The IgM and IgE Heavy Chain Domain 2 as Covalently Linked Homodimerization Modules for the Generation of Fusion Proteins with Dual Specificity

Abstract

The present invention provides a polypeptides comprising a heavy chain domain 2 (HD2) from IgM or IgE and at least one pharmaceutically active moiety, complexes thereof and their use for therapy and prophylaxis.

1 . A polypeptide comprising a heavy chain domain 2 (HD2) from IgM or IgE and at least one pharmaceutically active moiety, under the proviso that the pharmaceutically active moiety is not a Fab or Fc fragment from IgM or IgE. 
     
     
         2 . The polypeptide of  claim 1 , wherein the HD2 domain comprises an amino acid sequence according to SEQ ID NO: 1 or SEQ ID NO:2 or dimerizing variants thereof. 
     
     
         3 . The polypeptide of  claim 1 , wherein at least one pharmaceutically active moiety is connected to the N- and/or C-Terminus of the HD2. 
     
     
         4 . The polypeptide of  claim 1 , wherein at least one pharmaceutically active moiety is connected to the HD2 directly or indirectly via one or more linkers. 
     
     
         5 . The polypeptide of  claim 4 , wherein the one or more linkers comprise peptide linkers. 
     
     
         6 . The polypeptide of  claim 5 , wherein the one or more linkers comprise one or more cleavage sites. 
     
     
         7 . The polypeptide of  claim 1 , wherein at least two identical or at least two different pharmaceutically active moieties are connected to the HD2. 
     
     
         8 . The polypeptide of  claim 1 , wherein at least one pharmaceutically active moiety is selected from the group consisting of ligands, effector molecules, half-life extension modules, and imaging molecules. 
     
     
         9 . The polypeptide of  claim 8 , wherein the at least one pharmaceutically active moiety is a ligand, wherein the ligand is selected from the group consisting of antigen-binding molecules, scaffold proteins, natural ligands, ligand-binding receptor fragments, and apatamers. 
     
     
         10 . The polypeptide of  claim 9 , wherein the ligand is an antigen-binding molecule, wherein the antigen-binding molecule is selected from the group consisting of an antibody fragment, a Fab fragment, a Fab′ fragment, a heavy chain antibody, a single-domain antibody (sdAb), variable domain of a heavy chain antibody, VHH, Nanobodies, a single-chain variable fragment (scFv), a tandem scFv, a bispecific T-cell engager (BITEs), a diabody, a single-chain diabody, a DART, a triple body, a nanoantibody, an alternative scaffold protein, and a fusion protein thereof. 
     
     
         11 . The polypeptide of  claim 10 , wherein the antigen-binding molecule is a scFv, and wherein the scFv is an anti-HER2 or an anti-EGFR scFv. 
     
     
         12 . The polypeptide of  claim 8 , wherein the at least one pharmaceutically active moiety is an effector molecule, wherein the effector molecule is selected from the group consisting of cytokines, chemokines, immuno(co)-stimulatory molecules, immunosuppressive molecules, death ligands, apoptosis-inducing proteins, kinases, prodrug-converting enzymes, RNases, agonistic antibody or antibody fragment, antagonistic antibody or antibody fragment, toxins, growth factors, hormone, coagulation factor, fibrinolytic protein, peptides mimicking these, and fragments, fusion proteins or derivatives thereof. 
     
     
         13 . The polypeptide of  claim 12 , wherein the cytokine is the tumor-necrosis factor (TNF). 
     
     
         14 . The polypeptide of  claim 12 , wherein the cytokine is the TNF-relative apoptosis-inducing factor (TRAIL). 
     
     
         15 . The polypeptide of  claim 8 , wherein the at least one pharmaceutically active moiety is a half-life extension module, wherein the half-life extension module is selected from the group consisting of immunoglobulin binding domains (IgBD), albumin, albumin-binding domains (ABD), peptides, small molecules, fatty acids, antibody fragments, single-domain antibodies, VHH, scaffold proteins, and natural ligands exhibiting affinity for a long-circulating plasma protein, which are optionally PEGylated, HESylated, Polysialylated, N-glycosylated, O-glycosylated, or PEG-mimicking polypeptides. 
     
     
         16 . The polypeptide of  claim 8 , wherein the at least one pharmaceutically active moiety is an imaging molecule, wherein the imaging molecule is selected from the group consisting of bioluminescent reagents, chemiluminescent reagents, fluorescent imaging reagents, photosensitizers, chelating reagents, and radioactive moieties. 
     
     
         17 . A nucleic acid molecule comprising a sequence encoding the polypeptide of  claim 1 . 
     
     
         18 . A vector comprising the polynucleotide of  claim 17 . 
     
     
         19 . A complex comprising at least two polypeptides according to  claim 1 . 
     
     
         20 . The complex of  claim 19 , wherein the at least two polypeptides are connected via their HD2 domains. 
     
     
         21 . The complex of  claim 19 , wherein the at least two polypeptides are connected via covalent or non-covalent bonds. 
     
     
         22 . The complex of  claim 21 , wherein the covalent bond is a disulfide bond. 
     
     
         23 . The complex of  claim 19 , wherein the at least two polypeptides are identical or different. 
     
     
         24 . A cell comprising the polypeptide of  claim 1 . 
     
     
         25 . A pharmaceutical composition comprising the polypeptide of  claim 1 . 
     
     
         26 . The pharmaceutical composition of  claim 25 , which further comprises a pharmaceutically acceptable carrier and/or excipient and optionally one or more additional active substances.