Modified antibodies

Abstract

Provided herein are modified antibodies, pharmaceutical compositions thereof, as well as nucleic acids, and methods for making and discovering the same. The modified antibodies described herein are modified with a peptide. The peptide binds at or near the antigen binding site of the antibody at physiological pH, thus reducing binding affinity of the antibody for a target antigen. At acidic pH, the binding interaction of the peptide at or near the antigen binding site is disrupted, thus enabling binding with a target antigen.

1 . A modified antibody comprising a formula:
   A-L-P   
       wherein
 A is an antibody or antibody fragment that binds to a target antigen, 
 P is a peptide that reduces binding of A to the target antigen at physiological pH and that does not reduce binding of A to the target antigen at acidic pH, and 
 L is a linking moiety that connects A to P at physiological pH and in a tumor microenvironment and L is bound to A outside an antigen binding site. 
 
     
     
         2 . (canceled) 
     
     
         3 . The modified antibody of  claim 1 , wherein at physiological pH P is reversibly bound to A at or near the antigen binding site. 
     
     
         4 . The modified antibody of  claim 1 , wherein P inhibits the binding of A to the target antigen at physiological pH and P does not inhibit the binding of A to the target antigen at acidic pH. 
     
     
         5 . The modified antibody of  claim 1 , wherein in tissue other than the tumor microenvironment, P sterically blocks A from binding to the target antigen. 
     
     
         6 . (canceled) 
     
     
         7 . The modified antibody of  claim 1 , wherein the modified antibody has an increased binding affinity for the target antigen in the tumor microenvironment compared to the binding affinity of the modified antibody for the target antigen in a non-tumor microenvironment. 
     
     
         8 . The modified antibody of  claim 1 , wherein P comprises a peptide sequence with at least one histidine. 
     
     
         9 . The modified antibody of  claim 8 , wherein the histidine forms a binding interaction at or near the antigen binding site of A at physiological pH. 
     
     
         10 .- 19 . (canceled) 
     
     
         20 . The modified antibody of  claim 8 , wherein at acidic pH P is reversibly bound to L. 
     
     
         21 . The modified antibody of  claim 20 , wherein L comprises a peptide sequence with at least one aspartic acid or glutamic acid, or a combination thereof. 
     
     
         22 . The modified antibody of  claim 21 , wherein the histidine of P forms an interaction with the aspartic acid or glutamic acid of L. 
     
     
         23 .- 39 . (canceled) 
     
     
         40 . The modified antibody of  claim 1 , wherein A is a full length antibody, a single-chain antibody, an Fab fragment, an Fab′ fragment, an (Fab′)2 fragment, an Fv fragment, a divalent single chain antibody, bispecific antibody, a trispecific antibody, a tetraspecific antibody, or an antibody drug conjugate. 
     
     
         41 .- 49 . (canceled) 
     
     
         50 . The modified antibody of  claim 1 , wherein the target antigen is CTLA4 and P comprises an amino acid sequence selected from the group consisting of Peptide 1, Peptide 2, Peptide 5, Peptide 6, Peptide 10, Peptide 13, Peptide 26, Peptide 14, and Peptide 15. 
     
     
         51 .- 60 . (canceled) 
     
     
         61 . The modified antibody of  claim 1 , wherein the target antigen is PD-L1 and P comprises an amino acid sequence selected from the group consisting of Peptide 20, Peptide 27, Peptide 21, Peptide 22, Peptide 23, Peptide 28, Peptide 29, Peptide 30, Peptide 31, and Peptide 24. 
     
     
         62 .- 76 . (canceled) 
     
     
         77 . The modified antibody of  claim 1 , wherein P comprises a peptide sequence with at least two histidines. 
     
     
         78 . (canceled) 
     
     
         79 . The modified antibody of  claim 77 , wherein P comprises a peptide sequence with at least two histidines and at least two cysteines. 
     
     
         80 . The modified antibody of  claim 1 , wherein P comprises a peptide sequence with at least two charged amino acid residues wherein the charged amino acid residues are selected from the group consisting of aspartate, glutamate, and histidine. 
     
     
         81 . (canceled) 
     
     
         82 . The modified antibody of  claim 1 , wherein P comprises a peptide sequence with at least three charged amino acid residues wherein the charged amino acid residues are selected from the group consisting of aspartate, glutamate, and histidine. 
     
     
         83 . (canceled) 
     
     
         84 . The modified antibody of  claim 82 , wherein P comprises a peptide sequence with at least one histidine and at least two aspartates. 
     
     
         85 . The modified antibody of  claim 1 , wherein P comprises a peptide sequence with at least one cysteine. 
     
     
         86 . (canceled) 
     
     
         87 . The modified antibody of  claim 1 , wherein P comprises a peptide sequence with at least two cysteine amino acid residues. 
     
     
         88 . (canceled) 
     
     
         89 . The modified antibody of  claim 87 , wherein P comprises a peptide sequence with at least two cysteines and at least three charged amino acid residues wherein the charged amino acid residues are selected from the group consisting of aspartate, glutamate, and histidine. 
     
     
         90 .- 93 . (canceled) 
     
     
         94 . The modified antibody of  claim 1 , wherein P does not comprise a lysine or arginine. 
     
     
         95 . The modified antibody of  claim 1 , wherein P comprises at least one histidine and at least one aspartate. 
     
     
         96 . The modified antibody of  claim 1 , wherein P comprises at least one histidine and at least one glutamate. 
     
     
         97 . The modified antibody of  claim 1 , wherein P comprises at least one histidine and at least two glutamates. 
     
     
         98 . The modified antibody of  claim 1 , wherein P comprises at least two histidines and at least one aspartate or at least one glutamate. 
     
     
         99 . The modified antibody of  claim 1 , wherein P comprises at least one histidine, wherein at least one hydrogen bonding amino acid residue is within two amino acid positions to the histidine, wherein the hydrogen bonding amino acid residue is selected from the group consisting of serine, threonine, tyrosine, asparagine, and glutamine. 
     
     
         100 .- 105 . (canceled) 
     
     
         106 . The modified antibody of  claim 1 , wherein A-L-P does not comprise a protease cleavage site that releases A from P in a tumor microenvironment. 
     
     
         107 . The modified antibody of  claim 1 , wherein L comprises a peptide sequence with at least one histidine. 
     
     
         108 . The modified antibody of  claim 107 , wherein at acidic pH L is reversibly bound to P. 
     
     
         109 . The modified antibody of  claim 108 , wherein P comprises a peptide sequence with at least one aspartic acid or glutamic acid, or a combination thereof. 
     
     
         110 . The modified antibody of  claim 109 , wherein the histidine of L forms an interaction with the aspartic acid or glutamic acid of P. 
     
     
         111 . A pharmaceutical composition, comprising:
 (a) a modified antibody according to  claim 1 ; and   (b) a pharmaceutically acceptable excipient.