COMPOUNDS AND METHOD FOR TREATMENT OF CANCER

FIELD OF THE INVENTION

The present invention relates generally to therapeutic compounds and compositions, as well as methods for treatment of cancer.

BACKGROUND OF THE INVENTION

Cancer, irrespective of its pathogenesis, is characterized by uncontrolled growth and survival of cells. Common to most forms of cancer is an error in the cellular mechanism responsible for balancing cell survival and cell death.

According to the American Cancer Society, lung cancer is the leading cause of cancer death for both men and women. Small cell lung cancer (SCLC) accounts for approximately 20% of all lung cancers. The 5-year survival rate for small cell lung cancer is about 15%.

Certain thiosemicarbazones, such as those disclosed in British Patent No. 1 ,026,401 , International Patent Application No. WO2004/066725, Japanese Patent No. 56-95161 and U.S. Patent No. 4,927,843, have been used to treat, for example, a variety of viruses. Other thiosemicarbazones, however, may be used to treat cancer. French Patent No. 2,879,194 is directed to certain thiosemicarbazones that may be used in the treatment or prevention of cancer, in dermatological treatment, in the treatment of cardiovascular and immune diseases, lipid-metabolism related diseases and modulate PPAR's. International Patent Application No. WO 2006/009765 is directed to specific thiosemicarbazones that may be used in anti-cancer therapy that mitigates the development of drug resistance. U.S. Patent No. 4,593,027 is directed to hydrazone derivatives that may be used as a chemotherapeutic.

Chinese Patent Application No. 1891701 is directed to a thiosemicarbazone, which are anti-tumour drugs. Chinese Patent Application

No. 1907970 is directed to the synthesis of heteroaryl thiocarbonyl compounds. International Patent Application Nos. WO 01/34585 and WO 02/49413 encompass compounds that are thiosemicarbazones, which are used for thrombopoietin mimetrics. International Patent Application No. WO 2004/099371 is directed to thiosemicarbazones that treat ischemia-related conditions. International Patent Application No. WO 2005/087211 is directed to thiocarbazone compounds that are anti-parasitic and inhibit cellular replication associated with cancer cells.

There is a need, however, for new therapeutic drug treatments to treat cancers more effectively and/or with reduced toxicity, particularly lung cancer.

SUMMARY OF THE INVENTION

In accordance with an aspect, there is provided a compound of Formula I:

Formula I

and/or a pharmaceutically-acceptable salt, hydrate, solvate, tautomer, optical isomer, E-isomer, Z-isomer, or combination thereof; wherein: X is selected from S or O;

R ⁵ is selected from a substituted or unsubstituted aromatic group, a substituted or unsubstituted heteroaromatic group, or

when R ⁵ is:

R, R ³ and R ⁴ are each independently selected from H, halo, hydroxyl, amino, a substituted or unsubstituted hydrocarbon group, a substituted or unsubstituted heterogeneous group, a substituted or unsubstituted carbocyclic group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heteroaromatic group; and R ⁶ to R ⁸ are each independently selected from H, halo, hydroxyl, amino, nitro, a substituted or unsubstituted hydrocarbon group, a substituted or unsubstituted heterogeneous group, a substituted or unsubstituted carbocyclic group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heteroaromatic group; when R ⁵ is selected from a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heteroaromatic group, R ⁴ is selected from a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heteroaromatic group, wherein at least one of R ⁴ and R ⁵ is a halo-substituted aromatic group or a halo-substituted heteroaromatic group; and

R and R ³ are each independently selected from H, halo, hydroxyl, amino, a substituted or unsubstituted hydrocarbon group, a substituted or

unsubstituted heterogeneous group, a substituted or unsubstituted carbocyclic group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heteroaromatic group. In accordance with another aspect, there is provided a compound of

Formula II:

Formula I I

and/or a pharmaceutically-acceptable salt, hydrate, solvate, tautomer, optical isomer, E-isomer, Z-isomer, or combination thereof; wherein:

X is selected from S or O;

R, R ³ and R ⁴ are each independently selected from H, halo, hydroxyl, amino, a substituted or unsubstituted hydrocarbon group, a substituted or unsubstituted heterogeneous group, a substituted or unsubstituted carbocyclic group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heteroaromatic group; and R ⁶ to R ⁸ are each independently selected from H, halo, hydroxyl, amino, nitro, a substituted or unsubstituted hydrocarbon group, a substituted or unsubstituted heterogeneous group, a substituted or unsubstituted carbocyclic group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heteroaromatic group.

In another aspect, R, R ³ and R ⁴ are each independently selected from H, halo, hydroxyl, cyano, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted haloalkyl, substituted or unsubstituted hydroxyalkyl, substituted or unsubstituted alkoxy, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aromatic group, a substituted or unsubstituted heteroaromatic group, carboxyl, alkylcarbonyl, arylcarbonyl, cycloalkylcarbonyl, heterocyclylcarbonyl, amino, aminoalkyl, alkylaminoalkyl, heterocyclylalkyl, aralkyl, arylalkenyl, arylalkynyl, alkylthio, alkylamino, arylamino, heteroarylamino, aralkylamino, alkylaminoalkylamino, arylthio, aralkylthio, aryloxy, aralkoxy, heterocyclylalkoxy, heterocyclyloxyalkyl, cycloalkyl, and cycloalkenyl.

In another aspect, R ⁴ is selected from a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heteroaromatic group, the substituted aromatic group or heteroaromatic group being substituted with at least one group selected from halo, hydroxyl, amino, nitro, a substituted or unsubstituted hydrocarbon group, a substituted or unsubstituted heterogeneous group, a substituted or unsubstituted carbocyclic group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heteroaromatic group and R ³ is H or substituted or unsubstituted alkyl.

In another aspect, said at least one group is selected from halo, hydroxyl, cyano, amino, nitro, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted haloalkyl, substituted or unsubstituted hydroxyalkyl, substituted or unsubstituted alkoxy, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aromatic group, a substituted or unsubstituted heteroaromatic group, carboxyl, alkylcarbonyl, arylcarbonyl, cycloalkylcarbonyl, heterocyclylcarbonyl, aminoalkyl, alkylaminoalkyl, heterocyclylalkyl, aralkyl, arylalkenyl, arylalkynyl, alkylthio, alkylamino, arylamino, heteroarylamino, aralkylamino, alkylaminoalkylamino, arylthio,

aralkylthio, aryloxy, aralkoxy, heterocyclylalkoxy, heterocyclyloxyalkyl, cycloalkyl, and cycloalkenyl.

In another aspect, R ⁴ is selected from a substituted aromatic group or heteroaromatic group. In another aspect, said at least one group is selected from halo, hydroxyl, cyano, amino, aminoalkyl or nitro. In another aspect, R ⁴ is selected from a substituted pyridinyl group or a substituted phenyl group. In a further aspect, the substituted pyridinyl group is substituted in the para position or the substituted phenyl group is substituted in the ortho position. In another aspect, the substituted pyridinyl group or the substituted phenyl group is substituted with the hydroxyl, amino, or aminoalkyl. In another aspect, the substituted pyridinyl group is a substituted 2-pyridinyl group.

In another aspect, R ⁶ to R ⁸ are each independently selected from H, halo, hydroxyl, amino, nitro, a substituted or unsubstituted hydrocarbon group, a substituted or unsubstituted heterogeneous group. In another aspect, R ⁶ to R ⁸ are each H.

In another aspect, R is NR ¹ R ² , wherein:

R ¹ and R ² are each independently selected from H, halo, hydroxy, nitro, a substituted or unsubstituted hydrocarbon group, a substituted or unsubstituted heterogeneous group, a substituted or unsubstituted carbocyclic group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heteroaromatic group, or

R ¹ and R ² together form a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heteroaromatic group.

In another aspect, R ¹ and R ² together form a substituted or unsubstituted heterocyclic group. In another aspect, NR ¹ R ² is a substituted or unsubstituted piperazinyl group or pyridinyl group. In another aspect, NR ¹ R ² is a substituted or unsubstituted piperazinyl group. In another aspect, NR ¹ R ²

is:

In yet another aspect, X is S.

In another aspect, the compound is:

and/or a pharmaceutically-acceptable salt, hydrate, solvate, tautomer, optical isomer, E-isomer, Z-isomer, or combination thereof. In another aspect, the compound is:

and/or a pharmaceutically-acceptable salt, hydrate, solvate, tautomer, optical isomer, E-isomer, Z-isomer, or combination thereof.

In another aspect, the compound is:

and/or a pharmaceutically-acceptable salt, hydrate, solvate, tautomer, optical isomer, E-isomer, Z-isomer, or combination thereof.

In another aspect, the compound of the invention is orally absorbed by a mammal. In another aspect, at least about 50% of the compound is orally absorbed by a mammal. In another aspect, the mammal is a human. In another aspect, the compound has an IC ₅₀ for a cancer cell population of less than about 1000 nM. In another aspect, the compound is for treatment of a cancer.

In another aspect, the cancer is selected from lung cancer, cervical cancer, ovarian cancer, cancer of CNS, skin cancer, prostate cancer, sarcoma, breast cancer, leukemia, colorectal cancer, head cancer, neck cancer, lymphoma, pancreatic cancer, gastric cancer, or kidney cancer.

In another aspect, the cancer is selected from small cell lung cancer, hormone resistant breast cancer, hormone resistant prostate cancer, acute leukemia, chronic leukemia, colorectal cancer or melanoma.

In another aspect, the cancer is a carcinoma. In another aspect, the carcinoma is selected from small cell carcinomas, cervical carcinomas, glioma, astrocytoma, prostate carcinomas, ovarian carcinomas, melanoma, breast carcinomas, or colorectal carcinomas. In another aspect, the carcinoma is small cell lung carcinoma.

In another aspect, the compound is provided in combination with radiation therapy.

In another aspect, a pharmaceutical composition is provided comprising the compound of the invention and at least one pharmaceutically acceptable carrier and/or diluent. In another aspect, a pharmaceutical

composition comprising an anti-cancer agent and the compound according to the invention.

In another aspect, the anti-cancer agent is selected from DNA- interactive agents, antimetabolites, tubulin-interactive agents, hormonal agents, estrogen receptor modulators, androgen receptor modulators, retinoid receptor modulators, tyrosine kinase inhibitors, cytotoxic agents, antiproliferative agents, prenyl-protein transferase inhibitors, HMG-CoA reductase inhibitors, HIV protease inhibitors, reverse transcriptase inhibitors, other angiogenesis inhibitors or combinations thereof. In another aspect, the composition is provided in combination with radiation therapy. In another aspect, a method is provided for treating a cancer in a mammal, comprising administering to the mammal a therapeutically effective amount of the compound according to the invention. In another aspect, the compound is co-administered with radiation therapy. In another aspect, a method for treating a cancer in a mammal is provided, comprising administering to the mammal a therapeutically effective amount of the composition according to the invention. In another aspect, the composition is co-administered with radiation therapy. In another aspect, the compound or composition is administered orally and/or parenterally. In another aspect, the compound or composition is administered intravenously and/or intraperitoneally.

In another aspect, use of a compound according to the invention for the manufacture of a medicament for treatment of a cancer in a mammal is provided. In another aspect, use of a composition according to the invention for the manufacture of a medicament for treatment of a cancer in a mammal is provided. In another aspect, use of a compound according to the invention to treat a cancer in a mammal is provided. In another aspect, the use of the compound in combination with radiation therapy is provided. In another aspect, use of a composition according to the invention to treat a cancer in a mammal is provided. In another aspect, the use of the composition in combination with radiation therapy is provided.

In another aspect, the use is wherein the cancer is selected from lung cancer, cervical cancer, ovarian cancer, cancer of CNS, skin cancer, prostate cancer, sarcoma, breast cancer, leukemia, colorectal cancer, head cancer, neck cancer, lymphoma, pancreatic cancer, gastric cancer, or kidney cancer. In another aspect, the cancer is selected from small cell lung cancer, breast cancer, acute leukemia, chronic leukemia, colorectal cancer. In another aspect, the cancer is a carcinoma. In another aspect, the carcinoma is selected from small cell carcinomas, cervical carcinomas, glioma, astrocytoma, prostate carcinomas, ovarian carcinomas, melanoma, breast carcinomas, or colorectal carcinomas. In another aspect, the carcinoma is small cell lung carcinoma.

In another aspect, there is provided a method for treating a cancer in a mammal, comprising administering to the mammal a therapeutically effective amount of a compound of Formula VII:

Formula VII

and/or a pharmaceutically-acceptable salt, hydrate, solvate, tautomer, optical isomer, E-isomer, Z-isomer, or combination thereof; wherein:

X is selected from S or O;

R and R ³ are each independently selected from H, halo, hydroxyl, amino, a substituted or unsubstituted hydrocarbon group, a substituted or unsubstituted heterogeneous group, a substituted or unsubstituted carbocyclic group, a substituted or unsubstituted heterocyclic group, a substituted or

unsubstituted aromatic group, or a substituted or unsubstituted heteroaromatic group; and

R ¹⁰ and R ¹¹ are each independently selected from a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heteroaromatic group.

In another aspect, R and R ³ are each independently selected from H, halo, hydroxyl, cyano, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted haloalkyl, substituted or unsubstituted hydroxyalkyl, substituted or unsubstituted alkoxy, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aromatic group, a substituted or unsubstituted heteroaromatic group, carboxyl, alkylcarbonyl, arylcarbonyl, cycloalkylcarbonyl, heterocyclylcarbonyl, amino, aminoalkyl, alkylaminoalkyl, heterocyclylalkyl, aralkyl, arylalkenyl, arylalkynyl, alkylthio, alkylamino, arylamino, heteroarylamino, aralkylamino, alkylaminoalkylamino, arylthio, aralkytthio, aryloxy, aralkoxy, heterocyclylalkoxy, heterocyclyloxyalkyl, cycloalkyl, and cycloalkenyl.

In another aspect, R ¹⁰ and R ¹¹ are each independently selected from a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heteroaromatic group, the substituted aromatic group or heteroaromatic group being substituted with at least one group selected from halo, hydroxyl, amino, nitro, a substituted or unsubstituted hydrocarbon group, a substituted or unsubstituted heterogeneous group, a substituted or unsubstituted carbocyclic group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heteroaromatic group and R ³ is H or substituted or unsubstituted alkyl. In another aspect, said at least one group is selected from halo, hydroxyl, cyano, amino, nitro, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted haloalkyl, substituted or unsubstituted hydroxyalkyl, substituted or unsubstituted alkoxy, a substituted or unsubstituted heterocyclic group, a

substituted or unsubstituted aromatic group, a substituted or unsubstituted heteroaromatic group, carboxyl, alkylcarbonyl, arylcarbonyl, cycloalkylcarbonyl, heterocyclylcarbonyl, aminoalkyl, alkylaminoalkyl, heterocyclylalkyl, aralkyl, arylalkenyl, arylalkynyl, alkylthio, alkylamino, arylamino, heteroarylamino, aralkylamino, alkylaminoalkylamino, arylthio, aralkylthio, aryloxy, aralkoxy, heterocyclylalkoxy, heterocyclyloxyalkyl, cycloalkyl, and cycloalkenyl.

In another aspect, said at least one group is selected from halo, hydroxyl, cyano, amino, aminoalkyl or nitro. In another aspect, R ¹⁰ and R ¹¹ are each independently selected from a substituted or unsubstituted pyridinyl group or a substituted or unsubstituted phenyl group. In another aspect, the pyridinyl group is a 2-pyridinyl, 3- pyridinyl, or 4-pyridinyl group. In another aspect, R is as above. In another aspect, X is S. In another aspect, the compound is:

VIIE

VIID

VII J

VII I

and/or a pharmaceutically-acceptable salt, hydrate, solvate, tautomer, optical isomer, E-isomer, Z-isomer, or combination thereof.

In another aspect, the compound is co-administered with radiation therapy. In another aspect, the cancer is lung cancer, cervical cancer, ovarian cancer, cancer of CNS, skin cancer, prostate cancer, sarcoma, breast cancer, leukemia, colorectal cancer, head cancer, neck cancer, lymphoma, pancreatic

cancer, gastric cancer, or kidney cancer. In another aspect, the cancer is selected from small cell lung cancer, hormone resistant breast cancer, hormone resistant prostate cancer, acute leukemia, chronic leukemia, colorectal cancer, or melanoma. In another aspect, the cancer is a carcinoma. In another aspect, the carcinoma is selected from small cell carcinomas, cervical carcinomas, glioma, astrocytoma, prostate carcinomas, ovarian carcinomas, melanoma, breast carcinomas, or colorectal carcinomas. In another aspect, the carcinoma is small cell lung carcinoma.

Other features and advantages of the present invention will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples while indicating embodiments of the invention are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from the detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be described, by way of example only, with reference to the attached Figures.

Figure 1 shows the dose response of three human SCLC tumor cell lines (DMS-114, DMS-153 and SHP-77) to Gleevec®, as a comparison to Figure 2;

Figure 2 shows the dose response of human SCLC tumor cell lines to "COTI-4" according to the invention;

Figure 3 shows the dose response of NSCLC tumor cell lines to "COTI- 4" according to the invention;

Figure 4 shows the effect of a compound according to the invention, referred to herein throughout interchangeably as "COTI-4", "COTI-4MO5" or "Formula 1 B", in inhibiting tumor growth over 38 days of treatment. Also depicted for comparison is a saline control, and compound referred to as "COTI-2", also described as "COTI -2 M05", which is the subject of a co-

pending U.S. Provisional Patent Application 60/884,504, now International Publication No. WO 2008/083491 , published on July 17, 2008, both of which are hereby incorporated by reference;

Figure 5 is a comparative example, when viewed against data presented in Figure 4, showing the effect on tumor growth of Taxol® and cisplatin treatment against a saline control;

Figure 6 shows the number of tumors, expressed as a fraction of injection sites after 38 days of treatment with COTI-4, according to the invention, versus saline (as a control), Taxol® and cisplatin comparative controls. Also depicted are results from compounds referred to as "COTI-2", as referenced above, and "COTI-219", also described as "COTI-219M05", which is the subject of co-pending U.S. Provisional Patent 60/884,489, which is also incorporated herein by reference,

COTI-219MO5

Figure 7 shows the average weight of animals treated with COTI-4, according to the invention, versus saline (as a control), Taxol® and cisplatin

comparative controls. Also depicted are results from the compounds "COTI- 2" and "COTI-219", as referred to above;

Figure 8 shows the dose response of human SCLC cell line DMS-114 to COTI-4A, according to the invention (the two different lots relate to replicate experiments);

Figure 9 shows the dose response of human SCLC cell line DMS-153 to COTI-4A, according to the invention (the two different lots relate to replicate experiments);

Figure 10 shows the dose response of human SCLC cell line SHP-77 to COTI-4A, according to the invention (the two different lots relate to replicate experiments);

Figure 11 shows the dose response of human non-SCLC cell line A- 549 to COTI-4A, according to the invention (the two different lots relate to replicate experiments); Figure 12 shows the dose response of human non-SCLC cell line H-

226 to COTI-4A, according to the invention (the two different lots relate to replicate experiments);

Figure 13 shows the dose response of human non-SCLC cell line H- 460 to COTI-4A, according to the invention (the two different lots relate to replicate experiments);

Figure 14 shows lack of emerging resistance in DMS153 cells treated with COTI-4 and the prior art compounds COTI-2 and COTI-219;

Figure 15 shows lack of emerging resistance in SHP77 cells treated with COTI-4 and the prior art compounds COTI-2 and COTI-219; and, Figure 16 shows the effect on mouse weight of treatment with compounds according to the invention at three different doses.

DETAILED DESCRIPTION

The present invention is directed to a thiosemicarbazone, a semicarbazone, a composition comprising the thiosemicarbazone and/or the

semicarbazone, a method of administration thereof, and use thereof to treat a cancer.

Definitions When describing the compounds, compositions, methods and uses of this invention, the following terms have the following meanings unless otherwise indicated.

The term "therapeutically effective amount" as used herein means that amount of active compound or pharmaceutical agent that elicits the biological or medicinal response in a tissue, system, animal or human that is being sought by a researcher, veterinarian, medical doctor or other clinician. The compounds of the present invention may have asymmetric centers, chiral axes, and chiral planes (as described, for example, in: E. L. ENeI and S. H. Wilen, Stereo-chemistry of Carbon Compounds, John Wiley & Sons, New York, 1994, pages 1119-1190), and occur as racemates, racemic mixtures, and as individual diastereomers, with all possible isomers and mixtures thereof, including optical isomers, E isomers, and Z isomers, being included in the present invention. In addition, the compounds disclosed herein may exist as tautomers and both tautomeric forms are intended to be encompassed by the scope of the invention, even though only one tautomeric structure may be depicted.

Generally, reference to a certain element such as hydrogen or H is meant to, if appropriate, include all isotopes of that element.

Where the term "alkyl group" is used, either alone or within other terms such as "haloalkyl group" and "alkylamino group", it encompasses linear or branched carbon radicals having, for example, one to about twenty carbon atoms or, in specific embodiments, one to about twelve carbon atoms. In other embodiments, alkyl groups are "lower alkyl" groups having one to about six carbon atoms. Examples of such groups include, but are not limited thereto, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-

butyl, pentyl, iso-amyl, hexyl and the like. In more specific embodiments, lower alkyl groups have one to four carbon atoms.

The term "alkenyl group" encompasses linear or branched carbon radicals having at least one carbon-carbon double bond. The term "alkenyl group" can encompass conjugated and non-conjugated carbon-carbon double bonds or combinations thereof. An alkenyl group, for example and without being limited thereto, can encompass two to about twenty carbon atoms or, in a particular embodiment, two to about twelve carbon atoms. In embodiments, alkenyl groups are "lower alkenyl" groups having two to about four carbon atoms. Examples of alkenyl groups include, but are not limited thereto, ethenyl, propenyl, allyl, propenyl, butenyl and 4-methylbutenyl. The terms "alkenyl group" and "lower alkenyl group", encompass groups having "cis" and "trans" orientations, or alternatively, "E" and "Z" orientations.

The term "alkynyl group" denotes linear or branched carbon radicals having at least one carbon-carbon triple bond. The term "alkynyl group" can encompass conjugated and non-conjugated carbon-carbon triple bonds or combinations thereof. Alkynyl group, for example and without being limited thereto, can encompass two to about twenty carbon atoms or, in a particular embodiment, two to about twelve carbon atoms. In embodiments, alkynyl groups are "lower alkynyl" groups having two to about ten carbon atoms. Some examples are lower alkynyl groups having two to about four carbon atoms. Examples of such groups include propargyl, butynyl, and the like.

The term "halo" means halogens such as fluorine, chlorine, bromine or iodine atoms. The term "haloalkyl group" encompasses groups wherein any one or more of the alkyl carbon atoms is substituted with halo as defined above. Specifically encompassed are monohaloalkyl, dihaloalkyl and polyhaloalkyl groups including perhaloalkyl. A monohaloalkyl group, for one example, may have either an iodo, bromo, chloro or fluoro atom within the group. Dihalo and polyhaloalkyl groups may have two or more of the same halo atoms or a combination of different halo groups. "Lower haloalkyl group" encompasses

groups having 1- 6 carbon atoms. In some embodiments, lower haloalkyl groups have one to three carbon atoms. Examples of haloalkyl groups include fluoromethyl, difluoromethyl, trifluoromethyl, chloromethyl, dichloromethyl, trichloromethyl, pentafluoroethyl, heptafluoropropyl, difluorochloromethyl, dichlorofluoromethyl, difluoroethyl, difluoropropyl, dichloroethyl and dichloropropyl.

The term "hydroxyalkyl group" encompasses linear or branched alkyl groups having, for example and without being limited thereto, one to about ten carbon atoms, any one of which may be substituted with one or more hydroxyl groups. In embodiments, hydroxyalkyl groups are "lower hydroxyalkyl" groups having one to six carbon atoms and one or more hydroxyl groups. Examples of such groups include hydroxymethyl, hydroxyethyl, hydroxypropyl, hydroxybutyl and hydroxyhexyl.

The term "alkoxy group" encompasses linear or branched oxy- containing groups each having alkyl portions of, for example and without being limited thereto, one to about ten carbon atoms. In embodiments, alkoxy groups are "lower alkoxy" groups having one to six carbon atoms. Examples of such groups include methoxy, ethoxy, propoxy, butoxy and tert-butoxy. In certain embodiments, lower alkoxy groups have one to three carbon atoms. The "alkoxy" groups may be further substituted with one or more halo atoms, such as fluoro, chloro or bromo, to provide "haloalkoxy" groups. In other embodiments, lower haloalkoxy groups have one to three carbon atoms. Examples of such groups include fluoromethoxy, chloromethoxy, trifluoromethoxy, trifluoroethoxy, fluoroethoxy, and fluoropropoxy. The term "aromatic group" or "aryl group" means an aromatic group having one or more rings wherein such rings may be attached together in a pendent manner or may be fused. In particular embodiments, an aromatic group is one, two or three rings. Monocyclic aromatic groups may contain 4 to 10 carbon atoms, typically 4 to 7 carbon atoms, and more typically 4 to 6 carbon atoms in the ring. Typical polycyclic aromatic groups have two or three rings. Polycyclic aromatic groups having two rings typically have 8 to 12

carbon atoms, preferably 8 to 10 carbon atoms in the rings. Examples of aromatic groups include, but are not limited to, phenyl, naphthyl, tetrahydronaphthyl, indanyl, biphenyl, phenanthryl, anthryl or acenaphthyl.

The term "heteroatom" means an atom other than carbon. Typically, heteroatoms are selected from the group consisting of sulfur, phosphorous, nitrogen and oxygen atoms. Groups containing more than one heteroatom may contain different heteroatoms.

The term "heteroaromatic group" or "heteroaryl group" means an aromatic group having one or more rings wherein such rings may be attached together in a pendent manner or may be fused, wherein the aromatic group has at least one heteroatom. Monocyclic heteroaromatic groups may contain 4 to 10 member atoms, typically 4 to 7 member atoms, and more typically 4 to 6 member atoms in the ring. Typical polycyclic heteroaromatic groups have two or three rings. Polycyclic aromatic groups having two rings typically have 8 to 12 member atoms, more typically 8 to 10 member atoms in the rings. Examples of heteroaromatic groups include, but are not limited thereto, pyrrole, imidazole, thiazole, oxazole, furan, thiophene, triazole, pyrazole, isoxazole, isothiazole, pyridine, pyrazine, pyridazine, pyrimidine, triazine, indole, benzofuran, benzothiophene, benzimidazole, benzthiazole, quinoline, isoquinoline, quinazoline, quinoxaline and the like.

The term "carbocyclic group" means a saturated or unsaturated carbocyclic hydrocarbon ring. Carbocyclic groups are not aromatic. Carbocyclic groups are monocyclic or polycyclic. Polycyclic carbocyclic groups can be fused, spiro, or bridged ring systems. Monocyclic carbocyclic groups may contain 4 to 10 carbon atoms, typically 4 to 7 carbon atoms, and more typically 5 to 6 carbon atoms in the ring. Bicyclic carbocyclic groups may contain 8 to 12 carbon atoms, typically 9 to 10 carbon atoms in the rings.

The term "heterocyclic group" means a saturated or unsaturated ring structure containing carbon atoms and 1 or more heteroatoms in the ring. Heterocyclic groups are not aromatic. Heterocyclic groups are monocyclic or polycyclic. Polycyclic heterocyclic groups can be fused, spiro, or bridged ring

systems. Monocyclic heterocyclic groups may contain 4 to 10 member atoms (i.e., including both carbon atoms and at least 1 heteroatom), typically 4 to 7, and more typically 5 to 6 in the ring. Bicyclic heterocyclic groups may contain 8 to 18 member atoms, typically 9 or 10 member atoms in the rings. Representative heterocyclic groups include, by way of example, pyrrolidine, imidazolidine, pyrazolidine, piperidine, 1 ,4-dioxane, morpholine, thiomorpholine, piperazine, 3-pyrroline and the like.

The term "heterogeneous group" means a saturated or unsaturated chain of non-hydrogen member atoms comprising carbon atoms and at least one heteroatom. Heterogeneous groups typically have 1 to 25 member atoms. More typically, the chain contains 1 to 12 member atoms, 1 to 10, and most typically 1 to 6. The chain may be linear or branched. Typical branched heterogeneous groups have one or two branches, more typically one branch. Typically, heterogeneous groups are saturated. Unsaturated heterogeneous groups may have one or more double bonds, one or more triple bonds, or both. Typical unsaturated heterogeneous groups have one or two double bonds or one triple bond. More typically, the unsaturated heterogeneous group has one double bond.

The term "hydrocarbon group" or "hydrocarbyl group" means a chain of 1 to 25 carbon atoms, typically 1 to 12 carbon atoms, more typically 1 to 10 carbon atoms, and most typically 1 to 8 carbon atoms. Hydrocarbon groups may have a linear or branched chain structure. Typical hydrocarbon groups have one or two branches, typically one branch. Typically, hydrocarbon groups are saturated. Unsaturated hydrocarbon groups may have one or more double bonds, one or more triple bonds, or combinations thereof. Typical unsaturated hydrocarbon groups have one or two double bonds or one triple bond; more typically unsaturated hydrocarbon groups have one double bond.

When the term "unsaturated" is used in conjunction with any group, the group may be fully unsaturated or partially unsaturated. However, when the term "unsaturated" is used in conjunction with a specific group defined herein,

the term maintains the limitations of that specific group. For example, an unsaturated "carbocyclic group", based on the limitations of the "carbocyclic group" as defined herein, does not encompass an aromatic group.

The terms "carboxy group" or "carboxyl group", whether used alone or with other terms, such as "carboxyalkyl group", denotes -(C=O)-O-.

The term "carbonyl group", whether used alone or with other terms, such as "aminocarbonyl group", denotes -(C=O)-.

The terms "alkylcarbonyl group" denotes carbonyl groups which have been substituted with an alkyl group. In certain embodiments, "lower alkylcarbonyl group" has lower alkyl group as described above attached to a carbonyl group.

The term "aminoalkyl group" encompasses linear or branched alkyl groups having one to about ten carbon atoms any one of which may be substituted with one or more amino groups. In some embodiments, the aminoalkyl groups are "lower aminoalkyl" groups having one to six carbon atoms and one or more amino groups. Examples of such groups include aminomethyl, aminoethyl, aminopropyl, aminobutyl and aminohexyl.

The term "alkylaminoalkyl group" encompasses aminoalkyl groups having the nitrogen atom independently substituted with an alkyl group. In certain embodiments, the alkylaminoalkyl groups are "loweralkylaminoalkyl" groups having alkyl groups of one to six carbon atoms. In other embodiments, the lower alkylaminoalkyl groups have alkyl groups of one to three carbon atoms. Suitable alkylaminoalkyl groups may be mono or dialkyl substituted, such as N-methylaminomethyl, N, N-dimethyl-aminoethyl, N, N- diethylaminomethyl and the like.

The term "aralkyl group" encompasses aryl-substituted alkyl groups. In embodiments, the aralkyl groups are "lower aralkyl" groups having aryl groups attached to alkyl groups having one to six carbon atoms. In other embodiments, the lower aralkyl groups phenyl is attached to alkyl portions having one to three carbon atoms. Examples of such groups include benzyl,

diphenylmethyl and phenylethyl. The aryl in said aralkyl may be additionally substituted with halo, alkyl, alkoxy, haloalkyl and haloalkoxy.

The term "arylalkenyl group" encompasses aryl-substituted alkenyl groups. In embodiments, the arylalkenyl groups are "lower arylalkenyl" groups having aryl groups attached to alkenyl groups having two to six carbon atoms. Examples of such groups include phenylethenyl. The aryl in said arylalkenyl may be additionally substituted with halo, alkyl, alkoxy, haloalkyl and haloalkoxy.

The term "arylalkynyl group" encompasses aryl-substituted alkynyl groups. In embodiments, arylalkynyl groups are "lower arylalkynyl" groups having aryl groups attached to alkynyl groups having two to six carbon atoms. Examples of such groups include phenylethynyl. The aryl in said aralkyl may be additionally substituted with halo, alkyl, alkoxy, haloalkyl and haloalkoxy. The terms benzyl and phenylmethyl are interchangeable. The term "alkylthio group" encompasses groups containing a linear or branched alkyl group, of one to ten carbon atoms, attached to a divalent sulfur atom. In certain embodiments, the lower alkylthio groups have one to three carbon atoms. An example of "alkylthio" is methylthio, (CH ₃ S-).

The term "alkylamino group" denotes amino groups which have been substituted with one alkyl group and with two alkyl groups, including terms "N- alkylamino" and "N,N-dialkylamino". In embodiments, alkylamino groups are "lower alkylamino" groups having one or two alkyl groups of one to six carbon atoms, attached to a nitrogen atom. In other embodiments, lower alkylamino groups have one to three carbon atoms. Suitable "alkylamino" groups may be mono or dialkylamino such as N-methylamino, N-ethylamino, N ₁ N- dimethylamino, N,N-diethylamino and the like.

The term "arylamino group" denotes amino groups which have been substituted with one or two aryl groups, such as N-phenylamino. The "arylamino" groups may be further substituted on the aryl ring portion of the group.

The term "heteroarylamino" denotes amino groups which have been substituted with one or two heteroaryl groups, such as N-thienylamino. The "heteroarylamino" groups may be further substituted on the heteroaryl ring portion of the group. The term "aralkylamino group" denotes amino groups which have been substituted with one or two aralkyl groups. In other embodiments, there are phenyl-Ci-C ₃ -alkylamino groups, such as N-benzylamino. The "aralkylamino" groups may be further substituted on the aryl ring portion of the group.

The term "alkylaminoalkylamino group" denotes alkylamino groups which have been substituted with one or two alkylamino groups. In embodiments, there are CrC ₃ -alkylamino- CrC ₃ -alkylamino groups.

The term "arylthio group" encompasses aryl groups of six to ten carbon atoms, attached to a divalent sulfur atom. An example of "arylthio" is phenylthio. The term "aralkylthio group" encompasses aralkyl groups as described above, attached to a divalent sulfur atom. In certain embodiments there are phenyl- CrC ₃ -alkylthio groups. An example of "aralkylthio" is benzylthio.

The term "aryloxy group" encompasses optionally substituted aryl groups, as defined above, attached to an oxygen atom. Examples of such groups include phenoxy.

The term "aralkoxy group" encompasses oxy-containing aralkyl groups attached through an oxygen atom to other groups. In certain embodiments, aralkoxy groups are "lower aralkoxy" groups having optionally substituted phenyl groups attached to lower alkoxy group as described above. The term "cycloalkyl group" includes saturated carbocyclic groups. In certain embodiments, cycloalkyl groups include C ₃ -C ₆ rings. In embodiments, there are compounds that include, cyclopentyl, cyclopropyl, and cyclohexyl.

The term "cycloalkenyl group" includes carbocyclic groups that have one or more carbon-carbon double bonds; conjugated or non-conjugated, or a combination thereof. "Cycloalkenyl" and "cycloalkyldienyl" compounds are included in the term "cycloalkenyl". In certain embodiments, cycloalkenyl

groups include C ₃ -C ₆ rings. Examples include cyclopentenyl, cyclopentadienyl, cyclohexenyl and cycloheptadienyl. The "cycloalkenyl " group may have 1 to 3 substituents such as lower alkyl, hydroxyl, halo, haloalkyl, nitro, cyano, alkoxy, lower alkylamino, and the like. The term "suitable substituent", "substituent" or "substituted" used in conjunction with the groups described herein refers to a chemically and pharmaceutically acceptable group, i.e., a moiety that does not negate the therapeutic activity of the inventive compounds. It is understood that substituents and substitution patterns on the compounds of the invention may be selected by one of ordinary skill in the art to provide compounds that are chemically stable and that can be readily synthesized by techniques known in the art, as well as those methods set forth below. If a substituent is itself substituted with more than one group, it is understood that these multiple groups may be on the same carbon/member atom or on different carbons/member atoms, as long as a stable structure results. Illustrative examples of some suitable substituents include, cycloalkyl, heterocyclyl, hydroxyalkyl, benzyl, carbonyl, halo, haloalkyl, perfluoroalkyl, perfluoroalkoxy, alkyl, alkenyl, alkynyl, hydroxy, oxo, mercapto, alkylthio, alkoxy, aryl or heteroaryl, aryloxy or heteroaryloxy, aralkyl or heteroaralkyl, aralkoxy or heteroaralkoxy, HO-(C=O)--, amido, amino, alkyl- and dialkylamino, cyano, nitro, carbamoyl, alkylcarbonyl, alkoxycarbonyl, alkylaminocarbonyl, dialkylaminocarbonyl, arylcarbonyl, aryloxycarbonyl, alkylsulfonyl, and arylsulfonyl. Typical substituents include aromatic groups, substituted aromatic groups, hydrocarbon groups including alkyl groups such as methyl groups, substituted hydrocarbon groups such as benzyl, and heterogeneous groups including alkoxy groups such as methoxy groups.

The term "fused" means in which two or more carbons/member atoms are common to two adjoining rings, e.g., the rings are "fused rings". The pharmaceutically acceptable salts of the compounds of this invention include the conventional non-toxic salts of the compounds of this invention as formed, e.g., from non-toxic inorganic or organic acids. For

example, such conventional non-toxic salts include those derived from inorganic acids such as hydrochloric, hydrobromic, sulfuric, sulfamic, phosphoric, nitric and the like; and the salts prepared from organic acids such as acetic, propionic, succinic, glycolic, stearic, lactic, malic, tartaric, citric, ascorbic, pamoic, maleic, hydroxymaleic, phenylacetic, glutamic, benzoic, salicylic, sulfanilic, 2-acetoxy-benzoic, fumaric, toluenesulfonic, methanesulfonic, ethane disulfonic, oxalic, isethionic, trifluoroacetic and the like.

The pharmaceutically acceptable salts of the compounds of this invention can be synthesized from the compounds of this invention which contain a basic or acidic moiety by conventional chemical methods. Generally, the salts of the basic compounds are prepared either by ion exchange chromatography or by reacting the free base with stoichiometric amounts or with an excess of the desired salt-forming inorganic or organic acid in a suitable solvent or various combinations of solvents. Similarly, the salts of the acidic compounds are formed by reactions with the appropriate inorganic or organic base.

The present invention includes pharmaceutically acceptable salts, solvates and prodrugs of the compounds of the invention and mixtures thereof.

The terms "comprising", "having" and "including", and various endings thereof, are meant to be open ended, including the indicated component but not excluding other elements.

A compound of the invention is represented by a compound of Formula I:

Formula I wherein:

X is selected from S or O;

R ⁵ is selected from a substituted or unsubstituted aromatic group, a substituted or unsubstituted heteroaromatic group, or

when R ⁵ is:

R, R ³ and R ⁴ are each independently selected from H, halo, hydroxyl, amino, a substituted or unsubstituted hydrocarbon group, a substituted or unsubstituted heterogeneous group, a substituted or unsubstituted carbocyclic group, a substituted or unsubstituted heterocyclic group, a substituted or

unsubstituted aromatic group, or a substituted or unsubstituted heteroaromatic group; and

R ⁶ to R ⁸ are each independently selected from H, halo, hydroxyl, amino, nitro, a substituted or unsubstituted hydrocarbon group, a substituted or unsubstituted heterogeneous group, a substituted or unsubstituted carbocyclic group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heteroaromatic group; when R ⁵ is selected from a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heteroaromatic group, R ⁴ is selected from a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heteroaromatic group, wherein at least one of R ⁴ and R ⁵ is a halo-substituted aromatic group or a halo-substituted heteroaromatic group; and

R and R ³ are each independently selected from H, halo, hydroxyl, amino, a substituted or unsubstituted hydrocarbon group, a substituted or unsubstituted heterogeneous group, a substituted or unsubstituted carbocyclic group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heteroaromatic group. In one embodiment, a compound represented by a compound of

Formula II:

Formula Il

R, R ³ and R ⁴ are each independently selected from H, halo, hydroxyl, amino, a substituted or unsubstituted hydrocarbon group, a substituted or unsubstituted heterogeneous group, a substituted or unsubstituted carbocyclic group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heteroaromatic group. R ⁶ to R ⁸ are each independently selected from H, halo, hydroxyl, amino, nitro, a substituted or unsubstituted hydrocarbon group, a substituted or unsubstituted heterogeneous group, a substituted or unsubstituted carbocyclic group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heteroaromatic group.

In another embodiment, a compound represented by a compound of Formula III:

Formula III

R, R ³ and R ⁴ are each independently selected from H, halo, hydroxyl, amino, a substituted or unsubstituted hydrocarbon group, a substituted or unsubstituted heterogeneous group, a substituted or unsubstituted carbocyclic group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heteroaromatic group. R ⁶ to R ⁸ are each independently selected from H, halo, hydroxyl, amino, nitro, a substituted or unsubstituted hydrocarbon group, a substituted or unsubstituted heterogeneous group, a substituted or unsubstituted carbocyclic group, a substituted or unsubstituted heterocyclic

group, a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heteroaromatic group.

In another embodiment of Formulae Il or III, R, R ³ and R ⁴ are each independently selected from H, halo, hydroxyl, cyano, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted haloalkyl, substituted or unsubstituted hydroxyalkyl, substituted or unsubstituted alkoxy, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aromatic group, a substituted or unsubstituted heteroaromatic group, carboxyl, alkylcarbonyl, arylcarbonyl, cycloalkylcarbonyl, heterocyclylcarbonyl, amino, aminoalkyl, alkylaminoalkyl, heterocyclylalkyl, aralkyl, arylalkenyl, arylalkynyl, alkylthio, alkylamino, arylamino, heteroarylamino, aralkylamino, alkylaminoalkylamino, arylthio, aralkylthio, aryloxy, aralkoxy, heterocyclylalkoxy, heterocyclyloxyalkyl, cycloalkyl, and cycloalkenyl. R ³ can be specifically, H or substituted or unsubstituted alkyl. In a further embodiment, R ⁴ is selected from a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heteroaromatic group. The substituted aromatic group or heteroaromatic group can be substituted with at least one group (e.g. substituent) selected from halo, hydroxyl, amino, nitro, a substituted or unsubstituted hydrocarbon group, a substituted or unsubstituted heterogeneous group, a substituted or unsubstituted carbocyclic group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heteroaromatic group. The substituent can be more specifically selected from halo, hydroxyl, cyano, amino, nitro, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted haloalkyl, substituted or unsubstituted hydroxyalkyl, substituted or unsubstituted alkoxy, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aromatic group, a substituted or unsubstituted heteroaromatic group, carboxyl, alkylcarbonyl, arylcarbonyl, cycloalkylcarbonyl, heterocyclylcarbonyl, aminoalkyl, alkylaminoalkyl,

heterocyclylalkyl, aralkyl, arylalkenyl, arylalkynyl, alkylthio, alkylamino, arylamino, heteroarylamino, aralkylamino, alkylaminoalkylamino, arylthio, aralkylthio, aryloxy, aralkoxy, heterocyclylalkoxy, heterocyclyloxyalkyl, cycloalkyl, and cycloalkenyl. In a further embodiment of Formulae Il or III, R ⁴ is selected from a substituted or unsubstituted aromatic group, a substituted or unsubstituted heteroaromatic group. More specifically, the substituted aromatic or heteroaromatic groups are substituted with at least one group selected from halo, hydroxyl, cyano, amino, aminoalkyl or nitro. In a further embodiment, R ⁴ is selected from a substituted or unsubstituted pyridinyl group or a substituted or unsubstituted phenyl group. The substituted or unsubstituted pyridinyl group can be a 2-pyridinyl, 3-pyridinyl, or 4-pyridinyl group. The substituted pyridinyl group can be substituted in the para position or the substituted phenyl group can be substituted in the ortho position. In a more specific embodiment, the substituted pyridinyl group is substituted with a chloro or fluoro or the substituted phenyl group is substituted with the hydroxyl, amino, or aminoalkyl.

In another embodiment of Formula I, R ⁴ and R ⁵ are each independently selected from a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heteroaromatic group, wherein at least one of R ⁴ and R ⁵ is a halo-substituted aromatic group or a halo-substituted heteroaromatic group. R and R ³ are each independently selected from H, halo, hydroxyl, amino, a substituted or unsubstituted hydrocarbon group, a substituted or unsubstituted heterogeneous group, a substituted or unsubstituted carbocyclic group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heteroaromatic group. More specifically, R and R ³ can be each independently selected from H, halo, hydroxyl, cyano, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted haloalkyl, substituted or unsubstituted hydroxyalkyl, substituted or unsubstituted alkoxy, a substituted or unsubstituted heterocyclic group, a

substituted or unsubstituted aromatic group, a substituted or unsubstituted heteroaromatic group, carboxyl, alkylcarbonyl, arylcarbonyl, cycloalkylcarbonyl, heterocyclylcarbonyl, amino, aminoalkyl, alkylaminoalkyl, heterocyclylalkyl, aralkyl, arylalkenyl, arylalkynyl, alkylthio, alkylamino, arylamino, heteroarylamino, aralkylamino, alkylaminoalkylamino, arylthio, aralkylthio, aryloxy, aralkoxy, heterocyclylalkoxy, heterocyclyloxyalkyl, cycloalkyl, and cycloalkenyl.

In a further embodiment of Formula I, R ⁴ and R ⁵ are each independently selected from a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heteroaromatic group. The substituted aromatic group or heteroaromatic group can be substituted with at least one group (e.g. substituent) selected from halo, hydroxyl, amino, nitro, a substituted or unsubstituted hydrocarbon group, a substituted or unsubstituted heterogeneous group, a substituted or unsubstituted carbocyclic group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heteroaromatic group, wherein at least one of R ⁴ and R ⁵ is a halo-substituted aromatic group or a halo-substituted heteroaromatic group. More specifically, R ³ can be H or substituted or unsubstituted alkyl. The substituent can be more specifically selected from halo, hydroxyl, cyano, amino, nitro, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted haloalkyl, substituted or unsubstituted hydroxyalkyl, substituted or unsubstituted alkoxy, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aromatic group, a substituted or unsubstituted heteroaromatic group, carboxyl, alkylcarbonyl, arylcarbonyl, cycloalkylcarbonyl, heterocyclylcarbonyl, aminoalkyl, alkylaminoalkyl, heterocyclylalkyl, aralkyl, arylalkenyl, arylalkynyl, alkylthio, alkylamino, arylamino, heteroarylamino, aralkylamino, alkylaminoalkylamino, arylthio, aralkylthio, aryloxy, aralkoxy, heterocyclylalkoxy, heterocyclyloxyalkyl, cycloalkyl, and cycloalkenyl.

In a further embodiment, R ⁴ and R ⁵ are each independently selected from a substituted aromatic group or heteroaromatic group. More specifically, the group is substituted with at least one group selected from halo, hydroxyl, cyano, amino, aminoalkyl or nitro. In a further embodiment, R ⁴ and R ⁵ are selected from a substituted or unsubstituted pyridinyl group or a substituted or unsubstituted phenyl group. The substituted or unsubstituted pyridinyl group can be a 2-pyridinyl, 3-pyridinyl, or 4-pyridinyl group. The substituted pyridinyl group can be substituted in the para position. In a more specific embodiment, the substituted pyridinyl group is substituted with a chloro or fluoro. The substituted pyridinyl group can be a substituted 2-pyridinyl group.

In further embodiments of Formula I, X is S.

With respect to the above-identified embodiments and, in general, the compound(s) encompassed by Formula I, R can be NR ¹ R ² , wherein R ¹ and R ² are each independently selected from H, halo, hydroxy, nitro, a substituted or unsubstituted hydrocarbon group, a substituted or unsubstituted heterogeneous group, a substituted or unsubstituted carbocyclic group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heteroaromatic group, or R ¹ and R ² together form a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heteroaromatic group. More specifically, R ¹ and R ² together form a substituted or unsubstituted heterocyclic group. NR ¹ R ² can be a substituted or unsubstituted piperazinyl group or pyridinyl group. In a specific embodiment, NR ¹ R ² Js:

The compound described herein can be the compound of Formula I, a pharmaceutically-acceptable salt thereof, a hydrate thereof, a solvate thereof, a tautomer thereof, an optical isomer thereof, E-isomer thereof, Z-isomer thereof, or a combination thereof.

In specific embodiments, the compound of Formula I can be:

Such compounds may be used in the form of a pharmaceutically- acceptable salt, hydrate, solvate, an optical isomer thereof, E-isomer thereof, Z-isomer thereof, or a combination thereof.

The compounds of Formula I described herein can be prepared as follows: a) reacting a compound of Formula IV with an amine NHR ¹ R ² to form an intermediate of formula V:

b) reacting the intermediate of Formula V with NHR ³ NH ₂ to form an intermediate of Formula Vl:

Formula Vl

c) reacting the intermediate of Formula Vl with a ketone:

under condensation conditions, to form the compound of Formula I.

The compounds of Formulae Il or III described herein can be prepared as follows: a) reacting a compound of Formula IV with an amine NHR ¹ R ² to form an intermediate of formula V:

Formula IV Formula V b) reacting the intermediate of Formula V with NHR ³ Nh^ to form an intermediate of Formula Vl:

R Formula Vl

c) reacting the intermediate of Formula Vl with a ketone:

under condensation conditions, to form the compounds of Formulae Il or

In a further embodiment, there is provided a compound of Formula VII:

and/or a pharmaceutically-acceptable salt, hydrate, solvate, tautomer, optical isomer, E-isomer, Z-isomer, or combination thereof; wherein:

X is selected from S or O;

R and R ³ are each independently selected from H, halo, hydroxyl, amino, a substituted or unsubstituted hydrocarbon group, a substituted or unsubstituted heterogeneous group, a substituted or unsubstituted carbocyclic group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heteroaromatic group; and R ¹⁰ and R ¹¹ are each independently selected from a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heteroaromatic group.

In another embodiment of Formula VII, R and R ³ are each independently selected from H, halo, hydroxyl, cyano, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted haloalkyl, substituted or unsubstituted hydroxyalkyl, substituted or unsubstituted alkoxy, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aromatic group, a substituted or unsubstituted heteroaromatic group, carboxyl, alkylcarbonyl, arylcarbonyl, cycloalkylcarbonyl, heterocyclylcarbonyl, amino, aminoalkyl, alkylaminoalkyl, heterocyclylalkyl, aralkyl, arylalkenyl, arylalkynyl,

alkylthio, alkylamino, arylamino, heteroarylamino, aralkylamino, alkylaminoalkylamino, arylthio, aralkylthio, aryloxy, aralkoxy, heterocyclylalkoxy, heterocyclyloxyalkyl, cycloalkyl, and cycloalkenyl. In a further embodiment of Formula VII, R ¹⁰ and R ¹¹ are each independently selected from a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heteroaromatic group. The substituted aromatic group or heteroaromatic group can be substituted with at least one group (e.g. substituent) selected from halo, hydroxyl, amino, nitro, a substituted or unsubstituted hydrocarbon group, a substituted or unsubstituted heterogeneous group, a substituted or unsubstituted carbocyclic group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heteroaromatic group. More specifically, R ³ can be H or substituted or unsubstituted alkyl. The substituent can be more specifically selected from halo, hydroxyl, cyano, amino, nitro, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted haloalkyl, substituted or unsubstituted hydroxyalkyl, substituted or unsubstituted alkoxy, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aromatic group, a substituted or unsubstituted heteroaromatic group, carboxyl, alkylcarbonyl, arylcarbonyl, cycloalkylcarbonyl, heterocyclylcarbonyl, aminoalkyl, alkylaminoalkyl, heterocyclylalkyl, aralkyl, arylalkenyl, arylalkynyl, alkylthio, alkylamino, arylamino, heteroarylamino, aralkylamino, alkylaminoalkylamino, arylthio, aralkylthio, aryloxy, aralkoxy, heterocyclylalkoxy, heterocyclyloxyalkyl, cycloalkyl, and cycloalkenyl, more specifically, the substituent can be selected from halo, hydroxyl, cyano, amino, aminoalkyl or nitro.

In a further embodiment of Formula VII, R ¹⁰ and R ¹¹ are each independently selected from a substituted or unsubstituted pyridinyl group or a substituted or unsubstituted phenyl group. More specifically, the group is substituted with at least one group selected from halo, hydroxyl, cyano, amino, aminoalkyl or nitro. In a further embodiment, R ¹⁰ and R ¹¹ are selected

from a substituted or unsubstituted pyridinyl group or a substituted or unsubstituted phenyl group. The substituted or unsubstituted pyridinyl group can be a 2-pyridinyl, 3-pyridinyl, or 4-pyridinyl group. The substituted pyridinyl group can be substituted in the para position. In a more specific embodiment, the substituted pyridinyl group is substituted with a chloro or fluoro. The substituted pyridinyl group can be a substituted 2-pyridinyl group. In further embodiments of Formula VII, X is S. With respect to the above-identified embodiments and, in general, the compound(s) encompassed by Formula VII, R can be NR ¹ R ² , wherein R ¹ and R ² are each independently selected from H, halo, hydroxy, nitro, a substituted or unsubstituted hydrocarbon group, a substituted or unsubstituted heterogeneous group, a substituted or unsubstituted carbocyclic group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heteroaromatic group, or R ¹ and R ² together form a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heteroaromatic group. More specifically, R ¹ and R ² together form a substituted or unsubstituted heterocyclic group. NR ¹ R ² can be a substituted or unsubstituted piperazinyl group or pyridinyl group. In a specific embodiment, NR ¹ R ² Js:

The compound described herein can be the compound of Formula VII, a pharmaceutically-acceptable salt thereof, a hydrate thereof, a solvate thereof, a tautomer thereof, an optical isomer thereof, E-isomer thereof, Z- isomer thereof, or a combination thereof.

In specific embodiments, the compound of Formula VII can be:

VII J

VII I

COTI-4 (or COTI-4MO5)

Such compounds may be used in the form of a pharmaceutically- acceptable salt, hydrate, solvate, an optical isomer thereof, E-isomer thereof, Z-isomer thereof, or a combination thereof.

The compounds of the present invention are useful in the treatment of cancer. High levels of activity for in vitro and in vivo testing have been

observed against cancers and cancer models using the compounds of the present invention. This may lead to reduced dosages as compared with conventional therapeutic dosages of known agents.

The cancer treated may be, for example, lung cancer (particularly small cell or non-small cell lung cancer), cervical cancer, ovarian cancer, cancer of CNS, skin cancer, prostate cancer (e.g. hormone resistant prostate cancer), sarcoma, breast cancer, leukemia, colorectal cancer, head cancer, neck cancer, lymphoma, pancreatic cancer, gastric cancer, or kidney cancer. More typically, the cancer may be small cell lung cancer, breast cancer (e.g. hormone resistant breast cancer), acute leukemia, chronic leukemia, colorectal cancer. The cancer may be a carcinoma. The carcinoma may be selected from small cell carcinomas, cervical carcinomas, glioma, astrocytoma, prostate carcinomas, ovarian carcinomas, melanoma, breast carcinomas, or colorectal carcinomas. Compounds of the present invention may be even more particularly useful in the treatment of small cell lung cancer (SCLC) carcinomas.

Compounds of the present invention can have an IC ₅₀ for a cancer cell population of less than or equal to about 10,000 nM. In specific embodiments, compounds of the present invention show efficacy against SHP77 cells at IC ₅ o's of less than about 1000 nM, typically less than about 800 nM, more typically less than about 500 nM, even more typically less than about 200 nM.

Compounds of the present invention show efficacy against DMS144 cells at IC ₅₀ ¹ S of less than about 1000 nM, typically less than about 750 nM, more typically less than about 500 nM, even more typically less than about 300 nM, yet more typically less than about 100 nM.

Compounds of the present invention are effective in reducing the size of malignant human cancer tumors, particularly human small cell lung cancer tumors. Compounds of the present invention are effective in vitro at reducing the size of malignant human cancer tumors created from SHP77, DMS114, DMS-153 and/or DMS-253 small cell lung cancer lines.

Compounds of the present invention may exhibit a reduced tendency to induce cellular resistance to their own anti-cancer effects. Therefore, use of the compounds of the present invention to treat a cancer may inhibit or prevent development of a drug resistant form of that cancer. Certain compounds of the present invention may exhibit reduced toxicity as compared with conventionally administered agents.

The compounds of this invention may be administered to mammals, typically humans, either alone or, in combination with pharmaceutically acceptable carriers or diluents, optionally with known adjuvants, such as alum, in a pharmaceutical composition, according to standard pharmaceutical practice. The compounds can be administered orally or parenterally, including the intravenous, intramuscular, intraperitoneal, and subcutaneous routes of administration.

Compounds of the present invention may be advantageously administered orally, unlike most current cancer therapies, which are administered intravenously. For oral use of a compound or composition according to this invention, the selected compound may be administered, for example, in the form of tablets or capsules, or as an aqueous solution or suspension. In the case of tablets for oral use, carriers which are commonly used include lactose and corn starch, and lubricating agents, such as magnesium stearate, are commonly added. For oral administration in capsule form, useful diluents include lactose and dried corn starch. When aqueous suspensions are required for oral use, the active ingredient is combined with emulsifying and suspending agents. If desired, certain sweetening and/or flavoring agents may be added. For intramuscular, intraperitoneal, subcutaneous and intravenous use, sterile solutions of the active ingredient are usually prepared, and the pH of the solutions should be suitably adjusted and buffered. For intravenous use, the total concentration of solutes should be controlled in order to render the preparation isotonic. At least about 50% of the compound of the present invention can be orally absorbed by a mammal. In specific embodiments, at least about 60%;

about 60% to about 85%; about 65%; about 70%; about 72%; about 73%, about 75%; about 80%; about 82%; or about 85% of the compound of the present invention can be orally absorbed by a mammal, more typically, a human. "Oral absorption" is used in the context of how the compound/composition of the present invention are delivered and absorbed into the blood. Typically, the compound/composition is administered orally and crosses a mucosal membrane of the gastro-intestinal tract, typically in the intestines. However, other methods of contacting the compounds/compositions of the present invention with the mucosal membrane of the gastro-intestinal tract may also be used.

The term "administration" (e.g., "administering" a compound) in reference to a compound of the invention means introducing the compound or a prodrug of the compound into the system of the animal in need of treatment. The term "treating cancer" or "treatment of cancer" refers to administration to a mammal afflicted with a cancerous condition and refers to an effect that alleviates the cancerous condition by killing the cancerous cells, but also to an effect that results in the inhibition of growth and/or metastasis of the cancer. When a compound according to this invention is administered into a human subject, the daily dosage will normally be determined by the prescribing physician with the dosage generally varying according to the age, weight, and response of the individual patient, as well as the severity of the patient's symptoms.

In one exemplary application, a suitable amount of compound is administered to a mammal undergoing treatment for cancer. Administration occurs in an amount from about 0.01 mg/kg of body weight to greater than about 100 mg/kg of body weight per day; from about 0.01 mg/kg of body weight to about 500 mg/kg of body weight per day; from about 0.01 mg/kg of body weight to about 250 mg/kg of body weight per day; or 0.01 mg/kg of body weight to about 100 mg/kg of body weight per day. These dosages can be more particularly used orally.

The compounds of this invention may be prepared by employing reactions and standard manipulations that are known in the literature or exemplified herein.

When introducing elements disclosed herein, the articles "a", "an", "the", and "said" are intended to mean that there are one or more of the elements.

The above disclosure generally describes the present invention. A more complete understanding can be obtained by reference to the following specific Examples. These Examples are described solely for purposes of illustration and are not intended to limit the scope of the invention. Changes in form and substitution of equivalents are contemplated as circumstances may suggest or render expedient. Although specific terms have been employed herein, such terms are intended in a descriptive sense and not for purposes of limitation.

EXAMPLES

Synthesis of COTI-4 (1B)

Synthesis of the compound of COTI-4 (1B) was conducted according to the following synthetic methodology:

1

IB

lmidazol-1-yl-(4-methyl-piperazin-1-yl)-methanethione (intermediate 3) is formed as follows: λ/-Methyl piperazine (2; MW 100.16, 0.67 ml, 6.0 mmol, 1 eq) was added to a solution of 1 ,1 '-thiocarbonyldiimidazole (1; MW 178.22, 1.069 g, 6.0 mmol, 1 eq) in 50 ml dichloromethane at room temperature. The reaction mixture was stirred overnight at room temperature. This organic solution was washed with water, dried over sodium sulfate, filtered and concentrated to provide imidazol-1-yl-(4-methyl-piperazin-1-yl)-methanethione (3; MW 210.30, 1.040 g, 4.95 mmol, 82% yield) and used without further purification. TLC (CH ₂ CVMeOH: 95/5): Rf = 0.35, Product UV and Ninhydrine stain active. ¹ H-NMR (400 MHz, CDCI ₃ ), δ ppm: 2.37 (s, 3H), 2.56 (s, 4H), 3.94 (s, 4H), 7.11 (s, 1 H), 7.21 (s, 1 H), 7.88 (s, 1 H).

4-methylpiperazine-1-carbothiohydrazide (intermediate 6) can be formed according to the following scheme. Hydrazine hydrate (MW 50.06, 0.26 ml, 5.44 mmol, 1.1 eq) was added to a solution of imidazol-1-yl-(4- methyl-piperazin-1 -yl)-methanethione (3; MW 210.30, 1.040 g, 4.95 mmol, 1 eq) in 30 ml ethanol at room temperature. The reaction mixture was stirred under reflux for 2 hours. This organic solution was concentrated. The solid thus obtained was triturated with diethyl ether and filtered to yield A- methylpiperazine-1-carbothiohydrazide (6; MW 174.27, 0.53 g, 3.04 mmol, 61% yield) as a white solid which was used without further purification. TLC (CH ₂ CI ₂ /MeOH: 90/10): Rf = 0.15, Product UV and Ninhydrin stain active. ¹ H- NMR (400 MHz, DMSO-d ₆ ), δ ppm: 2.17 (s, 3H), 2.28 (t, 4H, J = 5 Hz), 3.69 (t, 4H ₁ J = 5 Hz).

Finally, A/^dipyridin^-ylmethylidene^-methylpiperazine-i - carbothiohydrazide (COTI-4; 1B) was formed as follows: 4-methylpiperazine- 1-carbothiohydrazide (6; MW 174.27, 0.349 g, 2.0 mmoles, 1 eq) and di-2- pyridyl ketone (8; MW 184.2, 0.368 g, 2.0 mmoles, 1 eq) was dissolved in 15 ml of ethanol at room temperature, in the presence of 1% of glacial acetic acid (MW 60.05, 0.15 ml, 2.6 mmoles, 1.3 eq). The mixture was stirred under reflux for 6 hours. After concentration, the crude thus obtained was taken up in dichloromethane, washed with a potassium carbonate aqueous solution,

then with water. The organic layer was dried over sodium sulfate, filtered and concentrated. The crude was purified by ISCO CombiFlash™ Companion (Redisep™ cartridge 12g, Normal phase, Gradient DCM/MeOH: 10/0 to 9/1 ) and provided /V-(dipyridin-2-ylmethylidene)-4-methylpiperazine-1 - carbothiohydrazide (1B; MW 340.45, 0.230 g, 0.68 mmole, 68% yield) as a yellow-brown solid. MS [ESI+, 90/10 MeOH/H ₂ O (5 mM NH ₄ OAc, 0.2% Acetic acid)]: [M+H] ⁺ = 341.0 ; ¹ H-NMR and HPLC analysis showed a mixture of isomers (approximately in 80/20 ratio), and >98% purity. ¹ H-NMR (400 MHz, CDCI ₃ ), δ.ppm (Major isomer): 2.34 (s, 3H), 2.54 (t, 4H, J = 5 Hz), 4.12 (t, 4H, J = 5 Hz), 7.31 (dd, 1 H, J = 8 and 5 Hz), 7.37 (dd, 1 H, J = 8 and 5 Hz), 7.66 (d, 1 H, J = 8 Hz), 7.81 (m, 2H), 8.00 (d, 1 H, J = 8 Hz), 8.58 (d, 1 H ₁ J = 5 Hz), 8.71 (d, 1 H, J = 5 Hz), 14.70 (s, 1 H). δ ppm (Minor isomer): 2.34 (s, 3H), 2.54 (t, 4H, J = 5 Hz), 4.12 (t, 4H, J = 5 Hz), 7.23 (m, 1 H), 7.30 (m, 1 H), 7.68 (d, 1H ₁ J = 8 Hz) ₁ 7.75 (m, 2H) ₁ 7.87 (d, 1H ₁ J = 8 Hz) ₁ 8.54 (d, 1H ₁ J = 5 Hz) ₁ 8.68 (d _l 1 H, J = 5 Hz), 14.70 (s, 1 H).

Synthesis of COTI-4A (1A)

Synthesis of the compound of COTI-4A (1A) was conducted according to the following synthetic methodology:

Synthon A Synthon B

Synthesis of Svnthon A

Step 1A: 4-Benzylpyridazine (11)

To a 7O ⁰ C solution of pyridazine (9;10g, 0.125 mole) in aqueous H ₂ SO ₄ (2N.125 ml_) was added AgNO ₃ (6.37g, 0.0375 mole). Phenylacetic acid (10; 85.06g 0.625 mole) was added to the mixture. The reaction mixture was stirred vigorously at 7O ⁰ C for 20 minutes and was degassed with a flow of nitrogen for 2 minutes, followed by a slow portionwise addition of ammonium persulfate (85.62, 0.375 mole) with rapid gas evolution. The reaction mixture was then heated at 9O ⁰ C for 30 minutes. The reaction mixture was then cooled at room temperature and the solution was extracted with CH ₂ CI ₂ . A

50% NaOH solution was added to the aqueous phase, which was re-extracted with CH ₂ CI ₂ twice. The combined extracts were dried over MgSO4. The solvent was evaporated to dryness and the residue was purified by silica gel chromatography using CH ₂ CI ₂ / 5% methanol as the eluent. The yield of 4- benzylpyridazine (11) obtained was 8.2 g or 39%. MS (ESI+): [M+H]+ =

171.47; ¹ H NMR (300 MHz, CDCI ₃ ), δ ppm: 4.0 (s,2H), 7.18-7.4 (m, 6H), 9.02- 9.18 (m, 2H).

Step 2A: Phenyl-Pyridazin-4-yl-Methanone (12) To a 100 ⁰ C suspension of SeO ₂ (4.75g, 0.043 mole) in acetic acid (216 ml_) was added dropwise to a solution of 4-benzylpyridazine (11 ; 7.6g, 0.044.6 mole) in acetic acid (216 ml.) . The mixture was heated for 1 hour at 100 ⁰ C. The reaction mixture was cooled to room temperature and was neutralized to a pH ~6-7 with 50 % NaOH. The neutralized mixture was extracted twice with CH ₂ CI ₂ . The combined extracts were dried over MgSO ₄ and were evaporated to dryness. The crude product was purified by crystallization in refluxing isopropyl alcohol (10 vol). The yield of phenylpyridazin-4-yl-methanone (12) obtained was 5.8g or 66%. MS (ESI+): [M+H]+ = 185.33; ¹ H NMR (300 MHz, CDCI ₃ ), δ ppm: 7.5-7.60(m, 2H), 7.64-7.83 (m, 4H), 9.42-9.51 (m, 2H).

Synthesis of Svnthon B

Step 1B: Imidazol- 1-yl-(4-Methyl-2-yl-Piperazin-1vO-Methanethione (3)

1-Methylpiperazine (2; 3.28 g, 32.8 mmoles, 1 eq.) was added to a solution of 1 ,1 '-thiocarbonyldiimidazole (3; 6.5 g, 32.8 mmoles, 1eq.) in dichloromethane (20OmL) at room temperature (RT). After stirring overnight at RT the mixture was washed with water, was dried over sodium sulfate, was filtered and was concentrated to provide imidazol-1-yl-(4-methyl-piperazin-1-yl)-methanethione (3). The yield was 99.43%. MS (ESI+): the product was not stable at high temperature. ¹ HNMR (300 MHz, CDCI ₃ ), δ ppm: 2.27 (s, 3H), 2.40 (s, 4H), 2.60 (s, 4H), 7.0-7.4 (s, 2H), 7.8-8.00 (s,1 H).

Step 2B: (N-Methylpiperazine)Carbothioacid Hvdrazide (6)

To a solution of imidazol-1yl-(4-methyl-piperazin-1-yl)-methanethione (3; 3.64 g, 17.3 mmoles 1eq.) in 70 ml of ethanol at RT was added hydrazine hydrate (0.953 g, 19.03 mmoles, 1.1 eq.). The reaction was stirred and refluxed for 2 hours during which time a white precipitate formed. The white precipitate (N- methylpiperazine)carbothioacid hydrazide (6)) was filtered off and was rinsed with t-butyl methyl ether. The yield was 72 %. MS (ESI+): 175; ¹ H NMR (300 MHz, CDCI ₃ ), δ ppm: 2.0 (s, 1 H ), 2.27 (s, 3H), 2.40 (s, 4H ), 3.8 (s, 4H ), 4.4 (S, 2H ).

Synthesis of COTI-4A (1 A)

Step 1 : 4-methyl-Ar-fphenyl(pyridazin-4-yl)methylidene1piperazine-1- carbothiohvdrazide (1A) A mixture of phenyl-pyridazin-4-yl-methanone (12; Synthon A, 2.3 g, 12.4 mmol) and 4-Methylpiperazine-1-carbothioic acid hydrazide (6; Synthon B, 2.82 g, 16.18 mmol) in ethanol (7.5 mL) was heated to 65 ⁰ C for 5h under N ₂ in a 50 mL pyrex tube equipped with a screw cap. The mixture remained heterogeneous during the heating and a brown suspension resulted at the end of the reaction. The mixture was diluted with CH ₂ CI ₂ (7.5 mL) and was chromatographed on silica gel that was eluted with MeOH/ CH ₂ CI ₂ (2.5-5%) to

give 1.8 g of a yellow foamy solid 1A (99.3% pure by HPLC); m.p. 141-143 ⁰ C (m.p. of a crystalline sample 143-145). TLC (CH ₂ CI ₂ /MeOH/NH ₄ OH:95/5/0.5): R _f =0.6, product is visibly yellow, UV and Dragendorff stain active. MS (ESI+): [M+H]+ = 340.93. HRMS: m/z calcd. for C ₁₇ H ₂ iN ₆ S ([M+H]+): 341.15429; found: 341.15501. ¹ H NMR (300 MHz, CDCI ₃ ), δ ppm: 2.38 (s, 3H), 2.61 (t, 4H ₁ J = 5.0 Hz), 4.12 (t, 4H, J = 5.0 Hz) ₁ 7.29 (m, 3H), 7.63 (m, 3H), 8.64 (s, 1 H), 9.14 (dd, 1 H ₁ J = 5.7 Hz, J' = 1.5 Hz), 9.44 (dd, 1 H ₁ J = 2.4 Hz, J' = 1.5 Hz). ¹³ C NMR (75.4 MHz, CDCI ₃ ), δ ppm: 45.75, 51.64, 54.75, 123.30, 128.29, 128.39, 130.40, 131.10, 134.86, 143.94, 148.31 , 151.31 , 181.49.

Example 1 (COTI-4 MB))

IC ₅₀ and Dose Response Determination

The ability of the compounds of Formula VII to inhibit tumor cell growth in vitro of three (3) human small cell lung cancer cell lines and three (3) human non-small cell lung cancer cell lines was evaluated. Specifically, COTI-4 (1B, also referred to as COTI-4MO5) was tested.

Table 1 shows the IC ₅₀ , or the molar concentration of the compound required to produce 50% of the maximum possible inhibitory response. As a comparative example, Gleevec® (imatinib mesylate, Novartis Pharmaceutical Inc.) was used. Gleevec® is an FDA-approved anti-tumor drug for chronic myelogenous leukemia, which acts as an ATP-analog to inhibit tyrosine kinase. In DMS-114, DMS-153 and SHP-77 SCLC tumor cells, compound COTI-4MO5 (1B) was found to be more effective than Gleevec®.

Figure 1 illustrates the dose response of three human SCLC tumor cell lines (DMS-114, DMS-153 and SHP-77) to Gleevec®, for comparison to Figure 2. Figure 2 illustrates the dose response of human SCLC tumor cell lines to COTI-4MO5 (1B). Figure 3 illustrates the dose response of NSCLC tumor cell lines to COTI- 4MO5 (1B).

The capacity of the compound COTI-4, to inhibit growth of human small cell lung cancer cell lines (DMS-114, DMS-153, and SHP-77) and human non- small cell lung cancer cell lines (A549 adenocarcinoma-derived cells, H226 squamous cell carcinoma-derived cells, and A460 large cell carcinoma- derived cells) was tested.

In vitro inhibition of small cell lung cancer (SCLC) cell lines by the compound of COTI-4 was done with standard human tumor cells (established cell lines available from the American Type Tissue culture collection). Cells were plated in plastic tissue culture plates and grown under standard conditions for each cell line, in carbon dioxide/oxygen atmosphere in plastic tissue culture plates, in the presence of each of the compound of COTI-4, as well as COTI-2MO5 (or COTI-2) and COTI-219MO5 (or COTI-219) compounds (0-1 mM), versus Gleevec® (0-100 mM) at 35 ⁰ C for 3 days. Control cultures were treated with vehicle minus compound or Gleevec®. Cells were counted after 3 days in culture and at a cell density of no more than 80%.

Figures 1 to 3 show cell numbers for the different cell lines after treatment with various concentrations of compounds. Concentrations of the COTI-4 (COTI-4MO5) and Gleevec® that inhibit growth of 3 human small cell lung cancer cell lines by 50% are shown in Table 1. Note that the compound of COTI-4 is over 100 times more effective than Gleevec® against these cell lines in vitro.

The compound of COTI-4 inhibits growth and/or kills SCLC cells with IC ₅₀ values that are at least 0.03 mM and generally less than 1 mM. On the other hand, Gleevec® has an IC ₅₀ value of 15-19 mM, depending on cell line

tested. IC ₅₀ values in the micromolar range, as seen here, indicate high capacity of the compound of formula 1B to inhibit human tumor cell growth.

In vitro inhibition of non-small cell lung cancer (NSCLC) cell lines by the compound of Formula 1 B (COTI-4) was evaluated. Standard numbers of human tumor cells (established cell lines available from the American Type Tissue culture collection) were plated in plastic tissue culture plates and grown under standard conditions for each cell line, in carbon dioxide/oxygen atmosphere in plastic tissue culture plates, in the presence of COTI-4 (0-1 mM) or Gleevec® (0-100 mM) at 35°C for 3 days. Control cultures were treated with vehicle minus compound or Gleevec®. Cells were counted after 3 days in culture and at a cell density of no more than 80%.

Figure 3 depicts a graph showing cell numbers after treatment with various concentrations of the compound of 1 B. The summary data of the concentrations required to inhibit growth by 50% are presented in Table 2.

COTI-4M05 inhibits growth and/or kills NSCLC cells with IC ₅₀ values of at least 2.5 mM. Thus, the selected compound of COTI-4MO5 is effective against NSCLC cell lines, but less so than against SCLC cell lines. COTI- 4MO5 was more effective than Gleevec® against NSCLC cell lines.

Example 2 (COTI-4)

Inhibition of Tumor Growth

In vivo testing of the capacity of COTI-4MO5 and Taxol® (paclitaxel, Bristol Myers Squibb) to inhibit the growth of human SHP-77 SCLC cells as xenograft in immunocompromised mice was evaluated.

SHP-77 SCLC cells were grown in culture and injected into each flank of NCr-nu mice (T cell-deficient immunocompromised mice, suitable for growth of this cell line)(2X 10 ⁶ cells per injection, in Matrigel™). Mice harbouring SHP-77 tumour xenografts were treated with COTI-2MO5 or COTI-4MO5, as described for the data shown in Figure 4. One day after injection of tumour cells, groups of 5 mice each were injected with 3 mg/kg of COTI-2MO5 or COTI-4MO5 (Lp.), once every 2 days, up to 38 days. Tumour size was estimated at 5, 10, 17, 24, and 38 days, by external caliper measurement. Animals were humanely euthanized after the 38 day tumour measurement.

Figure 4 depicts the effect of a compound, referred to herein interchangeably as COTI-4, COTI-4MO5, or the compound of formula 1 B, in inhibiting tumor growth over 38 days of treatment. Also depicted for comparison is a saline control, and compound referred to as COTI-2, which is the subject of a co-pending patent application, U.S. Provisional Patent

Application 60/884,504, incorporated herein by reference. Data are shown (each data point is the mean size of 3-10 tumours ± SE) in Figure 4.

The mean tumour size in mice treated with COTI-2MO5 or COTI-4MO5 is significantly lower than in mice treated with saline vehicle (p<0.05). For comparison, mice (5 mice per group, injected as described above with SHP-77 human tumor cells as described above) and harbouring SHP-77 xenografts were treated with Taxol® (12.5 mg/kg, i.p. in 0.5 ml isotonic saline) every 2 days (according to the report of J. Riondel et al., Anticancer Res. 8:387-90, 1988) or with cisplatin (3.0 mg/kg of DDP i.p., once per week for four weeks, in isotonic saline, according to the report of P.A. Andrews et al., Cancer Commun. 2:93-100, 1990). Tumour size was estimated at 5, 10, 17, 24, and 38 days, by external caliper measurement. Animals were humanely euthanized after the 38 day tumour measurement.

Figure 5 allows comparison, when viewed against data presented in Figure 4, showing the effect on tumor growth of Taxol® and cisplatin

treatment against a saline control. Data are shown (each data point is the mean size of 4-10 tumours ± SE) in Figure 5.

Tumour size in both Taxol®- and cisplatin-treated mice was significantly lower than in saline-treated mice (p<0.05). Figure 6 illustrates numbers of detectable tumors. When numbers of tumours (rather than tumour size) was plotted for all treatment groups, it was apparent that numbers of tumours in control (saline-treated) mice reached a maximum at day 24 post-tumour cell injection, and decreased thereafter. The maximum number of tumours in mice treated with Taxol®, cisplatin, COTI- 219MO5, COTI-4MO5, and COTI-2MO5 were all lower than that in control, saline-treated mice. The data are not subject to analysis of significance since single aggregate numbers of tumours at each day of treatment were available. Figure 7 shows the average weight of animals treated with COTI-4M05, versus saline (as a control), Taxol® and cisplatin comparative controls. Also depicted are results from compounds referred to as "COTI-2M05", and "COTI- 219M05", which are each the subject of co-pending U.S. Provisional Patent Applications 60/884,504 and 60/884,489, respectively, both provisionals are incorporated herein by reference.

Small cell lung cancer tumor size was determined and expressed as mean tumor volume. For COTI-4M05, mean tumor volume was 6.2 mm ³ , whereas values were much greater for cisplatin (132±26 mm ³ ), Taxol® (183 mm ³ ) and control (saline) treated tumors (260±33 mm ³ ).

Example 3 (COTI-4A M A)) IC ₅₀ and Dose Response Determination

The ability of compounds of COTI-4A (1A) to inhibit tumor cell growth in vitro of three (3) human small cell lung cancer cell lines and three (3) human non-small cell lung cancer cell lines was evaluated.

The capacity of the compounds of formula 1 A to inhibit growth of human small cell lung cancer cell lines (DMS-114, DMS-153, and SHP-77) and human non-small cell lung cancer cell lines (A549 adenocarcinoma-

derived cells, H226 squamous cell carcinoma-derived cells, and H460 large cell carcinoma-derived cells) was tested.

In vitro inhibition of small cell lung cancer (SCLC) cell lines by the compound of formula 1 A was done with standard human tumor cells (established cell lines available from the American Type Tissue culture collection). Cells were plated in plastic tissue culture plates and grown under standard conditions for each cell line, in carbon dioxide/oxygen atmosphere in plastic tissue culture plates, in the presence of the compounds of Formula 1 A versus Gleevec® (0-100 mM) at 35°C for 3 days. Control cultures were treated with vehicle minus compound or Gleevec®. Cells were counted after 3 days in culture and at a cell density of no more than 80%.

Figures 8 to 10 show cell numbers for the different small cell lung cancer cell lines after treatment with various concentrations of compounds according to Formula 1A. Figure 8 illustrates the dose response of human SCLC cell line DMS-

114 to COTI-4A. The two different lots relate to replicate experiments.

Figure 9 illustrates the dose response of human SCLC cell line DMS- 153 to COTI-4A. The two different lots relate to replicate experiments.

Figure 10 illustrates the dose response of human SCLC cell line SHP- 77 to COTI-4A. The two different lots relate to replicate experiments.

Concentrations of the compounds of Formula 1A and Gleevec® that inhibit growth of the 3 human small cell lung cancer cell lines by 50% were determined and are shown in Table 3.

COTI-4A inhibits growth and/or kills SCLC cells with IC50 values of at least 0.65 mM. It can be seen from Table 3 that COTI-4A is two orders of magnitude (about 100 times) more effective in vitro than Gleevec® against the two human SCLC cell lines DMS-114 and DMS-153 and about twice as effective as Gleevec® against human SCLC cell line SHP-77. SHP-77 is a notoriously difficult cell line to treat for most drugs, as evidenced by the higher IC _5O ¹ S for all drugs tested.

In vitro inhibition of non-small cell lung cancer (NSCLC) cell lines by the compound of Formula 1A is evaluated. Standard numbers of human tumor cells (established cell lines available from the American Type Tissue culture collection) were plated in plastic tissue culture plates and grown under standard conditions for each cell line, in carbon dioxide/oxygen atmosphere in plastic tissue culture plates, in the presence of compounds of formula 1A (0-1 mM) or Gleevec® (0-100 mM) at 35°C for 3 days. Control cultures are treated with vehicle minus compound or Gleevec®. Cells are counted after 3 days in culture and at a cell density of no more than 80%.

Figures 11 to 13 show cell numbers for the different non-small cell lung cancer cell lines after treatment with various concentrations of compounds according to Formula 1A. Figure 11 illustrates the dose response of human non-SCLC cell line A-

549 to COTI-4A. The two different lots relate to replicate experiments.

Figure 12 illustrates the dose response of human non-SCLC cell line H- 226 to COTI-4A. The two different lots relate to replicate experiments.

Figure 13 illustrates the dose response of human non-SCLC cell line H- 460 to COTI-4A. The two different lots relate to replicate experiments.

Concentrations of the compound of Formula 1A and Gleevec® that inhibit growth of the 3 human non-small cell lung cancer cell lines by 50% were

determined and are shown in Table 4.

COTI-4A inhibits growth and/or kills NSCLC cells with IC ₅₀ values of at least 1.5 mM. Thus, COTI-4A is effective against NSCLC cell lines, but less so than against SCLC cell lines. COTI-4A was more effective than Gleevec® against the NSCLC cell lines A549 and had comparable efficacy to Gleevec® for the other NSCLC cell lines that were tested, H226 and A460.

Example 4: In-silico Assessment of Properties

An in-silico assessment of the properties of compounds according to the present invention was performed using the CHEMSAS ^® computational platform. CHEMSAS ^® is a robust proprietary computational platform for accelerated drug discovery, optimization and lead selection based upon a unique combination of traditional and modern pharmacology principles, statistical modeling and machine learning technologies. At the centre of the CHEMSAS ^® platform is a hybrid machine learning technology that may be used to: find, profile and optimize new targeted lead compounds; find novel uses for known compounds; and, solve problems with existing or potential drugs. In using the CHEMSAS ^® platform, first a therapeutic target was selected, in this case cancer and more particularly Small Cell Lung Cancer. The second step involved the design of a candidate molecule library containing thousands of potential compounds through the assembly of privileged molecular fragments. Thirdly, the candidate library was profiled and optimized using a combination of validated computational models and traditional expert medicinal chemistry. In this step, the CHEMSAS ^® platform

developed 244 molecular descriptors for each candidate therapeutic compound. For example, molecular properties relating to a candidate compound's therapeutic efficacy, expected human toxicity, oral absorption, cumulative cellular resistance and/or kinetics were assessed. In some instances, comparative properties relating to commercially relevant benchmark compounds were also assessed. Potential lead compounds were then selected from the candidate library using a proprietary decision making tool designed to identify candidates with the optimal physical chemical properties, efficacy, ADME/Toxicity profile, etc. according to a pre-determined set of design criteria. The lead compounds selected from the candidate library were then synthesized for further pre-clinical development.

The properties of certain compounds according to the present invention, specifically COTI-4 (1B), COTI-4A (1A), and Formulae 1C, 1D, 1G, 1H, 11, and VIIA to VIIJ, that were assessed in-silico using the CHEMSAS ^® computational platform are shown in Tables 5 to 8. Some of the predicted properties are validated by the experimental data provided herein, while other properties have been validated elsewhere during the development of other clinical candidates. The CHEMSAS ^® platform therefore provides a means of determining, predicting and/or testing the properties of a compound, particularly when used to determine the properties of compounds according to the present invention. The CHEMSAS ^® platform is also particularly useful in comparing the properties of compounds according to the invention with prior art compounds on a relative basis in silico.

Tables 5A and 5B: Physical Chemical Properties

Tables 5A and 5B shows that COTI-4 (1B), COTI-4A (1A), and Formulae 1C, 1D, 1G, 1H, 11, and VIIA to VIIJ are "drug-like" with good drug like physical properties.

Table 5A

Table 5B

Legend for Table 5:

MolWeight stands for Molecular Weight measured in Daltons and is a size descriptor;

MnLogP is an average of MLogP, ALogP98 and CLogP, all of which are calculated lipophilicity/solubility estimates;

HBndDon stands for Hydrogen Bond Donor and refers to the number of atoms able to donate electrons to potentially form Hydrogen bonds;

HBndAcc stands for Hydrogen Bond Acceptor and refers to the number of atoms able to accept electrons to potentially form Hydrogen bonds;

TPSA stands for Topological Polar Surface Area and is a measure of

Molecular Surface Charge/Polarity; and

RotBnds stands for Rotatable Bonds which is a count of freely rotatable single bonds in the molecule.

Tables 6A and 6B: Solubility Properties

Tables 6A and 6B shows that COTI-4 (1B), COTI-4A (1A), and Formulae 1C, 1D, 1G, 1H, 11, and VIIA to VIIJ are expected to have acceptable solubility values for drug-like compounds.

Table 6A

Table 6B

Legend for Table 6:

LogD(7.4) is a measure of relative solubility in octanol vs water at a specific pH, in this case pH= 7.4;

LogS is the logarithm of the calculated solubility in pure water usually measured at 25 degrees centigrade; pKa is a calculated estimate of the pH at which the drug or substructures of the drug is 50% ionized and 50% is unionized.

Table 7: Efficacy (LoαlC™)

Tables 7A {in-silico) and 7B (actual in-vitro data) show that COTI-4 (1B), COTI-4A (1A), and Formulae 1C, 1D, 1G, 1H, 11, and VIIA to VIIJ are

predicted to have sub-micromolar in vitro IC ₅₀ vs human SCLC cell lines. Actual measurements obtained in vitro confirm the in silico prediction of activity at sub-micromolar IC ₅₀ levels for 1A and 1B.

Table 7A

Table 7B

Legend for Table 7:

DMS114 is a human small cell lung cancer line that is maintained by the National Cancer Institute in the United States;

SHP-77 is a human small cell lung cancer line that is maintained by the National Cancer Institute in the United States; and

DMS153 and DMS253 are human small cell lung cancer lines that are maintained by the National Cancer Institute in the United States. These two cell lines are expected to have similar properties in vitro.

Table 8: Efficacy (LoglCsn)

Tables 8A (in-silico) and 8B (actual in-vitro data) show that COTI-4 (1B), COTI-4A (1A), and Formulae 1C, 1D, 1G, 1H, 11, and VIIA to VIIJ are not predicted to have sub-micromolar in vitro IC ₅₀ vs human non-SCLC cell lines. Actual measurements obtained in vitro confirm the in silico prediction of IC ₅₀ levels for 1 A and 1 B. However, both compounds were effective in treating non-SCLC cell lines at higher IC ₅₀ levels.

Table 8A

Table 8B

Legend for Table 8:

A549 is a adenocarcinoma-derived cell line that is maintained by the National Cancer Institute in the United States;

H226 is a squamous cell carcinoma-derived cell line that is maintained by the National Cancer Institute in the United States; and,

H460 is a large cell carcinoma-derived cell line that is maintained by the National Cancer Institute in the United States.

Tables 9A, 9B. 1OA and 1OB: Physical Chemical Properties Tables 9A, 9B, 1OA and 1OB show that COTI-4 (1B), COTI-4A (1A), are "drug-like" with good drug like physical properties whereas Formulae S00115; S00340; and S00341 of Chinese Patent Application No. 1891701 are not.

S00115 S00340 S0034

Table 9A

Table 9B

Legend for Table 9:

MolWeight stands for Molecular Weight measured in Daltons and is a size descriptor;

MnLogP is an average of MLogP, ALogP98 and CLogP, all of which are calculated lipophilicity/solubility estimates;

HBndDon stands for Hydrogen Bond Donor and refers to the number of atoms able to donate electrons to potentially form Hydrogen bonds;

HBndAcc stands for Hydrogen Bond Acceptor and refers to the number of atoms able to accept electrons to potentially form Hydrogen bonds;

TPSA stands for Topological Polar Surface Area and is a measure of

Molecular Surface Charge/Polarity; and

RotBnds stands for Rotatable Bonds which is a count of freely rotatable single bonds in the molecule.

Table 1OA

Table 10B

Legend for Table 10:

LogD(7.4) is a measure of relative solubility in octanol vs water at a specific pH, in this case pH= 7.4;

LogS is the logarithm of the calculated solubility in pure water usually measured at 25 degrees centigrade; pKa is a calculated estimate of the pH at which the drug or substructures of the drug is 50% ionized and 50% is unionized.

Table 11: Efficacy (LoglC™)

Tables 11 A (in-silico) and 11 B (actual in-vitro data) show that COTI-4 (1B), COTI-4A (1A) are predicted to have sub-micromolar in vitro IC ₅₀ vs human SCLC cell lines, whereas Formulae S00115; S00340; and S00341 of Chinese Patent Application No. 1891701 are not. Actual measurements obtained in vitro confirm the in silico prediction of activity at sub-micromolar IC ₅₀ levels for 1A and 1B.

Table 11 A

Table 11B

Legend for Table 11:

DMS114 is a human small cell lung cancer line that is maintained by the

National Cancer Institute in the United States;

SHP-77 is a human small cell lung cancer line that is maintained by the

National Cancer Institute in the United States; and

DMS153 and DMS253 are human small cell lung cancer lines that are maintained by the National Cancer Institute in the United States. These two cell lines are expected to have similar properties in vitro.

Table 12: Efficacy (Logic™) Tables 12A (in-silico) and 12B (actual in-vitro data) show that COTI-4

(1B) and COTI-4A (1A) and Formulae S00115; S00340; and S00341 of Chinese Patent Application No. 1891701 are not predicted to have sub- micromolar in vitro IC ₅₀ vs human non-SCLC cell lines. Actual measurements obtained in vitro confirm the in silico prediction of IC ₅₀ levels for 1A and 1 B. However, both compounds were effective in treating non-SCLC cell lines at higher IC ₅₀ levels.

Table 12A

Table 12B

Legend for Table 12:

A549 is a adenocarcinoma-derived cell line that is maintained by the National

Cancer Institute in the United States;

H226 is a squamous cell carcinoma-derived cell line that is maintained by the

National Cancer Institute in the United States; and,

H460 is a large cell carcinoma-derived cell line that is maintained by the

National Cancer Institute in the United States.

Example 5 (COTI-4 (1B)) To assess the efficacy of compounds according to the present invention in the treatment of cancer, in vitro activity expressed as IC ₅₀ (represents the concentration of an inhibitor that is required for 50% inhibition of its target, in nmol) was measured for several cancer cell lines using standard methods for such tests known to persons skilled in the art. Briefly, cells were plated in plastic tissue culture plates and grown under standard conditions for each cell line, in carbon dioxide/oxygen atmosphere in plastic

tissue culture plates, in the presence of COTI-4 or COTI-4A compounds at 35°C for 3 days. Control cultures were treated with vehicle minus compound. Cells were counted after 3 days in culture and at a cell density of no more than 80%. The following cell lines, obtained from the National Cancer Institute, were tested: human SCLC cell lines DMS 153, DMS114, SHP77; human NSCLC cell lines H226, A460, A549; human breast cancer cell lines T47D, MCF7; human colon cancer cell line HT29; and, human Leukemia cell lines K562, HL60. The results of these assays are presented in Table 13.

Table 13: in vitro /CM against cancer cell lines

Table 13 shows that both COTI-4 and COTI-4A possess potent activity against SCLC tumor cell types, as well as several other tumor cell types such as breast cancer, colorectal cancer and Leukemia. Both drugs had an IC ₅₀ of less than 1000 nM for the DMS153 and DMS114 cell lines. Neither drug

possessed nanomolar level activity against NSCLC cell types, although both exhibited efficacy in the treatment of those cell types. Both drugs therefore exhibit selectivity in lung cancer treatment towards SCLC cell types. The in vitro data also confirms and validates the in-silico predictions of efficacy, which estimated that less than 1 μM (1000 nM) would be required for efficacy in the DMS 114 cell line and that neither drug would have sub-micromolar activity in treating NSCLC cell lines.

Example 6: Resistance Testing In order to evaluate the induction of resistance in vitro, compounds according to Formula 1 B (COTI-4) were tested in head to head comparisons against conventional therapeutic agents cisplatin and another member of the taxane family (to which paclitaxel belongs), docetaxel (sold under the brand name Taxotere® by Sanofi-Aventis). The compounds designated COTI-2 and COTI-219, previously referenced herein, were also tested.

IC ₅₀ values were obtained using methods known to persons skilled in the art with two different human SCLC cell lines (DMS153 and SHP77) obtained from the National Cancer Institute. The surviving 50% of cells from the initial IC ₅₀ tested were harvested and cultured for 5 days, after which time this new generation of cells was re-treated with the same agent and a new IC ₅ 0 value was established. The procedure was repeated for a total of 5 generations. Emerging resistance was identified by increasing IC ₅₀ values in successive generations. The results are shown in Figs. 14 and 15 (DMS153 and SHP77 cell lines, respectively), where the ordinate axis is provided in terms of the ratio of the IC50 value of the drug resistant cells to the IC ₅₀ value of the non-drug resistant parental generation.

Referring to Figs. 14 and 15, for all cell lines, compounds of the present invention were more effective in treating the drug resistant cells than the cisplation or the taxane docetaxel (labeled paclitaxel in Figs. 14 and 15). COTI-4 exhibited little to no emerging resistance over 5 generations. This was in marked contrast to the conventional therapies cisplatin and docetaxel,

which showed significant increases in IC ₅₀ for both cell lines, even after only one round of selection. The SHP77 cell line, in particular, is known to be resistant to conventional agents; however, COTI 4 showed only a marginal increase in resistance in this cell line, with less than a two fold increase in IC50 observed over five successive generations of cancerous cells treated with the compound.

In fact, COTI-4 demonstrated a statistically significant tendency to decrease resistance (less than a one fold increase in IC ₅₀ observed over five successive generations of cancerous cells treated with the compound) in the DMS153 cell line. The tendency of COTI-4 to decrease resistance in the

DMS 153 cell line was even greater than that of the prior art compounds COTI- 2 and COTI-219. COTI-4 therefore exhibits a collateral sensitivity whereby the resistance of cells is decreased over successive generations and the drug might actually become more effective over time against these cell lines.

Example 7: In Vivo Toxicity Testing

An escalating dose acute toxicity study was conducted with COTI-2, COTI-4 (Formula 1 B) and COTI-219. Standard lab mice were divided into four treatment groups (control, 4, 8, 16 mg/kg) with four animals per group. It should be noted that the highest dose was approximately 10 times the estimated effective dose. Mice were given alternate day IP injections for 28 days. Weight loss/gain of the mice was measured and the mice were observed for adverse effects such as vomiting, diarrhea, seizures, etc.

Referring to Fig. 16, the weight loss of the mice was plotted on the ordinate axis (in grams, +/- standard error), with the number of days of treatment plotted on the abscissa. None of the mice exhibited any signs of acute toxicity at any of the dosages and no adverse events were observed, although one mouse in the high dose control group was euthanized on day 18 due to non-drug related causes (this reduced the high dose group to n=3 for the final ten days of the study). These results indicated that COTI-4 is safe

and non-toxic at all dosage levels, even at up to 10 times the therapeutic dose, which is surprising in the field of anti-cancer drugs.

The above-described embodiments of the present invention are intended to be examples only. Alterations, modifications and variations may be effected to the particular embodiments by those of skill in the art without departing from the scope of the invention, which is defined solely by the claims appended hereto.