Merck Reports Phase 3 TroFuse-005 Trial Shows Sac-TMT Improves Overall And Progression-Free Survival, Meeting Both Dual Primary And Key Secondary Endpoints Of ORR In Advanced Or Recurrent Endometrial Cancer; FDA Priority Review Accepted

TroFuse-005 is the first and only global Phase 3 study of a TROP2 ADC to demonstrate improved overall survival (OS) and progression-free survival (PFS) compared to chemotherapy in these patients who have received prior platinum-based chemotherapy and anti-PD-1/L1 immunotherapy

Results from TroFuse-005 were selected for an official press briefing and will be presented during a Presidential Symposium session at the European Society for Medical Oncology (ESMO) Congress 2026 and published simultaneously in The Lancet

Based on these data, the U.S. FDA has accepted for priority review a Biologics License Application for sac-TMT for these patients

Merck (NYSE:MRK), known as MSD outside of the United States and Canada, today announced the first presentation of results from the pivotal Phase 3 TroFuse-005 trial evaluating sacituzumab tirumotecan (sac-TMT), an investigational TROP2-directed antibody-drug conjugate (ADC) being developed in collaboration with Kelun-Biotech, in patients with advanced or recurrent endometrial cancer who have received prior platinum-based chemotherapy and anti-PD-1/L1 immunotherapy. At a pre-specified interim analysis, the study demonstrated statistically significant and clinically meaningful improvement in its dual primary endpoints of overall survival (OS) and progression-free survival (PFS) as well as its key secondary endpoint of objective response rate (ORR) compared with treatment of physician’s choice (TPC; doxorubicin or paclitaxel). TroFuse-005 is the first global Phase 3 trial and the first ADC to demonstrate statistically significant improvement in both OS and PFS compared to chemotherapy for these patients with advanced or recurrent endometrial cancer. These late-breaking data will be presented for the first time today during a Presidential Symposium session at the European Society for Medical Oncology (ESMO) Congress 2026 [Presentation #LBA11], were selected for an official ESMO press briefing, and were published simultaneously in The Lancet.

At the time of analysis, with a median follow-up of 14.0 months, sac-TMT reduced the risk of death by 32% (HR=0.68; 95% CI, 0.55-0.84; P<0.0001), extending median OS by 6.9 months compared with TPC (19.0 months vs. 12.1 months). Sac-TMT also reduced the risk of disease progression or death by 41% (HR=0.59; 95% CI, 0.50-0.70; P<0.0001), extending median PFS by 3.3 months compared with TPC (7.2 months vs. 3.9 months). The study improved ORR by 17.8% (95% CI, 11.6–23.9; P <0.00001), double what was observed in the TPC arm (35.1% vs. 17.3%), and complete responses occurred in 6.1% of patients on the sac-TMT arm and 4.5% of patients on the chemotherapy. Responses were durable, with a median duration of response of 11.1 months (95% CI, 9.2–13.0) in the sac-TMT arm and 6.9 months (95% CI, 5.4–9.1) in the TPC arm.