The practical message from TroFuse-005 is straightforward: if approved, sacituzumab tirumotecan (sac-TMT) could replace single-agent doxorubicin or paclitaxel for many patients with advanced or recurrent endometrial cancer previously treated with platinum and anti–PD-1/PD-L1 therapy.

The benefit was not limited to radiographic response. Sac-TMT improved both independently reviewed progression-free survival and overall survival. The tradeoff was a higher rate of grade 3 or worse treatment-related toxicity, with cytopenias, stomatitis, and ocular toxicity requiring attention from the beginning of treatment.

Sac-TMT remains investigational for endometrial cancer in the United States. The FDA has accepted the application for Priority Review and set June 15, 2027, as its target action date.

TroFuse-005 Results

TroFuse-005/ENGOT-en23/GOG-3095 was a global, open-label phase 3 trial involving 776 patients with advanced or recurrent endometrial carcinoma, including a small number with carcinosarcoma. Eligible patients had received platinum chemotherapy and an anti–PD-1 or PD-L1 agent, either together or separately, and no more than three prior systemic regimens.

Patients were assigned 1:1 to:

• Sac-TMT 4 mg/kg intravenously every two weeks
• Physician’s choice of doxorubicin or paclitaxel

At a median follow-up of 14 months:

• Median OS was 19.0 versus 12.1 months, respectively (HR 0.68; 95% CI, 0.55–0.84).
• Median PFS by blinded independent central review was 7.2 versus 3.9 months (HR 0.59; 95% CI, 0.50–0.70).
• ORR was 35.1% versus 17.3%.
• Median duration of response was 11.1 versus 6.9 months.
• Twelve-month OS was 63.4% versus 50.8%.
• Twelve-month PFS was 29.4% versus 12.4%.

Sarah Lynam, MD, a gynecologic oncologist at UH Seidman Cancer Center, described this as the first reported phase 3 analysis of an ADC in this setting. She emphasized the nearly seven-month difference in median OS, but also cautioned that “almost all patients had some form of treatment-related side effects.”

What Changes in Practice?

Pending regulatory approval, the clearest candidates are patients whose disease has progressed after both platinum and checkpoint inhibition and who otherwise would be offered single-agent chemotherapy.

Patient selection may matter, however. Randomization was stratified by mismatch-repair status and by low versus medium-high TROP2 expression. Approximately 84% of patients had mismatch repair–proficient tumors, and about 80% had medium-high TROP2 expression. The OS benefit was concentrated in these groups (HR 0.62 and 0.58, respectively), with no clear benefit in mismatch repair–deficient (HR 0.99) or TROP2-low (HR 1.07) disease. These subgroups were small and should be interpreted cautiously, but they raise the question of whether TROP2 testing should guide use. Small subgroups, particularly carcinosarcoma, should not be overinterpreted. This is especially true for carcinosarcoma.

David G. Mutch, MD, a WashU Medicine professor of obstetrics and gynecology at Siteman Cancer Center and principal investigator of the Route 66 Endometrial Cancer SPORE, sees this as “a significant treatment breakthrough for patients pre-treated with platinum I/O therapy.”

Dr. Mutch also pointed to the drug’s bifunctional linker—the component joining the TROP2 antibody to its topoisomerase I inhibitor payload—as an area with wider research implications. He suggested that the platform could potentially become a backbone for other ADCs. That possibility remains investigational, but it is one reason sac-TMT may have importance beyond this single trial.

Toxicity Will Shape Real-World Use

Any-grade treatment-related adverse events occurred in 97.1% of patients receiving sac-TMT and 89.6% receiving chemotherapy. Grade 3 or higher events occurred in 54.4% and 41.4%, respectively.

With sac-TMT, the most common grade 3 or higher events included:

• Anemia: 23.7%
• Neutropenia: 20.1%
• Oral mucositis or stomatitis: 9.9%

Ocular surface toxicity of any grade occurred in 30.5% of patients receiving sac-TMT. Interstitial lung disease or pneumonitis was uncommon, reported in 1.8%.

These findings argue for early blood-count monitoring, proactive oral care, and direct questioning about dry eyes, irritation, and visual symptoms. Stomatitis decreased after mitigation measures, including preventive mouthwash, were introduced. Dose interruptions and reductions were common, but permanent discontinuation for treatment-related toxicity remained low at 3.1%, compared with 4.9% for chemotherapy. Quality-of-life scores were maintained over time.

As Dr. Lynam put it, the results require clinicians to focus on “quantity as well as quality of life.” That is the central clinical issue. Sac-TMT produced a meaningful survival advantage, but treatment planning will need to include supportive care, dose modification, and an honest discussion of what additional time on therapy may look like for the individual patient.

Questions That Remain

Longer follow-up will help define the durability of the OS benefit and later toxicities. Clinicians will also need more detail on outcomes by TROP2 level, molecular subtype and histology, as well as guidance on sequencing sac-TMT with other biomarker-directed treatments.

For now, TroFuse-005 establishes sac-TMT as the first agent in this setting to outperform physician’s-choice chemotherapy in a randomized phase 3 trial on PFS, OS, and response rate. If approved, it is likely to become a major post-platinum, post-immunotherapy option—but not one that can be separated from careful toxicity management.