Anti-HER2 monoclonal antibody for ADC

Monoclonal human IgG1 antibody against HER2 for antibody-drug conjugation

InvivoGen provides Anti-HER2-hIgG1, a monoclonal antibody (mAb) specifically developed for the generation of antibody-drug conjugates (ADCs). This mAb features:

Anti-HER2 PRR ligand bioconjugation
(click to enlarge)

• the variable region of trastuzumab, which specifically targets the human epidermal growth factor 2 (HER2),
• a human IgG1 constant region that displays high effector functions, including antibody-dependent cell-mediated cytotoxicity (ADCC), and complement-dependent cytotoxicity (CDC).

InvivoGen's Anti-HER2-hIgG1 has been generated by recombinant DNA technology, produced in CHO cells, and purified by affinity chromatography.

HER2 background

HER2 (human epidermal growth factor receptor 2), also known as HER2/neu or ERBB2, is a transmembrane protein expressed by epithelial cells that plays an important role in normal cell growth and differentiation [1]. HER2 overexpression causes uncontrollable cell proliferation, as most particularly evidenced in breast and ovarian cancers [1].
Therapeutic strategies aiming at killing HER2+ cancer cells use the FDA-approved trastuzumab, an anti-HER2-hIgG1 antibody. Binding of trastuzumab to HER2 results in cell death through different mechanisms, including antibody-dependent cell-mediated cytotoxicity and phagocytosis [2,3]. Antibody-drug conjugates (ADCs) combining trastuzumab with cytotoxic payloads allow targeted drug delivery to cancer cells in addition to the mAb-mediated effector functions [4].

Anti-HER2 ADC modes of action
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In a co-culture of HER2+ tumor cells and human peripheral blood monocytes (PBMCs), ADCs combining InvivoGen's Anti-HER2-hIgG1 and STING or TLR7 agonists induce a significantly higher production of IL-6 and CXCL10 pro-inflammatory cytokines than unconjugated agonists or negative control ADCs (see Figures).

Key features of Anti-HER2-hIgG1:

• Clinically-relevant variable region targeting human HER2 (trastuzumab)
• Human IgG1 constant region for high effector functions
• Functionally validated by flow cytometry and ADC-based cellular assays
• The absence of bacterial contamination has been confirmed

InvivoGen offers conjugatable PRR ligands for building immunostimulatory ADCs.
You may choose from TLR7 and STING agonists:
- Conjugatable TLR7 agonists: TL7-887 and TL7-975
- Conjugatable STING agonists: STG-982 and STG-968

Learn more about bioconjugation

InvivoGen’s products are for research use only, and not for clinical or veterinary use.

References

1. Rubin I. & Yarden Y. 2001. The basic biology of HER2. Ann Oncol.12 Suppl 1:S3-8.
2. Collins DM. et al., 2012. Trastuzumab induces antibody-dependent cell-mediated cytotoxicity (ADCC) in HER-2-non-amplified breast cancer cell lines. Ann Oncol. 23(7):1788-95.
3. Petricevic B. et al., 2013. Trastuzumab mediates antibody-dependent cell-mediated cytotoxicity and phagocytosis to the same extent in both adjuvant and metastatic HER2/neu breast cancer patients. J Transl Med. 11:307.
4. Tarantino P. et al., 2022. Antibody-drug conjugates: smart chemotherapy delivery across tumor histologies. CA Cancer J Clin. 72:165-182.

Figures

Cell surface staining of HER2 using Anti-HER2-hIgG1 mAb. ~5 x 10⁵ EL4-HER2 cells were incubated with 500 ng of Anti-HER2-hIgG1 mAb or an isotype control for 1h at 4°C. Cells were then washed and incubated with 250 ng of goat anti-human κ light chain antibody coupled to PE for 1h at 4°C. Cell surface staining was analyzed by flow cytometry.

Cell surface staining of HER2 using Anti-HER2-hIgG1 mAb. ~3 x 10⁵ SK-BR-3  cells were incubated with 1 µg of Anti-HER2-hIgG1 mAb or an isotype control for 30 min at 4°C. Cells were then washed and incubated with 250 ng of goat anti-human κ light chain antibody coupled to PE for 45 min at 4°C. Cell surface staining was analyzed by flow cytometry.

Dose-response of human PBMCs co-cultured with SK-BR-3 tumor cells and Anti-HER2/STG-982 ADC. 1.5x10⁵ human PBMCs and 5x10⁴ SK-BR-3 HER2⁺ tumor cells (A) or 1.5x10⁵ human PBMCs only (B) were incubated with increasing concentrations of Anti-HER2/STG-982 ADC (DAR ~5), Anti-β-Gal/STG-982 ADC (DAR ~5), or STG-982 only. After overnight incubation, the STING-mediated response was assessed by measuring the production of CXCL10 in PBMC and SK-BR-3 co-culture supernatants, using an ELISA. The optical density (OD) at 450 nm is shown.

Dose-response of human PBMCs co-cultured with SK-BR-3 tumor cells and Anti-HER2/TL7-887 ADC. 1.5x10⁵ human PBMCs and 5x10⁴ SK-BR-3 tumor cells (A) or 1.5x10⁵ human PBMCs only (B) were incubated with increasing concentrations of Anti-HER2/TL7-887 ADC (DAR ~6), Anti-β-Gal/TL7-887 ADC (DAR ~6), or TL7-887 only. After overnight incubation, the TLR7-mediated response was determined using HEK-Blue™ IL-6 reporter cells. Briefly, the levels of IL-6 production in PBMC and SK-BR-3 co-culture supernatants were assessed by measuring the SEAP activity of HEK-Blue™ IL-6 reporter cells, using QUANTI‑Blue™, a SEAP detection reagent. The optical density (OD) at 630 nm is shown.

Note: in the absence of tumor cells, PBMCs respond to higher doses of Anti-HER2/TL7-887 (panel B). This latter observation could be explained by cellular uptake through endocytosis after binding to Fc-receptor and/or to HER2 which is expressed at low levels by some PBMC subpopulations [1].
1. You F. et al., 2008. Low-level expression of HER2 and CK19 in normal peripheral blood mononuclear cells: relevance for detection of circulating tumor cells. J Hematol Oncol. 1(2): DOI: 10.1186/1756-8722-1-2

Specifications

Specificity: Targets cells expressing HER2

Variable region biosimilar: Trastuzumab

Isotype: Human IgG1, Kappa

Source: Chinese hamster ovary (CHO) cells 

Formulation: 0.2 μm filtered solution in 150 mM sodium chloride, 20 mM sodium phosphate buffer with 5% saccharose

Purification: Affinity chromatography with protein A

Tested Applications: Flow cytometry, Antibody-drug conjugation

Quality control:

• The binding of Anti-HER2-hIgG1 mAb to HER2 has been validated using flow cytometry and antibody-drug conjugate (ADC)-based cellular assays.
• The complete sequence of the antibody has been verified.
• The absence of bacterial contamination (e.g. lipoproteins and endotoxins) has been confirmed using HEK-Blue™ hTLR2 and HEK-Blue™ TLR4 cellular assays.

Contents

• 1 mg of purified Anti-HER2-hIgG1 monoclonal antibody (mAb), provided azide-free and lyophilized

 The product is shipped at room temperature.

 Store lyophilized antibody at -20 °C.

 Lyophilized product is stable for at least 1 year. Reconstituted antibody is stable for 1 month at 4°C and for 1 year at -20°C. Avoid repeated freeze-thaw cycles.

Citations