Phospholipid-FLAVAGLINE conjugates and methods of using them for targeted cancer therapy

Abstract

Disclosed herein are phospholipid ether (PLE) molecules. Also provided are phospholipid-flavagline conjugates. Phospholipid-flavagline conjugates may include a PLE conjugated to a flavagline via a linker. Also provided herein are methods of treating cancer in a subject and methods of targeting a drug to a tumor or cancer cell in a subject.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of and priority to U.S. Provisional Patent Application No. 62 / 913,571, filed on October 10, 2019, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] The present disclosure relates to phospholipid-flavagline conjugates and targeted cancer therapies. Background Art

[0004] The application of most anticancer drugs in clinical use is limited by their toxicity to all proliferating cells and / or their inability to act on all tumor cells. New agents with unique pharmacological actions are constantly being developed, providing enhanced targeting, however, many of these compounds still lack absolute tumor selectivity and continue to limit their therapeutic application due to off-target effects. Antibody drug conjugates (ADCs) have been designed to bind to specific epitopes on the surface of tumor cells and provide another method of targeting tumor cells, aiming to reduce the associated toxicity. Despite their high selectivity, only a few antibody drug conjugates can be used for treatment because they can only achieve moderate cellular uptake and limited cell killing activity. More effective tumor targeting platforms are needed. Summary of the invention

[0005] In one aspect, the present disclosure provides a compound of formula (I) or a pharmaceutically acceptable salt thereof,

[0006]

[0007] wherein Z is a flavagline analog.

[0008] Another aspect of the present disclosure provides a pharmaceutical composition comprising a compound described herein or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable carrier.

[0009] Another aspect of the present disclosure provides a method of treating cancer in a subject, the method comprising administering to the subject a compound described herein or a pharmaceutically acceptable salt thereof.

[0010] Another aspect of the present disclosure provides a method of targeting a drug to a tumor or cancer cell in a subject, the method comprising administering to the subject a compound described herein or a pharmaceutically acceptable salt thereof.

[0011] In some embodiments, the compounds described herein are located in or approach the cytoplasm or organelles of tumors or cancer cells. In some embodiments, the compound is selective for cancer cells in a subject. In some embodiments, the compound enters at least 2 times more tumors or cancer cells than healthy cells. In some embodiments, cancer is melanoma, brain cancer, lung cancer, adrenal cancer, liver cancer, kidney cancer or renal cancer, pancreatic cancer, esophageal cancer, gastric cancer, gastric cancer, colon cancer, colorectal cancer, anal cancer, prostate cancer, ovarian cancer, breast cancer, cervical cancer, lymphoma, leukemia, myeloma, blood cancer, liver cancer, retinoblastoma, glioma, sarcoma, blastoma, squamous cell carcinoma, adenocarcinoma or a combination thereof. In some embodiments, the subject is a person.

[0012] The present disclosure provides other aspects and embodiments, which will become apparent from the following detailed description and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1A , Figure 1B , Figure 1C , Figure 1D , Figure 1E This is a picture of a tumor cell with lipid rafts labeled. Tumor cells have a higher concentration of lipid rafts than normal cells. Figure 1F These are images of normal fibroblasts and Caki-2 tumor cells with CLR 1501 (compound (1)). CLR 1501 is highly present in Caki-2 cells and minimally present in normal fibroblasts. Figure 1G is an image of control A549 cells, and Figure 1H is an image of A549 treated with methyl-b-cyclodextrin to disrupt lipid rafts. Figure 1G and Figure 1H The cells in A549 were cultured with CLR1501 (Compound (1)), and then the disruption of most lipid rafts in A549 cells resulted in a 60% decrease in CLR1501 (Compound (1)) uptake. Fig. 1I , Figure 1J and Figure 1K The images are of PC3 cells cultured with CLR1501 (compound (1)) and stained for endoplasmic reticulum (ER). CLR1501 (compound (1)) co-localized with ER in malignant cells but not in normal cells (not shown). Figure 1L , Figure 1M and Figure 1N The images are of PC3 cells cultured with CLR1501 (compound (1)) and stained for nuclei and mitochondria. CLR1501 (compound (1)) colocalizes with mitochondria.

[0014] Figure 2Images of mice bearing colorectal (HCT-116) tumors injected with CLR1502 (compound (2)) showing localization to the tumor.

[0015] Figure 3 Graph showing cytotoxicity versus concentration of cytotoxic compound (FLV1) in A549 (human lung adenocarcinoma cells) or normal human dermal fibroblasts (NHDF) cells compared to cytotoxic compounds conjugated to PLE (CLR 1865, compound) (8).

[0016] Figure 4 is a graph of fold increase versus uptake of the PLE conjugate CLR1852 (compound (9)) in A375 (human melanoma) and HEK293 (human embryonic kidney) cells over time.

[0017] Figure 5 are images of a breast cancer model in mice, demonstrating the in vivo uptake of CLR1502 (compound (2)).

[0018] Figure 6 is an image of a myeloma cell line demonstrating the uptake of CLR1501 (compound (1)).

[0019] Figure 7 These are images of cancer stem cells, normal brain tissue, and normal stem cells, demonstrating the specific uptake of CLR1501 (compound (1)) into cancer cells.

[0020] Figure 8 The graphs compare the percentage of cytotoxicity relative to the concentration of CLR1852 (compound (9)) in FLV3, A549 (human lung adenocarcinoma) cells and normal human dermal fibroblasts (NHDF).

[0021] Fig. 9 Figure 2 is a graph of tumor volume versus time for vehicle versus CLR1852 (compound (9)) in the HCT116 tumor model.

[0022] Fig.10 Figure 2 is a graph of body weight versus time for vehicle versus CLR1852 (compound (9)) in the HCT116 tumor model.

[0023] Fig.11 Figure 2 is a graph of the concentration of FLV3 detected in the cytosol (normalized to the volume of the cytosol) versus time in A375 (human melanoma) and A549 (human lung adenocarcinoma) cell lines.

[0024] Fig.12 Representative results of body weight changes in mouse models after administration of CLR1899 (at 0.5 mg / kg, 1 mg / kg, and 2 mg / kg) are shown.

[0025] Fig.13 Representative results of the in vivo efficacy of CLR1899 in the MCF-7 xenograft model (10 mice per dose group) are shown. DETAILED DESCRIPTION

[0026] Described herein are phospholipid compounds and phospholipid-flavagline conjugates. Phospholipid ether (PLE) molecules were developed based on the fact that many animal and human tumors contain ether lipids at levels higher than those naturally occurring in normal tissues. The PLE molecules described herein can be used as tumor targeting platforms to selectively deliver drugs to tumors and cancer cells.

[0027] As described herein, the tissue distribution of PLE molecules was investigated in more than 100 different tumor cells, including fresh human tumor samples. PLE molecules exhibited stronger uptake in tumor tissues than in normal tissues. PLE molecules can be conjugated with flavagline molecules and their derivatives via linkers to generate phospholipid-flavagline conjugates.

[0028] 1. Definition

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as those generally understood by those of ordinary skill in the art. In the event of a conflict, this document, including definitions, shall prevail. Although similar or equivalent methods and materials described herein can be used to practice or test the present invention, preferred methods and materials are described below. All publications, patent applications, patents, and other citations mentioned herein are fully incorporated herein by reference. The materials, methods, and examples disclosed herein are illustrative only and are not intended to be limiting.

[0030] As used herein, the terms "include," "comprising," "having," "having," "can," "including," and variations thereof are intended to be open transitional phrases, terms, or words that do not exclude the possibility of adding other acts or structures. The singular forms "a," "an," and "the" include reference to the plural unless the context clearly indicates otherwise. The present disclosure also contemplates other embodiments "comprising," "consisting of," and "consisting essentially of" the embodiments and elements presented herein, whether expressly stated or not.

[0031] To express numerical ranges herein, each intervening digit of equal precision is expressly included. For example, for the range 6-9, the digits 7 and 8 are considered in addition to 6 and 9, and for the range 6.0-7.0, the digits 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, and 7.0 are expressly considered.

[0032] As used herein, the term "approximately" may be used for one or more related values ​​to refer to a value similar to a quoted value. In some aspects, the term "approximately" refers to a range of values ​​that fall within 20%, 19%, 18%, 17%, 16%, 15%, 14%, 13%, 12%, 11%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, or less of the stated quoted value (more or less), unless otherwise stated, or otherwise justified from the context (unless such a number would exceed 100% of a possible value).

[0033] Definitions of specific functional groups and chemical terms are described in more detail below. For the purposes of this disclosure, chemical elements are consistent with the Periodic Table of the Elements, CAS version, Handbook of Chemistry and Physics, 75 th Edition, inside pages, and specific functional groups are generally defined as described therein. In addition, the general laws of organic chemistry and specific functional moieties and reactivity are described in Organic Chemistry, Thomas Sorrell, University Science Books, Sausalito, 1999; Smith and March March's Advanced Organic Chemistry, 7th Edition, John Wiley & Sons, Inc., New York, 2013; Larock, Comprehensive Organic Transformations, VCH Publishers, Inc., New York, 1989; Carruthers, Some Modern Methods of Organic Synthesis, 3rd Edition, Cambridge University Press, Cambridge, 1987; the entire contents of each are fully incorporated herein by reference.

[0034] As used herein, the term "alkoxy" or "alkoxyl" refers to an alkyl group, as defined herein, attached to the parent molecular moiety through an oxygen atom. Representative examples of alkoxy include, but are not limited to, methoxy, ethoxy, propoxy, 2-propoxy, butoxy and tert-butoxy.

[0035] As used herein, the term "alkyl" refers to a straight or branched saturated hydrocarbon chain containing 1 to 20 carbon atoms. 1-6 "Alkyl" refers to a straight or branched chain hydrocarbon containing 1 to 6 carbon atoms.1-4 "Alkyl" refers to a straight or branched chain hydrocarbon containing 1 to 4 carbon atoms. 1-3 “Alkyl” refers to a straight or branched chain hydrocarbon containing 1 to 3 carbon atoms. Representative examples of alkyl include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, 3-methylhexyl, 2,2-dimethylpentyl, 2,3-dimethylpentyl, n-heptyl, n-octyl, n-nonyl, and n-decyl.

[0036] As used herein, the term "alkenyl" refers to an unsaturated hydrocarbon chain containing 2 to 20 carbon atoms and at least one carbon-carbon double bond.

[0037] As used herein, the term "alkynyl" refers to an unsaturated hydrocarbon chain containing 2 to 20 carbon atoms and at least one carbon-carbon triple bond.

[0038] The term "alkoxyalkyl" as used herein, means an alkoxy group, as defined herein, appended to the parent molecular moiety through an alkylene group, as defined herein.

[0039] The term "arylalkyl" as used herein, means an aryl group, as defined herein, appended to the parent molecular moiety through an alkylene group, as defined herein.

[0040] The term "alkylamino" as used herein, means at least one alkyl group, as defined herein, appended to the parent molecular moiety through an amino group, as defined herein.

[0041] As used herein, the term "alkylene" refers to a divalent group derived from a straight or branched hydrocarbon of 1 to 10 carbon atoms, such as 2 to 5 carbon atoms. Representative examples of alkylene include, but are not limited to, -CH 2 CH 2 -、-CH 2 CH 2 CH 2 -、-CH 2 CH 2 CH 2 CH 2 -, and –CH 2 CH 2 CH 2 CH 2 CH 2 -.

[0042] As used herein, the term "amide" refers to -C(O)NR- or -NRC(O)-, where R can be hydrogen, alkyl, cycloalkyl, aryl, heteroaryl, heterocycle, alkenyl, or heteroalkyl.

[0043] The term "aminoalkyl" as used herein, means at least one amino group, as defined herein, appended to the parent molecular moiety through an alkylene group, as defined herein.

[0044] As used herein, the term "amino" refers to -NR x R y , where R x and R y It can be hydrogen, alkyl, cycloalkyl, aryl, heteroaryl, heterocycle, alkenyl or heteroalkyl. In the case of aminoalkyl or any other moiety where the amino group links two other moieties together, the amino group can be -NR x -, where R x It may be hydrogen, alkyl, cycloalkyl, aryl, heteroaryl, heterocycle, alkenyl or heteroalkyl.

[0045] As used herein, the term "aryl" refers to an aromatic group, such as phenyl, or a bicyclic fused ring system. An example of a bicyclic fused ring system is a phenyl connected to a parent molecular moiety and fused to a cycloalkyl as defined herein, a phenyl, a heteroaryl as defined herein, or a heterocycle as defined herein. Representative examples of aryl include, but are not limited to, indolyl, naphthyl, phenyl, quinolyl, and tetrahydroquinolyl. "Arylalkyl" refers to an alkyl as defined herein substituted with an aryl.

[0046] "Arylene" refers to an aryl group, as defined herein, having two monovalent radical centers derived by removing two hydrogen atoms from two different carbon atoms of a parent aryl group. Typical arylene groups include, but are not limited to, phenylene and naphthylene. "Arylalkylene" refers to an arylalkyl group, as defined herein, having two monovalent radical centers derived by removing one hydrogen atom from the aryl group of the group and another hydrogen from the alkyl group of the group.

[0047] As used herein, the term "carboxy" refers to a carboxylic acid or -COOH.

[0048] The term "cycloalkyl" refers to a monovalent saturated hydrocarbon ring or a bicyclic group. Cycloalkyl has zero heteroatoms and zero double bonds. Cycloalkyl is monocyclic, or a fused, spirocyclic or bridged bicyclic ring system. Monocyclic cycloalkyl contains 3-10 carbon atoms, preferably 4-7 carbon atoms, more preferably 5-6 carbon atoms in the ring. Bicyclic cycloalkyl contains 8 to 12 carbon atoms, preferably 9 to 10 carbon atoms in the ring. Cycloalkyl can be substituted or unsubstituted. Cycloalkyl includes, for example, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and cycloheptyl.

[0049] As used herein, the term "cycloalkenyl" refers to a non-aromatic monocyclic or multicyclic ring system containing at least one carbon-carbon double bond and preferably having 5-10 carbon atoms per ring. Exemplary monocyclic cycloalkenyl rings include cyclopentenyl, cyclohexenyl, and cycloheptenyl.

[0050] As used herein, the term "cycloalkynyl" refers to a monocyclic or polycyclic ring system containing at least one carbon-carbon triple bond and preferably having 5-10 carbon atoms per ring or more than 10 carbon atoms per ring.

[0051] As used herein, the term "haloalkyl" refers to an alkyl as defined herein, wherein one, two, three, four, five, six, seven or eight hydrogen atoms are substituted by halogen. Representative examples of haloalkyl include, but are not limited to, 2-fluoroethyl, 2,2,2-trifluoroethyl, trifluoromethyl, difluoromethyl, pentafluoroethyl and trifluoropropyl such as 3,3,3-trifluoropropyl.

[0052] As used herein, the term "halogen" or "halo" refers to Cl, Br, I or F.

[0053] As used herein, the term "heteroalkyl" refers to an alkyl group as defined herein, wherein at least one carbon of the alkyl group is substituted by a heteroatom such as oxygen, nitrogen and sulfur. Representative examples of heteroalkyl groups include, but are not limited to, alkyl ethers, secondary and tertiary alkyl amines, amides and alkyl thioethers.

[0054] As used herein, the term "heteroaryl" refers to an aromatic monocyclic or aromatic bicyclic ring system containing at least one heteroatom independently selected from N, O and S. An aromatic monocyclic ring is a five- or six-membered ring containing at least one heteroatom independently selected from the group consisting of N, O and S. A five-membered aromatic monocyclic ring has two double bonds and a six-membered aromatic monocyclic ring has three double bonds. An example of a bicyclic heteroaryl is a monocyclic heteroaryl ring attached to a parent molecular moiety and fused to a monocyclic cycloalkyl as defined herein, a monocyclic aryl as defined herein, a monocyclic heteroaryl as defined herein, or a monocyclic heterocycle as defined herein. Representative examples of heteroaryl include, but are not limited to, indolyl, pyridyl (including pyridin-2-yl, pyridin-3-yl, pyridin-4-yl), pyrimidinyl, pyrazinyl, pyridazinyl, pyrazolyl, pyrrolyl, benzopyrazolyl, 1,2,3-triazolyl, 1,3,4-thiadiazolyl, 1,2,4-thiadiazolyl, 1,3,4-oxadiazolyl, 1,2,4-oxadiazolyl, imidazolyl, thiazolyl, isothiazolyl, thienyl, benzimidazolyl, benzothiazolyl, benzoxazolyl, benzoxadiazolyl, benzo Thiphenyl, benzofuranyl, isobenzofuranyl, furanyl, oxazolyl, isoxazolyl, purinyl, isoindolyl, quinoxalinyl, indazolyl, quinazolinyl, 1,2,4-triazinyl, 1,3,5-triazinyl, isoquinolyl, quinolyl, 6,7-dihydro-1,3-benzothiazolyl, imidazo[1,2-a]pyridinyl, naphthyridinyl, pyridoimidazolyl, thiazolo[5,4-b]pyridin-2-yl, thiazolo[5,4-d]pyrimidin-2-yl.

[0055] As used herein, the term "heterocycle" or "heterocyclic" or "heterocyclyl" refers to a monocyclic heterocycle, a bicyclic heterocycle (heterobicyclic) or a tricyclic heterocycle. A monocyclic heterocycle is a three-, four-, five-, six-, seven- or eight-membered ring containing at least one heteroatom independently selected from the group consisting of O, N and S. A three- or four-membered ring contains 0 or 1 double bond and 1 heteroatom selected from the group consisting of O, N and S. A five-membered ring contains 0 or 1 double bond and 1, 2 or 3 heteroatoms selected from the group consisting of O, N and S. A six-membered ring contains 0, 1 or 2 double bonds and 1, 2 or 3 heteroatoms selected from the group consisting of O, N and S. Seven- and eight-membered rings contain zero, one, two or three double bonds and one, two or three heteroatoms selected from the group consisting of O, N and S. Representative examples of monocyclic heterocycles include, but are not limited to, azetidinyl, azepanyl, aziridinyl, diazepanyl, 1,3-dioxanyl, 1,3-dioxolanyl, 1,3-dithiolanyl, 1,3-dithianyl, imidazolinyl, imidazolidinyl, isothiazolinyl, isothiazolidinyl, isoxazolinyl, isoxazolidinyl, morpholinyl, oxadiazolinyl, oxadiazolidinyl, oxazolinyl, oxazolidinyl, oxetanyl, piperazinyl, piperidinyl, pyranyl, pyrazolinyl, pyrazolidinyl, pyrrolinyl , pyrrolidinyl, tetrahydrofuranyl, tetrahydropyranyl, tetrahydropyridinyl, tetrahydrothiophenyl, thiadiazolinyl, thiadiazolidinyl, 1,2-thiazinanyl, 1,3-thiazinanyl, thiazolinyl, thiazolidinyl, thiomorpholinyl, 1,1-dioxidothiomorpholinyl (thiomorpholine sulfone), thiopyranyl, and trithianyl. The bicyclic heterocycle is a monocyclic heterocycle fused to a phenyl group, or a monocyclic heterocycle fused to a monocyclic cycloalkyl group, or a monocyclic heterocycle fused to a monocyclic cycloalkenyl group, or a monocyclic heterocycle fused to a monocyclic heterocycle, or a bridged monocyclic heterocycle ring system in which two non-adjacent atoms of the ring are linked by an alkylene bridge of 1, 2, 3 or 4 carbon atoms or an alkenylene bridge of 2, 3 or 4 carbon atoms.Representative examples of bicyclic heterocycles include, but are not limited to, benzopyranyl, benzothiopyranyl, chromanyl, 2,3-dihydrobenzofuranyl, 2,3-dihydrobenzothiophenyl, 2,3-dihydroisoquinolinyl, azabicyclo[2.2.1]heptyl (including 2-azabicyclo[2.2.1]hept-2-yl), 2,3-dihydro-1H-indolyl, isoindolinyl, octahydrocyclopenta[c]pyrrolyl, octahydropyrrolopyridinyl, and tetrahydroisoquinolinyl. Examples of tricyclic heterocycles include bicyclic heterocycles fused to phenyl, or bicyclic heterocycles fused to monocyclic cycloalkyl, or bicyclic heterocycles fused to monocyclic cycloalkenyl, or bicyclic heterocycles fused to monocyclic heterocycles, or bicyclic heterocycles wherein two non-adjacent atoms of the bicyclic ring are linked by an alkylene bridge of 1, 2, 3, or 4 carbon atoms, or an alkenylene bridge of 2, 3, or 4 carbon atoms. Examples of tricyclic heterocycles include, but are not limited to, octahydro-2,5-epoxypentane, hexahydro-2H-2,5-methanocyclopenta[b]furan, hexahydro-1H-1,4-methanocyclopenta[c]furan, azaadamantane (1-azatricyclo[3.3.1.1.3). 3,7 ]decane) and oxadamantane (2-oxatricyclo[3.3.1.1 3,7 The monocyclic, bicyclic and tricyclic heterocycles are attached to the parent molecular moiety through any carbon atom or any nitrogen atom contained within the rings and can be unsubstituted or substituted.

[0056] The term "heteroarylalkyl" as used herein, means a heteroaryl group, as defined herein, appended to the parent molecular moiety through an alkylene group, as defined herein.

[0057] The term "heterocyclylalkyl" as used herein, means a heterocyclyl group, as defined herein, appended to the parent molecular moiety through an alkylene group, as defined herein.

[0058] As used herein, the term "hydroxyl" or "hydroxy" refers to an -OH group.

[0059] The term "hydroxyalkyl" as used herein, means at least one -OH group, appended to the parent molecular moiety through an alkylene group, as defined herein.

[0060] In some cases, the number of carbon atoms in a hydrocarbyl substituent (e.g., alkyl or cycloalkyl) is indicated by the prefix "C x-y-" represents, where x is the minimum number of carbon atoms in the substituent and y is the maximum number of carbon atoms in the substituent. Thus, for example, "C 1-3 "Alkyl" refers to an alkyl substituent containing 1 to 3 carbon atoms.

[0061] The term "substituted" refers to a group that can be further substituted by one or more non-hydrogen substituents. Substituents include, but are not limited to, halogen, =O (oxo), =S (thio), cyano, nitro, fluoroalkyl, alkoxyfluoroalkyl, fluoroalkoxy, alkyl, alkenyl, alkynyl, haloalkyl, haloalkoxy, heteroalkyl, cycloalkyl, cycloalkenyl, aryl, heteroaryl, heterocycle, cycloalkylalkyl, heteroarylalkyl, arylalkyl, hydroxyl, hydroxyalkyl, alkoxy, alkoxyalkyl, alkylene, aryloxy, phenoxy, benzyloxy, amino, alkylamino, acylamino, aminoalkyl, arylamino, sulfonylamino, sulfinylamino, sulfonyl, alkylsulfonyl, arylsulfonyl, aminosulfonyl, sulfinyl, -COOH, ketone, amide, carbamate and acyl.

[0062] the term Refers to a single key or double bond or three keys

[0063] For the compounds described herein, radicals and substituents may be chosen based on the allowed valences of atoms and substituents such that selection and substitution results in stable compounds, e.g., which do not spontaneously undergo transformations such as by rearrangement, cyclization, elimination, and the like.

[0064] As used herein, the term "administering" or "administering" refers to providing, contacting and / or delivering a compound or conjugate by any suitable route to achieve a desired effect. These compounds or conjugates can be administered to a subject in a variety of ways, including but not limited to orally, ocularly, nasally, intravenously, topically, as an aerosol, suppository, etc., and can be used in combination.

[0065] As used herein, "cancer" may include any cell or tissue derived from a tumor, a neoplasm, a cancer, a precancerous lesion, a cell line, a malignant tumor, or any other cell source with unlimited expansion and growth potential. Cancer cells may be from natural sources or may be artificially produced. Cancer cells may also be able to invade other tissues and metastasize. Cancer cells further include any malignant cells that have invaded other tissues and / or metastasized. One or more cancer cells in the context of an organism may also be referred to as cancer, a tumor, a neoplasm, a growth, a malignant tumor, or any other term used in the art to describe cells in a cancerous state. Cancer may include, for example, melanoma, brain cancer, lung cancer, adrenal cancer, liver cancer, kidney cancer or renal cancer, pancreatic cancer, esophageal cancer, stomach cancer, gastric cancer, colon cancer, colorectal cancer, anal cancer, prostate cancer, ovarian cancer, breast cancer, cervical cancer, lymphoma, leukemia, myeloma, blood cancer, liver cancer, retinoblastoma, glioma, sarcoma, blastoma, squamous cell carcinoma, and adenocarcinoma

[0066] As used herein, the term "cancer stem cell" refers to a cancer cell that is capable of self-renewal and differentiation into different types of cancer cells found in malignant tumors.

[0067] In general, reference to "circulating tumor cells" (CTCs) is intended to refer to a single cell, while reference to "circulating tumor cells" or "circulating tumor cell clusters" is intended to refer to more than one cancer cell. However, it will be understood by those skilled in the art that reference to "circulating tumor cells" is intended to include circulating tumor cell populations, including one or more circulating tumor cells, while reference to "circulating tumor cells" may include more than one circulating tumor cell. As used herein, the term "circulating tumor cell" or "circulating tumor cell" refers to any cancer cell or cancer cell cluster found in a subject's blood or serum sample. CTCs may also include or consist of cancer stem cells or cancer stem cell clusters found in a subject's blood or serum sample.

[0068] The terms "control", "reference level" and "reference" used herein are interchangeable. A reference level can be a predetermined value or range used as a standard for evaluating a measurement result. A "control group" used herein refers to a group of control subjects. A predetermined level can be a cutoff value for a control group. A predetermined level can be an average value for a control group. A cutoff value (or a predetermined cutoff value) can be determined using an adaptive exponential model (AIM) method. A cutoff value (or a predetermined cutoff value) can be determined in a receiver operating curve (ROC) analysis of biological samples of a patient group. ROC analysis, which is generally known in the biological field, is a test determination method for distinguishing the ability of one situation from another. A description of ROC analysis is found in PJHeagerty et al. (Biometrics 2000, 56, 337-44), which is incorporated herein by reference in its entirety. Alternatively, a cutoff value is analyzed by four partitions of a biological sample of a patient group. For example, the cutoff value can be determined by selecting a value corresponding to any value in the 25th-75th percentile range, preferably, corresponding to the 25th percentile, the 50th percentile or the 75th percentile, more preferably, the 75th percentile. Such statistical analysis can be performed using any method known in the art, and can be implemented by any number of commercially available software packages (e.g., from Analyse-it Software Ltd., Leeds, UK; StataCorp LP, College Station, TX; SAS Institute Inc., Cary, NC.). The target or the healthy or normal level or range for protein activity can be defined according to standard operations. The control can be a subject, or a sample from a subject, and the disease condition of the subject is known. The subject or a sample from a subject can be healthy, sick, sick before treatment, sick during treatment, sick after treatment, or healthy after treatment or a combination thereof. As used herein, the term "normal subject" refers to a healthy subject, i.e., a subject without clinical signs or symptoms of disease. Normal subjects are clinically evaluated for otherwise undetected signs or symptoms of disease, which evaluation may include routine physical examination and / or laboratory testing. In some embodiments, the control is a healthy control. In some embodiments, the control includes cancer.

[0069] As used herein, the term "effective dose" or "therapeutic dose" or "therapeutically effective amount" or "effective amount" refers to an amount sufficient to cause a therapeutic effect or a dose of a drug that is effective over a necessary period of time to achieve the desired therapeutic effect. The effective dose can be determined by those skilled in the art and may vary according to factors such as the individual's disease state, age, sex and weight, mode of administration, stage and severity of the disease, general health of the subject, the judgment of the prescribing physician, and the ability of the drug to cause the desired response in the individual. A therapeutically effective amount is also an amount in which any toxic or deleterious effects of a substance are considered to be exceeded by the beneficial effects of the treatment. A "prophylactically effective amount" refers to an amount that is effective to achieve the desired preventive result at the necessary dose and time period. Typically, since a prophylactic dose is used in a subject before or at an early stage of the disease, the prophylactic effective amount will be less than the therapeutically effective amount.

[0070] The term "inhibit" or "inhibition" refers to a reduction or prevention of activity in the presence of an inhibitor, as opposed to in the absence of the inhibitor. The term "inhibit" refers to a reduction or downregulation of a process or the elimination of a stimulus in a process, which results in the absence or minimization of expression or activity of a biomarker or polypeptide. Inhibition may be direct or indirect. Inhibition may be specific, i.e., the inhibitor inhibits certain biomarkers or polypeptides but not others.

[0071] As used herein, "sample" or "test sample" may refer to any sample in which the presence and / or level of a compound or target is to be detected or determined. The sample may include a liquid, a solution, an emulsion, a mixture, or a suspension. The sample may include a medical sample. The sample may include any biological fluid or tissue, such as blood, whole blood, blood fractions such as plasma and serum, peripheral blood mononuclear cells (PBMC), muscle, interstitial fluid, sweat, saliva, urine, tears, synovial fluid, bone marrow, cerebrospinal fluid, nasal secretions, sputum, amniotic fluid, bronchoalveolar lavage fluid, gastric lavage fluid, vomitus, feces, lung tissue, peripheral blood mononuclear cells, total leukocytes, lymph node cells, spleen cells, tonsil cells, cancer cells, tumor cells, bile, digestive fluid, skin, or a combination thereof. In some embodiments, the sample includes an aliquot. In other embodiments, the sample includes a biological fluid. The sample can be obtained by any means known in the art. The sample can be directly obtained from the patient, or it can be pre-treated, for example, by filtering, distilling, extracting, concentrating, centrifuging, inactivating interfering components, adding reagents, etc., in a certain manner discussed herein or in other manners known in the art to change the properties of the sample. The sample can be obtained before diagnosis, before treatment, during treatment, after treatment, or after diagnosis, or a combination thereof.

[0072] As used herein, the term "specificity" refers to the number of true negatives divided by the number of true negatives plus the number of false positives, where specificity ("spec") can range from 0 < spec < 1. Thus, methods with both sensitivity and specificity equal to 1 or 100% are preferred.

[0073] "Specific binding" generally refers to when a compound or conjugate binds to a target more readily than it binds to a random, unrelated target.

[0074] As used herein, the term "subject" can refer to a mammal that desires or requires a compound or method described herein. A subject can be a human or a non-human animal. A subject can be a mammal. A mammal can be a primate or a non-primate. A mammal can be a primate animal, such as a human; a non-primate animal, such as a dog, cat, horse, cow, pig, mouse, rat, camel, llama, goat, rabbit, sheep, hamster, and guinea pig; or a non-human primate, such as a monkey, chimpanzee, gorilla, orangutan, and gibbon. A subject can be of any age or developmental stage, such as an adult, adolescent, or infant. A subject can be male or female. In some embodiments, the subject has a specific genetic marker.

[0075] As used herein, the term "toxic" refers to the amount of a chemical entity, reagent, or substance that is harmful to a subject or causes any adverse effect. The term "non-toxic" refers to a substance that causes a relatively low degree of harm to a subject. "Cytotoxic" refers to a chemical entity, reagent, or substance that is toxic to cells. Toxicity can refer to the effect on an entire organism such as an animal, bacterium, plant, or other subject as defined herein, as well as on substructures of an organism such as cells (cytotoxicity) or organs (organ toxicity), such as the liver (hepatotoxicity). A core concept in toxicology is that the effect is dose-dependent. Even water can cause water intoxication when ingested in a large enough dose, while even a highly toxic substance such as snake venom will not exhibit toxic effects below that dose. A relatively non-toxic composition or compound can allow a wider range of subjects to safely handle the composition or compound without serious safety concerns or risks.

[0076] As used herein, the terms "treat," "treated," or "treating" refer to a therapeutic agent wherein the objective is to mitigate (lessen) an undesirable physiological condition, disorder, or disease, or to obtain a beneficial or desired clinical outcome. For purposes of the present invention, beneficial or desired clinical outcomes include, but are not limited to, relief of symptoms; reduction in the extent of a condition, disorder, or disease; stabilization (i.e., not worsening) of a condition, disorder, or disease state; delay in the onset or slowing of progression of a condition, disorder, or disease; amelioration of a condition, disorder, or disease state; and remission (whether partial or total), whether detectable or undetectable, or enhancement or improvement of a condition, disorder, or disease. Treatment also includes prolonging survival compared to the expected survival if not receiving treatment. "Treatment" or "treating," when referring to protecting a subject from a disease, means inhibiting, suppressing, ameliorating, or completely eliminating the disease. Preventing a disease includes administering a composition of the present invention to a subject prior to the onset of the disease. Inhibiting a disease includes administering a composition of the present invention to a subject after the induction of the disease but prior to its clinical appearance. Suppressing or ameliorating a disease includes administering the composition of the invention to a subject after clinical manifestation of the disease. The disease may include cancer.

[0077] 2. Phospholipid ethers

[0078] Phospholipid ether (PLE) molecules are provided herein. PLE can be according to formula (I') or a salt thereof:

[0079]

[0080] wherein X is hydrogen, methyl or phenyl substituted by carboxyl.

[0081] In some embodiments, the PLE is selected from the group consisting of:

[0082]

[0083] The PLE can be conjugated to a detectable moiety (also referred to as a reporter or marker), such as a fluorescent molecule, a chemiluminescent molecule, a radioactive label, a magnetic label, an infrared molecule, or a combination thereof. A magnetic label is a labeling moiety that, when fully combined with a magnetic proximity sensor, can be detected by the magnetic proximity sensor and cause the magnetic proximity sensor to output a signal. The magnetic label can include one or more materials selected from paramagnetic, superparamagnetic, ferromagnetic, ferromagnetic, antiferromagnetic materials, combinations thereof, and the like. A fluorescent label is a labeling moiety that can be detected by a fluorescence detector. Suitable fluorescent molecules (fluorophores) include, but are not limited to, fluorescein, fluorescein isothiocyanate, succinimidyl ester of carboxyfluorescein, succinimidyl ester of fluorescein, 5-isomer of dichlorotriazine of fluorescein, caged carboxyfluorescein-alanine-carboxamide, Oregon Green 488, Oregon Green 514; Lucifer Yellow, acridine orange, rhodamine, tetramethylrhodamine, Texas Red, propidium iodide, JC-1 (5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolylcarbocyanine iodide), tetrabromo Rhodamine 123, Rhodamine 6G, TMRM (tetramethylrhodamine methyl ester), TMRE (tetramethylrhodamine ethyl ester), tetramethylrosamine, rhodamine B and 4-dimethylaminotetramethylrosamine, green fluorescent protein, blue-shifted green fluorescent protein, cyan-shifted green fluorescent protein, red-shifted green fluorescent protein, yellow-shifted green fluorescent protein, 4-acetamido-4'-isothiocyanatostilbene-2,2'disulfonicacid; acridine and its derivatives, such as acridine and acridine isothiocyanate; 5-(2'-aminoethyl)aminonaphthalene-1-sulfonic acid (EDANS); 4-amino-N-[3-vinylsulfonyl)phenyl]naphthamide-3,5-disulfonate (4-amino-N-[3-vinylsulfonyl)phenyl]naphthamide-3,5-disulfonate o-aminobenzamide; 4,4-difluoro-5-(2-thienyl)-4-bora-3a,4a diaza-5-indacene-3-propionic acid BODIPY; Cascade Blue; Brilliant Yellow;Coumarin and its derivatives: coumarin, 7-amino-4-methylcoumarin (AMC, coumarin 120), 7-amino-4-trifluoromethylcoumarin (coumarin 151); cyanine dyes; tetrachlorotetrabromofluorescein (cyanosine); 4',6-diaminidino-2-phenylindole (DAPI); 5',5"-dibromopyrogallol-sulfonaphtha lein)(bromopyrophenol red); 7-diethylamino-3-(4'-isothiocyanatophenyl)-4-methylcoumarin; diethylenetriamine pentaacetate; 4,4'-diisothiocyanatodihydro-stilbene-2,2'-disulfonic acid; 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid acid); 5-(dimethylamino)naphthalene-1-sulfonyl chloride (DNS, dansyl chloride); 4-dimethylaminophenylazophenyl-4'-isothiocyanate (DABITC); eosin and its derivatives: eosin, eosin isothiocyanate, erythrosine and its derivatives: erythrosine B, erythrosine, isothiocyanate; ethidium; fluorescein and its derivatives: 5-carboxyfluorescein (FAM), 5-(4,6-dichlorotriazin-2-yl)amino-1-fluorescein (DTAF), 2',7'-dimethoxy-4'5'-dichloro-6-carboxyfluorescein (JOE), fluorescein, fluorescein isothiocyanate, QFITC, (XRITC); fluorescamine; IR144; IR1446; malachite green isothiocyanate; 4-methylumbelli-feroneorthocresolphthalein cresolphthalein); nitrotyrosine; pararosamine; phenol red; B-phycoerythrin; o-phthalaldehyde; pyrene and its derivatives: pyrene, pyrene butyrate, succinimidyl 1-pyrene; butyric acid quantum dots; Reactive Red4 (Cibacron; TMBrilliant Red 3B-A) Rhodamine and its derivatives: 6-carboxy-X-rhodamine (ROX), 6-carboxyrhodamine (R6G), lissamine rhodamine B sulfonyl chloride rhodamine (Rhod), rhodamine B, rhodamine 123, rhodamine X isothiocyanate, sulforhodamine B, sulforhodamine 101, sulfonyl chloride derivatives of sulforhodamine 101 (Texas Red); N,N,N',N'-tetramethyl-6-carboxyrhodamine (TAMRA); tetramethylrhodamine; tetramethylrhodamine isothiocyanate (TRITC); riboflavin; 5-(2'-aminoethyl)aminonaphthalene-1-sulfonic acid (EDANS), 4-(4'-dimethylaminophenylazo)benzoic acid (DABCYL), rhodamine; CAL fluorescent orange 560; derivatives of terbium chelates; CY3; CY 5; Cy5.5; Cy 7; IRD 700; IRD 800; La Jolla Blue; phthalocyanines; and naphthalocyanines, coumarins and related dyes, xanthene dyes such as rhodols, resorufins, bimanes, acridines, isoindole, dansyl dyes, aminophthalic hydrazides such as luminol, and isoluminol derivatives, aminophthalimides, aminonaphthalimides, aminobenzofurans, aminoquinolines, dicyanohydroquinones, fluorescent europium and terbium complexes; combinations thereof, and the like.

[0084] The detectable moiety can be covalently or cleavably linked to the PLE. For example, the labeled PLE can be selected from the following options:

[0085]

[0086]

[0087] The above compound (1) is a PLE (3) having a fluorescent moiety BODIPY stably linked to the PLE, and may also be referred to as CLR 1501. The above compound (2) is a PLE (3) having a near-infrared molecule IR-775 stably linked to the PLE, and may also be referred to as CLR 1502. Compounds (1) and (2) may also be referred to as phospholipid drug conjugates (PDCs).

[0088] PLE or its conjugate can be specific to tumors or cancer cells. After administration to a subject, PLE or its conjugate can be localized to tumors or cancer cells. PLE or its conjugate can be incorporated into more tumors or cancer cells than healthy cells. PLE or its conjugate can be incorporated into tumors or cancer cells at least about 2 times, at least about 3 times, at least about 4 times, at least about 5 times, at least about 6 times, at least about 7 times, at least about 8 times, at least about 9 times, at least about 10 times, at least about 15 times, at least about 20 times, at least about 25 times, at least about 30 times more tumors or cancer cells than healthy cells.

[0089] 3. Phospholipid flavagline conjugate compounds

[0090] PLE can be conjugated to a flavagline compound via a linker to form a phospholipid-flavagline conjugate (also referred to as a PLE-flavagline conjugate).

[0091] In one aspect, the present application provides a compound of formula (I) or a pharmaceutically acceptable salt thereof,

[0092]

[0093]

[0094] wherein Z is a flavagline analog.

[0095] Flavagline is a family of natural products found in plants of Aglaia (Meliaceae). Flavagline is characterized by having a cyclopentadi[b]benzofuran skeleton. Flavagline compounds may have strong insecticidal, antifungal, anti-inflammatory, neuroprotective, cardioprotective and anticancer activities. Flavagline can enhance the efficacy of chemotherapy and / or reduce the cardiac side effects of chemotherapy. Suitable flavagline analogs include, for example, compounds disclosed in U.S. Patent Application Publication US 2018 / 0086729, the contents of which are incorporated herein by reference in their entirety. Flavagline compounds may include, for example, FLV1, FLV3, derivatives or structural analogs thereof, or combinations thereof. As used herein, the term "flavagline analog" or "flavagline anticancer drug" includes all natural and synthetic flavagline compounds, derivatives thereof and structural analogs thereof.

[0096] In some embodiments, the flavagline analog comprises FLV1, or a salt thereof:

[0097]

[0098] In some embodiments, the flavagline analog comprises FLV3, or a salt thereof:

[0099]

[0100] Suitable compounds as disclosed herein include:

[0101]

[0102] (CLR 1899), and

[0103]

[0104] or a pharmaceutically acceptable salt thereof.

[0105] In some embodiments, the compound is

[0106]

[0107] (CLR 1899), or a pharmaceutically acceptable salt thereof.

[0108] Also provided is a conjugate of formula (II) or a salt thereof:

[0109]

[0110] where X is or methylene, or bond; Y is a disulfide-containing linker; and Z is a flavagline anticancer drug. The conjugate compound of formula (II) may also be referred to as a phospholipid drug conjugate (PDC).

[0111] In formula (II), the linker can be a cleavable linker, such as a disulfide, and is specifically designed to deliver flavagline to a tumor or cancer cell. In some embodiments, the linker comprises a disulfide. In some embodiments, the linker comprises the following:

[0112]

[0113] In some embodiments, the phospholipid-flavagline conjugate of formula (II) is selected from the following, or a pharmaceutically acceptable salt thereof:

[0114]

[0115] CLR 1865 (with FLV1) (8), and

[0116]

[0117] CLR 1852 (with FLV3) (9).

[0118] Compounds as described herein may exist as stereoisomers, wherein there is an asymmetric or chiral center. A stereoisomer is either "R" or "S", depending on the configuration of the substituents around the chiral carbon atom. The terms "R" and "S" used herein are configurations defined in IUPAC 1974 Recommendations for Section E, Fundamental Stereochemistry, Pure Appl. Chem., 1976, 45, 13-30. Various stereoisomers and mixtures thereof are encompassed by the present disclosure, and these are specifically included within the scope of the present invention. Stereoisomers include enantiomers and diastereomers, as well as mixtures of enantiomers or diastereomers. Individual stereoisomers of a compound may be synthesized from commercially available starting materials containing an asymmetric or chiral center, or by preparing a racemic mixture and then using resolution methods well known to those of ordinary skill in the art. Examples of these resolution methods include (1) attaching the enantiomeric mixture to a chiral auxiliary, separating the resulting diastereomeric mixture by recrystallization or chromatography, and optionally liberating the optically pure product from the auxiliary, as described in Furniss, Hannaford, Smith and Tatchell, "Vogel's Textbook of Practical Organic Chemistry", 5th edition (1989), Longman Scientific & Technical, Essex CM20 2JE, England, or (2) directly separating the optical enantiomeric mixture on a chiral chromatographic column, or (3) fractional recrystallization. It should be understood that the compounds described herein may include tautomeric forms as well as geometric isomers, and that these isomers also constitute embodiments of the present disclosure. The compounds described herein may exist as racemic mixtures.

[0119] The present invention also includes isotopically labeled compounds, such as isotopically labeled PLE, isotopically labeled flavagline, isotopically labeled linker or isotopically labeled phospholipid-flavagline conjugate. Isotopically labeled compounds are identical to the compounds detailed herein except that one or more atoms are replaced by atoms having an atomic mass or mass number different from the atomic mass or mass number usually found in nature. Examples of isotopes suitable for inclusion in the compounds of the present invention are hydrogen, carbon, nitrogen, oxygen, phosphorus, sulfur, fluorine and chlorine, such as but not limited to 2 H. 3 H. 13 C. 14 C. 15 N. 18 O. 17 O. 31 P. 32P. 35 S. 18 F and 36 Cl. Using heavier isotopes such as deuterium, i.e. 2 H, substitution may offer certain therapeutic advantages resulting from greater metabolic stability, such as increased in vivo half-life or reduced dosage requirements, and may therefore be preferred in certain circumstances. The compound may contain a positron emitting isotope for use in medical imaging and in positron emission tomography (PET) studies for determining receptor distribution. Suitable positron emitting isotopes that may be incorporated into the compound are 11 C. 13 N. 15 O and 18 F. Isotopically labeled compounds 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, using an appropriate isotopically labeled reagent in place of a non-isotopically labeled reagent.

[0120] The disclosed PLE or phospholipid-flavagline conjugates may exist as pharmaceutically acceptable salts. The term "pharmaceutically acceptable salt" refers to a salt or zwitterion of a compound that is water-soluble or oil-soluble or dispersible, suitable for treating a disorder without excessive toxicity, irritation and allergic reaction, commensurate with a reasonable benefit / risk ratio, and effective for its intended use. Salts can be prepared during the final isolation and purification of the compound, or prepared separately by reacting the amino group of the compound with a suitable acid. For example, the compound can be dissolved in a suitable solvent, such as, but not limited to, methanol and water, and treated with at least one equivalent of an acid, such as hydrochloric acid. The resulting salt can be precipitated and separated by filtration and dried under reduced pressure. Alternatively, the solvent and excess acid can be removed under reduced pressure to provide a salt. Representative salts include acetate, adipate, alginate, citrate, aspartate, benzoate, benzenesulfonate, bisulfate, butyrate, camphorate, camphorsulfonate, digluconate, glycerophosphate, hemisulfate, heptanoate, hexanoate, formate, isethionate, fumarate, lactate, maleate, methanesulfonate, naphthylsulfonate, nicotinate, oxalate, pamoate, pectinate, persulfate, 3-phenylpropionate, picrate, oxalate, maleate, pivalate, propionate, succinate, tartrate, trichloroacetate, trifluoroacetate, glutamate, p-toluenesulfonate, undecanoate, hydrochloric acid, hydrobromic acid, sulfuric acid, phosphoric acid, etc. The amino groups of the compounds can also be quaternized with alkyl chlorides, bromides and iodides such as methyl, ethyl, propyl, isopropyl, butyl, lauryl, myristyl, stearyl, etc.

[0121] Basic addition salts can be prepared by reaction of a carboxyl group with a suitable base, such as a metal cation, such as a hydroxide, carbonate or bicarbonate of lithium, sodium, potassium, calcium, magnesium or aluminum, or an organic primary, secondary or tertiary amine, during the final separation and purification of the disclosed compounds. Quaternary ammonium salts can be prepared, for example, derived from methylamine, dimethylamine, trimethylamine, triethylamine, diethylamine, ethylamine, tributylamine, pyridine, N,N-dimethylaniline, N-methylpiperidine, N-methylmorpholine, dicyclohexylamine, procaine, dibenzylamine, N,N-dibenzylphenethylamine, 1-phenethylamine (1-ephenamine) and N,N'-dibenzylethylenediamine, ethylenediamine, ethanolamine, diethanolamine, piperidine, piperazine, and the like.

[0122] Phospholipid-flavagline conjugate compounds as described herein can be specific to tumors or cancer cells. After being administered to a subject, the compound can be localized to a tumor or cancer cell. These compounds can be localized or moved to the cytoplasm or organelles of a tumor or cancer cell. These compounds can be incorporated into more tumors or cancer cells than healthy cells. The compound can be incorporated into tumors or cancer cells that are at least about 2 times, at least about 3 times, at least about 4 times, at least about 5 times, at least about 6 times, at least about 7 times, at least about 8 times, at least about 9 times, at least about 10 times, at least about 15 times, at least about 20 times, at least about 25 times, at least about 30 times more than healthy cells.

[0123] Flavagline or a flavagline analog can be cleaved from the compounds of the invention, for example, in vivo after administration to a subject. Flavagline or a flavagline analog can be localized or travel to the cytoplasm or organelles of a tumor or cancer cell. Flavagline or a flavagline analog can be incorporated into more tumors or cancer cells than healthy cells. Flavagline or a flavagline analog can be incorporated into tumors or cancer cells that are at least about 2 times, at least about 3 times, at least about 4 times, at least about 5 times, at least about 6 times, at least about 7 times, at least about 8 times, at least about 9 times, at least about 10 times, at least about 15 times, at least about 20 times, at least about 25 times, at least about 30 times more than healthy cells.

[0124] The compounds described herein can be synthesized according to the methods described in Example 1 or other methods known in the art. The synthesis process may include steps for preparing the PLE portion, the flavagline analog portion, and the complete compound as shown in Example 1. Suitable flavaglines include commercially available products, such as those from Haoyuan Chemexpress Co. (Shanghai, China).

[0125] 4. Pharmaceutical Composition

[0126] The compounds described herein or their pharmaceutically acceptable salts can be formulated into pharmaceutical compositions according to standard techniques well known to those skilled in the art of pharmaceuticals. In one aspect, the present disclosure provides a pharmaceutical composition comprising a compound as described herein, or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier. As used herein, the term "pharmaceutically acceptable carrier" refers to any type of non-toxic, inert solid, semi-solid or liquid filler, diluent, encapsulating material or formulation adjuvant.

[0127] The form of the route of administration of the compounds of the present invention and the composition will determine the type of carrier used. The pharmaceutical composition can be in various forms, such as being suitable for systemic administration (e.g., oral, rectal, sublingual, oral, implant, intranasal, intravaginal, transdermal, intravenous, intraarterial, intratumoral, intraperitoneal or parenteral) or topical administration (e.g., skin, lung, nose, ear, eye, liposome delivery system or iontophoresis). In some embodiments, the pharmaceutical composition is used to be applied to the central nervous system of the subject. Technology and formulations can generally be found in "Remington's Pharmaceutical Sciences" (Meade Publishing Co., Easton, Pa.). The pharmaceutical composition must generally be sterile and stable under manufacturing and storage conditions. All carriers are optional in the composition.

[0128] Pharmaceutically acceptable carriers include, for example, diluents, lubricants, binders, disintegrants, colorants, flavorings, sweeteners, antioxidants, preservatives, glidants, solvents, suspending agents, wetting agents, surfactants, emollients, propellants, humectants, powders, pH adjusters, and combinations thereof.

[0129] Some examples of materials that can be used as pharmaceutically acceptable carriers include, but are not limited to, ion exchangers, alumina, aluminum stearate, lecithin, serum proteins (such as human serum albumin), buffer substances (such as phosphates), glycine, sorbic acid or potassium sorbate, partial glyceride mixtures of saturated vegetable fatty acids, water, salts or electrolytes (such as protamine sulfate, disodium hydrogen phosphate, potassium hydrogen phosphate, sodium chloride, zinc salts), colloidal silicon dioxide, magnesium trisilicate, polyvinyl pyrrolidone, polyacrylates, waxes, polyethylene polyoxypropylene block polymers, lanolin, sugars (such as lactose, glucose, sucrose), starches (such as corn starch, potato starch), powder), cellulose and its derivatives (such as sodium carboxymethylcellulose, ethylcellulose, cellulose acetate), tragacanth powder, malt, gelatin, talc, excipients (such as cocoa butter and suppository wax), oils (such as peanut oil, cottonseed oil, safflower oil, sesame oil, olive oil, corn oil, soybean oil), glycols (such as propylene glycol or polyethylene glycol), esters (such as ethyl oleate and ethyl laurate), agar, non-toxic compatible lubricants (such as sodium lauryl sulfate and magnesium stearate), colorants, release agents, coating agents, emulsifiers, sweeteners, flavoring agents, fragrances, preservatives, antioxidants, etc. may also be present in the composition according to the judgment of the formulator.

[0130] Although the amount of the components in the composition can vary depending on the type of composition being prepared, in general, systemic compositions can include 0.01% to 50% of the compound (e.g., PLE or phospholipid-flavagline conjugate) and 50% to 99.99% of one or more carriers. Compositions for parenteral administration can typically include 0.1% to 10% of the compound and 90% to 99.9% of one or more carriers. Oral dosage forms can include, for example, at least about 5%, or about 25% to about 50% of the compound. Oral dosage compositions can include about 50% to about 95% of the carrier, or about 50% to about 75% of the carrier. The amount of the carrier used in conjunction with the disclosed compound is sufficient to provide a practical amount of the composition for administration of the compound per unit dose. Techniques and compositions for preparing dosage forms useful in the methods of the present invention are described in the following references: Modern Pharmaceutics, Chapters 9 and 10, Banker & Rhodes, eds. (1979); Lieberman et al., Pharmaceutical Dosage Forms: Tablets (1981); and Ansel, Introduction to Pharmaceutical Dosage Forms, 2nd Edition, (1976).

[0131] In some embodiments, the pharmaceutical composition consists essentially of a therapeutically effective amount of a compound disclosed herein, or a pharmaceutically acceptable salt thereof.

[0132] Liquid dosage forms include, but are not limited to, pharmaceutically acceptable emulsions, microemulsions, solutions, suspensions, syrups and elixirs. Solid dosage forms include, but are not limited to, capsules, tablets, pills, powders, cements, putties and granules. Dosage forms for topical or transdermal administration of the compounds of the invention include, but are not limited to, ointments, pastes, creams, lotions, gels, powders, solutions, sprays, inhalants or patches.

[0133] The liquid carrier or vehicle can be a solvent or liquid dispersion medium including, for example, water, ethanol, polyol (eg, glycerol, propylene glycol, liquid polyethylene glycol, etc.), vegetable oils, non-toxic glycerides, and suitable mixtures thereof.

[0134] The pharmaceutical composition can be a dosage form suitable for injection or infusion, such as a sterile aqueous solution or dispersion or a sterile powder containing an active ingredient, which is suitable for the extemporaneous preparation of sterile injectable or infusible solutions or dispersions. The final dosage form should be sterile, mobile and stable under production and storage conditions. Sterile injectable solutions can be prepared by at least incorporating a compound disclosed herein or a pharmaceutically acceptable salt thereof in a suitable solvent with a desired amount of a suitable solvent and various other desired ingredients as required, optionally followed by filtration sterilization. In the case of a sterile powder for the preparation of a sterile injectable solution, the preparation method can include vacuum drying and freeze drying techniques, which produce one or more active ingredient powders plus any other desired ingredients present in the sterile solution.

[0135] In some embodiments, the composition is a solution, such as a solution suitable for administration by infusion or injection. The solution can be prepared in water, optionally mixed with a non-toxic surfactant. Dispersions can also be prepared in glycerol, liquid polyethylene glycol, triacetin and mixtures thereof, and oils. These preparations may contain preservatives to prevent microbial growth. The effects of microorganisms can be prevented by various antibacterial and antifungal agents, such as parabens, chlorobutanol, phenol, sorbic acid, thimerosal, etc.

[0136] Injectable forms can be prepared by forming a microencapsulation matrix of the compounds disclosed herein or their pharmaceutically acceptable salts in a biodegradable polymer such as polylactide-polyglycolide. Depending on the ratio of compound to polymer and the properties of the particular polymer used, the rate of drug release can be controlled. Examples of other biodegradable polymers include poly(orthoesters) and poly(anhydrides). Injectable formulations can also be prepared by embedding the drug in liposomes or microemulsions that are compatible with body tissues.

[0137] In some embodiments, compositions may include at least one compound as described herein and at least one additional anticancer agent. Anticancer drugs that can be used in the present disclosure include, but are not limited to, paclitaxel, irinotecan, topotecan, gemcitabine, cisplatin, geldanamycin, mertansine, abiraterone, afatinib, aminolevulinic acid, aprepitant, axitinib, azacitidine, belinostat, bendamustine, bexarotene, bleomycin, bortezomib, bosutinib, busulfan, cabazitazel, cabozantinib, capecitabine, carboplatin, carfilzomib, carmustine, ceritinib, cetuximab, chlorambucil, clofarabine, crizotinib, cyclophosphamide, cytarabine, dabrafenib, dacarbazine, dactinomycin, dasatinib, daunorubicin, decitabine, denosumab, dexrazoxane, docetaxel, dolastatins (e.g., monomethyl auristatin E), doxorubicin, enzalutamide, epirubicin, eribulin mesylate, erlotinib, etoposide, everolimus, floxuridine, fludarabine phosphate, fluorouracil, ganetespib, gefitinib, gemtuzumab ozogamicin, hexamethylmelamine, hydroxyurea, ibritumomab tiuxetan, ibrutinib, idelalisib, ifosfamide, imatinib, ipilimumab, ixabepilone, lapatinib, folinate, lomustine, maytansinoids, mesna, melphalan, mercaptopurine, mesna, methotrexate, mitomycin C, mitotane, mitoxantrone, nelarabine, nelfinavir, nilotinib, obinutuzumab, ofatumumab, omacetaxine mepesuccinate, oxaliplatin, panitumumab, pazopanib, pegaspargase, pembrolizumab, pemetrexed, pentosatatin, pertuzumab, plicamycin, pomalidomide, ponatinib hydrochloride, pralatrexate, procarbazine, radium-223 dichloride, ramucirumab, regorafenib, retaspimycin, ruxolitinib, methylcyclohexylnitrosourea, sutuximab, sorafenib, streptozotocin, sunitinib malate, tanespimycin, temozolomide, limus, teniposide, thalidomide, thioguanine, thiotepa, toremifene, trametinib, trastuzumab, vandetanib, vemurafenib, vinblastine, vincristine, vinorelbine, vismodegib, vorinostat, and aflibercept.Any compound currently known or capable of acting as an anticancer drug may also be used in the present disclosure.

[0138] 5. Drug administration

[0139] The compounds described herein or their pharmaceutically acceptable salts or pharmaceutical compositions described herein can be administered to a subject. Taking into account factors such as the age, sex, weight and condition of a particular subject and the route of administration, the compounds and compositions can be administered in dosages and techniques known to those skilled in the medical field.

[0140] The compounds and compositions of the present invention can be administered prophylactically or therapeutically. In prophylactic administration, the compounds and compositions can be administered in an effective amount to induce a prophylactic response. In therapeutic applications, an effective amount of the compounds and compositions can be administered to a subject in need to induce a therapeutic effect.

[0141] For example, a therapeutically effective amount of the compound can be from about 1 mg / kg to about 1000 mg / kg, from about 5 mg / kg to about 950 mg / kg, from about 10 mg / kg to about 900 mg / kg, from about 15 mg / kg to about 850 mg / kg, from about 20 mg / kg to about 800 mg / kg, from about 25 mg / kg to about 750 mg / kg, from about 30 mg / kg to about 700 mg / kg, from about 35 mg / kg to about 650 mg / kg, from about 40 mg / kg to about 600 mg / kg, from about 4 5 mg / kg to about 550 mg / kg, about 50 mg / kg to about 500 mg / kg, about 55 mg / kg to about 450 mg / kg, about 60 mg / kg to about 400 mg / kg, about 65 mg / kg to about 350 mg / kg, about 70 mg / kg to about 300 mg / kg, about 75 mg / kg to about 250 mg / kg, about 80 mg / kg to about 200 mg / kg, about 85 mg / kg to about 150 mg / kg and about 90 mg / kg to about 100 mg / kg.

[0142] The compounds can be administered by methods well known in the art, such as those described in Donnelly et al. (Ann. Rev. Immunol. 1997, 15, 617-648); Felgner et al. (U.S. Pat. No. 5,580,859, issued Dec. 3, 1996); Felgner (U.S. Pat. No. 5,703,055, issued Dec. 30, 1997); and Carson et al. (U.S. Pat. No. 5,679,647, issued Oct. 21, 1997), all of which are incorporated herein by reference in their entirety. The compounds can be compounded into particles or beads, which can be administered to an individual, for example, using a vaccine gun. Those skilled in the art will appreciate that the choice of a pharmaceutically acceptable carrier includes a physiologically acceptable compound, depending on, for example, the route of administration.

[0143] Compounds can be delivered by a variety of routes. Typical delivery routes include parenteral administration, such as intradermal, intramuscular or subcutaneous delivery. Other routes include oral, intranasal, intravaginal, transdermal, intravenous, intraarterial, intratumoral, intraperitoneal and epidermal routes. In some embodiments, the compound is administered to the subject intravenously, intraarterially or intraperitoneally. In some embodiments, the compound is administered to the subject intravenously. In some embodiments, the compound is administered orally to the subject.

[0144] In some embodiments, the compound is administered in a controlled release formulation. For example, the compound can be released into the circulation. In some embodiments, the compound can be released over a period of at least about 1 day, at least about 2 days, at least about 3 days, at least about 4 days, at least about 5 days, at least about 6 days, at least about 7 days, at least about 1 week, at least about 1.5 weeks, at least about 2 weeks, at least about 2.5 weeks, at least about 3.5 weeks, at least about 4 weeks, or at least about 1 month.

[0145] The compound can be administered in a single dose or in intermittent or repeated doses. For example, the compound can be administered once every hour, 2 hours, 4 hours, 8 hours, 12 hours, 25 hours, 36 hours, 2 days, 3 days, 4 days, 5 days, 6 days, 1 week, 2 weeks, 3 weeks or 4 weeks.

[0146] 6. Methods

[0147] The basis of the selective tumor targeting of the compounds described herein lies in the difference between the plasma membrane of cancer cells and the plasma membrane of most normal cells. Phospholipid ether (PLE) molecules use the metabolic shifts experienced by tumor cells to generate the energy required for rapid cell division. Tumors enhance the ability to convert long-chain fatty acids (LCFA) into energy using the β-oxidation pathway. In order to increase the uptake of LCFA, tumor cells change the cell membrane to form special microdomains called "lipid rafts". Due to metabolic changes and the demand for phospholipids, lipid rafts are formed. In tumor cells, these areas have become excessive and stable, making them potential tumor-specific targets. Specifically, cancer cell membranes are highly enriched in lipid rafts. In normal tissues, the presence of lipid rafts is limited and short-lived (about 2 nanoseconds). In tumors, the presence of lipid rafts increases and stabilizes (up to 10 days). Cancer cells have five to ten times more lipid rafts than healthy cells. In addition, lipid rafts have been shown to be very abundant in almost all tumor types and 100% of the individual cancer cells tested. Lipid rafts are highly organized and specialized regions of the membrane phospholipid bilayer that contain high concentrations of various signaling molecules, sphingolipids, glycosphingolipids, and cholesterol and serve to organize cell surface and intracellular signaling molecules (e.g., growth factor and cytokine receptors, phosphatidylinositol 3-kinase (PI3K) / Akt survival pathway). The data suggest that lipid rafts serve as a portal for phospholipid ethers. The remarkable selectivity of these compounds for cancer cells relative to non-cancerous cells is attributed to the high affinity of PLE for cholesterol and the cholesterol-rich lipid rafts in cancer cells. The fact that disruption of lipid raft structure inhibits the uptake of PLE by cancer cells highlights the critical role played by lipid rafts. It has been shown that when lipid rafts are prevented from forming, the uptake of PLE is reduced by 60%. These features, combined with lipid rafts that provide rapid internalization of phospholipid drug conjugates, make them ideal targets.

[0148] Compounds disclosed herein, such as PLE analogs, can be LCFA mimetics. Molecules disclosed herein have been subjected to extensive structure activity relationship (SAR) analysis related to lipid rafts on targeted tumor cells and have been shown to bind specifically to these regions. Molecules disclosed herein provide direct access to the cytoplasm and transport to the endoplasmic reticulum and mitochondria along the Golgi network within the cytoplasm. In some embodiments, compounds disclosed herein include uniquely designed phospholipid ethers conjugated to flavagline (FLV) analogs. FLV is an effective cytotoxin that inhibits translation, cell cycle progression, and induces apoptosis.

[0149] The compounds as described herein or their pharmaceutically acceptable salts or compositions comprising the compounds as described herein can be used to treat cancer. In one aspect, a method of treating cancer in a subject in need thereof is provided, comprising administering to the subject an effective amount of a compound as described herein, or its pharmaceutically acceptable salt, or a composition comprising a compound as described herein.

[0150] In another aspect, the present disclosure provides use of a compound as described herein, or a pharmaceutically acceptable salt thereof, for treating cancer in a subject in need thereof.

[0151] In another aspect, the present disclosure provides use of a compound as described herein, or a pharmaceutically acceptable salt thereof, in the preparation of a medicament for treating cancer in a subject in need thereof.

[0152] In one aspect, the present disclosure provides a method of targeting a drug to a tumor or cancer cell in a subject, the method comprising administering to the subject a compound as described herein, or a pharmaceutically acceptable salt thereof, or a composition comprising a compound as described herein. Targeting can result in targeted delivery of the compounds of the present invention to cancer cells and / or targeted treatment of cancer.

[0153] In some embodiments, the compound or a pharmaceutically acceptable salt thereof localizes or travels to the cytoplasm or organelles of a tumor or cancer cell.

[0154] In some embodiments, the compound or a pharmaceutically acceptable salt thereof is selective for cancer cells in a subject.

[0155] In some embodiments, the compound or a pharmaceutically acceptable salt thereof is incorporated into at least about 2 times more tumor or cancer cells than healthy cells. The compound or a pharmaceutically acceptable salt thereof can be incorporated into at least about 2 times, at least about 3 times, at least about 4 times, at least about 5 times, at least about 6 times, at least about 7 times, at least about 8 times, at least about 9 times, at least about 10 times, at least about 15 times, at least about 20 times, at least about 25 times, at least about 30 times more tumor or cancer cells than healthy cells.

[0156] Cancers that may be treated with the compounds described herein, or pharmaceutically acceptable salts thereof, or compositions comprising the compounds described herein include, but are not limited to: breast cancer, male breast cancer digestive / gastrointestinal cancer, including anal cancer, appendix cancer, extrahepatic bile duct cancer, gastrointestinal carcinoid tumors, colon cancer, esophageal cancer, gallbladder cancer, gastric cancer, gastrointestinal stromal tumors ("gist"), islet cell tumors, primary liver cancer in adults, liver cancer in children, pancreatic cancer, rectal cancer, small intestine cancer, and gastric cancer; endocrine and neuroendocrine cancer, including pancreatic adenocarcinoma, adrenocortical carcinoma, pancreatic neuroendocrine tumors, Merkel cell carcinoma, non-small cell lung neuroendocrine tumors, small cell lung neuroendocrine tumors, parathyroid cancer, pheochromocytoma, pituitary tumors, and thyroid cancer; eye cancer, including intraocular melanoma and retinoblastoma; genitourinary cancer, including bladder cancer, kidney (renal cell) cancer, penile cancer, prostate cancer, transitional cell renal pelvis and ureter cancer, testicular cancer, urethral cancer, and Wilms' tumor Germ cell cancers, including childhood central nervous system cancers, childhood extracranial germ cell tumors, extragonadal germ cell tumors, ovarian germ cell tumors, and testicular cancer; gynecological cancers, including cervical cancer, endometrial cancer, gestational trophoblastic tumors, ovarian epithelial cancer, ovarian germ cell tumors, uterine sarcomas, vaginal cancer, and vulvar cancer; head and neck cancers, including hypopharyngeal cancer, laryngeal cancer, lip cancer, and oral cancer, occult primary metastatic squamous neck cancer, oral cancer, nasopharyngeal cancer, oropharyngeal cancer, sinus and nasal cavity cancer, and thyroid cancer. cancer of the parathyroid gland, pharynx, salivary gland, and larynx; leukemias, including acute lymphocytic leukemia in adults, acute lymphocytic leukemia in children, acute myeloid leukemia in adults, acute myeloid leukemia in children, chronic lymphocytic leukemia, chronic myeloid leukemia, and hairy cell leukemia; lymphomas, including AIDS-related lymphoma, cutaneous T-cell lymphoma, Hodgkin's lymphoma in adults, Hodgkin's lymphoma in children, Hodgkin's lymphoma during pregnancy, Alibel's disease (mycosis fungoides), non-Hodgkin's lymphoma in adults, non-Hodgkin's lymphoma in children, non-Hodgkin's lymphoma during pregnancy, primary central nervous system lymphoma, Sézary syndrome, and Macroglobulinemia; musculoskeletal cancer, including Ewing sarcoma, osteosarcoma and malignant bone fibrous histiocytoma, childhood rhabdomyosarcoma and soft tissue sarcoma; nervous system cancer, including adult brain tumor, childhood brain tumor, astrocytoma, brain stem glioma, central nervous system atypical malformation / rhabdoid tumor, central nervous system embryonal tumor, craniopharyngioma, ependymoma, neuroblastoma, primary central nervous system (CNS) lymphoma; respiratory tract / thoracic cancer, including non-small cell lung cancer, small cell lung cancer, malignant mesothelioma, thymoma and thymic carcinoma; and skin cancer, including Kaposi's sarcoma, melanoma and squamous cell carcinoma. In specific embodiments, the cancer can be melanoma, lung cancer, colorectal cancer, breast cancer or a combination thereof.

[0157] In some embodiments, the cancer is melanoma, brain cancer, lung cancer, adrenal cancer, liver cancer, kidney cancer or renal cancer, pancreatic cancer, esophageal cancer, stomach cancer, gastric cancer, colon cancer, colorectal cancer, anal cancer, prostate cancer, ovarian cancer, breast cancer, cervical cancer, lymphoma, leukemia, myeloma, blood cancer, liver cancer, retinoblastoma, glioma, sarcoma, blastoma, squamous cell carcinoma, adenocarcinoma, or a combination thereof. In some embodiments, the cancer is melanoma, lung cancer, colorectal cancer, breast cancer, or a combination thereof.

[0158] In some embodiments, the cancer may comprise one or more circulating tumor cells. For example, the one or more circulating tumor cells may be selected from breast cancer, lung cancer, thyroid cancer, cervical cancer, melanoma, squamous cell carcinoma, prostate cancer, pancreatic cancer, colorectal cancer, cancer stem cells, and malignant plasma cells.

[0159] In some embodiments, the cancer may be metastatic. For example, the metastatic cancer may be selected from the group consisting of breast cancer, lung cancer, melanoma, and colorectal cancer.

[0160] In some embodiments, the cancer may include cancer stem cells. For example, the cancer stem cells may be selected from breast cancer, lung cancer, melanoma, and colorectal cancer.

[0161] In some embodiments, the lung cancer may include small cell lung cancer, non-small cell lung cancer, or a combination thereof.

[0162] In some embodiments, the melanoma can include superficial spreading melanoma, nodular melanoma, lentigo maligna melanoma, acral lentigo melanoma, amelanotic melanoma, pyomelanoma, spitzoid melanoma, desmoplastic melanoma, or a combination thereof.

[0163] In some embodiments, the colorectal cancer comprises adenocarcinoma.

[0164] In some embodiments, the breast cancer may include invasive ductal carcinoma, metastatic breast cancer, inflammatory breast cancer, triple negative breast cancer, ductal carcinoma in situ, or a combination thereof. In some embodiments, the cancer is breast cancer, and the subject may be estrogen receptor positive, estrogen receptor negative and progesterone receptor negative, express HER2 (HER2+), do not express HER2 (HER2-), or a combination thereof.

[0165] In some embodiments, the subject is a human, such as an adult or infant. In some embodiments, the subject is an animal, such as a mammal.

[0166] The method may include administering a compound of the invention or a pharmaceutically acceptable salt thereof in an amount as described herein. In some embodiments, the method includes administering about 0.0001 to about 1000 mg / kg of a compound as described herein, or administering a pharmaceutically acceptable salt thereof. The available dose of the compound may be determined by comparing their in vitro activity and in vivo activity in its animal model. Methods for extrapolating effective doses of rodents, pigs, and other animals to humans are known in the art; for example, see U.S. Patent No. 4,938,949.

[0167] In some embodiments, the compounds disclosed herein or their pharmaceutically acceptable salts or pharmaceutical compositions can be administered by oral administration or intravenous administration. However, in general, suitable dosages are generally in the range of about 0.0001 mg / kg to about 1000 mg / kg, for example, about 0.001 mg / kg to about 10.0 mg / kg. For example, suitable dosages can be in the range of about 0.001 mg / kg to about 5.0 mg / kg body weight per day, for example, about 0.01 mg / kg to about 1.0 mg / kg recipient body weight per day, about 0.01 mg / kg to about 3.0 mg / kg recipient body weight per day, about 0.1 mg / kg to about 5.0 mg / kg recipient body weight per day, about 0.2 mg / kg to 4.0 mg / kg recipient body weight per day. The compound can be administered in unit dosage form; for example, each unit dosage form contains 1 to 100 mg, 10 to 100 mg, or 5 to 50 mg of active ingredient.

[0168] The desired dose may conveniently be presented as a single dose or as divided doses administered at appropriate intervals, for example, as two, three, four or more sub-doses per day. The sub-dose itself may be further divided, for example, into a number of discrete, loosely spaced administrations.

[0169] Suitable in vivo dosages and specific modes of administration may vary depending on age, body weight, severity of disease and species of mammals being treated, specific compounds used and specific uses of these compounds. Effective dosage levels to achieve the desired results can be determined by known methods, such as human clinical trials, in vivo studies and in vitro studies. For example, the effective dose of a compound disclosed herein or a pharmaceutically acceptable salt thereof can be determined by comparing their in vitro activity and in vivo activity in an animal model. This comparison can be accomplished by comparison with established drugs.

[0170] Dosage and interval can be adjusted individually to provide plasma levels of the active portion sufficient to maintain the modulatory effect or minimum effective concentration (MEC). The MEC for each compound will vary, but can be estimated based on in vivo and / or in vitro data. The dose required to reach the MEC will depend on individual characteristics and route of administration. However, FIPLC assays or bioassays can be used to determine plasma concentrations. Dosage intervals can also be determined using MEC values. The composition should be administered using a regimen that maintains plasma levels 10-90%, preferably 30-90%, and most preferably 50-90% above the MEC. In the case of local administration or selective uptake, the effective local concentration of the drug may be independent of the plasma concentration.

[0171] The compositions described herein can be administered with additional compositions to extend the stability, delivery and / or activity of the compositions, or in combination with additional therapeutic agents, or provided before or after administration of additional therapeutic agents. Combination therapy includes administration of a single pharmaceutical dosage form containing one or more compounds described herein and one or more additional agents, as well as administration of the compound and each additional agent in its own separate pharmaceutical dosage form. For example, the compounds described herein can be administered to a subject together with additional anticancer agents described herein.

[0172] 7. Examples

[0173] Example 1

[0174] Chemical synthesis

[0175] PLE. PLE was synthesized according to Scheme 1 below:

[0176]

[0177] Solution 1

[0178] Flavagline compounds. Flavagline is commercially available. FLV1 and FLV3 were purchased from Haoyuan Chemexpress Co. (Shanghai, China). FLV1 and FLV3 were synthesized alternately according to the following scheme 2:

[0179]

[0180]

[0181] Solution 2

[0182] PLE-flavagline constructs. CLR 1852 (compound (9)) and CLR 1865 (compound (8)) were synthesized according to the following Scheme 3:

[0183]

[0184] Solution 3

[0185] Synthesis of CLR 1899. CLR 1899 was synthesized according to Scheme 4. The structure was verified by NMR and MS data.

[0186]

[0187] Solution 4

[0188] Example 2

[0189] Presence of lipid rafts in tumor cells

[0190] More than 100 cell lines were stained with cholera toxin subunit B, fixed with 4% formaldehyde, and stained with filipin III for 30 minutes. Figure 1A-Figure 1D As shown, almost all tumor types tested show high lipid raft concentrations in the cell membrane (over 100 cell lines, fresh patient samples, etc.). Figure 1E As shown, A549 cells were co-cultured with normal fibroblasts for 48 hours, then stained with cholera toxin subunit B, fixed with 4% formaldehyde, and stained with filipin III for 30 minutes. These results indicate that tumor cells have a higher concentration of lipid rafts than normal cells.

[0191] Example 3

[0192] PDC selectively takes up tumor cells

[0193] Normal fibroblasts and Caki-2 tumor cells (human clear cell renal cell carcinoma) were plated and co-cultured overnight ( Figure 1F ). The cells were then incubated with 5 μM CLR1501 (compound (1)) in complete medium at 37°C for 24 hours. The next day the cells were washed and co-stained with a nuclear stain (Hoescht 33342). CLR 1501 was excited and then detected using an Alexa-Fluor 488 filter. CLR 1501 was highly localized in Caki-2 cells and minimally in normal fibroblasts.

[0194] Example 4

[0195] Disruption of lipid rafts reduces PDC uptake

[0196] A549 cells were plated overnight into individual wells. The next day, cells were either left untreated ( Figure 1G ), or methyl β-cyclodextrin ( Figure 1H) treatment, methyl β-cyclodextrin has been shown to selectively disrupt lipid rafts. All cells were then incubated with 5 μM CLR1501 (compound (1)) for 24 hours. Figure 1G ), disrupting most lipid rafts in A549 cells resulted in CLR 1501 ( Figure 1H ) intake was reduced by 60%.

[0197] Example 5

[0198] PDC tracks to the endoplasmic reticulum

[0199] Human prostate adenocarcinoma cells (PC3) were plated overnight on microtiter plates VI (Ibidi, Verona, WI) and then incubated with 5 μM CLR1501 (compound (1)) in complete medium at 37°C for 24 hours. After washing, each protocol was performed using Cells were co-stained and imaged using a Nikon A1R confocal light microscope. CLR1501 and ER were excited and detected using Alexa-Fluor 488 using a standard fluorescein filter. CLR 1501 co-localizes with ER in malignant tumors ( Figure 1I-1K ), but not co-localized with normal cells (not shown).

[0200] Example 6

[0201] PDC tracks to the endoplasmic reticulum

[0202] PC3 (grade IV, human prostate adenocarcinoma cell line) cells were cultured overnight on microslides VI (Ibidi, Verona, WI). The next day, cells were incubated with 5 μM CLR1501 (compound (1)) in complete medium at 37°C for 24 h. The next day, after washing with PBS, cells were stained with a nuclear dye (Hoechst 33342) and a mitochondrial marker. (Invitrogen, Carlsbad, CA) were used to co-stain the cells. The cells were observed using a Nikon A1R confocal microscope. CLR 1501 was excited and detected using an Alexa-Fluor 488 filter, while nuclear staining and mitochondrial staining were excited and detected using a DAPI filter and a Texas-Red filter, respectively. Figure 1L-Figure 1N ).

[0203] Example 7

[0204] PDC provides targeted delivery in vivo

[0205] Nude mice bearing colorectal (HCT-116) tumors were injected with 1 mg of CLR 1502 (compound (2)) and imaged on a Pearl infrared imaging system. The different colors reflect the intensity of CLR 1502 over time. About 5.5 hours after injection, the tumor was still red (reflecting the highest distribution of CLR 1502) ( Figure 2 ). Within 24 hours, the maximum distribution of CLR 1502 was obtained. The initial target was recorded within 30 minutes (not shown).

[0206] Example 8

[0207] Cytotoxic PDCs offer targeted and potentially improved therapeutic index

[0208] A549 (human lung adenocarcinoma) cells and normal human dermal fibroblasts (NHDF) were plated overnight in 96-well culture dishes. All cells were treated with increasing concentrations of either the parent cytotoxic compound (FLV1 or FLV3) or PDC (the parent cytotoxic compound conjugated to the PLE moiety via a cleavable linker, CLR 1865 (compound (8)) or CLR 1852 (compound (9))) alone. The parent cytotoxic compound showed almost the same potency against A549 cells as against NHDF cells. However, the PDC molecule showed selectivity against A549 cells ( Figure 3 ). The PDC molecule showed little effect on NHDF cells until the highest concentration and approached the potency of the parent molecule in A549 cells. The difference between the cytotoxicity of the PDC molecule against tumor cells and normal cells may indicate the potential to improve the therapeutic index of the parent molecule.

[0209] Example 9

[0210] Cytotoxic PDCs provide targeted

[0211] The uptake of CLR 1852 (compound (9)) in A375 (human melanoma) and HEK293 (human embryonic kidney) cells was evaluated. The cells were incubated with CLR 1852 (compound (9)) for 24 hours. It was shown that within 24 hours of treatment, the PDC of tumor cells increased by 6 to 28 times compared with normal cells ( Figure 4 ).

[0212] The results of Examples 2-9 show that phospholipid ether molecules target tumor cells through lipid rafts. Compared with normal cells, PDCs also show obvious uptake into tumor cells even in co-culture. After entering tumor cells, PDCs track to mitochondria and endoplasmic reticulum. In vivo, PDCs target and accumulate rapidly in tumors. Cytotoxic PDCs provide improved targeting and the potential for increased safety.

[0213] Example 10

[0214] Cellular uptake of PLE

[0215] Various cancer cell lines were exposed to fluorescently labeled PLE (CLR 1501, compound (1)) in vitro and in vivo. Tumor cell uptake was measured for 24 hours. The results are shown in Tables 1 and Figure 5 , Figure 6 and Figure 7 The PLE compounds are specific for tumors and cancer cells.

[0216] When fluorescently labeled PLE (CLR 1501, compound (1)) was applied to benign tissue, no uptake was observed (Table 2).

[0217] Table 1. In vitro cellular uptake of PLE

[0218]

[0219]

[0220] Table 2. Uptake of CLR1404 in benign tissues

[0221]

[0222] Embodiment 11

[0223] Activity of PLE-Flavagline conjugate in cancer cells

[0224] PLE-flavagline conjugates CLR 1852 (compound (9)) and CLR 1865 (compound (8)) were applied to cell lines A375 (human malignant melanoma), A549 (human lung adenocarcinoma), HCT 116 (human colon cancer) and NHDF (normal human dermal fibroblasts). IC50 was calculated. The results are shown in Table 3.

[0225] Table 3. IC in various cancer cell lines 50 (μM / mL)

[0226]

[0227] The cytotoxicity of CLR 1852 was determined at different concentrations. Figure 8 As shown, CLR1852 showed a modest loss of potency compared to FLV3 alone, which may be due to incomplete release.

[0228] The stability of CLR1865 (compound (8)), CLR 1852 (compound (9)), and FLV3 in plasma was examined, with propantheline as a control (Table 4). Small amounts of the molecules were exposed to plasma, and the plasma was then analyzed by HPLC or MS to determine if the molecules were degraded. CLR 1865 and CLR1852 exhibited excellent stability in human plasma. CLR 1852 performed better than CLR 1865 in mouse plasma. CLR 1865 was only stable in mouse plasma for 3.3 hours. CLR 1852 was stable in plasma for at least 7 hours.

[0229] Table 4. Plasma stability

[0230]

[0231]

[0232] The therapeutic index (TI) of CLR 1865 and CLR 1852 was tested in mice (Table 5). Table 5 lists the doses given to mice, as well as the number of mice that survived after treatment ("3 / 3" means that 3 out of 3 mice survived). Both CLR 1852 and CLR 1865 showed excellent improvements in tolerability compared to FLV3 alone. CLR 1852 did not reach the maximum tolerated dose (MTD), probably because its solubility limits larger doses. The MTD of CLR 1865 is between 5 and 10 mg / kg. The in vivo therapeutic index of CLR 1852 is at least 25, and the in vivo therapeutic index of CLR 1865 is at least 12.5.

[0233] Table 5. In vivo therapeutic index

[0234] Dosage (mg / kg) FLV3 CLR 1852 CLR 1865 0.1 3 / 3 3 / 3 3 / 3 0.25 3 / 3 3 / 3 3 / 3 0.5 LD 3 / 3 3 / 3 1.0 n / a 3 / 3 3 / 3 5.0 n / a 3 / 3 3 / 3 10.0 n / a 3 / 3 2 / 3

[0235] The efficacy of CLR 1852 in HCT 116 cells (human colon cancer) was examined. CLR 1852 was administered to HCT 116 cells at three doses of 1 mg / mg each. Compared to vehicle, CLR 1852 reduced tumor volume starting at approximately day 27 ( Fig. 9 ). CLR 1582 caused modest weight loss compared with vehicle, likely due to toxicity ( Fig.10 CLR 1582 provided at least sixfold greater tolerance than FLV3 alone (data not shown).

[0236] CLR 1852 and FLV3 were administered individually to A375 and A549 cells. FLV3 levels in cell lysates and growth media were measured using LC / MS. Fig.11As shown, high levels of FLV3 were present in cell lysates after 24 hours. Moderate levels of FLV3 were present in the growth medium after 24 hours. The level of intracellular FLV3 appeared to level off at 24 hours, while the extracellular levels of FLV3 continued to increase.

[0237] Example 12

[0238] Activity of CLR 1899 in cancer cells

[0239] CLR 1899 was applied to cell lines A375 (human malignant melanoma), A549 (human lung adenocarcinoma), HCT 116 (human colon carcinoma) and NHDF (normal human dermal fibroblasts). The in vitro cytotoxicity results are shown in Table 6.

[0240] Table 6

[0241]

[0242] To determine whether CLR 1899 is tolerated in vivo, the compound was intravenously administered to healthy C57BL / 6 mice at a dose level of 0.5 mg / kg, 1.0 mg / kg, or 2.0 mg / kg, and the body weight changes were observed ( Fig.12 ). CLR 1899 showed no toxicity or adverse events as measured by body weight changes during repeated dosing. The in vivo efficacy of CLR 1899 was studied in the MCF-7 xenograft model ( Fig.13 In these studies, CLR 1899 showed comparable activity to docetaxel in preventing or slowing tumor growth.

[0243] The above description of specific aspects will reveal the general nature of the invention so fully that others can easily modify and / or adapt various applications of these specific aspects by applying the knowledge in the art without undue experimentation and without departing from the general concept of the present disclosure. Therefore, based on the teachings and guidance presented herein, such changes and modifications are intended to fall within the meaning and scope of equivalents of the disclosed aspects. It should be understood that the wording or terminology herein is for the purpose of description rather than limitation, so that the terms or wording of this specification will be interpreted by those skilled in the art based on the teachings and guidance.

[0244] The breadth and scope of the present disclosure should not be limited by any of the above-described exemplary aspects, but should be defined only in accordance with the following claims and their equivalents.

[0245] All publications, patents, patent applications and / or other documents cited in this application are incorporated by reference in their entirety for all purposes to the same extent as if each individual publication, patent, patent application and / or other document was individually indicated to be incorporated by reference for all purposes.

[0246] For the sake of completeness, various aspects of the disclosure are listed in the following numbered clauses:

[0247] Item 1. A compound of formula (I), or a pharmaceutically acceptable salt thereof,

[0248]

[0249] wherein Z is a flavagline analog.

[0250] Item 2. The compound of Item 1, selected from the group consisting of:

[0251]

[0252] or a pharmaceutically acceptable salt thereof.

[0253] Item 3. A pharmaceutical composition comprising the compound described in any one of Items 1-2 or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier.

[0254] Item 4. A method of treating cancer in a subject, comprising administering to the subject an effective amount of the compound described in any one of Items 1-2 or a pharmaceutically acceptable salt thereof.

[0255] Clause 5. A method for targeting a drug to a tumor or cancer cell in a subject, the method comprising administering to the subject a compound described in any one of Clauses 1-2 or a pharmaceutically acceptable salt thereof.

[0256] Clause 6. The method of any one of Clauses 4-5, wherein the compound or a pharmaceutically acceptable salt thereof is localized in or passes through the cytoplasm or organelles of a tumor or cancer cell.

[0257] Clause 7. The method of any one of Clauses 4-6, wherein the compound or a pharmaceutically acceptable salt thereof is selective for cancer cells in the subject.

[0258] Clause 8. The method of any one of Clauses 4-7, wherein the compound, or a pharmaceutically acceptable salt thereof, is incorporated into tumor or cancer cells at least about 2 times more than healthy cells.

[0259] Clause 9. The method described in any of Clauses 4-8, wherein the cancer is melanoma, brain cancer, lung cancer, adrenal cancer, liver cancer, kidney cancer or renal cancer, pancreatic cancer, esophageal cancer, stomach cancer, gastric cancer, colon cancer, colorectal cancer, anal cancer, prostate cancer, ovarian cancer, breast cancer, cervical cancer, lymphoma, leukemia, myeloma, blood cancer, hepatocellular carcinoma, retinoblastoma, glioma, sarcoma, blastoma, squamous cell carcinoma, adenocarcinoma or a combination thereof.

[0260] Clause 10. The method of any one of Clauses 4-9, wherein the cancer is melanoma, lung cancer, colorectal cancer, breast cancer, or a combination thereof.

[0261] Clause 11. The method of any one of clauses 4 to 10, wherein

[0262] The lung cancer includes small cell lung cancer, non-small cell lung cancer or a combination thereof;

[0263] The melanoma includes superficial spreading melanoma, nodular melanoma, lentigo maligna melanoma, acral lentigo melanoma, amelanotic melanoma, pyomelanoma, spitzoid melanoma, desmoplastic melanoma or a combination thereof;

[0264] The colorectal cancer comprises adenocarcinoma; or

[0265] The breast cancer includes invasive ductal carcinoma, metastatic breast cancer, inflammatory breast cancer, triple-negative breast cancer, ductal carcinoma in situ or a combination thereof.

[0266] Clause 12. The method of any one of Clauses 4-11, wherein the cancer comprises cancer stem cells.

[0267] Clause 13. The method of any one of Clauses 4-12, wherein the cancer comprises metastatic cancer cells.

[0268] Clause 14. The method of any one of Clauses 4-13, wherein the cancer comprises circulating tumor cells.

[0269] Clause 15. The method of any one of Clauses 4-14, wherein the subject is a human.

Claims

1. A compound selected from: or a pharmaceutically acceptable salt thereof.

2. A pharmaceutical composition comprising the compound according to claim 1 or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable carrier.

3. Use of an effective amount of the compound of claim 1 or a pharmaceutically acceptable salt thereof for preparing a medicament for treating cancer in a subject in need thereof, wherein the cancer is melanoma, lung cancer, colon cancer, or breast cancer.

4. Use of the compound according to claim 1 or a pharmaceutically acceptable salt thereof for preparing a drug for targeting a drug to a tumor or cancer cell in a subject, wherein the tumor or cancer cell is from melanoma, lung cancer, colon cancer, or breast cancer.

5. The use according to claim 3, wherein the cancer is melanoma, lung cancer, or breast cancer.

6. The use according to claim 4, wherein the tumor or cancer cell is from melanoma, lung cancer, or breast cancer.

7. The use according to claim 3 or 4, wherein The lung cancer includes small cell lung cancer, non-small cell lung cancer or a combination thereof; The melanoma includes superficial spreading melanoma, nodular melanoma, lentigo maligna melanoma, acral lentigo melanoma, amelanotic melanoma, pyomelanoma, spitzoid melanoma, desmoplastic melanoma or a combination thereof; or The breast cancer includes invasive ductal carcinoma, metastatic breast cancer, inflammatory breast cancer, triple-negative breast cancer, ductal carcinoma in situ or a combination thereof.

8. The use according to claim 3, wherein the cancer comprises cancer stem cells.

9. The use according to claim 3, wherein the cancer comprises metastatic cancer cells.

10. The use according to claim 3, wherein the cancer comprises circulating tumor cells.

11. The use according to claim 3 or 4, wherein the subject is a human.

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