Translational Research Results of Sacituzumab Tirumotecan (sac-TMT) in Combination with Osimertinib as First-Line Treatment for EGFR-Mutant NSCLC Published in Cancer Cell

— The study shows that EGFR-TKIs induce TROP2 upregulation in DTP cells, providing a mechanistic basis for combining sac-TMT with EGFR-TKI.

— The Company is conducting a Phase III registrational study of sac-TMT plus osimertinib as first-line treatment for advanced EGFR-mutant NSCLC (enrollment completed; follow‑up phase) and a Phase II study of the same combination as neoadjuvant treatment for EGFR-mutant resectable NSCLC.

— Sac-TMT has been approved in China for advanced EGFR-mutant NSCLC following progression on TKI therapy or TKI therapy and platinum-based chemotherapy, and has demonstrated significant PFS and OS benefits in TKI-resistant settings.

CHENGDU, China, June 22, 2026 /PRNewswire/ -- Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. ("Kelun-Biotech" or the "Company") announced that translational research results on its sacituzumab tirumotecan (sac-TMT, also known as SKB264/MK-2870)(佳泰莱^®) in combination with osimertinib as first-line treatment for advanced epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) have been published online in Cancer Cell, an international academic journal.

The paper, titled "Targeting TROP2 in drug-tolerant persister cells delays EGFR tyrosine kinase inhibitor resistance in non-small-cell lung cancer," was led by Professor Li Zhang and Professor Wenfeng Fang from the Sun Yat-sen University Cancer Center. The study shows that trophoblast cell-surface antigen 2 (TROP2) expression is upregulated in residual drug-tolerant persister (DTP) cells after EGFR tyrosine kinase inhibitor (TKI) treatment; in preclinical models, sac-TMT combined with osimertinib inhibited DTP cell formation and delayed tumor recurrence. These findings provide translational medicine evidence for the combination of TROP2-directed antibody drug conjugate (ADC) and EGFR‑TKI in delaying drug resistance, and further underscore the differentiated value of sac-TMT as a key combination partner for EGFR-TKIs.

Building on the above research and clinical development plans, the Company is advancing a Phase III registrational study (NCT06670196) of sac-TMT in combination with osimertinib versus osimertinib monotherapy as first-line treatment for locally advanced or metastatic EGFR-mutant non-squamous NSCLC. The study is designed to evaluate the efficacy and safety of sac-TMT (4 mg/kg, Q2W) plus osimertinib compared with osimertinib monotherapy in this indication. Patient enrollment in China has been completed, and the study is currently in the follow-up and data maturity phase.

In addition, the Company is advancing clinical exploration of sac-TMT for earlier-stage EGFR-mutant NSCLC. A Phase II study (NCT07329322) is ongoing to evaluate sac-TMT in combination with osimertinib or as monotherapy in the neoadjuvant setting for EGFR-mutant resectable NSCLC, further exploring the potential value of sac-TMT in perioperative treatment.

This publication in Cancer Cell reinforces the scientific foundation for combining sac-TMT with EGFR-TKIs as first-line treatment for EGFR-mutant NSCLC. The Company will continue to explore the potential of this combination regimen in earlier-line treatment, resistance delay, and long-term benefit, building on the approved indications and clinical development plan of sac-TMT in EGFR-mutant NSCLC. Kelun-Biotech remains committed to driving innovation in treatment paradigms for EGFR-mutant NSCLC and expanding therapeutic options for patients.

About sac-TMT(佳泰莱^®)

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 and genitourinary tumors, among others. Sac-TMT is developed with a unique, bifunctional linker that maximizes payload delivery to tumor cells both through its irreversible connection with the anti-TROP2 monoclonal antibody sacituzumab and its pH-sensitive cleavage from a belotecan-derivative topoisomerase I inhibitor payload in the lysosome, 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 (which includes Mainland China, Hong Kong, Macao and Taiwan).

To date, four indications for sac-TMT have been approved and marketed in China for: 1) 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); 2) EGFR mutant-positive locally advanced or metastatic non-squamous NSCLC following progression on EGFR-TKI therapy and platinum-based chemotherapy; 3) EGFR mutant-positive locally advanced or metastatic non-squamous NSCLC who progressed after treatment with EGFR-TKI therapy; 4) unresectable or metastatic hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) (Immunohistochemistry (IHC) 0, IHC 1+ or IHC 2+/In Situ Hybridization (ISH)-) BC who have received prior endocrine therapy and at least one line of chemotherapy in advanced setting. The first two indications above have been included in China's National Reimbursement Drug List (NRDL). This inclusion is expected to bring clinically meaningful benefits to a greater number of patients with BC and NSCLC. Additionally, sac-TMT has been granted six Breakthrough Therapy Designations (BTDs) by the National Medical Products Administration (NMPA).

Sac-TMT is the world's first TROP2 ADC drug approved for marketing in lung cancer. A new indication application for sac-TMT in combination with pembrolizumab (KEYTRUDA^®[1]) as first‑line treatment for locally advanced or metastatic NSCLC who have programmed death ligand 1 (PD-L1) tumor proportion score (TPS)≥1% and are EGFR-negative and anaplastic lymphoma kinase (ALK)-negative has been accepted for review by the NMPA, and has entered the priority review and approval process. As of today, Kelun-Biotech has initiated 9 registrational clinical studies in China. MSD is evaluating 17 ongoing global Phase III clinical studies of sac-TMT as a monotherapy or in combination with pembrolizumab 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, which focuses on the R&D, manufacturing, commercialization and global collaboration of innovative biological drugs and small molecule drugs. Kelun-Biotech focuses on major disease areas such as solid tumors, autoimmune, 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. Kelun-Biotech is committed to becoming a leading global enterprise in the field of innovative drugs. At present, Kelun-Biotech has more than 30 ongoing key innovative drug projects, of which 4 projects with 8 indications have been approved for marketing, 1 project is in the NDA stage and more than 10 projects are in the clinical stage. Kelun-Biotech has established one of the world's leading proprietary ADC and novel DC platforms, OptiDC™, and has 2 ADC projects with 5 indications approved for marketing, and multiple ADC and novel DC assets in clinical or preclinical research stage. For more information, please visit https://en.kelun-biotech.com/.  

SOURCE Kelun-Biotech