Antibody-drug conjugates targeting DDR1 as a novel strategy for treatment of breast cancer.

Antibody-drug conjugates (ADCs) have emerged as a novel class of targeted cancer therapies and been successfully applied in the treatment of breast cancer (BC). Discoidin domain receptor 1 (DDR1) is a single transmembrane receptor tyrosine kinase and has been identified as a possible target for cancer. In this study, we explored the potential of an anti-DDR1 ADC, named T₄H₁₁-DM4, for the treatment of DDR1-positive BC. We demonstrated that high protein expression and RNA expression of DDR1 in BC tissues. In vitro, T₄H₁₁-DM4 was potently cytotoxic to DDR1-expressing BC cells, with IC50 in the nanomolar range. In mice BC xenograft models, T₄H₁₁-DM4 dramatically eliminated BC tumours, without observable toxicity. Taken together, our findings demonstrated that DDR1 can serve as a promising therapeutic target for BC.