Anti-Claudin-2 Antibody-Drug Conjugates for the Treatment of Colorectal Cancer Liver Metastasis.

We have demonstrated that Claudin-2 is required for colorectal cancer (CRC) liver metastasis. Expression of Claudin-2 in primary CRC is associated with poor survival and is highly expressed in liver metastases. Claudin-2 also promotes breast cancer liver metastasis by enabling seeding and cancer cell survival. These observations support Claudin-2 as a potential therapeutic target for managing patients with liver metastases. Antibody-drug conjugates (ADCs) are promising anti-tumor therapeutics that combine the specific targeting ability of monoclonal antibodies with the potent cell killing activity of cytotoxic drugs. Here we report the generation of twenty-eight anti-Claudin-2 antibodies for which the binding specificities, the cross-reactivity with Claudin family members and the cross-species reactivity were assessed by flow cytometry analysis. Multiple drug conjugates were tested and PNU was selected for conjugation with anti-Claudin-2 antibodies binding either extracellular loop 1 or extracellular loop 2. Anti-Claudin-2 ADCs were efficiently internalized and effective at killing Claudin-2-expressing CRC cancer cells in vitro. Importantly, PNU-conjugated-anti-Claudin-2 ADCs impaired the development of replacement type CRC liver metastases in vivo, using established CRC cell lines and patient-derived xenograft (PDX) models of CRC liver metastases. Our results suggest that the development of ADCs targeting Claudin-2 is a promising therapeutic strategy for managing CRC liver-metastatic patients that present with replacement type liver metastases.