Anti-pvrig antibodies and uses thereof

Abstract

The invention provides an antibody or an antigen binding fragment thereof, which is specifically bound with PVRIG and has high binding affinity to human PVRIG protein and cynomolgus monkey PVRIG protein; and the compound has strong activity in the aspects of reporter gene level and CD8T cell activation. Compared with known SRF813 and COM701, the antibody disclosed by the invention comprehensively shows better in-vitro activity, and a part of the antibody is combined with the PD-1 antibody to have an obvious anti-tumor effect, so that the antibody becomes an excellent candidate drug molecule for treatment and diagnosis.

Description

[0001] The application date of this case is: December 22, 2023; the application number is: 202311790630.9; the name of the invention is: Divisional application for invention patent application for anti-PVRIG antibodies and their uses. Technical Field

[0002] The present disclosure relates to the field of antibodies, and more particularly to an antibody against PVRIG. Background Art

[0003] Tumor immunotherapy is one of the mainstays in today's oncology field, especially for the treatment of unresectable, metastatic and recurrent cancers. The success of immune checkpoint inhibitors (ICIs), and their combination with chemotherapy, immunotherapy and targeted drugs, has changed the paradigm of cancer treatment. However, PD-1 treatment still only shows long-term, durable responses in 10-30% of patients, and the majority of the population lacks response. Acquired resistance and immune-related adverse events (IRAEs) are also huge obstacles. One of the mechanisms to overcome the limitations of PD-1 therapy is the development of other ICIs related to the tumor microenvironment, which, in combination with anti-PD-1 / PD-L1, may help overcome the limitations of previous treatments. Studies have shown that in patients resistant to targeted PD-1 immunotherapy, higher levels of PVRL2 (CD112) in cancer cells are a potential key biomarker for disease treatment and are overexpressed in multiple tumor types including breast cancer and ovarian cancer. PVRL2 is currently identified as the only functional ligand of PVRIG and can bind to PVRIG with high affinity.

[0004] PVRIG, also known as CD112R, was identified as a new inhibitory receptor in 2016 and is expressed in natural killer cells (NK cells) and T lymphocytes. PVRIG binds to its ligand PVRL2, mediates intracellular signal transduction, and leads to reduced T cell cytotoxicity. In addition, it can inhibit TCR-mediated NFAT activation, further inhibiting T cell activation, and also compete with DNAM-1 for PVRL2 ligands to block the stimulatory signals it transmits, thereby achieving dual negative regulation of T cell function to exert an immunosuppressive effect.

[0005] Preclinical studies have shown that blocking PVRIG can inhibit tumor growth in both mouse and human solid tumors, and combined PD-1 / TIGIT treatment significantly improved the therapeutic effect; anti-PVRIG antibodies enhance NK cell activation through the DNAM-1-PVRL2 signaling pathway, and their anti-tumor activity depends on NK cells and CD8+T cells. According to existing clinical data, its monotherapy and combined anti-PD-1 antibody treatment of advanced solid tumors have shown good therapeutic effects, especially in patients who have received immune checkpoint inhibitors, there is still a 72% best response rate (≥SD). In terms of safety, no DLT was observed when used alone or in combination with Opdivo, and there was no increase in toxicity when used in combination with PD-1 monoclonal antibodies, and no subject stopped the study treatment due to the toxicity of any study drug. Based on the existing clinical data, the drugability of this target has been preliminarily demonstrated and has shown considerable efficacy.

[0006] As a new type of immune checkpoint inhibitor for NK cells and T cells, PVRIG has a clear target mechanism. On the one hand, the antibody can relieve the immunosuppression of NK cells and CD8+T cells, and on the other hand, it can also mediate the activation signals of NK cells and CD8+T cells to enhance tumor killing. Currently, there is no drug on the market in the world. COM701, the fastest-developed drug for tumor indications, has just entered Phase II clinical trials. The results of preclinical in vivo efficacy studies are significant, and clinical data show good safety and positive efficacy in combination with PD-1 monoclonal antibodies. Summary of the invention

[0007] In view of the above problems, the present disclosure provides antibodies, preparation methods and compositions thereof, etc. The benefits provided by the present disclosure are widely applicable to the fields of antibody therapy and diagnosis, and can be used in combination with antibodies reactive with various targets.

[0008] The present invention discloses an isolated antibody or an antigen-binding fragment thereof, wherein the antibody or the antigen-binding fragment thereof specifically binds to PVRIG and comprises a heavy chain variable region (VH) and a light chain variable region (VL),

[0009] The heavy chain variable region comprises:

[0010] (i) HCDR1, which comprises a sequence having at least 80%, at least 85%, at least 95%, or 100% sequence identity to one of SEQ ID NOs: 35-39 or consists of SEQ ID NOs: 35-39;

[0011] (ii) HCDR2, which comprises or consists of a sequence having at least 80%, at least 85%, at least 95%, or 100% sequence identity to one of SEQ ID NOs: 40-45; and

[0012] (iii) HCDR3, which comprises or consists of a sequence having at least 80%, at least 85%, at least 95%, or 100% sequence identity to one of SEQ ID NOs: 48-53;

[0013] The light chain variable region comprises:

[0014] (i) LCDR1, comprising or consisting of a sequence having at least 80%, at least 85%, at least 95%, or 100% sequence identity to one of SEQ ID NOs: 56-62;

[0015] (ii) LCDR2, comprising or consisting of a sequence having at least 80%, at least 85%, at least 95%, or 100% sequence identity to one of SEQ ID NOs: 63-67; and

[0016] (iii) LCDR3, comprising or consisting of a sequence having at least 80%, at least 85%, at least 95%, or 100% sequence identity to one of SEQ ID NOs: 68-73.

[0017] In some embodiments of the present invention, the antibody or fragment comprises:

[0018] (i) HCDR1 shown in SEQ ID NO:35, HCDR2 shown in SEQ ID NO:40, and HCDR3 shown in SEQ ID NO:48, LCDR1 shown in SEQ ID NO:56, LCDR2 shown in SEQ ID NO:63, and LCDR3 shown in SEQ ID NO:68; or

[0019] (ii) HCDR1 set forth in SEQ ID NO:35, HCDR2 set forth in SEQ ID NO:41, and HCDR3 set forth in SEQ ID NO:48, LCDR1 set forth in SEQ ID NO:57, LCDR2 set forth in SEQ ID NO:63, and LCDR3 set forth in SEQ ID NO:68; or

[0020] (iii) HCDR1 of SEQ ID NO:36, HCDR2 of SEQ ID NO:42, and HCDR3 of SEQ ID NO:49, LCDR1 of SEQ ID NO:58, LCDR2 of SEQ ID NO:64, and LCDR3 of SEQ ID NO:69; or

[0021] (iv) HCDR1 of SEQ ID NO:37, HCDR2 of SEQ ID NO:43, and HCDR3 of SEQ ID NO:50, LCDR1 of SEQ ID NO:59, LCDR2 of SEQ ID NO:65, and LCDR3 of SEQ ID NO:70; or

[0022] (v) HCDR1 of SEQ ID NO:37, HCDR2 of SEQ ID NO:43, and HCDR3 of SEQ ID NO:51, LCDR1 of SEQ ID NO:60, LCDR2 of SEQ ID NO:65, and LCDR3 of SEQ ID NO:71; or

[0023] (vi) HCDR1 of SEQ ID NO:38, HCDR2 of SEQ ID NO:44, and HCDR3 of SEQ ID NO:52, LCDR1 of SEQ ID NO:61, LCDR2 of SEQ ID NO:66, and LCDR3 of SEQ ID NO:72; or

[0024] (vii) HCDR1 shown in SEQ ID NO:39, HCDR2 shown in SEQ ID NO:45, and HCDR3 shown in SEQ ID NO:53, LCDR1 shown in SEQ ID NO:62, LCDR2 shown in SEQ ID NO:67, and LCDR3 shown in SEQ ID NO:73.

[0025] In some embodiments of the present invention, the antibody or fragment, wherein the heavy chain variable region comprises a sequence having at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to one of SEQ ID NOs: 17-23 or consists of one of SEQ ID NOs: 17-23.

[0026] In some embodiments of the present invention, the antibody or fragment, wherein the light chain variable region comprises a sequence having at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to one of SEQ ID NOs: 28-34 or consists of one of SEQ ID NOs: 28-34.

[0027] In some embodiments of the present invention, the antibody or fragment further comprises a heavy chain constant region and a light chain constant region, the heavy chain constant region comprises a sequence having at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 15, or consists of SEQ ID NO: 15; the light chain constant region comprises a sequence having at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to SEQ ID NO: 16, or consists of SEQ ID NO: 16.

[0028] In some embodiments of the present invention, the antibody or fragment comprises:

[0029] a light chain comprising or consisting of a sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to one of SEQ ID NOs: 2, 4, 6, 8, 10, 12, 14;

[0030] A heavy chain comprising a sequence having at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to one of SEQ ID NOs: 1, 3, 5, 7, 9, 11, 13 or consisting of one of SEQ ID NOs: 1, 3, 5, 7, 9, 11, 13.

[0031] In some embodiments of the present invention, the antibody or fragment comprises:

[0032] (i) the light chain shown in SEQ ID NO: 2, and the heavy chain shown in SEQ ID NO: 1; or

[0033] (ii) the light chain shown in SEQ ID NO: 4, and the heavy chain shown in SEQ ID NO: 3; or

[0034] (iii) the light chain shown in SEQ ID NO: 6, and the heavy chain shown in SEQ ID NO: 5; or

[0035] (iv) the light chain shown in SEQ ID NO: 8, and the heavy chain shown in SEQ ID NO: 7; or

[0036] (v) the light chain shown in SEQ ID NO:10, and the heavy chain shown in SEQ ID NO:9; or (vi) the light chain shown in SEQ ID NO:12, and the heavy chain shown in SEQ ID NO:11; or (vii) the light chain shown in SEQ ID NO:14, and the heavy chain shown in SEQ ID NO:13.

[0037] In some embodiments of the present invention, the antibody or fragment is subjected to hotspot removal modification to avoid the influence of aspartic acid isomerization on the antibody structure and function; wherein, preferably,

[0038] The heavy chain variable region comprises HCDR2 as shown in SEQ ID NO: 46 or 47, and\or,

[0039] HCDR3 shown in SEQ ID NO:54 or 55.

[0040] In some embodiments of the present invention, the antibody or fragment, wherein the heavy chain variable region comprises a sequence having at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% or 100% sequence identity to one of SEQ ID NOs: 24-27 or consists of one of SEQ ID NOs: 24-27.

[0041] In some embodiments of the present invention, the antibody or fragment, wherein the antibody is a whole antibody, a monoclonal antibody, a chimeric antibody or a humanized antibody or an improved antibody thereof such as an improved chimeric antibody;

[0042] The fragment is a Fab fragment, a Fab' fragment, a F(ab')2 fragment, a Fv fragment, or a single-chain Fv fragment (scFv).

[0043] On the other hand, the present invention also provides an isolated nucleic acid molecule comprising a nucleic acid sequence encoding the antibody or fragment.

[0044] On the other hand, the present invention also provides a vector comprising the nucleic acid molecule.

[0045] On the other hand, the present invention also provides a host cell, comprising the nucleic acid molecule or the vector.

[0046] In another aspect, the present invention also provides a conjugate comprising the antibody or fragment coupled to at least one detectable label.

[0047] In another aspect, the present invention also provides an antibody drug conjugate comprising an antibody, wherein the antibody comprises one or more drug moieties, wherein the drug moieties are covalently linked to the antibody or fragment directly or via a linker.

[0048] On the other hand, the present invention also provides a multispecific molecule, which comprises the antibody or antigen-binding fragment; preferably, the multispecific molecule specifically binds to PVRIG, and additionally specifically binds to one or more other targets; further preferably, the multispecific molecule also comprises at least one molecule having a second binding specificity for a second target.

[0049] On the other hand, the present invention also provides a pharmaceutical composition or kit, comprising the antibody or fragment, or the nucleic acid molecule, or the vector, or the host cell, or the conjugate, or the antibody-drug conjugate, or the multispecific molecule, and a pharmaceutically acceptable carrier.

[0050] On the other hand, the present invention also provides use of the antibody or fragment, or the nucleic acid molecule, or the vector, or the host cell, or the conjugate, or the antibody-drug conjugate, or the multispecific molecule, or the pharmaceutical composition or kit in the preparation of a kit for diagnosing, detecting or monitoring diseases related to PVRIG expression.

[0051] On the other hand, the present invention also provides the use of the antibody or fragment, or the nucleic acid molecule, or the vector, or the host cell, or the conjugate, or the antibody-drug conjugate, or the multispecific molecule, or the pharmaceutical composition or kit in the preparation of a drug for treating a disease related to PVRIG expression or determining its prognosis.

[0052] On the other hand, the above-mentioned disease associated with PVRIG expression is cancer, and the cancer is selected from the following group: squamous cell carcinoma, small cell lung cancer, pituitary cancer, esophageal cancer, astrocytoma, soft tissue sarcoma, non-small cell lung cancer (including squamous cell non-small cell lung cancer), lung adenocarcinoma, lung squamous carcinoma, peritoneal cancer, esophageal cancer, gastrointestinal cancer, pancreatic cancer, glioblastoma, cervical cancer, ovarian cancer, bladder cancer, hepatoma, breast cancer, colon cancer, colorectal cancer, cervical cancer, uterine cancer, salivary gland cancer, kidney cancer, renal cell carcinoma, liver cancer, prostate cancer, vulvar cancer, thyroid cancer, brain cancer, endometrial cancer, testicular cancer, biliary tract cancer, gallbladder cancer, gastric cancer, melanoma or various types of head and neck cancer (including head and neck squamous cell carcinoma), blood system cancer or any other disease or condition characterized by uncontrolled cell growth.

[0053] The PVRIG antibody provided by the present invention has high binding affinity to human PVRIG protein and cynomolgus monkey PVRIG protein; and has potent activity at both reporter gene level and CD8T cell activation. Compared with the known SRF813 and COM701, the antibodies of the present invention comprehensively show better in vitro activity, and some antibodies combined with PD-1 antibodies have obvious anti-tumor effects, making them excellent candidate drug molecules for treatment and diagnosis. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The accompanying drawings are used to provide further understanding of the present disclosure and constitute a part of the specification. They are used to explain the present disclosure together with the embodiments of the present disclosure and do not constitute a limitation of the present disclosure.

[0055] Figure 1A is the result of FACS detection of the binding of antibody 1 to CHOK1 overexpressing PVRIG of different species, where CHOK1 / Human PVRIG represents a stable cell line overexpressing human PVRIG antigen, CHOK1 / cyno PVRIG represents a stable cell line overexpressing monkey PVRIG antigen, CHOK1 / mouse PVRIG represents a stable cell line overexpressing mouse PVRIG antigen, CHOK1 is a normal cell line that does not express PVRIG antigen, and MFI represents mean fluorescence intensity;

[0056] Figure 1B is the result of FACS detection of the binding of antibody 6 to CHOK1 overexpressing PVRIG of different species, where CHOK1 / Human PVRIG represents a stable cell line overexpressing human PVRIG antigen, CHOK1 / cyno PVRIG represents a stable cell line overexpressing monkey PVRIG antigen, CHOK1 / mouse PVRIG represents a stable cell line overexpressing mouse PVRIG antigen, CHOK1 is a normal cell line that does not express PVRIG antigen, and MFI represents mean fluorescence intensity;

[0057] Figure 1C is the result of FACS detection of the binding of antibody 7 to CHOK1 overexpressing PVRIG of different species, where CHOK1 / Human PVRIG represents a stable cell line overexpressing human PVRIG antigen, CHOK1 / cyno PVRIG represents a stable cell line overexpressing monkey PVRIG antigen, CHOK1 / mouse PVRIG represents a stable cell line overexpressing mouse PVRIG antigen, CHOK1 is a normal cell line that does not express PVRIG antigen, and MFI represents mean fluorescence intensity;

[0058] Figure 1Dis the result of FACS detection of the binding of antibody 16 to CHOK1 overexpressing PVRIG of different species, where CHOK1 / Human PVRIG represents a stable cell line overexpressing human PVRIG antigen, CHOK1 / cyno PVRIG represents a stable cell line overexpressing monkey PVRIG antigen, CHOK1 / mouse PVRIG represents a stable cell line overexpressing mouse PVRIG antigen, CHOK1 is a normal cell line that does not express PVRIG antigen, and MFI represents mean fluorescence intensity;

[0059] Figure 1E is the result of FACS detection of the binding of antibody 27 to CHOK1 overexpressing PVRIG of different species, where CHOK1 / Human PVRIG represents a stable cell line overexpressing human PVRIG antigen, CHOK1 / cyno PVRIG represents a stable cell line overexpressing monkey PVRIG antigen, CHOK1 / mouse PVRIG represents a stable cell line overexpressing mouse PVRIG antigen, CHOK1 is a normal cell line that does not express PVRIG antigen, and MFI represents mean fluorescence intensity;

[0060] Figure 1F is the result of FACS detection of the binding of antibody 52 to CHOK1 overexpressing PVRIG of different species, where CHOK1 / Human PVRIG represents a stable cell line overexpressing human PVRIG antigen, CHOK1 / cyno PVRIG represents a stable cell line overexpressing monkey PVRIG antigen, CHOK1 / mouse PVRIG represents a stable cell line overexpressing mouse PVRIG antigen, CHOK1 is a normal cell line that does not express PVRIG antigen, and MFI represents mean fluorescence intensity;

[0061] Figure 1G is the result of FACS detection of the binding of antibody 55 to CHOK1 overexpressing PVRIG of different species, where CHOK1 / Human PVRIG represents a stable cell line overexpressing human PVRIG antigen, CHOK1 / cyno PVRIG represents a stable cell line overexpressing monkey PVRIG antigen, CHOK1 / mouse PVRIG represents a stable cell line overexpressing mouse PVRIG antigen, CHOK1 is a normal cell line that does not express PVRIG antigen, and MFI represents mean fluorescence intensity;

[0062] Figure 2: CHOK1 / Human PVRIG cell binding curves of antibodies 1, 6, 7, 16, 27, 52, 55 and reference antibodies SRF813 and COM701; wherein the abscissa Conc. is the antibody concentration in nM, the ordinate Geom.Mean is the mean fluorescence intensity, and Human lgG1 is human lgG1;

[0063] Figure 3 are the CHOK1 / Cyno PVRIG cell binding curves of antibodies 1, 6, 7, 16, 27, 52, 55 and reference antibodies SRF813 and COM701, wherein the abscissa Conc. is the antibody concentration in nM, the ordinate Geom.Mean is the mean fluorescence intensity, and Human lgG1 is human lgG1;

[0064] Figure 4 is the Human PVRIG protein (human PVRIG protein) binding curve of antibodies 1, 6, 7, 16, 27, 52, 55 and reference antibodies SRF813 and COM701, wherein the abscissa Conc. is the antibody concentration in nM, the ordinate is the reading of the microplate reader at OD450nm, and Human lgG1 is human lgG1;

[0065] Figure 5 is the Cyno PVRIG protein (monkey PVRIG protein) binding curve of antibodies 1, 6, 7, 16, 27, 52, 55 and reference antibodies SRF813 and COM701, wherein the abscissa Conc. is the antibody concentration in nM, the ordinate is the reading of the microplate reader at OD450nm, and Human lgG1 is human lgG1;

[0066] Figure 6 are the results of protein level blocking activity of antibodies 1, 6, 7, 16, 27, 52, 55 and reference antibodies SRF813 and COM701, wherein the abscissa Conc. is the antibody concentration in nM, the ordinate is the reading of the microplate reader at OD450 nm, and Human lgG1 is human lgG1;

[0067] Figure 7 is the reporter gene activity detection curve of antibodies 1, 6, 7, 16, 27, 52, 55 and reference antibodies SRF813 and COM701, wherein the abscissa Conc. is the antibody concentration in ug / ml, the ordinate Luminescence (RLU) is the relative luminescence unit, and Human lgG1 is human lgG1;

[0068] Fig. 8A , Figure 8B , Figure 8CIt is the result of cytokine hIFNγ (human interferon γ) secretion detection, the horizontal axis is the antibody concentration, in ug / ml, the vertical axis is the hIFNγ concentration, in pg / ml, Human lgG4 is human lgG4, and the dotted line position in the figure refers to the cytokine hIFNγ detection value after incubation of CTV-Colo205 cells treated with 5ug / ml pp65 and CD8+T cells;

[0069] Fig.8D , Fig. 8E , Fig.8F It is the detection result of the target cell killing level. The horizontal axis is the antibody concentration in ug / ml, and the vertical axis Target cell killing is the target cell killing ability; Human lgG4 is human lgG4. The dotted line position in the figure refers to the cytokine hIFNγ detection value after incubation of CTV-Colo205 cells treated with 5ug / ml pp65 and CD8+T cells;

[0070] Fig. 9 is the epitope classification of antibodies 1, 6, 7, 16, 27, 52, 55 and reference antibodies SRF813 and COM701 binding to PVRIG;

[0071] Fig.10 The results of in vivo pharmacodynamic activity test of antibodies 1, 6, 7, 16, 27, 52, 55 combined with PD-1 antibody. The horizontal axis Days Post Treatment is the number of days after treatment, in days, and the vertical axis Tumor Volume (mm 3 ) is the tumor volume in cubic millimeters (mm 3 ), Vehicle represents 10 mM phosphate buffered saline (PBS), ip represents intraperitoneal administration, BIW represents twice a week, and BIW*3 represents twice a week for three consecutive weeks;

[0072] Fig.11 is the Human PVRIG protein (human PVRIG protein) binding curve of antibody 52, and variants 52_vH (DG / EG-DS / ES), 52_vH (DG / EG-DS / DA), 52_vH (DG / DA-DS / ES), and 52_vH (DG / DA-DS / DA), wherein the abscissa Conc. is the antibody concentration in nM, and the ordinate is the reading of the microplate reader at OD450 nm;

[0073] Fig.12is the Cyno PVRIG protein (monkey PVRIG protein) binding curve of antibodies 52, 52_vH(DG / EG-DS / ES), 52_vH(DG / EG-DS / DA), 52_vH(DG / DA-DS / ES), and 52_vH(DG / DA-DS / DA), where the abscissa Conc. is the antibody concentration in nM, and the ordinate is the reading of the microplate reader at OD450 nm;

[0074] Fig.13 The antibody is the protein level blocking activity results of antibody 52, and variants 52_vH(DG / EG-DS / ES), 52_vH(DG / EG-DS / DA), 52_vH(DG / DA-DS / ES), and 52_vH(DG / DA-DS / DA), wherein the abscissa Conc. is the antibody concentration in nM, and the ordinate is the reading of the microplate reader at OD450 nm;

[0075] Fig.14 52_vH(DG / EG-DS / ES), 52_vH(DG / EG-DS / DA), 52_vH(DG / DA-DS / ES), 52_vH(DG / DA-DS / DA) are CHOK1 / Human PVRIG cell binding curves of antibody 52, and variants 52_vH(DG / EG-DS / ES), 52_vH(DG / DA-DS / DA); wherein the abscissa Conc. is the antibody concentration in nM, and the ordinate Geom.Mean is the mean fluorescence intensity;

[0076] Fig.15 are the CHOK1 / Cyno PVRIG cell binding curves of antibody 52, and variants 52_vH(DG / EG-DS / ES), 52_vH(DG / EG-DS / DA), 52_vH(DG / DA-DS / ES), and 52_vH(DG / DA-DS / DA), where the abscissa Conc. is the antibody concentration in nM, and the ordinate Geom.Mean is the mean fluorescence intensity;

[0077] Fig.16 This is the reporter gene activity detection curve of antibody 52, and variants 52_vH (DG / EG-DS / ES), 52_vH (DG / EG-DS / DA), 52_vH (DG / DA-DS / ES), and 52_vH (DG / DA-DS / DA), where the abscissa Conc. is the antibody concentration in ug / ml, and the ordinate Luminescence (RLU) is the relative luminescence unit. DETAILED DESCRIPTION

[0078] In order to make those skilled in the art better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only illustrative embodiments of a part of the present invention, rather than all embodiments. Therefore, the present invention is not limited to the specific embodiments illustrated. In addition, any section titles used herein are not to be construed as limiting the subject matter described.

[0079] Unless otherwise defined herein, scientific and technical terms used in conjunction with the present invention will have the meanings commonly understood by those of ordinary skill in the art. In addition, unless the context requires otherwise, terms in the singular shall include plural forms, and terms in the plural shall include singular forms. More specifically, as used in this specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" include plural indicators. In this application, unless otherwise stated, the use of "or" means "and / or". In addition, the use of the term "comprising" and other forms (such as "including" and "containing") is not restrictive. In addition, the ranges provided in the specification and the appended claims include endpoints and all values ​​between the endpoints.

[0080] definition

[0081] In order to better understand the present invention, definitions and explanations of relevant terms are provided below.

[0082] The term "antibody" or "Ab" generally refers to a Y-shaped tetrameric protein comprising two heavy (H) and two light (L) polypeptide chains held together by covalent disulfide bonds and non-covalent interactions. The light chains of antibodies can be divided into κ or λ light chains. The heavy chains can be divided into μ, δ, γ, α or ε, which define the isotype of the antibody as IgM, IgD, IgG, IgA or IgE, respectively. In the light and heavy chains, the variable region is connected to the constant region by a "J" region of about 12 or more amino acids, and the heavy chain also contains a "D" region of about 3 or more amino acids. Each heavy chain consists of a heavy chain variable region (VH) and a heavy chain constant region (CH). The heavy chain constant region consists of 3 domains (CH1, CH2 and CH3). Each light chain consists of a light chain variable region (VL) and a light chain constant region (CL). The VH and VL regions can be further divided into hypervariable regions (called complementary determining regions, or CDRs) separated by relatively conserved regions (called framework regions, or FRs). Each VH and VL consists of 3 CDRs and 4 FRs in the following order: FR1, CDR1, FR2, CDR2, FR3, CDR3, and FR4 from N-terminus to C-terminus. The CDRs on VH are HCDR1, HCDR2, and HCDR3; the CDRs on VL are LCDR1, LCDR2, and LCDR3. The variable regions (VH and VL) of each heavy chain / light chain pair form antigen binding sites / parts, respectively. The distribution of amino acids in various regions or domains follows the numbering definitions in common systems such as Kabat, IMGT, or Chothia. In the specific embodiments of the present disclosure, the CDR sequences are determined using the numbering definitions in the Kabat system.

[0083] Antibodies in the present disclosure also include antigen binding portions (interchangeably used with the term "antigen binding fragment"). Antigen binding portions refer to polypeptides comprising fragments of intact antibodies that retain the ability to specifically bind to an antigen that specifically binds to a full-length or intact antibody, and / or that compete with a full-length antibody for binding to the same antigen. Under some conditions, antigen binding portions include Fab, Fab', F(ab')2, Fd, Fv, dAb and complementary determining region (CDR) fragments, single-chain antibodies (e.g., scFv), chimeric antibodies, diabodies, and antibodies that contain at least a portion of an antibody sufficient to confer specific antigen binding ability to a polypeptide. The antigen binding portion of an antibody can be obtained from a given antibody by conventional techniques known to those skilled in the art (e.g., recombinant DNA techniques or enzymatic or chemical cleavage methods), and can be screened for specificity in the same manner as intact antibodies.

[0084] The term "isotype" refers to the antibody class (eg, IgM or IgG1) encoded by the heavy chain constant region genes.

[0085] The term "monoclonal antibody" or "mAb" refers to an antibody molecule / preparation of single molecular composition. A monoclonal antibody displays a single binding specificity and affinity for a particular epitope. The antibodies of the present invention may be derived from different species, including but not limited to mouse, rat, rabbit, guinea pig and human.

[0086] The term "epitope" refers to an antigenic determinant in a molecule, which refers to a portion of a molecule that is recognized by the immune system (e.g., by an antibody), such as a discrete three-dimensional site on an antigen recognized by the immune system. In the present invention, the epitope is, for example, the PVRIG protein.

[0087] The term "chimeric antibody" as used herein refers to an antibody whose variable region sequence is from one species and the constant region sequence is from another species, for example, an antibody in which the variable region sequence is derived from a mouse antibody and the constant region sequence is derived from a human antibody.

[0088] The term "humanized antibody" is intended to refer to antibodies in which CDR sequences / antigen binding portions or sites derived from the germline of another mammalian species, such as a mouse, have been grafted onto human framework sequences. In addition, additional framework region modifications may also be made within the human framework sequences.

[0089] The term "KD value" is the equilibrium dissociation constant between an antibody and its antigen, that is, the ratio of koff / kon or kd / ka (which can be measured by SPR technology). Therefore, the lower the KD value (the lower the concentration), the higher the affinity of the antibody. Therefore, the "KD value" can be used to measure the binding affinity between an antibody and its antigen. The kd dissociation constant reflects the affinity of the compound for the target. The smaller the value, the stronger the affinity. The ka association constant, in contrast to kd, the larger the value, the stronger the affinity.

[0090] The terms "PVRIG" and "PVRIG antigen" are used interchangeably herein and include any variants, isoforms, and species homologs of human PVRIG that are naturally expressed by cells or expressed on cells transfected with the PVRIG gene. In some embodiments, binding of the antibodies of the present disclosure to the PVRIG antigen mediates killing of cells expressing PVRIG (e.g., tumor cells) by inactivating PVRIG. Killing of cells expressing PVRIG may occur by one or more of the following mechanisms: cell death / apoptosis induction, ADCC, and CDC.

[0091] The term "anti-PVRIG antibody" or "PVRIG antibody" refers to an antibody capable of binding to the PVRIG antigen or to cells expressing PVRIG as defined herein. Two types of anti-PVRIG antibodies (type I and type II anti-PVRIG antibodies) can be distinguished according to Cragg, MS et al., Blood 103 (2004) 2738-2743; and Cragg, MS et al., Blood 101 (2003) 1045-1052, based on their binding properties to the PVRIG antigen and their biological activity.

[0092] The term "specific binding" refers to a non-random binding reaction between two molecules, such as the reaction between an antibody and its antigen.

[0093] The term "isolated" refers to a state obtained from a natural state by artificial means. If a certain "isolated" substance or component exists in nature, it may be because its natural environment has changed, or the substance has been separated from the natural environment, or both. For example, a certain unisolated polynucleotide or polypeptide exists naturally in a living organism, and the same polynucleotide or polypeptide with high purity separated from this natural state is called an isolated polynucleotide or polypeptide. The term "isolated" neither excludes mixed artificial or synthetic substances, nor excludes other impure substances that do not affect the activity of the isolated substance. For example, an isolated antibody may be substantially free of other cellular materials and / or chemicals.

[0094] The term "vector" refers to a nucleic acid vector into which a polynucleotide can be inserted. When a vector allows the expression of a protein encoded by a polynucleotide inserted therein, the vector is called an expression vector. The vector can be transformed, transduced or transfected into a host cell to express the genetic material elements carried in the host cell. Vectors are well known to those skilled in the art, and include but are not limited to plasmids, bacteriophages, cosmids, artificial chromosomes such as yeast artificial chromosomes (YAC), bacterial artificial chromosomes (BAC) or P1-derived artificial chromosomes (PAC); bacteriophages such as lambda phage or M13 phage and animal viruses. Animal viruses that can be used as vectors include but are not limited to retroviruses (including lentiviruses), adenoviruses, adeno-associated viruses, herpes viruses (such as herpes simplex virus), poxviruses, baculoviruses, papillomaviruses, papovaviruses (such as SV40). The vector may contain multiple elements for controlling expression, including but not limited to promoter sequences, transcription initiation sequences, enhancer sequences, selection elements and reporter genes. In addition, the vector may contain an origin of replication. As for the vector for expressing the antibody, a vector type in which the antibody heavy chain and light chain exist in different vectors or a vector type in which the heavy chain and light chain exist in the same vector can be used.

[0095] The term "host cell" refers to a cell system that can be engineered to produce a target protein, protein fragment or peptide. Host cells include, but are not limited to, cultured cells, such as mammalian cultured cells derived from rodents (rat, mouse, guinea pig or hamster), such as CHO, CHOK1, BHK, NSO, SP2 / 0, YB2 / 0; or human tissue or hybridoma cells, yeast cells and insect cells, as well as cells contained in transgenic animals or cultured tissues. The term covers not only specific test cells, but also the offspring of such cells. Because certain modifications may occur in subsequent generations due to mutations or environmental influences, such offspring may be different from parental cells, but are still included in the scope of the term "host cell".

[0096] The term "identity" refers to the relationship between the sequences of two or more polypeptide molecules (or protein molecules) or two or more nucleic acid molecules determined by alignment and comparison of the sequences. "Percent identity" refers to the percentage of identical residues between amino acids or nucleotides in the compared molecules and is calculated based on the size of the smallest molecules being compared. For these calculations, gaps in the alignment, if any, are preferably addressed by a specific mathematical model or computer program (i.e., an "algorithm"). Methods that can be used to calculate the identity of aligned nucleic acids or polypeptides include those described in Computational Molecular Biology, (Lesk, AM, ed.), 1988, New York: Oxford University Press; Biocomputing Informatics and Genome Projects, (Smith, DW, ed.), 1993, New York: Academic Press; Computer Analysis of Sequence Data, Part I, (Griffin, AM, and Griffin, HG, eds.), 1994, New Jersey: Humana Press; von Heinje, G., 1987, Sequence Analysis in Molecular Biology, New York: Academic Press; Sequence Analysis Primer, (Gribskov, M. and Devereux, J., eds.), 1991, New York: M. Stockton Press; and Carillo et al, 1988, SIAM J. Applied Math. 48:1073.

[0097] The term "immunogenicity" refers to the ability to stimulate the formation of specific antibodies or sensitized lymphocytes in an organism. It not only refers to the property of antigens to stimulate the activation, proliferation and differentiation of specific immune cells to ultimately produce immune effector substances such as antibodies and sensitized lymphocytes, but also refers to the specific immune response of antibodies or sensitized T lymphocytes that can be formed in the immune system of an organism after stimulating the organism with an antigen. Immunogenicity is the most important property of an antigen. Whether an antigen can successfully induce the generation of an immune response in a host depends on three factors: the nature of the antigen, the reactivity of the host and the means of immunity.

[0098] The term "transfection" refers to the process of introducing nucleic acids into eukaryotic cells, particularly mammalian cells. Protocols and techniques for transfection include, but are not limited to, lipid transfection and chemical and physical methods such as electroporation. Many transfection techniques are well known in the art and disclosed herein. See, for example, Graham et al., 1973, Virology 52:456; Sambrook et al., 2001, Molecular Cloning: A Laboratory Manual, supra; Davis et al., 1986, Basic Methods in Molecular Biology, Elsevier; Chu et al, 1981, Gene 13:197.

[0099] The term "hybridoma" and the term "hybridoma cell line" are used interchangeably. When referring to the term "hybridoma" and the term "hybridoma cell line", they also include subclones and progeny cells of the hybridoma.

[0100] The term "immune effector function" includes any function mediated by components of the immune system that results in inhibition of tumor growth and / or inhibition of tumorigenesis, including inhibition of tumor dissemination and metastasis. Preferably, the immune effector function results in killing tumor cells. Preferably, the immune effector function in the present invention is an antibody-mediated effector function. Such functions include complement-dependent cytotoxicity (CDC), antibody-dependent cell-mediated cytotoxicity (ADCC), induction of apoptosis in cells carrying tumor-associated antigens (e.g., by binding of antibodies to surface antigens) and / or inhibition of proliferation of cells carrying tumor-associated antigens, preferably ADCC and / or CDC. Antibodies can also simply act by binding to tumor-associated antigens on the surface of tumor cells. For example, antibodies can block the function of tumor-associated antigens or induce apoptosis simply by binding to tumor-associated antigens on the surface of tumor cells.

[0101] The term "cancer" refers to any tumor or malignant cell growth, proliferation or metastasis-mediated solid tumors and non-solid tumors such as leukemia that cause a medical condition. For example, cancers associated with PVRIG expression or caused by abnormal expression include, but are not limited to: B-cell lymphomas, including NHL, pre-B-cell lymphocytic leukemia / lymphomas and mature B-cell tumors, such as B-cell chronic lymphocytic leukemia (CLL) / small lymphocytic lymphoma (SLL), B-cell prolymphocytic leukemia, lymphoplasmacytic lymphoma, mantle cell lymphoma (MCL), follicular lymphoma (FL), including low-grade, intermediate-grade and high-grade FL, cutaneous follicle center lymphoma, marginal zone B-cell lymphoma (MALT-type, nodal and splenic), hairy cell leukemia, diffuse large B-cell lymphoma, Burkitt's lymphoma, plasmacytoma, plasma cell myeloma, post-transplant lymphoproliferative disorder, Waldenstrom's macroglobulinemia and anaplastic large cell lymphoma (ALCL)

[0102] The term "pharmaceutically acceptable" means that the carrier, diluent, excipient and / or salt thereof is chemically and / or physically compatible with the other ingredients of the formulation and physiologically compatible with the recipient.

[0103] The term "pharmaceutically acceptable carrier and / or excipient" refers to a carrier and / or excipient that is pharmacologically and / or physiologically compatible with the subject and the active agent and is well known in the art (see, e.g., Remington's Pharmaceutical Sciences. Edited by Gennaro AR, 19 th Ed. Pennsylvania: Mack Publishing Company, 1995), and includes but is not limited to pH adjusters, surfactants, adjuvants and ionic strength enhancers. For example, pH adjusters include but are not limited to phosphate buffer; surfactants include but are not limited to cationic, anionic or nonionic surfactants, such as Tween-80; ionic strength enhancers include but are not limited to sodium chloride.

[0104] The term "adjuvant" refers to a non-specific immunopotentiator, which can enhance the immune response to the antigen in the organism or change the type of immune response when it is delivered to the organism together with the antigen or delivered to the organism in advance. There are multiple adjuvants, including but not limited to aluminum adjuvants (such as aluminum hydroxide), Freund's adjuvants (such as Freund's complete adjuvant and Freund's incomplete adjuvant), Corynebacterium brevis, lipopolysaccharide, cytokines, etc. Freund's adjuvant is the most commonly used adjuvant in current animal experiments. Aluminum hydroxide adjuvant is more commonly used in clinical trials.

[0105] Anti-PVRIG antibody

[0106] In some aspects, the invention includes isolated antibodies or antigen-binding fragments thereof.

[0107] In the context of the present application, "antibodies" may include polyclonal antibodies, monoclonal antibodies, chimeric antibodies, humanized and primatized antibodies, CDR-grafted antibodies, human antibodies, recombinantly produced antibodies, intracellular antibodies, bifunctional antibodies, multispecific antibodies, bispecific antibodies, monovalent antibodies, multivalent antibodies, anti-idiotypic antibodies, synthetic antibodies, including mutant proteins and variants thereof, improved antibodies; and derivatives thereof (including Fc fusion proteins and other modifications), as well as any other immunoreactive molecules, as long as they show preferential association or binding with the PVRIG protein. In addition, unless the context otherwise dictates, the term also includes antibodies of all classes (i.e., IgA, IgD, IgE, IgG, and IgM) and all subclasses (i.e., IgG1, IgG2, IgG3, IgG4, IgA1, and IgA2). In a preferred embodiment, the antibody is a monoclonal antibody. In a more preferred embodiment, the antibody is a chimeric monoclonal antibody or a humanized monoclonal antibody or an improved chimeric monoclonal antibody.

[0108] The variable regions and CDRs in an antibody sequence can be identified according to the general rules (such as Kabat) numbering system developed in the art or by aligning the sequence with a database of known variable regions.

[0109] Regardless of how the antibody is produced, methods for testing the ability of the antibody to bind to an antigen (e.g., PVRIG) are known in the art and include any antibody-antigen binding assay, such as radioimmunoassay (RIA), ELISA, Western blot, immunoprecipitation, SPR, and competitive inhibition assays (see, e.g., Janeway et al., infra, and U.S. Patent Application Publication No. 2002 / 0197266 and the above section on competition assays).

[0110] According to the present invention, in a standard assay (such as the assay described in the present invention), if the antibody has a significant affinity to the predetermined target (such as PVRIG protein or cells expressing PVRIG), the antibody is capable of binding to the predetermined target. In order to test the binding of the monoclonal antibody to living cells expressing PVRIG, flow cytometry (FCM) can be used. Preferably, in a flow cytometric fluorescence sorting technique (FACS) analysis, the antibody is measured for binding to a target expressed on the cell surface. If the antibody can detectably bind to the target (PVRIG protein or cells expressing PVRIG), the antibody is capable of binding to the target and has "affinity".

[0111] The PVRIG specificity described in the present invention refers to the ability to bind to one or more PVRIG epitopes, especially PVRIG epitopes in natural conformation, especially human PVRIG specificity.

[0112] In the art, various methods are used to modify the desired properties of antibodies without changing them, such as the method used in the present disclosure of recombining the light chain and heavy chain of the antibody, replacing amino acids, etc. For example, the sequences of the present invention, including chimeric antibody sequences or humanized antibody sequences, can be subjected to conservative amino acid substitutions.

[0113] In some embodiments, the antibody is a bifunctional antibody or a bispecific antibody.

[0114] In some embodiments, the antibody is a whole antibody, a monoclonal antibody, a chimeric antibody or a humanized antibody or an improved antibody thereof such as an improved chimeric antibody;

[0115] The fragment is a Fab fragment, a Fab' fragment, a F(ab')2 fragment, a Fv fragment, or a single-chain Fv fragment (scFv).

[0116] In some embodiments, the isolated antibody or antigen-binding fragment thereof comprises a constant region of IgG. The constant region of IgG is preferably selected from IgG1, IgG2, IgG3, or IgG4 constant region. The constant region of IgG is more preferably selected from the constant region of IgG1.

[0117] Antibodies interact with target antigens primarily through amino acid residues located in the six heavy and light chain complementary determining regions (CDRs). For this reason, the amino acid sequences of CDRs are more diverse between antibodies than other sequences. Since CDR sequences are responsible for most antibody-antigen interactions, it is possible to express recombinant antibodies that mimic the properties of a specific naturally occurring antibody by constructing an expression vector comprising CDR sequences from the specific naturally occurring antibody grafted onto framework sequences from different antibodies with different properties (see, e.g., Riechmann, L. et al. (1998) Nature 332: 323-327; Jones, P. et al. (1986) Nature 321: 522-525; and Queen, C. et al. (1989) Proc. Natl. Acad. Sci. USA 86: 10029-10033). Such framework sequences can be obtained from public DNA databases that include germline antibody gene sequences. These germ lines are sequences that are different from mature antibody gene sequences because they do not contain fully assembled variable genes, which are formed by V(D)J joining during B cell maturation. Germline gene sequences will also have sequences that are different from the high-affinity second antibody library (secondary repertoireantibody) at individual locations evenly across the variable region.

[0118] Mouse antibodies are highly immunogenic in humans, resulting in reduced therapeutic efficacy when used repeatedly, with the main immunogenicity mediated by the heavy chain constant region. If the individual antibodies are chimerized or humanized, the immunogenicity of mouse antibodies in humans can be reduced or completely avoided.

[0119] Chimeric antibodies refer to antibodies in which different parts are from different animal species, for example, antibodies with variable regions from mouse antibodies and human immunoglobulin constant regions. The variable regions of mouse antibody heavy and light chains are linked together with the constant regions of human heavy and light chains to obtain the chimeric nature of the antibody (for example, as described in Kraus et al., in Methods in Molecular Biology series, Recombinant antibodies for cancer therapy ISBN-0-89603-918-8). In a preferred embodiment, chimeric antibodies are produced by connecting human kappa light chain constant regions to mouse light chain variable regions. In another preferred embodiment, chimeric antibodies can be produced by connecting human lambda light chain constant regions to mouse light chain variable regions.

[0120] Humanized antibodies are antibodies in which CDR sequences / antigen-binding portions or sites derived from the germline of another mammalian species, such as a mouse, are grafted onto human framework sequences.

[0121] In order to reduce the immunogenicity of the antibody to humans, the sequence of the PVRIG antibody disclosed in the present invention is used to produce a humanized anti-PVRIG antibody, and the CDR region of the anti-PVRIG antibody of mouse origin is combined with the framework region of human origin (e.g., human immunoglobulin) to form the humanized anti-PVRIG antibody of the present invention. The humanized antibody is expected to retain the function of binding to human PVRIG as well as the function of binding to monkey PVRIG.

[0122] Preparation or generation of antibodies

[0123] The antibodies of the present invention can be produced by a variety of techniques, including conventional monoclonal antibody methods, such as the standard somatic cell hybridization technique of Kohler and Milstein, Nature 256: 495 (1975). Although hybridoma technology is preferred, in principle, other techniques for producing monoclonal antibodies can be used, such as virus or oncogene transformation of B lymphocytes or phage display technology using antibody gene libraries, somatic cell hybridization methods, and for example, obtaining through genetic engineering recombinant technology. For example, DNA molecules encoding the heavy chain and light chain genes of the antibodies of the present invention are obtained by chemical synthesis or PCR amplification, the resulting DNA molecules are inserted into expression vectors, and then transfected into host cells, and then, the transfected host cells are cultured under specific conditions, and the antibodies of the present invention are expressed.

[0124] Other preferred animal systems for preparing hybridomas that secrete monoclonal antibodies are rat and rabbit systems (described, for example, in Spieker-Polet et al., Proc. Natl. Acad. Sci. USA 92: 9348 (1995), see also Rossie et al.. Am. J. Clin. Pathol. 124: 295 (2005)). Hybridoma production in mice is a very well established method. Immunization protocols and techniques for isolating immunized spleen cells for fusion are known in the art. Fusion partners (e.g., mouse myeloma cells) and fusion methods are also known.

[0125] Monoclonal antibodies can be prepared using a variety of techniques known in the art, including hybridoma technology, recombinant technology, phage display technology, transgenic animals or some combination thereof. For example, hybridomas and biochemical and genetic engineering techniques recognized in the art can be used to produce monoclonal antibodies, as described in detail in An, Zhigiang (ed.) Therapeutic Monoclonal Antibodies: From Bench to Clinic, John Wiley and Sons, 1st ed.2009; Shire et al. (eds.) Current Trends in Monoclonal Antibody Development and Manufacturing, Springer Science + Business Media LLC, 1st ed.2010; Harlow et al., Antibodies: A Laboratory Manual, Cold Spring Harbor Laboratory Press, 2nd ed.1988; Hammerling, et al., in: Monoclonal Antibodies and T-Cell Hybridomas 563-681 (Elsevier, NY, 1981), each of which is incorporated herein by reference in its entirety.

[0126] It should be understood that the selected binding sequence can be further altered, for example, to increase affinity for the target, humanize the target binding sequence, improve its production in cell culture, reduce its immunogenicity in vivo, generate multispecific antibodies, etc., and antibodies comprising altered target binding sequences are also antibodies of the present invention.

[0127] In some embodiments, the method of producing the antibodies or fragments described herein comprises the following steps:

[0128] (i) expressing the antibody or fragment in a host cell; and optionally

[0129] (ii) isolating the antibody or antigen-binding fragment thereof from the host cell.

[0130] In a preferred embodiment, anti-PVRIG monoclonal antibodies are prepared by using hybridomas.

[0131] In order to obtain hybridomas that produce antibodies of the invention, such as human monoclonal antibodies of the invention, spleen cells and / or lymph node cells from immunized mice can be isolated and fused to a suitable immortalized cell line, such as a mouse myeloma cell line. The resulting hybridomas are screened for the production of antigen-specific antibodies. The production of hybridomas is well known in the art. See, for example, Harlow and Lane (1988) Antibodies, A Laboratory Manual, Cold Spring Harbor Publications, New York.

[0132] The antibodies of the present invention can also be produced in host cell transfectomas using, for example, a combination of recombinant DNA technology and gene transfection methods well known in the art (e.g., Morrison, S. (1985) Science 229: 1202). In some embodiments, DNA encoding partial or full-length light and heavy chains obtained by standard molecular biology techniques is inserted into one or more expression vectors so that the genes are operably linked to transcriptional and translational regulatory sequences. In this context, the term "operably linked" is intended to mean that the antibody gene is linked to the vector so that the transcriptional and translational control sequences within the vector perform their intended functions of regulating transcription and translation of the antibody gene.

[0133] The antibody light chain gene and the antibody heavy chain gene can be inserted into the same or different expression vectors.In some embodiments, the variable region is used to produce the full-length antibody gene of any antibody isotype by inserting it into the expression vector of the heavy chain constant region and the light chain constant region encoding the desired isotype, so that the VH segment is operably connected to the CH segment and the VL segment in the carrier are operably connected to the CL segment in the carrier.In addition or alternatively, the recombinant expression vector can encode the signal peptide that promotes the secretion of the antibody chain from the host cell.The antibody chain gene can be cloned into a vector so that the signal peptide is connected to the amino terminal of the antibody chain gene.The signal peptide can be an immunoglobulin signal peptide or a heterologous signal peptide (i.e., a signal peptide from a non-immunoglobulin protein).

[0134] To express the light and heavy chains, expression vectors encoding the heavy and light chains are transfected into host cells by standard techniques. The various forms of the term "transfection" are intended to encompass various techniques commonly used to introduce exogenous DNA into prokaryotic or eukaryotic host cells, such as electroporation, calcium phosphate precipitation, DEAE-dextran transfection, etc. The antibodies of the present invention can be expressed in prokaryotic or eukaryotic host cells, such as mammalian host cells, which can assemble and secrete appropriately folded and immunologically active antibodies.

[0135] Mammalian host cells for expressing the recombinant antibodies of the invention include Chinese hamster ovary cells (CHO cells) (including dhfr CHO cells described in Urlaub and Chasin, (1980) Proc. Natl. Acad. Sci. USA 77: 4216-4220) used with a DHFR selection marker (e.g., as described in RJ Kaufman and PA Sharp (1982) J. MoI. Biol. 159: 601-621), NSO myeloma cells, COS cells and SP2 cells. In particular, for use with NSO myeloma, another expression system is the GS gene expression system disclosed in WO 87 / 04462, WO 89 / 01036 and EP 338,841. When a recombinant expression vector encoding an antibody gene is introduced into a mammalian host cell, the antibody is produced by culturing the host cell for a period of time sufficient to allow the antibody to be expressed in the host cell or secreted into the culture medium in which the host cell is grown. The antibody can be recovered from the culture medium using standard protein purification methods.

[0136] In another preferred embodiment, transgenic or transchromosomal mice carrying parts of the human immune system (rather than the mouse system) can be used to generate human monoclonal antibodies against PVRIG.

[0137] Another strategy for generating monoclonal antibodies is to directly isolate the gene encoding the antibody from the lymphocytes producing antibodies of a defined strategy, for example, see Babcock et al., 1996; A novel strategy for generating monoclonal antibodies from single, isolated lymphocytes producing antibodies of defined strategy. For details of recombinant antibody engineering, see Welschof and Krau, Recombinant antibodies for cancer therapy ISBN-0-89603-918-8 and Benny KC Lo Antibody Engineering ISBN 1-58829-092-1.

[0138] To prepare chimeric antibodies, murine immunoglobulin variable regions can be linked to human immunoglobulin constant regions using methods known in the art (see, e.g., U.S. Pat. No. 4,816,567 to Cabilly et al.). The isolated nucleic acid encoding the VH region can be converted into a full-length heavy chain gene by operably linking the nucleic acid encoding the VH to another DNA molecule encoding the heavy chain constant region (CH1, CH2, and CH3). The sequences of human heavy chain constant region genes are known in the art (see, e.g., Kabat et al. (1991), Sequences Of Proteins of Immunological Interest, Fifth Edition, US Department of Health and Human Services, NIH Publication No. 91-3242). The heavy chain constant region can be an IgG1, IgG2, IgG3, IgG4, IgA, IgE, IgM, or IgD constant region, but more preferably an IgG1 or IgG4 constant region. The isolated nucleic acid encoding the VL region can be converted into a full-length light chain gene (as well as a Fab light chain gene) by operably linking the DNA encoding the VL to another DNA molecule encoding the light chain constant region CL. The sequences of human light chain constant region genes are known in the art (see, e.g., Kabat et al., supra), and DNA fragments comprising these regions can be obtained by standard PCR amplification. In a preferred embodiment, the light chain constant region can be a kappa or lambda constant region, but is generally preferably a kappa constant region. Once DNA fragments encoding VH and VL segments are obtained, these DNA fragments can be further manipulated by standard recombinant DNA techniques, such as converting variable region genes into full-length antibody chain genes, Fab fragment genes, or scFv genes. In these operations, the DNA fragment encoding VL or VH is operably connected to another DNA fragment encoding another protein, such as an antibody constant region or a flexible linker. The term "operably connected" as used herein is intended to indicate that two DNA fragments are connected so that the amino acid sequences encoded by the two DNA fragments remain in frame.

[0139] To prepare humanized antibodies, mouse CDR regions can be inserted into human framework sequences using methods known in the art (see Winter, U.S. Pat. No. 5,225,539; Queen et al., U.S. Pat. No. 5,530,101; U.S. Pat. No. 5,585,089; U.S. Pat. No. 5,693,762; and Lo, Benny, KC, editor, in Antibody Engineering: Methods and Protocols, volume 248, Humana Press, New Jersey, 2004). Alternatively, transgenic animals can be used that are capable of not producing endogenous immunoglobulins after immunization and are capable of producing a complete human antibody repertoire. For example, it has been reported that the homozygous deletion of the antibody heavy-chain joining region (JH) gene in chimeric and germ-line mutant mice can completely inhibit endogenous antibody production, and then transfer of the human germ-line immunoglobulin gene array into the germ-line mutant mice will result in the mice producing human antibodies when challenged with antigen (see, e.g., Jakobovits et al., 1993, Proc. Natl. Acad. Sci. USA 90:2551; Jakobovits et al., 1993, Nature 362:255-258; Bruggermann et al., 1993, Year in Immunology 7:33; and Duchosal et al., 1992, Nature 355:258). Non-limiting examples of the above transgenic animals include, HuMAb mice (Medarex, Inc.), which contain human immunoglobulin gene miniloci encoding unrearranged human heavy chain (μ and γ) and κ light chain immunoglobulin sequences, plus targeted mutations that inactivate endogenous μ and κ chain loci (see, e.g., Lonberg et al. (1994) Nature 368 (6474): 856-859); or "KM mice TM" carrying human heavy chain transgenes and human light chain transchromosomes (see patent application WO02 / 43478). Other methods for antibody humanization include phage display technology (Hoogenboom et al., 1991, J. Mol. Biol. 227: 381; Marks et al., J. Mol. Biol. 1991, 222: 581-597; Vaughan et al., 1996, Nature Biotech 14: 309).

[0140] Nucleic acid molecules encoding the antibodies of the present invention

[0141] In some aspects, the present invention relates to an isolated nucleic acid molecule comprising a nucleic acid sequence encoding the above-mentioned isolated antibody or fragment thereof as disclosed herein.

[0142] Nucleic acids of the present invention can be obtained using standard molecular biology techniques. For hybridoma-expressed antibodies (e.g., hybridomas prepared by transgenic mice carrying human immunoglobulin genes as further described below), cDNA encoding the light and heavy chains of antibodies prepared by hybridomas can be obtained by standard PCR amplification or cDNA cloning techniques. For antibodies obtained from immunoglobulin gene libraries (e.g., using phage display technology), nucleic acids encoding such antibodies can be recovered from gene libraries.

[0143] In order to prepare chimeric antibodies, methods known in the art can be used to connect the mouse immunoglobulin variable region to the human immunoglobulin constant region (see, for example, U.S. Pat. No. 4,816,567 to Cabilly et al.). The isolated nucleic acid encoding the VH region can be converted into a full-length heavy chain gene by operably connecting the nucleic acid encoding the VH to another DNA molecule encoding the heavy chain constant region (CH1, CH2 and CH3), and DNA fragments containing these regions can be obtained by standard PCR amplification. The isolated nucleic acid encoding the VL region can be converted into a full-length light chain gene (and a Fab light chain gene) by operably connecting the DNA encoding the VL to another DNA molecule encoding the light chain constant region CL. Once the DNA fragments encoding the VH and VL segments are obtained, these DNA fragments can be further manipulated by standard recombinant DNA techniques, such as converting the variable region gene into a full-length antibody chain gene, a Fab fragment gene or a scFv gene. In these operations, the DNA fragment encoding VL or VH is operably connected to another DNA fragment encoding another protein, such as an antibody constant region or a flexible linker.

[0144] Conjugate

[0145] In one aspect, the present disclosure provides a conjugate comprising an antibody or fragment thereof as described above coupled to at least one detectable marker. Detectable markers include, but are not limited to: (i) providing a detectable signal; (ii) interacting with a second marker to modify the detectable signal provided by the first or second marker, such as FRET (Fluorescence Resonance Energy Transfer); (iii) affecting mobility (e.g., electrophoretic mobility) by charge, hydrophobicity, shape or other physical parameters, or (iv) providing a capture moiety, such as affinity, antibody / antigen or ion complexation.

[0146] Suitable structures as labels include fluorescent labels, luminescent labels, chromophore labels, radioisotope labels, isotope labels, preferably stable isotope labels, isobaric labels, enzyme labels (such as horseradish peroxidase, alkaline phosphatase, β-galactosidase, urease, glucose oxidase, etc.), particle labels (especially metal particle labels, magnetic particle labels, polymer particle labels), organic small molecules (such as biotin, receptor ligands or binding molecules (such as cell adhesion proteins or phosphatidylcholine), which can be used to bind The marker sequence containing nucleic acid and / or amino acid residues can be detected by the marker. The marker includes, but is not limited to, barium sulfate, iodine, iopanoic acid, amiopromide calcium, diatrizoate sodium, diatrizoate meglumine, meglumine, sodium tyropanate, and radiodiagnostic agents (including positron emitters, (e.g., fluorine-18 and carbon-11), gamma emitters (e.g., iodine-123, iodine-125, technetium-99m, iodine-131 and indium-111), nuclear magnetic resonance nuclides (e.g., fluorine and gadolinium)), luminescent substances (e.g., isoluminol and acridinium esters), fluorescent substances (e.g., fluorescein and rhodamine), and colored substances (e.g., latex particles and colloidal gold).

[0147] Detectable labels as described above can be detected by methods known in the art. For example, fluorescent markers can be detected using a photodetector to detect emitted light. Enzyme labels are generally detected by providing a substrate to the enzyme and detecting the reaction product produced by the action of the enzyme on the substrate. In certain embodiments, such labels can be suitable for immunological detection (e.g., enzyme-linked immunosorbent assay, radioimmunoassay, fluorescent immunoassay, chemiluminescent immunoassay, etc.). In certain embodiments, detectable labels as described above can be connected to antibodies or antigen-binding fragments thereof of the present invention by linkers of varying lengths to reduce potential steric hindrance.

[0148] Antibody Drug Conjugates / Immunoconjugates

[0149] In one aspect, the present disclosure provides an antibody-drug conjugate comprising an antibody, which includes one or more drug moieties / therapeutic agents, wherein the drug moieties are directly or via a linker (e.g., covalently linked) to an antibody or fragment thereof as described above. In the antibody-drug conjugate of the present application, the linker structure for conjugating the anti-PVRIG antibody to the drug is not particularly limited, as long as the resulting antibody-drug conjugate can be used.

[0150] Since antibody-drug conjugates have the ability to selectively deliver one or more drugs to target tissues (e.g., tumor-associated antigens, such as tumors expressing PVRIG), antibody-drug conjugates can improve the therapeutic efficacy of the antibodies or antigen-binding fragments thereof of the present invention in treating diseases (e.g., cancer).

[0151] Multispecific molecules

[0152] The antibodies or antigen-binding fragments thereof of the present invention can be used to form multispecific molecules (e.g., bispecific molecules). The antibodies or antigen-binding fragments thereof of the present invention can be part of a multispecific molecule (e.g., a bispecific molecule), wherein the bispecific or multispecific molecule comprises a second functional module (e.g., a second antibody) or a third functional module (e.g., a third antibody) having a binding specificity different from that of the antibodies or antigen-binding fragments thereof of the present invention, thereby being able to bind to at least two different binding sites and / or target molecules. For example, the antibodies or antigen-binding fragments thereof of the present invention can be connected to a second antibody or antigen-binding fragment thereof that can specifically bind to any protein that can be used as a potential target for combined therapy. To produce the bispecific or multispecific molecules, the antibodies or antigen-binding fragments thereof of the present invention can be connected (e.g., by chemical coupling, genetic fusion, non-covalent association or other means) to one or more other binding molecules (e.g., additional antibodies, antibody fragments, peptides, or binding mimetics).

[0153] Thus, in some aspects, the invention provides a multispecific molecule comprising an antibody or antigen-binding fragment thereof of the invention.

[0154] In certain preferred embodiments, the multispecific molecule specifically binds PVRIG (eg, human PVRIG or monkey PVRIG) and specifically binds one or more additional targets.

[0155] In certain preferred embodiments, the multispecific molecule further comprises at least one molecule having a second binding specificity for a second target (eg, a second antibody).

[0156] In certain preferred embodiments, the multispecific molecule is a bispecific antibody.

[0157] Pharmaceutical composition

[0158] In some aspects, the present invention relates to a pharmaceutical composition. The present disclosure provides a pharmaceutical composition or kit comprising the antibody or fragment as described above, the nucleic acid molecule as described above, the vector as described above, the host cell as described above, the conjugate as described above, the antibody-drug conjugate as described above, the multispecific molecule as described above; and a pharmaceutically acceptable carrier.

[0159] The pharmaceutical composition may optionally contain one or more additional pharmaceutically active ingredients, such as another antibody or drug. The pharmaceutical composition of the present invention may also be administered in combination with, for example, another immunostimulant, anticancer agent, antiviral agent or vaccine, such that the anti-PVRIG antibody enhances the immune response to the vaccine. Pharmaceutically acceptable carriers may include, for example, pharmaceutically acceptable liquid, gel or solid carriers, aqueous media, non-aqueous media, antimicrobial agents, isotonic agents, buffers, antioxidants, anesthetics, suspending / dispersing agents, chelating agents, diluents, adjuvants, excipients or non-toxic auxiliary substances, combinations of various components known in the art or more.

[0160] Suitable components may include, for example, antioxidants, fillers, binders, disintegrants, buffers, preservatives, lubricants, flavoring agents, thickeners, colorants, emulsifiers or stabilizers such as sugars and cyclodextrins. Suitable antioxidants may include, for example, methionine, ascorbic acid, EDTA, sodium thiosulfate, platinum, catalase, citric acid, cysteine, mercaptoglycerol, thioglycolic acid, mercaptosorbitol, butylmethylanisole, butylated hydroxytoluene and / or propyl arsenate. As disclosed in the present invention, in a solvent containing an antibody or its antigen-binding fragment of the composition disclosed in the present invention containing one or more antioxidants such as methionine that reduce the antibody or its antigen-binding fragment, it may be oxidized. Redox can prevent or reduce the reduction of binding affinity, thereby enhancing antibody stability and extending shelf life. Therefore, in some embodiments, the present invention provides a composition comprising one or more antibodies or their antigen-binding fragments and one or more antioxidants such as methionine. The present invention further provides methods wherein the antibodies or antigen-binding fragments thereof are mixed with one or more antioxidants such as methionine, whereby the antibodies or antigen-binding fragments thereof can be protected from oxidation to extend their shelf life and / or increase their activity.

[0161] To further illustrate, pharmaceutically acceptable carriers can include, for example, aqueous vehicles such as sodium chloride injection, Ringer's injection, isotonic dextrose injection, sterile water injection, or dextrose and lactated Ringer's injection, non-aqueous vehicles such as fixed oils of vegetable origin, cottonseed oil, corn oil, sesame oil, or peanut oil, antimicrobial agents at bacteriostatic or fungistatic concentrations, isotonic agents such as sodium chloride or dextrose, buffers such as phosphate or citrate buffers, antioxidants such as sodium bisulfate, local anesthetics such as procaine hydrochloride, suspending and dispersing agents such as sodium carboxymethylcellulose, hydroxypropyl methylcellulose or polyvinylpyrrolidone, emulsifiers such as polysorbate 80 (TWEEN-80), partitioning agents or chelating agents such as EDTA (ethylenediaminetetraacetic acid) or EGTA (ethylene glycol tetraacetic acid), ethanol, polyethylene glycol, propylene glycol, sodium hydroxide, hydrochloric acid, citric acid or lactic acid. Antimicrobial agents used as carriers can be added to pharmaceutical compositions in multiple dose containers comprising phenols or cresols, mercurials, benzyl alcohol, chlorobutanol, methyl and propyl parabens, thimerosal, benzalkonium chloride and benzethonium chloride. Suitable excipients can include, for example, water, saline, dextrose, glycerol or ethanol. Suitable nontoxic auxiliary substances can include, for example, wetting agents or emulsifiers, pH buffers, stabilizers, solubility enhancers or reagents such as sodium acetate, sorbitan monolaurate, triethanolamine oleate or cyclodextrins.

[0162] Administration, formulation and dosage

[0163] The pharmaceutical compositions of the present invention can be administered to a subject in need thereof in vivo by various routes, including but not limited to oral, intravenous, intraarterial, subcutaneous, parenteral, intranasal, intramuscular, intracranial, intracardiac, intraventricular, intratracheal, oral, rectal, intraperitoneal, intradermal, topical, transdermal and intrathecal, or by implantation or inhalation. The compositions of the present invention can be formulated into solid, semisolid, liquid or gaseous preparations; including but not limited to tablets, capsules, powders, granules, ointments, solutions, suppositories, enemas, injections, inhalants and aerosols. Suitable preparations and routes of administration can be selected according to the intended application and treatment regimen.

[0164] Suitable formulations for enteral administration include hard or soft gelatin capsules, pills, tablets (including coated tablets), elixirs, suspensions, syrups or inhalants and controlled release forms thereof.

[0165] Preparations suitable for parenteral administration (e.g., by injection) include aqueous or non-aqueous, isotonic, pyrogen-free, sterile liquids (e.g., solutions, suspensions) in which the active ingredient is dissolved, suspended, or otherwise provided (e.g., in liposomes or other microparticles). These liquids may additionally contain other pharmaceutically acceptable ingredients, such as antioxidants, buffers, preservatives, stabilizers, bacteriostats, suspending agents, thickeners, and solutes that make the preparation isotonic with the blood (or other relevant body fluids) of the intended recipient. Examples of excipients include, for example, water, alcohol, polyols, glycerol, vegetable oils, etc. Examples of isotonic carriers suitable for such preparations include sodium chloride injection, Ringer's solution, or lactated Ringer's injection. Similarly, specific dosage regimens (including dosage, time, and repetition) will depend on specific individuals and individual medical history as well as empirical considerations such as pharmacokinetics (e.g., half-life, clearance, etc.).

[0166] The requirements for effective pharmaceutical carriers for injectable formulations / compositions are well known to those of ordinary skill in the art (see, e.g., Pharmaceutics and Pharmacy Practice, JB Lippincott Company, Philadelphia, PA, eds. Banker and Chalmers, pp. 238-250 (1982), and ASHP Handbook on Injectable Drugs, Toissel, 4th ed., pp. 622-630 (1986)).

[0167] The frequency of administration can be determined and adjusted during the course of treatment and is based on reducing the number of proliferating or tumorigenic cells, maintaining the reduction of such tumor cells, reducing the proliferation of tumor cells or delaying the development of metastasis. In some embodiments, the dose administered can be adjusted or reduced to control potential side effects and / or toxicity. Alternatively, a sustained continuous release formulation of the therapeutic composition of the present invention may be suitable.

[0168] Those skilled in the art will appreciate that the appropriate dosage may vary from patient to patient. Determining the optimal dosage generally involves a balance between the level of therapeutic benefit and any risk or adverse side effects. The selected dosage level will depend on a variety of factors, including but not limited to the activity of the specific compound, administration, administration time, compound clearance rate, duration of treatment, other drugs, compounds and / or materials used in combination, severity of the condition, and species, sex, age, weight, condition, general health and previous medical history of the patient. However, the dosage is generally selected to achieve a local concentration at the site of action that achieves the desired effect without causing substantial harmful or adverse side effects.

[0169] Generally, the antibodies or antigen-binding fragments thereof of the present invention can be administered in various ranges.

[0170] In certain preferred embodiments, the course of treatment involving the antibodies or antigen-binding fragments thereof of the present invention will include multiple doses of the selected pharmaceutical product administered over a period of weeks or months. More specifically, the antibodies or antigen-binding fragments thereof of the present invention may be administered every day, every two days, every four days, every week, every ten days, every two weeks, every three weeks, every month, every six weeks, every two months, every ten weeks or every three months. In this regard, it is understood that the dosage may be changed or the interval may be adjusted based on patient response and clinical practice.

[0171] Compatible formulations for parenteral administration (eg, intravenous injection) will contain an antibody or antigen-binding fragment thereof as disclosed herein at a concentration of about 5 μg / mL to about 100 mg / mL.

[0172] The antibodies of the invention can be co-administered with one or more other therapeutic agents (e.g., cytotoxic agents, radiotoxic agents, anti-tumor agents, anti-angiogenic agents or immunosuppressants) to reduce the induction of an immune response against the antibodies of the invention. The antibody can be linked to the therapeutic agent (as an immune complex) or can be administered separately from the therapeutic agent.

[0173] In the context of administering a treatment, the term "combination" or "co-administration" as used herein refers to the use of more than one treatment or therapeutic agent. The use of the term "combination" does not limit the order in which the treatment or therapeutic agent is administered to a subject. The treatment or therapeutic agent may be administered before, simultaneously, or after the second treatment or therapeutic agent is administered to the patient. Preferably, the treatment or therapeutic agent is administered to the subject in a certain order, amount, and / or within a certain time interval so that the treatment or therapeutic agent can work together. In a specific embodiment, the treatment or therapeutic agent is administered to the subject in a certain order, amount, and / or within a certain time interval so that they provide an increased benefit than if they were administered in other ways (particularly independently of each other). Preferably, the increased benefit is a synergistic effect.

[0174] Medical Uses

[0175] The antibodies, antibody compositions and methods of the invention have many in vitro and in vivo uses, including, for example, detection of PVRIG or enhancement of immune responses. For example, these molecules can be administered to cultured cells in vitro or ex vivo, or, for example, administered to human subjects in vivo.

[0176] Preferred subjects include mammals, such as humans / patients. Mammals in the context of the present invention are humans, non-human primates, domesticated animals such as dogs, cats, sheep, cows, goats, pigs, horses, etc., laboratory animals such as mice, rats, rabbits, guinea pigs, etc., and captive animals, such as zoo animals.

[0177] Treating conditions associated with PVRIG expression

[0178] In some aspects, the invention provides methods of treating a disorder in a mammal comprising administering to a subject (eg, a human) in need of treatment a therapeutically effective amount of an antibody or antigen-binding fragment thereof disclosed herein.

[0179] As described herein, the antibodies disclosed herein have one or more activities that can be therapeutically applied to kill cells and / or inhibit cells. In particular, killing cells, inhibiting the proliferation of cells and / or inhibiting the colony formation of cells can be used to treat or prevent cancer (including cancer metastasis). Inhibiting the proliferation, colony formation and / or metastasis of cells can be applied, especially for treating or preventing cancer metastasis and metastatic spread of cancer cells.

[0180] In some aspects, the present disclosure provides a method for treating a disease associated with PVRIG expression or determining its prognosis in a subject, comprising administering an effective dose of the antibody or antigen-binding fragment thereof, the nucleic acid molecule, the vector, the host cell, the conjugate, the antibody-drug conjugate, the multispecific molecule, or the pharmaceutical composition or kit to a subject in need thereof.

[0181] In some aspects, the present disclosure provides the antibody or antigen-binding fragment thereof, the nucleic acid molecule, the vector, the host cell, the conjugate, the antibody-drug conjugate, the multispecific molecule, or the pharmaceutical composition or kit for use in a method for treating a disease associated with PVRIG expression or determining the prognosis thereof in a subject.

[0182] In some aspects, the present disclosure provides use of the antibody or antigen-binding fragment thereof, the nucleic acid molecule, the vector, the host cell, the conjugate, the antibody-drug conjugate, the multispecific molecule, or the pharmaceutical composition or kit in the preparation of an agent (or drug) for treating a disease associated with PVRIG expression or determining the prognosis thereof.

[0183] In one embodiment, the disease associated with PVRIG expression includes a neoplastic disease, such as cancer.

[0184] The antibodies or antigen-binding fragments thereof can be used alone as a monotherapy or can be used in combination with chemotherapy or radiation therapy.

[0185] The antibodies or antigen-binding fragments thereof can be used in combination with anticancer agents, cytotoxic agents, or chemotherapeutic agents.

[0186] The term "anticancer agent" or "antiproliferative agent" means any agent that can be used to treat a cell proliferative disorder such as cancer, and includes, but is not limited to, cytotoxic agents, cytostatic agents, anti-angiogenic agents, radiotherapy and radiotherapeutic agents, targeted anticancer agents, BRMs, therapeutic antibodies, cancer vaccines, cytokines, hormone therapy, radiotherapy, anti-metastatic agents, and immunotherapeutic agents. It should be understood that in selected embodiments as described above, such anticancer agents may comprise a conjugate and may be combined with the disclosed site-specific antibodies prior to administration. More specifically, in certain embodiments, the selected anticancer agent is linked to an unpaired cysteine ​​of an engineered antibody to provide an engineered conjugate as described herein. Therefore, such an engineered conjugate is explicitly contemplated within the scope of the present invention. In other embodiments, the disclosed anticancer agent will be administered in combination with a site-specific conjugate comprising a different therapeutic agent as described above.

[0187] diagnosis

[0188] The present invention provides in vitro and in vivo methods for detecting, diagnosing or monitoring proliferative disorders and methods for screening cells from patients to identify tumor cells including tumorigenic cells. Such methods include identifying individuals with cancer for treatment or monitoring the progression of cancer, including contacting the patient or a sample obtained from the patient (in vivo or in vitro) with an antibody as described herein, and detecting the presence or absence or binding level of the antibody bound to a bound or free target molecule in the sample. In some embodiments, the antibody will comprise a detectable label or reporter molecule as described herein.

[0189] In some aspects, the present disclosure provides a method for diagnosing, detecting or monitoring a disease associated with PVRIG expression, comprising administering an effective dose of the antibody or antigen-binding fragment thereof, the nucleic acid molecule, the vector, the host cell, the conjugate, the antibody-drug conjugate, the multispecific molecule, or the pharmaceutical composition or kit to a subject in need thereof.

[0190] In some aspects, the present disclosure provides the antibody or antigen-binding fragment thereof, the nucleic acid molecule, the vector, the host cell, the conjugate, the antibody-drug conjugate, the multispecific molecule, or the pharmaceutical composition or kit for use in a method for diagnosing, detecting or monitoring a disease associated with PVRIG expression in a subject.

[0191] In another aspect, the present disclosure provides use of the antibody or antigen-binding fragment thereof, the nucleic acid molecule, the vector, the host cell, the conjugate, the antibody-drug conjugate, the multispecific molecule, or the pharmaceutical composition or kit in the preparation of an agent (or drug) for diagnosing, detecting or monitoring a disease associated with PVRIG expression.

[0192] Samples can be analyzed by a variety of assays, such as radioimmunoassays, enzyme immunoassays (e.g., ELISA), competitive binding assays, fluorescent immunoassays, immunoblotting assays, Western blot analysis, and flow cytometry assays. Compatible in vivo diagnostics or diagnostic assays can include imaging or monitoring techniques known in the art, such as magnetic resonance imaging, computerized tomography (e.g., CAT scans), positron emission tomography (e.g., PET scans), radiography, ultrasound, etc., known to those skilled in the art.

[0193] The methods described in the present invention for detecting or monitoring PVRIG expression or PVRIG-expressing cell levels in vitro can also be used for non-diagnostic purposes.

[0194] Preferred subjects include mammals, such as humans / patients in need thereof.

[0195] The sample from the subject is blood, excreta (urine or feces), oral or nasal secretions, or alveolar lavage fluid, tissue fluid, sweat, or extracts thereof from the subject.

[0196] Pharmaceutical packaging and kits

[0197] Also provided are pharmaceutical packaging and kits containing one or more containers of one or more doses of an antibody or an antigen-binding fragment thereof. In certain embodiments, a unit dose is provided, wherein the unit dose contains a predetermined amount of a composition comprising, for example, an antibody or an antigen-binding fragment thereof, with or without one or more other agents. For other embodiments, such a unit dose is supplied in a disposable prefilled syringe for injection. In other embodiments, the composition contained in the unit dose may contain saline, sucrose or the like; a buffer such as phosphate, etc.; and / or be formulated in a stable and effective pH range. Alternatively, in certain embodiments, the conjugate composition may be provided as a lyophilized powder, which may be reconstituted after adding a suitable liquid (e.g., sterile water or saline). In certain preferred embodiments, the composition comprises one or more substances that inhibit protein aggregation, including but not limited to sucrose and arginine. Any label on or associated with the container indicates that the encapsulated conjugate composition is used to treat a selected tumor disease condition.

[0198] Such kits typically include a pharmaceutically acceptable formulation of the engineered conjugate in a suitable container, and optionally include one or more anticancer agents or other agents in the same or different containers. The kit may also contain other pharmaceutically acceptable formulations for diagnosis or combined therapy.

[0199] More specifically, the kit can have a single container containing an antibody or antigen-binding fragment thereof of the present disclosure, with or without additional components, or they can have different containers for each required reagent. In the case of providing a combination therapeutic agent for conjugation, a single solution can be premixed in a molar equivalent combination or one component more than another. Alternatively, the conjugate of the kit and any optional anticancer agent can be stored separately in different containers before being administered to a patient. The kit can also include a second / third container device for containing a sterile pharmaceutically acceptable buffer or other diluent such as bacteriostatic water for injection (BWFI), phosphate buffered saline (PBS), Ringer's solution, and glucose solution.

[0200] When the components of the kit are provided in one or more liquid solutions, the liquid solution is preferably an aqueous solution, particularly preferably a sterile aqueous solution or a saline solution. However, the components of the kit may be provided as dry powders. When the reagents or components are provided in dry powder form, the powder may be reconstituted by adding a suitable solvent. It is contemplated that the solvent may also be provided in another container.

[0201] Example

[0202] The invention generally described herein will be more readily understood by reference to the following examples, which are provided by way of illustration and are not intended to limit the invention. In addition, the experimental methods in the following examples are conventional methods unless otherwise specified. The raw materials, reagent materials, etc. used in the following examples are commercially available products unless otherwise specified.

[0203] Example 1 Production of Antibodies 1, 6, 7, 16, 27, 52, 55

[0204] A variety of different immunization strategies (DNA immunization, protein immunization, cell immunization) were used to immunize mice of different species (Balb / c, SJL, A / J strains). Beacon was used to screen mouse B cells that positively bind to human PVRIG, or hybridoma was used to obtain subclones that can bind to human and monkey PVRIG, and candidate molecules that can specifically recognize human and monkey PVRIG were isolated through sequence extraction and sequencing1, 6, 7, 16, 27, 52, 55.

[0205] The amino acid sequence of the variable region of Antibody 1 was analyzed according to the Kabat sequence analysis method and is shown below.

[0206] 1_VH

[0207] QVQLQQSGAELARPGASVKMSCKASGYTFTDYWMQWIKQRPGQGLEWIGAIYPGNDDTRYTQKFKGRATLTADKSSSTVYMQLSNLTSEDSAVYYCATFRYYLDYWGQGTTLTVSS

[0208] 1_VL

[0209] QIILTQSPAIMSASPGEKVTMTCSASSSVSYIHWYQQKSDTSPKRWIYDTSKLVSGVPPRFSGTGSGTSYSLTISSMEAEDAATYYCQQWSSNPYTFGGGTKLEVK

[0210] The amino acid sequence of the variable region of Antibody 6 was analyzed according to the Kabat sequence analysis method and is shown below.

[0211] 6_VH

[0212] QVQLQQSGAELARPGASVKMSCKASGYTFTDYWMQWIKQRPGQGLEWIGAIFPGNDDIRYTQKFKGRATLTADKSSSTAYMQLSNLTSEDSAVYYCATFRYYLDYWGQGTTLTVSS

[0213] 6_VL

[0214] QIILTQSPAIMSASPGEKVTMTCSASSSVSYMHWYQQKSDTSPKRWIYDTSKLVSGVPPRFSGSGSGTSYSLTISSVEAEDAATYYCQQWSSNPYTFGGGTKLEIK

[0215] The amino acid sequence of the variable region of Antibody 7 was analyzed according to the Kabat sequence analysis method and is shown below.

[0216] 7_VH

[0217] QVHLQQSGDDLVKPGASVKLSCKASGYTFTNYLINWIKQRPGQGLEWIGIAPGSGSFYSNEV FKGKATLTVDTSSSTAYIQLSGLSSEDSAVYFCAREKNWDHFDFWGQGTTLTVSS

[0218] 7_VL

[0219] DIQMTQSSSSFSVSLGDRVTITCKASEDINNRLAWYQQKPGNAPRVLISGAVSLEAGVPSRFSG SGSGRDYTLTIISLQTEDVATYYCQQYWSTPFTFGGSGTKLEIK

[0220] The amino acid sequence of the variable region of antibody 16 was analyzed according to the Kabat sequence analysis method and is shown below.

[0221] 16_VH

[0222] QVQLQQPGADLVRPGASVKMSCKASGYTFTSYLMDWVKQRPGQGFEWIGNIDPNSGSTYYN EKFKDKAKLTVDKSSSTAYMQLSSLTSEDSAVYYCAIPYYSEYFGFDVWGTGTTVTVSS

[0223] 16_VL

[0224] DIVMTQSQKFMSTSVGDRVNITCKASQNVRTAVAWYQQKPGQSPKSLIYLASNRHTGVPDRF TGSGSGTDFTLTISNVQSEDLADYFCLQHWSYPYTFGGGTKLEIK

[0225] The amino acid sequence of the variable region of antibody 27 was analyzed according to the Kabat sequence analysis method and is shown below.

[0226] 27_VH

[0227] QVQLQQPGAELVRPGASVKMSCKASGYTFTSYLMDWVKQRPGQGFEWIGNIDPNSGSTYYN EKFKDKAKLTVDKSSSTAYIQLSSLTSEDSAVYYCAIPYYSEYYGFDVWGTGTTVTVSS

[0228] 27_VL

[0229] DIVMTQSQKFMSTSVGDRVNITCKASQNVRSAVAWYQQKPGQSPKTLIYLASNRHTGVPDRF TGSGSGTDFTLTISNVQSEDLADYFCLQHWNYPYTFGGGTKLEIK

[0230] The amino acid sequence of the variable region of antibody 52 was analyzed according to the Kabat sequence analysis method and is shown below.

[0231] 52_VH

[0232] QVQLQQPGAEFVKPGASVKLSCKASGYTFTSYWMQWVKQRPGQGLEWIGEIDPSDGYTNYN RKFKGKATLTIDTSSNTGYMQLSSLTSEDSAVYYCARGTYYYGSSLMDSWGQGTSVTVSS

[0233] 52_VL

[0234] DIVLTQSPASLAVSLGQRAIISCKASQSVSFADTSLMHWYQQKPGQQPKVLIYRASNLEAEVPT RFSGSGSGTDFTLNIHPVEEDDAATYYCQQSREYPPTFGGGTKLEIK

[0235] The amino acid sequence of the variable region of antibody 55 was analyzed according to the Kabat sequence analysis method and is shown below.

[0236] 55_VH

[0237] QVQLQQPGAELVRPGSSVKLSCKASGYTFTSYWMHWVRQRPIQGLEWIGIIDLFDSKIHYSQK FKDKATLTVDKSSSTAYMQLSSLTSEDSAVYYCARERGLGRAGAMDYWGQGTSVTVSS

[0238] 55_VL

[0239] DTVMTQSQKLMSTSVGDRVSVTCKASQNVDTDVVWYQQKPGQSPKALIYSASYRYSGVPDR FTGSGSGTDFTLTISNVQSEDLTEYFCQQYNSYPLTFGAGTKLELK

[0240] Example 2 Species Cross-Reactivity of Antibodies 1, 6, 7, 16, 27, 52, 55

[0241] The binding of antibodies 1, 6, 7, 16, 27, 52, and 55 to CHOK1 overexpressing PVRIG of different species was detected by FACS to evaluate their species cross-reactivity.

[0242] According to the SOP of cell culture, the corresponding stable cell lines expressing human, monkey and mouse PVRIG antigens were cultured and treated, including CHOK1 / Human PVRIG (homemade), CHOK1 / cyno PVRIG (homemade), and CHOK1 / mouse PVRIG (homemade). The cells harvested after digestion were centrifuged at 300g for 5 minutes at room temperature, the supernatant was discarded, and the cells were washed twice with 1×PBS (Gibco, 14190144). 1E+05 cells / well were placed in a 96-well plate, the supernatant was discarded after centrifugation, and the cells were resuspended with 20μg / mL antibody solution, 50uL / well, mixed, and incubated at 4°C for 1 hour. Centrifuge at 4°C, 300g for 5 minutes, discard the supernatant antibody solution, wash the cells twice with 1×PBS, add the corresponding 1μg / mL goat anti-human secondary antibody solution (Jackson, 109-605-088), 100uL / well, and incubate at 4 degrees for 30min. The cells were centrifuged at 300 g for 5 minutes at 4°C, and the supernatant antibody solution was discarded. The cells were washed twice with 1× PBS, and finally the cells were resuspended with PBS and the signal value was detected on a BD flow cytometer.

[0243] The results are as follows Figure 1A-1G As shown in Table 1, 1, 6, 7, 16, 27, 52, and 55 can all recognize and bind to PVRIG of primates humans and cynomolgus monkeys, but cannot recognize PVRIG of rodent mice.

[0244] Table 1

[0245]

[0246] Example 3 Cell-level binding activity of antibodies 1, 6, 7, 16, 27, 52, 55

[0247] The binding activity of 1, 6, 7, 16, 27, 52, and 55 to cell surface human PVRIG and cynoPVRIG was evaluated by FACS detection and EC50.

[0248] As described above, the stable cell lines CHOK1 / Human PVRIG and CHOK1 / Cyno PVRIG expressing human PVRIG antigen and monkey PVRIG antigen were cultured and treated by flow cytometry. The cells harvested after digestion were centrifuged at 300g for 5 minutes at room temperature, the supernatant was discarded, and the cells were washed twice with 1×PBS. 1E+05 cells / well were placed in a 96-well plate, the supernatant was discarded after centrifugation, and the cells were resuspended with diluted antibody solutions of different concentrations (300nM, 3-fold dilution, 12 dilution points), 50uL / well, mixed, and incubated at 4°C for 1 hour. Centrifuge at 300g for 5 minutes at 4°C, discard the supernatant antibody solution, wash the cells twice with 1×PBS, add the corresponding 1μg / mL goat anti-human secondary antibody solution (Jackson, 109-605-088), 100uL / well, and incubate at 4 degrees for 30min. The cells were centrifuged at 300 g for 5 minutes at 4°C, and the supernatant antibody solution was discarded. The cells were washed twice with 1× PBS, and finally the cells were resuspended with PBS and the signal value was detected on a BD flow cytometer.

[0249] The results are as follows Figure 2 and Figure 3 As shown, 1, 6, 7, 16, 27, 52, and 55 have strong binding activity with human and monkey PVRIG on the cell surface. This indicates that 1, 6, 7, 16, 27, 52, and 55 can effectively bind to the surface of CHOK1 / HumanPVRIG and CHOK1 / cyno PVRIG cells that overexpress human and monkey PVRIG, and have a certain dose dependence. The binding ability of these 7 candidate molecules to human and monkey PVRIG overexpressing cell lines is better than that of reference antibodies SRF813 and COM701.

[0250] Example 4 Protein Level Binding Activity of Antibodies 1, 6, 7, 16, 27, 52, 55

[0251] The binding of 1, 6, 7, 16, 27, 52, 55 at different concentrations to Human PVRIG protein (Acro, PVG-H52H4) and Cyno PVRIG (Acro, PVG-C5253) protein was detected by ELISA, and the EC50 was measured to evaluate its binding activity.

[0252] The antigen was diluted to 0.5 μg / ml with the coating solution, mixed and added to the designed ELISA plate, 100 μL / well; after coating, placed in a 4°C refrigerator overnight for 16 hours; discarded the coating solution, washed the plate once, and patted the ELISA plate dry; added 150 μL of blocking solution (2% BSA, self-prepared) to each well, and placed in a 37°C constant temperature incubator for incubation for 1 hour; took out the ELISA plate and discarded the blocking solution; the concentration of the first well of the antibody to be tested was 10 nM, and it was diluted 3 times to the 10th well, and the diluent was added to the remaining 2 wells as a blank control, and finally The control well data is reflected as the average value of two wells, 100 μL / well; incubate at 37°C for 1 hour, remove the ELISA plate, discard the internal solution, and wash the plate 3 times; add 100 μL of diluted ELISA goat anti-human secondary antibody (Rockland, 609-103-123) to each well and incubate in a 37°C incubator for 1 hour; remove the ELISA plate, discard the internal solution, wash the plate 3 times, pat dry and add 100 μL of colorimetric solution (Biyuntian, P0209), react at 25°C for 15 minutes; add 50 μL of 1M HCl to terminate the reaction; read the results at OD450 nm using an ELISA reader.

[0253] The results are as follows Figure 4 and Figure 5 As shown, 1, 6, 7, 16, 27, 52, and 55 have strong binding activity to both human and monkey PVRIG proteins, and have a certain dose dependence. The binding ability of these 7 candidate molecules to human and monkey PVRIG proteins is comparable to that of the reference antibodies SRF813 and COM701.

[0254] Example 5 Protein level blocking activity of antibodies 1, 6, 7, 16, 27, 52, 55

[0255] The inhibition rate of candidate antibody molecules was evaluated by blocking experiments. The specific method was to detect the inhibition of PVRL2 ligand binding to Human PVRIG protein by ELISA at different concentrations of 1, 6, 7, 16, 27, 52, 55 to measure IC50 and evaluate its blocking activity.

[0256] Human PVRIG protein (Acro, PVG-H52H4) was diluted to 1.0 μg / ml with coating solution, mixed and added to the designed ELISA plate, 100 μL / well; after coating, placed in a 4°C refrigerator overnight for 16 hours; discarded the coating solution, washed once, and patted the ELISA plate dry; added 150 μL of blocking solution (2% BSA, self-prepared) to each well, placed in a 37°C incubator for 1 hour, and then discarded the blocking solution; 4.0 nM PVRL2 ligand (Acro, CD2-H82A3) and the diluted antibody to be tested (100 nM, 3-fold dilution, 11 dilution points) were added 5 times each. 0 μL was added to the ELISA plate, and 50 μL of PVRL2 ligand (Acro, CD2-H82A3) and diluent (4 wells) were added to the ELISA plate as a blank value, incubated at 37°C for 1 h, the ELISA plate was taken out, the internal solution was discarded, and the plate was washed 3 times; 100 μL of 1:5000 diluted enzyme-labeled secondary antibody (Genscript, M00091) was added to each well, and incubated in a 37°C constant temperature box for 1 h; the ELISA plate was taken out, the internal solution was discarded, the plate was washed 3 times, 100 μL of color development solution was added after patting dry, and the reaction was carried out at 25°C for 15 min; 50 μL of 1M HCl was added to terminate the reaction, and the OD450nm reading was read on a ELISA reader.

[0257] The results are as follows Figure 6 As shown, 1, 6, 7, 16, 27, 52, and 55 all have strong ligand blocking activity and have a certain dose dependence. The ligand blocking activity of these 7 candidate molecules is comparable to that of the reference antibodies SRF813 and COM701.

[0258] Example 6 Affinity Testing of Antibodies 1, 6, 7, 16, 27, 52, 55

[0259] The affinity of 1, 6, 7, 16, 27, 52, and 55 was tested by Biacore. The detection temperature of the affinity determination experiment was 25°C, and the buffer system was HBS-EP+ (Cytiva, BR-1006-69). The antibody was captured on the proteinA chip (Cytiva, 29-1275-55) as a stationary phase. The diluted human PVRIG antigen (Acro, PVG-H52H4) was injected into the chip surface in sequence as the binding phase, followed by the injection of the running buffer as the dissociation phase to detect its affinity. The data was processed using Biacore 8K analysis software version 3.0.

[0260] The experimental parameters for the run are shown in Table 2 below:

[0261] Table 2: Key experimental parameters

[0262]

[0263] The results are shown in Table 3 below. Antibodies 16, 27 and 52 have high affinity for PVRIG target protein, with an affinity of 10 -11 M level, significantly better than the reference antibodies SRF813 and COM701, while the affinities of 1, 6, 7 and 55 can also reach a level comparable to that of the reference antibodies.

[0264] Table 3: Binding dissociation constants of 1, 6, 7, 16, 27, 52, 55 and human PVRIG

[0265]

[0266]

[0267] Example 7 Detection of reporter gene activity of antibodies 1, 6, 7, 16, 27, 52, 55

[0268] The PVRL2 / PVRIG reporter gene assay is a rapid and reproducible cell-based assay. The reporter gene assay consists of two genetically engineered cell lines, one is the GS-J2C / PVRIG effector cell line expressing human PVRIG protein and a luciferase reporter gene driven by NFAT-RE, and the other is the GS-C2 / PVRL2 target cell line expressing human PVRL2 protein and anti-human CD3ScFv. When the GS-J2C / PVRIG effector cell line is co-cultured with the GS-C2 / PVRL2 target cell line, the PVRL2 / PVRIG interaction inhibits the activation of the cell TCR pathway by anti-CD3, thereby inhibiting the expression of NFAT-driven luciferase, and the corresponding fluorescence signal is low; the addition of PVRIG therapeutic antibodies blocks the PVRL2 / PVRIG interaction, thereby restoring the TCR signaling pathway and increasing the fluorescence signal value.

[0269] The specific method is to digest and collect GS-C2 / PVRL2 target cells (Genscript construction) by centrifugation and resuspend the cells in the corresponding complete medium (F-12K (Gibco, 21127-022) + 10% FBS (Gibco, 10091-148)); adjust the target cell density, inoculate in the experimental plate and transfer the experimental plate to a cell culture incubator (37°C / 5% CO2) for incubation for about 16 hours; use the experimental buffer (RPMI 1640 (Gibco, 22400-089) + 1.25% FBS (Gibco, 10091-148)) was used to prepare the reference antibody and the antibody to be tested working solution; the effector cells were collected by centrifugation, and the cells were resuspended in the experimental buffer and the cell density was adjusted; the experimental plate incubated with the target cells was taken out from the cell culture incubator and the culture medium was removed; the reference antibody and the antibody to be tested working solution and the GS-J2C / PVRIG effector cell (Genscript constructed) suspension were transferred to the experimental plate in sequence; the experimental plate was transferred to a cell culture incubator (37°C / 5% CO2) and incubated for 6 hours; the luciferase detection reagent working solution (GenScript, L00877C) was prepared; the incubated experimental plate was taken out from the cell culture incubator, the luciferase detection reagent working solution was transferred to the corresponding wells of the experimental plate, and incubated at room temperature for 3-5 minutes; the chemiluminescence value was read using a PHERA Star microplate reader and the data was recorded.

[0270] The results are as follows Figure 7 As shown, the reporter gene activity of the reference antibody SRF813 is weaker than that of COM701 (EC50: 0.142ug / ml vs 0.087ug / ml, Span: 168139 vs 238134). Compared with COM701, the reporter gene activities of 16, 27 and 52 are significantly better than the reference antibody COM701, among which the reporter gene activity of antibody 52 is about 3 times that of COM701. The reporter gene activities of 1, 6, 7 and 55 are all between 0.9 and 1.1ug / ml, which can also reach a level comparable to that of the reference antibody.

[0271] Example 8 Detection of CD8+ T cell activation levels of antibodies 1, 6, 7, 16, 27, 52, 55

[0272] In order to further detect the level of CD8 T cell activation in vitro, antigen-specific CD8+ T cell activation experiments were performed on 1, 6, 7, 16, 27, 52, and 55.

[0273] PBMCs (Miaoshun Bio, PB100C-W) were revived using RPMI 1640 complete medium (RPMI 1640 + 10% FBS) and induced and cultured for 12 days according to the established induction protocol. After 12 days, PBMCs were collected by centrifugation and primary CD8+T cells were sorted. At the same time, the levels of PVRIG, TIGIT, pp65, and CD226 in CD8+T were analyzed by flow cytometry for the induced PBMCs or sorted CD8+T. Colo205 target cells (ATCC, CCL-222) were collected by digestion and centrifugation and resuspended in experimental buffer (RPMI 1640 + 10% FBS). Pre-incubate a certain amount of Colo205 target cells (ATCC, CCL-222) with a high concentration of pp65 (GenScript, RP11781) working solution (4×) in a cell culture incubator (37°C / 5% CO2) for 0.5-2 hours; after premixing, centrifuge to remove pp65; adjust the density of Colo205 target cells (ATCC, CCL-222) and transfer the cell suspension to a 96-well plate. Prepare the control / test working solution (4×) using RPMI 1640 complete medium. Transfer the control / test working solution to the corresponding wells of the 96-well experimental plate. According to the effector-target ratio (1:1) set in the protocol, adjust the CD8+T cell density and transfer the cell suspension to the corresponding wells of the 96-well experimental plate. Incubate the experimental plate in a cell culture incubator (37°C / 5% CO2) for about 16-18 hours. After incubation, the supernatant was centrifuged for human hINFγ cytokine detection (Cisbio, 62HIFNGPEH), and the cells were digested, washed with FACS buffer, and stained with 7-AAD (Biolegend, 420403). After staining, the supernatant was centrifuged and discarded, and the cells were washed and resuspended with FACS buffer. The cells were collected using a flow cytometer and the fluorescence signal values ​​were read. The raw data of the cytokine release experiment were exported via the PHERA Star FSX system and analyzed using Microsoft Office Excel 2016 and GraphPad Prism 6 software. The raw data of the cell flow analysis experiment were exported via the BD FACSDiva Software v8.0.1.1 system and analyzed using FlowJo 7.6.1 and Microsoft Office Excel 2016 software. The results were used to evaluate the level of target cell killing (percentage of 7-AAD positive cells).

[0274] The results are as follows Figure 8A-8C and 8D- Fig.8FAs shown in the figure, the cytokine induction secretion ability and cell killing activity of the reference antibody COM701 are weak. Compared with COM701, 6, 55, 27 and 52 have stronger ability to induce human hINFγ cytokine secretion, among which 27 and 52 are the best, significantly stronger than the reference antibody. 52 is significantly better than other antibody molecules including the reference molecule in the detection of CD8+T killing activity, and has obvious cell killing activity.

[0275] Example 9 Classification of Antigen Epitopes of Antibodies 1, 6, 7, 16, 27, 52, and 55

[0276] In order to further clarify the epitopes of 1, 6, 7, 16, 27, 52, and 55 binding to PVRIG, the antigen binding regions were clarified by competitive ELSA method with reference antibodies SRF813 and COM701, which are known to bind to different epitopes in PVRIG regions.

[0277] Epitope competition ELISA detection: Human PVRIG protein (Acro, PVG-H52H4) was diluted to 0.5 μg / ml with coating solution, mixed and added to the designed ELISA plate, 100 μL / well; after coating, placed in a 4°C refrigerator overnight for 16 hours; discard the coating solution, wash the plate once, and pat the ELISA plate dry; add 150 μL of blocking solution (2% BSA, self-prepared) to each well, put it in a 37°C constant temperature box for 1 hour, and then discard the blocking solution; each biotin-labeled antibody as a competitor (self-prepared) and the diluted antibody sample (see Table 4) were added 5 0μL was added to the ELISA plate, and 50μL of the competitor and diluent (4 wells) were added to the ELISA plate as the blank value, incubated at 37℃ for 1h, the ELISA plate was taken out, the internal solution was discarded, and the plate was washed 3 times; 100μL of the diluted enzyme-labeled secondary antibody (Genscript, M00091) was added to each well, and incubated at 37℃ for 1h; the ELISA plate was taken out, the internal solution was discarded, and the plate was washed 3 times, 100μL of the color developing solution was added after patting dry, and the reaction was carried out at 25℃ for 15min; 50μL of 1M HCl was added to terminate the reaction, and the OD450 nm reading was performed on the ELISA reader. The results are shown in Table 4.

[0278] Table 4: Classification of antigenic epitopes of 1, 6, 7, 16, 27, 52, 55

[0279]

[0280] The results are shown in the table above. The binding epitopes of COM701 and SRF8131 are different; the binding epitopes of 16, 27 and 52 completely overlap, and the three partially overlap with the binding epitopes of COM701 and SRF8131; 7 partially overlaps with the binding epitope of COM701; the binding epitopes of 1, 6 and 55 completely overlap, and the three do not overlap with the binding epitopes of COM701 and SRF8131. The specific results are as follows Fig. 9 shown.

[0281] Example 10 In vivo efficacy of antibodies 1, 6, 7, 16, 27, 52, 55

[0282] The efficacy of the test drugs 1, 6, 7, 16, 27, 52, and 55 was evaluated in an animal model in which human melanoma A375 cells (ATCC, CRL-1619) were subepithelially inoculated into PBMC-reconstructed B-NDG mice (Biocytogen).

[0283] Will contain 5×10 7 0.1 mL of A375 cell suspension was subcutaneously inoculated above the right shoulder blade of each B-NDG mouse. After tumor cell inoculation, PBMC (Miaoshun Biotechnology, PB100C-W) was inoculated the next day, 2.5×10 7 / mL, 0.2mL was inoculated into the tail vein of each mouse. When the tumor volume of the mouse reached 50-100mm 3 The mice were randomly divided into groups according to the tumor volume. The CV value of the tumor volume of the mice enrolled was ≤30%. There were 8 mice in each group, and the dosage was 10mg / kg PD-1 + 30mg / kg of the antibody to be tested, twice a week for 3 weeks. If the body weight dropped by more than 15%, the administration should be stopped immediately until the body weight recovered to more than 98% of the initial body weight and then normal administration was resumed; if the body weight dropped by more than 20% and did not recover within 72h, the mice would be euthanized.

[0284] The results are as follows Fig.10 As shown in the figure, from the tumor volume and TGI values ​​at D20, compared with the Vehicle (PBS administration group), the PD1+6, 7, 10, 16, 27, 52 combination groups all showed certain tumor inhibition effects (TGI: 16.93%, 17.03%, 10.5%, 18.71%, 25.01%, 16.06%). Among them, antibody No. 27 had the best anti-tumor effect. The specific results are shown in Table 5.

[0285] Table 5

[0286]

[0287] Example 11 Hotspot Removal of Antibody 52

[0288] After sequence analysis, there is an aspartate isomerization site in CDRH2 of 52, which has a high risk of PTM, so a hotspot removal modification was performed to avoid the effect of aspartate isomerization on the antibody structure and function. The hotspot removal modification variants are shown in Table 6. The four variants are 52_vH (DG / EG-DS / ES), 52_vH (DG / EG-DS / DA), 52_vH (DG / DA-DS / ES), and 52_vH (DG / DA-DS / DA).

[0289] Table 6

[0290]

[0291]

[0292] Hotspot removal variants were transiently transfected with ExpiCHO-S cells (Thermo) to express antibodies. 24 h before transfection, ExpiCHO-S cells were cultured normally with expression medium at a cell density of 3.8 × 10 6 cells / mL, and then cultured in a shaker at 37°C, 8% CO2; on the day of transfection, the live cell density and cell viability were calculated. The cells were then diluted to the density required for transfection. The liposome method was used for transfection. After the transfection was completed, the shake flask was returned to a shaker at 37°C, 8% CO2 for continued culture; feed and additives (Gibco, A29129) were added to the cells 18-22h after transfection, and samples were taken 7-10 days after transfection to run SDS-PAGE to confirm that the expression level was sufficient, and the supernatant was collected by centrifugation for purified antibody preparation.

[0293] The hotspot removal variants at different concentrations were tested by ELISA to determine the EC50 of binding to Human PVRIG and Cyno PVRIG proteins and evaluate their binding activity. The detection process is shown in Example 4. The results of the identification of the properties of the hotspot removal variants are shown in Fig.11 and Fig.12 As shown in the figure, the target protein binding activity of the four variants is comparable to that of the 52 original sequences. It can be seen that these four hotspot removal variants have little effect on the target protein binding activity of the original sequence.

[0294] The inhibition rate of the candidate antibody molecule was evaluated by blocking experiments. The specific method was to detect the inhibition of the hotspot removal variants at different concentrations by ELISA to measure the IC50 and evaluate their blocking activity. The detection process is shown in Example 5. The results of the identification of the properties of the hotspot removal variants are shown in Fig.13As shown, the ligand receptor blocking activities of 52_vH(DG / EG-DS / ES), 52_vH(DG / EG-DS / DA) and 52_vH(DG / DA-DS / DA) are comparable to those of the original sequence 52. The blocking activity of 52_vH(DG / DA-DS / ES) is slightly weaker than that of the original sequence 52.

[0295] The hotspot removal variants at different concentrations were detected by FACS to bind to human PVRIG and cyno PVRIG on the cell surface and the EC50 was measured to evaluate their binding activity. The detection process is shown in Example 3. The results of the identification of the properties of the hotspot removal variants are shown in Fig.14 , Fig.15 As shown. The human and monkey cell FACS binding activities of 52_vH(DG / DA-DS / ES) and 52_vH(DG / DA-DS / DA) variants are comparable to the 52 original sequence. The human and monkey cell FACS binding activities of 52_vH(DG / EG-DS / ES) and 52_vH(DG / EG-DS / DA) variants are weaker than those of the 52 original sequence.

[0296] The affinity of the hotspot removal variants was tested by Biacore. The specific detection method is shown in Example 6. The results of the characterization of the hotspot removal variants are shown in Table 7. The affinity of 52_vH (DG / DA-DS / ES) and 52_vH (DG / DA-DS / DA) variants is comparable to that of the 52 original sequence. The affinity of 52_vH (DG / EG-DS / ES) and 52_vH (DG / EG-DS / DA) variants decreased compared to the 52 original sequence.

[0297] Table 7

[0298]

[0299] The reporter gene activity of the hotspot removal variant was detected by reporter gene experiment. The specific detection method is shown in Example 7. The property identification results of the hotspot removal variant are as follows: Fig.16 As shown in Figure 5, the affinities of 52_vH(DG / DA-DS / ES) and 52_vH(DG / DA-DS / DA) variants were comparable to the original sequence of 52.

[0300] In summary, the 52_vH(DG / DA-DS / ES) and 52_vH(DG / DA-DS / DA) variants had the weakest effect on activity, and their ELISA binding activity, blocking activity, FACS binding activity, affinity and reporter gene activity were comparable to those of the 52 original sequence.

[0301] Incorporated by Reference

[0302] Each patent document and scientific document mentioned herein is incorporated by reference in its entirety for all purposes.

[0303] Equivalence

[0304] The present invention may be embodied in other specific ways without departing from its spirit or essential characteristics. Therefore, the above embodiments should be regarded as illustrative in all cases, rather than limiting the invention described herein. Therefore, the scope of the present invention is indicated by the appended claims rather than by the above description, and it is intended that all changes within the equivalent meaning and scope of the claims are included therein.

Claims

1. An isolated antibody or antigen-binding fragment thereof, wherein the antibody or antigen-binding fragment thereof specifically binds to PVRIG and comprises a heavy chain variable region (VH) and a light chain variable region (VL), The heavy chain variable region and the light chain variable region comprise: HCDR1 shown in SEQ ID NO:38, HCDR2 shown in SEQ ID NO:44, and HCDR3 shown in SEQ ID NO:52, LCDR1 shown in SEQ ID NO:61, LCDR2 shown in SEQ ID NO:66, and LCDR3 shown in SEQ ID NO:

72.

2. The antibody or fragment of claim 1, wherein the heavy chain variable region is as shown in SEQ ID NO: 22; The light chain variable region is shown in SEQ ID NO:

33.

3. The antibody or fragment according to claim 2, further comprising a heavy chain constant region and a light chain constant region, wherein the heavy chain constant region is as shown in SEQ ID NO: 15; and the light chain constant region is as shown in SEQ ID NO:

16.

4. The antibody or fragment of claim 3, comprising: The light chain is shown in SEQ ID NO:12, and the heavy chain is shown in SEQ ID NO:

11.

5. The antibody or fragment as described in any one of claims 1 to 4, wherein the antibody is a whole antibody; The fragment is a Fab fragment, a Fab' fragment, a F(ab')2 fragment, a Fv fragment, or a single-chain Fv fragment (scFv).

6. The antibody or fragment as claimed in any one of claims 1 to 4, wherein the antibody is a chimeric antibody.

7. The antibody or fragment as claimed in any one of claims 1 to 4, wherein the antibody is a monoclonal antibody.

8. A variant of the antibody or fragment of any one of claims 1 to 7, comprising a heavy chain variable region (VH) and a light chain variable region (VL), The heavy chain variable region and the light chain variable region comprise: HCDR1 shown in SEQ ID NO:38, HCDR2 shown in SEQ ID NO:46 or 47, and HCDR3 shown in SEQ ID NO:54 or 55; LCDR1 shown in SEQ ID NO:61, LCDR2 shown in SEQ ID NO:66, and LCDR3 shown in SEQ ID NO:

72.

9. The variant of claim 8, wherein the heavy chain variable region is shown as SEQ ID NO: 24, SEQ ID NO: 25, SEQ ID NO: 26 or SEQ ID NO: 27; wherein the light chain variable region is shown as SEQ ID NO:

33.

10. An isolated nucleic acid molecule comprising a nucleic acid sequence encoding the antibody or fragment as claimed in any one of claims 1 to 7, or the variant as claimed in claim 8 or 9.

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