Merck ADC cuts death risk by one-third in advanced endometrial cancer

A Phase 3 trial of an antibody-drug conjugate developed by Merck and China’s Kelun-Biotech reduced the risk of death by one-third in patients with advanced endometrial cancer, according to results reported by STAT News.

The trial tested the targeted therapy, known as sac-TMT, against existing treatment options for the disease. Endometrial cancer, which begins in the lining of the uterus, has historically offered patients with advanced or recurrent disease few effective options once standard chemotherapy fails. STAT News reported the data were presented at the European Society for Medical Oncology meeting in 2026.

Merck licensed rights to the drug from Kelun-Biotech as part of a broader push by Western pharmaceutical companies to acquire antibody-drug conjugates developed by Chinese biotech firms. Antibody-drug conjugates combine a targeting antibody with a cytotoxic payload, delivering chemotherapy directly to cancer cells while limiting damage to healthy tissue.

STAT News characterized the one-third reduction in death risk as a significant finding for a disease area that has seen comparatively slow progress relative to other cancers. The report did not specify the full patient population size or the comparator arm’s exact outcomes beyond the topline risk reduction.

Further detail on the trial’s design, patient demographics, and side-effect profile was not included in the available reporting. The findings mark a notable data point in the competition among drugmakers to develop and acquire next-generation antibody-drug conjugates for solid tumors.