Rahway, N.J., USA – May 18, 2026
Merck announced that its pivotal Phase 3 TroFuse-005 clinical trial evaluating sacituzumab tirumotecan (sac-TMT) achieved its primary endpoints of overall survival (OS) and progression-free survival (PFS) in patients with advanced or recurrent endometrial cancer. The investigational TROP2-directed antibody-drug conjugate (ADC) demonstrated statistically significant improvement compared with standard chemotherapy, marking a major breakthrough in the treatment landscape for patients who previously received platinum-based chemotherapy and anti-PD-1/L1 immunotherapy. The results position sac-TMT as a potential new standard for difficult-to-treat gynecologic cancers and strengthen Merck’s rapidly expanding oncology pipeline.
TroFuse-005 Becomes First Global Phase 3 Success for TROP2 ADC
According to Merck, the TroFuse-005 trial is the first global Phase 3 study to demonstrate significant improvement in both OS and PFS for patients with advanced or recurrent endometrial cancer who progressed after prior platinum chemotherapy and immunotherapy treatment. Importantly, sac-TMT also became the first and only ADC to achieve this milestone in this patient population, highlighting the growing importance of targeted oncology therapies in gynecologic cancers.
The randomized, open-label, multicenter global trial enrolled 776 patients with endometrial carcinoma and carcinosarcoma. Participants received either sac-TMT or physician’s choice chemotherapy, including doxorubicin or paclitaxel. The trial also met its key secondary endpoint of objective response rate, while maintaining a safety profile consistent with previously reported studies and showing no new safety signals.
Clinical investigators noted that patients with disease progression after platinum-based chemotherapy and immunotherapy currently face limited treatment options and poor long-term outcomes. The success of sac-TMT therefore represents a potentially transformative advancement for women with aggressive or treatment-resistant endometrial cancer.
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Merck Expands Leadership in ADC and Women’s Cancer Research
Merck emphasized that the positive TroFuse-005 outcome validates its strategy to build one of the pharmaceutical industry’s largest and most ambitious ADC clinical development programs. The company’s broader TroFuse program currently includes 17 ongoing global Phase 3 trials spanning multiple tumor types, including endometrial, bladder, cervical, ovarian, breast, gastric, and non-small cell lung cancers.
Among these, more than 10 Phase 3 studies focus specifically on women’s cancers, reinforcing Merck’s long-term commitment to advancing treatment innovation in oncology. Researchers are evaluating sac-TMT both as a standalone therapy and in combination with immunotherapies across early-stage and late-stage disease settings. The company stated that more than 15,000 patients worldwide are participating in the sac-TMT development program, making it one of the broadest global ADC initiatives currently underway.
Merck researchers highlighted sac-TMT’s specialized bifunctional linker technology, which was designed to maximize payload delivery directly to tumor cells while minimizing effects on healthy tissue. This mechanism may contribute to improved efficacy and tolerability compared with traditional chemotherapy approaches.
Growing Need for Advanced Endometrial Cancer Therapies
Endometrial cancer remains one of the fastest-growing gynecologic cancer burdens worldwide. Merck noted that the disease is among the few cancers experiencing increases in both incidence and mortality globally. In the United States alone, approximately 68,270 new cases and 14,450 deaths from endometrial cancer are expected in 2026.
Medical experts believe the TroFuse-005 findings could significantly influence future standards of care for recurrent endometrial cancer, especially for patients who have exhausted existing treatment options. The company plans to present detailed trial results at an upcoming medical conference and discuss the findings with regulatory authorities worldwide to support future approvals.
The study also highlights the growing momentum behind precision oncology and ADC-based cancer therapeutics, which are increasingly being viewed as next-generation targeted treatment platforms capable of improving survival while reducing systemic toxicity. As competition intensifies within the oncology sector, Merck’s latest success further strengthens its position in the global cancer therapeutics market.
Source: Merck press release
