Daiichi Sankyo has presented initial Phase I/II data for MUC1-targeting antibody-drug conjugate (ADC) DS-3939, showing tumour reduction in 31 of 38 evaluable patients including ten confirmed partial responses in non-small cell lung cancer (NSCLC), ovarian cancer and breast cancer. The results were published at the European Society for Medical Oncology 2025 congress. The candidate utilises novel topoisomerase I inhibitor payload MAAA-1181a with a drug-to-antibody ratio (DAR) of eight through a cleavable tetrapeptide linker, demonstrating a manageable safety profile with nausea and vomiting as the most common treatment-emergent adverse events (TEAEs).

The MUC1 transmembrane glycoprotein represents a promising target due to overexpression in pancreatic, bladder and other epithelial cancers through tumour-associated epitope exposure from aberrant glycosylation. DS-3939 advances as the first clinical-stage MUC1 ADC, with potential applications across multiple solid tumours exhibiting MUC1 overexpression and polarity loss characteristic of aggressive malignancies.

Global pipeline analysis .

PharmCube's NextBiopharm® database identifies 18 MUC1 ADC active projects by 12 developers. Click here to request a free trial for NextBiopharm®.