small cell lymphocytic lymphoma-chronic lymphocytic leukemia, Mantle cell lymphoma, mediastinal (thymic) large B-cell lymphoma, lymphoplasmacytic lymphoma-Waldenstrom macroglobulinemia, peripheral T-cell lymphoma (PTCL), angioimmunoblastic T-cell lymphoma (AITL)/follicular T-cell lymphoma (FTCL), anaplastic large cell lymphoma (ALCL), enteropathy-associated T-cell lymphoma (EATL), adult T-cell leukaemia/lymphoma (ATLL), or extranodal NK/T-cell lymphoma, nasal type.

The term “melanoma,” as used herein, is taken to mean a tumor arising from the melanocytic system of the skin and other organs. Melanomas that may be treated with a compound or method provided herein include, e.g., acral-lentiginous melanoma, amelanotic melanoma, benign juvenile melanoma, Cloudman's melanoma, S91 melanoma, Harding-Passey melanoma, juvenile melanoma, lentigo maligna melanoma, malignant melanoma, nodular melanoma, subungual melanoma, and superficial spreading melanoma.

The term “nitro,” as used herein, represents an —NO₂group.

The term “oxo,” as used herein, represents a divalent oxygen atom (e.g., the structure of oxo may be shown as ═O).

The term “PARP inhibitor,” as used herein, represents a compound that upon contacting PARP, whether in vitro, in cell culture, or in an animal, reduces the activity of PARP, such that the measured PARP IC₅₀is 10 μM or less (e.g., 5 μM or less or 1 μM or less). For certain PARP inhibitors, the PARP IC₅₀may be 100 nM or less (e.g., 10 nM or less, or 1 nM or less) and could be as low as 100 μM or 10 μM. Preferably, the PARP IC₅₀is 0.1 nM to 1 μM (e.g., 0.5 nM to 750 nM, 1 nM to 500 nM, or 1 nM to 250 nM).

The term “PARP,” as used herein, refers to poly ADP ribose polymerase (PARP).

The term “Ph,” as used herein, represents phenyl.

The term “pharmaceutical composition,” as used herein, represents a composition containing a compound described herein, formulated with a pharmaceutically acceptable excipient, and manufactured or sold with the approval of a governmental regulatory agency as part of a therapeutic regimen for the treatment of disease in a mammal. Pharmaceutical compositions can be formulated, for example, for oral administration in unit dosage form (e.g., a tablet, capsule, caplet, gelcap, or syrup); for topical administration (e.g., as a cream, gel, lotion, or ointment); for intravenous administration (e.g., as a sterile solution free of particulate emboli and in a solvent system suitable for intravenous use); or in any other formulation described herein.

The term “pharmaceutically acceptable excipient” or “pharmaceutically acceptable carrier,” as used interchangeably herein, refers to any ingredient other than the compounds described herein (e.g., a vehicle capable of suspending or dissolving the active compound) and having the properties of being nontoxic and non-inflammatory in a patient. Excipients may include, for example: antiadherents, antioxidants, binders, coatings, compression aids, disintegrants, dyes (colors), emollients, emulsifiers, fillers (diluents), film formers or coatings, flavors, fragrances, glidants (flow enhancers), lubricants, preservatives, printing inks, sorbents, suspending or dispersing agents, sweeteners, or waters of hydration. Exemplary excipients include, but are not limited to: butylated hydroxytoluene (BHT), calcium carbonate, calcium phosphate (dibasic), calcium stearate, croscarmellose, crosslinked polyvinyl pyrrolidone, citric acid, crospovidone, cysteine, ethylcellulose, gelatin, hydroxypropyl cellulose, hydroxypropyl methylcellulose, lactose, magnesium stearate, maltitol, mannitol, methionine, methylcellulose, methyl paraben, microcrystalline cellulose, polyethylene glycol, polyvinyl pyrrolidone, povidone, pregelatinized starch, propyl paraben, retinyl palmitate, shellac, silicon dioxide, sodium carboxymethyl cellulose, sodium citrate, sodium starch glycolate, sorbitol, starch (corn), stearic acid, stearic acid, sucrose, talc, titanium dioxide, vitamin A, vitamin E, vitamin C, and xylitol.

The term “pharmaceutically acceptable salt,” as use herein, represents those salts which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of humans and animals without undue toxicity, irritation, allergic response and the like and are commensurate with a reasonable benefit/risk ratio. Pharmaceutically acceptable salts are well known in the art. For example, pharmaceutically acceptable salts are described in: Berge et al., J. Pharmaceutical Sciences 66:1-19, 1977 and in Pharmaceutical Salts: Properties, Selection, and Use, (Eds. P. H. Stahl and C. G. Wermuth), Wiley-VCH, 2008. The salts can be prepared in situ during the final isolation and purification of the compounds described herein or separately by reacting the free base group with a suitable organic acid. Representative acid addition salts include acetate, adipate, alginate, ascorbate, aspartate, benzenesulfonate, benzoate, bisulfate, borate, butyrate, camphorate, camphorsulfonate, citrate, cyclopentanepropionate, digluconate, dodecylsulfate, ethanesulfonate, fumarate, glucoheptonate, glycerophosphate, hemisulfate, heptonate, hexanoate, hydrobromide, hydrochloride, hydroiodide, 2-hydroxy-ethanesulfonate, lactobionate, lactate, laurate, lauryl sulfate, malate, maleate, malonate, methanesulfonate, 2-naphthalenesulfonate, nicotinate, nitrate, oleate, oxalate, palmitate, pamoate, pectinate, persulfate, 3-phenylpropionate, phosphate, picrate, pivalate, propionate, stearate, succinate, sulfate, tartrate, thiocyanate, toluenesulfonate, undecanoate, valerate salts, and the like. Representative alkali or alkaline earth metal salts include sodium, lithium, potassium, calcium, magnesium, and the like, as well as nontoxic ammonium, quaternary ammonium, and amine cations, including, but not limited to ammonium, tetramethylammonium, tetraethylammonium, methylamine, dimethylamine, trimethylamine, triethylamine, ethylamine, and the like.

The term “protecting group,” as used herein, represents a group intended to protect a hydroxy, an amino, or a carbonyl from participating in one or more undesirable reactions during chemical synthesis. The term “O-protecting group,” as used herein, represents a group intended to protect a hydroxy or carbonyl group from participating in one or more undesirable reactions during chemical synthesis. The term “N-protecting group,” as used herein, represents a group intended to protect a nitrogen containing (e.g., an amino, amido, heterocyclic N—H, or hydrazine) group from participating in one or more undesirable reactions during chemical synthesis. Commonly used O- and N-protecting groups are disclosed in Greene, “Protective Groups in Organic Synthesis,” 3rd Edition (John Wiley & Sons, New York, 1999), which is incorporated herein by reference. Exemplary O- and N-protecting groups include alkanoyl, aryloyl, or carbamyl groups such as formyl, acetyl, propionyl, pivaloyl, t-butylacetyl, 2-chloroacetyl, 2-bromoacetyl, trifluoroacetyl, trichloroacetyl, phthalyl, o-nitrophenoxyacetyl, α-chlorobutyryl, benzoyl, 4-chlorobenzoyl, 4-bromobenzoyl, t-butyldimethylsilyl, tri-iso-propylsilyloxymethyl, 4,4′-dimethoxytrityl, isobutyryl, phenoxyacetyl, 4-isopropylpehenoxyacetyl, dimethylformamidino, and 4-nitrobenzoyl.

Exemplary O-protecting groups for protecting carbonyl containing groups include, but are not limited to: acetals, acylals, 1,3-dithianes, 1,3-dioxanes, 1,3-dioxolanes, and 1,3-dithiolanes.

Other O-protecting groups include, but are not limited to: substituted alkyl, aryl, and aryl-alkyl ethers (e.g., trityl; methylthiomethyl; methoxymethyl; benzyloxymethyl; siloxymethyl; 2,2,2,-trichloroethoxymethyl; tetrahydropyranyl; tetrahydrofuranyl; ethoxyethyl; 1-[2-(trimethylsilyl)ethoxy]ethyl; 2-trimethylsilylethyl; t-butyl ether; p-chlorophenyl, p-methoxyphenyl, p-nitrophenyl, benzyl, p-methoxybenzyl, and nitrobenzyl); silyl ethers (e.g., trimethylsilyl; triethylsilyl; triisopropylsilyl; dimethylisopropylsilyl; t-butyldimethylsilyl; t-butyldiphenylsilyl; tribenzylsilyl; triphenylsilyl; and diphenymethylsilyl); carbonates (e.g., methyl, methoxymethyl, 9-fluorenylmethyl; ethyl; 2,2,2-trichloroethyl; 2-(trimethylsilyl)ethyl; vinyl, allyl, nitrophenyl; benzyl; methoxybenzyl; 3,4-dimethoxybenzyl; and nitrobenzyl).

Other N-protecting groups include, but are not limited to, chiral auxiliaries such as protected or unprotected D, L or D, L-amino acids such as alanine, leucine, phenylalanine, and the like; sulfonyl-containing groups such as benzenesulfonyl, p-toluenesulfonyl, and the like; carbamate forming groups such as benzyloxycarbonyl, p-chlorobenzyloxycarbonyl, p methoxybenzyloxycarbonyl, p-nitrobenzyloxycarbonyl, 2-nitrobenzyloxycarbonyl, p bromobenzyloxycarbonyl, 3,4-dimethoxybenzyloxycarbonyl, 3,5 dimethoxybenzyl oxycarbonyl, 2,4-dimethoxybenzyloxycarbonyl, 4 methoxybenzyloxycarbonyl, 2-nitro-4,5-dimethoxybenzyloxycarbonyl, 3,4,5 trimethoxybenzyloxycarbonyl, 1-(p-biphenylyl)-1-methylethoxycarbonyl, α,α-dimethyl-3,5 dimethoxybenzyloxycarbonyl, benzhydryloxy carbonyl, t-butyloxycarbonyl, diisopropylmethoxycarbonyl, isopropyloxycarbonyl, ethoxycarbonyl, methoxycarbonyl, allyloxycarbonyl, 2,2,2,-trichloroethoxycarbonyl, phenoxycarbonyl, 4-nitrophenoxy carbonyl, fluorenyl-9-methoxycarbonyl, cyclopentyloxycarbonyl, adamantyloxycarbonyl, cyclohexyloxycarbonyl, phenylthiocarbonyl, and the like, aryl-alkyl groups such as benzyl, p-methoxybenzyl, 2,4-dimethoxybenzyl, triphenylmethyl, benzyloxymethyl, and the like, silylalkylacetal groups such as [2-(trimethylsilyl)ethoxy]methyl and silyl groups such as trimethylsilyl, and the like. Useful N-protecting groups are formyl, acetyl, benzoyl, pivaloyl, t-butylacetyl, alanyl, phenylsulfonyl, benzyl, dimethoxybenzyl, [2-(trimethylsilyl)ethoxy]methyl (SEM), tetrahydropyranyl (THP), t-butyloxycarbonyl (Boc), and benzyloxycarbonyl (Cbz).

The term “RNAse H2A,” as used herein, refers to Ribonuclease H2, subunit A.

The term “RNAse H2B,” as used herein, refers to Ribonuclease H2, subunit B.

The term “sarcoma” generally refers to a tumor which is made up of a substance like the embryonic connective tissue and is generally composed of closely packed cells embedded in a fibrillar or homogeneous substance. Non-limiting examples of sarcomas that may be treated with a compound or method provided herein include, e.g., a chondrosarcoma, fibrosarcoma, lymphosarcoma, melanosarcoma, myxosarcoma, osteosarcoma, Abernethy's sarcoma, adipose sarcoma, liposarcoma, alveolar soft part sarcoma, ameloblastic sarcoma, botryoid sarcoma, chloroma sarcoma, chorio carcinoma, embryonal sarcoma, Wilms' tumor sarcoma, endometrial sarcoma, stromal sarcoma, Ewing's sarcoma, fascial sarcoma, fibroblastic sarcoma, giant cell sarcoma, granulocytic sarcoma, Hodgkin's sarcoma, idiopathic multiple pigmented hemorrhagic sarcoma, immunoblastic sarcoma of B cells, immunoblastic sarcoma of T-cells, Jensen's sarcoma, Kaposi's sarcoma, Kupffer cell sarcoma, angiosarcoma, leukosarcoma, malignant mesenchymoma sarcoma, parosteal sarcoma, reticulocytic sarcoma, Rous sarcoma, serocystic sarcoma, synovial sarcoma, and telangiectaltic sarcoma.

The term “tautomer” refers to structural isomers that readily interconvert, often by relocation of a proton. Tautomers are distinct chemical species that can be identified by differing spectroscopic characteristics, but generally cannot be isolated individually. Non-limiting examples of tautomers include ketone—enol, enamine—imine, amide—imidic acid, nitroso—oxime, ketene—ynol, and amino acid—ammonium carboxylate.

The term “therapeutically effective amount,” as used herein, means the amount of a compound or a pharmaceutically acceptable salt thereof that, in a combination of an ATR inhibitor and PARP inhibitor, is sufficient to treat cancer. Typically, a therapeutically effective amount is a subtherapeutic regimen.

The term “subject,” as used herein, represents a human or non-human animal (e.g., a mammal) that is suffering from, or is at risk of, disease or condition, as determined by a qualified professional (e.g., a doctor or a nurse practitioner) with or without known in the art laboratory test(s) of sample(s) from the subject. Preferably, the subject is a human. Non-limiting examples of diseases and conditions include diseases having the symptom of cell hyperproliferation, e.g., a cancer.

The term “subtherapeutic regimen,” as used herein, refers to a dosing regimen that is at least 5% less (e.g., at least 10%, 20%, 50%, 80%, 90%, or even 95%) than the lowest standard recommended dosing regimen of a particular compound formulated for a given route of administration for treatment of cancer. A subtherapeutic regimen of a compound may be therapeutically ineffective for the compound in a monotherapy regimen. In the methods of the invention, a therapeutically effective amount of a PARP inhibitor is preferably a subtherapeutic regimen (e.g., a regimen that is therapeutically ineffective for the PARP inhibitor in a monotherapy regimen). A subtherapeutic regimen of a PARP inhibitor that is formulated for oral administration may differ from a subtherapeutic regimen of the same agent formulated for intratumoral administration. A subtherapeutic regiment may include a “subtherapeutic starting regimen” and a “subtherapeutic maintenance regiment.” A “subtherapeutic starting regiment” of a compound (e.g., a PARP inhibitor) is lower than the lowest standard starting dosage of the same compound (e.g., a PARP inhibitor). Similarly, a “subtherapeutic maintenance regimen” of a compound (e.g., a PARP inhibitor) is lower than the lowest standard maintenance regimen of the same compound (e.g., a PARP inhibitor). Typically, the subtherapeutic regimen is at least 1% of the lowest standard subtherapeutic regimen.

“Treatment” and “treating,” as used herein, refer to the medical management of a subject with the intent to improve, ameliorate, stabilize, prevent or cure a disease or condition. This term includes active treatment (treatment directed to improve the disease or condition); causal treatment (treatment directed to the cause of the associated disease or condition); palliative treatment (treatment designed for the relief of symptoms of the disease or condition); preventative treatment (treatment directed to minimizing or partially or completely inhibiting the development of the associated disease or condition); and supportive treatment (treatment employed to supplement another therapy). A disease or condition may be a cancer. Non-limiting examples of cancers include, e.g., renal cell carcinoma, mature B-cell neoplasms, endometrial cancer, ovarian cancer, colorectal cancer, skin cancer (non-melanoma), small bowel cancer, non-small cell lung cancer, melanoma, bladder cancer, pancreatic cancer, head and neck cancer, mesothelioma, glioma, prostate cancer, breast cancer, and esophagogastric cancer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is chart showing ZIP synergy score matrix in RNASEH2B+/+ cells. Mean ZIP scores from three independent experiments at indicated concentrations of Compound 121 and niraparib are plotted. Score of >10 indicates synergy, while <(−10) indicates antagonism. Dashed lines represent the IC₅₀value of each compound in the respective cell line.

FIG. 1B is chart showing ZIP synergy score matrix in RNASEH2B−/− cells. Mean ZIP scores from three independent experiments at indicated concentrations of Compound 121 and niraparib are plotted. Score of >10 indicates synergy, while <(−10) indicates antagonism. Dashed lines represent the IC₅₀value of each compound in the respective cell line.

FIG. 2A is a chart showing dose response curves of 5637 RNASEH2B+/+ cells to niraparib in absence (DMSO) or presence of indicated concentrations of Compound 121. Viability was measured with a 7-day CTG assay. Mean of three independent experiments±SD. Solid lines, non-linear least squares fit to a four-parameter dose-response model. IC₅₀values are indicated below panels.

FIG. 2B is a chart showing dose response curves of 5637 RNASEH2B−/− cells to niraparib in absence (DMSO) or presence of indicated concentrations of Compound 121. Viability was measured with a 7-day CTG assay. Mean of three independent experiments±SD. Solid lines, non-linear least squares fit to a four-parameter dose-response model. IC₅₀values are indicated below panels.

FIG. 3A is a chart showing dose response curves of RPE1-hTERT TP53−/− RNASEH2B+/+ cells to niraparib in absence (DMSO) or presence of indicated concentrations of Compound 43. Viability was measured with a 6-day CTG assay. Mean of three independent experiments±SD. Solid lines, non-linear least squares fit to a four-parameter dose-response model. IC₅₀values are indicated below panels.

FIG. 3B is a chart showing dose response curves of RPE1-hTERT TP53−/− RNASEH2B−/− cells to niraparib in absence (DMSO) or presence of indicated concentrations of Compound 43. Viability was measured with a 6-day CTG assay. Mean of three independent experiments±SD. Solid lines, non-linear least squares fit to a four-parameter dose-response model. IC₅₀values are indicated below panels.

FIG. 4A is a chart showing dose response curves of 5637 RNASEH2B+/+ cells to talazoparib in absence (DMSO) or presence of indicated concentrations of Compound 121. Viability was measured with a 7-day CTG assay. Mean of three technical replicates±SD. Solid lines, non-linear least squares fit to a four-parameter dose-response model. IC₅₀values are indicated below panels.

FIG. 4B is a chart showing dose response curves of 5637 RNASEH2B−/− cells to talazoparib in absence (DMSO) or presence of indicated concentrations of Compound 121. Viability was measured with a 7-day CTG assay. Mean of three technical replicates±SD. Solid lines, non-linear least squares fit to a four-parameter dose-response model. IC₅₀values are indicated below panels.

FIG. 5A is a scheme showing the experimental design. 5637 cells were treated with niraparib alone or niraparib combined with an IC₅₀concentration of Compound 121 for indicated times with or without removal of compounds. Cell viability was analyzed by a CellTiter Glo (CTG) assay 168 h post treatment.

FIG. 5B is a chart showing apparent niraparib IC₅₀values in 5637 RNASEH2B+/+ and −/− cells from experiments described in FIG. 5A. Values were obtained by fitting mean data from three independent experiments to a four-parameter dose-response model. Error bars, 95% confidence interval (CI).

FIG. 6A is a chart showing dose response curves of MIAPACA2 ATM+/+ cells to niraparib in the absence (DMSO) or presence of indicated concentrations of Compound 121. Cells were treated for 48 h, followed by removal of the compounds and growth in fresh media. Viability was measured at day 6 by a CTG assay. Mean of three technical replicates±SD. Solid lines, non-linear least squares fit to a four-parameter dose-response model. IC₅₀values are indicated below panels.

FIG. 6B is a chart showing dose response curves of MIAPACA2 ATM−/− cells to niraparib in the absence (DMSO) or presence of indicated concentrations of Compound 121. Cells were treated for 48 h, followed by removal of the compounds and growth in fresh media. Viability was measured at day 6 by a CTG assay. Mean of three technical replicates±SD. Solid lines, non-linear least squares fit to a four-parameter dose-response model. IC₅₀values are indicated below panels.

FIG. 7A is a chart showing dose response curves of RPE1-hTERT TP53−/− CDK12+/+ cells to niraparib in the absence (DMSO) or presence of indicated concentrations of Compound 121. Cells were treated for 48 h, followed by removal of the compounds and growth in fresh media. Viability was measured at day 6 by a CTG assay. Mean of three independent experiments±SD. Solid lines, non-linear least squares fit to a four-parameter dose-response model. IC₅₀values are indicated below panels.

FIG. 7B is a chart showing dose response curves of RPE1-hTERT TP53−/− CDK12−/− cells to niraparib in the absence (DMSO) or presence of indicated concentrations of Compound 121. Cells were treated for 48 h, followed by removal of the compounds and growth in fresh media. Viability was measured at day 6 by a CTG assay. Mean of three independent experiments±SD. Solid lines, non-linear least squares fit to a four-parameter dose-response model. IC₅₀values are indicated below panels.

FIG. 8A is a chart showing dose response curves of DLD1 BRCA2+/+ cells to talazoparib in the absence (DMSO) or presence of indicated concentrations of Compound 121. Cells were treated for 48 h, followed by removal of the compounds and growth in fresh media. Viability was measured at day 6 by a CTG assay. Mean of three independent experiments±SD. Solid lines, non-linear least squares fit to a four-parameter dose-response model. IC₅₀values are indicated below panels.

FIG. 8B is a chart showing dose response curves of DLD1 BRCA2−/− cells to talazoparib in the absence (DMSO) or presence of indicated concentrations of Compound 121. Cells were treated for 48 h, followed by removal of the compounds and growth in fresh media. Viability was measured at day 9 by a CTG assay. Mean of three independent experiments±SD. Solid lines, non-linear least squares fit to a four-parameter dose-response model. IC₅₀values are indicated below panels.

FIG. 9A is a chart showing cell viability for ALT+ and ALT− cell lines that were untreated, treated with talazoparib alone, treated with compound 121 alone, or treated with a combination of talazoparib and compound 121.

FIG. 9B is a chart showing the cell viability for ALT+ and ALT− cells that were treated with a combination of talazoparib and compound 121.

DETAILED DESCRIPTION

In general, the invention relates to a combination of an ATR inhibitor, or a pharmaceutically acceptable salt thereof, and a PARP inhibitor, or a pharmaceutically acceptable salt thereof for the treatment of cancers or for inducing cell death in cancer cells. The cancers included herein may be, e.g., cancers having a loss of function of ATM, BRCA2, RNAse H2A, RNAse H2B, CDK12, or a combination thereof. Alternatively, the cancer may be, e.g., an ALT+ cancer.

Advantageously, an ATR inhibitor and a PARP inhibitor act synergistically to induce cell death in cancer cells having a loss of function of ATM, BRCA2, RNAse H2A, RNAse H2B, or CDK12, or in ALT+ cancer cells. Advantageously, combination cancer therapies including an ATR inhibitor and a PARP inhibitor may exhibit reduced morbidities, as ATR inhibitor and PARP inhibitor dosages may be reduced, e.g., relative to those administered in corresponding monotherapies. Thus, ATR and PARP inhibitors may be used in subtherapeutic regimens in the methods of the invention.

Synergy between ATR inhibitors and PARP inhibitors has been observed, but continuous combination treatment has been historically poorly tolerated in preclinical models (Fang et al., Cancer Cell, 35:851-867, 2019) and there are potentially overlapping toxicities observed for each drug class in the clinic (Sachdev et al., Targeted Oncology, 14:657-679, 2019, Mei et al., J. Hematol. Oncol., 12:43, 2019). Until the present invention, specific populations of cancer patients that could benefit from a combination of an ATR inhibitor and a PARP inhibitor were limited (Kim et al., Clin. Cancer Res., 23:3097-3108, 2017), especially those that could benefit from the dose reductions for the ATR inhibitors and/or PARP inhibitors.

ATR Inhibitors

ATR inhibitors a compound that upon contacting the enzyme ATR kinase, whether in vitro, in cell culture, or in an animal, reduces the activity of ATR kinase, such that the measured ATR kinase IC₅₀is 10 μM or less (e.g., 5 μM or less or 1 μM or less). For certain ATR inhibitors, the ATR kinase IC₅₀may be 100 nM or less (e.g., 10 nM or less, or 1 nM or less) and could be as low as 100 μM or 10 μM. Preferably, the ATR kinase IC₅₀is 0.1 nM to 1 μM (e.g., 0.1 nM to 750 nM, 0.1 nM to 500 nM, or 0.1 nM to 250 nM).

Non-limiting examples of ATR inhibitors include, e.g.:

[Image Omitted]

and pharmaceutically acceptable salts thereof.

Non-limiting examples of ATR inhibitors include, e.g., those described in, e.g., International Application Nos. PCT/US2019/051539 and PCT/US2018/034729, each of which is incorporated by reference herein; U.S. Pat. Nos. 9,663,535, 9,549,932, 8,552,004, and 8,841,308, each of which is incorporated by reference herein; and U.S. Patent Application Publication No. 2019/0055240, which is incorporated by reference herein.

In one embodiment, an ATR inhibitor is a compound of formula (I):

[Image Omitted]

or a pharmaceutically acceptable salt thereof,

where

- is a double bond, and each Y is independently N or CR⁴; or is a single bond, and each Y is independently NR^Y, carbonyl, or C(R^Y)₂; where each R^Yis independently H or optionally substituted C_1-6alkyl;
- R¹is optionally substituted C_1-6alkyl or H;
- R²is optionally substituted C_2-9heterocyclyl, optionally substituted C_1-6alkyl, optionally substituted C_3-8cycloalkyl, optionally substituted C_2-9heterocyclyl C_1-6alkyl, optionally substituted C_6-10aryl, optionally substituted C_1-9heteroaryl, optionally substituted C_1-9heteroaryl C_1-6alkyl, halogen, —N(R⁵)₂, —OR⁵, —CON(R⁶)₂, —SO₂N(R⁶)₂, —SO₂R^5A, or -Q-R^5B;
- R³is optionally substituted C_1-9heteroaryl or optionally substituted C_1-9heteroaryl C_1-6alkyl;
- each R⁴is independently hydrogen, halogen, optionally substituted C_1-6alkyl, optionally substituted C_2-6alkenyl, or optionally substituted C_2-6alkynyl;
- each R⁵is independently hydrogen, optionally substituted C_1-6alkyl, optionally substituted C_6-10aryl C_1-6alkyl, optionally substituted C_6-10aryl, optionally substituted C_1-9heteroaryl, or —SO₂R^5A; or both R⁵, together with the atom to which they are attached, combine to form an optionally substituted C_2-9heterocyclyl;
- each R^5Ais independently optionally substituted C_1-6alkyl, optionally substituted C_3-8cycloalkyl, or optionally substituted C_6-10aryl;
- R^5Bis hydroxyl, optionally substituted C_1-6alkyl, optionally substituted C_6-10aryl, optionally substituted C_1-9heteroaryl, —N(R⁵)₂, —CON(R⁶)₂, —SO₂N(R⁶)₂, —SO₂R^5A, or optionally substituted alkoxy;
- each R⁶is independently hydrogen, optionally substituted C_1-6alkyl, optionally substituted C_2-6alkoxyalkyl, optionally substituted C_6-10aryl C_1-6alkyl, optionally substituted C_6-10aryl, optionally substituted C_3-8cycloalkyl, or optionally substituted C_1-9heteroaryl; or both R⁶, together with the atom to which they are attached, combine to form an optionally substituted C_2-9heterocyclyl;
- Q is optionally substituted C_2-9heterocyclylene, optionally substituted C_3-8cycloalkylene, optionally substituted C_1-9heteroarylene, or optionally substituted C_6-10arylene; and
- X is hydrogen or halogen.

The ATR inhibitor may be, e.g., a compound of formula (II):

[Image Omitted]

or a pharmaceutically acceptable salt thereof,

where

- each Y is independently N or CR⁴;
- R¹is optionally substituted C_1-6alkyl or H;
- R²is optionally substituted C_2-9heterocyclyl, optionally substituted C_1-6alkyl, optionally substituted C_3-8cycloalkyl, optionally substituted C_2-9heterocyclyl C_1-6alkyl, optionally substituted C_6-10aryl, optionally substituted C_1-9heteroaryl, optionally substituted C_1-9heteroaryl C_1-6alkyl, halogen, —N(R⁵)₂, —OR⁵, —CON(R⁶)₂, —SO₂N(R⁶)₂, —SO₂R^5A, or -Q-R^5B;
- R³is optionally substituted C_1-9heteroaryl or optionally substituted C_1-9heteroaryl C_1-6alkyl;
- each R⁴is independently hydrogen, halogen, optionally substituted C_1-6alkyl, optionally substituted C_2-6alkenyl, or optionally substituted C_2-6alkynyl;
- each R⁵is independently hydrogen, optionally substituted C_1-6alkyl, optionally substituted C_6-10aryl C_1-6alkyl, optionally substituted C_6-10aryl, optionally substituted C_1-9heteroaryl, or —SO₂R^5A; or both R⁵, together with the atom to which they are attached, combine to form an optionally substituted C_2-9heterocyclyl;
- each R^5Ais independently optionally substituted C_1-6alkyl, optionally substituted C_3-8cycloalkyl, or optionally substituted C_6-10aryl;
- R^5Bis hydroxyl, optionally substituted C_1-6alkyl, optionally substituted C_6-10aryl, optionally substituted C_1-9heteroaryl, —N(R⁵)₂, —CON(R⁶)₂, —SO₂N(R⁶)₂, —SO₂R^5A, or optionally substituted alkoxy;
- each R⁶is independently hydrogen, optionally substituted C_1-6alkyl, optionally substituted C_2-6alkoxyalkyl, optionally substituted C_6-10aryl C_1-6alkyl, optionally substituted C_6-10aryl, optionally substituted C_3-8cycloalkyl, or optionally substituted C_1-9heteroaryl; or both R⁶, together with the atom to which they are attached, combine to form an optionally substituted C_2-9heterocyclyl;
- Q is optionally substituted C_2-9heterocyclylene, optionally substituted C_3-8cycloalkylene, optionally substituted C_1-9heteroarylene, or optionally substituted C_6-10arylene; and
- X is hydrogen or halogen.

In some embodiments, in the compound of formula (II), (I), or (I-b):

- each Y is independently N or CR⁴;
- R¹is H or optionally substituted C_1-6alkyl;
- R²is optionally substituted C_1-6alkyl, optionally substituted C_3-8cycloalkyl, optionally substituted C_2-9heterocyclyl, optionally substituted C_6-10aryl, optionally substituted C_1-9heteroaryl, optionally substituted C_1-9heteroaryl C_1-6alkyl, —N(R⁵)₂, —CON(R⁶)₂, —SO₂N(R⁶)₂, or —SO₂R^5A;
- R³is optionally substituted C_1-9heteroaryl;
- each R⁴is independently H or optionally substituted C_1-6alkyl;
- each R⁵is independently hydrogen, optionally substituted C_1-6alkyl, optionally substituted C_6-10aryl C_1-6alkyl, optionally substituted C_6-10aryl, optionally substituted C_1-9heteroaryl, or —SO₂R^5A, where each R^5Ais independently optionally substituted C_1-6alkyl or optionally substituted C_3-8cycloalkyl; or both R⁵, together with the atom to which they are attached, combine to form an optionally substituted C_2-9heterocyclyl;
- each R^5Ais independently optionally substituted C_1-6alkyl or optionally substituted C_3-8cycloalkyl; and
- each R⁶is independently hydrogen, optionally substituted C_1-6alkyl, optionally substituted C_6-10aryl C_1-6alkyl, optionally substituted C_6-10aryl, or optionally substituted C_1-9heteroaryl; or both R⁶, together with the atom to which they are attached, combine to form an optionally substituted C_2-9heterocyclyl.

Methods of making compounds of formula (I) are described, e.g., in International Application No. PCT/US2019/051539, hereby incorporated by reference.

The ATR inhibitor may be, e.g., a compound of formula (I-a):

[Image Omitted]

or a pharmaceutically acceptable salt thereof, where Y, R¹, R², R³, and R⁴are as described for formula (I).

The ATR inhibitor may be, e.g., a compound of formula (I-b):

[Image Omitted]

or a pharmaceutically acceptable salt thereof, where Y, R, R², R³, and R⁴are as described for formula (I).

The ATR inhibitor may be, e.g., a compound of formula (IA):

[Image Omitted]