Biological Products

Abstract

A multivalent antibody fusion protein which comprises an immunoglobulin moiety, for example a Fab or Fab′ fragment, with a first specificity for an antigen of interest, and further comprises two single domain antibodies (dAb) with specificity for a second antigen of interest, wherein the two single domain antibodies are linked by a disulfide bond. There is also provided particular dual specificity antibody fusion proteins comprising a Fab or Fab′ fragment and one or more single domain antibodies which may be stabilised by a disulfide bond therebetween.

1 . A nucleic acid molecule encoding a divalent antibody fusion protein, comprising:
 (i) an immunoglobulin moiety with a specificity for an antigen of interest,
 wherein the immunoglobulin moiety is a Fab or Fab′ fragment having a heavy chain and a light chain; and 
   (ii) two single domain antibodies (dAb), a VH dAb and a VL dAb, that together bind to the same human serum albumin,   wherein the VH dAB comprises complementary determining region (CDR)-H1 having the amino acid sequence set forth in SEQ ID NO:56, CDR-H2 having the amino acid sequence set forth in SEQ ID NO:57, and CDR-H3 having the amino acid sequence set forth in SEQ ID NO:58;   wherein the VL dAB comprises CDR-L1 having the amino acid sequence set forth in SEQ ID NO:59, CDR-L2 having the amino acid sequence set forth in SEQ ID NO:60, and CDR-L3 having the amino acid sequence set forth in SEQ ID NO:61;—   wherein (i) the VH dAb is connected directly or via a linker to the C-terminus of the Fab or Fab′ heavy chain and the VL dAb is connected directly or via a linker to the C-terminus of the Fab or Fab′ light chain, or (ii) the VH dAb is connected directly or via a linker to the C-terminus of the Fab or Fab′ light chain and the VL dAb is connected directly or via a linker to the Fab or Fab′ heavy chain; and   wherein the VH dAb and the VL dAb are linked by a disulfide bond between two engineered cysteine residues at positions VH44 and VL100.   
     
     
         2 . The nucleic acid molecule of  claim 1 , wherein the nucleic acid molecule is cDNA. 
     
     
         3 . An expression vector comprising the nucleic acid molecule of  claim 1 . 
     
     
         4 . A recombinant host cell comprising the expression vector of  claim 3 . 
     
     
         5 . The nucleic acid molecule of  claim 1 , wherein the VH dAb and the VL dAb of the divalent antibody fusion protein are humanised. 
     
     
         6 . The nucleic acid molecule of  claim 1 , wherein the Fab or Fab′ of the divalent antibody fusion protein is fully human or humanised. 
     
     
         7 . The nucleic acid molecule of  claim 1 , wherein the VH dAb is connected to the C-terminus of the Fab or Fab′ heavy chain directly or via a linker and the VL dAb is connected to the C-terminus of the Fab or Fab′ light chain directly or via a linker. 
     
     
         8 . The nucleic acid molecule of  claim 1 , wherein in the divalent antibody fusion protein the VH dAb is connected to the C-terminus of the Fab or Fab′ heavy chain and the VL dAb is connected to the C-terminus of the Fab or Fab′ light chain via a linker having the amino acid sequence set forth in any one of SEQ ID NOs: 13 or 45. 
     
     
         9 . The nucleic acid molecule of  claim 1 , wherein in the divalent antibody fusion protein the VH dAb is fused to the C-terminus of the heavy chain constant region (CH1) of the Fab or Fab′ and the VL dAb is fused to the C-terminus of the light chain constant region of the Fab or Fab′ or wherein the VL dAb antibody is fused to the C-terminus of the heavy chain constant region (CH1) of the Fab or Fab′ and the VH dAb antibody is fused to the C-terminus of the light chain constant region of the Fab or Fab′. 
     
     
         10 . The nucleic acid molecule of  claim 1 , wherein the divalent antibody fusion protein contains one CL and one CH1 domain, wherein the CL and the CH1 domains are in the Fab or Fab′ fragment. 
     
     
         11 . A pharmaceutical composition, comprising the divalent antibody fusion protein encoded by the nucleic acid of  claim 1 . 
     
     
         12 . The pharmaceutical composition of  claim 11 , wherein the composition is for the treatment of a disease or disorder;
 wherein the disease or disorder is an inflammatory disease or disorder, an immune disease or disorder, a fibrotic disorder, and/or a cancer;   wherein the inflammatory disease or disorder and/or the immune disease or disorder comprise rheumatoid arthritis, psoriatic arthritis, still's disease, Muckle Wells disease, psoriasis, Crohn's disease, ulcerative colitis, SLE (Systemic Lupus Erythematosus), asthma, allergic rhinitis, atopic dermatitis, multiple sclerosis, vasculitis, Type I diabetes mellitus, transplantation and graft-versus-host disease;   wherein the fibrotic disorder comprises idiopathic pulmonary fibrosis (IPF), systemic sclerosis (or scleroderma), kidney fibrosis, diabetic nephropathy, IgA nephropathy, hypertension, end-stage renal disease, peritoneal fibrosis (continuous ambulatory peritoneal dialysis), liver cirrhosis, age-related macular degeneration (ARMD), retinopathy, cardiac reactive fibrosis, scarring, keloids, burns, skin ulcers, angioplasty, coronary bypass surgery, arthroplasty and cataract surgery; and   wherein the cancer comprises (i) a malignant new growth that arises from epithelium, found in skin or the lining of breast, ovary, prostate, lung, kidney, pancreas, stomach, bladder or bowel and/or (ii) bone, liver, lung or brain cancer.