Heterodimeric proteins and methods for producing and purifying them
The present invention relates to engineered heteromultimeric proteins, and more specifically, to methods for producing and purifying heterodimeric proteins, such as bispecific antibodies and other heterodimeric proteins comprising immunoglubulin-like hinge sequences. Methods for producing and purifying such engineered heterodimeric proteins and their use in diagnostics and therapeutics are also provided.
1 . A method of purifying a heterodimeric protein, wherein the purification comprises a chromatography step, wherein the heterodimeric protein comprises:
a hinge region comprising a first immunoglobulin-like hinge polypeptide and a second immunoglobulin-like hinge polypeptide which interact together to form a dimeric hinge interface, wherein electrostatic interactions between one or more charged amino acids within the hinge interface favor interaction between the first and second hinge polypeptides over interaction between two first hinge polypeptides or two second hinge polypeptides, thereby promoting heterodimer formation over homodimer formation,
wherein the hinge region is a human IgG2 hinge region, wherein each of the first hinge polypeptide and the second hinge polypeptide comprises at least two amino acid modifications relative to a wild-type IgG2 hinge region at a position of Cys223, Glu225 or Pro228, according to EU numbering scheme, wherein the wild-type amino acid in the first hinge polypeptide is replaced with an amino acid having an opposite charge to the corresponding amino acid in the second hinge polypeptide, and the heterodimeric protein further comprising an immunoglobulin-like CH3 region comprising a first CH3 polypeptide fused to the first hinge polypeptide and a second CH3 polypeptide fused to the second hinge polypeptide, wherein the first CH3 polypeptide and the second CH3 polypeptide comprise at least one amino acid modification relative to a wild-type IgG2 CH3 region sequence at a position of Leu368 or Lys409, according to EU numbering scheme.
2 . The method of claim 1 , wherein the chromatography step is ion exchange chromatography.
3 . The method of claim 1 , wherein the heterodimeric protein is a bispecific IgG2 antibody.
4 . The method of claim 3 , wherein the bispecific antibody comprises a first heavy chain, a first light chain, a second heavy chain, and a second light chain,
wherein the first heavy chain comprises the first hinge polypeptide and the first CH3 polypeptide, and
wherein the second heavy chain comprises the second hinge polypeptide and the second CH3 polypeptide.
5 . The method of claim 4 , wherein the first heavy chain and second heavy chain each comprise an amino aid modification of Ala330Ser and Pro331Ser, according to the EU numbering scheme.
6 . The method of claim 5 , wherein a first antibody variable domain of the bispecific antibody binds to a T cell receptor and the second and a second antibody variable domain of the bispecific antibody binds to a tumor antigen.
7 . The method of claim 6 , wherein the first antibody variable domain binds to CD3.