An experimental targeted drug called sac-TMT significantly reduced the risk of cancer progression and death in patients with advanced endometrial cancer, according to results from a large Phase 3 clinical trial published on October 26, 2026, in The Lancet.
For individuals whose uterine lining cancer returns or advances after standard chemotherapy and immunotherapy, treatment choices remain limited. Sac-TMT is an antibody-drug conjugate that pairs a monoclonal antibody with a potent cell-killing payload to home in on specific tumor proteins.
In Plain English: The Clinical Takeaway
- Targeted Delivery: Sac-TMT acts like a guided missile, attaching to TROP2 proteins on cancer cells to deliver a chemotherapy payload directly where it is needed.
- Delaying Progression: Clinical trial data showed patients taking the experimental drug lived a median of 7.2 months without their cancer worsening, compared to 3.9 months on standard chemotherapy.
- Survival Gains: Median overall survival reached 19 months for the sac-TMT group, versus 12.1 months for standard chemotherapy.
Trial Results and Survival Data
The TroFuse-005 trial enrolled 776 patients across 242 cancer centers in 31 countries and regions. Participants had advanced or recurrent endometrial cancer that had progressed after platinum-based chemotherapy and an anti-PD-1 or anti-PD-L1 immunotherapy.
Researchers randomly assigned 386 patients to receive sac-TMT and 390 patients to receive standard chemotherapy, which consisted of either doxorubicin or paclitaxel. The trial evaluated progression-free survival, overall survival, and measurable tumor shrinkage.
| Outcome Measure | Sac-TMT Group | Standard Chemotherapy |
|---|---|---|
| Median Progression-Free Survival | 7.2 months | 3.9 months |
| Median Overall Survival | 19 months | 12.1 months |
| Tumor Shrinkage Rate | 35.1% | 17.3% |
The rate of cancer progression or death was 41 percent lower in the sac-TMT group. The drug also lowered the risk of death by 32 percent.
“For most patients whose cancer progresses after platinum chemotherapy and immunotherapy, the main option today is single-agent chemotherapy, such as doxorubicin or paclitaxel. There is no established standard of care,” expressed Dr. Domenica Lorusso, PhD, who serves as global lead investigator for the study and holds a professorship in obstetrics and gynecology at Humanitas University located in Milan.
Side Effects and Regulatory Review
The trial noted notable adverse events associated with the treatment. Common side effects included anemia, neutropenia, oral mucositis, and dry, itchy eyes.
Data showed that 69 percent of patients receiving sac-TMT experienced at least one grade 3 or higher adverse event, compared to 57 percent of those on standard chemotherapy. Serious adverse events occurred in 35 percent of the sac-TMT group and 32 percent of the chemotherapy group, with treatment-related deaths occurring in less than 1 percent of patients in either arm.
The U.S. Food and Drug Administration accepted Merck’s Biologics License Application for priority review. The agency set June 15, 2027, as its target action date.
Contraindications & When to Consult a Doctor
Sac-TMT is not approved for general use and remains under regulatory review. It was not studied as a replacement for surgery or standard early-stage treatments.
Patients with advanced or recurrent endometrial cancer should consult their oncology team regarding prior treatment history, required blood-count monitoring for anemia and neutropenia, and any new eye symptoms. Longer-term follow-up data are still needed to determine the durability of these clinical benefits.
References
- Lorusso D, Martin-Babau J, Floor B, et al. Sacituzumab tirumotecan versus treatment of physician’s choice in previously treated endometrial cancer (TroFuse-005/ENGOT-en23/GOG-3095): a randomised, open-label, phase 3 trial. The Lancet. Published online October 26, 2026.
- National Cancer Institute. Endometrial SPOREs. Cancer.gov. March 27, 2025.
