Third Indication for Kelun-Biotech's TROP2 ADC Sac-TMT Approved for Marketing by NMPA in EGFRm NSCLC Following Progression on EGFR-TKI Therapy

CHENGDU, China, Oct. 11, 2025 /PRNewswire/ -- Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. (the "Company") announced that the Company's trophoblast cell-surface antigen 2 (TROP2)-directed antibody-drug conjugate (ADC) sacituzumab tirumotecan (sac-TMT, also known as SKB264/MK-2870) was approved for marketing by the National Medical Products Administration (NMPA) for its third indication, the treatment of adult patients with epidermal growth factor receptor (EGFR) mutant-positive locally advanced or metastatic non-squamous non-small cell lung cancer (NSCLC) who progressed after treatment with EGFR-tyrosine kinase inhibitor (TKI) therapy.

Sac-TMT is the first and only ADC globally to show an overall survival (OS) benefit compared with platinum doublet chemotherapy and be approved for advanced NSCLC that has progressed after only TKI therapy (second line). Currently sac-TMT monotherapy is the only regimen approved for advanced EGFR-mutant NSCLC following progression on TKI therapy or TKI therapy and platinum-based chemotherapy (used sequentially or in combination)—achieving comprehensive coverage across the TKI-resistant population.

In a pre-specified interim analysis of OS, compared with the current standard of care of platinum-based doublet chemotherapy, sac-TMT monotherapy demonstrated a statistically significant and clinically meaningful improvement in both progression-free survival (PFS) and OS, and significantly extends survival outcomes for these patients. More importantly, it remains the only monotherapy regimen not based on platinum-based doublet chemotherapy approved for NSCLC following progression after TKI therapy.

The approval is based on a randomized, open-label, multi-center Phase III study (OptiTROP-Lung04) which has been selected as a late-breaking abstract (LBA) at the 2025 European Society for Medical Oncology (ESMO) Congress and will be presented as an oral report in the Presidential Symposium session (Presentation # LBA5). The OptiTROP-Lung04 study evaluates the efficacy and safety profile of sac-TMT monotherapy at 5mg/kg every other week (Q2W) as an intravenous injection versus pemetrexed plus platinum chemotherapy for the treatment of patients with EGFR-mutant locally advanced or metastatic non-squamous NSCLC who have failed after treatment with EGFR-TKI therapy. This is the first Phase III trial globally in a Chinese population demonstrating significant OS improvement with an ADC compared to platinum-based doublet chemotherapy in EGFR-mutant NSCLC following TKI-resistance. Sac-TMT demonstrated statistically significant and clinically meaningful improvement in both OS and PFS.

In March 2025, sac-TMT was approved for EGFR mutant-positive locally advanced or metastatic non-squamous NSCLC following progression on EGFR-TKI therapy and platinum-based chemotherapy. Compared with current standard of care of docetaxel, sac-TMT monotherapy significantly extends the PFS and OS for these patients. Additionally, the patient enrollment for a Phase III registrational study in China of sac-TMT combined with osimertinib as first-line treatment of locally advanced or metastatic non-squamous EGFR-mutant NSCLC has been completed.

Dr. Michael Ge, CEO of Kelun-Biotech said, "We are delighted to announce the approval of the third indication for our core product, sac-TMT, marking another major milestone in lung cancer treatment. EGFR mutations are the most common oncogenic driver in lung cancer, accounting for approximately 40–50% of non-squamous NSCLC cases in China. Third-generation EGFR-TKIs are the standard first-line therapy for these patients, yet resistance inevitably develops, leaving few effective treatment options. The approval of this new indication highlights sac-TMT's broad coverage across TKI-treated NSCLC, offering a more precise and effective treatment with a proven survival benefit for a larger patient population. Looking ahead, we are advancing the clinical development of sac-TMT in combination with osimertinib for first-line EGFR-mutant NSCLC."

About NSCLC
Lung cancer is the leading malignant tumor in China. According to statistics from the National Cancer Center, approximately 1.06 million^[1] new lung cancer cases are diagnosed annually in the country. Pathological classification of lung cancer primarily includes non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC), with NSCLC being the most common pathological type, accounting for about 80–85% of all lung cancer patients. According to the 2025 Chinese Society of Clinical Oncology (CSCO) Guidelines for Diagnosis and Treatment of Non-Small Cell Lung Cancer and the Chinese Medical Association Guidelines for Clinical Diagnosis and Treatment of Lung Cancer (2025 Edition), EGFR-TKI therapy is the first-line treatment for advanced NSCLC with EGFR mutations^[2],[3]. Following resistance to EGFR-TKIs, platinum-based doublet chemotherapy remains the primary standard treatment regimen. Current treatment options demonstrate suboptimal efficacy, particularly in extending overall survival, leaving significant unmet clinical needs where there's urgent requirement for new drugs to improve patient survival outcomes.

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 the payload 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 (the tradename of Merck & Co., Inc., Rahway, NJ, USA) 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, three indications for sac-TMT have been approved and marketed in China for the treatment of adult patients with unresectable locally advanced or metastatic triple negative breast cancer (TNBC) who have received at least two prior systemic therapies (at least one of them for advanced or metastatic setting), EGFR mutation-positive locally advanced or metastatic non-squamous NSCLC following progression on EGFR-TKI therapy and platinum-based chemotherapy and EGFR mutant-positive locally advanced or metastatic non-squamous NSCLC who progressed after treatment with EGFR-TKI therapy. Sac-TMT is the first TROP2 ADC drug approved for marketing in lung cancer globally. In addition, the new indication application for sac-TMT for the treatment of adult patients with unresectable locally advanced, metastatic hormone receptor positive (HR+) and human epidermal growth factor receptor 2-negative (HER2-) BC who have received prior endocrine therapy and other systemic treatments in the advanced or metastatic setting was accepted by the Center for Drug Evaluation of the NMPA, and was included in the priority review and approval process.

As of today, the Company has initiated 9 registrational clinical studies in China. MSD has initiated 14 ongoing Phase 3 global clinical studies of sac-TMT as a monotherapy or with pembrolizumab^[4] or other anti-cancer 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, 2 projects are 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 and novel DC platforms, OptiDC™, and has 1 ADC project approved for marketing, 1 ADC project in NDA stage and multiple ADC and novel DC assets in clinical or preclinical research stage. For more information, please visit https://kelun-biotech.com/. 

SOURCE Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd.