WO2012033016A1

WO2012033016A1 - Drug for treating tumor, antitumor agent, method for treating tumor and kit for treating tumor

Info

Publication number: WO2012033016A1
Application number: PCT/JP2011/070022
Authority: WO
Inventors: 勉和田; 正樹藤岡; 文乃小長井
Original assignee: 株式会社クレハ
Priority date: 2010-09-10
Filing date: 2011-09-02
Publication date: 2012-03-15
Also published as: TW201215396A; JP2014001141A

Abstract

The purpose of the present invention is to provide a drug for treating tumor which is capable of exhibiting a therapeutic effect on non-responders, from among patients with gastric cancer, colorectal cancer and small cell lung cancer, said non-responders showing little response (sensitivity) to an antitumor agent containing, as the active ingredient, protein polysaccharides derived from Trametes versicolor. The purpose can be achieved by a drug for treating tumor comprising an antitumor agent, which contains protein polysaccharides derived from Trametes versicolor as the active ingredient, together with an inhibitor of immunosuppressive cells which contains a compound having an activity of inhibiting immunosuppressive cells.

Description

Tumor treatment agent, antitumor agent, tumor treatment method and tumor treatment kit

The present invention relates to a tumor therapeutic agent using an antitumor agent containing a protein polysaccharide derived from Kawaratake as an active ingredient.

Protein polysaccharide extracted from Kawaratake shows antitumor activity and the like. For example, JP-A-60-45533 (Patent Document 1) describes an antitumor agent containing a protein polysaccharide derived from Kawaratake as an active ingredient. Among such protein polysaccharides, PSK (registered trademark) (trade name “Krestin” (registered trademark)), which is a kind of protein polysaccharide derived from Kawaratake, is used not only intradermally or intravenously but also orally. It is characterized by exhibiting antitumor activity even when administered, and is clinically used as a preparation for oral administration.

PSK is a protein polysaccharide containing about 18 to 38% protein, and has a molecular weight of 5000 or more (gel filtration method), for example, 5000 to 300,000 (gel filtration method). The sugar part of the main fraction is β-D-glucan, and the structure of this glucan part is a branched structure containing 1 → 3, 1 → 4 and 1 → 6 bonds.

Antitumor agents (eg, PSK) containing Kawaratake-derived protein polysaccharide as an active ingredient prolong survival by combined use with chemotherapy in gastric cancer (surgery) patients and colorectal cancer (curative resection) patients In addition, the effect of prolonging the response period by combination with chemotherapy for small cell lung cancer has been confirmed, and application to gastric cancer patients, colorectal cancer patients, and small cell lung cancer patients has been approved.

Japanese Patent Laid-Open No. 60-45533

However, there are non-responders with low efficacy of PSK administration in patients with stomach cancer, colorectal cancer, and small cell lung cancer. In other words, gastric cancer patients, colorectal cancer patients, and small cell lung cancer patients have non-responders with low reactivity (sensitivity) to antitumor agents containing protein polysaccharides from Kawaratake as active ingredients. Yes. Therefore, an object of the present invention is to provide a tumor therapeutic agent or an antitumor agent that exhibits a therapeutic effect even for these non-responders.

In addition, application of PSK to cancer patients other than gastric cancer patients, colorectal cancer patients, and small cell lung cancer patients has not been approved at present. A further object of the present invention is to provide a tumor therapeutic agent or an antitumor agent using a protein polysaccharide derived from Kawaratake with few side effects for cancer patients to which PSK has not been applied.

As a result of intensive studies on compounds that can enhance the therapeutic effect on malignant tumors of the protein polysaccharide derived from Kawaratake, the present inventors have found that the compound having inhibitory activity against immunosuppressive cells is a protein polysaccharide derived from Kawaratake. It has been found that by administering in combination with the body, the inhibitory effect on the proliferation of cancer cells of the protein polysaccharide derived from Kawaratake can be enhanced and can be an excellent drug for treating tumors against many cancers. The present invention is based on such findings and includes the following inventions.

The present invention relates to a tumor therapeutic agent comprising a combination of an antitumor agent comprising a protein polysaccharide derived from Kawaratake as an active ingredient and an immunosuppressive cell inhibitor comprising a compound having an inhibitory activity on immunosuppressive cells. About. The therapeutic agent for tumor according to the present invention has a high therapeutic effect even for a non-responder having low reactivity with an antitumor agent containing a protein polysaccharide derived from Kawaratake as an active ingredient.

In the tumor therapeutic agent of the present invention, it is preferable that the compound further has antitumor activity. A compound having an inhibitory activity on immunosuppressive cells has an antitumor activity, whereby a synergistic effect is obtained in the treatment of tumors.

In the tumor therapeutic agent of the present invention, the immunosuppressive cell is preferably a myeloid-derived suppressor cell (MDSC). Since the compound has an inhibitory activity on MDSC, it is possible to eliminate the inhibition of the action of an antitumor agent containing a protein polysaccharide derived from Kawaratake by MDSC as an active ingredient, and to improve the therapeutic effect of the drug for tumor treatment. is there.

In the tumor therapeutic agent of the present invention, the immunosuppressive cell is preferably a regulatory T cell (Treg). Since the compound has Treg inhibitory activity, it is possible to eliminate the suppression of the action of an antitumor agent containing a protein polysaccharide derived from Kawaratake by Treg as an active ingredient, and to improve the therapeutic effect of a drug for tumor treatment. is there.

In the tumor therapeutic agent of the present invention, the compound is gemcitabine, phosphodiesterase-5 (PDE-5) inhibitory compound, all-trans-retinoic acid (ATRA), arginase inhibitory compound, sunitinib, cyclophosphami Preferably, the compound is selected from the group consisting of: Denileukindiftitox, CTLA-4 inhibitory compound, CD25 inhibitory compound, and IL-2R inhibitory compound.

The present invention also relates to an antitumor agent comprising a protein polysaccharide derived from Kawaratake as an active ingredient, characterized in that it is used in combination with an immunosuppressive cell inhibitor comprising a compound having an inhibitory activity on immunosuppressive cells. It relates to an antitumor agent. The antitumor agent according to the present invention has a high therapeutic effect even for a non-responder having a low reactivity with an antitumor agent containing a protein polysaccharide derived from Kawaratake as an active ingredient.

The present invention also relates to a tumor treatment comprising a combination of an antitumor agent comprising a protein polysaccharide derived from Kawaratake as an active ingredient and an immunosuppressive cell inhibitor comprising a compound having immunosuppressive cell inhibitory activity. Regarding the method.

The present invention also relates to a tumor treatment kit comprising a combination of a plurality of active ingredients, wherein the active ingredient comprises a protein polysaccharide derived from Kawaratake and a compound having an inhibitory activity on immunosuppressive cells. .

According to the tumor therapeutic agent of the present invention, an antitumor agent comprising a protein polysaccharide derived from Kawaratake as an active ingredient and an immunosuppressive cell inhibitor comprising a compound having an inhibitory activity on immunosuppressive cells are used in combination. By doing so, the proliferation of cancer cells can be suppressed and a high therapeutic effect can be obtained. That is, the tumor therapeutic agent of the present invention has a high therapeutic effect even for a non-responder having low reactivity (sensitivity) to an antitumor agent containing a protein polysaccharide derived from Kawaratake as an active ingredient.

In addition, the tumor therapeutic agent of the present invention suppresses the growth of cancer cells even for tumors for which application of an antitumor agent containing a protein polysaccharide derived from Kawaratake, such as PSK, as an active ingredient has not been approved. There is also an effect that can be made.

For example, at present, application of an antitumor agent containing protein polysaccharide derived from Kawaratake such as PSK as an active ingredient is not approved for breast cancer, but the tumor therapeutic agent of the present invention suppresses the growth of cancer cells, It can also be retracted. Furthermore, when the immunosuppressive cell inhibitor used in the present invention has immunosuppressive cell inhibitory activity and (direct) cytotoxic (disorder) activity, the tumor therapeutic agent of the present invention is The effect which synergized the effect which this compound originally has is shown.

The data regarding Example 1 are shown, (A) is the figure which showed the administration schedule of an antitumor agent and an immunosuppressive cell inhibitor, (B) is a graph which shows the suppression effect of a tumor volume, ( C) is a graph showing the effect of suppressing tumor weight. The data regarding Example 2 are shown, (A) is the figure which showed the administration schedule of an antitumor agent and an immunosuppressive cell inhibitor, (B) is a graph which shows the suppression effect of a tumor volume, ( C) is a graph showing the effect of suppressing tumor weight. 4 is a graph showing the effect of suppressing the tumor volume of a tumor therapeutic agent in Example 3. FIG. 6 is a graph showing the effect of suppressing the tumor volume of a tumor therapeutic agent in Example 4. The data regarding Example 5 are shown, (A) is a graph which shows the inhibitory effect of a tumor volume, (B) is a graph which shows the inhibitory effect of a tumor weight. 10 is a graph showing the tumor volume inhibitory effect of a tumor therapeutic agent in Example 6. FIG.

[1] Drug for tumor treatment The drug for tumor treatment of the present invention comprises an antitumor agent comprising a protein polysaccharide derived from Kawaratake as an active ingredient, and an immunosuppressive cell inhibitor comprising a compound having an inhibitory activity on immunosuppressive cells, Are used together. Details of the antitumor agent and immunosuppressive cell inhibitor in the tumor therapeutic agent according to the present invention are described below.

In the present specification and the like, “combination” means administration of a drug for tumor treatment containing a protein polysaccharide derived from Kawaratake and a compound having an inhibitory activity on immunosuppressive cells as a single agent. Furthermore, an antitumor agent comprising a protein polysaccharide derived from Kawaratake, which is in the form of a single preparation, as an active ingredient and an immunosuppressive cell inhibitor comprising a compound having an inhibitory activity on immunosuppressive cells, either simultaneously or with a time difference. It also means that two drugs are administered. In the latter case, the number of administrations of the antitumor agent and the immunosuppressive cell inhibitor may be the same or different.

(Anti-tumor agent containing Kawaratake-derived protein polysaccharide as an active ingredient)
As an antitumor agent containing a protein polysaccharide derived from Kawaratake as an active ingredient, for example, PSK can be mentioned. PSK is sold under the trade name “Krestin”, and mycelium of Kawaratake fungus CM101 strain [FERM-P2412 (ATCC20547)] is used in an aqueous solvent such as hot water or an alkaline solution (for example, alkali metal hydroxide). Product, in particular, an aqueous solution of sodium hydroxide), purified and dried. The sugar portion of the main fraction is β-D-glucan, and the structure of this glucan portion is a branched structure containing β1 → 3, β1 → 4 and β1 → 6 bonds. The main constituent monosaccharides are glucose and mannose and contain about 18-38% protein. The constituent amino acids of proteins are mostly acidic amino acids such as aspartic acid and glutamic acid, and neutral amino acids such as valine and leucine, and few basic amino acids such as lysine and arginine.

In the present specification and the like, Kawaratake is not limited to the CM101 strain, and may contain any protein polysaccharide having antitumor activity. Moreover, the antitumor agent containing protein polysaccharide derived from Kawaratake as an active ingredient is not limited as long as it has antitumor activity. For example, PSK and PSK generic drugs such as Ascle (Nichi-Iko), Cretile powder (Sawai Pharmaceutical), Thiorestin powder (Chaseido), Thiorestin powder (Tanabe Seiyaku Sales), Carbocline powder (Taiyo Pharmaceutical Co., Ltd.), and Carbocline powder (Nippon Chemifa) may be used.

Antitumor agents containing Kawaratake-derived protein polysaccharide as an active ingredient are prolongation of survival by combined use with chemotherapy in patients with gastric cancer (surgery) and colorectal cancer (curative resection), and small cell lung cancer Has been confirmed to be effective in prolonging the response period by combination with chemotherapy, etc., and is approved for gastric cancer patients, colorectal cancer patients, and small cell lung cancer patients.

(Immunosuppressive cell inhibitor comprising a compound having inhibitory activity on immunosuppressive cells)
The immunosuppressive cell inhibitor used in the tumor therapeutic agent of the present invention contains a compound having an inhibitory activity on immunosuppressive cells. The immunosuppressive cell is not particularly limited as long as it has a function of suppressing the immune response of the living body. Examples of immunosuppressive cells include myeloid-derived suppressor cells (hereinafter sometimes referred to as MDSC) and regulatory T cells (hereinafter sometimes referred to as Treg). The myeloid-derived suppressor cells and regulatory T cells will be described below.

(Myeloid-derived suppressor cells)
MDSC is a general term for myeloid cells having immunosuppressive ability. MDSCs are heterogeneous cell groups that interact with T cells, macrophages, and NK cells. It has also been reported that it increases in peripheral blood and tumor tissue of cancer patients. Although it does not specifically limit as a surface marker of mouse | mouth MDSC, CD11b ^<+> , Gr1 ^<+> can be mentioned. CD31 ⁺ and IL-4α may be used as markers. In addition, human MDSC surface markers are CD11b ⁺ , Gr1 ⁺ , CD14 ^+/− , and HLA-DR ^low , but no specific markers have been identified. Therefore, human MDSCs are not limited to cells having the aforementioned markers as long as they have any one of the immunosuppressive functions described below.

The immunosuppressive function of MDSC is 2 of inducible nitric oxide synthase (inducible nitric-oxide synthase 2: hereinafter referred to as NOS2) and arginase-1 (hereinafter referred to as ARG1) expressed in MDSC. Related to two enzymes. NOS2 suppresses T cell IL-2 receptor signaling through the production of NO and induces apoptosis. On the other hand, ARG1 is an arginine metabolizing enzyme that suppresses the function of T cells by consuming arginine from the surrounding environment. Furthermore, as immunosuppressive function of MDSC, immunosuppression by TGF-β and IL-10 secreted by MDSC and cysteine deficiency due to the presence of MDSC have been reported.

(Regulatory T cells)
Tregs are T cells that suppressively act on immunocompetent cells such as T cells or dendritic cells, and an increase in Tregs is observed in human tumor tissue or peripheral blood. Although the surface marker of human Treg is not limited, it is assumed to be CD4 ⁺ , CD25 ⁺ (IL-2 receptor α chain), and accounts for 5 to 10% of CD4 ⁺ cells in the peripheral blood of healthy people Yes. Treg constantly expresses glucocorticoid-induced TNF receptor (GITR), cytotoxic T lymphocyte antigen 4 (CTLA-4), and FOXP3. ing. In CD4 ⁺ Treg, IL-10-producing Tr1, TGF-β-producing Th3, spontaneous Treg (nTreg) and inducible Treg (iTreg) have been reported. Physiologically, nTreg prevents the development of autoimmune diseases by suppressing peripherally self-reactive T cells that have escaped central immune tolerance in the thoracic line.

(Compound having inhibitory activity of immunosuppressive cells)
Examples of the compound having an inhibitory activity on immunosuppressive cells include a compound that inhibits the function of MDSC, a compound that inhibits the function of Treg, and a compound that inhibits the function of MDSC and Treg.

In the present specification and the like, "inhibiting MDSC function" means reducing MDSC cells, inhibiting immunosuppressive substances secreted from MDSC, inhibiting MDSC immunosuppressive substance secretion, Or inhibition of antigen presentation ability and effector ability by MDSC. Note that “inhibiting the function of Treg” in this specification and the like may be obtained by replacing MDSC in the above description of MDSC with Treg. In addition, “decrease” here means suppression and elimination of induction of MDSC or Treg.

Compounds that inhibit the function of MDSC include gemcitabine, phosphodiesterase-5 (PDE-5) inhibitory compounds (eg, sildenafil, tadalafil, and vardenafil), all-trans-retinoic acid (hereinafter referred to as ATRA). ), Or arginase-inhibiting compounds (for example, boronic-acid derivative 2 (S) -amino-6-boronohexanoinic acid (ABH), S- (2boronoethyl) -L-cystein (BEC)), COX-2 inhibitor (SC58236) KIT-specific antibody, Nitroaspirin, VitaminD3, avastin, VEGF-trap, Doxorubicin, 5-FU and cyclophosphamide. For example, ATRA induces differentiation of MDSC and inhibits the immunosuppressive activity of MDSC. Further, boronic-acid derivative 2 (S) -amino-6-boronohexanoinic acid (ABH) and S- (2boronoethyl) -L-cystein (BEC) are analogs of arginine.

Compounds that inhibit Treg function include cyclophosphamide, Denileukindiftitox, CTLA-4 inhibitory compound (eg, anti-CTLA-4 antibody), CD25 inhibitory compound (eg, anti-CD25 antibody) And IL-2R inhibitory compounds (eg, anti-IL-2R antibodies). Denileukin diftitox is a fusion protein of IL-2 and diphtheria and damages CD25 positive cells.

Sunitinib (Sunitinib) can be mentioned as a compound which inhibits the function of MDSC and Treg.

The compound having immunosuppressive cell inhibitory activity preferably has antitumor activity (direct cytotoxic activity) in addition to immunosuppressive cell inhibitory activity. Thus, a compound having an inhibitory activity on immunosuppressive cells enhances the antitumor effect of an antitumor agent containing a protein polysaccharide derived from Kawaratake as an active ingredient by inhibiting immunosuppressive cells, Tumor cells can be suppressed.

Therefore, in addition to the inhibitory activity of immunosuppressive cells, a tumor therapeutic agent using an immunosuppressive cell inhibitor containing a compound having antitumor activity can provide a synergistic effect on the suppression of tumor cell proliferation. Become.

Examples of compounds having immunosuppressive cell inhibitory activity and antitumor activity (direct cytotoxic activity) include gemcitabine, cyclophosphamide, and sunitinib. In a compound having immunosuppressive cell inhibitory activity and antitumor activity, if the effective amount showing immunosuppressive cell inhibitory activity differs from the effective amount showing antitumor activity, at least immunosuppression An amount of the compound exhibiting sex cell inhibitory activity is administered.

(Gemcitabine)
Gemcitabine is a compound represented by the following formula (1), and a pharmaceutical composition containing gemcitabine hydrochloride is applied to non-small cell cancer, pancreatic cancer, biliary tract cancer, urothelial cancer, and inoperable or recurrent breast cancer. It is approved and marketed as an antitumor agent (trade name: Gemzar). Gemcitabine has also been reported to be effective for breast cancer, bladder cancer, ovarian cancer and the like. The action of gemcitabine is DNA synthesis inhibition, apoptosis induction, and MDSC reduction.

In the case of non-small cell lung cancer, pancreatic cancer, biliary tract cancer, and urothelial cancer, gemcitabine is administered by intravenously injecting 1000 mg / m ² of gemcitabine over 30 minutes. Administration once a week for 3 consecutive weeks, withdrawn during the 4th week. This is repeated as one course. The dose may be reduced according to the patient's condition. In the case of inoperable or recurrent breast cancer, 1250 mg / m ² of gemcitabine is infused intravenously over 30 minutes as gemcitabine. In this case, administration once a week is continued for 2 weeks, and the drug is withdrawn during the 3rd week. This is repeated as one course.

(Cyclophosphamide)
Cyclophosphamide is a compound represented by the following formula (2): multiple myeloma, malignant lymphoma (Hodgkin's disease, lymphosarcoma, reticulosarcoma), lung cancer, breast cancer, acute leukemia, polycythemia vera, child Approved for application to cervical cancer, endometrial cancer, ovarian cancer, neuronal tumors (neuroblastoma, retinoblastoma), and bone tumors. Also, chronic lymphocytic leukemia, chronic myeloid leukemia, pharyngeal cancer, stomach cancer, pancreatic cancer, liver cancer, colon cancer, testicular tumor, choriocarcinoma (chorionic cancer, destructive hydatidiform mole, hydatidiform mole), rhabdomyosarcoma, and It is approved for use in combination with other antineoplastic agents for melanoma. In addition, breast cancer (preoperative or postoperative chemotherapy in operable cases) is approved for combination therapy with other antineoplastic agents. Cyclophosphamide is a compound that inhibits the function of Treg when administered in small doses.

Administration of cyclophosphamide as an antitumor agent is carried out by injecting 100 mg of cyclophosphamide (anhydrous equivalent) into a vein once a day when administered alone. If the patient can tolerate, the daily dose is increased to 200 mg. Cyclophosphamide is administered in a total amount of 3000-8000 mg, but lasts as long as possible when the effect is observed.

(Sunitinib)
Sunitinib is a compound represented by the following formula (3), and has been approved for imatinib-resistant gastrointestinal stromal tumor (GIST) and unresectable or metastatic renal cell carcinoma. It is sold under the brand name Sutent. Sunitinib is a compound that inhibits the functions of Treg and MDSC. The main functions are VEGF (vascular endothelial growth factor) receptor involved in angiogenesis and PDGF (platelet derived growth factor) receptor involved in tumor growth. It targets multiple receptors such as the body.

The administration of sunitinib as an antitumor agent is performed by daily oral administration of 50 mg of sunitinib to adults once a day for 4 weeks. The drug will be withdrawn for 2 weeks. This is repeated as one course. The dose may be reduced according to the patient's condition.

(Advantages of tumor treatment drugs)
An anti-tumor agent containing a protein polysaccharide derived from Kawaratake as an active ingredient is considered to exhibit an anti-tumor effect by restoring and enhancing the biological defense function of cancer patients, specifically the immune function. Therefore, by administering an immunosuppressive cell inhibitor containing a compound having an inhibitory activity on immunosuppressive cells to a cancer patient, immunosuppressive cells (for example, MDSC or Treg) of the cancer patient are inhibited. As described above, the suppression of the immune function is released by the inhibition of the immunosuppressive cells, whereby the immunostimulatory action of the antitumor agent containing the protein polysaccharide derived from Kawaratake as an active ingredient is further enhanced.

Therefore, by using a combination of an antitumor agent containing an agaric protein-derived polysaccharide as an active ingredient and an immunosuppressive cell inhibitor containing a compound having an inhibitory activity on immunosuppressive cells, a protein polysaccharide derived from agaricus so far For which the immunostimulatory action of an antitumor agent containing as an active ingredient has been inhibited by immunosuppressive cells (for example, non-responsible for the treatment of antitumor agents using protein polysaccharides from Kawaratake) It is possible to enhance the therapeutic effect on cancer patients for whom application of an antitumor agent using a protein polysaccharide derived from Ponder and Kawaratake is not approved.

In addition, when an immunosuppressive cell inhibitor containing a compound having an immunosuppressive cell inhibitory activity has antitumor activity, it has a synergistic effect with the antitumor activity of the antitumor agent using a protein polysaccharide derived from Kawaratake. You can expect.

It should be noted that an antitumor agent containing a protein polysaccharide derived from Kawaratake as an active ingredient is not currently approved for use in cancer patients other than gastric cancer patients, colorectal cancer patients, and small cell lung cancer patients. Therefore, in the present invention, a drug using a protein polysaccharide derived from Kawaratake, which has low side effects on cancer patients, including gastric cancer patients, colorectal cancer patients, and cancer patients other than small cell lung cancer patients, Another object of the present invention is to provide a tumor therapeutic agent that can provide a therapeutic effect.

Here, when the antitumor activity possessed by the immunosuppressive cell inhibitor is activity against tumors other than gastric cancer, colorectal cancer, and small cell lung cancer, it is effective against tumors other than gastric cancer, colorectal cancer, and small cell lung cancer. In contrast, the therapeutic effect of an antitumor agent using a protein polysaccharide derived from Kawaratake is obtained. That is, when the immunosuppressive cell inhibitor has antitumor activity (direct cytotoxic activity) against tumors other than gastric cancer, colorectal cancer, and small cell lung cancer, the tumor therapeutic agent according to the present invention is used. By using it, an antitumor agent using a protein polysaccharide derived from Kawaratake with small side effects can be provided for treatment of cancer patients other than gastric cancer, colorectal cancer, and small cell lung cancer.

Furthermore, for tumors where the application of antitumor agents containing Kawaratake protein polysaccharide as an active ingredient has not been approved, and for tumors where immunosuppressive cell inhibitors with antitumor activity have not been applied as antitumor agents However, the tumor therapeutic agent of the present invention is effective.

(Regarding the dosage form of drugs for tumor treatment)
The dosage form of the therapeutic agent for tumor of the present invention may be two agents in which the antitumor agent and the immunosuppressive cell inhibitor are separated as a single preparation, respectively, and the antitumor agent (protein isolate from Kawaratake) and the immunity One agent mixed with a suppressor cell inhibitor (a compound having an inhibitory activity of immunosuppressive cells) may be used.

The combination ratio of the protein polysaccharide derived from Kawaratake and the compound having an inhibitory activity on immunosuppressive cells (mixing ratio in one drug or use ratio in two drugs) is not particularly limited as long as it is an amount effective for cancer treatment. It is not something.

(When tumor treatment drug is one)
When the drug for treating tumor is one agent, the compounding ratio of the protein polysaccharide derived from Kawaratake and the compound having an inhibitory activity on immunosuppressive cells is not particularly limited as long as it is effective for treating tumor. In addition, the dosage form of the tumor treatment drug is not particularly limited. For example, it may be orally administered in the form of a conventional pharmaceutical preparation such as a capsule, a microcapsule, a tablet, a granule, a fine granule, or a powder. Can do. It can also be administered parenterally (for example, intravenous injection, intramuscular injection, subcutaneous administration, intraperitoneal administration, rectal administration, transdermal administration) in the form of conventional pharmaceutical preparations such as injections such as intravenous injection and intramuscular injection. .

Various preparations are commonly used excipients, extenders, binders, wetting agents, disintegrants, surfactants, lubricants, dispersants, buffers, preservatives, solubilizers, preservatives, It can be produced by a conventional method using a flavoring agent, a soothing agent, a stabilizer and the like. Examples of the non-toxic additive that can be used include lactose, fructose, glucose, starch, gelatin, magnesium carbonate, synthetic magnesium silicate, talc, magnesium stearate, methylcellulose, carboxymethylcellulose or a salt thereof, gum arabic, and polyethylene. Examples include glycol, syrup, petrolatum, glycerin, ethanol, propylene glycol, citric acid, sodium chloride, sodium sulfite, and sodium phosphate.

In addition, the administration method, dose, administration period, and administration interval of the drug for treating tumor can be appropriately set depending on, for example, the patient's weight, age, symptom level, and the like.

In addition, when the drug for tumor treatment is one agent, it is provided as a pharmaceutical composition comprising a protein polysaccharide derived from Kawaratake and a compound having an inhibitory activity on immunosuppressive cells as active ingredients, and further comprising a pharmaceutically acceptable carrier. May be. This pharmaceutical composition is a novel pharmaceutical composition.

(Advantages of using one drug for tumor treatment)
By using one drug for treating tumors, it is possible to avoid administering a plurality of drugs to a patient. That is, administration of one agent as before suppresses the growth of cancer cells and provides a high therapeutic effect, thereby avoiding an increase in the burden on the patient with respect to drug administration.

(When there are two drugs for tumor treatment)
In the case where the tumor therapeutic agent is two agents separated into an antitumor agent and an immunosuppressive cell inhibitor, the usage ratio of the antitumor agent and the immunosuppressive cell inhibitor should be effective for the treatment of malignant tumors. It is not particularly limited. In addition, the dosage forms of the antitumor agent and the immunosuppressive cell inhibitor are not particularly limited, and the same dosage form as that of the one drug for treating a tumor can be used. In addition, the administration method, the dose, the administration period, and the administration interval can be appropriately set depending on, for example, the patient's weight, age, degree of symptoms, and the like.

For example, when PSK is used as an anti-tumor agent and gemcitabine is used as an immunosuppressive cell inhibitor, gemcitabine is administered as a single course of intravenous administration of 1000 mg / mm ² once a week for 2 consecutive weeks. , PSK may be orally administered daily for 3 g daily from the 2nd week to 3 weeks. Alternatively, as a course dose, gemcitabine is orally administered once a week at 1000 mg / mm ² once a week for 3 consecutive weeks, and PSK is orally administered daily for 3 weeks from the 2nd week to 3 weeks. You may do it.

Of course, the above administration method is an example, and other administration methods may be used. Desirably, the administration method, dose, administration period, and administration interval of the antitumor agent and immunosuppressive cell inhibitor to humans are determined by a controlled clinical trial.

The antitumor agent may be provided as a pharmaceutical composition containing a protein polysaccharide derived from Kawaratake as an active ingredient and further containing a pharmaceutically acceptable carrier. The immunosuppressive cell inhibitor may also be provided as a pharmaceutical composition containing a compound having immunosuppressive cell inhibitory activity as an active ingredient and further containing a pharmaceutically acceptable carrier.

(Advantages of using two tumor treatment drugs)
When using an immunosuppressive cell inhibitor with antitumor activity, two drugs for tumor treatment are used so that the other drug can be administered even while one drug is being withdrawn. You can continue. For example, if the side effect of one drug is large and the side effect of the other drug is small, even if it is not necessary to administer a drug with a large side effect, it is necessary to administer a drug with a large side effect. May increase. By using two drugs for tumor treatment, it becomes possible to administer the other drug with the smaller side effect even while the drug with the larger side effect is suspended.

Thus, by using two tumor therapeutic agents, it is possible to avoid an increase in the burden on the patient with respect to side effects while obtaining a high therapeutic effect by suppressing the growth of cancer cells.

In setting the appropriate combination ratio (formulation ratio or use ratio) of the antitumor agent and immunosuppressive cell inhibitor in the drug for tumor treatment of the present invention, the administration period, and the administration interval are controlled. Preferably determined by clinical trials. The administration method, dose, administration period, and administration interval for the combined use of the antitumor agent and the immunosuppressive cell inhibitor may be described in the package insert or pamphlet of the tumor therapeutic agent of the present invention.

(Tumor to be treated with a drug for tumor treatment)
The tumor to be treated by the tumor therapeutic agent of the present invention is not particularly limited, and the following can be mentioned. Specifically, breast cancer, squamous cell carcinoma, lung cancer (eg, small cell or non-small cell lung cancer), pancreatic cancer, glioblastoma, ovarian cancer, vulvar cancer, liver cancer, hepatocellular carcinoma, colorectal cancer, uterine cancer ( For example, endometrial cell tumor, cervical cancer, endometrial cancer) salivary gland cancer, kidney cancer, thyroid cancer, bladder cancer, kidney cancer, head and neck cancer, gastric cancer, esophageal cancer, prostate cancer, biliary tract cancer, nervous system Mention may be made of cancer (eg neuroblastoma), retinal cancer, skin cancer, leukemia, urothelial cancer, brain tumor, osteosarcoma or transitional cell carcinoma. More specifically, the following can be mentioned as cancers to which PSK, gemcitabine, cyclophosphamide, or sunitinib is applied, and other cancers.
(1) Cancer with PSK application (gastric cancer, colorectal cancer, and small cell lung cancer)
(2) Cancer to which gemcitabine is applied (non-small cell cancer, pancreatic cancer, biliary tract cancer, urothelial cancer, and inoperable or recurrent breast cancer)
(3) Cancer to which cyclophosphamide is applied (multiple myeloma, malignant lymphoma (Hodgkin's disease, lymphosarcoma, reticulosarcoma), lung cancer, breast cancer, acute leukemia, polycythemia vera, cervical cancer, uterine body Cancer, ovarian cancer, neuronal tumor (neuroblastoma, retinoblastoma), bone tumor, chronic lymphocytic leukemia, chronic myelogenous leukemia, pharyngeal cancer, stomach cancer, pancreatic cancer, liver cancer, colon cancer, testicular tumor, choriocarcinoma (villus) Cancer, disrupted hydatidiform mole, hydatidiform mole), rhabdomyosarcoma, malignant melanoma, breast cancer (preoperative or postoperative chemotherapy in operable cases))
(4) Cancer to which sunitinib is applied (imatinib-resistant gastrointestinal stromal tumor (GIST) and radically unresectable or metastatic renal cell carcinoma)
(5) Other cancers (squamous cell carcinoma, glioblastoma, vulvar cancer, liver cancer, hepatocellular carcinoma, colorectal cancer, uterine cancer (eg, endometrial cell carcinoma, cervical cancer, or endometrial cancer) , Salivary gland cancer, kidney cancer, thyroid cancer, bladder cancer, head and neck cancer, esophageal cancer, prostate cancer, nervous system cancer (eg neuroblastoma), retinal cancer, skin cancer, leukemia, brain tumor, osteosarcoma, transitional epithelium cancer)
Among these, the tumors to be treated with the tumor therapeutic agent are preferably non-small cell lung cancer, pancreatic cancer, biliary tract cancer, urothelial cancer, gastric cancer, colon / rectal cancer, and small cell lung cancer.

[2] Antitumor Agent Containing Kawaratake-derived Protein Polysaccharide as an Active Ingredient The antitumor agent comprising the Kawaratake-derived protein polysaccharide as an active ingredient is an immunosuppressive agent comprising a compound having an inhibitory activity on immunosuppressive cells. Used in combination with cell inhibitors.

Since the antitumor agent containing the protein polysaccharide derived from Kawaratake as an active ingredient is the same as the antitumor agent in the above-mentioned tumor therapeutic agent, detailed description thereof is omitted. Moreover, as an immunosuppressive cell inhibitor to be administered in combination with an antitumor agent containing a protein polysaccharide derived from Kawaratake as an active ingredient, the same immunosuppressive cell inhibitors as those in the above-mentioned tumor therapeutic agents can be used.

It is preferable that the appropriate use ratio, dose, administration period, and administration interval of the antitumor agent in combination with the immunosuppressive cell inhibitor are determined by controlled clinical trials. What is necessary is just to describe an administration method, dosage amount, administration period, administration interval, etc. for using an antitumor agent together with an immunosuppressive cell inhibitor in the package insert or pamphlet of the antitumor agent.

The tumor to be treated with the antitumor agent is not particularly limited, and examples thereof include tumors to be treated with the above-mentioned drug for tumor treatment, and preferably non-small cell lung cancer, pancreatic cancer, biliary tract cancer Urothelial cancer, stomach cancer, colorectal cancer, small cell lung cancer.

In the antitumor agent of the present invention, it is preferable that the compound having an inhibitory activity on immunosuppressive cells further has an antitumor activity. A compound having an inhibitory activity on immunosuppressive cells has an antitumor activity, so that a synergistic effect is obtained in the treatment of tumors, and further, a therapeutic effect on tumors for which the antitumor agent of the present invention is not approved. Is obtained.

In the antitumor agent of the present invention, the immunosuppressive cells are preferably myeloid-derived suppressor cells (MDSC). Since the compound having the inhibitory activity of immunosuppressive cells has the inhibitory activity of MDSC, the suppression of the action of the antitumor agent containing protein polysaccharide derived from Kawaratake by MDSC as an active ingredient is eliminated, and the antitumor of the present invention It is possible to improve the therapeutic effect of the agent.

In the antitumor agent of the present invention, the immunosuppressive cell is preferably a regulatory T cell (Treg). Since the compound having the inhibitory activity of immunosuppressive cells has the inhibitory activity of Treg, the suppression of the action of the antitumor agent containing the protein polysaccharide derived from Kawaratake by Treg as an active ingredient is eliminated, and the antitumor of the present invention It is possible to improve the therapeutic effect of the agent.

In the antitumor agent of the present invention, the compound having an inhibitory activity on immunosuppressive cells is gemcitabine, a phosphodiesterase-5 (PDE-5) inhibitory compound, all-trans-retinoic acid (ATRA), It is preferably a compound selected from the group consisting of arginine inhibitory compounds, sunitinib, cyclophosphamide, Denileukindiftitox, CTLA-4 inhibitory compounds, CD25 inhibitory compounds, and IL-2R inhibitory compounds. .

[3] An immunosuppressive cell inhibitor comprising a compound having an inhibitory activity on immunosuppressive cells An immunosuppressive cell inhibitor comprising a compound having an inhibitory activity on immunosuppressive cells described in this specification and the like is a protein derived from Kawaratake It is used in combination with an antitumor agent containing a polysaccharide as an active ingredient.

An immunosuppressive cell inhibitor comprising a compound having an inhibitory activity on immunosuppressive cells is an immunosuppressive cell inhibitor in the tumor therapeutic agent. An anti-tumor agent administered in combination with an immunosuppressive cell inhibitor containing a compound having an inhibitory activity on immunosuppressive cells uses an anti-tumor agent containing a protein polysaccharide derived from Kawaratake as an active ingredient in the tumor therapeutic agent. be able to.

In setting the appropriate use ratio, dose, administration period, and administration interval of each of the immunosuppressive cell inhibitor and the antitumor agent in the immunosuppressive cell inhibitor of the present specification, a controlled clinical trial is used. It is determined. The package insert or pamphlet of the immunosuppressive cell inhibitor of the present invention describes the administration method, dose, administration period, and administration interval for the combined use of the immunosuppressive cell inhibitor and the antitumor agent.

[4] Tumor treatment method The present specification describes an antitumor agent comprising a protein polysaccharide derived from Kawaratake as an active ingredient and an immunosuppressive cell inhibitor comprising a compound having an inhibitory activity on immunosuppressive cells. Disclosed is a method for treating tumors comprising administering to a subject in need thereof in an effective amount.

The immunosuppressive cell inhibitor used in the present treatment method preferably further has antitumor activity. Moreover, the immunosuppressive cell in which the immunosuppressive cell inhibitor used in this treatment method has inhibitory activity is, for example, a myeloid-derived suppressor cell (MDSC) and a regulatory T cell (Treg). The immunosuppressive cell inhibitor may have inhibitory activity on both MDSC and Treg, or may have inhibitory activity on only one of them.

Compounds having inhibitory activity on immunosuppressive cells include gemcitabine, phosphodiesterase-5 (PDE-5) inhibitory compound, all-trans-retinoic acid (ATRA), arginase inhibitory compound, sunitinib, cyclophosphami And Denileukin diftitox, CTLA-4 inhibitory compound, CD25 inhibitory compound, and IL-2R inhibitory compound.

In the tumor treatment method of the present invention, it is preferable that the compound having an inhibitory activity on immunosuppressive cells further has an antitumor activity.

In the tumor treatment method of the present invention, the immunosuppressive cells are preferably myeloid-derived suppressor cells (MDSC).

In the tumor treatment method of the present invention, the immunosuppressive cell is preferably a regulatory T cell (Treg).

In the tumor treatment method of the present invention, the compound having immunosuppressive cell inhibitory activity is gemcitabine, a phosphodiesterase-5 (PDE-5) inhibitory compound, all-trans-retinoic acid (ATRA), Preferably, the compound is selected from the group consisting of an arginase inhibitor compound, sunitinib, cyclophosphamide, Denileukin diftitox, CTLA-4 inhibitor compound, CD25 inhibitor compound, and IL-2R inhibitor compound .

[5] Tumor treatment kit The tumor treatment kit of the present invention is a tumor treatment kit comprising a combination of a plurality of active ingredients, and as an active ingredient, the protein polysaccharide derived from Kawaratake and the inhibitory activity of immunosuppressive cells A compound having As the compound having the inhibitory activity of Kawaratake-derived protein polysaccharide and immunosuppressive cells, the compound having the inhibitory activity of Kawaratake-derived protein polysaccharide and immunosuppressive cells in the above-mentioned tumor therapeutic agent can be used.

The tumor treatment kit of the present invention is a tumor treatment kit comprising a combination of a plurality of active ingredients, comprising as an active ingredient a protein polysaccharide derived from Kawaratake and a compound having an inhibitory activity on immunosuppressive cells, Instructions may be included for administering the medication to the patient simultaneously, sequentially or individually. In addition, as in the case of the tumor treatment drug, a protein polysaccharide derived from Kawaratake and an inhibitory activity on immunosuppressive cells may be included as one agent, and an inhibitory activity on the protein polysaccharide derived from Kawaratake and immunosuppressive cells. You may include the compound which has as 2 agents. Furthermore, the administration method, dose, administration period, administration interval, etc. are not particularly limited.

In the tumor treatment kit of the present invention, it is preferable that the compound having an inhibitory activity on immunosuppressive cells further has an antitumor activity.

In the tumor treatment kit of the present invention, the immunosuppressive cell is preferably a myeloid-derived suppressor cell (MDSC).

In the tumor treatment kit of the present invention, the immunosuppressive cells are preferably regulatory T cells (Treg).

In the tumor treatment kit of the present invention, the compound having an inhibitory activity on immunosuppressive cells is gemcitabine, a phosphodiesterase-5 (PDE-5) inhibitory compound, all-trans-retinoic acid (ATRA), It is preferably a compound selected from the group consisting of arginine inhibitory compounds, sunitinib, cyclophosphamide, Denileukindiftitox, CTLA-4 inhibitory compounds, CD25 inhibitory compounds, and IL-2R inhibitory compounds. .

[6] Kawaratake-derived protein polysaccharide The Kawaratake-derived protein polysaccharide, which is an active ingredient of an antitumor agent, is used in combination with a compound having an inhibitory activity on immunosuppressive cells when used in a method for treating tumors. is there.

In the use of protein polysaccharides in tumor treatment methods, it is preferable that the compound having immunosuppressive cell inhibitory activity further has antitumor activity.

In the use of the protein polysaccharide in the method for treating tumors, the immunosuppressive cells are preferably myeloid-derived suppressor cells (MDSC).

In the use of a protein polysaccharide in a method for treating tumors, the immunosuppressive cells are preferably regulatory T cells (Tregs).

In the use of protein polysaccharides in tumor treatment methods, compounds having epithelial suppressive cell inhibitory activity include gemcitabine, phosphodiesterase-5 (PDE-5) inhibitory compounds, all-trans-retinoic acid: ATRA), an arginine inhibitor compound, sunitinib, cyclophosphamide, Denileukindiftitox, a CTLA-4 inhibitor compound, a CD25 inhibitor compound, and an IL-2R inhibitor compound. It is preferable.

The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the claims, and the present invention also includes an embodiment obtained by appropriately combining technical means disclosed in the embodiment. Is included in the technical scope. Moreover, all the literatures described in this specification are used as reference.

Hereinafter, the present invention will be specifically described by way of examples, but these do not limit the scope of the present invention.

Example 1
In this example, in order to examine the effect of the tumor therapeutic agent of the present invention in mice transplanted with breast cancer cells, the effect of combined administration of PSK and gemcitabine (Gemzar injection) was examined. Female BALB / c mice were transplanted subcutaneously with 1 × 10 ⁵ mouse breast cancer cell line 4T1 per mouse. When breast cancer cells grew to 200 mm ^3, they were divided into 4 groups of 8 (PSK and gemcitabine administration group, PSK single administration group, gemcitabine single administration group, and non-administration group). Gemcitabine was administered intraperitoneally at a dose of 120 mg / kg immediately after grouping and after 7 days. After administration of gemcitabine twice, PSK was administered intraperitoneally at a dose of 50 mg / kg three times a week from the next day. In the non-administration group, physiological saline was administered intraperitoneally as a control for gemcitabine or PSK. After grouping, tumor volumes were measured on the 7th, 14th, and 21st days. The day after the last administration of PSK, necropsy was performed and the tumor weight was measured.

The administration schedule and results are shown in FIG. FIG. 1 is a graph showing the effect of suppressing tumor volume (FIG. 1B) and tumor weight (FIG. 1C) in a breast cancer transplanted mouse of a tumor therapeutic agent, and the administration schedule of an antitumor agent and an immunosuppressive cell inhibitor (FIG. 1A). ).

The administration schedule shown in FIG. 1 is an administration schedule of each drug in the PSK and gemcitabine administration groups. In the administration schedule, “G” indicates gemcitabine, and “P” indicates PSK. That is, in the gemcitabine single administration group, PSK was not administered in the administration schedule, and physiological saline was administered instead of PSK. On the other hand, the PSK single administration group is a schedule in which gemcitabine is not administered in the administration schedule, and is a schedule in which physiological saline is administered instead of gemcitabine.

As shown in FIG. 1, in the PSK single administration group, although there was no significant difference in the antitumor tendency, gemcitabine alone showed an antitumor effect.

Furthermore, the combined use effect was recognized significantly with respect to the tumor volume and the tumor weight by using gemcitabine and PSK together. In addition, in the gemcitabine single administration group in FIG. 1, the tumor growth was promoted by gemcitabine withdrawal, as the tumor volume increased after 14 days. However, during the gemcitabine withdrawal in the PSK and gemcitabine administration group, The growth promotion (recovery) was suppressed by administering only PSK. More specifically, the tumor volume increased by about 600 mm ³ in the gemcitabine alone administration group, whereas the increase was only about 100 mm ^{3 in} the PSK and gemcitabine administration group. That is, by administering PSK while gemcitabine was withdrawn, tumor volume growth could be suppressed to about 1/6.

Further, comparing the tumor weights at the time of necropsy of the PSK and gemcitabine administration group, the PSK single administration group, the gemcitabine single administration group, and the non-administration group, the decrease in the tumor weight relative to the non-administration group of the PSK and gemcitabine administration group is The combined effect in the PSK and gemcitabine administration group is considered to have a synergistic effect, more than the addition of the decrease in the single administration group and the gemcitabine administration group.

In FIG. 1, the white triangle (Δ) is the PSK and gemcitabine administration group, the black triangle (▲) is the gemcitabine single administration group, the white rhombus (◇) is the PSK single administration group, and the black rhombus (♦) is the non-administration group Indicates.

Example 2
In this example, the administration frequency of gemcitabine in Example 1 was increased, and the effect of combined administration of PSK and gemcitabine was examined. The procedure of Example 1 was repeated except that the administration of gemcitabine was changed immediately after grouping, after 7 days, after 14 days, and after 21 days.

The administration schedule and results are shown in FIG. FIG. 2 is a graph showing the effect of suppressing tumor volume (FIG. 2B) and tumor weight (FIG. 2C) in a breast cancer transplanted mouse of a tumor therapeutic agent, and the administration schedule of an antitumor agent and an immunosuppressive cell inhibitor (FIG. 2A). ).

The administration schedule shown in FIG. 2 is an administration schedule of each drug in the PSK and gemcitabine administration groups. In the administration schedule, “G” indicates gemcitabine, and “P” indicates PSK. That is, in the gemcitabine single administration group, it becomes a schedule which does not administer PSK in an administration schedule. On the other hand, the PSK single administration group is a schedule in which gemcitabine is not administered in the administration schedule, and is a schedule in which physiological saline is administered instead of gemcitabine.

In this administration schedule, gemcitabine alone showed an antitumor effect, although no significant difference was observed in 4T1 cells, although PSK alone showed an antitumor tendency.

Furthermore, the combined use effect on tumor volume and tumor weight was significantly recognized by the combined use of gemcitabine and PSK. As shown in FIG. 2, although the tumor volume increased from day 7 to day 21 in the gemcitabine alone administration group, in the PSK and gemcitabine administration group in this example, the increase in tumor volume was not limited to 7 days to On day 21, the tumor volume could be reduced. More specifically, in the gemcitabine alone administration group, the tumor volume increased by about 200 mm ³ between day 7 and day 21, whereas in the PSK and gemcitabine administration group, the tumor volume was reduced to near zero. I was able to.

Moreover, since the decrease of the tumor volume started with the start of the administration of PSK after the 7th day, it was shown that PSK has a great influence on the decrease of the tumor volume.

In FIG. 2, the white triangle (Δ) is the PSK and gemcitabine administration group, the black triangle (▲) is the gemcitabine single administration group, the white rhombus (◇) is the PSK single administration group, and the black rhombus (♦) is the non-administration group Indicates.

Example 3
In this example, the effect of combined administration of PSK and gemcitabine (Gemzar injection) when the dose of gemcitabine was decreased was examined. The procedure of Example 1 was repeated except that the dose of gemcitabine was replaced with a dose of 60 mg / kg instead of a dose of 120 mg / kg.

The results are shown in FIG. FIG. 3 is a graph showing the suppressive effect of tumor volume in a breast cancer transplanted mouse of a tumor therapeutic agent. As shown in FIG. 3, the PSK single administration group showed an anti-tumor tendency, but no significant difference was observed, whereas gemcitabine showed an anti-tumor effect alone.

Furthermore, the combined use effect on the tumor volume was recognized significantly by using gemcitabine and PSK in combination. In addition, in the gemcitabine single administration group in FIG. 3, tumor growth was promoted by gemcitabine withdrawal as the tumor volume increased after 14 days, but during the gemcitabine withdrawal in the PSK and gemcitabine administration group The growth promotion (recovery) was suppressed by administering only PSK. More specifically, the tumor volume increased by about 500 mm ³ in the gemcitabine alone administration group, whereas it hardly increased in the PSK and gemcitabine administration group.

Comparing the tumor volume on the day before the autopsy date of the PSK and gemcitabine administration group, the PSK monotherapy group, the gemcitabine monotherapy group, and the non-administration group, the decrease in tumor volume relative to the non-administration group of the PSK and gemcitabine administration group is The combined effect in the PSK and gemcitabine administration group is considered to have a synergistic effect, more than the addition of the decrease in the single administration group and the gemcitabine administration group. In addition, a sufficient antitumor effect was obtained even at a dose of gemcitabine of 60 mg / kg.

In FIG. 3, white squares (□) are PSK and gemcitabine (60 mg / kg) administration group, black squares (■) are gemcitabine (60 mg / kg) single administration group, white diamonds (◇) are PSK single administration group, And black diamonds (♦) indicate non-administration groups.

Example 4
In this example, the effect of combined administration of PSK and gemcitabine (Gemzar injection) when the dose of gemcitabine was decreased was examined. The procedure of Example 2 was repeated except that the dose of gemcitabine was replaced with a dose of 60 mg / kg instead of the dose of 120 mg / kg.

The results are shown in FIG. FIG. 4 is a graph showing the effect of suppressing tumor volume in a breast cancer transplanted mouse of a tumor therapeutic agent. As shown in FIG. 4, gemcitabine alone showed an antitumor effect, although no significant difference was observed in 4T1 cells, although PSK alone showed an antitumor tendency.

Furthermore, the combined use effect on the tumor volume was significantly recognized by the combined use of gemcitabine and PSK. As shown in FIG. 4, although the tumor volume increased from day 7 to day 21 in the gemcitabine alone administration group, the tumor volume was almost from day 7 to day 21 in the PSK and gemcitabine administration group in this example. It did not increase. More specifically, in the gemcitabine alone administration group, the tumor volume increased by about 200 mm ³ between day 7 and day 21, whereas in the PSK and gemcitabine administration group, no increase in tumor volume was observed. It was. Even when the dose of gemcitabine was reduced from 120 mg / kg to 60 mg / kg, a sufficient antitumor effect was obtained.

In the graph of tumor volume in FIG. 4, the white square (□) is the PSK and gemcitabine (60 mg / kg) administration group, the black square (■) is the gemcitabine (60 mg / kg) single administration group, the white rhombus (◇) Indicates a PSK single administration group, and a black diamond (♦) indicates a non-administration group.

Example 5
In this example, in order to examine the effect of the therapeutic agent for tumor of the present invention in mice transplanted with pancreatic cancer cells, the effect of combined administration of PSK and gemcitabine (Gemzar injection) was examined. Female BALB / c mice were implanted subcutaneously with 1 × 10 ⁶ mouse pancreatic cancer cell line PAN-02. Nine days after transplantation, 7 mice were divided into 4 groups (PSK and gemcitabine administration group, PSK single administration group, gemcitabine single administration group, and non-administration group). Gemcitabine was administered intraperitoneally at a dose of 60 mg / kg immediately after grouping and after 7 days. After administration of gemcitabine twice, PSK was administered intraperitoneally at a dose of 50 mg / kg three times a week from the next day. In the non-administration group, physiological saline was administered intraperitoneally as a control for gemcitabine or PSK. Tumor volume measured after grouping (9 days after transplantation), 13 days, 17 days, 20 days, 24 days, 27 days, 31 days, 34 days, 38 days, 41 days, 45 days, and 48 days after transplantation did. At day 48 after tumor transplantation, necropsy was performed and the tumor weight was measured.

The administration schedule and results are shown in FIG. FIG. 5 is a graph showing the inhibitory effect on tumor volume (FIG. 5A) and tumor weight (FIG. 5B) in mice transplanted with pancreatic cancer as a therapeutic drug for tumors.

The administration schedule of the antitumor agent (PSK) and immunosuppressive cell inhibitor (gemcitabine) is shown in FIG. 5A. In the administration schedule, “G” indicates gemcitabine, and “P” indicates PSK. In the gemcitabine single administration group, PSK was not administered in the administration schedule, and physiological saline was administered instead of PSK. On the other hand, the PSK single administration group is a schedule in which gemcitabine is not administered in the administration schedule, and is a schedule in which physiological saline is administered instead of gemcitabine.

As shown in FIG. 5, the tumor volume was p = 0.288 in the PSK single administration group and p = 0.292 in the gemcitabine single administration group with respect to the control. I couldn't. In addition, regarding the tumor weight, the PSK single administration group and the gemcitabine single administration group showed an antitumor tendency, but no significant difference was observed.

On the other hand, the combined use of gemcitabine and PSK has a significant effect on the tumor volume and tumor weight. Specifically, the tumor weight is p = 0.034, and the tumor volume is p = 0.075. Yes, the effect of the combined use of gemcitabine and PSK was observed.

In FIG. 5A, the white triangle (Δ) indicates the PSK and gemcitabine administration group, the black triangle (▲) indicates the gemcitabine single administration group, the white circle (◯) indicates the PSK single administration group, and the black circle (●) indicates the non-administration group. .

Example 6
In this example, it was examined that the effect of combined administration of PSK and gemcitabine can be obtained even when the administration start time of the tumor therapeutic agent of the present invention in Example 5 is delayed. The procedure of Example 5 was repeated except that the start of gemcitabine administration was changed 34 days after transplantation. Tumor volumes were measured after grouping (34 days after transplantation), 36 days, 40 days, 43 days, 47 days, 50 days, and 54 days after transplantation. 54 days after tumor implantation, one mouse in each of the non-administration group and the PSK single administration group died.

FIG. 6 shows a graph showing the effect of suppressing tumor volume in mice transplanted with pancreatic cancer, which is a drug for treating tumors.

As shown in FIG. 6, there was no significant difference in the anti-tumor tendency in the PSK and gemcitabine single administration groups.

Furthermore, the combined use effect on the tumor volume was recognized significantly by using gemcitabine and PSK in combination. That is, the tumor volume of the mice combined with gemcitabine and PSK 54 days after transplantation was p = 0.055 compared to the control, and a significant tendency was observed, and mucitabine and PSK 50 days after transplantation were observed. The tumor volume of the mice used in combination with p was 0.03 compared to the control, confirming a significant difference. In addition, in the gemcitabine single administration group in FIG. 6, tumor growth was promoted by gemcitabine withdrawal as the tumor volume increased after 43 days, but during the gemcitabine withdrawal in the PSK and gemcitabine administration group The growth promotion (recovery) was suppressed by administering only PSK. More specifically, in the gemcitabine single administration group, the tumor volume was increased by about 350 mm ³ , whereas in the PSK and gemcitabine administration group, the increase was only about 200 mm ³ . In other words, tumor volume growth could be suppressed by administering PSK while gemcitabine was withdrawn. This combined effect in the PSK and gemcitabine administration group is considered to be a synergistic effect.

In FIG. 2, the white triangle (Δ) represents the PSK and gemcitabine administration group, the black triangle (▲) represents the gemcitabine single administration group, the white circle (◯) represents the PSK single administration group, and the black circle (●) represents the non-administration group. .

The tumor therapeutic drug of the present invention can be suitably used as a drug that enhances the therapeutic effect on a non-responder having low reactivity (sensitivity) to an antitumor agent containing PSK as an active ingredient, and at the present time PSK. It can be used as a drug having a high therapeutic effect even for cancer patients for which application of an antitumor agent containing as an active ingredient has not been approved.
As mentioned above, although this invention was demonstrated along the specific aspect, the deformation | transformation and improvement obvious to those skilled in the art are included in the scope of the present invention.

Claims

An anti-tumor agent comprising a protein polysaccharide derived from Kawaratake as an active ingredient and an immunosuppressive cell inhibitor comprising a compound having an inhibitory activity on immunosuppressive cells, in combination.
The tumor therapeutic agent according to claim 1, wherein the compound further has an antitumor activity.
The tumor therapeutic agent according to claim 1 or 2, wherein the immunosuppressive cells are myeloid-derived suppressor cells (MDSC).
The tumor therapeutic agent according to claim 1 or 2, wherein the immunosuppressive cells are regulatory T cells (Treg).
The compounds include gemcitabine, phosphodiesterase-5 (PDE-5) inhibitory compound, all-trans-retinoic acid (ATRA), arginase inhibitory compound, sunitinib, cyclophosphamide, Denilekin diftitox The drug for tumor treatment according to claim 1, which is a compound selected from the group consisting of diftitox), CTLA-4 inhibitory compound, CD25 inhibitory compound, and IL-2R inhibitory compound.
An antitumor agent comprising a protein polysaccharide derived from Kawaratake as an active ingredient, which is used in combination with an immunosuppressive cell inhibitor comprising a compound having an inhibitory activity on immunosuppressive cells.
An antitumor agent comprising a protein polysaccharide derived from Kawaratake as an active ingredient and an immunosuppressive cell inhibitor comprising a compound having an inhibitory activity on immunosuppressive cells, in combination.
A tumor treatment kit comprising a combination of a plurality of active ingredients,
A kit for treating tumors comprising, as the active ingredient, a protein polysaccharide derived from Kawaratake and a compound having an inhibitory activity on immunosuppressive cells.