Multispecific antibody platform and related methods
Novel multispecific antibody platform, multispecific antibodies and a method to make the antibodies is disclosed here. The CH3 domain harboring polypeptide chains of the Fc-regions are modified by increasing the positive charge of one chain and negative charge of another chain. Heterodimer formation in cotransfection with the modified chains is comparable to formation of wild type antibodies when same cell line is transfected with wild type polypeptides. Moreover, the modification provides a simple one step purification of the heterodimers.
1. An isolated polypeptide comprising: a CH3 domain, said CH3 domain comprising an amino acid sequence selected from the group consisting of SEQ ID NO:1, 3, 3, 5, 7, 9, 11, 13, 15, 17, 21, 23, 27, 27, 29, 31, 33 and 35.
2. A multispecific heterodimeric antibody comprising: a first immunoglobulin heavy chain comprising a first CH3 domain and a second immunoglobulin heavy chain comprising a second CH3 domain, wherein the first immunoglobulin heavy chain comprising the first CH3 domain has an amino acid sequence selected from the group consisting of SEQ ID No 3, 5, 9, 13, 17, 21, 25, 31, 35, and wherein the second immunoglobulin heavy chain comprising the second CH3 domain has an amino acid sequence selected from the group consisting of SEQ ID No 1, 7, 11, 15, 19, 23, 27, 29, 33.
3. The multispecific heterodimeric antibody of claim 2 , wherein a first Fc region has positively charged amino acid substitutions and retains Protein A binding activity; wherein a second Fc region has negatively charged amino acid substitutions and has an altered or significantly reduced protein A binding affinity.
4. The multispecific heterodimeric antibody of claim 2 , wherein the multispecific heterodimeric antibody presents a reduced Protein A binding affinity compared to wild type monoclonal antibody, such that the multispecific heterodimeric antibody can be eluted out from Protein A columns at pH 4.0 rather than pH 3.0, due to that only one of the Fc regions within the multispecific heterodimeric antibody retains Protein A binding activity.
5. The multispecific heterodimeric antibody of claim 2 , wherein the first immunoglobulin heavy chain and the second immunoglobulin heavy chain further comprise one or two binding domains, selected from the group consisting of: Fab, ScFv, monoclonal antibody, monovalent antibody, bispecific antibody, multi-specific antibody, antibody drug conjugate, monobody, diabody, nanobody, probody, enzymatic domain, ligand, receptor fusion protein, and mini-binding domain.
6. The multispecific heterodimeric antibody of claim 2 , wherein the multispecific heterodimeric antibody is human or humanized IgG, IgA, IgM, IgE or IgD.
7. The multispecific heterodimeric antibody of claim 2 , wherein the multispecific heterodimeric antibody is human or humanized IgG1, IgG2, IgG3, or IgG4.
8. An antibody comprising: a first immunoglobulin heavy chain and a second immunoglobulin heavy chain, wherein the first immunoglobulin heavy chain comprises one of the following triple amino acid substitutions (P395K, P396K, V397K), (P395K, P396K, V397C) or (P395R, P396R, V397R), wherein the numbering is according to the EU numbering scheme; and the second immunoglobulin heavy chain comprises one of the following triple amino acid substitutions (T394D, P395D, P396D), (T394C, P395D, P396D) or (T394E, P395E, P396E), wherein the numbering is according to the EU numbering scheme, and vice versa.
9. A composition comprising: the multispecific heterodimeric antibody of claim 2 and a pharmaceutically acceptable carrier.
10. The isolated polypeptide of claim 1 , wherein the isolated polypeptide is conjugated to a drug or a detectable label.
11. The multispecific heterodimeric antibody of claim 2 , wherein the multispecific heterodimeric antibody is conjugated to a drug or a detectable label.
12. The multispecific heterodimeric antibody of claim 2 , wherein the first CH3 domain comprises the amino acid sequence according to SEQ ID NO: 5 (OA) or SEQ ID NO: 9 (OC), and the second CH3 domain comprises the amino acid sequence according to SEQ ID NO:7 (OB) or SEQ ID NO: 11 (OD).