Fc binding fragments comprising a pd-l1 antigen-binding site

Abstract

The application relates to specific binding members which bind to programmed death-ligand 1 (PD-L1). The specific binding members preferably comprise a PD-L1 antigen-binding site located in structural loops of a constant domain of the specific binding member. The specific binding members find application, for example, in the treatment of cancer, as well as infectious diseases, inflammation, diseases and conditions associated with inflammation, and inflammatory diseases.

1 . An antibody molecule, or fragment thereof, which binds to programmed death-ligand 1 (PD-L1), comprising a PD-L1 antigen-binding site located in a CH3 domain of the antibody molecule, or fragment thereof, wherein the PD-L1 binding site comprises:
 (i) a first sequence located in the AB structural loop at positions 14 to 18 of the CH3 domain, wherein the antibody molecule, or fragment thereof, comprises an amino acid deletion at position 14, 15 or 16 of the CH3 domain, and wherein the first sequence consists of:   (a) amino acid sequence SGYW (SEQ ID NO: 23), or   (b) a variant of SEQ ID NO: 23, wherein   the serine (S) is substituted with amino acid A, E, F, G, H, I, L, P, R, T, V, or Y, and/or   the glycine (G) is substituted with amino acid A, D, E, F, H, K, L, N, P, R, T, V, or Y;   (ii) a second sequence located in the CD structural loop at positions 45.1 to 78 of the CH3 domain, wherein the second sequence consists of:   (a) amino acid sequence EPQYWA (SEQ ID NO: 11), or   (b) a variant of SEQ ID NO: 11, wherein   the glutamic acid (E) is substituted with amino acid A, G, H, I, L, N, Q, R, S, or W, and/or   the proline (P) is substituted with amino acid A, D, E, G, H, N, Q, W, or Y, and/or   the glutamine (Q) is substituted with amino acid H, or N, and/or   the tyrosine (Y) is substituted with amino acid A, D, H, T, or V, and/or   the alanine (A) is substituted with amino acid D, E, G, L, R, S, or W; and   (iii) a third sequence located in the EF structural loop at positions 92 to 100 of the CH3 domain, wherein the third sequence consists of:   (a) amino acid sequence SNWRWQMDD (SEQ ID NO: 19), or   (b) a variant of SEQ ID NO: 19, wherein   the serine (S) at position 92 is substituted with amino acid A, or G, and/or   the asparagine (N) at position 93 is substituted with amino acid A, E, F, G, H, I, K, L, Q, R, S, T, or Y, and/or   the glutamine (Q) at position 97 is substituted with amino acid A, D, E, F, G, H, K, L, N, R, S, or V, and/or   the methionine (M) at position 98 is substituted with amino acid F, I, L, V, W, or Y, and/or   the aspartic acid (D) at position 99 is substituted with amino acid A, I, L, R, S, T, V, W, Y, or G, and/or   the aspartic acid (D) at position 100 is substituted with amino acid A, E, F, I, K, L, N, R, V, W, or Y; and   wherein the amino acid at position 101 of the CH3 domain is valine (V), alanine (A) or is absent;   wherein the amino acid residue numbering is according to the ImMunoGeneTics (IMGT) numbering scheme; and   wherein the antibody molecule, or antigen-binding fragment thereof, is not an antibody molecule, or antigen-binding fragment thereof, which comprises a CDR-based antigen-binding site which binds Inducible T-cell COStimulator (ICOS) and a PD-L1 binding site comprising a first sequence located in the AB structural loop at positions 14 to 18 of the CH3 domain, wherein the antibody molecule, or antigen-binding fragment thereof, comprises an amino acid deletion at position 14, 15 or 16 of the CH3 domain, and wherein the first sequence consists of the sequence set forth in SEQ ID NO: 23, a second sequence located in the CD structural loop at positions 45.1 to 78 of the CH3 domain, wherein the second sequence consists of the sequence set forth in SEQ ID NO: 11, and a third sequence located in the EF structural loop at positions 92 to 100 of the CH3 domain, wherein the third sequence consists of the sequence set forth in SEQ ID NO: 31.   
     
     
         2 .- 4 . (canceled) 
     
     
         5 . The antibody molecule, or fragment thereof, according to  claim 1 , wherein:
 (i) the first sequence has the sequence set forth in SEQ ID NO: 23, the second sequence has the sequence set forth in SEQ ID NO: 11, and the third sequence has the sequence set forth in SEQ ID NO: 19;   (ii) the first sequence has the sequence set forth in SEQ ID NO: 23, the second sequence has the sequence set forth in SEQ ID NO: 11, and the third sequence has the sequence set forth in SEQ ID NO: 27;   (iii) the first sequence has the sequence set forth in SEQ ID NO: 23, the second sequence has the sequence set forth in SEQ ID NO: 11, and the third sequence has the sequence set forth in SEQ ID NO: 35; or   (iv) the first sequence has the sequence set forth in SEQ ID NO: 23, the second sequence has the sequence set forth in SEQ ID NO: 11, and the third sequence has the sequence set forth in SEQ ID NO: 31, and the residue at position 38 of the CH3 domain of the antibody molecule, or fragment thereof, is valine (V) or alanine (A).   
     
     
         6 .- 11 . (canceled) 
     
     
         12 . The antibody molecule, or fragment thereof, according to  claim 5 , wherein the first sequence has the sequence set forth in SEQ ID NO: 23, the second sequence has the sequence set forth in SEQ ID NO: 11, and the third sequence has the sequence set forth in SEQ ID NO: 19. 
     
     
         13 . The antibody molecule, or fragment thereof, according to  claim 5 , wherein the first sequence has the sequence set forth in SEQ ID NO: 23, the second sequence has the sequence set forth in SEQ ID NO: 11, and the third sequence has the sequence set forth in SEQ ID NO: 27. 
     
     
         14 . The antibody molecule, or fragment thereof, according to  claim 5 , wherein the first sequence has the sequence set forth in SEQ ID NO: 23, the second sequence has the sequence set forth in SEQ ID NO: 11, and the third sequence has the sequence set forth in SEQ ID NO: 35. 
     
     
         15 . (canceled) 
     
     
         16 . The antibody molecule, or fragment thereof, according to  claim 1 , wherein the CH3 domain is a human IgG1 CH3 domain. 
     
     
         17 . The antibody molecule, or fragment thereof, according to  claim 1 , wherein the amino acid at position 38 of the CH3 domain is a valine or an alanine residue. 
     
     
         18 . The antibody molecule, or fragment thereof, according to  claim 1 , wherein the amino acid at position 38 of the CH3 domain is an alanine residue. 
     
     
         19 . The antibody molecule, or fragment thereof, according to  claim 1 , wherein the antibody molecule, or fragment thereof, comprises the CH3 domain set forth in SEQ ID NO: 24, 28, 36, or 39. 
     
     
         20 . (canceled) 
     
     
         21 . The antibody molecule, or fragment thereof, according to  claim 19 , wherein the antibody molecule, or fragment thereof, further comprises a CH2 domain. 
     
     
         22 .- 23 . (canceled) 
     
     
         24 . The antibody molecule, or fragment thereof, according to  claim 21 , wherein the CH2 domain has the sequence set forth in SEQ ID NO: 5, 6, or 82. 
     
     
         25 . The antibody molecule, or fragment thereof, according to  claim 21 , wherein the antibody molecule, or fragment thereof, further comprises an immunoglobulin hinge region, or part thereof, at the N-terminus of the CH2 domain. 
     
     
         26 .- 27 . (canceled) 
     
     
         28 . The antibody molecule, or fragment thereof, according to  claim 25 , wherein the hinge region comprises or consists of the sequence set forth in SEQ ID NO: 7. 
     
     
         29 . The antibody molecule, or fragment thereof, according to  claim 25 , wherein the antibody molecule, or fragment thereof, comprises or consists of the sequence set forth in SEQ ID NO: 25, 26, 29, 30, 37, 38, 40, or 41. 
     
     
         30 . (canceled) 
     
     
         31 . The antibody molecule, or fragment thereof, according to  claim 1 , wherein the antibody molecule, or fragment thereof, further comprises a second antigen-binding site. 
     
     
         32 . The antibody molecule, or fragment thereof, according to  claim 5 , wherein the antibody molecule, or fragment thereof, further comprises a second antigen-binding site, wherein the second antigen-binding site is a CDR-based antigen-binding site. 
     
     
         33 .- 35 . (canceled) 
     
     
         36 . The antibody molecule, or fragment thereof, according to  claim 32 , wherein the CDR-based antigen-binding site binds to a checkpoint inhibitor, costimulatory molecule, or tumour-associated antigen. 
     
     
         37 .- 39 . (canceled) 
     
     
         40 . The antibody molecule, or fragment thereof, according to  claim 31 , wherein the second antigen-binding site is a CDR-based antigen-binding site, and wherein the antibody molecule, or fragment thereof, is conjugated to an immune system modulator, cytotoxic molecule, radioisotope, or detectable label. 
     
     
         41 .- 55 . (canceled) 
     
     
         56 . The antibody molecule, or fragment thereof, according to  claim 5 , wherein the first sequence has the sequence set forth in SEQ ID NO: 23, the second sequence has the sequence set forth in SEQ ID NO: 11, and the third sequence has the sequence set forth in SEQ ID NO: 31, and the residue at position 38 of the CH3 domain of the antibody molecule, or fragment thereof, is valine (V) or alanine (A). 
     
     
         57 . The antibody molecule, or fragment thereof, according to  claim 19 , wherein the lysine residue (K) at the immediate C-terminus of the sequence shown in SEQ ID NO: 24, 28, 36, or 39 has been deleted.