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BR-112018071288-B1 - Modified-affinity serum protein carrier binding domain, antibody molecule, and pharmaceutical composition.

BR112018071288B1BR 112018071288 B1BR112018071288 B1BR 112018071288B1BR-112018071288-B1

Abstract

This disclosure relates to a method for modulating the half-life of a specific binding domain for a serum carrier protein by sequence mutation and a specific modulated binding domain for a serum carrier protein.

Inventors

  • Ralph Adams
  • SAM PHILIP HEYWOOD

Assignees

  • UCB Biopharma SRL

Dates

Publication Date
20260310
Application Date
20170428
Priority Date
20160501

Claims (10)

  1. 1. Binding domain comprising a variable heavy chain (VH) domain and a variable light chain (VL) domain specific for a serum carrier protein, wherein the serum carrier protein is albumin or a fragment thereof; characterized in that the VH and VL sequences are selected from the combinations SEQ ID NO: 3 & 9, 4 & 8, 4 & 9 and 5 & 9.
  2. 2. Binding domain, according to claim 1, characterized in that the serum carrier protein is human serum albumin.
  3. 3. Binding domain, according to claim 1 or 2, characterized in that the binding domain binds to domain II of albumin.
  4. 4. Linkage domain, according to any one of claims 1 to 3, characterized in that the VL and VH sequences are SEQ ID NO: 9 and SEQ ID NO: 3, respectively.
  5. 5. A linking domain, according to any one of claims 1 to 3, characterized in that the VL and VH sequences are SEQ ID NO: 8 and SEQ ID NO: 4, respectively.
  6. 6. A linking domain, according to any one of claims 1 to 3, characterized in that the VL and VH sequences are SEQ ID NO: 9 and SEQ ID NO: 5, respectively.
  7. 7. A linking domain, according to any one of claims 1 to 3, characterized in that the VL and VH sequences are SEQ ID NO: 9 and SEQ ID NO: 4, respectively.
  8. 8. Antibody molecule characterized by comprising a binding domain as defined in any one of claims 1 to 7.
  9. 9. Pharmaceutical composition, characterized by comprising a binding domain as defined in any one of claims 1 to 7.
  10. 10. Pharmaceutical composition, characterized by comprising an antibody molecule as defined in claim 8.

Description

[0001] This disclosure relates to a method that modulates the half-life of a specific binding domain for a serum carrier protein by sequence mutation and a specific modulated binding domain for a serum carrier protein. FUNDAMENTALS [0002] Increasing the serum half-life of biological drugs by targeting serum protein carriers, for example, human serum albumin (HSA), is well established1,2. HSA is used because its half-life is 19 days. It is the most abundant protein in blood serum (34-54 g/L) and is widely distributed in tissues.3 Therefore, it is a readily available and safe target for binding, particularly because a small percentage of total albumin is used in this approach. [0003] Of the serum proteins, only IgG has a similarly long half-life (21 days). The long serum half-lives of HSA and IgG are primarily due to protection from intracellular lysosomal degradation by the neonatal Fc receptor (FcRn).4,5 FcRn recycles HSA and IgG back to the cell surface after nonspecific pinocytosis from plasma into vesicles by endothelial cells and hematopoietic cells lining the vascular space. Pinocytotic vesicles acidify by fusion with the initial endosome, allowing HSA and IgG to bind to FcRn in a pH-dependent manner. Vesicles bearing membrane receptors, including FcRn, and bound HSA and IgG, are recycled back to the cell surface while the remaining unbound material is channeled to the lysosome for degradation. HSA and IgG bind weakly to FcRn at neutral pH and are therefore released back into circulation when recycled vesicles are exposed to the neutral pH of blood.2 [0004] HSA can be exploited in two ways. One approach is to directly couple the therapeutic protein to HSA, either genetically or chemically.6,7 A second approach is to use an albumin-binding domain. Examples of binding domains used so far include fatty acids (myristic acid),8 organic molecules (Albutag),9 synthetic peptides,10,11 bacterial albumin-binding domains (AlbumodTm),12,13 single-domain antibodies (NanobodyTm, AlbudAbTm)14-17 and a Fab.18 [0005] Nguyen et al 2006 investigated the half-life of Fab fragments bound to a C-terminal albumin-binding peptide. Nguyen concluded that reduced affinity for albumin correlated with a reduced half-life and higher clearance rates. Figure 3 suggests that the relationship is nearly linear. This article also went on to say that a very small difference in the fraction of antibody that is not bound in vivo will have a profound effect on the clearance rate. [0006] The present inventors investigated the correlation between the affinity of binding domains comprising a specific VH and VL for a serum protein carrier and the in vivo half-life of the same. They established that the half-life duration for binding domains is more complicated than the response for albumin-binding peptides, insofar as large reductions in affinity often translate into a moderate reduction in half-life and, in some cases, the reduction in affinity leads to increases in half-life, which is counterintuitive. SUMMARY OF THE DISCLOSURE [0007] Thus, providing a binding domain comprising a VH and VL specific for a serum carrier protein, wherein the domain is mutated by a modification in the variable light chain (VL) domain, in the variable heavy chain (VH) domain and a combination thereof, and the mutated binding domain has a half-life that is longer or shorter than the half-life for the non-mutated binding domain, for example on the condition that the mutation is different from a mutation consisting of I50A, T56A, T95A, V96A, P97A, G98A, Y99A, S100A, T100Aa, Y100Ca, I50A and T95A, I50A and G98A, I50A and Y99A, T56A and T95A, T56A and G98A, and T56A and Y99A of SEQ ID NO:1. [0008] Thus, providing a binding domain comprising a VH and VL specific to a serum carrier protein, wherein the domain is mutated by a modification selected from one or two amino acid substitutions in the variable light chain (VL) domain, in the variable heavy chain (VH) domain and a combination thereof, and the mutated binding domain has a half-life that is longer or shorter than the half-life for the non-mutated binding domain, for example on the condition that the mutation is different from a mutation consisting of I50A, T56A, T95A, V96A, P97A, G98A, Y99A, S100A, T100Aa, Y100Ca, I50A and T95A, I50A and G98A, I50A and Y99A, T56A and T95A, T56A and G98A, and T56A and Y99A of SEQ ID NO:1. [0009] In one embodiment, the serum carrier protein is selected from, for example, thyroxine-binding protein, transthyretin, al-acid glycoprotein, transferrin, fibrinogen and albumin, or a fragment of any of these, such as albumin, in particular human serum albumin. [0010] In one embodiment, the binding domain is specific to domain II of albumin. [0011] In one embodiment, the mutation is a modification in the VL, for example, where the mutation is the substitution of one or two amino acids in the VL, such as a modification/substitution in a selected CDR of L1, L2, L3 and a combination thereof, in pa