Table 1 Characteristics of bsAbs used in this study

Description	Ab code	Clone CD3-arm	Clone HER2-arm	kD CD3 (nM)*	Apparent affinity EC50 HER2 (nM)**	kD HER2 (nM)***
bsAb CD3_wt × HER2_Herceptin	BisG1-huCACAO-FEAL/Herceptin-FEAR	huCACAO	Herceptin	15	5.7	0.1
bsAb CD3_wt × HER2_LbD2	BisG1-huCACAO-FEAL/Herceptin-FEAR LbD2	huCACAO	LbD2	15		100
bsAb CD3_wt × HER2₁₅₃	BisG1-huCACAO-FEAL/153-FEAR	huCACAO	153	15	4.2
bsAb CD3_wt × HER2₁₆₉	BisG1-huCACAO-FEAL/169-FEAR	huCACAO	169	15	6.1
bsAb CD3_wt × ctrl	BisG1-huCACAO-FEAL/b12-FEAR	huCACAO	b12	15	N.A.
bsAb CD3_Low × HER2_Herceptin	BisG1-huCACAO-H101G-FEAL/Herceptin-FEAR	huCACAO-H101G	Herceptin	310	5.7	0.1
bsAb CD3_Low × HER2_LbD2	BisG1-huCACAO-H101G-FEAL/Herceptin-FEAR LbD2	huCACAO-H101G	LbD2	310		100
bsAb CD3_Low × HER2₁₅₃	BisG1-huCACAO-H101G-FEAL/153-FEAR	huCACAO-H101G	153	310	4.2
bsAb CD3_Low × HER2₁₆₉	BisG1-huCACAO-H101G-FEAL/169-FEAR	huCACAO-H101G	169	310	6.1
bsAb CD3_Low × ctrl	BisG1-huCACAO-H101G-FEAL/b12-FEAR	huCACAO-H101G	b12	310	N.A.
bsAb ctrl × HER2_Herceptin	BisG1-b12-FEAL/Herceptin-FEAR	b12	Herceptin	N.A.	5.7	0.1
bsAb ctrl × HER2_LbD2	BisG1-b12-FEAL/Herceptin-FEAR LbD2	b12	LbD2	N.A.		100
bsAb ctrl × HER2₁₅₃	BisG1-b12-FEAL/153-FEAR	b12	153	N.A.	4.2
bsAb ctrl × HER2₁₆₉	BisG1-b12-FEAL/169-FEAR	b12	169	N.A.	6.1

Wt high affinity binding to CD3, low low affinity binding to CD3, ctrl non-binding arm using HIV-1 gp120-specific mAb IgG1-b12, Herceptin interaction with HER2 at Herceptin epitope, LbD2 low affinity interaction with HER2 at Herceptin epitope due to light chain bD2 mutation, 153 high affinity interaction with membrane distal HER2 epitope “153”, 169 high affinity interaction with membrane proximal HER2 epitope “169”, N.A. not applicable, FEAL L234F, L235E, D265A Fc-inert with F405L mutations, FEAR L234F, L235E, D265A Fc-inert with K409R mutations.
*kD values for WT CD3 arm described in patent WO-2017/009442 and for H101G mutant in ref. ⁵⁹.
**kD values for Herceptin and LbD2 mutant arms determined in ref. ⁶⁰.
***Apparent affinities determined in house.

Search