Anti-PD-L1 antigen binding protein and application thereof

1 . An isolated antigen binding protein that binds to PD-L1, comprising a light chain variable region (VL) and a heavy chain variable region (VH), wherein the VL comprises a light chain complementarity determining region (LCDR) 1, LCDR2, and LCDR3, and the VH comprises a heavy chain complementarity determining region (HCDR) 1, HCDR2, and HCDR3, wherein:

the LCDR1 comprises the amino acid sequence set forth in SEQ ID NO: 51, the LCDR2 comprises the amino acid sequence set forth in SEQ ID NO: 64, the LCDR3 comprises the amino acid sequence set forth in SEQ ID NO: 78, the HCDR1 comprises the amino acid sequence set forth in SEQ ID NO: 5, the HCDR2 comprises the amino acid sequence set forth in SEQ ID NO: 16, and the HCDR3 comprises the amino acid sequence set forth in SEQ ID NO: 29;

the LCDR1 comprises the amino acid sequence set forth in SEQ ID NO: 51, the LCDR2 comprises the amino acid sequence set forth in SEQ ID NO: 64, the LCDR3 comprises the amino acid sequence set forth in SEQ ID NO: 78, the HCDR1 comprises the amino acid sequence set forth in SEQ ID NO: 5, the HCDR2 comprises the amino acid sequence set forth in SEQ ID NO: 14, and the HCDR3 comprises the amino acid sequence set forth in SEQ ID NO: 29;

the LCDR1 comprises the amino acid sequence set forth in SEQ ID NO: 51, the LCDR2 comprises the amino acid sequence set forth in SEQ ID NO: 64, the LCDR3 comprises the amino acid sequence set forth in SEQ ID NO: 78, the HCDR1 comprises the amino acid sequence set forth in SEQ ID NO: 5, the HCDR2 comprises the amino acid sequence set forth in SEQ ID NO: 17, and the HCDR3 comprises the amino acid sequence set forth in SEQ ID NO: 29;

the LCDR1 comprises the amino acid sequence set forth in SEQ ID NO: 48; the LCDR2 comprises the amino acid sequence set forth in SEQ ID NO: 63; the LCDR3 comprises the amino acid sequence set forth in SEQ ID NO: 77; the HCDR1 comprises the amino acid sequence set forth in SEQ ID NO: 5; the HCDR2 comprises the amino acid sequence set forth in SEQ ID NO: 14; and the HCDR3 comprises the amino acid sequence set forth in SEQ ID NO: 29;

the LCDR1 comprises the amino acid sequence set forth in SEQ ID NO: 49, the LCDR2 comprises the amino acid sequence set forth in SEQ ID NO: 64, the LCDR3 comprises the amino acid sequence set forth in SEQ ID NO: 78, the HCDR1 comprises the amino acid sequence set forth in SEQ ID NO: 5, the HCDR2 comprises the amino acid sequence set forth in SEQ ID NO: 14, and the HCDR3 comprises the amino acid sequence set forth in SEQ ID NO: 29;

the LCDR1 comprises the amino acid sequence set forth in SEQ ID NO: 48, the LCDR2 comprises the amino acid sequence set forth in SEQ ID NO: 64, the LCDR3 comprises the amino acid sequence set forth in SEQ ID NO: 78, the HCDR1 comprises the amino acid sequence set forth in SEQ ID NO: 5, the HCDR2 comprises the amino acid sequence set forth in SEQ ID NO: 14, and the HCDR3 comprises the amino acid sequence set forth in SEQ ID NO: 30;

the LCDR1 comprises the amino acid sequence set forth in SEQ ID NO: 50, the LCDR2 comprises the amino acid sequence set forth in SEQ ID NO: 63, the LCDR3 comprises the amino acid sequence set forth in SEQ ID NO: 77, the HCDR1 comprises the amino acid sequence set forth in SEQ ID NO: 5, the HCDR2 comprises the amino acid sequence set forth in SEQ ID NO: 14, and the HCDR3 comprises the amino acid sequence set forth in SEQ ID NO: 29;

the LCDR1 comprises the amino acid sequence set forth in SEQ ID NO: 50, the LCDR2 comprises the amino acid sequence set forth in SEQ ID NO: 63, the LCDR3 comprises the amino acid sequence set forth in SEQ ID NO: 79, the HCDR1 comprises the amino acid sequence set forth in SEQ ID NO: 5, the HCDR2 comprises the amino acid sequence set forth in SEQ ID NO: 14, and the HCDR3 comprises the amino acid sequence set forth in SEQ ID NO: 31;

the LCDR1 comprises the amino acid sequence set forth in SEQ ID NO: 51, the LCDR2 comprises the amino acid sequence set forth in SEQ ID NO: 63, the LCDR3 comprises the amino acid sequence set forth in SEQ ID NO: 77, the HCDR1 comprises the amino acid sequence set forth in SEQ ID NO: 5, the HCDR2 comprises the amino acid sequence set forth in SEQ ID NO: 14, and the HCDR3 comprises the amino acid sequence set forth in SEQ ID NO: 32;

the LCDR1 comprises the amino acid sequence set forth in SEQ ID NO: 50, the LCDR2 comprises the amino acid sequence set forth in SEQ ID NO: 64, the LCDR3 comprises the amino acid sequence set forth in SEQ ID NO: 77, the HCDR1 comprises the amino acid sequence set forth in SEQ ID NO: 5, the HCDR2 comprises the amino acid sequence set forth in SEQ ID NO: 14, and the HCDR3 comprises the amino acid sequence set forth in SEQ ID NO: 33;

the LCDR1 comprises the amino acid sequence set forth in SEQ ID NO: 48, the LCDR2 comprises the amino acid sequence set forth in SEQ ID NO: 64, the LCDR3 comprises the amino acid sequence set forth in SEQ ID NO: 78, the HCDR1 comprises the amino acid sequence set forth in SEQ ID NO: 5, the HCDR2 comprises the amino acid sequence set forth in SEQ ID NO: 16, and the HCDR3 comprises the amino acid sequence set forth in SEQ ID NO: 30;

the LCDR1 comprises the amino acid sequence set forth in SEQ ID NO: 48, the LCDR2 comprises the amino acid sequence set forth in SEQ ID NO: 64, the LCDR3 comprises the amino acid sequence set forth in SEQ ID NO: 78, the HCDR1 comprises the amino acid sequence set forth in SEQ ID NO: 5, the HCDR2 comprises the amino acid sequence set forth in SEQ ID NO: 17, and the HCDR3 comprises the amino acid sequence set forth in SEQ ID NO: 30;

the LCDR1 comprises the amino acid sequence set forth in SEQ ID NO: 51, the LCDR2 comprises the amino acid sequence set forth in SEQ ID NO: 63, the LCDR3 comprises the amino acid sequence set forth in SEQ ID NO: 77, the HCDR1 comprises the amino acid sequence set forth in SEQ ID NO: 5, the HCDR2 comprises the amino acid sequence set forth in SEQ ID NO: 16, and the HCDR3 comprises the amino acid sequence set forth in SEQ ID NO: 32;

the LCDR1 comprises the amino acid sequence set forth in SEQ ID NO: 51, the LCDR2 comprises the amino acid sequence set forth in SEQ ID NO: 63, the LCDR3 comprises the amino acid sequence set forth in SEQ ID NO: 77, the HCDR1 comprises the amino acid sequence set forth in SEQ ID NO: 5, the HCDR2 comprises the amino acid sequence set forth in SEQ ID NO: 17, and the HCDR3 comprises the amino acid sequence set forth in SEQ ID NO: 32;

the LCDR1 comprises the amino acid sequence set forth in SEQ ID NO: 50, the LCDR2 comprises the amino acid sequence set forth in SEQ ID NO: 64, the LCDR3 comprises the amino acid sequence set forth in SEQ ID NO: 77, the HCDR1 comprises the amino acid sequence set forth in SEQ ID NO: 5, the HCDR2 comprises the amino acid sequence set forth in SEQ ID NO: 16, and the HCDR3 comprises the amino acid sequence set forth in SEQ ID NO: 33; or

the LCDR1 comprises the amino acid sequence set forth in SEQ ID NO: 50, the LCDR2 comprises the amino acid sequence set forth in SEQ ID NO: 64, the LCDR3 comprises the amino acid sequence set forth in SEQ ID NO: 77, the HCDR1 comprises the amino acid sequence set forth in SEQ ID NO: 5, the HCDR2 comprises the amino acid sequence set forth in SEQ ID NO: 17, and the HCDR3 comprises the amino acid sequence set forth in SEQ ID NO: 33.

2 . The isolated antigen binding protein of claim 1 , wherein

the VH comprises the amino acid sequence set forth in SEQ ID NO: 101, the VL comprises the amino acid sequence set forth in SEQ ID NO: 114;

the VH comprises the amino acid sequence set forth in SEQ ID NO: 90, the VL comprises the amino acid sequence set forth in SEQ ID NO: 114;

the VH comprises the amino acid sequence set forth in SEQ ID NO: 102, the VL comprises the amino acid sequence set forth in SEQ ID NO: 114;

the VH comprises the amino acid sequence set forth in SEQ ID NO: 90; the VL comprises the amino acid sequence set forth in SEQ ID NO: 108;

the VH comprises the amino acid sequence set forth in SEQ ID NO: 90, the VL comprises the amino acid sequence set forth in SEQ ID NO: 109;

the VH comprises the amino acid sequence set forth in SEQ ID NO: 91, the VL comprises the amino acid sequence set forth in SEQ ID NO: 110;

the VH comprises the amino acid sequence set forth in SEQ ID NO: 90, the VL comprises the amino acid sequence set forth in SEQ ID NO: 111;

the VH comprises the amino acid sequence set forth in SEQ ID NO: 92, the VL comprises the amino acid sequence set forth in SEQ ID NO: 112;

the VH comprises the amino acid sequence set forth in SEQ ID NO: 93, the VL comprises the amino acid sequence set forth in SEQ ID NO: 113;

the VH comprises the amino acid sequence set forth in SEQ ID NO: 95, the VL comprises the amino acid sequence set forth in SEQ ID NO: 116;

the VH comprises the amino acid sequence set forth in SEQ ID NO: 97, the VL comprises the amino acid sequence set forth in SEQ ID NO: 118;

the VH comprises the amino acid sequence set forth in SEQ ID NO: 98, the VL comprises the amino acid sequence set forth in SEQ ID NO: 118;

the VH comprises the amino acid sequence set forth in SEQ ID NO: 99, the VL comprises the amino acid sequence set forth in SEQ ID NO: 113;

the VH comprises the amino acid sequence set forth in SEQ ID NO: 100, the VL comprises the amino acid sequence set forth in SEQ ID NO: 113;

the VH comprises the amino acid sequence set forth in SEQ ID NO: 103, the VL comprises the amino acid sequence set forth in SEQ ID NO: 116; or

the VH comprises the amino acid sequence set forth in SEQ ID NO: 104, the VL comprises the amino acid sequence set forth in SEQ ID NO: 116.

3 . The isolated antigen binding protein of claim 1 , having one or more of following properties:

1) capable of binding to PD-L1 derived from a primate with a K D value of 1×10 −8 M or less;

2) capable of blocking the binding of PD-1 to PD-L1;

3) capable of blocking the binding of CD80 to PD-L1;

4) capable of stimulating secretion of IFN-γ and/or IL2 in an immune cell;

5) capable of inhibiting tumor growth and/or tumor cell proliferation;

6) Binding to an epitope of PD-L1 derived from a primate that does not completely overlap with the epitope of a control antibody,

wherein the control antibody comprises a LCDR1 set forth in SEQ ID NO: 52, a LCDR2 set forth in SEQ ID NO: 65 and a LCDR3 set forth in SEQ ID NO: 81, and the control antibody comprises a HCDR1 set forth in SEQ ID NO: 6, a HCDR2 set forth in SEQ ID NO: 15 and a HCDR3 set forth in SEQ ID NO: 34;

wherein the control antibody comprises a LCDR1 set forth in SEQ ID NO: 53, a LCDR2 set forth in SEQ ID NO: 66 and a LCDR3 set forth in SEQ ID NO: 82, and the control antibody comprises a HCDR1 set forth in SEQ ID NO: 5, a HCDR2 set forth in SEQ ID NO: 18 and a HCDR3 set forth in SEQ ID NO: 35;

or

wherein the control antibody comprises a LCDR1 set forth in SEQ ID NO: 55, a LCDR2 set forth in SEQ ID NO: 68 and a LCDR3 set forth in SEQ ID NO: 84, and the control antibody comprises a HCDR1 set forth in SEQ ID NO: 8, a HCDR2 set forth in SEQ ID NO: 20 and a HCDR3 set forth in SEQ ID NO: 37.

4 . A fusion protein, comprising: a) a human TGFBRII or a fragment thereof; and b) the isolated antigen binding protein of claim 1 .

5 . The fusion protein of claim 4 , wherein the isolated antigen binding protein comprises a heavy chain or a fragment thereof comprising the VH, and a light chain or a fragment thereof comprising the VL; and

wherein the fusion protein comprises a first polypeptide and a second polypeptide, the first polypeptide comprising the heavy chain of the isolated antigen binding protein, or the fragment thereof, and the human TGFBRII or the fragment thereof; and the second polypeptide comprising the light chain of the isolated antigen binding protein, or the fragment thereof.

6 . The fusion protein of claim 5 , wherein the heavy chain of the isolated antigen binding protein or the fragment thereof is linked to the human TGFBRII or the fragment thereof via a peptide linker, and wherein the peptide linker comprises the amino acid sequence set forth in any one of SEQ ID NOs: 167-169.

7 . The fusion protein of claim 5 , wherein,

the first polypeptide comprises the amino acid sequence set forth in SEQ ID NO: 143, and the second polypeptide comprises the amino acid sequence set forth in SEQ ID NO: 162;

the first polypeptide comprises the amino acid sequence set forth in SEQ ID NO: 138, and the second polypeptide comprises the amino acid sequence set forth in SEQ ID NO: 162;

the first polypeptide comprises the amino acid sequence set forth in SEQ ID NO: 139, and the second polypeptide comprises the amino acid sequence set forth in SEQ ID NO: 162;

the first polypeptide comprises the amino acid sequence set forth in SEQ ID NO: 142, and the second polypeptide comprises the amino acid sequence set forth in SEQ ID NO: 162;

the first polypeptide comprises the amino acid sequence set forth in SEQ ID NO: 147, and the second polypeptide comprises the amino acid sequence set forth in SEQ ID NO: 162;

the first polypeptide comprises the amino acid sequence set forth in SEQ ID NO: 148, and the second polypeptide comprises the amino acid sequence set forth in SEQ ID NO: 162;

the first polypeptide comprises the amino acid sequence set forth in SEQ ID NO: 145, and the second polypeptide comprises the amino acid sequence set forth in SEQ ID NO: 163; or

the first polypeptide comprises the amino acid sequence set forth in SEQ ID NO: 146, and the second polypeptide comprises the amino acid sequence set forth in SEQ ID NO: 163.

8 . The fusion protein of claim 5 , wherein the heavy chain of the isolated antigen binding protein or the fragment thereof is linked, directly or indirectly, to the N-terminus of the human TGFBRII or the fragment thereof.

9 . The fusion protein of claim 4 , wherein a) is the fragment of the human TGFBRII, which comprises an extracellular domain of the human TGFBRII.

10 . The fusion protein of claim 4 , wherein the human TGFBRII or the fragment thereof comprises the amino acid sequence set forth in any one of SEQ ID NOs: 176-178.

11 . An antibody-drug conjugate, comprising a cytotoxic agent and the isolated antigen binding protein of claim 1 .

12 . A pharmaceutical composition comprising the isolated antigen binding protein of claim 1 or a fusion protein, and a pharmaceutically acceptable carrier, wherein the fusion protein comprises a) a human TGFBRII or a fragment thereof; and b) the isolated antigen binding protein.

13 . The pharmaceutical composition of claim 12 , further comprising one or more components selected from the group consisting of a hormone formulation, a targeted small molecule formulation, a proteasome inhibitor, an imaging agent, a diagnostic agent, a chemotherapeutic agent, an oncolytic medicament, a cytotoxic agent, a cytokine, an activator of co-stimulatory molecule, an inhibitor of inhibitory molecule, and a vaccine.

14 . A method of alleviating or treating a tumor, inhibiting tumor growth and/or inhibiting tumor cell proliferation in a subject in need thereof, comprising administering to the subject the isolated antigen binding protein of claim 1 or a fusion protein, wherein the fusion protein comprises: a) a human TGFBRII or a fragment thereof; and b) the isolated antigen binding protein, and

wherein the tumor is a tumor with abnormal expression of PD-L1.

15 . The method of claim 14 , wherein the tumor is a colorectal tumor.

16 . A method of inhibiting the binding of PD-L1 and/or CD80 with PD-1, comprising contacting immune cells with the isolated antigen binding protein of claim 1 .

17 . The isolated antigen binding protein of claim 1 , wherein the isolated antigen binding protein comprises an antibody heavy chain (HC) comprising the VH and an antibody light chain (LC) comprising the VL, wherein,

the LC comprises the amino acid sequence set forth in SEQ ID NO: 162, and the HC comprises the amino acid sequence set forth in SEQ ID NO: 133;

the LC comprises the amino acid sequence set forth in SEQ ID NO: 162, and the HC comprises the amino acid sequence set forth in SEQ ID NO: 134;

the LC comprises the amino acid sequence set forth in SEQ ID NO: 156, and the HC comprises the amino acid sequence set forth in SEQ ID NO: 122;

the LC comprises the amino acid sequence set forth in SEQ ID NO: 162, and the HC comprises the amino acid sequence set forth in SEQ ID NO: 137;

the LC comprises the amino acid sequence set forth in SEQ ID NO: 150, and the HC comprises the amino acid sequence set forth in SEQ ID NO: 122;

the LC comprises the amino acid sequence set forth in SEQ ID NO: 151, and the HC comprises the amino acid sequence set forth in SEQ ID NO: 122;

the LC comprises the amino acid sequence set forth in SEQ ID NO: 152, and the HC comprises the amino acid sequence set forth in SEQ ID NO: 123;

the LC comprises the amino acid sequence set forth in SEQ ID NO: 153, and the HC comprises the amino acid sequence set forth in SEQ ID NO: 122;

the LC comprises the amino acid sequence set forth in SEQ ID NO: 154, and the HC comprises the amino acid sequence set forth in SEQ ID NO: 124;

the LC comprises the amino acid sequence set forth in SEQ ID NO: 155, and the HC comprises the amino acid sequence set forth in SEQ ID NO: 125;

the LC comprises the amino acid sequence set forth in SEQ ID NO: 158, and the HC comprises the amino acid sequence set forth in SEQ ID NO: 127;

the LC comprises the amino acid sequence set forth in SEQ ID NO: 160, and the HC comprises the amino acid sequence set forth in SEQ ID NO: 129;

the LC comprises the amino acid sequence set forth in SEQ ID NO: 160, and the HC comprises the amino acid sequence set forth in SEQ ID NO: 130;

the LC comprises the amino acid sequence set forth in SEQ ID NO: 161, and the HC comprises the amino acid sequence set forth in SEQ ID NO: 131;

the LC comprises the amino acid sequence set forth in SEQ ID NO: 161, and the HC comprises the amino acid sequence set forth in SEQ ID NO: 132;

the LC comprises the amino acid sequence set forth in SEQ ID NO: 163, and the HC comprises the amino acid sequence set forth in SEQ ID NO: 135; or

the LC comprises the amino acid sequence set forth in SEQ ID NO: 163, and the HC comprises the amino acid sequence set forth in SEQ ID NO: 136.

18 . An isolated nucleic acid molecule encoding the antigen binding protein of claim 1 or a fusion protein comprising a) a human TGFBRII or a fragment thereof; and b) the antigen binding protein.

19 . An antibody that binds to PD-L1, comprising an antibody heavy chain (HC) and an antibody light chain (LC), wherein the LC comprises the amino acid sequence set forth in SEQ ID NO: 162, and the HC comprises the amino acid sequence set forth in SEQ ID NO: 133.

20 . A method of alleviating or treating a tumor in a subject in need there, comprising administering to the subject the antibody of claim 19 , wherein the tumor is the tumor with abnormal expression of PD-L1.