Merck sac-TMT cuts death risk in endometrial cancer

Merck and Kelun-Biotech's sacituzumab tirumotecan cut the risk of death by 32 percent in advanced or recurrent endometrial cancer in the Phase 3 TroFuse-005 trial, with median survival of 19 months against 12.1 months on chemotherapy.

Why it matters: TroFuse-005 is the first Phase 3 trial of a TROP2 antibody-drug conjugate to improve survival in this setting, and sac-TMT is central to Merck's plan to replace Keytruda revenue when that drug loses patent protection in 2028.

Data as of Phase 3 TroFuse-005 results presented at the ESMO Congress in Madrid on October 26, 2026 and published simultaneously in The Lancet, as reported by FirstWord Pharma from the presentation and by STAT, whose full text beyond its opening section is paywalled; trial population and design are from Merck's own ESMO release, read in full. Survival figures are the presentation figures as reported, not yet in a Merck results release read in this run.

Sacituzumab tirumotecan, or sac-TMT, the TROP2 antibody-drug conjugate Merck is developing with China’s Kelun-Biotech, reduced the risk of death by 32 percent in patients with advanced or recurrent endometrial cancer in the Phase 3 TroFuse-005 trial, according to results presented at the ESMO Congress in Madrid on Monday and published simultaneously in The Lancet. At 14 months of follow-up, median overall survival was 19 months on sac-TMT against 12.1 months on chemotherapy, the risk of progression or death was reduced by 41 percent, and the response rate was 35.1 percent against 17.3 percent, FirstWord Pharma reported from the presentation.

The trial enrolled 776 patients whose cancer had progressed after platinum based chemotherapy and anti PD-1 or anti PD-L1 immunotherapy, and compared sac-TMT with a physician’s choice of doxorubicin or paclitaxel. STAT reported that Merck is running 18 global Phase 3 studies of sac-TMT, including 10 in women’s cancers, to support approvals outside China, where Kelun has already won approval, and that the drug is crucial to replacing revenue lost when Keytruda loses patent protection in 2028.

Merck sac-TMT cuts death risk in endometrial cancer

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