Anti-serum albumin biding variable domains

Abstract

The invention relates to improved anti-serum albumin immunoglobulin single variable domains, as well as ligands and drug conjugates comprising such variable domains, compositions, nucleic acids, vectors and hosts.

1 . An anti-serum albumin (SA) immunoglobulin single variable domain comprising an amino acid sequence that is at least 80% identical to an amino acid sequence selected from SEQ ID NOs: 97 to 191 and 198 to 203. 
     
     
         2 . An anti-serum albumin (SA) immunoglobulin single variable domain comprising an amino acid sequence having up to 4 amino acid changes compared to an amino acid sequence selected from SEQ ID NOs: 97 to 191 and 198 to 203. 
     
     
         3 . An anti-serum albumin (SA) immunoglobulin single variable domain comprising an amino acid sequence that is encoded by a nucleotide sequence which is at least 80% identical to a sequence selected from SEQ ID NOs 1 to 96 and 192 to 197. 
     
     
         4 . The variable domain of  claim 1 , wherein the variable domain comprises the amino acid sequence of any one of SEQ ID NOs: 97 to 103 and 198 to 203. 
     
     
         5 . The variable domain of  claim 1 , comprising a binding site that specifically binds human SA with a dissociation constant (KD) of from about 0.1 to about 10000 nM, optionally from about 1 to about 6000 nM, as determined by surface plasmon resonance. 
     
     
         6 . The variable domain of  claim 1 , comprising a binding site that specifically binds human SA with an off-rate constant (K d ) of from about 1.5×10 −4  to about 0.1 sec −1 , optionally from about 3×10 −4  to about 0.1 sec as determined by surface plasmon resonance. 
     
     
         7 . The variable domain of  claim 1 , comprising a binding site that specifically binds human SA with an on-rate constant (K a ) of from about 2×10 6  to about 1×10 4  M −1 sec −1 , optionally from about 1×10 6  to about 2×10 4 M −1 sec −1  as determined by surface plasmon resonance. 
     
     
         8 . The variable domain of  claim 1 , comprising a binding site that specifically binds  Cynomolgus  monkey SA with a dissociation constant (KD) of from about 0.1 to about 10000 nM, optionally from about 1 to about 6000 nM, as determined by surface plasmon resonance. 
     
     
         9 . The variable domain of  claim 1 , comprising a binding site that specifically binds  Cynomolgus  monkey SA with an off-rate constant (K d ) of from about 1.5×10 −4  to about 0.1 sec −1 , optionally from about 3×10 −4  to about 0.1 sec −1  as determined by surface plasmon resonance. 
     
     
         10 . The variable domain of  claim 1 , comprising a binding site that specifically binds  Cynomolgus  monkey SA with an on-rate constant (K a ) of from about 2×10 6  to about 1×10 4 M −1 sec −1 , optionally from about 1×10 6  to about 5×10 3 M −1 sec −1  as determined by surface plasmon resonance. 
     
     
         11 . The variable domain of  claim 1 , wherein the variable domain has a melting temperature (Tm) of at least 55 degrees centigrade, optionally 55≦Tm≦75 degrees centigrade, as determined by DSC (differential scanning calorimetry). 
     
     
         12 . The variable domain of  claim 1 , wherein the variable domain is substantially monomeric as determined by SEC-MALLS (size exclusion chromatography with multi-angle-LASER-light-scattering). 
     
     
         13 . A multispecific ligand comprising an anti-SA variable domain of  claim 1  and a binding moiety that specifically binds a target antigen other than SA, optionally wherein the binding moiety is an TNFR1 antagonist. 
     
     
         14 . An anti-SA single variable domain of  claim 1 , wherein the variable domain is conjugated to a drug (optionally an NCE drug). 
     
     
         15 . A fusion protein comprising a polypeptide or peptide drug fused to a variable domain according to  claim 1 . 
     
     
         16 . A composition comprising a variable domain, fusion protein or ligand of  claim 1  and a pharmaceutically acceptable diluent, carrier, excipient or vehicle. 
     
     
         17 . A nucleic acid comprising a nucleotide sequence encoding a variable domain according to  claim 1 . 
     
     
         18 . A vector comprising the nucleic acid of  claim 17 . 
     
     
         19 . An isolated host cell comprising the vector of  claim 18 . 
     
     
         20 . A method of treating or preventing a disease or disorder in a patient, comprising administering at least one dose of a variable domain according to  claim 1 .