Anti-CD73 Antibodies and Uses

Abstract

The present application relates to a new anti-CD73 antibody and its use. The anti-CD73 antibody binds to CD73 (CD73 + ) can be used to treat tumors expressing the

Description

[Technical field]

[0001] [Reference to Related Applications] This application claims priority to Chinese Patent Application No. 202210098976.1, filed on January 25, 2022, the entirety of which is incorporated herein by reference for all purposes.

[0002] [Technical field] This application relates generally to the biopharmaceutical field. Specifically, this application relates to novel anti-CD73 antibodies or antigen-binding fragments thereof, pharmaceutical compositions comprising said antibodies or antigen-binding fragments thereof, and medical uses of said antibodies or antigen-binding fragments thereof. [Background technology]

[0003] CD73 is an extracellular 5'-nucleotidase encoded by the NT5E gene, which contains two parts, N-terminal and C-terminal, and is anchored to the outer surface of the cell membrane via glycosylphosphatidylinositol (GPI) to form a homodimer. CD73 is widely expressed on the surface of cells such as human endothelial cells and lymphocytes. It is highly expressed in various tumor tissues such as gastric cancer, renal cancer, prostate cancer, breast cancer (such as triple-negative breast cancer), and non-small cell adenocarcinoma, and indicates poor prognosis. CD73 can hydrolyze extracellular adenosine monophosphate (AMP) to adenosine. Adenosine is a functionally potent immunoinhibitory molecule that weakens antitumor immunity by inhibiting the function of protective immune cells (such as effector T cells, NK cells, DCs, and B cells) while maintaining the function of regulatory immune cells (such as Tregs, MDSCs, TAMs, and CAFs), and is involved in immune escape of tumors. In addition to inhibiting immune cell function, a growing number of studies suggest that CD73 can also directly stimulate tumor cell proliferation, migration, invasion and tumor angiogenesis, and that inhibiting extracellular nucleotidase CD73 can reverse adenosine-mediated immune inhibition. Studies have found that hypoxia, radiotherapy and chemotherapy lead to upregulation of PDL1, CD73 and CD47 expression. Therefore, a therapeutic policy targeting CD73 is likely to be used clinically as a single agent or combination therapy. Currently, there are nearly 30 anti-CD73 antibody products in development, including Mediimmune's oleclumab and Tenkyo Bio's uliledlimab. The most advanced CD73 antibodies are in clinical phase III, and there are no commercially available products, so the development and use of CD73 antibodies is urgently needed in the field. Summary of the Invention

[0004] In a first aspect, the present application provides an anti-CD73 antibody, or antigen-binding portion thereof, comprising a heavy chain variable region comprising a heavy chain CDR1 (HCDR1), a heavy chain CDR2 (HCDR2) and a heavy chain CDR3 (HCDR3), and a light chain variable region comprising a light chain CDR1 (LCDR1), a light chain CDR2 (LCDR2) and a light chain CDR3 (LCDR3), wherein the sequence of HCDR1 is the sequence shown in SEQ ID NO:1 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:1, the sequence of HCDR2 is the sequence shown in SEQ ID NO:2 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:2, the sequence of HCDR3 is the sequence shown in SEQ ID NO:3 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:3, and L the sequence of CDR1 is the sequence shown in SEQ ID NO:5 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:5, the sequence of LCDR2 is the sequence shown in SEQ ID NO:6 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:6, and the sequence of LCDR3 is the sequence shown in SEQ ID NO:7 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:7, or the sequence of HCDR1 is the sequence shown in SEQ ID NO:1 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:1, the sequence of HCDR2 is the sequence shown in SEQ ID NO:17 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:17, the sequence of HCDR3 is the sequence shown in SEQ ID NO:3 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:3, and L the sequence of CDR1 is the sequence shown in SEQ ID NO:5 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:5, the sequence of LCDR2 is the sequence shown in SEQ ID NO:32 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:32, the sequence of LCDR3 is the sequence shown in SEQ ID NO:7 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:7, or the sequence of HCDR1 is the sequence shown in SEQ ID NO:1 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:1, the sequence of HCDR2 is the sequence shown in SEQ ID NO:17 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:17, and the sequence of HCDR3 is the sequence shown in SEQ ID NO:3 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:3; the sequence of LCDR1 is the sequence shown in SEQ ID NO:5 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:5, the sequence of LCDR2 is the sequence shown in SEQ ID NO:6 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:6, the sequence of LCDR3 is the sequence shown in SEQ ID NO:7 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:7, or the sequence of HCDR1 is the sequence shown in SEQ ID NO:1 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:1, the sequence of HCDR2 is the sequence shown in SEQ ID NO:2 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:2, the sequence of HCDR3 is the sequence shown in SEQ ID NO:3 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:3, and the sequence of DR1 is as set forth in SEQ ID NO:5 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence set forth in SEQ ID NO:5; the sequence of LCDR2 is as set forth in SEQ ID NO:32 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence set forth in SEQ ID NO:32; the sequence of LCDR3 is as set forth in SEQ ID NO:7 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence set forth in SEQ ID NO:7; or the sequence of HCDR1 is the sequence shown in SEQ ID NO:1 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:1, the sequence of HCDR2 is the sequence shown in SEQ ID NO:21 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:21, the sequence of HCDR3 is the sequence shown in SEQ ID NO:3 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:3, and L the sequence of CDR1 is the sequence shown in SEQ ID NO:5 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:5, the sequence of LCDR2 is the sequence shown in SEQ ID NO:32 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:32, the sequence of LCDR3 is the sequence shown in SEQ ID NO:7 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:7, or the sequence of HCDR1 is the sequence shown in SEQ ID NO:1 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:1, the sequence of HCDR2 is the sequence shown in SEQ ID NO:21 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:21, and the sequence of HCDR3 is the sequence shown in SEQ ID NO:3 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:3; the sequence of LCDR1 is the sequence shown in SEQ ID NO:5 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:5, the sequence of LCDR2 is the sequence shown in SEQ ID NO:6 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:6, the sequence of LCDR3 is the sequence shown in SEQ ID NO:7 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:7, or the sequence of HCDR1 is the sequence shown in SEQ ID NO:1 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:1, the sequence of HCDR2 is the sequence shown in SEQ ID NO:23 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:23, the sequence of HCDR3 is the sequence shown in SEQ ID NO:3 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:3, and L the sequence of CDR1 is the sequence shown in SEQ ID NO:5 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:5, the sequence of LCDR2 is the sequence shown in SEQ ID NO:32 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:32, the sequence of LCDR3 is the sequence shown in SEQ ID NO:7 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:7, or the sequence of HCDR1 is the sequence shown in SEQ ID NO:1 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:1, the sequence of HCDR2 is the sequence shown in SEQ ID NO:23 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:23, and the sequence of HCDR3 is the sequence shown in SEQ ID NO:3 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:3; the sequence of LCDR1 is the sequence shown in SEQ ID NO:5 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:5, the sequence of LCDR2 is the sequence shown in SEQ ID NO:6 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:6, the sequence of LCDR3 is the sequence shown in SEQ ID NO:7 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:7, or the sequence of HCDR1 is the sequence shown in SEQ ID NO: 9 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 9, the sequence of HCDR2 is the sequence shown in SEQ ID NO: 10 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 10, the sequence of HCDR3 is the sequence shown in SEQ ID NO: 11 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 11, the sequence of DR1 is as set forth in SEQ ID NO: 13 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence set forth in SEQ ID NO: 13, the sequence of LCDR2 is as set forth in SEQ ID NO: 14 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence set forth in SEQ ID NO: 14, and the sequence of LCDR3 is as set forth in SEQ ID NO: 15 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence set forth in SEQ ID NO: 15; or the sequence of HCDR1 is the sequence shown in SEQ ID NO: 9 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 9, the sequence of HCDR2 is the sequence shown in SEQ ID NO: 10 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 10, the sequence of HCDR3 is the sequence shown in SEQ ID NO: 11 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 11, the sequence of DR1 is as set forth in SEQ ID NO:35 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence set forth in SEQ ID NO:35, the sequence of LCDR2 is as set forth in SEQ ID NO:14 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence set forth in SEQ ID NO:14, the sequence of LCDR3 is as set forth in SEQ ID NO:15 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence set forth in SEQ ID NO:15, or the sequence of HCDR1 is the sequence shown in SEQ ID NO: 9 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 9; the sequence of HCDR2 is the sequence shown in SEQ ID NO: 27 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 27; the sequence of HCDR3 is the sequence shown in SEQ ID NO: 11 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 11; the sequence of DR1 is as set forth in SEQ ID NO:35 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence set forth in SEQ ID NO:35, the sequence of LCDR2 is as set forth in SEQ ID NO:14 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence set forth in SEQ ID NO:14, the sequence of LCDR3 is as set forth in SEQ ID NO:15 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence set forth in SEQ ID NO:15, or the sequence of HCDR1 is the sequence shown in SEQ ID NO: 9 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 9; the sequence of HCDR2 is the sequence shown in SEQ ID NO: 27 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 27; the sequence of HCDR3 is the sequence shown in SEQ ID NO: 11 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 11; the sequence of DR1 is as set forth in SEQ ID NO: 13 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence set forth in SEQ ID NO: 13, the sequence of LCDR2 is as set forth in SEQ ID NO: 14 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence set forth in SEQ ID NO: 14, and the sequence of LCDR3 is as set forth in SEQ ID NO: 15 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence set forth in SEQ ID NO: 15; or the sequence of HCDR1 is the sequence shown in SEQ ID NO: 9 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 9, the sequence of HCDR2 is the sequence shown in SEQ ID NO: 30 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 30, the sequence of HCDR3 is the sequence shown in SEQ ID NO: 11 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 11, the sequence of DR1 is as set forth in SEQ ID NO:35 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence set forth in SEQ ID NO:35, the sequence of LCDR2 is as set forth in SEQ ID NO:14 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence set forth in SEQ ID NO:14, the sequence of LCDR3 is as set forth in SEQ ID NO:15 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence set forth in SEQ ID NO:15, or the sequence of HCDR1 is the sequence shown in SEQ ID NO: 9 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 9; the sequence of HCDR2 is the sequence shown in SEQ ID NO: 30 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 30; the sequence of HCDR3 is the sequence shown in SEQ ID NO: 11 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 11; the sequence of CDR1 is the sequence shown in SEQ ID NO: 13 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 13, the sequence of LCDR2 is the sequence shown in SEQ ID NO: 14 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 14, and the sequence of LCDR3 is the sequence shown in SEQ ID NO: 15 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 15; Among them, the HCDR and LCDR sequences are defined according to Kabat.

[0005] In a second aspect, the present application provides an anti-CD73 antibody, or antigen-binding portion thereof, comprising a heavy chain variable region and a light chain variable region, the heavy chain variable region has an amino acid sequence as set forth in SEQ ID NO: 4, 18, 19, 20, 22, 24, 12, 25, 26, 28, 29, or 31, or an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identity to the amino acid sequence as set forth in SEQ ID NO: 4, 18, 19, 20, 22, 24, 12, 25, 26, 28, 29, or 31; and / or The light chain variable region has an amino acid sequence set forth in SEQ ID NO: 8, 33, 34, 16, 36, 37 or 38, or an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95% or at least 99% identity to the amino acid sequence set forth in SEQ ID NO: 8, 33, 34, 16, 36, 37 or 38.

[0006] In a third aspect, the present application provides an anti-CD73 antibody, or antigen-binding portion thereof, comprising a heavy chain variable region comprising a heavy chain CDR1 (HCDR1), a heavy chain CDR2 (HCDR2), and a heavy chain CDR3 (HCDR3), wherein (1) the sequence of HCDR1 is the sequence shown in SEQ ID NO:1 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:1, the sequence of HCDR2 is the sequence shown in SEQ ID NO:2 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:2, and the sequence of HCDR3 is the sequence shown in SEQ ID NO:3 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:3, or (2) the sequence of HCDR1 is the sequence shown in SEQ ID NO:1 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:1, the sequence of HCDR2 is the sequence shown in SEQ ID NO:17 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:17, and the sequence of HCDR3 is the sequence shown in SEQ ID NO:3 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:3, or (3) the sequence of HCDR1 is the sequence shown in SEQ ID NO:1 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:1, the sequence of HCDR2 is the sequence shown in SEQ ID NO:21 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:21, and the sequence of HCDR3 is the sequence shown in SEQ ID NO:3 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:3, or (4) the sequence of HCDR1 is the sequence shown in SEQ ID NO:1 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:1, the sequence of HCDR2 is the sequence shown in SEQ ID NO:23 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:23, and the sequence of HCDR3 is the sequence shown in SEQ ID NO:3 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:3, or (5) the sequence of HCDR1 is the sequence shown in SEQ ID NO: 9 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 9, the sequence of HCDR2 is the sequence shown in SEQ ID NO: 10 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 10, and the sequence of HCDR3 is the sequence shown in SEQ ID NO: 11 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 11, or (6) the sequence of HCDR1 is the sequence shown in SEQ ID NO: 9 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 9, the sequence of HCDR2 is the sequence shown in SEQ ID NO: 27 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 27, and the sequence of HCDR3 is the sequence shown in SEQ ID NO: 11 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 11, or (7) The sequence of HCDR1 is a sequence shown in SEQ ID NO: 9 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 9, the sequence of HCDR2 is a sequence shown in SEQ ID NO: 30 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 30, and the sequence of HCDR3 is a sequence shown in SEQ ID NO: 11 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 11; Among them, the HCDR sequence is defined based on Kabat.

[0007] In a fourth aspect, the present application provides an anti-CD73 antibody, or antigen-binding portion thereof, comprising a light chain variable region comprising a light chain CDR1 (LCDR1), a light chain CDR2 (LCDR2), and a light chain CDR3 (LCDR3), wherein: (1) the sequence of LCDR1 is set forth in SEQ ID NO:5 or has at least 80%, 85%, 90%, 95% or 99% identity to the sequence set forth in SEQ ID NO:5, the sequence of LCDR2 is set forth in SEQ ID NO:6 or has at least 80%, 85%, 90%, 95% or 99% identity to the sequence set forth in SEQ ID NO:6, and the sequence of LCDR3 is set forth in SEQ ID NO:7 or has at least 80%, 85%, 90%, 95% or 99% identity to the sequence set forth in SEQ ID NO:7, or (2) the sequence of LCDR1 is set forth in SEQ ID NO:5 or has at least 80%, 85%, 90%, 95% or 99% identity to the sequence set forth in SEQ ID NO:5; the sequence of LCDR2 is set forth in SEQ ID NO:32 or has at least 80%, 85%, 90%, 95% or 99% identity to the sequence set forth in SEQ ID NO:32; and the sequence of LCDR3 is set forth in SEQ ID NO:7 or has at least 80%, 85%, 90%, 95% or 99% identity to the sequence set forth in SEQ ID NO:7; or (3) the sequence of LCDR1 is set forth in SEQ ID NO: 13 or has at least 80%, 85%, 90%, 95% or 99% identity to the sequence set forth in SEQ ID NO: 13, the sequence of LCDR2 is set forth in SEQ ID NO: 14 or has at least 80%, 85%, 90%, 95% or 99% identity to the sequence set forth in SEQ ID NO: 14, and the sequence of LCDR3 is set forth in SEQ ID NO: 15 or has at least 80%, 85%, 90%, 95% or 99% identity to the sequence set forth in SEQ ID NO: 15; or (4) the sequence of LCDR1 is a sequence as set forth in SEQ ID NO: 35 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence as set forth in SEQ ID NO: 35; the sequence of LCDR2 is a sequence as set forth in SEQ ID NO: 14 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence as set forth in SEQ ID NO: 14; and the sequence of LCDR3 is a sequence as set forth in SEQ ID NO: 15 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence as set forth in SEQ ID NO: 15; Among them, the LCDR sequence is defined based on Kabat.

[0008] In a fifth aspect, the present application provides an isolated nucleic acid molecule encoding an anti-CD73 antibody, or an antigen-binding portion thereof, according to the first to fourth aspects.

[0009] In a sixth aspect, the present application provides a vector comprising the nucleic acid molecule according to the fifth aspect.

[0010] In a seventh aspect, the present application provides a host cell comprising the nucleic acid molecule according to the fifth aspect or the vector according to the sixth aspect.

[0011] In an eighth aspect, the present application provides an antibody-drug conjugate comprising an anti-CD73 antibody, or an antigen-binding portion thereof, according to any one of the first to fourth aspects coupled to a therapeutic agent.

[0012] In a ninth aspect, the present application provides a pharmaceutical composition comprising an anti-CD73 antibody or an antigen-binding portion thereof according to the first to fourth aspects, or an antibody-drug conjugate according to the eighth aspect, and a pharma- ceutically acceptable vector.

[0013] In a tenth aspect, the present application provides a method for detecting CD73 (CD73 + The present invention provides use of an anti-CD73 antibody or antigen-binding portion thereof according to any one of the first to fourth aspects, a nucleic acid molecule according to the fifth aspect, a vector according to the sixth aspect, a host cell according to the seventh aspect or an antibody-drug conjugate according to the eighth aspect in the manufacture of a medicament for treating a tumour expressing CD73.

[0014] In an eleventh aspect, the present application relates to a method for detecting CD73 (CD73 + The present invention provides a method for treating a tumor expressing CD73, the method comprising administering to said individual a therapeutically effective amount of an anti-CD73 antibody or antigen-binding portion thereof according to any one of the first to fourth aspects, an antibody-drug conjugate according to the eighth aspect, or a pharmaceutical composition according to the ninth aspect.

[0015] In a twelfth aspect, the present application provides a conjugate comprising an anti-CD73 antibody, or an antigen-binding portion thereof, according to the first to fourth aspects and a detectable label.

[0016] In a thirteenth aspect, the present application provides a fusion protein comprising an anti-CD73 antibody or an antigen-binding portion thereof according to the first to fourth aspects. [Brief description of the drawings]

[0017] [Figure 1] 1 shows the results of a test of the binding ability of an exemplary antibody of the present application to soluble CD73. [Diagram 2] 1 shows the binding capacity test results of an exemplary humanized antibody of the present application against soluble CD73. [Diagram 3] 1 shows the results of a test of the binding ability of an exemplary humanized antibody of the present application to CD73 on the surface of human breast cancer MDA-MB-231 cells. [Figure 4] 1 shows the results of a test of the binding ability of an exemplary humanized antibody of the present application to CD73 on the surface of human ovarian cancer SKOV3 cells. [Diagram 5] 1 shows the results of a test of the binding ability of an exemplary humanized antibody of the present application to cell surface cynomolgus monkey CD73. [Figure 6] 1 shows the results of enzyme activity inhibition experiments of exemplary humanized antibodies of the present application against CD73 protein. [Figure 7] 1 shows the results of enzyme activity inhibition experiments of an exemplary humanized antibody of the present application against cell surface CD73 protein. [Figure 8] 1 shows experimental results showing that an exemplary humanized antibody of the present application induces CD73 internalization. [Figure 9A] 1 shows the detection results that an exemplary humanized antibody of the present application recognizes the N-terminus of the CD73 protein. [Figure 9B] 1 shows the detection results that an exemplary humanized antibody of the present application recognizes the C-terminus of the CD73 protein. [Figure 10A] 1 shows the results of changes in the volume of transplanted tumors in A375 tumor-bearing mice following administration of exemplary antibodies and other test substances of the present application. [Figure 10B] 1 shows the results of changes in transplanted tumor volume in individual A375 tumor-bearing mice following administration of exemplary antibodies and other test articles of the present application. [Figure 10C] 1 shows the effect of administration of an exemplary antibody of the present application and other test articles on the body weight of A375 tumor-bearing mice. [Figure 11A] 1 shows the results of changes in the volume of transplanted tumors in CT26 tumor-bearing mice following administration of an exemplary humanized antibody of the present application and other test substances. [Figure 11B] 1 shows the results of changes in transplanted tumor volume in individual CT26 tumor-bearing mice following administration of an exemplary humanized antibody of the present application and other test substances. [Figure 11C] 1 shows the effect of administration of an exemplary humanized antibody of the present application and other test substances on the body weight of CT26 tumor-bearing mice. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] definition Unless otherwise defined, all scientific and technical terms used herein have the same meaning as understood by those skilled in the art. For definitions and terms in the field, experts may refer in particular to Current Protols in Molecular Biology (Ausubel). The abbreviations of amino acid residues are the standard three-letter and / or one-letter codes used in the field to refer to one of the 20 commonly used L-amino acids.

[0019] Although the present application has set forth numerical ranges and parameter approximations in broad ranges, the numerical values ​​set forth in the specific examples are described as precisely as possible. However, any numerical value inherently contains a certain degree of error due to the standard deviation present in their respective measurements. Furthermore, all ranges disclosed herein should be understood to encompass any and all subranges contained therein. For example, a range described as "1-10" should be considered to encompass any and all subranges between a minimum value of 1 and a maximum value of 10 (inclusive), i.e., subranges beginning with a minimum value of 1 or greater, e.g., 1-6.1, and subranges ending with a maximum value of 10 or less, e.g., 5.5-10. Additionally, any reference referred to as "incorporated herein" is understood to be incorporated in its entirety.

[0020] As used herein, the term "subject" or "individual" refers to a mammal, such as a human, but may also be other animals, such as wild, domestic, or laboratory animals (orangutans, monkeys, rats, mice, rabbits, guinea pigs, prairie dogs, ground squirrels, etc.).

[0021] The term "antigen" as used herein is a predetermined target to which an antibody can selectively bind. Examples of antigens include, but are not limited to, polypeptides, sugars, nucleic acids, lipids, haptens, or other naturally occurring or synthetic compounds.

[0022] In the broadest sense, an "antibody" may refer to an immunoglobulin molecule capable of specifically binding to a target via at least one antigen recognition site located within the variable region of the immunoglobulin molecule. It therefore encompasses an antibody / full length, a single antibody chain, or any antigen-binding fragment of an antibody (also called an "antigen-binding portion"). When "antibody" and "antigen-binding fragment / portion" appear in the same context, it may be understood that "antibody" is a complement to "antigen-binding fragment / portion" and that both commonly correspond to the broader antibody concept.

[0023] The term "anti-CD73 antibody" or "antibody that binds to CD73" includes antibodies that can bind to CD73 with sufficient affinity such that the antibody can be used as a diagnostic and / or therapeutic agent when targeting CD73. In some embodiments, the extent of binding of an anti-CD73 antibody to an unrelated, non-CD73 protein is less than about 10% of the binding of the antibody to CD73, as measured, for example, by fluorescence activated cell sorting (FACS) analysis or an immunoassay, such as a radioimmunoassay (RIA). For an antibody that "specifically binds" or is "specific" for CD73, in some embodiments the dissociation constant (KD) of the antibody that binds to CD73 is less than or equal to 500 nM, 100 nM, 10 nM, 9 nM, 8 nM, 7 nM, 6 nM, 5 nM, 4 nM, 0.9 nM, 0.8 nM, 0.7 nM, 0.6 nM, 0.5 nM, 0.4 nM, 0.3 nM, 0.2 nM, or 0.1 nM. In some embodiments, the anti-CD73 antibody binds to a conserved CD73 protein epitope between CD73 from different species (e.g., between human and cynomolgus CD73).

[0024] The term "agonist antibody" refers to an antibody that induces a response, for example, an antibody that mimics at least one functional activity of a polypeptide of interest. Agonist antibodies include antibodies that are ligand mimetics. For example, a ligand binds to a cell surface receptor, and the binding induces cell signaling or activity through a cell signaling pathway within the cell, and an antibody induces similar cell signaling or activation. A "full-length antibody" refers to a protein that includes at least two heavy (H) chains and two light (L) chains interconnected by disulfide bonds. Each heavy chain includes one heavy chain variable region (abbreviated as VH) and one heavy chain constant region. The heavy chain constant region includes three domains: CH1, CH2, and CH3. Each light chain includes one light chain variable region (abbreviated as VL) and one light chain constant region. The light chain constant region includes one domain: CL. The VH and VL regions may be further subdivided into multiple regions of high variability called complementarity determining regions (CDRs), interspersed with more conservative regions called framework regions (FRs). Each VH and VL each includes three CDRs and four FRs, arranged in the following order from amino terminus to carboxy terminus: FR1, CDR1, FR2, CDR2, FR3, CDR3, FR4. These variable regions of the heavy and light chains contain the binding domains that interact with the antigen. The constant region of the antibody can mediate the binding of the immunoglobulin to host tissues or factors, including various cells of the immune system (such as effector cells) and the first component (Clq) of the classical complement system. The full-length antibody can be any type of antibody, such as IgD, IgE, IgG, IgA, or IgM (or a subclass of the above), but the antibody does not have to belong to any particular class. Immunoglobulins can be assigned to different classes depending on the antibody amino acid sequence of the constant domain of the heavy chain. In general, there are five main classes of immunoglobulins: IgA, IgD, IgE, IgG, and IgM, and some of these classes can be further divided into subclasses (isotypes), such as IgG1, IgG2, IgG3, IgG4, IgA1, and IgA2. The heavy chain constant domains that correspond to the different classes of immunoglobulins are called α, δ, ε, γ, and μ, respectively. The subunit structures and three-dimensional structures of different classes of immunoglobulins are known. Chimeric or humanized antibodies are also encompassed by the antibodies of the present application. As is well known to those skilled in the art, the complementarity determining regions (CDRs, usually CDR1, CDR2 and CDR3) are the regions within the variable region that have the greatest influence on the affinity and specificity of the antibody.The CDR amino acid sequence of VH or VL has various general definitions, such as Kabat definition, IMGT definition, Chothia definition, etc. For a given antibody variable region amino acid sequence, the CDR amino acid sequence in the VH and VL amino acid sequence can generally be determined according to different definitions. In the embodiment of the present application, Kabat is used to define the CDR amino acid sequence. For a given antibody variable region amino acid sequence, the CDR amino acid sequence in the variable region amino acid sequence can be analyzed by various methods.

[0025] The term "mouse antibody" refers to an antibody derived from the fusion of B cells and myeloma cells from an immunized mouse, screening the mouse hybrid fusion cells capable of both indefinite proliferation and antibody secretion, and further screening, producing and purifying the resulting antibodies; mouse antibodies are generally immunogenic and therefore require subsequent humanization. The term "humanized antibody" refers to an antibody obtained by grafting CDR sequences derived from another mammalian species, such as the mouse germline, onto human framework sequences. Some residues in the framework (referred to as FR) segment can be modified to retain binding affinity. Humanized antibodies or fragments thereof according to the present application can be produced by techniques known to those skilled in the art.

[0026] The term "chimeric antibody" refers to an antibody whose variable region sequences are from one species and whose constant region sequences are from another species, e.g., whose variable region sequences are from a mouse antibody and whose constant region sequences are from a human antibody. The chimeric antibody or a fragment thereof according to the present application can be produced by using recombinant gene technology. For example, the chimeric antibody can be produced by cloning a recombinant DNA comprising a promoter, a sequence encoding the variable region of a non-human, particularly mouse, monoclonal antibody according to the present application, and a sequence encoding the constant region of a human antibody. The chimeric antibody according to the present application encoded by such a recombinant gene is, for example, a mouse-human chimera, whose specificity is determined by the variable region derived from mouse DNA and whose isotype is determined by the constant region derived from human DNA.

[0027] The term "partially humanized antibody" refers to an antibody that comprises a constant region of human origin and a variable region (including the CDRs) of non-human (such as murine) origin.

[0028] The term "semi-humanized antibody" refers to a type of humanized antibody, in which one antibody chain contains a mouse variable region and the other antibody chain contains a humanized variable region, i.e., a semi-humanized antibody.

[0029] The term "monoclonal antibody" refers to an antibody obtained from an essentially homogeneous population of antibodies, i.e., each antibody comprising the population is identical except for possible naturally occurring mutations in a few individuals.

[0030] The terms "antigen-binding fragment" or "antigen-binding portion" or "antigen-binding region", as used herein, are used interchangeably and refer to a portion of an antibody that comprises amino acid residues that interact with an antigen and confer specificity and affinity to the binding agent for the antigen, in particular antibody fragments such as Fv, Fab, F(ab')2 or Fab', or any fragment whose half-life could be extended by chemical modification such as the addition of a poly(alkylene) glycol, such as polyethylene glycol ("pegylation, PEGylation") (pegylated fragments of Fv-PEG, scFv-PEG, Fab-PEG, F(ab')2-PEG or Fab'-PEG), where "PEG" is polyethylene glycol), or by incorporation into liposomes, said fragments having CD73 binding activity. Preferably, the functional fragment consists of or comprises a subsequence of the heavy or light variable chain of the derived antibody, the subsequence being sufficient to retain the same binding specificity and sufficient affinity as the derived antibody, and the functional fragment comprises at least 5 amino acids, preferably 10, 15, 25, 50 and 100 consecutive amino acids of the derived antibody sequence. Examples of antigen-binding fragments include, but are not limited to, (1) a Fab fragment, which may be a monovalent fragment having a VL-CL chain and a VH-CH1 chain, (2) a F(ab')2 fragment, which may be a bivalent fragment having two Fab' fragments linked by a disulfide bridge in the hinge region (i.e., a Fab' dimer), and (3) an Fv fragment of the VL and VH domains with a single arm of an antibody.

[0031] The term "single chain antibody (scFv)" refers to a single polypeptide chain in which the VH and VL domains are linked via a peptide linker. (scFv)2 comprises two VH domains linked by a peptide linker and two VL domains combined with the two VH domains via disulfide bridges.

[0032] The terms "Fc fragment", "Fc region", "Fc domain", "Fc portion" or similar terms refer to a portion of the antibody heavy chain constant region, including the hinge region, the CH2 fragment and the CH3 fragment of the constant region. The Fc region of an anti-CD73 antibody can be engineered to modify it, including effector function-related modifications, to reduce or eliminate antibody-dependent cellular cytotoxicity (ADCC) and / or complement-dependent cytotoxicity (CDC), which can be achieved, for example, by introducing one or more amino acid substitutions / mutations into the Fc region of the antibody.

[0033] As used herein, the term "specific binding" refers to a non-random binding reaction between two molecules, for example, the binding of an antibody to an antigen epitope.

[0034] The term "multiple antibodies", also called "multispecific antibodies", are molecules that have binding specificities for at least two different antigens, of which such molecules that bind only two antigens are also called dual antibodies (i.e., bispecific antibodies, BsAbs).

[0035] The term "bispecific antibody" refers to an antibody that has two antigen epitope binding capabilities simultaneously. The two antigen epitopes may be on different antigens or on the same antigen. Bispecific antibodies may have various structural configurations. For example, a bispecific antibody may be composed of two Fc fragments and two antigen binding moieties (similar to natural antibodies, except that the two arms bind to different antigen targets or epitopes), each of which is fused to the other, and the antigen binding moieties may be in the form of a single chain antibody (scfv) or in the form of a Fab fragment.

[0036] In general, for producing monoclonal antibodies or functional fragments thereof, in particular murine-derived monoclonal antibodies or functional fragments thereof, reference can be made in particular to the techniques described in the manual "Antibodies" (Harlow and Lane, Antibodies: A Laboratory Manual, Cold Spring Harbor Laboratory, Cold Spring Harbor NY, pp. 726, 1988) or the production technique from hybridoma cells described by Kohler and Milstein (Nature, 256: 495-497, 1975).

[0037] The term "conservative variant" or "conservative amino acid substitution" is a substitution that does not substantially affect or reduces the affinity of a protein, e.g., the affinity of an antibody for CD73. For example, a human antibody that specifically binds to CD73 can contain no more than about 1, no more than about 2, no more than about 5, no more than about 10, or no more than about 15 conservative substitutions and specifically bind to a CD73 polypeptide. The term "conservative variant" further includes the use of a substituted amino acid in place of an unsubstituted parent amino acid, so long as the antibody specifically binds to CD73. A non-conservative substitution is one that reduces activity or binding to CD73.

[0038] When describing some embodiments of amino acid or nucleic acid sequence mutations, the present application uses the "XaaaY" definition (e.g., L234A, L235A, etc.), where "aaa" represents the sequence position of the amino acid or base (where a specific reference sequence exists, "aaa" may represent the ordinal position of the residue in the reference sequence, or may follow position numbering common in the art, such as the EU numbering system), "X" represents the amino acid or base originally in "aaa", and "Y" represents the amino acid or base after the change in "aaa". By way of illustration, when describing the L234A mutation in a human heavy chain constant region, this means that the leucine (L) at position 234 according to the EU numbering system of the human heavy chain constant region is mutated to an alanine (A).

[0039] In the present specification, when "combination therapy" with drugs A and B, "combination therapy" or similar terms are described, the administration method and administration schedule of the combination therapy with drugs A and B are not particularly limited, unless there is technical conflict or interchangeability. For example, drugs A and B can be administered separately in sequence, separately at the same time, or formulated into the same drug and administered together. Alternatively, drugs A and B can be manufactured in the same composition or in the same drug kit at the time of manufacture. Drugs A and B may be physically separated or may be bonded to each other. The administration of drugs A and B may be separate, simultaneous, or overlapping in time.

[0040] The term "isolated" biological component (such as a nucleic acid, protein (including antibodies) or organelle) is one that has been essentially separated or purified from other biological components (i.e., other chromosomal and additional chromosomal DNA and RNA, proteins and organelles) in the environment (such as a cell) in which the component naturally occurs. "Isolated" nucleic acids and proteins include nucleic acids and proteins that have been purified using standard purification methods. The term further includes nucleic acids, proteins produced by recombinant expression in a host cell and nucleic acids that are chemically synthesized.

[0041] The term "derived sequence" refers to a sequence that has at least 80% (preferably 85%, 90%, 95%, 98% or 99%) sequence identity to the related sequence and still has the same or a similar function.

[0042] The term "pharmaceutical composition" as used herein means a combination of at least one drug and, optionally, a medicable vector or auxiliary agent, combined together to achieve a specific purpose. In some embodiments, the pharmaceutical composition includes combinations that are separated in time and / or space, so long as they can work together to achieve the purpose of the present application. For example, the components included in the pharmaceutical composition (such as the antibody, nucleic acid molecule, combination of nucleic acid molecules and / or complexes according to the present application) may be administered to an individual as a whole or separately. When the components included in the pharmaceutical composition are administered to an individual separately, the components may be administered to the individual simultaneously or sequentially. Preferably, the medicable vector is water, a buffered aqueous solution, an isotonic saline solution such as PBS (phosphate buffer), glucose, mannitol, dextrose, lactose, starch, magnesium stearate, cellulose, magnesium carbonate, 0.3% glycerin, hyaluronic acid, ethanol or a polyalkylene glycol such as polypropylene glycol, a triglyceride, or the like. The type of medicinal vector used will depend, inter alia, on whether the composition according to the present application is formulated for oral, intranasal, intradermal, subcutaneous, intramuscular or intravenous administration. The composition according to the present application may contain as additives wetting agents, emulsifiers or buffer substances. The pharmaceutical composition or pharmaceutical formulation according to the present application may be administered by any suitable route, for example by oral, intranasal, intradermal, subcutaneous, intramuscular or intravenous administration.

[0043] The term "therapeutically effective amount" or "effective amount" as used herein refers to a dose sufficient to show its benefit to the individual to whom it is administered. The actual amount administered, as well as the rate and time course of administration, depends on the condition and severity of the subject being treated itself. The prescription of treatment (e.g., determining the dosage, etc.) is ultimately the responsibility and decision of general practitioners and other physicians. Generally, it takes into account the disease being treated, the condition of the individual patient, the site of delivery, the method of administration, and other factors known to physicians.

[0044] EC 50The value primarily refers to the concentration of a drug, antibody, or toxin, etc., that corresponds to 50% of the maximum biological effect after a certain exposure time. In pharmacology, in addition to being used to characterize the activation capacity of an agonist in in vitro experiments, it is also used to express the blood drug concentration required to achieve half of the maximum biological effect in vivo. In some literature, the EC 50 EC is also used to characterize the potency (including agonism and antagonism) of a compound at the cellular level. 50 The value can be measured.

[0045] The term "fusion protein" as used herein, in a general context, refers to a protein consisting of at least two domains, each of which is not naturally associated and is encoded by a separate gene, which is linked and transcribed and translated as a whole to produce a single protein. In the technical background of this application, a "fusion protein" comprising an antibody or antigen-binding portion refers to the product obtained by fusing an antibody or antigen-binding portion with another biologically active protein by genetic engineering techniques. Such a fusion protein possesses both the antigen-binding ability of an antibody and the unique biological properties of the biologically active protein fused to the antibody.

[0046] The term "identity / homology / matching" with respect to amino acid or nucleic acid sequences is defined as the percentage of identical residues in variants of amino acid or nucleotide sequences after sequence alignment and introduction of gaps, if necessary, to achieve the maximum percentage identity. Methods and computer programs for alignment are known in the art.

[0047] The term "tumor" as used herein refers to a neoplasm or solid lesion formed by abnormal cell growth. Tumors may be benign, pre-malignant, or malignant.

[0048] The term "malignant tumor" as used herein refers to or describes a physiological condition in a mammal that is typically characterized by unregulated cell growth. Exemplary malignant tumors include carcinoma, solid tumor, melanoma, sarcoma, hematological tumor, germ cell tumor and germ cell tumor. More specific examples of malignant tumors include multiple myeloma, renal cancer, lung cancer including small cell lung cancer, non-small cell lung cancer, lung adenocarcinoma and lung squamous cell carcinoma, bladder cancer, breast cancer, cervical cancer, colon cancer, gastric cancer including gastrointestinal cancer, prostate cancer, pancreatic cancer, peritoneal cancer, hepatocellular carcinoma, glioblastoma, ovarian cancer, liver cancer, urinary tract cancer, hepatoma, rectal cancer, colorectal cancer, endometrial or uterine cancer, salivary gland cancer, squamous cell carcinoma (such as squamous cell carcinoma), vulvar cancer, thyroid cancer, anal cancer, penile cancer, melanoma and B-cell lymphoma, brain cancer and head and neck cancer, and associated metastases.

[0049] The term "hematological tumors" as used herein refers to those caused by uncontrolled growth and proliferation of abnormal cells, often the site of origin of these abnormal cells is the bone marrow where blood cells are produced. Exemplary hematological tumors include various types of leukemia, multiple myeloma, and malignant lymphoma. More specific examples of hematological tumors include acute lymphoblastic leukemia (ALL), chronic lymphocytic leukemia (CLL), acute myeloid leukemia (AML), chronic myeloid leukemia (CML), hairy cell leukemia (HCL), T-cell prolymphocytic leukemia, large granular lymphocytic leukemia, juvenile granulocytic-monocytic leukemia, B-cell prolymphocytic leukemia, Burkitt's leukemia and adult T-cell leukemia, non-Hodgkin's lymphoma, B-cell lymphoma, small lymphocytic lymphoma, lymphoplasmacytic lymphoma, primary macroglobulinemia (Waldenstrom's lymphoma), and leukemia. macroglobulinemia), splenic marginal zone lymphoma, plasmacytoma, extranodal marginal zone B-cell lymphoma, MALT lymphoma, intranodal marginal zone B-cell lymphoma (NMZL), follicular lymphoma, mantle cell lymphoma, diffuse large B-cell lymphoma, mediastinal (thymic) large B-cell lymphoma, intravascular large B-cell lymphoma, primary effusion lymphoma, Burkitt lymphoma, B-cell chronic lymphocytic lymphoma, typical Hodgkin lymphoma These include: nodular lymphocytic major Hodgkin lymphoma, adult T-cell lymphoma, extranodal nasal NK / T-cell lymphoma, enteropathy-type T-cell lymphoma, splenic T-cell lymphoma, blastic NK-cell lymphoma, mycosis, Usher syndrome, primary cutaneous CD30-positive T-cell lymphoproliferative disorder, primary cutaneous anaplastic large cell lymphoma, lymphomatoid papulosis, angioimmunoblastic T-cell lymphoma, peripheral T-cell lymphoma not otherwise specified, and anaplastic large cell lymphoma.

[0050] The term "solid tumor" as used herein refers to a tangible mass that can be palpated by X-ray, CT scan, B-ultrasound, or clinical examination such as palpation. Clinically treated solid tumors are divided into two types: malignant and benign. Malignant solid tumors include pediatric Hodgkin's lymphoma, which may be lymphocyte predominant, nodular sclerosis, mixed cell, or lymphocytopenic, pediatric non-Hodgkin's lymphoma, such as prolymphoblastic lymphoma, small noncleaved cell lymphoma (Burkitt / non-Burkitt lymphoma), diffuse large B-cell lymphoma, and anaplastic large cell lymphoma; pediatric kidney tumors, such as nephroblastoma (Wilms' tumor), renal clear cell carcinoma, renal rhabdoid tumor, renal clear cell sarcoma, and renal primitive neuroectodermal tumor; pediatric neuroblastomas, such as neuroblastoma, ganglioneuroblastoma, and ganglioneural tumor; pediatric neuroblastomas, such as mature teratoma, immature teratoma, endothelial sinus tumor (yolk sac tumor), seminoma, zygomeroma, choriocarcinoma, and embryonal carcinoma; Other tumors include extracranial germ cell tumors, osteosarcoma and chondrosarcoma, pediatric rhabdomyosarcoma such as embryonal, acinar, and pleomorphic types, fibrosarcoma, malignant fibrohistiocytoma, liposarcoma, leiomyosarcoma, angiosarcoma, lymphangiosarcoma, malignant schwannoma, adenoid soft tissue sarcoma, epithelioid sarcoma, clear cell sarcoma, malignant melanoma, synovial sarcoma, and desmoplastic small round cell tumor, pediatric soft tissue sarcomas such as Ewing's sarcoma and primitive neuroectodermal tumor, pediatric liver tumors such as hepatoblastoma (embryonic, fetal, and undifferentiated types) and hepatocellular carcinoma, retinoblastoma, posterior fossa medulloblastoma, nasopharyngeal carcinoma, papillary thyroid carcinoma, thymoma, pulmonary blastoma, pancreatoblastoma, islet cell tumor, ileocecal carcinoid, and mesothelioma. Benign solid tumors include lymphangioma, hemangioma, and thyroglossal cyst.

[0051] In a first aspect, the present application provides an anti-CD73 antibody, or antigen-binding portion thereof, comprising a heavy chain variable region comprising a heavy chain CDR1 (HCDR1), a heavy chain CDR2 (HCDR2) and a heavy chain CDR3 (HCDR3), and a light chain variable region comprising a light chain CDR1 (LCDR1), a light chain CDR2 (LCDR2) and a light chain CDR3 (LCDR3), wherein the sequence of HCDR1 is the sequence shown in SEQ ID NO:1 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:1, the sequence of HCDR2 is the sequence shown in SEQ ID NO:2 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:2, the sequence of HCDR3 is the sequence shown in SEQ ID NO:3 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:3, and L the sequence of CDR1 is the sequence shown in SEQ ID NO:5 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:5, the sequence of LCDR2 is the sequence shown in SEQ ID NO:6 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:6, and the sequence of LCDR3 is the sequence shown in SEQ ID NO:7 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:7, or the sequence of HCDR1 is the sequence shown in SEQ ID NO:1 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:1, the sequence of HCDR2 is the sequence shown in SEQ ID NO:17 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:17, the sequence of HCDR3 is the sequence shown in SEQ ID NO:3 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:3, and L the sequence of CDR1 is the sequence shown in SEQ ID NO:5 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:5, the sequence of LCDR2 is the sequence shown in SEQ ID NO:32 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:32, the sequence of LCDR3 is the sequence shown in SEQ ID NO:7 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:7, or the sequence of HCDR1 is the sequence shown in SEQ ID NO:1 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:1, the sequence of HCDR2 is the sequence shown in SEQ ID NO:17 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:17, and the sequence of HCDR3 is the sequence shown in SEQ ID NO:3 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:3; the sequence of LCDR1 is the sequence shown in SEQ ID NO:5 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:5, the sequence of LCDR2 is the sequence shown in SEQ ID NO:6 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:6, the sequence of LCDR3 is the sequence shown in SEQ ID NO:7 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:7, or the sequence of HCDR1 is the sequence shown in SEQ ID NO:1 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:1, the sequence of HCDR2 is the sequence shown in SEQ ID NO:2 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:2, the sequence of HCDR3 is the sequence shown in SEQ ID NO:3 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:3, and the sequence of DR1 is as set forth in SEQ ID NO:5 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence set forth in SEQ ID NO:5; the sequence of LCDR2 is as set forth in SEQ ID NO:32 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence set forth in SEQ ID NO:32; the sequence of LCDR3 is as set forth in SEQ ID NO:7 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence set forth in SEQ ID NO:7; or the sequence of HCDR1 is the sequence shown in SEQ ID NO:1 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:1, the sequence of HCDR2 is the sequence shown in SEQ ID NO:21 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:21, the sequence of HCDR3 is the sequence shown in SEQ ID NO:3 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:3, and L the sequence of CDR1 is the sequence shown in SEQ ID NO:5 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:5, the sequence of LCDR2 is the sequence shown in SEQ ID NO:32 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:32, the sequence of LCDR3 is the sequence shown in SEQ ID NO:7 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:7, or the sequence of HCDR1 is the sequence shown in SEQ ID NO:1 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:1, the sequence of HCDR2 is the sequence shown in SEQ ID NO:21 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:21, and the sequence of HCDR3 is the sequence shown in SEQ ID NO:3 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:3; the sequence of LCDR1 is the sequence shown in SEQ ID NO:5 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:5, the sequence of LCDR2 is the sequence shown in SEQ ID NO:6 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:6, the sequence of LCDR3 is the sequence shown in SEQ ID NO:7 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:7, or the sequence of HCDR1 is the sequence shown in SEQ ID NO:1 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:1, the sequence of HCDR2 is the sequence shown in SEQ ID NO:23 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:23, the sequence of HCDR3 is the sequence shown in SEQ ID NO:3 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:3, and L the sequence of CDR1 is the sequence shown in SEQ ID NO:5 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:5, the sequence of LCDR2 is the sequence shown in SEQ ID NO:32 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:32, the sequence of LCDR3 is the sequence shown in SEQ ID NO:7 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:7, or the sequence of HCDR1 is the sequence shown in SEQ ID NO:1 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:1, the sequence of HCDR2 is the sequence shown in SEQ ID NO:23 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:23, and the sequence of HCDR3 is the sequence shown in SEQ ID NO:3 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:3; the sequence of LCDR1 is the sequence shown in SEQ ID NO:5 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:5, the sequence of LCDR2 is the sequence shown in SEQ ID NO:6 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:6, the sequence of LCDR3 is the sequence shown in SEQ ID NO:7 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:7, or the sequence of HCDR1 is the sequence shown in SEQ ID NO: 9 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 9, the sequence of HCDR2 is the sequence shown in SEQ ID NO: 10 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 10, the sequence of HCDR3 is the sequence shown in SEQ ID NO: 11 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 11, the sequence of DR1 is as set forth in SEQ ID NO: 13 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence set forth in SEQ ID NO: 13, the sequence of LCDR2 is as set forth in SEQ ID NO: 14 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence set forth in SEQ ID NO: 14, and the sequence of LCDR3 is as set forth in SEQ ID NO: 15 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence set forth in SEQ ID NO: 15; or the sequence of HCDR1 is the sequence shown in SEQ ID NO: 9 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 9, the sequence of HCDR2 is the sequence shown in SEQ ID NO: 10 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 10, the sequence of HCDR3 is the sequence shown in SEQ ID NO: 11 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 11, the sequence of DR1 is as set forth in SEQ ID NO:35 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence set forth in SEQ ID NO:35, the sequence of LCDR2 is as set forth in SEQ ID NO:14 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence set forth in SEQ ID NO:14, the sequence of LCDR3 is as set forth in SEQ ID NO:15 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence set forth in SEQ ID NO:15, or the sequence of HCDR1 is the sequence shown in SEQ ID NO: 9 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 9; the sequence of HCDR2 is the sequence shown in SEQ ID NO: 27 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 27; the sequence of HCDR3 is the sequence shown in SEQ ID NO: 11 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 11; the sequence of DR1 is as set forth in SEQ ID NO:35 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence set forth in SEQ ID NO:35, the sequence of LCDR2 is as set forth in SEQ ID NO:14 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence set forth in SEQ ID NO:14, the sequence of LCDR3 is as set forth in SEQ ID NO:15 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence set forth in SEQ ID NO:15, or the sequence of HCDR1 is the sequence shown in SEQ ID NO: 9 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 9; the sequence of HCDR2 is the sequence shown in SEQ ID NO: 27 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 27; the sequence of HCDR3 is the sequence shown in SEQ ID NO: 11 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 11; the sequence of DR1 is as set forth in SEQ ID NO: 13 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence set forth in SEQ ID NO: 13, the sequence of LCDR2 is as set forth in SEQ ID NO: 14 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence set forth in SEQ ID NO: 14, and the sequence of LCDR3 is as set forth in SEQ ID NO: 15 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence set forth in SEQ ID NO: 15; or the sequence of HCDR1 is the sequence shown in SEQ ID NO: 9 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 9, the sequence of HCDR2 is the sequence shown in SEQ ID NO: 30 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 30, the sequence of HCDR3 is the sequence shown in SEQ ID NO: 11 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 11, the sequence of DR1 is as set forth in SEQ ID NO:35 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence set forth in SEQ ID NO:35, the sequence of LCDR2 is as set forth in SEQ ID NO:14 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence set forth in SEQ ID NO:14, the sequence of LCDR3 is as set forth in SEQ ID NO:15 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence set forth in SEQ ID NO:15, or the sequence of HCDR1 is the sequence shown in SEQ ID NO: 9 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 9; the sequence of HCDR2 is the sequence shown in SEQ ID NO: 30 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 30; the sequence of HCDR3 is the sequence shown in SEQ ID NO: 11 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 11; the sequence of CDR1 is the sequence shown in SEQ ID NO: 13 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 13, the sequence of LCDR2 is the sequence shown in SEQ ID NO: 14 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 14, and the sequence of LCDR3 is the sequence shown in SEQ ID NO: 15 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 15; Among them, the HCDR and LCDR sequences are defined according to Kabat.

[0052] In some embodiments, the heavy chain variable region has an amino acid sequence set forth in SEQ ID NO: 4, 18, 19, 20, 22, 24, 12, 25, 26, 28, 29, or 31, or an amino acid sequence that has at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identity to the amino acid sequence set forth in SEQ ID NO: 4, 18, 19, 20, 22, 24, 12, 25, 26, 28, 29, or 31.

[0053] In some embodiments, the light chain variable region has an amino acid sequence set forth in SEQ ID NO: 8, 33, 34, 16, 36, 37, or 38, or an amino acid sequence that has at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identity to the amino acid sequence set forth in SEQ ID NO: 8, 33, 34, 16, 36, 37, or 38.

[0054] In some embodiments, the heavy chain variable region sequence is the sequence set forth in SEQ ID NO:4 and the light chain variable region sequence is the sequence set forth in SEQ ID NO:8; or the heavy chain variable region sequence is the sequence shown in SEQ ID NO: 18 and the light chain variable region sequence is the sequence shown in SEQ ID NO: 33; or the heavy chain variable region sequence is the sequence shown in SEQ ID NO: 18 and the light chain variable region sequence is the sequence shown in SEQ ID NO: 34; or the heavy chain variable region sequence is the sequence shown in SEQ ID NO: 19 and the light chain variable region sequence is the sequence shown in SEQ ID NO: 33; or the heavy chain variable region sequence is the sequence shown in SEQ ID NO: 19 and the light chain variable region sequence is the sequence shown in SEQ ID NO: 34; or the heavy chain variable region sequence is the sequence shown in SEQ ID NO:20 and the light chain variable region sequence is the sequence shown in SEQ ID NO:33; or the heavy chain variable region sequence is the sequence shown in SEQ ID NO:20 and the light chain variable region sequence is the sequence shown in SEQ ID NO:34; or the heavy chain variable region sequence is the sequence shown in SEQ ID NO:22 and the light chain variable region sequence is the sequence shown in SEQ ID NO:33; or the heavy chain variable region sequence is the sequence shown in SEQ ID NO:22 and the light chain variable region sequence is the sequence shown in SEQ ID NO:34; or the heavy chain variable region sequence is the sequence shown in SEQ ID NO:24 and the light chain variable region sequence is the sequence shown in SEQ ID NO:33; or the heavy chain variable region sequence is the sequence shown in SEQ ID NO:24 and the light chain variable region sequence is the sequence shown in SEQ ID NO:34; or the heavy chain variable region sequence is the sequence shown in SEQ ID NO: 12 and the light chain variable region sequence is the sequence shown in SEQ ID NO: 16; or the heavy chain variable region sequence is the sequence shown in SEQ ID NO:25 and the light chain variable region sequence is the sequence shown in SEQ ID NO:36; or the heavy chain variable region sequence is the sequence shown in SEQ ID NO:25 and the light chain variable region sequence is the sequence shown in SEQ ID NO:37; or the heavy chain variable region sequence is the sequence shown in SEQ ID NO:25 and the light chain variable region sequence is the sequence shown in SEQ ID NO:38; or the heavy chain variable region sequence is the sequence shown in SEQ ID NO:26 and the light chain variable region sequence is the sequence shown in SEQ ID NO:36; or the heavy chain variable region sequence is the sequence shown in SEQ ID NO:26 and the light chain variable region sequence is the sequence shown in SEQ ID NO:37; or the heavy chain variable region sequence is the sequence shown in SEQ ID NO:26 and the light chain variable region sequence is the sequence shown in SEQ ID NO:38; or the heavy chain variable region sequence is the sequence shown in SEQ ID NO:28 and the light chain variable region sequence is the sequence shown in SEQ ID NO:36; or the heavy chain variable region sequence is the sequence shown in SEQ ID NO:28 and the light chain variable region sequence is the sequence shown in SEQ ID NO:37; or the heavy chain variable region sequence is the sequence shown in SEQ ID NO:28 and the light chain variable region sequence is the sequence shown in SEQ ID NO:38; or the heavy chain variable region sequence is the sequence shown in SEQ ID NO:29 and the light chain variable region sequence is the sequence shown in SEQ ID NO:36; or the heavy chain variable region sequence is the sequence shown in SEQ ID NO:29 and the light chain variable region sequence is the sequence shown in SEQ ID NO:37; or the heavy chain variable region sequence is the sequence shown in SEQ ID NO:29 and the light chain variable region sequence is the sequence shown in SEQ ID NO:38; or the heavy chain variable region sequence is the sequence shown in SEQ ID NO:31 and the light chain variable region sequence is the sequence shown in SEQ ID NO:36; or the heavy chain variable region sequence is the sequence shown in SEQ ID NO:31 and the light chain variable region sequence is the sequence shown in SEQ ID NO:37; or The heavy chain variable region sequence is the sequence shown in SEQ ID NO:31, and the light chain variable region sequence is the sequence shown in SEQ ID NO:38.

[0055] In a second aspect, the present application provides an anti-CD73 antibody, or antigen-binding portion thereof, comprising a heavy chain variable region and a light chain variable region, the heavy chain variable region has an amino acid sequence as set forth in SEQ ID NO: 4, 18, 19, 20, 22, 24, 12, 25, 26, 28, 29, or 31, or an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identity to the amino acid sequence as set forth in SEQ ID NO: 4, 18, 19, 20, 22, 24, 12, 25, 26, 28, 29, or 31; and / or The light chain variable region has an amino acid sequence set forth in SEQ ID NO: 8, 33, 34, 16, 36, 37 or 38, or an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95% or at least 99% identity to the amino acid sequence set forth in SEQ ID NO: 8, 33, 34, 16, 36, 37 or 38.

[0056] In a third aspect, the present application provides an anti-CD73 antibody, or antigen-binding portion thereof, comprising a heavy chain variable region comprising a heavy chain CDR1 (HCDR1), a heavy chain CDR2 (HCDR2), and a heavy chain CDR3 (HCDR3), wherein (1) the sequence of HCDR1 is the sequence shown in SEQ ID NO:1 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:1, the sequence of HCDR2 is the sequence shown in SEQ ID NO:2 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:2, and the sequence of HCDR3 is the sequence shown in SEQ ID NO:3 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:3, or (2) the sequence of HCDR1 is the sequence shown in SEQ ID NO:1 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:1, the sequence of HCDR2 is the sequence shown in SEQ ID NO:17 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:17, and the sequence of HCDR3 is the sequence shown in SEQ ID NO:3 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:3, or (3) the sequence of HCDR1 is the sequence shown in SEQ ID NO:1 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:1, the sequence of HCDR2 is the sequence shown in SEQ ID NO:21 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:21, and the sequence of HCDR3 is the sequence shown in SEQ ID NO:3 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:3, or (4) the sequence of HCDR1 is the sequence shown in SEQ ID NO:1 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:1, the sequence of HCDR2 is the sequence shown in SEQ ID NO:23 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:23, and the sequence of HCDR3 is the sequence shown in SEQ ID NO:3 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO:3, or (5) the sequence of HCDR1 is the sequence shown in SEQ ID NO: 9 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 9, the sequence of HCDR2 is the sequence shown in SEQ ID NO: 10 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 10, and the sequence of HCDR3 is the sequence shown in SEQ ID NO: 11 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 11, or (6) the sequence of HCDR1 is the sequence shown in SEQ ID NO: 9 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 9, the sequence of HCDR2 is the sequence shown in SEQ ID NO: 27 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 27, and the sequence of HCDR3 is the sequence shown in SEQ ID NO: 11 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 11, or (7) The sequence of HCDR1 is a sequence shown in SEQ ID NO: 9 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 9, the sequence of HCDR2 is a sequence shown in SEQ ID NO: 30 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 30, and the sequence of HCDR3 is a sequence shown in SEQ ID NO: 11 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence shown in SEQ ID NO: 11; Among them, the HCDR sequence is defined based on Kabat.

[0057] In a fourth aspect, the present application provides an anti-CD73 antibody, or antigen-binding portion thereof, comprising a light chain variable region comprising a light chain CDR1 (LCDR1), a light chain CDR2 (LCDR2), and a light chain CDR3 (LCDR3), wherein: (1) the sequence of LCDR1 is set forth in SEQ ID NO:5 or has at least 80%, 85%, 90%, 95% or 99% identity to the sequence set forth in SEQ ID NO:5, the sequence of LCDR2 is set forth in SEQ ID NO:6 or has at least 80%, 85%, 90%, 95% or 99% identity to the sequence set forth in SEQ ID NO:6, and the sequence of LCDR3 is set forth in SEQ ID NO:7 or has at least 80%, 85%, 90%, 95% or 99% identity to the sequence set forth in SEQ ID NO:7, or (2) the sequence of LCDR1 is set forth in SEQ ID NO:5 or has at least 80%, 85%, 90%, 95% or 99% identity to the sequence set forth in SEQ ID NO:5; the sequence of LCDR2 is set forth in SEQ ID NO:32 or has at least 80%, 85%, 90%, 95% or 99% identity to the sequence set forth in SEQ ID NO:32; and the sequence of LCDR3 is set forth in SEQ ID NO:7 or has at least 80%, 85%, 90%, 95% or 99% identity to the sequence set forth in SEQ ID NO:7; or (3) the sequence of LCDR1 is set forth in SEQ ID NO: 13 or has at least 80%, 85%, 90%, 95% or 99% identity to the sequence set forth in SEQ ID NO: 13, the sequence of LCDR2 is set forth in SEQ ID NO: 14 or has at least 80%, 85%, 90%, 95% or 99% identity to the sequence set forth in SEQ ID NO: 14, and the sequence of LCDR3 is set forth in SEQ ID NO: 15 or has at least 80%, 85%, 90%, 95% or 99% identity to the sequence set forth in SEQ ID NO: 15; or (4) the sequence of LCDR1 is a sequence as set forth in SEQ ID NO: 35 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence as set forth in SEQ ID NO: 35; the sequence of LCDR2 is a sequence as set forth in SEQ ID NO: 14 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence as set forth in SEQ ID NO: 14; and the sequence of LCDR3 is a sequence as set forth in SEQ ID NO: 15 or has at least 80%, 85%, 90%, 95% or 99% identity with the sequence as set forth in SEQ ID NO: 15; Among them, the LCDR sequence is defined based on Kabat.

[0058] In some embodiments of the first through fourth aspects, the anti-CD73 antibody, or antigen-binding portion thereof, binds to human CD73. In some specific embodiments, the anti-CD73 antibody, or antigen-binding portion thereof, binds to a conserved CD73 protein epitope between CD73 from different species (e.g., between human and cynomolgus monkey CD73).

[0059] In some embodiments of the first to fourth aspects, the anti-CD73 antibody, or antigen-binding portion thereof, has ADCC activity.

[0060] In some embodiments of the first to fourth aspects, the anti-CD73 antibody, or antigen-binding portion thereof, has CDC activity.

[0061] In some embodiments of the first to fourth aspects, the anti-CD73 antibody is a whole antibody, a single chain antibody (scFv), an scFv-Fc, a bispecific antibody, or a multispecific antibody.

[0062] In some embodiments of the first through fourth aspects, the antigen-binding portion of the anti-CD73 antibody is a Fab, Fab', Fv, or F(ab')2.

[0063] In some embodiments of the first to fourth aspects, the anti-CD73 antibody is a murine antibody, a chimeric antibody, a humanized antibody or a fully human antibody.

[0064] In some embodiments of the first to fourth aspects, the anti-CD73 antibody is a monoclonal antibody.

[0065] In some embodiments of the first to fourth aspects, the anti-CD73 antibody is an IgM, IgD, IgG, IgA, or IgE type antibody. In some specific embodiments, the anti-CD73 antibody is an IgG antibody. In some more specific embodiments, the anti-CD73 antibody is an IgG1 antibody.

[0066] In some embodiments of the first through fourth aspects, the anti-CD73 antibody is of the IgG1, IgG2, or IgG4 isotype.

[0067] In some embodiments of the first through fourth aspects, the anti-CD73 antibody comprises a light chain constant region of the κ or λ isoform.

[0068] In some embodiments of the first to fourth aspects, the anti-CD73 antibody comprises a human IgG1 heavy chain constant region and a human κ light chain constant region.

[0069] In some embodiments of the first through fourth aspects, the anti-CD73 antibody, or antigen-binding portion thereof, is used in medical therapy.

[0070] In some embodiments of the first to fourth aspects, the anti-CD73 antibody comprises a wild-type Fc region.

[0071] In some embodiments of the first to fourth aspects, the anti-CD73 antibody, or antigen-binding portion thereof, is engineered to have enhanced ADCC or CDC activity. In some specific embodiments, the anti-CD73 antibody comprises an Fc region that has been engineered such that the antibody has enhanced ADCC and / or CDC effects.

[0072] In some embodiments of the first to fourth aspects, the anti-CD73 antibody or antigen-binding portion thereof is engineered to have reduced ADCC or CDC activity. In some specific embodiments, the anti-CD73 antibody comprises an Fc region that is engineered such that the antibody has reduced ADCC and / or CDC effect. With respect to targeting CD73 and in vivo applications of antibodies of interest herein, antibodies with reduced or even eliminated ADCC or CDC activity may be advantageous since excessive Fc effect may affect or even reduce the therapeutic effect of the antibody. Methods for reducing or eliminating Fc effect are known in the art, such as, for example, 1) amino acid residue mutational modification (mainly to reduce binding to relevant receptors), 2) glycosylation modification, 3) IgG4 type antibody modification. As a non-limiting example, the antibody has a human IgG1 heavy chain constant region and includes mutations at one or more of L234, L235, P329, P331, where the residue numbering is according to the EU numbering system. For example, the mutation is one or more of the following mutations: L234A, L235A, P329A, P331S.

[0073] In some embodiments of the first to fourth aspects, the antibody has a heavy chain variable region shown in SEQ ID NO: 20, a light chain variable region shown in SEQ ID NO: 33, a heavy chain constant region shown in SEQ ID NO: 39, and a light chain constant region shown in SEQ ID NO: 40.

[0074] In some embodiments of the first to fourth aspects, the antibody has a heavy chain variable region shown in SEQ ID NO: 31, a light chain variable region shown in SEQ ID NO: 38, a heavy chain constant region shown in SEQ ID NO: 39, and a light chain constant region shown in SEQ ID NO: 40.

[0075] In a fifth aspect, the present application provides an isolated nucleic acid molecule encoding an anti-CD73 antibody or antigen-binding portion thereof according to any one of the first to fourth aspects. In some embodiments, the present application provides an isolated combination of polynucleotides comprising a polynucleotide encoding a light chain of the antibody or antigen-binding portion thereof of the present application and a polynucleotide encoding a heavy chain of the antibody or antigen-binding portion thereof of the present application. In some embodiments, the polynucleotide is operably linked to a regulatory sequence recognized by a host cell transformed with the vector.

[0076] In a sixth aspect, the present application provides a vector (e.g. an expression vector) comprising a combination of nucleic acid molecules or polynucleotides according to the fifth aspect.

[0077] In some embodiments, the expression vectors of the present application comprise a combination of the nucleic acid molecules or polynucleotides described herein, which are operatively linked to regulatory sequences that allow expression of the polypeptides they encode in a host cell or cell-free expression system. The choice of expression vector depends on the choice of host cell and can be selected to have the necessary expression and regulatory characteristics in the selected host cell.

[0078] An "expression vector" is a vector that contains one or more expression control sequences; an "expression control sequence" is a DNA sequence that controls and regulates the transcription and / or translation of another DNA sequence.

[0079] The nucleic acid in the vector can be operably linked to one or more expression control sequences. As used herein, "operably linked" means that the expression control sequence is incorporated into a genetic construct so as to effectively control the expression of a coding sequence of interest. Examples of expression control sequences include promoters, enhancers, and transcription termination regions. A promoter is an expression control sequence that consists of a region of a DNA molecule that is usually within 100 nucleotides upstream of the transcription start point (usually near the start site of RNA polymerase II). In order for a coding sequence to be under the control of a promoter, the translation start site of the translation reading frame of the polypeptide should be located between 1 and about 50 nucleotides downstream of the promoter. Enhancers provide expression specificity with respect to time, location, and level. Unlike promoters, enhancers can function when located at different distances from the transcription site. Enhancers may also be located downstream of the transcription start site. A coding sequence is "operably linked to" and "under the control" of an expression control sequence in a cell if RNA polymerase transcribes the coding sequence into mRNA that can be translated into the protein encoded by the coding sequence.

[0080] Suitable expression vectors include, but are not limited to, plasmids and viral vectors derived from bacteriophage, baculovirus, tobacco mosaic virus, herpes virus, cytomegalovirus, retrovirus, vaccinia virus, adenovirus and adeno-associated virus, etc. Many vectors and expression systems may be commercially available from companies such as Novagen (Madison, WI), Clontech (Palo Alto, CA), Stratagene (LaJolla, CA) and Invitrogen Life Technologies (Carlsbad, CA).

[0081] The expression vector may contain a tag sequence. The tag sequence is usually expressed as a fusion with the encoded polypeptide. Such tags can be inserted anywhere within the polypeptide, including at the carboxy or amino terminus. Examples of useful tags include, but are not limited to, Fc fragment, polyhistidine, green fluorescent protein (GFP), glutathione S-transferase (GST), c-myc, hemagglutinin, FlagTM tag (Kodak, New Haven, CT), maltose E binding protein, and protein A. In some embodiments, the nucleic acid molecule encoding the CD73 fusion polypeptide is present in a vector that also contains a nucleic acid encoding one or more domains of an Ig heavy chain constant region, such as those corresponding to the amino acid sequences of the hinge, CH2, and CH3 regions of the human immunoglobulin Cγ1 chain (Fc fragment).

[0082] In a seventh aspect, the present application provides a host cell comprising a nucleic acid molecule according to the fifth aspect or a vector according to the sixth aspect. In some embodiments, the host cell may be a prokaryotic host cell, a eukaryotic host cell or a bacteriophage. The prokaryotic host cell may be Escherichia coli, Bacillus subtilis, Streptomyces or Proteus mirabilis. The eukaryotic host cell may be a fungus such as Pastupichia, Saccharomyces, Schizosaccharomyces, Trichoderma, an insect cell such as Cutworm moth, a plant cell such as tobacco, or a mammalian cell such as a BHK cell, a CHO cell, a COS cell, a myeloma cell. In some embodiments, the host cell is preferably a mammalian cell, more preferably a BHK cell, a CHO cell, an NSO cell or a COS cell.

[0083] In an eighth aspect, the present application provides an antibody-drug conjugate, also referred to as antibody-drug conjugate, comprising an anti-CD73 antibody, or antigen-binding portion thereof, according to any one of the first to fourth aspects coupled to a therapeutic agent.

[0084] In some embodiments of the eighth aspect, the therapeutic agent is an anti-tumor drug, such as a cytotoxic drug, an immune enhancing agent, or a radioisotope.

[0085] In some embodiments, the cytotoxic drug class includes tubulin inhibitors (such as alkaloids), DNA topoisomerase inhibitors, DNA damaging agents, antimetabolites, or antitumor antibiotics.

[0086] In some embodiments, tubulin inhibitors include, but are not limited to, auristatin derivatives (e.g., Monomethyl auristatin E (MMAE), Monomethyl auristatin F (MMAF)) or maytansine alkaloid derivatives (e.g., DM1, DM4, ansamitocin, mertansine, or dolastatin and its derivatives).

[0087] In some embodiments, the DNA topoisomerase inhibitor is a camptothecin analog or a DNA topoisomerase I inhibitor and its derivatives, such as DXD, SN38, irinotecan, irinotecan hydrochloride, camptothecin, 9-aminocamptothecin, 9-nitrocamptothecin, 10-hydroxycamptothecin, 9-chloro-10-hydroxycamptothecin, 22-hydroxyecliptaline, topotecan, retotecan, belotecan, ixotecan, homosilatecan, 6,8-dibromo-2-methyl-3-[2-(D-xylopyranosylamino)phenyl]-4(3H)-quinazolinone, 2-cyano-3- (3,4-dihydroxyphenyl)-N-(phenylmethyl)-(2E)-2-acrylamide, 2-cyano-3-(3,4-dihydroxyphenyl)-N-(3-hydroxyphenylpropyl)-(E)-2-acrylamide, 12-β-D-glucopyranosyl-12,13-dihydro-2,10-dihydroxy-6-[[2-hydroxy-1-(hydroxymethyl)ethyl]amino]-5H-indolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7(6H)-dione, N-[2-(dimethylamino)ethyl]-4-acridinecarboxamide dihydrochloride, N-[2-(dimethylamino)ethyl]-4-acridinecarboxamide.

[0088] In some embodiments, DNA damaging agents include, but are not limited to, calicheamicins, duocarmycins, anthromycin derivatives PBD (pyrrolobenzodiazepine).

[0089] In some embodiments, antimetabolites include but are not limited to methotrexate, 6-mercaptopurine, or 5-fluorouracil.

[0090] In some embodiments, the antitumor antibiotic includes, but is not limited to, a polypeptide antibiotic (e.g., actinomycin D or bleomycin) or an anthraquinone drug (e.g., doxorubicin or mitoxantrone hydrochloride). 211 At, 131 I, 125 I, 90 Y, 186 Re, 188 Re, 153 Sm, 212 Bi, 32 P, 60 Co or 177 These include, but are not limited to, Lu.

[0091] In some embodiments, immune enhancing agents include but are not limited to levamisole, pidotimod, imiquimod, isopyridine, polyinosinic acid, or polymyoslidylic acid.

[0092] In some embodiments, the anti-CD73 antibody of the present application is covalently linked to the drug moiety via a linker. In some embodiments, the linker is a cleavable linker. In some embodiments, the linker is cleavable under intracellular conditions. In one embodiment, the linker is hydrolyzable at a pH of less than 5.5. In some embodiments, the linker is cleavable by intracellular proteases. In some embodiments, the linker is a cathepsin-cleavable linker. In some embodiments, the linker comprises a dipeptide. In some embodiments, the dipeptide is valine (Val)-citrulline (Cit). In some embodiments, the antibody is attached to the linker via a cysteine ​​sulfhydryl group of the antibody. In one embodiment, the antibody is linked to the linker via an amino group of the antibody, particularly the amino group of a glutamine residue. Non-limiting examples of linkers include mc-Val-Cit-pAB, mc-Val-Cit-pABC, mc-Val-Cit, NH2-(PEG)m-Val-Cit, NH2-(PEG)m-Val-Cit-pAB, where m is an integer from 1 to 8. In some embodiments, the linker is a non-cleavable linker, including, but not limited to, an acid-labile linker (e.g., a hydrazone linker), a disulfide bond-containing linker, a peptidase-sensitive linker (e.g., a peptide linker comprising amino acids such as valine and / or citrulline, such as citrulline-valine or phenylalanine-lysine), a photolabile linker, a dimethyl linker, a thioether linker, or a hydrophilic linker designed to circumvent multidrug transport protein-mediated resistance.

[0093] In a ninth aspect, the present application provides a pharmaceutical composition comprising an anti-CD73 antibody or an antigen-binding portion thereof according to the first to fourth aspects, or an antibody-drug conjugate according to the eighth aspect, and a pharma- ceutically acceptable vector.

[0094] In some embodiments, the pharmaceutical composition is used to treat a tumor in an individual.

[0095] In some embodiments, tumors express CD73 (CD73 + ) is a tumor that expresses

[0096] In some embodiments, tumors express CD73 (CD73 + In some embodiments, the tumor is a tumor that highly expresses CD73 (CD73 + A tumor that highly expresses CD73 (CD73) refers to a tumor in which at least 60% of the tumor cells in a tumor cell population express CD73. + A tumor that highly expresses CD73 (CD73) refers to a tumor in which at least 70% of the tumor cells in a tumor cell population express CD73. + A tumor that highly expresses CD73 (CD73) refers to at least 80% of tumor cells in a tumor cell population expressing CD73. + A tumor that highly expresses CD73 (CD73) refers to at least 90% of the tumor cells in a tumor cell population expressing CD73. + A tumor that highly expresses CD73 (CD73) refers to at least 95% of tumor cells in a tumor cell population expressing CD73. + A tumor that highly expresses CD73 (CD73) refers to at least 98% of tumor cells in a tumor cell population expressing CD73. + A tumor that highly expresses CD73 refers to one in which at least 99% of the tumor cells in a tumor cell population express CD73.

[0097] In some embodiments, the tumor is a solid tumor.

[0098] In some embodiments, the tumor is a hematological tumor.

[0099] In some embodiments, the tumor is a malignant tumor.

[0100] In some embodiments, the tumor is a cancer.

[0101] In some embodiments, the tumor is selected from ovarian cancer, breast cancer, melanoma, colorectal cancer, gastric cancer, renal cancer, prostate cancer, pancreatic cancer, esophageal cancer, head and neck cancer, thyroid cancer, lung cancer, bladder cancer, cervical cancer, colon cancer, liver cancer, peritoneal cancer, hepatocellular carcinoma, glioblastoma, urinary tract cancer, rectal cancer, endometrial cancer, uterine cancer, salivary gland cancer, squamous cell carcinoma, vulvar cancer, anal cancer, penile cancer, brain cancer, lymphoma (such as B cell lymphoma), leukemia, and metastases of the above tumors.

[0102] In some embodiments, the pharmaceutical composition may further comprise one or more of the following: lubricants such as talc powder, magnesium stearate and mineral oil, wetting agents, emulsifying agents, suspending agents, preservatives such as benzoic acid, sorbic acid and calcium propionate, sweeteners and / or flavoring agents, etc. In some embodiments, the pharmaceutical composition herein may be prepared in the form of tablets, pills, powders, topical applications, lozenges, suspensions, emulsions, solutions, syrups, suppositories, capsules, etc.

[0103] In some embodiments, the pharmaceutical compositions of the present application can be delivered using any physiologically acceptable method of administration, including, but not limited to, oral administration, parenteral administration, nasal administration, rectal administration, intraperitoneal administration, intravascular injection, subcutaneous administration, transdermal administration, inhalation administration, and the like.

[0104] In some embodiments, a therapeutic pharmaceutical composition can be prepared for storage in the form of a lyophilized formulation or aqueous solution by mixing reagents having the desired purity with pharma- ceutically acceptable vectors, excipients, etc., as necessary.

[0105] In a tenth aspect, the present application provides a method for detecting CD73 (CD73 + The present invention provides use of an anti-CD73 antibody or antigen-binding portion thereof according to any one of the first to fourth aspects, a nucleic acid molecule according to the fifth aspect, a vector according to the sixth aspect, a host cell according to the seventh aspect or an antibody-drug conjugate according to the eighth aspect in the manufacture of a medicament for treating a tumour expressing CD73.

[0106] In some embodiments, tumors express CD73 (CD73 + ) is a tumor that expresses

[0107] In some embodiments, tumors express CD73 (CD73 + In some embodiments, the tumor is a tumor that highly expresses CD73 (CD73 + A tumor that highly expresses CD73 (CD73) refers to a tumor in which at least 60% of the tumor cells in a tumor cell population express CD73. + A tumor that highly expresses CD73 (CD73) refers to a tumor in which at least 70% of the tumor cells in a tumor cell population express CD73. + A tumor that highly expresses CD73 (CD73) refers to at least 80% of tumor cells in a tumor cell population expressing CD73. + A tumor that highly expresses CD73 (CD73) refers to at least 90% of the tumor cells in a tumor cell population expressing CD73. + A tumor that highly expresses CD73 (CD73) refers to at least 95% of tumor cells in a tumor cell population expressing CD73. + A tumor that highly expresses CD73 (CD73) refers to at least 98% of tumor cells in a tumor cell population expressing CD73. + A tumor that highly expresses CD73 refers to one in which at least 99% of the tumor cells in a tumor cell population express CD73.

[0108] In some embodiments, the tumor is a solid tumor.

[0109] In some embodiments, the tumor is a hematological tumor.

[0110] In some embodiments, the tumor is a malignant tumor.

[0111] In some embodiments, the tumor is a cancer.

[0112] In some embodiments, the tumor is selected from ovarian cancer, breast cancer, melanoma, colorectal cancer, gastric cancer, renal cancer, prostate cancer, pancreatic cancer, esophageal cancer, head and neck cancer, thyroid cancer, lung cancer, bladder cancer, cervical cancer, colon cancer, liver cancer, peritoneal cancer, hepatocellular carcinoma, glioblastoma, urinary tract cancer, rectal cancer, endometrial cancer, uterine cancer, salivary gland cancer, squamous cell carcinoma, vulvar cancer, anal cancer, penile cancer, brain cancer, lymphoma (such as B cell lymphoma), leukemia, and metastases of the above tumors.

[0113] In an eleventh aspect, the present application relates to a method for detecting CD73 (CD73 + The present invention provides a method of treating a tumor expressing CD73, the method comprising administering to said individual a therapeutically effective amount of an anti-CD73 antibody or antigen-binding portion thereof according to any one of the first to fourth aspects, an antibody-drug conjugate according to any one of the eighth aspect, or a pharmaceutical composition according to any one of the ninth aspect. In some embodiments of the methods of treating or preventing a disease, condition or pathology, the method comprises exposing a cell in vitro to the anti-CD73 antibody.

[0114] In some embodiments, tumors express CD73 (CD73 + ) is a tumor that expresses

[0115] In some embodiments, tumors express CD73 (CD73 + In some embodiments, the tumor is a tumor that highly expresses CD73 (CD73 + A tumor that highly expresses CD73 (CD73) refers to a tumor in which at least 60% of the tumor cells in a tumor cell population express CD73. + A tumor that highly expresses CD73 (CD73) refers to a tumor in which at least 70% of the tumor cells in a tumor cell population express CD73. + A tumor that highly expresses CD73 (CD73) refers to at least 80% of tumor cells in a tumor cell population expressing CD73. +A tumor that highly expresses CD73 (CD73) refers to at least 90% of the tumor cells in a tumor cell population expressing CD73. + A tumor that highly expresses CD73 (CD73) refers to at least 95% of tumor cells in a tumor cell population expressing CD73. + A tumor that highly expresses CD73 (CD73) refers to at least 98% of tumor cells in a tumor cell population expressing CD73. + A tumor that highly expresses CD73 refers to one in which at least 99% of the tumor cells in a tumor cell population express CD73.

[0116] In some embodiments, the tumor is a solid tumor.

[0117] In some embodiments, the tumor is a hematological tumor.

[0118] In some embodiments, the tumor is a malignant tumor.

[0119] In some embodiments, the tumor is a cancer.

[0120] In some embodiments, the tumor is selected from ovarian cancer, breast cancer, melanoma, colorectal cancer, gastric cancer, renal cancer, prostate cancer, pancreatic cancer, esophageal cancer, head and neck cancer, thyroid cancer, lung cancer, bladder cancer, cervical cancer, colon cancer, liver cancer, peritoneal cancer, hepatocellular carcinoma, glioblastoma, urinary tract cancer, rectal cancer, endometrial cancer, uterine cancer, salivary gland cancer, squamous cell carcinoma, vulvar cancer, anal cancer, penile cancer, brain cancer, lymphoma (such as B cell lymphoma), leukemia, and metastases of the above tumors.

[0121] In some embodiments of the ninth to eleventh aspects, the anti-CD73 antibody or antigen-binding portion thereof of the present application can be used alone or in combination with other compositions in anti-tumor therapy. For example, the anti-CD73 antibody can be co-administered with at least one additional therapeutic agent and / or adjuvant. In some embodiments, the additional compound is a therapeutic antibody other than an anti-CD73 antibody. In some embodiments, the other therapeutic agent is a therapeutic agent that targets the cancer immune cycle (e.g., an immune checkpoint inhibitor (such as an anti-PD-1 antibody, an anti-PD-L1 antibody, or an anti-CTLA4 antibody), an A2AR antagonist, a STAT-3 inhibitor), and such therapeutic combination therapy can be used to reduce tumor-mediated immune inhibition.

[0122] In a twelfth aspect, the present application provides a conjugate comprising an anti-CD73 antibody or an antigen-binding portion thereof according to any one of the first to fourth aspects and a detectable label, such as a detectable fluorescent label, a chemiluminescent label, an isotopic label, etc.

[0123] In a thirteenth aspect, the present application provides a fusion protein comprising an anti-CD73 antibody, or an antigen-binding portion thereof, according to aspects 1 to 4. Examples of antibody fusion proteins include Fab fusion proteins, Fc fusion proteins and single-chain antibody (scFv) fusion proteins, named according to the site to which an effector protein (such as a cytokine) is fused.

[0124] In some embodiments of the twelfth or thirteenth aspect, the conjugates can be formed by synthesizing the anti-CD73 antibodies of the present application with a linker covalently attached to one or more non-antibody binding agents. In some embodiments, the antibodies of the present application are conjugated or recombinantly fused to a diagnostic, detection or therapeutic agent or any other molecule. The conjugated or recombinantly fused antibodies can be used, for example, to monitor or predict the onset, development, progression and / or severity of a CD73-mediated disease as part of a clinical testing regimen, for example to measure the efficacy of a particular therapy. Such diagnosis and detection can be achieved, for example, by coupling the antibody to a detectable label. Detectable labels include, but are not limited to, enzymes, prosthetic groups, fluorescent labels, chemiluminescent labels, isotopic labels, and the like. In some embodiments, the antibodies of the present application can be conjugated or recombinantly fused to a therapeutic or drug moiety that modifies a designated biological response, among which are the antibody drug conjugates described in the eighth aspect. The therapeutic or drug moiety is not limited to typical chemotherapeutic agents. For example, the drug moiety can be a protein, peptide, polypeptide, small molecule toxin, and the like, having a desired biological activity.

[0125] It should be understood that the above detailed description is merely intended to enable those skilled in the art to more clearly understand the contents of the present application, and is not intended to be limiting in any respect. Those skilled in the art may make various modifications and variations to the described embodiments.

[0126] Working Example Specific embodiments of the present application will be described in detail below with reference to examples. However, as will be understood by those skilled in the art, the following examples are merely illustrative of the present invention and should not be construed as limiting the scope of the present application.

[0127] Example 1: Production of anti-human CD73 monoclonal antibody Healthy BALB / c mice were immunized with recombinant human CD73 protein (Arco, catalog number CD3-H52H7), and after the first immunization, they were boosted three times every 14 days. Mouse peripheral serum was collected, mouse serum titers were detected by enzyme-linked immunosorbent assay (ELISA), and mice with high plasma antibody titers were selected for cell fusion. Three days before fusion, shock immunization was performed via the tail vein or intraperitoneally. On the day of fusion, mouse spleens were collected and prepared into single cell suspensions, and SP2 / 0 cells and splenocytes were mixed in a 1:2 ratio and fused by electrofusion. The cells were incubated at 37°C in a CO2 incubator, and when the hybridoma cells grew to a certain amount, the hybridoma supernatant was screened by ELISA. Positive clones were selected and subcloned by limiting dilution for screening. Finally, the obtained monoclonal positive cells were subjected to RNA extraction, reverse transcription and PCR amplification to obtain mouse immunoglobulin heavy and light chain variable region fragments, which were then sequenced. Finally, the heavy and light chain CDR region sequences and the amino acid sequences of the variable regions of the 7C3C2 and 1F2F9 clones were obtained, as follows:

[0128] 7C3C2 Heavy chain CDR1: SYDIN (SEQ ID NO: 1) Heavy chain CDR2: WIYPRDGFTKYNEKFKG (SEQ ID NO: 2) Heavy chain CDR3: KEGYRGDWYFDV (SEQ ID NO: 3) Heavy chain variable region sequence

[0129] [ka]

[0130] Light chain CDR1: RASGNVHNYLA (SEQ ID NO:5) Light chain CDR2: NAKTLAD (SEQ ID NO: 6) Light chain CDR3: QHFWSTPWT (SEQ ID NO: 7) Light chain variable region sequence

[0131] [ka]

[0132] 1F2F9 Heavy chain CDR1: SYWMH (SEQ ID NO: 9) Heavy chain CDR2: NINPSNGGTKYNEKFKS (SEQ ID NO: 10) Heavy chain CDR3: RDYGSPSY (SEQ ID NO: 11) Heavy chain variable region sequence

[0133] [ka]

[0134] Light chain CDR1: KASQDINSYLT (SEQ ID NO: 13) Light chain CDR2: RTNILLD (SEQ ID NO: 14) Light chain CDR3: LQYHEFPVT (SEQ ID NO: 15) Light chain variable region sequence

[0135] [ka]

[0136] Note: In the above antibody variable region sequences, the underlines are the CDR sequences (determined and noted based on the Kabat numbering system).

[0137] Example 2: Detection of affinity of chimeric antibodies by ELISA method Based on the variable region sequence information of the gene encoding the above monoclonal antibody, a human-mouse chimeric antibody expression vector was constructed. VH and VL were each constructed in a eukaryotic expression vector containing the hIgG1-kappa constant region with L234A, L235A, P329A, P331S mutations (abbreviated as hIgG1 in this application, the heavy chain constant region sequence is shown in SEQ ID NO: 39, and the light chain constant region sequence is shown in SEQ ID NO: 40, which is the same as in the following examples).

[0138] ASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPEAAGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALAASIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK (SEQ ID NO: 39) RTVAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC (SEQ ID NO: 40) The obtained eukaryotic expression vector was transiently introduced into HEK293 cells and cultured for 6 days. The collected culture supernatant was purified by Protein A column to obtain the target antibodies named 7C3C2-hIgG1 and 1F2F9-hIgG1, respectively, and the affinity of the antibodies to recombinant human CD73 protein (same as in Example 1) was measured using ELISA. A microplate reader was coated with recombinant human CD73 protein at a concentration of 1 μg / mL, the plate was washed three times with PBST buffer, and then blocked for 2 h at 37 ° C. with PBS buffer containing 2% BSA, the plate was washed three times with PBST buffer, and a 5-fold gradient diluted antibody (0 to 133.3 nM) was added to the measurement-ready antibody, incubated at 37 ° C. for 2 h, and washed three times with PBST buffer. A horseradish peroxidase-labeled secondary antibody was added, incubated at 37 ° C. for 1 h, and the plate was washed three times with PBST buffer. The color was developed, and the absorbance value was read after completion. The affinities obtained are shown in FIG.

[0139] [Table 1]

[0140] EC of 7C3C2-hIgG1 and 1F2F9-hIgG1 binding to CD73 protein 50 The EC values ​​of these two antibodies were 0.017 nM and 0.028 nM, respectively. 50 The values ​​met the requirements for further experiments.

[0141] Example 3: Antibody Humanization Homology modeling was performed using Discovery Studio and Schrodinger Antibody Modeling. Through structural simulation and rational design, the closest human framework regions to the mouse antibody framework regions were analyzed and obtained. The humanized light chain template of mouse 7C3C2 was IGKV1-NL1, and for the heavy chain, the closest human matching sequence was IGHV1-8 gene, and the humanized light chain template of mouse 1F2F9 was IGKV1-16 gene, and the closest human heavy chain matching sequence was IGHV1-3 gene. The CDRs of the light chain and heavy chain were grafted into the framework sequences of the matched light chain and heavy chain genes, respectively, to obtain humanized antibodies Hab7C3C2 and Hab1F2F9. Then, 3D models were constructed by Discovery Studio and Schrodinger Antibody Modeling, and the framework positions where mouse amino acids were replaced with human amino acids were analyzed to see whether there were any sites that affected binding and / or CDR conformation, and back mutations were performed, and the sequences were shown in Tables 2 and 3. The related humanized antibodies were shown in Tables 4 and 5.

[0142] [Table 2]

[0143] JPEG2025504496000007.jpg250169

[0144] [Table 3]

[0145] [Table 4]

[0146] [Table 5]

[0147] Example 4: Detection of affinity of humanized anti-CD73 antibodies 4.1 Detection of affinity of humanized antibodies to human CD73 protein by Fortebio The humanized antibody VH and VL were constructed in a eukaryotic expression vector containing the hIgG1-kappa constant region with L234A, L235A, P329A, and P331S mutations (abbreviated as hIgG1 in this application), and the affinity of all humanized antibodies was detected in this example. Using a HIS1K biosensor, human CD73 protein was immobilized on the biosensor until the binding of 0.3 nm responded to the threshold. After a baseline step of 120 s, the sensor was immersed in the anti-CD73 antibody analyte gradient diluted with 0.02% PBST buffer, with the starting concentration of the antibody being 25 nM, diluted 2-fold gradient, and seven concentration gradients were set up. The binding and dissociation times of the ligand to the analyte were 120 s and 300 s, respectively. Based on the binding curve, the antigen-antibody affinity data was regressed by the analysis software. Of all the detected antibodies, Hab7C3C2.5, Huab7C3C2.9, Huab1F2F9.12 and Huab1F2F9.15 showed the highest affinity and relatively few back mutations, the results of which are shown in Table 6.

[0148] [Table 6]

[0149] 4.2 Detection of affinity of humanized antibodies to human CD73 protein by ELISA The affinity of the humanized antibodies to recombinant CD73 protein was measured using ELISA. A microplate reader was coated with CD73 protein at a concentration of 1 μg / mL, and 5-fold gradient dilutions of the antibodies (0-66.7 nM) were added. The affinities obtained with the antibodies are shown in Figure 2 and Table 7.

[0150] [Table 7]

[0151] EC of Hab7C3C2.5 and Huab1F2F9.15 binding to CD73 protein 50 were 0.013 nM and 0.011 nM, respectively. As can be seen from the above, the affinity of the humanized antibody was not affected compared to that of the mouse antibody.

[0152] Example 5: Binding of humanized antibodies to human tumor cells In this example, exemplary antibodies of the present application were compared to anti-CD73 antibodies described in other patent applications. MEDI9447 and Hu101-28 (CDR region sequences from PCT patent applications WO2016 / 075099 and WO2018 / 137598, respectively) antibodies were cloned into eukaryotic expression vectors containing the hIgG1-kappa constant region. The tumor cell lines MDA-MB-231 and SKOV3, which endogenously express human CD73 on the cell surface, were used to evaluate the binding ability of humanized antibodies Hab7C3C2.5 and Hab1F2F9.15 to cell surface CD73. Cells were cultured at 2×10 6The cells were seeded into a 96-well plate at a density of 100 μL / mL and 4-fold gradient dilution of the antibody (0-100 nM) was added and incubated at 4°C for 1 h. Goat anti-human secondary antibody was added and labeled in the dark at 4°C for 50 min, and the fluorescence intensity of the cells was read by flow cytometry. The experimental results are shown in Figures 3 and 4 and Table 8. The results showed that the exemplary humanized antibodies of the present application can bind to the CD73 protein expressed in the cell line in a dose-dependent manner. At the same time, the ability of Hab7C3C2.5 and Hab1F2F9.15 to recognize cell surface CD73 was comparable to MEDI9447 and superior to the corresponding molecule Hu101-28.

[0153] [Table 8]

[0154] Example 6: Cross-reactivity of humanized anti-CD73 antibodies with cynomolgus monkey CD73 6.1 Detection of cross-recognition between humanized antibodies and monkey CD73 protein by the Fortebio method In this example, the cross-binding ability of the exemplary humanized anti-CD73 antibody of the present application and cynomolgus monkey CD73 was detected by Fortebio experiment. The specific implementation steps include: Cynomolgus monkey CD73 protein was immobilized on a HIS1K biosensor. After a baseline step of 120 s, the sensor was immersed in the anti-CD73 antibody analyte gradient diluted with 0.02% PBST buffer, the starting concentration of the antibody was 25 nM, and seven concentration gradients were set, respectively, to perform affinity analysis experiments. The binding and dissociation times of the ligand to the analyte were 120 s and 300 s, respectively. Based on the binding curve, the affinity data of the antigen-antibody was regressed by the analysis software. The results are shown in Table 9, and the exemplary antibody of the present application can cross-recognize cynomolgus monkey CD73 protein.

[0155] [Table 9]

[0156] 6.2 Detection of cross-recognition between humanized antibodies and monkey CD73 protein by flow cytometry To characterize the recognition ability of the humanized antibodies produced in this application to the cynomolgus monkey CD73 molecule on the cell membrane, CHO-K1 cells capable of stably expressing full-length monkey CD73 were constructed. The cells were cultured at 2 × 10 6 The cells were seeded into a 96-well plate at a density of 100 μL / mL and 100 μL / well. The cells were washed three times with PBS buffer and the supernatant was discarded. Gradient-diluted antibodies were added in PBS buffer and incubated at 4°C for 1 h. The cells were washed three times with PBS buffer and then labeled with Alexa Fluor 488-conjugated goat anti-human IgG antibody for 50 min in the dark at 4°C. The cells were washed three times with PBS buffer and the fluorescence intensity of the cells was read by a flow cytometer.

[0157] As shown by the results in FIG. 5 and Table 10, the produced humanized antibodies can bind to monkey CD73 protein expressed in cells in a dose-dependent manner.

[0158] [Table 10]

[0159] Example 7: Anti-CD73 antibody-mediated inhibition of CD73 enzyme activity 7.1 Inhibition of CD73 protease activity Recombinant human CD73 protein was diluted to a final concentration of 0.5 μg / mL, and anti-CD73 antibody diluted 4-fold (0-5 nM) was added, and human IgG1 was used as a negative control. The plate was incubated at 37°C for 1 h. ATP (75 μM) and AMP (94 μM) were added to each well and incubated at 37°C for 1 h. An equal volume of CellTiter-Glo containing luciferase was added to each well, and the luminescence value was read by a microplate reader. The results, as shown in Figure 6 and Table 11, show that Hab7C3C2.5 and Hab1F2F9.15 can inhibit the activity of free CD73 protease.

[0160] [Table 11]

[0161] 7.2 Inhibitory activity of CD73 enzyme activity on human MDA-MB-231 cells CD73-expressing MDA-MB-231 cells were plated at 2 × 10 in the presence of 3-fold gradient dilutions (0–10 nM) of anti-CD73 antibodies or isotype control antibodies (human IgG1) at different doses in 50 μL / well. 5 100 μL / well of AMP was seeded into a 96-well plate at 100 μL / mL. The plate was incubated at 37°C for 1 h, then AMP (1800 μM) was added to each well at 50 μL / well and incubated at 37°C for 2 h. The cells were centrifuged at 1000 rpm for 5 min, 50 μL of the supernatant was transferred to a new 96-well plate, and 50 μL of ATP was added to a final concentration of 75 μM. CellTiter-Glo reagent (Promega) was added at a 1:1 ratio to measure cellular CD73 enzyme activity. The results, as shown in Figure 7 and Table 12, indicate that Hab7C3C2.5 and Hab1F2F9.15 can inhibit CD73 enzyme activity in MDA-MB-231 cells.

[0162] [Table 12]

[0163] Example 8: Antibody-induced cell surface CD73 internalization In this example, antibody-mediated CD73 internalization was evaluated by flow cytometry. Cells were suspended in serum-free DMEM medium and incubated with the antibody to be tested on ice for 1 h, respectively, with the antibody concentration at 10 μg / mL. Cells were washed three times with serum-free DMEM medium, and cells incubated with different antibodies were suspended in serum-free DMEM medium, respectively, and seeded in two 24-well plates in two parts, respectively. One culture plate was incubated in a 37°C incubator, and another culture plate was incubated in a 4°C refrigerator as a control group for 24 h. Cells were collected and washed, and Alexa Fluor 488-labeled goat anti-human secondary antibody was added and stained for 1 h in the dark at 4°C. They were washed three times with PBS buffer and detected by flow cytometer.

[0164] The results show that an exemplary antibody of the present application can induce approximately 60% internalization of the CD73 receptor while maintaining approximately 40% of the initial surface staining, as shown in Figure 8. All calculations were percentage internalization relative to the control, which was set at 100%.

[0165] Example 9: Identification of epitopes recognized by antibodies In this example, the C-terminal part (SEQ ID NO: 41) and N-terminal part (SEQ ID NO: 42) of CD73 protein were constructed, respectively, and the antibody recognition epitopes were detected by ELISA. The N-terminal and C-terminal proteins of CD73 were coated on a microplate reader at a concentration of 1 μg / mL, respectively, and the antibodies to be measured were gradient diluted. The obtained affinities are shown in Figures 9A (N-terminus) and 9B (C-terminus). The experimental results showed that compared with the control antibodies (MEDI9447 and Hu101-28), there were differences in the binding epitopes of Hab7C3C2.5 and Hab1F2F9.15, Hab7C3C2.5 and Hab1F2F9.15 did not bind to the N-terminus and C-terminus of CD73 protein, MEDI9447 bound to the N-terminus of CD73 protein, and Hu101-28 bound to the C-terminus of CD73 protein. The binding epitopes of Hab7C3C2.5 and Hab1F2F9.15 of the present application are clearly different from those of MEDI9447 and Hu101-28.

[0166] Example 10: Evaluation of the biological activity of anti-CD73 antibodies in vivo in animals Evaluation of single-agent efficacy of chimeric antibodies in PBMC-immune reconstituted mice The monotherapy efficacy of the 1F2F9 chimeric antibody was evaluated in tumor xenograft models. 6 A375 melanoma cells and 4 x 10 5 Human PBMCs were mixed 1:1 with Matrigel and then inoculated into NCG immunodeficient mice. On the day of implantation, 30 mg / kg of 1F2F9 chimeric antibody or PBS control was injected intraperitoneally, followed by one injection every other day. 24 days after treatment, multiple mice had tumors with sizes up to the upper limit (2000 mm 3 ) after treatment. Therefore, the analysis data end point was 24 days after treatment. In the control group, the mean tumor volume was 1448 ± 176.76 mm after treatment. 3 Compared with the control group, administration of 1F2F9-hIgG1 and MEDI9447 reduced tumor growth, resulting in tumor inhibition of 31.14% and 16.88%, respectively, with tumor volumes of 997.37 ± 131.39 mm. 3 and 1203.95±158.01 mm 3 (Figure 10A). The results of single tumor volume are shown in Figure 10B (multiple lines each represent multiple mice). The body weight change in each experimental group was not significant (Figure 10C), indicating that the treatment was well tolerated.

[0167] Example 11: Evaluation of the efficacy of CD73 humanized antibodies in genetic mice In this example, the efficacy of Huab1F2F9.15, anti-PD-1 antibodies, and their combinations was evaluated using human CD73 / PD1 / PDL1 knock-in BALB / c mice and CT26 cells (colon cancer cell line) overexpressing human CD73 / PDL1. 6 CT26-hCD73 / hPDL1 cells were subcutaneously inoculated into transgenic mice. The mean tumor volume was 60–80 mm. 3If the tumor volume was about 100%, the mice were divided into groups according to the tumor volume. The day of grouping was defined as D0, and treatment was started on the day of grouping. The indicated doses of antibodies or PBS control were intraperitoneally injected twice a week. Mice were treated with anti-PD-1 antibody alone (1 mg / kg), anti-CD73 antibody alone (Huab1F2F9.15 and MEDI9447, 15 mg / kg), and anti-PD-1 antibody + anti-CD73 antibody (1 mg / kg + 15 mg / kg). The results showed that the combined administration of Huab1F2F9.15 and anti-PD-1 antibody, as well as MEDI9447 and anti-PD1 antibody, reduced tumor growth, resulting in 53.74% and 37.67% tumor inhibition, respectively, and the combined effect of Huab1F2F9.15 and anti-PD-1 antibody was significantly superior to the combination of MEDI9447 and anti-PD1 antibody (Figure 11A). The results of single tumor volume are shown in Figure 11B (each line represents a different mouse). The body weight change in each experimental group was not significant (Figure 11C), indicating that the treatment was well tolerated. To summarize the above experimental results, the present application has obtained a CD73 antibody at the cellular level that recognizes CD73 protein with high affinity. The representative antibodies tested can potently inhibit the enzymatic activity of CD73 while inducing the internalization of CD73 protein in tumor cells, and further reduce the enzymatic activity of CD73 by reducing the cell surface CD73 molecules, thereby achieving the effect of inhibiting CD73 enzymatic activity by various routes. Epitope analysis shows that the exemplary antibodies of the present application do not bind to both the N-terminal and C-terminal proteins of the CD73 protein alone, and have differentiated epitope binding characteristics from prior art antibodies such as MEDI9447 and Hu101-28. Animal in vivo experiments demonstrated that the 1F2F9 chimeric antibody and the humanized Huab1F2F9.15 antibody can effectively inhibit the proliferation of animal in vivo tumor cells. In particular, the combination of humanized Huab1F2F9.15 antibody and anti-PD-1 antibody achieved excellent tumor inhibition effects and was well tolerated.

[0168] The use of any and all examples or exemplary language (e.g., "such as") provided herein is intended merely to better describe the application and does not limit the scope of the application, unless otherwise required. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the application.

[0169] All publications and patent applications cited in this specification are incorporated herein by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference. Furthermore, any theory, mechanism, demonstration, or discovery described herein is intended to further enhance the understanding of the present application, and is not intended to limit the present application in any manner to such theory, mechanism, demonstration, or discovery. Although the present application has been shown and described in detail in the drawings and foregoing description, the present application should be considered as illustrative and not limiting.

Claims

1. an anti-CD73 antibody, or an antigen-binding portion thereof, comprising a heavy chain variable region comprising heavy chain CDR1 (HCDR1), heavy chain CDR2 (HCDR2), and heavy chain CDR3 (HCDR3), and a light chain variable region comprising light chain CDR1 (LCDR1), light chain CDR2 (LCDR2), and light chain CDR3 (LCDR3), the sequence of HCDR1 is the sequence shown in SEQ ID NO: 1, the sequence of HCDR2 is the sequence shown in SEQ ID NO: 2, the sequence of HCDR3 is the sequence shown in SEQ ID NO: 3, the sequence of LCDR1 is the sequence shown in SEQ ID NO: 5, the sequence of LCDR2 is the sequence shown in SEQ ID NO: 6, and the sequence of LCDR3 is the sequence shown in SEQ ID NO: 7, or the sequence of HCDR1 is the sequence shown in SEQ ID NO: 1, the sequence of HCDR2 is the sequence shown in SEQ ID NO: 17, the sequence of HCDR3 is the sequence shown in SEQ ID NO: 3, the sequence of LCDR1 is the sequence shown in SEQ ID NO: 5, the sequence of LCDR2 is the sequence shown in SEQ ID NO: 32, and the sequence of LCDR3 is the sequence shown in SEQ ID NO: 7, or the sequence of HCDR1 is the sequence shown in SEQ ID NO: 1, the sequence of HCDR2 is the sequence shown in SEQ ID NO: 17, the sequence of HCDR3 is the sequence shown in SEQ ID NO: 3, the sequence of LCDR1 is the sequence shown in SEQ ID NO: 5, the sequence of LCDR2 is the sequence shown in SEQ ID NO: 6, and the sequence of LCDR3 is the sequence shown in SEQ ID NO: 7, or the sequence of HCDR1 is the sequence shown in SEQ ID NO: 1, the sequence of HCDR2 is the sequence shown in SEQ ID NO: 2, the sequence of HCDR3 is the sequence shown in SEQ ID NO: 3, the sequence of LCDR1 is the sequence shown in SEQ ID NO: 5, the sequence of LCDR2 is the sequence shown in SEQ ID NO: 32, and the sequence of LCDR3 is the sequence shown in SEQ ID NO: 7, or the sequence of HCDR1 is the sequence shown in SEQ ID NO: 1, the sequence of HCDR2 is the sequence shown in SEQ ID NO: 21, the sequence of HCDR3 is the sequence shown in SEQ ID NO: 3, the sequence of LCDR1 is the sequence shown in SEQ ID NO: 5, the sequence of LCDR2 is the sequence shown in SEQ ID NO: 32, and the sequence of LCDR3 is the sequence shown in SEQ ID NO: 7, or the sequence of HCDR1 is the sequence shown in SEQ ID NO: 1, the sequence of HCDR2 is the sequence shown in SEQ ID NO: 21, the sequence of HCDR3 is the sequence shown in SEQ ID NO: 3, the sequence of LCDR1 is the sequence shown in SEQ ID NO: 5, the sequence of LCDR2 is the sequence shown in SEQ ID NO: 6, and the sequence of LCDR3 is the sequence shown in SEQ ID NO: 7, or the sequence of HCDR1 is the sequence shown in SEQ ID NO: 1, the sequence of HCDR2 is the sequence shown in SEQ ID NO: 23, the sequence of HCDR3 is the sequence shown in SEQ ID NO: 3, the sequence of LCDR1 is the sequence shown in SEQ ID NO: 5, the sequence of LCDR2 is the sequence shown in SEQ ID NO: 32, and the sequence of LCDR3 is the sequence shown in SEQ ID NO: 7, or the sequence of HCDR1 is the sequence shown in SEQ ID NO: 1, the sequence of HCDR2 is the sequence shown in SEQ ID NO: 23, the sequence of HCDR3 is the sequence shown in SEQ ID NO: 3, the sequence of LCDR1 is the sequence shown in SEQ ID NO: 5, the sequence of LCDR2 is the sequence shown in SEQ ID NO: 6, and the sequence of LCDR3 is the sequence shown in SEQ ID NO: 7, or the sequence of HCDR1 is the sequence shown in SEQ ID NO: 9, the sequence of HCDR2 is the sequence shown in SEQ ID NO: 10, the sequence of HCDR3 is the sequence shown in SEQ ID NO: 11, the sequence of LCDR1 is the sequence shown in SEQ ID NO: 13, the sequence of LCDR2 is the sequence shown in SEQ ID NO: 14, and the sequence of LCDR3 is the sequence shown in SEQ ID NO: 15, or the sequence of HCDR1 is the sequence shown in SEQ ID NO: 9, the sequence of HCDR2 is the sequence shown in SEQ ID NO: 10, the sequence of HCDR3 is the sequence shown in SEQ ID NO: 11, the sequence of LCDR1 is the sequence shown in SEQ ID NO: 35, the sequence of LCDR2 is the sequence shown in SEQ ID NO: 14, and the sequence of LCDR3 is the sequence shown in SEQ ID NO: 15, or the sequence of HCDR1 is the sequence shown in SEQ ID NO: 9, the sequence of HCDR2 is the sequence shown in SEQ ID NO: 27, the sequence of HCDR3 is the sequence shown in SEQ ID NO: 11, the sequence of LCDR1 is the sequence shown in SEQ ID NO: 35, the sequence of LCDR2 is the sequence shown in SEQ ID NO: 14, and the sequence of LCDR3 is the sequence shown in SEQ ID NO: 15, or the sequence of HCDR1 is the sequence shown in SEQ ID NO: 9, the sequence of HCDR2 is the sequence shown in SEQ ID NO: 27, the sequence of HCDR3 is the sequence shown in SEQ ID NO: 11, the sequence of LCDR1 is the sequence shown in SEQ ID NO: 13, the sequence of LCDR2 is the sequence shown in SEQ ID NO: 14, and the sequence of LCDR3 is the sequence shown in SEQ ID NO: 15, or the sequence of HCDR1 is the sequence shown in SEQ ID NO: 9, the sequence of HCDR2 is the sequence shown in SEQ ID NO: 30, the sequence of HCDR3 is the sequence shown in SEQ ID NO: 11, the sequence of LCDR1 is the sequence shown in SEQ ID NO: 35, the sequence of LCDR2 is the sequence shown in SEQ ID NO: 14, and the sequence of LCDR3 is the sequence shown in SEQ ID NO: 15, or the sequence of HCDR1 is the sequence shown in SEQ ID NO: 9, the sequence of HCDR2 is the sequence shown in SEQ ID NO: 30, the sequence of HCDR3 is the sequence shown in SEQ ID NO: 11, the sequence of LCDR1 is the sequence shown in SEQ ID NO: 13, the sequence of LCDR2 is the sequence shown in SEQ ID NO: 14, and the sequence of LCDR3 is the sequence shown in SEQ ID NO: 15; Among them, the HCDR and LCDR sequences are defined based on Kabat: An anti-CD73 antibody or an antigen-binding portion thereof.

2. the heavy chain variable region has an amino acid sequence set forth in SEQ ID NO: 4, 18, 19, 20, 22, 24, 12, 25, 26, 28, 29, or 31, or an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identity to the amino acid sequence set forth in SEQ ID NO: 4, 18, 19, 20, 22, 24, 12, 25, 26, 28, 29, or 31; the light chain variable region has an amino acid sequence set forth in SEQ ID NO: 8, 33, 34, 16, 36, 37, or 38, or an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identity to the amino acid sequence set forth in SEQ ID NO: 8, 33, 34, 16, 36, 37, or 38; The anti-CD73 antibody or its antigen-binding portion described in claim 1.

3. the heavy chain variable region sequence is the sequence set forth in SEQ ID NO:4 and the light chain variable region sequence is the sequence set forth in SEQ ID NO:8; or the heavy chain variable region sequence is the sequence set forth in SEQ ID NO: 18 and the light chain variable region sequence is the sequence set forth in SEQ ID NO: 33; or the heavy chain variable region sequence is the sequence set forth in SEQ ID NO: 18 and the light chain variable region sequence is the sequence set forth in SEQ ID NO: 34; or the heavy chain variable region sequence is the sequence set forth in SEQ ID NO: 19 and the light chain variable region sequence is the sequence set forth in SEQ ID NO: 33; or the heavy chain variable region sequence is the sequence set forth in SEQ ID NO: 19 and the light chain variable region sequence is the sequence set forth in SEQ ID NO: 34; or the heavy chain variable region sequence is the sequence set forth in SEQ ID NO:20 and the light chain variable region sequence is the sequence set forth in SEQ ID NO:33; or the heavy chain variable region sequence is the sequence set forth in SEQ ID NO:20 and the light chain variable region sequence is the sequence set forth in SEQ ID NO:34; or the heavy chain variable region sequence is the sequence set forth in SEQ ID NO: 22 and the light chain variable region sequence is the sequence set forth in SEQ ID NO: 33; or the heavy chain variable region sequence is the sequence set forth in SEQ ID NO: 22 and the light chain variable region sequence is the sequence set forth in SEQ ID NO: 34; or the heavy chain variable region sequence is the sequence set forth in SEQ ID NO: 24 and the light chain variable region sequence is the sequence set forth in SEQ ID NO: 33; or the heavy chain variable region sequence is the sequence set forth in SEQ ID NO:24 and the light chain variable region sequence is the sequence set forth in SEQ ID NO:34; or the heavy chain variable region sequence is the sequence set forth in SEQ ID NO: 12 and the light chain variable region sequence is the sequence set forth in SEQ ID NO: 16; or the heavy chain variable region sequence is the sequence set forth in SEQ ID NO:25 and the light chain variable region sequence is the sequence set forth in SEQ ID NO:36; or the heavy chain variable region sequence is the sequence set forth in SEQ ID NO:25 and the light chain variable region sequence is the sequence set forth in SEQ ID NO:37; or the heavy chain variable region sequence is the sequence set forth in SEQ ID NO:25 and the light chain variable region sequence is the sequence set forth in SEQ ID NO:38; or the heavy chain variable region sequence is the sequence set forth in SEQ ID NO: 26 and the light chain variable region sequence is the sequence set forth in SEQ ID NO: 36; or the heavy chain variable region sequence is the sequence set forth in SEQ ID NO:26 and the light chain variable region sequence is the sequence set forth in SEQ ID NO:37; or the heavy chain variable region sequence is the sequence set forth in SEQ ID NO:26 and the light chain variable region sequence is the sequence set forth in SEQ ID NO:38; or the heavy chain variable region sequence is the sequence set forth in SEQ ID NO:28 and the light chain variable region sequence is the sequence set forth in SEQ ID NO:36; or the heavy chain variable region sequence is the sequence set forth in SEQ ID NO:28 and the light chain variable region sequence is the sequence set forth in SEQ ID NO:37; or the heavy chain variable region sequence is the sequence set forth in SEQ ID NO:28 and the light chain variable region sequence is the sequence set forth in SEQ ID NO:38; or the heavy chain variable region sequence is the sequence set forth in SEQ ID NO:29 and the light chain variable region sequence is the sequence set forth in SEQ ID NO:36; or the heavy chain variable region sequence is the sequence set forth in SEQ ID NO:29 and the light chain variable region sequence is the sequence set forth in SEQ ID NO:37; or the heavy chain variable region sequence is the sequence set forth in SEQ ID NO:29 and the light chain variable region sequence is the sequence set forth in SEQ ID NO:38; or the heavy chain variable region sequence is the sequence set forth in SEQ ID NO: 31 and the light chain variable region sequence is the sequence set forth in SEQ ID NO: 36; or the heavy chain variable region sequence is the sequence set forth in SEQ ID NO: 31 and the light chain variable region sequence is the sequence set forth in SEQ ID NO: 37; or The heavy chain variable region sequence is the sequence shown in SEQ ID NO: 31, and the light chain variable region sequence is the sequence shown in SEQ ID NO:

38. The anti-CD73 antibody or its antigen-binding portion according to claim 1 or 2.

4. the anti-CD73 antibody, or antigen-binding portion thereof, binds to human CD73; and / or the anti-CD73 antibody, or antigen-binding portion thereof, has ADCC activity; and / or the anti-CD73 antibody, or antigen-binding portion thereof, has CDC activity; and / or the anti-CD73 antibody is a whole antibody, a single chain antibody (scFv), an scFv-Fc, a bispecific antibody or a multispecific antibody; and / or The antigen-binding portion of the anti-CD73 antibody may be Fab, Fab', Fv, or F(ab'). 2 and / or the anti-CD73 antibody is a murine antibody, a chimeric antibody, a humanized antibody or a fully human antibody, and / or the anti-CD73 antibody is a monoclonal antibody, and / or the anti-CD73 antibody is an IgG1, IgG2, or IgG4 isotype, and / or the anti-CD73 antibody comprises a light chain constant region of the κ or λ isoform; and / or the anti-CD73 antibody comprises a human IgG1 heavy chain constant region and a human kappa light chain constant region; and / or the anti-CD73 antibody comprises a wild-type Fc region, and / or the anti-CD73 antibody comprises an engineered Fc region such that the antibody has reduced ADCC and / or CDC effects; preferably, the antibody has a human IgG1 heavy chain constant region and comprises mutations at one or more of L234, L235, P329, and P331, e.g., one or more of L234A, L235A, P329A, and P331S, wherein residue numbering is according to the EU numbering system; The antibody or antigen-binding portion thereof according to claim 1 or 2.

5. The antibody or antigen-binding portion thereof according to claim 1 or 2, wherein the antibody has a heavy chain variable region shown in SEQ ID NO: 20, a light chain variable region shown in SEQ ID NO: 33, a heavy chain constant region shown in SEQ ID NO: 39, and a light chain constant region shown in SEQ ID NO:

40.

6. The antibody or antigen-binding portion thereof according to claim 1 or 2, wherein the antibody has a heavy chain variable region shown in SEQ ID NO: 31, a light chain variable region shown in SEQ ID NO: 38, a heavy chain constant region shown in SEQ ID NO: 39, and a light chain constant region shown in SEQ ID NO:

40.

7. A gene encoding the anti-CD73 antibody or antigen-binding portion thereof of claim 1. Isolated nucleic acid molecules.

8. 8. The nucleic acid molecule of claim 7, vector.

9. 9. A nucleic acid molecule according to claim 7 or a vector according to claim 8. host cell.

10. 10. The anti-CD73 antibody, or antigen-binding portion thereof, of claim 1 coupled to a therapeutic agent. Antibody-drug conjugates.

11. The antibody-drug conjugate of claim 10 , wherein the therapeutic agent is an anti-tumor drug.

12. The antibody-drug conjugate described in claim 11, wherein the anti-tumor drug is a cytotoxic drug, an immunopotentiator or a radioactive isotope.

13. A pharmaceutical composition comprising the anti-CD73 antibody or antigen-binding portion thereof of claim 1 or 2, or the antibody-drug conjugate of claim 10, and a pharmaceutically acceptable vector.

14. The pharmaceutical composition of claim 13, CD73 (CD73 + 2. A pharmaceutical composition for use in the treatment of tumors expressing IL-1.

15. the tumor is a solid tumor; A pharmaceutical composition for use according to claim 14.

16. the tumor is a malignant tumor; A pharmaceutical composition for use according to claim 14.

17. the tumor is cancer; A pharmaceutical composition for use according to claim 14.

18. The tumor is selected from ovarian cancer, breast cancer, melanoma, colorectal cancer, gastric cancer, kidney cancer, prostate cancer, pancreatic cancer, esophageal cancer, head and neck cancer, thyroid cancer, lung cancer, bladder cancer, cervical cancer, colon cancer, liver cancer, peritoneal cancer, hepatocellular carcinoma, glioblastoma, urinary tract cancer, rectal cancer, endometrial cancer, uterine cancer, salivary gland cancer, squamous cell carcinoma, vulvar cancer, anal cancer, penile cancer, brain cancer, lymphoma, leukemia, and metastases of the above tumors; 18. A pharmaceutical composition for use according to claim 17.

19. The pharmaceutical composition of claim 13, A pharmaceutical composition for use in the treatment of said tumors in combination with an immune checkpoint inhibitor, an A2AR antagonist or a STAT-3 inhibitor.

20. the immune checkpoint inhibitor is an anti-PD-1 antibody, an anti-PD-L1 antibody, or an anti-CTLA4 antibody; 20. A pharmaceutical composition for use according to claim 19.

21. the immune checkpoint inhibitor is an anti-PD-1 antibody; 21. A pharmaceutical composition for use according to claim 20.

22. A composition comprising the anti-CD73 antibody or antigen-binding portion thereof of claim 1 or 2 and a detectable label. Complex.

23. 3. The antibody or antigen-binding portion thereof of claim 1, Fusion proteins.

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