FUSION PROTEINS COMPRISING A BINDING PROTEIN AND AN INTERLEUKIN-15 POLYPEPTIDE HAVING A REDUCED AFFINITY FOR IL15Ra AND THERAPEUTIC USES THEREOF

Abstract

The present invention relates to fusion proteins comprising a binding protein and an IL-15 polypeptide as well as uses thereof, pharmaceutical compositions comprising such fusion proteins and a method for producing such fusion proteins.

1 . A fusion protein comprising
 a) a binding protein comprising at least one binding site, wherein the binding site binds to an antigen associated with a target cell and wherein the binding protein is selected from the group consisting of: an antibody, a divalent antibody fragment, and a monovalent antibody fragment; and   b) an IL-15 polypeptide, wherein the IL-15 polypeptide is a fragment having an amino acid sequence as shown in SEQ ID NO: 4 having at least one amino acid substitution selected from the group consisting of E46K, V49D and I50D or a mutant of the fragment having an amino acid sequence being at least 90% identical to SEQ ID NO: 1 having at least one amino acid substitution selected from the group consisting of E46K, V49D and I50D;   thereby having a reduced affinity for IL-15Rα compared to the affinity of wild-type IL-15 of SEQ ID NO: 1 (Uniprot number: P40933-1); and   wherein the fragment and/or the mutant further has the capability of binding to IL-2/IL-15Rβγ.   
     
     
         2 . (canceled) 
     
     
         3 . The fusion protein of  claim 1 , wherein the divalent antibody fragment is an (Fab)2′-fragment, a divalent single-chain Fv fragment, a bsFc-1/2-dimer or a bsFc-CH3-1/2 dimer. 
     
     
         4 . The fusion protein of  claim 1 , wherein the monovalent antibody fragment is selected from the group consisting of a Fab fragment, a Fv fragment, a single-chain Fv fragment (scFv) or an scFv-Fc fragment. 
     
     
         5 . (canceled) 
     
     
         6 . The fusion protein of  claim 1 , wherein the binding protein is modified such that it has an enhanced antibody dependent cellular cytotoxicity (ADCC)-activity compared to the unmodified binding protein. 
     
     
         7 . The fusion protein of  claim 6 , wherein the modified binding protein is Fc optimized. 
     
     
         8 . The fusion protein of  claim 7 , wherein the modified binding protein is an antibody, a scFv-Fc fragment, a bsFc-1/2 dimer or a bsFc-CH3-1/2 dimer. 
     
     
         9 . The fusion protein of  claim 7 , wherein the Fc-optimization comprises an amino acid substitution, which is selected from F243L and/or D270E and/or R292P and/or S298A and/or S298N and/or Y300L and/or 305I and/or A330V and/or A330L and/or I332E and/or E333A and/or K334A and/or P396L and/or S239D, wherein the positional numbering is according to the EU index. 
     
     
         10 - 17 . (canceled) 
     
     
         18 . The fusion protein of  claim 1 , wherein the target cell is a tumor/cancer cell and/or a B cell. 
     
     
         19 - 25 . (canceled) 
     
     
         26 . The fusion protein of  claim 1 , wherein the mutant of the fragment has an amino acid sequence being at least 90% identical to SEQ ID NO: 4 having at least one amino acid substitution selected from the group consisting of E46K, V49D and I50D. 
     
     
         27 . (canceled) 
     
     
         28 . (canceled) 
     
     
         29 . The fusion protein of  claim 1 , wherein the IL-2/IL-15Rβγ is expressed by an effector cell. 
     
     
         30 . (canceled) 
     
     
         31 . The fusion protein of  claim 29 , wherein the effector cell is a NK cell or a T-cell. 
     
     
         32 . The fusion protein of  claim 1 , wherein the fusion protein further comprises a linker. 
     
     
         33 . The fusion protein of  claim 32 , wherein the linker comprises glycine and serine. 
     
     
         34 . (canceled) 
     
     
         35 . The fusion protein of  claim 33 , wherein the linker comprises the amino acid sequence GGGGSGGGGSGGGGSGGGGS ((4-glycine 1-serine)4) (SEQ ID NO: 24). 
     
     
         36 . The fusion protein of  claim 32 , wherein the IL-15 polypeptide is linked to the CH3 domain of the binding protein via the linker. 
     
     
         37 - 50 . (canceled) 
     
     
         51 . A nucleic acid molecule encoding for the fusion protein of  claim 1 . 
     
     
         52 . The nucleic acid molecule of  claim 51  comprised in a vector. 
     
     
         53 . A host cell comprising the nucleic acid molecule of  claim 51 . 
     
     
         54 . (canceled) 
     
     
         55 . (canceled) 
     
     
         56 . A method of treating a disease in a subject in need thereof, the method comprising administering a therapeutically effective amount of the fusion protein as defined in  claim 1  to the subject. 
     
     
         57 . The method of  claim 56 , wherein the disease is a proliferatory or autoimmune disease. 
     
     
         58 - 61 . (canceled) 
     
     
         62 . A method for reducing unspecific target cell activation in therapy in a subject in need thereof, the method comprising administering to the subject a fusion protein of  claim 1 . 
     
     
         63 . A method for reducing a side effect in therapy in a subject in need thereof, the method comprising administering to the subject a fusion protein of  claim 1 . 
     
     
         64 . (canceled) 
     
     
         65 . (canceled) 
     
     
         66 . The fusion protein of  claim 1 , wherein the amino acid substitution is E46K. 
     
     
         67 . The fusion protein of  claim 1 , wherein the amino acid substitution is V49D. 
     
     
         68 . The fusion protein of  claim 1 , wherein the amino acid substitution is I50D.