Sichuan Kelun Pharmaceutical Co., Ltd. announced that its subsidiary’s core product TROP2 ADC sacituzumab tirumotecan (sac-TMT) has been approved by the National Medical Products Administration for the fourth indication (for the treatment of 2L+ HR+/HER2- breast cancer).
Securities code: 002422 Securities abbreviation: Kelun Pharmaceutical Announcement number: 2026-008
The company and all members of the board of directors guarantee that the information disclosed is true, accurate and complete, and that there are no false records, misleading statements or major omissions.
Sichuan Kelun Pharmaceutical Co., Ltd. (the “Company”) recently learned that a new indication application for sacituzumab tirumotecan (sac-TMT, also known as SKB264/MK-2870; Jiatelai®), the human trophoblast cell-surface antigen 2 (TROP2)-targeting antibody–drug conjugate (ADC) of its controlled subsidiary Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. (“Kelun-Biotech”), has been approved by China’s National Medical Products Administration (NMPA). The indication is for adult patients with unresectable or metastatic hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2−; IHC 0, IHC 1+, or IHC 2+/in situ hybridization [ISH]−) breast cancer (BC) who have received prior endocrine therapy and at least one line of chemotherapy in the advanced setting. This is sac-TMT’s fourth approved indication in China.
1. Basic information about the drug This approval is based on the positive results of the Phase 3 clinical study of OptiTROP-Breast02, which has been selected as the latest breakthrough abstract (LBA) at the 2025 European Society for Medical Oncology (ESMO) Congress and released in the form of an oral report.
The OptiTROP-Breast02 study evaluated the efficacy and safety of sacituzumab tirumotecan (sac-TMT) alone versus the investigator's choice of chemotherapy in patients with unresectable or metastatic HR+/HER2- BC.
Among the patients enrolled in this phase 3 study, 95.7% of patients had visceral metastases and 75.9% had liver metastases; 52.9% of patients had HER2 expression of 0 (IHC 0) and 47.1% of patients had low HER2 expression (IHC 1+ or IHC 2+/ISH-); all patients had previously received CDK4/6 inhibitors and taxanes. In the advanced or metastatic stage, 56.6% of patients had previously received ≥2 lines of chemotherapy. The results showed that the progression-free survival (PFS) assessed by the Blinded Independent Review Committee (BIRC) in the sacituzumab tirumotecan (sac-TMT) group showed statistically significant and clinically meaningful improvements compared with the chemotherapy group (8.3 months vs. 4.1 months; hazard ratio (HR): 0.35; 95% confidence interval (CI): 0.26-0.48; p<0.0001);
Consistent PFS benefit was observed in each prespecified subgroup, including HER2 expression of 0 and low HER2 expression, the number of lines of chemotherapy received in advanced or metastatic stages, the presence of baseline visceral metastases, baseline liver metastases, and the duration of previous CDK4/6 inhibitor treatment. The PFS results assessed by BIRC showed that in the HER2 expression 0 and HER2 low expression (IHC 1+ or IHC 2+/ISH-) subgroups, the HR was 0.39 (95% CI: 0.26-0.57) and
0.31 (95% CI: 0.20-0.48). At the same time, compared with the chemotherapy group, it showed a benefit trend in overall survival (OS) and a significant improvement in objective response rate (ORR) (41.5% vs 24.1%)1.
Currently, global (NCT06312176) and Chinese (NCT07071337) phase 3 clinical studies of sacituzumab tirumotecan (sac-TMT) with/without pembrolizumab (Keytruda® 2) for the treatment of HR+/HER2- BC patients who have previously received endocrine therapy but not chemotherapy have been initiated.
2. About sacituzumab tirumotecan (sac-TMT) (Jiatelai®) As the core product of Kelun-Biotech, sacituzumab tirumotecan (sac-TMT) is a new TROP2 ADC with independent intellectual property rights by Kelun-Biotech, targeting advanced solid tumors such as non-small cell lung cancer (NSCLC), BC, gastric cancer (GC), and gynecological tumors. Sacituzumab tirumotecan (sac-TMT) was developed using a novel linker by conjugating a belotecan-derived topoisomerase I inhibitor as the payload, achieving a drug-to-antibody ratio (DAR) of 7.4. Sacituzumab tirumotecan (sac-TMT) specifically recognizes TROP2 on the surface of tumor cells through a recombinant anti-TROP2 humanized monoclonal antibody, which is then internalized by the tumor cells and releases the payload KL610023 within the cells. As a topoisomerase I inhibitor, KL610023 can induce DNA damage in tumor cells, leading to cell cycle arrest and apoptosis. In addition, it also releases KL610023 in the tumor microenvironment. Given that KL610023 is cell membrane permeable, it can achieve the bystander effect, killing neighboring tumor cells.
In May 2022, Kelun-Biotech granted Merck (a trading name of Merck & Co., Rowe, New Jersey, USA) the exclusive rights to develop, use, manufacture and commercialize sacituzumab tirumotecan (sac-TMT) in all regions except Greater China (including mainland China, Hong Kong, Macau and Taiwan).
1 Fan Y, Li H, Wang H, et al. ESMO Congress 2025, LBA23.2 Keytruda® (pembrolizumab) is a registered trademark of Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Rowe, New Jersey, USA.
So far, 4 indications of sacituzumab tirumotecan (sac-TMT) have been approved for marketing in China, which are respectively used for: locally advanced or metastatic non-squamous NSCLC with positive EGFR gene mutations that have progressed after treatment with epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKI) and platinum-containing chemotherapy; patients who have received at least 2 previous systemic treatments (of which at least 1 This treatment is indicated for unresectable locally advanced or metastatic triple-negative breast cancer (TNBC) in advanced or metastatic stages; EGFR mutation-positive locally advanced or metastatic non-squamous NSCLC that has progressed after treatment with an EGFR-TKI; unresectable or metastatic HR+/HER2- (IHC 0, IHC 1+, or IHC 2+/ISH-) BC who have received prior endocrine therapy and at least first-line chemotherapy in advanced disease stages. The first two indications have been included in the scope of medical insurance and will bring clinical benefits to more BC and NSCLC patients. In addition, sacituzumab tirumotecan (sac-TMT) has been granted 6 Breakthrough Therapy Designations (BTD) by the NMPA.
Sacituzumab tirumotecan (sac-TMT) is the world's first TROP2 ADC drug approved for lung cancer indications. Currently, Kelun-Biotech has conducted 9 registered clinical studies in China. Merck has deployed 16 ongoing global phase 3 clinical studies of sacituzumab tirumotecan (sac-TMT) as monotherapy or in combination with pembrolizumab or other anti-cancer drugs for various types of cancer (these studies are sponsored and led by Merck).
3. Risk warning The commercialization of innovative drugs involves certain uncertainties. Investors are advised to make prudent decisions and pay attention to preventing investment risks. The company will promptly fulfill its information disclosure obligations based on subsequent progress.
Announcement is hereby made.
Board of Directors of Sichuan Kelun Pharmaceutical Co., Ltd. February 7, 2026