Trispecific antibodies
The invention provides trispecific antibodies that co-engage CD3, CD8 and a tumor target antigen.
1. A tetravalent, trispecific antibody comprising:
a) a first monomer comprising from N to C-terminus, a first variable heavy domain, a first CH1 domain, an optional domain linker, a first scFv domain, an optional domain linker, a hinge domain and a first variant Fc domain comprising a first CH2-CH3 domain;
b) a second monomer comprising from N to C-terminus, a second variable heavy domain, a second CH1 domain, an optional domain linker, a second scFv domain, an optional domain linker, a hinge domain and a second variant Fc domain comprising a second CH2-CH3 domain; and
c) a first light chain comprising a constant light domain and a first variable light domain; and
d) a second light chain comprising a constant light domain and a second variable light domain;
wherein said first variable heavy domain and said first variable light domain forms a first antigen binding domain that binds a first antigen, said second variable heavy domain and said second variable light domain forms a second antigen binding domain that binds said first antigen, said first scFv domain forms a third antigen binding domain that binds a second antigen, and said second scFv domain forms a fourth antigen binding domain that binds a third antigen,
wherein said first scFv domain binds CD8 and comprises a first scFv variable heavy domain comprising SEQ ID NO: 127 and a first scFv variable light domain comprising SEQ ID NO; 131,
wherein said second scFv domain binds CD3 and comprises a second scFv variable heavy domain comprising SEQ ID NO: 46 and a second scFv variable light domain comprising SEQ ID NO: 50,
wherein said first variable heavy domain and said first variable light domain comprise SEQ ID NOs: 73 and 77, respectively or SEQ ID NOs: 91 and 95, respectively,
wherein said second variable heavy domain and said second variable light domain comprise SEQ ID NOs: 73 and 77, respectively or SEQ ID NOs: 91 and 95, respectively, and
wherein said first and said second variant Fc domains comprise a pair of sets of amino acid substitutions selected from the group consisting of S364K/E357Q: L368D/K370S; L368D/K370S: S364K; L368E/K370S: S364K; T411T/E360E/Q362E: D401K; L368D/K370S: S364K/E357L and K370S: S364K/E357Q.
2. The tetravalent, trispecific antibody of claim 1 , wherein said first variable heavy domain and said second variable heavy domain each comprise SEQ ID NO: 73, and said first variable light domain and said second variable light domain each comprise SEQ ID NO: 77.
3. The tetravalent, trispecific antibody of claim 2 , wherein said first monomer comprises SEQ ID NO: 191, said second monomer comprises SEQ ID NO: 192, and said first and second light chains each comprise SEQ ID NO: 193.
4. The tetravalent, trispecific antibody of claim 1 , wherein said first variable heavy domain and said second variable heavy domain each comprise SEQ ID NO: 91, and said first variable light domain and said second variable light domain each comprise SEQ ID NO: 95.
5. The tetravalent, trispecific antibody of claim 4 , wherein said first monomer comprises SEQ ID NO: 188, said second monomer comprises SEQ ID NO: 189, and said first and second light chains each comprise SEQ ID NO: 190.