Anti-PD-L1 antibodies
Anti-PD-L1 antibodies are disclosed. Also disclosed are pharmaceutical compositions comprising such antibodies, and methods of using such antibodies to restore T-cell function in T-cells exhibiting T-cell exhaustion or T-cell anergy.
1. An isolated antibody or antigen binding fragment that specifically binds to human PD-L1, having at least one light chain variable region incorporating the following CDRs:
(SEQ ID NO: 18)
LC-CDR1: TGSSSNIGAGYDVH
(SEQ ID NO: 19)
LC-CDR2: GNSNRPS
(SEQ ID NO: 20)
LC-CDR3: QSYDSSLSGSYVV;
and
having at least one heavy chain variable region incorporating the following CDRs:
(SEQ ID NO: 21)
HC-CDR1: SYAIS
(SEQ ID NO: 22)
HC-CDR2: RIIPILGIANYAQKFQG
(SEQ ID NO: 25)
HC-CDR3: SGHGYSYGAFDY.
2. The isolated antibody or antigen binding fragment according to claim 1 , that specifically binds to murine PD-L1.
3. The isolated antibody, or antigen binding fragment, according to claim 1 , that inhibits interaction between human PD-1 and human PD-L1, or inhibits interaction between murine PD-1 and murine PD-L1.
4. The isolated antibody or antigen binding fragment of claim 1 , wherein the antibody is effective to restore T-cell function in T-cells exhibiting T-cell exhaustion or T-cell anergy.
5. The isolated antibody or antigen binding fragment of claim 1 , comprising a heavy chain variable region sequence and a light chain variable region sequence, wherein:
the heavy chain variable region sequence has at least 70% sequence identity to the heavy chain variable region sequence of SEQ ID NO:8 or 35 ( FIG. 2 ), and
the light chain variable region sequence has at least 70% sequence identity to the light chain variable region sequence of SEQ ID NO:4 ( FIG. 1 ).
6. The isolated antibody or antigen binding fragment of claim 1 , which is a bispecific antibody or a bispecific antigen binding fragment comprising (i) an antigen binding fragment according to claim 3 , and (ii) an antigen binding fragment which binds to a target protein other than PD-L1.
7. The isolated antibody or antigen binding fragment of claim 6 , wherein the antigen binding fragment of (ii) specifically binds to one of CD27, CD28, ICOS, CD40, CD122, OX40, 4-1BB, GITR, LAG-3, B7-H3, B7-H4, BTLA, CTLA-4, A2AR, VISTA, TIM-3, PD-1, KIR, HER-2, HER-3, EGFR, EpCAM, CD30, CD33, CD38, CD20, CD24, CD90, CD15, CD52, CA-125, CD34, CA-15-3, CA-19-9, CEA, CD99, CD117, CD31, CD44, CD123, CD133, ABCB5 and CD45.
8. The isolated antibody or antigen binding fragment of claim 1 , comprising a heavy chain variable region sequence and a light chain variable region sequence, wherein:
the heavy chain variable region sequence has at least 85% sequence identity to the heavy chain variable region sequence of SEQ ID NO:8 ( FIG. 2 ), and
the light chain variable region sequence has at least 85% sequence identity to the light chain variable region sequence of SEQ ID NO:4 ( FIG. 1 ).
9. The isolated antibody or antigen binding fragment of claim 1 , comprising a heavy chain variable region sequence and a light chain variable region sequence, wherein:
the heavy chain variable region sequence has at least 85% sequence identity to the heavy chain variable region sequence of SEQ ID NO:35 ( FIG. 2 ), and
the light chain variable region sequence has at least 85% sequence identity to the light chain variable region sequence of SEQ ID NO:4 ( FIG. 1 ).
10. The isolated antigen binding fragment of claim 1 , wherein the antigen binding fragment is a Fab fragment or scFv fragment.
11. The isolated antibody of claim 1 , wherein the antibody comprises a human constant region selected from IgG1, IgG2, IgG3 and IgG4.
12. A method of treating an infectious disease, comprising administering an antibody or antigen binding fragment to a patient suffering from the infectious disease, wherein the antibody or antigen binding fragment specifically binds to human PD-L1, and comprises:
at least one light chain variable region incorporating the following CDRs:
(SEQ ID NO: 18)
LC-CDR1: TGSSSNIGAGYDVH
(SEQ ID NO: 19)
LC-CDR2: GNSNRPS
(SEQ ID NO: 20)
LC-CDR3: QSYDSSLSGSYVV;
and
at least one heavy chain variable region incorporating the following CDRs:
(SEQ ID NO: 21)
HC-CDR1: SYAIS
(SEQ ID NO: 22)
HC-CDR2: RIIPILGIANYAQKFQG
(SEQ ID NO: 25)
HC-CDR3: SGHGYSYGAFDY,
wherein the infectious disease is influenza.