Consider Eurofins DiscoverX’s custom development capabilities for custom cell line assays, ready-to-use kits, and enzyme development.
Assay Solutions for Antibody Drug Conjugates (ADCs)
Cell-based Assays for Screening and Characterization of ADCs
Antibody Drug Conjugates (ADCs) are an important and growing modality in oncology, offering highly targeted delivery of cytotoxic agents, including PROTACs, siRNA, steroids, and more, to tumor cells while minimizing systemic toxicity. Their potential is now expanding beyond cancer, with emerging applications in areas such as inflammation and immunology. ADCs link monoclonal antibodies to highly potent cytotoxic agents via specialized linkers, enabling selective delivery to antigen-expressing tumor cells. This targeted approach enhances antitumor efficacy while minimizing off-target toxicity. Currently, approved ADCs, including trastuzumab deruxtecan, brentuximab vedotin, and enfortumab vedotin, have demonstrated strong clinical activity across a broad range of solid tumors and hematologic malignancies. As precision oncology advances, the growing success of ADCs across multiple cancer indications underscores their increasing clinical relevance and is driving exploration of their utility beyond oncology, including emerging opportunities in inflammatory and immunologic diseases.
Comprehensive MOA (mechanism of action) evaluation is critical for ADC discovery and optimization, capturing multiple functional layers: antigen recognition, receptor internalization, intracellular trafficking, payload release, cytotoxic activity, and Fc-mediated immune responses. Eurofins DiscoverX provides high-throughput, cell-based assays to quantify these mechanisms:
- Receptor Internalization PathHunter® Assays: Track ADC-mediated endosomal uptake to assess potency, internalization kinetics, and rank candidates
- Cytotoxicity (KILR® Platform): Measures payload-dependent killing in antigen-specific cancer cell models, reflecting target-dependent cytotoxic activity
- Effector Function Assays: Quantify ADCC, ADCP, and CDC to evaluate Fc-mediated immune contributions to antitumor effects
By providing mechanism-relevant data across the full ADC workflow, these assays support preclinical optimization, enabling selection of the most promising candidates and accelerating their path to clinic. Specific cell models can also be custom‑generated to support the unique requirements of your ADC development program. Please contact Customer Support to discuss your specific program needs.
Product Highlights
- Antibody-mediated Receptor Internalization Assay – Quantitative ADC-mediated receptor internalization by detecting endosomal localization of the internalized receptor, reflecting the MOA and enabling rank-ordering and characterization of ADC potency
- Cytotoxicity Assays for Measuring ADC Payload-mediated Killing – Sensitive detection of payload-mediated cytotoxicity by targeting specific antigens in relevant cancer cell models, supporting evaluation of target-dependent killing activity
- Fc-mediated Effector Function – Assays specifically measures ADCC, ADCP, and CDC activity of ADCs
Receptor Internalization
Payload-mediated Cytotoxicity
Fc-mediated ADCC & ADCP
Resources
Related Pages
Receptor Internalization
Antibody-Drug Conjugates (ADCs) generally enter cells via receptor-mediated endocytosis, trafficking through the endosomal system before maturing into lysosomes, where most of the drug release occurs. Measure the ability of antibodies targeting specific receptors, such as immune checkpoint receptors, to trigger receptor internalization by quantitatively assessing ADC trafficking through endosomes. Identify and prioritize antibodies with high internalization efficiency that are critical for effective payload delivery and optimal for candidate selection in ADC development.
Assay Principle: Measure ADC-mediated Receptor Internalization
Measure the ability of antibodies targeting specific receptors, such as immune checkpoint receptors, to trigger receptor internalization by quantitatively assessing endosomal trafficking. Identify and prioritize antibodies with high internalization efficiency that are critical for effective payload delivery and optimal for candidate selection in ADC development.
Assay principle for antibody-mediated receptor internalization assays. The PathHunter internalization assay platform is based on the industry-validated Enzyme-Fragment Complementation (EFC) technology. Stably engineered cell lines co-express two β-galactosidase (β-gal) fragments: a small donor (orange U symbol) either attached to the receptor (as in this example) or the endosome and a larger enzyme acceptor (EA; blue E symbol) that is tagged to the endosome (as in this example) or the receptor. Upon ADC binding, receptor-ADC complexes internalize via endocytosis into early endosomes, bringing fragments into proximity to form active β-gal. The resulting chemiluminescent signal is proportional to the extent of internalization. Learn more about Eurofins DiscoverX internalization assays.
Assays
Eurofins DiscoverX ADC internalization assays are MOA-reflective and enable rank-ordering and characterization of ADC potency in inducing receptor internalization. These assays provide a highly specific and quantitative measure of ADC-mediated receptor internalization by measuring endosomal localization of the internalized receptor.
| Target | Product Description | Catalog Number |
|---|---|---|
| BCMA | PathHunter Human BCMA Stable Cell Line Internalization Assay (U2OS) | 793-1145C3 |
| CD33 | PathHunter Human CD33 (SIGLEC3) Stable Cell Line Internalization Assay (U2OS) | 793-1148C3 |
| ErbB2 (Her2) | PathHunter ErbB2 Cell Line Internalization Assay (constitutive) (U2OS) | Inquire |
| PathHunter ErbB2 Cell Line Internalization Assay (inducible) (U2OS) | Inquire |
Applications
Belantumab Mafodotin, BCMA Internalization
The PathHunter BCMA Internalization Cell Line Assay measures BCMA internalization mediated by antibodies or ADCs. A. The BCMA internalization assay demonstrates dose-dependent receptor internalization upon treatment with an anti-BCMA antibody, whereas the isotype IgG1 control shows no response. B. Both belantamab-mafodotin and the belantamab-biosimilar induce robust, concentration-dependent internalization in BCMA-expressing U2OS cells, but not in native U2OS cells, confirming target specificity.
Trastuzumab Emtansine, ErbB2 Internalization
ADC-Induced ErbB2 internalization in PathHunter cell line assays with constitutive and inducible promoters. A. U2OS cells with constitutive (CMV-driven) ErbB2 expression were treated with increasing concentrations of trastuzumab emtansine (Kadcyla®) or trastuzumab in the presence of L26 (a second anti-ErbB2 antibody). Both induce a strong, dose-dependent internalization response in the PathHunter ErbB2 Internalization Cell Line, demonstrating specific receptor-mediated trafficking and robust assay performance B. U2OS cells with inducible (Tet-responsive) ErbB2 expression were treated with increasing concentrations of trastuzumab emtansine (Kadcyla), trastuzumab, pertuzumab, or L26 antibody. A strong, dose-dependent internalization response is observed only for trastuzumab emtansine and trastuzumab co-treated with L26. This confirms ErbB2-dependent receptor internalization can be modulated through controlled expression, enabling sensitive evaluation of antibody- and ADC-driven trafficking activity. Kadcyla is a registered trademarks owned by Genentech, Inc.
Gemtuzumab Ozagamicin and Lintuzuman, CD33 Internalization
Cross-linking enhances ADC-driven CD33 internalization in the PathHunter CD33 Internalization Cell Line Assay. A. Gemtuzumab ozagamicin induces CD33 internalization in U2OS cells with a markedly stronger response when co-treated with anti-IgG4. This indicates Fc-mediated enhancement of receptor trafficking. B. Lintuzumab shows increased, dose-dependent CD33 internalization in the presence of anti-IgG1, confirming Fc-driven amplification of antibody-mediated internalization.