Inhibitors of KIF18a and uses thereof

Abstract

Provided is a compound of the Formula (I): or pharmaceutically acceptable salts thereof, which are useful for the inhibition of KIF18A and in the treatment of a variety of KIF18A mediated conditions or diseases, such as cancer.

Description

[0001] INHIBITORS OF KIF18A AND USES THEREOF

[0002] RELATED APPLICATIONS

[0003] This application claims priority to U.S. Provisional Application No. 63 / 656,255, filed on June 5, 2024. The entire contents of the foregoing application are expressly incorporated herein by reference.

[0004] FIELD OF THE INVENTION

[0005] The present disclosure relates to an inhibitor of kinesin family member 18A (KIF18A), and pharmaceutically acceptable salts thereof, compositions of this compound, processes for its preparation, and its use in the treatment of diseases.

[0006] BACKGROUND OF THE INVENTION

[0007] Chromosomal abnormalities, such as an aneuploidy, are common in a number of different cancer types. For example, whole-genome duplication has been found in more than 30% of tumors, and can act as a biomarker for tumorigenesis. (Prasad et. al., Cancer Res. 2022 May 3;82(9):1736-1752; Bielski et al., Nat Genet. 2018 Aug;50(8): 1189-1195). This genomic instability and duplication is believed to be the result of errors in cell division and propagation which occur and / or support the rapid cell division which characterize cancer cells. (Davoli, Annu Rev Cell Dev Biol. 2011;27:585-610). In order to target this rapid cell division and genetic instability, many traditional cancer drugs, such as Paclitaxel, target tubulin and prevents mitosis of cells. However, these drugs are generally cytotoxic, and often have issues with side effects and off-target toxicity. As such, research has been focused on compounds with more selectivity and less side effects.

[0008] Kinesin family member 18A (KIF18A) is, as the name suggests, a member of the kinesin protein family, which are a group of motor proteins that use ATP hydrolysis to move along microtubule filaments and support mitosis and meiosis. KIF18A has been found to be a key enzyme in the proliferation of cancers with chromosomal instability (Marquis et al., Nat Commun. 2021 Feb 22; 12(1): 1213). Further, KIF18A knockout models show viability in non-cancer cells and mice, indicating that KIF18A is not essential for normal cell division, and as such, may be able to be targeted with less side effects than essential targets. (Tamayo et al., J Med Chem. 2022 Mar 24;65(6):4972-4990). The clinical utility of previous inhibitors of the kinesin motor protein target class, such as KIF18A, has been limited by several properties of these compounds, such as high cellular efflux, long pharmacokinetic terminal half-life and dose-limiting myelosuppression, specifically neutropenia and thrombocytopenia, as previously seen, for example, with the kinesin motor protein KIF11 (Eg-5) inhibitors, as discussed in P. Navais, et, al. Pharmaceutics 2021, 13, 1011.

[0009] Thus, there is a need for KIF18A inhibitors as potential therapeutic agents for treating diseases or disorders that are responsive to KIF18A inhibition, and specifically compounds which demonstrate improvements in the properties described above (i.e., better cellular efflux, different pharmacokinetic terminal half-life, and decreased myelosuppression, specifically neutropenia and thrombocytopenia).

[0010] BRIEF DESCRIPTION OF THE FIGURES

[0011] Fig. la shows 28 day in vivo efficacy for the compound of Example 1 in OVCAR-3 Xenografts.

[0012] Fig. lb shows tolerability for the compound of Example 1 in a 28 day in vivo efficacy study in OVCAR-3 Xenografts.

[0013] Fig. 2a shows 28 day in vivo efficacy for the compound of Example 1 in OVCAR-8 Xenografts.

[0014] Fig. 2b shows tolerability for the compound of Example 1 in a 28 day in vivo efficacy study in OVCAR-8 Xenografts.

[0015] SUMMARY OF THE INVENTION

[0016] The present disclosure provides a compound that is a KIF18A inhibitor. In a first aspect, the present disclosure relates to a compound having the Formula I: or a pharmaceutically acceptable salt thereof.

[0017] Another aspect of the disclosure relates to pharmaceutical compositions comprising the compound of Formula (I) or pharmaceutically acceptable salts thereof, and a pharmaceutical carrier. In yet another aspect, the present disclosure provides a method of treating a disease or disorder that is responsive to inhibition of KIF18A in a subject comprising administering to said subject an effective amount of the compound described herein, or a pharmaceutically acceptable salt thereof. In some embodiments, the method is for the treatment of cancer.

[0018] Another aspect of the present disclosure relates to the use of the compound described herein, or a pharmaceutically acceptable salt thereof, for the manufacture of a medicament for the treatment of a disease or disorder responsive to inhibition of KIF18A. Also provided is a compound described herein or a pharmaceutically acceptable salt thereof for use in treating a disease or disorder responsive to inhibition of KIF18A.

[0019] In some aspects, the compound of the present disclosure has low efflux, especially in comparison to otherwise similar compounds known in the art. The benefits of compounds with low efflux are well known, such as overcoming resistance of cells with increased efflux pump prevalence, greater disease scope and targeting abilities, and higher cellular concentration.

[0020] In some aspects, the compound of the present disclosure has favorable pharmacokinetic properties, especially in comparison to otherwise similar compounds known in the art. Favorable pharmacokinetic properties include, but are not limited to, low clearance (both total clearance and unbound clearance), favorable oral bioavailability, longer half-life and higher Cmax concentration. These favorable pharmacokinetic properties culminate in improved druggability, which may be measured by composite parameters such as Fa*Fgand P ratio (Maurer et al., J. Med. Chem. 2020;63:6423-6435; Miller et al., J. Med. Chem. 2020;63, 12156-12170).

[0021] DETAILED DESCRIPTION OF THE INVENTION

[0022] The present disclosure provides a compound and pharmaceutical compositions thereof that may be useful in the treatment of diseases or disorders through mediation of KIF18A function / activity. In some embodiments, the compound of present disclosure is a KIF18A inhibitor.

[0023] COMPOUNDSAND COMPOSITIONS

[0024] In a first embodiment, the present disclosure provides a compound of Formula (I): or a pharmaceutically acceptable salt thereof.

[0025] The compound and intermediates described herein may be isolated and used as the compound per se. Alternatively, when a moiety is present that is capable of forming a salt, the compound or intermediate may be isolated and used as its corresponding salt. As used herein, the terms “salt” or “salts” refers to an acid addition or base addition salt of a compound described herein. “Salts” include in particular “pharmaceutical acceptable salts”. The term “pharmaceutically acceptable salts” refers to salts that retain the biological effectiveness and properties of the compounds described herein and, which typically are not biologically or otherwise undesirable. In many cases, the compounds of the present disclosure are capable of forming acid and / or base salts by virtue of the presence of amino and / or carboxyl groups or groups similar thereto.

[0026] Pharmaceutically acceptable acid addition salts can be formed with inorganic acids or organic acids, e.g., acetate, aspartate, benzoate, besylate, bromide / hydrobromide, bicarbonate / carbonate, bisulfate / sulfate, camphorsulfonate, chloride / hydrochloride, chlortheophyllonate, citrate, ethandisulfonate, fumarate, gluceptate, gluconate, glucuronate, hippurate, hydroiodide / iodide, isethionate, lactate, lactobionate, laurylsulfate, malate, maleate, malonate, mandelate, mesylate, methyl sulphate, naphthoate, napsylate, nicotinate, nitrate, octadecanoate, oleate, oxalate, palmitate, pamoate, phosphate / hydrogen phosphate / dihydrogen phosphate, polygalacturonate, propionate, stearate, succinate, sulfate, sulfosalicylate, tartrate, tosylate and trifluoroacetate salts.

[0027] Inorganic acids from which salts can be derived include, for example, hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, and the like.

[0028] Organic acids from which salts can be derived include, for example, acetic acid, propionic acid, glycolic acid, oxalic acid, maleic acid, malonic acid, succinic acid, fumaric acid, tartaric acid, citric acid, benzoic acid, mandelic acid, methanesulfonic acid, ethanesulfonic acid, toluenesulfonic acid, sulfosalicylic acid, and the like. Pharmaceutically acceptable base addition salts can be formed with inorganic and organic bases.

[0029] Inorganic bases from which salts can be derived include, for example, ammonium salts and metals from columns I to XII of the periodic table. In certain embodiments, the salts are derived from sodium, potassium, ammonium, calcium, magnesium, iron, silver, zinc, and copper; particularly suitable salts include ammonium, potassium, sodium, calcium and magnesium salts.

[0030] Organic bases from which salts can be derived include, for example, primary, secondary, and tertiary amines, substituted amines including naturally occurring substituted amines, cyclic amines, basic ion exchange resins, and the like. Certain organic amines include isopropylamine, benzathine, cholinate, diethanolamine, diethylamine, lysine, meglumine, piperazine and tromethamine.

[0031] The salts can be synthesized by conventional chemical methods from a compound containing a basic or acidic moiety. Generally, such salts can be prepared by reacting free acid forms of these compounds with a stoichiometric amount of the appropriate base (such as Na, Ca, Mg, or K hydroxide, carbonate, bicarbonate or the like), or by reacting free base forms of these compounds with a stoichiometric amount of the appropriate acid. Such reactions are typically carried out in water or in an organic solvent, or in a mixture of the two. Generally, use of non-aqueous media like ether, ethyl acetate, ethanol, isopropanol, or acetonitrile is desirable, where practicable. Lists of additional suitable salts can be found, e.g., in “Remington's Pharmaceutical Sciences”, 20th ed., Mack Publishing Company, Easton, Pa., (1985); and in “Handbook of Pharmaceutical Salts: Properties, Selection, and Use” by Stahl and Wermuth (Wiley-VCH, Weinheim, Germany, 2002).

[0032] Isotopically-labeled compounds of Formula (I) can generally be prepared by conventional techniques known to those skilled in the art or by processes analogous to those described in the accompanying Examples and Preparations using appropriate isotopically- labeled reagents in place of the non-labeled reagent previously employed. In one embodiment, the present disclosure provides deuterated compounds described herein or a pharmaceutically acceptable salt thereof.

[0033] Pharmaceutically acceptable solvates in accordance with the disclosure include those wherein the solvent of crystallization may be isotopically substituted, e.g., D2O, de-acetone, de-DMSO.

[0034] The present disclosure also provides a pharmaceutical composition comprising a compound described herein (e.g., a compound according to any one of the preceding embodiments), or a pharmaceutically acceptable salt thereof, and one or more pharmaceutically acceptable carriers.

[0035] METHODS OF USE

[0036] The compound described herein has KIF18A inhibitory activity. As used herein, “KIF18A inhibitory activity” refers to the ability of a compound or composition to induce a detectable decrease in KIF18A activity in vivo or in vitro (e.g., at least 10% decrease in KIF18A activity as measured by a given assay such as the bioassay described in the examples and known in the art).

[0037] In certain embodiments, the present disclosure provides a method of treating a disease or disorder responsive to inhibition of KIF18A activity (referred herein as “KIF18A mediated disease or disorder”) in a subject in need of the treatment. The method comprises administering to the subject a compound described herein (e.g., a compound of Formula (I)) or a pharmaceutically acceptable salt thereof or a pharmaceutical composition thereof.

[0038] In certain embodiments, the present disclosure provides the use of a compound described herein (e.g., a compound of Formula (I)) or a pharmaceutically acceptable salt thereof or a pharmaceutical composition comprising a compound described herein (e.g., a compound of Formula (I)) or a pharmaceutically acceptable salt thereof for the manufacture of a medicament for the treatment of a KIF18A mediated disorder or disease in a subject in need of the treatment.

[0039] In certain embodiments, the present disclosure provides a compound described herein (e.g., a compound of Formula (I)) or a pharmaceutically acceptable salt thereof or a pharmaceutical composition comprising a compound described herein (e.g., a compound of Formula (I)) or a pharmaceutically acceptable salt thereof for use in the treatment of a KIF18A mediated disorder or disease in a subject in need of the treatment.

[0040] In certain embodiments, the KIF18A mediated disease or disorder is a cancer.

[0041] In some embodiments, the cancer is a cancer with chromosomal instability. In other embodiments, the cancer displays whole-genome doubling. In other embodiment, the cancer has a mutation in the TP53, BRCA1, BRCA2, RBI genes and / or an amplification in the CCNE1 gene.

[0042] In some embodiments, the cancer is small-cell lung cancer, non-small cell lung cancer, pancreatic cancer, triple-negative breast cancer, colorectal cancer, hepatobiliary cancer, esophagogastric cancer, endometrial cancer, head and neck squamous cell carcinoma, ovarian cancer, platinum resistant ovarian cancer, bladder cancer, soft-tissue sarcoma, renal cell cancer, uterine cancer, cervical cancer, or bone cancer.

[0043] In other embodiments, the KIF18A mediated disease or disorder is (a) a solid or hematologically derived tumor selected from the cancer of the bladder, endometrial, lung squamous cell, breast, colon, kidney, liver, lung, small cell lung cancer, esophagus, gallbladder, brain, head and neck, ovary, pancreas, stomach, cervix, thyroid, prostate and skin, (b) a hematopoietic tumor of lymphoid lineage selected from leukemia, acute lymphocitic leukemia, acute lymphoblastic leukemia, B-cell lymphoma, T-cell-lymphoma, Hodgkin's lymphoma, non-Hodgkin's lymphoma, hairy cell lymphoma and Burkett's lymphoma, (c) a hematopoietic tumor of myeloid lineage selected from acute and chronic myelogenous leukemias, myelodysplastic syndrome and promyelocytic leukemia (d) a tumor of mesenchymal origin selected from fibrosarcoma and rhabdomyosarcoma, (e) a tumor of the central and peripheral nervous system selected from astrocytoma, neuroblastoma, glioma and schwannoma, or (f) a melanoma, seminoma, teratocarcinoma, osteosarcoma, xenoderoma pigmentosum, keratoctanthoma, thyroid follicular cancer or Kaposi's sarcoma.

[0044] The compound, or pharmaceutically acceptable salts thereof described herein (e.g., a compound of Formula (I)) may be used to decrease the expression or activity of KIF18A, or to otherwise affect the properties and / or behavior of KIF18A in a cell.

[0045] One embodiment of the present disclosure includes a method of decreasing the expression or activity of KIF18A, or to otherwise affect the properties and / or behavior of KIF18A in a subject comprising administering to said subject an effective amount of at least one compound described herein (e.g., a compound of Formula (I)), or a pharmaceutically acceptable salt thereof.

[0046] In certain embodiments, the present disclosure relates to the aforementioned methods, wherein said subject is a mammal.

[0047] In certain embodiments, the present disclosure relates to the aforementioned methods, wherein said subject is a primate.

[0048] In certain embodiments, the present disclosure relates to the aforementioned methods, wherein said subject is a human.

[0049] As used herein, an “effective amount” and a “therapeutically effective amount” can used interchangeably. It means an amount effective for treating or lessening the severity of one or more of the diseases, disorders or conditions as recited herein. In some embodiments, the effective dose can be between 10 pg and 500 mg. The compounds and compositions, according to the methods of the present disclosure, may be administered using any amount and any route of administration effective for treating or lessening the severity of one or more of the diseases, disorders or conditions recited above.

[0050] In certain embodiments, the present disclosure relates to the aforementioned methods, wherein said compound is administered parenterally.

[0051] In certain embodiments, the present disclosure relates to the aforementioned methods, wherein said compound is administered intramuscularly, intravenously, subcutaneously, orally, pulmonary, rectally, intrathecally, topically or intranasally.

[0052] In certain embodiments, the present disclosure relates to the aforementioned methods, wherein said compound is administered systemically.

[0053] The compounds of the present disclosure are typically used as a pharmaceutical composition (e.g., a compound of the present disclosure and at least one pharmaceutically acceptable carrier). As used herein, the term “pharmaceutically acceptable carrier” includes generally recognized as safe (GRAS) solvents, dispersion media, surfactants, antioxidants, preservatives (e.g., antibacterial agents, antifungal agents), isotonic agents, salts, preservatives, drug stabilizers, buffering agents (e.g., maleic acid, tartaric acid, lactic acid, citric acid, acetic acid, sodium bicarbonate, sodium phosphate, and the like), and the like and combinations thereof, as would be known to those skilled in the art (see, for example, Remington's Pharmaceutical Sciences, 18th Ed. Mack Printing Company, 1990, pp. 1289- 1329). Except insofar as any conventional carrier is incompatible with the active ingredient, its use in the therapeutic or pharmaceutical compositions is contemplated. For purposes of this disclosure, solvates and hydrates are considered pharmaceutical compositions comprising a compound of the present disclosure and a solvent (i.e., solvate) or water (i.e., hydrate).

[0054] The formulations may be prepared using conventional dissolution and mixing procedures. For example, the bulk drug substance (i.e., compound of the present disclosure or stabilized form of the compound (e.g., complex with a cyclodextrin derivative or other known complexation agent)) is dissolved in a suitable solvent in the presence of one or more of the excipients described above. The compound of the present disclosure is typically formulated into pharmaceutical dosage forms to provide an easily controllable dosage of the drug and to give the patient an elegant and easily handleable product.

[0055] The pharmaceutical composition (or formulation) for application may be packaged in a variety of ways depending upon the method used for administering the drug. Generally, an article for distribution includes a container having deposited therein the pharmaceutical formulation in an appropriate form. Suitable containers are well-known to those skilled in the art and include materials such as bottles (plastic and glass), sachets, ampoules, plastic bags, metal cylinders, and the like. The container may also include a tamper-proof assemblage to prevent indiscreet access to the contents of the package. In addition, the container has deposited thereon a label that describes the contents of the container. The label may also include appropriate warnings.

[0056] The pharmaceutical composition comprising a compound of the present disclosure is generally formulated for use as a parenteral or oral administration or alternatively suppositories.

[0057] For example, the pharmaceutical oral compositions of the present disclosure can be made up in a solid form (including without limitation capsules, tablets, pills, granules, powders or suppositories), or in a liquid form (including without limitation solutions, suspensions or emulsions). The pharmaceutical compositions can be subjected to conventional pharmaceutical operations such as sterilization and / or can contain conventional inert diluents, lubricating agents, or buffering agents, as well as adjuvants, such as preservatives, stabilizers, wetting agents, emulsifiers and buffers, etc.

[0058] Typically, the pharmaceutical compositions are tablets or gelatin capsules comprising the active ingredient together with a) diluents, e.g., lactose, dextrose, sucrose, mannitol, sorbitol, cellulose and / or glycine; b) lubricants, e.g., silica, talcum, stearic acid, its magnesium or calcium salt and / or polyethylene glycol; for tablets also c) binders, e.g., magnesium aluminum silicate, starch paste, gelatin, tragacanth, methylcellulose, sodium carboxymethylcellulose and / or polyvinylpyrrolidone; if desired d) disintegrants, e.g., starches, agar, alginic acid or its sodium salt, or effervescent mixtures; and / or e) absorbents, colorants, flavors and sweeteners.

[0059] Tablets may be either film coated or enteric coated according to methods known in the art.

[0060] Suitable compositions for oral administration include a compound of the disclosure in the form of tablets, lozenges, aqueous or oily suspensions, dispersible powders or granules, emulsion, hard or soft capsules, or syrups or elixirs. Compositions intended for oral use are prepared according to any method known in the art for the manufacture of pharmaceutical compositions and such compositions can contain one or more agents selected from the group consisting of sweetening agents, flavoring agents, coloring agents and preserving agents in order to provide pharmaceutically elegant and palatable preparations. Tablets may contain the active ingredient in admixture with nontoxic pharmaceutically acceptable excipients which are suitable for the manufacture of tablets. These excipients are, for example, inert diluents, such as calcium carbonate, sodium carbonate, lactose, calcium phosphate or sodium phosphate; granulating and disintegrating agents, for example, com starch, or alginic acid; binding agents, for example, starch, gelatin or acacia; and lubricating agents, for example magnesium stearate, stearic acid or talc. The tablets are uncoated or coated by known techniques to delay disintegration and absorption in the gastrointestinal tract and thereby provide a sustained action over a longer period. For example, a time delay material such as glyceryl monostearate or glyceryl distearate can be employed. Formulations for oral use can be presented as hard gelatin capsules wherein the active ingredient is mixed with an inert solid diluent, for example, calcium carbonate, calcium phosphate or kaolin, or as soft gelatin capsules wherein the active ingredient is mixed with water or an oil medium, for example, peanut oil, liquid paraffin or olive oil.

[0061] The parenteral compositions (e.g., intravenous (IV) formulation) are aqueous isotonic solutions or suspensions. The parenteral compositions may be sterilized and / or contain adjuvants, such as preserving, stabilizing, wetting or emulsifying agents, solution promoters, salts for regulating the osmotic pressure and / or buffers. In addition, they may also contain other therapeutically valuable substances. The compositions are generally prepared according to conventional mixing, granulating or coating methods, respectively, and contain about 0.1- 75%, or contain about 1-50%, of the active ingredient.

[0062] The compound of the present disclosure or pharmaceutical composition thereof for use in a subject (e.g., human) is typically administered orally or parenterally at a therapeutic dose. When administered intravenously via infusion, the dosage may depend upon the infusion rate at which an IV formulation is administered. In general, the therapeutically effective dosage of a compound, the pharmaceutical composition, or the combinations thereof, is dependent on the species of the subject, the body weight, age and individual condition, the disorder or disease or the severity thereof being treated. A physician, pharmacist, clinician or veterinarian of ordinary skill can readily determine the effective amount of each of the active ingredients necessary to prevent, treat or inhibit the progress of the disorder or disease. The above-cited dosage properties are demonstrable in vitro and in vivo tests using advantageously mammals, e.g., mice, rats, dogs, monkeys or isolated organs, tissues and preparations thereof. The compounds of the present disclosure can be applied in vitro in the form of solutions, e.g., aqueous solutions, and in vivo either enterally, parenterally, advantageously intravenously, e.g., as a suspension or in aqueous solution. The dosage in vitro may range between about 10'3molar and 10'9molar concentrations.

[0063] DEFINITIONS

[0064] As used herein, a “patient,” “subject” or “individual” are used interchangeably and refer to either a human or non-human animal. The term includes mammals such as humans. Typically, the animal is a mammal. A subject also refers to for example, primates (e.g., humans, male or female), cows, sheep, goats, horses, dogs, cats, rabbits, rats, mice, fish, birds and the like. In certain embodiments, the subject is a primate. In some embodiments, the subject is a human.

[0065] As used herein, the term “inhibit”, “inhibition” or “inhibiting” refers to the reduction or suppression of a given condition, symptom, or disorder, or disease, or a significant decrease in the baseline activity of a biological activity or process.

[0066] As used herein, the term “treat”, “treating” or “treatment” of any disease, condition or disorder, refers to the management and care of a patient for the purpose of combating the disease, condition, or disorder and includes the administration of a compound of the present disclosure to obtaining desired pharmacological and / or physiological effect. The effect can be therapeutic, which includes achieving, partially or substantially, one or more of the following results: partially or totally reducing the extent of the disease, condition or disorder; ameliorating or improving a clinical symptom, complications or indicator associated with the disease, condition or disorder; or delaying, inhibiting or decreasing the likelihood of the progression of the disease, condition or disorder; or eliminating the disease, condition or disorder. In certain embodiments, the effect can be to prevent the onset of the symptoms or complications of the disease, condition or disorder.

[0067] As used herein the term “cancer” has the meaning normally accepted in the art. The term can broadly refer to abnormal cell growth.

[0068] As used herein, a subject is “in need of’ a treatment if such subject would benefit biologically, medically or in quality of life from such treatment (in some embodiments, a human). The phrase “pharmaceutically acceptable” indicates that the substance, composition or dosage form must be compatible chemically and / or toxicologically, with the other ingredients comprising a formulation, and / or the mammal being treated therewith.

[0069] Unless specified otherwise, the term “compound of the present disclosure” refers to the compound of Formula (I), as well as all stereoisomers (including diastereoisomers and enantiomers), rotamers, tautomers, isotopically labeled compounds (including deuterium substitutions). When a moiety is present that is capable of forming a salt, then salts are included as well, in particular pharmaceutically acceptable salts.

[0070] As used herein, the term “a,” “an,” “the” and similar terms used in the context of the present disclosure (especially in the context of the claims) are to be construed to cover both the singular and plural unless otherwise indicated herein or clearly contradicted by the context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein is intended merely to better illuminate the disclosure and does not pose a limitation on the scope of the disclosure otherwise claimed.

[0071] It is also possible that the intermediates and compounds of the present disclosure may exist in different tautomeric forms, and all such forms are embraced within the scope of the disclosure. The term “tautomer” or “tautomeric form” refers to structural isomers of different energies which are interconvertible via a low energy barrier. For example, proton tautomers (also known as prototropic tautomers) include interconversions via migration of a proton, such as keto-enol and imine-enamine isomerizations. A specific example of a proton tautomer is the imidazole moiety where the proton may migrate between the two ring nitrogens. Valence tautomers include interconversions by reorganization of some of the bonding electrons.

[0072] In one embodiment, the present disclosure relates to the compound of the Formula (I) as defined herein, in free form. In another embodiment, the present disclosure relates to the compound of the Formula (I) as defined herein, in salt form. In another embodiment, the present disclosure relates to the compound of the Formula (I) as defined herein, in acid addition salt form. In a further embodiment, the present disclosure relates to the compound of the Formula (I) as defined herein, in pharmaceutically acceptable salt form. In yet a further embodiment, the present disclosure relates to the compound of the Formula (I) as defined herein, in pharmaceutically acceptable acid addition salt form.

[0073] The compound of the present disclosure may be synthesized by synthetic routes that include processes analogous to those well-known in the chemical arts, particularly in light of the description contained herein. The starting materials are generally available from commercial sources such as Sigma- Aldrich or are readily prepared using methods well known to those skilled in the art (e.g., prepared by methods generally described in Louis F. Fieser and Mary Fieser, Reagents for Organic Synthesis, v. 1-19, Wiley, New York (1967- 1999 ed.), or Beilsteins Handbuch der organischen Chemie, 4, Aufl. ed. Springer-Verlag, Berlin, including supplements (also available via the Beilstein online database)).

[0074] For illustrative purposes, the reaction schemes depicted below provide potential routes for synthesizing the compound of the present disclosure as well as key intermediates. For a more detailed description of the individual reaction steps, see the Examples section below. Although specific starting materials and reagents are depicted in the schemes and discussed below, other starting materials and reagents can be easily substituted to provide a variety of derivatives and / or reaction conditions.

[0075] EXEMPLIFICATION Abbreviations:

[0076] DCM = dichloromethane

[0077] DMEDA = dimethylethylenediamine

[0078] DMSO = dimethylsulfoxide

[0079] ESI = electrospray ionisation

[0080] EtOAc = ethyl acetate

[0081] FA = formic acid

[0082] HPLC = high pressure liquid chromatography

[0083] LCMS = liquid chromatography mass spectrometry

[0084] MeCN = acetonitrile

[0085] MeOH = methanol

[0086] MS = mass spectrometry

[0087] [TBAFCUI]2 = bis[(tetrabutylammonium iodide)copper(I) iodide]

[0088] TEA = triethylamine

[0089] THF = tetrahydrofuran

[0090] GENERAL METHODS

[0091] 1.1H NMR spectra were recorded on a Bruker AVANCE NEO 400MHz. 2. LCMS measurement was run on SHIMADZU LCMS-2020 using the follow conditions:

[0092] Method A: Mobile Phase: A: Water (0.05%TFA) B: Acetonitrile (0.05%TFA);

[0093] Gradient Phase: 5%B to 100%B within 2.0 min, 100%B with 0.7 min (total runtime:

[0094] 2.8 min); Flow Rate: 1.5 mL / min; Column: HALO C18, 3.0*30mm, 2.0pm; Column Temperature: 40 °C. Detectors: AD2 ELSD, PDA (220 nm and 254 nm), ESI.

[0095] Method B: Mobile Phase: A: Water (0.1%FA) B: Acetonitrile (0.1%FA);

[0096] Gradient Phase: 5%B to 100%B within 2.0 min, 100%B with 0.7 min (total runtime:

[0097] 2.8 min); Flow Rate: 1.5 mL / min; Column: HALO C18, 3.0*30mm, 2.0pm; Column Temperature: 40 °C. Detectors: AD2 ELSD, PDA (220 nm and 254 nm), ESI.

[0098] Method C: Mobile Phase: A: Water (5mM NH4HCO3) B: Acetonitrile;

[0099] Gradient Phase: 10%B to 95%B within 2.0 min, 100%B with 0.6 min (total runtime:

[0100] 2.8 min); Flow Rate: 1.5 mL / min; Column: Poroshell HPH-C18, 3.0*50mm, 4.0pm;

[0101] Column Temperature: 40 °C. Detectors: AD2 ELSD, PDA (220 nm and 254 nm), ESI.

[0102] The observed molecular ion for all compounds listed below is for [M+H]+, unless otherwise indicated.

[0103] Example 1: Synthesis of N-(5-(4,4-difluoropiperidin-l-yl)-[l,2,4]triazolo[l,5- c]pyrimidin-7-yl)-2-(4,4-dimethyl-l,4-azasilinan-l-yl)-4-(ethylsulfonamido)benzamide

[0104] Step 1. Preparation of 2-((7-iodo-[l,2,4]triazolo[l,5-c]pyrimidin-5-yl)thio)acetonitrile

[0105] To a mixture of Cui (92.35 g, 484.9 mmol) and tert-butyl nitrite (125 g, 1.21 mol) in MeCN (1,500 mL) was added 2-((7-amino-[l,2,4]triazolo[l,5-c]pyrimidin-5-yl)thio)acetonitrile (prepared according to the procedures described in W02024 / 035950, incorporated herein by reference) (100.0 g, 484.9 mmol) at 0 °C. The mixture was then stirred for 12 h at 40 °C. After cooling to room temperature, the reaction mixture was then acidified to pH < 3 using HC1 (2 M in H2O) and then extracted with ethyl acetate (3 x 150 mL). The combined organic extracts were washed with brine (100 mL), dried with anhydrous Na2SO4, filtered, and then concentrated under vacuum. The residue was purified by silica gel column chromatography (DCM:EtOAc gradient) to afford 2-((7-iodo-[l,2,4]triazolo[l,5-c]pyrimidin-5- yl)thio)acetonitrile (47.0 g, 145 mmol) as a yellow solid. LCMS: MS ESI (M+l)+318.0.

[0106] Step 2. Preparation of 5-(4,4-difluoropiperidin-l-yl)-7-iodo-[l,2,4]triazolo[l,5- c] pyrimidine

[0107] A mixture of 2-((7-iodo-[l,2,4]triazolo[l,5-c]pyrimidin-5-yl)thio)acetonitrile (5.00 g, 15.8 mmol) in 1,4-dioxane (10 mL) was added 4,4-difluoropiperidine (7.64 g, 63.1 mmol), and the mixture was stirred at 100 °C for 3 h. After cooling to room temperature, the mixture was then poured into water (100 mL) and stirred for 5 min before extracting with EtOAc (3 x 100 mL). The combined organic extracts were washed with brine (100 mL), dried with anhydrous Na2SO4, filtered, and concentrated under vacuum. The residue was purified by preparatory HPLC (column: Phenomenex Luna Cl 8, 10 pm, 250 x 50 mm; mobile phase: [A: H2O with FA; B: MeCN]; gradient: 30-60% B over 20 min) to afford 5-(4,4-difluoropiperidin-l-yl)-7- iodo-[l,2,4]triazolo[l,5-c]pyrimidine (4.00 g, 11.0 mmol) as a yellow solid. LCMS: MS ESI (M+l)+366.0. 'H NMR (400 MHz, DMSO-d6) 8 = 8.46 (s, 1H), 7.69 (s, 1H), 4.27 - 4.04 (m, 4H), 2.31 - 2.07 (m, 4H).

[0108] Step 3. Preparation of 2-(4,4-dimethyl-l,4-azasilinan-l-yl)-4-nitrobenzamide

[0109] To a mixture of 2-(4,4-dimethyl-l,4-azasilinan-l-yl)-4-nitrobenzoic acid (prepared according to the procedures described in W02024 / 035950, incorporated herein by reference) (34.00 g, 115.5 mmol) in DCM (200 mL) was added oxalyl chloride (29.32 g, 231.0 mmol) at 0 °C under N2 atmosphere. The mixture was stirred at 25 °C for 1 h and then concentrated under vacuum. The resulting yellow residue was taken up in DCM (1,000 mL) and treated with NH3 H2O (288 g, 2.30 mol). After stirring at 25 °C for 1 h, the mixture was poured into water (400 mL), stirred for 5 min, and then extracted with EtOAc (3 x 400 mL). The combined organic extracts were washed with brine (2 x 100 mL), dried with anhydrous Na2SO4, filtered, and concentrated under vacuum to afford 2-(4,4-dimethyl-l,4-azasilinan-l-yl)-4- nitrobenzamide (33.00 g, 106.9 mmol) as a yellow solid. LCMS: MS ESI (M+l)+294.2.JH NMR (400 MHz, DMSO-d6) 8 = 9.56 (br s, 1H), 8.31 (d, J= 8.6 Hz, 1H), 8.12 - 7.94 (m, 2H), 6.02 (br s, 1H), 3.30 - 3.21 (m, 4H), 1.12 - 0.91 (m, 4H), 0.19 (s, 6H).

[0110] Step 4. Preparation of N-(5-(4,4-difluoropiperidin-l-yl)-[l,2,4]triazolo[l,5-c]pyrimidin-

[0111] 7-yl)-2-(4,4-dimethyl-l,4-azasilinan-l-yl)-4-nitrobenzamide

[0112] To a solution of 5-(4,4-difluoropiperidin-l-yl)-7-iodo-[l,2,4]triazolo[l,5-c]pyrimidine (4.00 g, 11.0 mmol), 2-(4,4-dimethyl-l,4-azasilinan-l-yl)-4-nitrobenzamide (3.60 g, 12.3 mmol), and DMEDA (600 mg, 6.81 mmol) in 1,4-dioxane (40 mL) was added CS2CO3 (11.20 g,

[0113] 34.37 mmol) and [TBATCuI]2 (1.60 g, 1.43 mmol) at 25 °C. After stirring at 100 °C under N2 atmosphere for 16 h, the reaction was cooled to 25 °C, poured into water (300 mL), stirred for 5 min, and then extracted with EtOAc (3 x 200 mL). The combined organic extracts were washed with brine (2 x 100 mL), dried with anhydrous Na2SO4, filtered, and concentrated under vacuum. The residue was purified by silica gel column chromatography (DCM:EtOAc gradient) to afford N-(5-(4,4-difluoropiperidin-l-yl)-[l,2,4]triazolo[l,5-c]pyrimidin-7-yl)-2- (4,4-dimethyl-l,4-azasilinan-l-yl)-4-nitrobenzamide (3.70 g, 6.97 mmol) as a yellow solid. LCMS: MS ESI (M+l)+531.2.

[0114] Step 5. Preparation of 4-amino-N-(5-(4,4-difluoropiperidin-l-yl)-[l,2,4]triazolo[l,5- c]pyrimidin-7-yl)-2-(4,4-dimethyl-l,4-azasilinan-l-yl)benzamide

[0115] To a solution of N-(5-(4,4-difluoropiperidin-l-yl)-[l,2,4]triazolo[l,5-c]pyrimidin-7-yl)-2- (4,4-dimethyl-l,4-azasilinan-l-yl)-4-nitrobenzamide (4.00 g, 7.54 mmol) in THF (150 mL) and MeOH (150 mL) was added Pd(OH)2 on carbon (2.0 g, 10% w / w) under N2 atmosphere. The suspension was degassed under vacuum and purged with H2 three times. The mixture was then stirred under H2 atmosphere (15 psi) at 25 °C for 16 h. The reaction mixture was then filtered, and the filtrate was concentrated under vacuum. The residue was purified by silica gel column chromatography (DCM:EtOAc gradient) to afford 4-amino-N-(5-(4,4- difluoropiperidin- 1 -yl)-[ 1 , 2, 4]tri azolof 1 ,5-c]pyrimidin-7-yl)-2-(4,4-dimethyl- 1 ,4-azasilinan- l-yl)benzamide (3.50 g, 6.99 mmol) as a yellow solid. LCMS: MS ESI (M+l)+501.1.

[0116] Step 6. Preparation of N-(5-(4,4-difluoropiperidin-l-yl)-[l,2,4]triazolo[l,5-c]pyrimidin-

[0117] 7-yl)-2-(4,4-dimethyl-l,4-azasilinan-l-yl)-4-(N-

[0118] (ethylsulfonyl)ethylsulfonamido)benzamide

[0119] To a solution of 4-amino-N-(5-(4,4-difluoropiperidin-l-yl)-[l,2,4]triazolo[l,5-c]pyrimidin-7- yl)-2-(4,4-dimethyl-l,4-azasilinan-l-yl)benzamide (3.50 g, 6.99 mmol) in DCM (300 mL) was added TEA (2.83 g, 28.0 mmol) and ethanesulfonyl chloride (2.06 g, 16.0 mmol) at 0 °C under N2 atmosphere. The mixture was stirred at 25 °C for 30 min. The reaction was then poured into water (300 mL), stirred for 5 min, and was extracted with EtOAc (3 x 200 mL). The combined organic extracts were washed with brine (2 x 100 mL), dried with anhydrous Na2SO4, filtered, and concentrated under vacuum to afford N-(5-(4,4-difluoropiperidin-l-yl)- [ 1 ,2,4]triazolo[ 1 , 5-c]pyrimidin-7-yl)-2-(4,4-dimethyl- 1 ,4-azasilinan- 1 -yl)-4-(N- (ethylsulfonyl)ethylsulfonamido)benzamide (4.70 g, 6.86 mmol) as a yellow solid. LCMS: MS ESI (M+1)+685.1.

[0120] Step 7. Preparation of N-(5-(4,4-difluoropiperidin-l-yl)-[l,2,4]triazolo[l,5-c]pyrimidin- 7-yl)-2-(4,4-dimethyl-l,4-azasilinan-l-yl)-4-(ethylsulfonamido)benzamide

[0121] To a solution of N-(5-(4,4-difluoropiperidin-l-yl)-[l,2,4]triazolo[l,5-c]pyrimidin-7-yl)-2- (4,4-dimethyl-l,4-azasilinan-l-yl)-4-(N-(ethylsulfonyl)ethylsulfonamido)benzamide (4.70 g, 6.86 mmol) in MeOH (100 mL) was added K2CO3 (9.48 g, 68.6 mmol). The mixture was stirred at 80 °C for 2 h. After cooling to room temperature, the reaction was poured into saturated aqueous NH4CI (500 mL), stirred for 5 min, and then extracted with EtOAc (3 x 200 mL). The combined organic extracts were washed with brine (2 x 100 mL), dried with anhydrous Na2SO4, filtered, and concentrated under vacuum. The residue was purified by recrystallization from ethanol (40 mL) at 75 °C to afford N-(5-(4,4-difluoropiperidin-l-yl)- [ 1 ,2,4]triazolo[ 1 , 5-c]pyrimidin-7-yl)-2-(4,4-dimethyl- 1 ,4-azasilinan- 1 -yl)-4- (ethylsulfonamido)benzamide (4.00 g, 6.75 mmol) as a white solid. LCMS: MS ESI (M+l)+593.2. 'HNMR (400 MHz, DMSO-d6) 8 = 12.66 (s, 1H), 10.22 (br s, 1H), 8.42 (s, 1H), 8.00 (d, J= 8.6 Hz, 1H), 7.93 (s, 1H), 7.27 (d, J= 1.8 Hz, 1H), 7.11 (dd, J= 1.9, 8.7 Hz, 1H), 4.21 - 4.08 (m, 4H), 3.27 - 3.16 (m, 6H), 2.25 - 2.11 (m, 4H), 1.20 (t, J= 13 Hz, 3H), 1.06 - 0.96 (m, 4H), 0.15 (s, 6H).

[0122] Comparator “Compound A”, whose structure is shown below, was also synthesized according to known methods (z.e., as described in WO 2024 / 035950) and tested in the biological assays disclosed below. (Compound A).

[0123] As can be seen in the data table below, the compound of the present invention has improved efflux and pharmacokinetic properties in comparison to Compound A.

[0124] BIOLOGICAL ASSAYS

[0125] KIF18A Inhibition and Efflux Assays

[0126] The compound of Formula (I) (i.e., compound of Example 1) was tested in comparison to Compound A in Caco-2 Permeation Assay, KIF18A biochemical assay and in vitro anti-proliferative activity assay in cancer cell line OVCAR-3 as described in W02024 / 035950, incorporated herein by reference.

[0127] “++++” means <0.1 pM; “+++” means 0.1-0.5 pM; “++” means >0.5 - 1 pM; “+” means > 1 pM;

[0128] “**” means efflux ratio of <10; means efflux ratio of >=10

[0129] In Vivo Pharmacokinetic (PK) Evaluation ofKIF18A Compounds in Mouse

[0130] The compound of Formula (I) was tested in comparison to Compound A using the in vivo PK assay as described in W02024 / 035950, incorporated herein by reference. The PK of the test compounds were evaluated following a single intravenous bolus (IV) of solution at a dose of 3 mg / kg and oral administration (PO) of solution / suspension at doses of 10 mg / kg in female balb / c nude mice using a parallel study design. The data are shown in the table below.

[0131] Composite parameters and ratios may indicate the druggability of a compound (Maurer et al., J. Med. Chem. 2020;63:6423-6435; Miller et al., J. Med. Chem. 2020;63, 12156-12170). More favorable druggability may be indicated by a higher Fa*Fgvalue and a lower P Ratio. The Fa*Fgand P Ratio parameters were calculated as follows:

[0132] Fa*Fg= [oral bioavailability, %F] / [1 - (IV clearance) / (mouse liver blood flow)]

[0133] P Ratio = [OVCAR-3 cellular antiproliferation assay free-fraction adjusted IC50] *

[0134] [unbound clearance] / [Fa*Fg]

[0135] OVCAR-3 cellular antiproliferation assay free-fraction adjusted IC50 values were calculated using this formula:

[0136] Free-fraction adjusted IC50 = OVCAR-3 cellular antiproliferation assay IC50 * % Free in assay media

[0137] Unbound IV clearance = IV clearance / % Free in mouse plasma

[0138] Evaluation ofKIF18A Compounds in a Human Megakaryocyte Progenitor Colony Formation Assay

[0139] Clonogenic progenitors of human megakaryocyte (CFU-MK) progenitors were assessed in a collagen-based media formulation containing 3% BSA, rhIL-3 (10 ng / mL), rhIL-11 (10 ng / mL), rhIL-6 (10 ng / mL) and rhTpo (50 ng / mL).

[0140] Human bone marrow mononuclear cells (lot# 0230214, DLS, Seattle, WA) were stored at -152 °C until required for the assay. On the day of the experiment, the cells were thawed rapidly, the contents were diluted in 10 mL of Iscove’s modified Dulbecco’s medium containing 10% fetal bovine serum (IMDM + 10% FBS) and washed by centrifugation (approximately 1500 r.p.m. for 10 minutes, room temperature). The supernatant was discarded, and the cell pellets resuspended in a known volume of IMDM + 10% FBS. A cell count (3% glacial acetic acid) and viability assessment (trypan blue exclusion test) were performed for the bone marrow sample.

[0141] Compounds were tested at final concentrations of 125, 80, 50, 30, 10, 3, 1, and 0.3 pM. DMSO was added as the solvent control of CFU-MK assay. 5 -Fluorouracil (5-FU) was evaluated at 1.0, 0.1 and 0.01 pg / mL as a positive control for toxicity for all lineages. Solvent control cultures (containing no compound but 0.1% DMSO) as well as standard controls (containing no compound or DMSO) were also initiated. The cultures were incubated for 14 days. The human megakaryocyte cultures were then transferred from the 35 mm dishes to labeled glass slides, fixed with methanol / acetone fixative and then stained with anti-human CD41 antibody and an alkaline phosphate detection system according to manufacturers’ instructions. The colonies were assessed microscopically and scored by trained personnel and divided into the following categories based on size: CFU-MK (3-20), CFU-MK (21-49), and CFU-MK (>50).

[0142] The mean ± 1 standard deviation of three replicate cultures was calculated for the megakaryocyte progenitors. Two-tailed student’s t-tests were performed to assess if there was a difference in the number of colonies generated between solvent control and treated cultures. Due to the potential subjectivity of colony enumeration, a p-value of less than 0.01 was deemed significant. To calculate the concentration of 50% inhibition of colony growth (IC50), a dose response curve was generated plotting the log of the compound concentration versus the percentage of control colony growth using GraphPad Prism 9. The concentration of 50% inhibition of colony growth (IC50) was calculated based on the sigmoid curve fit using Dose- Response, One-Site Model formula: y = A + [(B - A) / (l + ((C / x)AD))], where A = the initial value (baseline response), B = maximum response, C = center (drug concentration that provokes a response halfway between A and B) and D= slope of the curve at midpoint.

[0143] Binding of compounds to components of the assay buffer system was also evaluated. BSA and collagen were added to DMEM to obtain a final concentration similar to the buffer described above. Working solutions of test compounds and control compound was prepared in DMSO at the concentration of 5 mM, and then the working solutions were spiked into DMEM with BSA and collagen. The final concentration of compound was 25 pM. The final concentration of DMSO was 0.5%. Ketoconazole was used as positive control in the assay.

[0144] The dialysis membranes were soaked in ultrapure water for 60 minutes to separate strips, then in 20% ethanol for 20 minutes, finally in dialysis buffer for 20 minutes. The dialysis set up assembled according to the manufacturer’s instruction. Each cell was treated with 150 pL of sample and dialyzed against equal volume of dialysis buffer (blank DMEM). The assay was performed in duplicate. The dialysis plate was sealed and incubated in an incubator at 37 °C with 5% CO2 at 100 rpm for 6 h. At the end of incubation, 50 pL of samples from both buffer and samples were transferred to wells of a 96-well plate.

[0145] 50 pL of blank DMEM with BSA and collagen was added to each buffer sample and an equal volume of blank DMEM was supplemented to the collected DMEM with BSA and collagen sample. 400 pL of precipitation buffer acetonitrile containing internal standards (IS, 100 nM alprazolam, 200 nM labetalol, 200 nM imipramine and 2 pM ketoprofen) was added to precipitate protein and release compounds. Samples were vortexed for 2 minutes and centrifuged for 30 minutes at 3,220 g. An aliquot of 100 pL of the supernatant was diluted by 100 pL ultra-pure H2O, and the mixture was used for LC-MS / MS analysis.

[0146] All calculations were carried out using Microsoft Excel. The concentrations of test compounds in the buffer and DMEM with BSA and collagen chambers were determined from peak area ratios. The percentages of bound compound were calculated as follows:

[0147] % Free = (Peak Area Ratio buffer chamber / Peak Area Ratio 2% BSA and collagen chamber) *100%

[0148] % Bound = 100% - % Free

[0149] Free-fraction adjusted IC50 values were calculated using this formula:

[0150] Free-fraction adjusted CFU-MK IC50 (pM) = CFU-MK IC50 (pM) * % Free Free-fraction adjusted IC50S for compounds tested are found in the table below. As can be seen, Example 1 has significantly less potency against the bone marrow mononuclear cell colony formation, in comparison to comparator Compound A, which indicates a significantly decreased risk of cytopenia or thrombocytopenia for this compound.

[0151] In Vivo Efficacy Demonstration for KIF18A Compounds

[0152] In Vivo Example 1

[0153] Experiments were performed in female NOD SCID mice (Shanghai Model Organisms). Animals were allowed to acclimate for 7 days before the study. The general health of the animals were evaluated by a veterinarian, and complete health checks were performed prior to the study. General procedures for animal care and housing were in accordance with the standard, Commission on Life Sciences, National Research Council, Standard Operating Procedures (SOPs) of Pharmaron, Inc. The mice were kept in laminar flow rooms at constant temperature and humidity with 3-5 mice in each cage. Animals were housed in polycarbonate cages which had dimensions of 300 x 180 x 150 mm3and in an environmentally monitored, well-ventilated room maintained at a temperature of 23 ± 3 °C and a relative humidity of 40%-70%. Fluorescent lighting provided illumination approximately 12 hours per day. Animals had free access to irradiation sterilized dry granule food during the entire study period except for time periods specified by the protocol, as well as sterile drinking water in a bottle that was available ad libitum during the quarantine and study periods.

[0154] The OVCAR-3 (ATCC) tumor cell lines were maintained in vitro as a monolayer in RPMI 1640 medium supplemented with 20% heat inactivated FBS, at 37 °C in an atmosphere of 5% CO2 in air. The tumor cells were sub-cultured, not exceeding 4-5 passages, and cells growing in an exponential growth phase were harvested and counted for tumor inoculation. Each mouse was inoculated subcutaneously on the right flank with OVCAR-3 tumor cells (2 x 107) in 0.2 mL of RPMI-1640 with Matrigel (1 : 1) for model development.

[0155] Treatment was started when the mean tumor size reached approximately 150-200 mm3, at which time the mice were randomized into treatment groups such that the average starting tumor size is similar for each treatment group. Animals were then treated with vehicle or indicated mg / kg of the compound of Example 1 QD (once daily) by oral gavage at a final dosing volume of 10 mL / kg.

[0156] All study animals were monitored for not only tumor growth but also behavior such as mobility, food and water consumption (by cage side checking only), body weight (BW), eye / hair matting and any other abnormal effects. Body weights of all animals were measured and recorded twice per week throughout the study. Body weight change, expressed in %, was calculated using the following formula:

[0157] BW change (%) = (BWDaypG-Dx / BWDaypo-Di)x100; PG-D1 is the first day of dosing. The measurement of tumor size was conducted with a caliper and recorded twice per week. The tumor volume (TV) (mm3) was estimated using the formula: TV = axb2 / 2, where “a” and “b” are long and short diameters of a tumor, respectively.

[0158] The TVs were used for calculation of the tumor growth inhibition and tumor growth delay. For the tumor growth inhibition (TGI), the value using the formula:

[0159] %T / C = (TreatedTVfmai-TreatedTVinitiai) / (VehicleTVfmai-VehicleTVinitiai)x100 %TGI = [l-(TreatedTVfmai-TreatedVTinitiai) / (VehicleTVfmai-VehicleTVinitiai)]x100 The “TVfmai” and “TVinitiai” are the mean tumor volumes on the final day and initial day, respectively.

[0160] All statistical tests were conducted on GraphPad, and the level of significance was set at 5% or P < 0.05. The group means and standard deviations were calculated for all measurement parameters. Two-way RM ANOVA followed by Tukey’s post hoc comparisons of the means was applied among groups.

[0161] Treatment was initiated with the compound of Example 1 treated at 5, 10 or 25 mg / kg using QD (once daily) oral application when the tumor volume was an average of 1171 mm3(n=8 / group). The initial treatment period with the compound of Example 1 was 28 days, after which overall efficacy and tolerability were evaluated based on tumor volume and body weight changes observed during the treatment period (Fig. la and Fig. lb). For vehicle and 5 mg / kg QD groups, mice were terminated after day 24 due to a subset of tumors within the group reaching the humane termination criteria of >2500 mm3.

[0162] On days 24-28, the compound of Example 1 dosed orally once daily induced a dosedependent antitumor response against OVCAR-3 xenografts in mice, where the %TGI was 43% at 5 mg / kg, 96% at 10 mg / kg, and 105% at 25 mg / kg. When compared with vehicle control using a one-way ordinary ANOVA test (see Fig. la), both the 10 and 25 mg / kg groups were statistically significant with a p-value <0.0001. Based on body weight, dosing of the compound of Example 1 was well tolerated (see Fig. lb). As can be seen, the compound of Example 1 shows significant reduction in tumor growth at both 10 mg / kg QD and 25 mg / kg QD doses.

[0163] In Vivo Example 2

[0164] Experiments were performed in female BALB / c nude mice (GenPharmatech Co.). Animals were allowed to acclimate for 7 days before the study. The general health of the animals was evaluated by a veterinarian, and complete health checks were performed prior to the study. General procedures for animal care and housing were in accordance with the standard, Commission on Life Sciences, National Research Council, Standard Operating Procedures (SOPs) of Pharmaron, Inc. The mice were kept in laminar flow rooms at constant temperature and humidity with 3-5 mice in each cage. Animals were housed in polycarbonate cages which had dimensions of 300 x 180 x 150 mm3and in an environmentally monitored, well-ventilated room maintained at a temperature of 23 ± 3 °C and a relative humidity of 40%-70%. Fluorescent lighting provided illumination approximately 12 hours per day. Animals had free access to irradiation sterilized dry granule food during the entire study period except for time periods specified by the protocol, as well as sterile drinking water in a bottle that was available ad libitum during the quarantine and study periods.

[0165] The OVCAR-8 (ATCC) tumor cell lines were maintained in vitro as a monolayer in RPMI 1640 medium supplemented with 10% heat inactivated FBS, at 37 °C in an atmosphere of 5% CO2 in air. The tumor cells were sub-cultured, not exceeding 4-5 passages, and cells growing in an exponential growth phase were harvested and counted for tumor inoculation. Each mouse was inoculated subcutaneously on the right flank with OVCAR-8 tumor cells (1 x 107) in 0.2 mL of RPMI-1640 with Matrigel (1 : 1) for model development.

[0166] Treatment was started when the mean tumor size reached approximately 150-200 mm3, at which time the mice were randomized into treatment groups such that the average starting tumor size is similar for each treatment group. Animals were then treated with vehicle or indicated mg / kg of compound of Example 1 BID (twice daily) by oral gavage at a final dosing volume of 10 mL / kg.

[0167] All study animals were monitored for not only tumor growth but also behavior such as mobility, food and water consumption (by cage side checking only), body weight (BW), eye / hair matting and any other abnormal effects. Body weights of all animals were measured and recorded twice per week throughout the study. Body weight change, expressed in %, was calculated using the following formula:

[0168] BW change (%) = (BWDaypG-Dx / BWDaypo-Di)x100; PG-D1 is the first day of dosing.

[0169] The measurement of tumor size was conducted with a caliper and recorded twice per week. The tumor volume (TV) (mm3) was estimated using the formula: TV = a x b2 / 2, where “a” and “b” are long and short diameters of a tumor, respectively.

[0170] The TVs were used for calculation of the tumor growth inhibition and tumor growth delay. For the tumor growth inhibition (TGI), the value using the formula:

[0171] %T / C = (TreatedTVfmai-TreatedTVinitiai) / (VehicleTVfmai-VehicleTVinitiai)x100

[0172] %TGI = [l-(TreatedTVfmai-TreatedVTinitiai) / (VehicleTVfmai-VehicleTVinitiai)]x100

[0173] The “TVfmai” and “TVinitiai” are the mean tumor volumes on the final day and initial day, respectively.

[0174] All statistical tests were conducted on GraphPad, and the level of significance was set at 5% or P < 0.05. The group means and standard deviations were calculated for all measurement parameters. Two-way RM ANOVA followed by Tukey’s post hoc comparisons of the means was applied among groups.

[0175] Treatment was initiated with the compound of Example 1 treated at 25 mg / kg BID (twice daily) oral application when the tumor volume was an average of approximately 161 mm3(n = 8 / group). The initial treatment period with the compound of Example 1 was 28 days, after which overall efficacy and tolerability were evaluated based on tumor volume and body weight changes observed during the treatment period (Fig. 2a and Fig. 2b).

[0176] On day 28, the compound of Example 1 dosed orally at 25 mg / kg twice daily induced an antitumor response against OVCAR-8 xenografts in mice, where the %T / C value was 10% and the %TGI was 90%, with a p-value = 0.0017 when compared with vehicle control using a one-way ordinary ANOVA test (see Fig. 2a). Based on body weight, dosing of the compound of Example 1 was well tolerated (see Fig. 2b). As can be seen, the compound of Example 1 shows significant reduction in tumor growth.

Claims

CLAIMSWhat is claimed is:

1. A compound represented by Formula (I):or a pharmaceutically acceptable salt thereof.

2. A pharmaceutical composition comprising a compound of claim 1, or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable excipient.

3. A method of treating a KIF18A mediated disease or disorder in a subject, comprising administering to the subject a compound, or pharmaceutically acceptable salt thereof, of claim 1, or the pharmaceutical composition of claim 2.

4. The method of claim 3, wherein the disease or disorder is a cancer.

5. The method of claim 4, wherein the cancer is a cancer with chromosomal instability.

6. The method of claim 4 or 5, wherein the cancer displays whole-genome doubling.

7. The method of any one of claims 4 to 6, wherein the cancer has a mutation in a TP53,BRCA1, BRCA2, RBI gene and / or an amplification in a CCNE1 gene.

8. The method of any one of claims 4 to 7, wherein the cancer is small-cell lung cancer, non-small cell lung cancer, pancreatic cancer, triple-negative breast cancer, colorectal cancer, hepatobiliary cancer, esophagogastric cancer, endometrial cancer, head and neck squamous cell carcinoma, ovarian cancer, platinum resistant ovarian cancer,bladder cancer, soft-tissue sarcoma, renal cell cancer, uterine cancer, cervical cancer, or bone cancer.

9. The method of claim 3, wherein the disease or disorder is (a) a solid or hematologically derived tumor selected from cancer of the cancer of the bladder, endometrial, lung squamous cell, breast, colon, kidney, liver, lung, small cell lung cancer, esophagus, gall-bladder, brain, head and neck, ovary, pancreas, stomach, cervix, thyroid, prostate and skin, (b) a hematopoietic tumor of lymphoid lineage selected from leukemia, acute lymphocytic leukemia, acute lymphoblastic leukemia, B-cell lymphoma, T-cell-lymphoma, Hodgkin’s lymphoma, non-Hodgkin's lymphoma, hairy cell lymphoma and Burkett’s lymphoma, (c) a hematopoietic tumor of myeloid lineage selected from acute and chronic myelogenous leukemias, myelodysplastic syndrome and promyelocytic leukemia (d) a tumor of mesenchymal origin selected from fibrosarcoma and rhabdomyosarcoma, (e) a tumor of the central and peripheral nervous system selected from astrocytoma, neuroblastoma, glioma and schwannoma, or (f) a melanoma, seminoma, teratocarcinoma, osteosarcoma, xenoderoma pigmentosum, keratoctanthoma, thyroid follicular cancer or Kaposi’s sarcoma.

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