Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. (Stock Code: 6990) announced that the National Medical Products Administration (NMPA) of China has approved a new indication for sacituzumab tirumotecan (sac-TMT, known as SKB264/MK-2870) targeting adult patients with unresectable or metastatic hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) breast cancer who have received prior endocrine therapy and at least one line of chemotherapy in the advanced setting. This represents the fourth indication approved in China for sac-TMT.
According to the announcement, approval was granted based on results from the Phase 3 OptiTROP-Breast02 study, presented as a Late-Breaking Abstract at the 2025 European Society for Medical Oncology (ESMO) Congress. In this study, sac-TMT monotherapy was compared to investigator’s choice of chemotherapy in patients with unresectable or metastatic HR+/HER2- breast cancer. A statistically significant and clinically meaningful progression-free survival (PFS) improvement was observed (8.3 vs. 4.1 months; hazard ratio 0.35, 95% confidence interval 0.26–0.48, p<0.0001). The objective response rate (ORR) was higher with sac-TMT compared to chemotherapy (41.5% vs. 24.1%). Subgroup analyses indicated consistent PFS benefits across HER2-zero and HER2-low cohorts, as well as in patients with baseline visceral and liver metastases.
Sac-TMT, marketed under the name 佳泰萊®, is a novel human TROP2 antibody-drug conjugate that deploys a topoisomerase I inhibitor payload via a proprietary linker. It was licensed in May 2022 to MSD (Merck & Co., Inc., Rahway, NJ, USA) for territories outside Greater China. To date, four indications for sac-TMT have been approved and marketed in China: for epidermal growth factor receptor (EGFR) mutant-positive locally advanced or metastatic non-squamous non–small cell lung cancer (NSCLC) following progression on EGFR-tyrosine kinase inhibitor therapy and platinum-based chemotherapy; for unresectable locally advanced or metastatic triple-negative breast cancer; for EGFR mutant-positive locally advanced or metastatic non-squamous NSCLC following progression on EGFR-TKI therapy; and most recently for HR+/HER2- breast cancer in the advanced setting after at least one chemotherapy line. Two of these indications have been included in China’s National Reimbursement Drug List.
The announcement notes that sac-TMT has also received six Breakthrough Therapy Designations from the NMPA and is the first TROP2 ADC drug approved for lung cancer globally. Nine registrational clinical studies of sac-TMT have been initiated in China, while MSD is conducting a further 16 Phase 3 global clinical trials, both as monotherapy and in combination with pembrolizumab and other anti-cancer agents.
Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. has reminded shareholders and potential investors that sac-TMT for any unapproved uses may not ultimately be successfully developed or commercialized, advising caution when dealing in the company’s securities.