Merck (MSD) said its next-generation Antibody-Drug Conjugate (ADC) cancer therapy candidate "sac-TMT," under development, improved survival in a global phase 3 trial for endometrial cancer. If the drug wins global approval, competition is expected to intensify in the market for ADC cancer drugs targeting TROP2.
MSD and China-based biotech Kelun (Kelun Biotech, hereafter Kelun) said on the 18th (local time) that in a global phase 3 study of patients with advanced or recurrent endometrial cancer, sac-TMT significantly improved both overall survival (OS) and progression-free survival (PFS) compared with standard chemotherapy.
Sac-TMT is a new ADC cancer drug candidate that targets TROP2, a protein overexpressed on the surface of cancer cells. ADCs are next-generation anti-cancer agents that combine a potent anti-cancer drug with an antibody that homes to cancer cells, and they have recently emerged as the most competitive field in the global pharmaceutical industry.
The trial enrolled 776 patients with endometrial cancer or carcinosarcoma. Patients had previously received platinum-based chemotherapy and immunotherapy (PD-1/PD-L1) but experienced disease progression. The control arm received standard chemotherapies such as doxorubicin or paclitaxel.
The company said, "This is the first global phase 3 to improve both overall survival (OS) and progression-free survival (PFS) over standard chemotherapy in this patient population." The objective response rate (ORR), the share of patients whose tumors shrank, also met a key secondary endpoint.
However, specific survival figures and hazard ratios (HR) were not disclosed. In the industry, there is talk that detailed data could be released at the American Society of Clinical Oncology (ASCO 2026) meeting opening in Chicago on the 29th (local time).
TROP2 has recently become one of the main targets for ADC cancer drugs. The current TROP2-targeted ADC market is led by Gilead Sciences' Trodelvy, and competition is heating up with the addition of "Datroway," co-developed by AstraZeneca and Daiichi Sankyo.
Among domestic companies, LigaChem Biosciences transferred its TROP2-targeting ADC candidate LCB84 to Janssen, a subsidiary of Johnson & Johnson (J&J). In the industry, the more global companies intensify their ADC competition, the more interest is expected to grow in domestic companies with related platform technologies.