Bispecific Asymmetric Heterodimers Comprising Anti-CD3 Constructs
Disclosed herein are isolated multi-specific heteromultimer constructs that bind to CD3 expressed on T-cells and to an antigen expressed on B-cells. The multi-specific heteromultimer constructs are capable of bridging T- and B-cells and mediating killing of B-cells. The multi-specific heteromultimer constructs are based on a heterodimeric Fc scaffold or on a segmented albumin scaffold. Also disclosed herein are multi-specific heteromultimer constructs that bind to HER2 and HER3.
1 . An isolated dimer comprising a first polypeptide and a second polypeptide, each polypeptide comprising a human IgG Fc region comprising a variant CH2 domain, each variant CH2 domain comprising a L234A amino acid substitution, a L235A amino acid substitution, and a D265S amino acid substitution, wherein the amino acid positions are numbered according to the EU index of Kabat.
2 . The isolated dimer of claim 1 , wherein at least one of the first and second polypeptides further comprises an antigen-binding domain.
3 . The isolated dimer of claim 2 , wherein the antigen-binding domain comprises an scFv.
4 . The isolated dimer of claim 2 , wherein the antigen-binding domain comprises a Fab.
5 . The isolated dimer of claim 1 , wherein one of the first and second polypeptides further comprises an scFv and the other of the polypeptides further comprises a Fab.
6 . The isolated dimer of claim 1 , wherein one of the first and second polypeptides further comprises amino acid substitutions T350V, L351Y, F405A, and Y407V, and the other of the polypeptides further comprises amino acid substitutions T350V, T366L, K392L, and T394W.
7 . The isolated dimer of claim 1 , wherein the IgG is an IgG1.
8 . An antibody comprising the isolated dimer of claim 1 .
9 . The antibody of claim 8 , wherein the antibody is a monoclonal antibody, a humanized antibody, or a human antibody.
10 . The antibody of claim 8 , wherein the antibody is multispecific.
11 . The antibody of claim 8 , wherein the antibody is bispecific.
12 . The isolated dimer of claim 1 , wherein the dimer is a heterodimer.
13 . A pharmaceutical composition comprising the isolated dimer of claim 1 and a pharmaceutically acceptable carrier.
14 . A pharmaceutical composition comprising the antibody of claim 8 and a pharmaceutically acceptable carrier.
15 . An isolated nucleotide sequence encoding the isolated dimer of claim 1 .
16 . A vector comprising the nucleotide sequence of claim 15 .
17 . A host cell comprising the vector of claim 16 .
18 . A method of producing a polypeptide, comprising culturing the host cell of claim 17 , and producing the polypeptide.
19 . The isolated dimer of claim 12 , wherein each of the first and second polypeptides further comprises an antigen-binding domain.
20 . The isolated dimer of claim 19 , wherein each antigen-binding domain binds a different antigen.
21 . The isolated dimer of claim 20 , wherein one of the antigen-binding domains binds to a CD3 complex.