Merck’s sacituzumab tirumotecan (sacituzumab tirumotecan; sac-TMT) scored a major regulatory and efficacy milestone in advanced endometrial cancer, delivering a global Phase 3 win that met both overall survival and progression-free survival endpoints. Merck said the study makes sac-TMT the first antibody-drug conjugate to improve survival in a global Phase 3 setting for this indication. The advance comes as the company continues to build an ADC-led oncology portfolio ahead of future patent cliffs, with additional expansion plans across multiple indications tied to its TROP2 ADC franchise. The endometrial result is positioned as the clearest late-stage readout supporting Merck’s global women’s cancer push. Industry attention is likely to center on how quickly Merck can convert the Phase 3 outcome into labeling and access in major markets and whether additional ongoing late-stage studies strengthen the durability of sac-TMT’s clinical differentiation versus other ADC mechanisms. Separately, Merck has multiple late-stage studies underway for the therapy and related assets, making the endometrial win a key datapoint for the near-term pace of oncology momentum.