Protein containing heterodimer antibody Fc, and preparation method therefor
The present invention relates to novel proteins containing heterodimeric antibody Fc such as bispecific antibodies, and novel methods for preparing such proteins.
1 . A heterodimeric Fc scaffold, comprising: a first Fc region comprising a first CH3 region, and a second Fc region comprising a second CH3 region, wherein the first CH3 region and the second CH3 region are different in sequence, wherein the heterodimeric interaction between the first CH3 region and the second CH3 region is stronger than the homodimeric interactions of the first CH3 region and the second CH3 region;
wherein, compared to a parent CH3 region, the first CH3 region comprises S364R and D399K, and the second CH3 region comprises K370S, Y349T and K409D, based on the EU numbering system; and
wherein the parent CH3 region is a CH3 region from wild type human IgG1.
2 . The heterodimeric Fc scaffold according to claim 1 , wherein the first CH3 region further comprises E357N, and/or the second CH3 region further comprises Q347D.
3 . The heterodimeric Fc scaffold according to claim 2 , wherein either of the first CH3 region or the second CH3 region further comprises T350V, or both comprise T350V.
4 . The heterodimeric Fc scaffold according to claim 1 , wherein the first CH3 region and the second CH3 region have the following combinations of mutations:
(i) the first CH3 region comprises S364R, D399K, E357N and T350V, and the second CH3 region comprises K370S, Y349T, Q347D, K409D and T350V;
(ii) the first CH3 region comprises S364R, D399K and E357N, and the second CH3 region comprises K370S, Y349T, Q347D and K409D; or
(iii) the first CH3 region comprises S364R and D399K, and the second CH3 region comprises K370S, Y349T, Q347D and K409D.
5 . The heterodimeric Fc scaffold according to claim 1 , wherein the first Fc region and the second Fc region further comprise a CH2 region; wherein the CH2 region comprises or consists of
the amino acid sequence set forth in SEQ ID NO: 24.
6 . The heterodimeric Fc scaffold according to claim 1 , wherein the parent CH3 region comprises or consists of an amino acid sequence set forth in SEQ ID NO: 49.
7 . An Fc heterodimer, comprising the heterodimeric Fc scaffold according to claim 1 .
8 . An Fc heterodimer, comprising: a first target-binding region comprising a first Fc region comprising a first CH3 region, and a second target-binding region comprising a second Fc region comprising a second CH3 region, wherein the first CH3 region and the second CH3 region are different in sequence, wherein the heterodimeric interaction between the first CH3 region and the second CH3 region is stronger than the homodimeric interactions of the first CH3 region and the second CH3 region; wherein the first CH3 region and the second CH3 region are as defined in claim 4 .
9 . The Fc heterodimer according to claim 8 , wherein the target-binding region is an antigen-binding fragment linked to an Fc region, or wherein the target-binding region is a ligand.
10 . The Fc heterodimer according to claim 8 , wherein the first target-binding region and the second target-binding region bind to an antigen and a receptor, respectively.
11 . The Fc heterodimer according to claim 8 , wherein
a) the first/second target-binding region comprises an Fab fragment derived from an antibody and the first/second Fc region linked thereto, the second/first target-binding region comprises a ligand and the second/first Fc region linked thereto;
b) the first/second target-binding region comprises an Fab fragment derived from an antibody and the first/second Fc region linked thereto, the second/first target-binding region comprises an scFv derived from an antibody and the second/first Fc region linked thereto;
c) the first/second target-binding region comprises an Fab fragment derived from an antibody and the first/second Fc region linked thereto, the second/first target-binding region comprises a VHH derived from an antibody and the second/first Fc region linked thereto;
d) the first/second target-binding region comprises an Fab fragment derived from an antibody and the first/second Fc region linked thereto, the second/first target-binding region comprises an Fab fragment derived from an antibody and the second/first Fc region linked thereto.
12 . An Fc heterodimer, comprising the heterodimeric Fc scaffold according to claim 4 .
13 . The Fc heterodimer according to claim 8 , wherein the target-binding region is Fab, VH region, VHH or scFv, linked to an Fc region, or wherein the target binding region is IL-2.
14 . The Fc heterodimer according to claim 8 , wherein the first target-binding region and the second target-binding region bind to an antigen and a receptor, respectively, wherein the antigen is selected from PD1, PDL1, PDL2, CD20, CD47, HER2 and GPC3, and wherein the receptor is IL-2R.