Merck's sac-TMT cut endometrial cancer death risk 32% vs chemo; FDA grants priority review

Merck (MSD outside the US and Canada) on 26 October 2026 presented pivotal phase 3 TroFuse-005 results for sacituzumab tirumotecan (sac-TMT), an investigational TROP2-directed antibody-drug conjugate developed with Kelun-Biotech, in women with advanced or recurrent endometrial cancer who had already received platinum chemotherapy and anti-PD-1/L1 immunotherapy. Data were shown at ESMO 2026 and published simultaneously in The Lancet; the US FDA accepted a biologics licence application for priority review, with a target action (PDUFA) date of 15 June 2027.

Key results (company-reported interim analysis)

• 776 patients randomised to sac-TMT (4 mg/kg every two weeks) or physician’s choice of doxorubicin or paclitaxel.
• Median follow-up 14.0 months.
• Overall survival: risk of death cut by 32% (HR 0.68); median OS 19.0 vs 12.1 months.
• Progression-free survival: risk of progression or death cut by 41% (HR 0.59); median PFS 7.2 vs 3.9 months.
• Objective response: 35.1% vs 17.3%; median duration of response 11.1 vs 6.9 months.

Safety and limitations

Grade ≥3 treatment-related adverse events were more common with sac-TMT (54.4% vs 41.4%), led by anaemia, neutropenia and oral mucositis/stomatitis; treatment discontinuation was 3.1% vs 4.9%. TRAEs led to death in 0.8% (n=3) in each arm. The trial was open-label (patients and investigators knew the assigned therapy), though PFS was assessed by blinded independent review. Results come from a manufacturer press release and conference presentation; suitability for any patient depends on individual factors — talk to your oncologist.