Application of compound PGG in the preparation of sensitizers for PD-1 inhibitors

Abstract

This invention belongs to the pharmaceutical field, specifically relating to a novel use of the compound PGG as a sensitizer for PD-1 inhibitors. This invention first discovers that PGG combined with PD-1 inhibitor treatment can significantly inhibit the growth of pancreatic cancer tumors; PGG combined with PD-1 inhibitor treatment can significantly prolong the survival time of pancreatic cancer patients and significantly improve the tumor microenvironment of pancreatic cancer; indicating that PGG can sensitize PD-1 inhibitors, thereby enhancing the therapeutic effect of PD-1 inhibitors in pancreatic cancer, and has broad application prospects.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of medicine, and particularly relates to application of a compound PGG in preparation of a sensitizer for a PD-1 inhibitor. BACKGROUND

[0002] Anti-programmed cell death protein 1 antibody (aPD-1) is an immune checkpoint inhibitor, which can block the binding of PD-1 receptor to its ligands PD-L1 and PD-L2, thereby activating the anti-tumor effect of T cells and inhibiting the growth and spread of cancer cells. It is mainly used for the treatment of non-small cell lung cancer, melanoma, renal cell carcinoma, esophageal cancer, gastric cancer, liver cancer, Hodgkin's lymphoma and other malignant tumors. Although anti-PD-1 therapy shows effective anti-tumor effect in some patients, most patients cannot benefit from it due to primary or acquired treatment resistance. Therefore, overcoming treatment resistance of PD-1 inhibitors is crucial to improve the immunotherapy effect of tumor patients.

[0003] Pancreatic cancer is a highly malignant digestive tract malignant tumor with difficult diagnosis and treatment. Due to the dense extracellular matrix and immunosuppressive tumor microenvironment of pancreatic cancer, PD-1 inhibitor immunotherapy is basically ineffective for pancreatic cancer.

[0004] 1,2,3,4,6-O-galloyl glucose (PGG) is a gallic tannin existing in plants, which has anti-inflammatory, antioxidant, antiviral, anticancer and other biological activities. However, there is no report on PGG and its compounds with similar structure as a PD-1 inhibitor sensitizer.

[0005] However, the present application unexpectedly found that PGG can enhance the effect of PD-1 inhibitor treatment for pancreatic cancer, and PGG combined with PD-1 inhibitor treatment can significantly prolong the survival time of pancreatic cancer and significantly improve the tumor microenvironment of pancreatic cancer, thereby enhancing the therapeutic effect of PD-1 inhibitor in pancreatic cancer, which has broad application prospects. SUMMARY

[0006] The present application found that PGG combined with PD-1 inhibitor for the treatment of pancreatic cancer can improve the therapeutic effect of PD-1 inhibitor, and found that PGG can sensitize PD-1 inhibitor, thereby enhancing the therapeutic effect of PD-1 inhibitor in pancreatic cancer, and PGG combined with PD-1 inhibitor can increase the infiltration of CD8 + T cells in the tumor microenvironment of pancreatic cancer. Specifically includes the following contents:

[0007] In a first aspect, the present application provides a use of a compound PGG in the preparation of a PD-1 inhibitor sensitizer, wherein the compound PGG has the following structural formula (I):

[0008]

[0009] Preferably, the compound PGG enhances the anti-tumor effect of the PD-1 inhibitor.

[0010] Preferably, the tumor is pancreatic cancer.

[0011] Preferably, the PD-1 inhibitor comprises: Pembrolizumab, Nivolumab, Cemiplimab, Camrelizumab, Toripalimab, Tislelizumab, Cemiplimab, Spartalizumab, Anti-Mouse CD279 (PD-1).

[0012] Preferably, the compound PGG is added to a pharmaceutically acceptable carrier or excipient to form any pharmaceutically acceptable dosage form.

[0013] In a second aspect, the present application provides a pharmaceutical composition comprising a compound PGG and a PD-1 inhibitor, wherein the compound PGG has the following structural formula (I):

[0014]

[0015] Preferably, the PD-1 inhibitor comprises: Pembrolizumab, Nivolumab, Cemiplimab, Camrelizumab, Toripalimab, Tislelizumab, Cemiplimab, Spartalizumab, Anti-Mouse CD279 (PD-1).

[0016] In a third aspect, the present application provides a use of the pharmaceutical composition of the second aspect in the preparation of an anti-tumor drug.

[0017] Preferably, the tumor is pancreatic cancer.

[0018] Preferably, the pharmaceutical composition is added to a pharmaceutically acceptable carrier or excipient to form any pharmaceutically acceptable dosage form.

[0019] As used herein, the term "sensitizing" a PD-1 inhibitor means enhancing the effect of a PD-1 inhibitor in treating cancer.

[0020] The beneficial effects of the present application are: when the present application is used for the treatment of pancreatic cancer by combining PGG with a PD-1 inhibitor, it is unexpectedly found that the PD-1 inhibitor has little therapeutic effect on pancreatic cancer, but when it is combined with PGG, it can significantly prolong the survival time of pancreatic cancer, improve the tumor microenvironment of pancreatic cancer, and has a significant anti-pancreatic cancer effect; it is shown that PGG can sensitize PD-1 inhibitors, thereby enhancing the therapeutic effect of PD-1 inhibitors on pancreatic cancer, and PGG combined with PD-1 inhibitors can increase the CD8 + T cell infiltration. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 Tumor volume of each group of pancreatic cancer spontaneous tumor mice (KPC mice) after drug treatment of allogeneic transplantation model;

[0022] Figure 2 Change in tumor volume of each group of KPC mice during drug treatment of allogeneic transplantation model;

[0023] Figure 3 Change in survival time of each group of KPC mice after drug treatment of allogeneic transplantation model;

[0024] Figure 4 Change in tumor volume of each group of KPC mice before reaching the survival endpoint of allogeneic transplantation model;

[0025] Figure 5 CD8 + T cell infiltration in tumor tissue of each group of KPC mice after drug treatment of allogeneic transplantation model. EMBODIMENT

[0026] The embodiments of the present application will be described in detail below with reference to the examples, which are only used to illustrate the present application and should not be regarded as limiting the scope of the present application. The specific conditions not indicated in the examples are carried out according to the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products that can be obtained by purchase.

[0027] The PD-1 inhibitor described in the following examples is Anti-Mouse CD279 (PD-1), which is purchased from Leinco Technologies, Inc. Other PD-1 inhibitors are suitable for the present application in addition to the PD-1 inhibitor described in the present application.

[0028] Example 1 Effect of PGG combined with PD-1 inhibitor on tumor growth of KPC mice allogeneic transplantation model

[0029] (1) Surgical acquisition of KPC mouse pancreatic cancer tumor tissue that has spontaneously formed a tumor, transfer to PBS containing 1x double antibody, clean and cut into about 3mm in diameter, then put into high concentration matrix glue and mix well;

[0030] (2) Grasp the 6-week-old C57BL / 6 mouse, after isoflurane anesthesia, use 75% alcohol to disinfect the axillary region, use ophthalmic scissors to cut a surgical opening of about 1cm in size, implant the tumor tissue wrapped in matrix glue subcutaneously in the mouse armpit, use absorbable antibacterial suture to suture and put it back into the mouse cage, and then transfer it to the cage after it fully awakens;

[0031] (3) Observe the mice every two days to evaluate the tumor size, and when the tumor volume of the mouse reaches 500mm 3 , anesthetize the mouse and obtain the tumor tissue, and use the same method to implant the tumor in a suitable age C57BL / 6 mouse, and at the same time, fix part of the tumor tissue with paraformaldehyde for HE staining to confirm the pathological type of pancreatic cancer;

[0032] (4) After 3 passages, sufficient KPC allogeneic transplantation model is obtained, and when the subcutaneously transplanted tumor of the mouse grows to 150mm 3 , start dosing;

[0033] Dosing regimen and group:

[0034] (1) Control group: normal saline gavage and intraperitoneal injection;

[0035] (2) αPD-1 group: PD-1 inhibitor intraperitoneal injection, 200μg / each / 3 days;

[0036] (3) PGG group: PGG gavage, 20mg / kg / day;

[0037] (4) PGG combined with αPD-1 group: PGG gavage, 20mg / kg / day, PD-1 inhibitor intraperitoneal injection, 200μg / each / 3 days;

[0038] Observe the changes of subcutaneous tumor volume of mice in each group.

[0039] The results are shown in Figure 1 and Figure 2 , compared with the control group, the tumor volume of the αPD-1 group of mice did not change, the tumor volume of the PGG group and the PGG combined with αPD-1 group of mice decreased, and compared with the PGG group, the tumor volume of the PGG combined with αPD-1 group of mice significantly decreased. It is shown that PGG combined with PD-1 inhibitor treatment can significantly inhibit the growth of pancreatic cancer tumor, that is, PGG as a PD-1 inhibitor sensitizer, significantly enhances the effect of PD-1 inhibitor in inhibiting pancreatic cancer tumor.

[0040] Example 2 Effect of PGG combined with PD-1 inhibitor on survival time of KPC mouse xenograft model

[0041] KPC mouse xenograft model was constructed according to Example 1, and tumor tissue of KPC mouse was transplanted subcutaneously into C57BL / 6 mouse, and sufficient KPC xenograft model was obtained after 3 passages;

[0042] When the subcutaneously transplanted tumor of the mouse grew to 150mm 3 , the administration was started;

[0043] The administration regimen and groups were the same as in Example 1;

[0044] When the tumor volume reached 1500mm 3 , the survival end point of the mouse was considered, and the survival time of the mice in each group was recorded.

[0045] The results are shown in Figure 3 and Figure 4 Compared with the control group, the survival time of the mice in the aPD-1 group did not change significantly (the median survival time was 17.5 days), and the survival time of the mice was basically the same as that of the control group (the median survival time was 19 days). The survival time of the mice in the PGG group and the PGG combined with aPD-1 group was relatively prolonged, and compared with the PGG group (the median survival time was 31.5 days), the survival time of the mice in the PGG combined with aPD-1 group according to the present application was significantly prolonged, and the median survival time was 40.5 days. It is shown that PGG combined with PD-1 inhibitor treatment can significantly prolong the survival time of pancreatic cancer, that is, PGG as a PD-1 inhibitor sensitizer significantly enhances the effect of PD-1 inhibitor in inhibiting pancreatic cancer tumor.

[0046] Example 3 Effect of PGG combined with PD-1 inhibitor on tumor microenvironment

[0047] The tumor tissue of each group in Example 1 was washed with PBS and cut into small pieces, 1 mg / mL collagenase XI was added for digestion and lysis for 30 min, and the digestion product was filtered using a cell sieve to obtain a single cell suspension;

[0048] After washing with PBS and centrifugation, CD45, CD3, CD4, and CD8 flow cytometry antibodies were added and incubated at room temperature for 30 min in the dark;

[0049] After centrifugation and resuspension in PBS, an appropriate volume of cell suspension was taken and loaded onto a high-speed analytical flow cytometer.

[0050] The results are shown in Figure 5 Compared with the control group, the infiltration of CD8 + T cells in the tumor tissue of the mice in the aPD-1 group did not change significantly, and the infiltration of CD8 +The infiltration of T cells was relatively increased, and compared with the PGG group, the CD8 + The infiltration of T cells was significantly increased. It was shown that the treatment of PGG combined with PD-1 inhibitor could significantly improve the tumor microenvironment of pancreatic cancer, that is, PGG as a PD-1 inhibitor sensitizer significantly enhanced the effect of PD-1 inhibitor in inhibiting pancreatic cancer tumor.

[0051] According to the experimental results, it was shown that PD-1 inhibitor alone had no therapeutic effect on pancreatic cancer, and when PGG was combined with PD-1 inhibitor, PGG could sensitize PD-1 inhibitor, thereby enhancing the therapeutic effect of PD-1 inhibitor in pancreatic cancer, and

[0052] PGG combined with PD-1 inhibitor could increase the infiltration of CD8 + T cells in the tumor microenvironment of pancreatic cancer. That is, the PGG described in the present application

[0053] PGG can be used as a PD-1 inhibitor sensitizer, which has broad application prospects.

Claims

1. Use of a compound PGG in the preparation of a sensitizer of a PD-1 inhibitor, the compound PGG has the following structural formula (I): ， Formula (I); The compound PGG enhances the effect of the PD-1 inhibitor on pancreatic cancer.

2. Use according to claim 1, wherein The PD-1 inhibitor includes: pembrolizumab, nivolumab, sintilimab, camrelizumab, toripalimab, tislelizumab, cemiplimab, spartalizumab.

3. Use according to any one of claims 1-2, characterized in that, The compound PGG is added to a pharmaceutically acceptable carrier or excipient to form any pharmaceutically acceptable dosage form.

4. A pharmaceutical composition comprising a compound PGG and a PD-1 inhibitor; the compound PGG has the following structural formula (I): ， Formula (I).

5. The pharmaceutical composition of claim 4, wherein The PD-1 inhibitor includes: pembrolizumab, nivolumab, sintilimab, camrelizumab, toripalimab, tislelizumab, cemiplimab, spartalizumab.

6. Use of the pharmaceutical composition of claim 4 or 5 in the preparation of an anti-pancreatic cancer drug.

7. The pharmaceutical composition according to claim 4 or 5, wherein The pharmaceutical composition is added to a pharmaceutically acceptable carrier or excipient to form any pharmaceutically acceptable dosage form.

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