WO2025217597A1

WO2025217597A1 - A cdk9 inhibitor for use in the treatment of cancer in a subject having an asxl1 mutation

Info

Publication number: WO2025217597A1
Application number: PCT/US2025/024396
Authority: WO
Inventors: Dragan CICIC; Angelos M. Stergiou; Tapan KADIA; Omer JAMY
Original assignee: Sellas Life Sciences Group Inc
Current assignee: Sellas Life Sciences Group Inc
Priority date: 2024-04-12
Filing date: 2025-04-11
Publication date: 2025-10-16
Anticipated expiration: 2026-10-12

Abstract

Disclosed herein are CDK9 inhibitor compositions and methods for treating a cancer in a subject having an ASXL1 mutation. The methods include administering a therapeutically effective amount of a CDK9 inhibitor to the subject. Also disclosed is the use of CDK9 inhibitors in the manufacture of a medicament for treating a cancer in a subject having an ASXL1 mutation.

Description

METHODS OF TREATING CANCER IN SUBJECTS HAVING AN ASXL1 MUTATION

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of and priority from U.S. Provisional Application Nos. 63/633,662, filed April 12, 2024, and 63/725,404, filed November 26, 2024, the contents of which are each hereby incorporated by reference in their entirety.

FIELD OF THE DISCLOSURE

[0002] This disclosure relates to methods of treating cancer in subjects having an ASXL1 mutation.

BACKGROUND

[0003] The ability to sustain chronic proliferation is a fundamental trait of cancer cells. Conventional chemotherapy strategies target rapidly dividing cells, e.g., by inhibiting critical steps of cell division, such as mitosis or DNA synthesis, or by exploiting the increased vulnerability of cycling cells to genotoxic or metabolic stress. While such chemotherapy treatments can be effective in treating a diverse array of different cancer types, chemotherapy treatments are, however, typically accompanied by side effects that adversely affect a patient’s quality of life because the chemotherapy agents can target healthy cells in addition to cancerous cells. Moreover, cancers can develop a resistance to chemotherapy treatments which render the chemotherapy treatments less effective over time.

[0004] Recently, the World Health Organization released its 5^th edition on the classification of cancers. A particular emphasis of the World Health Organization’s classification of cancers is classification based on defining genetic abnormalities. One reason for this classification scheme is because different cancer treatments can be effective depending on the cancer type and the genetic abnormalities present.

[0005] Accordingly, there is a need for more specific cancer treatments tailored to particular cancer types based on the presence of defining genetic abnormalities).

SUMMARY OF THE DISCLOSURE

[0006] In one aspect, the disclosure provides methods of treating a cancer in a subject having an ASXL1 mutation. The methods include administering a therapeutically effective amount of a CDK9 inhibitor to the subject in need thereof. [0007] In one aspect, the disclosure provides a use of a CDK9 inhibitor in the manufacture of a medicament for treating a cancer in a subject, wherein the subject has an ASXL1 mutation.

[0008] In one aspect, the disclosure provides a CDK9 inhibitor for use in treating a cancer in a subject, wherein the subject has an ASXL1 mutation.

[0009] In some embodiments, the cancer is a hematologic malignancy. For example, in some embodiments, the cancer is at least one cancer selected from the group consisting of a myeloproliferative neoplasm, a myelodysplasia, a mastocytosis, an acute myeloid leukemia, a chronic lymphocytic leukemia, a small lymphocytic lymphoma, a lymphoma, a myeloid sarcoma, a myeloid neoplasm, a lymphoid neoplasm, a histiocytic cell neoplasm, and a dendritic cell neoplasm. In some embodiments, the cancer is at least one cancer selected from the group consisting of a hematologic malignancy or a solid malignancy. In some embodiments, the cancer is at least one cancer selected from the group consisting of a relapsed hematologic malignancy and a refractory hematologic malignancy. In some embodiments, the cancer is a myeloid malignancy. For example, in some embodiments, the cancer is at least one cancer selected from the group consisting of an acute myeloid leukemia, a myelodysplastic syndrome, a chronic myelomonocytic leukemia, and a myeloproliferative neoplasm.

[0010] In some embodiments, the CDK9 inhibitor is a compound of Formula 1 :

Formula or a pharmaceutically acceptable salt, solvate, ester, acid or prodaig thereof.

[0011] For example, in some embodiments, the CDK9 inhibitor is the compound of Formula 2: or a pharmaceutically acceptable salt, solvate, ester, acid or prodrug thereof. [0012] In some embodiments, the CDK9 inhibitor has an equilibrium dissociation constant for CDK9 of less than or equal to one nanomolar. For example, in some embodiments, the CDK9 inhibitor comprises at least one selected from the group consisting of 4-[[[4-[5-chloro-2-[[trans-4-[[(lR)-2-methoxy-l-methyl ethyl] amino] cyclohexyl] amino] -4-pyridinyl]-2 -thiazolyl] amino] methyl] tetrahydro-2H-pyran-4-carbonitrile dimaleate; 5- fhroro-4-(4-fluoro-2-methoxyphenyl)-N-{4-[(S-methylsulfonimidoyl)methyl]-2-pyridinyl}-2- pyridinamine); (lS,3R)-3-acetamido-N-[5-chloro-4-(5,5-dimethyl-4,6-dihydropyrrolo[l,2- b]pyrazol-3-yl)pyridin-2-yl]cyclohexane-l-carboxamide; (lS,3S)-Nl-(5-(pentan-3- yl)pyrazolo[l,5-a]pyrimidin-7-yl)cyclopentane-l,3-diamine); and 4-(4-fluoro-2- methoxyphenyl)-N-[3-[(methylsulfonimidoyl)methyl]phenyl]-l,3,5-triazin-2-amine, or a pharmaceutically acceptable salt, solvate, ester, acid or prodrug thereof.. In some embodiments, the CDK9 inhibitor comprises at least one selected from the group consisting of 4-[[[4-[5-chloro-2-[[trans-4-[[(lR)-2-methoxy-l-methyl ethyl] amino] cyclohexyl] amino] -4-pyridinyl]-2 -thiazolyl] amino] methyl] tetrahydro-2H-pyran-4-carbonitrile devaluate; 5- fluoro-4-(4-fluoro-2-methoxyphenyl)-N-{4-[(S-methylsulfonimidoyl)methyl]-2-pyridinyl}-2- pyridinamine); (lS,3R)-3-acetamido-N-[5-chloro-4-(5,5-dimethyl-4,6-dihydropyrrolo[l,2- b]pyrazol-3-yl)pyridin-2-yl]cyclohexane-l-carboxamide; (lS,3S)-Nl-(5-(pentan-3- yl)pyrazolo[l,5-a]pyrimidin-7-yl)cyclopentane-l,3-diamine); and 4-(4-fluoro-2- methoxyphenyl)-N-[3-[(methylsulfonimidoyl)methyl]phenyl]-l,3,5-triazin-2-amine.

[0013] In some embodiments, the ASXL1 mutation is a frameshift mutation. In some embodiments, the ASXL1 mutation is a point mutation. In some embodiments, the ASXL1 mutation is a nonsense mutation. In some embodiments, the ASXL1 mutation is a ASXLIc.l934dupG mutation. In some embodiments, the subject has a nonmutated ASXL1 gene and the mutated ASXL1 gene has at least 99% homology with the nonmutated ASXL1 gene. In some embodiments, the subject also has at least one additional mutation selected from the group consisting of a BCOR mutation, a EZH2 mutation, a SF3B1 mutation, a SRSF2 mutation, a STAG2 mutation, a U2AF1 mutation, and a ZRSR2 mutation.

[0014] Also disclosed are methods of identifying subjects with increased probability of responsiveness to CDK9 inhibitor therapy. A method of identifying a subject with increased probability of responsiveness to CDK9 inhibitor therapy comprises determining the presence of an ASXL1 mutation in the subject.

[0015] Further disclosed are methods of treating cancer in subjects in need thereof, which includes identifying subjects who have an increased probability of responsiveness to CDK9 inhibitor therapy. One such method comprises determining the presence of an ASXL1 mutation in the subject and administering a CDK9 inhibitor to the subject.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] FIG. 1 is a schematic representation of a cancer treatment mechanism.

[0017] FIG. 2 is a study design diagram.

[0018] FIG. 3 is a study flow diagram for the twice per week dosing regimen in Groups

1 and 2 in Example 2.

[0019] FIG. 4 is a study flow diagram for the once per week dosing regimen in Groups 1 and 2 in Example 2.

[0020] FIG. 5 is a study flow diagram for the once per week dosing regimen in Group 3 Cohorts 1 and 2 in Example 2.

[0021] FIG. 6 is a study flow diagram for the twice per week dosing regimen in Group 3 Cohort 3, 4 and 5 in Example 2.

[0022] FIG. 7 is a flowchart for conducting a trial using the Bayesian optimal interval design in Example 2.

[0023] FIG. 8 depicts the anti-proliferation activity of the compound of Formula 2 in solid tumor cell lines.

DEFINITIONS AND ABBREVIATIONS

[0024] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the subject matter pertains.

[0025] It should be understood that any of the embodiments described herein, including those described in the context of different aspects of the disclosure and different parts of the specification (including embodiments described only in the Examples), can be combined with one or more other embodiments of the disclosure, unless such combination is improper or is disclaimed.

[0026] As used herein, the singular forms “a,” “an,” and “the” include the plural reference unless the context clearly dictates otherwise.

[0027] As used herein, the term “about” refers to plus or minus 10% of the indicated value. Unless otherwise stated, weight percentages are provided based on the total amount of the composition in which they are described. [0028] Throughout the specification, the term “comprise,” “comprises” or “comprising” or variants thereof will be understood to imply the inclusion of a stated integer (element or component) or group of integers (elements or components), but not the exclusion of any other integer (element or component) or group of integers (elements or components).

[0029] The disclosure of numerical ranges within this specification is considered to be a disclosure of all numerical values and ranges within that range. For example, if a range is from about 1 to about 50, it is deemed to include, for example, 1, 7, 34, 46.1, 23.7, 50 or any other value or range within the range. Moreover, as used herein, the term “at least” includes the stated number, e.g., “at least 50” includes 50.

[0030] All references cited herein, including patent applications and publications, are incorporated by reference in their entirety for any purpose.

[0031] As used herein, “subject” or “patient” refers to an animal, preferably a mammal, including a human or a non-human animal such as livestock animals and domestic animals including, but not limited to, cattle, horses, sheep, swine, goats, rabbits, cats, dogs, and other mammals in need of treatment. In some embodiments, the subject is a human.

[0032] As used herein, a subject “in need” of treatment for an existing condition or inhibition of activity, or of prophylactic treatment or inhibition of activity encompasses both a determination of need by a medical professional as well as the desire of a patient for such treatment or inhibition.

[0033] As used herein, the term “cancer” refers to cells which exhibit relatively autonomous growth, so that they exhibit an aberrant growth phenotype characterized by a significant loss of control of cell proliferation. In general, cells of interest for detection or treatment in the present application include precancerous (e.g., benign), malignant, pre- metastatic, metastatic, and non-metastatic cells.

[0034] As used herein, the term “administration” and variants thereof (e.g., “administering”) in reference to a compound or composition means providing the compound or composition to a subject in need of treatment or inhibition. Administering of a compound or composition to the subject includes both self-administration and administration to the subject by another, including a medical professional.

[0035] As used herein, a “dosage” refers to the combined amount of the active ingredients.

[0036] As used herein, a “unit dosage” refers to an amount of active pharmaceutical agents administered to a patient in a single dose. [0037] As used herein, a “daily dosage” refers to the total amount of active pharmaceutical agent administered to a patient in a day.

[0038] As used herein, “treat,” “treatment,” or “treating” and variants thereof, are meant to include alleviating or abrogating a disorder, disease, or condition; or one or more of the symptoms associated with the disorder, disease, or condition; or alleviating or eradicating the cause(s) of the disorder, disease, or condition itself.

[0039] As used herein, “inhibit,” “inhibition,” or “inhibiting” refer to any statistically significant decrease in biological activity, including full blocking of the activity. For example, “inhibition” can refer to a decrease of at least about 10%, at least about 20%, at least about 30%, at least about 40%, at least about 50%, at least about 60%, at least about 70%, at least about 80%, at least about 90%, or 100%, or any percentage therebetween, in biological activity.

[0040] As used herein, “preventing” or “prevent” describes reducing or eliminating the onset of the symptoms or complications of the disease, condition or disorder.

[0041] As used herein, the term “alleviate” is meant to describe a process by which the severity of a sign or symptom of a disease or disorder is decreased. Importantly, a sign or symptom can be alleviated without being eliminated. In some embodiments, the administration of a CDK9 inhibitor leads to the elimination of a sign or symptom, however, elimination is not required.

[0042] As used herein, the term “therapeutically effective amount” and similar descriptions refers to the amount of a compound needed to achieve the desired effect in a subject. The desired effect may be, for example, to treat, alleviate, ameliorate or prevent a targeted disease or condition, for example, cancer, or to inhibit activity of, for example, CDK9. Amounts may vary, as a person of ordinary skill in the art will appreciate, according to various factors, including but not limited to the disease type and state, age, sex, and weight of the individual, the particular compound, the route of administration, and the frequency and/or duration of dosing. The response may be measured by one or more recognized techniques, for example, by in vivo non-human animal studies and/or further supported from clinical trials.

[0043] As used herein, a “pharmaceutical composition” is a formulation containing at least one pharmaceutically active agent, such as a CDK9 inhibitor, in a form suitable for administration to a subject. [0044] As used herein, the term “pharmaceutically acceptable salt” refers to a salt of a pharmaceutically active agent, such as a CDK9 inhibitor, that is substantially non-toxic to living organisms, e.g., subjects in need of methods of treatment. Typical pharmaceutically acceptable salts include those salts prepared by reaction of the one or more pharmaceutically active agents with an inorganic or organic acid, or an organic base, depending on the substituents present on the one or more pharmaceutically active agents.

[0045] Inorganic acids that can be used to prepare pharmaceutically acceptable salts include, but are not limited to, hydrochloric acid, phosphoric acid, sulfuric acid, nitric acid, hydrobromic acid, hydroiodic acid, phosphorous acid, metaphosphoric acid, and the like. Organic acids that can be used to prepare pharmaceutically acceptable salts include, without limitation, aliphatic mono- and dicarboxylic acids, such as oxalic acid, carbonic acid, citric acid, succinic acid, phenyl-heteroatom-substituted alkanoic acids, aliphatic and aromatic sulfuric acids and the like. Other organic acids that can be used to prepare pharmaceutically acceptable salts include, without limitation, acetic acid, propionic acid, caproic acid, cyclopentanepropionic acid, glycolic acid, pyruvic acid, lactic acid, malonic acid, malic acid, maleic acid, tartaric acid, fumaric acid, trifluoroacetic acid, benzoic acid, 3-(4- hydroxybenzoyljbenzoic acid, cinnamic acid, mandelic acid, methanesulfonic acid, ethanesulfonic acid, 1,2-ethanedisulfonic acid, 2-hydroxy ethanesulfonic acid, benzenesulfonic acid, toluenesulfonic acid, 4-methylbicyclo-[2.2.2]oct-2-ene-l -carboxylic acid, 2-naphthalenesulfonic acid, tert-butylacetic acid, glucoheptonic acid, 4,4'-methylene bis-(3-hydroxy-2-ene-l-carboxylic acid), 3 -phenyl propionic acid, trimethylacetic acid, dodecyl sulfate, gluconic acid, glutamic acid, salicylic acid, hydroxynaphthoic acid, stearic acid, muconic acid. Pharmaceutically acceptable salts prepared from inorganic or organic acids thus include, but are not limited to, hydrochloride, hydrobromide, nitrate, sulfate, pyrosulfate, bisulfate, sulfite, bisulfite, phosphate, monohydrogenphosphate, dihydrogenphosphate, metaphosphate, pyrophosphate, hydroiodide, hydrofluoride, acetate, propionate, formate, fumarate, oxalate, citrate, lactate, p-toluenesulfonate, methanesulfonate, and maleate. Inorganic bases that can be used to prepare pharmaceutically acceptable salts include, but are not limited to, aluminum hydroxide, calcium hydroxide, potassium hydroxide, sodium carbonate, sodium hydroxide, and the like. Suitable pharmaceutically acceptable salts may also be formed by reacting the pharmaceutical active agents with an organic base such as methylamine, ethylamine, ethanolamine, lysine, ornithine, diethanolamine, triethanolamine, trimethylamine, N-methylglucamine, and the like. Pharmaceutically acceptable salts include the salts formed between carboxylate or sulfonate groups that may be found on some of the pharmaceutical active agents and inorganic cations, such as sodium, potassium, ammonium, or calcium, or such organic cations as isopropylammonium, trimethylammonium, tetramethylammonium, and imidazolium. [0046] Corresponding counterions of pharmaceutically acceptable salts can be analyzed and characterized using a variety of methods including, but not limited to, ion exchange chromatography, ion chromatography, capillary electrophoresis, inductively coupled plasma, atomic absorption spectroscopy, mass spectrometry, or any combination of them.

[0047] The salt can be recovered using at least one of the following techniques: filtration, precipitation with a non-solvent followed by filtration, evaporation of the solvent, or lyophilization in the case of an aqueous solution.

[0048] Screening and characterization of pharmaceutically acceptable salts, polymorphs, and/or solvates can be accomplished using a variety of techniques including, but not limited to, thermal analysis, X-ray diffraction, spectroscopy, microscopy, and elemental analysis. Various spectral techniques used include, but are not limited to, Raman, FTIR, UVIS, and NMR (liquid and solid state). Various microscopy techniques include, but are not limited to,

IR microscopy and Raman microscopy.

[0049] List of Abbreviations:

DETAILED DESCRIPTION

[0050] As discussed above, there is a need for more specific cancer treatments tailored to particular cancer types based on the presence of defining genetic abnormalities. One class of defining genetic abnormalities relates to mutations in the additional sex comb-like 1 (ASXL1) gene. The ASXL1 gene is located in the human chromosome 20ql 1 region and mutations of the ASXL1 gene occur frequently in various cancers. The present disclosure provides methods of treating cancer in a subject having an ASXL1 mutation in need thereof, wherein the method comprises administering a therapeutically effective amount of a CDK9 inhibitor to the subj ect. [0051] Some such ASXL1 mutations are point mutations, frameshift mutations (e.g., an

ASXLIc.l934dupG mutation in ASXL1 exon 12 that results in a truncated ASXL1 protein), and nonsense mutations. Subjects having a mutated ASXL1 gene are typically heterozygous such that the subject also carries a nonmutated version of the ASXL1 gene. For example, the subject may have a nonmutated ASXL1 gene and the mutated ASXL1 gene has at least 99% homology with the nonmutated ASXL1 gene. ASXL1 mutations may also occur in tandem with other gene mutations. For example, the subject having an ASXL1 mutation may also have at least one selected from the group consisting of a BCOR mutation, a EZH2 mutation, a SF3B1 mutation, a SRSF2 mutation, a STAG2 mutation, a U2AF1 mutation, and a ZRSR2 mutation. The presence of mutations (e.g., of the ASXL1 gene) in the subject can be determined by, for example, gene sequencing or single nucleotide polymorphism (SNP) array techniques.

[0052] Mutations of the ASXL1 gene occur frequently in various cancers, such as myeloid malignancies, and may be associated with poor prognosis. For example, the subject having an ASXL1 mutation can be treated for at least one hematologic malignancy selected from the group consisting of a myeloproliferative neoplasm, a mastocytosis, an acute myeloid leukemia, a myelodysplastic syndrome, a chronic lymphocytic leukemia, a small lymphocytic lymphoma, a lymphoma, a myeloid sarcoma, a myeloid neoplasm, a lymphoid neoplasm, a myelodysplasia a histiocytic cell neoplasm, and a dendritic cell neoplasm. In some embodiments, the cancer is a lymphoma. In some embodiments, the cancer is at least one cancer selected from the group consisting of an acute myeloid leukemia, a chronic lymphocytic leukemia, and a small lymphocytic lymphoma. The cancer can be a relapsed hematologic malignancy and/or a refractory hematologic malignancy. In some embodiments, the cancer is a myelodysplasia. In some embodiments, the cancer is a solid cancer, including but not limited to cervical cancer, colorectal cancer, liver cancer, prostate cancer, head and neck squamous cell cancer, and breast cancer.

[0053] Some ASXL1 mutations, such as those ASXL1 mutations disclosed herein, can cause the formation of a truncated ASXL1 protein that gains the ability to bind and change the activity of BRD4. When the truncated ASXL1 protein binds BRD4, BRD4 then triggers P-TEFb mediated oncogenic protein transcription. P-TEFb includes CDK9 and Cyclin T subunits. Therefore, it is believed that inhibition of CDK9 can abrogate the activity of P- TEFb caused by BRD4 that is modulated by the truncated ASXL1 protein. As such, and without wishing to be bound by theory, it is believed a therapeutically effective amount of a CDK9 inhibitor can counteract the change in activity of the P-TEFb protein that occurs due to the presence of an ASXL1 mutation. The mechanism by which presence of an ASXL1 mutation may confer enhanced efficacy to a cancer treatment with a CDK9 inhibitor is shown schematically in FIG. 1. Thus, it is believed that CDK9 inhibitor therapy can enhance efficacy in treating in a subject having an ASXL1 mutation as compared to subjects who do not have an ASXL1 mutation.

[0054] The methods of treating cancer in a subject having an ASXL1 mutation in need thereof, as provided in accordance with this disclosure, comprise administering a therapeutically effective amount of a CDK9 inhibitor to the subject. Cyclin-dependent kinases (CDKs) are a family of serine/threonine kinases that are conserved across eukaryotes. In humans, there are 20 members of this family: CDKs 1, 2, 4, and 6 regulate cell cycle progression, while CDKs 7 through 13 regulate gene transcription. CDKs 14-20 are less understood but have widespread cellular activities varying from Wnt signaling to vesicle transport.

[0055] CDKs are serine/threonine kinases that regulate cell proliferation, differentiation and apoptosis. Whereas CDKs 1, 2, 4, and 6 are primarily involved in the regulation of the cell cycle, CDK7, CDK8, and CDK9 play a role in regulating transcription to further influence cell proliferation and survival by driving the expression of numerous target genes. [0056] CDK9 associates with cyclin T1 (CycT), forming the positive transcription elongation factor b (P-TEFb) complex that regulates gene transcription elongation and mRNA maturation. Prominent oncogenes regulated by CDK9 include, but are not limited, to c-Myc (a protooncogene transcription factor involved in cell growth and cell-cycle progression) and Mcl-1 (a regulator of the mitochondrial pathway of apoptosis), which together increase proliferation and survival of cancer cells. Mcl-1, along with Bcl-2, Bcl-XL, Bcl2-Al, and Bcl-W, include the antiapoptotic sub-group that counter the activity of the proapoptosis proteins.

[0057] Deregulations in the CDK9-related pathway are present in a number of malignancies, such as acute leukemia, lymphomas, neuroblastoma, primary neuroectodermal tumor, rhabdomyosarcoma, glioblastoma, and prostate cancer.

[0058] The Mcl-1 and Myc aspects of the CDK9 pathway may be associated with the pathogenesis of acute myeloid leukemia (AML). For example, various translocation products of the MLL gene found in leukemias such as AML associate with P-TEFb and constitutively activate transcription. Abnormal mRNA levels of CDK9 and cyclin T1 may be found in Burkitt’s lymphoma, diffuse large B cell lymphoma with germinal center phenotype, classical Hodgkin’s lymphoma-derived cell lines, and follicular lymphoma.

[0059] The CDK9 inhibitor for use in accordance with the present disclosure can be any CDK9 inhibitor.

[0060] The first wave CDK9 inhibitors developed were relatively nonspecific and may therefore be referred to as ‘pan-CDK’ inhibitors. Of these pan-CDK inhibitors, flavopiridol (also known as alvocidib; developed by Sanofi -Aventis) is the most extensively investigated CDK inhibitor so far, with > 60 clinical trials carried out between 1998 and 2014. Flavopiridol inhibits CDK1, CDK2, CDK4, CDK6, CDK7 and CDK9. [0061] The CDK9 inhibitor for use in accordance with the present disclosure can be, for example, a pan CDK9 inhibitor. In some embodiments, the CDK9 inhibitor is any pan-CDK inhibitor selected from the group consisting of 2-(2-chlorophenyl)-5,7-dihydroxy-8-[(3S,4R)- 3 -hydroxy- l-methylpiperidin-4-yl]-4H-l-benzopyran-4-one (alvocidib), 3-[({3-ethyl-5-[(2S)- 2-(2-hydroxyethyl)piperidin- 1 -yl]pyrazolo[ 1 ,5-a]pyrimidin-7-yl } amino)methyl]pyridin- 1 - ium-l-olate (dinaciclib), (2R,3S)-3-[[6-[(4,6-dimethylpyridin-3-yl)methylamino]-9-propan-2- ylpurin-2-yl]amino]pentan-2-ol (fadraciclib), (2R)-2-{ [6-(benzylamino)-9-(propan-2-yl)-9H- purin-2-yl]amino}butan-l-ol (seliciclib), 3-((5-fluoro-4-(4-methyl-2-(methylamino)thiazol-5- yl)pyrimidin-2-yl)amino)benzenesulfonamide (CDKI-73), (lr,4r)-Nl-(4-(3-isopropyl-2- methyl-2H-indazol-5-yl)pyrimidin-2-yl)-N4-(tetrahydro-2H-pyran-4-yl)cyclohexane-l,4- diamine (LY2857785), N-[5-[[[5-(l,l -dimethyl ethyl)-2-oxazolyl]methyl]thio]-2-thiazolyl]-4- piperidinecarboxamide (SNS-032), l-[3-[4-[[4-(2-methoxyethyl)piperazin-l- yl]methyl]phenyl]-4-oxo-lH-indeno[l,2-c]pyrazol-5-yl]-3-morpholin-4-ylurea (RGB- 286638), and 14-methyl-20-oxa-5, 7,14, 27-tetrazatetracyclo[19.3.1.12, 6.18, 12]heptacosa- 1 (25), 2(27), 3 ,5, 8, 10, 12(26), 16,21 ,23 -decaene (TG02).

[0062] The CDK9 inhibitor for use in accordance with the present disclosure can be a selective CDK9 inhibitor. Selective CDK9 inhibitors more specifically inhibit CDK9 over other CDKs. In some embodiments, the method of treating a cancer in a subject in need thereof having an ASXL1 mutation comprises administering a selective CDK9 inhibitor to the subject.

[0063] For example, the CDK9 inhibitor can be a selective CDK9 inhibitor selected from the group consisting of 4-[[[4-[5-chloro-2-[[trans-4-[[(lR)-2-methoxy-l -methyl ethyl] amino] cyclohexyl] amino]-4-pyridinyl]-2-thiazolyl] amino] methyl] tetrahydro-2H-pyran-4- carbonitrile dimaleate, (1 S,3R)-3-acetamido-N-[5-chloro-4-(5,5-dimethyl-4,6- dihydropyrrolo[l,2-b]pyrazol-3-yl)pyridin-2-yl]cyclohexane-l-carboxamide (AZD4573), 5- fluoro-4-(4-fluoro-2-methoxyphenyl)-N-[4-[(methylsulfonimidoyl)methyl]pyridin-2- yl]pyridin-2-amine (VIP 152), 4-[(2,6-dichlorobenzoyl)amino]-N-piperidin-4-yl-lH-pyrazole- 5-carboxamide (AT7519), 2-(2-chlorophenyl)-5,7-dihydroxy-8-[2-(hydroxymethyl)-l- methylpyrrolidin-3-yl]chromen-4-one (P276-00), N-(5-(((5-(tert-Butyl)oxazol-2- yl)methyl)thio)thiazol-2-yl)-l-(14-((2-(2,6-dioxopiperidin-3-yl)-l,3-dioxoisoindolin-4- yl)amino)-2-oxo-6,9,12-trioxa-3-azatetradecyl)piperidine-4-carboxamide, N-(5-(((5-(tert- butyl)oxazol-2-yl)methyl)thio)thiazol-2-yl)piperidine-4-carboxamide (SNS-032), (R)-l - cyanobutan-2-yl ((S)-l-(3-(3-(3-methoxy-4-(oxazol-5- yl)phenyl)ureido)phenyl)ethyl)carbamate (KB-0742), PRT2527, and/or 5-hydroxy-7- methoxy-2-(4-(4-methylpiperazin- 1 -yl)phenyl)-8-(piperazin- 1 -yl)-4H-chromen-4-one) (LZT- 106).

[0064] The CDK9 inhibitor for use in accordance with the present disclosure can be, for example, any one of the following selective CDK9 inhibitors:

[0065] CDK9 Inhibitor A has been tested in two Phase I studies, one in 30 AML patients and the other of 31 patients with advanced cancers (solid tumor or aggressive non-Hodgkin’s lymphoma, NHL). Of the trial in AML patients, a maximum tolerated dose was not reached (the highest tested dose was 30 mg). Overall treatment-emergent G3/G4 adverse events were recorded in > 10% of patients included anemia (G3 26.7%/G4 6.7%), lung infection (G3 23.3%), neutrophil count decreased (G4 20%), febrile neutropenia (G3 13.3%), and leukocytosis (G310%). Of the trial in advanced solid tumor or aggressive NHL, dose limiting toxi cities (DLTs) that occurred at the maximum tolerated dose included grade 3 and 4 neutropenia but no other > grade 3 drug-related adverse events or deaths were attributed to the study drug. There is a dose-dependent reduction in biomarker expression (Mcl-1, c-Myc, and PCNA mRNA). Three patients experienced durable stable disease. CDK9 Inhibitor B is currently in a Phase I study in patients with hematologic malignancies. Both CDK9 inhibitor A and CDK9 Inhibitor B are administered intravenously, however oral selective CDK9 inhibitors have been investigated. CDK9 Inhibitor D was the first selective, orally available PTEFb/CDK9 inhibitor that entered clinical development.

[0066] [0060] In some embodiments, the CDK9 inhibitor has a CDK9/cyclin T1 activity

IC50 value ranging from one nanomolar to one micromolar. In some embodiments, the CDK9 inhibitor has an equilibrium dissociation constant for CDK9 of less than or equal to one nanomolar. In some embodiments, the CDK9 inhibitor is selected from the group consisting of CDK9 Inhibitors A, B, C, and D.

[0067] In some embodiments, the CDK9 inhibitor is free from pan-CDK inhibitors. For example, in some embodiments, the CDK9 inhibitor is free from alvocidib.

[0068] The CDK9 inhibitor for use in accordance with the present disclosure can be, for example, a compound of Formula 1 :

For uia 1 or a pharmaceutically acceptable salt, solvate, ester, acid, polymorph, stereoisomer, metabolite, or prodrug thereof. In some embodiments, the CDK9 inhibitor is a compound of Formula 1. In some embodiments, the CDK9 inhibitor is a pharmaceutically acceptable salt of a compound of Formula 1. In some embodiments, the CDK9 inhibitor is a solvate of a compound of Formula 1. In some embodiments, the CDK9 inhibitor is an ester of a compound of Formula 1. In some embodiments, the CDK9 inhibitor is an acid of a compound of Formula 1. In some embodiments, the CDK9 inhibitor is a polymorph of a compound of Formula 1. In some embodiments, the CDK9 inhibitor is a stereoisomer of a compound of Formula 1. In some embodiments, the CDK9 inhibitor is a metabolite of a compound of Formula 1. In some embodiments, the CDK9 inhibitor is a prodrug of a compound of Formula 1. In some embodiments, the CDK9 inhibitor is 4-[[[4-[5-chloro-2- [[trans-4-[[(lR)-2-methoxy-l -methyl ethyl] amino] cyclohexyl] amino]-4-pyridinyl]-2- thiazolyl] amino] methyl] tetrahydro-2H-pyran-4-carbonitrile. In some embodiments, the CDK9 inhibitor is a dimaleate salt of a compound of Formula 1.

[0069] A compound of Formula 1 can be prepared by a variety of synthetic methods well known to those skilled in the art, the embodiments formed by combining them with other chemical synthesis methods, and the equivalent alternatives well known to those skilled in the art. For example, such various chemical synthesis methods are described in U.S. Patent No. 10,952,999.

[0070] The CDK9 inhibitors disclosed herein, including the compounds represented by Formula 1, may contain one or more asymmetric centers and can thus occur as racemates and racemic mixtures, single enantiomers, diastereoisomeric mixtures and individual diastereoisomers.

[0071] Centers of asymmetry that are present in the CDK9 inhibitors disclosed herein, such as the compounds represented by Formula 1, can all independently of one another have an S configuration or an R configuration. The CDK9 inhibitors disclosed herein include all possible enantiomers and diastereomers and mixtures of two or more stereoisomers, for example, mixtures of enantiomers and/or diastereomers, in all ratios. The present disclosure is meant to encompass all such stereoisomeric forms of the compounds disclosed herein.

[0072] In some embodiments, the CDK9 inhibitor is a compound of Formula 2:

Formula 2 or a pharmaceutically acceptable salt, solvate, ester, acid, polymorph, metabolite, or prodrug thereof. In some embodiments, the CDK9 inhibitor is a compound of Formula 2. In some embodiments, the CDK9 inhibitor is a pharmaceutically acceptable salt of a compound of Formula 2. In some embodiments, the CDK9 inhibitor is an ester of a compound of Formula 2. In some embodiments, the CDK9 inhibitor is an acid of a compound of Formula 2. In some embodiments, the CDK9 inhibitor is a polymorph of a compound of Formula 2. In some embodiments, the CDK9 inhibitor is a metabolite of a compound of Formula 2. In some embodiments, the CDK9 inhibitor is a prodrug of a compound of Formula 2. In some embodiments, the CDK9 inhibitor is a dimaleate salt of the compound of Formula 2.

[0073] A CDK9 inhibitor as used in accordance with the present disclosure can be, for example, a salt form or a polymorph as described in U.S. Patent Application Publication No. 2022/0315576, including different crystal forms of the maleate of the compound of Formula 2, and can be prepared by various methods as disclosed therein.

[0074] In some embodiments, the pharmaceutically acceptable salt is prepared from maleic acid, resulting in a mono- or dimaleate salt. For example, U.S. Patent Application Publication No. 2022/0315576 describes the mono- and dimaleate salts, as well as various polymorphs of the maleate form of the compound of Formula 2. In some embodiments, the molar ratio of the compound of Formula 2 to maleic acid is 1 :2.

[0075] In some embodiments, the CDK9 inhibitor is crystal form 1 of the maleate of the compound of Formula 2, which has an X-ray powder diffraction pattern including diffraction angle 20(°) values of 5.48±0.2°, 14.26±0.2°, 19.68±0.2°, and/or 22.44±0.2°. In some embodiments, the CDK9 inhibitor is crystal form 1 of the maleate of the compound of Formula 2, which has an X-ray powder diffraction pattern including diffraction angle 20(°) values of 5.02±0.2°, 9.86±0.2°, 10.88±0.2°, 11.22±0.2°, 15.06±0.2°, 16.82±0.2°, 17.48±0.2°, 18.18±0.2°, 20.50±0.2°, 23.24±0.2°, 24.90±0.2°, 26.76±0.2°, 27.16±0.2°, 28.48±0.2°, and/or 30.86±0.2°. In some embodiments, the CDK9 inhibitor is crystal form 1 of the maleate of the compound of Formula 2, which has an X-ray powder diffraction pattern including diffraction angle 20 (°) values of 9.86±0.2°, 11.22±0.2°, 15.06±0.2°, 23.24±0.2°, and/or 24.90±0.2°. In some embodiments, the CDK9 inhibitor is crystal form 1 of the maleate of the compound of Formula 2, which has an X-ray powder diffraction pattern including diffraction angle 20 (°) values of 5.02±0.2°, 16.82±0.2°, 26.76±0.2°, and/or 27.16±0.2°. In some embodiments, the CDK9 inhibitor is crystal form 1 of the maleate of the compound of Formula 2, which has an X-ray powder diffraction pattern including diffraction angle 20 (°) values of 18.18±0.2° and/or 20.50±0.2°. In some embodiments, the CDK9 inhibitor is crystal form 1 of the maleate of the compound of Formula 2, which has a differential scanning calorimetry analysis spectrum including a characteristic peak at 162.45±5°C. In some embodiments, the CDK9 inhibitor is crystal form 1 of the maleate of the compound of Formula 2, which has a differential scanning calorimetry analysis spectrum including a characteristic peak at 162.45±2°C (or 162.45±1°C). In some embodiments, the CDK9 inhibitor is crystal form 1 of the maleate of the compound of Formula 2, which has a thermogravimetric analysis spectrum including characteristic peaks at 179.19±5°C and/or 366.44±5°C. In some embodiments, the CDK9 inhibitor is crystal form 1 of the maleate of the compound of Formula 2, which has a thermogravimetric analysis spectrum including characteristic peaks at 179.19±2°C and 366.44±2° C. In some embodiments, the CDK9 inhibitor is crystal form 1 of the maleate of the compound of Formula 2, which has an infrared spectrum including characteristic peaks at

[0076] In some embodiments, the CDK9 inhibitor is crystal form 2 of the maleate of the compound of Formula 2, which has an X-ray powder diffraction pattern including diffraction angle 20(°) values of 5.02±0.2°, 5.36±0.2°, 14.04±0.2°, 20.96±0.2°, 21.42±0.2°, and/or23.00±0.2°. In some embodiments, the CDK9 inhibitor is crystal form 2 of the maleate of the compound of Formula 2, which has an X-ray powder diffraction pattern including diffraction angle 20(°) values of 8.56±0.2°, 9.00±0.2°, 15.16±0.2°, 17.40±0.2°, 18.10±0.2°, 19.22±0.2°, 21.96±0.2°, 24.46±0.2°, 26.90±0.2°, 27.34±0.2°, 28.02±0.2°, 31.40±0.2°, and/or 32.08±0.2°. In some embodiments, the CDK9 inhibitor is crystal form 2 of the maleate of the compound of Formula 2, which has an X-ray powder diffraction pattern including diffraction angle 20 (°) values of 8.56±0.2°, 9.00±0.2°, 17.40±0.2°, 19.22±0.2°, 24.46±0.2°, 27.34±0.2°, 28.02±0.2°, and/or 32.08±0.2°. In some embodiments, the CDK9 inhibitor is crystal form 2 of the maleate of the compound of Formula 2, which has an X-ray powder diffraction pattern including diffraction angle 20 (°) values of 15.16±0.2° and/or 18.10±0.2°. In some embodiments, the CDK9 inhibitor is crystal form 2 of the maleate of the compound of Formula 2, which has a differential scanning calorimetry analysis spectrum including a characteristic peak at 159.25±5°C. In some embodiments, the CDK9 inhibitor is crystal form 2 of the maleate of the compound of Formula 2, which has a differential scanning calorimetry analysis spectrum including a characteristic peak at 159.25±2°C (or 159.25±1°C). In some embodiments, the CDK9 inhibitor is crystal form 2 of the maleate of the compound of Formula 2, which has a thermogravimetric analysis spectrum including characteristic peaks at 174.38±5°C and/or 366.44±5° C. In some embodiments, the CDK9 inhibitor is crystal form 2 of the maleate of the compound of Formula 2, which has a thermogravimetric analysis spectrum including characteristic peaks at 174.38±2°C and/or 366.44±2°C. In some embodiments, the CDK9 inhibitor is crystal form 2 of the maleate of the compound of Formula 2, which has an infrared spectrum including characteristic peaks at the following [0077] In some embodiments, the CDK9 inhibitor is crystal form 3 of the maleate of the compound of Formula 2, which has an X-ray powder diffraction pattern including diffraction angle 20(°) values of 5.64±0.2°, 11.28±0.2°, 16.96±0.2°, and/or 24.92±0.2°. In some embodiments, the CDK9 inhibitor is crystal form 3 of the maleate of the compound of Formula 2, which has an X-ray powder diffraction pattern including diffraction angle 20(°) values of 8.26±0.2°, 12.21±0.2°, 16.22±0.2°, 18.52±0.2°, 19.18±0.2°, 21.28±0.2°, 22.40±0.2°, 22.98±0.2°,23.54±0.2°, 24.50±0.2°, 26.62±0.2°, 29.42±0.2°, and/or 37.48±0.2°. In some embodiments, the CDK9 inhibitor is crystal form 3 of the maleate of the compound of Formula 2, which has an X-ray powder diffraction pattern including diffraction angle 20 (°) values of 19.18±0.2°, 26.62±0.2°, and/or 29.42±0.2°. In some embodiments, the CDK9 inhibitor is crystal form 3 of the maleate of the compound of Formula 2, which has an X-ray powder diffraction pattern including diffraction angle 20 (°) values of 8.26±0.2°, 16.22±0.2°, 18.52±0.2°, 23.54±0.2°, and/or 24.50±0.2°. In some embodiments, the CDK9 inhibitor is crystal form 3 of the maleate of the compound of Formula 2, which has a differential scanning calorimetry analysis spectrum including a characteristic peak at 114.72±5°C. In some embodiments, the CDK9 inhibitor is crystal form 3 of the maleate of the compound of Formula 2, which has a differential scanning calorimetry analysis spectrum including a characteristic peak at 114.72±2°C (or 114.72±1°C).

[0078] In some embodiments, the CDK9 inhibitor is crystal form 4 of the maleate of the compound of Formula 2, which has an X-ray powder diffraction pattern including diffraction angle 20(°) values of 5.08±0.2°, 5.62±0.2°, 13.98±0.2°, and/or 22.72±0.2°. In some embodiments, the CDK9 inhibitor is crystal form 4 of the maleate of the compound of Formula 2, which has an X-ray powder diffraction pattern including diffraction angle 20(°) values of 8.54±0.2°, 11.32±0.2°, 15.78±0.2°, 17.08±0.2°, 18.10±0.2°, 20.66±0.2°, 21.56±0.2°, 23.50±0.2°, 25.76±0.2°, 27.08±0.2°, 28.02±0.2°, 28.45±0.2°, 28.55±0.2°, 32.16±0.2°, and/or 34.48±0.2°. In some embodiments, the CDK9 inhibitor is crystal form 4 of the maleate of the compound of Formula 2, which has an X-ray powder diffraction pattern including diffraction angle 20 (°) values of 8.54±0.2°, 11.32±0.2°, 17.08±0.2°, 18.10±0.2°, 20.66±0.2°, and/or 25.76±0.2°. In some embodiments, the CDK9 inhibitor is crystal form 4 of the maleate of the compound of Formula 2, which has a differential scanning calorimetry analysis spectrum including a characteristic peak at 175.74±5°C. In some embodiments, the CDK9 inhibitor is crystal form 4 of the maleate of the compound of Formula 2, which has a differential scanning calorimetry analysis spectrum including a characteristic peak at 175.74±2°C (or 175.74±1°C).

[0079] In some embodiments, the CDK9 inhibitor is crystal form I of the maleate of the compound of Formula 2, which has an X-ray powder diffraction pattern including diffraction angle 20(°) values of 5.00±0.2°, 5.40±0.2°, 14.23±0.2°, 22.40±0.2°, and/or 23.28±0.2°. In some embodiments, the CDK9 inhibitor is crystal form I of the maleate of the compound of Formula 2, which has an X-ray powder diffraction pattern including diffraction angle 20(°) values of 8.64±0.2°, 9.80±0.2°, 15.04±0.2°, 16.60±0.2°, 17.40±0.2°, 18.13±0.2°, 19.64±0.2°, 20.41±0.2°, 24.72±0.2°, 27.09±0.2°, and/or 28.40±0.2°. In some embodiments, the CDK9 inhibitor is crystal form I of the maleate of the compound of Formula 2, which has an X-ray powder diffraction pattern including diffraction angle 29 (°) values of 11.16±0.2° and/or 31.00±0.2°. In some embodiments, the CDK9 inhibitor is crystal form I of the maleate of the compound of Formula 2, which has a differential scanning calorimetry analysis spectrum including a characteristic peak at 159.91±5°C. In some embodiments, the CDK9 inhibitor is crystal form I of the maleate of the compound of Formula 2, which has a differential scanning calorimetry analysis spectrum including a characteristic peak at 159.91±2°C (or 159.91±1°C).

[0080] The compound of Formula 2 is a potent and highly selective CDK9 inhibitor. The compound of Formula 2 has low nanomolar activity against CDK9/cyclin Tl, at least 100- fold selectivity against other CDKs in enzymatic assays and broad anti-proliferative activity against a panel of tumor cell lines with sub-micromolar IC50 values. The compound of Formula 2 has single agent in vivo efficacy at tolerated doses in various xenograft tumor models in mice.

[0081] The compound of Formula 2 is a potent and selective CDK9 inhibitor. The compound of Formula 2 can potently inhibit the CDK9/cyclin Tl activity with an IC50 of 9 nM. The inhibitory effects against MV-4-11 cancer cell lines take place fast, reaching the maximum after 8 hours and 6 hours of treatment with 0.1 and 1 pM of the compound of Formula 2, respectively. The compound of Formula 2 is able to dose-dependently downregulate phospho-Rpbl CTD Ser2, Mcl-1, and c-Myc, and, therefore, induce cell cycle arrest, apoptosis and ultimately cell death. Overall, the compound of Formula 2 has potent inhibitory effects against AML cancer cell lines with IC50 values in the range of 0.0048 - 0.033 pM. [0082] The compound of Formula 2 exhibits strong in vivo anti -tumor efficacy against established human acute myeloid leukemia MV-4-11, human acute promyelocytic leukemia HL-60 and human breast cancer MDA-MB-231 xenografts in immunodeficient mice. Twice weekly i.v. doses of the compound of Formula 2 at > 5 mg/kg can potently inhibit the MV-4- 11 tumor growth.

[0083] The compound of Formula 2 inhibits human ether-a-go-go related gene (hERG) channel activity in vitro with an IC50 value of 8.81 pM, suggesting low potential for causing QT prolongation at physiologically relevant levels. The compound of Formula 2 has no effects on the central nervous, respiratory, or cardiovascular systems following a single i.v. dose up to 6 mg/kg in rats and 1.5 mg/kg in dogs. Additionally, twice a week (2-day on by 5- day off) repeated i.v. dose with the compound of Formula 2 up to 3/2 mg/kg has no effects on ECG in a 4-week (10 doses in total) good laboratory practice (GLP) compliant toxicology study in dogs.

[0084] Pharmacokinetic (PK) characteristics of the compound of Formula 2 are evaluated by a series of in vitro and in vivo studies. The in vitro studies mainly include plasma protein binding, liver microsomes and hepatocyte metabolic stability and metabolite identification, human CYP450 inhibition and induction, phenotype identification of metabolic enzymes. The in vivo studies include toxicokinetic studies of repeated intravenous administration in rats and dogs, identification of metabolites in rats, mass balance and tissue distribution in rats, and pharmacokinetic bridging studies with two batches of injections (different pH) in rats.

[0085] Toxicokinetic studies, following i.v. administration of the compound of Formula 2 maleate, show that there is no gender difference in systemic exposure between rats and dogs and systemic exposure increases slightly more than dose-proportionally. An accumulation (2- fold) in rats is observed following multiple dosing, but no accumulation in dogs is observed. [0086] After intravenous administration, the compound of Formula 2 distributes widely in rats. The compound of Formula 2 is predominately distributed to the following organs/tissues in descending order: kidneys, lungs, liver, heart, intestinal wall, spleen, bone marrow, gastric wall, skeletal muscle, thymus, and uterus/ovary. The compound of Formula 2 has relatively low penetration into the blood brain barrier and the testis. The compound of Formula 2 is moderately to highly bound to plasma proteins (plasma protein binding > 90%) in rat, dog, and human plasma. The unbound fraction in plasma (fu%) is slightly concentration-dependent ranging from 0.2 pM to 10 pM. [0087] The compound of Formula 2 is highly metabolized in CD-I mouse liver microsomes and moderately metabolized in SD rat, beagle dog, cynomolgus monkey and slightly metabolized in human liver microsomes. Metabolic pathways include O- demethylation, N-de-methoxypropane moiety, oxidation and N-de-4-methyltetrahydro-2H- pyran moiety, mainly mediated by CYP3 A4. The metabolic profiles are qualitatively similar between species.

[0088] The compound of Formula 2 can be eliminated via renal or biliary pathways, followed by hepatic metabolism. Rat mass balance studies after intravenous administration of radiolabeled compound of Formula 2 show that most of the compound of Formula 2 is excreted by bile and then by feces.

[0089] The compound of Formula 2 has potential inhibition to CYP2C19, CYP2D6 and CYP3A4 (testosterone) with the IC50 values of 11.0 pM, 6.97 pM and 43.0 pM, respectively. For CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP3A4 (midazolam), IC50 are all > 100 pM. The compound of Formula 2 is not an inducer for CYP1 A2, CYP2B6, or CYP3A4. The possibility of drug-drug interaction with the compound of Formula 2 as a causative agent is low. In vitro studies suggest that the compound of Formula 2 is a substrate for CYP3A4 (major) and CYP2D6 (minor) enzymes.

[0090] The compound of Formula 2 is well tolerated in the single dose toxicity studies and the maximum tolerated dose is 12 mg/kg and 2.5 mg/kg for rats and dogs, respectively. Following compound of Formula 2 i.v. administration at 2 mg/kg, 4 mg/kg, and 8 mg/kg, twice a week (2-day on by 5-day off) for 4 consecutive weeks (10 doses in total) in SD rats, followed by a 4-week recovery period, the toxicity target organs include lymphohematopoietic system, gastrointestinal tract, pancreas, lacrimal gland, kidney, bladder, sciatic nerve, bones, and mammary gland. Moribundity/mortality is observed in nearly 50% animals in the high dose group, while doses in the middle dose group are well tolerated with toxi cities recovering after a recovery period. The highest non-severe toxic dose (HNSTD) of the compound of Formula 2 may be around 4 mg/kg with a corresponding AUC0-24h at last dose of 1170 ng*h/mL for females and 1410 ng*h/mL for males.

[0091] In dogs, the compound of Formula 2 can be administered, for example, via i.v. at 0.5 mg/kg and 1.5 mg/kg, twice a week (2-day on by 5-day off) for 4 weeks (10 doses in total), followed by a 4-week recovery. The toxicity target organs are hematopoietic immune organs (bone marrow, spleen, thymus, mesenteric lymph node, submandibular lymph node, and Peyer’s node), digestive system (pancreas, esophagus, stomach, duodenum jejunum, ileum, cecum, colon, and rectum), kidney, liver, and male reproductive organs (testis, epididymis, and prostate). The HNSTD of the compound of Formula 2 in beagle dogs is about 1.5 mg/kg with the corresponding AUC0-24h at last dose is 1550 ng*h/mL for females and 2070 ng*h/mL for males.

[0092] As discussed above, in accordance with the present disclosure, in one aspect, the method of treating a cancer in a subject in need thereof, wherein the subject has an ASXL1 mutation, comprises administering a therapeutically effective amount of a CDK9 inhibitor to the subject.

[0093] In one aspect, the disclosure provides the use of a CDK9 inhibitor in the manufacture of a medicament for treating a cancer in a subject, wherein the subject has an ASXL1 mutation.

[0094] In one aspect, the disclosure provides a CDK9 inhibitor for use in treating a cancer in a subject, wherein the subject has an ASXL1 mutation.

[0095] In some embodiments, the cancer is a solid tumor. In some embodiments, the cancer is a hematologic malignancy. For example, in some embodiments, the cancer is at least one cancer selected from the group consisting of a myeloproliferative neoplasm, a myelodysplasia, a mastocytosis, an acute myeloid leukemia, a chronic lymphocytic leukemia, a small lymphocytic lymphoma, a lymphoma, a myeloid sarcoma, a myeloid neoplasm, a lymphoid neoplasm, a histiocytic cell neoplasm, and a dendritic cell neoplasm. In some embodiments, the cancer is at least one cancer selected from the group consisting of a myeloproliferative neoplasm, a mastocytosis, an acute myeloid leukemia, a chronic lymphocytic leukemia, a small lymphocytic lymphoma, a lymphoma, a myeloid sarcoma, a myeloid neoplasm, a lymphoid neoplasm, a histiocytic cell neoplasm, and a dendritic cell neoplasm. In some embodiments, the cancer is a myelodysplasia. In some embodiments, the cancer is not a myelodysplasia. In some embodiments, the cancer is at least one cancer selected from the group consisting of a relapsed hematologic malignancy and a refractory hematologic malignancy. In some embodiments, the cancer is a lymphoma. For example, in some embodiments, the cancer is at least one cancer selected from the group consisting of an acute myeloid leukemia, a chronic lymphocytic leukemia, and a small lymphocytic lymphoma. In some embodiments, the cancer is associated with CDK9 activity.

[0096] In some embodiments, the cancer is acute myeloid leukemia, acute lymphocytic leukemia chordoma, glioblastoma, diffuse intrinsic pontine glioma, medulloblastoma, neuroblastoma, osteosarcoma, non-small cell lung cancer, small cell lung cancer, prostate cancer, bladder cancer, liver cancer, skin cancer, glioma, breast cancer, melanoma, malignant glioma, rhabdomyosarcoma, ovarian cancer, astrocytoma, Ewing's sarcoma, retinoblastoma, epithelial cell carcinoma, colon cancer, renal cancer, gastrointestinal stromal tumor, leukemia, histiocytic lymphoma, or nasopharyngeal carcinoma.

[0097] In some embodiments, the cancer is a pediatric cancer.

[0098] In some embodiments, the subject is a mammal. In some embodiments, the subject is a human. In some embodiments, the subject is a human at least 6 months old, at least 2 years old, at least 5 years old, at least 10 years old, at least 12 years old, at least 15 years old, at least 16 years old, at least 18 years old, at least 20 years old, at least 30 years old, at least 40 years old, at least 50 years old, at least 60 years old, at least 70 years old, at least 80 years old, at least 85 years old, or any age therebetween. In some embodiments, the subject is a pediatric human subject less than or equal to 6 months old, less than or equal to 2 years old, less than or equal to 5 years old, less than or equal to 10 years old, less than or equal to 12 years old, less than or equal to 15 years old, less than or equal to 16 years old, less than or equal to 18 years old, or any age therebetween. In some embodiments, the subject in need thereof has cancer, is suspected of having cancer, or is at a risk of having cancer.

[0099] The ASXL1 mutation can be any ASXL1 mutation. For example, in some embodiments, the ASXL1 mutation is a frameshift mutation. In some embodiments, the ASXL1 mutation is a point mutation. In some embodiments, the ASXL1 mutation is a nonsense mutation. In some embodiments, the ASXL1 mutation is a ASXLIc.l934dupG mutation. In some embodiments, the subject has a nonmutated ASXL1 gene and the mutated ASXL1 gene has at least 99% homology with the nonmutated ASXL1 gene. In some embodiments, the ASXL1 mutation results in a truncated ASXL1 protein. In some embodiments, the ASXL1 mutation results in a truncated ASXL1 protein with the ability to bind BRD4.

[00100] The subject may also have one or more additional mutations. For example, in some embodiments, the subject also has at least one additional mutation selected from the group consisting of a BCOR mutation, a EZH2 mutation, a SF3B1 mutation, a SRSF2 mutation, a STAG2 mutation, a U2AF1 mutation, and a ZRSR2 mutation.

[00101] In some embodiments, the method can comprise administering to the subject in need thereof one or more additional active pharmaceutical agents in addition the CDK9 inhibitor (i.e., a combination therapy). As used herein, an “additional active pharmaceutical agent(s)” is intended to mean a pharmaceutically active agent(s) that is active in the body, including pro-drugs that convert to pharmaceutically active form after administration, which are different from the CDK9 inhibitor, and also includes pharmaceutically acceptable salts of the additional active pharmaceutical agents. Any suitable additional active pharmaceutical agent(s) may be used in any combination with the CDK9 inhibitor in a single dosage form (a fixed dose drug combination) or may be administered to the subject in one or more separate dosage formulations, which allows for concurrent or sequential administration of the CDK9 inhibitor and the additional active pharmaceutical agent(s) (co-admini strati on of the additional active pharmaceutical agents). The sequence in which the active pharmaceutical agents are administered can vary. Active pharmaceutical agents may also be administered in alternation. In some embodiments, the additional active pharmaceutical agents can be coadministered to the subject with the CDK9 inhibitor. In some embodiments, the additional active pharmaceutical agents can be administered to the subject before the administration of the CDK9 inhibitor, after the administration of the CDK9 inhibitor, or both. In some embodiments, the additional active pharmaceutical agent(s) can be concurrently administered to the subject with the CDK9 inhibitor. The additional active pharmaceutical agent(s) can be administered in the same way as the CDK9 inhibitor or the additional active pharmaceutical agent(s) can be administered in a different way from the CDK9 inhibitor. For example, in some embodiments, the CDK9 inhibitor is administered intravenously, and the additional active pharmaceutical agent(s) is administered orally. In some embodiments, the CDK9 inhibitor is administered intravenously, and the additional active pharmaceutical agent(s) is administered intravenously. In some embodiments, the CDK9 inhibitor is administered orally, and the additional active pharmaceutical agent(s) is administered intravenously. In some embodiments, the CDK9 inhibitor is administered orally, and the additional active pharmaceutical agent(s) is administered orally. In some embodiments, a composition comprising the CDK9 inhibitor comprises one or more additional active pharmaceutical agents.

[00102] Non-limiting examples of the one or more additional active pharmaceutical agents include, BCL2 and/or BCL-xL inhibitors such as venetoclax and navitoclax, hypomethylating agents such as azacytidine and decitabine, any and all chemotherapeutic cytotoxic agents such as docetaxel, therapeutic irradiation, checkpoint inhibitors such as pembrolizumab, menin inhibitors, JAK1 inhibitors, JAK1/JAK2 inhibitors, BTK inhibitors, PARP inhibitors, and blood brain barrier penetrating agents such as temozolomide. In some embodiments, the subject is administered at least one additional active pharmaceutical agent selected from the group consisting of a BCL-2 inhibitor and an azanucleoside. In some embodiments, the BCL- 2 inhibitor is venetoclax. In some embodiments, the azanucleoside is azacitidine. For example, in some embodiments, the subject is administered at least one additional active pharmaceutical agent selected from the group consisting of venetoclax and azacitidine. In some embodiments, the subject is administered venetoclax and azacytidine in addition to the CDK9 inhibitor (e.g., compound of Formula 2).

[00103] As disclosed herein, combination therapy with particular ratios and/or amounts of the CDK9 inhibitor and one or more additional active pharmaceutical agents can result in synergistic effects in treating cancer and/or inhibition of CDK9. These synergistic effects can be such that the one or more effects of the combination compositions are greater than the one or more effects of each component alone at a comparable dosing level, or they can be greater than the predicted sum of the effects of all of the components at a comparable dosing level, assuming that each component acts independently. The synergistic effect can be, be about, be greater than, or be greater than about, 5%, 10%, 20%, 30%, 50%, 75%, 100%, 110%, 120%, 150%, 200%, 250%, 350%, or 500% better than the effect of treating a subject with one of the components alone, or the additive effects of each of the components when administered individually. The effect can be any of the measurable effects described herein. Combination therapy can be such that the synergistic effect is a cancer cell proliferation reduction that is reduced to a greater degree as compared to the sum of the effects of administering each component, determined as if each component exerted its effect independently (z.e., the predicted additive effect).

[00104] A synergistic combination can have an effect that is greater than the predicted additive effect of administering each active pharmaceutical agent of the combination alone as if each active pharmaceutical agent exerted its effect independently. For example, if the predicted additive effect is 70%, an actual effect of 140% is 70% greater than the predicted additive effect or is 1-fold greater than the predicted additive effect. The synergistic effect can be at least, or at least about, 20%, 50%, 75%, 90%, 100%, 150%, 200% or 300% greater than the predicted additive effect. In some embodiments, the synergistic effect can be at least, or at least about, 0.2, 0.5, 0.9, 1.1, 1.5, 1.7, 2, or 3-fold greater than the predicted additive effect.

[00105] In some embodiments, the synergistic effect of combination therapy can also allow for reduced dosing amounts, leading to reduced side effects to the subject and reduced cost of treatment. Furthermore, the synergistic effect can allow for results that are not achievable through any other treatments. Therefore, proper identification, specification, and use of combination therapies can allow for significant improvements in the treatment of cancer.

[00106] The CDK9 inhibitor may be administered by any appropriate route of administration. Potential routes of administration of the CDK9 inhibitor include, without limitation, oral, parenteral (including intramuscular, subcutaneous, intradermal, intravascular, intravenous, intraarterial, intraperitoneal, intramedullary, intrathecal and topical), intracavitary, and topical (including dermal/epicutaneous, transdermal, mucosal, transmucosal, intranasal [e.g., by nasal spray or drop], pulmonary [e.g., by oral or nasal inhalation], buccal, sublingual, rectal [e.g., by suppository], and vaginal [e.g., by suppository]). In some embodiments, the CDK9 inhibitor is administered intravenously. [00107] As an example, formulations of the CDK9 inhibitor suitable for oral administration can be presented as, e.g., boluses; tablets, capsules, pills, cachets or lozenges; as powders or granules; as semisolids, electuaries, pastes or gels; as solutions or suspensions in an aqueous liquid or/and a non-aqueous liquid; or as oil-in-water liquid emulsions or water- in-oil liquid emulsions.

[00108] Where a CDK9 inhibitor, or a pharmaceutical composition comprising a CDK9 inhibitor, is to be administered orally, any suitable orally deliverable dosage form can be used. The oral dosage forms according to the disclosure can be solid, semi-solid or liquid. Such oral dosage forms include, but are not limited to, powders, dispersible granules, minitablets, and beads (which can be used, for example, for tableting, encapsulation, or direct administration), pills, tablets, lacquered tablets, sugar-coated tablets, hard and soft capsules including gelatin capsules, lozenges, rapidly dissolving tablets, aqueous, alcoholic or oily solutions, gels, syrups, emulsions or suspensions. The oral dosage forms according to the disclosure may additionally comprise one or more coatings which modify release properties, for example, coatings which impart delayed release or formulations which have extended- release properties. Also included in the present disclosure are formulations which are intended to be converted, before use, to a suspension or a solution; examples include, but are not limited to, freeze-dried formulations and liquid formulations adsorbed into a solid absorbent medium, including without limitation, tablets, capsules (solid or liquid filled), powders, granules, syrups and other liquids, elixirs, troches, lozenges, gels, pastes, solutions or suspensions in an aqueous liquid or/and a non-aqueous liquid, or oil-in-water liquid emulsions or water- in-oil liquid emulsions. [00109] Tablets can contain the CDK9 inhibitor in admixture with, e.g., a filler or inert diluent (e.g., calcium carbonate, calcium phosphate, lactose, mannitol or microcrystalline cellulose), a binding agent (e.g., a starch, gelatin, acacia, alginic acid or a salt thereof, or microcrystalline cellulose), a lubricating agent (e.g., stearic acid, magnesium stearate, talc or silicon dioxide), and a disintegrating agent (e.g., crospovidone, croscarmellose sodium or colloidal silica), and optionally a surfactant (e.g., sodium lauryl sulfate). The tablets can be uncoated or can be coated with, e.g., an enteric coating that protects the active ingredient from the acidic environment of the stomach, or with a material that delays disintegration and absorption of the active ingredient in the gastrointestinal tract and thereby provides a sustained action over a longer time period. In some embodiments, a tablet comprises the CDK9 inhibitor, mannitol, microcrystalline cellulose, magnesium stearate, silicon dioxide, croscarmellose sodium and sodium lauryl sulfate, and optionally lactose monohydrate, and the tablet is optionally film-coated (e.g., with Opadry®).

[00110] Push-fit capsules or two-piece hard gelatin capsules can contain the CDK9 inhibitor in admixture with, e.g., a filler or inert solid diluent (e.g., calcium carbonate, calcium phosphate, kaolin or lactose), a binder (e.g., a starch), a glidant or lubricant (e.g., talc or magnesium stearate), and a disintegrant (e.g., crospovidone), and optionally a stabilizer or/and a preservative. For soft capsules or single-piece gelatin capsules, the CDK9 inhibitor can be dissolved or suspended in a suitable liquid (e.g., liquid polyethylene glycol or an oil medium, such as a fatty oil, peanut oil, olive oil or liquid paraffin), and the liquid-filled capsules can contain one or more other liquid excipients or/and semi- solid excipients, such as a stabilizer or/and an amphiphilic agent (e.g., a fatty acid ester of glycerol, propylene glycol or sorbitol). [00111] Compositions for oral administration can also be formulated as solutions or suspensions in an aqueous liquid or/and a non-aqueous liquid, or as oil-in-water liquid emulsions or water-in-oil liquid emulsions. Dispersible powder or granules of the CDK9 inhibitor can be mixed with any suitable combination of an aqueous liquid, an organic solvent or/and an oil and any suitable excipients (e.g., any combination of a dispersing agent, a wetting agent, a suspending agent, an emulsifying agent or/and a preservative) to form a solution, suspension or emulsion.

[00112] The CDK9 inhibitor can be contained in an amphiphilic vehicle of a liquid or semisolid formulation for oral administration which provides improved solubility, stability and bioavailability of the CDK9 inhibitor. The amphiphilic vehicle contains a solution, suspension, emulsion (e.g., oil-in-water emulsion) or semi-solid mixture of the CDK9 inhibitor admixed with liquid or/and semi-solid excipients which fills an encapsulated dosage form (e.g., a hard gelatin capsule or a soft gelatin capsule containing a plasticizer [e.g., glycerol or/and sorbitol]). In some embodiments, the amphiphilic vehicle comprises an amphiphilic agent selected from fatty acid esters of glycerol (glycerin), propylene glycol and sorbitol. In some embodiments, the amphiphilic agent is selected from mono- and di-glycerides of C8-C12 saturated fatty acids. In some embodiments, the amphiphilic agent is selected from CAPMUL® MCM, CAPMUL® MCM 8, CAPMUL® MCM 10, IMWITOR® 308, IMWITOR® 624, IMWITOR® 742, IMWITOR® 988, CAPRYOLTM PGMC, CAPRYOLTM 90, LAUROGLYCOLTM 90, CAPTEX® 200, CRILLTM 1, CRILLTM 4, PECEOL® and MAIS INETM 35-1. In some embodiments, the amphiphilic vehicle further comprises propylene glycol, a propylene glycol-sparing agent (e.g., ethanol or/and glycerol), or an antioxidant (e.g., butylated hydroxyanisole, butylated hydroxytoluene, propyl gallate or/and sodium sulfite), or any combination thereof. In additional embodiments, the amphiphilic vehicle contains on a weight basis about 0.1-5% of the CDK9 inhibitor, about 50- 90% of the amphiphilic agent, about 5-40% of propylene glycol, about 5-20% of the propylene glycol- sparing agent, and about 0.01-0.5% of the antioxidant.

[00113] In some embodiments, the CDK9 inhibitor is formulated for parenteral administration by injection or infusion to circumvent gastrointestinal absorption and first-pass metabolism. In some embodiments, a representative parenteral route is intramuscular, subcutaneous, or intravenous.

[00114] Additional advantages of intramuscular, subcutaneous, or intravenous administration include direct administration of an active pharmaceutical agent into systemic circulation to achieve a rapid systemic effect, and the ability to administer the agent continuously or/and in a large volume if desired. Formulations for injection or infusion can be in the form of, e.g., solutions, suspensions or emulsions in oily or aqueous vehicles, and can contain excipients such as suspending agents, dispersing agents or/and stabilizing agents. For example, aqueous or non-aqueous (e.g., oily) sterile injection solutions can contain the CDK9 inhibitor along with excipients such as an antioxidant, a buffer, a bacteriostat and solutes that render the formulation isotonic with the blood of the subject. Aqueous or non-aqueous sterile suspensions can contain the CDK9 inhibitor along with excipients such as a suspending agent and a thickening agent, and optionally a stabilizer and an agent that increases the solubility the CDK9 inhibitor to allow for the preparation of a more concentrated solution or suspension. As another example, a sterile aqueous solution for injection or infusion (e.g., subcutaneously or intravenously) can contain the CDK9 inhibitor, NaCl, a buffering agent (e.g., sodium citrate), a preservative (e.g., meta-cresol), and optionally a base (e.g., NaOH) or/and an acid (e.g., HC1) to adjust pH. Additional advantages of intramuscular, subcutaneous, or intravenous administration include direct administration of an active pharmaceutical agent into systemic circulation to achieve a rapid systemic effect, and the ability to administer the agent continuously and/or in a large volume if desired.

[00115] In some embodiments, subcutaneous or intramuscular administration is performed by injection using a syringe, or using other injection devices, injector pens, or needleless devices. An injection device is usually a device that introduces a substance into the body of a patient via a parenteral route, e.g., intramuscular, subcutaneous, or intravenous. For example, an injection device may be a syringe (e.g., pre-filled with a pharmaceutical composition, such as an auto-injector) which, for example, includes a cylinder or barrel for holding fluid to be injected (e.g., a CDK9 inhibitor or a pharmaceutical composition thereof), a needle for piecing skin and/or blood vessels for injection of the fluid; and a plunger for pushing the fluid out of the cylinder and through the needle bore. In some embodiments, an injection device is an autoinjector, a jet injector or an external infusion pump.

[00116] For intramuscular, subcutaneous, or intravenous administration, the CDK9 inhibitor may be dissolved or dispersed in a pharmaceutically acceptable diluent, such as a saline or dextrose solution. Suitable excipients may be included to achieve the desired pH, including but not limited to NaOH, sodium carbonate, sodium acetate, HC1, and citric acid. In some embodiments, the pH of the final composition ranges from 2 to 8 (e.g., from 4 to 7). Antioxidant excipients may include, for example, sodium bisulfite, acetone sodium bisulfite, sodium formaldehyde, sulfoxylate, thiourea, and EDTA. Other non-limiting examples of suitable excipients found in the final intramuscular, subcutaneous, or intravenous composition may include sodium or potassium phosphates, citric acid, tartaric acid, gelatin, and carbohydrates such as dextrose, mannitol, and dextran. Antimicrobial agents may also be included to achieve a bacteriostatic or fungistatic solution, including but not limited to phenyl mercuric nitrate, thimerosal, benzethonium chloride, benzalkonium chloride, phenol, cresol, and chlorobutanol.

[00117] In some embodiments, the CDK9 inhibitor for intramuscular, subcutaneous, or intravenous administration is provided in the form of one more solids that are reconstituted with a suitable diluent such as sterile water, saline or dextrose in water shortly prior to administration. In some embodiments, the CDK9 inhibitor is provided in solution ready to administer parenterally. In some embodiments, the CDK9 inhibitor is provided in a solution that is further diluted prior to administration. In embodiments that include administering the CDK9 inhibitor and another agent, the combination may be provided as a mixture. In some embodiments, the CDK9 inhibitor and another agent may be mixed prior to administration, or may be administered separately.

[00118] Formulations for injection or infusion can be in the form of, e.g., solutions, suspensions or emulsions in oily or aqueous vehicles, and can contain excipients such as suspending agents, dispersing agents and/or stabilizing agents. For example, aqueous or nonaqueous (e.g., oily) sterile injection solutions can contain the CDK9 inhibitor along with excipients such as an antioxidant, a buffer, a bacteriostat and solutes that render the formulation isotonic with the blood of the subject. Aqueous or non-aqueous sterile suspensions can contain the CDK9 inhibitor, or a pharmaceutical composition comprising the CDK9 inhibitor, along with excipients such as a suspending agent and a thickening agent, and optionally a stabilizer and an agent that increases the solubility of the CDK9 inhibitor to allow for the preparation of a more concentrated solution or suspension. As another example, a sterile aqueous solution for injection or infusion (e.g., intramuscularly, subcutaneously or intravenously) can contain the CDK9 inhibitor along with NaCl, a buffering agent (e.g., sodium citrate), a preservative (e.g., meta-cresol), and optionally a base (e.g., NaOH) and/or an acid (e.g., HC1) to adjust pH. In some embodiments, aqueous or non-aqueous (e.g., oily) sterile injection solutions contain the CDK9 inhibitor and do not contain excipients or carriers. [00119] For topical administration, the CDK9 inhibitor can be formulated as, e.g., a buccal or sublingual tablet or pill. Advantages of a buccal or sublingual tablet or pill include avoidance of first-pass metabolism and circumvention of gastrointestinal absorption. A buccal or sublingual tablet or pill can also be designed to provide faster release of the CDK9 inhibitor for more rapid uptake of it into systemic circulation. In addition to a therapeutically effective amount of the CDK9 inhibitor, the buccal or sublingual tablet or pill can contain suitable excipients, including without limitation any combination of fillers and diluents (e.g., mannitol and sorbitol), binding agents (e.g., sodium carbonate), wetting agents (e.g., sodium carbonate), disintegrants (e.g., crospovidone and croscarmellose sodium), lubricants (e.g., silicon dioxide [including colloidal silicon dioxide] and sodium stearyl fumarate), stabilizers (e.g., sodium bicarbonate), flavoring agents (e.g., spearmint flavor), sweetening agents (e.g., sucralose), and coloring agents (e.g., yellow iron oxide). [00120] For topical administration, the CDK9 inhibitor can also be formulated for intranasal administration. The nasal mucosa provides a big surface area, a porous endothelium, a highly vascular subepithelial layer and a high absorption rate, and hence allows for high bioavailability. Moreover, intranasal administration avoids first-pass metabolism and can introduce a significant concentration of the CDK9 inhibitor to the central nervous system, allowing the CDK9 inhibitor to block the central cough reflex via the nucleus tractus solitarius in the cough center in the medulla oblongata, where vagal afferent nerves terminate. An intranasal solution or suspension formulation can comprise the CDK9 inhibitor along with excipients such as a solubility enhancer (e.g., propylene glycol), a humectant (e.g., mannitol or sorbitol), a buffer and water, and optionally a preservative (e.g., benzalkonium chloride), a mucoadhesive agent (e.g., hydroxyethylcellulose) or/and a penetration enhancer. In some embodiments, a nasal spray formulation comprises the CDK9 inhibitor, microcrystalline cellulose, sodium carboxymethylcellulose, dextrose and water, and optionally an acid (e.g., HC1) to adjust pH. An intranasal solution or suspension formulation can be administered to the nasal cavity by any suitable means, including but not limited to a dropper, a pipette, or spray using, e.g., a metering atomizing spray pump.

[00121] The topical administration can be pulmonary, including by oral inhalation and nasal inhalation. Other suitable topical formulations and dosage forms include without limitation ointments, creams, gels, lotions, pastes and the like.

[00122] Ointments are semi-solid preparations that are typically based on petrolatum or a petroleum derivative. Creams are viscous liquids or semi-solid emulsions, either oil-in-water or water-in-oil. Cream bases are water-washable, and contain an oil phase, an emulsifier and an aqueous phase. The oil phase, also called the “internal” phase, generally comprises petrolatum and a fatty alcohol (e.g., cetyl or stearyl alcohol). The aqueous phase typically, although not necessarily, exceeds the oil phase in volume, and usually contains a humectant. The emulsifier in a cream formulation is generally a non-ionic, anionic, cationic or amphoteric surfactant. Gels are semi-solid, suspension-type systems. Single-phase gels contain organic macromolecules (polymers) distributed substantially uniformly throughout the carrier liquid, which is typically aqueous but can also contain an alcohol (e.g., ethanol or isopropanol) and optionally an oil. Lotions are preparations to be applied to the skin surface without friction, and are typically liquid or semi-liquid preparations in which solid particles, including the active agent, are present in a water or alcohol base. Lotions are usually suspensions of finely divided solids and typically contain suspending agents to produce better dispersion as well as compounds useful for localizing and holding the active agent in contact with the skin. Pastes are semi-solid dosage forms in which the active agent is suspended in a suitable base. Depending on the nature of the base, pastes are divided between fatty pastes or those made from single-phase aqueous gels.

[00123] Various excipients can be included in a topical formulation. For example, solvents, including a suitable amount of an alcohol, can be used to solubilize the active agent. Other optional excipients include without limitation gelling agents, thickening agents, emulsifiers, surfactants, stabilizers, buffers, antioxidants, preservatives, cooling agents (e.g., menthol), opacifiers, fragrances and colorants. For an active agent having a low rate of permeation through the skin or mucosal tissue, a topical formulation can contain a permeation enhancer to increase the permeation of the active agent through the skin or mucosal tissue. A topical formulation can also contain an irritation-mitigating excipient that reduces any irritation to the skin or mucosa caused by the active agent, the permeation enhancer or any other component of the formulation.

[00124] In some embodiments, the CDK9 inhibitor is delivered from an immediate release composition. In some embodiments, the CDK9 inhibitor is delivered from a sustained-release composition. As used herein, the term “sustained- release composition” includes sustained- release, prolonged-release, extended-release, slow-release, and controlled-release compositions, systems and devices. Use of a sustained-release composition can have benefits, such as an improved profile of the amount of the drug or an active metabolite thereof delivered to the target site(s) over a time period, including delivery of a therapeutically effective amount of the drug or an active metabolite thereof over a prolonged time period. In some embodiments, the sustained-release composition delivers the CDK9 inhibitor over a period of at least about 1 day, 2 days, 3 days, 1 week, 2 weeks, 3 weeks, 1 month, 2 months, 3 months or longer. In some embodiments, the sustained-release composition is a drug-encapsulation system, such as nanoparticles, microparticles or a capsule made of, e.g., a biodegradable polymer or/and a hydrogel. In some embodiments, the sustained-release composition comprises a hydrogel. Non-limiting examples of polymers of which a hydrogel can be composed include polyvinyl alcohol, acrylate polymers (e.g., sodium poly acrylate), and other homopolymers and copolymers having a relatively large number of hydrophilic groups (e.g., hydroxyl or/and carboxylate groups). In some embodiments, the sustained-release drugencapsulation system comprises a membrane- enclosed reservoir, wherein the reservoir contains a drug and the membrane is permeable to the drug. Such a drug-delivery system can be in the form of, e.g., a transdermal patch.

[00125] The sustained-release composition can be an oral dosage form, such as a tablet or capsule. For example, a drug can be embedded in an insoluble porous matrix such that the dissolving drag must make its way out of the matrix before it can be absorbed through the gastrointestinal tract. A drug can be embedded in a matrix that swells to form a gel through which the drug exits. Sustained release can also be achieved by way of a single-layer or multilayer osmotic controlled-release oral delivery system (OROS). An OROS is a tablet with a semipermeable outer membrane and one or more small laser- drilled holes in it. As the tablet passes through the body, water is absorbed through the semipermeable membrane via osmosis, and the resulting osmotic pressure pushes the drug out through the hole(s) in the tablet and into the gastrointestinal tract where it can be absorbed.

[00126] In some embodiments, the sustained-release composition is formulated as polymeric nanoparticles or microparticles, wherein the polymeric particles can be delivered, e.g., by inhalation or injection or from an implant. In some embodiments, the polymeric implant or polymeric nanoparticles or microparticles are composed of a biodegradable polymer. In some embodiments, the biodegradable polymer comprises lactic acid or/and glycolic acid [e.g., an L-lactic acid-based copolymer, such as poly(L-lactide-co-glycolide) or poly(L-lactic acid-co-D,L-2-hydroxyoctanoic acid)]. For example, biodegradable polymeric microspheres composed of polylactic acid or/and polyglycolic acid can serve as sustained- release pulmonary drug-delivery systems. The biodegradable polymer of the polymeric implant or polymeric nanoparticles or microparticles can be selected so that the polymer substantially completely degrades around the time the period of treatment is expected to end, and so that the byproducts of the polymer's degradation, like the polymer, are biocompatible. [00127] For a delayed or sustained release of the CDK9 inhibitor, a composition can also be formulated as a depot that can be implanted in or injected into a subject, e.g., intramuscularly or subcutaneously. A depot formulation can be designed to deliver the CDK9 inhibitor over a longer period of time, e.g., over a period of at least about 1 week, 2 weeks, 3 weeks, 1 month, 6 weeks, 2 months, 3 months or longer. For example, the CDK9 inhibitor can be formulated with a polymeric material (e.g., polyethylene glycol (PEG), polylactic acid (PLA) or polyglycolic acid (PGA), or a copolymer thereof (e.g., PLGA)), a hydrophobic material (e.g., as an emulsion in an oil) or/and an ion- exchange resin, or as a sparingly soluble derivative (e.g., a sparingly soluble salt). As an illustrative example, the CDK9 inhibitor can be incorporated or embedded in sustained-release microparticles composed of PLGA and formulated as a monthly depot.

[00128] The CDK9 inhibitor can also be contained or dispersed in a matrix material. The matrix material can comprise a polymer (e.g., ethylene-vinyl acetate) and controls the release of the compound by controlling dissolution or/and diffusion of the compound from, e.g., a reservoir, and can enhance the stability of the compound while contained in the reservoir. Such a release system can be designed as a sustained-release system, can be configured as, e.g., a transdermal or transmucosal patch, and can contain an excipient that can accelerate the compound's release, such as a water-swellable material (e.g., a hydrogel) that aids in expelling the compound out of the reservoir. For example, U.S. Patent Nos. 4,144,317 and 5,797,898 describe examples of such a release system.

[00129] The release system can provide a temporally modulated release profile (e.g., pulsatile release) when time variation in plasma levels is desired, or a more continuous or consistent release profile when a constant plasma level is desired. Pulsatile release can be achieved from an individual reservoir or from a plurality of reservoirs. For example, where each reservoir provides a single pulse, multiple pulses (“pulsatile” release) are achieved by temporally staggering the single pulse release from each of multiple reservoirs.

[00130] Alternatively, multiple pulses can be achieved from a single reservoir by incorporating several layers of a release system and other materials into a single reservoir. Continuous release can be achieved by incorporating a release system that degrades, dissolves, or allows diffusion of a compound through it over an extended time period. In addition, continuous release can be approximated by releasing several pulses of a compound in rapid succession (“digital” release). An active release system can be used alone or in conjunction with a passive release system, as described in U.S. Patent No. 5,797,898.

[00131] Oral or nasal inhalation can be achieved by means of, e.g., a metered-dose inhaler (MDI), a nebulizer or a dry powder inhaler (DPI). For example, the CDK9 inhibitor can be formulated for aerosol administration to the respiratory tract by oral or nasal inhalation. A composition can be delivered in a small particle size (e.g., between about 0.5 micron and about 5 microns), which can be obtained by micronization, to improve, e.g., drug deposition in the lungs and drug suspension stability. A composition can be provided in a pressurized pack with a suitable propellant, such as a hydrofluoroalkane (HF A, e.g., 1,1,1,2-tetrafluoroethane [HFA-134a]), a chlorofluorocarbon (CFC, e.g., dichlorodifluoromethane, tri chi orofluorom ethane or di chlorotetrafluoroethane), or a suitable gas (e.g., oxygen, compressed air or carbon dioxide). In some embodiments, a composition in the aerosol formulation is dissolved, or suspended, in the propellant for delivery to the lungs. The aerosol can contain excipients such as a surfactant (which enhances penetration into the lungs by reducing the high surface tension forces at the air-water interface within the alveoli, may also emulsify, solubilize or/and stabilize the drug, and can be, e.g., a phospholipid such as lecithin) or/and a stabilizer. For example, an MDI formulation can comprise the CDK9 inhibitor, a propellant (e.g., an HF A such as 1,1,1,2-tetrafluoroethane), a surfactant (e.g., a fatty acid such as oleic acid), and a co-solvent (e.g., an alcohol such as ethanol). The MDI formulation can optionally contain a dissolved gas (e.g., CO2). After device actuation, the bursting of CO2 bubbles within the emitted aerosol droplets breaks up the droplets into smaller droplets, thereby increasing the respirable fraction of drug. As another example, a nebulizer formulation can comprise the CDK9 inhibitor, a surfactant (e.g., a Tween® such as polysorbate 80), a chelator or preservative (e.g., edetate disodium), an isotonicity agent (e.g., sodium chloride), pH buffering agents (e.g., citric acid/sodium citrate), and water. A composition can be delivered by means of, e.g., a nebulizer or an MDI with or without a spacer, and the drug dose delivered can be controlled by a metering chamber (nebulizer) or a metering valve (MDI). [00132] For oral or nasal inhalation using a dry powder inhaler (DPI), the CDK9 inhibitor can be provided in the form of a dry micronized powder, where the drug particles are of a certain small size (e.g., between about 0.5 micron and about 5 microns) to improve, e.g., aerodynamic properties of the dispersed powder and drug deposition in the lungs. Particles between about 0.5 micron and about 5 microns deposit by sedimentation in the terminal bronchioles and the alveolar regions. By contrast, the majority of larger particles (> 5 microns) do not follow the stream of air into the many bifurcations of the airways, but rather deposit by impaction in the upper airways, including the oropharyngeal region of the throat. A DPI formulation can contain the drug particles alone or blended with a powder of a suitable larger base/carrier, such as lactose, starch, a starch derivative (e.g., hydroxypropylmethyl cellulose) or polyvinylpyrrolidine. The carrier particles enhance flow, reduce aggregation, improve dose uniformity and aid in dispersion of the drug particles. A DPI formulation can optionally contain an excipient such as magnesium stearate or/and leucine that improves the performance of the formulation by interfering with inter-particle bonding (by anti-adherent action). The powder formulation can be provided in unit dose form, such as a capsule (e.g., a gelatin capsule) or a cartridge in a blister pack, which can be manually loaded or pre-loaded in an inhaler. The drug particles can be drawn into the lungs by placing the mouthpiece or nosepiece of the inhaler into the mouth or nose, taking a sharp, deep inhalation to create turbulent airflow, and holding the breath for a period of time (e.g., about 5-10 seconds) to allow the drug particles to settle down in the bronchioles and the alveolar regions.

[00133] Lactose (e.g., alpha-lactose monohydrate) is the most commonly used carrier in DPI formulations. Other carriers for DPI formulations include without limitation glucose, mannitol (e.g., crystallized mannitol [Pearlitol HO C] and spray-dried mannitol [Pearlitol 100 SD]), maltitol (e.g., crystallized maltitol [Maltisorb P90]), sorbitol and xylitol.

[00134] Dry powder inhalers can be classified by dose type into single-unit dose (including disposable and reusable) and multi-dose (including multi-dose reservoirs and multi-unit dose). In a single-unit dose DPI, the formulation can be a powder mix of a micronized drug powder and a carrier and can be supplied in individual capsules, which are inserted into the inhaler for a single dose and are removed and discarded after use. The capsule body containing the dose falls into the device, while the cap is retained in the entry port for subsequent disposal. As the user inhales, the portion of the capsule containing the drug experiences erratic motion in the airstream, causing dislodged particles to be entrained and subsequently inhaled. Particle deaggregation is caused mainly by turbulence promoted by the grid upstream of the mouthpiece or nosepiece. Examples of single-unit dose DPIs include without limitation Aerolizer®, AIR®, Conix One® (foil seal), Diskhaler®, Diskus®, Handihaler®, Microhaler®, Rotahaler® and Turbo spin®.

[00135] In addition, pharmaceutical compositions comprising the CDK9 inhibitor can be formulated as, e.g., liposomes, micelles (e.g., those composed of biodegradable natural or/and synthetic polymers, such as lactosomes), microspheres, microparticles or nanoparticles, whether or not designed for sustained release. For example, liposomes can be used as sustained release pulmonary drug-delivery systems that deliver drugs to the alveolar surface for treatment of systemic diseases.

[00136] The pharmaceutical compositions can be manufactured in any suitable manner known in the art, e.g., by means of conventional mixing, dissolving, nanomilling, suspending, granulating, dragee-making, levigating, emulsifying, encapsulating, entrapping or compressing processes.

[00137] A pharmaceutical composition can be presented in unit dosage form as a single dose wherein all active and inactive ingredients are combined in a suitable system, and components do not need to be mixed to form the composition to be administered. The unit dosage form can contain an effective dose, or an appropriate fraction thereof, of a CDK9 inhibitor. Representative examples of a unit dosage form include a tablet, capsule or pill for oral administration, or a single use sterile vial for intravenous administration.

[00138] In some embodiments, for example where a more rapid establishment of a therapeutic level of the CDK9 inhibitor is desired, the CDK9 inhibitor is administered under a dosing schedule in which a first dosage amount is administered, followed by one or more therapeutically effective subsequent dosage amounts. In some embodiments, a first dosage amount is larger (e.g., about 1.5, 2, 3, 4 or 5 times larger) than a subsequent dosage amount and is designed to establish a therapeutic level of the drug more quickly. In some embodiments, the first dosage amount is about 1.5 times, or about two times, or about three times, or about four times, or about five times greater than the subsequent dosage amount.

[00139] The therapeutically effective amount, the frequency of administration of, and/or the duration of treatment with, a CDK9 inhibitor may vary based on various factors, including, but not limited to, the nature and severity of the disease and/or at least one symptom thereof, the subject to be treated, the general health of the subject, the age, weight, gender, and/or diet of the subject, route of administration, drug interact! on(s), reaction sensitivities, and tolerance/response to therapy, all of which can be determined by one of ordinary skill in the art such as a medical professional. The dosage amount and/or duration may be adjusted by a medical professional, such as a physician or veterinarian, including in the event of any complication. Dosage amounts and/or duration can be adjusted to provide sufficient levels of the CDK9 inhibitor or to maintain the desired effect. For example, the dosage amount may be increased or decreased.

[00140] The CDK9 inhibitor may be administered alone or in the form of a composition (e.g., pharmaceutical composition or formulation). In some embodiments, a pharmaceutical composition comprises the CDK9 inhibitor and one or more pharmaceutically acceptable excipients. Pharmaceutical compositions may be conveniently presented as one or more unit dose forms containing a predetermined amount of an active agent per dose.

[00141] In some embodiments, a pharmaceutical composition comprises the CDK9 inhibitor and one or more pharmaceutically acceptable carriers or excipients. Pharmaceutically acceptable carriers and excipients include pharmaceutically acceptable materials, vehicles and substances, including for example any and all solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic and absorption delaying agents and the like. The use of such media and agents for pharmaceutically active substances is well known in the art. Except insofar as any conventional media or agent is incompatible with the active ingredient, its use in the therapeutic compositions is contemplated. In addition, various adjuvants such as are commonly used in the art may be included.

[00142] Non-limiting examples of excipients include liquid and solid fillers, diluents, binders, lubricants, glidants, solubilizers, surfactants, dispersing agents, disintegration agents, emulsifying agents, wetting agents, suspending agents, thickeners, solvents, isotonic agents, buffers, pH adjusters, stabilizers, preservatives, antioxidants, antimicrobial agents, antibacterial agents, antifungal agents, absorption- delaying agents, sweetening agents, flavoring agents, coloring agents, adjuvants, encapsulating materials and coating materials. For example, conventional vehicles and carriers include without limitation oils (e.g., vegetable oils, such as sesame oil), aqueous solvents (e.g., saline, phosphate-buffered saline [PBS] and isotonic solutions [e.g., Ringer's solution]), and solvents (e.g., dimethyl sulfoxide [DMSO] and alcohols [e.g., ethanol, glycerol and propylene glycol]). Except insofar as any conventional carrier or excipient is incompatible with the active ingredient, the disclosure includes the use of all conventional carriers and excipients in formulations containing the CDK9 inhibitor.

[00143] As will be appreciated by the ordinarily skilled artisan, a pharmaceutically acceptable excipient is any constituent which adapts the composition to a particular route of administration or aids the processing of a composition into a dosage form without itself exerting an active pharmaceutical effect. In general, compositions comprise more than one pharmaceutically acceptable excipient, and the pharmaceutically acceptable excipient(s) is selected based on the form of an oral dosage form. Examples of pharmaceutically acceptable excipients and methods of manufacture of oral dosage forms such as those mentioned above may be found in A. Gennaro (ed.), Remington: The Science and Practice of Pharmacy, 20th Edition, (2000), Lippincott Williams & Wilkins, Baltimore, MD.

[00144] Pharmaceutically acceptable excipients suitable for use in the present disclosure include, without limitation, carriers (such as lactose, starch, starch derivatives, talc, stearic acid or its salts for, e.g., pills, tablets, sugar-coated tablets and hard gelatin capsules; such as fats, waxes, semisolid and liquid polyols, natural or hardened oils, etc. for soft capsules; such as water, physiologically acceptable sodium chloride solution, alcohols, glycerol, polyols, sucrose, invert sugar, glucose, mannitol, vegetable oils, etc. for solutions, emulsions or syrups), fillers, disintegrants, binders, lubricants, pressing aids, wetting agents, stabilizers, emulsifiers, absorption enhancers, penetration enhancers, permeation enhancers, dispersants, preservatives, sweeteners, colorants, flavorings, aromatizers, thickeners, diluents, buffer substances, solvents, solubilizers, agents for achieving a depot effect, salts for altering the osmotic pressure, coating agents and/or antioxidants. A particular pharmaceutically acceptable excipient(s), as well as an amount(s) thereof, is selected for use in an oral dosage form so as to provide the desired amount of the CDK9 inhibitor in an oral dosage form of acceptable volume such that it can provide a therapeutic serum level of the active for an acceptable period of time in the subject to whom the oral dosage form is administered and such that the oral dosage form will retain biological activity during storage within an acceptable temperature range for an acceptable period of time.

[00145] In some embodiments, the CDK9 inhibitor is administered intravenously. In some embodiments, the CDK9 inhibitor is administered from one to three times per week intravenously. For example, in some embodiments, the CDK9 inhibitor is administered from once per week intravenously. In some embodiments, the CDK9 inhibitor is administered from twice per week intravenously. In some embodiments, the CDK9 inhibitor is administered from three times per week intravenously.

[00146] As used herein, the terms “first dosage amount” and “subsequent dosage amount” refer to the temporal sequence of administration of a CDK9 inhibitor. For example, the “first dosage amount” is the dosage amount which is administered at the beginning of the treatment regimen; it may also be referred to as a “baseline dose,” “initial dose,” or “loading dose.” The “subsequent dosage amount” is the dosage amount which is administered after the first dosage amount, which may also be referred to as a “maintenance dosage amount.”

[00147] In some embodiments, the first dosage period is about one day to about one year, or about two days, or about three days, or about four days, or about five days, or about six days, or about one week, or about two weeks, or about three weeks, or about one month, or about two months, or about three months, or about four months, or about five months, or about six months, or about seven months, or about eight months, or about nine months, or about ten months, or about eleven months, or about one year.

[00148] In some embodiments, the subsequent dosage period is at least about one week, at least about two weeks, at least about three weeks, at least about four weeks, at least about one month, or at least about two months, or at least about three months, or at least about four months, or at least about five months, or at least about six months, or at least about seven months, or at least about eight months, or at least about nine months, or at least about ten months, or at least about eleven months, or at least about one year, or at least about one year and six months, or at least about two years, or at least about two years and six months, or at least about three years, or at least about four years, or at least about five years, or at least about six years, or at least about seven years, or at least about eight years, or at least about nine years, or at least about ten years. In some embodiments, the subsequent dosage period is for the remaining lifetime of the subject.

[00149] In some embodiments, the first dosage amount and the subsequent dosage amount are the same amount of the CDK9 inhibitor. In some embodiments, the first dosage amount is greater than the subsequent dosage amount. In some embodiments, the first dosage amount is less than the subsequent dosage amount. In some embodiments, the subsequent dosage amount may be increased anytime during the subsequent dosage period. In some embodiments, the subsequent dosage amount may be decreased at any time during the subsequent dosage period. The first dosage amount and the subsequent dosage amount can, independently, be any therapeutically effective amount disclosed herein.

[00150] The first dosage amount and the at least one subsequent dosage amount may be administered by the same or different route of administration. For example, the first dosage amount can be administered intravenously and the at least one subsequent dosage amount can be administered orally.

[00151] The therapeutically effective amount and the frequency of administration of, and the length of treatment with, the CDK9 inhibitor, may depend on various factors, including the nature and the severity of the cancer, the potency of the compound, the mode of administration, the age, the body weight, the general health, the gender and the diet of the subject, and the response of the subject to the treatment, and can be determined by a medical professional.

[00152] The CDK9 inhibitor can also be dosed in an irregular manner. For example, the CDK9 inhibitor can be administered once, twice, or three times in a period of two weeks in an irregular manner. Furthermore, the CDK9 inhibitor can be taken pro re rata (as needed). For instance, the CDK9 inhibitor can be administered 1, 2, 3, 4, 5 or more times, in a regular or irregular manner. Dosing of the CDK9 inhibitor can optionally be discontinued or reduced in amount or frequency. Administration of the CDK9 inhibitor, whether in a regular or irregular manner, can be resumed. The appropriate dosage or frequency of dosing of, and length of treatment with the CDK9 inhibitor can be determined by a medical professional.

[00153] In some embodiments, the therapeutically effective amount of the CDK9 inhibitor ranges from 0.1 mg/kg to 15 mg/kg (or any subrange contained therein) of the CDK9 inhibitor per mass of the subject. In some embodiments, the therapeutically effective amount of the CDK9 inhibitor is a fixed dose ranges 2 mg to 200 mg (or any subrange contained therein).

For example, in some embodiments, the therapeutically effective amount of the CDK9 inhibitor ranges from 2.5 mg to 200 mg, 3.5 mg to 200 mg, 4.5 mg to 200 mg, 5 mg to 200 mg, 10 mg to 200 mg, 15 mg to 200 mg, 25 mg to 200 mg, 30 mg to 200 mg, 45 mg to 200 mg, or 55 mg to 200 mg. In some embodiments, the therapeutically effective amount of the CDK9 inhibitor ranges from 2.5 mg to 100 mg, 3.5 mg to 100 mg, 4.5 mg to 100 mg, 5 mg to 100 mg, 10 mg to 100 mg, 15 mg to 100 mg, 25 mg to 100 mg, 30 mg to 100 mg, 45 mg to 100 mg, or 55 mg to 100 mg. For example, in some embodiments, the therapeutically effective amount of the CDK9 inhibitor ranges from 2.5 mg to 80 mg, 3.5 mg to 80 mg, 4.5 mg to 80 mg, 5 mg to 80 mg, 10 mg to 80 mg, 15 mg to 80 mg, 25 mg to 80 mg, 30 mg to 80 mg, 45 mg to 80 mg, or 55 mg to 80 mg. For example, in some embodiments, the therapeutically effective amount of the CDK9 inhibitor ranges from 2.5 mg to 70 mg, 3.5 mg to 70 mg, 4.5 mg to 70 mg, 5 mg to 70 mg, 10 mg to 70 mg, 15 mg to 70 mg, 25 mg to 70 mg, 30 mg to 70 mg, 45 mg to 70 mg, or 55 mg to 70 mg. For example, in some embodiments, the therapeutically effective amount of the CDK9 inhibitor ranges from 2.5 mg to 60 mg, 3.5 mg to 60 mg, 4.5 mg to 60 mg, 5 mg to 60 mg, 10 mg to 60 mg, 15 mg to 80 mg, 25 mg to 60 mg, 30 mg to 60 mg, 45 mg to 60 mg, or 55 mg to 60 mg. For example, in some embodiments, the therapeutically effective amount of the CDK9 inhibitor ranges from 2.5 mg to 50 mg, 3.5 mg to 50 mg, 4.5 mg to 50 mg, 5 mg to 50 mg, 10 mg to 50 mg, 15 mg to 50 mg, 25 mg to 50 mg, 30 mg to 50 mg, or 45 mg to 50 mg. In some embodiments, the therapeutically effective amount of the CDK9 inhibitor (e.g., compound of Formula 2) ranges from 5 mg to 80 mg. In some embodiments, the therapeutically effective amount of the CDK9 inhibitor (e.g., compound of Formula 2) ranges from 10 mg to 80 mg. In some embodiments, the therapeutically effective amount of the CDK9 inhibitor (e.g., compound of Formula 2) ranges from 15 mg to 80 mg. In some embodiments, the therapeutically effective amount of the CDK9 inhibitor (e.g., compound of Formula 2) ranges from 5 mg to 60 mg. In some embodiments, the therapeutically effective amount of the CDK9 inhibitor (e.g., compound of Formula 2) ranges from 10 mg to 60 mg. In some embodiments, the therapeutically effective amount of the CDK9 inhibitor (e.g., compound of Formula 2) ranges from 15 mg to 60 mg. In some embodiments, the therapeutically effective amount of the CDK9 inhibitor (e.g., compound of Formula 2) is about 45 mg. In some embodiments, the therapeutically effective amount of the CDK9 inhibitor (e.g., compound of Formula 2) is about 60 mg. In some embodiments, the therapeutically effective amount of the CDK9 inhibitor (e.g., compound of Formula 2) is about 30 mg. In some embodiments, the therapeutically effective amount of the CDK9 inhibitor (e.g., compound of Formula 2) is 45 mg. In some embodiments, the therapeutically effective amount of the CDK9 inhibitor (e.g., compound of Formula 2) is 60 mg. In some embodiments, the therapeutically effective amount of the CDK9 inhibitor (e.g., compound of Formula 2) is 30 mg. In some embodiments, the therapeutically effective amount of the CDK9 inhibitor (e.g., compound of Formula 2) is 45 mg administered intravenously once per week. In some embodiments, the therapeutically effective amount of the CDK9 inhibitor (e.g., compound of Formula 2) is 60 mg administered intravenously once per week. In some embodiments, the therapeutically effective amount of the CDK9 inhibitor (e.g., compound of Formula 2) is 30 mg administered intravenously twice per week.

[00154] The CDK9 inhibitor can be administered in different forms. For example, the CDK9 inhibitor can be administered as a pharmaceutically acceptable salt, a solvate, an ester, a free acid, a free base, or a prodrug.

[00155] The disclosed methods and uses are effective for treating cancer in subjects having an ASXL1 mutation. For example, in some embodiments, the treatment is to increase a probability of remission of the cancer by at least 10% (e.g., from 10% to 100%, from 10% to 90%, from 10% to 80%, from 10% to 70%, from 10% to 60%, from 10% to 50%, from 15% to 50%, from 20% to 50%, from 25% to 50%, or any subrange contained within any of the preceding ranges). In some embodiments, the treatment is to increase a probability that the subject experiences at least a 10% (e.g., from 10% to 100%, from 10% to 90%, from 10% to 80%, from 10% to 70%, from 10% to 60%, from 10% to 50%, from 15% to 50%, from 20% to 50%, from 25% to 50%, or any subrange contained within any of the preceding ranges) reduction in peripheral myeloblast count by at least 10% (e.g., from 10% to 100%, from 10% to 90%, from 10% to 80%, from 10% to 70%, from 10% to 60%, from 10% to 50%, from 15% to 50%, from 20% to 50%, from 25% to 50%, or any subrange contained within any of the preceding ranges). In some embodiments, the treatment is to increase a probability that the subject experiences at least a 10% (e.g., from 10% to 100%, from 10% to 90%, from 10% to 80%, from 10% to 70%, from 10% to 60%, from 10% to 50%, from 15% to 50%, from 20% to 50%, from 25% to 50%, or any subrange contained within any of the preceding ranges) reduction in peripheral blood levels of at least one selected from the group consisting of Mcl-1 mRNA and c-Myc mRNA by at least 10% (e.g., from 10% to 100%, from 10% to 90%, from 10% to 80%, from 10% to 70%, from 10% to 60%, from 10% to 50%, from 15% to 50%, from 20% to 50%, from 25% to 50%, or any subrange contained within any of the preceding ranges).

[00156] The present disclosure provides methods for treating cancer, generally comprising administering to an individual in need thereof a CDK9 inhibitor that delays, reduces, or reverses cancer cell growth, in an amount sufficient to delay, reduce, or reverse cancer cell growth and treat the cancer. The present disclosure also provides methods for treating, preventing, and/or ameliorating a disease, disorder, or condition regulated or effected by serine kinase activity or related to cyclin-dependent kinase activity. Whether a substance, or a specific amount of the substance, is effective in treating cancer can be assessed using any of a variety of known diagnostic assays for cancer, including, but not limited to biopsy, contrast radiographic studies, CAT scan, and detection of a tumor marker associated with cancer in the blood of the individual. The CDK9 inhibitor can be administered systemically or locally. In some embodiments, the CDK9 inhibitor is administered systemically.

[00157] Also disclosed are methods of identifying subjects with increased probability of responsiveness to CDK9 inhibitor therapy. A method of identifying a subject with increased probability of responsiveness to CDK9 inhibitor therapy comprises determining the presence of an ASXL1 mutation in the subject. In some embodiments, subject has an increased probability of responsiveness to a selective CDK9 inhibitor. In some embodiments, subject has an increased probability of responsiveness to the compound of Formula 2.

[00158] Further disclosed are methods of identifying and treating cancer in subjects wherein the cancer has an increased probability of responsiveness to CDK9 inhibitor therapy. A method of identifying and treating cancer in subjects, wherein the cancer has an increased probability of responsiveness to CDK9 inhibitor therapy, comprises determining the present of an ASXL1 mutation in the subject and administering a CDK9 inhibitor to the subject. In some embodiments, the subject has an increased probability of responsiveness to a selective CDK9 inhibitor and the selective inhibitor is administered to the subject. In some embodiments, the subject has an increased probability of responsiveness to the compound of Formula 2 and the compound of Formula 2 is administered to the subject.

EXAMPLES

[00159] These examples are provided for the purpose of further illustration only and are not intended to be limitations on the disclosure. For example, some examples may recite various constraints, limitations, and requirements for the purposes of the example only and such constraints, limitations, and requirements are not limitations to the disclosure as a whole. Rather, such constraints, limitations, and requirements may be implemented in the example, e.g., to improve data quality by, for example, reducing the number or influence of some variables that may or may not influence the example. In these Examples, “compound of Formula 2” and “GFH009” in FIGS. 3-6 refer to the compound of Formula 2 in its dimaleate salt form.

[00160] Example 1:

[00161] Three cohorts of human subjects were treated for cancer using the compound of Formula 2.

[00162] The first cohort of 10 patients received 45 mg of the compound of Formula 2 once per week intravenously. The second cohort of 4 patients received 60 mg of the compound of Formula 2 once per week intravenously. The third cohort of 6 patients received 30 mg of the compound of Formula 2 twice per week intravenously. Of the patients in the first cohort, 70% experienced at least a 50% reduction in immature cells (“blasts”) and one patient experienced objective response (“OR”), where objective response is defined as a sum of complete response (CR), complete response with insufficient peripheral count recovery (CRi), partial response (PR) and morphologic leukemia free state (MLFS) . Of the patients in the second cohort, 40% experienced at least a 50% reduction in blasts and one patient experienced an overall response . Of the patients in the third cohort, 67% experienced at least a 50% reduction in blasts and three patients experienced composite complete remission. These results are summarized in Table 1.

[00163] Table 1

[00164] Table 2 depicts the patients from each cohort who had myelodysplasia with related genetic abnormalities as defined in Table 8 of the 5th Edition of WHO Classification of Haematolymphoid Tumors: Myeloid/Dendritic Neoplasms.

[00165] Table 2 [00166] Table 3 depicts the patients from each cohort who had myelodysplasia with related molecular abnormalities as defined in Table 8 of the 5th Edition of WHO

Classification of Haematolymphoid Tumors: Myeloid/Dendritic Neoplasms.

[00167] Table 3

[00168] Table 4 depicts the patients from each cohort who had AML, myelodysplasia- related with an ASXL1 mutation.

[00169] Table 4

[00170] Table 5 summarizes the results provided in Tables 1-4.

[00171] Table 5

[00172] Comparing the results in Tables 1-5, the CDK9 inhibitor therapy demonstrated unexpectedly enhanced efficacy for patients with an ASXL1 mutation or a molecular abnormality as compared to the patient population as a whole. For example, across all dose levels, of the 7 patients enrolled with an ASXL1 mutation 6/7 (86%) had BMB decrease >50% and 4/7 (57%) experienced a response (defined as the sum of CR, CRp, CRi, PR and MLFS). Additionally, the only patient who responded to monotherapy after azacitidine/venetoclax failure achieved MRD- CR that lasted for 8 months and had next generation sequencing results as follows: ASXL1 31.26%, CEBPA 42.1%, SRSF2 49%, STAG2 91.5%, TET2 46.2%. These percentages are variant allele frequencies calculated as the percentage of sequence reads observed matching the specific DNA variant divided by the overall coverage at that locus. [00173] Example 2

[00174] A first in human, multicenter, open-label dose finding escalation with expansion study to evaluate the compound of Formula 2 administered intravenously (IV) is described.

[00175] The following are primary objectives of the study.

• To evaluate the safety and tolerability of the compound of Formula 2 single agent in patients with relapsed/refractory (r/r) hematologic malignancies, including acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL) and lymphoma.

• To evaluate the safety, tolerability and efficacy of the compound of Formula 2 in patients with r/r AML who failed venetoclax containing regimens.

• To determine the maximum tolerated dose (MTD) and/or the recommended phase II dose (RP2D) of the compound of Formula 2.

[00176] The primary endpoints of the study are the following.

• To assess safety by the incidence of DLTs, incidence and severity of all adverse events (AEs) and serious adverse events (SAEs), including changes in laboratory parameters, vital signs, physical examinations, and electrocardiograms (ECGs).

• To assess tolerability by assessing dose interruptions and reductions due to toxicity. [00177] The following are secondary objectives of the study.

• To characterize the pharmacokinetic (PK) profile of the compound of Formula 2 as a single agent and in combination with venetoclax and azacitidine.

• To characterize the pharmacokinetic (PK) profile of venetoclax in combination with the compound of Formula 2 and azacitidine.

• To evaluate preliminary anti-tumor activities of the compound of Formula 2 as a single agent in r/r AML, and as a single agent in r/r CLL, SLL and lymphoma patients.

• To evaluate pharmacodynamic (PD) biomarkers of the compound of Formula 2 including Mcl-1 and c-Myc expression (mRNA level in peripheral blood).

[00178] Description of Study Design

[00179] The compound of Formula 2 is administered intravenously (IV)) as follows: [00180] Group 1 & 2 over 0.5- 1 hour twice a week (BIW, Dl-2, D8-9, D15-16 of each 21 -day cycle);

[00181] Group 1 & 2 for 4 hours once a week (QW, DI, D8 and D15 of each 21-day cycle); [00182] Group 3 Cohort 1 & 2 for 4 hours once a week (QW, DI, D8, DI 5, D22 of each 28-day cycle);

[00183] Group 3 Cohorts 3 over 0.5 - 1 hour twice a week (BIW, Dl-2, D8-9, D15-16, D22-23 of each 28-day cycle);

[00184] Group 3 Cohorts 4 and 5 for 1 hour twice a week (BIW, Dl-2, D8-9, DI 5- 16, D22-23 of each 28-day cycle),

[00185] In patients with relap sed/refractory hematologic malignancies, including AML, CLL/SLL and lymphoma, and a separate group to evaluate safety, tolerability and efficacy of the compound of Formula 2 in combination with venetoclax and azacitidine in relapsed/refractory AML patients who failed any venetoclax containing regimens.

[00186] The study includes a dose escalation and a dose expansion part.

[00187] FIG. 2 depicts a study design.

[00188] Dose Escalation Part

[00189] The primary objective of the dose escalation part is to estimate the MTD/RP2D of the compound of Formula 2. The secondary objectives are to explore PK, PD and preliminary antitumor activity of the compound of Formula 2 in the studied population.

[00190] The study flow for the BIW and QW dosing regimen in Groups 1 and 2 for the BIW and QW dosing regimen and for Group 3 is shown is shown in FIGS. 3-6.

[00191] FIG. 3 depicts a study flow for the BIW dosing regimen in Groups 1 and 2. [00192] FIG. 4 depicts a study flow for the QW dosing regimen in Groups 1 and 2.

[00193] FIG. 5 depicts the study flow for the QW dosing regimen in Group 3 Cohorts 1 and 2.

[00194] FIG. 6 depicts Study flow for the BIW dosing regimen in Group 3 Cohort 3, 4 and 5.

[00195] The dose escalation part employs a Bayesian optimal interval (BOIN) design to find the MTD/RP2D.

[00196] For the first dose level (2.5 mg) of Group 2, an accelerated titration method is adopted. One patient is enrolled in the cohort. If in the first three weeks, any CTCAE grade > 2 adverse event occurs and the causality with the compound of Formula 2 could not be excluded, the accelerated titration method goes back to the BOIN design. If no compound of Formula 2 related CTCAE grade > 2 adverse events are observed, the study moves to the next dose level. The BOIN design is implemented for the second and higher dose levels. [00197] The dose escalation part is performed for two groups separately starting with different dose level:

[00198] Group 1 : consists of patients with AML.

[00199] Group 2: consists of patients with CLL/SLL and lymphoma.

[00200] The safety and tolerability of the compound of Formula 2 is evaluated in these two groups, respectively. Accrual to the dose escalation phase of the study begins with enrollment of patients with CLL/SLL or lymphoma. Patients with AML dosed BIW are enrolled and receive a dose of 9 mg (third dose level) or higher dose level. In addition, PD markers (Mcl-1 and c-Myc) is measured to confirm whether target modulation is achieved in humans for this cohort before enrolling AML patients. An alternative dosing regimen of the compound of Formula 2, QW 4-hour IV infusion, is added to evaluate the safety and preliminary anti-tumor efficacy.

[00201] Dose Expansion Part

[00202] Group 3 : Consists of patients with AML relapsed after or are refractory to venetocl ax-based regimens.

[00203] The expansion part is to further evaluate the safety of the RP2D - 1 dose level and RP2D of the compound of Formula 2 in two alternative dosing regimens (QW and BIW) in combination with venetoclax and azacitidine. The patients with AML relapsed after or are refractory to venetoclax-based regimens are dosed at the RP2D level and one dose level below RP2D. An additional aim of this dose expansion part is to explore anti-tumor activity in the selected population with signs of preliminary tumor response in the dose escalation part. [00204] The study flow is similar to that described for dose escalation part, and includes screening, treatment and a follow up period. Patients are monitored for overall safety PK, Disease-specific response and Overall Survival (OS) assessments are performed.

[00205] Approximately 15- 40 patients are enrolled in total in Group 3, 5-10 patients in Cohort 1, 2 & 3 and 5-15 patients in Cohort 4 & 5.

[00206] The decision whether to expand groups is made by evaluating available data of safety, efficacy, PK and PD from dose escalation part.

[00207] Starting Dose

[00208] The starting dose is calculated based on the ICH S9 recommendation on the maximal recommended starting dose (MRSD) method. Using a safety factor of 10 and a body weight of 60 kg, the human equivalent dose is calculated to be 3.87 mg. If using a body weight of 70 kg, the human equivalent starting dose is calculated to be 4.5 mg. A relatively more conservative approach (body weight of 60 kg) is taken in this FIH study to control the risk. Also considering the feasibility of drug preparation before administration (the strength is 10 mg/1 mL), the starting dose is chosen to be 2.5 mg.

[00209] The starting dose of 2.5 mg is lower than the estimated biologically active dose in humans (which may be between 5 mg and 10 mg). To minimize the number of patients exposed to the potentially sub-efficacious dose, the accelerated titration design is adopted for the first dose level, as introduced above.

[00210] Provisional Dose Levels

[00211] Provisional Dose Levels for the BIW Dosing Regimen in Groups 1 and 2

[00212] The escalation dose levels follow a modified Fibonacci Sequence.

[00213] Provisional dose levels are listed in Table 6 for the BIW dosing regimen. Each 21- day cycle consists of 6 doses of the compound of Formula 2 administered IV on Day 1 and Day 2, Day 8 and Day 9, Day 15 and Day 16 of each cycle. The intermediate dose between provisional dose levels may be adopted based on available information, if deemed appropriate.

[00214] Table 6 Provisional dose levels for the BIW dosing regimen in Groups 1 and 2

[00215] Dose escalation is stopped once the expansion dose level is determined based on the totality of the clinical data including PK, PD, efficacy and safety.

[00216] Provisional Dose Levels for the QW Dosing Regimen

[00217] Provisional dose levels for the QW dosing regimen are listed in Table 7. Each 21- day cycle consists of 3 IV doses of the compound of Formula 2 administered on Day 1, Day 8, and Day 15. The intermediate dose between provisional dose levels can be adopted based on available information, if deemed appropriate.

[00218] Table 7 Provisional dose levels for the QW dosing regimen [00219] The recruitment of the QW dosing regimen in Group 1 and Group 2 might be at different time points depending on escalation status:

[00220] Group 1 (AML): The starting dose of the QW dosing regimen is 30 mg. If 22.5 mg BIW cohort is not complete, the recruitment of QW dosing regimen is started after the totality of the PK, PD, safety, and efficacy data from the BIW dosing regimens up to and including the 22.5 mg dose level in either Group is available and is reviewed before initiation of QW dosing regimen at the dose level of 30 mg. The 30 mg BIW cohort continues in parallel if 22.5 mg BIW is safe. If 30 mg BIW cohort is ongoing, it continues until completion and the recruitment of the QW dosing regimen is started after the review of the totality of the PK, PD, safety, and efficacy data from the BIW dosing regimens up to and including the 22.5 mg dose level.

[00221] Group 2 (lymphoma and CLL/SLL): QW dosing regimen at 30 mg dose level can start after the totality of the PK, PD, safety, and efficacy data from the BIW dosing regimens up to and including the 22.5 mg dose level in either Group is available and has been reviewed by the SMC and SMC recommended initiation of QW dosing regimen at the dose level of 30 mg. The next higher dose level of BIW dosing regimen (z.e., 30 mg and above) can be canceled after safety and efficacy data of 30 mg or above QW dosing regimen has been reviewed.

[00222] The starting dose level for QW dosing regimen at 30 mg is justified by the available PK data from this study, the preclinical data, and the time of actual implementation. CDK9 is a regular of neutrophil lifespan, preventing apoptosis by maintaining levels of short lived anti-apoptotic proteins such as Mcl-1. The concentrations of CDK9 inhibitors above efficacious exposure that last for ~6 h can result in significant decreasing in viability of murine bone-marrow neutrophils. The results of the pharmacometrics analysis with preliminary clinical PK data indicated that the median duration for the predicted the compound of Formula 2 concentration above IC90, which was estimated based on preclinical data, post 30 mg 4-hour IV infusion was still less than 6 h. Therefore, the risk of neutropenia for patients with the dose regimen of QW 4-hour IV infusion at 30 mg may be limited.

[00223] Adding Compound of Formula 2 to the Venetoclax and Azacitidine Regimen [00224] Based on preclinical data demonstrating an excellent synergy of the compound of Formula 2 with venetoclax and preclinical synergy between other CDK9 inhibitors and venetoclax, the addition of the compound of Formula 2 to venetoclax could potentially overcome resistance in AML blasts that do not respond to or have only a modest response to treatment with venetoclax alone or the compound of Formula 2 alone. There was only one objective response in a relap sed/refractory AML population with the compound of Formula 2 as a single agent, at the dose level of 30 mg QW with a 4 hour infusion. The highest antitumor biological activity was seen at the dose levels of 60 mg QW, with an observed bone marrow blast burden decrease of 77% in a patient with baseline blast burden of 66% in a hypercellular marrow. In patients relapsed on or refractory to venetoclax plus HMAs it may not be possible to maintain or achieve complete response with that combination. Therefore, the compound of Formula 2 can be combined with venetoclax and HMA regimens to achieve complete responses. Potential compounding of toxicities of the compound of Formula 2 and venetoclax combination regimens may occur as neutropenia and/or thrombocytopenia. Although drug related > grade 3 neutropenias and thrombocytopenias have been observed in treatment with the compound of Formula 2, patients’ safety is ensured via two mechanisms in this protocol:

[00225] Bone marrow aspirate/biopsy is performed after the first 14 days of treatment for Group 3 Cohorts 1-3, excluding Cohorts 4 & 5 and combination drugs administration is held until recovery if there is a finding of aplastic marrow and <5% of blasts.

[00226] All treatment related cytopenias in the absence of detectable leukemia are defined as potential DLTs and closely monitored in this trial.

[00227] CYP3A4 is the major metabolism enzyme of venetoclax in humans. In vitro study demonstrated the compound of Formula 2 is a mild CYP3A4 inhibitor with IC50 of 43.0 pM, which is much higher than the peak exposure of the compound of Formula 2 in this study based on the observed preliminary clinical PK data and model estimates. Administration of the compound of Formula 2 at the dose levels in this study does not cause clinically meaningful CYP3A4 inhibition, and co-administration of the compound of Formula 2 and venetoclax does not result in any drug-drug interaction.

[00228] The compound of Formula 2 is metabolized mainly by CYP3A4. The major metabolite of venetoclax, M27, is a weak inhibitor of CYP3 A4 with IC50 of 6.07 pm, which is higher than the mean Cmax of M27 at the steady state of maximum daily dose 400 mg, 0.86 pm. In vitro studies indicated that venetoclax does not induce CYP3 A4 up to 5 pM, which is higher than the mean Cmax of venetoclax at the steady state of maximum daily dose 400 mg, 2.4 pm. A major metabolite of venetoclax, M27, is a potential inducer of CYP3A4 in cryopreserved human hepatocytes at estimated human efficacious concentration. However, due to high protein binding (fub < 0.01) of M27, induction of CYP3A4 may not occur even at the clinically relevant maximum concentrations for venetoclax (2.4 pM) and M27 (0.86 pM) after multiple doses of 400 mg. Therefore, administration of venetoclax at the recommend dose levels does not cause clinically meaningful CYP3 A4 inhibition or induction, and coadministration of the compound of Formula 2 and venetoclax does not result in any drug-drug interaction.

[00229] In vitro studies in human liver microsomes suggest that decitabine may not inhibit or induce CYP450 enzymes. In vitro metabolism studies have suggested that decitabine is not a substrate for human CYP450 enzymes. Therefore, co-medication of decitabine and other investigational drugs do not result in any drug-drug interaction.

[00230] In vitro study in human microsomes demonstrated azacitidine is not an inhibitor or inducer of CYP3A4/5. Azacitidine undergoes deamination and CYP450 enzymes do not have an impact on the biotransformation of azacitidine. Therefore, co-medication of azacitidine and other investigational drugs do not result in any drug-drug interaction.

[00231] Dose Levels for Phase Ila: Dose Expansion (Group 3)

[00232] In the Phase I portion of the trial, single agent dose in AML was determined to be 60 mg QW. Dose levels and the compound of Formula 2 dosing regimens for Group 3 are listed in Table 8. There are 5 Cohorts in Group 3. In Cohorts 1 and 2, subjects are dosed with the compound of Formula 2 QW, 4-hour infusion, Day 1 of each week (e.g., Days 1, 8, 15, and 22). In Cohort 3, subjects are dosed with the compound of Formula 2 BIW, 30- or 60- minutes infusion, Day 1 and 2 of each week (e.g., Day 1, 2, 8, 9, 15, 16, 22 and 23). In Cohort 4 and 5, subjects are dosed with the compound of Formula 2 BIW, 60 minutes infusion, Day 1 and 2 of each week (e.g., Day 1, 2, 8, 9, 15, 16, 22 and 23). For this group (Group 3) four weeks constitute one 28-day cycle. Cycle duration is based on the compound of Formula 2 dosing, with treatment with venetoclax and azacitidine in combination with administration of the compound of Formula 2. Concurrently administered venetoclax and azacitidine at all the compound of Formula 2 dose levels is started on azacitidine 75 mg/m2 SQ/IV for 7 days and venetoclax 400 mg daily for up to 28 days of each cycle in patients who are receiving venetoclax 400 mg daily at the time of consent. In patients who are not receiving venetoclax at 400 mg daily dose at the time of consent, the venetoclax dose is ramped up per venetoclax product insert. Bone marrow aspirate and/or biopsy is performed on Day 14 (Group 3 Cohorts 1-3 excluding Cohort 4 &5) to assess the patient’s bone marrow. If the bone marrow is aplastic and contains <5% of blasts, dosing of all three drugs is held until cytopenia recovery and all subsequent cycles the dosing continues with the compound of Formula 2, venetoclax per product insert and azacitidine 75 mg/m2 SQ/IV for days 1-5.

[00233] Table 8 Provisional dose levels of the compound of Formula 2 for Group 3 (Expansion Cohort)

[00234] The starting dose level for Group 3 was determined as RP2D - 1, 45 mg QW.

[00235] Inclusion Criteria

[00236] Patients eligible for inclusion have to meet all of the following criteria:

[00237] Male or female > 18 years and pediatric patients ages 12-18 and >40 kg body mass. [00238] Written informed consent must be obtained prior to any screening procedures.

[00239] Patients with cytological or histologically confirmed relapsed or refractory hematologic malignancies (AML, CLL/SLL and lymphoma):

[00240] For AML, acute promyelocytic leukemia (APL) patients are not included in the study.

[00241] For Lymphoma, Burkitt lymphoma, lymphoblastic lymphoma, cutaneous T-Cell lymphoma and lymphoplasmacytic lymphoma (LPL)/ Waldenstrom’s macroglobulinemia (WM) is excluded.

[00242] Patients must not be candidates for hematopoietic cell transplant (HCT) at the time of screening.

[00243] AML (only for Group 3): Patients relapsed on or refractory to venetoclax containing regimens.

[00244] Additional requirements for specific disease conditions are:

[00245] CLL/SLL: Peripheral blood lymphocytosis (with no other cause), CLL present on BM aspirate, or enlarged lymph node (LN), liver or spleen. CLL/SLL patients must have an indication that in the judgement of their physician requires treatment, such as evidence of progressive marrow failure (e.g., worsening anemia or thrombocytopenia), massive or progressive splenomegaly and/or adenopathy, significant progressive lymphocytosis, autoimmune anemia or thrombocytopenia not responding to corticosteroids, symptomatic extra nodal involvement, or B-symptoms. [00246] Lymphoma (Except for other leukemias*): At least one measurable or evaluable lesion as defined by the Lugano (2014) response criteria. Patients must have received at least 2 prior lines of systemic therapy.

[00247] * The 2016 World Health Organization (WHO) classification of mature lymphoid, histiocytic, and dendritic neoplasms defines several types of mature B-cell and T-cell leukemia, e.g., B-cell prolymphocytic leukemia, Hairy cell leukemia, T-cell prolymphocytic leukemia, T-cell large granular lymphocytic leukemia, Adult T-cell leukemia. These neoplasms could have overlapping features with lymphomas involving bone marrow (BM) and peripheral blood. The clinical presenting could be more similar to leukemia. In this protocol, ‘other leukemia’ is used referring to these leukemias.

[00248] AML, Group 3, Cohort 4 (ASXL1 Cohort): AML patients relapsed on and/or refractory to therapies containing venetoclax combinations and with documented ASXL1 mutation.

[00249] AML, Group 3, Cohort 5 (Other than ASXL1 Myelodysplasia related AML defining somatic mutations: AML patients relapsed on and/or refractory to therapies containing venetoclax combinations and with documented Defining somatic mutations, Cytogenetic abnormalities defining acute myeloid leukemia, myelodysplasia related, other than ASXL1 mutation per WHO 5th Edition classification (The 5th edition of the World Health Organization Classification of Haematolymphoid Tumours: Myeloid and Histiocytic/Dendritic Neoplasms). Mutations in Cohort 5 include: BCOR, EZH2, SF3B1, SRSF2, STAG2, U2AF1 and ZRSR2. If any of those mutations is present concurrently with ASXL1 mutation, patients are enrolled in the Cohort 4 and only patients harboring the above listed mutations without concurrent ASXL1 mutation are enrolled in ASXL1 cohort.

[00250] Eastern cooperative oncology group (ECOG) performance status 0-2.

[00251] Life expectancy > 12 weeks.

[00252] Adequate hepatic function as evidenced by meeting all the following requirements: [00253] Total bilirubin < 1.5 x upper limit of normal (ULN) except for patients with Gilbert’s syndrome, who are included if total bilirubin is < 3 * ULN or if direct bilirubin is < 1.5 x ULN.

[00254] Aspartate aminotransferase (AST), alanine aminotransferase (ALT) < 2.5 x ULN. For those with hepatic metastases, AST and ALT < 5 x ULN.

[00255] Measured or calculated (determined by the Cockcroft-Gault equation) serum creatinine clearance (CrCl) > 60 mL/min (glomerular filtration rate can be an alternative to CrCl) for adult patients or serum creatinine < 1.5 x ULN; or if serum creatinine > 1.5 x ULN, then serum creatinine clearance (CrCl) > 50 mL/min (estimated by Cockcroft-Gault formula or other appropriate formula) for pediatric patients. Whether the value is calculated by equation or measured directly can be based on institutional standard practice.

[00256] Amylase < 1.5 x ULN.

[00257] The electrolytes and uric acid level need to be stable judged by investigators for at least 3 days before the first dose of the compound of Formula 2 (Medical intervention is permitted).

[00258] The following hematological clinical laboratory results during screening:

[00259] For lymphoma, CLL/SLL patients:

[00260] Absolute neutrophil count: for lymphoma, > 1,000/pL without growth factor support in the 2 weeks prior to study entry; for CLL/SLL, ANC must be > 500/pL if myelosuppression is known to be due to BM involvement with leukemia.

[00261] Hemoglobin > 7.5 g/dL without transfusion or erythropoietin treatment in the 2 weeks prior to study entry.

[00262] Platelet count > 50,000/pL without transfusion or other interventions in the 2 weeks prior to study entry.

[00263] For AML and other leukemias:

[00264] Peripheral WBC counts < 50,000/pL. Cytoreduction prior to study is allowed with hydroxyurea; hydroxyurea use is also be permitted during treatment period in patients with proliferative, progressive disease. Use of leukapheresis for the purpose of lowering WBC counts to make the patient eligible for enrolment is not permitted.

[00265] Recovery to grade 0-1 from adverse events related to prior anti -tumor therapy except alopecia, fatigue, < Grade 2 sensory neuropathy and endocrinopathies controlled with hormone replacement therapy.

[00266] For women of childbearing potential, she must consent to use highly effective methods (e.g., total abstinence, placement of an intrauterine device) of contraception during the compound of Formula 2 treatment and for an additional 90 days after the last administration of study drug, if enrolled in Groups 1 or 2, and 6 months if enrolled in Group 3.

[00267] Men with a partner of childbearing potential, must consent to use highly effective methods of contraception during the compound of Formula 2 treatment and for an additional 90 days after the last administration of study drug.

[00268] Exclusion Criteria [00269] Patients eligible for inclusion must not meet any of the following criteria:

[00270] For AML and other leukemias: Systemic chemotherapy or demethylating agent therapy within 7 days, or targeted therapy within 7 days or 5 half-lives whichever is shorter, or immunotherapy within 4 weeks, or CAR-T therapy within 12 weeks before the first dose. If a patient is receiving high dose cytarabine, liposomal cytarabine, or standard dose cytarabine (100-200 mg/m2/day), the patient must be off the drug for at least 2 weeks or until the patient has recovered from toxic effects. Patients in Group 3 are allowed to receive venetoclax and/or hypomethylating agents (HMAs) prior to screening and can continue receiving venetoclax in combination with azacitidine throughout the duration of the trial. No washout from HMAs and/or venetoclax is required for this group.

[00271] For lymphoma and CLL/SLL: Patients who have received chemotherapy or targeted therapy within 4 weeks (6 weeks for nitrosourea or mitomycin-C) or 5 half-lives whichever is shorter, or immunotherapy (e.g., CD20 monoclonal antibody, CD38 monoclonal antibody, PD1 or PD-L1 antibody) within 4 weeks, or CAR-T therapy within 12 weeks prior to starting study drug.

[00272] Patients with bulky disease (> 10 cm) who require cytoreductive therapy.

[00273] Radiotherapy with wide field radiation within 28 days or radiotherapy with a limited field of radiation for palliation within 7 days of the first dose.

[00274] Symptomatic central nervous system (CNS) metastases or primary lymphoma such as primary CNS lymphoma, leptomeningeal disease, or spinal cord compression. Patients with asymptomatic CNS metastases who are radiologically and neurologically stable > 4 weeks following CNS-directed therapy and are on a stable or decreasing dose of corticosteroids are eligible for study entry.

[00275] Ongoing therapy with corticosteroids greater than 20 mg of prednisone or its equivalent per day. Inhaled and topical steroids are allowed.

[00276] Uncontrolled medical conditions such as hypertension (systolic blood pressure > 160 mmHg and/or diastolic blood pressure > 100 mmHg), a history of hypertensive crisis, or a history of hypertensive encephalopathy.

[00277] History of previous exposure to any other CDK9 inhibitors.

[00278] Known hypersensitivity to the study drug or excipients of the preparation or any agent given in association with this study.

[00279] Severe cardiovascular disease within 6 months of study entry, including any of the following: [00280] Clinically significant heart disease such as congestive heart failure requiring treatment (NYHA class III or IV), left ventricular ejection fraction (LVEF) < 50% as determined by MUGA scan or echocardiogram (ECHO), (if only with historical occasional low LVEF but without any symptoms or relevant medical history, and the LVEF at screening is > 50%, the subject is eligible), or clinically significant arrythmia.

[00281] History/evidence of acute coronary syndromes (including myocardial infarction, unstable angina, coronary artery bypass graft (CABG), coronary angioplasty, or stenting). [00282] Average QTcF > 450 msec (males) or > 470 msec (females) on screening ECG. [00283] Moderate or above regurgitation on echocardiogram.

[00284] Patients with prior treatment with cardiotoxic agents who have experienced drug induced cardiotoxicities during or after treatment, where cardiotoxic agents include but are not limited to: anthracyclines (doxorubicin, daunorubicin, epirubicin, idarubicin, mitoxantrone); trastuzumab and trastuzumab based ADCs; tyrosine kinase inhibitors (sunitinib, imatinib); alkylating agents (cyclophosphamide).

[00285] Patients with a baseline cardiac biomarker abnormality (CKMB/cTnl) are excluded.

[00286] Patients with hypereosinophilic syndrome defined as eosinophil counts in peripheral blood of >l,500/pL.

[00287] Pulmonary embolism within 6 months before study entry. Patients with a history of other clinically venous or arterial thrombotic events that the investigator feels puts the patient at risk for participation in the study (based on overall status, medical history, or other factors) are excluded.

[00288] Concurrent malignancy within 5 years (for AML patients, 2 years) prior to entry other than adequately treated cervical carcinoma-in-situ, localized squamous cell cancer of the skin, basal cell carcinoma, prostate cancer not requiring treatment, ductal carcinoma in situ of the breast, and superficial non-muscle invasive urothelial carcinoma (excluding T1 lesions and CIS).

[00289] Patients who are on systemic antibiotics are eligible to participate as long as the antibiotics agents are not expected to have significant DDI with the compound of Formula 2 (A list of approved concomitant medications are provided to investigators. If any antibiotic that is not included in the approved list, it can be discussed with the sponsor or designated CRO on a case-by-case basis). [00290] Active hepatitis B or hepatitis C virus infection. Patients with chronic HBV infection with active disease who meet the criteria for anti HBV therapy have to be on a suppressive antiviral therapy prior to enrollment.

[00291] Patients with HCV may be enrolled if the HCV is stable, and the patient is not at risk for hepatic decompensation.

[00292] Patients with known HIV infection except if:

[00293] They have CD4+ T-cell (CD4+) counts > 350 cells/pL, and

[00294] No history of AIDS-defining opportunistic infections within the last 12 months preceding screening, and

[00295] Are on established ART for at least four weeks and have an HIV viral load less than 400 copies/mL prior to enrollment.

[00296] Concomitant medications that are strong CYP3 A4 inhibitors or strong inducers within 7 days prior to the first dose. Avoid consumption of Seville orange (and juice), grapefruit or grapefruit juice, grapefruit hybrids, pomelos, star citrus fruits or St. John’s wort within 7 days of first dose.

[00297] For AML patients only: Given that the compound of Formula 2 is a CYP3A4 substrate and the critical role of azole antifungals (commonly strong CYP3 A4 inhibitors) in the treatment of patients with AML, if use of azole antifungals is necessary for the patients in AML groups, and if azoles cannot be substituted with alternative antifungal drugs (e.g., caspofungin, amphotericin B etc.), use of isavuconazole, the only azole antifungal that is a moderate CYP3 A4 inhibitors and does not prolong QT interval, is recommended. Other azoles are allowed if deemed necessary by the investigator. If azoles are used, AML patients receiving azole antifungals are subject to enhanced monitoring plan. PK of the compound of Formula 2 is compared in patients with coadministration of azole antifungals versus those without azole antifungals.

[00298] Medications that are known to prolong the QT interval that could not be stopped prior to study entry judged by investigator, except azole antifungal medications in AML patients.

[00299] Subjects with high risk of gastrointestinal hemorrhage, including but not limiting to: active ulcer with fecal occult blood test >++; history of haematemesis or melena within 2 months prior first dose.

[00300] Stroke or intracranial hemorrhage within 6 months.

[00301] Major surgery within 4 weeks prior to study entry. [00302] Pregnant or breast-feeding females.

[00303] Prior allogeneic stem cell transplant within 6 months of study entry. Patients who received autologous HCT, if considered to be enrolled, the patient must be off all immunosuppressive drugs and must be > 3 months post-transplant and meet hematologic inclusion criteria.

[00304] Any uncontrolled intercurrent illness or condition that in the judgement of the investigator may endanger the patient.

[00305] Treatment

[00306] The compound of Formula 2 is diluted using 0.9% normal saline (NS) and packaged in 2-mL and lOmL single-dose neutral borosilicate type I glass injection vials, capped with PTFE hexafluoropropylene copolymer film-coated chlorobutyl rubber stopper, and sealed with an aluminum and plastic combined cover. All container closure system materials are commonly used for marketed injections. The vials are then placed into cartons. The drug products are sealed, protected from light, stored at 36°F-46°F (2°C-8°C) in a refrigerator.

[00307] Administration of the compound of Formula 2

[00308] The compound of Formula 2 is administered as an IV infusion at the dose levels outlined above. For the purposes of this study only, the compound of Formula 2 is not administered as an intravenous push or bolus, and the compound of Formula 2 is not mixed or, or administered as an infusion, with other medicinal products.

[00309] For the Group 3 Cohort 3 BIW dosing regimen, the C1D1 infusion is administered in about 60 minutes. Monitor vital signs prior to administration (-1 h), every 15 minutes (±2 min) during the infusion, at the end of infusion (+10 min), and then every 30 minutes (±5 min) for a 2-hour observation period. If no infusion-related reactions occur, subsequent infusions are administered over 30 minutes with vital signs monitored prior to administration (-1 h), every 15~ GO minutes during the infusion, at the end of infusion (+10 min), and then every 30- 60 minutes for a 1-hour observation period. For the QW dosing regimen, Group 3 Cohort 4 and 5 BIW dosing regimen, the C1D1 infusion is administered in about 60 minutes. Monitor vital signs prior to administration (-1 h), every 15 minutes (±2 min) during the infusion, at the end of infusion (+10 min), and then every 30 minutes (±5 min) for a 2-hour observation period. If no infusion-related reactions occur, subsequent infusions are administered over 60 minutes with vital signs monitored prior to administration (-1 h), every 15-30 minutes during the infusion, at the end of infusion (+10 min), and then every 30-60 minutes for a 1-hour observation period. For the QW dosing regimen, the infusion time is administered in 4 hours (+15 min). On CID 1, vital signs are monitored prior to administration (-1 h), every 1 hour (±10 min) during the infusion, at the end of infusion (±10 min), and then every 1 hour (±10 min) for a 2-hour observation period. If no infusion-related reactions occur, vital signs are monitored during subsequent infusions prior to administration (-1 h), every 2 hours (±30 min) during the infusion, at the end of infusion (±10 min), and 1 hour (±30 min) after infusion. All patients with symptoms during infusion or at the end of infusion are observed until symptoms subside or resolved to baseline.

[00310] For Group 3, on the days when patients are receiving both azacitidine and the compound of Formula 2 (QW -Day 1 of each cycle for Cohorts 1 and 2 and BIW - Days 1 and 2 of each cycle for Cohort 3, 4 & 5), patients are administered azacitidine first and approximately half an hour upon completion of azacitidine administration the compound of Formula 2 is administered per the QW and BIW administration instructions above for Cohorts 1 and 2 as a 4 hour infusion and for Cohort 3, 4 & 5 as a 30 or 60 minutes infusion. Azacitidine and venetoclax are administered per respective product inserts.

[00311] At least a 24-hour interval is provided between dosing the first and second patients in each cohort.

[00312] For Grade 1-2 infusion reactions, the infusion is stopped, treatment is administered as per the local standard of care (SOC), and once resolved, the infusion can be restarted at half of the initial rate. Prophylaxis per local SOC can be administered prior to subsequent cycles.

[00313] Treatment Duration

[00314] All patients begin the compound of Formula 2 treatment on C1D1. Patients may continue treatment with the compound of Formula 2 until disease progression or intolerable toxicity, or withdrawal of consent, or the end of the study, or initiation of new anti-tumor therapies, or death, or lack of efficacy (defined as at least a partial response) is observed in the first 4 cycles of treatment, whichever occurs first. In this protocol only benefit is defined as a decrease of > 50% in bone marrow blasts or achieving > 500 neutrophils per microliter or achieving RBC or platelet transfusion independence.

[00315] Dose Escalation Guidelines and Determination of MTD/RP2D

[00316] Study Definitions of Dose Limiting Toxicities (DLTs)

[00317] A DLT is defined as an adverse event or abnormal laboratory value assessed as drug-related (definitely related, probably related, possibly related) that occurs within the first 21 days of treatment for Groups 1 and 2 and 28 days for Group 3. For the patients dosed QW in whom dose delays occurred during cycle 1, the DLT observation period is extended to Day 7 after the third dose administration. All toxicities are graded according to the NCI-CTCAE Version 5.0. The hematological toxicity is assessed according to iwCLL 2018 criteria for patients with CLL/SLL.

[00318] The investigator notifies the sponsor immediately of any unexpected grade > 3 adverse events or laboratory abnormalities or possible DLTs.

[00319] For the patients dosed BIW in Groups 1 and 2, the observation period for DLT for Cycle 1 may be extended to 28 days for patients experiencing AE onset within the first 21 days of treatment and which requires to be followed up for up to 7 days to determine whether the AE is considered to be a DLT.

[00320] Study Definition of Maximal Tolerated Dose (MTD)/RP2D

[00321] After the dose escalation is completed, the MTD is identified based on isotonic regression. Specifically, MTD is the dose for which the isotonic estimate of the toxicity rate is closest to the target toxicity rate. If there are ties, select the higher dose level when the isotonic estimate is lower than the target toxicity rate and select the lower dose level when the isotonic estimate is greater than or equal to the target toxicity rate.

[00322] RP2D is either the MTD or a dose lower than the MTD. RP2D selection is based on the integrated safety (within and after DLT observation period), efficacy, PK and PD data in the dose escalation part.

[00323] The RP2D is determined based on all the available information (safety, PK, PD and preliminary efficacy) from dose escalation and dose expansion parts.

[00324] Guidance for Dose Escalation

[00325] The target toxicity rate for the MTD is 0.25 and the planned maximum sample size of DLT evaluable patients is 22 for group 2, 18 for group 1 regarding the BIW dosing regimen. The maximum sample size of DLT evaluable patients is 18 for Group 1 and Group 2 regarding the QW dosing regimen, respectively. QW dosing regimen starts enrollment after the totality of the PK, PD, safety, and efficacy data from the BIW dosing regimens up to and including the 22.5 mg dose level in either Group is available and has been reviewed by the SMC and SMC recommended initiation of QW dosing regimen at the dose level of 30 mg. For the first dose level (2.5 mg), accelerated titration method is adopted. One patient is enrolled in the cohort. If in the first three weeks, any CTCAE grade > 2 adverse event occurs and the causality with the compound of Formula 2 could not be excluded, accelerated titration method goes back to the BOIN design. If no compound of Formula 2 related CTCAE grade > 2 adverse events are observed, move to the next dose level. The BOIN design is implemented for the second and higher dose level.

[00326] When employing BOIN design, patients are enrolled and treated in cohorts of size 3-6. DLTs, and only DLTs that occur within the DLT observation period are used for dose finding. As shown in FIG. 7, the BOIN design uses the following rule, to minimize the probability of incorrect dose assignment, to guide dose escalation/de-escalation:

[00327] If the observed DLT rate at current dose is < 0.224, escalate the dose to the next higher dose level;

[00328] If the observed DLT rate at current dose is > 0.334, de-escalate the dose to the next lower dose level;

[00329] Otherwise, stay at the current dose.

[00330] FIG. 7 depicts a flowchart for conducting a trial using the BOIN design.

[00331] For the purpose of overdose control, doses j and higher levels are eliminated from further examination if Pr(pj > 0.25 | data) > 0.95, where pj is the true DLT rate of dose level j, j =1,- 5. This posterior probability is evaluated based on the beta-binomial model yj I pj ~ binomial(pj) with pj ~ uniform(0,l), where yj is the number of patients that experience DLT at dose level j. When the lowest dose is eliminated, stop the trial for safety. The probability cutoff 0.95 is chosen to be consistent with the common practice that when the target DLT rate < 1/6, a dose with 2/3 patients experienced DLT is eliminated.

[00332] Implementation of Dose Escalation Decisions

[00333] For the purpose of dose escalations, patients can be considered evaluable after having met the following criteria: have received at least 4 of the 6 planned doses regarding the BIW dosing regimen, OR total 3 planned doses regarding the QW dosing regimen for Group 1 and Group 2, and total of 4 planned doses for Group 3 Cohorts 1 and 2 and 8 planned doses for Cohort 3 and 4 during the DLT observation period, or developed a DLT during the DLT observation period, and have no major protocol deviations that would impact the safety analyses.

[00334] Dose Modifications

[00335] For patients who do not tolerate the protocol-specified dosing schedule, dose adjustments are permitted in order to allow the patient to continue the study treatment. [00336] For the dose escalation part, dose reductions during Cycle 1 are not permitted. If a patient experiences a DLT in Cycle 1, the study treatment is discontinued. For Cycle 2 and afterwards cycles, two dosing delays (same dose level) and one dose reduction due to toxicity is permitted. If a patient requires a dose reduction for toxicity, dose re-escalation to previous dose level is not permitted in this study. A patient must discontinue treatment with the compound of Formula 2 if the toxicity recurs with the same or worse severity at the lower dose level.

[00337] Dose Modifications for Group 3

[00338] During the trial, doses of venetoclax and azacitidine are adjusted as needed per the following recommendations:

[00339] Dose modifications for concomitant use with strong or moderate CYP3 A Inhibitors or P-gp inhibitor:

[00340] If a strong CYP3 A inhibitor posaconazole must be used, reduce the dose of venetoclax to 70 mg per day.

[00341] If a strong CYP3A inhibitor other than posaconazole must be used reduce the dose of venetoclax to 100 mg per day. If a moderate CYP3 A inhibitor or a P-gp inhibitor must be used, reduce the dose of venetoclax by 50% if using concomitant medications that are moderate CYP3A4 inhibitors (e.g., erythromycin, ciprofloxacin, diltiazem, dronedarone, fluconazole, verapamil) or P-gp inhibitors (e.g., amiodarone, azithromycin, captopril, carvedilol, cyclosporine, felodipine, quercetin, quinidine, ranolazine, ticagrelor) with venetoclax. Consider alternative treatments.

[00342] If a moderate CYP3 A inhibitor or a P-gp inhibitor must be used, reduce the venetoclax dose by at least 50%. Monitor patients more closely for signs of venetoclax toxicities. Resume the venetoclax dose that was used prior to initiating the CYP3 A inhibitor or P-gp inhibitor 2 to 3 days after discontinuation of the inhibitor.

[00343] Avoid grapefruit products, Seville oranges, and starfruit during treatment with [00344] venetoclax, as they contain inhibitors of CYP3 A.

[00345] Avoid concomitant use of venetoclax with strong CYP3 A inducers (e.g., carbamazepine, phenytoin, rifampin, St. John’s wort) or moderate CYP3A inducers (e.g., bosentan, efavirenz, etravirine, modafinil, nafcillin). Consider alternative treatments with less CYP3 A induction.

[00346] It is recommended that the international normalized ratio (INR) be monitored closely in patients receiving warfarin.

[00347] Dose modifications due to toxicities: [00348] If Grade 4 neutropenia with or without fever or infection or Grade 4 thrombocytopenia occur:

[00349] Occurrence prior to achieving remission: Transfuse blood products, administer prophylactic and treatment anti-infectives as clinically indicated. In most instances, treatment cycles should not be interrupted due to cytopenias prior to achieving remission.

[00350] First occurrence after achieving remission and lasting at least 7 days: Delay subsequent treatment cycles and monitor blood counts. Administer granulocyte-colony stimulating factor (G-CSF) if clinically indicated for neutropenia. Once the toxicity has resolved to Grade 1 or 2, resume therapy with the compound of Formula 2 and venetoclax. [00351] Subsequent occurrences after achieving remission and lasting at least 7 days: Delay subsequent treatment cycles and monitor blood counts. Administer G-CSF if clinically indicated for neutropenia. Once the toxicity has resolved to Grade 1 or 2, resume therapy with the compound of Formula 2 and venetoclax.

[00352] Dose modifications due to aplastic marrow in the absence of leukemic blasts: [00353] If the remission or morphologic leukemia free state is not achieved, dosing continues without modifications. For the purposes of this study, cycles should not be interrupted due to cytopenias prior to achieving remission. If Grade 4 neutropenias and/or thrombocytopenias lasting > 7 days occur after a remission or morphologic leukemia free state, administration of all three drugs in the combination (the compound of Formula 2, venetoclax and azacitidine) is stopped and continuation of therapy is delayed until the toxicity has resolved to Grade 1 or 2. At that point, therapy is resumed at the same dose level for all three drugs in the combination. If Grade 4 cytopenias lasting > 7 days recur after resuming the therapy, treatment with all three drugs in the combination (the compound of Formula 2, venetoclax and azacitidine) is stopped and continuation of therapy is delayed until the toxicity has resolved to Grade 1 or 2 but at lower dose levels as follows: venetoclax is administered at the same dose level but frequency of administration is decreased by 7 days in each subsequent cycle. Azacitidine is continued at the same dose level, but the frequency of administration is decreased to Days 1-5 only in each cycle. If the therapy cannot be continued within 42 days, subjects is taken off the study therapy.

[00354] If treatment related (possibly, likely or definitely) non-hematologic toxicities > Grade 3 occur, treatment with the compound of Formula 2, venetoclax and azacitidine are interrupted until the toxicities have been resolved to Grade 1 or baseline level. [00355] Toxicity monitoring for Group 3 Expansion Cohorts

[00356] Bayesian stopping boundaries are used to monitor the dose-limiting toxicity rate within each of the Group 3 expansion cohorts. A DLT rate of 20% would be considered as acceptable while a DLT rate of 33% would be considered too high and unacceptable. A non- informative prior, Beta(0.5, 0.5), is used for the DLT rate, assuming 10 patients per cohort, with a toxicity stopping criterion that the posterior probability of the DLT rate exceeding 33% is > 0.65. At least 3 patients are treated before the early stopping rule is applied. The early stopping rule is then applied continuously for each patient after the third. The accrual is halted if excessive numbers of dose-limiting toxicities are seen, that is, if the number of dose-limiting toxi cities is > the following boundary b out of n patients currently studied:

[00357] for each cohort, the boundary is b/n=2/3, 2/4, 3/5, 3/6, 3/7, 4/8, 4/9, 4/10.

[00358] For example, if among the first 6 patients, there are 3 or more DLTs, then the accrual for the corresponding cohort would be paused. This is looked at separately for the compound of Formula 2 IV - 45 mg QW (RP2D - 1), 60 mg QW (RP2D), and 30 mg BIW (RP2D alternative dosing) cohorts.

[00359] Based on this rule, for each cohort, if the “true” DLT rate is 20%, then the probability of early stopping is about 23.5% with expected sample size of 8.6. If the “true” DLT rate is 33%, then the probability of early stopping is about 53.4% with expected sample size of 6.9

[00360] Treatment Period

[00361] The treatment period begins on Day 1 with the administration of the study drug and a treatment cycle consists of 21 days for Groups 1 and 2, and 28 days for Group 3. During the treatment period, the patient is obliged to follow the investigators’ instructions with regards to contraception, concomitant medications, and dosing regimen.

[00362] There is no fixed treatment duration. Patients may continue treatment with the study drugs until the development of any unacceptable toxicity that precludes any further treatment, or disease progression (except those who may get benefit from continuing treatment judged by the investigator), or withdrawal of consent, or the end of the study, or initiate new anti-tumor therapies or death, or lack of efficacy (defined as at least a partial response) is observed in the first 4 cycles of treatment, whichever occurs first. In this protocol benefit is defined as a decrease of > 50% in bone marrow blasts or achieving > 500 neutrophils per microliter or achieving RBC or platelet transfusion independence.

[00363] Dose escalation part. [00364] Group 1 : approximately 45 patients are planned to be enrolled to ensure 36 DLT evaluable patients by assuming 20% drop-out rate.

[00365] Group 2: approximately 50 patients are planned to be enrolled to ensure 40 DLT evaluable patients by assuming 20% drop-out rate.

[00366] Dose expansion part.

[00367] In total, 20-40 additional patients are enrolled to the dose expansion part. 5-10 patients are enrolled at each dose level. A sample size of 20 provides an approximate 87.8% probability of detecting an adverse event with an incidence of 10%.

[00368] While the disclosure has been described above with reference to specific embodiments thereof, it is apparent that many changes, modification, and variations can be made without departing from scope of the disclosure. Accordingly, the disclosure is intended to embrace, e.g., all such changes, modifications, and variations that fall within the scope of the appended claims.

[00369] Example 3

[00370] Studies were performed to determine whether ASXL1 mutation is a predictor for responsiveness of solid cancers to the compound of Formula 2.

[00371] Eighteen patient derived solid tumor cell lines (PDCs) were exposed to the compound of Formula 2 at various concentrations (9-point dilution series) in the presence of 10 pM ATP and the inhibitory concentration (IC50) for each cell line was determined via an in vitro anti-proliferation assay 72 hours post-treatment. All cell lines were analyzed for presence of ASXL1 mutations and other genetic markers. High efficacy was prespecified as IC50 < lOO nM.

[00372] Negative controls consisted of untreated cell lines, while active negative control consisted of varying concentrations of revumenib (drug used in hematologic malignancies). Positive controls involved cell lines treated with staurosporine (a broad-spectrum protein kinase inhibitor) at different concentrations.

[00373] Of the 18 studied solid cancer cell lines, ASXL1 mutations were identified in 9 cell lines. The remaining 9 cell lines in which no ASXL1 mutations were identified were designated as control.

[00374] In colorectal carcinomas (CRC) with high level microsatellite instability (MSI-H) , ASXL1 mutations were observed in about 58% of PDCs. See Table 9.

[00375] In NSCLC, ASXL1 mutations occurred in about 33% of the studied cell lines. See Table 9 [00376] In ASXL1 mutated cell lines, the compound of Formula 2 exhibited high efficacy (IC50 <100 nM) in about 67% of solid cancer cell lines tested. In non-ASXLl mutated cancer high efficacy of the compound of Formula 2 was not observed in any of the studied solid cancer cell lines tested. In CRC MSI-H, the compound of Formula 2 exhibited high efficacy (IC50 <100 nM) in about 57% of ASXL1 mutated cell lines tested, but did not exhibit efficacy in any of the non-ASXLl mutated CRC MSI-H cell lines tested. See Table 9.

[00377] In NSCLC cell lines, the compound of Formula 2 exhibited high efficacy (IC50 <100 nM) in 100% of ASXL1 mutated cell lines, but did not exhibit efficacy in any of the non-ASXLl mutated NSCLC cell lines tested. No activity was observed in any of the studied cell lines with revumenib (negative control) at any concentration. Staurosporine activity (positive control) was confirmed. The compound of Formula 2 outperformed positive control staurosporine in 5/9 cell lines tested. See Table 9.

[00378] The anti -proliferation activity of the compound of Formula 2 in solid tumor cell lines is provided in Figure 8. [00379] Table 9 Efficacy to compound of Formula 2 in Non-small Cell Lung Cancer and Colorectal Carcinomas Cell Lines NUMBERED EMBODIMENTS

[00380] Particular embodiments of the disclosure are set forth below:

[00381] 1. A method of treating a cancer in a subj ect in need thereof, the method comprising: administering a therapeutically effective amount of a CDK9 inhibitor to the subject, wherein the subject has an ASXL1 mutation.

[00382] 2. The method of embodiment 1, wherein the cancer is a hematologic malignancy.

[00383] 3. The method of embodiment 1, wherein the cancer is at least one selected from the group consisting of a myeloproliferative neoplasm, a myelodysplasia, a mastocytosis, an acute myeloid leukemia, a myelomonocytic leukemia, a chronic lymphocytic leukemia, a small lymphocytic lymphoma, a lymphoma, a myeloid sarcoma, a myeloid neoplasm, a lymphoid neoplasm, a histiocytic cell neoplasm, and a dendritic cell neoplasm.

[00384] 4. The method of embodiment 1, wherein the cancer is at least one selected from the group consisting of a relapsed hematologic malignancy and a refractory hematologic malignancy.

[00385] 5. The method of embodiment 1, wherein the cancer is a lymphoma.

[00386] 6. The method of embodiment 1, wherein the cancer is a solid cancer selected from the group consisting of a cervical cancer, a colorectal cancer, a liver cancer, a prostate cancer, a head and neck squamous cell cancer, and a breast cancer.

[00387] 7. The method of embodiment 1, wherein the cancer is at least one selected from the group consisting of an acute myeloid leukemia, a myelodysplasia, a mastocytosis, an acute myeloid leukemia, a myelomonocytic leukemia, a chronic lymphocytic leukemia, and a small lymphocytic lymphoma.

[00388] 8. The method of any one of embodiments 1-7, wherein the subject is also administered at least one selected from the group consisting of a BCL-2 inhibitor and an azanucleoside.

[00389] 9. The method of any one of embodiments 1-8, wherein the subject is also administered at least one selected from the group consisting of venetoclax and azacitidine.

[00390] 10. The method of any one of embodiments 1-9, wherein the CDK9 inhibitor has an equilibrium dissociation constant for CDK9 of less than or equal to one nanomolar. [00391] 11. The method of any one of embodiments 1-10, wherein the CDK9 inhibitor has a CDK9/cyclin T1 activity IC50 value ranging from one nanomolar to one micromolar.

[00392] 12. The method of any one of embodiments 1-11, wherein the CDK9 inhibitor is administered intravenously.

[00393] 13. The method of any one of embodiments 1-12, wherein the therapeutically effective amount of the CDK9 inhibitor is from 0.1 mg/kg to 15 mg/kg of the CDK9 inhibitor per mass of the subject.

[00394] 14. The method of any one of embodiments 1-13, wherein the therapeutically effective amount is 2 mg to 200 mg or 2 mg to 100 mg.

[00395] 15. The method of any one of embodiments 1-14, wherein the CDK9 inhibitor is administered from one to seven times per week intravenously.

[00396] 16. The method of any one of embodiments 1-15, wherein the ASXL1 mutation is a frameshift mutation.

[00397] 17. The method of any one of embodiments 1-15, wherein the ASXL1 mutation is a nonsense mutation.

[00398] 18. The method of any one of embodiments 1-15, wherein the ASXL1 mutation is a ASXLIc.1934dupG mutation.

[00399] 19. The method of any one of embodiments 1-18, wherein the subject also has a nonmutated ASXL1 gene and the mutated ASXL1 gene has at least 99% homology with the nonmutated ASXL1 gene.

[00400] 20. The method of any one of embodiments 1-19, wherein the subject also has at least one selected from the group consisting of a BCOR mutation, a EZH2 mutation, a SF3B1 mutation, a SRSF2 mutation, a STAG2 mutation, a U2AF1 mutation, and a ZRSR2 mutation.

[00401] 21. The method of any one of embodiments 1-20, wherein the treatment is to increase a probability of remission of the cancer by at least 10%.

[00402] 22. The method of any one of embodiments 1-21, wherein the treatment is to increase a probability that the subject experiences at least a 10% reduction in peripheral myeloblast count by at least 10%.

[00403] 23. The method of any one of embodiments 1-22, wherein the CDK9 inhibitor comprises at least one selected from the group consisting of: 4-[[[4-[5-chloro-2-[[trans-4-[[(lR)-2-methoxy-l -methyl ethyl] amino] cyclohexyl] amino] -4-pyridinyl]-2 -thiazolyl] amino] methyl] tetrahydro-2H-pyran-4-carbonitrile dimaleate;

5-fluoro-4-(4-fluoro-2-methoxyphenyl)-N-{4-[(S-methylsulfonimidoyl)methyl]-2- pyridinyl}-2-pyridinamine);

(lS,3R)-3-acetamido-N-[5-chloro-4-(5,5-dimethyl-4,6-dihydropyrrolo[l,2-b]pyrazol- 3-yl)pyridin-2-yl]cyclohexane-l-carboxamide;

(lS,3S)-Nl-(5-(pentan-3-yl)pyrazolo[l,5-a]pyrimidin-7-yl)cyclopentane-l,3- diamine); and

4-(4-fluoro-2-methoxyphenyl)-N-[3-[(methylsulfonimidoyl)methyl]phenyl]-l,3,5- triazin-2-amine.

[00404] 24. The method of any one of embodiments 1-22, wherein the CDK9 inhibitor is a compound of Formula 1 :

Formula 1 or a pharmaceutically acceptable salt, solvate, ester, acid or prodrug thereof.

[00405] 25. The method of any one of embodiments 1-22, wherein the CDK9 inhibitor is the compound of Formula 2:

Formula 2 or a pharmaceutically acceptable salt, solvate, ester, acid or prodrug thereof.

[00406] 26. The method of any one of embodiments 1-22, wherein the CDK9 inhibitor is the compound of Formula 2:

Formula 2 or a pharmaceutically acceptable salt thereof; the therapeutically effective amount is from 1 mg to 200 mg; the therapeutically effective amount is administered from one to seven times per week; and the cancer is any cancer selected from the group consisting of an acute myeloid leukemia, a chronic lymphocytic leukemia, and a small lymphocytic lymphoma. [00407] 27. The method of any one of embodiments 1-22, wherein the CDK9 inhibitor is the compound of Formula 2:

Formula 2 , or a maleate salt, a dimaleate salt, or crystal form 1 thereof, the therapeutically effective amount is from 5 mg to 80 mg, the therapeutically effective amount is administered once, twice, or three times per week, and the cancer is any cancer selected from the group consisting of an acute myeloid leukemia, a chronic lymphocytic leukemia, and a small lymphocytic lymphoma.

[00408] 28. The method of any one of embodiments 1-22, wherein the CDK9 inhibitor is the compound of Formula 2:

Formula 2 , or a maleate salt, a dimaleate salt, or crystal form 1 thereof; the therapeutically effective amount is 30 mg administered twice per week, 45 mg administered once per week, or 60 mg administered once per week; and the subject is also administered venetoclax and azacitidine.

[00409] 29. The method of any one of embodiments 1-22, wherein the CDK9 inhibitor is the compound of Formula 2:

Formula 2 or a maleate salt, a dimaleate salt, or crystal form 1 thereof; the therapeutically effective amount is 30 mg administered twice per week, 45 mg administered once per week, or 60 mg administered once per week; and the subject is also administered 400 mg of venetoclax daily and azacitidine.

[00410] 30. The method of any one of embodiments 1-22, wherein the CDK9 inhibitor is the compound of Formula 2: or a maleate salt, a dimaleate salt, or crystal form 1 thereof;

Formula 2 the therapeutically effective amount is 30 mg administered twice per week, 45 mg administered once per week, or 60 mg administered once per week; and the subject is administered a therapeutically effective amount of venetoclax and 75 mg/m2 of azacitidine subcutaneously or intravenously daily.

[00411] 31. The method of any one of embodiments 25-30, wherein the CDK9 inhibitor is the dimaleate salt of the compound of Formula (2).

[00412] 32. The method of any one of embodiments 25-31, wherein the CDK9 inhibitor is administered intravenously.

[00413] 33. The method of any one of embodiments 25-32, wherein the cancer is any cancer selected from the group consisting of a cervical cancer, a colorectal cancer, a liver cancer, a prostate cancer, a head and neck squamous cell cancer, a breast cancer, an acute myeloid leukemia, myelodysplastic syndrome, myeloproliferative neoplasm, chronic myelomonocytic leukemia, a chronic lymphocytic leukemia, and a small lymphocytic lymphoma.

[00414] 34. Use of a CDK9 inhibitor in the preparation of a medicament for treating a cancer in a subject, wherein the subject has an ASXL1 mutation. [00415] 35. The use of embodiment 34, wherein the cancer is a hematologic malignancy.

[00416] 36. The use of embodiment 34, wherein the cancer is at least one selected from the group consisting of a myeloproliferative neoplasm, a myelodysplasia, a mastocytosis, an acute myeloid leukemia, a myelomonocytic leukemia, a chronic lymphocytic leukemia, a small lymphocytic lymphoma, a lymphoma, a myeloid sarcoma, a myeloid neoplasm, a lymphoid neoplasm, a histiocytic cell neoplasm, and a dendritic cell neoplasm.

[00417] 37. The use of embodiment 34, wherein the cancer is at least one selected from the group consisting of a relapsed hematologic malignancy and a refractory hematologic malignancy.

[00418] 38. The use of embodiment 34, wherein the cancer is a lymphoma.

[00419] 39. The use of embodiment 34, wherein the cancer is a solid cancer selected from the group consisting of a cervical cancer, a colorectal cancer, a liver cancer, a prostate cancer, a head and neck squamous cell cancer, and a breast cancer.

[00420] 40. The use of embodiment 34, wherein the cancer is at least one selected from the group consisting of an acute myeloid leukemia, a myelodysplasia, a mastocytosis, an acute myeloid leukemia, a myelomonocytic leukemia, a chronic lymphocytic leukemia, and a small lymphocytic lymphoma.

[00421] 41. The use of any one of embodiments 34-40, wherein said use is in combination with at least one additional agent selected from the group consisting of a BCL-2 inhibitor and an azanucleoside.

[00422] 42. The use of any one of embodiments 34-41 wherein the at least one additional agent is selected from the group consisting of venetoclax and azacitidine.

[00423] 43. The use of any one of embodiments 34-42, wherein the CDK9 inhibitor when administered to a subject has an equilibrium dissociation constant for CDK9 of less than or equal to one nanomolar.

[00424] 44. The use of any one of embodiments 34-43, wherein the CDK9 inhibitor when administered to a subject has a CDK9/cyclin T1 activity IC50 value ranging from one nanomolar to one micromolar.

[00425] 45. The use of any one of embodiments 34-44, wherein the CDK9 inhibitor is administered intravenously. [00426] 46. The use of any one of embodiments 34-45, wherein the amount of the

CDK9 inhibitor administered to the subject is from 0.1 mg/kg to 15 mg/kg of the CDK9 inhibitor per mass of the subject.

[00427] 47. The use of any one of embodiments 34-46, wherein the amount of the

CDK9 inhibitor administered to the subject is 2 mg to 200 mg or 2 mg to 100 mg.

[00428] 48. The use of any one of embodiments 34-47, wherein the CDK9 inhibitor is administered from one to seven times per week intravenously.

[00429] 49. The use of any one of embodiments 34-48, wherein the ASXL1 mutation is a frameshift mutation.

[00430] 50. The use of any one of embodiments 34-48, wherein the ASXL1 mutation is a nonsense mutation.

[00431] 51. The use of any one of embodiments 34-48, wherein the ASXL1 mutation is a ASXLIc.1934dupG mutation.

[00432] 52. The use of any one of embodiments 34-51, wherein the subject also has a nonmutated ASXL1 gene and the mutated ASXL1 gene has at least 99% homology with the nonmutated ASXL1 gene.

[00433] 53. The use of any one of embodiments 34-52, wherein the subject also has at least one selected from the group consisting of a BCOR mutation, a EZH2 mutation, a SF3B1 mutation, a SRSF2 mutation, a STAG2 mutation, a U2AF1 mutation, and a ZRSR2 mutation.

[00434] 54. The use of any one of embodiments 34-53, wherein the treatment increases a probability of remission of the cancer by at least 10%.

[00435] 55. The use of any one of embodiments 34-54, wherein the treatment increases a probability that the subject experiences at least a 10% reduction in peripheral myeloblast count by at least 10%.

[00436] 56. The use of any one of embodiments 34-55, wherein the CDK9 inhibitor comprises at least one compound selected from the group consisting of:

4-[[[4-[5-chloro-2-[[trans-4-[[(lR)-2-methoxy-l -methyl ethyl] amino] cyclohexyl] amino] -4-pyridinyl]-2 -thiazolyl] amino] methyl] tetrahydro-2H-pyran-4-carbonitrile dimaleate;

5-fluoro-4-(4-fluoro-2-methoxyphenyl)-N-{4-[(S-methylsulfonimidoyl)methyl]-2- pyridinyl}-2-pyridinamine); (lS,3R)-3-acetamido-N-[5-chloro-4-(5,5-dimethyl-4,6-dihydropyrrolo[l,2-b]pyrazol- 3-yl)pyridin-2-yl]cyclohexane-l-carboxamide;

[00437] 57. The use of any one of embodiments 34-55, wherein the CDK9 inhibitor is a compound of Formula 1 :

[00438] 58. The use of any one of embodiments 34-55, wherein the CDK9 inhibitor is the compound of Formula 2:

[00439] 59. The use of any one of embodiments 34-55, wherein the CDK9 inhibitor is the compound of Formula 2: or a pharmaceutically acceptable salt thereof; wherein the amount of the CDK9 inhibitor to be administered to the subject ranges from 1 mg to 200 mg; wherein the CDK9 inhibitor administered from one to seven times per week; and wherein the cancer is any cancer selected from the group consisting of an acute myeloid leukemia, a chronic lymphocytic leukemia, and a small lymphocytic lymphoma. [00440] 60. The use of any one of embodiments 34-55, wherein the CDK9 inhibitor is the compound of Formula 2:

Formula 2 , or a maleate salt, a dimaleate salt, or crystal form 1 thereof, wherein the amount of the CDK9 inhibitor to be administered to the subject ranges from 5 mg to 80 mg, wherein the CDK9 inhibitor is administered once, twice, or three times per week, and wherein the cancer is any cancer selected from the group consisting of an acute myeloid leukemia, a chronic lymphocytic leukemia, and a small lymphocytic lymphoma. [00441] 61. The use of any one of embodiments 34-55, wherein the CDK9 inhibitor is the compound of Formula 2:

Formula 2 or a maleate salt, a dimaleate salt, or crystal form 1 thereof; the amount of the CDK9 inhibitor to be administered to the subject is 30 mg administered twice per week, 45 mg administered once per week, or 60 mg administered once per week; and wherein said use is in combination with venetoclax and azacitidine.

[00442] 62. The use of any one of embodiments 34-55, wherein the CDK9 inhibitor is the compound of Formula 2: or a maleate salt, a dimaleate salt, or crystal form 1 thereof; the amount of the CDK9 inhibitor to be administered to the subject is 30 mg administered twice per week, 45 mg administered once per week, or 60 mg administered once per week; and wherein said use is in combination with 400 mg of venetoclax daily and azacitidine.

[00443] 63. The use of any one of embodiments 34-55, wherein the CDK9 inhibitor is the compound of Formula 2: or a maleate salt, a dimaleate salt, or crystal form 1 thereof;

Formula 2 , the amount of the CDK9 inhibitor to be administered to the subject is 30 mg administered twice per week, 45 mg administered once per week, or 60 mg administered once per week; and wherein said use is in combination with venetoclax and 75 mg/m2 of azacitidine subcutaneously or intravenously daily.

[00444] 64. The use of any one of embodiments 58-63, wherein the CDK9 inhibitor is the dimaleate salt of the compound of Formula (2).

[00445] 65. The use of any one of embodiments 58-64, wherein the CDK9 inhibitor is administered intravenously.

[00446] 66. The use of any one of embodiments 58-65, wherein the cancer is any cancer selected from the group consisting of a cervical cancer, a colorectal cancer, a liver cancer, a prostate cancer, a head and neck squamous cell cancer, a breast cancer, an acute myeloid leukemia, myelodysplastic syndrome, myeloproliferative neoplasm, chronic myelomonocytic leukemia, a chronic lymphocytic leukemia, and a small lymphocytic lymphoma.

[00447] 67. A CDK9 inhibitor for use in treating a cancer in a subject, wherein the subject has an ASXL1 mutation.

[00448] 68. The CDK9 inhibitor for use of embodiment 67, wherein the cancer is a hematologic malignancy.

[00449] 69. The CDK9 inhibitor for use of embodiment 67, wherein the cancer is at least one selected from the group consisting of a myeloproliferative neoplasm, a myelodysplasia, a mastocytosis, an acute myeloid leukemia, a myelomonocytic leukemia, a chronic lymphocytic leukemia, a small lymphocytic lymphoma, a lymphoma, a myeloid sarcoma, a myeloid neoplasm, a lymphoid neoplasm, a histiocytic cell neoplasm, and a dendritic cell neoplasm.

[00450] 70. The CDK9 inhibitor for use of embodiment 67, wherein the cancer is at least one selected from the group consisting of a relapsed hematologic malignancy and a refractory hematologic malignancy.

[00451] 71. The CDK9 inhibitor for use of embodiment 67, wherein the cancer is a lymphoma.

[00452] 72. The CDK9 inhibitor for use of embodiment 67, wherein the cancer is a solid cancer selected from the group consisting of a cervical cancer, a colorectal cancer, a liver cancer, a prostate cancer, a head and neck squamous cell cancer, and a breast cancer.

[00453] 73. The CDK9 inhibitor for use of embodiment 67, wherein the cancer is at least one selected from the group consisting of an acute myeloid leukemia, a myelodysplasia, a mastocytosis, an acute myeloid leukemia, a myelomonocytic leukemia, a chronic lymphocytic leukemia, and a small lymphocytic lymphoma.

[00454] 74. The CDK9 inhibitor for use of any one of embodiments 67-73, wherein said use is in combination with at least one additional agent selected from the group consisting of a BCL-2 inhibitor and an azanucleoside.

[00455] 75. The CDK9 inhibitor for use of any one of embodiments 67-74, wherein the at least one additional agent is selected from the group consisting of venetoclax and azacitidine.

[00456] 76. The CDK9 inhibitor for use of any one of embodiments 67-75, wherein the CDK9 inhibitor when administered to a subject has an equilibrium dissociation constant for CDK9 of less than or equal to one nanomolar.

[00457] 77. The CDK9 inhibitor for use of any one of embodiments 67-76, wherein the CDK9 inhibitor when administered to a subject has a CDK9/cyclin T1 activity IC50 value ranging from one nanomolar to one micromolar.

[00458] 78. The CDK9 inhibitor for use of any one of embodiments 67-77, wherein the CDK9 inhibitor is administered intravenously.

[00459] 79. The CDK9 inhibitor for use of any one of embodiments 67-78, wherein the amount of the CDK9 inhibitor administered to the subject is from 0.1 mg/kg to 15 mg/kg of the CDK9 inhibitor per mass of the subject. [00460] 80. The CDK9 inhibitor for use of any one of embodiments 67-79, wherein the amount of the CDK9 inhibitor administered to the subject is 2 mg to 200 mg or 2 mg to 100 mg.

[00461] 81. The CDK9 inhibitor for use of any one of embodiments 67-80, wherein the CDK9 inhibitor is administered from one to seven times per week intravenously.

[00462] 82. The CDK9 inhibitor for use of any one of embodiments 67-81, wherein the ASXL1 mutation is a frameshift mutation.

[00463] 83. The CDK9 inhibitor for use of any one of embodiments 67-81, wherein the ASXL1 mutation is a nonsense mutation.

[00464] 84. The CDK9 inhibitor for use of any one of embodiments 67-81, wherein the ASXL1 mutation is a ASXLIc.1934dupG mutation.

[00465] 85. The CDK9 inhibitor for use of any one of embodiments 67-84, wherein the subject also has a nonmutated ASXL1 gene and the mutated ASXL1 gene has at least 99% homology with the nonmutated ASXL1 gene.

[00466] 86. The CDK9 inhibitor for use of any one of embodiments 67-88, wherein the subject also has at least one selected from the group consisting of a BCOR mutation, a EZH2 mutation, a SF3B1 mutation, a SRSF2 mutation, a STAG2 mutation, a U2AF1 mutation, and a ZRSR2 mutation.

[00467] 87. The CDK9 inhibitor for use of any one of embodiments 67-86, wherein the treatment increases a probability of remission of the cancer by at least 10%.

[00468] 88. The CDK9 inhibitor for use of any one of embodiments 67-87, wherein the treatment increases a probability that the subject experiences at least a 10% reduction in peripheral myeloblast count by at least 10%.

[00469] 89. The CDK9 inhibitor for use of any one of embodiments 67-88, wherein the CDK9 inhibitor comprises at least one compound selected from the group consisting of:

(lS,3R)-3-acetamido-N-[5-chloro-4-(5,5-dimethyl-4,6-dihydropyrrolo[l,2-b]pyrazol- 3-yl)pyridin-2-yl]cyclohexane-l-carboxamide; (lS,3S)-Nl-(5-(pentan-3-yl)pyrazolo[l,5-a]pyrimidin-7-yl)cyclopentane-l,3- diamine); and

[00470] 90. The CDK9 inhibitor for use of any one of embodiments 67-88, wherein the CDK9 inhibitor is a compound of Formula 1 :

[00471] 91. The CDK9 inhibitor for use of any one of embodiments 67-88, wherein the CDK9 inhibitor is the compound of Formula 2:

[00472] 92. The CDK9 inhibitor for use of any one of embodiments 67-88, wherein the CDK9 inhibitor is the compound of Formula 2:

Formula 2 or a pharmaceutically acceptable salt thereof; wherein the amount of the CDK9 inhibitor to be administered to the subject ranges from 1 mg to 200 mg; wherein the CDK9 inhibitor administered from one to seven times per week; and wherein the cancer is any cancer selected from the group consisting of an acute myeloid leukemia, a chronic lymphocytic leukemia, and a small lymphocytic lymphoma. [00473] 93. The CDK9 inhibitor for use of any one of embodiments 67-88, wherein the CDK9 inhibitor is the compound of Formula 2: or a maleate salt, a dimaleate salt, or crystal form 1 thereof, wherein the amount of the CDK9 inhibitor to be administered to the subject ranges from 5 mg to 80 mg, wherein the CDK9 inhibitor is administered once, twice, or three times per week, and wherein the cancer is any cancer selected from the group consisting of an acute myeloid leukemia, a chronic lymphocytic leukemia, and a small lymphocytic lymphoma. [00474] 94. The CDK9 inhibitor for use of any one of embodiments 67-88, wherein the CDK9 inhibitor is the compound of Formula 2:

[00475] 95. The CDK9 inhibitor for use of any one of embodiments 67-88, wherein the CDK9 inhibitor is the compound of Formula 2: or a maleate salt, a dimaleate salt, or crystal form 1 thereof; the amount of the CDK9 inhibitor to be administered to the subject is 30 mg administered twice per week, 45 mg administered once per week, or 60 mg administered once per week; and wherein said use is in combination with 400 mg of venetoclax daily and azacitidine.

[00476] 96. The CDK9 inhibitor for use of any one of embodiments 67-88, wherein the CDK9 inhibitor is the compound of Formula 2: or a maleate salt, a dimaleate salt, or crystal form 1 thereof; the amount of the CDK9 inhibitor to be administered to the subject is 30 mg administered twice per week, 45 mg administered once per week, or 60 mg administered once per week; and wherein said use is in combination with venetoclax and 75 mg/m2 of azacitidine subcutaneously or intravenously daily.

[00477] 97. The CDK9 inhibitor for use of any one of embodiments 91-96, wherein the CDK9 inhibitor is the dimaleate salt of the compound of Formula (2).

[00478] 98. The CDK9 inhibitor for use of any one of embodiments 91-97, wherein the CDK9 inhibitor is administered intravenously.

[00479] 99. The CDK9 inhibitor for use of any one of embodiments 91-98, wherein the cancer is any cancer selected from the group consisting of a cervical cancer, a colorectal cancer, a liver cancer, a prostate cancer, a head and neck squamous cell cancer, a breast cancer, an acute myeloid leukemia, myelodysplastic syndrome, myeloproliferative neoplasm, chronic myelomonocytic leukemia, a chronic lymphocytic leukemia, and a small lymphocytic lymphoma.

Claims

CLAIMS We claim:

1. A method of treating a cancer in a subject in need thereof, the method comprising: administering a therapeutically effective amount of a CDK9 inhibitor to the subject, wherein the subject has an ASXL1 mutation.

2. The method of claim 1, wherein the cancer is a hematologic malignancy.

3. The method of claim 1, wherein the cancer is at least one selected from the group consisting of a myeloproliferative neoplasm, a myelodysplasia, a mastocytosis, an acute myeloid leukemia, a myelomonocytic leukemia, a chronic lymphocytic leukemia, a small lymphocytic lymphoma, a lymphoma, a myeloid sarcoma, a myeloid neoplasm, a lymphoid neoplasm, a histiocytic cell neoplasm, and a dendritic cell neoplasm.

4. The method of claim 1, wherein the cancer is at least one selected from the group consisting of a relapsed hematologic malignancy and a refractory hematologic malignancy.

5. The method of claim 1, wherein the cancer is a lymphoma.

6. The method of claim 1, wherein the cancer is a solid cancer selected from the group consisting of a cervical cancer, a colorectal cancer, a liver cancer, a prostate cancer, a head and neck squamous cell cancer, and a breast cancer.

7. The method of claim 1, wherein the cancer is at least one selected from the group consisting of an acute myeloid leukemia, a myelodysplasia, a mastocytosis, an acute myeloid leukemia, a myelomonocytic leukemia, a chronic lymphocytic leukemia, and a small lymphocytic lymphoma.

8. The method of any one of claims 1-7, wherein the subject is also administered at least one selected from the group consisting of a BCL-2 inhibitor and an azanucleoside.

9. The method of any one of claims 1-8, wherein the subject is also administered at least one selected from the group consisting of venetoclax and azacitidine.

10. The method of any one of claims 1-9, wherein the CDK9 inhibitor is administered intravenously.

11. The method of any one of claims 1-10, wherein the ASXL1 mutation is a frameshift mutation.

12. The method of any one of claims 1-10, wherein the ASXL1 mutation is a nonsense mutation.

13. The method of any one of claims 1-10, wherein the ASXL1 mutation is a ASXLIc.1934dupG mutation.

14. The method of any one of claims 1-13, wherein the subject also has a nonmutated ASXL1 gene and the mutated ASXL1 gene has at least 99% homology with the nonmutated ASXL1 gene.

15. The method of any one of claims 1-14, wherein the subject also has at least one selected from the group consisting of a BCOR mutation, a EZH2 mutation, a SF3B1 mutation, a SRSF2 mutation, a STAG2 mutation, a U2AF1 mutation, and a ZRSR2 mutation.

16. The method of any one of claims 1-15, wherein the treatment increases a probability of remission of the cancer by at least 10%.

17. The method of any one of claims 1-15, wherein the treatment increases a probability that the subject experiences at least a 10% reduction in peripheral myeloblast count by at least 10%.

18. The method of any one of claims 1-7, wherein the CDK9 inhibitor comprises at least one selected from the group consisting of:

19. The method of any one of claims 1-17, wherein the CDK9 inhibitor is a compound of Formula 1 :

20. The method of any one of claims 1-17, wherein the CDK9 inhibitor is the compound of Formula 2:

Formula 2 , or a pharmaceutically acceptable salt, solvate, ester, acid or prodrug thereof

21. Use of a CDK9 inhibitor in the preparation of a medicament for treating a cancer in a subject, wherein the subject has an ASXL1 mutation.

22. The use of claim 21, wherein the cancer is a hematologic malignancy.

23. The use of claim 21 , wherein the cancer is at least one selected from the group consisting of a myeloproliferative neoplasm, a myelodysplasia, a mastocytosis, an acute myeloid leukemia, a myelomonocytic leukemia, a chronic lymphocytic leukemia, a small lymphocytic lymphoma, a lymphoma, a myeloid sarcoma, a myeloid neoplasm, a lymphoid neoplasm, a histiocytic cell neoplasm, and a dendritic cell neoplasm.

24. The use of claim 21, wherein the cancer is at least one selected from the group consisting of a relapsed hematologic malignancy and a refractory hematologic malignancy.

25. The use of claim 21, wherein the cancer is a lymphoma.

26. The use of claim 21, wherein the cancer is a solid cancer selected from the group consisting of a cervical cancer, a colorectal cancer, a liver cancer, a prostate cancer, a head and neck squamous cell cancer, and a breast cancer.

27. The use of claim 21, wherein the cancer is at least one selected from the group consisting of an acute myeloid leukemia, a myelodysplasia, a mastocytosis, an acute myeloid leukemia, a myelomonocytic leukemia, a chronic lymphocytic leukemia, and a small lymphocytic lymphoma.

28. The use of any one of claims 21-27, wherein said use is in combination with at least one additional agent selected from the group consisting of a BCL-2 inhibitor and an azanucleoside.

29. The use of any one of claims 21-28, wherein the at least one additional agent is selected from the group consisting of venetoclax and azacitidine.

30. The use of any one of claims 21-29, wherein the CDK9 inhibitor comprises at least one compound selected from the group consisting of: 4-[[[4-[5-chloro-2-[[trans-4-[[(lR)-2-methoxy-l -methyl ethyl] amino] cyclohexyl] amino] -4-pyridinyl]-2 -thiazolyl] amino] methyl] tetrahydro-2H-pyran-4-carbonitrile dimaleate;

31. The use of any one of claims 21-27, wherein the CDK9 inhibitor is a compound of Formula 1 :

Formula 1 , or a pharmaceutically acceptable salt, solvate, ester, acid or prodrug thereof.

32. The use of any one of claims 21-27, wherein the CDK9 inhibitor is the compound of Formula 2:

Formula 2 , or a pharmaceutically acceptable salt, solvate, ester, acid or prodrug thereof.

33. A CDK9 inhibitor for use in treating a cancer in a subject, wherein the subject has an ASXL1 mutation.

34. The CDK9 inhibitor for use of claim 33, wherein the cancer is a hematologic malignancy.

35. The CDK9 inhibitor for use of claim 33, wherein the cancer is at least one selected from the group consisting of a myeloproliferative neoplasm, a myelodysplasia, a mastocytosis, an acute myeloid leukemia, a myelomonocytic leukemia, a chronic lymphocytic leukemia, a small lymphocytic lymphoma, a lymphoma, a myeloid sarcoma, a myeloid neoplasm, a lymphoid neoplasm, a histiocytic cell neoplasm, and a dendritic cell neoplasm.

36. The CDK9 inhibitor for use of claim 33, wherein the cancer is at least one selected from the group consisting of a relapsed hematologic malignancy and a refractory hematologic malignancy.

37. The CDK9 inhibitor for use of claim 33, wherein the cancer is a lymphoma.

38. The CDK9 inhibitor for use of claim 33, wherein the cancer is a solid cancer selected from the group consisting of a cervical cancer, a colorectal cancer, a liver cancer, a prostate cancer, a head and neck squamous cell cancer, and a breast cancer.

39. The CDK9 inhibitor for use of claim 33, wherein the cancer is at least one selected from the group consisting of an acute myeloid leukemia, a myelodysplasia, a mastocytosis, an acute myeloid leukemia, a myelomonocytic leukemia, a chronic lymphocytic leukemia, and a small lymphocytic lymphoma.

40. The CDK9 inhibitor for use of any one of claims 33-39, wherein said use is in combination with at least one additional agent selected from the group consisting of a BCL-2 inhibitor and an azanucleoside.

41. The CDK9 inhibitor for use of any one of claims 33-40, wherein the at least one additional agent is selected from the group consisting of venetoclax and azacitidine.

42. The CDK9 inhibitor for use of any one of claims 33-41, wherein the CDK9 inhibitor comprises at least one compound selected from the group consisting of:

43. The CDK9 inhibitor for use of any one of claims 33-41, wherein the CDK9 inhibitor is a compound of Formula 1 :

44. The CDK9 inhibitor for use of any one of claims 33-41, wherein the CDK9 inhibitor is the compound of Formula 2: