Pharmaceutical combinations comprising histone deacetylase inhibitor and BCL-2 inhibitor and methods of use thereof

Abstract

To provide effective methods of treating or preventing cancers, especially cancers resistant and / or refractive to current therapies.SOLUTION: The present disclosure relates to: a pharmaceutical combination comprising (a) a histone deacetylase 6 inhibitor and (b) a BCL-2 inhibitor, including combined preparations and pharmaceutical compositions thereof; uses of such a combination in the treatment or prevention of cancers; and methods of treating or preventing cancers in a subject comprising administering a therapeutically effective amount of such a combination.SELECTED DRAWING: None

Description

[Technical field]

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 62 / 417,670, filed November 4, 2016, the entire contents of which are incorporated herein by reference. [Background technology]

[0002] Histone deacetylase (HDAC) inhibition can block cancer cell proliferation, but the side effects of pan-HDAC inhibition are severe, making alternative HDAC inhibition profiles desirable.

[0003] HDAC6 is a class IIb HDAC known to remove acetyl groups from many cellular proteins, including α-tubulin and HSP90. As previously reported, hyperacetylation of HSP90 destabilizes its target proteins, such as ER and EGFR. HDAC6 inhibitors have demonstrated anti-cancer proliferation activity in various types of cancer. Blocking HDAC6 activity has been shown to inhibit cancer cell proliferation through multiple mechanisms. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] PCT Application No. WO2011 / 091213 [Non-patent literature]

[0005] [Non-Patent Document 1] Danial, NNand Korsmeyer, SJCell (2004) 116, 205-219 [Non-Patent Document 2] Adams, JMand Cory, S.Science(1998)281,1322-1326 Summary of the Invention [Problem to be solved by the invention]

[0006] Despite the large number of treatment options available to cancer patients, there remains a need for effective and safe treatment options. In particular, there is a need for effective methods for treating or preventing cancer, especially cancers that are resistant and / or refractory to current therapies. This need can be achieved by using combination therapies, such as those described herein. [Means for solving the problem]

[0007] Provided herein is a pharmaceutical combination comprising an inhibitor of histone deacetylase 6 (herein referred to as "HDAC6") and an inhibitor of B cell lymphoma 2 (herein referred to as "BCL-2").

[0008] In one aspect, the pharmaceutical formulation provided herein comprises: (a) Formula I: [ka] Histone deacetylase 6 (HDAC6) inhibitors or pharma- ceutical acceptable salts thereof wherein ring B is aryl or heteroaryl; R1 is aryl or heteroaryl, each of which is optionally OH, halo, or C 1-6 can be substituted with alkyl, and R is H or C 1-6 alkyl), and (b) BCL-2 inhibitors.

[0009] In various embodiments of the pharmaceutical formulation, Ring B is aryl.

[0010] In various embodiments of the pharmaceutical formulation, R1 is aryl or heteroaryl, each of which can be optionally substituted with halo.

[0011] In certain embodiments of formula I, R is OH, halo, or C 1-6 It is an aryl substituted with an alkyl.

[0012] In another embodiment of formula I, R1 is OH, halo, or C 1-6 It is a C5-C7 aryl substituted with alkyl.

[0013] In another embodiment of formula I, R1 is OH, halo, or C 1-6 It is a C4-C7 heteroaryl substituted with alkyl.

[0014] In yet another embodiment of formula I, R1 is OH, halo, or C 1-6 It is phenyl substituted with alkyl.

[0015] In yet another embodiment of formula I, R1 is phenyl substituted with halo.

[0016] In yet another embodiment of formula I, R1 is phenyl substituted with chloro.

[0017] In another embodiment of Formula I, Ring B is C5-C7 aryl.

[0018] In another embodiment of Formula I, Ring B is a C4-C7 heteroaryl.

[0019] In yet another embodiment of Formula I, ring B is phenyl.

[0020] In various embodiments of the pharmaceutical formulation: The HDAC6 inhibitors of formula I are [ka] or a pharma- ceutically acceptable salt thereof.

[0021] In various embodiments of the pharmaceutical combination, the HDAC6 inhibitor of formula I is [ka] or a pharma- ceutically acceptable salt thereof.

[0022] In various embodiments of the pharmaceutical combination, the BCL-2 inhibitor is 4-[4-[[2-(4-chlorophenyl)-5,5-dimethyl-1-cyclohexen-1-yl]methyl]-1-piperazinyl]-N-[[4-[[(1R)-3-(4-morpholinyl)-1-[(phenylthio)methyl]propyl]amino]-3-[(trifluoromethyl)sulfonyl]phenyl]sulfonyl]benzamide (navitoclax or ABT-263); tetrocarcin A; antimycin; gossypol (e.g., (-)-gossypol acetic acid); obatoclax; ethyl 2-amino-6-bromo-4-(1-cyano-2-ethoxy-2-oxoethyl)-4H-chromene-3-carboxylate (HA 14-1); oblimersen; Bak BH3 peptides; 4-[4-[(4'-chloro[1,1'-biphenyl]-2-yl)methyl]-1-piperazinyl]-N-[[4-[[(1R)-3-(dimethylamino)-1-[(phenylthio)methyl]propyl]amino]-3-nitrophenyl]sulfonyl]-benzamide (ABT-737); 2-((1H-pyrrolo[2,3-b]pyridin-5-yl)oxy)-4-(4-((4' -chloro-5,5-dimethyl-3,4,5,6-tetrahydro-[1,1'-biphenyl]-2-yl)methyl)piperazin-1-yl)-N-((3-nitro-4-(((tetrahydro-2H-pyran-4-yl)methyl)amino)phenyl)sulfonyl)benzamide (venetoclax), and S55746 (BCL201), or a pharma- ceutical acceptable salt thereof.

[0023] In various embodiments of the pharmaceutical combination, the BCL-2 inhibitor is venetoclax, or a pharma- ceutically acceptable salt thereof.

[0024] In various embodiments of the pharmaceutical combination, the HDAC6 inhibitor and the BCL-2 inhibitor are in the same formulation. In other embodiments of the pharmaceutical combination, the HDAC6 inhibitor and the BCL-2 inhibitor are in separate formulations.

[0025] In various embodiments of the pharmaceutical combination, the combination is for simultaneous or sequential administration.

[0026] In various embodiments, the pharmaceutical formulation is intended for use in treating cancer in a subject in need thereof.

[0027] In various other embodiments, the pharmaceutical formulation is for use in the preparation of a medicament for treating cancer.

[0028] In various embodiments of the pharmaceutical combination, the cancer is a hematological cancer.

[0029] In various embodiments of the pharmaceutical combination, the cancer is acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL), non-Hodgkin's lymphoma (e.g., mantle cell lymphoma), multiple myeloma, or myelodysplastic syndrome (MDS).

[0030] In various embodiments of the pharmaceutical combination, the cancer is refractory or resistant to treatment with at least one prior therapy.

[0031] In one aspect, provided herein is a method of treating or preventing cancer in a subject in need thereof, the method comprising administering to the subject a therapeutically effective amount of a pharmaceutical formulation provided herein.

[0032] In various embodiments of the methods, the cancer is a hematological cancer.

[0033] In various embodiments of the method, the cancer is acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL), non-Hodgkin's lymphoma (e.g., mantle cell lymphoma), multiple myeloma, or myelodysplastic syndrome (MDS).

[0034] In various embodiments of the methods, the cancer is refractory or resistant to treatment with at least one prior therapy.

[0035] In various embodiments of the method, the HDAC6 inhibitor and the BCL-2 inhibitor are administered at about the same time. In other embodiments of the method, the HDAC6 inhibitor and the BCL-2 inhibitor are administered at different times.

[0036] In one aspect, provided herein is a method of reducing the proliferation and viability of leukemic cells comprising contacting the cells with a pharmaceutical combination provided herein.

[0037] In one aspect, the pharmaceutical compositions provided herein comprise: (a) Formula I: [ka] Histone deacetylase 6 (HDAC6) inhibitors or pharma- ceutical acceptable salts thereof wherein ring B is aryl or heteroaryl; R1 is aryl or heteroaryl, each of which is optionally OH, halo, or C 1-6 can be substituted with alkyl, and R is H or C 1-6 alkyl), and (b) BCL-2 inhibitors.

[0038] In some embodiments of the composition, the pharmaceutical composition further comprises one or more excipients.

[0039] In some embodiments of the composition, Ring B is aryl. In various embodiments, R1 is aryl or heteroaryl, each of which can be optionally substituted with halo.

[0040] In another embodiment of the composition, the compound of formula I is [ka] or a pharma- ceutically acceptable salt thereof.

[0041] In another embodiment of the composition, the compound of formula I is [ka] or a pharma- ceutically acceptable salt thereof.

[0042] In various embodiments of the composition, the BCL-2 inhibitor is 4-[4-[[2-(4-chlorophenyl)-5,5-dimethyl-1-cyclohexen-1-yl]methyl]-1-piperazinyl]-N-[[4-[[(1R)-3-(4-morpholinyl)-1-[(phenylthio)methyl]propyl]amino]-3-[(trifluoromethyl)sulfonyl]phenyl]sulfonyl]benzamide (navitoclax or ABT-263); tetrocarcin A; antimycin; gossypol (e.g., (-)-gossypol acetic acid); obatoclax; ethyl 2-amino-6-bromo-4-(1-cyano-2-ethoxy-2-oxoethyl)-4H-chromene-3-carboxylate (HA 14-1); oblimersen; Bak BH3 peptides; 4-[4-[(4'-chloro[1,1'-biphenyl]-2-yl)methyl]-1-piperazinyl]-N-[[4-[[(1R)-3-(dimethylamino)-1-[(phenylthio)methyl]propyl]amino]-3-nitrophenyl]sulfonyl]-benzamide (ABT-737); 2-((1H-pyrrolo[2,3-b]pyridin-5-yl)oxy)-4-(4-((4' -chloro-5,5-dimethyl-3,4,5,6-tetrahydro-[1,1'-biphenyl]-2-yl)methyl)piperazin-1-yl)-N-((3-nitro-4-(((tetrahydro-2H-pyran-4-yl)methyl)amino)phenyl)sulfonyl)benzamide (venetoclax), and S55746 (BCL201), or a pharma- ceutical acceptable salt thereof.

[0043] In various embodiments of the composition, the BCL-2 inhibitor is venetoclax, or a pharma- ceutically acceptable salt thereof. [Brief description of the drawings]

[0044] [Figure 1A] FIG. 1A shows the viability of the following cell lines: MOLM-13 (FIG. 1A) upon exposure to the indicated concentrations of Compound B alone, ABT-199 (also referred to herein as "venetoclax") alone, or a combination of Compound B and ABT-199. [Figure 1B]FIG. 1B shows the viability of the following cell lines: Kasumi-1 (FIG. 1B) upon exposure to the indicated concentrations of Compound B alone, ABT-199 (also referred to herein as "venetoclax") alone, or a combination of Compound B and ABT-199. [Figure 1C] FIG. 1C shows the viability of the following cell lines: MV-4-11 (FIG. 1C) upon exposure to the indicated concentrations of Compound B alone, ABT-199 (also referred to herein as "venetoclax") alone, or a combination of Compound B and ABT-199. [Figure 2A] FIG. 2A shows the extent of apoptosis, as measured by Annexin V staining, as a function of treatment of MV-4-11 cells (FIG. 2A) with the indicated concentrations of Compound B alone, ABT-199 (also referred to herein as "venetoclax") alone, or the combination of Compound B and ABT-199. [Figure 2B] FIG. 2B shows the extent of apoptosis, as measured by Annexin V staining, as a function of treatment of HL-60 cells (FIG. 2B) with the indicated concentrations of Compound B alone, ABT-199 (also referred to herein as "venetoclax") alone, or the combination of Compound B and ABT-199. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0045] The pharmaceutical combinations provided herein include a histone deacetylase (HDAC) inhibitor and a BCL-2 inhibitor. Specifically, the pharmaceutical combinations provided herein include: (a) Formula I: [ka] or a pharma- ceutical acceptable salt thereof, wherein ring B is aryl or heteroaryl; R1 is aryl or heteroaryl, each of which is optionally OH, halo, or C 1-6 can be substituted with alkyl, and R is H or C1-6 alkyl), and (b) a BCL-2 inhibitor, or a pharma- ceutically acceptable salt thereof.

[0046] Certain terms used herein are explained below. Standard nomenclature is used to describe the compounds of the present invention. Unless otherwise defined, the meanings of all technical and scientific terms used herein are the same as those commonly understood by those skilled in the art to which the present invention belongs.

[0047] The term "alkyl," in certain embodiments, refers to a saturated, straight- or branched-chain hydrocarbon residue containing 1 to 6 or 1 to 8 carbon atoms, respectively. 1-6 Examples of alkyl radicals include, but are not limited to, methyl, ethyl, propyl, isopropyl, n-butyl, tert-butyl, neopentyl, and n-hexyl radicals; 1-8 Examples of alkyl radicals include, but are not limited to, methyl, ethyl, propyl, isopropyl, n-butyl, tert-butyl, neopentyl, n-hexyl, heptyl, and octyl radicals. The number of carbon atoms in an alkyl substituent is indicated by the prefix "C x-y " where: x is the minimum number of carbon atoms in the substituent and y is the maximum number of carbon atoms in the substituent.

[0048] As used herein, the terms "halo" or "halogen," by themselves or as part of another substituent, mean, unless otherwise stated, a fluorine, chlorine, bromine, or iodine atom, preferably fluorine, chlorine or bromine, and more preferably chlorine.

[0049] The term "aryl" refers to a monocyclic or polycyclic carbocyclic ring system having one or more fused or non-fused aromatic rings, including, but not limited to, phenyl, naphthyl, tetrahydronaphthyl, indanyl, indenyl, and the like. In some embodiments, an aryl group has 6 carbon atoms. In some embodiments, an aryl group has 6-10 carbon atoms. In some embodiments, an aryl group has 6-16 carbon atoms. In some embodiments, C5-C7 aryl groups are provided herein.

[0050] The term "heteroaryl" refers to a monocyclic or polycyclic (e.g., bicyclic or tricyclic or higher) fused or unfused residue or ring system having at least one aromatic ring in which one or more ring-forming atoms are heteroatoms such as oxygen, sulfur, or nitrogen. In some embodiments, heteroaryl groups have about 1-6 carbon atoms, and in further embodiments, 1-15 carbon atoms. In some embodiments, heteroaryl groups contain 5-16 ring atoms, of which one ring atom is selected from oxygen, sulfur, and nitrogen. 0, 1, 2, or 3 ring atoms are additional heteroatoms independently selected from oxygen, sulfur, and nitrogen, and the remaining ring atoms are carbon. Heteroaryl includes, but is not limited to, pyridinyl, pyrazinyl, pyrimidinyl, pyrrolyl, pyrazolyl, imidazolyl, thiazolyl, oxazolyl, isoxazolyl, thiazolyl, thiadiazolyl, oxadiazolyl, thiophenyl, furanyl, indolyl, quinolinyl, isoquinolinyl, benzimidazolyl, benzoxazolyl, quinoxalinyl, acridinyl, and the like. In certain embodiments, C4-C7 heteroaryl groups are provided herein.

[0051] The terms "combination," "therapeutic combination," or "pharmaceutical combination" as used herein refer to either a fixed combination in dosage unit form, or a non-fixed combination, or a kit of parts for combined administration, in which two or more therapeutic agents can be administered independently, simultaneously, or separately within an interval of time (especially when these time intervals allow for a coordinated, e.g., synergistic, effect of the combination partners).

[0052] The term "combination therapy" refers to the administration of two or more therapeutic agents for the purpose of treating the therapeutic conditions or disorders described in this disclosure. Such administration includes the administration of these therapeutic agents substantially simultaneously, for example in a single formulation having a fixed ratio of active ingredients or in separate formulations for each active ingredient (e.g., capsules and / or intravenous formulations). In addition, such administration also includes the use of each type of therapeutic agent sequentially or separately (either at about the same time or at different times). Regardless of whether the active ingredients are administered as a single formulation or as separate formulations, the drugs are administered to the same patient as part of the same course of treatment. In any case, the treatment regimen provides beneficial effects in treating the conditions or disorders described herein.

[0053] As used herein, the term "pharmaceutical acceptable salt" refers to derivatives of the disclosed compounds, in which the parent compound is modified by converting an existing acid or base residue into its salt form. Examples of pharmaceutical acceptable salts include, but are not limited to, inorganic or organic acid salts of basic residues such as amines, alkali or organic salts of acidic residues such as carboxylic acids, and the like. The pharmaceutical acceptable salts of the present invention include, for example, conventional non-toxic salts of the parent compound formed from non-toxic inorganic or organic acids. The pharmaceutical acceptable salts of the present invention can be synthesized by conventional chemical methods from the parent compound containing a basic or acidic residue. Such salts can generally be prepared by reacting the free acid or base form of these compounds with a stoichiometric amount of the appropriate base or acid in water or an organic solvent, or in a mixture of the two. Non-aqueous media such as ether, ethyl acetate, ethanol, isopropanol, or acetonitrile are generally preferred. Lists of suitable salts can be found in Remington's Pharmaceutical Sciences, 17th ed., Mack Publishing Company, Easton, Pa., 1985, p. 1418, and Journal of Pharmaceutical Science, 66, 2 (1977), each of which is incorporated by reference in its entirety.

[0054] Unless otherwise specified or clearly indicated by the context, references to useful therapeutic agents in the pharmaceutical formulations provided herein include both the free bases of the compounds, and all pharma- ceutically acceptable salts of the compounds.

[0055] As used herein, the term "pharmaceutical acceptable" refers to those compounds, materials, compositions and / or dosage forms that are suitable for contact with the tissues of warm-blooded animals, e.g., mammals, within the scope of sound medical judgment, without undue toxicity, irritation allergic response and other problematic complications, commensurate with a reasonable benefit / risk ratio.

[0056] As used herein, the terms "fixed combination," "fixed dose," and "single formulation" refer to a single carrier or vehicle or dosage form formulated to deliver to a patient a synergistically therapeutically effective amount of both therapeutic agents for the treatment of cancer. The single vehicle is designed to deliver a certain amount of each agent along with any pharma- ceutically acceptable carriers or excipients. In some embodiments, the vehicle is a tablet, capsule, pill, or patch. In other embodiments, the vehicle is a solution or suspension.

[0057] The terms "non-fixed combination", "kit of parts" and "separate formulations" refer to active ingredients, i.e., HDAC6 inhibitor and BCL-2 inhibitor, that are administered to a patient as separate entities without specific time limits, either simultaneously, in parallel or sequentially, such administration providing therapeutically effective levels of the two compounds in the body of a subject in need thereof. The latter also applies to cocktail therapy, e.g., the administration of three or more active ingredients.

[0058] "Oral dosage form" includes a unit dosage form formulated or intended for oral administration. In some embodiments of the pharmaceutical formulations provided herein, the HDAC6 inhibitor (e.g., Compound A or B) is administered as an oral dosage form.

[0059] The term "treating" or "treatment" as used herein includes treatment that is effective to reduce, alleviate or ameliorate at least one symptom in a subject, or to delay the progression of a disease. For example, treatment can be the gradual reduction of one or several symptoms of a disorder, or the complete eradication of a disorder such as cancer.

[0060] As used herein, the terms "prevent," "preventing," or "prevention" include preventing at least one symptom associated with or caused by the condition, disease, or disorder being prevented.

[0061] The terms "pharmaceutical effective amount," "therapeutically effective amount," or "clinically effective amount" of a therapeutic combination is an amount sufficient to result in an observable or clinically significant improvement beyond the baseline clinically observable signs and symptoms of the disorder being treated with the combination.

[0062] The term "jointly therapeutically active" or "joint therapeutic effect" as used herein means that the therapeutic agents can be administered separately (chronologically alternating, especially in a sequence-specific manner) at a time interval that is favorable but that exhibits a (preferably synergistic) interaction (joint therapeutic effect) in the warm-blooded animal, especially a human, being treated. Whether this is the case can be determined, inter alia, by following the blood concentration of the compounds, which will demonstrate that both compounds are present in the blood of the human being being treated for at least a certain time interval.

[0063] The term "subject" or "patient" as used herein is intended to include animals that may be suffering from or afflicted with cancer or any disorder that directly or indirectly involves cancer. Examples of subjects include mammals, such as humans, apes, monkeys, dogs, cows, horses, pigs, sheep, goats, cats, mice, rabbits, rats, and transgenic non-human animals. In some embodiments, the subject is a human (e.g., suffering from, at risk of, or likely to suffer from cancer).

[0064] As used herein, the term "resistance" or "refractive" to a therapeutic agent, when referring to a cancer patient, means that the cancer has inherent or has acquired resistance to the effects of the therapeutic agent as a result of contact with the agent. In other words, the cancer is resistant to the usual standard of care associated with a particular therapeutic agent.

[0065] The terms "comprising" and "including" are used herein in their open and non-limiting sense, unless otherwise noted.

[0066] The terms "a," "an," and "the," and similar references in the context of describing the invention (particularly in the context of the claims) should be construed to cover both the singular and the plural, unless otherwise specified herein or clearly contradicted by context. When the plural is used for compounds, salts, and the like, this is also construed to mean a single compound, salt, or the like.

[0067] The terms "about" or "approximately" are generally understood by those familiar with the relevant subject matter, but in certain circumstances can mean within 20%, within 10%, or within 5% of a given value or range. Alternatively, particularly in biological systems, the term "about" can mean within approximately a logarithm (i.e., an order of magnitude) or within 2-fold of a given value.

[0068] The term "synergy" as used herein refers to the effect of two drugs, e.g., a compound of formula I or a pharma- ceutically acceptable salt thereof and a BCL-2 inhibitor (e.g., venetoclax), in producing an effect in slowing the progression or progression of a cancer condition, which is greater than the simple addition of the effect of each drug administered alone. Synergy can be calculated using any suitable method, such as, for example, the sigmoid-Emax formula (Holford, NHG and Scheiner, LB, Clin. Pharmacokinet. 6:429-453 (1981)), the Loewe additivity equation (Loewe, S. and Muischnek, H., Arch. Exp. Pathol Pharmacol. 114:313-326 (1926)) and the median effect equation (Chou, TC and Talalay, P., Adv. Enzyme Regul. 22:27-55 (1984)). Each of the above-mentioned formulas can be applied to experimental data to generate corresponding graphs to aid in evaluating the effect of drug combinations. The corresponding graphs associated with the above-mentioned formulas are concentration-effect curves, isobologram curves, and combination index curves, respectively. The pharmaceutical combinations provided herein exhibit synergistic effects in relation to cell proliferation and viability in relation to leukemia cell lines (see, e.g., Example 3 and Example 4). In some embodiments, the pharmaceutical combinations provided herein are administered in amounts that result in synergistic effects. In some embodiments, the pharmaceutical combinations provided herein are administered in amounts that result in greater than additive effects.

[0069] The term "histone deacetylase" or "HDAC" refers to enzymes that remove acetyl groups from lysine residues in core histones, thus forming condensed, transcriptionally repressive chromatin. There are currently 18 known histone deacetylases, which are classified into four groups. Class I HDACs, including HDAC1, HDAC2, HDAC3, and HDAC8, are associated with the RPD3 gene in yeast. Class II HDACs, including HDAC4, HDAC5, HDAC6, HDAC7, HDAC9, and HDAC10, are associated with the Hda1 gene in yeast. Class III HDACs, also known as sirtuins, are associated with the Sir2 gene and include SIRT1-7. Class IV HDACs, which only include HDAC11, have the functions of both class I and II HDACs. The term "HDAC" refers to any one or more of the 18 known histone deacetylases, unless otherwise specified.

[0070] The term "histone deacetylase inhibitor" (HDAC inhibitor, HDACi, HDI) as used herein refers to compounds that selectively target, decrease or inhibit at least one activity of histone deacetylase.

[0071] Histone deacetylase inhibitors The pharmaceutical formulations provided herein comprise a compound represented by Formula I: [ka] (also referred to herein as "the compound of formula I"), or a pharma- ceutical acceptable salt thereof; wherein ring B is aryl or heteroaryl; R1 is aryl or heteroaryl, each of which is optionally OH, halo, or C 1-6 can be substituted with alkyl, and R is H or C 1-6 alkyl).

[0072] In certain embodiments of the compound of formula I, Ring B is aryl. In various embodiments, R1 is aryl or heteroaryl, each of which can be optionally substituted with halo.

[0073] In certain embodiments of formula I, R is OH, halo, or C 1-6 It is an aryl substituted with an alkyl.

[0074] In another embodiment of formula I, R1 is OH, halo, or C 1-6 It is a C5-C7 aryl substituted with alkyl.

[0075] In another embodiment of formula I, R1 is OH, halo, or C 1-6 It is a C4-C7 heteroaryl substituted with alkyl.

[0076] In yet another embodiment of formula I, R1 is OH, halo, or C 1-6 It is phenyl substituted with alkyl.

[0077] In yet another embodiment of formula I, R1 is phenyl substituted with halo.

[0078] In yet another embodiment of formula I, R1 is phenyl substituted with chloro.

[0079] In another embodiment of Formula I, Ring B is C5-C7 aryl.

[0080] In another embodiment of Formula I, Ring B is a C4-C7 heteroaryl.

[0081] In yet another embodiment of Formula I, ring B is phenyl.

[0082] In a specific embodiment, the compound of formula I is compound A or a pharma- ceutically acceptable salt thereof, or compound B or a pharma- ceutically acceptable salt thereof, as shown in Table 1.

[0083] [Table 1]

[0084] For convenience, the group of histone deacetylase 6 inhibitors of formula I and salts thereof will be referred to collectively as compounds of formula I, and references to compounds of formula I are meant to refer alternatively to any of the compounds or a pharma- ceutically acceptable salt thereof.

[0085] The compounds of formula I (e.g., Compound A and Compound B) are known HDAC6 inhibitors and are described in PCT Application No. WO2011 / 091213, the entire contents of which are incorporated herein by reference. Compound A and Compound B are currently being investigated in Phase 1b clinical development for the treatment of multiple myeloma.

[0086] The preparation of Compound A and Compound B is also described herein as Example 1. Compound A and Compound B are preferably in the free base form.

[0087] The salts of the compounds of formula I are preferably pharma- ceutically acceptable salts. Suitable counterion forming pharma- ceutically acceptable salts are well known in the art.

[0088] BCL-2 inhibitors The term "BCL-2 inhibitor" as used herein refers to a compound that selectively targets, reduces, or inhibits at least one activity of BCL-2. The B-cell lymphoma 2 (Bcl-2) family of proteins has been implicated as regulators of the mitochondrial (aka "intrinsic") apoptosis pathway. See Danial, NN and Korsmeyer, SJ Cell (2004) 116, 205-219. Misregulation of BCL-2 has been implicated in a wide variety of cancers, particularly hematological cancers such as follicular lymphoma, diffuse large cell lymphoma, and chronic lymphocytic leukemia. Adams, JM and Cory, S. Science (1998) 281, 1322-1326.

[0089] Examples of BCL-2 inhibitors include, but are not limited to, 4-[4-[[2-(4-chlorophenyl)-5,5-dimethyl-1-cyclohexen-1-yl]methyl]-1-piperazinyl]-N-[[4-[[(1R)-3-(4-morpholinyl)-1-[(phenylthio)methyl]propyl]amino]-3-[(trifluoromethyl)sulfonyl]phenyl]sulfonyl]benzamide (navitoclax or ABT-263); tetrocarcin A; antimycin; gossypol (e.g., (-)-gossypol acetic acid); obatoclax (GX15-070); ethyl 2-amino-6-bromo-4-(1-cyano-2-ethoxy-2-oxoethyl)-4H-chromene-3-carboxylate (HA 14-1); oblimersen; Bak BH3 peptides; 4-[4-[(4'-chloro[1,1'-biphenyl]-2-yl)methyl]-1-piperazinyl]-N-[[4-[[(1R)-3-(dimethylamino)-1-[(phenylthio)methyl]propyl]amino]-3-nitrophenyl]sulfonyl]-benzamide (ABT-737); 2-((1H-pyrrolo[2,3-b]pyridin-5-yl)oxy)-4-(4-((4'-chloro-5,5-dimethyl-3,4,5,6-tetrahydro-[1,1'-biphenyl]-2-yl)methyl)piperazin-1-yl)-N-((3-nitro-4-(((tetrahydro-2H-pyran-4-yl)methyl)amino)phenyl)sulfonyl)benzamide (venetoclax), and S55746 (BCL201).

[0090] Any of these BCL-2 inhibitors can be used in the pharmaceutical formulations provided herein.

[0091] The structures of certain BCL-2 inhibitors are shown in Table 2.

[0092] [Table 2-1] [Table 2-2]

[0093] In certain embodiments, the BCL-2 inhibitor is a compound shown in Table 2, or a pharma- ceutically acceptable salt thereof.

[0094] In certain embodiments, the BCL-2 inhibitor is venetoclax (also known as "ABT-199"), or a pharma- ceutically acceptable salt thereof.

[0095] Venetoclax is approved by the FDA for the treatment of patients with chronic lymphocytic leukemia (CLL) with 17p deletion who have received at least one prior therapy (e.g., see FDA labeling for VENCLEXTA™ at http: / / www.accessdata.fda.gov / drugsatfda_docs / label / 2016 / 208573s000lbl.pdf).

[0096] In another specific embodiment, the BCL-2 inhibitor is S55746. S55746 is currently being studied in clinical trials in patients with chronic lymphocytic leukemia (CLL), B-cell non-Hodgkin's lymphoma, or multiple myeloma. (See, e.g., https: / / clinicaltrials.gov / ct2 / show / NCT02920697). In another embodiment, the BCL-2 inhibitor is navitoclax. In another embodiment, the BCL-2 inhibitor is ABT-737, or a pharma- ceutically acceptable salt thereof. In another embodiment, the BCL-2 inhibitor is HA-14-1, or a pharma-ceutically acceptable salt thereof. In another embodiment, the BCL-2 inhibitor is obatoclax, or a pharma-ceutically acceptable salt thereof. In another embodiment, the BCL-2 inhibitor is oblemersone, or a pharma-ceutically acceptable salt thereof. In another embodiment, the BCL-2 inhibitor is tetrocarcin A, or a pharma-ceutically acceptable salt thereof. In another embodiment, the BCL-2 inhibitor is BAK BH3 peptide, or a pharma- ceutically acceptable salt thereof.In another embodiment, the BCL-2 inhibitor is antimycin, or a pharma-ceutically acceptable salt thereof.In another embodiment, the BCL-2 inhibitor is antimycin, or a pharma-ceutically acceptable salt thereof.In another embodiment, the BCL-2 inhibitor is gossypol, or a pharma-ceutically acceptable salt thereof.

[0097] Data provided herein demonstrate that the combination therapies provided herein (e.g., HDAC6 inhibitors and BCL-2 inhibitors) synergistically reduce the viability of certain cancer cell lines (see, e.g., Example 3). Additionally, the combination therapies provided herein synergistically increase apoptosis in certain cancer cell lines (see, e.g., Example 4).

[0098] The compound of formula I or the BCL-2 inhibitor, or both, can be administered in free form or in a pharma- ceutically acceptable salt form.

[0099] Also provided herein is a commercial package containing the combinations provided herein as therapeutic agents for use in delaying or treating the progression of cancer, together with instructions for their simultaneous, separate or sequential administration.

[0100] Treatment method Provided herein is a method of treating or preventing cancer in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of a pharmaceutical formulation provided herein, the pharmaceutical formulation comprising: (a) Formula I: [ka] Histone deacetylase 6 (HDAC6) inhibitors or pharma- ceutical acceptable salts thereof wherein ring B is aryl or heteroaryl; R1 is aryl or heteroaryl, each of which is optionally OH, halo or C 1-6 can be substituted with alkyl, and R is H or C 1-6 alkyl), and (b) a BCL-2 inhibitor, or a pharma- ceutically acceptable salt thereof.

[0101] In some embodiments, provided herein is a method of treating cancer in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of a pharmaceutical formulation provided herein.

[0102] In a specific embodiment of this method, the HDAC6 inhibitor is compound B, or a pharma- ceutically acceptable salt thereof, and the BCL-2 inhibitor is venetoclax, or a pharma- ceutically acceptable salt thereof.

[0103] The methods provided herein can be used for both solid and liquid tumors. Furthermore, depending on the type of tumor and the particular formulation used, a reduction in tumor volume can be obtained. The formulations disclosed herein are also suitable for preventing metastatic spread of tumors and the growth or development of micrometastases. The formulations disclosed herein are suitable for treating patients with poor prognosis.

[0104] In various embodiments of the method, the cancer is a hematological cancer, including leukemia, lymphoma, and myeloma.

[0105] In various embodiments of the method, the cancer is acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL), non-Hodgkin's lymphoma, multiple myeloma, or myelodysplastic syndrome (MDS). In further embodiments, the cancer is mantle cell lymphoma (MCL). In yet further embodiments, the cancer is B-cell lymphoma.

[0106] In various embodiments of the methods, the cancer is refractory or resistant to treatment with at least one prior therapy.

[0107] In one embodiment, provided herein is a method of treating cancer in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of an HDAC inhibitor of Formula I, or a pharma- ceutically acceptable salt thereof, and a therapeutically effective amount of a BCL-2 inhibitor. In some embodiments, provided herein is a method of treating cancer in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of Compound A, or a pharma- ceutically acceptable salt thereof, and a therapeutically effective amount of a BCL-2 inhibitor.

[0108] In another embodiment, provided herein is a method of treating a hematological cancer in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of an HDAC inhibitor of Formula I, or a pharma- ceutical acceptable salt thereof, and a therapeutically effective amount of a BCL-2 inhibitor, or a pharma- ceutical acceptable salt thereof. In some embodiments, provided herein is a method of treating a hematological cancer in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of Compound A, or a pharma- ceutical acceptable salt thereof, and a therapeutically effective amount of a BCL-2 inhibitor, or a pharma- ceutical acceptable salt thereof.

[0109] In another embodiment, provided herein is a method of treating leukemia in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of an HDAC inhibitor of Formula I, or a pharma- ceutical acceptable salt thereof, and a therapeutically effective amount of a BCL-2 inhibitor, or a pharma- ceutical acceptable salt thereof. In some embodiments, provided herein is a method of treating leukemia in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of Compound A, or a pharma- ceutical acceptable salt thereof, and a therapeutically effective amount of a BCL-2 inhibitor, or a pharma- ceutical acceptable salt thereof.

[0110] In another embodiment, provided herein is a method of treating cancer in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of Compound A, or a pharma- ceutical acceptable salt thereof, and a therapeutically effective amount of venetoclax, or a pharma- ceutical acceptable salt thereof. This embodiment exhibits a synergistic effect such that sub-therapeutic amounts of Compound A or venetoclax can be used in the method.

[0111] In another embodiment, there is provided a method of treating hematological cancer in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of Compound A, or a pharma- ceutical acceptable salt thereof, and a therapeutically effective amount of venetoclax, or a pharma-ceutical acceptable salt thereof.

[0112] In another embodiment, there is provided a method of treating leukemia in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of Compound A, or a pharma- ceutical acceptable salt thereof, and a therapeutically effective amount of venetoclax, or a pharma-ceutical acceptable salt thereof.

[0113] Yet another embodiment is a combination of a therapeutically effective amount of Compound A, or a pharma- ceutical acceptable salt thereof, and 4-[4-[[2-(4-chlorophenyl)-5,5-dimethyl-1-cyclohexen-1-yl]methyl]-1-piperazinyl]-N-[[4-[[(1R)-3-(4-morpholinyl)-1-[(phenylthio)methyl]propyl]amino]-3-[(trifluoromethyl)sulfonyl]phenyl]sulfonyl]benzamide (navitoclax or ABT-263); tetrocarcin A; antimycin; gossypol; obatoclax; ethyl 2-amino-6-bromo-4-(1-cyano-2-ethoxy-2-oxoethyl)-4H-chromene-3-carboxylate (HA 14-1); oblimersen; Bak BH3 peptides; 4-[4-[(4'-chloro[1,1'-biphenyl]-2-yl)methyl]-1-piperazinyl]-N-[[4-[[(1R)-3-(dimethylamino)-1-[(phenylthio)methyl]propyl]amino]-3-nitrophenyl]sulfonyl]-benzamide (ABT-737); 2-((1H-pyrrolo[2,3-b]pyridin-5-yl)oxy)-4-(4-((4'-chloro-5,5-dimethyl-3,4,5,6-tetrahydro and S55746 (BCL201), or a pharma- ceutical acceptable salt thereof. A method of treating cancer in a subject in need thereof comprising administering to the subject a therapeutically effective amount of a BCL-2 inhibitor selected from the group consisting of -[1,1'-biphenyl]-2-yl)methyl)piperazin-1-yl)-N-((3-nitro-4-(((tetrahydro-2H-pyran-4-yl)methyl)amino)phenyl)sulfonyl)benzamide (venetoclax), and S55746 (BCL201), or a pharma-ceutical acceptable salt thereof.

[0114] In other embodiments, provided herein are methods of treating cancer in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of Compound B, or a pharma- ceutical acceptable salt thereof, and a therapeutically effective amount of a BCL-2 inhibitor, or a pharma- ceutical acceptable salt thereof. In some embodiments, the method includes administering a therapeutically effective amount of Compound B, or a pharma- ceutical acceptable salt thereof, to a patient having a medicament for treating or preventing rheumatoid arthritis, comprising administering to the patient a therapeutically effective amount of Compound B, or a pharma- ceutical acceptable salt thereof, and administering to the patient a therapeutically effective amount of Compound B, or a pharma- ceutical acceptable salt thereof, and administering to the patient a therapeutically effective amount of Compound B, or a pharma- ceutical acceptable salt thereof, and administering to the patient a therapeutically effective amount of Compound B, or a pharma- ceutical acceptable salt thereof, and administering to the patient a therapeutically effective amount of Compound B, or a pharma- ceutical acceptable salt thereof, BH3 peptides; 4-[4-[(4'-chloro[1,1'-biphenyl]-2-yl)methyl]-1-piperazinyl]-N-[[4-[[(1R)-3-(dimethylamino)-1-[(phenylthio)methyl]propyl]amino]-3-nitrophenyl]sulfonyl]-benzamide (ABT-737); 2-((1H-pyrrolo[2,3-b]pyridin-5-yl)oxy)-4-(4-((4'-chloro-5,5-dimethyl- The method comprises administering to the subject a therapeutically effective amount of a BCL-2 inhibitor selected from the group consisting of 3,4,5,6-tetrahydro-[1,1'-biphenyl]-2-yl)methyl)piperazin-1-yl)-N-((3-nitro-4-(((tetrahydro-2H-pyran-4-yl)methyl)amino)phenyl)sulfonyl)benzamide (venetoclax), and S55746 (BCL201), or a pharma- ceutical acceptable salt thereof.

[0115] In some embodiments, provided herein is a method of treating a hematological cancer in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of Compound B, or a pharma- ceutical acceptable salt thereof, and a therapeutically effective amount of a BCL-2 inhibitor, or a pharma- ceutical acceptable salt thereof.

[0116] In some embodiments, provided herein is a method of treating leukemia in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of Compound B, or a pharma- ceutical acceptable salt thereof, and a therapeutically effective amount of a BCL-2 inhibitor, or a pharma- ceutical acceptable salt thereof.

[0117] In another embodiment, provided herein is a method of treating cancer in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of Compound B, or a pharma- ceutical acceptable salt thereof, and a therapeutically effective amount of venetoclax, or a pharma- ceutical acceptable salt thereof. This embodiment exhibits a synergistic effect such that sub-therapeutic amounts of Compound B or venetoclax can be used in the method.

[0118] In another embodiment, provided herein is a method of treating hematological cancer in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of Compound B, or a pharma- ceutical acceptable salt thereof, and a therapeutically effective amount of venetoclax, or a pharma-ceutical acceptable salt thereof.

[0119] In another embodiment, provided herein is a method of treating leukemia in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of Compound B, or a pharma- ceutical acceptable salt thereof, and a therapeutically effective amount of venetoclax, or a pharma- ceutical acceptable salt thereof.

[0120] The subjects contemplated herein are typically humans, but the subject may be any mammal for which treatment is desired, and therefore the methods described herein may be adapted for both human and veterinary use.

[0121] Pharmaceutical Formulations and Compositions The pharmaceutical combinations provided herein include a histone deacetylase (HDAC) inhibitor and a BCL-2 inhibitor.

[0122] In one aspect, the pharmaceutical formulation provided herein comprises: (a) Formula I: [ka] Histone deacetylase 6 (HDAC6) inhibitors or pharma- ceutical acceptable salts thereof wherein ring B is aryl or heteroaryl; R1 is aryl or heteroaryl, each of which is optionally OH, halo, or C 1-6 can be substituted with alkyl, and R is H or C 1-6 alkyl), and (b) a BCL-2 inhibitor, or a pharma- ceutically acceptable salt thereof.

[0123] In various embodiments of the pharmaceutical formulation, Ring B is aryl.

[0124] In various embodiments of the pharmaceutical formulation, R1 is aryl or heteroaryl, each of which can be optionally substituted with halo.

[0125] In various embodiments of the pharmaceutical formulation, the compound of formula I is Compound A, or a pharma- ceutically acceptable salt thereof. In another embodiment, the compound of formula I is Compound B, or a pharma- ceutically acceptable salt thereof.

[0126] In various embodiments of the pharmaceutical combination, the BCL-2 inhibitor is 4-[4-[[2-(4-chlorophenyl)-5,5-dimethyl-1-cyclohexen-1-yl]methyl]-1-piperazinyl]-N-[[4-[[(1R)-3-(4-morpholinyl)-1-[(phenylthio)methyl]propyl]amino]-3-[(trifluoromethyl)sulfonyl]phenyl]sulfonyl]benzamide (navitoclax or ABT-263); tetrocarcin A; antimycin; gossypol (e.g., (-)-gossypol acetic acid); obatoclax; ethyl 2-amino-6-bromo-4-(1-cyano-2-ethoxy-2-oxoethyl)-4H-chromene-3-carboxylate (HA 14-1); oblimersen; Bak BH3 peptides; 4-[4-[(4'-chloro[1,1'-biphenyl]-2-yl)methyl]-1-piperazinyl]-N-[[4-[[(1R)-3-(dimethylamino)-1-[(phenylthio)methyl]propyl]amino]-3-nitrophenyl]sulfonyl]-benzamide (ABT-737); 2-((1H-pyrrolo[2,3-b]pyridin-5-yl)oxy)-4-(4-((4' -chloro-5,5-dimethyl-3,4,5,6-tetrahydro-[1,1'-biphenyl]-2-yl)methyl)piperazin-1-yl)-N-((3-nitro-4-(((tetrahydro-2H-pyran-4-yl)methyl)amino)phenyl)sulfonyl)benzamide (venetoclax), and S55746 (BCL201), or a pharma- ceutical acceptable salt thereof.

[0127] In various embodiments of the pharmaceutical combination, the BCL-2 inhibitor is venetoclax, or a pharma- ceutically acceptable salt thereof.

[0128] In certain embodiments of the pharmaceutical combination, the HDAC6 inhibitor is compound B or a pharma- ceutically acceptable salt thereof, and the BCL-2 inhibitor is venetoclax.

[0129] In various embodiments of the pharmaceutical combination, the HDAC6 inhibitor and the BCL-2 inhibitor are in the same formulation. In other embodiments of the pharmaceutical combination, the HDAC6 inhibitor and the BCL-2 inhibitor are in separate formulations.

[0130] In various embodiments of the pharmaceutical combination, the combination is for simultaneous or sequential administration.

[0131] In various embodiments, the pharmaceutical formulation is intended for use in treating cancer in a subject in need thereof.

[0132] In some embodiments, the combination of the present invention is used to treat or prevent cancer, comprising administering to a subject a combination therapy comprising an effective amount of an HDAC6 inhibitor (i.e., a compound of formula I) and an effective amount of a BCL-2 inhibitor. These compounds are preferably administered in therapeutically effective dosages that exert a beneficial effect when combined. Administration may include separate administration of each component, either simultaneously or sequentially.

[0133] In various embodiments, the pharmaceutical formulation is for use in the preparation of a medicament for the treatment or prevention of cancer. In further embodiments, the pharmaceutical formulation is for use in the preparation of a medicament for the treatment of cancer.

[0134] The pharmaceutical formulations provided herein are also capable of inhibiting the growth of both solid and liquid tumors. Furthermore, depending on the type of tumor and the particular formulation used, a reduction in tumor volume can be obtained. The formulations disclosed herein are also suitable for preventing the metastatic spread of tumors and the growth or development of micrometastases. The formulations disclosed herein are suitable for treating patients with poor prognosis.

[0135] In various other embodiments, the pharmaceutical formulation is for use in the preparation of a medicament for treating cancer.

[0136] In various embodiments of the pharmaceutical combination, the cancer is a hematological cancer, including leukemia, lymphoma, and myeloma.

[0137] In various embodiments of the pharmaceutical combination, the cancer is acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL), non-Hodgkin's lymphoma, multiple myeloma, or myelodysplastic syndrome (MDS). In further embodiments, the cancer is mantle cell lymphoma (MCL). In yet further embodiments, the cancer is B-cell lymphoma.

[0138] In various embodiments of the pharmaceutical combination, the cancer is refractory or resistant to treatment with at least one prior therapy.

[0139] The pharmaceutical compositions provided herein comprise a histone deacetylase (HDAC) inhibitor and a BCL-2 inhibitor.

[0140] As used herein, the term "pharmaceutical composition" is defined to refer to a mixture or solution containing a therapeutic agent(s) that is administered to a subject, such as a mammal or human, for the prevention or treatment of a particular disease or condition affecting the mammal.

[0141] In one aspect, the pharmaceutical compositions provided herein comprise: (a) Formula I: [ka] Histone deacetylase 6 (HDAC6) inhibitors or pharma- ceutical acceptable salts thereof (In the formula: Ring B is aryl or heteroaryl; R1 is aryl or heteroaryl, each of which is optionally OH, halo, or C 1-6 can be substituted with alkyl, and R is H or C 1-6 alkyl), and (b) BCL-2 inhibitors.

[0142] In some embodiments of the composition, Ring B is aryl. In various embodiments, R1 is aryl or heteroaryl, each of which can be optionally substituted with halo.

[0143] In another embodiment of the composition, the compound of formula I is Compound A or a pharma- ceutically acceptable salt thereof.In another embodiment of the composition, the compound of formula I is Compound B or a pharma- ceutically acceptable salt thereof.

[0144] In various embodiments of the composition, the BCL-2 inhibitor is 4-[4-[[2-(4-chlorophenyl)-5,5-dimethyl-1-cyclohexen-1-yl]methyl]-1-piperazinyl]-N-[[4-[[(1R)-3-(4-morpholinyl)-1-[(phenylthio)methyl]propyl]amino]-3-[(trifluoromethyl)sulfonyl]phenyl]sulfonyl]benzamide (navitoclax or ABT-263); tetrocarcin A; antimycin; gossypol (e.g., (-)-gossypol acetic acid); obatoclax; ethyl 2-amino-6-bromo-4-(1-cyano-2-ethoxy-2-oxoethyl)-4H-chromene-3-carboxylate (HA 14-1); oblimersen; Bak BH3 peptides; 4-[4-[(4'-chloro[1,1'-biphenyl]-2-yl)methyl]-1-piperazinyl]-N-[[4-[[(1R)-3-(dimethylamino)-1-[(phenylthio)methyl]propyl]amino]-3-nitrophenyl]sulfonyl]-benzamide (ABT-737); 2-((1H-pyrrolo[2,3-b]pyridin-5-yl)oxy)-4-(4-((4' -chloro-5,5-dimethyl-3,4,5,6-tetrahydro-[1,1'-biphenyl]-2-yl)methyl)piperazin-1-yl)-N-((3-nitro-4-(((tetrahydro-2H-pyran-4-yl)methyl)amino)phenyl)sulfonyl)benzamide (venetoclax), and S55746 (BCL201), or a pharma- ceutical acceptable salt thereof.

[0145] In various embodiments of the composition, the BCL-2 inhibitor is venetoclax, or a pharma- ceutically acceptable salt thereof.

[0146] In a specific embodiment of the composition, the compound of formula I is Compound A, or a pharma- ceutically acceptable salt thereof, and the BCL-2 inhibitor is venetoclax, or a pharma- ceutically acceptable salt thereof.

[0147] In a specific embodiment of the composition, the compound of formula I is compound B, or a pharma- ceutically acceptable salt thereof, and the BCL-2 inhibitor is venetoclax, or a pharma- ceutically acceptable salt thereof.

[0148] In some embodiments of the composition, the pharmaceutical composition further comprises one or more excipients. As used herein, the term "pharmaceutical acceptable excipient" or "pharmaceutical acceptable carrier" includes any and all solvents, dispersion media, coatings, surfactants, antioxidants, preservatives (e.g., antibacterial agents, antifungal agents), isotonicity agents, absorption retardants, salts, preservatives, drugs, drug stabilizers, binders, excipients, disintegrants, lubricants, sweeteners, flavoring agents, dyes, and the like, and combinations thereof, known to those skilled in the art (see, for example, Remington's Pharmaceutical Sciences, 18th Ed. Mack Printing Company, 1990, pp. 1289-1329). Except in the case that any conventional carrier is incompatible with the active ingredient, its use in the therapeutic or pharmaceutical composition is contemplated.

[0149] The pharmaceutical compositions may contain from about 0.1% to about 99.9%, preferably from about 1% to about 60%, of the therapeutic agent(s).

[0150] Pharmaceutical compositions suitable for combination therapy for enteral or parenteral administration are, for example, in unit dosage forms, such as sugar-coated tablets, tablets, capsules or suppositories, or ampoules. These are produced in a manner known per se, for example by various conventional mixing, grinding, direct compression, granulation, sugar-coating, dissolving, lyophilization processes, melt granulation, or other manufacturing techniques readily apparent to those skilled in the art, unless otherwise indicated. It is understood that the unit content of the combination partners contained in each individual dose of each dosage form does not necessarily constitute an effective amount per se, since the required effective amount can be achieved by administration of a number of dosage units.

[0151] Administration The method of treating cancer according to the disclosure provided herein may include (i) (a) administering an HDAC6 inhibitor in free form or in pharma- ceutically acceptable salt form, and (ii) (b) administering a BCL-2 inhibitor in free form or in pharma- ceutically acceptable salt form, simultaneously or sequentially, in any order, in a jointly therapeutically effective amount, preferably in a synergistically effective amount, for example, in a daily dose or intermittent dosing. The individual combination partners of the pharmaceutical combinations provided herein may be administered separately at different times throughout the course of treatment, or may be administered simultaneously in a divided or single combination form. Thus, the methods provided herein should be understood as embracing all such regimes of simultaneous or alternating treatment, and the term "administering" should be interpreted accordingly.

[0152] For example, in one embodiment of the method, the HDAC6 inhibitor is administered first, followed by the BCL-2 inhibitor, in another embodiment of the method, the BCL-2 inhibitor is administered first, followed by the HDAC6 inhibitor.

[0153] The compound of formula I can be administered orally in an amount of about 10 mg to about 1000 mg (e.g., about 10 mg to about 500 mg) per day, either in a single dose or for divided use. Thus, in certain embodiments of the methods of treatment provided herein, the compound of formula I can be administered in an amount of about 10 mg, 20 mg, 30 mg, 40 mg, 50 mg, 60 mg, 70 mg, 80 mg, 90 mg, 100 mg, 110 mg, 120 mg, 130 mg, 140 mg, 150 mg, 160 mg, 170 mg, 180 mg, 190 mg, 200 mg, 210 mg, 220 mg, 230 mg, 240 mg, 250 mg, 260 mg, 270 mg, 280 mg, 290 mg, 300 mg, 310 mg, 320 mg, 330 mg, 340 mg, 350 mg, 360 mg, 370 mg, 380 mg, 390 mg, 400 mg, 410 mg, 420 mg, 430 mg, 440 mg, 450 mg, 460 mg, 470 mg, 480 mg, 490 mg, 500 mg, 510 mg, 520 mg, 530 mg, 540 mg, 550 mg, 560 mg, 570 mg, 580 mg, 590 mg, 600 mg, 610 mg, 620 mg, 630 mg, 640 mg, 650 mg, 660 mg, 670 mg, 680 mg, 690 mg, 700 mg, 710 mg, 720 mg, 73 , 240mg, 250mg, 260mg, 270mg, 280mg, 290mg, 300mg, 310mg, 320mg, 330mg, 340mg, 350mg, 360mg, 370mg, 380mg, 390mg, 400mg, 410mg, 420mg, 430mg, 440mg, 450mg, 460mg, 470mg, 480mg, 490mg or 500mg dosages. In a further embodiment, the compound of formula I is administered in a dosage of about 20 mg, 30 mg, 40 mg, 50 mg, 60 mg, 70 mg, 80 mg, 90 mg, 100 mg, 110 mg, 120 mg, 130 mg, 140 mg, 150 mg, 160 mg, 170 mg, 180 mg, 190 mg, or 200 mg per day. In some embodiments of the pharmaceutical formulation, compound A is in an amount of 600 mg to 3000 mg (e.g., about 600 mg, about 800 mg, about 1000 mg, about 1200 mg, about 1400 mg, about 1600 mg, about 1800 mg, about 2000 mg). In a further embodiment of the pharmaceutical formulation, compound A is in an amount of 600 mg to 2000 mg. In a preferred embodiment of the pharmaceutical formulation, compound A is in an amount of 180 mg to 480 mg.

[0154] In another embodiment of the pharmaceutical formulation, compound A is in an amount of 5 mg to 600 mg (e.g., about 5 mg, about 25 mg, about 50 mg, about 100 mg, about 200 mg, about 300 mg, about 400 mg, about 500 mg, about 600 mg). In yet another embodiment of the pharmaceutical formulation, compound A is in an amount of 10 mg to 200 mg.

[0155] In certain embodiments of the pharmaceutical formulation, compound B is in an amount of 600 mg to 3000 mg (e.g., about 600 mg, about 800 mg, about 1000 mg, about 1200 mg, about 1400 mg, about 1600 mg, about 1800 mg, about 2000 mg). In further embodiments of the pharmaceutical formulation, compound B is in an amount of 600 mg to 2000 mg. In a preferred embodiment of the pharmaceutical formulation, compound B is in an amount of 180 mg to 480 mg.

[0156] In another embodiment of the pharmaceutical formulation, compound B is in an amount of 5 mg to 600 mg (e.g., about 5 mg, about 25 mg, about 50 mg, about 100 mg, about 200 mg, about 300 mg, about 400 mg, about 500 mg, about 600 mg). In yet another embodiment of the pharmaceutical formulation, compound B is in an amount of 10 mg to 200 mg.

[0157] In certain embodiments of the combination therapies provided herein, venetoclax is administered orally. In further embodiments, the daily dose of venetoclax is about 10 to about 500 mg per day (e.g., about 10 mg to about 400 mg, about 10 mg to about 300 mg, or about 10 mg to about 200 mg per day), either in a single dose or for divided use.

[0158] In other embodiments of the combination therapy provided herein, the BCL-2 inhibitor (e.g., venetoclax) is administered at about 10 mg, 20 mg, 30 mg, 40 mg, 50 mg, 60 mg, 70 mg, 80 mg, 90 mg, 100 mg, 110 mg, 120 mg, 130 mg, 140 mg, 150 mg, 160 mg, 170 mg, 180 mg, 190 mg, 200 mg, 210 mg, 220 mg, Administered in dosages of 230mg, 240mg, 250mg, 260mg, 270mg, 280mg, 290mg, 300mg, 310mg, 320mg, 330mg, 340mg, 350mg, 360mg, 370mg, 380mg, 390mg, 400mg, 410mg, 420mg, 430mg, 440mg, 450mg, 460mg, 470mg, 480mg, 490mg, or 500mg. In further embodiments, the BCL-2 inhibitor is administered at a dosage of about 10 mg, 20 mg, 30 mg, 40 mg, 50 mg, 60 mg, 70 mg, 80 mg, 90 mg, 100 mg, 110 mg, 120 mg, 130 mg, 140 mg, 150 mg, 160 mg, 170 mg, 180 mg, or 200 mg per day. In some embodiments of the pharmaceutical combination, the ratio of the compound of Formula I to the BCL-2 inhibitor is in the range of 700:1 to 1:40. In another embodiment, the ratio of the compound of formula I to the BCL-2 inhibitor is within the range of 2:1 to 1:2, such as 2:1, 1:1 or 1:2; 170:1 to 150:1, such as 170:1, 160:1 or 150:1; 3:1 to 1:1, such as 3:1, 2:1 or 1:1; 4:1 to 1:1, such as 4:1, 3:1, 2:1 or 1:1; or 30:1 to 10:1, such as 30:1, 20:1 or 10:1.

[0159] In another embodiment of the pharmaceutical combination, the ratio of compound A to BCL-2 inhibitor is in the range of 700:1 to 1:40. In another embodiment, the ratio of compound A to BCL-2 inhibitor is in the range of 2:1 to 1:2, such as 2:1, 1:1, or 1:2; 170:1 to 150:1, such as 170:1, 160:1, or 150:1; 3:1 to 1:1, such as 3:1, 2:1, or 1:1; 4:1 to 1:1, such as 4:1, 3:1, 2:1, or 1:1; or 30:1 to 10:1, such as 30:1, 20:1, or 10:1.

[0160] In another embodiment of the pharmaceutical combination, the ratio of compound B to BCL-2 inhibitor is in the range of 700:1 to 1:40. In another embodiment, the ratio of compound B to BCL-2 inhibitor is in the range of 2:1 to 1:2, such as 2:1, 1:1, or 1:2; 170:1 to 150:1, such as 170:1, 160:1, or 150:1; 3:1 to 1:1, such as 3:1, 2:1, or 1:1; or 30:1 to 10:1, such as 30:1, 20:1, or 10:1.

[0161] In another embodiment of the pharmaceutical combination, the ratio of compound A to venetoclax is within the range of 700:1 to 1:40. In another embodiment, the ratio of compound A to venetoclax is within the range of 2:1 to 1:2, such as 2:1, 1:1, or 1:2; 170:1 to 150:1, such as 170:1, 160:1, or 150:1; 3:1 to 1:1, such as 3:1, 2:1, or 1:1; or 30:1 to 10:1, such as 30:1, 20:1, or 10:1.

[0162] In another embodiment of the pharmaceutical combination, the ratio of compound B to venetoclax is within the range of 700:1 to 1:40. In another embodiment, the ratio of compound B to venetoclax is within the range of 2:1 to 1:2, such as 2:1, 1:1, or 1:2; 170:1 to 150:1, such as 170:1, 160:1, or 150:1; 3:1 to 1:1, such as 3:1, 2:1, or 1:1; or 30:1 to 10:1, such as 30:1, 20:1, or 10:1.

[0163] As can be demonstrated by established test models, the pharmaceutical combinations as provided herein provide the beneficial effects described hereinabove. Those skilled in the art are fully capable of selecting an appropriate test model to demonstrate such beneficial effects. The pharmacological activity of the pharmaceutical combinations provided herein can be demonstrated, for example, in clinical trials or animal models.

[0164] In certain embodiments, the pharmaceutical combinations or compositions, or both, provided herein exhibit a synergistic effect.

[0165] In a further embodiment, provided herein is a synergistic combination administered to a subject, the combination comprising a combination of the invention, the dosage ranges of each component corresponding to the synergistic ranges indicated in appropriate tumor models or clinical trials.

[0166] When calculating synergistic interactions between one or more components, the optimal range for efficacy and absolute dose range for each component can be determined definitively by administering the components across a range of different w / w ratios and doses to a patient in need of treatment. In humans, the complexity and cost of conducting clinical trials on patients can make this type of study impractical as a primary model for synergy, but observing synergy in a particular experiment can predict efficacy in other species, and animal models exist that can be used to further quantify synergy. Results of such studies can also be used to predict effective dose ratio ranges, absolute doses, and plasma concentrations.

[0167] In a further embodiment, provided herein is a synergistic combination administered to a subject, the combination comprising a combination of the invention, the dosage ranges of each component corresponding to the synergistic ranges indicated in appropriate tumor models or clinical trials.

[0168] The effective dosage of each combination partner used in the combination of the invention may vary depending on the particular compound or pharmaceutical composition used, the method of administration, the condition being treated, and the severity of the condition being treated. Thus, the dosage regimen of the combination of the invention is selected according to a variety of factors, including the route of administration, and the renal and hepatic function of the patient.

[0169] Optimal ratios of the combinations provided herein, individual and combined dosages, and concentrations of the combination partners (e.g., compounds of Formula I and BCL-2 inhibitors) that are effective without toxicity can be calculated using methods known to those of skill in the art based on the kinetics of the availability of the therapeutic agents to target sites.

[0170] To effect a dosage of each of the combination partners, one of the compound(s) may need to be administered more frequently compared to the other compound(s) in the combination. Thus, to allow for proper dosing, one or more dosage forms containing the combination of compounds and one or more dosage forms containing one of the compounds of the combination but not the other may be included in the packaged pharmaceutical product.

[0171] Unless otherwise stated herein, when the combination partners used in the combination of the present invention are applied in a form marketed as a single drug, their dosage and mode of administration may be in accordance with the information provided in the package insert of each marketed drug.

[0172] The optimal dosage of each combination partner for cancer treatment can be empirically determined for each individual using known methods and depends on a variety of factors. These factors include, but are not limited to, the extent of disease progression, the individual's age, weight, general health, sex, and diet, the time and route of administration, and other medications taken by the individual. The optimal dosage can be established using routine tests and procedures well known in the art.

[0173] The amount of each combination partner that can be combined with a carrier material to produce a single dosage form can vary depending on the individual being treated and the particular mode of administration, hi some embodiments, a unit dosage form containing a combination of agents described herein contains the amount of each agent of the combination that would typically be administered when that agent was administered alone.

[0174] The frequency of administration may vary depending on the compound used and the particular condition being treated or prevented. Patients may generally be monitored for therapeutic effectiveness using assays suitable for the condition being treated or prevented, as will be known to those of skill in the art.

[0175] In various embodiments of the pharmaceutical combination, the HDAC6 inhibitor and the BCL-2 inhibitor are in the same formulation. Alternatively, the HDAC6 inhibitor and the BCL-2 inhibitor are in separate formulations.

[0176] In various embodiments of the pharmaceutical combination, the combination is for simultaneous or sequential administration.

[0177] The contents of all sources cited throughout this application, including literature references, issued patents, published patent applications, and co-pending patent applications, are expressly incorporated herein by reference in their entirety. Unless otherwise defined, all technical and scientific terms used herein are accorded the meaning commonly known to those skilled in the art. EXAMPLES

[0178] The following examples are illustrative of the invention described above, but are not intended to limit the scope of the invention in any way. The beneficial effects of the pharmaceutical formulations of the invention can also be determined by other test models known per se to those skilled in the art.

[0179] Example 1: Synthesis of 2-(diphenylamino)-N-(7-(hydroxyamino)-7-oxoheptyl)pyrimidine-5-carboxamide (Compound A) and 2-((2-chlorophenyl)(phenyl)amino)-N-(7-(hydroxyamino)-7-oxoheptyl)pyrimidine-5-carboxamide (Compound B) [ka]

[0180] Synthesis of intermediate 2: A mixture of aniline (3.7 g, 40 mmol), compound 1 (7.5 g, 40 mmol), and K2CO3 (11 g, 80 mmol) in DMF (100 ml) was degassed and stirred under N2 at 120 °C overnight. The reaction mixture was cooled to room temperature, diluted with EtOAc (200 ml), and washed with saturated brine (200 ml x 3). The organic layer was separated, dried over Na2SO4, evaporated to dryness, and purified by silica gel chromatography (petroleum ether / EtOAc = 10 / 1) to give the desired product as a white solid (6.2 g, 64%).

[0181] Synthesis of intermediate 3: Compound 2 (6.2 g, 25 mmol), iodobenzene (6.12 g, 30 mmol), CuI (955 mg, 5.0 mmol), CsCO 3( A mixture of 16.3 g, 50 mmol) in TEOS (200 ml) was degassed and purged with nitrogen. The resulting mixture was stirred at 140 °C for 14 h, cooled to room temperature, and the residue was diluted with EtOAc (200 ml). 95% EtOH (200 ml) and NHF-H2O were added onto silica gel [50 g, pre-prepared by adding a mixture of NHF (100 g) in water (1500 ml) to silica gel (500 g, 100-200 mesh)], and the resulting mixture was kept at room temperature for 2 h. The solidified material was filtered and washed with EtOAc. The filtrate was evaporated to dryness, and the residue was purified by silica gel chromatography (petroleum ether / EtOAc = 10 / 1) to give a yellow solid (3 g, 38%).

[0182] Synthesis of intermediate 4: 2N NaOH (200 ml) was added to a solution of compound 3 (3.0 g, 9.4 mmol) in EtOH (200 ml). The mixture was stirred at 60° C. for 30 min. After evaporation of the solvent, the solution was neutralized with 2N HCl to give a white precipitate. The suspension was extracted with EtOAc (2×200 ml), the organic layer was separated, washed with water (2×100 ml), brine (2×100 ml), and then dried over Na2SO4. The solvent was removed to give a brown solid (2.5 g, 92%).

[0183] Synthesis of intermediate 6: A mixture of compound 4 (2.5 g, 8.58 mmol), compound 5 (2.52 g, 12.87 mmol), HATU (3.91 g, 10.30 mmol), and DIPEA (4.43 g, 34.32 mmol) was stirred at room temperature overnight. After the reaction mixture was filtered, the filtrate was evaporated to dryness, and the residue was purified by silica gel chromatography (petroleum ether / EtOAc=2 / 1) to give a brown solid (2 g, 54%).

[0184] Synthesis of 2-(diphenylamino)-N-(7-(hydroxyamino)-7-oxoheptyl)pyrimidine-5-carboxamide: A mixture of compound 6 (2.0 g, 4.6 mmol), sodium hydroxide (2N, 20 mL) in MeOH (50 ml) and DCM (25 ml) was stirred at 0° C. for 10 min, and hydroxylamine (50%) (10 ml) was cooled to 0° C. and added to the mixture. The resulting mixture was stirred at room temperature for 20 min, and after removal of the solvent, the mixture was neutralized with 1M HCl to give a white precipitate. The crude product was filtered and purified by preparative HPLC to give a white solid (950 mg, 48%).

[0185] [ka]

[0186] Synthesis of intermediate 2: A mixture of aniline (3.7 g, 40 mmol), ethyl 2-chloropyrimidine-5-carboxylate 1 (7.5 g, 40 mmol), K2CO3 (11 g, 80 mmol) in DMF (100 ml) was degassed and stirred at 120 °C under N2 overnight. The reaction mixture was cooled to room temperature, diluted with EtOAc (200 ml), and washed with saturated brine (200 ml x 3). The organic layer was separated, dried over Na2SO4, evaporated to dryness, and purified by silica gel chromatography (petroleum ether / EtOAc = 10 / 1) to give the desired product as a white solid (6.2 g, 64%).

[0187] Synthesis of intermediate 3: A mixture of compound 2 (69.2 g, 1 equiv.), 1-chloro-2-iodobenzene (135.7 g, 2 equiv.), Li2CO3 (42.04 g, 2 equiv.), K2CO3 (39.32 g, 1 equiv.), and Cu (1 equiv. 45 μm) in DMSO (690 ml) was degassed and purged with nitrogen. The resulting mixture was stirred at 140° C. for 36 h. The reaction was worked up to give compound 3 in 93% yield.

[0188] Synthesis of intermediate 4: 2N NaOH (200 ml) was added to a solution of compound 3 (3.0 g, 9.4 mmol) in EtOH (200 ml). The mixture was stirred at 60° C. for 30 min. After evaporation of the solvent, the solution was neutralized with 2N HCl to give a white precipitate. The suspension was extracted with EtOAc (2×200 ml), the organic layer was separated, washed with water (2×100 ml), brine (2×100 ml), and then dried over Na2SO4. The solvent was removed to give a brown solid (2.5 g, 92%).

[0189] Synthesis of intermediate 5: A procedure similar to that used for the synthesis of intermediate 6 in Part I of this Example was used.

[0190] Synthesis of 2-((2-chlorophenyl)(phenyl)amino)-N-(7-(hydroxyamino)-7-oxoheptyl)pyrimidine-5-carboxamide: A procedure similar to that used for the synthesis of 2-(diphenylamino)-N-(7-(hydroxyamino)-7-oxoheptyl)pyrimidine-5-carboxamide in Part I of this Example was used.

[0191] [ka]

[0192] Step (1): Synthesis of compound 11: Ethyl 2-chloropyrimidine-5-carboxylate (7.0 Kg), ethanol (60 Kg), 2-chloroaniline (9.5 Kg, 2 equiv.) and acetic acid (3.7 Kg, 1.6 equiv.) were charged to a reactor under inert atmosphere. The mixture was heated to reflux. After at least 5 hours, the reaction was sampled for HPLC analysis (Method TM-113.1016). When analysis showed the reaction was complete, the mixture was cooled to 70±5°C and N,N-diisopropylethylamine (DIPEA) was added. The reaction was then cooled to 20±5°C and the mixture was stirred for an additional 2-6 hours. The resulting precipitate was filtered and washed with ethanol (2×6 Kg) and heptane (24 Kg). The cake was dried to constant weight under reduced pressure at 50±5°C to give 8.4 Kg of compound 11 (81% yield and 99.9% purity).

[0193] Step (2): Synthesis of compound 3: Copper powder (0.68 Kg, 1 equiv, <75 microns), potassium carbonate (4.3 Kg, 1.7 equiv), and dimethyl sulfoxide (DMSO, 12.3 Kg) were added to a reactor (vessel A). The resulting solution was heated to 120±5° C., and in another reactor (vessel B), a solution of compound 11 (2.9 Kg) and iodobenzene (4.3 Kg, 2 equiv) in DMSO (5.6 Kg) was heated to 40±5° C., and the mixture was then transferred to vessel A over 2-3 hours. The reaction mixture was heated at 120±5° C. for 8-24 hours until HPLC analysis (Method TM-113.942) determined that less than 1% of compound 11 remained.

[0194] Step (3): Synthesis of compound 4: The mixture from step (2) was cooled to 90-100°C and purified water (59 Kg) was added. The reaction mixture was stirred at 90-100°C for 2-8 hours until HPLC showed less than 1% compound 3 remained. The reactor was cooled to 25°C and the reaction mixture was filtered through Celite and then a 0.2 micron filter and the filtrate was collected. The filtrate was extracted twice with methyl t-butyl ether (2 x 12.8 Kg). The aqueous layer was cooled to 0-5°C and then acidified to pH 2-3 with 6N hydrochloric acid (HCl) while maintaining the temperature below 25°C. The reaction was then cooled to 5-15°C and the precipitate was filtered and washed with cold water. The cake was dried to constant weight under reduced pressure at 45-55°C to give 2.2 kg (65% yield) of compound 4 with an AUC purity of 90.3%.

[0195] Step (4): Synthesis of compound 5: Dichloromethane (40.3 Kg), DMF (33 g, 0.04 equiv.) and compound 4 (2.3 Kg) were charged to a reaction flask. The solution was filtered through a 0.2 μm filter and returned to the flask. Oxalyl chloride (0.9 Kg, 1 equiv.) was added via addition funnel over 30-120 min at <30° C. The batch was then stirred at <30° C. until the reaction was complete (compound 4≦3%) as determined by HPLC (Method TM-113.946). The dichloromethane solution was then concentrated and residual allyl chloride was removed under reduced pressure at <40° C. When HPLC analysis indicated <0.10% oxalyl chloride remained, the concentrate was dissolved in fresh dichloromethane (24 Kg) and returned to the reaction vessel (Vessel A).

[0196] A second vessel (Vessel B) was charged with methyl 7-aminoheptane hydrochloride (Compound A1, 1.5 Kg, 1.09 equiv.), DIPEA (2.5 Kg, 2.7 equiv.), 4-(dimethylamino)pyridine (DMAP, 42 g, 0.05 equiv.), and DCM (47.6 Kgs). The mixture was cooled to 0-10° C. and the acid chloride solution in Vessel A was transferred to Vessel B while maintaining the temperature at 5-10° C. The reaction was stirred at 5-10° C. for 3-24 hours, at which point HPLC analysis indicated completion of the reaction (Method TM-113.946, Compound 4≦5%). The mixture was then extracted with 1M HCl solution (20 Kg), purified water (20 Kg), 7 sodium bicarbonate (20 Kg), purified water (20 Kg), and 25% sodium chloride solution (20 Kg). The dichloromethane was then vacuum distilled below 40°C and chased repeatedly with isopropyl alcohol. When analysis showed less than 1 mol% DCM remained, the mixture was gradually cooled to 0-5°C and stirred at 0-5°C for at least 2 hours. The resulting precipitate was collected by filtration and washed with cold isopropyl alcohol (6.4 Kg). The cake was sucked dry on the filter for 4-24 hours and then further dried at 45-55°C under reduced pressure to constant weight. 2.2 Kg (77% yield) was isolated with 95.9% AUC purity method and 99.9% by weight.

[0197] Step (5): Synthesis of compound (B): Hydroxylamine hydrochloride (3.3 Kg, 10 equiv.) and methanol (9.6 Kg) were charged to the reactor. The resulting solution was cooled to 0-5°C and 25% sodium methoxide (11.2 Kgs, 11 equiv.) was added slowly while maintaining the temperature at 0-10°C. Once the addition was complete, the reaction was mixed at 20°C for 1-3 hours, filtered and the filter cake was washed with methanol (2 x 2.1 Kg). The filtrate (hydroxylamine free base) was returned to the reactor and cooled to 0±5°C. Compound 5 (2.2 Kg) was added. The reaction was stirred until the reaction was complete (Method TM-113.964, Compound 5 ≤ 2%). The mixture was filtered and water (28 Kg) and ethyl acetate (8.9 Kg) were added to the filtrate. The pH was adjusted to 8-9 using 6N HCl and stirred for up to 3 hours before filtering. The filter cake was washed with cold water (25.7 Kg) and then dried under reduced pressure to a constant weight. The crude solid compound (B) was determined to be Form IV / Pattern D.

[0198] The crude solid (1.87 Kg) was suspended in isopropyl alcohol (IPA, 27.1 Kg). The slurry was heated to 75±5° C. to dissolve the solid. Compound (B) crystals (Form I / Pattern A) were seeded into the solution and cooled to ambient temperature. The resulting precipitate was stirred for 1-2 hours and then filtered. The filter cake was rinsed with IPA (2×9.5 Kgs) and then dried to constant weight under reduced pressure at 45-55° C. to give 1.86 kg of crystalline white solid Compound (B) in 85% yield and 99.5% purity (AUC%, HPLC method in Table 3).

[0199] [Table 3]

[0200] Example 2: HDAC enzyme assay Compound B was first tested at 50x the final concentration in DMSO, followed by a 10.3x dilution series. Compounds were diluted to 6x the final concentration in assay buffer (50mM HEPES, pH 7.4, 100mM KCl, 0.001% Tween-20, 0.05% BSA, 20μM TCEP). HDAC enzymes (purchased from BPS Bioscience; San Diego, CA) were diluted to 1.5x the final concentration in assay buffer. Tripeptide substrates at a final concentration of 0.05μM and trypsin were diluted to 6x the final concentration in assay buffer. Final enzyme concentrations used in these assays were 3.3ng / ml (HDAC1), 0.2ng / ml (HDAC2), 0.08ng / ml (HDAC3) and 2ng / ml (HDAC6). Final substrate concentrations used were 16 μM (HDAC1), 10 μM (HDAC2), 17 μM (HDAC3) and 14 μM (HDAC6). 5 μl of compound and 20 μl of enzyme were added in duplicate to wells of an opaque black 384-well plate. Enzyme and compound were incubated together for 10 minutes at room temperature. 5 μl of substrate was added to each well and the plate was shaken for 60 seconds and placed in a Victor 2 microtiter plate reader. Fluorescence development was monitored for 60 minutes and the linear rate of the reaction was calculated. IC was determined by fitting a four-parameter curve using Graph Pad Prism. 50 The IC associated with Compound A and Compound B was calculated. 50 For details, see Table 1.

[0201] Example 3: Synergistic reduction in viability of AML cell lines by the combination of ABT-199 and Compound B Compound B synergizes with ABT-199 to reduce the viability of AML cell lines (Figure 1A-C). In 384-well plates, the approximate IC 50 :I C 50MOLM-13, Kasumi-1 and MV-4-11 cells were treated four times over 72 hours with a fixed ratio of compound B and ABT-199 selected to reflect the effect of the AML cell lines. The combination index (CI) was calculated using Calcusyn software. The CI value at which the estimated 50% decrease in viability was calculated for each cell line CI value: MOLM-13: CI=0.745; Kasumi-1: CI=0.442; MV-4-11: CI=0.779. CI<1 indicates synergy. Therefore, the combination of compound B and ABT-199 synergistically decreased the viability of all three AML cell lines tested.

[0202] Example 4: Synergistic induction of apoptosis by the combination of Compound B and ABT-199 (venetoclax) Apoptosis was further increased when Compound B was combined with ABT-199 compared to single agent treatment in AML cells (Figures 2A-B). MV-4-11 and HL-60 cells were treated with the indicated doses of Compound B alone, ABT-199 (venetoclax) alone, and the combination of Compound B and venetoclax for 48 hours. Apoptosis was assessed by measuring Annexin V positive cells using FACS. Treatment with the combination of Compound B and ABT-199 resulted in a synergistic increase in apoptotic cells compared to treatment with either agent alone.

Claims

1. 1. A pharmaceutical formulation comprising: (a) a compound of formula I: 【Chemistry 1】 Histone deacetylase 6 (HDAC6) inhibitors or pharma- ceutical acceptable salts thereof wherein ring B is aryl or heteroaryl; R １ is aryl or heteroaryl, each of which is optionally OH, halo, or C １－６ can be substituted with alkyl, and R is H or C １－６ alkyl), and (b) 4-[4-[[2-(4-chlorophenyl)-5,5-dimethyl-1-cyclohexen-1-yl]methyl]-1-piperazinyl]-N-[[4-[[(1R)-3-(4-morpholinyl)-1-[(phenylthio)methyl]propyl]amino]-3-[(trifluoromethyl)sulfonyl]phenyl]sulfonyl]benzamide (navitoclax or ABT-263); tetrocarcin A; antimycin; gossypol; obatoclax; ethyl 2-amino-6-bromo-4-(1-cyano-2-ethoxy-2-oxoethyl)-4H-chromene-3-carboxylate (HA 14-1); oblimersen; Bak BH3 peptides; 4-[4-[(4'-chloro[1,1'-biphenyl]-2-yl)methyl]-1-piperazinyl]-N-[[4-[[(1R)-3-(dimethylamino)-1-[(phenylthio)methyl]propyl]amino]-3-nitrophenyl]sulfonyl]-benzamide (ABT-737); 2-((1H-pyrrolo[2,3-b]pyridin-5-yl)oxy)-4-(4-((4'-chloro-5,5-dimethyl) and a BCL-2 inhibitor selected from the group consisting of (3-nitro-4-(((tetrahydro-2H-pyran-4-yl)methyl)amino)phenyl)sulfonyl)benzamide (venetoclax), and S55746 (BCL201), or a pharma- ceutical acceptable salt thereof.

2. The compound of formula I is 【Chemistry 2】 2. The pharmaceutical formulation of claim 1, which is:

3. The compound of formula I is 【Chemistry 3】 2. The pharmaceutical formulation of claim 1, which is:

4. The pharmaceutical combination according to any one of claims 1 to 3, wherein the BCL-2 inhibitor is venetoclax or a pharma- ceutically acceptable salt thereof.

5. The pharmaceutical combination according to any one of claims 1 to 4, wherein said HDAC6 inhibitor and said BCL-2 inhibitor are in the same formulation.

6. The pharmaceutical combination according to any one of claims 1 to 4, wherein said HDAC6 inhibitor and said BCL-2 inhibitor are in separate formulations.

7. A pharmaceutical combination according to any one of claims 1 to 4, wherein the combination is for simultaneous or sequential administration.

8. 5. The pharmaceutical formulation according to any one of claims 1 to 4, for use in treating cancer in a subject in need thereof.

9. A pharmaceutical formulation according to any one of claims 1 to 4 intended for use in the preparation of a medicament for the treatment of cancer.

10. The pharmaceutical combination according to any one of claims 1 to 4, wherein the cancer is a hematological cancer.

11. 10. The pharmaceutical combination of claim 8 or 9, wherein the cancer is refractory or resistant to treatment with at least one prior therapy.

12. A method of treating or preventing cancer in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of (a) a compound of formula I: 【Chemistry 4】 Histone deacetylase 6 (HDAC6) inhibitors or pharma- ceutical acceptable salts thereof wherein ring B is aryl or heteroaryl; R １ is aryl or heteroaryl, each of which is optionally OH, halo, or C １－６ can be substituted with alkyl, and R is H or C １－６ alkyl), and (b) 4-[4-[[2-(4-chlorophenyl)-5,5-dimethyl-1-cyclohexen-1-yl]methyl]-1-piperazinyl]-N-[[4-[[(1R)-3-(4-morpholinyl)-1-[(phenylthio)methyl]propyl]amino]-3-[(trifluoromethyl)sulfonyl]phenyl]sulfonyl]benzamide (navitoclax or ABT-263); tetrocarcin A; antimycin; gossypol; obatoclax; ethyl 2-amino-6-bromo-4-(1-cyano-2-ethoxy-2-oxoethyl)-4H-chromene-3-carboxylate (HA 14-1); oblimersen; Bak BH3 peptides; 4-[4-[(4'-chloro[1,1'-biphenyl]-2-yl)methyl]-1-piperazinyl]-N-[[4-[[(1R)-3-(dimethylamino)-1-[(phenylthio)methyl]propyl]amino]-3-nitrophenyl]sulfonyl]-benzamide (ABT-737); 2-((1H-pyrrolo[2,3-b]pyridin-5-yl)oxy)-4-(4-((4'-chloro-5,5-dimethyl) 16. The method of claim 15, further comprising administering a BCL-2 inhibitor selected from the group consisting of 3-nitro-4-(((tetrahydro-2H-pyran-4-yl)methyl)amino)phenyl)sulfonyl)benzamide (venetoclax), and S55746 (BCL201), or a pharma- ceutical acceptable salt thereof.

13. The compound of formula I is 【Chemistry 5】 or a pharma- ceutically acceptable salt thereof.

14. The compound of formula I is 【Chemistry 6】 or a pharma- ceutically acceptable salt thereof.

15. The method of any one of claims 12 to 14, wherein the BCL-2 inhibitor is venetoclax or a pharma- ceutical acceptable salt thereof.

16. The method of any one of claims 12 to 15, wherein the cancer is a blood cancer.

17. The method of any one of claims 12 to 16, wherein the cancer is refractory or resistant to treatment with at least one prior therapy.

18. The method of any one of claims 12 to 16, wherein the HDAC6 inhibitor and the BCL-2 inhibitor are administered approximately simultaneously.

19. The method of any one of claims 12 to 16, wherein the HDAC6 inhibitor and the BCL-2 inhibitor are administered at different times.

20. 8. A method for reducing cell proliferation and viability, comprising contacting said cells with a pharmaceutical formulation according to any one of claims 1 to 7, wherein said cells are leukemic cells.

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