Bispecific antibody against human EpCAM and human CD3

Anti-hEpCAM-CD3 binds to hCD3
on T cells and to hEpCAM on cancer cells

Monoclonal scFv antibody against human EpCAM and human CD3

Anti-hEpCAM-CD3 is a bispecific antibody that recognizes two human cell markers: human epithelial cell adhesion molecule (hEpCAM) and hCD3. It features solitomab's single-chain variable fragments (scFv) joined by a glycine-serine linker and a hexahistidine-tag (His6).

Solitomab was developed for the treatment of relapsed/refractory EpCAM-positive solid tumors [1]. By binding to hCD3 and hEpCAM, this dual-targeting antibody engages unstimulated T cells to proliferate and subsequently trigger T cell-mediated lysis of hEpCAM-positive cells (see figure).

 More details

Key features

• Reacts with human EpCAM and human CD3
• ScFv of clinical relevant bispecific mAb solitomab
• Hexahistidine (His6) tag
• Provided azide-free
• Each lot is functionally tested

Applications

• Adjustment studies of cancer cell contact-dependent killing
• Improving T cell activation

1. Kebenko M, et al., 2018. A multicenter phase 1 study of solitomab (MT110, AMG 110), a bispecific EpCAM/CD3 T-cell engager (BiTE®) antibody construct, in patients with refractory solid tumors. Oncoimmunology. 7(8):e1450710

Figures

Jurkat-Lucia™ NFAT cell activation upon incubation with hEpCAM-expression cancer cells and Anti-hEpCAM-CD3.

Dose-dependent activation of Jurkat-Lucia™ NFAT cells with Anti-hEpCAM-CD3 in the presence of coated human EpCAM-Fc protein. Human EpCAM-Fc fusion protein (2 µg/ml) was coated on ELISA plates overnight. Jurkat-Lucia™ NFAT cells were added together with Anti hEpCAM-CD3 (red curve), Anti-βGal-hCD3 (grey curve), or Anti-hEpCAM-βGal (blue curve) mAb, alone or in combination (black curve). After 24 hours of incubation, T cell activation was determined by measuring the Lucia luciferase activity using QUANTI-Luc™ detection reagent. Results are presented as fold change over non-induced cells (mean ± SEM).

Specifications

Clonality: Monoclonal bispecific antibody.

Specificity: Targets human EpCAM and human CD3.

Isotype: none (scFv).

Source: CHO (Chinese hamster ovary) cells.

Purity: >90%. Purified by affinity chromatography.

Tested application: ELISA, flow cytometry

Quality control:

•    Binding to human EpCAM and hCD3 has been confirmed by ELISA and flow cytometry, respectively.
•    The complete sequence of this antibody has been verified.
•    The absence of bacterial contamination (e.g. lipoproteins and endotoxins) has been confirmed using HEK-Blue™ TLR2 and HEK-Blue™ TLR4 cells.

Contents

Anti-hEpCAM-hCD3 purified monoclonal antibody is provided azide-free and lyophilized. It is available in two quantities:

• bimab-ecamcd3-01: 10 µg
• bimab-epamcd3-05: 5 x 10 µg

Product is shipped at room temperature.

 Upon receipt, store lyophilized antibody at -20°C.

 Lyophilized product is stable for at least 1 year.

Details

EpCAM

The human epithelial cell adhesion molecule (EpCAM, CD326, Trop1) is a transmembrane, 40 kDa glycoprotein highly abundant in almost all human carcinomas, including colon, prostate, ovarian, or breast cancer [1]. In healthy tissue, EpCAM expression is generally low [1-2]. In cancer, EpCAM overexpression is responsible for tumor proliferation, invasion, and migration and is often correlated with a poor prognosis [1]. Thus, EpCAM represents an attractive therapeutic target. The number of EpCAM-positive cancers with limited therapeutic options at the advanced stage formed the rationale for developing the EpCAM/CD3 BiTE® antibody solitomab (MT110, AMG 110) [1]. 

CD3

The cluster of differentiation 3 (CD3, formerly named T3) is a multimeric protein complex consisting of four polypeptides (CD3ε, CD3γ, CD3δ, and CD3ζ) that assemble as three dimers (εγ, εδ, and ζζ) [4]. It is a marker of T cells, which recognizes and participates in the elimination of infected cells and tumor cells through the interaction between the TCR (T cell receptor) on T cells and the MHC-peptide complex on antigen-presenting cells [4-5]. Because of its short cytoplasmic tail, the TCR lacks the ability to signal and requires non-covalent association with the CD3. Upon antigen recognition, T cells' TCR/CD3 complex triggers downstream intracellular signaling and activates T cell cells [4].

References:

1. Brischwein K, et al., 2006. MT110: a novel bispecific single-chain antibody construct with high efficacy in eradicating established tumors. Mol Immunol. 43(8):1129-43. 
2. Kebenko M, et al., 2018. A multicenter phase 1 study of solitomab (MT110, AMG 110), a bispecific EpCAM/CD3 T-cell engager (BiTE®) antibody construct, in patients with refractory solid tumors. Oncoimmunology. 7(8):e1450710.
3. Chetty R. & Gatter K., 1994. CD3: structure, function, and role of immunostaining in clinical practice. J. Pathol. 173(4):303-307.
4. Smith-Garvin J.E. et al., 2009. T Cell Activation. Ann. Rev. Immunol. 27:591-619.3.