US 11,866,507 B2
Multispecific polypeptide constructs having constrained CD3 binding and methods of using the same
Brendan P. Eckelman, La Jolla, CA (US); Michael D. Kaplan, La Jolla, CA (US); Katelyn M. Willis, La Jolla, CA (US); Quinn Deveraux, La Jolla, CA (US); and John C. Timmer, La Jolla, CA (US)
Assigned to Inhibrx, Inc., La Jolla, CA (US)
Filed by Inhibrx, Inc., La Jolla, CA (US)
Filed on Apr. 11, 2018, as Appl. No. 15/951,137.
Claims priority of provisional application 62/484,217, filed on Apr. 11, 2017.
Prior Publication US 2019/0010242 A1, Jan. 10, 2019
This patent is subject to a terminal disclaimer.
Int. Cl. C07K 16/30 (2006.01); C07K 16/28 (2006.01); C07K 16/46 (2006.01); A61P 35/00 (2006.01)
CPC C07K 16/30 (2013.01) [A61P 35/00 (2018.01); C07K 16/28 (2013.01); C07K 16/2809 (2013.01); C07K 16/2827 (2013.01); C07K 16/2863 (2013.01); C07K 16/2887 (2013.01); C07K 16/468 (2013.01); C07K 2317/31 (2013.01); C07K 2317/52 (2013.01); C07K 2317/55 (2013.01); C07K 2317/56 (2013.01); C07K 2317/569 (2013.01); C07K 2317/62 (2013.01); C07K 2317/624 (2013.01); C07K 2317/64 (2013.01); C07K 2317/66 (2013.01); C07K 2317/73 (2013.01); C07K 2317/75 (2013.01)] 10 Claims
 
1. A multispecific polypeptide construct, the multispecific polypeptide construct comprising a first component comprising a heterodimeric immunoglobulin Fc region and a second component comprising a CD3-binding region wherein:
the first and second components are coupled by a first linker that is a polypeptide of 2-18 amino acids in length composed of at least 50% Glycine residues, wherein the Fc region is amino-terminal to the CD3-binding region;
the CD3-binding region is an anti-CD3 disulfide stabilized Fv antibody fragment (dsFv) comprising a variable heavy chain (VH) and a variable light chain (VL), wherein the VH has the amino acid sequence of SEQ ID NO: 44 or a sequence that exhibits at least 90% sequence identity to SEQ ID NO: 44, and the VL has the amino acid sequence of SEQ ID NO: 72 or a sequence that exhibits at least 90% sequence identity to SEQ ID NO: 72, wherein the VH and VL are each linked to opposite polypeptides of the heterodimeric Fc by the first linker;
each of the Fc polypeptides of the heterodimeric Fc region comprises a knob-into-hole modification or a charge mutation to increase electrostatic complementarity of the Fc polypeptides;
the first component comprises at least one antigen binding domain that is a single domain antibody (sdAb) and binds a tumor associated antigen (TAA), wherein each of the at least one antigen binding domain of the first component is linked amino-terminal to the Fc region by a second linker that is a polypeptide of 2-6 amino acids in length composed of at least 50% Glycine residues; and
the second component further comprises at least one antigen binding domain that is a sdAb and binds to the same TAA as the first component, wherein each of the at least one antigen binding domain of the second component is linked carboxy-terminal to the CD3-binding region by a third linker that is a polypeptide of 2-6 amino acids in length composed of at least 50% Glycine residues,
wherein (i) each of the sdAbs is a camelid VHH or a humanized camelid VHH; and (ii) the CD3-binding region is not able to bind cell surface CD3 as determined by flow cytometry, unless the at least one antigen binding domain is bound to its TAA.