Results from Phase 1/2 Study of Kelun-Biotech's TROP2 ADC Sacituzumab Tirumotecan (sac-TMT) in Patients with Unresectable Locally Advanced or Metastatic Solid Tumors Refractory to Standard Therapies, Published in Journal of Hematology & Oncology

CHENGDU, China, June 10, 2025 /PRNewswire/ -- Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. (the "Company") today announced that results from the Phase 1/2 study (KL264-01/MK-2870-001) evaluating the novel TROP2 antibody drug conjugate (ADC) sacituzumab tirumotecan (sac-TMT) as monotherapy were published in the international medical journal, Journal of Hematology & Oncology (Impact Factor (IF) = 29.9). Published results include those from the Phase 1 dose-escalation part of the study which evaluated sac-TMT in advanced solid tumors, and those from the Phase 2 expansion cohorts of the study, evaluating sac-TMT in metastatic triple-negative breast  . The results of the study demonstrated the therapeutic potential of sac-TMT in this patient population.

Results

KL264-01/MK-2870-001 is a Phase 1/2 first-in-human trial of sac-TMT as monotherapy in patients who have an unresectable locally advanced or metastatic solid tumor which is refractory to standard therapies, which is a global multi-centre study. Presented results include those from the Phase 1 portion of this study, and the Phase 2 expansion cohorts for TNBC and HR+/HER2– breast cancer. The results of the study showed that sac-TMT demonstrated a manageable safety profile in patients with unresectable locally advanced/metastatic solid tumors and promising antitumor activity in metastatic TNBC and HR+/HER2− breast cancer. Currently, sac-TMT is being investigated in several Phase 3 studies in China, led by the Company, as well as globally, where MSD (the tradename of Merck & Co., Inc., Rahway, NJ, USA) holds the exclusive rights. In May 2022, the Company licensed the exclusive rights to MSD to develop, use, manufacture and commercialize sac-TMT in all territories outside of Greater China (includes Mainland China, Hong Kong, Macau, and Taiwan).

About sac-TMT

Sac-TMT, a core product of the Company, is a novel human TROP2 ADC in which the Company has proprietary intellectual property rights, targeting advanced solid tumors such as NSCLC, breast cancer (BC), gastric cancer (GC), gynecological tumors, among others. Sac-TMT is developed with a novel linker to conjugate the payload, a belotecan-derivative topoisomerase I inhibitor with a drug-to-antibody-ratio (DAR) of 7.4. Sac-TMT specifically recognizes TROP2 on the surface of tumor cells by recombinant anti-TROP2 humanized monoclonal antibodies, which is then endocytosed by tumor cells and releases KL610023 intracellularly. KL610023, as a topoisomerase I inhibitor, induces DNA damage to tumor cells, which in turn leads to cell-cycle arrest and apoptosis. In addition, it also releases KL610023 in the tumor microenvironment. Given that KL610023 is membrane permeable, it can enable a bystander effect, or in other words kill adjacent tumor cells.

In May 2022, the Company licensed the exclusive rights to MSD to develop, use, manufacture and commercialize sac-TMT in all territories outside of Greater China (includes Mainland China, Hong Kong, Macau, and Taiwan).

To date, two indications for sac-TMT have been approved and marketed in China for the treatment of adult patients with unresectable locally advanced or metastatic TNBC who have received at least two prior systemic therapies (at least one of them for advanced or metastatic setting) and EGFR mutation-positive locally advanced or metastatic non-squamous NSCLC following progression on EGFR-TKI therapy and platinum-based chemotherapy. Sac-TMT became the first domestically developed and fully approved-for-marketing ADC in China with global intellectual property rights. It is also the world's first TROP2 ADC to be approved for marketing in a lung cancer indication. In addition, two new indication applications for sac-TMT for the treatment of adult patients with EGFR-mutant locally advanced or metastatic NSCLC who progressed after treatment with EGFR-TKI therapy and with unresectable locally advanced, metastatic HR+/HER2- BC who have received prior endocrine therapy and other systemic treatments in the advanced or metastatic setting were accepted by the NMPA, and were included in the priority review and approval process. As of today, Kelun-Biotech has initiated 8 registrational clinical studies in China. MSD has initiated 14 ongoing Phase 3 global clinical studies of sac-TMT as a monotherapy or with pembrolizumab or other agents for several types of cancer. These studies are sponsored and led by MSD.

About Kelun-Biotech

Kelun-Biotech（6990.HK）is a holding subsidiary of Kelun Pharmaceutical (002422.SZ), which focuses on the R&D, manufacturing, commercialization and global collaboration of innovative biological drugs and small molecule drugs. The company focuses on major disease areas such as solid tumors, autoimmune, inflammatory, and metabolic diseases, and in establishing a globalized drug development and industrialization platform to address the unmet medical needs in China and the rest of world. The Company is committed to becoming a leading global enterprise in the field of innovative drugs. At present, the Company has more than 30 ongoing key innovative drug projects, of which 3 projects have been approved for marketing, 1 project is in the NDA stage, and more than 10 projects are in the clinical stage. The company has established one of the world's leading proprietary ADC platforms, OptiDC™, and has 1 ADC project approved for marketing, 1 ADC project in NDA stage, and multiple ADC or novel DC aseets in clinical or preclinical research stage. For more information, please visit https://kelun-biotech.com/.

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