October 19, 2025 — Leads & Copy — Initial results from a phase 1/2 trial of Daiichi Sankyo’s DS-3939 demonstrate promising clinical activity in patients with previously treated advanced solid tumors. The data was presented at the 2025 European Society for Medical Oncology (#ESMO25).
DS-3939, a potential first-in-class tumor-associated mucin-1 (TA-MUC1) directed DXd antibody drug conjugate (ADC), showed preliminary safety and efficacy in 64 patients with advanced solid tumors. One confirmed complete response was observed in a patient with ovarian cancer, and 10 confirmed partial responses were seen in patients with ovarian, non-small cell lung, and breast cancers.
The most common treatment-emergent adverse events were nausea, vomiting, and fatigue. Enrollment continues into the dose expansion part of the trial.
Manish R. Patel, MD, Director of Drug Development, Florida Cancer Specialists and Sarah Cannon Research Institute, noted the encouraging nature of the results for patients with limited treatment options. Ken Takeshita, MD, Global Head, R&D, Daiichi Sankyo, stated that the results offer preliminary evidence that targeting the novel tumor antigen TA-MUC1 may be a promising treatment approach.
The trial is ongoing and enrolling patients across multiple tumor types at sites globally.
Source: Daiichi Sankyo
