Related Experiment Video
Updated: May 23, 2025
Tracking Bispecific Antibody-Induced T Cell Trafficking Using Luciferase-Transduced Human T Cells
Published on: May 12, 2023
Development of a bispecific antibody-drug conjugate targeting EpCAM and CLDN3 for the treatment of multiple solid
Meiying Luo1, Xiaohuan Wang2, Guoji Yu3
1State Key Laboratory of Nonlinear Mechanics, Beijing Key Laboratory of Engineered Construction and Mechanobiology, Institute of Mechanics, Chinese Academy of Sciences, No. 15, North Fourth Ring Road West, Beijing, 100190, China.
Abstract:
Epithelial cell adhesion molecule (EpCAM), a tumor antigen for antibody-drug conjugates (ADCs), is highly expressed in many epithelial cancers. However, the clinical progress of EpCAM ADCs has been challenging, primarily due to their toxicity in normal high-expression tissues such as the gastrointestinal tract. CLDN3 is highly co-expressed with EpCAM in various human malignancies, coupled with its minimal presence in normal tissues, rendering it an ideal target for developing potent therapeutic ADCs. Here, we developed a bispecific ADC (BsADC) targeting EpCAM and CLDN3, designed to avoid toxicity in normal tissues with high EpCAM expression. The parental monoclonal antibodies (mAbs) were screened for high binding and endocytosis activities on tumor cell lines. We then modified them into monovalent structures and selected clones with decreased binding and endocytosis activities. We combined these clones into bispecific antibodies (BsAbs) and finally chose the molecules with restored binding and endocytosis activities as lead molecules. The BsADCs were generated by conjugating the Drutecan (Dxd) to BsAbs via a cleavable linker. These conjugates exhibit potent binding and effectively inhibit the growth of tumor cells with high levels of both EpCAM and CLDN3, indicating their anti-tumor efficacy. Importantly, they show weak binding to cells with high EpCAM but low CLDN3, implying minimal toxicity to normal tissues with elevated EpCAM expression. Moreover, the BsADCs displayed advantageous pharmacokinetics and low toxicity in mice. These findings position the BsADCs targeting EpCAM and CLDN3 as promising candidates for treating multiple solid tumors.
Insights
A novel bispecific antibody-drug conjugate (ADC) targets both EpCAM and CLDN3, reducing toxicity in normal tissues. This EpCAM and CLDN3 targeting ADC shows potent anti-tumor efficacy and low toxicity in preclinical studies.
Area of Science:
- Oncology
- Immunology
- Biotechnology
Background:
- Epithelial cell adhesion molecule (EpCAM) is a key target for antibody-drug conjugates (ADCs) in epithelial cancers.
- Clinical use of EpCAM ADCs is limited by toxicity in normal tissues with high EpCAM expression.
- Claudin 3 (CLDN3) is co-expressed with EpCAM in malignancies and minimally expressed in normal tissues, making it an attractive co-target.
Purpose of the Study:
- To develop a bispecific ADC (BsADC) targeting both EpCAM and CLDN3 to mitigate toxicity in normal tissues.
- To engineer ADCs with improved therapeutic index by leveraging differential expression of EpCAM and CLDN3.
Main Methods:
- Screening and modification of monoclonal antibodies for EpCAM and CLDN3 binding and endocytosis.
- Construction of bispecific antibodies (BsAbs) with restored binding and endocytosis.
- Generation of BsADCs by conjugating Drutecan (Dxd) to BsAbs via a cleavable linker.
Main Results:
- The developed BsADCs demonstrated potent binding and inhibited tumor cell growth in vitro.
- BsADCs showed weak binding to cells with high EpCAM but low CLDN3, suggesting reduced normal tissue toxicity.
- In vivo studies in mice revealed favorable pharmacokinetics and low toxicity profiles for the BsADCs.
Conclusions:
- Bispecific ADCs targeting EpCAM and CLDN3 are effective against tumors co-expressing these antigens.
- This dual-targeting strategy offers a promising approach to reduce ADC-related toxicities.
- EpCAM/CLDN3 BsADCs represent a potential new therapeutic option for various solid tumors.
