Methods of enhancing immune checkpoint inhibitor therapy

Abstract

Compositions and methods are provided for enhancing immune checkpoint inhibitor therapy of cancer by combination therapy with cyclic peptides. Such cyclic peptides may be naturally occurring or of synthetic origin.

Description

[0001] This work was performed with government support from the National Institutes of Health (NIH) under Grant Nos. AI22931, AI125141, DE021341, and CA014089. The government has certain rights to this invention.

[0002] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 283,152, filed November 24, 2021, U.S. Provisional Patent Application Serial No. 63 / 283,155, filed November 24, 2021, and U.S. Provisional Patent Application Serial No. 63 / 283,158, filed November 24, 2021. These and all other cited extrinsic materials are incorporated herein by reference in their entirety. When a definition or use of a term in a reference incorporated by reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein is deemed to control. Technical Field

[0003] The present disclosure relates to the treatment of cancer, in particular immunotherapeutic interventions. Background Art

[0004] Immunotherapy approaches to treating cancer use elements of a patient's own immune system to treat the disease. Such immunotherapy may involve administering antibodies, cytokines, and / or cells that are retrieved from the patient and processed before being re-administered.

[0005] Antibodies used in immune checkpoint inhibitor therapy are often directed against cell surface markers expressed by tumor cells to activate the body's complement system or otherwise recognize cells of the immune system. Alternatively, such antibodies can be directed against cell surface receptors on cancer cells or T cells, with the result usually being downregulation of T cell activity against cancer cells (e.g., PD-1, PD-L1). Antibodies used for this purpose include Alemtuzumab, a monoclonal antibody that targets CD52 and activates complement, Atezolizumab, another monoclonal antibody that targets PD-L1 and interferes with T cell inactivation, and Ilipimumab, a monoclonal antibody that targets CTLA4 and shifts the T-cell balance toward cytotoxicity. Unfortunately, the use of these therapeutic antibodies can produce unwanted side effects, including the precipitation of autoimmune diseases, increased infection rates, and neurological disorders.

[0006] Immunotherapy using cells involves removing cells from a patient, activating and expanding the cells in culture, and returning the activated cells to the patient. TMFor the treatment of prostate cancer, it involves removing antigen-presenting dendritic cells from the blood via leukemia, incubating them with a fusion protein consisting of GM-CSF and prostatic acid phosphatase, and then injecting them. The resulting improvement in the presentation of cancer-specific antigens to the immune system is intended to improve the immune response. In another approach, CAR-T inhibitors remove T cells and genetically modify them to express chimeric receptors that specifically recognize target cancer cells. These modified T cells are returned to the patient in the hope that they will selectively target cancer cells. Unfortunately, this approach is expensive and time-consuming, can cause flu-like symptoms, and has mixed results.

[0007] Therefore, there is still a need for a simple and well-tolerated immunotherapy approach to treat cancer. Summary of the invention

[0008] Cyclic peptides, which may be naturally occurring (e.g., θ-defensins) or synthetic (e.g., naturally occurring cyclic peptide analogs), have been found to enhance the effects of immune checkpoint inhibitors in treating cancer. Compositions and methods for using such cyclic peptides in combination with immune checkpoint inhibitors (e.g., 0.01 mg / kg to 15 mg / kg) to provide more effective cancer treatment than either the cyclic peptide or the immune checkpoint inhibitor alone are described herein. These and other aspects of the invention disclosed herein will be described in more detail as the patent disclosure proceeds.

[0009] Embodiments of the present invention include methods of treating cancer by administering an effective amount of a cyclic peptide (e.g., 0.01 mg / kg to 15 mg / kg) and an effective amount of an immune checkpoint inhibitor (ICI, such as an antibody to PD-1) to a patient in need of cancer treatment. In some embodiments, such cyclic peptides may be analogs of θ-defensins. Suitable analogs include peptide 1 (SEQ ID NO.1), peptide 2 (SEQ ID NO.2), peptide 3 (SEQ ID NO.3), peptide 4 (SEQ ID NO 4), peptide 5 (SEQ ID NO.5), peptide 6 (SEQ ID NO.6), peptide 7 (SEQ ID NO.7), peptide 8 (SEQ ID NO.8), peptide 9 (SEQ ID NO.9), peptide 10 (SEQ ID NO.10), peptide 11 (SEQ ID NO.11), peptide 12 (SEQ ID NO.12), peptide 13 (SEQ ID NO.13), peptide 14 (SEQ ID NO.14), peptide 15 (SEQ ID NO.15) and peptide 16 (SEQ ID NO.16). In other embodiments, such cyclic peptides may be naturally occurring θ-defensins, such as peptide 17 (SEQ ID NO. 17), peptide 18 (SEQ ID NO. 18), peptide 19 (SEQ ID NO. 19), peptide 20 (SEQ ID NO. 20), peptide 21 (SEQ ID NO. 21), peptide 22 (SEQ ID NO. 22), peptide 23 (SEQ ID NO. 23), peptide 24 (SEQ ID NO. 24), peptide 25 (SEQ ID NO. 25), peptide 26 (SEQ ID NO. 26), peptide 27 (SEQ ID NO. 27), peptide 28 (SEQ ID NO. 28), peptide 29 (SEQ ID NO. 29), peptide 30 (SEQ ID NO. 30), peptide 31 (SEQ ID NO. 31), peptide 32 (SEQ ID NO. 32), and peptide 33 (SEQ ID NO. 33). When used in combination with ICI, such treatment may include or provide for inducing tumor (e.g., melanoma) regression, preventing tumor (e.g., melanoma or cancer colon cancer) recurrence, inhibiting the infiltration of myeloid-derived suppressor cells into the tumor microenvironment, and / or enhancing CD8+T cell responses in the tumor microenvironment. In some embodiments, the use of cyclic peptides allows for a reduction in the dose of ICI while maintaining effectiveness, the reduction being relative to the amount of ICI administered in the absence of the peptide. In some embodiments, the use of cyclic peptides reduces or eliminates side effects associated with the administration of ICI (e.g., by allowing a reduction in the amount of ICI required).

[0010] Embodiments of the present invention include methods of enhancing immune checkpoint inhibitor therapy by administering an effective amount of a cyclic peptide (0.01 mg / kg to 15 mg / kg) and an immune checkpoint inhibitor (ICI, such as an antibody to PD-1) to a patient in need of cancer treatment. In some embodiments, such cyclic peptides may be analogs of θ-defensins. Suitable analogs include peptide 1 (SEQ ID NO.1), peptide 2 (SEQ ID NO.2), peptide 3 (SEQ ID NO.3), peptide 4 (SEQ ID NO 4), peptide 5 (SEQ ID NO.5), peptide 6 (SEQ ID NO.6), peptide 7 (SEQ ID NO.7), peptide 8 (SEQ ID NO.8), peptide 9 (SEQ ID NO.9), peptide 10 (SEQ ID NO.10), peptide 11 (SEQ ID NO.11), peptide 12 (SEQ ID NO.12), peptide 13 (SEQ ID NO.13), peptide 14 (SEQ ID NO.14), peptide 15 (SEQ ID NO.15) and peptide 16 (SEQ ID NO.16). In other embodiments, such cyclic peptides may be naturally occurring θ-defensins, such as peptide 17 (SEQ ID NO. 17), peptide 18 (SEQ ID NO. 18), peptide 19 (SEQ ID NO. 19), peptide 20 (SEQ ID NO. 20), peptide 21 (SEQ ID NO. 21), peptide 22 (SEQ ID NO. 22), peptide 23 (SEQ ID NO. 23), peptide 24 (SEQ ID NO. 24), peptide 25 (SEQ ID NO. 25), peptide 26 (SEQ ID NO. 26), peptide 27 (SEQ ID NO. 27), peptide 28 (SEQ ID NO. 28), peptide 29 (SEQ ID NO. 29), peptide 30 (SEQ ID NO. 30), peptide 31 (SEQ ID NO. 31), peptide 32 (SEQ ID NO. 32), and peptide 33 (SEQ ID NO. 33). In some embodiments, the enhancement provided by the cyclic peptide is a reduction in the dose of the ICI while maintaining effectiveness, relative to the amount of ICI administered in the absence of the peptide. In some embodiments, the enhancement provided by the cyclic peptide is a reduction or elimination of side effects associated with administration of an ICI (eg, by allowing a reduction in the amount of ICI required).

[0011] Embodiments of the present invention include pharmaceutical compositions that provide an amount of cyclic peptides (e.g., 0.01 mg / kg to 15 mg / kg) that effectively enhances immune checkpoint therapy. In some embodiments, such cyclic peptides may be analogs of θ-defensins. Suitable analogs include peptide 1 (SEQ ID NO.1), peptide 2 (SEQ ID NO.2), peptide 3 (SEQ ID NO.3), peptide 4 (SEQ ID NO 4), peptide 5 (SEQ ID NO.5), peptide 6 (SEQ ID NO.6), peptide 7 (SEQ ID NO.7), peptide 8 (SEQ ID NO.8), peptide 9 (SEQ ID NO.9), peptide 10 (SEQ ID NO.10), peptide 11 (SEQ ID NO.11), peptide 12 (SEQ ID NO.12), peptide 13 (SEQ ID NO.13), peptide 14 (SEQ ID NO.14), peptide 15 (SEQ ID NO.15) and peptide 16 (SEQ ID NO.16). In other embodiments, such cyclic peptides may be naturally occurring θ-defensins, such as peptide 17 (SEQ ID NO. 17), peptide 18 (SEQ ID NO. 18), peptide 19 (SEQ ID NO. 19), peptide 20 (SEQ ID NO. 20), peptide 21 (SEQ ID NO. 21), peptide 22 (SEQ ID NO. 22), peptide 23 (SEQ ID NO. 23), peptide 24 (SEQ ID NO. 24), peptide 25 (SEQ ID NO. 25), peptide 26 (SEQ ID NO. 26), peptide 27 (SEQ ID NO. 27), peptide 28 (SEQ ID NO. 28), peptide 29 (SEQ ID NO. 29), peptide 30 (SEQ ID NO. 30), peptide 31 (SEQ ID NO. 31), peptide 32 (SEQ ID NO. 32) and peptide 33 (SEQ ID NO. 33). Such pharmaceutical compositions may include immune checkpoint inhibitors, such as antibodies to PD-1.

[0012] Embodiments of the present invention include the use of cyclic peptides in treating cancer in patients. In this use, an effective amount of the cyclic peptide (e.g., 0.01 mg / kg to 15 mg / kg) is provided in combination with the administration of an effective amount of an immune checkpoint inhibitor (ICI, such as an antibody against PD-1). In some embodiments, such cyclic peptides can be analogs of θ-defensins. Suitable analogs include peptide 1 (SEQ ID NO.1), peptide 2 (SEQ ID NO.2), peptide 3 (SEQ ID NO.3), peptide 4 (SEQ ID NO.4), peptide 5 (SEQ ID NO.5), peptide 6 (SEQ ID NO.6), peptide 7 (SEQ ID NO.7), peptide 8 (SEQ ID NO.8), peptide 9 (SEQ ID NO.9), peptide 10 (SEQ ID NO.10), peptide 11 (SEQ ID NO.11), peptide 12 (SEQ ID NO.12), peptide 13 (SEQ ID NO.13), peptide 14 (SEQ ID NO.14), peptide 15 (SEQ ID NO.15) and peptide 16 (SEQ ID NO.16). In other embodiments, such cyclic peptides may be naturally occurring θ-defensins, such as peptide 17 (SEQ ID NO. 17), peptide 18 (SEQ ID NO. 18), peptide 19 (SEQ ID NO. 19), peptide 20 (SEQ ID NO. 20), peptide 21 (SEQ ID NO. 21), peptide 22 (SEQ ID NO. 22), peptide 23 (SEQ ID NO. 23), peptide 24 (SEQ ID NO. 24), peptide 25 (SEQ ID NO. 25), peptide 26 (SEQ ID NO. 26), peptide 27 (SEQ ID NO. 27), peptide 28 (SEQ ID NO. 28), peptide 29 (SEQ ID NO. 29), peptide 30 (SEQ ID NO. 30), peptide 31 (SEQ ID NO. 31), peptide 32 (SEQ ID NO. 32), and peptide 33 (SEQ ID NO. 33). Such uses may include inducing tumor (e.g., melanoma) regression, preventing tumor (e.g., melanoma or cancer colon cancer) recurrence, inhibiting the infiltration of myeloid-derived suppressor cells into the tumor microenvironment, enhancing the CD8+ T cell response of the tumor microenvironment when used in combination with an ICI, reducing the dose of the ICI relative to the amount of ICI administered without the use of the peptide while maintaining effectiveness, and / or reducing or eliminating side effects associated with the administration of the ICI.

[0013] Embodiments of the present invention include the use of cyclic peptides to enhance immune checkpoint inhibitor therapy, wherein an effective amount of cyclic peptides (e.g., 0.01 mg / kg to 15 mg / kg) is provided in combination with an immune checkpoint inhibitor (ICI, such as an antibody to PD-1). In some embodiments, such cyclic peptides can be analogs of θ-defensins. Suitable analogs include peptide 1 (SEQ ID NO.1), peptide 2 (SEQ ID NO.2), peptide 3 (SEQ ID NO.3), peptide 4 (SEQ ID NO 4), peptide 5 (SEQID NO.5), peptide 6 (SEQ ID NO.6), peptide 7 (SEQ ID NO.7), peptide 8 (SEQ ID NO.8), peptide 9 (SEQ ID NO.9), peptide 10 (SEQ ID NO.10), peptide 11 (SEQ ID NO.11), peptide 12 (SEQ ID NO.12), peptide 13 (SEQ ID NO.13), peptide 14 (SEQ ID NO.14), peptide 15 (SEQ ID NO.15), and peptide 16 (SEQ ID NO.16). In other embodiments, such cyclic peptides may be naturally occurring θ-defensins, such as peptide 17 (SEQ ID NO. 17), peptide 18 (SEQ ID NO. 18), peptide 19 (SEQ ID NO. 19), peptide 20 (SEQ ID NO. 20), peptide 21 (SEQ ID NO. 21), peptide 22 (SEQ ID NO. 22), peptide 23 (SEQ ID NO. 23), peptide 24 (SEQ ID NO. 24), peptide 25 (SEQ ID NO. 25), peptide 26 (SEQ ID NO. 26), peptide 27 (SEQ ID NO. 27), peptide 28 (SEQ ID NO. 28), peptide 29 (SEQ ID NO. 29), peptide 30 (SEQ ID NO. 30), peptide 31 (SEQ ID NO. 31), peptide 32 (SEQ ID NO. 32), and peptide 33 (SEQ ID NO. 33). Such enhancement includes reducing the dose of the ICI while maintaining effectiveness and / or reducing or eliminating side effects associated with the administration of the ICI, the enhancement being relative to the amount of the ICI administered in the absence of the peptide.

[0014] Embodiments of the present inventive concept include cyclic peptides consisting of peptide 2 (SEQ ID NO. 2) and having the following structure:

[0015]

[0016] Such embodiments may include a pharmaceutical composition comprising Peptide 2 and a pharmaceutically acceptable excipient.

[0017] Embodiments of the present invention include kits including cyclic peptides and immune checkpoint inhibitors (ICIs, such as PD-1 antibodies). In some embodiments, such cyclic peptides may be analogs of θ-defensins. Suitable analogs include peptide 1 (SEQ ID NO.1), peptide 2 (SEQ ID NO.2), peptide 3 (SEQ ID NO.3), peptide 4 (SEQ ID NO 4), peptide 5 (SEQ ID NO.5), peptide 6 (SEQ ID NO.6), peptide 7 (SEQ ID NO.7), peptide 8 (SEQ ID NO.8), peptide 9 (SEQID NO.9), peptide 10 (SEQ ID NO.10), peptide 11 (SEQ ID NO.11), peptide 12 (SEQ ID NO.12), peptide 13 (SEQ ID NO.13), peptide 14 (SEQ ID NO.14), peptide 15 (SEQ ID NO.15) and peptide 16 (SEQ ID NO.16). In other embodiments, such cyclic peptides may be naturally occurring θ-defensins, such as peptide 17 (SEQ ID NO.17), peptide 18 (SEQ ID NO.18), peptide 19 (SEQ ID NO.19), peptide 20 (SEQ ID NO.20), peptide 21 (SEQ ID NO.21), peptide 22 (SEQ ID NO.22), peptide 23 (SEQ ID NO.23), peptide 24 (SEQ ID NO.24), peptide 25 (SEQ ID NO.25), peptide 26 (SEQ ID NO.26), peptide 27 (SEQ ID NO.27), peptide 28 (SEQ ID NO.28), peptide 29 (SEQ ID NO.29), peptide 30 (SEQ ID NO.30), peptide 31 (SEQ ID NO.31), peptide 32 (SEQ ID NO.32) and peptide 33 (SEQ ID NO.33). The cyclic peptide is provided in an amount (e.g., 0.01 mg / kg to 15 mg / kg) effective to enhance the activity of immune checkpoint inhibitors. In some embodiments, the cyclic peptide and the immune checkpoint inhibitor are mixed. Such kits can include instructions for combining the cyclic peptide with the immune checkpoint inhibitor for treating cancer.

[0018] Various objects, features, aspects and advantages of the present subject matter will become more apparent from the following detailed description of preferred embodiments and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Exemplary cyclic peptide 1 (SEQ ID NO. 1), peptide 2 (SEQ ID NO. 2), and peptide 3 (SEQ ID NO. 3) are shown.

[0020] Figure 2 Additional exemplary cyclic peptides are shown: peptide 4 (SEQ ID NO.4), peptide 5 (SEQ ID NO.5), peptide 6 (SEQ ID NO.6), peptide 7 (SEQ ID NO.7), peptide 8 (SEQ ID NO.8), peptide 9 (SEQ ID NO.9), peptide 10 (SEQ ID NO.10), peptide 11 (SEQ ID NO.11), peptide 12 (SEQ ID NO.12) and peptide 13 (SEQ ID NO.13).

[0021] Figure 3 A typical regimen for co-administration of the cyclic peptides described herein and an immune checkpoint inhibitor (ICI), in this case anti-PD-1, is shown.

[0022] Figure 4 Cumulative survival curves resulting from the indicated treatments are shown (efficacy of treatment with peptide 1 (SEQ ID NO. 1) and anti-PD-1 versus saline or anti-PD-1 alone (P<0.005).

[0023] Figure 5 Shown are the results of tumor growth in mice treated with peptide 1 (SEQ ID NO. 1) in combination with anti-PD-1 antibody (IgG2a-κ isotype, clone: ​​RMP1-14, obtained from BioXcell).

[0024] Figure 6 A regimen of co-treatment of the cyclic peptides described herein with an anti-PD-1 antibody is shown.

[0025] Figure 7 The results of monotherapy with peptide 1 (SEQ ID NO.1), peptide 2 (SEQ ID NO.2) or peptide 3 (SEQ ID NO.3), combined therapy with peptide 1 (SEQ ID NO.1), peptide 2 (SEQ ID NO.2) or peptide 3 (SEQ ID No.3) in combination with anti-PD-1 monoclonal antibody, and monotherapy with anti-PD-1 monoclonal antibody in mice challenged with MC38 mouse colon adenocarcinoma cells are shown.

[0026] Figure 8 (Top) Shows tumors in untreated control mice formed by challenge with MC38 mouse colon adenocarcinoma cells. Figure 8 The figure below shows that when MC38 cells were used to restore the function of mice without MC38 tumors (such as Figure 7 Results when the mice were re-challenged with the poison and tumor development was observed within 30 days after re-challenge.

[0027] Fig. 9Shown are the results of treatment with 4 doses of the indicated cyclic peptide (0.1 mg / kg), 4 doses of the indicated cyclic peptide plus 3 doses of anti-PD-1 monoclonal antibody (1 mg / kg), or saline (control) in C57BL / 6 mice implanted subcutaneously with 5 x 106 MC38 colon adenocarcinoma cells.

[0028] Fig.10 Shown are the results of treatment with cyclic peptide (0.1 mg / kg) and 3 doses of anti-PD-1 monoclonal antibody (1 mg / kg), or saline in mice.

[0029] Fig.11 The results of combined treatment with peptide 1 (SEQ ID NO. 1), 2 or 3 and anti-PD-1 antibody are shown ( Fig.11 Panel A shows the effect of combined treatment on the expression of exhaustion marker TIM3 on CD8+ T cells.

[0030] Figures 12A to 12H The structures of cyclic peptides peptide 17 (SEQ ID NO.17), peptide 18 (SEQ ID NO.18), peptide 19 (SEQID NO.19), peptide 20 (SEQ ID NO.20), peptide 21 (SEQ ID NO.21), peptide 22 (SEQ ID NO.22), peptide 23 (SEQID NO.23), peptide 24 (SEQ ID NO.24), peptide 25 (SEQ ID NO.25), peptide 26 (SEQ ID NO.26), peptide 27 (SEQID NO.27), peptide 28 (SEQ ID NO.28), peptide 29 (SEQ ID NO.29), peptide 30 (SEQ ID NO.30), peptide 31 (SEQID NO.31), peptide 32 (SEQ ID NO.32) and peptide 33 (SEQ ID NO.33) are shown.

[0031] Fig.13 A typical protocol for co-administration of a cyclic peptide (in this case peptide 17 (SEQ ID NO. 17)) and an ICI is shown.

[0032] Fig.14 Shown by Fig.13 Cumulative survival curves resulting from the indicated treatments shown in (Efficacy of treatment with peptide 17 and anti-PD-1 compared with saline or anti-PD-1 alone (P<0.005). DETAILED DESCRIPTION

[0033] Synthetic and naturally occurring cyclic peptides and their use in enhancing immune checkpoint inhibitor therapy are described herein. Such synthetic cyclic peptides are effective at a dosage of 0.001mg / kg to 50mg / kg, 0.005mg / kg to 30mg / kg, 0.01mg / kg to 15mg / kg or an intermediate range. It should be understood that the disclosed technology provides many favorable technical effects, including but not limited to improving the effectiveness of immunotherapy methods for treating cancer. Suitable cyclic peptides can be produced by known peptide synthesis methods, such as Gunasekera et al., Int J Pept Res Ther (2013) 19: Methods described in 43-54.

[0034] In the context of the present application, an effective synthetic or naturally occurring cyclic peptide is a cyclic peptide that uses immune checkpoint inhibitors at a concentration that can be achieved by the human body to improve the anti-cancer treatment effect (e.g., reducing the tumor mass or quantity of cancer cells, inhibiting cancer cell proliferation, reducing metastasis, increasing survival time, preventing recurrence, etc.) after oral administration, injection, infusion, inhalation and / or application to the eye or mucosa. Similarly, the method conceived by the present invention can use an effective amount of effective synthetic or naturally occurring cyclic peptides and immune checkpoint inhibitors to treat cancer together. In the context of the present application, an effective amount is an amount of synthetic or naturally occurring cyclic peptides sufficient to improve the effect of immune checkpoint inhibitors in treating cancer. This effective synthetic or naturally occurring cyclic peptide can be identified using the method described in detail below. Similarly, the effective amount of this effective synthetic or naturally occurring cyclic peptide can be determined using the method described in detail below.

[0035] In some embodiments, such cyclic peptides may be θ-defensins or analogs of θ-defensins. Analogs of defensin analogs may be cyclic peptides having about 40%, 50%, 60%, 70%, 80%, 90% or higher sequence identity with naturally occurring defensin peptide sequences. Defensin analogs may comprise one, two, three or more core features of natural defensins. Exemplary core features include a cyclic structure, one, two, three or more disulfide bonds within the peptide (e.g., between cysteine ​​pairs of the analog), a positive charge in solution under physiological conditions, and the presence of a β-pleated sheet secondary structure. Such defensin analogs may include 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 or more amino acids, and in some embodiments may be combined with non-naturally occurring amino acids. Analogs of θ-defensins may include one or more L-amino acids, one or several D-amino acids and / or a mixture of L- and D-amino acids. In some embodiments, non-peptide bonds may be utilized between adjacent amino acid residues of theta-defensin analogs - defensin analogs may represent a deletion or substitution of one or more amino acids of a naturally occurring defensin sequence. Such substitutions may be conservative (e.g., wherein the substituted amino acids retain the charge, hydrophobicity, hydrophilicity, and / or steric properties of the naturally occurring amino acids). In some embodiments, defensin analogs may include grafting or conjugation of non-peptide moieties, such as polyethylene glycol and / or other hydrophilic polymers, cell receptor targeting moieties, and / or moieties that aid in processing / purification.

[0036] The following discussion provides many example embodiments. Although any one embodiment may represent a single combination of elements, the disclosed subject matter is considered to include any or all possible combinations of disclosed elements. Therefore, if one embodiment includes elements A, B, and C, and a second embodiment includes elements B and D, then even if not explicitly disclosed, the disclosure is considered to include other remaining combinations of A, B, C, or D.

[0037] In some embodiments, the digits representing the number of components, properties (such as concentration, reaction conditions, etc.) used to describe and claim certain embodiments should be understood to be modified by the term "approximately" in some cases. Therefore, in some embodiments, the numerical parameters specified in the written description and the appended claims are approximate values, which can change according to the performance required for a specific embodiment. In some embodiments, the numerical parameters should be interpreted according to the number of significant figures reported and by applying common rounding techniques. Although the numerical ranges and parameters of the wide range of some embodiments are approximate values, the numerical values ​​described in the specific embodiments will be reported as accurately as possible. The numerical values ​​presented in some embodiments may include some errors, which are necessarily caused by the standard deviation found in their respective test measurements.

[0038] As used in this specification and the claims that follow, the meanings of "a," "an," and "the" include plural references unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of "in" includes "in" and "on" unless the context clearly dictates otherwise.

[0039] The description of numerical ranges herein is intended only as a shorthand method, citing each individual numerical value falling within the range separately. Unless otherwise specified herein, each individual value is incorporated into the specification as if it were listed separately herein. All methods described herein can be performed in any suitable order, unless otherwise indicated herein or clearly contradictory to the context. The use of any and all examples or exemplary language (e.g., "such as") provided with respect to certain embodiments herein is intended only to better illustrate the present disclosure, without limiting the scope of the elements otherwise claimed. Any language in the specification should not be interpreted as indicating any unclaimed element that is essential to its practice.

[0040] The grouping of alternative elements or embodiments disclosed herein should not be construed as limiting. The member of each group may be referred to and claimed individually or in any combination with other members of the group or other elements found herein. For convenience and / or patentability reasons, one or more members of a group may be included in a group or may be deleted from the group. When any such inclusion or deletion occurs, the specification is deemed to include the modified group in this article, thereby satisfying the written description of all Markush groups used in the appended claims.

[0041] Suitable cyclic peptides have the effect of enhancing immune checkpoint therapy. Such cyclic peptides include a "CXC box" structure defined by two pairs of cysteines, which are connected by a pair of disulfide bonds across the cyclic structure. Otherwise, adjacent cysteines within the CXC box are separated by a single hydrophobic amino acid, or in some embodiments, by a positively charged amino acid such as arginine. Such peptides also include multiple arginines, and in preferred embodiments include at least one arginine triplet consisting of three adjacent arginines. These cyclic peptides have a net positive charge at neutral pH. Examples of the structures of suitable synthetic cyclic peptides that are analogs of naturally occurring cyclic peptides are shown in Figure 1 (Peptide 1 (SEQ ID NO. 1), Peptide 2 (SEQ ID NO. 2) and Peptide 3) and Figure 2 (peptides 4-13). The structures of suitable naturally occurring cyclic peptides are shown in Figures 12A to 12H middle.

[0042] Suitable cyclic peptides that can be used in the method for the present invention's concept can be naturally occurring cyclic peptides (e.g., RTD-1) and / or analogs of naturally occurring cyclic peptides. Suitable analogs of naturally occurring cyclic peptides include peptide 1 (SEQ ID NO.1), peptide 2 (SEQ ID NO.2), peptide 3 (SEQ ID NO.3), peptide 4 (SEQ ID NO 4), peptide 5 (SEQ ID NO.5), peptide 6 (SEQ ID NO.6), peptide 7 (SEQ ID NO.7), peptide 8 (SEQ ID NO.8), peptide 9 (SEQ ID NO.9), peptide 10 (SEQ ID NO.10), peptide 11 (SEQ ID NO.11), peptide 12 (SEQ ID NO.12), peptide 13 (SEQ ID NO.13), peptide 14 (SEQ ID NO.14), peptide 15 (SEQ ID NO.15) and peptide 16 (SEQ ID NO.16) (see Table 1). It should be understood that although the sequences provided in Table 1 are provided in linear text, the peptides represented are cyclic (ie, without free amino and / or carboxyl termini). Such cyclic peptides are peptide drugs that provide immunomodulatory activity without immunosuppression.

[0043] Table 1

[0044]

[0045]

[0046] As described above, suitable cyclic peptides can be naturally occurring and isolated from natural sources, such as described in Garcia et al., Infection and Immunity (2008) 76: 5883-5891. Alternatively, such naturally occurring cyclic peptides can be produced by synthetic methods, such as the methods described in Gunasekera et al., Int J Pept Res Ther (2013) 19: 43-54. Examples of suitable naturally occurring cyclic peptides are provided in Table 2. It should be understood that although the sequences provided in Table 2 are provided in the form of linear text, the peptides represented are cyclic (i.e., without free amino and / or carboxyl termini).

[0047] Table 2

[0048]

[0049]

[0050] It is believed that such cyclic peptides can enhance ICI therapy by counteracting immunosuppressive pathways in the tumor microenvironment (TME). As shown below, naturally occurring and cyclic peptides can inhibit immunosuppressive cytokines, inhibit the infiltration of tumor-promoting myeloid-derived suppressor cells (MDSCs) into the TME, recruit cytotoxic T cells, and reduce T cell exhaustion.

[0051] Immune checkpoint inhibitors

[0052] As described above, cyclic peptides can be used in combination with immune checkpoint inhibitors. Immune checkpoint inhibitors include, but are not limited to, anti-natural killer cell receptor 2B4 (2B4), anti-B-lymphocyte and T lymphocyte attenuator (BTLA), anti-CD160 antigen (CD160), anti-cytotoxic T lymphocyte protein 4 (CTLA-4), anti-lymphocyte activation gene 3 protein (LAG-3), anti-programmed cell death protein 1 (PD-1), anti-T-cell immunoglobulin mucin receptor 3 (TIM-3) or anti-T-cell immunology receptor (TIGIT) agents / inhibitors with Ig and ITIM domains.

[0053] In some embodiments, immune checkpoint inhibitors include but are not limited to anti-2B4, anti-BTLA, anti-CD160, anti-CTLA-4, anti-LAG-3, anti-PD-1, anti-TIM-3 or anti-TIGIT antibodies. In some embodiments, immune checkpoint inhibitors include but are not limited to anti-2B4, anti-BTLA, anti-CD160, anti-CTLA-4, anti-LAG-3, anti-TIM-3 or anti-TIGIT antibodies.

[0054] Inhibitors of immune checkpoint ligands include, but are not limited to, anti-CD48 antigen (CD48), anti-CD80 antigen (CD80), anti-D86 antigen (CD86), anti-CD112 antigen (CD112), anti-CD155 antigen (CD155), anti-carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1), anti-fibrinogen-like protein 1 (FGL1), anti-galectin 9 (Gal-9), class I histocompatibility antigen alpha chain B (HLA-B), class I histocompatibility antigen alpha chain C (HLA-C), class I histocompatibility antigen alpha chain E (HLA-E), class I histocompatibility antigen alpha chain G (HLA-G), anti-high mobility group protein B1 (HMG1), anti-herpes virus entry mediator A (HVEM), anti-programmed cell death 1 ligand 1 (PD-L1) and anti-programmed cell death 1 ligand 2 (PD-L2) agents / inhibitors. In some embodiments, the cyclic peptide described herein is combined with an inhibitor and applied to an immune checkpoint ligand other than PD-L1 / 2 ligand. In some embodiments, the inhibitor of the immune checkpoint ligand includes but is not limited to anti-CD48, anti-CD80, anti-CD86, anti-CD112, anti-CD155, anti-CEACAM1, anti-FGL1, anti-Gal-9, anti-HLA-B, anti-HLA-C, anti-HLA-E, anti-HLA-G, anti-HMG1, anti-HVEM, anti-PD-L1 and anti-PD-L2 antibodies. In some embodiments, the inhibitor of the immune checkpoint ligand includes but is not limited to anti-CD48, anti-CD80, anti-CD86, anti-CD112, anti-CD155, anti-CEACAM1, anti-FGL1, anti-Gal-9, anti-HLA-B, anti-HLA-C, anti-HLA-E, anti-HLA-G, anti-HMG1, anti-HVEM, anti-PD-L1 and anti-PD-L2 antibodies.

[0055] Anti-2B4 / anti-CD48 agents

[0056] As used herein, "2B4" refers to the natural killer cell (2B4) receptor. Other names include NK cell activation ligand (NAIL), NK cell type I receptor protein 2B4, signal lymphocyte activation molecule 4 (SLAM4) and CD244 (differentiation cluster 244). 2B4 has at least one ligand CD48 (differentiation cluster 48). In some embodiments, targeting 2B4 restores immune function in the tumor microenvironment. In some embodiments, anti-2B4 or anti-CD48 agents are antibodies, peptides, small molecules or nucleic acids.

[0057] In some embodiments, the anti-2B4 agent is an anti-2B4 antibody. In some embodiments, the anti-CD48 agent is an anti-CD48 antibody.

[0058] "Anti-2B4 antibody" refers to an antibody directed against the natural killer cell (2B4) receptor. In some embodiments, the anti-2B4 antibody binds to an epitope of 2B4 that blocks the binding of 2B4 to any one or more of its putative ligands. In some embodiments, the anti-2B4 antibody binds to an epitope of the 2B4 protein that blocks the binding of 2B4 to CD48. "Anti-CD48 antibody" refers to an antibody directed against the CD48 antigen (CD48).

[0059] The terms "antibody" and "antibodies" used herein include all types of immunoglobulins, including IgG, IgM, IgA, IgD and IgE, or active fragments thereof, which may be suitable for medical use as disclosed herein. Antibodies may be monoclonal or polyclonal, and may be of any species of origin, including, for example, mouse, rat, rabbit, horse or human. Antibody fragments that retain specific binding to a protein or epitope (e.g., 2B4 or CD48) to which an antibody used in the present disclosure binds are included within the scope of the term "antibody". Antibodies may be chimeric or humanized, particularly when they are used for therapeutic purposes. Antibodies and antibody fragments may be obtained or prepared using a variety of methods.

[0060] Anti-BTLA / Anti-HVEM Agents

[0061] As used herein, "BTLA" refers to the B- and T lymphocyte attenuator (BTLA) receptor. Other names include B- and T lymphocyte-associated protein and CD272 (differentiation cluster 272). BTLA has at least one ligand, herpes virus entry mediator A (HVEM). In some embodiments, targeting BTLA restores immune function in the tumor microenvironment.

[0062] In some embodiments, the anti-BTLA or anti-HVEM agent is an antibody, a peptide, a small molecule, or a nucleic acid.

[0063] "Anti-BTLA antibodies" refers to antibodies against the B and T lymphocyte attenuator (BTLA) receptor. In some embodiments, the anti-BTLA antibody binds to an epitope of BTLA that blocks the binding of BTLA to any one or more of its putative ligands. In some embodiments, the anti-BTLA antibody binds to an epitope of the BTLA protein that blocks the binding of BTLA to HVEM. "Anti-HVEM antibodies" refers to antibodies against herpes virus entry mediator A (HVEM).

[0064] Anti-CD160 / anti-MHCI reagents

[0065] As used herein, "CD160" refers to the CD160 antigen (CD160) receptor. Other names include natural killer cell receptor BY55 (BY55) and CD160 (differentiation cluster 160). CD160 has at least two ligands, herpes virus entry mediator A (HVEM) and major histocompatibility complex (MHC) class I proteins, including HLA class I histocompatibility antigen alpha chain B (HLA-B), HLA class I group compatibility antigen alpha chain C (HLA-C), HLA class I group compatibility antigen alpha chain E (HLA-E) and HLA class I histocompatibility antigen alpha chain G (HLA-G). In some embodiments, targeting CD160 restores immune function in the tumor microenvironment.

[0066] In some embodiments, the anti-CD160, anti-HLA-B, anti-HLA-C, anti-HLA-E, anti-HLA-G, or anti-HVEM agent is an antibody, a peptide, a small molecule, or a nucleic acid.

[0067] In some embodiments, the anti-CD160 agent is an anti-CD160 antibody. In some embodiments, the anti-HLA-B agent is an anti-HLA-B antibody. In some embodiments, the anti-HLA-C agent is an anti-HLA-C antibody. In some embodiments, the anti-HLA-E agent is an anti-HLA-E antibody. In some embodiments, the anti-HLA-G agent is an anti-HLA-G antibody. In some embodiments, the anti-HVEM agent is an anti-HVEM antibody.

[0068] "Anti-CD160 antibody" refers to an antibody against the CD160 antigen (CD160) receptor. In some embodiments, the anti-CD160 antibody binds to an epitope of CD160 that blocks the binding of CD160 to any one or more of its putative ligands. In some embodiments, the anti-CD160 antibody binds to an epitope of the CD160 protein that blocks the binding of CD160 to HLA-B, HLA-C, HLA-E, HLA-G or HVEM. "Anti-HLA-B antibody" refers to an antibody against HLA class I histocompatibility antigen alpha chain B (HLA-B). "Anti-HLA-C antibody" refers to an antibody against HLA class I histocompatibility antigen alpha chain C (HLA-C). "Anti-HLA-E antibody" refers to an antibody against HLA class I histocompatibility antigen, alpha chain E (HLA-E). "Anti-HLA-G antibody" refers to an antibody against HLA class I histocompatibility antigen, alpha chain G (HLA-G).

[0069] Anti-CTLA-4 / anti-CD80 / anti-CD86 drugs

[0070] As used herein, "CTLA-4" or "CTLA4" refers to the cytotoxic T lymphocyte protein 4 (CTLA-4) receptor. Other names include cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) and CD152 (differentiation cluster 152). CTLA-4 has at least two ligands, namely the T lymphocyte activation antigen CD80 (CD80) and the T lymphocyte activation antibody CD86 (CD86). In some embodiments, targeting CTLA-4 restores immune function in the tumor microenvironment.

[0071] In some embodiments, the anti-CTLA-4, anti-CD80, or anti-CD86 agent is an antibody, a peptide, a small molecule, or a nucleic acid.

[0072] In some embodiments, the anti-CTLA-4 agent is an anti-CTLA-4 antibody. In some embodiments, the anti-CD80 agent is an anti-CD80 antibody. In some embodiments, the anti-CD86 agent is an anti-CD86 antibody. "Anti-CTLA-4 antibody" refers to an antibody directed against the cytotoxic T-lymphocyte protein 4 (CTLA-4) receptor. In some embodiments, the anti-CTLA-4 antibody binds to an epitope of CTLA-4 that blocks the binding of CTLA-4 to any one or more of its putative ligands. In some embodiments, the anti-CTLA-4 antibody binds to an epitope of the CTLA-4 protein that blocks the binding of CTLA-4 to CD80 or CD86. "Anti-CD80 antibody" refers to an antibody directed against the CD80 antigen (CD80). "Anti-CD86 antibody" refers to an antibody directed against the CD86 antigen (CD80).

[0073] Anti-LAG-3 / Anti-FGL1 / Anti-MHC Class II Reagents

[0074] As used herein, "LAG-3" refers to the lymphocyte activation gene 3 protein (LAG-3) receptor. Other names include CD223 (cluster of differentiation 223). LAG-3 has at least two ligands, fibrinogen-like protein 1 (FGL1) and major histocompatibility complex (MHC) class II protein. In some embodiments, targeting CD160 restores immune function in the tumor microenvironment.

[0075] In some embodiments, the anti-LAG-3, anti-FGL1 or anti-MHC class II agent is an antibody, a peptide, a small molecule or a nucleic acid.

[0076] In some embodiments, the anti-LAG-3 agent is an anti-LAG-3 antibody. In some embodiments, the anti-FGL1 agent is an anti-FGL1 antibody. In some embodiments, the anti-MHC class II agent is an anti-MHC class II antibody.

[0077] "Anti-LAG-3 antibody" refers to an antibody directed against the lymphocyte activation gene 3 protein (LAG-3) receptor. In some embodiments, the anti-LAG-3 antibody binds to an epitope of LAG-3 that blocks the binding of LAG-3 to any one or more of its putative ligands. In some embodiments, the anti-LAG-3 antibody binds to an epitope of the LAG-3 protein that blocks the binding of LAG-3 to FGL1 or MHC class II. "Anti-FGL1 antibody" refers to an antibody directed against fibrinogen-like protein 1 (FGL1). "Anti-MHC class II antibody" refers to an antibody directed against major histocompatibility complex (MHC) class II protein.

[0078] Anti-PD-1 / anti-PD-L1 / anti-PDL2 reagents

[0079] As used herein, "PD-1" or "PD1" refers to the programmed death 1 (PD-1) receptor. Other names include programmed cell death protein 1 and CD279 (cluster of differentiation 279). PD-1 has two ligands, PD-L1 and PD-L2. In some embodiments, targeting PD-1 restores immune function in the tumor microenvironment. As used herein, "PD-L1" or "PDL1" refers to programmed death ligand 1 (PD-L1). As used herein, "PD-L2" or "PDL2" refers to programmed death ligand 2 (PD-L2). In some embodiments, anti-PD-1 or anti-PDL-1 agents are antibodies, peptides, small molecules, or nucleic acids.

[0080] In some embodiments, the anti-PD-1 agent used in combination with the compounds described herein is nivolumab, pembrolizumab, atezolizumab, durvalumab, pidilizumab, avelumab, TSR-042, PDR-001, tislelizumab (BGB-A317), cemiplimab (REGN2810), LY-3300054, JNJ- 63723283, MGA012, BI-754091, IBI-308, camrelizumab (HR-301210), BCD-100, JS-001, CX-072, BGB-A333, AMP-514 (MEDI-0680), AGEN-2034, CSIOO.I, Sym-021, SHR-1316, PF-06801591, LZM009, KN-035, AB122, genolimzumab (CBT-501), FAZ-053, CK-301, AK 104 or GLS-010, BGB-108, SHR-1210, PDR-001, PF-06801591, STI-1110, mDX-400, Spartalizumab (PDR001), Carrelizumab (SHR1210), Sintilimab (IBI308), Tislelizumab (BGB-A317), Toripalimab (JS 001), Dostarlimab (TSR-042, WBP-285), INCMGA00012 (MGA012), AMP-224 or AMP-514 (MEDI0680).

[0081] In some embodiments, the anti-PD-1 agent is an anti-PD-1 antibody. "Anti-PD-1 antibody" refers to an antibody against programmed death protein 1 (PD1). In some embodiments, the anti-PD-1 antibody binds to an epitope of PD-1 that blocks the binding of PD-1 to any one or more of its putative ligands. In some embodiments, the anti-PD-1 antibody binds to an epitope of the PD-1 protein that blocks the binding of PD-1 to PD-L1 and / or PD-L2.

[0082] Exemplary anti-PD-1 antibodies include, but are not limited to: nivolumab / MDX-1106 / BMS-9300 / ONO1152, a fully human IgG4 anti-PD-1 monoclonal antibody; humanized IgG1 monoclonal antibody pembrolizumab (MDV9300 / CT-011); pembrolizumab (MK-3475 / pembrolizumab / lamprolizumab), a humanized monoclonal IgG4 antibody; durvalumab (MEDI-4736) and atezolizumab.

[0083] In some embodiments, the anti-PD-1 antibody is nivolumab ( Bristol-MyersSquibb), pembrolizumab ( Merck), cemiplimab (Libtayo), labrolizumab (Merck), or BGB-A317.

[0084] In some embodiments, the anti-PD1 antibody is an antibody described in U.S. Patent Nos. 7,029,674, 7,488,802, 7,521,051, 8,008,449, 8,354,509, 8,617,546, 8,709,417, or WO 2014 / 179664.

[0085] In some embodiments, the anti-PD-1 agent used in combination is atezolizumab, avelumab, AMP-224, MEDI-0680, RG-7446, GX-P2, durvalumab, KY-1003, KD-033, MSB-0010718C, TSR-042, ALN-PDL, STI-A1014, CX-072, BMS-936559, KN035, CK-301 (Checkpoint Therapeutics), AUNP12, CA-170 (Aurigene / Curis), MEDI4736, MSB0010718C, MDX 1105-01, or BMS-986189.

[0086] In some embodiments, the anti-PD-L1 agent is an anti-PD-L1 antibody. "Anti-PD-L1 antibody" refers to an antibody against programmed death ligand 1 (PD-L1). Anti-PD-L1 antibodies include: avelumab; BMS-936559, a fully human IgG4 antibody; atelizumab (MPDL3280A / RG-7446), a human monoclonal antibody; MEDI4736; MSB0010718C and MDX 1105-01.

[0087] In some embodiments, the anti-PD-L1 antibody is avelumab ( Merck KGA / Pfizer), durvalumab (AstraZeneca), and atezolizumab ( Roche).

[0088] Other exemplary antibodies include, but are not limited to, those described in U.S. Patent Nos. 8,217,149, 8,383,796, 8,552,154, and 8,617,546.

[0089] Peptide anti-PD-1 / PD-L1 agents include AUNP12 (29-mer peptide from Aurigene and Laboratoires Pierre Fabre), CA-170 (Aurigene / Curis), and BMS-986189 (macrocyclic peptide from BMS).

[0090] Small molecule anti-PD-1 / PD-L1 agents include WO / 2020 / 086556, WO / 2020 / 014643, WO / 2019 / 204609, WO / 2019 / 160882, WO / 2018 / 195321, WO2018026971, US20180044329, US20180044305, US20180044304, US20180044303 , US20180044350, US20180057455, US20180057486, US20180045142, WO20180044963, WO20180447 83. WO2018009505, WO20180044329, WO2017066227, WO2017087777, US20170145025, WO201707966 9. W02017070089, US2017107216, WO2017222976, US20170262253, WO2017205464, US2017032087 5. WO2017192961, WO2017112730, US20170174679, WO2017106634, WO2017202744, WO2017202275, Those described in WO2017202273, WO2017202274, WO2017202276, WO2017180769, WO2017118762, WO2016041511, WO2016039749, WO2016142835, WO2016142852, WO2016142886, WO2016142894 and WO2016142833.

[0091] Anti-TIM-3 / Anti-Gal-9 / Anti-HMG1 / Anti-CEACAM1 Agents

[0092] As used herein, "TIM-3" refers to the T cell immunoglobulin mucin receptor 3 (TIM-3) receptor. Other names include hepatitis A virus cell receptor 2 (HAVcr-2), protein 3 containing T cell immunoglobulin and mucin domains (TIMD-3), T cell membrane protein 3, and CD366 (differentiation cluster 366). TIM-3 has at least three ligands, galectin-9 (Gal-9), high mobility group protein B1 (HMG1), and carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1). In some embodiments, targeting TIM-3 restores immune function in the tumor microenvironment.

[0093] In some embodiments, the anti-TIM-3, anti-Gal-9, anti-HMG1 or anti-CEACAM1 agent is an antibody, peptide, small molecule or nucleic acid. In some embodiments, the anti-TIM-3 agent is an anti-TIM-3 antibody. In some embodiments, the anti-Gal-9 agent is an anti-Gal-9 antibody. In some embodiments, the anti-HMG1 agent is an anti-HMG1 antibody. In some embodiments, the anti-CACAM1 agent is an anti-CECAM1 antibody.

[0094] "Anti-TIM-3 antibody" refers to an antibody against the T cell immunoglobulin mucin receptor 3 (TIM-3) receptor. In some embodiments, the anti-TIM-3 antibody binds to an epitope of TIM-3 that blocks the binding of TIM-3 to any one or more of its putative ligands. In some embodiments, the anti-TIM-3 antibody binds to an epitope of the TIM-3 protein that blocks the binding of TIM-3 to Gal-9, HMG1, or CEACAM1. "Anti-Gal-9 antibody" refers to an antibody against galactose lectin 9 (Gal-9). "Anti-HMG1 antibody" refers to an antibody against high mobility group protein B1 (HMG1). "Anti-CEACAM1 antibody" refers to an antibody against carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1).

[0095] Anti-TIGIT / anti-CD112 / anti-CD255 agents

[0096] As used herein, "TIGIT" refers to the T cell immunoreceptor (TIGIT) receptor with Ig and ITIM domains. Other names include protein 9 containing V-set and immunoglobulin domains (VSIG9) and protein 3 containing V-set and transmembrane domains (VSTM3). TIGIT has at least two ligands, CD112 (cluster of differentiation 112) and CD155 (cluster of differentiation 155). In some embodiments, targeting TIGIT restores immune function in the tumor microenvironment.

[0097] In some embodiments, anti-TIGIT, anti-CD112 or CD155 agents are antibodies, peptides, small molecules or nucleic acids. In some embodiments, anti-TIGIT agents are anti-TIGIT antibodies. In some embodiments, anti-CD112 agents are anti-CD112 antibodies. In some embodiments, anti-CD155 agents are anti-CD155 antibodies. "Anti-TIGIT antibodies" refer to antibodies against T cell immune receptors with Ig and ITIM domain (TIGIT) receptors. In some embodiments, anti-TIGIT antibodies bind to an epitope of TIGIT that blocks the binding of TIGIT to any one or more of its putative ligands. In some embodiments, anti-TIGIT antibodies bind to an epitope of TIGIT protein that blocks TIGIT from binding to CD112 or CD155. "Anti-CD112 antibodies" refer to antibodies against CD112 (differentiation cluster 112). "Anti-CD155 antibodies" refer to antibodies against CD155 (differentiation cluster 155).

[0098] Example

[0099] It has been found that the use of cyclic peptides, including naturally occurring cyclic peptides and analogs of naturally occurring cyclic peptides, can enhance ICI therapy against PD-1 expression. Typical protocols for identifying or characterizing naturally occurring cyclic peptides or effective analogs of naturally occurring cyclic peptides are as follows: Figure 3 shown.

[0100] like Figure 3 As shown, 3×10 5 B16K1 melanoma cells were then intraperitoneally (IP) administered with the indicated cyclic peptides (3 times per week for 3 weeks) with or without anti-PD-1 monoclonal antibody (anti-PD-1 RMP1-14 from BioXcell, 1 mg kg -1 ) (n=10 mice per group). Other suitable anti-PD-1 antibodies include, but are not limited to, MEDI0680, nivolumab, pembrolizumab, cemiplizumab, atelizumab, dostallimab, durvalumab, and avelumab. Figure 3 The results for the analogs of the naturally occurring cyclic peptides peptide 1 (SEQ ID NO. 1) and peptide 2 (SEQ ID NO. 2) of the scheme shown are shown in Figure 4 middle.

[0101] Figure 4Cumulative survival curves resulting from the indicated treatments are shown (p < 0.005 for efficacy of anti-PD-1 peptide treatment compared to saline or anti-PD-1 alone). As shown, combined treatment with anti-PD-1 and cyclic peptides enhanced anti-PD-1 treatment and in fact provided an effect that exceeded the sum of the effects provided by anti-PD1 or cyclic peptides as monotherapy. It should also be recognized that surviving mice were re-challenged with B16K1 cells on day 65 (arrow). Surprisingly, none of these mice developed tumors.

[0102] The effects of anti-PD-1 therapy and cyclic peptide combination therapy on melanoma regression were also investigated. C57BL / 6 mice were implanted with B16K1 melanoma and treated as Figure 3 The cells were treated with saline, anti-PD-1 alone, peptide 1 (SEQ ID NO. 1) alone, or peptide 1 (SEQ ID NO. 1) in combination with anti-PD-1 as shown. Figure 5 shown.

[0103] Surprisingly, 40% of mice treated with peptide 1 (SEQ ID NO. 1) in combination with anti-PD-1 antibodies achieved complete tumor regression, compared to 10% of mice treated with anti-PD-1 alone. This effect was not observed in mice treated with saline or cyclic peptide alone, suggesting that combined treatment with cyclic peptide enhanced anti-PD-1 treatment. In fact, this synergistic treatment provided an effect that exceeded the sum of the effects provided by anti-PD-1 or cyclic peptide as monotherapy.

[0104] In a mouse colon cancer model, the efficacy of anti-PD-1 therapy was also found to be enhanced by co-administration of the cyclic peptides described herein. A typical protocol for identifying or characterizing a naturally occurring cyclic peptide or an effective analog of an effective naturally occurring cyclic peptide is shown in Figure 6 middle.

[0105] Mice were challenged with MC38 mouse colon adenocarcinoma cells and treated with peptide 1 (SEQ ID NO.1), peptide 2 (SEQ ID NO.2), or peptide 3 (SEQ ID NO.3), peptide 1 (SEQ ID NO.1), peptide 2 (SEQ ID NO.2), or peptide 3 (SEQ ID NO.3) in combination with anti-PD-1 monoclonal antibody, or anti-PD-1 monoclonal antibody alone. Figure 7 shown.

[0106] As shown, peptide 1 (SEQ ID NO.1), peptide 2 (SEQ ID NO.2), and peptide 3 (SEQ ID NO.3) all enhanced the effect of anti-PD-1 monoclonal antibody on survival. The effect provided by this combination therapy exceeded the sum of the effects provided by anti-PD1 or cyclic peptides as monotherapy. As described above, the re-challenge studies on melanoma showed that the combination treatment of synthetic cyclic peptides and ICIs was effective in preventing recurrence of cancer cell reintroduction. The use of cyclic peptides in combination with anti-PD-1 ICIs was also effective in immunizing mice to re-challenge with MC38 colon cancer cells. The results of these studies are shown in Figure 8 In. Figure 8 As shown in the upper panel, MC38 cells formed tumors in untreated control mice. Figure 8 The lower panel shows the results of rechallenging mice without MC38 tumors with MC38 cells (Fig. Figure 7 The results were shown in Figure 2 and observed for tumor development within 30 days after rechallenge. No tumors were formed, suggesting that the tumor immunity provided by the combination of cyclic peptides and ICI therapy may be widely applicable.

[0107] The cyclic peptide was also found to inhibit the infiltration of myeloid-derived suppressor cells (MDSC) into the tumor microenvironment. 5×10 6 MC38 colon adenocarcinoma cells were then treated with 4 doses of the cyclic peptide (0.1 mg / kg), 4 doses of the cyclic peptide (1 mg / kg) and 3 doses of anti-PD-1 monoclonal antibody, or saline (control). Tumors were harvested on day 13, and the percentage of myeloid-derived suppressor cells (MDSCs) was quantified by FACS.

[0108] As shown in the figure, peptide 1 (SEQ ID NO.1), peptide 2 (SEQ ID NO.2) and peptide 3 (SEQ ID NO.3) each showed significant activity in reducing the percentage of MDSCs in the tumor microenvironment. Although the anti-PD-1 antibody alone had little effect, when peptide 1 (SEQ ID NO.1) was used in combination with the anti-PD-1 monoclonal antibody, the enhancement was obvious. This enhanced effect exceeded the sum of the effects of anti-PD-1 monoclonal monotherapy and peptide 1 (SEQ ID NO.1) monotherapy.

[0109] It is believed that cyclic peptides (eg, peptide 1 (SEQ ID NO. 1), peptide 2 (SEQ ID NO. 2), peptide 3) may provide less toxic and potentially more effective treatments in a wide range of oncology indications, where inhibition of MDSCs is a therapeutic goal.

[0110] It was also found that the combination of cyclic peptides and ICI (e.g., anti-PD-1 monoclonal antibody) can enhance the penetration of cytotoxic T cells into the tumor microenvironment. C57BL / 6 mice were implanted subcutaneously with 5×10 6 MC38 colon adenocarcinoma cells. Mice were treated with 4 doses of the indicated cyclic peptide (0.1 mg / kg), 4 doses of the indicated cyclic peptide (0.1 m / kg) and 3 doses of anti-PD-1 monoclonal antibody (1 mg / kg), or saline (control). Tumors were harvested on day 13, and the percentage of CD8+ T cells was quantified by FACS. The results are shown in Fig. 9 shown.

[0111] As shown in the figure, each combination of cyclic peptides and anti-PD-1 mAbs increased CD8+ T cells, reaching statistical significance (Mann-Whitney test) compared with peptide 1. The effect of this combination therapy exceeded the effect of anti-PD-1 mAb monotherapy and monotherapy with the corresponding cyclic peptide.

[0112] It has also been found that cyclic peptides used in combination with ICIs (such as anti-PD-1 monoclonal antibodies) can enhance CD8+ T cell responses in the tumor microenvironment (TME). After treatment with cyclic peptides in combination with anti-PD-1, cell populations from MC38 colon cancer tumors ( Fig.10 Figure A) showed that the ratio of CD8+T cells to T regulatory cells in the TME increased, and the effects of peptide 1 (SEQ ID NO.1) and peptide 2 (SEQ ID NO.2) reached statistical significance (Mann-Whitney test). The combined treatment also reduced the expression of TIM3, an exhaustion marker on CD8+T cells ( Fig.10 Figure B).

[0113] Modulation of T cell activity in the tumor microenvironment is believed to be an important component of the beneficial effects of treatment with synthetic cyclic peptides, with or without concurrent immune checkpoint therapy.

[0114] Given the effects of cyclic peptides (e.g., peptide 1 (SEQ ID NO. 1), peptide 2 (SEQ ID NO. 2), peptide 3) on enhancing immune checkpoint inhibitor (ICI) therapy, it is believed that members of this peptide drug family can make ICI effective in patients who are currently not successfully treated with current ICIs. Similarly, it is believed that this combination therapy can produce longer-lasting remissions compared to ICI treatment in the absence of synthetic cyclic peptides, and this combination therapy can enable patients whose disease initially responded but subsequently progressed during ICI treatment to obtain new remissions.

[0115] In addition, it is believed that combination therapy with cyclic peptides may enable the use of ICI therapy in some first-line indications where ICI alone is currently not feasible. Similarly, the low to absent toxicity of cyclic peptides at effective doses suggests that they have the potential to reduce the dose of ICI (while maintaining efficacy). It is envisioned that ICI-cyclic peptide combination therapy could be used as an adjuvant therapy in some oncology indications.

[0116] As shown, the use of cyclic peptides can significantly enhance the broad effects of immune checkpoint therapy. Therefore, it is believed that synergistic treatment with one or more cyclic peptides (e.g., peptide 1 (SEQ ID NO.1), peptide 2 (SEQ ID NO.2), peptide 3) can allow the use of ICI at lower doses currently used. This lower dose can reduce the occurrence and / or severity of side effects or adverse immune effects associated with ICI therapy.

[0117] Cyclic peptides (e.g., peptide 1 (SEQ ID NO. 1), peptide 2 (SEQ ID NO. 2), peptide 3) may have the effect of downregulating proinflammatory cytokines such as TNFα and IL-6. It is believed that in oncology indications, cyclic peptides can provide a low toxicity option for downregulating TNF-α and IL-6.

[0118] As described above, a suitable cyclic peptide may be a naturally occurring cyclic peptide. Suitable naturally occurring cyclic peptides include θ-defensins. It is believed that such naturally occurring cyclic peptides can enhance ICI therapy by counteracting immunosuppressive pathways in the tumor microenvironment (TME). Studies on θ-defensins and their synthetic analogs have shown that such cyclic peptides can inhibit immunosuppressive cytokines, inhibit the infiltration of tumor-promoting myeloid-derived suppressor cells (MDSCs) into the TME, recruit cytotoxic T cells, and reduce T cell exhaustion.

[0119] It has been found that ICI treatment for PD-1 expression can use naturally occurring cyclic octapeptides (such as peptide 17 (SEQ ID NO.17), peptide 18 (SEQ ID NO.18), peptide 19 (SEQ ID NO.19), peptide 20 (SEQ ID NO.20), peptide 21 (SEQ ID NO.21), peptide 22 (SEQ ID NO.22), peptide 23 (SEQ ID NO.23), peptide 24 (SEQ ID NO.24), peptide 25 (SEQ ID NO.25), peptide 26 (SEQ ID NO.26), peptide 27 (SEQ ID NO.27), peptide 28 (SEQ ID NO.28), peptide 29 (SEQ ID NO.29), peptide 30 (SEQ ID NO.30), peptide 31 (SEQ ID NO.31), peptide 32 (SEQ ID NO.32) and peptide 33 (SEQ ID NO.33)), such as Fig. 12A A typical scheme for identifying effective naturally occurring cyclic peptides (i.e., cyclic peptides that effectively enhance the effect of immune checkpoint therapy) or analogs of naturally occurring cyclic peptides is as follows: Fig.13 shown.

[0120] like Fig.13 As shown, 3×10 6 C57BL / 6 wild-type (WT) mice were intradermally implanted with B16K1 melanoma cells, and then peptide 17 (SEQ ID NO. 17) (5 mg / kg) was administered intraperitoneally (IP) on days 6, 8, 10, 13, 15, 17, 20, 22, 24, and 41 (n=10 mice per group), 1 mg / kg of anti-PD-1 monoclonal antibody (BioXcell RMP-1-14) was administered on days 6, 9, and 13, and peptide 17 and anti-PD-1 monoclonal antibody were administered according to the corresponding schedule, or anti-TNF monoclonal antibody (XT3.11, positive control) was combined with 10 mg / kg of anti-PD-1 monoclonal antibody. Mice were injected with normal saline as a negative control. The results are shown in Fig.14 shown.

[0121] Fig.14 Cumulative survival curves resulting from the indicated treatments as shown in Figure 12 are shown. As shown, treatment with anti-PD-1 antibody alone was indistinguishable from saline. Similarly, treatment with peptide 17 (SEQ ID NO.17) alone had no significant effect (data not shown). In contrast, combined treatment with peptide 17 (SEQ ID NO.17) and anti-PD-1 monoclonal antibody (1 mg / kg) was effective in prolonging survival. Other studies have shown that this anti-PD-1 monoclonal antibody is effective in prolonging survival in a melanoma model when used at a dose of 10 mg / kg. It is expected that peptide 18 (SEQ ID NO.18), peptide 19 (SEQ ID NO.19), peptide 20 (SEQ ID NO.20), peptide 21 (SEQ ID NO.21), peptide 22 (SEQ ID NO.22), peptide 23 (SEQ ID NO.23), peptide 24 (SEQ ID NO.24), peptide 25 (SEQ ID NO.25), peptide 26 (SEQ ID NO.26), peptide 27 (SEQ ID NO.27), peptide 28 (SEQ ID NO.28), peptide 29 (SEQ ID NO.29), peptide 30 (SEQ ID NO.30), peptide 31 (SEQ ID NO.31), peptide 32 (SEQ ID NO.32) and peptide 33 (SEQ ID NO.33) have similar activities.

[0122] It is believed that cyclic octapeptides (e.g., peptide 17 (SEQ ID NO. 17), peptide 18 (SEQ ID NO. 18), peptide 19 (SEQ ID NO 19), peptide 20 (SEQ ID NO. 20), peptide 21 (SEQ ID NO. 21), peptide 22 (SEQ ID NO. 22), peptide 23 (SEQ ID NO. 23), peptide 24 (SEQ ID NO. 24), peptide 25 (SEQ ID NO. 25), peptide 26 (SEQ ID NO. 26), peptide 27 (SEQ ID NO. 27), peptide 28 (SEQ ID NO. 28), peptide 29 (SEQ ID NO. 29), peptide 30 (SEQ ID NO. 30), peptide 31 (SEQ ID NO. 31), peptide 32 (SEQ ID NO. 32), and peptide 33 (SEQ ID NO. 33)) can provide less toxic and potentially more effective treatments in a wide range of oncology indications, where inhibition of MDSCs is a therapeutic goal.

[0123] cancer

[0124] The disclosed methods can be used to treat or prevent cancer, including metastatic cancer. Cancer is a group of related diseases that may include sustained proliferation signaling, escape from growth inhibitors, resistance to cell death, achievement of replicative immortality, induction of angiogenesis, and activation of invasion and metastasis. The disclosed methods can enhance or elicit an immune response to cancer in a subject. The immune response can result in an increase in one or more of leukocytes, lymphocytes, monocytes, and eosinophils.

[0125] Cancers that can be treated by the disclosed methods include, but are not limited to, astrocytomas, adrenocortical carcinomas, appendix carcinomas, basal cell carcinomas, bile duct carcinomas, bladder cancers, bone cancers, brain cancers, brain stem cancers, brain stem gliomas, breast cancers, cervical cancers, colon cancers, colorectal cancers, cutaneous T-cell lymphomas, diffuse intrinsic pontine gliomas, ductal carcinomas, endometrial carcinomas, ependymomas, Ewing's sarcomas, esophageal cancers, eye cancers, fibrosarcomas, gallbladder cancers, gastric cancers, cancer), gastrointestinal cancer, germ cell tumor, glioma, hepatocellular carcinoma, histiocytosis, Hodgkin lymphoma, hypopharyngeal cancer, intraocular melanoma, Kaposi sarcoma, kidney cancer, laryngeal cancer, leukemia, liver cancer, lung cancer, lymphoma, macroglobulinemia, melanoma, mesothelioma, oral cancer, multiple myeloma, nasopharyngeal cancer, neuroblastoma, non-Hodgkin lymphoma, osteosarcoma, ovarian cancer, pancreatic cancer, parathyroid cancer, penile cancer, pharyngeal cancer, pituitary cancer, prostate cancer, rectal cancer, renal cell carcinoma, retinoblastoma, rhabdomyosarcoma, sarcoma, skin cancer, small cell lung cancer, small intestine cancer, soft tissue cancer, soft tissue sarcoma, solid tumors, squamous cell carcinoma, stomach cancer, T-cell lymphoma, testicular cancer, pharyngeal cancer, thymoma, thyroid cancer, trophoblastic tumor, urethral cancer, uterine cancer, uterine sarcoma, vaginal cancer, vulvar cancer, and Wilms' tumor.

[0126] In some embodiments, the cancer treatable by the disclosed methods is melanoma, cancer kidney, cancer prostate, cancer ovarian, cancer breast, glioma, cancer lung, soft tissue cancer, soft tissue sarcoma, osteosarcoma, or pancreatic cancer. In some embodiments, the cancer is a solid tumor. In some embodiments, the cancer is a soft tissue cancer. In some embodiments, the cancer is a fibrosarcoma. In some embodiments, the cancer is a diffuse intrinsic pontine glioma. In some embodiments, the cancer is a metastatic cancer.

[0127] Pharmaceutical composition

[0128] In some embodiments, the cyclic peptides described herein are formulated into pharmaceutical compositions. Pharmaceutical compositions are formulated in a conventional manner using one or more pharmaceutically acceptable inactive ingredients that aid in processing the active compound into a pharmaceutically useful preparation. The correct formulation depends on the chosen route of administration. An overview of the pharmaceutical compositions described herein can be found in, for example, Remington: The Science and Practice of Pharmacy, 19th Ed (Easton, Pa: Mack Publishing Company, 1995); Hoover, John E., Remington's Pharmaceutical Sciences, Mack Publishing Co., Easton, Pennsylvania 1975; Liberman, HA and Lachman, L., Eds., Pharmaceutical Dosage Forms, Marcel Decker, New York, NY, 1980; and Pharmaceutical Dosage Forms and Drug Delivery Systems, Seventh Ed. (Lippincott Williams & Wilkins 1999), which are incorporated herein by reference for such disclosure.

[0129] In some embodiments, the compounds described herein are administered alone or in combination with a pharmaceutically acceptable carrier, excipient or diluent in a pharmaceutical composition. The administration of the compounds and compositions described herein can be achieved by any method capable of delivering the compounds to the site of action. These methods include, but are not limited to, delivery by enteral routes (including oral, gastric or duodenal feeding tubes, rectal suppositories and rectal enemas), parenteral routes (injection or infusion, including intra-arterial, intracardiac, intradermal, intraduodenal, intramedullary, intramuscular, intraosseous, intraperitoneal, intrathecal, intravascular, intravenous, intravitreal, epidural and subcutaneous), inhalation, transdermal, transmucosal, sublingual, oral and topical (including transdermal, dermal, enema, eye drops, ear drops, intranasal, vaginal) administration, although the most suitable route may depend on, for example, the condition and illness of the receptor. As an example only, the compounds described herein can be topically applied to the area in need of treatment by, for example, local infusion during surgery, topical application such as cream or ointment, injection, catheter or implant. Administration can also be by direct injection at the site of the diseased tissue or organ.

[0130] In some embodiments, pharmaceutical compositions suitable for oral administration are in the form of discrete units, such as capsules, cachets, or tablets, each containing a predetermined amount of active ingredient; as a powder or granules; as a solution or suspension in an aqueous liquid or a non-aqueous liquid; or as an oil-in-water liquid emulsion or a water-in-oil liquid emulsion. In some embodiments, the active ingredient is in the form of a pill, ointment, or paste.

[0131] Pharmaceutical compositions that can be used orally include tablets, push-in capsules made of gelatin, and soft sealed capsules made of gelatin and plasticizers (such as glycerol or sorbitol). Tablets can be made by compression or molding, optionally with one or more auxiliary ingredients. Compressed tablets can be prepared by compressing the active ingredient in a free-flowing form (such as powder or granules) in a suitable machine, optionally mixed with a binder, an inert diluent or lubricant, a surfactant or a dispersant. Molded tablets can be prepared by molding a mixture of powdered compounds moistened with an inert liquid diluent in a suitable machine. In some embodiments, the tablets are coated or scored and are formulated to provide a slow or controlled release of the active ingredient therein. The dosage of all oral administration preparations should be suitable for such administration. Push-in capsules may contain active ingredients mixed with fillers such as lactose, binders such as starches and / or lubricants such as talc or magnesium stearate and optional stabilizers. In soft capsules, the active compound can be dissolved or suspended in a suitable liquid, such as a fatty oil, liquid paraffin or liquid polyethylene glycol. In some embodiments, stabilizers are added. The tablet cores are provided with suitable coatings. For this purpose, concentrated sugar solutions may be used, which may optionally contain gum arabic, talc, polyvinyl pyrrolidone, carbopol gel, polyethylene glycol and / or titanium dioxide, lacquer solutions and suitable organic solvents or solvent mixtures. Dyes or pigments may be added to the tablet or tablet coatings for identification or characterization of different combinations of active compound dosages.

[0132] In some embodiments, the pharmaceutical composition is formulated for parenteral administration by injection, for example, by push injection or continuous infusion. Injectable preparations can be provided in unit dose form, for example, in ampoules or multi-dose containers, with the addition of preservatives. The composition can take the form of a suspension, solution or emulsion in an oily or aqueous vehicle, and can contain a formulation, such as a suspending agent, a stabilizer and / or a dispersant. The composition can exist in the form of a unit dose or multi-dose container (e.g., sealed ampoules and vials), and can be stored in powder form or freeze-dried (lyophilized) conditions, requiring only the addition of a sterile liquid carrier, such as saline or sterile pyrogen-free water, immediately before use. External injection solutions and suspensions can be prepared from sterile powders, granules and tablets of the aforementioned types.

[0133] Pharmaceutical compositions for parenteral administration include aqueous and non-aqueous (oily) sterile injection solutions of the active compound, which may contain antioxidants, buffers, bacteriostats and solutes to make the preparation isotonic with the blood of the intended recipient; and aqueous and non-aqueous sterile suspensions, which may include suspending agents and thickening agents. Suitable lipophilic solvents or carriers include fatty oils such as sesame oil, or synthetic fatty acid esters such as ethyl oleate or triglycerides, or liposomes. Aqueous injection suspensions may contain substances that increase the viscosity of the suspension, such as sodium carboxymethylcellulose, sorbitol or dextran. Optionally, the suspension may also contain a suitable stabilizer or agent that increases the solubility of the compound to allow the preparation of a high concentration solution.

[0134] It should be understood that in addition to the ingredients specifically mentioned above, the compounds and compositions described herein may also include other formulations conventional in the art. For example, formulations suitable for oral administration may include flavoring agents.

[0135] The embodiments of the present invention include immune checkpoint inhibitors and cyclic peptides, which are effective in enhancing the effect of immune checkpoint inhibitors for treating cancer. In some embodiments, such kits may include immune checkpoint inhibitors and cyclic peptides in mixed form (e.g., the same preparation). In other embodiments, such kits may provide immune checkpoint inhibitors and cyclic peptides as separate preparations. Such kits may include instructions for use. For example, such instructions may provide a treatment regimen, wherein an effective amount of effective cyclic peptides and immune checkpoint inhibitors are provided in combination with a person who needs to treat cancer. In some embodiments, cyclic peptides and immune checkpoint inhibitors are administered with the same plan and may be administered together. In other embodiments, cyclic peptides and immune checkpoint inhibitors are administered with different schedules. This different schedule may provide a period of time, during which cyclic peptides and immune checkpoint inhibitors are administered. Alternatively, this different schedule may provide a period of time, during which cyclic peptides or immune checkpoint inhibitors are administered. Such schedules may provide cyclic peptides and / or immune checkpoint inhibitors continuously (e.g., by infusion) or periodically. Cyclic peptides and / or immune checkpoint inhibitors can be delivered on a periodic schedule every hour, every two hours, or every three hours.

[0136] Although the data provided above are from animal models of melanoma and colon cancer, the combinations described herein may also be effective in treating pancreatic cancer, aggressive lymphomas, or metastatic cancers. In view of these data, it is expected that cyclic peptides (such as, but not limited to, peptide 1 (SEQ ID NO. 1), peptide 2 (SEQ ID NO. 2), peptide 3) will have utility that extends to a wide range of cancers and stages beyond the scope of the current data.

[0137] It will be apparent to those skilled in the art that, without departing from the disclosure provided herein, further modifications may be made in addition to those already described. Therefore, the disclosed subject matter is not limited except in the spirit of the appended claims. In addition, when interpreting the specification and claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms "comprises" and "comprising" should be interpreted as referring to elements, components or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may exist, be used or be combined with other elements, components or steps that are not explicitly referenced. When the specification claims involve at least one selected from A, B, C ... and N, the text should be interpreted as requiring only one element of the group, rather than A plus N or B plus N, and so on.

Claims

1. A method for treating cancer in a patient in need thereof, comprising administering to the patient an effective amount of a cyclic peptide and an effective amount of an immune checkpoint inhibitor (ICI).

2. The method of claim 1, wherein the cyclic peptide is an analog of theta-defensin.

3. The method according to claim 2, wherein the cyclic peptide is selected from peptide 1 (SEQ ID NO.1), peptide 2 (SEQ ID NO.2), peptide 3 (SEQ ID NO.3), peptide 4 (SEQ ID NO.4), peptide 5 (SEQ ID NO.5), peptide 6 (SEQ ID NO.6), peptide 7 (SEQ ID NO.7), peptide 8 (SEQ ID NO.8), peptide 9 (SEQ ID NO.9), peptide 10 (SEQ ID NO.10), peptide 11 (SEQID NO.11), peptide 12 (SEQ ID NO.12), peptide 13 (SEQ ID NO.13), peptide 14 (SEQ ID NO.14), peptide 15 (SEQID NO.15) and peptide 16 (SEQ ID NO.16).

4. The method of claim 1, wherein the cyclic peptide is a naturally occurring θ-defensin.

5. The method according to claim 1, wherein the cyclic peptide is selected from peptide 17 (SEQ ID NO.17), peptide 18 (SEQ ID NO.18), peptide 19 (SEQ ID NO.19), peptide 20 (SEQ ID NO.20), peptide 21 (SEQ ID NO.21), peptide 22 (SEQ ID NO.22), peptide 23 (SEQ ID NO.23), peptide 24 (SEQ ID NO.24), peptide 25 (SEQ ID NO.25), peptide 26 (SEQID NO.26), peptide 27 (SEQ ID NO.27), peptide 28 (SEQ ID NO.28), peptide 29 (SEQ ID NO.29), peptide 30 (SEQID NO.30), peptide 31 (SEQ ID NO.31), peptide 32 (SEQ ID NO.32) and peptide 33 (SEQ ID NO.33).

6. The method of any one of claims 1-5, wherein treating cancer comprises inducing tumor regression.

7. The method of claim 6, wherein tumor regression is induced in melanoma.

8. The method of any one of claims 1 to 7, wherein treating cancer comprises preventing tumor recurrence.

9. The method of claim 8, wherein tumor recurrence of melanoma or colon cancer is prevented.

10. The method of any one of claims 1 to 9, wherein treating cancer comprises inhibiting the infiltration of myeloid-derived suppressor cells into the tumor microenvironment.

11. The method of any one of claims 1 to 10, wherein treating cancer comprises enhancing CD8+ T cell responses in the tumor microenvironment when used in combination with an ICI.

12. The method according to any one of claims 1 to 11, wherein the ICI comprises an antibody against PD-1.

13. The method of any one of claims 1 to 12, wherein treating cancer comprises reducing the dosage of the ICI relative to the amount of ICI administered without the peptide while maintaining effectiveness.

14. The method of claim 13, wherein treating cancer further comprises reducing or eliminating side effects associated with administration of the ICI.

15. The method according to any one of claims 1 to 14, wherein the effective amount of the cyclic peptide is 0.01 mg / kg to 15 mg / kg.

16. The method according to any one of claims 1 to 15, wherein the ICI is selected from anti-natural killer cell receptor 2B4 (2B4), anti-B lymphocyte and T lymphocyte attenuator (BTLA), anti-CD160 antigen (CD160), anti-cytotoxic T lymphocyte protein 4 (CTLA-4), anti-lymphocyte activation gene 3 protein (LAG-3), anti-programmed cell death protein 1 (PD-1), anti-T-cell immunoglobulin mucin receptor 3 (TIM-3) and anti-T-cell immunodeficiency receptor (TIGIT) agents / inhibitors with Ig and ITIM domains.

17. The method of claim 16, wherein the ICI is an anti-PD-1 antibody.

18. A method of enhancing immune checkpoint inhibitor therapy comprising administering an effective amount of a cyclic peptide in combination with an immune checkpoint inhibitor (ICI).

19. The method of claim 18, wherein the cyclic peptide is an analog of theta defensin.

20. The method of claim 19, wherein the cyclic peptide is selected from the group consisting of peptide 1 (SEQ ID NO. 1), peptide 2 (SEQ ID NO. 2) and peptide 3 (SEQ ID NO. 3).

21. The method of claim 19, wherein the cyclic peptide is selected from peptide 4 (SEQ ID NO. 4), peptide 5 (SEQ ID NO. 5), peptide 6 (SEQ ID NO. 6), peptide 7 (SEQ ID NO. 7), peptide 8 (SEQ ID NO. 8), peptide 9 (SEQ ID NO. 9), peptide 10 (SEQ ID NO. 10), peptide 11 (SEQ ID NO. 11), peptide 12 (SEQ ID NO. 12), peptide 13 (SEQ ID NO. 13), peptide 14 (SEQ ID NO. 14), peptide 15 (SEQ ID NO. 15) and peptide 16 (SEQ ID NO. 16).

22. The method of claim 18, wherein the cyclic peptide is a naturally occurring θ-defensin.

23. The method of claim 22, wherein the cyclic peptide is selected from the group consisting of peptide 17 (SEQ ID NO. 17), peptide 18 (SEQ ID NO. 18), peptide 19 (SEQ ID NO. 19), peptide 20 (SEQ ID NO. 20), peptide 21 (SEQ ID NO. 21), peptide 22 (SEQ ID NO. 22), peptide 23 (SEQ ID NO. 23), peptide 24 (SEQ ID NO. 24), peptide 25 (SEQ ID NO. 25), peptide 26 (SEQ ID NO. 26), peptide 27 (SEQ ID NO. 27), peptide 28 (SEQ ID NO. 28), peptide 29 (SEQ ID NO. 29), peptide 30 (SEQ ID NO. 30), peptide 31 (SEQ ID NO. 31), peptide 32 (SEQ ID NO. 32) and peptide 33 (SEQ ID NO. 33).

24. The method of any one of claims 16 to 21, wherein the immune checkpoint inhibitor is an antibody against PD-1.

25. The method of any one of claims 18-24, wherein enhancing immune checkpoint inhibitor therapy comprises reducing the amount of ICI administered while maintaining effectiveness, the reduction being relative to the dose of the ICI in the absence of the peptide.

26. The method of claim 25, wherein enhancing immune checkpoint inhibitor therapy further comprises reducing or eliminating side effects associated with administration of the ICI.

27. The method of any one of claims 18-26, wherein the effective amount of the cyclic peptide is 0.01 mg / kg to 15 mg / kg.

28. The method according to any one of claims 18-27, wherein the ICI is selected from anti-natural killer cell receptor 2B4 (2B4), anti-B lymphocyte and T lymphocyte attenuator (BTLA), anti-CD160 antigen (CD160), anti-cytotoxic T lymphocyte protein 4 (CTLA-4), anti-lymphocyte activation gene 3 protein (LAG-3), anti-programmed cell death protein 1 (PD-1), anti-T-cell immunoglobulin mucin receptor 3 (TIM-3) and anti-T-cell immunodeficiency receptor (TIGIT) agent / inhibitor with Ig and ITIM domains.

29. The method of claim 28, wherein the ICI is an anti-PD-1 antibody.

30. A pharmaceutical composition comprising a cyclic peptide in an amount effective to enhance immune checkpoint therapy.

31. The pharmaceutical composition of claim 30, wherein the cyclic peptide is an analog of theta-defensin.

32. The pharmaceutical composition according to claim 31, wherein the cyclic peptide is selected from peptide 1 (SEQ ID NO. 1), peptide 2 (SEQ ID NO. 2) and peptide 3 (SEQ ID NO. 3).

33. A pharmaceutical composition according to claim 31, wherein the cyclic peptide is selected from peptide 4 (SEQ ID NO. 4), peptide 5 (SEQ ID NO.5), peptide 6 (SEQ ID NO.6), peptide 7 (SEQ ID NO.7), peptide 8 (SEQ ID NO.8), peptide 9 (SEQ ID NO.9), peptide 10 (SEQ ID NO.10), peptide 11 (SEQ ID NO.11), peptide 12 (SEQ ID NO.12), peptide 13 (SEQ ID NO.13), peptide 14 (SEQ ID NO.14), peptide 15 (SEQ ID NO.15) and peptide 16 (SEQ ID NO.16).

34. The pharmaceutical composition of claim 27, wherein the cyclic peptide is a naturally occurring θ-defensin.

35. The pharmaceutical composition of claim 34, wherein the cyclic peptide is selected from the group consisting of peptide 17 (SEQ ID NO. 17), peptide 18 (SEQ ID NO. 18), peptide 19 (SEQ ID NO. 19), peptide 20 (SEQ ID NO. 20), peptide 21 (SEQ ID NO. 21), peptide 22 (SEQ ID NO. 22), peptide 23 (SEQ ID NO. 23), peptide 24 (SEQ ID NO. 24), peptide 25 (SEQ ID NO. 25), peptide 26 (SEQ ID NO. 26), peptide 27 (SEQ ID NO. 27), peptide 28 (SEQ ID NO. 28), peptide 29 (SEQ ID NO. 29), peptide 30 (SEQ ID NO. 30), peptide 31 (SEQ ID NO. 31), peptide 32 (SEQ ID NO. 32) and peptide 33 (SEQ ID NO. 33).

36. according to the pharmaceutical composition described in any one of claims 30 to 35, wherein the immune checkpoint therapy comprises administering ICI, and the ICI is selected from anti-natural killer cell receptor 2B4 (2B4), anti-B lymphocyte and T lymphocyte attenuator (BTLA), anti-CD160 antigen (CD160), anti-cytotoxic T lymphocyte protein 4 (CTLA-4), anti-lymphocyte activation gene 3 protein (LAG-3), anti-programmed cell death protein 1 (PD-1), anti-T-cell immunoglobulin mucin receptor 3 (TIM-3) and anti-T cell immune receptor with Ig and ITIM domain (TIGIT) agent / inhibitor.

37. A pharmaceutical composition according to any one of claims 30 to 36, further comprising an immune checkpoint inhibitor.

38. A pharmaceutical composition according to claim 37, wherein the ICI is selected from anti-natural killer cell receptor 2B4 (2B4), anti-B lymphocyte and T lymphocyte attenuator (BTLA), anti-CD160 antigen (CD160), anti-cytotoxic T lymphocyte protein 4 (CTLA-4), anti-lymphocyte activation gene 3 protein (LAG-3), anti-programmed cell death protein 1 (PD-1), anti-T-cell immunoglobulin mucin receptor 3 (TIM-3) and anti-T-cell immunodeficiency receptor (TIGIT) agent / inhibitor with Ig and ITIM domains.

39. The pharmaceutical composition according to any one of claims 36 to 38, wherein the immune checkpoint inhibitor is an antibody against PD-1.

40. The pharmaceutical composition according to any one of claims 30 to 39, wherein the effective amount of the cyclic peptide is 0.01 mg / kg to 15 mg / kg.

41. Use of a cyclic peptide in treating cancer in a patient, wherein an effective amount of the cyclic peptide is provided in combination with administration of an effective amount of an immune checkpoint inhibitor (ICI).

42. The use according to claim 41, wherein the cyclic peptide is an analogue of theta-defensin.

43. The use according to claim 42, wherein the cyclic peptide is selected from peptide 1 (SEQ ID NO. 1), peptide 2 (SEQ ID NO. 2) and peptide 3 (SEQ ID NO. 3).

44. The use according to claim 42, wherein the cyclic peptide is selected from peptide 4 (SEQ ID NO. 4), peptide 5 (SEQ ID NO. 5), peptide 6 (SEQ ID NO. 6), peptide 7 (SEQ ID NO. 7), peptide 8 (SEQ ID NO. 8), peptide 9 (SEQ ID NO. 9), peptide 10 (SEQ ID NO. 10), peptide 11 (SEQ ID NO. 11), peptide 12 (SEQ ID NO. 12), peptide 13 (SEQ ID NO. 13), peptide 14 (SEQ ID NO. 14), peptide 15 (SEQ ID NO. 15) and peptide 16 (SEQ ID NO. 16).

45. The use according to claim 41, wherein the cyclic peptide is a naturally occurring θ-defensin.

46. ​​The use according to claim 45, wherein the cyclic peptide is selected from peptide 17 (SEQ ID NO.17), peptide 18 (SEQ ID NO.18), peptide 19 (SEQ ID NO.19), peptide 20 (SEQ ID NO.20), peptide 21 (SEQ ID NO.21), peptide 22 (SEQ ID NO.22), peptide 23 (SEQ ID NO.23), peptide 24 (SEQ ID NO.24), peptide 25 (SEQ ID NO.25), peptide 26 (SEQID NO.26), peptide 27 (SEQ ID NO.27), peptide 28 (SEQ ID NO.28), peptide 29 (SEQ ID NO.29), peptide 30 (SEQID NO.30), peptide 31 (SEQ ID NO.31), peptide 32 (SEQ ID NO.32) and peptide 33 (SEQ ID NO.33).

47. The use according to any one of claims 41 to 46, wherein treating cancer comprises inducing tumor regression.

48. The use according to claim 47, wherein tumor regression is induced in melanoma.

49. The use according to any one of claims 41 to 48, wherein treating cancer comprises preventing tumor recurrence.

50. The use according to claim 49, wherein tumor recurrence of melanoma or colon cancer is prevented.

51. The use according to any one of claims 41 to 50, wherein treating cancer comprises inhibiting the infiltration of myeloid-derived suppressor cells into the tumor microenvironment.

52. The use according to any one of claims 41 to 51, wherein treating cancer comprises enhancing CD8+ T cell responses in the tumor microenvironment when used in combination with an ICI.

53. The use according to any one of claims 41 to 52, wherein the ICI is selected from anti-natural killer cell receptor 2B4 (2B4), anti-B lymphocyte and T lymphocyte attenuator (BTLA), anti-CD160 antigen (CD160), anti-cytotoxic T lymphocyte protein 4 (CTLA-4), anti-lymphocyte activation gene 3 protein (LAG-3), anti-programmed cell death protein 1 (PD-1), anti-T-cell immunoglobulin mucin receptor 3 (TIM-3) and anti-T cell immune receptor (TIGIT) agent / inhibitor with Ig and ITIM domains.

54. The use according to any one of claims 41 to 52, wherein the ICI comprises an antibody against PD-1.

55. The use according to any one of claims 41 to 54, wherein treating cancer comprises reducing the dose of the ICI while maintaining effectiveness, the reduction being relative to the amount of the ICI administered without the use of the peptide.

56. The use according to claim 55, wherein treating cancer further comprises reducing or eliminating side effects associated with the administration of ICI.

57. The use according to any one of claims 41 to 56, wherein the effective amount of the cyclic peptide is 0.01 mg / kg to 15 mg / kg.

58. Use of a cyclic peptide for enhancing immune checkpoint inhibitor therapy, wherein an effective amount of the cyclic peptide is provided in combination with an immune checkpoint inhibitor (ICI).

59. The use according to claim 58, wherein the cyclic peptide is an analogue of theta-defensin.

60. The use according to claim 59, wherein the cyclic peptide is selected from peptide 1 (SEQ ID NO. 1), peptide 2 (SEQ ID NO. 2) and peptide 3 (SEQ ID NO. 3).

61. The use according to claim 59, wherein the cyclic peptide is selected from peptide 4 (SEQ ID NO. 4), peptide 5 (SEQ ID NO. 5), peptide 6 (SEQ ID NO. 6), peptide 7 (SEQ ID NO. 7), peptide 8 (SEQ ID NO. 8), peptide 9 (SEQ ID NO. 9), peptide 10 (SEQ ID NO. 10), peptide 11 (SEQ ID NO. 11), peptide 12 (SEQ ID NO. 12), peptide 13 (SEQ ID NO. 13), peptide 14 (SEQ ID NO. 14), peptide 15 (SEQ ID NO. 15) and peptide 16 (SEQ ID NO. 16).

62. The use according to claim 58, wherein the cyclic peptide is a naturally occurring theta-defensin.

63. The use according to claim 62, wherein the cyclic peptide is selected from peptide 17 (SEQ ID NO. 17), peptide 18 (SEQ ID NO. 18), peptide 19 (SEQ ID NO. 19), peptide 20 (SEQ ID NO. 20), peptide 21 (SEQ ID NO. 21), peptide 22 (SEQ ID NO. 22), peptide 23 (SEQ ID NO. 23), peptide 24 (SEQ ID NO. 24), peptide 25 (SEQ ID NO. 25), peptide 26 (SEQ ID NO. 26), peptide 27 (SEQ ID NO. 27), peptide 28 (SEQ ID NO. 28), peptide 29 (SEQ ID NO. 29), peptide 30 (SEQ ID NO. 30), peptide 31 (SEQ ID NO. 31), peptide 32 (SEQ ID NO. 32) and peptide 33 (SEQ ID NO. 33).

64. The use according to any one of claims 58 to 63, wherein the ICI is selected from anti-natural killer cell receptor 2B4 (2B4), anti-B lymphocyte and T lymphocyte attenuator (BTLA), anti-CD160 antigen (CD160), anti-cytotoxic T lymphocyte protein 4 (CTLA-4), anti-lymphocyte activation gene 3 protein (LAG-3), anti-programmed cell death protein 1 (PD-1), anti-T-cell immunoglobulin mucin receptor 3 (TIM-3) and anti-T cell immune receptor (TIGIT) agent / inhibitor with Ig and ITIM domains.

65. The use according to any one of claims 58 to 64, wherein the immune checkpoint inhibitor is an antibody against PD-1.

66. The use of any one of claims 58 to 65, wherein enhancement comprises reducing the dose of the ICI while maintaining effectiveness, the enhancement being relative to the amount of the ICI administered in the absence of the peptide.

67. The use of claim 77, wherein enhancing further comprises reducing or eliminating side effects associated with administration of the ICI.

68. The use according to any one of claims 58 to 67, wherein the effective amount of the synthetic cyclic peptide is 0.01 mg / kg to 15 mg / kg.

69. A synthetic cyclic peptide consisting of peptide 2 (SEQ ID NO. 2) and having the following structure:

70. A pharmaceutical composition comprising peptide 2 and a pharmaceutically acceptable excipient.

71. A kit comprising: Cyclic peptides; and Immune checkpoint inhibitors.

72. The kit of claim 71, wherein the cyclic peptide is an analog of theta-defensin.

73. The kit of claim 72, wherein the cyclic peptide is selected from the group consisting of peptide 1 (SEQ ID NO. 1), peptide 2 (SEQ ID NO. 2) and peptide 3 (SEQ ID NO. 3).

74. A kit according to claim 72, wherein the cyclic peptide is selected from peptide 4 (SEQ ID NO. 4), peptide 5 (SEQID NO.5), peptide 6 (SEQ ID NO.6), peptide 7 (SEQ ID NO.7), peptide 8 (SEQ ID NO.8), peptide 9 (SEQ ID NO.9), peptide 10 (SEQ ID NO.10), peptide 11 (SEQ ID NO.11), peptide 12 (SEQ ID NO.12), peptide 13 (SEQ ID NO.13), peptide 14 (SEQ ID NO.14), peptide 15 (SEQ ID NO.15) and peptide 16 (SEQ ID NO.16).

75. The kit of claim 71, wherein the cyclic peptide is a naturally occurring theta-defensin.

76. The use according to claim 75, wherein the cyclic peptide is selected from peptide 17 (SEQ ID NO.17), peptide 18 (SEQ ID NO.18), peptide 19 (SEQ ID NO.19), peptide 20 (SEQ ID NO.20), peptide 21 (SEQ ID NO.21), peptide 22 (SEQ ID NO.22), peptide 23 (SEQ ID NO.23), peptide 24 (SEQ ID NO.24), peptide 25 (SEQ ID NO.25), peptide 26 (SEQID NO.26), peptide 27 (SEQ ID NO.27), peptide 28 (SEQ ID NO.28), peptide 29 (SEQ ID NO.29), peptide 30 (SEQID NO.30), peptide 31 (SEQ ID NO.31), peptide 32 (SEQ ID NO.32) and peptide 33 (SEQ ID NO.33).

77. A kit according to any one of claims 71 to 76, wherein the cyclic peptide is provided in an amount effective to enhance the activity of the immune checkpoint inhibitor.

78. The kit of any one of claims 71 to 77, wherein the cyclic peptide and the immune checkpoint inhibitor are mixed.

79. A kit according to any one of claims 71 to 78, wherein the ICI is selected from anti-natural killer cell receptor 2B4 (2B4), anti-B lymphocyte and T lymphocyte attenuator (BTLA), anti-CD160 antigen (CD160), anti-cytotoxic T lymphocyte protein 4 (CTLA-4), anti-lymphocyte activation gene 3 protein (LAG-3), anti-programmed cell death protein 1 (PD-1), anti-T-cell immunoglobulin mucin receptor 3 (TIM-3) and anti-T-cell immunodeficiency receptor (TIGIT) agent / inhibitor with Ig and ITIM domains.

80. The kit of any one of claims 71 to 79, wherein the immune checkpoint inhibitor is an anti-PD-1 monoclonal antibody.

81. The kit of any one of claims 71 to 80, comprising instructions for using the cyclic peptide in combination with the immune checkpoint inhibitor to treat cancer.

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