Abstract 3131: Novel CDH17-targeting antibody-drug conjugate exhibits anti-tumor efficacy in preclinical models of gastrointestinal cancers

Abstract Antibody-drug conjugates (ADC) for oncology indications have been developed, however, only few of them are approved for the treatment of gastrointestinal (GI) cancers, which represent as a huge unmet medical need. As such, we developed a novel ADC of which monomethyl auristatin E (MMAE), an antimitotic agent, was conjugated to a cadherin-17 (CDH17) -targeting monoclonal antibody via protease-cleavable peptide valine-citrulline linker. CDH17 is highly restricted to the intestinal adherent junctions which is not accessible in healthy individuals. In contrast, it is overexpressed and becomes reachable in over half of the gastric and pancreatic cancer patients and in more than 95% of patients with colorectal cancer, making it a perfect target for ADC. Our ADC is designed to deliver MMAE specifically to CDH17-expressing tumors to exert the cytotoxic effect of MMAE on cancer cell, mitigating the undesired off-target cytotoxicity. LC/MS analysis revealed that MMAE was conjugated in a drug-to-antibody ratio of 4 with a yield of higher than 75%. ELISA showed that the binding of naked antibody and ADC to CDH17 was comparable (EC50, 0. 17 nM Part 1 (Regular Abstracts) ; 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84 (6Suppl): Abstract nr 3131.