FDA Grants Priority Review to Sac-TMT for Endometrial Cancer

Sacituzumab tirumotecan (sac-TMT; Merck/Kelun-Biotech), an investigational TROP2-directed antibody-drug conjugate (ADC), improved overall survival (OS) and progression-free survival (PFS) compared with chemotherapy in patients with advanced or recurrent endometrial cancer previously treated with platinum-based chemotherapy and anti-PD-1/PD-L1 immunotherapy, according to Merck. Results from the phase 3 TroFuse-005 trial were presented at the European Society for Medical Oncology (ESMO) Congress 2026 and published simultaneously in The Lancet.

Based on these data, the FDA has accepted for Priority review a biologics license application (BLA) for sac-TMT for adults with endometrial cancer who previously received platinum-containing chemotherapy and a PD-1 or PD-L1 inhibitor, separately or in combination. The target action date is June 15, 2027. Sac-TMT, developed by Kelun-Biotech, carries a belotecan-derived topoisomerase I inhibitor payload.

The randomized, open-label, multicenter trial enrolled 776 patients, who received sac-TMT 4mg/kg every 2 weeks or physician’s choice of doxorubicin or paclitaxel. At a prespecified interim analysis with a median follow-up of 14.0 months, sac-TMT was associated with a 32% lower risk of death (hazard ratio, 0.68; 95% CI, 0.55-0.84), with median OS of 19.0 months vs 12.1 months. Median PFS was 7.2 months vs 3.9 months, which Merck reported as a 41% reduction in the risk of disease progression or death.

The objective response rate was 35.1% with sac-TMT and 17.3% with chemotherapy, and median duration of response was 11.1 and 6.9 months, respectively. Grade ≥3 treatment-related adverse events occurred in 54.4% and 41.4% of patients; the most common grade ≥3 events with sac-TMT were anemia (23.7%), neutropenia (20.1%), and oral mucositis/stomatitis (9.9%). Treatment-related adverse events led to death in 3 patients (0.8%) in each arm. Merck said no new safety signals were observed.

The efficacy results are from an interim analysis of an open-label trial..

Source: Merck. Sacituzumab tirumotecan (sac-TMT) reduced the risk of death by 32% and the risk of disease progression or death by 41% compared to chemotherapy in certain patients with advanced or recurrent endometrial cancer. News release. Merck; October 26, 2026. Accessed October 28, 2026.