Recombinant binding proteins targeting her2 and serum albumin, and their uses

Abstract

New recombinant binding proteins, comprising designed ankyrin repeat domain(s) with binding specificity for HER2, and comprising designed ankyrin repeat domain(s) with binding specificity for serum albumin, are disclosed, as well as nucleic acids encoding such recombinant binding proteins, pharmaceutical compositions comprising such recombinant binding proteins or nucleic acids and the use of such recombinant binding proteins, nucleic acids or pharmaceutical compositions in the treatment of diseases.

1 - 20 . (canceled) 
     
     
         21 . A recombinant binding protein comprising two ankyrin repeat domains with binding specificity for Human Epidermal Growth Factor Receptor 2 (HER2) and two ankyrin repeat domains with binding specificity for human serum albumin, wherein said recombinant binding protein is capable of binding HER2 and human serum albumin simultaneously. 
     
     
         22 . The recombinant binding protein of  claim 21 , wherein each of said two ankyrin repeat domains with binding specificity for human serum albumin independently comprises an amino acid sequence that has at least 90% amino acid sequence identity with SEQ ID NO: 14. 
     
     
         23 . The recombinant binding protein of  claim 21 , wherein said two ankyrin repeat domains with binding specificity for serum albumin are able to simultaneously bind one human serum albumin molecule each. 
     
     
         24 . The recombinant binding protein of  claim 21 , wherein one of said two ankyrin repeat domains with binding specificity for HER2 comprises an amino acid sequence that has at least 90% amino acid sequence identity with SEQ ID NO: 16. 
     
     
         25 . The recombinant binding protein of  claim 21 , wherein one of said two ankyrin repeat domains with binding specificity for HER2 comprises an amino acid sequence that has at least 90% amino acid sequence identity with SEQ ID NO: 17. 
     
     
         26 . The recombinant binding protein of  claim 21 , wherein one of said two ankyrin repeat domains with binding specificity for HER2 comprises an amino acid sequence that has at least 90% amino acid sequence identity with SEQ ID NO: 16, and wherein one of said two ankyrin repeat domains with binding specificity for HER2 comprises an amino acid sequence that has at least 90% amino acid sequence identity with SEQ ID NO: 17. 
     
     
         27 . The recombinant binding protein of  claim 21 , wherein said ankyrin repeat domains are linked by polypeptide linkers. 
     
     
         28 . The recombinant binding protein of  claim 21 , wherein said ankyrin repeat domains are ordered, from N-terminus to C-terminus: ankyrin repeat domain with binding specificity for serum albumin-ankyrin repeat domain with binding specificity for HER2-ankyrin repeat domain with binding specificity for HER2-ankyrin repeat domain with binding specificity for serum albumin. 
     
     
         29 . The recombinant binding protein of  claim 28 , wherein the more N-terminal ankyrin repeat domain with binding specificity for HER2 binds to domain II of HER2 and the more C-terminal ankyrin repeat domain with binding specificity for HER2 binds to domain IV of HER2. 
     
     
         30 . A recombinant protein comprising a binding domain with binding specificity for HER2 and a binding domain with binding specificity for human serum albumin, wherein said binding domain with binding specificity for HER2 comprises an amino acid sequence with at least 90% amino acid sequence identity with SEQ ID NO:16, and wherein said binding domain with binding specificity for human serum albumin comprises an amino acid sequence with at least 90% amino acid sequence identity with SEQ ID NO: 14. 
     
     
         31 . The recombinant protein of  claim 30 , wherein said recombinant protein comprises an amino acid sequence that has at least 90% amino acid sequence identity with SEQ ID NO: 21. 
     
     
         32 . The recombinant protein of  claim 30 , wherein said recombinant protein is capable of binding HER2 and human serum albumin simultaneously. 
     
     
         33 . The recombinant protein of  claim 30 , wherein said recombinant protein binds human serum albumin with a dissociation constant (KD) of or below about 100 nM. 
     
     
         34 . The recombinant protein of  claim 30 , wherein said recombinant protein binds human HER2 with a dissociation constant (KD) of or below about 100 nM. 
     
     
         35 . The recombinant protein of  claim 30 , wherein said recombinant protein has a terminal half-life in mice of at least about 25 hours. 
     
     
         36 . A recombinant protein comprising an amino acid sequence that has at least 92% amino acid sequence identity with SEQ ID NO: 21, wherein said protein has binding specificity for HER2 and for human serum albumin. 
     
     
         37 . A nucleic acid encoding the recombinant binding protein of  claim 36 . 
     
     
         38 . A pharmaceutical composition comprising the recombinant protein of  claim 36  and a pharmaceutically acceptable carrier and/or diluent. 
     
     
         39 . A method of treating a disease in a subject in need of such treatment, the method comprising administering a therapeutically effective amount of the recombinant protein of  claim 36  to said subject, wherein the disease is a HER2 expressing cancer. 
     
     
         40 . A method for producing the recombinant binding protein of  claim 21 , the method comprising the steps of (i) expressing said recombinant binding protein in bacteria, and (ii) purifying said recombinant binding protein using chromatography.