CROSS REFERENCE TO RELATED APPLICATIONS

Benefit is claimed to United States Provisional Patent Application No. 63/123,202, filed December 9, 2020, the contents of which are incorporated by reference herein in their entirety.

FIELD

This disclosure relates to treatments for cancer, and particular in solid tumors.

BACKGROUND

Cancer is a leading cause of death worldwide. Cancer, also called tumor, is a mass of cells composed of undifferentiated cells which proliferate in an unlimited manner irrespective of conditions required in tissues, unlike normal cells which can proliferate in a regular and controllable manner and can be suppressed, according to the individual's needs. Cancer cells, which proliferate in such an unlimited manner, penetrate into surrounding tissues and, in some cases, metastasize to other organs of the body, thereby causing an intractable disease that involves severe pain and eventually leads to death.

Cancer is largely classified into blood cancer and solid cancer and can develop in almost all parts of the body. Some specific types of cancer include pancreatic cancer, breast cancer, oral cancer, liver cancer, uterine cancer, esophageal cancer, and skin cancer. As therapeutic methods therefor, a small number of targeted biological therapeutic agents have recently been used to treat certain cancers. However, up to now, surgery or radiation therapy and anti-cancer agent therapy using a chemotherapeutic agent that inhibits cell proliferation are mainly used methods. A disadvantage associated with conventional chemotherapeutic agents is that they are not targeted therapeutic agents. Thus, the biggest problem of the conventional chemotherapeutic agents is side effects due to their cytotoxicity and drug resistance, which are the main factors that eventually result in failure of treatment despite initial successful response caused by anticancer agents. Therefore, in order to overcome limitations of these chemotherapeutic agents, there is a need to develop therapeutic agents having a clear mechanism of anti-cancer action.

Among types of cancer, pancreatic cancer is one of the leading causes of death. Pancreatic cancer is an aggressive disease as compared with cancer diseases of other organs such as uterine cancer, breast cancer, rectal cancer, colorectal cancer, skin cancer, lung cancer, and liver cancer. Pancreatic cancer has a disadvantage of being very difficult to diagnose. In addition, pancreatic cancer is one of the most serious malignant tumors with acute onset, delayed diagnosis, and low survival rate.

SUMMARY

Provided herein are compositions for use in treatment of cancer comprising a therapeutically effective amount of harmine or a pharmaceutically acceptable salt thereof in combination with a therapeutically effective amount of cordycepin.

Further provided herein are methods for treatment of cancer comprising administering to a patient in need thereof a therapeutically effective amount of harmine or a pharmaceutically acceptable salt thereof in combination with a therapeutically effective amount of cordycepin. Optionally, the amounts are synergistic and together provide an enhanced therapeutic effect.

The foregoing and other objects, features, and advantages will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig- 1 is a graph showing percentage of KPCY (2838c3) mouse pancreatic cancer cells which underwent apoptosis, either untreated, treated with DMSO (positive control) or treated with harmine, cordycepin and combinations thereof;

Figs 2A and 2B are graphs showing tumor growth over time (2A) and tumor volume on day 25 (2B) in groups of mice implanted with Lewis Lung Carcinoma (LLC), administered either vehicle (as a control), harmine alone, or combinations of harmine and cordycepin.

DETAILED DESCRIPTION

I. Terms

Unless otherwise explained, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The singular terms “a,” “an,” and “the” include plural referents unless context clearly indicates otherwise. Similarly, the word “or” is intended to include “and” unless the context clearly indicates otherwise. The term “comprises” means “includes.” The abbreviation, “e.g.” is derived from the Latin exempli gratia, and is used herein to indicate a non-limiting example. Thus, the abbreviation “e.g.” is synonymous with the term “for example.” In case of conflict, the present specification, including explanations of terms, will control. In addition, all the materials, methods, and examples are illustrative and not intended to be limiting. Administration: The introduction of a composition into a subject by a chosen route. Administration of an active compound or composition can be by any route known to one of skill in the art. Administration can be local or systemic. Examples of local administration include, but are not limited to, topical administration, intratumoral administration, subcutaneous administration, intramuscular administration, intrathecal administration, intra-ocular administration, topical ophthalmic administration, or administration to the nasal mucosa or lungs by inhalational administration. In addition, local administration includes routes of administration typically used for systemic administration, for example by directing intravascular administration to the arterial supply for a particular organ. Thus, in particular embodiments, local administration includes intra-arterial administration and intravenous administration when such administration is targeted to the vasculature supplying a particular organ. Local administration also includes the incorporation of active compounds and agents into implantable devices or constructs (such as the drug delivery devices described herein), which release the active agents and compounds over extended time intervals for sustained treatment effects. An implantable device is "implanted" by any means known to the art of insertion into the tissue or tissue environment that is the area of a given treatment.

Systemic administration includes any route of administration designed to distribute an active compound or composition widely throughout the body via the circulatory system. Thus, systemic administration includes, but is not limited to intra-arterial and intravenous administration. Systemic administration also includes, but is not limited to, topical administration, subcutaneous administration, intramuscular administration, or administration by inhalation, when such administration is directed at absorption and distribution throughout the body by the circulatory system.

Botanical Drug Substance: A drug derived from one or more plants, algae, or fungi, prepared from raw materials by one or more than one of: pulverization, decoction, expression, extraction (water or ethanol) or similar processes. A botanical drug substance does not include a highly purified or chemically modified substance derived from natural sources.

Cancer: The product of neoplasia is a neoplasm (a tumor or cancer), which is an abnormal growth of tissue that results from excessive cell division. Neoplasia is one example of a proliferative disorder. A “cancer cell” is a cell that is neoplastic, for example a cell or cell line isolated from a tumor.

Examples of solid tumors, such as sarcomas and carcinomas, include fibrosarcoma, myxosarcoma, liposarcoma, chondrosarcoma, osteogenic sarcoma, and other sarcomas, synovioma, mesothelioma, Ewing's tumor, leiomyosarcoma, rhabdomyosarcoma, colon carcinoma, lymphoid malignancy, pancreatic cancer, breast cancer, lung cancers (such as small cell lung carcinoma and non-small cell lung carcinoma), ovarian cancer, prostate cancer, hepatocellular carcinoma, squamous cell carcinoma, basal cell carcinoma, adenocarcinoma, sweat gland carcinoma, medullary thyroid carcinoma, papillary thyroid carcinoma, pheochromocytomas sebaceous gland carcinoma, papillary carcinoma, papillary adenocarcinomas, medullary carcinoma, bronchogenic carcinoma, renal cell carcinoma, hepatoma, bile duct carcinoma, choriocarcinoma, Wilms’ tumor, cervical cancer, testicular tumor, seminoma, bladder carcinoma, melanoma, and CNS tumors (such as a glioma, astrocytoma, medulloblastoma, craniopharyogioma, ependymoma, pinealoma, hemangioblastoma, acoustic neuroma, oligodendroglioma, menangioma, neuroblastoma and retinoblastoma). In particular embodiments, the cancer that is targeted for treatment by the described compositions and methods is a metastasis which is not the primary tumor.

Examples of hematological tumors include leukemias, including acute leukemias (such as acute lymphocytic leukemia, acute myelocytic leukemia, acute myelogenous leukemia and myeloblastic, promyelocytic, myelomonocytic, monocytic and erythroleukemia), chronic leukemias (such as chronic myelocytic (granulocytic) leukemia, chronic myelogenous leukemia, and chronic lymphocytic leukemia), polycythemia vera, lymphoma, Hodgkin's disease, nonHodgkin’s lymphoma (indolent and high grade forms), multiple myeloma, Waldenstrom’s macroglobulinemia, heavy chain disease, myelodysplastic syndrome, hairy cell leukemia and myelodysplasia.

Chemotherapeutic agent: An anti-cancer agent with therapeutic usefulness in the treatment of diseases characterized by abnormal cell growth or hyperplasia. Such diseases include cancer, autoimmune disease as well as diseases characterized by hyperplastic growth such as psoriasis. One of skill in the art can readily identify a chemotherapeutic agent (for instance, see Slapak and Kufe, Principles of Cancer Therapy, Chapter 86 in Harrison's Principles of Internal Medicine, 14th edition; Perry el al., Chemotherapy, Ch. 17 in Abeloff, Clinical Oncology 2 ^nd ed., © 2000 Churchill Livingstone, Inc; Baltzer L, Berkery R (eds): Oncology Pocket Guide to Chemotherapy, 2nd ed. St. Louis, Mosby -Year Book, 1995; Fischer DS, Knobf MF, Durivage HJ (eds): The Cancer Chemotherapy Handbook, 4th ed. St. Louis, Mosby-Year Book, 1993). Non-limiting examples of chemotherapeutic agents include ICL- inducing agents, such as melphalan (Alkeran™), cyclophosphamide (Cytoxan™), cisplatin (Platinol™) and busulfan (Busilvex™, Myleran™). Chemotherapeutic agents include small molecules, nucleic acid, peptide, and antibody -based therapeutic agents; examples of all of which are known in the art. Immunomodulatory agents, which enhance the activity of a subject’s immune system against a foreign body, such as a tumor, including a solid tumor, are other examples of chemotherapeutic agents.

Combination: A treatment modality combining two or more treatments (therapies or agents). Combination therapy may involve administration of the two or more treatments at the same time, sequentially, or with a gap of time between the administrations. In combination therapy, although not always administered simultaneously, the biological effects of both of the drugs or treatments occur on the subject at relatively the same time. Combination therapy may involve two (or more) drugs or treatments in one dosage form or multiple drugs or treatments in separate dosage forms.

Cordycepin: a purine nucleoside which has been found in in fungus Cordyceps miltaris. Its structure is:

Effective amount of a compound: A quantity of compound sufficient to achieve a desired effect in a subject being treated. An effective amount of a compound can be administered in a single dose, or in several doses, for example daily, during a course of treatment. However, the effective amount of the compound will be dependent on the compound applied, the subject being treated, the severity, and type of the affliction, and the manner of administration of the compound.

Harmine: a harmala alkaloid found in a variety of plants including the vine Banisteriopsis caapi, which has been identified as a reversible inhibitor of monoamine oxidase A (MAO- A). Its structure is:

Neoplasia, malignancy, cancer and tumor: A neoplasm is an abnormal growth of tissue or cells that results from excessive cell division. Neoplastic growth can produce a tumor. The amount of a tumor in an individual is the “tumor burden” which can be measured as the number, volume, or weight of the tumor. A tumor that does not metastasize is referred to as “benign.” A tumor that invades the surrounding tissue and/or can metastasize is referred to as “malignant.” Malignant tumors are also referred to as “cancer.”

Pharmaceutically Acceptable Salt: The term "pharmaceutically acceptable salt" of a given compound refers to salts that retain the biological effectiveness and properties of the given compound, and which are not biologically or otherwise undesirable. Pharmaceutically acceptable acid addition salts may be prepared from inorganic and organic acids. Salts derived from inorganic acids include hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, and the like. Salts derived from organic acids include acetic acid, propionic acid, glycolic acid, pyruvic acid, oxalic acid, malic acid, malonic acid, succinic acid, maleic acid, fumaric acid, tartaric acid, citric acid, methanesulfonic acid, ethanesulfonic acid, p-toluene- sulfonic acid, and the like.

Radiation Therapy (Radiotherapy): The treatment of disease (e.g., cancer or another hyperproliferative disease or condition) by exposure of a subject or their tissue to a radioactive substance. Radiation therapy is the medical use of ionizing radiation as part of cancer treatment to control malignant cells. Radiotherapy may be used for curative or adjuvant cancer treatment. It is used as palliative treatment where cure is not possible and the aim is for local disease control or symptomatic relief.

Subject: Living multi-cellular organisms, including vertebrate organisms, a category that includes both human and non -human mammals.

Subject susceptible to a disease or condition: A subject capable of, prone to, or predisposed to developing a disease or condition. It is understood that a subject already having or showing symptoms of a disease or condition is considered “susceptible” since they have already developed it.

Synergy: refers to a clinical observation wherein a combination of two treatments, such as harmine therapy and cordycepin therapy, when administered in combination, provides more than additive effect of the thymoquinone therapy alone and the psilocybin therapy alone.

Therapeutically effective amount: A quantity of compound sufficient to achieve a desired effect in a subject being treated. An effective amount of a compound may be administered in a single dose, or in several doses, for example daily, during a course of treatment. However, the effective amount will be dependent on the compound applied, the subject being treated, the severity and type of the affliction, and the manner of administration of the compound. II. Overview of Several Embodiments

Provided herein are compositions for use in treating cancer comprising a harmine or a pharmaceutically acceptable salt thereof in combination with cordycepin.

When harmine was evaluated for altering metastatic tumor cell progression in vitro and in vivo, results demonstrated that Harmine induced Gl/S phase cell cycle arrest and apoptosis in NSCLC cells. Further study suggested that Harmine treatment led to inhibition of cell metastasis and invasion properties of NSCLC cells. Moreover, Harmine suppressed xenograft of A549 tumor growth and metastasis in vivo. Reversion-inducing cysteine-rich protein with kazal motifs (RECK) is a novel tumor suppressor gene that is critical for regulating tumor cell invasion and metastasis. The expression of RECK is dramatically down-regulated in human cancers. Mechanistically, in harmine-treated NSCLC cells, RECK expression and its downstream signaling cascade were dramatically activated. As a consequence, the expression level of MMP- 9 and E-cadherin were significantly decreased It has been suggested by the inventor that harmine is a promising candidate for metastatic non-small cell lung cancer (NSCLC) treatment, when used in combination with cordycepin as described.

Pancreatic carcinoma is one of the deadliest types of cancer, and relatively insensitive to currently available chemotherapy. Data showed that harmine exerted an anti-proliferative effect and cell cycle arrest at G2/M in pancreatic cancer cells. Harmine also induced apoptosis and enhanced the gemcitabine-induced apoptosis in pancreatic cancer cells. It also inhibited the proliferation of pancreatic cancer cells. It has been suggested by the inventor that harmine is a promising candidate for pancreatic cancer treatment, when used in combination with cordycepin as described.

Cordycepin has a structure similar to the cellular nucleoside adenosine and can act as a nucleoside analogue. During the process of RNA synthesis (transcription), some enzymes are not able to distinguish between an adenosine and cordycepin which leads to incorporation of cordycepin to induce premature termination of transcription. Cordycepin has been shown to inhibit growth of gallbladder cancer cell lines and human lung cancer cell lines. A high dosage of cordycepin can block mTOR (mammalian target of rapamycin) signaling pathway. Cordycepin can activate AMPK which blocks the activity of mT0RCl/mT0RC2 complex. The inactivated complex cannot activate AKT 1 kinase fully, which suppress mTOR signal transduction inhibiting translation, and further cell proliferation and growth. Cordycepin can induce cancer cell apoptosis in caspase-dependent pathways. In human Non-Small Cell Lung Cancer (NSCLC), Cordycepin-induced apoptosis was also associated with down-regulation of protein c-ELIP, which inhibited the activity of caspase-8. Cordycepin inhibited cell growth by inducing apoptosis and autophagy. The cordycepin-stimulated autophagy was mediated by suppressing mTOR signaling pathway in lung cancer cells. In addition, suppression of autophagy could also elevate the protein level of c-FLIP which indicated cordycepin-triggered autophagy promoted the degradation of c-FLIP. Therefore, Cordycepin induced apoptosis through autophagy-mediated downregulation of c-FLIP in human NSCLC cells. In addition, cordycepin also inhibits the ERK/Slug signaling pathway through the activation of GSK3P which, upregulates Bax to result in apoptosis of lung cancer cells.

Cordycepin also induces cancer cell apoptosis in caspase-independent pathways. Cordycepin decreased cell mitosis and EGFR signaling in one murine oral tumor mouse model. The treatment distinctly reduced the levels of ki-67 and EGFR signaling molecules to induce cancer cell apoptosis. Cordycepin inhibited the migration and invasion of human oral squamous cell carcinoma (OSCC) cell through upregulating E-cadherin and downregulating N-cadherin protein expression, implying the inhibition of Cordycepin on epithelial-mesenchymal transition (EMT). Cordycepin inhibited cell viability, proliferation and colony formation ability and induced cell cycle arrest and early apoptosis of human pancreatic cancer cells. A decrease of A'Pm and upregulation of Bax, cleaved caspase-3, cleaved caspase-9, and cleaved PARP as well as downregulation of Bcl-2 both in vitro and in vivo indicated that the mitochondria-mediated intrinsic pathway was involved in cordycepin’ s antitumor effect.

It has been suggested by the inventor that cordycepin is a promising candidate for pancreatic cancer and metastatic non-small cell lung cancer (NSCLC) treatment, when used in combination with harmine as described.

Pharmaceutical compositions described herein may comprise cordycepin and harmine in combination, either in a single dosage form or in multiple dosage forms.

According to an embodiment, the pharmaceutical composition is in the form of a solid dosage form or a liquid dosage form. The solid dosage form may be in the form of tablets, capsules, pills, powders, granules. The liquid dosage form may be in the form of tinctures, suspensions, syrups, and emulsions. The compositions may be formulated for administration through the following routes: intravenous (bolus or infusion), intraperitoneal, subcutaneous, or intramuscular.

When the pharmaceutical compositions are prepared in tablet form, they may further comprise: binders, lubricants, diluents, disintegrating agents, coloring agents, flavoring agents and/or flow-inducing agents, for oral administration in the dosage unit form of a tablet or capsule, the active drug component can be combined with an oral, non-toxic, pharmaceutically acceptable, inert carrier such as lactose, gelatin, agar, starch, sucrose, glucose, methyl cellulose, magnesium stearate, dicalcium phosphate, calcium sulfate, mannitol, sorbitol and the like. Suitable binders include starch, gelatin, natural sugars such as glucose or beta-lactose, corn sweeteners, natural and synthetic gums such as acacia, tragacanth, or sodium alginate, carboxymethylcellulose, polyethylene glycol, waxes, and the like. Lubricants used in these dosage forms include sodium oleate, sodium stearate, magnesium stearate, sodium benzoate, sodium acetate, sodium chloride, and the like. Disintegrators include, without limitation, starch, methyl cellulose, agar, bentonite, xanthan gum, and the like.

The compositions in liquid form can also be administered in the form of liposome delivery systems, such as small unilamellar vesicles, large unilamallar vesicles, and multilamellar vesicles. Liposomes can be formed from a variety of phospholipids, such as cholesterol, stearylamine, or phosphatidylcholines. The compounds may be administered as components of tissue-targeted emulsions.

When the pharmaceutical compositions are prepared for parenteral administration, they may be in the form of a solutions, preferably containing a soluble salt of the active ingredient, suitable stabilizing agents, and if necessary, buffer substances. Sustained release liquid dosage forms suitable for parenteral administration, including, but not limited to, water-in-oil and oil- in-water microemulsions and biodegradable microsphere polymers, may be used according to methods well-known to those having ordinary skill in the art. Antioxidizing agents such as sodium bisulfite, sodium sulfite, or ascorbic acid, either alone or combined, are suitable stabilizing agents. Also used are citric acid and its salts and sodium EDTA. In addition, parenteral solutions can contain preservatives, such as benzalkonium chloride, methyl- or propyl-paraben, and chlorobutanol.

According to an embodiment, a method for treatment is described. The method comprises administering to the patient in need thereof, a pharmaceutically acceptable salt of harmine or harmine, and cordycepin, once daily, twice daily, three times daily, or four times daily. The daily administration may continue for one day, two days, or three days. Optionally, administration may continue until a therapeutic effect is observed in the patient, for example, a shrinking of a tumor. According to an embodiment, the method comprises administering to the patient in need thereof, a pharmaceutically acceptable salt of harmine or harmine, and cordycepin, both through the intravenous route.

Further described herein are methods for inducing apoptosis in a tumor comprising administering to a patient suffering from a tumor a pharmaceutically acceptable salt of harmine or harmine, and cordycepin, in an amount effective in inducing apoptosis in the tumor. Further described herein are methods for decreasing cell migration, invasion or metastasis comprising administering to a patient a pharmaceutically acceptable salt of harmine or harmine, and cordycepin, in an amount effective to decrease cell migration, invasion or metastasis.

According to an embodiment, harmine salt in the form of the hydrochloride (HC1) salt is administered.

According to an embodiment, a patient is administered a pharmaceutically acceptable salt of harmine or harmine, and cordycepin as a combination therapy in two or more dosage forms, one comprising harmine and the other cordycepin, or in one dosage form comprising comprising both harmine and cordycepin.

Embodiments described herein relate to methods for treatment of cancer in a patient in need thereof comprising administering to the patient a therapeutically effective amount of harmine or a pharmaceutically acceptable salt thereof, in combination with cordycepin. Optionally, the administration induces apoptosis in tumor cells. Optionally, the method decreases cell migration, invasion or metastasis. Optionally, the harmine or pharmaceutically acceptable salt thereof or the cordycepin is in the form of a botanical drug substance. Optionally, the harmine or pharmaceutically acceptable salt thereof or the cordycepin is in isolated form. Optionally, the harmine or a pharmaceutically acceptable salt thereof, in combination with cordycepin are each administered in an amount to have a synergistic effect. Optionally, the cancer is a solid tumor. Optionally, the solid tumor is selected from the group consisting of: pancreatic cancer, non small cell lung cancer, breast cancer, ovarian cancer, gastric cancer, bladder cancer, thyroid cancer, and neuroblastoma. Optionally, the solid tumor is selected from the group consisting of: pancreatic cancer and non small cell lung cancer. Optionally, the method further comprises administering to the patient an additional chemotherapeutic agent. Optionally, the method further comprises treating the patient with radiation. Optionally, the therapeutically effective amount of harmine or the equivalent amount of the pharmaceutically acceptable salt thereof is between 5- 100 milligrams per kilogram per day (mg/kg/day). Optionally, the therapeutically effective amount of harmine or the equivalent amount of the pharmaceutically acceptable salt thereof is between 10-40 mg/kg/day. Optionally, the therapeutically effective amount of cordycepin is between 5-200 mg/kg/day. Optionally, the therapeutically effective amount of cordycepin is between 8-60 mg/kg/day. Optionally, the ratio administered, by weight of harmine to cordycepin is between 1:1 and 1:3. Optionally, the ratio administered, by weight of harmine to cordycepin is between 1:1.25 and 1:2.5. Optionally, the harmine is administered in the form of harmine HC1. Optionally, harmine is administered in the form of free base. Optionally, the combination is administered for at least 14 days. Optionally, the harmine or pharmaceutically acceptable salt thereof and the cordycepin are administered intravenously.

Embodiments described herein relate to a pharmaceutical composition for use in treatment of cancer in a patient in need thereof comprising a therapeutically effective amount of harmine or a pharmaceutically acceptable salt thereof, in combination with cordycepin. Optionally, the pharmaceutical composition is for use in inducing apoptosis in tumor cells in a patient suffering from cancer comprising a therapeutically effective amount of harmine or a pharmaceutically acceptable salt thereof, in combination with cordycepin. Optionally, the pharmaceutical composition is for use in decreasing cell migration, invasion or metastasis in a patient suffering from cancer comprising a therapeutically effective amount of harmine or a pharmaceutically acceptable salt thereof, in combination with cordycepin. Optionally, the harmine or pharmaceutically acceptable salt thereof or the cordycepin is in the form of a botanical drug substance. Optionally, the harmine or pharmaceutically acceptable salt thereof or the cordycepin is in isolated form. Optionally, the harmine or a pharmaceutically acceptable salt thereof, in combination with cordycepin are each administered in an amount to have a synergistic effect. Optionally, the cancer is a solid tumor. Optionally, the solid tumor is selected from the group consisting of: pancreatic cancer, non small cell lung cancer, breast cancer, ovarian cancer, gastric cancer, bladder cancer, thyroid cancer, and neuroblastoma. Optionally, the solid tumor is selected from the group consisting of: pancreatic cancer and non small cell lung cancer. Optionally, the treatment further comprises administering to the patient an additional chemotherapeutic agent. Optionally, the treatment further comprises treating the patient with radiation. Optionally, the therapeutically effective amount of harmine or the equivalent amount of the pharmaceutically acceptable salt thereof is between 5-100 milligrams per kilogram per day (mg/kg/day). Optionally, the therapeutically effective amount of harmine or the equivalent amount of the pharmaceutically acceptable salt thereof is between 10-40 mg/kg/day. Optionally, the therapeutically effective amount of cordycepin is between 5-200 mg/kg/day. Optionally, the therapeutically effective amount of cordycepin is between 8-60 mg/kg/day. Optionally, the ratio administered, by weight of harmine to cordycepin is between 1:1 and 1:3. Optionally, the ratio administered, by weight of harmine to cordycepin is between 1:1.25 and 1:2.5. Optionally, the harmine is administered in the form of harmine HC1. Optionally, harmine is administered in the form of free base. Optionally, the combination is administered for at least 14 days. Optionally, the harmine or pharmaceutically acceptable salt thereof and the cordycepin are administered intravenously. The following examples are provided to illustrate certain particular features and/or embodiments. These examples should not be construed to limit the disclosure to the particular features or embodiments described.

EXAMPLES

Example 1: In vitro model of apoptosis in cancer cell lines

A model for induction of apoptosis in pancreatic cancer (pancreatic ductal adenocarcinoma) cells was performed using mouse pancreatic cancer cells, in order to determine effects of harmine and cordycepin at various concentrations, separately, and in combination. KPCY (2838c3) mouse pancreatic cancer cells were obtained, and were seeded into 6-well plates at a density of 2xl0 ⁵ per well. Cells were allowed to settle for 24 hours. Cells were then treated with the compounds at the indicated concentrations ranging from 1 micromolar (pM) to 40 pM for 24 hours. Apoptosis was detected by a Muse Annexin V & Dead Cell kit according to the manufacturer’s recommendations.

Fig. 1 shows results of percentage of cells which underwent apoptosis in the control, untreated cells as well as various concentrations of each of harmine and cordycepin. 10% DMSO was used as a positive control. Data is analyzed by unpaired t-test and presented as mean ± SEM. One asterisk indicates p-value of less than 0.05. Two asterisks indicate p-value of less than 0.01.

As can be seen, significant apoptosis relative to untreated cells is present only in cells in which both harmine and cordycepin were used as active agents. In particular, the cells which were exposed to 40 pM harmine and 1 pM cordycepin, or 40 pM harmine and 10 pM cordycepin showed apoptosis caused by administration of the agents. Harmine and cordycepin alone at these concentrations did not show significant apoptosis in the pancreatic cancer cell line.

This model indicates that harmine and cordycepin can act synergistically to induce apoptosis in cancer cells and may be used synergistically in humans for treatment of cancer, in particular, pancreatic cancer. In particular, the ratios which showed a significant amount of apoptosis were molar ratios of harmine to cordycepin of 40:1 and 4:1.

Example 2: In vivo model: Lewis Lung Carcinoma in Male Mice

Mouse-derived tumor cell models involve the subcutaneous or orthotopic implantation of tumor cell lines into mice of the same genetic background to conduct in vivo efficacy evaluation of potential cancer therapies. Harmine alone or harmine with cordycepin were dosed in C57B1/6 mice bearing Lewis Lung Carcinoma (LLC) tumors to determine if tumor growth can be inhibited. The LLC model is based on a cell line derived from a C57BL mouse, which produces very rapidly growing tumors in the lung either following direct implantation or as a result of metastases from subcutaneous xenografts and is representative of non-small cell lung carcinoma.

Male mice aged 6-7 weeks and weighing 25-30 grams were entered into the study after acclimation of not less than five days. Mice were kept in ventilated cages on a 12 hour light/ dark cycle with no more than 4 mice per cage and were given standard rodent chow and water ad libitum.

LLC cells were obtained from ATCC and cultured. Cells were harvested by trypsinization, washed, resuspended and 100 uL of the cell suspension in phosphate buffered saline, having 2.5xl0 ⁵ cells were injected subcutaneously into shaved right flank of the animals. Mice were monitored thrice weekly, dependent on tumor growth rate. Body weight was measured thrice weekly. Tumor growth was assessed and measured with calipers. No tumor was allowed to grow larger than 2 cm ³ . If a tumor reached that size, the animal was removed from the study and euthanized.

Once tumors reached a mean of 75-100 mm ³ , mice were divided into four groups of 15. Test agents or vehicle were administered in an amount of 100 pL, once daily, interperitoneally, for 14 days. Group 1 was administered vehicle (0.9% saline). Group 2 was administered harmine at a dose of 40 mg/kg. Group 3 was administered harmine at a dose of 20 mg/kg in combination with cordycepin at 50 mg/kg. This group was designated “low harmine, cordycepin”. Group 4 was administered harmine at a dose of 40 mg/kg in combination with cordycepin at 50 mg/kg. This group was designated “high harmine, cordycepin”. Harmine was obtained from Sigma Aldrich, USA. Harmine was made fresh daily and dissolved in saline with minor vortexing.

Tumor volume over the course of the study was monitored and is graphically shown in Fig. 2A. Tumor volume on day 25 is graphically shown in Fig. 2B. Data is presented in both figures as mean ± SEM. In Fig. 2B, asterisk indicates a p-value < 0.05.

Tumor growth was significantly higher in the untreated control and the harmine only groups when compared to the combinations of harmine and cordycepin. It is noteworthy that in the low harmine dose, when combined with cordycepin, tumor growth was lower than in a higher dose of harmine alone. This indicates a surprising ability of harmine and cordycepin to reduce tumor growth in a lung cancer in vivo model, even when harmine was used at lower doses.

In view of the many possible embodiments to which the principles of the disclosed invention may be applied, it should be recognized that the illustrated embodiments are only preferred examples of the invention and should not be taken as limiting the scope of the invention. Rather, the scope of the invention is defined by the following claims. We therefore claim as our invention all that comes within the scope and spirit of these claims.