CD73 antibody that activates B cells

Abstract

Provided herein are methods and compositions that use and encompass anti-CD73 antibodies that can, among other things, activate B cells and affect the redistribution of B cells from lymphoid tissues to lymphoid organs. This previously unknown unique effect of anti-CD73 antibodies may be useful in treating a variety of indications, for example, enhancing immunity against immunogenic cancers, autoimmune diseases (e.g., multiple sclerosis), inflammatory diseases, or infectious diseases.

Description

[Background technology]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application No. 62 / 855,601, filed May 31, 2019, U.S. Provisional Application No. 62 / 848,524, filed May 15, 2019, and U.S. Provisional Application No. 62 / 756,065, filed November 5, 2018, which are hereby incorporated by reference in their entirety for all purposes.

[0002] See "Sequence Listing", Table, or Computer Program Listing Appendix submitted as an ASCII file The sequence listing set forth in file 048517-543001WO_SEQUENCE_LISTING_ST25.txt (created October 31, 2019, 9,939 bytes, machine format IBM-PC, MS Windows operating system) is incorporated herein by reference.

[0003] Glycosylphosphatidylinositol-anchored CD73 antigen is considered the rate-limiting enzyme in the production of extracellular adenosine (Stagg J, Smyth MJ. Extracellular adenosine triphosphate and adenosine in cancer. Oncogene. 2010;29:5346-58). CD73 can be found constitutively expressed at high levels in various types of cancer cells. Adenosine generated by CD73 is believed to suppress adaptive anti-tumor immune responses, thereby promoting tumor growth and metastasis. There is a need in the art for antibody-based CD73 cancer therapy that inhibits the catalytic activity of CD73, thereby blocking adenosine production and relieving adenosine-mediated immune suppression. This disclosure addresses these and other needs in the art. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] Stagg J, Smyth MJ.Extracellular adenosine triphosphate and adenosine in cancer.Oncogene.2010;29:5346-58 Summary of the Invention

[0005] In one embodiment, a method of immunostimulating a subject is provided. The method comprises administering to the subject an effective amount of an anti-CD73 antibody, the anti-CD73 antibody comprising 1E9 antibody CDR L1, 1E9 antibody CDR L2, 1E9 antibody CDR L3, 1E9 antibody CDR H1, 1E9 antibody CDR H2, and 1E9 antibody CDR H3. In one embodiment, the anti-CD73 antibody comprises SEQ ID NO:7 (heavy chain) and SEQ ID NO:8 (light chain).

[0006] In one embodiment, a method of activating B cells in a subject is provided. The method comprises administering to the subject an effective amount of an anti-CD73 antibody, the anti-CD73 antibody comprising 1E9 antibody CDR L1, 1E9 antibody CDR L2, 1E9 antibody CDR L3, 1E9 antibody CDR H1, 1E9 antibody CDR H2, and 1E9 antibody CDR H3. In one embodiment, the anti-CD73 antibody comprises SEQ ID NO:7 (heavy chain) and SEQ ID NO:8 (light chain).

[0007] In one embodiment, a method is provided for reducing the release of B cells from lymphoid tissues of a subject compared to a standard control. The method comprises administering to the subject an effective amount of an anti-CD73 antibody, the anti-CD73 antibody comprising 1E9 antibody CDR L1, 1E9 antibody CDR L2, 1E9 antibody CDR L3, 1E9 antibody CDR H1, 1E9 antibody CDR H2, and 1E9 antibody CDR H3. In one embodiment, the anti-CD73 antibody comprises SEQ ID NO:7 (heavy chain) and SEQ ID NO:8 (light chain).

[0008] In one embodiment, a method is provided for increasing retention of B cells in lymphoid organs of a subject compared to a standard control. The method comprises administering to the subject an effective amount of an anti-CD73 antibody, the anti-CD73 antibody comprising 1E9 antibody CDR L1, 1E9 antibody CDR L2, 1E9 antibody CDR L3, 1E9 antibody CDR H1, 1E9 antibody CDR H2, and 1E9 antibody CDR H3. In one embodiment, the anti-CD73 antibody comprises SEQ ID NO:7 (heavy chain) and SEQ ID NO:8 (light chain).

[0009] In one embodiment, a method is provided for increasing internalization of sphingosine-1-phosphate receptor 1 (S1PR1) in a subject compared to a standard control. The method comprises administering to the subject an effective amount of an anti-CD73 antibody, the anti-CD73 antibody comprising 1E9 antibody CDR L1, 1E9 antibody CDR L2, 1E9 antibody CDR L3, 1E9 antibody CDR H1, 1E9 antibody CDR H2, and 1E9 antibody CDR H3. In one embodiment, the anti-CD73 antibody comprises SEQ ID NO:7 (heavy chain) and SEQ ID NO:8 (light chain).

[0010] In one embodiment, a method for treating a sphingosine-1-phosphate receptor 1 (S1PR1)-associated disease in a subject in need thereof is provided. The method comprises administering to the subject an effective amount of an anti-CD73 antibody, the anti-CD73 antibody comprising 1E9 antibody CDR L1, 1E9 antibody CDR L2, 1E9 antibody CDR L3, 1E9 antibody CDR H1, 1E9 antibody CDR H2, and 1E9 antibody CDR H3. In one embodiment, the anti-CD73 antibody comprises SEQ ID NO:7 (heavy chain) and SEQ ID NO:8 (light chain).

[0011] In one embodiment, a method of treating an infectious disease in a subject in need thereof is provided. The method comprises administering to the subject an effective amount of an anti-CD73 antibody, the anti-CD73 antibody comprising 1E9 antibody CDR L1, 1E9 antibody CDR L2, 1E9 antibody CDR L3, 1E9 antibody CDR H1, 1E9 antibody CDR H2, and 1E9 antibody CDR H3. In one embodiment, the anti-CD73 antibody comprises SEQ ID NO:7 (heavy chain) and SEQ ID NO:8 (light chain).

[0012] In one embodiment, a method of treating an inflammatory disease in a subject in need thereof is provided. The method comprises administering to the subject an effective amount of an anti-CD73 antibody, the anti-CD73 antibody comprising 1E9 antibody CDR L1, 1E9 antibody CDR L2, 1E9 antibody CDR L3, 1E9 antibody CDR H1, 1E9 antibody CDR H2, and 1E9 antibody CDR H3. In one embodiment, the anti-CD73 antibody comprises SEQ ID NO:7 (heavy chain) and SEQ ID NO:8 (light chain).

[0013] In one embodiment, a method of treating an autoimmune disease in a subject in need thereof is provided. The method comprises administering to the subject an effective amount of an anti-CD73 antibody, the anti-CD73 antibody comprising 1E9 antibody CDR L1, 1E9 antibody CDR L2, 1E9 antibody CDR L3, 1E9 antibody CDR H1, 1E9 antibody CDR H2, and 1E9 antibody CDR H3. In one embodiment, the anti-CD73 antibody comprises SEQ ID NO:7 (heavy chain) and SEQ ID NO:8 (light chain).

[0014] In one embodiment, an anti-cancer immunogenic composition is provided. The composition comprises an anti-cancer immunogenic agent and an anti-CD73 antibody, the anti-CD73 antibody comprising 1E9 antibody CDR L1, 1E9 antibody CDR L2, 1E9 antibody CDR L3, 1E9 antibody CDR H1, 1E9 antibody CDR H2, and 1E9 antibody CDR H3. In one embodiment, the anti-CD73 antibody comprises SEQ ID NO:7 (heavy chain) and SEQ ID NO:8 (light chain).

[0015] In one embodiment, an anti-viral immunogenic composition is provided. The composition comprises an anti-viral immunogenic agent and an anti-CD73 antibody, the anti-CD73 antibody comprising 1E9 antibody CDR L1, 1E9 antibody CDR L2, 1E9 antibody CDR L3, 1E9 antibody CDR H1, 1E9 antibody CDR H2, and 1E9 antibody CDR H3. In one embodiment, the anti-CD73 antibody comprises SEQ ID NO:7 (heavy chain) and SEQ ID NO:8 (light chain).

[0016] In one embodiment, the disclosure provides a method of treating cancer in a patient in need thereof by administering to the patient an effective amount of an anti-CD73 antibody to effectively activate antigen-presenting cells. In one embodiment, the method comprises administering to the patient an effective amount of an anti-CD73 antibody and monitoring the level of antigen-presenting cells. In embodiments, the method comprises administering to the patient an effective amount of an anti-CD73 antibody to effectively activate antigen-presenting cells and monitoring the level of antigen-presenting cells. In embodiments, monitoring the level of antigen-presenting cells comprises obtaining a biological sample from the patient and detecting the level of antigen-presenting cells in the biological sample. In one embodiment, the anti-CD73 antibody comprises 1E9 antibody CDR L1, 1E9 antibody CDR L2, 1E9 antibody CDR L3, 1E9 antibody CDR H1, 1E9 antibody CDR H2, and 1E9 antibody CDR H3. In one embodiment, the anti-CD73 antibody comprises SEQ ID NO: 7 (heavy chain) and SEQ ID NO: 8 (light chain). [Brief description of the drawings]

[0017] [Figure 1A] Figure 1A shows that CPI-006 blocks adenosine production and relieves adenosine-mediated immunosuppression. Figure 1A provides a schematic diagram of the structure of CD73. Figure 1B shows CD73 catalytic activity as a function of the concentration of the indicated antibodies. Figure 1C shows T cell proliferation based on the indicated antibodies. Figure 1D shows IFN-gamma secretion based on the indicated antibodies. Each symbol represents an independent donor. Figure 1E shows tumor volume (mm3) over the course of 20 days of treatment in an MDA-MB-231 xenograft model administered PBS, isotype control, and 10 mg / kg of CPI-006 daily. Figure 1F shows that CPI-006 blocks CD73 enzyme activity in an MDA-MB-231 human triple-negative breast cancer (TNBC) xenograft model, and methods for measuring CD73 enzyme activity are described in Silver et al, J. Clin Invest., 56(5):1324-1327 (1975). [Figure 1B]Figure 1A shows that CPI-006 blocks adenosine production and relieves adenosine-mediated immunosuppression. Figure 1A provides a schematic diagram of the structure of CD73. Figure 1B shows CD73 catalytic activity as a function of the concentration of the indicated antibodies. Figure 1C shows T cell proliferation based on the indicated antibodies. Figure 1D shows IFN-gamma secretion based on the indicated antibodies. Each symbol represents an independent donor. Figure 1E shows tumor volume (mm3) over the course of 20 days of treatment in an MDA-MB-231 xenograft model administered PBS, isotype control, and 10 mg / kg of CPI-006 daily. Figure 1F shows that CPI-006 blocks CD73 enzyme activity in an MDA-MB-231 human triple-negative breast cancer (TNBC) xenograft model, and methods for measuring CD73 enzyme activity are described in Silver et al, J. Clin Invest., 56(5):1324-1327 (1975). [Figure 1C] Figure 1A shows that CPI-006 blocks adenosine production and relieves adenosine-mediated immunosuppression. Figure 1A provides a schematic diagram of the structure of CD73. Figure 1B shows CD73 catalytic activity as a function of the concentration of the indicated antibodies. Figure 1C shows T cell proliferation based on the indicated antibodies. Figure 1D shows IFN-gamma secretion based on the indicated antibodies. Each symbol represents an independent donor. Figure 1E shows tumor volume (mm3) over the course of 20 days of treatment in an MDA-MB-231 xenograft model administered PBS, isotype control, and 10 mg / kg of CPI-006 daily. Figure 1F shows that CPI-006 blocks CD73 enzyme activity in an MDA-MB-231 human triple-negative breast cancer (TNBC) xenograft model, and methods for measuring CD73 enzyme activity are described in Silver et al, J. Clin Invest., 56(5):1324-1327 (1975). [Figure 1D]Figure 1A shows that CPI-006 blocks adenosine production and relieves adenosine-mediated immunosuppression. Figure 1A provides a schematic diagram of the structure of CD73. Figure 1B shows CD73 catalytic activity as a function of the concentration of the indicated antibodies. Figure 1C shows T cell proliferation based on the indicated antibodies. Figure 1D shows IFN-gamma secretion based on the indicated antibodies. Each symbol represents an independent donor. Figure 1E shows tumor volume (mm3) over the course of 20 days of treatment in an MDA-MB-231 xenograft model administered PBS, isotype control, and 10 mg / kg of CPI-006 daily. Figure 1F shows that CPI-006 blocks CD73 enzyme activity in an MDA-MB-231 human triple-negative breast cancer (TNBC) xenograft model, and methods for measuring CD73 enzyme activity are described in Silver et al, J. Clin Invest., 56(5):1324-1327 (1975). [Figure 1E] Figure 1A shows that CPI-006 blocks adenosine production and relieves adenosine-mediated immunosuppression. Figure 1A provides a schematic diagram of the structure of CD73. Figure 1B shows CD73 catalytic activity as a function of the concentration of the indicated antibodies. Figure 1C shows T cell proliferation based on the indicated antibodies. Figure 1D shows IFN-gamma secretion based on the indicated antibodies. Each symbol represents an independent donor. Figure 1E shows tumor volume (mm3) over the course of 20 days of treatment in an MDA-MB-231 xenograft model administered PBS, isotype control, and 10 mg / kg of CPI-006 daily. Figure 1F shows that CPI-006 blocks CD73 enzyme activity in an MDA-MB-231 human triple-negative breast cancer (TNBC) xenograft model, and methods for measuring CD73 enzyme activity are described in Silver et al, J. Clin Invest., 56(5):1324-1327 (1975). [Figure 1F]Figure 1A shows that CPI-006 blocks adenosine production and relieves adenosine-mediated immunosuppression. Figure 1A provides a schematic diagram of the structure of CD73. Figure 1B shows CD73 catalytic activity as a function of the concentration of the indicated antibodies. Figure 1C shows T cell proliferation based on the indicated antibodies. Figure 1D shows IFN-gamma secretion based on the indicated antibodies. Each symbol represents an independent donor. Figure 1E shows tumor volume (mm3) over the course of 20 days of treatment in an MDA-MB-231 xenograft model administered PBS, isotype control, and 10 mg / kg of CPI-006 daily. Figure 1F shows that CPI-006 blocks CD73 enzyme activity in an MDA-MB-231 human triple-negative breast cancer (TNBC) xenograft model, and methods for measuring CD73 enzyme activity are described in Silver et al, J. Clin Invest., 56(5):1324-1327 (1975). [Figure 2A]We show that CPI-006 directly activates human B lymphocytes. Figures 2A-2C show that CPI-006 induces expression of B cell activation markers CD69 (Figure 2A), CD83 (Figure 2B), and CD25 (Figure 2C). Figures 2D-2E show that CPI-006 activates CD86 (Figure 2D) and MHC-II (Figure 2E) on antigen presenting cells. Referring to Figures 2A-2E, each group of four bars from left to right represents data for an untreated donor, a donor treated with human IgG1 isotype control, a donor treated with BCR stimulation, and a donor treated with CPI-006. The experiments in Figures 2A-2E are based on PBMCs from healthy donors treated overnight with flow cytometry analysis of surface markers for B cells (CD19POSCD3NEG). These lymphocyte markers are consistent with activation of B cells and other antigen presenting cell populations. Figure 2F shows that induction of B cell activation is specific to CPI-006. Figure 2G shows that CPI-006 induces B cell activation through BTK, as evidenced by antibody staining for CD69 (left panel) and CD83 (right panel). The top-to-bottom bar legends represent data bars from left to right. Figures 2H-2I show that CPI-006 induces B cell activation independent of adenosine, as evidenced by antibody staining for CD69 (left panel) and CD83 (right panel). For Figure 2H, the top-to-bottom bar legends represent data bars from left to right. For Figure 2I, the top-to-bottom legends represent data from top to bottom. Figure 2J shows that CPI-006 induces phospho-ERK signaling in B cells to a greater extent than in CD4+ or CD8+ T cells. For each group of four bars, the top-to-bottom legends represent bars from left to right. [Figure 2B]We show that CPI-006 directly activates human B lymphocytes. Figures 2A-2C show that CPI-006 induces expression of B cell activation markers CD69 (Figure 2A), CD83 (Figure 2B), and CD25 (Figure 2C). Figures 2D-2E show that CPI-006 activates CD86 (Figure 2D) and MHC-II (Figure 2E) on antigen presenting cells. Referring to Figures 2A-2E, each group of four bars from left to right represents data for an untreated donor, a donor treated with human IgG1 isotype control, a donor treated with BCR stimulation, and a donor treated with CPI-006. The experiments in Figures 2A-2E are based on PBMCs from healthy donors treated overnight with flow cytometry analysis of surface markers for B cells (CD19POSCD3NEG). These lymphocyte markers are consistent with activation of B cells and other antigen presenting cell populations. Figure 2F shows that induction of B cell activation is specific to CPI-006. Figure 2G shows that CPI-006 induces B cell activation through BTK, as evidenced by antibody staining for CD69 (left panel) and CD83 (right panel). The top-to-bottom bar legends represent data bars from left to right. Figures 2H-2I show that CPI-006 induces B cell activation independent of adenosine, as evidenced by antibody staining for CD69 (left panel) and CD83 (right panel). For Figure 2H, the top-to-bottom bar legends represent data bars from left to right. For Figure 2I, the top-to-bottom legends represent data from top to bottom. Figure 2J shows that CPI-006 induces phospho-ERK signaling in B cells to a greater extent than in CD4+ or CD8+ T cells. For each group of four bars, the top-to-bottom legends represent bars from left to right. [Figure 2C]We show that CPI-006 directly activates human B lymphocytes. Figures 2A-2C show that CPI-006 induces expression of B cell activation markers CD69 (Figure 2A), CD83 (Figure 2B), and CD25 (Figure 2C). Figures 2D-2E show that CPI-006 activates CD86 (Figure 2D) and MHC-II (Figure 2E) on antigen presenting cells. Referring to Figures 2A-2E, each group of four bars from left to right represents data for an untreated donor, a donor treated with human IgG1 isotype control, a donor treated with BCR stimulation, and a donor treated with CPI-006. The experiments in Figures 2A-2E are based on PBMCs from healthy donors treated overnight with flow cytometry analysis of surface markers for B cells (CD19POSCD3NEG). These lymphocyte markers are consistent with activation of B cells and other antigen presenting cell populations. Figure 2F shows that induction of B cell activation is specific to CPI-006. Figure 2G shows that CPI-006 induces B cell activation through BTK, as evidenced by antibody staining for CD69 (left panel) and CD83 (right panel). The top-to-bottom bar legends represent data bars from left to right. Figures 2H-2I show that CPI-006 induces B cell activation independent of adenosine, as evidenced by antibody staining for CD69 (left panel) and CD83 (right panel). For Figure 2H, the top-to-bottom bar legends represent data bars from left to right. For Figure 2I, the top-to-bottom legends represent data from top to bottom. Figure 2J shows that CPI-006 induces phospho-ERK signaling in B cells to a greater extent than in CD4+ or CD8+ T cells. For each group of four bars, the top-to-bottom legends represent bars from left to right. [Figure 2D]We show that CPI-006 directly activates human B lymphocytes. Figures 2A-2C show that CPI-006 induces expression of B cell activation markers CD69 (Figure 2A), CD83 (Figure 2B), and CD25 (Figure 2C). Figures 2D-2E show that CPI-006 activates CD86 (Figure 2D) and MHC-II (Figure 2E) on antigen presenting cells. Referring to Figures 2A-2E, each group of four bars from left to right represents data for an untreated donor, a donor treated with human IgG1 isotype control, a donor treated with BCR stimulation, and a donor treated with CPI-006. The experiments in Figures 2A-2E are based on PBMCs from healthy donors treated overnight with flow cytometry analysis of surface markers for B cells (CD19POSCD3NEG). These lymphocyte markers are consistent with activation of B cells and other antigen presenting cell populations. Figure 2F shows that induction of B cell activation is specific to CPI-006. Figure 2G shows that CPI-006 induces B cell activation through BTK, as evidenced by antibody staining for CD69 (left panel) and CD83 (right panel). The top-to-bottom bar legends represent data bars from left to right. Figures 2H-2I show that CPI-006 induces B cell activation independent of adenosine, as evidenced by antibody staining for CD69 (left panel) and CD83 (right panel). For Figure 2H, the top-to-bottom bar legends represent data bars from left to right. For Figure 2I, the top-to-bottom legends represent data from top to bottom. Figure 2J shows that CPI-006 induces phospho-ERK signaling in B cells to a greater extent than in CD4+ or CD8+ T cells. For each group of four bars, the top-to-bottom legends represent bars from left to right. [Figure 2E]We show that CPI-006 directly activates human B lymphocytes. Figures 2A-2C show that CPI-006 induces expression of B cell activation markers CD69 (Figure 2A), CD83 (Figure 2B), and CD25 (Figure 2C). Figures 2D-2E show that CPI-006 activates CD86 (Figure 2D) and MHC-II (Figure 2E) on antigen presenting cells. Referring to Figures 2A-2E, each group of four bars from left to right represents data for an untreated donor, a donor treated with human IgG1 isotype control, a donor treated with BCR stimulation, and a donor treated with CPI-006. The experiments in Figures 2A-2E are based on PBMCs from healthy donors treated overnight with flow cytometry analysis of surface markers for B cells (CD19POSCD3NEG). These lymphocyte markers are consistent with activation of B cells and other antigen presenting cell populations. Figure 2F shows that induction of B cell activation is specific to CPI-006. Figure 2G shows that CPI-006 induces B cell activation through BTK, as evidenced by antibody staining for CD69 (left panel) and CD83 (right panel). The top-to-bottom bar legends represent data bars from left to right. Figures 2H-2I show that CPI-006 induces B cell activation independent of adenosine, as evidenced by antibody staining for CD69 (left panel) and CD83 (right panel). For Figure 2H, the top-to-bottom bar legends represent data bars from left to right. For Figure 2I, the top-to-bottom legends represent data from top to bottom. Figure 2J shows that CPI-006 induces phospho-ERK signaling in B cells to a greater extent than in CD4+ or CD8+ T cells. For each group of four bars, the top-to-bottom legends represent bars from left to right. [Figure 2F]We show that CPI-006 directly activates human B lymphocytes. Figures 2A-2C show that CPI-006 induces expression of B cell activation markers CD69 (Figure 2A), CD83 (Figure 2B), and CD25 (Figure 2C). Figures 2D-2E show that CPI-006 activates CD86 (Figure 2D) and MHC-II (Figure 2E) on antigen presenting cells. Referring to Figures 2A-2E, each group of four bars from left to right represents data for an untreated donor, a donor treated with human IgG1 isotype control, a donor treated with BCR stimulation, and a donor treated with CPI-006. The experiments in Figures 2A-2E are based on PBMCs from healthy donors treated overnight with flow cytometry analysis of surface markers for B cells (CD19POSCD3NEG). These lymphocyte markers are consistent with activation of B cells and other antigen presenting cell populations. Figure 2F shows that induction of B cell activation is specific to CPI-006. Figure 2G shows that CPI-006 induces B cell activation through BTK, as evidenced by antibody staining for CD69 (left panel) and CD83 (right panel). The top-to-bottom bar legends represent data bars from left to right. Figures 2H-2I show that CPI-006 induces B cell activation independent of adenosine, as evidenced by antibody staining for CD69 (left panel) and CD83 (right panel). For Figure 2H, the top-to-bottom bar legends represent data bars from left to right. For Figure 2I, the top-to-bottom legends represent data from top to bottom. Figure 2J shows that CPI-006 induces phospho-ERK signaling in B cells to a greater extent than in CD4+ or CD8+ T cells. For each group of four bars, the top-to-bottom legends represent bars from left to right. [Figure 2G]We show that CPI-006 directly activates human B lymphocytes. Figures 2A-2C show that CPI-006 induces expression of B cell activation markers CD69 (Figure 2A), CD83 (Figure 2B), and CD25 (Figure 2C). Figures 2D-2E show that CPI-006 activates CD86 (Figure 2D) and MHC-II (Figure 2E) on antigen presenting cells. Referring to Figures 2A-2E, each group of four bars from left to right represents data for an untreated donor, a donor treated with human IgG1 isotype control, a donor treated with BCR stimulation, and a donor treated with CPI-006. The experiments in Figures 2A-2E are based on PBMCs from healthy donors treated overnight with flow cytometry analysis of surface markers for B cells (CD19POSCD3NEG). These lymphocyte markers are consistent with activation of B cells and other antigen presenting cell populations. Figure 2F shows that induction of B cell activation is specific to CPI-006. Figure 2G shows that CPI-006 induces B cell activation through BTK, as evidenced by antibody staining for CD69 (left panel) and CD83 (right panel). The top-to-bottom bar legends represent data bars from left to right. Figures 2H-2I show that CPI-006 induces B cell activation independent of adenosine, as evidenced by antibody staining for CD69 (left panel) and CD83 (right panel). For Figure 2H, the top-to-bottom bar legends represent data bars from left to right. For Figure 2I, the top-to-bottom legends represent data from top to bottom. Figure 2J shows that CPI-006 induces phospho-ERK signaling in B cells to a greater extent than in CD4+ or CD8+ T cells. For each group of four bars, the top-to-bottom legends represent bars from left to right. [Figure 2H]We show that CPI-006 directly activates human B lymphocytes. Figures 2A-2C show that CPI-006 induces expression of B cell activation markers CD69 (Figure 2A), CD83 (Figure 2B), and CD25 (Figure 2C). Figures 2D-2E show that CPI-006 activates CD86 (Figure 2D) and MHC-II (Figure 2E) on antigen presenting cells. Referring to Figures 2A-2E, each group of four bars from left to right represents data for an untreated donor, a donor treated with human IgG1 isotype control, a donor treated with BCR stimulation, and a donor treated with CPI-006. The experiments in Figures 2A-2E are based on PBMCs from healthy donors treated overnight with flow cytometry analysis of surface markers for B cells (CD19POSCD3NEG). These lymphocyte markers are consistent with activation of B cells and other antigen presenting cell populations. Figure 2F shows that induction of B cell activation is specific to CPI-006. Figure 2G shows that CPI-006 induces B cell activation through BTK, as evidenced by antibody staining for CD69 (left panel) and CD83 (right panel). The top-to-bottom bar legends represent data bars from left to right. Figures 2H-2I show that CPI-006 induces B cell activation independent of adenosine, as evidenced by antibody staining for CD69 (left panel) and CD83 (right panel). For Figure 2H, the top-to-bottom bar legends represent data bars from left to right. For Figure 2I, the top-to-bottom legends represent data from top to bottom. Figure 2J shows that CPI-006 induces phospho-ERK signaling in B cells to a greater extent than in CD4+ or CD8+ T cells. For each group of four bars, the top-to-bottom legends represent bars from left to right. [Figure 2I]We show that CPI-006 directly activates human B lymphocytes. Figures 2A-2C show that CPI-006 induces expression of B cell activation markers CD69 (Figure 2A), CD83 (Figure 2B), and CD25 (Figure 2C). Figures 2D-2E show that CPI-006 activates CD86 (Figure 2D) and MHC-II (Figure 2E) on antigen presenting cells. Referring to Figures 2A-2E, each group of four bars from left to right represents data for an untreated donor, a donor treated with human IgG1 isotype control, a donor treated with BCR stimulation, and a donor treated with CPI-006. The experiments in Figures 2A-2E are based on PBMCs from healthy donors treated overnight with flow cytometry analysis of surface markers for B cells (CD19POSCD3NEG). These lymphocyte markers are consistent with activation of B cells and other antigen presenting cell populations. Figure 2F shows that induction of B cell activation is specific to CPI-006. Figure 2G shows that CPI-006 induces B cell activation through BTK, as evidenced by antibody staining for CD69 (left panel) and CD83 (right panel). The top-to-bottom bar legends represent data bars from left to right. Figures 2H-2I show that CPI-006 induces B cell activation independent of adenosine, as evidenced by antibody staining for CD69 (left panel) and CD83 (right panel). For Figure 2H, the top-to-bottom bar legends represent data bars from left to right. For Figure 2I, the top-to-bottom legends represent data from top to bottom. Figure 2J shows that CPI-006 induces phospho-ERK signaling in B cells to a greater extent than in CD4+ or CD8+ T cells. For each group of four bars, the top-to-bottom legends represent bars from left to right. [Figure 2J]We show that CPI-006 directly activates human B lymphocytes. Figures 2A-2C show that CPI-006 induces expression of B cell activation markers CD69 (Figure 2A), CD83 (Figure 2B), and CD25 (Figure 2C). Figures 2D-2E show that CPI-006 activates CD86 (Figure 2D) and MHC-II (Figure 2E) on antigen presenting cells. Referring to Figures 2A-2E, each group of four bars from left to right represents data for an untreated donor, a donor treated with human IgG1 isotype control, a donor treated with BCR stimulation, and a donor treated with CPI-006. The experiments in Figures 2A-2E are based on PBMCs from healthy donors treated overnight with flow cytometry analysis of surface markers for B cells (CD19POSCD3NEG). These lymphocyte markers are consistent with activation of B cells and other antigen presenting cell populations. Figure 2F shows that induction of B cell activation is specific to CPI-006. Figure 2G shows that CPI-006 induces B cell activation through BTK, as evidenced by antibody staining for CD69 (left panel) and CD83 (right panel). The top-to-bottom bar legends represent data bars from left to right. Figures 2H-2I show that CPI-006 induces B cell activation independent of adenosine, as evidenced by antibody staining for CD69 (left panel) and CD83 (right panel). For Figure 2H, the top-to-bottom bar legends represent data bars from left to right. For Figure 2I, the top-to-bottom legends represent data from top to bottom. Figure 2J shows that CPI-006 induces phospho-ERK signaling in B cells to a greater extent than in CD4+ or CD8+ T cells. For each group of four bars, the top-to-bottom legends represent bars from left to right. [Figure 3A]Pharmacokinetics / pharmacodynamics of CPI-006 and CD73 receptor occupancy after initial infusion in human patients. FIG. 3A shows serum CPI-006 concentrations as a function of time based on dosage, with the top two lines seen on day 7 being the 12 mg / kg dose, the next three lowest lines seen on day 7 being the 6 mg / kg dose, the next three lowest lines seen on day 7 being the 3 mg / kg dose, and the bottom line with no data points on day 7 being the 1 mg / kg dose. FIG. 3B shows CD73 receptor occupancy based on CPI-006 dose and time, with the top line on day 21 being the 12 mg / kg dose, the next lowest line on day 21 being the 6 mg / kg dose, the next lowest line on day 21 being the 3 mg / kg dose, and the bottom line on day 21 being the 1 mg / kg dose. The dotted lines indicate CD73 receptor occupancy, which is 100 percent occupancy. Figure 3C shows CD73 competing versus non-competing antibodies at baseline (left panel) and 24 hours later (right panel), and Figure 3D shows total and free cell surface CD73 before administration of CPI-006 and 30 minutes after administration of CPI-66. [Figure 3B] Pharmacokinetics / pharmacodynamics of CPI-006 and CD73 receptor occupancy after initial infusion in human patients. FIG. 3A shows serum CPI-006 concentrations as a function of time based on dosage, with the top two lines seen on day 7 being the 12 mg / kg dose, the next three lowest lines seen on day 7 being the 6 mg / kg dose, the next three lowest lines seen on day 7 being the 3 mg / kg dose, and the bottom line with no data points on day 7 being the 1 mg / kg dose. FIG. 3B shows CD73 receptor occupancy based on CPI-006 dose and time, with the top line on day 21 being the 12 mg / kg dose, the next lowest line on day 21 being the 6 mg / kg dose, the next lowest line on day 21 being the 3 mg / kg dose, and the bottom line on day 21 being the 1 mg / kg dose. The dotted lines indicate CD73 receptor occupancy, which is 100 percent occupancy. Figure 3C shows CD73 competing versus non-competing antibodies at baseline (left panel) and 24 hours later (right panel), and Figure 3D shows total and free cell surface CD73 before administration of CPI-006 and 30 minutes after administration of CPI-66. [Figure 3C]Pharmacokinetics / pharmacodynamics of CPI-006 and CD73 receptor occupancy after initial infusion in human patients. FIG. 3A shows serum CPI-006 concentrations as a function of time based on dosage, with the top two lines seen on day 7 being the 12 mg / kg dose, the next three lowest lines seen on day 7 being the 6 mg / kg dose, the next three lowest lines seen on day 7 being the 3 mg / kg dose, and the bottom line with no data points on day 7 being the 1 mg / kg dose. FIG. 3B shows CD73 receptor occupancy based on CPI-006 dose and time, with the top line on day 21 being the 12 mg / kg dose, the next lowest line on day 21 being the 6 mg / kg dose, the next lowest line on day 21 being the 3 mg / kg dose, and the bottom line on day 21 being the 1 mg / kg dose. The dotted lines indicate CD73 receptor occupancy, which is 100 percent occupancy. Figure 3C shows CD73 competing versus non-competing antibodies at baseline (left panel) and 24 hours later (right panel), and Figure 3D shows total and free cell surface CD73 before administration of CPI-006 and 30 minutes after administration of CPI-66. [Figure 3D] Pharmacokinetics / pharmacodynamics of CPI-006 and CD73 receptor occupancy after initial infusion in human patients. FIG. 3A shows serum CPI-006 concentrations as a function of time based on dosage, with the top two lines seen on day 7 being the 12 mg / kg dose, the next three lowest lines seen on day 7 being the 6 mg / kg dose, the next three lowest lines seen on day 7 being the 3 mg / kg dose, and the bottom line with no data points on day 7 being the 1 mg / kg dose. FIG. 3B shows CD73 receptor occupancy based on CPI-006 dose and time, with the top line on day 21 being the 12 mg / kg dose, the next lowest line on day 21 being the 6 mg / kg dose, the next lowest line on day 21 being the 3 mg / kg dose, and the bottom line on day 21 being the 1 mg / kg dose. The dotted lines indicate CD73 receptor occupancy, which is 100 percent occupancy. Figure 3C shows CD73 competing versus non-competing antibodies at baseline (left panel) and 24 hours later (right panel), and Figure 3D shows total and free cell surface CD73 before administration of CPI-006 and 30 minutes after administration of CPI-66. [Figure 4A]Figure 4A shows that CPI-006 transiently redistributes peripheral B cells. Figure 4A shows the levels of B cells (CD19+CD3-) as a percentage of total lymphocytes based on CPI-006 doses of 1 mg / kg (left panel), 3 mg / kg (middle panel), and 6 mg / kg (right panel). Figure 4B shows the expression of CD73 using a non-competitive anti-CD73 antibody reported for B cells (two left panels) and T cells (two right panels). Figure 4C shows the surface levels of CD69 (left panel) and S1P1 (right panel) on B cells treated with various doses of CPI-006. The legend from top to bottom represents each group of three bars from left to right. Without intending to be bound by the theory of the present invention, Figure 4D provides a model for the mechanism that leads to the reduction of peripheral B cell levels by CPI-006. [Figure 4B] Figure 4A shows that CPI-006 transiently redistributes peripheral B cells. Figure 4A shows the levels of B cells (CD19+CD3-) as a percentage of total lymphocytes based on CPI-006 doses of 1 mg / kg (left panel), 3 mg / kg (middle panel), and 6 mg / kg (right panel). Figure 4B shows the expression of CD73 using a non-competitive anti-CD73 antibody reported for B cells (two left panels) and T cells (two right panels). Figure 4C shows the surface levels of CD69 (left panel) and S1P1 (right panel) on B cells treated with various doses of CPI-006. The legend from top to bottom represents each group of three bars from left to right. Without intending to be bound by the theory of the present invention, Figure 4D provides a model for the mechanism that leads to the reduction of peripheral B cell levels by CPI-006. [Figure 4C]Figure 4A shows that CPI-006 transiently redistributes peripheral B cells. Figure 4A shows the levels of B cells (CD19+CD3-) as a percentage of total lymphocytes based on CPI-006 doses of 1 mg / kg (left panel), 3 mg / kg (middle panel), and 6 mg / kg (right panel). Figure 4B shows the expression of CD73 using a non-competitive anti-CD73 antibody reported for B cells (two left panels) and T cells (two right panels). Figure 4C shows the surface levels of CD69 (left panel) and S1P1 (right panel) on B cells treated with various doses of CPI-006. The legend from top to bottom represents each group of three bars from left to right. Without intending to be bound by the theory of the present invention, Figure 4D provides a model for the mechanism that leads to the reduction of peripheral B cell levels by CPI-006. [Figure 4D] Figure 4A shows that CPI-006 transiently redistributes peripheral B cells. Figure 4A shows the levels of B cells (CD19+CD3-) as a percentage of total lymphocytes based on CPI-006 doses of 1 mg / kg (left panel), 3 mg / kg (middle panel), and 6 mg / kg (right panel). Figure 4B shows the expression of CD73 using a non-competitive anti-CD73 antibody reported for B cells (two left panels) and T cells (two right panels). Figure 4C shows the surface levels of CD69 (left panel) and S1P1 (right panel) on B cells treated with various doses of CPI-006. The legend from top to bottom represents each group of three bars from left to right. Without intending to be bound by the theory of the present invention, Figure 4D provides a model for the mechanism that leads to the reduction of peripheral B cell levels by CPI-006. [Diagram 5] Figure 1 shows CD73 occupancy and inhibition in tumor biopsies from colorectal patients treated with CPI-006 at 12 mg / kg.Tumor biopsies were retroperitoneal lesions obtained at trough 3 pre-dose. [Figure 6A]Cancer patients treated with various doses of CPI-006 alone (Figure 6A) or CPI-006 in combination with ciforadenant (Figure 6B) are shown. Cycles were once every 21 days. Disease assessments were performed every 3-4 cycles. The dashed lines indicate that there was sustained CD73 receptor occupancy in peripheral blood at doses of 6 mg / kg and 12 mg / kg, but not at doses of 1 mg / kg and 3 mg / kg. HDNCK refers to head and neck cancer. mCRPC refers to metastatic castration-resistant prostate cancer. BLADD refers to bladder cancer. PANC refers to pancreatic cancer. COLORECT refers to colorectal cancer. RCC refers to renal cell carcinoma. SD indicates stable disease and PD indicates progression. [Figure 6B] Cancer patients treated with various doses of CPI-006 alone (Figure 6A) or CPI-006 in combination with ciforadenant (Figure 6B) are shown. Cycles were once every 21 days. Disease assessments were performed every 3-4 cycles. The dashed lines indicate that there was sustained CD73 receptor occupancy in peripheral blood at doses of 6 mg / kg and 12 mg / kg, but not at doses of 1 mg / kg and 3 mg / kg. HDNCK refers to head and neck cancer. mCRPC refers to metastatic castration-resistant prostate cancer. BLADD refers to bladder cancer. PANC refers to pancreatic cancer. COLORECT refers to colorectal cancer. RCC refers to renal cell carcinoma. SD indicates stable disease and PD indicates progression. [Figure 7A]Figure 7 shows that treatment with CPI-006 induces rapid changes in blood B and T cells. Figure 7A shows the percentage of lymphocytes containing CD73POS B cells before treatment and 0.5 hours after CPI-006 administration at dosages of 1 mg / kg to 12 mg / kg. Figure 7B shows the fold change in cell frequency of CD73POS CD4 T cells, CD73NEG CD4 T cells, CD73POS CD8 T cells, CD73NEG CD8 T cells, and monocytes 0.5 hours after CPI-004 administration. Figure 7C shows the change in CD73POS B cells over time at four different CPI-006 doses. The highest line on day 10 represents 1 mg / kg, the second highest line on day 10 represents 3 mg / kg, the second lowest line on day 10 represents 6 mg / kg, and the lowest line on day 10 represents 12 mg / kg. Figure 7D shows the change in HLA-DR (human leukocyte antigen, DR isotype) expression in a cancer patient receiving 6 mg / kg CPI-006 monotherapy. Figure 7E shows the prostate tumor before treatment (left panel) and the reduction in size of the prostate tumor after two cycles of treatment, i.e., 42 days later (right panel). Figure 7F shows the change in circulating CD73POS B cells (solid line) and CD73NEG B cells (dashed line) over time in a 72-year-old metastatic prostate cancer patient shown in Figure 7E, who had previously been treated with leuprolide / bicalutamide, abiraterone, enzalutamide, and docetaxel. [Figure 7B]Figure 7 shows that treatment with CPI-006 induces rapid changes in blood B and T cells. Figure 7A shows the percentage of lymphocytes containing CD73POS B cells before treatment and 0.5 hours after CPI-006 administration at dosages of 1 mg / kg to 12 mg / kg. Figure 7B shows the fold change in cell frequency of CD73POS CD4 T cells, CD73NEG CD4 T cells, CD73POS CD8 T cells, CD73NEG CD8 T cells, and monocytes 0.5 hours after CPI-004 administration. Figure 7C shows the change in CD73POS B cells over time at four different CPI-006 doses. The highest line on day 10 represents 1 mg / kg, the second highest line on day 10 represents 3 mg / kg, the second lowest line on day 10 represents 6 mg / kg, and the lowest line on day 10 represents 12 mg / kg. Figure 7D shows the change in HLA-DR (human leukocyte antigen, DR isotype) expression in a cancer patient receiving 6 mg / kg CPI-006 monotherapy. Figure 7E shows the prostate tumor before treatment (left panel) and the reduction in size of the prostate tumor after two cycles of treatment, i.e., 42 days later (right panel). Figure 7F shows the change in circulating CD73POS B cells (solid line) and CD73NEG B cells (dashed line) over time in a 72-year-old metastatic prostate cancer patient shown in Figure 7E, who had previously been treated with leuprolide / bicalutamide, abiraterone, enzalutamide, and docetaxel. [Figure 7C]Figure 7 shows that treatment with CPI-006 induces rapid changes in blood B and T cells. Figure 7A shows the percentage of lymphocytes containing CD73POS B cells before treatment and 0.5 hours after CPI-006 administration at dosages of 1 mg / kg to 12 mg / kg. Figure 7B shows the fold change in cell frequency of CD73POS CD4 T cells, CD73NEG CD4 T cells, CD73POS CD8 T cells, CD73NEG CD8 T cells, and monocytes 0.5 hours after CPI-004 administration. Figure 7C shows the change in CD73POS B cells over time at four different CPI-006 doses. The highest line on day 10 represents 1 mg / kg, the second highest line on day 10 represents 3 mg / kg, the second lowest line on day 10 represents 6 mg / kg, and the lowest line on day 10 represents 12 mg / kg. Figure 7D shows the change in HLA-DR (human leukocyte antigen, DR isotype) expression in a cancer patient receiving 6 mg / kg CPI-006 monotherapy. Figure 7E shows the prostate tumor before treatment (left panel) and the reduction in size of the prostate tumor after two cycles of treatment, i.e., 42 days later (right panel). Figure 7F shows the change in circulating CD73POS B cells (solid line) and CD73NEG B cells (dashed line) over time in a 72-year-old metastatic prostate cancer patient shown in Figure 7E, who had previously been treated with leuprolide / bicalutamide, abiraterone, enzalutamide, and docetaxel. [Figure 7D]Figure 7 shows that treatment with CPI-006 induces rapid changes in blood B and T cells. Figure 7A shows the percentage of lymphocytes containing CD73POS B cells before treatment and 0.5 hours after CPI-006 administration at dosages of 1 mg / kg to 12 mg / kg. Figure 7B shows the fold change in cell frequency of CD73POS CD4 T cells, CD73NEG CD4 T cells, CD73POS CD8 T cells, CD73NEG CD8 T cells, and monocytes 0.5 hours after CPI-004 administration. Figure 7C shows the change in CD73POS B cells over time at four different CPI-006 doses. The highest line on day 10 represents 1 mg / kg, the second highest line on day 10 represents 3 mg / kg, the second lowest line on day 10 represents 6 mg / kg, and the lowest line on day 10 represents 12 mg / kg. Figure 7D shows the change in HLA-DR (human leukocyte antigen, DR isotype) expression in a cancer patient receiving 6 mg / kg CPI-006 monotherapy. Figure 7E shows the prostate tumor before treatment (left panel) and the reduction in size of the prostate tumor after two cycles of treatment, i.e., 42 days later (right panel). Figure 7F shows the change in circulating CD73POS B cells (solid line) and CD73NEG B cells (dashed line) over time in a 72-year-old metastatic prostate cancer patient shown in Figure 7E, who had previously been treated with leuprolide / bicalutamide, abiraterone, enzalutamide, and docetaxel. [Figure 7E]Figure 7 shows that treatment with CPI-006 induces rapid changes in blood B and T cells. Figure 7A shows the percentage of lymphocytes containing CD73POS B cells before treatment and 0.5 hours after CPI-006 administration at dosages of 1 mg / kg to 12 mg / kg. Figure 7B shows the fold change in cell frequency of CD73POS CD4 T cells, CD73NEG CD4 T cells, CD73POS CD8 T cells, CD73NEG CD8 T cells, and monocytes 0.5 hours after CPI-004 administration. Figure 7C shows the change in CD73POS B cells over time at four different CPI-006 doses. The highest line on day 10 represents 1 mg / kg, the second highest line on day 10 represents 3 mg / kg, the second lowest line on day 10 represents 6 mg / kg, and the lowest line on day 10 represents 12 mg / kg. Figure 7D shows the change in HLA-DR (human leukocyte antigen, DR isotype) expression in a cancer patient receiving 6 mg / kg CPI-006 monotherapy. Figure 7E shows the prostate tumor before treatment (left panel) and the reduction in size of the prostate tumor after two cycles of treatment, i.e., 42 days later (right panel). Figure 7F shows the change in circulating CD73POS B cells (solid line) and CD73NEG B cells (dashed line) over time in a 72-year-old metastatic prostate cancer patient shown in Figure 7E, who had previously been treated with leuprolide / bicalutamide, abiraterone, enzalutamide, and docetaxel. [Figure 7F]Figure 7 shows that treatment with CPI-006 induces rapid changes in blood B and T cells. Figure 7A shows the percentage of lymphocytes containing CD73POS B cells before treatment and 0.5 hours after CPI-006 administration at dosages of 1 mg / kg to 12 mg / kg. Figure 7B shows the fold change in cell frequency of CD73POS CD4 T cells, CD73NEG CD4 T cells, CD73POS CD8 T cells, CD73NEG CD8 T cells, and monocytes 0.5 hours after CPI-004 administration. Figure 7C shows the change in CD73POS B cells over time at four different CPI-006 doses. The highest line on day 10 represents 1 mg / kg, the second highest line on day 10 represents 3 mg / kg, the second lowest line on day 10 represents 6 mg / kg, and the lowest line on day 10 represents 12 mg / kg. Figure 7D shows the change in HLA-DR (human leukocyte antigen, DR isotype) expression in a cancer patient receiving 6 mg / kg CPI-006 monotherapy. Figure 7E shows the prostate tumor before treatment (left panel) and the reduction in size of the prostate tumor after two cycles of treatment, i.e., 42 days later (right panel). Figure 7F shows the change in circulating CD73POS B cells (solid line) and CD73NEG B cells (dashed line) over time in a 72-year-old metastatic prostate cancer patient shown in Figure 7E, who had previously been treated with leuprolide / bicalutamide, abiraterone, enzalutamide, and docetaxel. [Figure 8A] We show that treatment with CPI-006 induces cytokines consistent with immune activation. In particular, there is a rapid induction of proinflammatory cytokines (Figure 8A); followed by induction of CRP (C-reactive protein) and SAA (serum amyloid A) (Figure 8B). [Figure 8B] We show that treatment with CPI-006 induces cytokines consistent with immune activation. In particular, there is a rapid induction of proinflammatory cytokines (Figure 8A); followed by induction of CRP (C-reactive protein) and SAA (serum amyloid A) (Figure 8B). [Figure 9] Without intending to be bound by theory of the mechanism of action of CPI-006, a proposed model for the immunomodulatory activity of CPI-006 is presented. [Figure 10] Without intending to be bound by theory of the mechanism of action of CPI-006, a schematic diagram of the present disclosure is provided. [Figure 11A] Clonal abundance plots of T cell clones for three patients treated with CP1-006. Sequencing of the Vb region of the T cell receptor was performed to identify the frequency of unique T cell clones in peripheral blood samples taken before and during 6 weeks of treatment with 12 mg / kg CPI-006 + ciphoradenant (Figure 11A), 12 mg / kg CPI-006 (Figure 11B), or 18 mg / kg CPI-006 (Figure 11C). Expansion of new T cell clones was observed after 6 weeks in three of the eight evaluated patients treated with CPI-006. [Figure 11B] Clonal abundance plots of T cell clones for three patients treated with CP1-006. Sequencing of the Vb region of the T cell receptor was performed to identify the frequency of unique T cell clones in peripheral blood samples taken before and during 6 weeks of treatment with 12 mg / kg CPI-006 + ciphoradenant (Figure 11A), 12 mg / kg CPI-006 (Figure 11B), or 18 mg / kg CPI-006 (Figure 11C). Expansion of new T cell clones was observed after 6 weeks in three of the eight evaluated patients treated with CPI-006. [Figure 11C] Clonal abundance plots of T cell clones for three patients treated with CP1-006. Sequencing of the Vb region of the T cell receptor was performed to identify the frequency of unique T cell clones in peripheral blood samples taken before and during 6 weeks of treatment with 12 mg / kg CPI-006 + ciphoradenant (Figure 11A), 12 mg / kg CPI-006 (Figure 11B), or 18 mg / kg CPI-006 (Figure 11C). Expansion of new T cell clones was observed after 6 weeks in three of the eight evaluated patients treated with CPI-006. [Figure 12]Circulating lymphocyte kinetics during the first 24 hours after treatment with CPI-006 or the combination of CPI-006 and ciforadenant (PCI-444). Whole blood was collected before treatment, or 0.5 or 24 hours after administration of CPI-006 as a single agent (left) or in combination with CPI-444 (right). Absolute numbers of CD19+ B cells, CD3+ T cells, CD3+CD4+ T cells, CD3+CD8+ T cells, and CD3-CD16+CD56+ NK cells were determined by flow cytometry using quantification beads. The numbers of circulating cells were decreased 0.5 hours after treatment for all lymphocyte subsets evaluated, but recovered 24 hours after treatment; in the case of B cells, this was a partial recovery, while the other cell types had recovered to near baseline levels by 24 hours. [Figure 13] Levels of circulating CD73+ and CD73- B cells following treatment with CPI-006 are shown. Blood was drawn before treatment or 0.5 hours after CPI-006 administration. Absolute numbers of CD19+ B cells, and percentages of CD73 positive B cells were determined using flow cytometry. Numbers of circulating CD73+ B cells were substantially reduced 0.5 hours after treatment, while CD73- B cells were unchanged or slightly reduced between patients. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] I. Definition "CPI-006" or "CPX-006" is a humanized CD73 antibody, wherein the light chain is SEQ ID NO: 8 and the heavy chain is SEQ ID NO: 7 as described herein. CPI-006 is also described in WO2017 / 100670, the disclosure of which is incorporated herein by reference in its entirety, wherein the heavy chain is SEQ ID NO: 53 and the light chain is SEQ ID NO: 55, which correspond to SEQ ID NO: 9 and SEQ ID NO: 10, respectively.

[0019] In this disclosure, "comprises," "comprising," "containing," "having," and the like can have the meaning ascribed to them in U.S. Patent Law and can mean "includes," "including," and the like. "Consisting essentially of" or "consists essentially" likewise has the meaning ascribed to them in U.S. Patent Law, where the term is open-ended and allows for the presence of more than the recited items, but excludes prior art embodiments, so long as the basic or novel characteristics of the recited items are not changed by the presence of more than the recited items.

[0020] The term "gene" refers to a segment of DNA involved in the production of a protein, including the regions preceding and following the coding region (leader and trailer), and the intervening sequences (introns) between individual coding segments (exons). The leader, trailer, and introns contain regulatory elements required during transcription and translation of a gene. Additionally, a "protein gene product" is a protein expressed from a particular gene.

[0021] For certain proteins (antibodies or fragments thereof) described herein, the designated protein includes either the naturally occurring form of the protein, a variant or homolog that maintains the activity of the protein transcription factor (e.g., within at least 50%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, or 100% activity compared to the native protein). In embodiments, the variant or homolog has at least 90%, 95%, 96%, 97%, 98%, 99%, or 100% amino acid sequence identity over the entire sequence or a portion of the sequence (e.g., a 50, 100, 150, or 200 contiguous amino acid portion) compared to the naturally occurring form. In embodiments, the protein is a protein identified by its NCBI sequence reference. In embodiments, the protein is a protein identified by its NCBI sequence reference, a homolog or a functional fragment thereof.

[0022] An amino acid residue of a protein "corresponds to" a given residue if it occupies the same essential structural position within the protein as the given residue.

[0023] The term "isolated," as applied to a nucleic acid or protein, means that the nucleic acid or protein is essentially free from other cellular components with which it is naturally associated. It can be, for example, in a homogeneous state, either dry or in an aqueous solution. Purity and homogeneity are usually determined using analytical chemistry techniques such as polyacrylamide gel electrophoresis or high performance liquid chromatography. A protein that is the predominant species present in a preparation is substantially purified.

[0024] The term "amino acid" refers to naturally occurring and synthetic amino acids, as well as amino acid analogs and amino acid mimetics that function similarly to naturally occurring amino acids. Naturally occurring amino acids are those encoded by the genetic code, as well as those that are later modified, such as, for example, hydroxyproline, γ-carboxyglutamate, and O-phosphoserine. Amino acid analogs refer to compounds that have the same basic chemical structure as a naturally occurring amino acid, i.e., an α carbon attached to a hydrogen, a carboxyl group, an amino group, and an R group, such as homoserine, norleucine, methionine sulfoxide, and methionine methylsulfonium. Such analogs have modified R groups (e.g., norleucine) or modified peptide backbones, but retain the same basic chemical structure as a naturally occurring amino acid. Amino acid mimetics refer to compounds that have a structure that differs from the general chemical structure of an amino acid, but function similarly to a naturally occurring amino acid. The terms "non-naturally occurring amino acid" and "unnatural amino acid" refer to amino acid analogs, synthetic amino acids, and amino acid mimetics that are not found in nature.

[0025] Amino acids may be referred to herein by either their commonly known three letter symbols or by the one-letter symbols recommended by the IUPAC-IUB Biochemical Nomenclature Commission. Similarly, nucleotides may be referred to by their commonly accepted single-letter codes.

[0026] The terms "polypeptide", "peptide" and "protein" are used interchangeably herein to refer to a polymer of amino acid residues, which may be linked to moieties not composed of amino acids. The term applies to amino acid polymers in which one or more amino acid residues are artificial chemical mimetics of the corresponding naturally occurring amino acids, as well as to naturally occurring and non-naturally occurring amino acid polymers. A "fusion protein" refers to a chimeric protein encoding two or more separate protein sequences that are recombinantly expressed as a single moiety.

[0027] As used herein, the terms "nucleic acid", "nucleic acid molecule", "nucleic acid oligomer", "oligonucleotide", "nucleic acid sequence", "nucleic acid fragment" and "polynucleotide" are used interchangeably and are intended to include, but are not limited to, polymeric forms of nucleotides covalently linked to one another that may have various lengths, either deoxyribonucleotides or ribonucleotides, or analogs, derivatives or modifications thereof. Different polynucleotides may have different three-dimensional structures and perform various functions, known or unknown. Non-limiting examples of polynucleotides include genes, gene fragments, exons, introns, intergenic DNA (including but not limited to heterochromatic DNA), messenger RNA (mRNA), transfer RNA, ribosomal RNA, ribozymes, cDNA, recombinant polynucleotides, branched polynucleotides, plasmids, vectors, isolated DNA sequences, isolated RNA sequences, nucleic acid probes, and primers. Polynucleotides useful in the methods of the present disclosure may include naturally occurring nucleic acid sequences and variants thereof, artificial nucleic acid sequences, or combinations of such sequences.

[0028] A polynucleotide is typically composed of a specific sequence of the four nucleotide bases, adenine (A), cytosine (C), guanine (G), and thymine (T) (if the polynucleotide is RNA, uracil (U) is substituted for thymine (T)). Thus, the term "polynucleotide sequence" is the alphabetical representation of a polynucleotide molecule, or the term may be applied to the polynucleotide molecule itself. This alphabetical representation can be entered into a database in a computer with a central processing unit and used for bioinformatics applications such as functional genomics and homology searching. A polynucleotide may optionally contain one or more non-standard nucleotides, nucleotide analogs, and / or modified nucleotides.

[0029] "Conservatively modified variants" applies to both amino acid and nucleic acid sequences. With respect to a particular nucleic acid sequence, "conservatively modified variants" refers to nucleic acids that code for the same or essentially the same amino acid sequence. Due to the degeneracy of the genetic code, many nucleic acid sequences code for any given protein. For example, the codons GCA, GCC, GCG, and GCU all code for the amino acid alanine. Thus, at every position where alanine is specified by a codon, the codon can be changed to any of the corresponding codons described without changing the encoded polypeptide. Such nucleic acid variations are "silent variations," which are one type of conservatively modified variation. Every nucleic acid sequence herein that codes for a polypeptide also describes every possible silent variation of the nucleic acid. Those skilled in the art will recognize that each codon of a nucleic acid (except AUG, which is usually the only codon for methionine, and TGG, which is usually the only codon for tryptophan) can be modified to produce a functionally identical molecule. Thus, every silent variation of a nucleic acid that codes for a polypeptide is implicit in each described sequence.

[0030] With respect to amino acid sequences, those skilled in the art will recognize that individual substitutions, deletions, or additions to nucleic acid, peptide, polypeptide, or protein sequences that change, add, or delete a single amino acid or a small portion of the amino acid in the coding sequence are "conservatively modified variants" where these modifications result in the replacement of amino acids with chemically similar amino acids. Conservative substitution tables providing functionally similar amino acids are well known in the art. Such conservatively modified variants are in addition to and do not exclude polymorphic variants, interspecies homologs, and alleles of the present disclosure.

[0031] The following eight groups each contain amino acids that are conservative substitutions for one another: (1) alanine (A), glycine (G), (2) aspartic acid (D), glutamic acid (E), (3) asparagine (N), glutamine (Q), (4) arginine (R), lysine (K), (5) isoleucine (I), leucine (L), methionine (M), valine (V), (6) phenylalanine (F), tyrosine (Y), tryptophan (W), (7) serine (S), threonine (T), and (8) cysteine ​​(C), methionine (M) (see, e.g., Creighton, Proteins (1984)).

[0032] The "position" of an amino acid or nucleotide base is indicated by a number that sequentially identifies each amino acid (or nucleotide base) in the reference sequence based on its position relative to the N-terminus (or 5'-terminus). Because of deletions, insertions, truncations, fusions, etc. that must be considered when determining optimal alignment, the number of amino acid residues in a test sequence, determined simply by counting from the N-terminus, is generally not necessarily the same as the number of corresponding positions in the reference sequence. For example, if a variant has a deletion compared to the aligned reference sequence, there will be no amino acid in the variant that corresponds to the position of the reference sequence at the site of the deletion. If there is an insertion in the aligned reference sequence, the insertion does not correspond to a numbered amino acid position in the reference sequence. In the case of a truncation or fusion, there may be a stretch of amino acids in either the reference sequence or the aligned sequence that does not correspond to any amino acid in the corresponding sequence.

[0033] When used in the context of numbering of a given amino acid or polynucleotide sequence, the term "numbered with reference to" or "corresponding to" refers to the numbering of the residues of a particular reference sequence when the given amino acid or polynucleotide sequence is compared to the reference sequence.

[0034] The term "amino acid side chain" refers to a functional substituent contained in an amino acid. For example, the amino acid side chain can be the side chain of a naturally occurring amino acid. Naturally occurring amino acids are those encoded by the genetic code (e.g., alanine, arginine, asparagine, aspartic acid, cysteine, glutamine, glutamic acid, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, or valine), as well as amino acids that are later modified, such as hydroxyproline, γ-carboxyglutamate, and O-phosphoserine. In embodiments, the amino acid side chain can be a non-natural amino acid side chain. In embodiments, the amino acid side chain can be H, [ka] It is.

[0035] The term "unnatural amino acid side chain" refers to a functional substituent of a compound that has the same basic chemical structure as a naturally occurring amino acid, i.e., an alpha carbon attached to a hydrogen, a carboxyl group, an amino group, and an R group, e.g., homoserine, norleucine, methionine sulfoxide, methionine methylsulfonium, allylalanine, 2-aminoisobutyric acid. Unnatural amino acids are non-proteinogenic amino acids that are either naturally occurring or chemically synthesized. Such analogs have modified R groups (e.g., norleucine) or modified peptide backbones, but retain the same basic chemical structure as a naturally occurring amino acid. Non-limiting examples include exo-cis-3-aminobicyclo[2.2.1]hept-5-ene-2-carboxylic acid hydrochloride, cis-2-aminocycloheptane carboxylic acid hydrochloride, cis-6-amino-3-cyclohexene-1-carboxylic acid hydrochloride, cis-2-amino-2-methylcyclohexane carboxylic acid hydrochloride, cis-2-amino-2-methylcyclopentane carboxylic acid hydrochloride, 2-(Boc-aminomethyl)benzoic acid, 2-(Boc-amino)octanedioic acid, Boc-4,5-dehydro-Leu-OH (dicyclohexylammonium), Boc-4-(Fmoc-amino)-L-phenylalanine, and the like. 4-Boc-3-morpholineacetic acid, 4-Boc-3-morpholineacetic acid, Boc-pentafluoro-D-phenylalanine, Boc-pentafluoro-L-phenylalanine, Boc-Phe(2-Br)-OH, Boc-Phe(4-Br)-OH, Boc-D-Phe(4-Br)-OH, Boc-D-Phe(3-Cl)-OH, Boc-Phe(4-NH2)-OH, Boc-Phe(3-NO2)-OH, Boc-Phe(3,5-F2)-OH, 2-(4-Boc-piperazino)-2-(3,4-Dimethoxyphenyl)acetic acid (pure (purum)), 2-(4-Boc-piperazino)-2-(2-fluorophenyl)acetic acid (pure), 2-(4-Boc-piperazino)-2-(3-fluorophenyl)acetic acid (pure), 2-(4-Boc-piperazino)-2-(4-fluorophenyl)acetic acid (pure), 2-(4-Boc-piperazino)-2-(4-methoxyphenyl)-acetic acid (pure), 2-(4-Boc-piperazino)-2-phenylacetic acid (pure), 2-(4-Boc-piperazino)-2-(3-pyridyl)acetic acid (pure), 2-(4-Boc-piperazino)-2-[4-(trifluoromethyl)phenyl]-acetic acid (pure), Boc-β-(2-quinolyl)-Ala-OH, N-Boc-1,2,3,6-tetrahydro-2-pyridinecarboxone Acid, Boc-β-(4-thiazolyl)-Ala-OH, Boc-β-(2-thienyl)-D-Ala-OH, Fmoc-N-(4-Boc-aminobutyl)-Gly-OH, Fmoc-N-(2-Boc-aminoethyl)-Gly-OH, Fmoc-N-(2,4-dimethoxybenzyl)-Gly-OH, Fmoc-(2-indanyl)-Gly-OH, Fmoc-penta These include fluoro-L-phenylalanine, Fmoc-Pen(Trt)-OH, Fmoc-Phe(2-Br)-OH, Fmoc-Phe(4-Br)-OH, Fmoc-Phe(3,5-F2)-OH, Fmoc-β-(4-thiazolyl)-Ala-OH, Fmoc-β-(2-thienyl)-Ala-OH, and 4-(hydroxymethyl)-D-phenylalanine.

[0036] "Nucleic acid" refers to nucleotides (e.g., deoxyribonucleotides or ribonucleotides) and polymers thereof, or their complements, in either single-stranded, double-stranded, or multi-stranded form. Terms such as "polynucleotide," "oligonucleotide," "oligo," and the like refer to a linear sequence of nucleotides in the usual and customary sense. The term "nucleotide" refers to a single polynucleotide unit, i.e., monomer, in the usual and customary sense. A nucleotide can be a ribonucleotide, a deoxyribonucleotide, or a modified form thereof. Examples of polynucleotides contemplated herein include single-stranded and double-stranded DNA, single-stranded and double-stranded RNA, and hybrid molecules having a mixture of single-stranded and double-stranded DNA and RNA. Examples of nucleic acids, e.g., polynucleotides, contemplated herein include any type of RNA, e.g., mRNA, siRNA, miRNA, and guide RNA, as well as any type of DNA, genomic DNA, plasmid DNA, and minicircle DNA, and any fragments thereof. The term "double-stranded" in the context of a polynucleotide refers to double-strandedness in the usual and customary sense. Nucleic acids can be linear or branched. For example, nucleic acids can be linear chains of nucleotides, or nucleic acids can be branched, for example, such that the nucleic acid comprises one or more arms or branches of nucleotides. Optionally, branched nucleic acids are repeatedly branched to form higher-order structures, such as dendrimers.

[0037] For example, nucleic acids, including nucleic acids with phosphothioate backbones, may contain one or more reactive moieties.As used herein, the term reactive moiety includes any group that can react with another molecule, such as a nucleic acid or a polypeptide, via covalent, non-covalent, or other interaction.As an example, a nucleic acid may contain an amino acid reactive moiety that reacts with an amino acid on a protein or polypeptide via covalent, non-covalent, or other interaction.

[0038] This term also includes nucleic acids that contain known nucleotide analogs or modified backbone residues or bonds, which are synthetic, naturally occurring, and non-naturally occurring, and have similar binding properties as reference nucleic acids, and are metabolized in the same manner as reference nucleotides.Examples of such analogs include, but are not limited to, for example, phosphoramidate, phosphorodiamidate, phosphorothioate (also known as phosphothioate, which replaces the oxygen of phosphate with double bond sulfur), phosphorodithioate, phosphonocarboxylic acid, phosphonocarboxylate, phosphonoacetic acid, phosphonoformic acid, methylphosphonate, boron phosphonate, or phosphodiester derivatives that contain O-methyl phosphoramidite bonds (see Eckstein, OLIGONUCLEOTIDES AND ANALOGUES: A PRACTICAL APPROACH, Oxford University Press), as well as modifications to nucleotide bases, such as in the case of 5-methylcytidine or pseudouridine, and the backbone and bonds of peptide nucleic acid. Other analog nucleic acids include those with cationic backbones, non-ionic backbones, modified sugars, and non-ribose backbones (e.g., phosphorodiamidate morpholino oligos or bridged nucleic acids (LNAs) as known in the art), including those described in U.S. Pat. Nos. 5,235,033 and 5,034,506, and Chapters 6 and 7, ASC Symposium Series 580, CARBOHYDRATE MODIFICATIONS IN ANTISENSE RESEARCH, Sanghui & Cook, eds. Nucleic acids containing one or more carbocyclic sugars are also included within one definition of nucleic acid. Modification of the ribose-phosphate backbone can be performed for a variety of reasons, for example, to increase the stability and half-life of such molecules in physiological environments or as probes on biochips. Mixtures of naturally occurring nucleic acids and analogs can be made, or mixtures of different nucleic acid analogs and mixtures of naturally occurring nucleic acids and analogs can be made. In embodiments, the internucleotide linkages of the DNA are phosphodiester, phosphodiester derivatives, or a combination of both.

[0039] Nucleic acid may contain non-specific sequences. As used herein, the term "non-specific sequence" refers to a nucleic acid sequence that contains a series of residues that are not designed to be complementary or only partially complementary to any other nucleic acid sequence. By way of example, a non-specific nucleic acid sequence is a sequence of nucleic acid residues that does not function as an inhibitory nucleic acid when contacted with a cell or organism.

[0040] The term "complement" as used herein refers to a nucleotide (e.g., RNA or DNA) or sequence of nucleotides that can base pair with a complementary nucleotide or sequence of nucleotides. As described herein and generally known in the art, the complementary (matching) nucleotide of adenosine is thymidine, and the complementary (matching) nucleotide of guanidine is cytosine. Thus, a complement can include a sequence of nucleotides that base pair with the corresponding complementary nucleotides of a second nucleic acid sequence. The nucleotides of the complement can partially or completely match with the nucleotides of the second nucleic acid sequence. If the nucleotides of the complement completely match with each nucleotide of the second nucleic acid sequence, the complement will base pair with each nucleotide of the second nucleic acid sequence. If the nucleotides of the complement partially match with the nucleotides of the second nucleic acid sequence, only a portion of the nucleotides of the complement will base pair with the nucleotides of the second nucleic acid sequence. Examples of complementary sequences include coding sequences and non-coding sequences, where the non-coding sequence includes complementary nucleotides to the coding sequence, thus forming the complement of the coding sequence. A further example of a complementary sequence is a sense sequence and an antisense sequence, where the sense sequence comprises a complementary nucleotide to the antisense sequence, thus forming the complement of the antisense sequence.

[0041] As described herein, when sequence complementarity is partial, only some nucleic acids match according to base pairing, or when it is complete, all nucleic acids match according to base pairing.Therefore, two sequences that are complementary to each other can have a certain percentage of identical nucleotides (i.e., about 60% identity over a certain region, preferably 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or more identity).

[0042] "Percentage of sequence identity" is determined by comparing two optimally aligned sequences over a comparison window, where the portion of the polynucleotide or polypeptide sequence in the comparison window may contain additions or deletions (i.e., gaps) compared to the reference sequence (which does not contain additions or deletions) for optimal alignment of the two sequences. The percentage is calculated by determining the number of positions where the same nucleic acid base or amino acid residue is present in both sequences, taking the number of matching positions, dividing the number of matching positions by the total number of positions in the comparison window, and multiplying the result by 100 to obtain the percentage of sequence identity.

[0043] The term "identical" or percentage of "identity" in the context of two or more nucleic acid or polypeptide sequences refers to two or more sequences or subsequences that are identical or have a certain percentage of identical amino acid residues or nucleotides (i.e., about 60% identity over a specified region, preferably 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity or more when compared and aligned for maximum correspondence over a comparison window or designated region) as measured using the BLAST or BLAST 2.0 sequence comparison algorithm with the default parameters described below, or by manual alignment and visual inspection (see, for example, the NCBI website http: / / www.ncbi.nlm.nih.gov / BLAST / , etc.). Such sequences are then said to be "substantially identical". This definition can also refer to or apply to the complement of a test sequence. The definition also includes sequences with deletions and / or additions, as well as sequences with substitutions. As explained below, preferred algorithms can account for gaps, etc. Preferably, the identity exists over a region that is at least about 25 amino acids or nucleotides in length, and more preferably over a region that is 50-100 amino acids or nucleotides in length.

[0044] The term "antibody" refers to a polypeptide encoded by an immunoglobulin gene or functional fragment thereof that specifically binds and recognizes an antigen. Recognized immunoglobulin genes include the kappa, lambda, alpha, gamma, delta, epsilon, and mu constant region genes, as well as the myriad immunoglobulin variable region genes. Light chains are classified as kappa or lambda. Heavy chains are classified as gamma, mu, alpha, delta, or epsilon, which in turn define the immunoglobulin classes IgG, IgM, IgA, IgD, and IgE, respectively.

[0045] The phrases "specifically (or selectively) bind" or "specifically (or selectively) immunoreact" with an antibody, when referring to a protein or peptide, refer to a binding reaction that determines the presence of the protein, often in a heterogeneous population of proteins and other biologics. Thus, under specified immunoassay conditions, a particular antibody will bind to a particular protein at least twice background, and more commonly more than 10-100 times background. Specific binding to an antibody under such conditions requires an antibody that is selected for its specificity for a particular protein. For example, polyclonal antibodies can be selected to obtain only an antibody subset that is specifically immunoreactive with a selected antigen and not with other proteins. This selection can be accomplished by subtracting out antibodies that cross-react with other molecules. A variety of immunoassay formats can be used to select antibodies that are specifically immunoreactive with a particular protein. For example, solid-phase ELISA immunoassays are routinely used to select antibodies specifically immunoreactive with a protein (see, e.g., Harlow & Lane, Using Antibodies, A Laboratory Manual (1998) for a description of immunoassay formats and conditions that can be used to determine specific immunoreactivity).

[0046] An exemplary immunoglobulin (antibody) structural unit comprises a tetramer. Each tetramer consists of two identical pairs of polypeptide chains, each pair having one "light" chain (about 25 kDa) and one "heavy" chain (about 50-70 kDa). The N-terminus of each chain defines a variable region of about 100-110 or more amino acids that is primarily responsible for antigen recognition. The "variable heavy chain", "V H The terms "variable light chain," "VH," or "VH" refer to the variable region of an immunoglobulin heavy chain, including an Fv, scFv, dsFv, or Fab, while the terms "variable light chain," "V LThe term "VL" or "VL" refers to the variable region of an immunoglobulin light chain, including Fv, scFv, dsFv or Fab.

[0047] Examples of antibody functional fragments include, but are not limited to, complete antibody molecules, antibody fragments such as Fv, single chain Fv (scFv), complementarity determining regions (CDRs), VL (light chain variable region), VH (heavy chain variable region), Fab, F(ab)2', and any combination thereof or any other functional portion of an immunoglobulin peptide capable of binding to a target antigen (see, for example, FUNDAMENTAL IMMUNOLOGY (Paul ed., 4th ed. 2001)). As will be appreciated by those skilled in the art, various antibody fragments can be obtained by various methods, for example, digestion of intact antibodies with enzymes such as pepsin, or de novo synthesis. Antibody fragments are often synthesized de novo, either chemically or by using recombinant DNA methods. Thus, the term antibody as used herein includes antibody fragments produced by the modification of whole antibodies or antibody fragments synthesized de novo using recombinant DNA methods (e.g., single-chain Fv) or identified using a phage display library (see, e.g., McCafferty et al., (1990) Nature 348:552). The term "antibody" also includes bivalent or bispecific molecules, diabodies, triabodies, and tetrabodies. Bivalent and bispecific molecules are described, for example, in Kostelny et al. (1992) J. Immunol. 148:1547, Pack and Pluckthun (1992) Biochemistry 31:1579, Hollinger et al. (1993), PNASUSA 90:6444, Gruber et al. (1994) J Immunol. 152:5368, Zhu et al. (1997) Protein Sci. 6:781, Hu et al. (1996) Cancer Res. 56:3055, Adams et al. (1993) Cancer Res. 53:4026, and McCartney, et al. (1995) Protein Eng. 8:301.

[0048] Chimeric antibodies are antibodies in which the variable regions of a mouse (or other rodent) antibody are combined with the constant regions of a human antibody, and their genetic engineering construction is well known. Such antibodies are approximately two-thirds human while retaining the binding specificity of mouse antibodies. The proportion of non-human sequences present in mouse, chimeric and humanized antibodies suggests that the immunogenicity of chimeric antibodies is intermediate between mouse and humanized antibodies. Other types of engineered antibodies that may have reduced immunogenicity compared to murine antibodies include human antibodies produced using phage display methods (Dower et al., WO91 / 17271; McCafferty et al., WO92 / 001047; Winter, WO92 / 20791, and Winter, FEBS Lett. 23:92, 1998, each of which is incorporated herein by reference) or using transgenic animals (Lonberg et al., WO93 / 12227; Kucherlapati WO91 / 10741, each of which is incorporated herein by reference).

[0049] Other approaches to designing humanized antibodies can also be used to achieve the same results as the methods of U.S. Pat. Nos. 5,530,101 and 5,585,089 discussed above, e.g., "superhumanization" (see Tan et al. J. Immunol. 169:1119, 2002, and U.S. Pat. No. 6,881,557) or the methods of Studnicak et al., Protein Eng. 7:805, 1994. Additionally, other approaches to producing genetically engineered mAbs with reduced immunogenicity include "remodeling," "hyperchimerization," and veneering / resurfacing, as described, for example, in Vaswami et al., Annals of Allergy, Asthma and Immunology 81:105, 1998; Roguska et al. Protein Eng. 9:895, 1996; and U.S. Patent Nos. 6,072,035 and 5,639,641.

[0050] A humanized antibody is a genetically engineered antibody in which at least one CDR (or functional fragment thereof) from a mouse antibody (the "donor antibody", which can be a rat, hamster, or other non-human species) is grafted onto a human antibody (the "acceptor antibody"). A human antibody is a non-naturally occurring (e.g., not naturally occurring or not naturally produced by humans) antibody that does not elicit an immune response in humans, does not elicit a significant immune response in humans, or elicits an immune response that is less than that elicited in mice. In embodiments, two or more mouse CDRs are grafted (e.g., all six mouse CDRs are grafted). The sequence of the acceptor antibody can be, for example, a mature human antibody sequence (or a fragment thereof), a consensus sequence of a human antibody sequence (or a fragment thereof), or a germline region sequence (or a fragment thereof). Thus, a humanized antibody can be an antibody having one or more CDRs and a variable region framework (FR) from a donor antibody. The FRs can form part of the constant and / or variable regions in a human antibody. Additionally, to retain high binding affinity, amino acids of the human acceptor sequence can be replaced with corresponding amino acids from the donor sequence, e.g., (1) the amino acids are in the CDRs, (2) the amino acids are in the human framework regions (e.g., the amino acids are directly adjacent to one of the CDRs). See U.S. Patent Nos. 5,530,101 and 5,585,089, which are incorporated herein by reference, and which provide a detailed description of the construction of humanized antibodies.Humanized antibodies often incorporate all six CDRs from a murine antibody (e.g., as defined by Kabat, but often also including hypervariable loop H1 as defined by Chothia), but can also be made with fewer murine CDRs and / or less than the entire murine CDR sequences (e.g., functional fragments of the CDRs) (e.g., Pascalis et al., J. Immunol. 169:3076, 2002; Vajdos et al., Journal of Molecular Biology, 320:415-428, 2002; Iwahashi et al., Mol. Immunol. 36:1079-1091, 1999; Tamura et al, Journal of Immunology, 164:1432-1441, 2000).

[0051] Typically, the humanized antibody provided herein may comprise (i) a light chain comprising at least one CDR (often three CDRs) from a mouse antibody (also referred to herein as mouse CDRs) and a human variable region framework, and (ii) a heavy chain comprising at least one CDR (often three CDRs) from a mouse antibody and a human variable region framework (FR). The light and heavy chain variable region frameworks (FR) may each be a variable region framework sequence (or a fragment thereof) of a mature human antibody, a germline variable region framework sequence (in combination with a J region sequence) (or a fragment thereof), or a consensus sequence of a variable region framework sequence (or a fragment thereof) of a human antibody. In embodiments, the humanized antibody comprises a light chain as described in (i), a heavy chain as described in (ii), together with a light chain human constant region and a heavy chain constant region.

[0052] A "CD73 protein" or "CD73 antigen" as referred to herein includes any recombinant or native form of cluster of differentiation 73 (CD73), also known as 5'-nucleotidase (5'-NT) or ecto-5' nucleotidase, or a variant or homologue thereof that maintains CD73 nucleotidase activity (e.g., within at least 50%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, or 100% activity compared to CD73). In some embodiments, the variant or homologue has at least 90%, 95%, 96%, 97%, 98%, 99%, or 100% amino acid sequence identity over the entire sequence or a portion of the sequence (e.g., a 50, 100, 150, or 200 contiguous amino acid portion) compared to a naturally occurring CD73 protein. In embodiments, the CD73 protein is substantially identical to the protein identified by UniProt reference number 21589, or a variant or homologue having substantial identity thereto. In embodiments, the CD73 protein is substantially identical to the protein identified by UniProt reference number Q61503, or a variant or homologue having substantial identity thereto.

[0053] "MEDI9447" as provided herein refers to the anti-CD73 antibody described by Hay CM et al. ("Targeting CD73 in the tumor microenvironment with MEDI9447." Oncoimmunology. 2016 Jul 11;5(8)), which is incorporated herein in its entirety for all purposes.

[0054] As provided herein, "AD2" refers to the anti-CD73 antibody described by Borrione P et al. ("CD38 stimulation lowers the activation threshold and enhances the alloreactivity of cord blood T cells by activating the phosphatidylinositol 3-kinase pathway and inducing CD73 expression." J Immunol 162:6238-46 (1999), which is incorporated herein in its entirety for all purposes.

[0055] As used herein, a "cell" refers to a cell that performs metabolic or other functions sufficient to preserve or replicate its genomic DNA. Cells can be identified by methods well known in the art, including, for example, the presence of an intact membrane, staining with certain dyes, the ability to produce progeny, or, in the case of gametes, the ability to combine with a second gamete to produce viable offspring. Cells can include prokaryotic and eukaryotic cells. Prokaryotic cells include, but are not limited to, bacteria. Eukaryotic cells include, but are not limited to, yeast cells and cells derived from plants and animals, such as mammalian cells, insect cells (e.g., Spodoptera), and human cells. Cells can be useful when they are naturally non-adherent or have been treated to prevent them from adhering to surfaces, for example, by trypsinization.

[0056] "Lymphoid cells" is used according to its plain and ordinary meaning to refer to white blood cell subsets involved in immunity, including T cells, B cells, and natural killer cells. T cells and B cells form the cellular component of the adaptive immune response upon antigen recognition. Natural killer cells are part of the innate immune system and defend the host against cancer cells and virus-infected cells by recognizing changes in cell surface receptors, for example, MHC class I.

[0057] "Dendritic cell" is used according to its plain and ordinary meaning to refer to antigen-presenting cells of the immune system that process and present antigens on their surface for recognition by T cells.

[0058] "Plasmacytoid dendritic cells" (pDCs) refer to a type of immune cell that can link the innate and adaptive immune systems and participate in antiviral mechanisms. For example, pDCs secrete large amounts of type 1 interferon (IFN) in response to viral infection. In contrast to conventional dendritic cells, which leave the bone marrow as precursors, pDCs leave the bone marrow upon completion of development and go to lymphoid organs and peripheral blood.

[0059] "Control" or "control experiment" is used according to its plain and ordinary meaning and refers to an experiment in which an experimental subject or reagent is treated, such as in a parallel experiment, but omitting an experimental procedure, reagent, or variable. In some cases, a control is used as a standard of comparison in evaluating experimental effects. In aspects, a control is a measurement of protein activity in the absence of a compound described herein (including embodiments and examples).

[0060] "Contacting" is used according to its plain and ordinary meaning to refer to a process that allows at least two different species (e.g., compounds, including biomolecules or cells) to come into sufficient proximity to react, interact, or physically contact. However, it should be understood that the resulting reaction product may be produced directly from the reaction between the added reagents, or from an intermediate derived from one or more of the added reagents that may be produced in the reaction mixture.

[0061] The term "contacting" includes allowing two species to react, interact, or come into physical contact, and the two species can be a compound described herein and a protein or enzyme. In embodiments, contacting includes allowing a compound described herein to interact with a protein or enzyme involved in a signal transduction pathway.

[0062] As defined herein, the terms "activation," "activating," "activating," "activator," and the like, in reference to cell (e.g., B cell)-ligand interactions, refer to positively affecting (e.g., increasing) the activity or function of a cell compared to the activity or function of the cell in the absence of the ligand. In embodiments, activation refers to positively affecting (e.g., increasing) the proliferation rate or biological activity of a cell compared to the proliferation rate or biological activity of a cell in the absence of the activator. These terms may refer to activation, i.e., activating, sensitizing, or upregulating the signal transduction or enzymatic activity or gene expression of a cell. Thus, activation may include at least in part, partially or completely increasing stimulation, increasing or enabling activation, or activating, sensitizing, or upregulating signal transduction or enzymatic activity or gene expression compared to the absence of the activator. Activation may include at least in part, partially or completely increasing stimulation, increasing or enabling activation, or activating, sensitizing, or upregulating signal transduction or enzymatic activity or gene expression.

[0063] The terms "agonist," "activator," "upregulator," and the like refer to a substance that can detectably increase the activity or proliferation of a given cell. An agonist can increase activity or proliferation by 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90% or more compared to a control in the absence of the agonist. In embodiments, proliferation or activity is 1.5-fold, 2-fold, 3-fold, 4-fold, 5-fold, or 10-fold or more greater than proliferation or activity in the absence of the agonist.

[0064] The term "expression" includes any step involved in polypeptide production, including, but not limited to, transcription, post-transcriptional modification, translation, post-translational modification, and secretion. Expression can be detected using conventional techniques for detecting proteins (e.g., ELISA, Western blotting, flow cytometry, immunofluorescence, immunohistochemistry, etc.).

[0065] The term "modulator" refers to an agent that increases or decreases the level of a target molecule or the function of a target molecule or the physical state of a molecular target compared to the absence of the modulator. In embodiments, a modulator increases or decreases the proliferation rate of a cell (e.g., a B cell) or the function or physical state of a cell compared to the absence of the modulator.

[0066] The term "modulate" is used according to its plain and ordinary meaning and refers to the act of changing or varying one or more properties. "Modulation" refers to the process of changing or varying one or more properties. For example, as applied to the effect of a modulator on a target protein, modulating means changing the property or function of the target molecule or the amount of the target molecule by increasing or decreasing it.

[0067] In the context of a substance or an activity or function of a substance that is associated with a disease (e.g., a protein-related disease, cancer (e.g., cancer, an inflammatory disease, an autoimmune disease, or an infectious disease)), the term "associated" or "related to" means that the disease (e.g., cancer, an inflammatory disease, an autoimmune disease, or an infectious disease) is caused (in whole or in part) or a symptom of the disease is caused (in whole or in part) by the substance or an activity or function of the substance. As used herein, something that is described as associated with a disease may be a target for disease treatment if it is a causative agent.

[0068] The term "abnormal" as used herein refers to something that is different from normal. When used to describe enzyme activity or protein function, abnormal refers to activity or function that is higher or lower than the average of normal control or normal non-disease control samples. Abnormal activity may refer to the amount of activity that results in disease, and restoring the abnormal activity to a normal or non-disease-related amount (e.g., by administering a compound or using the methods described herein) results in a reduction of the disease or one or more symptoms.

[0069] As used herein, the term "signal transduction pathway" refers to a series of interactions between cellular and optionally extracellular components (e.g., proteins, nucleic acids, small molecules, ions, lipids) that transmit a change in one component to one or more other components, which in turn transmit changes to additional components, which are optionally propagated to other signal transduction pathway components.

[0070] The term "disease" or "condition" refers to a state of existence or health of a patient or subject that can be treated with the compounds or methods provided herein. The disease can be cancer. The disease can be an autoimmune disease. The disease can be an inflammatory disease. The disease can be an infectious disease. In some further examples, "cancer" refers to human cancer and carcinoma, sarcoma, adenocarcinoma, lymphoma, leukemia, etc., including solid and lymphatic cancer, renal cancer, breast cancer, lung cancer, bladder cancer, colon cancer, ovarian cancer, prostate cancer, pancreatic cancer, gastric cancer, brain cancer, head and neck cancer, skin cancer, uterine cancer, testicular cancer, glioma, esophageal cancer, and liver cancer, including hepatocellular carcinoma, lymphoma, including B acute lymphoblastic lymphoma, non-Hodgkin's lymphoma (e.g., Burkitt's, small cell, and large cell lymphoma), Hodgkin's lymphoma, leukemia (including AML, ALL, and CML), or multiple myeloma.

[0071] As used herein, the term "inflammatory disease" refers to a disease or condition characterized by abnormal inflammation (e.g., increased levels of inflammation compared to a control, such as a healthy individual not suffering from the disease). Examples of inflammatory diseases include autoimmune diseases, arthritis, rheumatoid arthritis, psoriatic arthritis, juvenile idiopathic arthritis, multiple sclerosis, systemic lupus erythematosus (SLE), myasthenia gravis, juvenile onset diabetes, type 1 diabetes mellitus, Guillain-Barré syndrome, Hashimoto's encephalopathy, Hashimoto's thyroiditis, ankylosing spondylitis, psoriasis, Sjogren's syndrome, vasculitis, glomerulonephritis, autoimmune thyroiditis, Behcet's disease, Crohn's disease, ulcers, and the like. These include inflammatory bowel disease, bullous pemphigoid, sarcoidosis, ichthyosis, Graves' ophthalmopathy, inflammatory bowel disease, Addison's disease, vitiligo, asthma, allergic asthma, acne vulgaris, celiac disease, chronic prostatitis, inflammatory bowel disease, pelvic inflammatory disease, reperfusion injury, ischemia-reperfusion injury, stroke, sarcoidosis, transplant rejection, interstitial cystitis, atherosclerosis, scleroderma, and atopic dermatitis.

[0072] As used herein, the term "cancer" refers to all types of cancer, neoplasm, or malignant tumors found in mammals (e.g., humans), including leukemia, lymphoma, carcinoma, and sarcoma. Exemplary cancers that may be treated using the compounds or methods provided herein include brain cancer, glioma, glioblastoma, neuroblastoma, prostate cancer, colorectal cancer, pancreatic cancer, medulloblastoma, melanoma, cervical cancer, gastric cancer, ovarian cancer, lung cancer, head cancer, Hodgkin's disease, and non-Hodgkin's lymphoma. Exemplary cancers that may be treated using the compounds or methods provided herein include thyroid cancer, endocrine system cancer, brain cancer, breast cancer, cervical cancer, colon cancer, head and neck cancer, liver cancer, kidney cancer, lung cancer, ovarian cancer, pancreatic cancer, rectal cancer, gastric cancer, and uterine cancer. Further examples include thyroid cancer, bile duct cancer, pancreatic adenocarcinoma, cutaneous melanoma of the skin, colon adenocarcinoma, rectal adenocarcinoma, gastric adenocarcinoma, esophageal cancer, squamous cell carcinoma of the head and neck, invasive carcinoma of the breast, lung adenocarcinoma, squamous cell carcinoma of the lung, non-small cell lung cancer, mesothelioma, multiple myeloma, neuroblastoma, glioma, glioblastoma multiforme, ovarian cancer, rhabdomyosarcoma, primary thrombocythemia, primary macroglobulinemia, primary brain tumors, malignant pancreatic insulinoma, malignant carcinoid, bladder cancer, premalignant skin lesions, testicular cancer, thyroid cancer, neuroblastoma, esophageal cancer, genitourinary cancer, malignant hypercalcemia, endometrial cancer, adrenal cortical carcinoma, endocrine or exocrine pancreatic neoplasms, medullary thyroid cancer, carcinoma, melanoma, colorectal cancer, papillary thyroid cancer, hepatocellular carcinoma, or prostate cancer.

[0073] The term "leukemia" refers broadly to progressive, malignant diseases of the blood-forming organs and is generally characterized by distorted proliferation and development of white blood cells and their precursor cells in the blood and bone marrow. Leukemias are generally classified clinically based on (1) the duration and character of the disease-acute or chronic, (2) the type of cells involved, i.e., bone marrow (myeloid), lymphatic (lymphatic), or monocytic, and (3) the increased or non-increased number of abnormal cells in the blood-leukemic or nonleukemic (subleukemic). Exemplary leukemias that may be treated using the compounds or methods provided herein include, for example, acute nonlymphocytic leukemia, chronic lymphocytic leukemia, acute granulocytic leukemia, chronic granulocytic leukemia, acute promyelocytic leukemia, adult T-cell leukemia, non-leukemic leukemia, leukocythemic leukemia, basophilic leukemia, blastic leukemia, bovine leukemia, chronic myelocytic leukemia, leukemia cutis, fetal leukemia, eosinophilic leukemia, Gross' leukemia, hairy cell leukemia, hemoblastic leukemia, hemocytoblastic leukemia, leukemia), histiocytic leukemia, stem cell leukemia, acute monocytic leukemia, leukopenic leukemia, lymphocytic leukemia, lymphoblastic leukemia, lymphocytic leukemia, lymphogeneic leukemia, lymphoid leukemia, lymphosarcoma cell leukemia, mast cell leukemia, megakaryocytic leukemia, small myeloblastic leukemia, monocytic leukemia, myeloblastic leukemia, myelogranulocytic leukemia, myelomonocytic leukemia, Naegeli leukemia, plasma cell leukemia, multiple myeloma, plasma cell leukemia, promyelocytic leukemia, Rieder cell leukemia, Schilling leukemia, stem cell leukemia, subleukemic leukemia, or anaplastic cell leukemia.

[0074] As used herein, the term "lymphoma" refers to a group of cancers that affect hematopoietic and lymphatic tissues. It develops primarily in lymphocytes, which are blood cells found in lymph nodes, spleen, thymus, and bone marrow. The two main types of lymphoma are non-Hodgkin's lymphoma and Hodgkin's disease. Hodgkin's disease represents approximately 15% of all diagnosed lymphomas. It is a Reed-Sternberg malignant B-lymphocyte-associated cancer. Non-Hodgkin's lymphoma (NHL) can be classified based on how fast the cancer grows and the type of cells involved. There are aggressive (high-grade) and indolent (low-grade) types of NHL. Based on the type of cells involved, there are B-cell and T-cell NHL. Exemplary B-cell lymphomas that can be treated using the compounds or methods provided herein include, but are not limited to, small lymphocytic lymphoma, mantle cell lymphoma, follicular lymphoma, marginal zone lymphoma, extranodal (MALT) lymphoma, nodal (monocytic B-cell) lymphoma, splenic lymphoma, diffuse large cell B-cell lymphoma, Burkitt's lymphoma, lymphoblastic lymphoma, immunoblastic large cell lymphoma, or precursor B-lymphoblastic lymphoma. Exemplary T-cell lymphomas that can be treated using the compounds or methods provided herein include, but are not limited to, cutaneous T-cell lymphoma, peripheral T-cell lymphoma, anaplastic large cell lymphoma, mycosis fungoides, and precursor T-lymphoblastic lymphoma.

[0075] The term "sarcoma" generally refers to tumors composed of embryonic connective tissue-like material, generally composed of closely packed cells embedded in a fibrous or homogeneous substance. Sarcomas that may be treated using the compounds or methods provided herein include chondrosarcoma, fibrosarcoma, lymphosarcoma, melanosarcoma, myxosarcoma, osteosarcoma, Abemethy's sarcoma, liposarcoma, liposarcoma, alveolar soft part sarcoma, ameloblastoma, botryoid fibrosarcoma, chlorosarcoma, choriocarcinoma, embryonal sarcoma, Wilms' tumor sarcoma, endometrial sarcoma, stromal sarcoma, Ewing's sarcoma, and sarcoma of the pediatric and pediatric sarcomas. sarcoma, fascial sarcoma, fibroblastic sarcoma, giant cell sarcoma, granulocytic sarcoma, Hodgkin's sarcoma, idiopathic multiple chromatohemorrhagic sarcoma, B-cell immunoblastic sarcoma, lymphoma, T-cell immunoblastic sarcoma, Jensen's sarcoma, Kaposi's sarcoma, Kupffer cell sarcoma, angiosarcoma, leukemia sarcoma, malignant mesenchymal sarcoma, parosteal sarcoma, reticulocytic sarcoma, Rous sarcoma, serous cystic sarcoma, synovial sarcoma, or telangiectatic sarcoma.

[0076] The term "melanoma" is intended to mean a tumor arising from the melanocytic system of the skin and other organs. Melanomas that may be treated with the compounds or methods provided herein include, for example, acral lentiginous melanoma, amelanotic melanoma, benign juvenile melanoma, Cloudman melanoma, S91 melanoma, Harding-Passey melanoma, juvenile melanoma, lentigo maligna melanoma, malignant melanoma, nodular melanoma, subungual melanoma, or superficial spreading melanoma.

[0077] The term "carcinoma" refers to a malignant neoplasm composed of epithelial cells that tend to invade surrounding tissues and give rise to metastases. Exemplary carcinomas that may be treated using the compounds or methods provided herein include, for example, medullary thyroid carcinoma, familial medullary thyroid carcinoma, lobular cell carcinoma, acinic cell carcinoma, adenoid cystic carcinoma, adenomatous carcinoma, adenocortical carcinoma, alveolar carcinoma, alveolar cell carcinoma, basal cell carcinoma, basocellulare, basaloid cell carcinoma, basal squamous cell carcinoma, bronchioloalveolar carcinoma, bronchiolar carcinoma, bronchogenic carcinoma, cerebriform carcinoma, cholangiocarcinoma, choriocarcinoma, gelatinous carcinoma, comedo carcinoma, corpus carcinoma, cribriform carcinoma, armored carcinoma, skin carcinoma, cylindrical carcinoma, cylindrical cell carcinoma, ductal carcinoma, sclera ... durum, embryonal carcinoma, encephalo-like carcinoma, epidermoid carcinoma, epithelial adenoid carcinoma, exophytic carcinoma, ulcerative carcinoma, fibrous carcinoma, colloid carcinoma, gelatinous carcinoma, giant cell carcinoma, adenocarcinoma, granulosa cell carcinoma, hair matrix carcinoma, blood-like carcinoma, hepatocellular carcinoma, Hürthle cell carcinoma, vitreous carcinoma, adrenal-like carcinoma, infantile embryonal carcinoma, carcinoma in situ, carcinoma in situ, carcinoma in situ, Krompecher's carcinoma, Kulchitzky cell carcinoma, large cell carcinoma, lenticular carcinoma, lipomatous carcinoma, lymphoepithelial carcinoma, medullary carcinoma, melanoma, carcinoma molle, mucinous carcinoma, mucin-secreting carcinoma muciparum, mucous cell carcinoma, mucoepidermoid carcinoma, mucosal carcinoma (carcinoma mucosum), mucinous carcinoma, myxomatous carcinoma, nasopharyngeal carcinoma, oat cell carcinoma, ossifying carcinoma, osteoid carcinoma, papillary carcinoma, periportal carcinoma, preinvasive carcinoma, squamous cell carcinoma, medullary carcinoma, renal cell carcinoma of the kidney, storage cell carcinoma, sarcomatoid carcinoma, Schneiderian carcinoma, scirrhous carcinoma, scrotal carcinoma, signet ring cell carcinoma, simplex carcinoma, small cell carcinoma, solanoid carcinomaThese include globular cell carcinoma, spindle cell carcinoma, cavernous carcinoma, squamous cell carcinoma, squamous cell carcinoma, string carcinoma, telangiectatic carcinoma, telangiectatic carcinoma, transitional cell carcinoma, carcinoma tuberosum, nodular carcinoma, warty carcinoma, and choriocarcinoma.

[0078] As used herein, the terms "metastasis", "metastatic" and "metastatic cancer" can be used interchangeably and refer to the spread of a proliferative disease or disorder, e.g., cancer, from one organ or another non-adjacent organ or part of the body. "Metastatic cancer" is also called "stage IV cancer". Cancer originates at a site of origin, e.g., the breast, which is referred to as the primary tumor, e.g., primary breast cancer. Some cancer cells in the primary tumor or site of origin acquire the ability to penetrate and invade surrounding normal tissues in the local area and / or penetrate the walls of the lymphatic or vascular system and circulate through the system to other sites and tissues of the body. A second clinically detectable tumor formed from cancer cells of the primary tumor is called a metastatic tumor or secondary tumor. When cancer cells metastasize, the metastatic tumor and its cells are presumed to be similar to those of the original tumor. Thus, when lung cancer metastasizes to the breast, the secondary tumor at the breast site is composed of abnormal lung cells, not abnormal breast cells. The secondary tumor in the breast is referred to as metastatic lung cancer. Therefore, the term metastatic cancer refers to the disease in which the subject has or has had a primary tumor, and has one or more secondary tumors.The term non-metastatic cancer or the subject with non-metastatic cancer refers to the disease in which the subject has a primary tumor but does not have one or more secondary tumors.For example, metastatic lung cancer refers to the disease in which the subject has or has had a history of a primary lung tumor, and has one or more secondary tumors at a second site or multiple sites, for example, at breast.

[0079] The term "skin metastasis" or "cutaneous metastasis" refers to secondary malignant cell growth in the skin, where the malignant cells originate from a primary cancer site (e.g., breast). In skin metastasis, cancerous cells from the primary cancer site migrate to the skin, where they may divide and cause lesions. Skin metastasis may result from the migration of cancer cells from a breast cancer tumor to the skin.

[0080] The term "visceral metastasis" refers to secondary malignant cell growth in an organ (e.g., heart, lung, liver, pancreas, intestine) or body cavity (e.g., pleura, peritoneum) where the malignant cells originate from a primary cancer site (e.g., head and neck, liver, breast). In visceral metastasis, cancerous cells from the primary cancer site migrate to a visceral organ where they may divide and cause disease. Visceral metastasis may result from the migration of cancer cells from a liver cancer tumor or a head and neck tumor to a visceral organ.

[0081] As used herein, the term "autoimmune disease" refers to a disease or condition in which a subject's immune system mounts an abnormal immune response to a substance that does not normally elicit an immune response in a healthy individual. Examples of autoimmune diseases that can be treated with the compounds, pharmaceutical compositions, or methods described herein include acute disseminated encephalomyelitis (ADEM), acute necrotizing hemorrhagic leukoencephalitis, Addison's disease, agammaglobulinemia, alopecia areata, amyloidosis, ankylosing spondylitis, anti-GBM / anti-TBM nephritis, antiphospholipid syndrome (APS), autoimmune angioedema, autoimmune aplastic anemia, autoimmune autonomic neuropathy, autoimmune hepatitis, autoimmune hyperlipidemia, autoimmune immunodeficiency, autoimmune inner ear disease (AIED), autoimmune myocarditis, autoimmune ovarian failure ... Focal inflammation, autoimmune pancreatitis, autoimmune retinopathy, autoimmune thrombocytopenic purpura (ATP), autoimmune thyroid disease, autoimmune urticaria, axonal or neuronal neuropathy, Baro's disease, Behçet's disease, bullous pemphigoid, cardiomyopathy, Castleman's disease, celiac disease, Chagas disease, chronic fatigue syndrome, chronic inflammatory demyelinating polyneuropathy (CIDP), chronic relapsing multifocal osteomyelitis (CRMO), Churg-Strauss syndrome, cicatricial pemphigoid / benign mucous membrane pemphigoid, Crohn's disease, Cogan's syndrome, cold agglutinin disease, congenital heart block , Coxsackie myocarditis, CREST disease, essential mixed cryoglobulinemia, demyelinating neuropathy, dermatitis herpetiformis, dermatomyositis, Devic's disease (neuromyelitis optica), discoid lupus, Dressler's syndrome, endometriosis, eosinophilic esophagitis, eosinophilic fasciitis, erythema nodosum, experimental allergic encephalomyelitis, Evans syndrome, fibromyalgia, fibrosing alveolitis, giant cell arteritis (temporal arteritis), giant cell myocarditis, glomerulonephritis, Goodpasture's syndrome, granulomatosis with polyangiitis (GPA) (formerly called Wegener's granulomatosis), Graves' syndrome disease, Guillain-Barre syndrome, Hashimoto's encephalitis, Hashimoto's thyroiditis, hemolytic anemia, Henoch-Schönlein purpura, herpes gestationis, hypogammaglobulinemia, idiopathic thrombocytopenic purpura (ITP), IgA nephropathy, IgG4-related sclerosing disease, immunoregulatory lipoproteins, inclusion body myositis, interstitial cystitis, juvenile arthritis, juvenile diabetes mellitus (type 1 diabetes), juvenile myositis, Kawasaki syndrome, Lambert-Eaton syndrome, leukocytoclastic vasculitis, lichen planus, lichen sclerosus, ligneous conjunctivitis, linear immunoglobulin A disease (LAD), lupus (SLE), Lyme disease, chronic,Meniere's disease, microscopic polyangiitis, mixed connective tissue disease (MCTD), Mooren's ulcer, Mucha-Habermann disease, multiple sclerosis, myasthenia gravis, myositis, narcolepsy, neuromyelitis optica (Devic), neutropenia, ocular cicatricial pemphigoid, optic neuritis, relapsing rheumatism, PANDAS (Streptococcus associated pediatric autoimmune neuropsychiatric disorders), paraneoplastic cerebellar degeneration, paroxysmal nocturnal hemoglobinuria (PNH), Lee-Romberg syndrome, Parsonage-Turner syndrome, pars planitis (peripheral uveitis), pemphigus, peripheral neuropathy, perivenous encephalomyelitis, pernicious anemia, POEMS syndrome, polyarteritis nodosa, autoimmune polyglandular syndrome type I, type II, type III, polymyalgia rheumatica, polymyositis, post-myocardial infarction syndrome, post-pericardiotomy syndrome, progesterone dermatitis, primary biliary cirrhosis, primary sclerosing biliary Tubulitis, psoriasis, psoriatic arthritis, idiopathic pulmonary fibrosis, pyoderma gangrenosum, pure red cell aplasia, Raynaud's phenomenon, reactive arthritis, reflex sympathetic dystrophy, Reiter's syndrome, relapsing polychondritis, restless legs syndrome, retroperitoneal fibrosis, rheumatic fever, rheumatoid arthritis, sarcoidosis, Schmidt's syndrome, scleritis, scleroderma, Sjogren's syndrome, sperm and testicular autoimmunity, stiff-body syndrome, These include subacute bacterial endocarditis (SBE), Susac syndrome, sympathetic ophthalmia, Takayasu's arteritis, temporal arteritis / giant cell arteritis, thrombocytopenic purpura (TTP), Tolosa-Hunt syndrome, transverse myelitis, type 1 diabetes mellitus, ulcerative colitis, undifferentiated connective tissue disease (UCTD), uveitis, vasculitis, bullous dermatoses, vitiligo, or Wegener's granulomatosis (i.e., granulomatosis with polyangiitis (GPA)).

[0082] As used herein, the term "inflammatory disease" refers to a disease or condition characterized by abnormal inflammation (e.g., increased levels of inflammation compared to a control, such as a healthy individual not afflicted with the disease). Examples of inflammatory diseases include traumatic brain injury, arthritis, rheumatoid arthritis, psoriatic arthritis, juvenile idiopathic arthritis, multiple sclerosis, systemic lupus erythematosus (SLE), myasthenia gravis, juvenile onset diabetes, diabetes mellitus type 1, Guillain-Barré syndrome, Hashimoto's encephalitis, Hashimoto's thyroiditis, ankylosing spondylitis, psoriasis, Sjogren's syndrome, vasculitis, glomerulonephritis, autoimmune thyroiditis, Behcet's disease, Crohn's disease, ulcerative colitis, bullous pemphigoid, sarcoidosis, ichthyosis, Graves' ophthalmopathy, inflammatory bowel disease, Addison's disease, vitiligo, asthma, allergic asthma, acne vulgaris, celiac disease, chronic prostatitis, inflammatory bowel disease, pelvic inflammatory disease, reperfusion injury, sarcoidosis, transplant rejection, interstitial cystitis, atherosclerosis, and atopic dermatitis.

[0083] As used herein, "immune deficiency" or "immunodeficiency" refers to a state in which the immune system is weak, impaired, or completely absent. Immune deficiency may be due to exogenous factors or may be endogenous. Immune deficiency may result from disease, injury, nutrition, or medicines. Medicines that may cause immune deficiency include steroids, chemotherapy, and radiation therapy. Secondary diseases that may cause immune deficiency include AIDS, leukemia, lymphoma, and viral hepatitis. Primary immune deficiency disorders may include common variable immunodeficiency and X-linked agammaglobulinemia.

[0084] As used herein, the term "neurodegenerative disease" refers to a disease or condition in which the function of a subject's nervous system is impaired. Examples of neurodegenerative diseases that may be treated using the compounds, pharmaceutical compositions, or methods described herein include Alexander disease, Alper's disease, Alzheimer's disease, amyotrophic lateral sclerosis, ataxia telangiectasia, Batten disease (also known as Spielmeyer-Vogt-Sjogren-Batten disease), bovine spongiform encephalopathy (BSE), Canavan disease, chronic fatigue syndrome, Cockayne syndrome, corticobasal degeneration, Creutzfeldt-Jakob disease, frontotemporal dementia, Gerstmann-Sträussler-Scheinker syndrome, Huntington's disease, HIV-associated dementia, Kennedy's disease, and others. Examples of conditions that may be considered include: Lewy body dementia, Krabbe disease, kuru, dementia with Lewy bodies, Machado-Joseph disease (spinocerebellar ataxia type 3), multiple sclerosis, multiple system atrophy, myalgic encephalomyelitis, narcolepsy, neuroborreliosis, Parkinson's disease, Pelizaeus-Merzbach disease, Pick's disease, primary lateral sclerosis, prion diseases, Refsum disease, Sandhoff disease, Schilder's disease, subacute combined degeneration of the spinal cord secondary to pernicious anemia, schizophrenia, spinocerebellar ataxia (several types with varying features), spinal muscular atrophy, Steele-Richardson-Olszewski disease, progressive supranuclear palsy, or tabes dorsalis.

[0085] The term "treat" or "treatment" refers to an indication of success in treating or ameliorating an injury, disease, condition, or condition, including any objective or subjective parameter, such as remission, remission, alleviating symptoms, or making the injury, condition, or condition more tolerable to the patient, slowing the rate of degeneration or decline; making the end point of degeneration less debilitating; improving the patient's physical or mental health. The treatment or amelioration of symptoms can be based on objective or subjective parameters, including the results of a physical exam, neuropsychiatric exam, and / or psychiatric evaluation. The term "treat" and its conjugations can include prevention of an injury, condition, condition, or disease. In embodiments, treatment is prophylaxis. In embodiments, treatment does not include prophylaxis.

[0086] "Treating" or "treatment" as used herein (and well understood in the art) broadly includes any approach to obtain beneficial or desired results in a subject's condition, including clinical results. Beneficial or desired clinical results may include, but are not limited to, alleviation or amelioration of one or more symptoms or conditions, whether partial or total, and whether detectable or undetectable, reduction in the extent of disease, stabilization of disease condition (i.e., not worsening), prevention of disease infection or spread, delay or slowing disease progression, improvement or reduction of disease condition, reduction of disease recurrence, and remission. In other words, "treatment" as used herein includes any cure, amelioration, or prevention of disease. Treatment may prevent disease from developing, inhibit disease spread, reduce symptoms of disease (e.g., eye pain, seeing halos around lights, bloodshot eyes, very high intraocular pressure), completely or partially eliminate the underlying cause of disease, shorten disease duration, or a combination thereof.

[0087] As used herein, "treating" and "treatment" include prophylactic treatment. The treatment method includes administering a therapeutically effective amount of an active agent to a subject. The administration step may consist of a single administration or may include a series of administrations. The length of the treatment period depends on various factors, such as the severity of the condition, the age of the patient, the concentration of the active agent, the activity of the composition used for treatment, or a combination thereof. It will also be understood that the effective dosage of the agent used for treatment or prevention may increase or decrease during a particular treatment or prevention plan. Dosage changes may be made and may be evident by standard diagnostic assays known in the art. In some instances, chronic administration may be required. For example, the composition is administered to the subject in an amount and for a period sufficient to treat the patient. In aspects, the treating or treatment is not a prophylactic treatment.

[0088] The term "prevent" refers to a reduction in the occurrence of disease symptoms in a patient. As noted above, prevention can be complete (no detectable symptoms) or partial, such that fewer symptoms are observed than would likely develop without treatment.

[0089] "Patient" or "subject in need of treatment" refers to an organism suffering from or susceptible to a disease or condition that can be treated by administration of a pharmaceutical composition as provided herein. Non-limiting examples include humans, other mammals, cows, rats, mice, dogs, monkeys, goats, sheep, cattle, deer, and other non-mammals. In embodiments, the patient is a human.

[0090] An "effective amount" is an amount of a compound sufficient to achieve a stated purpose (e.g., achieve the effect for which the compound is administered, treat a disease, reduce enzyme activity, increase enzyme activity, reduce a signal transduction pathway, or reduce one or more symptoms of a disease or condition) compared to the absence of the compound. An example of an "effective amount" is an amount sufficient to contribute to the treatment, prevention, or reduction of a symptom(s) of a disease, which may also be referred to as a "therapeutically effective amount." A "reduction" of a symptom(s) (and grammatical equivalents of this phrase) refers to a decrease in the severity or frequency of the symptom(s), or the elimination of the symptom(s). A "prophylactically effective amount" of a drug is an amount of a drug that, when administered to a subject, will have an intended prophylactic effect, for example, an amount of a drug that prevents or delays the onset (or recurrence) of an injury, disease, pathology, or condition, or reduces the likelihood of the onset (or recurrence) of an injury, disease, pathology, or condition, or of the onset (or recurrence) of an injury, disease, pathology, or condition, or of the symptoms thereof. A complete prophylactic effect does not necessarily occur by administration of a single dose, but may occur only after administration of a series of doses. Thus, a prophylactically effective amount can be administered in one or more doses. As used herein, "activity-reducing amount" refers to the amount of antagonist required to reduce the activity of an enzyme compared to the absence of antagonist. As used herein, "function-interfering amount" refers to the amount of antagonist required to interfere with the function of an enzyme or protein compared to the absence of antagonist. The exact amount depends on the purpose of treatment and can be ascertained by those skilled in the art using known techniques (see, for example, Lieberman, Pharmaceutical Dosage Forms (vols.1-3, 1992); Lloyd, The Art, Science and Technology of Pharmaceutical Compounding (1999); Pickar, Dosage Calculations (1999); and Remington: The Science and Practice of Pharmacy, 20th Edition, 2003, Gennaro, Ed., Lippincott, Williams & Wilkins).

[0091] For any compound (antibody or other agent) described herein, the therapeutically effective amount can be initially determined from cell culture assays. The target concentration will be the concentration of active compound(s) that is capable of achieving the methods described herein, as measured using methods described herein or known in the art.

[0092] As is well known in the art, the therapeutically effective amount used in humans can also be determined from animal models.For example, human doses can be formulated to achieve the concentration found to be effective in animals.Human dosages can be adjusted by monitoring the effectiveness of the compound and adjusting the dosage upwards or downwards, as described above.Based on the above and other methods, it is well within the capabilities of those skilled in the art to adjust dosages to achieve maximum effectiveness in humans.

[0093] The term "therapeutically effective amount" as used herein refers to an amount of a therapeutic agent sufficient to improve a disorder, as described above. For example, for a given parameter, a therapeutically effective amount will show an increase or decrease of at least 5%, 10%, 15%, 20%, 25%, 40%, 50%, 60%, 75%, 80%, 90%, or at least 100%. Therapeutic efficacy can also be expressed as an increase or decrease of "-fold". For example, a therapeutically effective amount can have an effect of at least 1.2-fold, 1.5-fold, 2-fold, or 5-fold or more than that of a control.

[0094] Dosage may vary depending on the patient's requirements and the compound used. In light of the present disclosure, the dose administered to a patient should be sufficient to cause the patient to have a beneficial therapeutic response over time. The size of the dose will also be determined by the existence, nature, and extent of any adverse side effects. Determining the appropriate dosage in a particular situation is within the ability of one of ordinary skill in the art. Generally, treatment is initiated with a smaller dosage that is less than the optimal dose of the compound. Thereafter, dosage is increased by small increments until the optimal effect is reached under the circumstances. Dosage amount and interval can be individually adjusted to provide a level of administered compound that is effective for the particular clinical indication being treated. This will provide a treatment plan that is appropriate to the severity of the individual's condition.

[0095] As used herein, the term "administering" refers to oral administration, administration as a suppository, topical contact, intravenous, parenteral, intraperitoneal, intramuscular, intralesional, intrathecal, intranasal, or subcutaneous administration, or implantation of a sustained release device, such as a mini-osmotic pump, to a subject. Administration is by any route, including parenteral and transmucosal (e.g., buccal, sublingual, palatal, gingival, nasal, vaginal, rectal, or transdermal). Parenteral administration includes, for example, intravenous, intramuscular, intraarteriolar, intradermal, subcutaneous, intraperitoneal, intraventricular, and intracranial administration. Other modes of delivery include, but are not limited to, the use of liposomal formulations, intravenous infusion, transdermal patches, and the like. In embodiments, administration does not include administration of any active agent other than the listed active agents.

[0096] "Co-administer" means that the compositions described herein are administered simultaneously, immediately before, or immediately after the administration of one or more additional therapeutic agents. The compounds provided herein can be administered alone or simultaneously to a patient. Co-administration is intended to include simultaneous or sequential administration of the compounds, individually or in combination (two or more compounds). Thus, the preparations can also be combined with other active substances, if desired (e.g., to reduce metabolic degradation). The compositions of the present disclosure can be delivered transdermally by topical route, or formulated as applicator sticks, solutions, suspensions, emulsions, gels, creams, ointments, pastes, jellies, paints, powders, and aerosols.

[0097] A cancer model organism as used herein is an organism that exhibits a phenotype that indicates cancer or the activity of a factor that causes cancer in the organism. The term cancer is defined above. A wide variety of organisms can serve as a cancer model organism, including, for example, cancer cells and mammalian organisms such as rodents (e.g., mice or rats) and primates (e.g., humans). A cancer cell line is generally understood by those skilled in the art as a cell that exhibits a phenotype or genotype similar to cancer in vivo. A cancer cell line as used herein includes cell lines derived from animals (e.g., mice) and humans.

[0098] The term "infection" or "infectious disease" refers to a disease or condition that may be caused by an organism such as a bacterium, a virus, a fungus, or any other pathogenic microbial agent. In embodiments, the infectious disease is caused by a pathogenic bacterium. A pathogenic bacterium is a bacterium that causes disease (e.g., in humans). In embodiments, the infectious disease is a bacteria-related disease (e.g., tuberculosis caused by Mycobacterium tuberculosis). Non-limiting bacteria-related diseases include pneumonia, which may be caused by bacteria such as Streptococcus and Pseudomonas, or food poisoning, which may be caused by bacteria such as Shigella, Campylobacter, and Salmonella. Bacteria-related diseases also include tetanus, typhoid, diphtheria, syphilis, and leprosy. In embodiments, the disease is bacterial vaginosis (i.e., bacteria that alter the vaginal microbiome caused by bacterial overgrowth that crowds out Lactobacilli species that maintain a healthy vaginal microbiome) (e.g., yeast infection, or Trichomonas vaginalis), bacterial meningitis (i.e., bacterial inflammation of the meninges), bacterial pneumonia (i.e., bacterial infection of the lungs), urinary tract infection, bacterial gastroenteritis, or bacterial skin infection (impetigo, or cellulitis). In embodiments, the infectious disease is an infection with Campylobacter jejuni, Enterococcus faecalis, Haemophilus influenzae, Helicobacter pylori, Klebsiella pneumoniae, Legionella pneumophila, Neisseria gonorrhoeae, Neisseria meningitides, Staphylococcus aureus, Streptococcus pneumonia, or Vibrio cholera.

[0099] Terms such as "immune response" refer in their normal, customary sense to a response by an organism that protects against disease. The response can be initiated by the innate immune system or by the adaptive immune system, as is well known in the art.

[0100] "Modulating an immune response" and the like terms refer to a change in a subject's immune response as a result of administration of an agent, e.g., a compound disclosed herein, including embodiments thereof. Thus, the immune response can be activated or inactivated as a result of administration of an agent, e.g., a compound disclosed herein, including embodiments thereof.

[0101] "B cell" or "B lymphocyte" refer to standard usage in the art. B cells are lymphocytes, a type of white blood cell (leukocyte), that develop into plasma cells ("mature B cells") and produce antibodies. "Immature B cells" are cells that can develop into mature B cells. Generally, pro-B cells undergo immunoglobulin heavy chain rearrangement to become pro-B pre-B cells, which then undergo immunoglobulin light chain rearrangement to become immature B cells. Immature B cells include T1 and T2 B cells.

[0102] As used herein, "T cells" or "T lymphocytes" are a type of lymphocyte (a subtype of white blood cells) that play a central role in cell-mediated immunity. They can be distinguished from other lymphocytes, such as B cells and natural killer cells, by the presence of T cell receptors on the cell surface. T cells include, for example, natural killer T (NKT) cells, cytotoxic T lymphocytes (CTL), regulatory T (Treg) cells, and T helper cells. Various types of T cells can be distinguished by using T cell detection agents.

[0103] The term "CD4" as referred to herein is a glycoprotein expressed on the surface of T helper cells, regulatory T cells, monocytes, macrophages, and dendritic cells. CD4 was originally known as leu-3 and T4 (after the OKT4 monoclonal antibody). CD4 as referred to herein has four immunoglobulin domains (D1-D4) exposed on the extracellular surface of the cell. ENTREZ No. 920, UNIPROT No. P01730, and GENBANK® Accession No. NP, incorporated by reference. - See 000607.

[0104] The term "CD8" as referred to herein is a transmembrane glycoprotein that functions as a co-receptor for the T cell receptor (TCR). Like the TCR, CD8 binds to major histocompatibility complex (MHC) molecules, but is specific for class I MHC proteins. See ENTREZ No. 925 and UNIPROT No. P01732, which are incorporated herein by reference.

[0105] The term "CD19 protein" or "CD19" as used herein includes any recombinant or native form of the B lymphocyte antigen CD19, also known as the CD19 molecule (surface antigen cluster 19), the B lymphocyte surface antigen B4, the T cell surface antigen Leu-12, and CVID3, or a variant or homolog thereof that maintains CD19 activity (e.g., within at least 50%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, or 100% activity compared to CD19). In some embodiments, the variant or homolog has at least 90%, 95%, 96%, 97%, 98%, 99%, or 100% amino acid sequence identity over the entire sequence or a portion of the sequence (e.g., a portion of 50, 100, 150, or 200 contiguous amino acids) compared to a naturally occurring CD19 protein. In various embodiments, the CD19 protein is substantially identical to the protein identified by UniProt reference number P15391, or a variant or homolog having substantial identity thereto.

[0106] The "CD73 level" referred to herein is the level of CD73 expressed by the tumor.

[0107] An "elevated level of CD73" as referred to herein is an elevated level of CD73 expressed (e.g., mRNA, protein) by a tumor of a subject when compared to a control. CD73 levels can be measured from a biological sample, such as a tumor sample (e.g., resection, biopsy) or a blood sample (e.g., peripheral blood) obtained from a subject. The tumor can be a primary tumor or metastatic. The tumors provided herein are cell masses that include cancer cells and non-cancer cells. The non-cancer cells that form part of the tumor can be stromal cells and immune cells (e.g., T cells, dendritic cells, B cells, macrophages). Thus, the elevated level of CD73 can be expressed by non-cancer cells (e.g., stromal cells) or cancer cells (e.g., malignant T cells). This term is further defined herein.

[0108] "Anti-CD73 compound" refers to any compound (e.g., small molecule, peptide, protein, antibody) capable of binding to CD73 or otherwise inhibiting the ability of CD73 to exert its normal function in the adenosine pathway. In embodiments, the anti-CD73 compound is an anti-CD73 antibody. Exemplary anti-CD73 antibodies include 1E9 antibody, IgG1 antibody, humanized 1E9 antibody, humanized IgG1 antibody, and the like.

[0109] "Biological sample" refers to any biological sample taken from a subject. Biological samples include blood, plasma, serum, tumor, tissue, cells, and the like. In aspects, the biological sample is a blood sample. In aspects, the biological sample is a peripheral blood sample. In aspects, the biological sample is a tumor sample. In aspects, the biological sample is a primary tumor sample. In aspects, the biological sample is a metastatic tumor sample. In aspects, the biological sample is a resected tumor sample. In aspects, the biological sample is a tumor biopsy sample. In aspects, the biological sample is a tumor sample resected from a primary tumor. In aspects, the biological sample is a tumor sample resected from a metastatic tumor. In aspects, the biological sample is a tumor biopsy sample from a primary tumor. In aspects, the biological sample is a tumor biopsy sample from a metastatic tumor. Biological samples may be taken from a subject by methods known in the art and analyzed by methods known in the art.

[0110] As used herein, "treating cancer" and "treating a cancer tumor" refer to preventing an increase in size or volume of a cancer tumor. In embodiments, the cancer tumor is a solid tumor. In embodiments, treating a cancer tumor includes reducing the size of the volume of the cancer tumor. In embodiments, treating a cancer tumor includes eliminating the cancer tumor completely. In embodiments, a cancer tumor is eliminated when it cannot be detected by imaging tests such as magnetic resonance imaging (MRI), positron emission tomography (PET) scan, X-ray computed tomography (CT), ultrasound, or single photon emission computed tomography (SPECT). In embodiments, treating a cancer tumor further includes reducing or preventing metastasis of the cancer tumor.

[0111] Anti-CD73 antibody The anti-CD73 antibodies used in the methods and included in the compositions provided herein, including embodiments, can, among other things, bind to CD73 protein and inhibit CD73 catalytic activity, thereby preventing metastasis. Any of the anti-CD73 antibodies (e.g., 1E9 antibody) described in WO2017 / 100670 can be used in the methods and compositions provided herein, which is incorporated by reference in its entirety for all purposes. The following embodiments described below are applicable to the methods and compositions provided herein, including embodiments thereof.

[0112] The antibodies provided herein bind to CD73 protein, activate and redistribute B cells, and can include the CDRs (CDR L1, CDR L2, CDR L3, CDR H1, CDR H2, and CDR H3) of the murine monoclonal antibody 1E9, or functional fragments thereof (also referred to herein as 1E9 antibodies) (Thomson LF et al. Tissue Antigens 2008, Volume 35, Issue 1: Production and characterization of monoclonal antibodies to the glycosyl phosphatidylinositol-anchored lymphocyte differentiation antigen ecto-5′-nucleotidase (CD73)). The antibodies described herein, including this embodiment, can be used in any of the methods or compositions described herein and below.

[0113] The anti-CD73 antibodies provided herein may comprise a humanized light chain variable region comprising 1E9 antibody CDR L1, 1E9 antibody CDR L2, and 1E9 antibody CDR L3, and a humanized heavy chain variable region comprising 1E9 antibody CDR H1, 1E9 antibody CDR H2, and 1E9 antibody CDR H3. In embodiments, CDR L1 has the sequence of SEQ ID NO:1, CDR L2 has the sequence of SEQ ID NO:2, CDR L3 has the sequence of SEQ ID NO:3, CDR H1 has the sequence of SEQ ID NO:4, CDR H2 has the sequence of SEQ ID NO:5, and CDR H3 has the sequence of SEQ ID NO:6. In embodiments, the humanized light chain variable region comprises at least one binding framework region residue. In embodiments, the humanized heavy chain variable region comprises at least one binding framework region residue. Framework region residues involved (or important) in epitope binding (e.g., CD73 binding) are referred to herein as binding framework region residues. The binding framework region residues may be present in the framework region of the humanized light chain variable region (i.e., FR L1, FR L2, FR L3, FR L4) or may be present in the framework of the humanized heavy chain variable region (i.e., FR H1, FR H2, FR H3, FR H4). The binding framework region residues present in the FR L3 region of the humanized light chain are referred to herein as FR L3 binding framework region residues. Thus, the binding framework region residues present in the FR H3 region of the humanized heavy chain are referred to herein as FR H3 binding framework region residues.

[0114] The anti-CD73 antibodies provided herein may comprise a humanized light chain variable region and a humanized heavy chain variable region. The humanized light chain variable region comprises: (i) CDR L1 set forth in SEQ ID NO: 1, CDR L2 set forth in SEQ ID NO: 2, CDR L3 set forth in SEQ ID NO: 3, CDR L4 set forth in SEQ ID NO: 4, CDR L5 set forth in SEQ ID NO: 5, CDR L6 set forth in SEQ ID NO: 6, CDR L7 set forth in SEQ ID NO: 7, CDR L8 set forth in SEQ ID NO: 8, CDR L9 set forth in SEQ ID NO: 9, CDR L10 set forth in SEQ ID NO: 10, CDR L11 set forth in SEQ ID NO: 11, CDR L12 set forth in SEQ ID NO: 12, CDR L13 set forth in SEQ ID NO: 13, CDR L14 set forth in SEQ ID NO: L3, and (ii) a valine at position corresponding to Kabat position 2, a methionine at position corresponding to Kabat position 4, an aspartic acid or leucine at position corresponding to Kabat position 9, a proline or serine at position corresponding to Kabat position 12, a lysine or proline at position corresponding to Kabat position 18, an alanine at position corresponding to Kabat position 43, a proline or serine at position corresponding to Kabat position 60, a threonine at position corresponding to Kabat position 74, an asparagine or serine at position corresponding to Kabat position 76, an asparagine or serine at position corresponding to Kabat position 77, an isoleucine or leucine at position corresponding to Kabat position 78, a serine or alanine at position corresponding to Kabat position 80, a glutamine at position corresponding to Kabat position 100, a valine at position corresponding to Kabat position 104, a glutamic acid or alanine at position corresponding to Kabat position 1 and / or arginine at Kabat position 45; isoleucine at Kabat position 58; tyrosine at Kabat position 67; phenylalanine at Kabat position 73; tyrosine at Kabat position 85; or phenylalanine at Kabat position 87.

[0115] The humanized heavy chain variable region comprises (i) murine CDR H1 set forth in SEQ ID NO:4, murine CDR H2 set forth in SEQ ID NO:5, and murine CDR H3 set forth in SEQ ID NO:6, and (ii) an isoleucine at position corresponding to Kabat position 37, an alanine or proline at position corresponding to Kabat position 40, a lysine at position corresponding to Kabat position 43, a serine at position corresponding to Kabat position 70, an isoleucine or threonine at position corresponding to Kabat position 75, a tryptophan at position corresponding to Kabat position 82, an arginine or lysine at position corresponding to Kabat position 83, an alanine at position corresponding to Kabat position 84, a serine at position corresponding to Kabat position 85, a valine or methionine at position corresponding to Kabat position 89, a valine at position corresponding to Kabat position 5, a serine at position corresponding to Kabat position 7, a valine at position corresponding to Kabat position 11, a valine at position corresponding to Kabat position 12, and a tryptophan at position corresponding to Kabat position 13. It may contain glutamic acid or lysine, isoleucine or valine at the position corresponding to Kabat position 20, arginine at the position corresponding to Kabat position 38, arginine at the position corresponding to Kabat position 66, valine at the position corresponding to Kabat position 67, isoleucine at the position corresponding to Kabat position 69, alanine at the position corresponding to Kabat position 71, lysine at the position corresponding to Kabat position 73, threonine at the position corresponding to Kabat position 87, glutamic acid at the position corresponding to Kabat position 1, valine at the position corresponding to Kabat position 24, arginine at the position corresponding to Kabat position 44, methionine at the position corresponding to Kabat position 48, leucine at the position corresponding to Kabat position 80, or glutamic acid at the position corresponding to Kabat position 81.

[0116] In various embodiments, the humanized light chain variable region comprises a binding framework region residue that is a valine at a position corresponding to Kabat position 2, a methionine at a position corresponding to Kabat position 4, an aspartic acid or leucine at a position corresponding to Kabat position 9, a proline or serine at a position corresponding to Kabat position 12, a lysine or proline at a position corresponding to Kabat position 18, an alanine at a position corresponding to Kabat position 43, a proline or serine at a position corresponding to Kabat position 60, a threonine at a position corresponding to Kabat position 74, an asparagine or serine at a position corresponding to Kabat position 76, an asparagine or serine at a position corresponding to Kabat position 77, an isoleucine or leucine at a position corresponding to Kabat position 78, a serine or alanine at a position corresponding to Kabat position 80, a glutamine at a position corresponding to Kabat position 100, a valine at a position corresponding to Kabat position 104, a lysine or proline at a position corresponding to Kabat position 106, a lysine or proline at a position corresponding to Kabat position 110, a lysine or proline at a position corresponding to Kabat position 122, a lysine or proline at a position corresponding to Kabat position 126, a threonine at a position corresponding to Kabat position 74, a threonine at a position corresponding to Kabat position 76, a lysine or serine at a position corresponding to Kabat position 77, a lysine or serine at a position corresponding to Kabat position 78, a lysine or alanine at a position corresponding to Kabat position 80, a lysine or alanine at a position corresponding to Kabat position 82, a lysine or alanine at a position corresponding to Kabat position 84, a lysine or alanine at a position corresponding at position corresponding to Kabat position 16; glutamic acid or aspartic acid at position corresponding to Kabat position 17; threonine at position corresponding to Kabat position 22; lysine at position corresponding to Kabat position 42; arginine at position corresponding to Kabat position 45; isoleucine at position corresponding to Kabat position 58; tyrosine at position corresponding to Kabat position 67; phenylalanine at position corresponding to Kabat position 73; tyrosine at position corresponding to Kabat position 85; or phenylalanine at position corresponding to Kabat position 87.

[0117] In embodiments, the humanized light chain variable region comprises a combining framework region residue that is a valine at a position corresponding to Kabat position 2. In aspects, the humanized light chain variable region comprises a combining framework region residue that is a methionine at a position corresponding to Kabat position 4. In aspects, the humanized light chain variable region comprises a combining framework region residue that is an aspartic acid or a leucine at a position corresponding to Kabat position 9. In aspects, the humanized light chain variable region comprises a combining framework region residue that is a proline or a serine at a position corresponding to Kabat position 12. In aspects, the humanized light chain variable region comprises a combining framework region residue that is a lysine or a proline at a position corresponding to Kabat position 18. In aspects, the humanized light chain variable region comprises a combining framework region residue that is an alanine at a position corresponding to Kabat position 43. In aspects, the humanized light chain variable region comprises a combining framework region residue that is a proline or a serine at a position corresponding to Kabat position 60.

[0118] In embodiments, the humanized light chain variable region comprises a connecting framework region residue that is a threonine at a position corresponding to Kabat position 74. In aspects, the humanized light chain variable region comprises a connecting framework region residue that is an asparagine or serine at a position corresponding to Kabat position 76. In aspects, the humanized light chain variable region comprises a connecting framework region residue that is an asparagine or serine at a position corresponding to Kabat position 77. In aspects, the humanized light chain variable region comprises a connecting framework region residue that is an isoleucine or leucine at a position corresponding to Kabat position 78. In aspects, the humanized light chain variable region comprises a connecting framework region residue that is a serine or alanine at a position corresponding to Kabat position 80. In aspects, the humanized light chain variable region comprises a connecting framework region residue that is a glutamine at a position corresponding to Kabat position 100. In aspects, the humanized light chain variable region comprises a connecting framework region residue that is a valine at a position corresponding to Kabat position 104. In embodiments, the humanized light chain variable region comprises a combining framework region residue that is a glutamic acid or an alanine at the position corresponding to Kabat position 1. In embodiments, the humanized light chain variable region comprises a combining framework region residue that is a glutamine at the position corresponding to Kabat position 3.

[0119] In embodiments, the humanized light chain variable region comprises a combining framework region residue that is a phenylalanine or a threonine at a position corresponding to Kabat position 10. In aspects, the humanized light chain variable region comprises a combining framework region residue that is a glutamine at a position corresponding to Kabat position 11. In aspects, the humanized light chain variable region comprises a combining framework region residue that is an alanine or a leucine at a position corresponding to Kabat position 13. In aspects, the humanized light chain variable region comprises a combining framework region residue that is a threonine at a position corresponding to Kabat position 14. In aspects, the humanized light chain variable region comprises a combining framework region residue that is a valine or a proline at a position corresponding to Kabat position 15. In aspects, the humanized light chain variable region comprises a combining framework region residue that is a lysine at a position corresponding to Kabat position 16. In aspects, the humanized light chain variable region comprises a combining framework region residue that is a glutamic acid or an aspartic acid at a position corresponding to Kabat position 17. In embodiments, the humanized light chain variable region comprises a binding framework region residue that is a threonine at the position corresponding to Kabat position 22.

[0120] In embodiments, the humanized light chain variable region comprises a connecting framework region residue that is a lysine at a position corresponding to Kabat position 42. In aspects, the humanized light chain variable region comprises a connecting framework region residue that is an arginine at a position corresponding to Kabat position 45. In aspects, the humanized light chain variable region comprises a connecting framework region residue that is an isoleucine at a position corresponding to Kabat position 58. In aspects, the humanized light chain variable region comprises a connecting framework region residue that is a tyrosine at a position corresponding to Kabat position 67. In aspects, the humanized light chain variable region comprises a connecting framework region residue that is a phenylalanine at a position corresponding to Kabat position 73. In aspects, the humanized light chain variable region comprises a connecting framework region residue that is an isoleucine at a position corresponding to Kabat position 78. In aspects, the humanized light chain variable region comprises a connecting framework region residue that is a tyrosine at a position corresponding to Kabat position 85. In aspects, the humanized light chain variable region comprises a connecting framework region residue that is a phenylalanine at a position corresponding to Kabat position 87.

[0121] The humanized heavy chain variable regions provided herein comprise a binding framework region residue that is an isoleucine at position corresponding to Kabat position 37, an alanine or proline at position corresponding to Kabat position 40, a lysine at position corresponding to Kabat position 43, a serine at position corresponding to Kabat position 70, an isoleucine or threonine at position corresponding to Kabat position 75, a tryptophan at position corresponding to Kabat position 82, an arginine or lysine at position corresponding to Kabat position 83, an alanine at position corresponding to Kabat position 84, a serine at position corresponding to Kabat position 85, a valine or methionine at position corresponding to Kabat position 89, a valine at position corresponding to Kabat position 5, a serine at position corresponding to Kabat position 7, and a valine at position corresponding to Kabat position 11. , glutamic acid or lysine at position corresponding to Kabat position 12, isoleucine or valine at position corresponding to Kabat position 20, arginine at position corresponding to Kabat position 38, arginine at position corresponding to Kabat position 66, valine at position corresponding to Kabat position 67, isoleucine at position corresponding to Kabat position 69, alanine at position corresponding to Kabat position 71, lysine at position corresponding to Kabat position 73, threonine at position corresponding to Kabat position 87, glutamic acid at position corresponding to Kabat position 1, valine at position corresponding to Kabat position 24, arginine at position corresponding to Kabat position 44, methionine at position corresponding to Kabat position 48, leucine at position corresponding to Kabat position 80, or glutamic acid at position corresponding to Kabat position 81.

[0122] In embodiments, the humanized heavy chain variable region comprises a connecting framework region residue that is isoleucine at a position corresponding to Kabat position 37. In aspects, the humanized heavy chain variable region comprises a connecting framework region residue that is alanine or proline at a position corresponding to Kabat position 40. In aspects, the humanized heavy chain variable region comprises a connecting framework region residue that is lysine at a position corresponding to Kabat position 43. In aspects, the humanized heavy chain variable region comprises a connecting framework region residue that is serine at a position corresponding to Kabat position 70. In aspects, the humanized heavy chain variable region comprises a connecting framework region residue that is isoleucine or threonine at a position corresponding to Kabat position 75. In aspects, the humanized heavy chain variable region comprises a connecting framework region residue that is tryptophan at a position corresponding to Kabat position 82. In aspects, the humanized heavy chain variable region comprises a connecting framework region residue that is arginine or lysine at a position corresponding to Kabat position 83. In embodiments, the humanized heavy chain variable region comprises a binding framework region residue at the position corresponding to Kabat position 84 that is an alanine.

[0123] In embodiments, the humanized heavy chain variable region comprises a connecting framework region residue that is a serine at a position corresponding to Kabat position 85. In aspects, the humanized heavy chain variable region comprises a connecting framework region residue that is a valine or a methionine at a position corresponding to Kabat position 89. In aspects, the humanized heavy chain variable region comprises a connecting framework region residue that is a valine at a position corresponding to Kabat position 5. In aspects, the humanized heavy chain variable region comprises a connecting framework region residue that is a serine at a position corresponding to Kabat position 7. In aspects, the humanized heavy chain variable region comprises a connecting framework region residue that is a valine at a position corresponding to Kabat position 11. In aspects, the humanized heavy chain variable region comprises a connecting framework region residue that is a glutamic acid or a lysine at a position corresponding to Kabat position 12. In aspects, the humanized heavy chain variable region comprises a connecting framework region residue that is an isoleucine or a valine at a position corresponding to Kabat position 20. In embodiments, the humanized heavy chain variable region comprises a combining framework region residue that is an arginine at the position corresponding to Kabat position 38. In embodiments, the humanized heavy chain variable region comprises a combining framework region residue that is an arginine at the position corresponding to Kabat position 66. In embodiments, the humanized heavy chain variable region comprises a combining framework region residue that is a valine at the position corresponding to Kabat position 67.

[0124] In embodiments, the humanized heavy chain variable region comprises a connecting framework region residue that is isoleucine at a position corresponding to Kabat position 69. In aspects, the humanized heavy chain variable region comprises a connecting framework region residue that is alanine at a position corresponding to Kabat position 71. In aspects, the humanized heavy chain variable region comprises a connecting framework region residue that is lysine at a position corresponding to Kabat position 73. In aspects, the humanized heavy chain variable region comprises a connecting framework region residue that is threonine at a position corresponding to Kabat position 87. In aspects, the humanized heavy chain variable region comprises a connecting framework region residue that is glutamic acid at a position corresponding to Kabat position 1. In aspects, the humanized heavy chain variable region comprises a connecting framework region residue that is valine at a position corresponding to Kabat position 24. In aspects, the humanized heavy chain variable region comprises a connecting framework region residue that is arginine at a position corresponding to Kabat position 44. In aspects, the humanized heavy chain variable region comprises a connecting framework region residue that is methionine at a position corresponding to Kabat position 48. In embodiments, the humanized heavy chain variable region comprises a combining framework region residue that is a leucine at the position corresponding to Kabat position 80. In embodiments, the humanized heavy chain variable region comprises a combining framework region residue that is a glutamic acid at the position corresponding to Kabat position 81.

[0125] In various embodiments, the humanized light chain variable region comprises a valine at position corresponding to Kabat position 2, a methionine at position corresponding to Kabat position 4, a leucine at position corresponding to Kabat position 9, a proline at position corresponding to Kabat position 12, or a proline at position corresponding to Kabat position 18, and the humanized heavy chain variable region comprises an isoleucine at position corresponding to Kabat position 37, a proline at position corresponding to Kabat position 40, a lysine at position corresponding to Kabat position 43, a serine at position corresponding to Kabat position 70, an isoleucine at position corresponding to Kabat position 75, a tryptophan at position corresponding to Kabat position 82, a lysine at position corresponding to Kabat position 83, an alanine at position corresponding to Kabat position 84, a serine at position corresponding to Kabat position 85, or a methionine at position corresponding to Kabat position 89.

[0126] In various embodiments, the humanized light chain variable region comprises a valine at position corresponding to Kabat position 2, a methionine at position corresponding to Kabat position 4, a leucine at position corresponding to Kabat position 9, a proline at position corresponding to Kabat position 12, and a proline at position corresponding to Kabat position 18, and the humanized heavy chain variable region comprises an isoleucine at position corresponding to Kabat position 37, a proline at position corresponding to Kabat position 40, a lysine at position corresponding to Kabat position 43, a serine at position corresponding to Kabat position 70, an isoleucine at position corresponding to Kabat position 75, a tryptophan at position corresponding to Kabat position 82, a lysine at position corresponding to Kabat position 83, an alanine at position corresponding to Kabat position 84, a serine at position corresponding to Kabat position 85, or a methionine at position corresponding to Kabat position 89.

[0127] In various embodiments, the humanized light chain variable region comprises a valine at position corresponding to Kabat position 2, a methionine at position corresponding to Kabat position 4, a leucine at position corresponding to Kabat position 9, a proline at position corresponding to Kabat position 12, or a proline at position corresponding to Kabat position 18, and the humanized heavy chain variable region comprises an isoleucine at position corresponding to Kabat position 37, a proline at position corresponding to Kabat position 40, a lysine at position corresponding to Kabat position 43, a serine at position corresponding to Kabat position 70, an isoleucine at position corresponding to Kabat position 75, a tryptophan at position corresponding to Kabat position 82, a lysine at position corresponding to Kabat position 83, an alanine at position corresponding to Kabat position 84, a serine at position corresponding to Kabat position 85, and a methionine at position corresponding to Kabat position 89.

[0128] In embodiments, the humanized light chain variable region comprises a valine at position corresponding to Kabat position 2, a methionine at position corresponding to Kabat position 4, a leucine at position corresponding to Kabat position 9, a proline at position corresponding to Kabat position 12, and a proline at position corresponding to Kabat position 18; and the humanized heavy chain variable region comprises an isoleucine at position corresponding to Kabat position 37, a proline at position corresponding to Kabat position 40, a lysine at position corresponding to Kabat position 43, a serine at position corresponding to Kabat position 70, an isoleucine at position corresponding to Kabat position 75, a tryptophan at position corresponding to Kabat position 82, a lysine at position corresponding to Kabat position 83, an alanine at position corresponding to Kabat position 84, a serine at position corresponding to Kabat position 85, and a methionine at position corresponding to Kabat position 89.

[0129] In various embodiments, the humanized light chain variable region comprises a proline or serine at position corresponding to Kabat position 12, an alanine at position corresponding to Kabat position 43, a proline or serine at position corresponding to Kabat position 60, a threonine at position corresponding to Kabat position 74, an asparagine or serine at position corresponding to Kabat position 76, an asparagine or serine at position corresponding to Kabat position 77, an isoleucine or leucine at position corresponding to Kabat position 78, a serine or alanine at position corresponding to Kabat position 80, a glutamine at position corresponding to Kabat position 100, or a valine at position corresponding to Kabat position 104; and the humanized heavy chain variable region comprises a valine at position corresponding to Kabat position 5, a ribozyme at position corresponding to Kabat position 6, a ribozyme at position corresponding to Kabat position 7, a ribozyme at position corresponding to Kabat position 8, a ribozyme at position corresponding to Kabat position 9, a ribozyme at position corresponding to Kabat position 10, or a valine at position corresponding to Kabat position 110. at position corresponding to Kabat position 73, isoleucine or threonine at position corresponding to Kabat position 75, arginine at position corresponding to Kabat position 73, valine at position corresponding to Kabat position 11, glutamic acid or lysine at position corresponding to Kabat position 12, isoleucine or valine at position corresponding to Kabat position 20, arginine at position corresponding to Kabat position 38, alanine or proline at position corresponding to Kabat position 40, arginine at position corresponding to Kabat position 66, valine at position corresponding to Kabat position 67, isoleucine at position corresponding to Kabat position 69, alanine at position corresponding to Kabat position 71, lysine at position corresponding to Kabat position 73, isoleucine or threonine at position corresponding to Kabat position 75, arginine or lysine at position corresponding to Kabat position 83, or threonine at position corresponding to Kabat position 87.

[0130] In embodiments, the humanized light chain variable region comprises a proline or serine at position corresponding to Kabat position 12, an alanine at position corresponding to Kabat position 43, a proline or serine at position corresponding to Kabat position 60, a threonine at position corresponding to Kabat position 74, an asparagine or serine at position corresponding to Kabat position 76, an asparagine or serine at position corresponding to Kabat position 77, an isoleucine or leucine at position corresponding to Kabat position 78, a serine or alanine at position corresponding to Kabat position 80, a glutamine at position corresponding to Kabat position 100, and a valine at position corresponding to Kabat position 104; and the humanized heavy chain variable region comprises a valine at position corresponding to Kabat position 5, a ribozyme at position corresponding to Kabat position 6, a ribozyme at position corresponding to Kabat position 7, and a ribozyme at position corresponding to Kabat position 8. at position corresponding to Kabat position 73, isoleucine or threonine at position corresponding to Kabat position 75, arginine at position corresponding to Kabat position 73, valine at position corresponding to Kabat position 11, glutamic acid or lysine at position corresponding to Kabat position 12, isoleucine or valine at position corresponding to Kabat position 20, arginine at position corresponding to Kabat position 38, alanine or proline at position corresponding to Kabat position 40, arginine at position corresponding to Kabat position 66, valine at position corresponding to Kabat position 67, isoleucine at position corresponding to Kabat position 69, alanine at position corresponding to Kabat position 71, lysine at position corresponding to Kabat position 73, isoleucine or threonine at position corresponding to Kabat position 75, arginine or lysine at position corresponding to Kabat position 83, or threonine at position corresponding to Kabat position 87.

[0131] In various embodiments, the humanized light chain variable region comprises a proline or serine at position corresponding to Kabat position 12, an alanine at position corresponding to Kabat position 43, a proline or serine at position corresponding to Kabat position 60, a threonine at position corresponding to Kabat position 74, an asparagine or serine at position corresponding to Kabat position 76, an asparagine or serine at position corresponding to Kabat position 77, an isoleucine or leucine at position corresponding to Kabat position 78, a serine or alanine at position corresponding to Kabat position 80, a glutamine at position corresponding to Kabat position 100, or a valine at position corresponding to Kabat position 104; and the humanized heavy chain variable region comprises a valine at position corresponding to Kabat position 5, a ribozyme at position corresponding to Kabat position 6, a ribozyme at position corresponding to Kabat position 7, a ribozyme at position corresponding to Kabat position 8, a ribozyme at position corresponding to Kabat position 9, a ribozyme at position corresponding to Kabat position 10, or a valine at position corresponding to Kabat position 110. at Kabat position 71, a valine at position corresponding to Kabat position 11, a glutamic acid or lysine at position corresponding to Kabat position 12, an isoleucine or valine at position corresponding to Kabat position 20, an arginine at position corresponding to Kabat position 38, an alanine or proline at position corresponding to Kabat position 40, an arginine at position corresponding to Kabat position 66, a valine at position corresponding to Kabat position 67, an isoleucine at position corresponding to Kabat position 69, an alanine at position corresponding to Kabat position 71, a lysine at position corresponding to Kabat position 73, an isoleucine or threonine at position corresponding to Kabat position 75, an arginine or lysine at position corresponding to Kabat position 83, and a threonine at position corresponding to Kabat position 87.

[0132] In embodiments, the humanized light chain variable region comprises a proline or serine at position corresponding to Kabat position 12, an alanine at position corresponding to Kabat position 43, a proline or serine at position corresponding to Kabat position 60, a threonine at position corresponding to Kabat position 74, an asparagine or serine at position corresponding to Kabat position 76, an asparagine or serine at position corresponding to Kabat position 77, an isoleucine or leucine at position corresponding to Kabat position 78, a serine or alanine at position corresponding to Kabat position 80, a glutamine at position corresponding to Kabat position 100, and a valine at position corresponding to Kabat position 104; and the humanized heavy chain variable region comprises a valine at position corresponding to Kabat position 5, a ribozyme at position corresponding to Kabat position 6, a ribozyme at position corresponding to Kabat position 7, and a ribozyme at position corresponding to Kabat position 8. at Kabat position 71, a valine at position corresponding to Kabat position 11, a glutamic acid or lysine at position corresponding to Kabat position 12, an isoleucine or valine at position corresponding to Kabat position 20, an arginine at position corresponding to Kabat position 38, an alanine or proline at position corresponding to Kabat position 40, an arginine at position corresponding to Kabat position 66, a valine at position corresponding to Kabat position 67, an isoleucine at position corresponding to Kabat position 69, an alanine at position corresponding to Kabat position 71, a lysine at position corresponding to Kabat position 73, an isoleucine or threonine at position corresponding to Kabat position 75, an arginine or lysine at position corresponding to Kabat position 83, and a threonine at position corresponding to Kabat position 87.

[0133] In various embodiments, the humanized light chain variable region comprises a glutamic acid or alanine at position corresponding to Kabat position 1, a valine at position corresponding to Kabat position 2, a glutamine at position corresponding to Kabat position 3, a methionine at position corresponding to Kabat position 4, an aspartic acid or leucine at position corresponding to Kabat position 9, a phenylalanine or threonine at position corresponding to Kabat position 10, a glutamine at position corresponding to Kabat position 11, a serine or proline at position corresponding to Kabat position 12, an alanine or leucine at position corresponding to Kabat position 13, a threonine at position corresponding to Kabat position 14, a valine or proline at position corresponding to Kabat position 15, a lysine at position corresponding to Kabat position 16, a glutamic acid or aspartic acid at position corresponding to Kabat position 17, a lysine or proline at position corresponding to Kabat position 18, a threonine at position corresponding to Kabat position 22, a lysine at position corresponding to Kabat position 42, an arginine at position corresponding to Kabat position 45, an isoleucine at position corresponding to Kabat position 58, an isoleucine at position corresponding to Kabat position 59, an isoleucine at position corresponding to Kabat position 60, an isoleucine at position corresponding to Kabat position 61, an isoleucine at position corresponding to Kabat position 62, an isoleucine at position corresponding to Kabat position 63, an isoleucine at position corresponding to Kabat position 64, an isoleucine at position corresponding to Kabat position 65, an isoleucine at position corresponding to Kabat position 66, an isoleucine at position corresponding to Kabat position 67, an isoleucine at position corresponding to Kabat position 68, an isoleucine at position corresponding to Kabat position 69, an isoleucine at position corresponding to Kabat position and the humanized heavy chain variable region comprises a proline or serine at position corresponding to Kabat position 60, a tyrosine at position corresponding to Kabat position 67, a phenylalanine at position corresponding to Kabat position 73, an isoleucine at position corresponding to Kabat position 78, a serine or alanine at position corresponding to Kabat position 80, a tyrosine at position corresponding to Kabat position 85, or a phenylalanine at position corresponding to Kabat position 87, and the humanized heavy chain variable region comprises a glutamic acid at position corresponding to Kabat position 1, a valine at position corresponding to Kabat position 24, and an isoleucine at position corresponding to Kabat position 37. at position corresponding to Kabat position 47; an isoleucine at position corresponding to Kabat position 43; a lysine at position corresponding to Kabat position 43; an arginine at position corresponding to Kabat position 44; a methionine at position corresponding to Kabat position 48; a serine at position corresponding to Kabat position 70; a leucine at position corresponding to Kabat position 80; a glutamic acid at position corresponding to Kabat position 81; a tryptophan at position corresponding to Kabat position 82; an alanine at position corresponding to Kabat position 84; a serine at position corresponding to Kabat position 85; or a valine or methionine at position corresponding to Kabat position 89.

[0134] In various embodiments, the humanized light chain variable region comprises a glutamic acid or alanine at position corresponding to Kabat position 1, a valine at position corresponding to Kabat position 2, a glutamine at position corresponding to Kabat position 3, a methionine at position corresponding to Kabat position 4, an aspartic acid or leucine at position corresponding to Kabat position 9, a phenylalanine or threonine at position corresponding to Kabat position 10, a glutamine at position corresponding to Kabat position 11, a serine or proline at position corresponding to Kabat position 12, an alanine or leucine at position corresponding to Kabat position 13, a threonine at position corresponding to Kabat position 14, a valine or proline at position corresponding to Kabat position 15, a lysine at position corresponding to Kabat position 16, a glutamic acid or aspartic acid at position corresponding to Kabat position 17, a lysine or proline at position corresponding to Kabat position 18, a threonine at position corresponding to Kabat position 22, a lysine at position corresponding to Kabat position 42, an arginine at position corresponding to Kabat position 45, an isoleucine at position corresponding to Kabat position 58, an isoleucine at position corresponding to Kabat position 59, an isoleucine at position corresponding to Kabat position 60, an isoleucine at position corresponding to Kabat position 61, an isoleucine at position corresponding to Kabat position 62, an isoleucine at position corresponding to Kabat position 63, an isoleucine at position corresponding to Kabat position 64, an isoleucine at position corresponding to Kabat position 65, an isoleucine at position corresponding to Kabat position 66, an isoleucine at position corresponding to Kabat position 67, an isoleucine at position corresponding to Kabat position 68, an isoleucine at position corresponding to Kabat position 69, an isoleucine at position corresponding to Kabat position and a proline or serine at position corresponding to Kabat position 60, a tyrosine at position corresponding to Kabat position 67, a phenylalanine at position corresponding to Kabat position 73, an isoleucine at position corresponding to Kabat position 78, a serine or alanine at position corresponding to Kabat position 80, a tyrosine at position corresponding to Kabat position 85, and a phenylalanine at position corresponding to Kabat position 87; and the humanized heavy chain variable region comprises a glutamic acid at position corresponding to Kabat position 1, a valine at position corresponding to Kabat position 24, and an isoleucine at position corresponding to Kabat position 37. at position corresponding to Kabat position 47; an isoleucine at position corresponding to Kabat position 43; a lysine at position corresponding to Kabat position 43; an arginine at position corresponding to Kabat position 44; a methionine at position corresponding to Kabat position 48; a serine at position corresponding to Kabat position 70; a leucine at position corresponding to Kabat position 80; a glutamic acid at position corresponding to Kabat position 81; a tryptophan at position corresponding to Kabat position 82; an alanine at position corresponding to Kabat position 84; a serine at position corresponding to Kabat position 85; or a valine or methionine at position corresponding to Kabat position 89.

[0135] In various embodiments, the humanized light chain variable region comprises a glutamic acid or alanine at position corresponding to Kabat position 1, a valine at position corresponding to Kabat position 2, a glutamine at position corresponding to Kabat position 3, a methionine at position corresponding to Kabat position 4, an aspartic acid or leucine at position corresponding to Kabat position 9, a phenylalanine or threonine at position corresponding to Kabat position 10, a glutamine at position corresponding to Kabat position 11, a serine or proline at position corresponding to Kabat position 12, an alanine or leucine at position corresponding to Kabat position 13, a threonine at position corresponding to Kabat position 14, a valine or proline at position corresponding to Kabat position 15, a lysine at position corresponding to Kabat position 16, a glutamic acid or aspartic acid at position corresponding to Kabat position 17, a lysine or proline at position corresponding to Kabat position 18, a threonine at position corresponding to Kabat position 22, a lysine at position corresponding to Kabat position 42, an arginine at position corresponding to Kabat position 45, an isoleucine at position corresponding to Kabat position 58, an isoleucine at position corresponding to Kabat position 59, an isoleucine at position corresponding to Kabat position 60, an isoleucine at position corresponding to Kabat position 61, an isoleucine at position corresponding to Kabat position 62, an isoleucine at position corresponding to Kabat position 63, an isoleucine at position corresponding to Kabat position 64, an isoleucine at position corresponding to Kabat position 65, an isoleucine at position corresponding to Kabat position 66, an isoleucine at position corresponding to Kabat position 67, an isoleucine at position corresponding to Kabat position 68, an isoleucine at position corresponding to Kabat position 69, an isoleucine at position corresponding to Kabat position and the humanized heavy chain variable region comprises a proline or serine at position corresponding to Kabat position 60, a tyrosine at position corresponding to Kabat position 67, a phenylalanine at position corresponding to Kabat position 73, an isoleucine at position corresponding to Kabat position 78, a serine or alanine at position corresponding to Kabat position 80, a tyrosine at position corresponding to Kabat position 85, or a phenylalanine at position corresponding to Kabat position 87, and the humanized heavy chain variable region comprises a glutamic acid at position corresponding to Kabat position 1, a valine at position corresponding to Kabat position 24, and an isoleucine at position corresponding to Kabat position 37. at position corresponding to Kabat position 45; an isoleucine at position corresponding to Kabat position 46; a lysine at position corresponding to Kabat position 47; an arginine at position corresponding to Kabat position 48; a serine at position corresponding to Kabat position 70; a leucine at position corresponding to Kabat position 80; a glutamic acid at position corresponding to Kabat position 81; a tryptophan at position corresponding to Kabat position 82; an alanine at position corresponding to Kabat position 84; a serine at position corresponding to Kabat position 85; and a valine or methionine at position corresponding to Kabat position 89.

[0136] In various embodiments, the humanized light chain variable region comprises a glutamic acid or alanine at position corresponding to Kabat position 1, a valine at position corresponding to Kabat position 2, a glutamine at position corresponding to Kabat position 3, a methionine at position corresponding to Kabat position 4, an aspartic acid or leucine at position corresponding to Kabat position 9, a phenylalanine or threonine at position corresponding to Kabat position 10, a glutamine at position corresponding to Kabat position 11, a serine or proline at position corresponding to Kabat position 12, an alanine or leucine at position corresponding to Kabat position 13, a threonine at position corresponding to Kabat position 14, a valine or proline at position corresponding to Kabat position 15, a lysine at position corresponding to Kabat position 16, a glutamic acid or aspartic acid at position corresponding to Kabat position 17, a lysine or proline at position corresponding to Kabat position 18, a threonine at position corresponding to Kabat position 22, a lysine at position corresponding to Kabat position 42, an arginine at position corresponding to Kabat position 45, an isoleucine at position corresponding to Kabat position 58, an isoleucine at position corresponding to Kabat position 59, an isoleucine at position corresponding to Kabat position 60, an isoleucine at position corresponding to Kabat position 61, an isoleucine at position corresponding to Kabat position 62, an isoleucine at position corresponding to Kabat position 63, an isoleucine at position corresponding to Kabat position 64, an isoleucine at position corresponding to Kabat position 65, an isoleucine at position corresponding to Kabat position 66, an isoleucine at position corresponding to Kabat position 67, an isoleucine at position corresponding to Kabat position 68, an isoleucine at position corresponding to Kabat position 69, an isoleucine at position corresponding to Kabat position and a proline or serine at position corresponding to Kabat position 60, a tyrosine at position corresponding to Kabat position 67, a phenylalanine at position corresponding to Kabat position 73, an isoleucine at position corresponding to Kabat position 78, a serine or alanine at position corresponding to Kabat position 80, a tyrosine at position corresponding to Kabat position 85, and a phenylalanine at position corresponding to Kabat position 87; and the humanized heavy chain variable region comprises a glutamic acid at position corresponding to Kabat position 1, a valine at position corresponding to Kabat position 24, and an isoleucine at position corresponding to Kabat position 37. at position corresponding to Kabat position 45; an isoleucine at position corresponding to Kabat position 46; a lysine at position corresponding to Kabat position 47; an arginine at position corresponding to Kabat position 48; a serine at position corresponding to Kabat position 70; a leucine at position corresponding to Kabat position 80; a glutamic acid at position corresponding to Kabat position 81; a tryptophan at position corresponding to Kabat position 82; an alanine at position corresponding to Kabat position 84; a serine at position corresponding to Kabat position 85; and a valine or methionine at position corresponding to Kabat position 89.

[0137] In various embodiments, the humanized heavy chain variable region comprises a valine at a position corresponding to Kabat position 5, a serine at a position corresponding to Kabat position 7, a valine at a position corresponding to Kabat position 11, a glutamic acid at a position corresponding to Kabat position 12, a valine at a position corresponding to Kabat position 20, an arginine at a position corresponding to Kabat position 38, an alanine at a position corresponding to Kabat position 40, a methionine at a position corresponding to Kabat position 48, an arginine at a position corresponding to Kabat position 66, a valine at a position corresponding to Kabat position 67, an isoleucine at a position corresponding to Kabat position 69, an alanine at a position corresponding to Kabat position 71, a lysine at a position corresponding to Kabat position 73, a threonine at a position corresponding to Kabat position 75, a glutamic acid at a position corresponding to Kabat position 81, an arginine at a position corresponding to Kabat position 83, a threonine at a position corresponding to Kabat position 87, or a valine at a position corresponding to Kabat position 89.

[0138] In embodiments, the humanized heavy chain variable region comprises a valine at position corresponding to Kabat position 5, a serine at position corresponding to Kabat position 7, a valine at position corresponding to Kabat position 11, a glutamic acid at position corresponding to Kabat position 12, a valine at position corresponding to Kabat position 20, an arginine at position corresponding to Kabat position 38, an alanine at position corresponding to Kabat position 40, a methionine at position corresponding to Kabat position 48, an arginine at position corresponding to Kabat position 66, a valine at position corresponding to Kabat position 67, an isoleucine at position corresponding to Kabat position 69, an alanine at position corresponding to Kabat position 71, a lysine at position corresponding to Kabat position 73, a threonine at position corresponding to Kabat position 75, a glutamic acid at position corresponding to Kabat position 81, an arginine at position corresponding to Kabat position 83, a threonine at position corresponding to Kabat position 87, and a valine at position corresponding to Kabat position 89.

[0139] In embodiments, the humanized heavy chain variable region comprises the sequence of SEQ ID NO: 7. In aspects, the humanized heavy chain variable region is SEQ ID NO: 7. In aspects, the humanized light chain variable region comprises the sequence of SEQ ID NO: 8. In aspects, the humanized light chain variable region is SEQ ID NO: 8. In aspects, the humanized heavy chain variable region comprises the sequence of SEQ ID NO: 7 and the humanized light chain variable region comprises the sequence of SEQ ID NO: 8. In aspects, the humanized heavy chain variable region is SEQ ID NO: 7 and the humanized light chain variable region is SEQ ID NO: 8.

[0140] The anti-CD73 antibodies provided herein can be Fab' fragments. When the anti-CD73 antibody is a Fab' fragment, the anti-CD73 antibody comprises a humanized heavy chain (e.g., comprising a constant region and a variable region) and a humanized light chain (e.g., comprising a constant region and a variable region). In embodiments, the anti-CD73 antibody is a Fab' fragment. In embodiments, the anti-CD73 antibody comprises a human constant region. In embodiments, the anti-CD73 antibody is an IgG. In embodiments, the anti-CD73 antibody is an IgG1. In embodiments, the anti-CD73 antibody is an IgG4. In embodiments, the anti-CD73 antibody is an IgA. In embodiments, the anti-CD73 antibody is an IgM.

[0141] In embodiments, the anti-CD73 antibody is a single chain antibody. Single chain antibodies include a variable light chain and a variable heavy chain. Those skilled in the art will immediately understand that in contrast to immunoglobulin antibodies, which include two identical pairs of polypeptide chains, each pair having one light chain and one heavy chain, single chain antibodies include a single light chain and a single heavy chain. Each light and heavy chain, in turn, consists of two regions: a variable ("V") region (i.e., a variable light chain and a variable heavy chain) that is involved in binding the target antigen, and a constant ("C") region that interacts with other components of the immune system. The variable light and variable heavy chains of a single chain antibody may be linked via a linker peptide. Examples of linker peptides for single chain antibodies are described in Bird, RE, Hardman, KD, Jacobson, JW, Johnson, S., Kaufman, BM, Lee, SM, Lee, T., Pope, SH, Riordan, GS and Whitlow, M. (1988). Methods for producing scFv antibodies have been described. See Huse et al., Science 246:1275-1281 (1989), Ward et al., Nature 341:544-546 (1989), and Vaughan et al., Nature Biotech. 14:309-314 (1996). Briefly, mRNA from B cells from immunized animals is isolated and cDNA is prepared. Primers specific to the variable regions of immunoglobulin heavy and light chains are used to amplify the cDNA. The PCR product is purified and the nucleic acid sequences are joined. If a linker peptide is desired, a nucleic acid sequence encoding the peptide is inserted between the nucleic acid sequences of the heavy and light chains. The nucleic acid encoding the scFv is inserted into a vector and expressed in a suitable host cell.

[0142] The ability of an antibody to bind to a particular epitope (e.g., CD73) is determined by the equilibrium dissociation constant (K D ) can be described by the equilibrium dissociation constant (K D ) is the ratio of the dissociation rate (Koff) and association rate (Kon) of an anti-CD73 antibody to the CD73 protein. It is expressed by the following formula: K D= Koff / Kon. In various embodiments, the anti-CD73 antibody has an equilibrium dissociation constant (Koff) of about 0.5 to about 25 nM. D In various embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K D In various embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of about 1.5 to about 25 nM. D In various embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of about 2 to about 25 nM. D In various embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K D In various embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of about 3 to about 25 nM. D In various embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K D In various embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of about 4 to about 25 nM. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than 7.5. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than about 7.5. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than about 7.0. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than about 6.5. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than about 6.0. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than about 5.5. DIn embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than about 5. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than about 4.5. D ) at a pH between about 6.0 and about 7.0. In some embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.0. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.1. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.2. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.3. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.4. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.5. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.6. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.7. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.8. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.9. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 7.0. D) and can bind to the CD73 antigen.

[0143] In various embodiments, the anti-CD73 antibody has an equilibrium dissociation constant (K D In various embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of about 5 to about 25 nM. D In various embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of about 5.5 to about 25 nM. D In various embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of about 6 to about 25 nM. D In various embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K D In various embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of about 7 to about 25 nM. D In various embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K D In various embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of about 8 to about 25 nM. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than 7.5. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than about 7.5. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than about 7.0. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than about 6.5. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than about 6.0. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than about 5.5. DIn embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than about 5. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than about 4.5. D ) at a pH between about 6.0 and about 7.0. In some embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.0. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.1. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.2. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.3. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.4. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.5. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.6. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.7. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.8. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.9. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 7.0. D) and can bind to the CD73 antigen.

[0144] In various embodiments, the anti-CD73 antibody has an equilibrium dissociation constant (K D In various embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of about 9 to about 25 nM. D In various embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K D In various embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of about 10 to about 25 nM. D In various embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K D In various embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of about 12 to about 25 nM. D In various embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of about 13 to about 25 nM. D In various embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K D In various embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K D In various embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than 7.5. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than about 7.5. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than about 7.0. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than about 6.5. DIn embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than about 6.0. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than about 5.5. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than about 5. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than about 4.5. D ) at a pH between about 6.0 and about 7.0. In some embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.0. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.1. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.2. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.3. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.4. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.5. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.6. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.7. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.8. DIn embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.9. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 7.0. D ) and can bind to the CD73 antigen.

[0145] In various embodiments, the anti-CD73 antibody has an equilibrium dissociation constant (K D In various embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of about 18 to about 25 nM. D In various embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K D In various embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K D In various embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K D In various embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K D In various embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K D In various embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of about 0.5, 12, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 nM. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than 7.5. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than about 7.5. DIn embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than about 7.0. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than about 6.5. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than about 6.0. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than about 5.5. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than about 5. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than about 4.5. D ) at a pH between about 6.0 and about 7.0. In some embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.0. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.1. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.2. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.3. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.4. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.5. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.6. DIn embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.7. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.8. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.9. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 7.0. D ) and can bind to the CD73 antigen.

[0146] In embodiments, the anti-CD73 antibody has an equilibrium dissociation constant (K D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than 7.5. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than about 7.5. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than about 7.0. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than about 6.5. DIn embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than about 6.0. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than about 5.5. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than about 5. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of less than about 4.5. D ) at a pH between about 6.0 and about 7.0. In some embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.0. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.1. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.2. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.3. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.4. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.5. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.6. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.7. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.8. DIn embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 6.9. D In embodiments, the anti-CD73 antibody can bind to the CD73 antigen with an equilibrium dissociation constant (K) of this paragraph at a pH of about 7.0. D ) and can bind to the CD73 antigen.

[0147] Anti-CD73 antibodies provided herein, including this embodiment, may include a glutamine at a position corresponding to Kabat position 297. In aspects, the anti-CD73 antibody binds to the CD73 antigen. In aspects, the CD73 antigen forms part of a cell. In aspects, the cell is a lymphoid cell. In aspects, the cell is a B cell.

[0148] Methods of immune stimulation and B cell modulation The anti-CD73 antibodies used in the methods and included in the compositions provided herein, including embodiments, can, among other things, bind to CD73 protein and inhibit CD73 catalytic activity, thereby preventing metastasis. Provided herein are novel methods and compositions based on Applicant's surprising discovery that the anti-CD73 antibodies described herein not only reverse immune suppression of T cells, but also exert a previously unknown and unexpected direct effect on B cells. Applicant was the first to describe that, in contrast to other known anti-CD73 antibodies (e.g., MEDI9447, AD2), the 1E9 anti-CD73 antibody can activate B cells and affect the redistribution of B cells from the periphery to lymphoid tissues / organs. Applicant shows that direct B cell activation occurs specifically with Applicant's anti-CD73 antibodies, while other anti-CD73s do not exhibit this effect. This previously unknown and unique feature of anti-CD73 antibodies may be useful in the treatment of various indications, for example, enhancing immunity against immunogenic cancers, treating autoimmune diseases (e.g., multiple sclerosis), inflammatory diseases, or infectious diseases.

[0149] Any of the embodiments described above for anti-CD73 antibodies may be applicable to the methods provided herein, including those embodiments. Thus, the anti-CD73 antibodies used in the compositions provided herein may, for example, comprise heavy and light chain CDRs (CDR L1 has the sequence of SEQ ID NO: 1, CDR L2 has the sequence of SEQ ID NO: 2, CDR L3 has the sequence of SEQ ID NO: 3, CDR H1 has the sequence of SEQ ID NO: 4, CDR H2 has the sequence of SEQ ID NO: 5, and the CDR H3 has the sequence of SEQ ID NO: 6), comprise a humanized heavy chain variable region comprising the sequence of SEQ ID NO: 7, be IgG4, and have an equilibrium dissociation constant (K D ) and optionally further comprises a glutamine at the position corresponding to Kabat position 297, or optionally forms part of a cell, which cell is a B cell. In embodiments, the anti-CD73 antibody used in the methods described herein is CPI-006.

[0150] In one embodiment, a method of immunostimulating a subject is provided. The method comprises administering an effective amount of an anti-CD73 antibody to the subject, the anti-CD73 antibody comprises 1E9 antibody CDR L1, 1E9 antibody CDR L2, 1E9 antibody CDR L3, 1E9 antibody CDR H1, 1E9 antibody CDR H2, and 1E9 antibody CDR H3. In embodiments, the anti-CD73 antibody is CPI-006. In embodiments, the anti-CD73 antibody is CPI-006. The term "immunostimulating" or "immunostimulation" as provided herein refers to the ability to activate the immune system or increase the activity of any of its components. In embodiments, the method of immunostimulating a subject comprises increasing inflammatory cytokines in the subject. In embodiments, methods of immunostimulating a subject include increasing a proinflammatory cytokine in the subject, the proinflammatory cytokine being TNF-α, TNF-β, MIP-1α, MIP-1β, IL-6, IL-10, IL-8, IP-10, MCP-1, MCP-2, IL-1Ra, GRO-α, MIP-3α, TNF-RII, IL-7, MMP-9, CRP, SAA, MMP-3, MDC, YKL-40, IL-27, or a combination of two or more thereof. In embodiments, a method of immunostimulating a subject includes increasing a proinflammatory cytokine in the subject, the proinflammatory cytokine being TNF-α, TNF-β, MIP-1α, MIP-1β, IL-6, IL-10, IL-8, IP-10, MCP-1, MCP-2, IL-1Ra, GRO-α, MIP-3α, TNF-RII, IL-7, MMP-9, or a combination of two or more thereof. In embodiments, methods of immunostimulating a subject include increasing a proinflammatory cytokine in the subject, the proinflammatory cytokine being TNF-α, TNF-β, MIP-1α, MIP-1β, IL-6, IL-10, IL-8, IP-10, MCP-1, MCP-2, IL-1Ra, GRO-α, MIP-3α, or a combination of two or more thereof, and optionally, the proinflammatory cytokine has a log2 fold increase of at least 2 from about 0.5 hours to about 2 hours after administration of the anti-CD73 antibody.In embodiments, the method of immunostimulating a subject includes increasing an inflammatory cytokine in the subject, the inflammatory cytokine being CRP, SAA, MMP-3, MDC, YKL-40, IL-27, or a combination of two or more thereof. In embodiments, the method of immunostimulating a subject includes increasing an inflammatory cytokine in the subject, the inflammatory cytokine being C-reactive protein (CRP), serum amyloid A (SAA), or a combination thereof, and optionally, the inflammatory cytokine has a log2 fold increase of at least 2 from about 1 day to about 8 days after administration of the anti-CD73 antibody. In embodiments, the method of immunostimulating a subject includes increasing an activation marker in the subject. In embodiments, the method of immunostimulating a subject includes increasing antigen presenting cells in the subject. In embodiments, the method of immunostimulating a subject includes increasing B cells in the subject. In embodiments, the method of immunostimulating a subject includes increasing dendritic cells in the subject. In various embodiments, a method of immunostimulating a subject includes expanding the subject's antigen presenting cells, the antigen presenting cells expressing any of the following antigens: CD3, CD14, CD19, CD25, CD69, CD83, CD86, MHC class II (e.g., HLA-DR), BDCA-2, BDCA-4, CD11c. 低 In some embodiments, the subject expresses (i.e., contains) CD45RA, CD123, ILT-7, TLR7, TLR9, or a combination of two or more thereof. In some embodiments, the method of immunostimulating a subject includes reducing monocytes in the subject, e.g., blood of the subject. In some embodiments, the method of immunostimulating a subject includes reducing CD73 in the subject, e.g., blood of the subject. NEG In embodiments, the method of immunostimulating a subject includes decreasing CD73 T cells in the subject, e.g., blood of the subject. POS In embodiments, the method of immunostimulating a subject includes decreasing CD73 T cells in the subject, e.g., blood of the subject. NEG In embodiments, the method of immunostimulating a subject includes decreasing CD4 T cells in the subject, e.g., in the blood of the subject, CD73 POSIn some embodiments, the method of immunostimulating a subject includes increasing the CD4 / CD8 ratio in the subject, e.g., in the blood of the subject. In some embodiments, the method of immunostimulating a subject includes increasing the CD73 / CD8 ratio in the subject, e.g., in the blood of the subject. NEG CD4 / CD73 NEG This includes increasing the CD8 ratio.

[0151] In embodiments, the method of immunostimulating a subject in need of immune stimulation further comprises obtaining a biological sample from the subject and monitoring an activation marker in the biological sample. In embodiments, the activation marker is B cells, dendritic cells, CD69, CD83, CD25, or a combination of two or more thereof. In embodiments, the activation marker is B cells. In embodiments, the activation marker is dendritic cells. In embodiments, the activation marker is CD69. In embodiments, the activation marker is CD83. In embodiments, the activation marker is CD25. In embodiments, the activation marker in the biological sample is increased compared to a control (e.g., compared to an activation marker in a biological sample taken before administration of the anti-CD73 antibody). In embodiments, the method further comprises administering an effective amount of an anti-CD73 antibody when the activation marker is increased compared to the control.

[0152] In embodiments, the method of immunostimulating a subject in need thereof further comprises obtaining a biological sample from the subject and monitoring antigen presenting cells of the biological sample. In embodiments, the antigen presenting cells are B cells. In embodiments, the antigen presenting cells are dendritic cells. In embodiments, the antigen presenting cells are CD3, CD14, CD19, CD25, CD69, CD83, CD86, MHC class II (e.g., HLA-DR), BDCA-2, BDCA-4, CD11c, 低 , CD45RA, CD123, ILT-7, TLR7, TLR9, or a combination of two or more thereof. In embodiments, the antigen presenting cells comprise CD3, CD14, CD19, CD86, MHC class II (e.g., HLA-DR), BDCA-2, BDCA-4, CD11c 低, CD45RA, CD123, ILT-7, TLR7, TLR9, or a combination of two or more thereof. In embodiments, the antigen presenting cells include CD3, CD14, CD86, MHC class II (e.g., HLA-DR), BDCA-2, BDCA-4, CD11c 低 , CD45RA, CD123, ILT-7, TLR7, TLR9, or a combination of two or more thereof. In embodiments, the antigen presenting cells comprise CD86. In embodiments, the antigen presenting cells comprise MHC class II. In embodiments, the antigen presenting cells comprise HLA-DR. In embodiments, the antigen presenting cells of the biological sample are increased compared to a control (e.g., compared to antigen presenting cells of a biological sample taken prior to administration of the anti-CD73 antibody). In embodiments, the method further comprises administering an effective amount of an anti-CD73 antibody if the antigen presenting cells are increased compared to the control.

[0153] In embodiments, a method of immunostimulating a subject in need thereof includes obtaining a biological sample (e.g., a blood sample) from the subject, detecting monocytes, CD73 POS CD4 T cells, CD73 NEG CD4 T cells, CD73 POS CD8 T cells, CD73 NEG and monitoring monocytes, CD73 T cells, CD8 T cells, or a combination of two or more thereof in the biological sample. POS CD8 T cells, CD73 NEG CD8 T cells, or a combination of two or more thereof, compared to a control (e.g., monocyte CD73 T cells in a biological sample taken prior to administration of an anti-CD73 antibody, POS CD8 T cells, CD73 NEG In embodiments, the methods include the use of monocytes, CD73 T cells, and / or CD8 T cells. POS CD8 T cells, CD73 NEG In some embodiments, the method further comprises administering an effective amount of an anti-CD73 antibody when the CD73 in the biological sample is decreased relative to a control, or a combination of two or more thereof. POS CD4 T cells, CD73NEG CD4 T cells, or both, are expressed in a proportion of CD73 T cells, as compared to a control (e.g., CD73 T cells in a biological sample taken prior to administration of an anti-CD73 antibody). POS CD4 T cells or CD73 NEG In some embodiments, the method includes increasing the expression of CD73 T cells. POS CD4 T cells, CD73 NEG If CD4 T cells, or both, are decreased compared to a control, the method further comprises administering an effective amount of an anti-CD73 antibody.

[0154] In one embodiment, a method of activating B cells of a subject is provided. The method includes administering an effective amount of an anti-CD73 antibody to the subject, the anti-CD73 antibody includes 1E9 antibody CDR L1, 1E9 antibody CDR L2, 1E9 antibody CDR L3, 1E9 antibody CDR H1, 1E9 antibody CDR H2, and 1E9 antibody CDR H3. In embodiments, the anti-CD73 antibody is CPI-006. The terms "B cell activation" or "activating B cells" provided herein are terms well known in the art and are used according to their conventional meaning in the art. For example, B cell activation includes the binding of the B cell receptor (BCR) to an antigen or T cells providing an activation signal to B cells (thymus-dependent activation). Upon activation, B cells upregulate the expression of certain B cell activation marker proteins (e.g., CD69, CD83) that are characteristic of activated B cells.

[0155] In one embodiment, a method of redistributing peripheral B cells in a subject is provided. The method includes administering an effective amount of an anti-CD73 antibody to the subject, the anti-CD73 antibody includes 1E9 antibody CDR L1, 1E9 antibody CDR L2, 1E9 antibody CDR L3, 1E9 antibody CDR H1, 1E9 antibody CDR H2, and 1E9 antibody CDR H3. In embodiments, the anti-CD73 antibody is CPI-006. The term "redistribute" or "redistribution" as provided herein refers to the effect of a compound (e.g., an anti-CD73 antibody provided herein) on the location of B cells in an organism. In embodiments, the compound (e.g., an anti-CD73 antibody provided herein) binds to B cells expressing CD73 and regulates the location of B cells in the organism compared to a standard control. In embodiments, when a compound (e.g., an anti-CD73 antibody provided herein) regulates the location of B cells in an organism, there are fewer B cells in the periphery (e.g., peripheral blood) of the organism compared to the absence of the compound. In embodiments, the amount (number) of B cells present in the peripheral blood of the subject is reduced compared to the absence of the anti-CD73 antibody. In embodiments, the amount (number) of B cells present in the primary lymphoid organs (e.g., spleen or thymus) of the subject is increased compared to the absence of the anti-CD73 antibody.

[0156] In one embodiment, a method is provided for reducing the release of B cells from lymphoid tissues of a subject compared to a standard control. The method includes administering to the subject an effective amount of an anti-CD73 antibody, the anti-CD73 antibody comprising 1E9 antibody CDR L1, 1E9 antibody CDR L2, 1E9 antibody CDR L3, 1E9 antibody CDR H1, 1E9 antibody CDR H2, and 1E9 antibody CDR H3. In embodiments, the anti-CD73 antibody is CPI-006. As provided herein, "lymphoid tissue" includes any diffuse or unencapsulated bundle of lymphoid cells. Lymphoid tissue is composed of lymphocytes and macrophages associated with a reticular fiber network, including, but not limited to, lymph nodules, Peyer's patches, and tonsils.

[0157] A "standard control" as provided herein refers to a sample that serves as a reference for comparison with a test sample, usually a known reference. For example, a test sample can be taken from a patient suspected of disease (e.g., autoimmune disease, inflammatory disease, cancer) and compared to a sample from a patient known to have the disease or a known normal (non-disease) individual. A control can also represent an average value collected from a group of similar individuals, e.g., diseased patients or healthy individuals with similar medical background, the same age, weight, etc. A control value can also be obtained from the same individual, e.g., from a sample obtained previously, before disease or before treatment. A person skilled in the art will recognize that a control can be designed for any number of parameter evaluations. A person skilled in the art will know which control is useful in a given situation and will be able to analyze data based on comparison with the control value. A control is also useful for determining the significance of data. For example, if the value of a given parameter varies widely in the control, the variation of the test sample is not considered significant.

[0158] In some examples of the disclosed method, when the amount (number) of B cells present in lymphoid tissue or lymphoid organ or B cell activity is evaluated or the release of B cells from lymphoid tissue is measured, this amount (number) is compared to a control amount (number) of B cells or B cell activity (e.g., healthy subjects or untreated subjects). By control, we mean the amount (number) of B cells in lymphoid tissue or lymphoid organ or the activity of B cells in the absence of a particular variable, such as a sample or subject without a disease, a sample or subject at a selected stage of a disease or condition, or a therapeutic agent. Alternatively, the control includes a known amount (number) of B cells present in lymphoid tissue or organ or the activity of B cells. Such a known amount is correlated with the average level of subjects without a disease, a subject at a selected stage of a disease or condition, or a subject at the absence of a particular variable, such as a therapeutic agent. The control also includes the amount (number) of B cells present in lymphoid tissue or lymphoid organ or the B cell activity of one or more selected samples or subjects described herein. For example, a control includes an assessment of the amount (number) of B cells or B cell activity in a sample from a subject who does not have the disease, who has a selected stage of the disease or condition, or who is not receiving treatment for the disease. Another exemplary control level includes an assessment of the amount (number) of B cells or B cell activity in samples taken from multiple subjects who do not have the disease, who have a selected stage of the disease, or who are not receiving treatment for the disease.

[0159] When the control amount (number) of B cell or B cell activity comprises the B cell amount or B cell activity of sample or subject in the absence of therapeutic agent, the control sample or subject is optionally the same sample or subject tested before and after treatment with therapeutic agent, or the sample or subject selected in the absence of therapeutic agent.Alternatively, the standard control is the average expression level calculated from many subjects who do not have a particular disease.Control level also includes a known control level or a value known in the art.

[0160] In one embodiment, a method is provided for increasing retention of B cells in lymphoid organs of a subject compared to a standard control. The method includes administering an effective amount of an anti-CD73 antibody to a subject, the anti-CD73 antibody includes 1E9 antibody CDR L1, 1E9 antibody CDR L2, 1E9 antibody CDR L3, 1E9 antibody CDR H1, 1E9 antibody CDR H2, and 1E9 antibody CDR H3. In embodiments, the anti-CD73 antibody is CPI-006. The term "lymphoid organ" as provided herein is a term well known in the art and is used herein according to its conventional meaning in the art. Examples of lymphoid organs include the thymus and spleen. In embodiments, a compound (e.g., an anti-CD73 antibody provided herein) modulates the location of B cells in an organism compared to a standard control. In embodiments, when a compound (e.g., an anti-CD73 antibody provided herein) modulates the location of B cells in an organism, there are more B cells in the lymphoid organs (e.g., the spleen) of the organism compared to the absence of the compound. In embodiments, the amount of B cells in the subject's primary lymphoid organs (e.g., spleen or thymus) is greater compared to the absence of the anti-CD73 antibody.

[0161] In one embodiment, a method is provided for increasing the internalization of sphingosine-1-phosphate receptor 1 (S1PR1) in cells of a subject compared to a standard control. The method comprises administering to the subject an effective amount of an anti-CD73 antibody, the anti-CD73 antibody comprising 1E9 antibody CDR L1, 1E9 antibody CDR L2, 1E9 antibody CDR L3, 1E9 antibody CDR H1, 1E9 antibody CDR H2, and 1E9 antibody CDR H3. In embodiments, the anti-CD73 antibody is CPI-006.

[0162] In embodiments, the subject has cancer. In aspects, the subject is immunocompromised. In aspects, the subject has an immunodeficiency disease or an autoimmune disease.

[0163] Treatment method The methods provided herein are useful for treating, inter alia, diseases associated with or related to S1PR1 function, infectious diseases, inflammatory diseases, and autoimmune diseases.

[0164] Any of the embodiments described above for anti-CD73 antibodies may be applicable to the methods provided herein, including those embodiments. Thus, the anti-CD73 antibodies used in the compositions provided herein may, for example, comprise heavy and light chain CDRs (CDR L1 has the sequence of SEQ ID NO: 1, CDR L2 has the sequence of SEQ ID NO: 2, CDR L3 has the sequence of SEQ ID NO: 3, CDR H1 has the sequence of SEQ ID NO: 4, CDR H2 has the sequence of SEQ ID NO: 5, and the CDR H3 has the sequence of SEQ ID NO: 6), may comprise a humanized heavy chain variable region comprising the sequence of SEQ ID NO: 7, may be IgG4, and may have an equilibrium dissociation constant (K D ) and may be capable of binding to the CD73 antigen, may further comprise a glutamine at the position corresponding to Kabat position 297, or may form part of a cell (wherein the cell is a B cell).

[0165] The term "sphingosine-1-phosphate receptor 1," "S1P1," or "S1PR1," as provided herein, includes any recombinant or native form of sphingosine-1-phosphate receptor 1 (S1PR1), also known as endothelial differentiation gene 1 (EDG1), or a variant or homolog thereof that maintains S1PR1 activity (e.g., within at least 50%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, or 100% activity compared to S1PR1). In some embodiments, the variant or homolog has at least 90%, 95%, 96%, 97%, 98%, 99%, or 100% amino acid sequence identity over the entire sequence or a portion of the sequence (e.g., a portion of 50, 100, 150, or 200 contiguous amino acids) compared to a naturally occurring S1PR1 protein. In embodiments, the S1PR1 protein is substantially identical to the protein identified by UniProt reference number P21453, or a variant or homolog having substantial identity thereto.

[0166] As provided herein, "sphingosine-1-phosphate receptor 1 (S1PR1)-related disease" is used to broadly refer to disease disorders or symptoms associated with S1PR1 function. In various embodiments, the disease is caused or the disease symptoms are caused by abnormal S1PR1 function. The S1PR1 function described herein refers to any cellular function that is affected by S1PR1, including but not limited to endothelial cell cytoskeleton structure, migration, capillary-like network formation, vascular maturation, regulation of lymphocyte maturation, lymphocyte migration and lymphocyte trafficking.

[0167] The term "internalization" as provided herein refers to the cellular uptake of a molecule (e.g., S1PR1) via endocytosis. As provided herein, endocytosis refers to the cellular process of a molecule being surrounded by a region of the plasma membrane, thereby forming an ingested molecule. The region of the plasma membrane containing the ingested molecule then buds off within the cell, forming a vesicle containing the ingested molecule.

[0168] Thus, in one embodiment, a method for treating a sphingosine-1-phosphate receptor 1 (S1PR1)-related disease in a subject in need of treatment is provided. The method comprises administering an effective amount of an anti-CD73 antibody to the subject, the anti-CD73 antibody comprising 1E9 antibody CDR L1, 1E9 antibody CDR L2, 1E9 antibody CDR L3, 1E9 antibody CDR H1, 1E9 antibody CDR H2 and 1E9 antibody CDR H3. In embodiments, the S1PR1-related disease is graft-versus-host disease, autoimmune disease, inflammatory disease, viral myocarditis, viral disease caused by viral myocarditis, demyelinating disease, or organ or tissue transplant rejection. In embodiments, the S1PR1-related disease is an autoimmune disease. In various embodiments, the S1PR1-related disease is multiple sclerosis, rheumatoid arthritis, atopic eczema (atopic dermatitis), Behcet's disease, uveal disease, systemic lupus erythematosus, Sjogren's syndrome, multiple sclerosis, myasthenia gravis, type I diabetes, endocrine ophthalmopathy, primary biliary cirrhosis, Crohn's disease, glomerulonephritis, sarcoidosis, psoriasis, pemphigus, aplastic anemia, idiopathic thrombocytopenic purpura, allergy, polyarteritis nodosa, progressive systemic sclerosis, mixed connective tissue disease, aortitis syndrome, polymyositis, dermatomyositis, Wegener's granulomatosis, ulcerative colitis, active chronic hepatitis, autoimmune hemolytic anemia, Evans syndrome, bronchial asthma, liver failure, kidney failure, or hay fever.

[0169] In one embodiment, a method of treating an infectious disease in a subject in need thereof is provided. The method comprises administering to the subject an effective amount of an anti-CD73 antibody, the anti-CD73 antibody comprising 1E9 antibody CDR L1, 1E9 antibody CDR L2, 1E9 antibody CDR L3, 1E9 antibody CDR H1, 1E9 antibody CDR H2, and 1E9 antibody CDR H3. In embodiments, the anti-CD73 antibody is CPI-006.

[0170] In one embodiment, a method of treating an inflammatory disease in a subject in need thereof is provided. The method comprises administering to the subject an effective amount of an anti-CD73 antibody, the anti-CD73 antibody comprising 1E9 antibody CDR L1, 1E9 antibody CDR L2, 1E9 antibody CDR L3, 1E9 antibody CDR H1, 1E9 antibody CDR H2, and 1E9 antibody CDR H3. In embodiments, the anti-CD73 antibody is CPI-006.

[0171] In one embodiment, a method of treating an autoimmune disease in a subject in need thereof is provided. The method comprises administering to the subject an effective amount of an anti-CD73 antibody, the anti-CD73 antibody comprising 1E9 antibody CDR L1, 1E9 antibody CDR L2, 1E9 antibody CDR L3, 1E9 antibody CDR H1, 1E9 antibody CDR H2, and 1E9 antibody CDR H3. In embodiments, the anti-CD73 antibody is CPI-006.

[0172] Cancer Treatment Methods In embodiments, the disclosure provides a method of treating cancer in a patient in need of treatment, comprising administering an effective amount of an anti-CD73 antibody to the patient to effectively activate antigen-presenting cells. In aspects, the disclosure provides a method of treating cancer in a patient in need of treatment, comprising administering an effective amount of an anti-CD73 antibody to the patient and monitoring the level of antigen-presenting cells. In aspects, the disclosure provides a method of treating cancer in a patient in need of treatment, comprising administering an effective amount of an anti-CD73 antibody to the patient to effectively activate antigen-presenting cells and monitoring the level of antigen-presenting cells. In aspects, the level of antigen-presenting cells in the biological sample is monitored by flow cytometry, immunohistochemistry, or a combination thereof. In aspects, the antigen-presenting cells are in a cancer tumor microenvironment. In aspects, the level of antigen-presenting cells is monitored via a patient biological sample, e.g., a blood sample, such as a peripheral blood sample. In aspects, the biological sample comprises B cells in an amount of about 0.2×10e6 cells / mL or greater as measured by flow cytometry. In embodiments, the biological sample comprises B cells in an amount of about 0.3×10e6 cells / mL or greater, as measured by flow cytometry. In embodiments, the biological sample comprises B cells in an amount of about 0.4×10e6 cells / mL or greater, as measured by flow cytometry. In embodiments, the biological sample comprises B cells in an amount of about 0.5×10e6 cells / mL or greater, as measured by flow cytometry. In embodiments, the biological sample comprises B cells in an amount of about 0.6×10e6 cells / mL or greater, as measured by flow cytometry. In embodiments, the biological sample comprises dendritic cells in an amount of about 0.03×10e6 cells / mL or greater, as measured by flow cytometry. In embodiments, the biological sample comprises dendritic cells in an amount of about 0.04×10e6 cells / mL or greater, as measured by flow cytometry. In embodiments, the biological sample comprises dendritic cells in an amount of about 0.05×10e6 cells / mL or greater as measured by flow cytometry. In embodiments, the biological sample comprises dendritic cells in an amount of about 0.06×10e6 cells / mL or greater as measured by flow cytometry.In embodiments, the biological sample comprises dendritic cells in an amount of about 0.07×10e6 cells / mL or greater as measured by flow cytometry. In embodiments, the antigen presenting cells are B cells. In embodiments, the antigen presenting cells are B cells that are CD19+. In embodiments, the antigen presenting cells are dendritic cells. In embodiments, the antigen presenting cells are classical dendritic cells. In embodiments, the antigen presenting cells are plasmacytoid dendritic cells. In embodiments, the antigen presenting cells are CD3, CD14, CD19, CD69, CD83, CD86, MHC class II (e.g., HLA-DR), BDCA-2, BDCA-4, CD11c. 低 , CD45RA, CD123, ILT-7, TLR7, TLR9, or a combination of two or more thereof. In embodiments, the anti-CD73 antibody is any of those described herein. In embodiments, the anti-CD73 antibody comprises 1E9 antibody CDR L1, 1E9 antibody CDR L2, 1E9 antibody CDR L3, 1E9 antibody CDR H1, 1E9 antibody CDR H2, and 1E9 antibody CDR H3. In embodiments, the anti-CD73 antibody is CPI-006.

[0173] In embodiments, the present disclosure provides a method of treating cancer in a patient in need of treatment, comprising administering an effective amount of an anti-CD73 antibody to the patient to effectively activate antigen presenting cells, obtaining a biological sample from the patient, and detecting the level of antigen presenting cells in the biological sample. In aspects, the present disclosure provides a method of treating cancer in a patient in need of treatment, comprising administering an effective amount of an anti-CD73 antibody to the patient, obtaining a biological sample from the patient, and detecting the level of antigen presenting cells in the biological sample. In aspects, the present disclosure provides a method of treating cancer in a patient in need of treatment, comprising administering an effective amount of an anti-CD73 antibody to the patient to effectively activate antigen presenting cells, obtaining a biological sample from the patient, and detecting the level of antigen presenting cells in the biological sample. In aspects, the level of antigen presenting cells in the biological sample is monitored by flow cytometry, immunohistochemistry, or a combination thereof. In aspects, the antigen presenting cells are in the cancer tumor microenvironment. In embodiments, the level of antigen presenting cells is monitored via a patient biological sample, e.g., a blood sample, such as a peripheral blood sample. In embodiments, the biological sample comprises B cells in an amount of about 0.2×10e6 cells / mL or more, as measured by flow cytometry. In embodiments, the biological sample comprises B cells in an amount of about 0.3×10e6 cells / mL or more, as measured by flow cytometry. In embodiments, the biological sample comprises B cells in an amount of about 0.4×10e6 cells / mL or more, as measured by flow cytometry. In embodiments, the biological sample comprises B cells in an amount of about 0.5×10e6 cells / mL or more, as measured by flow cytometry. In embodiments, the biological sample comprises B cells in an amount of about 0.6×10e6 cells / mL or more, as measured by flow cytometry. In embodiments, the biological sample comprises dendritic cells in an amount of about 0.03×10e6 cells / mL or more, as measured by flow cytometry. In embodiments, the biological sample comprises dendritic cells in an amount of about 0.04 x 10e6 cells / mL or greater, as measured by flow cytometry.In embodiments, the biological sample comprises dendritic cells in an amount of about 0.05×10e6 cells / mL or greater as measured by flow cytometry. In embodiments, the biological sample comprises dendritic cells in an amount of about 0.06×10e6 cells / mL or greater as measured by flow cytometry. In embodiments, the biological sample comprises dendritic cells in an amount of about 0.07×10e6 cells / mL or greater as measured by flow cytometry. In embodiments, the antigen presenting cells are B cells. In embodiments, the antigen presenting cells are B cells that are CD19+. In embodiments, the antigen presenting cells are dendritic cells. In embodiments, the antigen presenting cells are classical dendritic cells. In embodiments, the antigen presenting cells are plasmacytoid dendritic cells. In various embodiments, the antigen presenting cells are CD3, CD14, CD19, CD69, CD83, CD86, MHC class II (e.g., HLA-DR), BDCA-2, BDCA-4, CD11c. 低 , CD45RA, CD123, ILT-7, TLR7, TLR9, or a combination of two or more thereof. In embodiments, the anti-CD73 antibody is any of those described herein. In embodiments, the anti-CD73 antibody comprises 1E9 antibody CDR L1, 1E9 antibody CDR L2, 1E9 antibody CDR L3, 1E9 antibody CDR H1, 1E9 antibody CDR H2, and 1E9 antibody CDR H3. In embodiments, the anti-CD73 antibody is CPI-006.

[0174] In embodiments, the disclosure provides a method of treating cancer in a patient in need of treatment comprising administering an effective amount of an anti-CD73 antibody to the patient to effectively activate an activation marker. In aspects, the disclosure provides a method of treating cancer in a patient in need of treatment comprising administering an effective amount of an anti-CD73 antibody to the patient and monitoring a level of the activation marker. In aspects, the disclosure provides a method of treating cancer in a patient in need of treatment comprising administering an effective amount of an anti-CD73 antibody to the patient to effectively activate an activation marker and monitoring a level of the activation marker. In aspects, the activation marker is B cells. In aspects, the activation marker is dendritic cells. In aspects, the activation marker is CD69. In aspects, the activation marker is CD83. In aspects, the activation marker is CD25. In aspects, the level of the activation marker in the biological sample is monitored by flow cytometry, immunohistochemistry, or a combination thereof. In embodiments, the level of activation markers is monitored via a patient biological sample, e.g., a blood sample, such as a peripheral blood sample. In embodiments, the biological sample comprises B cells in an amount of about 0.2×10e6 cells / mL or more, as measured by flow cytometry. In embodiments, the biological sample comprises B cells in an amount of about 0.3×10e6 cells / mL or more, as measured by flow cytometry. In embodiments, the biological sample comprises B cells in an amount of about 0.4×10e6 cells / mL or more, as measured by flow cytometry. In embodiments, the biological sample comprises B cells in an amount of about 0.5×10e6 cells / mL or more, as measured by flow cytometry. In embodiments, the biological sample comprises B cells in an amount of about 0.6×10e6 cells / mL or more, as measured by flow cytometry. In embodiments, the biological sample comprises dendritic cells in an amount of about 0.03×10e6 cells / mL or more, as measured by flow cytometry. In embodiments, the biological sample comprises dendritic cells in an amount of about 0.04 x 10e6 cells / mL or greater, as measured by flow cytometry.In embodiments, the biological sample comprises dendritic cells in an amount of about 0.05×10e6 cells / mL or greater as measured by flow cytometry. In embodiments, the biological sample comprises dendritic cells in an amount of about 0.06×10e6 cells / mL or greater as measured by flow cytometry. In embodiments, the biological sample comprises dendritic cells in an amount of about 0.07×10e6 cells / mL or greater as measured by flow cytometry.

[0175] In embodiments, the disclosure provides a method of treating cancer in a patient in need of treatment, comprising administering an effective amount of an anti-CD73 antibody to the patient to effectively activate an activation marker, obtaining a biological sample from the patient, and detecting a level of the activation marker in the biological sample. In aspects, the disclosure provides a method of treating cancer in a patient in need of treatment, comprising administering an effective amount of an anti-CD73 antibody to the patient, obtaining a biological sample from the patient, and detecting a level of the activation marker in the biological sample. In aspects, the disclosure provides a method of treating cancer in a patient in need of treatment, comprising administering an effective amount of an anti-CD73 antibody to the patient to effectively activate an activation marker, obtaining a biological sample from the patient, and detecting a level of the activation marker in the biological sample. In aspects, the level of the activation marker in the biological sample is monitored by flow cytometry, immunohistochemistry, or a combination thereof. In aspects, the activation marker is B cells. In aspects, the activation marker is dendritic cells. In aspects, the activation marker is CD69. In embodiments, the activation marker is CD83. In embodiments, the activation marker is CD25. In embodiments, the level of the activation marker in the biological sample is monitored by flow cytometry, immunohistochemistry, or a combination thereof. In embodiments, the level of the activation marker is monitored via a patient biological sample, e.g., a blood sample, such as a peripheral blood sample. In embodiments, the biological sample comprises B cells in an amount of about 0.2×10e6 cells / mL or more, as measured by flow cytometry. In embodiments, the biological sample comprises B cells in an amount of about 0.3×10e6 cells / mL or more, as measured by flow cytometry. In embodiments, the biological sample comprises B cells in an amount of about 0.4×10e6 cells / mL or more, as measured by flow cytometry. In embodiments, the biological sample comprises B cells in an amount of about 0.5×10e6 cells / mL or more, as measured by flow cytometry. In embodiments, the biological sample comprises B cells in an amount of about 0.6×10e6 cells / mL or greater as measured by flow cytometry.In embodiments, the biological sample comprises dendritic cells in an amount of about 0.03×10e6 cells / mL or greater, as measured by flow cytometry. In embodiments, the biological sample comprises dendritic cells in an amount of about 0.04×10e6 cells / mL or greater, as measured by flow cytometry. In embodiments, the biological sample comprises dendritic cells in an amount of about 0.05×10e6 cells / mL or greater, as measured by flow cytometry. In embodiments, the biological sample comprises dendritic cells in an amount of about 0.06×10e6 cells / mL or greater, as measured by flow cytometry. In embodiments, the biological sample comprises dendritic cells in an amount of about 0.07×10e6 cells / mL or greater, as measured by flow cytometry.

[0176] Dosage The anti-CD73 inhibitor is administered to the subject in an amount effective to treat the disease of the subject. In embodiments, the effective amount is about 1 mg / kg, 3 mg / kg, 6 mg / kg, 10 mg / kg, 30 mg / kg, 40 mg / kg, or 120 mg / kg. In aspects, the effective amount is about 0.05 mg / kg, 0.1 mg / kg, 0.3 mg / kg, 1 mg / kg, 3 mg / kg, 6 mg / kg, 10 mg / kg, 30 mg / kg, 40 mg / kg, or 120 mg / kg. In aspects, the effective amount is about 0.05 mg / kg. In aspects, the effective amount is 0.05 mg / kg. In aspects, the effective amount is about 0.1 mg / kg. In aspects, the effective amount is 0.1 mg / kg. In aspects, the effective amount is about 0.3 mg / kg. In aspects, the effective amount is 0.3 mg / kg. In embodiments, the effective amount is about 1 mg / kg. In embodiments, the effective amount is 1 mg / kg. In embodiments, the effective amount is about 3 mg / kg. In embodiments, the effective amount is 3 mg / kg. In embodiments, the effective amount is about 6 mg / kg. In embodiments, the effective amount is 6 mg / kg. In embodiments, the effective amount is about 10 mg / kg. In embodiments, the effective amount is 10 mg / kg. In embodiments, the effective amount is about 12 mg / kg. In embodiments, the effective amount is 12 mg / kg. In embodiments, the effective amount is about 30 mg / kg. In embodiments, the effective amount is 30 mg / kg. In embodiments, the effective amount is about 40 mg / kg. In embodiments, the effective amount is 40 mg / kg. In embodiments, the effective amount is about 120 mg / kg. In embodiments, the effective amount is 120 mg / kg. In embodiments, the effective amount administered results in a serum level of antibody of about 10 μg / ml.

[0177] In embodiments, the anti-CD73 antibody is administered to the subject in an effective amount of at least 1 mg / kg. In embodiments, the effective amount is at least 2 mg / kg. In embodiments, the effective amount is at least 2 mg / kg. In embodiments, the effective amount is at least 3 mg / kg. In embodiments, the effective amount is at least 4 mg / kg. In embodiments, the effective amount is at least 5 mg / kg. In embodiments, the effective amount is at least 6 mg / kg. In embodiments, the effective amount is at least 7 mg / kg. In embodiments, the effective amount is at least 8 mg / kg. In embodiments, the effective amount is at least 9 mg / kg. In embodiments, the effective amount is at least 10 mg / kg. In embodiments, the effective amount is at least 11 mg / kg. In embodiments, the effective amount is at least 12 mg / kg. In embodiments, the effective amount is at least 13 mg / kg. In embodiments, the effective amount is at least 14 mg / kg. In embodiments, the effective amount is at least 15 mg / kg. In various embodiments, the effective amount is about 1 mg / kg to about 100 mg / kg. In various embodiments, the effective amount is about 2 mg / kg to about 90 mg / kg. In various embodiments, the effective amount is about 3 mg / kg to about 80 mg / kg. In various embodiments, the effective amount is about 4 mg / kg to about 70 mg / kg. In various embodiments, the effective amount is about 5 mg / kg to about 60 mg / kg. In various embodiments, the effective amount is about 6 mg / kg to about 50 mg / kg. In various embodiments, the effective amount is about 4 mg / kg to about 25 mg / kg. In various embodiments, the effective amount is about 5 mg / kg to about 25 mg / kg. In various embodiments, the effective amount is about 6 mg / kg to about 25 mg / kg. In various embodiments, the effective amount is about 7 mg / kg to about 25 mg / kg. In various embodiments, the effective amount is about 8 mg / kg to about 25 mg / kg. In embodiments, the effective amount is about 9 mg / kg to about 25 mg / kg. In embodiments, the effective amount is about 10 mg / kg to about 25 mg / kg. In embodiments, the effective amount is about 5 mg / kg to about 15 mg / kg. In embodiments, the effective amount is about 6 mg / kg to about 12 mg / kg. In embodiments, the effective amount is about 4 mg / kg. In embodiments, the effective amount is about 5 mg / kg. In embodiments, the effective amount is about 6 mg / kg. In embodiments, the effective amount is about 7 mg / kg. In embodiments, the effective amount is about 8 mg / kg.In embodiments, the effective amount is about 9 mg / kg. In embodiments, the effective amount is about 10 mg / kg. In embodiments, the effective amount is about 11 mg / kg. In embodiments, the effective amount is about 12 mg / kg. In embodiments, the effective amount is about 13 mg / kg. In embodiments, the effective amount is about 14 mg / kg. In embodiments, the effective amount is about 15 mg / kg. In embodiments, the effective amount is about 16 mg / kg. In embodiments, the effective amount is about 17 mg / kg. In embodiments, the effective amount is about 18 mg / kg. In embodiments, the effective amount is about 19 mg / kg. In embodiments, the effective amount is about 20 mg / kg. In embodiments, the effective amount is about 21 mg / kg. In embodiments, the effective amount is about 22 mg / kg. In embodiments, the effective amount is about 23 mg / kg. In embodiments, the effective amount is about 24 mg / kg. In embodiments, the effective amount is about 25 mg / kg.

[0178] In embodiments, the anti-CD73 antibody is administered by parenteral injection. In embodiments, the injection is a bolus injection. In embodiments, the injection is an infusion (e.g., for between 5 minutes and 2 hours, or for between about 30 minutes and about 90 minutes). In embodiments, the anti-CD73 antibody is administered once a week (i.e., once every 7 days), once every two weeks (e.g., once every 14 days), once every three weeks (e.g., once every 21 days), or once a month (e.g., once every 28 days).

[0179] In embodiments of the methods provided herein, the anti-CD73 antibody has a half maximal effective concentration (EC) of at least 100 nM (e.g., 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, 200, 210, 220, 230, 240, 250 nM). 50 In some embodiments, the anti-CD73 antibody may be administered at a half maximal effective concentration (EC 50 In embodiments, the antibody is administered at a half maximal effective concentration (EC 50 In embodiments, the antibody is administered at a half maximal effective concentration (EC 50In embodiments, the antibody is administered at a half maximal effective concentration (EC 50 In embodiments, the antibody is administered at a half maximal effective concentration (EC 50 In embodiments, the antibody is administered at a half maximal effective concentration (EC 50 In embodiments, the antibody is administered at a half maximal effective concentration (EC 50 In embodiments, the antibody is administered at a half maximal effective concentration (EC 50 In embodiments, the antibody is administered at a half maximal effective concentration (EC 50 In embodiments, the antibody is administered at a half maximal effective concentration (EC 50 In embodiments, the antibody is administered at a half maximal effective concentration (EC 50 In embodiments, the antibody is administered at a half maximal effective concentration (EC 50 In embodiments, the antibody is administered at a half maximal effective concentration (EC 50 In embodiments, the antibody is administered at a half maximal effective concentration (EC 50 In embodiments, the antibody is administered at a half maximal effective concentration (EC 50 In embodiments, the antibody is administered at a half maximal effective concentration (EC 50 In embodiments, the antibody is administered at a half maximal effective concentration (EC 50 In embodiments, the antibody is administered at a half maximal effective concentration (EC 50 In embodiments, the antibody is administered at a half maximal effective concentration (EC 50 In embodiments, the antibody is administered at a half maximal effective concentration (EC 50 In embodiments, the antibody is administered at a half maximal effective concentration (EC 50 In embodiments, the antibody is administered at a half maximal effective concentration (EC 50 In embodiments, the antibody is administered at a half maximal effective concentration (EC 50In embodiments, the antibody is administered at a half maximal effective concentration (EC 50 In embodiments, the antibody is administered at a half maximal effective concentration (EC 50 ) is administered.

[0180] In various embodiments, the antibody has an EC 50 In embodiments, the antibody is administered at an EC 50 In embodiments, the antibody is administered at an EC 50 In embodiments, the antibody is administered at an EC 50 It is administered at .

[0181] composition Any of the embodiments described above for anti-CD73 antibodies may be applicable to the compositions provided herein, including those embodiments. Thus, the anti-CD73 antibodies used in the compositions provided herein may, for example, comprise heavy and light chain CDRs (CDR L1 has the sequence of SEQ ID NO: 1, CDR L2 has the sequence of SEQ ID NO: 2, CDR L3 has the sequence of SEQ ID NO: 3, CDR H1 has the sequence of SEQ ID NO: 4, CDR H2 has the sequence of SEQ ID NO: 5, and the CDR H3 has the sequence of SEQ ID NO: 6), may comprise a humanized heavy chain variable region comprising the sequence of SEQ ID NO: 7, may be IgG4, and may have an equilibrium dissociation constant (K D ) and may be capable of binding to the CD73 antigen, may further comprise a glutamine at the position corresponding to Kabat position 297, or may form part of a cell (wherein the cell is a B cell).

[0182] In one embodiment, an anti-cancer immunogenic composition is provided. The composition includes an anti-cancer immunogenic agent and an anti-CD73 antibody, the anti-CD73 antibody includes 1E9 antibody CDR L1, 1E9 antibody CDR L2, 1E9 antibody CDR L3, 1E9 antibody CDR H1, 1E9 antibody CDR H2, and 1E9 antibody CDR H3. As provided herein, an "anti-cancer immunogenic agent" refers to an agent having anti-cancer and immunogenic capabilities. The term "immunogenic" is a term well known in the art and is used herein according to its conventional meaning. An immunogenic agent is an agent (e.g., a compound molecule, an antigen, an epitope) that has the ability to induce an immune response in the human or other animal body. The term "immunogenic" refers to the ability to induce a humoral and / or cellular immune response. In embodiments, the anti-cancer immunogenic agent is an oncolytic virus or a cancer cell component.

[0183] In another embodiment, an anti-viral immunogenic composition is provided, the composition comprising an anti-viral immunogenic agent and an anti-CD73 antibody, the anti-CD73 antibody comprising 1E9 antibody CDR L1, 1E9 antibody CDR L2, 1E9 antibody CDR L3, 1E9 antibody CDR H1, 1E9 antibody CDR H2, and 1E9 antibody CDR H3.

[0184] It will be understood that the examples and embodiments described herein are for illustrative purposes only, and that various modifications or changes in light thereof will be suggested to those skilled in the art and are to be included within the spirit and scope of this application and the scope of the appended claims. All publications, patents, and patent applications cited herein are hereby incorporated by reference in their entirety for all purposes. EXAMPLES

[0185] The following examples are for illustrative purposes and are not intended to limit the spirit or scope of the disclosure or claims.

[0186] Example 1 MDA-MB-231 cells (available, for example, from ATCC® as HTB-26™) were incubated with human IgG1 isotype control, CPI-006, CPX-016, or adenosine 5'-(α,β-methylene) diphosphate (also known as APCP, a small molecule inhibitor of CD73 enzymatic activity) followed by the addition of 250 μM adenosine monophosphate (AMP). The catalytic activity of CD73 is shown in FIG. 1B. Phosphate levels were measured in cell culture supernatants using the Sensolyte Malachite Green Assay Kit. Peripheral blood mononuclear cells (PBMCs) were isolated from healthy donors and labeled with CellTrace™ Violet (ThermoFisher Scientific) before being cultured with 1 μg / mL anti-CD3 and anti-CD28, 200 units / mL IL-2, 3 mM AMP, and the indicated treatments (CPI-006 at 500 nM, CPX-016 at 500 nM, human IgG1 isotype control at 890 nM). T cell proliferation was measured by Cell Trace Violet dilution and defined by gating compared to unstimulated PBMCs (Figure 1C). IFN-gamma production was measured in cell culture supernatants by AlphaLISA (Figure 1D). The results shown in Figure 1B-D indicate that inhibition of CD73 activity exerts an agonistic effect on immunomodulatory activity.

[0187] Example 2 PBMCs were isolated from healthy donors and incubated overnight with anti-IgM conjugated to beads, CPI-006 (10 μg / mL), or human IgG1 isotype control (10 μg / mL). Flow cytometry analysis was performed gating on B cells (CD19+CD3-), and mean fluorescence intensity (MFI) was reported for staining with antibodies against cell surface markers CD69, CD83, and CD25, as shown in Figures 2A-2C. PBMCs were isolated from healthy donors and incubated with CPI-006, CPI-016, human IgG1 isotype control, and anti-human CD73 antibody, clone AD2 (available from Bio-Rad Antibodies), at concentrations ranging from approximately 0.1 μg / mL to greater than 10 μg / mL. Flow cytometry analysis was performed by gating on B cells (CD19+CD3-) and mean fluorescence intensity (MFI) is reported for antibody staining of CD69 as shown in Figure 2F. PBMCs were isolated from healthy donors and incubated overnight with anti-IgM coupled to beads or CPI-006 (1 μg / mL) + / - BTK inhibitor ibrutinib (100 nM). Flow cytometry analysis was performed by gating on B cells (CD19+CD3-) and mean fluorescence intensity (MFI) is reported for antibody staining of CD69 and CD83 as shown in Figure 2G. PBMCs were isolated from healthy donors and incubated overnight with APCP (1 μM) or CPI-006 (1 μg / mL) + / - NECA (5'-N-ethylcarboxamidoadenosine). Flow cytometry analysis was performed by gating on B cells (CD19+CD3-) and mean fluorescence intensity (MFI) is reported for antibody staining of CD69 as shown in Figure 2H-2I. PBMCs were isolated from healthy donors and incubated with the indicated treatments for 15 min. Flow cytometry analysis was performed by gating on the indicated cell populations and phospho-ERK staining was assessed as shown in Figure 2J. The results of the above studies indicate that CPI-006 directly activates human B lymphocytes.

[0188] Example 3 The Phase 1 / 1B clinical trial was designed using the protocol shown in Table 1. The primary objective of the study was to demonstrate the safety and tolerability of the active agent, and the secondary objective of the study was to identify the PK / PD profile, drug efficacy, and biomarkers. Eligible patients were adults with solid tumors that had progressed on 1–5 prior therapies, had adequate organ function with ECOG status of 0 or 1, and demonstrated CD73 expression (required for dose expansion trials, but not for dose escalation trials). Adenosine gene signatures were not used for patient selection. Dose expansion includes treatment of non-small cell lung cancer, renal cell carcinoma, non-Hodgkin lymphoma, and other types of cancer (e.g., squamous cell carcinoma of the bladder, prostate, pancreas, colorectum, and head and neck). CPI-006 was administered as a 1-h infusion every 3 weeks, and in the combination therapy, 100 mg of ciforadenant was administered orally twice daily. Biomarker assessment was performed for the impact of CD73 expression in tumors, peripheral blood lymphocyte subsets, antibody occupancy of targets, and serum cytokines. If one or more responses were observed in the stage 1 disease cohort, the study progressed to stage 2. [Table 1]

[0189] Baseline patient demographics are shown below in Table 2, and adverse events are shown in Table 3 (TEAEs refer to treatment-related adverse events based on grade 3 or 4 events or ≥2 of any grade). [Table 2] [Table 3]

[0190] With reference to Table 1, as shown in Figure 3A, serum samples were taken from patients treated with CPI-006 alone (i.e., monotherapy) and the levels of free CPI-006 were measured by ELISA. As shown in Figure 3B, whole blood samples from patients treated with CPI-006 alone were fixed and receptor occupancy was measured by flow cytometry gating on CD73+CD8 T cells. As shown in Figures 3A-3D, with increasing doses of CPI-006, receptor exposure to CPI-006 increases and clearance decreases, and CPI-006 is detectable for 21 days after administration of a single dose of 6 mg / kg or more. Furthermore, total cell surface CD73 remains unchanged and CPI-006 binding sites are occupied. Other results of this study are described below and in Table 4. BLQ is below the limit of quantification. TBD is undetermined. No grade 3 / 4 adverse events were reported. [Table 4]

[0191] Tumor biopsies taken from colorectal cancer patients treated with CPI-006 were evaluated for inhibition of CD73 enzymatic activity. The results, shown in Figure 5, indicate that CD73 is present on tumor cells and that CPI-006 binds and saturates CD73. Furthermore, CPI-006 binding was shown to inhibit CD73 enzymatic activity, confirming that CPI-006 is functional in vivo.

[0192] Cancer patients treated with CPI-006 monotherapy or CPI-006 and ciforadenant combination therapy were evaluated for disease control. As shown in Figure 6A, higher doses of CPI-006 monotherapy provide longer disease control. Furthermore, combination therapy also improves disease control, as shown in Figure 6B.

[0193] We evaluated changes in B and T cells following treatment with CPI-006. As shown in Figures 7A-7B, treatment with CPI-006 significantly reduced the CD73 POS Trafficking of B cells, T cells (CD73 NEG) and monocyte redistribution, and CD73 NEG Results are consistent with an increase in the CD4 / CD8 ratio, including the CD73 POS B cell levels decline with each infusion of CPI-006 and then partially recover to a new steady-state level. These results are consistent with a redistribution of B cells to lymphoid tissues. CD73 NEG No significant changes occurred in B cells. Results in Figure 7D show an increase in HLA-DR expression followed by a gradual decrease in HLA-DR levels. In a patient receiving 6 mg / mkg CPI-006 monotherapy, a decrease in the target legion was observed with ongoing treatment over 11 cycles, as shown in Figure 7E. Figure 7F shows the same patient receiving 6 mg / mkg CPI-006 monotherapy with circulating CD73 POS These results suggest that CPI-006 reduces the expression of CD74 POS It has been shown that B cell levels are reduced and patients treated with CPI-006 exhibit favorable response criteria including a reduction in target populations.

[0194] The immunomodulatory activity of CPI-006 was evaluated in patients receiving CPI-006. Changes in the cytokine levels of patients were measured after CPI-006 treatment, as shown in Figures 8A-8B. The rapid induction of cytokines, including TNF-α, TNF-β, MIP-1α, MIP-1β, IL-6, IL-10, IL-8, IP-10, MCP-1, MCP-2, IL-1Ra, GRO-α, MIP-3α, TNF-RII, IL-7, and MMP-9, and the subsequent elevated levels of CRP and SAA, are consistent with an early inflammatory response. These results indicate that CP1-006 blocks the production of adenosine by CD73, thus modulating the immune response. Furthermore, T cell activation was evaluated with treatment with various dosages of CPI-006 monotherapy or combination therapy of CPI-006 and ciphoradenant. Once a T cell clone is activated, the clone can proliferate and generate clonal copies of the original clone. As shown in Figures 11A-11C, new T cell clones were generated upon treatment with monotherapy and combination therapy. The results further confirm that CPI-006 is an immunomodulator of CD73 positive cells.

[0195] Without being bound by scientific theory, FIG. 10 shows a schematic diagram of the agonist immunomodulatory effect of CPI-006 with ciphoradenant. Adenosine in the tumor microenvironment is an immunosuppressant. CD73 is a surface enzyme present in many tissues, including subsets of T and B cells, where CD73 converts AMP to adenosine and functions in lymphocyte adhesion, migration, and activation. CPI-006 is a humanized IgG1 Fcγ receptor-deficient anti-CD73 with unique properties such as blocking catalytic activity and exerting agonist immunomodulatory activity on CD73-positive cells. Ciphoradenant is an adenosine A2A receptor antagonist with antitumor activity in animal and human clinical trials, and the adenosine signature of tumors correlates with adenosine response.

[0196] Whole blood samples from patients treated with a single dose of CPI-006 monotherapy (i.e., 1 mg / kg, 3 mg / kg, or 6 mg / kg) were analyzed by flow cytometry to further evaluate the immunomodulatory effects. Levels of B cells (CD19+CD3-) are reported as a percent of total lymphocytes (gated based on scatter properties) as shown in Figure 4A. CD73 expression was assessed using a non-competitive anti-CD73 antibody and is reported for B cells (CD19+CD3-) and T cells (CD19-CD3+) as shown in Figure 4B. Purified B cells from healthy human donors were incubated with CPI-006 or human IgG1 isotype control at concentrations of 0.1 μg / mL, 1 μg / mL, and 10 μg / mL for 30 min. Surface levels of CD69 and S1P1 were determined by flow cytometry gating on CD73+ B cells as shown in Figure 4C.

[0197] Without intending to be bound by any theory of the invention, FIG. 4D provides a model for the mechanism that results in the reduction of peripheral B cell levels by CPI-006. CPI-006 binding to CD73+ B cells induces expression of CD69, which promotes internalization of S1P1. Internalization of S1P1 promotes lymphocyte retention in lymphoid organs. Shiow et al, Nature (2006) Vol 440, 540-544. S1P is abundant in blood, and peripheral lymphocytes have low levels of their receptor S1P1 on their surface. S1P1 is upregulated on lymphocytes after they migrate to lymphoid organs. S1P1 signaling mediates lymphocyte egress from lymphoid tissues, and surface expression of S1P1 is required for signaling to promote egress. In contrast, downregulation of S1P1 blocks egress from lymphoid organs.

[0198] Conclusion: Based on the data presented herein, CPI-006 is found to target a novel epitope on CD73 and activate B cells by blocking the production of adenosine by inhibiting the enzyme active site, which leads to increased expression of CD69. Clinical data show that CPI-006 was well tolerated at doses of 1, 3, and 6 mg / kg with no dose-limiting toxicity, dose-proportional PK and receptor occupancy were observed, and CPI-006 affects B lymphocyte trafficking as indicated by a transient redistribution of B cells.

[0199] It will be understood that the examples and embodiments described herein are for illustrative purposes only, and that various modifications or changes in light thereof will be suggested to those skilled in the art and are to be included within the spirit and scope of this application and the scope of the appended claims. All publications, patents, and patent applications cited herein are hereby incorporated by reference in their entirety for all purposes.

[0200] Unofficial sequence listing SEQ ID NO: 1: RASKNVSTSGYSYMH SEQ ID NO:2: LASNLES SEQ ID NO:3: QHSRELPFT SEQ ID NO: 4: GYTFTSYWIT SEQ ID NO: 5: PGSGNTNYNEKFKT SEQ ID NO: 6: EGGLTTEDYALDY SEQ ID NO:7: QVQLVQSGAEVEKPGASVKVSCKASGYTFTSYWITWVRQAPGQGLEWMGDIYPGSGNTNYNEKFKTRVTITADKSTSTAYMELSSLRSEDTAVYYCAKEGGLTTEDYALDYWGQGTLVTV SEQ ID NO:8: EIVLTQSPATLSLSPGERATLSCRASKNVSTSGYSYMHWYQQKPGQAPRLLIYLASNLESGIPPRFSGSGYGTDFTLTINNIESEDAAYYFCQHSRELPFTFGQGTKVEIK SEQ ID NO:9 MEWSWVFLFFLSVTTGVHS QVQLVQSGAEVEKPGASVKVSCKASGYTFTSYWITWVRQAPGQGLEWMGDIYPGSGNTNYNEKFKTRVTITADKSTSTAYMELSSLRSEDTAVYYCAKEGGLTTEDYALDYWG QGTLVTVSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSCD KTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYQSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEK TISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK SEQ ID NO:10 MSVPTQVLGLLLLWLTDARC EIVLTQSPATLSLSPGERATLSCRASKNVSTSGYSYMHWYQQKPGQAPRLLIYLASNLESGIPPRFSGSGYGTDFTLTINNIESEDAAYYFCQHSRELPFTFGQGTKVE IKRTVAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC

[0201] Embodiment The present disclosure further provides the following embodiments.

[0202] Embodiment 1. A method of immunostimulating a subject, comprising administering to the subject an effective amount of an anti-CD73 antibody, wherein the anti-CD73 antibody comprises 1E9 antibody CDR L1, 1E9 antibody CDR L2, 1E9 antibody CDR L3, 1E9 antibody CDR H1, 1E9 antibody CDR H2, and 1E9 antibody CDR H3.

[0203] Embodiment 2. A method of activating B cells in a subject, comprising administering to the subject an effective amount of an anti-CD73 antibody, wherein the anti-CD73 antibody comprises 1E9 antibody CDR L1, 1E9 antibody CDR L2, 1E9 antibody CDR L3, 1E9 antibody CDR H1, 1E9 antibody CDR H2, and 1E9 antibody CDR H3.

[0204] Embodiment 3. A method of reducing B cell shedding from lymphoid tissue in a subject compared to a standard control, comprising administering to the subject an effective amount of an anti-CD73 antibody, wherein the anti-CD73 antibody comprises 1E9 antibody CDR L1, 1E9 antibody CDR L2, 1E9 antibody CDR L3, 1E9 antibody CDR H1, 1E9 antibody CDR H2, and 1E9 antibody CDR H3.

[0205] Embodiment 4. A method of increasing B cell retention in lymphoid organs of a subject compared to a standard control, comprising administering to the subject an effective amount of an anti-CD73 antibody, wherein the anti-CD73 antibody comprises 1E9 antibody CDR L1, 1E9 antibody CDR L2, 1E9 antibody CDR L3, 1E9 antibody CDR H1, 1E9 antibody CDR H2, and 1E9 antibody CDR H3.

[0206] Embodiment 5. A method of increasing internalization of sphingosine-1-phosphate receptor 1 (S1PR1) in cells of a subject compared to a standard control, comprising administering to the subject an effective amount of an anti-CD73 antibody, wherein the anti-CD73 antibody comprises 1E9 antibody CDR L1, 1E9 antibody CDR L2, 1E9 antibody CDR L3, 1E9 antibody CDR H1, 1E9 antibody CDR H2, and 1E9 antibody CDR H3.

[0207] Embodiment 6. The method of one of embodiments 1 to 5, wherein the subject has cancer.

[0208] Embodiment 7. The method of one of embodiments 1 to 5, wherein the subject is immunocompromised.

[0209] Embodiment 8. The method of one of embodiments 1 to 5, wherein the subject has an immunodeficiency disease or an autoimmune disease.

[0210] Embodiment 9. A method of treating a sphingosine-1-phosphate receptor 1 (S1PR1) associated disease in a subject in need thereof, comprising administering to the subject an effective amount of an anti-CD73 antibody, wherein the anti-CD73 antibody comprises 1E9 antibody CDR L1, 1E9 antibody CDR L2, 1E9 antibody CDR L3, 1E9 antibody CDR H1, 1E9 antibody CDR H2, and 1E9 antibody CDR H3.

[0211] Embodiment 10. The method of embodiment 9, wherein the S1PR1-associated disease is graft-versus-host disease, an autoimmune disease, an inflammatory disease, viral myocarditis, a viral disease caused by viral myocarditis, a demyelinating disease, or an organ or tissue transplant rejection.

[0212] Embodiment 11 The method of embodiment 9, wherein the S1PR1-associated disease is an autoimmune disease.

[0213] Embodiment 12. The method according to embodiment 10 or 11, wherein the S1PR1-related disease is multiple sclerosis, rheumatoid arthritis, atopic eczema (atopic dermatitis), Behcet's disease, uveal disease, systemic lupus erythematosus, Sjogren's syndrome, multiple sclerosis, myasthenia gravis, type I diabetes mellitus, endocrine ophthalmopathy, primary biliary cirrhosis, Crohn's disease, glomerulonephritis, sarcoidosis, psoriasis, pemphigus, aplastic anemia, idiopathic thrombocytopenic purpura, allergy, polyarteritis nodosa, progressive systemic sclerosis, mixed connective tissue disease, aortitis syndrome, polymyositis, dermatomyositis, Wegener's granulomatosis, ulcerative colitis, active chronic hepatitis, autoimmune hemolytic anemia, Evans syndrome, bronchial asthma, liver failure, kidney failure, or hay fever.

[0214] Embodiment 13. A method of treating an infectious disease in a subject in need thereof, comprising administering to the subject an effective amount of an anti-CD73 antibody, wherein the anti-CD73 antibody comprises 1E9 antibody CDR L1, 1E9 antibody CDR L2, 1E9 antibody CDR L3, 1E9 antibody CDR H1, 1E9 antibody CDR H2, and 1E9 antibody CDR H3.

[0215] Embodiment 14. A method of treating an inflammatory disease in a subject in need thereof, comprising administering to the subject an effective amount of an anti-CD73 antibody, wherein the anti-CD73 antibody comprises 1E9 antibody CDR L1, 1E9 antibody CDR L2, 1E9 antibody CDR L3, 1E9 antibody CDR H1, 1E9 antibody CDR H2, and 1E9 antibody CDR H3.

[0216] Embodiment 15. A method of treating an autoimmune disease in a subject in need thereof, comprising administering to the subject an effective amount of an anti-CD73 antibody, wherein the anti-CD73 antibody comprises 1E9 antibody CDR L1, 1E9 antibody CDR L2, 1E9 antibody CDR L3, 1E9 antibody CDR H1, 1E9 antibody CDR H2, and 1E9 antibody CDR H3.

[0217] Embodiment 16. The anti-CD73 antibody has a half maximal effective concentration (EC 50 The method of any one of embodiments 1 to 15, wherein the administration is

[0218] Embodiment 17. The anti-CD73 antibody has an EC of about 137 nM. 50 The method of any one of embodiments 1 to 15, wherein the administration is

[0219] Embodiment 18. The anti-CD73 antibody has an EC of about 189 nM. 50 The method of any one of embodiments 1 to 15, wherein the administration is

[0220] Embodiment 19. The method of any one of embodiments 1-18, wherein the effective amount is about 1 mg / kg, 3 mg / kg, 6 mg / kg, 10 mg / kg, 30 mg / kg, 40 mg / kg, or 120 mg / kg.

[0221] Embodiment 20. The method according to any one of embodiments 1 to 19, wherein the CDR L1 has the sequence of SEQ ID NO: 1, the CDR L2 has the sequence of SEQ ID NO: 2, the CDR L3 has the sequence of SEQ ID NO: 3, the CDR H1 has the sequence of SEQ ID NO: 4, the CDR H2 has the sequence of SEQ ID NO: 5 and the CDR H3 has the sequence of SEQ ID NO: 6.

[0222] Embodiment 21. The anti-CD73 antibody comprises a humanized light chain variable region and a humanized heavy chain variable region, the humanized light chain variable region comprises a valine at position corresponding to Kabat position 2, a methionine at position corresponding to Kabat position 4, an aspartic acid or leucine at position corresponding to Kabat position 9, a proline or serine at position corresponding to Kabat position 12, a lysine or proline at position corresponding to Kabat position 18, an alanine at position corresponding to Kabat position 43, a proline or serine at position corresponding to Kabat position 60, a threonine at position corresponding to Kabat position 74, an asparagine or serine at position corresponding to Kabat position 76, an asparagine or serine at position corresponding to Kabat position 77, an isoleucine or leucine at position corresponding to Kabat position 78, a serine or alanine at position corresponding to Kabat position 80, a glutamine at position corresponding to Kabat position 100, a valine at position corresponding to Kabat position 104, and a glutamic acid or acetylcholine at position corresponding to Kabat position 1 leucine at position corresponding to Kabat position 3, phenylalanine or threonine at position corresponding to Kabat position 10, glutamine at position corresponding to Kabat position 11, alanine or leucine at position corresponding to Kabat position 13, threonine at position corresponding to Kabat position 14, valine or proline at position corresponding to Kabat position 15, lysine at position corresponding to Kabat position 16, glutamic acid or aspartic acid at position corresponding to Kabat position 17, threonine at position corresponding to Kabat position 22, lysine at position corresponding to Kabat position 42, arginine at position corresponding to Kabat position 45, isoleucine at position corresponding to Kabat position 58, tyrosine at position corresponding to Kabat position 67, phenylalanine at position corresponding to Kabat position 73, tyrosine at position corresponding to Kabat position 85, or phenylalanine at position corresponding to Kabat position 87; the humanized heavy chain variable region is selected from the group consisting of isoleucine at position 37 of Kabat, alanine or proline at position 40 of Kabat, lysine at position 43 of Kabat, serine at position 70 of Kabat, isoleucine or threonine at position 75 of Kabat, tryptophan at position 82 of Kabat, arginine or lysine at position 83 of Kabat, alanine at position 84 of Kabat, serine at position 85 of Kabat, valine or methionine at position 89 of Kabat, valine at position 5 of Kabat, serine at position 7 of Kabat, valine at position 11 of Kabat, and glutamic acid or 21. The method of any one of embodiments 1-20, wherein the amino acid sequence comprises lysine, isoleucine or valine at position corresponding to Kabat position 20, arginine at position corresponding to Kabat position 38, arginine at position corresponding to Kabat position 66, valine at position corresponding to Kabat position 67, isoleucine at position corresponding to Kabat position 69, alanine at position corresponding to Kabat position 71, lysine at position corresponding to Kabat position 73, threonine at position corresponding to Kabat position 87, glutamic acid at position corresponding to Kabat position 1, valine at position corresponding to Kabat position 24, arginine at position corresponding to Kabat position 44, methionine at position corresponding to Kabat position 48, leucine at position corresponding to Kabat position 80, or glutamic acid at position corresponding to Kabat position 81.

[0223] Embodiment 22. The method of embodiment 21, wherein the humanized heavy chain variable region comprises a valine at position corresponding to Kabat position 5, a serine at position corresponding to Kabat position 7, a valine at position corresponding to Kabat position 11, a glutamic acid at position corresponding to Kabat position 12, a valine at position corresponding to Kabat position 20, an arginine at position corresponding to Kabat position 38, an alanine at position corresponding to Kabat position 40, a methionine at position corresponding to Kabat position 48, an arginine at position corresponding to Kabat position 66, a valine at position corresponding to Kabat position 67, an isoleucine at position corresponding to Kabat position 69, an alanine at position corresponding to Kabat position 71, a lysine at position corresponding to Kabat position 73, a threonine at position corresponding to Kabat position 75, a glutamic acid at position corresponding to Kabat position 81, an arginine at position corresponding to Kabat position 83, a threonine at position corresponding to Kabat position 87, or a valine at position corresponding to Kabat position 89.

[0224] Embodiment 23. The method of embodiment 21 or 22, wherein the humanized heavy chain variable region comprises a valine at position corresponding to Kabat position 5, a serine at position corresponding to Kabat position 7, a valine at position corresponding to Kabat position 11, a glutamic acid at position corresponding to Kabat position 12, a valine at position corresponding to Kabat position 20, an arginine at position corresponding to Kabat position 38, an alanine at position corresponding to Kabat position 40, a methionine at position corresponding to Kabat position 48, an arginine at position corresponding to Kabat position 66, a valine at position corresponding to Kabat position 67, an isoleucine at position corresponding to Kabat position 69, an alanine at position corresponding to Kabat position 71, a lysine at position corresponding to Kabat position 73, a threonine at position corresponding to Kabat position 75, a glutamic acid at position corresponding to Kabat position 81, an arginine at position corresponding to Kabat position 83, a threonine at position corresponding to Kabat position 87, and a valine at position corresponding to Kabat position 89.

[0225] Embodiment 24 The method of any one of embodiments 21 to 23, wherein the humanized heavy chain variable region comprises the sequence of SEQ ID NO:7.

[0226] Embodiment 25 The method of any one of embodiments 21 to 24, wherein the humanized light chain variable region comprises the sequence of SEQ ID NO:8.

[0227] Embodiment 26 The method of any one of embodiments 1 to 25, wherein the anti-CD73 antibody is an IgG.

[0228] Embodiment 27. The method of any one of embodiments 1 to 26, wherein the anti-CD73 antibody is an IgG1.

[0229] Embodiment 28. The method of any one of embodiments 1 to 26, wherein the anti-CD73 antibody is IgG4.

[0230] Embodiment 29. The method of any one of embodiments 1 to 25, wherein the anti-CD73 antibody is a Fab' fragment.

[0231] Embodiment 30 The method of any one of embodiments 1 to 25, wherein the anti-CD73 antibody is a single chain antibody (scFv).

[0232] Embodiment 31. The anti-CD73 antibody has an equilibrium dissociation constant (K D 31. The method according to any one of embodiments 1 to 30, wherein the antibody can bind to the CD73 antigen via the antibody binding domain.

[0233] Embodiment 32. The anti-CD73 antibody has an equilibrium dissociation constant (K D 32. The method according to any one of embodiments 1 to 31, wherein the antibody can bind to the CD73 antigen via the antibody binding domain.

[0234] Embodiment 33 The method of any one of embodiments 1 to 32, wherein the anti-CD73 antibody is capable of binding to the CD73 antigen at a pH of less than about 7.5.

[0235] Embodiment 34. The method of any one of embodiments 1 to 33, wherein the anti-CD73 antibody is capable of binding to the CD73 antigen at a pH of about 6.0 to about 7.0.

[0236] Embodiment 35 The method of any one of embodiments 1 to 34, wherein the anti-CD73 antibody is capable of binding to the CD73 antigen at a pH of about 6.3.

[0237] Embodiment 36 The method of any one of embodiments 1 to 35, wherein the anti-CD73 antibody further comprises a glutamine at the position corresponding to Kabat position 297.

[0238] Embodiment 37 The method of any one of embodiments 1 to 35, wherein the anti-CD73 antibody binds to the CD73 antigen.

[0239] Embodiment 38 The method of embodiment 37, wherein the CD73 antigen forms part of a cell.

[0240] Embodiment 39 The method of embodiment 38, wherein the cell is a lymphoid cell.

[0241] Embodiment 40 The method of embodiment 38, wherein the cell is a B cell.

[0242] Embodiment 41. An anti-cancer immunogenic composition comprising an anti-cancer immunogenic agent and an anti-CD73 antibody, wherein the anti-CD73 antibody comprises 1E9 antibody CDR L1, 1E9 antibody CDR L2, 1E9 antibody CDR L3, 1E9 antibody CDR H1, 1E9 antibody CDR H2, and 1E9 antibody CDR H3.

[0243] Embodiment 42. The anti-cancer immunogenic composition of embodiment 41, wherein the anti-cancer immunogenic agent is an oncolytic virus or a cancer cell component.

[0244] Embodiment 43. An anti-viral immunogenic composition comprising an anti-viral immunogenic agent and an anti-CD73 antibody, wherein the anti-CD73 antibody comprises 1E9 antibody CDR L1, 1E9 antibody CDR L2, 1E9 antibody CDR L3, 1E9 antibody CDR H1, 1E9 antibody CDR H2, and 1E9 antibody CDR H3.

[0245] Embodiment 44. The composition according to any one of embodiments 41 to 43, wherein the CDR L1 has the sequence of SEQ ID NO: 1, the CDR L2 has the sequence of SEQ ID NO: 2, the CDR L3 has the sequence of SEQ ID NO: 3, the CDR H1 has the sequence of SEQ ID NO: 4, the CDR H2 has the sequence of SEQ ID NO: 5, and the CDR H3 has the sequence of SEQ ID NO: 6.

[0246] Embodiment 45. The anti-CD73 antibody comprises a humanized light chain variable region and a humanized heavy chain variable region; the humanized light chain variable region comprises a valine at position corresponding to Kabat position 2, a methionine at position corresponding to Kabat position 4, an aspartic acid or leucine at position corresponding to Kabat position 9, a proline or serine at position corresponding to Kabat position 12, a lysine or proline at position corresponding to Kabat position 18, an alanine at position corresponding to Kabat position 43, a proline or serine at position corresponding to Kabat position 60, a threonine at position corresponding to Kabat position 74, an asparagine or serine at position corresponding to Kabat position 76, an asparagine or serine at position corresponding to Kabat position 77, an isoleucine or leucine at position corresponding to Kabat position 78, a serine or alanine at position corresponding to Kabat position 80, a glutamine at position corresponding to Kabat position 100, a valine at position corresponding to Kabat position 104, and a glutamic acid or acetylcholine at position corresponding to Kabat position 1 leucine at position corresponding to Kabat position 3, phenylalanine or threonine at position corresponding to Kabat position 10, glutamine at position corresponding to Kabat position 11, alanine or leucine at position corresponding to Kabat position 13, threonine at position corresponding to Kabat position 14, valine or proline at position corresponding to Kabat position 15, lysine at position corresponding to Kabat position 16, glutamic acid or aspartic acid at position corresponding to Kabat position 17, threonine at position corresponding to Kabat position 22, lysine at position corresponding to Kabat position 42, arginine at position corresponding to Kabat position 45, isoleucine at position corresponding to Kabat position 58, tyrosine at position corresponding to Kabat position 67, phenylalanine at position corresponding to Kabat position 73, tyrosine at position corresponding to Kabat position 85, or phenylalanine at position corresponding to Kabat position 87; the humanized heavy chain variable region comprises an isoleucine at position corresponding to Kabat position 37, an alanine or proline at position corresponding to Kabat position 40, a lysine at position corresponding to Kabat position 43, a serine at position corresponding to Kabat position 70, an isoleucine or threonine at position corresponding to Kabat position 75, a tryptophan at position corresponding to Kabat position 82, an arginine or lysine at position corresponding to Kabat position 83, an alanine at position corresponding to Kabat position 84, a serine at position corresponding to Kabat position 85, a valine or methionine at position corresponding to Kabat position 89, a valine at position corresponding to Kabat position 5, a serine at position corresponding to Kabat position 7, a valine at position corresponding to Kabat position 11, and a glutamic acid or 45. The composition of any one of embodiments 41-44, comprising lysine, isoleucine or valine at position corresponding to Kabat position 20, arginine at position corresponding to Kabat position 38, arginine at position corresponding to Kabat position 66, valine at position corresponding to Kabat position 67, isoleucine at position corresponding to Kabat position 69, alanine at position corresponding to Kabat position 71, lysine at position corresponding to Kabat position 73, threonine at position corresponding to Kabat position 87, glutamic acid at position corresponding to Kabat position 1, valine at position corresponding to Kabat position 24, arginine at position corresponding to Kabat position 44, methionine at position corresponding to Kabat position 48, leucine at position corresponding to Kabat position 80, or glutamic acid at position corresponding to Kabat position 81.

[0247] Embodiment 46. The composition of embodiment 45, wherein the humanized heavy chain variable region comprises a valine at position corresponding to Kabat position 5, a serine at position corresponding to Kabat position 7, a valine at position corresponding to Kabat position 11, a glutamic acid at position corresponding to Kabat position 12, a valine at position corresponding to Kabat position 20, an arginine at position corresponding to Kabat position 38, an alanine at position corresponding to Kabat position 40, a methionine at position corresponding to Kabat position 48, an arginine at position corresponding to Kabat position 66, a valine at position corresponding to Kabat position 67, an isoleucine at position corresponding to Kabat position 69, an alanine at position corresponding to Kabat position 71, a lysine at position corresponding to Kabat position 73, a threonine at position corresponding to Kabat position 75, a glutamic acid at position corresponding to Kabat position 81, an arginine at position corresponding to Kabat position 83, a threonine at position corresponding to Kabat position 87, or a valine at position corresponding to Kabat position 89.

[0248] Embodiment 47. The composition of embodiment 45 or 46, wherein the humanized heavy chain variable region comprises a valine at position corresponding to Kabat position 5, a serine at position corresponding to Kabat position 7, a valine at position corresponding to Kabat position 11, a glutamic acid at position corresponding to Kabat position 12, a valine at position corresponding to Kabat position 20, an arginine at position corresponding to Kabat position 38, an alanine at position corresponding to Kabat position 40, a methionine at position corresponding to Kabat position 48, an arginine at position corresponding to Kabat position 66, a valine at position corresponding to Kabat position 67, an isoleucine at position corresponding to Kabat position 69, an alanine at position corresponding to Kabat position 71, a lysine at position corresponding to Kabat position 73, a threonine at position corresponding to Kabat position 75, a glutamic acid at position corresponding to Kabat position 81, an arginine at position corresponding to Kabat position 83, a threonine at position corresponding to Kabat position 87, and a valine at position corresponding to Kabat position 89.

[0249] Embodiment 48. The composition of any one of embodiments 45 to 47, wherein the humanized heavy chain variable region comprises the sequence of SEQ ID NO:7.

[0250] Embodiment 49. The composition of any one of embodiments 45 to 48, wherein the humanized light chain variable region comprises the sequence of SEQ ID NO:8.

[0251] Embodiment 50. The composition of any one of embodiments 41 to 49, wherein the anti-CD73 antibody is an IgG.

[0252] Embodiment 51. The composition of any one of embodiments 41 to 50, wherein the anti-CD73 antibody is an IgG1.

[0253] Embodiment 52. The composition of any one of embodiments 41 to 50, wherein the anti-CD73 antibody is IgG4.

[0254] Embodiment 53. The composition of any one of embodiments 41 to 49, wherein the anti-CD73 antibody is a Fab' fragment.

[0255] Embodiment 54. The composition of any one of embodiments 41 to 49, wherein the anti-CD73 antibody is a single chain antibody (scFv).

[0256] Embodiment 55. The anti-CD73 antibody has an equilibrium dissociation constant (K D 55. The composition according to any one of embodiments 41 to 54, which is capable of binding to the CD73 antigen via the antibody.

[0257] Embodiment 56. The anti-CD73 antibody has an equilibrium dissociation constant (K D 56. The composition according to any one of embodiments 41 to 55, which is capable of binding to the CD73 antigen via the IL-11 domain.

[0258] Embodiment 57. The composition of any one of embodiments 41 to 56, wherein the anti-CD73 antibody is capable of binding to the CD73 antigen at a pH of less than about 7.5.

[0259] Embodiment 58. The composition of any one of embodiments 41 to 57, wherein the anti-CD73 antibody is capable of binding to the CD73 antigen at a pH of about 6.0 to about 7.0.

[0260] Embodiment 59. The composition of any one of embodiments 41 to 58, wherein the anti-CD73 antibody is capable of binding to the CD73 antigen at a pH of about 6.3.

[0261] Embodiment 60. The composition of any one of embodiments 41 to 59, wherein the anti-CD73 antibody further comprises a glutamine at the position corresponding to Kabat position 297.

[0262] Embodiment 61. The composition of any one of embodiments 41 to 60, wherein the anti-CD73 antibody is bound to the CD73 antigen.

[0263] Embodiment 62. The composition of embodiment 61, wherein the CD73 antigen forms part of a cell.

[0264] Embodiment 63 The method of embodiment 62, wherein the cell is a lymphoid cell.

[0265] Embodiment 64. The composition of embodiment 62, wherein the cell is a B cell.

[0266] Embodiment 65. A method for treating cancer in a patient in need thereof, comprising administering to the patient an effective amount of an anti-CD73 antibody to effectively activate antigen-presenting cells.

[0267] Embodiment 66. A method of treating cancer in a patient in need thereof, comprising: (i) administering to the patient an effective amount of an anti-CD73 antibody; and (ii) monitoring levels of antigen presenting cells.

[0268] Embodiment 67. A method of treating cancer in a patient in need thereof, comprising: (i) administering to the patient an effective amount of an anti-CD73 antibody to effectively activate antigen-presenting cells; and (ii) monitoring the level of antigen-presenting cells.

[0269] Embodiment 68. The method of embodiment 66 or 67, wherein monitoring the level of antigen-presenting cells comprises: (a) obtaining a biological sample from the patient; and (b) detecting the level of antigen-presenting cells in the biological sample.

[0270] Embodiment 69. The method of embodiment 68, wherein the biological sample is a blood sample.

[0271] Embodiment 70. The method of embodiment 68, wherein the biological sample is a peripheral blood sample.

[0272] Embodiment 71. The method of any one of embodiments 68 to 70, wherein detecting the level of antigen-presenting cells in the biological sample comprises flow cytometry, immunohistochemistry, or a combination thereof.

[0273] Embodiment 72. The method of any one of embodiments 65 to 71, wherein the antigen-presenting cells are in a cancer tumor microenvironment.

[0274] Embodiment 73. The method of any one of embodiments 65 to 72, wherein the antigen-presenting cell is a B cell.

[0275] Embodiment 74. The method of embodiment 73, wherein the B cells are CD19+.

[0276] Embodiment 75. The method of embodiment 73 or 74, wherein the B cells are present in the biological sample in an amount of about 0.5 x 10e6 cells / mL or more.

[0277] Embodiment 76. The method of any one of embodiments 65 to 72, wherein the antigen-presenting cell is a dendritic cell.

[0278] Embodiment 77 The method of embodiment 76, wherein the dendritic cells are classical dendritic cells.

[0279] Embodiment 78. The method of embodiment 76, wherein the dendritic cells are plasmacytoid dendritic cells.

[0280] Embodiment 79. The metho...

Claims

1. 1. A composition for activating B cells in a subject, the composition comprising an effective amount of an anti-CD73 antibody, the anti-CD73 antibody comprising 1E9 antibody CDR L1, 1E9 antibody CDR L2, 1E9 antibody CDR L3, 1E9 antibody CDR H1, 1E9 antibody CDR H2, and 1E9 antibody CDR H3; said CDR L1 having the sequence of SEQ ID NO:1, said CDR L2 having SEQ ID NO:2, said CDR L3 having SEQ ID NO:3, said CDR H1 having SEQ ID NO:4, said CDR H2 having SEQ ID NO:5, and said CDR H3 having SEQ ID NO:

6.

2. The composition described in claim 1, which reduces the release of B cells from a subject's lymphatic tissue compared to a standard control.

3. The composition of claim 1 , wherein retention of said B cells in lymphoid organs is increased compared to a standard control.

4. The composition of claim 1 , wherein the subject has cancer.

5. The composition of claim 1 , wherein the subject is immunocompromised.

6. The composition of claim 1, wherein the anti-CD73 antibody is administered at a half maximal effective concentration (EC50) of at least 100 nM.

7. The composition of claim 1, wherein the anti-CD73 antibody is capable of binding to the CD73 antigen with an equilibrium dissociation constant (KD) of about 0.3 to about 25 nM.

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