Multi-valent hepatitis B virus antigen binding molecules and uses thereof
This disclosure provides a multimeric hepatitis B virus (HBV) protein binding molecule, e.g., a dimeric IgA or a pentameric or hexameric IgM binding molecule, comprising at least two bivalent binding units, or variants or fragments thereof, each comprising at least two antibody heavy chain constant regions or fragments thereof, wherein each heavy chain constant region or fragment thereof is associated with an HBV antigen binding domain. The disclosure also provides compositions comprising the multimeric binding molecules, polynucleotides encoding the multimeric binding molecules, and methods to make and use the multimeric binding molecules.
1. A multimeric antibody comprising at least two bivalent binding units;
wherein each binding unit comprises two IgM or IgA antibody heavy chain constant regions, each associated with an antigen binding domain;
wherein the antigen binding domains specifically bind to a hepatitis B virus (HBV) antigen expressed on the surface of infectious viral particles, on the surface of HBV infected cells, or a combination thereof, and
wherein the binding molecule is more potent than a reference IgG antibody comprising the antigen binding domain that specifically binds to the HBV antigen.
2. The antibody of claim 1 , which is a dimeric antibody comprising two bivalent IgA binding units thereof, four antigen binding domains that specifically bind to a hepatitis B virus (HBV) antigen expressed on the surface of infectious viral particles, on the surface of HBV infected cells, or a combination thereof, and a J-chain or variant thereof, wherein each binding unit comprises two IgA heavy chain constant regions each associated with a VH situated amino terminal to the IgA constant region, and two immunoglobulin light chains each comprising a VL situated amino terminal to an immunoglobulin light chain constant region, wherein the IgA heavy chain constant regions each comprise a Cα1 domain, a Cα2 domain, and a Cα3-tp domain.
3. The antibody of claim 1 , which is a pentameric or a hexameric antibody comprising five or six bivalent IgM binding units, respectively, and ten or twelve antigen binding domains, respectively, which specifically bind to a hepatitis B virus (HBV) antigen expressed on the surface of infectious viral particles, on the surface of HBV infected cells, or a combination thereof, wherein each binding unit comprises two IgM heavy chain constant regions each associated with a VH situated amino terminal to the IgM constant region, and two immunoglobulin light chains each comprising a VL situated amino terminal to an immunoglobulin light chain constant region, and wherein the IgM heavy chain constant regions each comprise a Cμ1 domain, a Cμ2 domain, a Cμ3 domain, and a Cμ4-tp domain.
4. The antibody of claim 3 , which is pentameric, and further comprises a J-chain or variant thereof, and wherein J-chain comprises the amino acid sequence SEQ ID NO: 54 or a functional variant thereof.
5. The antibody of claim 4 , wherein the J-chain or variant thereof is a modified J-chain further comprising a heterologous polypeptide, wherein the heterologous polypeptide is directly or indirectly fused to the J-chain.
6. The antibody of claim 5 , wherein the heterologous polypeptide is fused to the N-terminus of the J-chain, the C-terminus of the J-chain, or to both the N-terminus and C-terminus of the J-chain.
7. The antibody of claim 5 , wherein the heterologous polypeptide comprises a scFv antibody fragment.
8. The antibody of claim 7 wherein the scFv antibody fragment can specifically bind to CD3ε.
9. The antibody of claim 3 , wherein the IgM heavy chain constant regions are human IgM constant regions.
10. The antibody of claim 3 , wherein the ten or twelve antigen binding domains are identical.
11. The antibody of claim 10 , wherein the HBV antigen is a hepatitis B surface antigen (HBsAg), a precore antigen, a core antigen, or an X-antigen.
12. The antibody of claim 11 , wherein the antigen binding domains comprise an antibody heavy chain variable region (VH) and an antibody light chain variable region (VL), wherein the VH and VL comprise, respectively, HCDR1, HCDR2, and HCDR3 regions, or HCDR1, HCDR2, and HCDR3 regions containing one or two single amino acid substitutions, and LCDR1, LCDR2, and LCDR3 regions, or LCDR1, LCDR2, and LCDR3 regions containing one or two single amino acid substitutions, of the VH and VL amino acid sequences SEQ ID NO: 1 and SEQ ID NO: 3, SEQ ID NO: 2 and SEQ ID NO: 3, SEQ ID NO: 4 and SEQ ID NO: 3, SEQ ID NO: 5 and SEQ ID NO: 6, SEQ ID NO: 7 and SEQ ID NO: 8, SEQ ID NO: 7 and SEQ ID NO: 9, SEQ ID NO: 10 and SEQ ID NO: 11, SEQ ID NO: 14 and SEQ ID NO: 15, SEQ ID NO: 16 and SEQ ID NO: 21, SEQ ID NO: 17 and SEQ ID NO: 22, SEQ ID NO: 18 and SEQ ID NO: 23, SEQ ID NO: 19 and SEQ ID NO: 24, SEQ ID NO: 20 and SEQ ID NO: 25, SEQ ID NO: 26 and SEQ ID NO: 27, SEQ ID NO: 26 and SEQ ID NO: 28, SEQ ID NO: 26 and SEQ ID NO: 29, SEQ ID NO: 30 and SEQ ID NO: 31, SEQ ID NO: 32 and SEQ ID NO: 33, SEQ ID NO: 34 and SEQ ID NO: 35, SEQ ID NO: 34 and SEQ ID NO: 36, SEQ ID NO: 37 and SEQ ID NO: 38, SEQ ID NO: 39 and SEQ ID NO: 40, SEQ ID NO: 41 and SEQ ID NO: 42, SEQ ID NO: 43 and SEQ ID NO: 44, SEQ ID NO: 45 and SEQ ID NO: 46, SEQ ID NO: 47 and SEQ ID NO: 48, SEQ ID NO: 49 and SEQ ID NO: 50, SEQ ID NO: 51 and SEQ ID NO: 52, SEQ ID NO: 62 and SEQ ID NO: 6, SEQ ID NO: 73 and SEQ ID NO: 74, or SEQ ID NO: 75 and SEQ ID NO: 76, respectively, or the HCDR1, HCDR2, and HCDR3 regions, or the HCDR1, HCDR2, and HCDR3 regions containing one or two single amino acid substitutions, of the VH amino acid sequence SEQ ID NO: 12 or SEQ ID NO: 13.
13. The antibody of claim 11 , wherein the antigen binding domains comprise an antibody heavy chain variable region (VH) and an antibody light chain variable region (VL), wherein the VH and VL comprise, respectively, amino acid sequences that are at least 80%, at least 85%, at least 90%, at least 95% or 100% identical to SEQ ID NO: 1 and SEQ ID NO: 3, SEQ ID NO: 2 and SEQ ID NO: 3, SEQ ID NO: 4 and SEQ ID NO: 3, SEQ ID NO: 5 and SEQ ID NO: 6, SEQ ID NO: 7 and SEQ ID NO: 8, SEQ ID NO: 7 and SEQ ID NO: 9, SEQ ID NO: 10 and SEQ ID NO: 11, SEQ ID NO: 14 and SEQ ID NO: 15, SEQ ID NO: 16 and SEQ ID NO: 21, SEQ ID NO: 17 and SEQ ID NO: 22, SEQ ID NO: 18 and SEQ ID NO: 23, SEQ ID NO: 19 and SEQ ID NO: 24, SEQ ID NO: 20 and SEQ ID NO: 25, SEQ ID NO: 26 and SEQ ID NO: 27, SEQ ID NO: 26 and SEQ ID NO: 28, SEQ ID NO: 26 and SEQ ID NO: 29, SEQ ID NO: 30 and SEQ ID NO: 31, SEQ ID NO: 32 and SEQ ID NO: 33, SEQ ID NO: 34 and SEQ ID NO: 35, SEQ ID NO: 34 and SEQ ID NO: 36, SEQ ID NO: 37 and SEQ ID NO: 38, SEQ ID NO: 39 and SEQ ID NO: 40, SEQ ID NO: 41 and SEQ ID NO: 42, SEQ ID NO: 43 and SEQ ID NO: 44, SEQ ID NO: 45 and SEQ ID NO: 46, SEQ ID NO: 47 and SEQ ID NO: 48, SEQ ID NO: 49 and SEQ ID NO: 50, SEQ ID NO: 51 and SEQ ID NO: 52, SEQ ID NO: 62 and SEQ ID NO: 6, SEQ ID NO: 73 and SEQ ID NO: 74, or SEQ ID NO: 75 and SEQ ID NO: 76, or wherein the at least one antigen binding domain comprises an antibody VH, wherein the VH comprises an amino acid sequence at least 80%, at least 85%, at least 90%, at least 95% or 100% identical to SEQ ID NO: 12 or SEQ ID NO: 13.
14. The antibody of claim 13 comprising an IgM heavy chain comprising the amino acid sequence SEQ ID NO: 58 and a light chain comprising the amino acid sequence SEQ ID NO: 59, or comprising an IgM heavy chain comprising the amino acid sequence SEQ ID NO: 63 and a light chain comprising the amino acid sequence SEQ ID NO: 59.
15. An isolated IgM antibody comprising a modified J-chain and five binding units, each comprising two heavy chains and two light chains, wherein each heavy chain comprises a human Mu constant region, and the heavy chain variable region amino acid sequence SEQ ID NO: 62, and wherein each light chain comprises a human kappa constant region and the light chain variable region amino acid sequence SEQ ID NO: 6; wherein the antibody can assemble into a pentameric IgM antibody that can specifically bind to the pre-S1 region of HBV surface antigen, and wherein the modified J-chain comprises the amino acid sequence SEQ ID NO: 68 (V15J) or SEQ ID NO: 71 (J15V).
16. A polynucleotide comprising a nucleic acid sequence that encodes at least one polypeptide subunit of the antibody of claim 3 , wherein the polypeptide subunit comprises the IgM heavy chain constant region and at least the antibody VH portion of an antibody binding domain that specifically binds to a hepatitis B virus (HBV) antigen expressed on the surface of infectious viral particles, on the surface of HBV-infected cells, or a combination thereof, and/or the polypeptide subunit comprises the antibody VL portion of an antibody binding domain that specifically binds to a hepatitis B virus (HBV) antigen expressed on the surface of infectious viral particles, on the surface of HBV-infected cells, or a combination thereof.
17. A method of treating a disease or condition caused by or exacerbated by hepatitis B virus (HBV) infection in a patient, comprising administering to a patient infected with HBV or susceptible to HBV infection the antibody of claim 3 , wherein the antibody is more potent than a reference single binding unit antibody comprising the antigen binding domain that specifically binds to the HBV antigen.
18. The antibody of claim 11 , wherein the HBsAg comprises the S region, the S and pre-S2 regions, or the S, pre-S2, and pre-S1 regions.