• This is the seventh indication application for sacituzumab tirumotecan (sac-TMT) and the second application for the ADC plus IO combination regimen of sac-TMT plus pembrolizumab accepted for review.
• The Phase III OptiTROP-Lung06 study supporting this application showed that sac-TMT plus pembrolizumab demonstrated a statistically significant and clinically meaningful improvement in progression-free survival compared with pembrolizumab plus pemetrexed and platinum-based chemotherapy.
• OptiTROP-Lung06 is the world's first Phase III study of an ADC combined with an immune checkpoint inhibitor to meet its primary endpoint in first-line treatment of driver gene‑negative and PD‑L1‑negative non-squamous NSCLC.
• The detailed results of this study had been presented as a LBA oral report at the 2026 ESMO Congress.

CHENGDU, China, Oct. 27, 2026 /PRNewswire/ -- Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. ("Kelun-Biotech" or the "Company", 6990.HK) announced that a new indication application ("the application") for its trophoblast cell-surface antigen 2 (TROP2)-directed antibody-drug conjugate (ADC) sacituzumab tirumotecan (sac-TMT, also known as SKB264/MK-2870) (佳泰莱^®) has been accepted for review by the Center for Drug Evaluation (CDE) of the National Medical Products Administration (NMPA) of China, in combination with MSD^[1]'s anti-programmed cell death protein 1 (PD-1) monoclonal antibody pembrolizumab (KEYTRUDA^®[2]) as first-line treatment for adult patients with locally advanced or metastatic non-squamous non-small cell lung cancer (NSCLC) whose tumors have a programmed cell death ligand 1 (PD-L1) tumor proportion score (TPS) <1% and are epidermal growth factor receptor (EGFR)-negative and anaplastic lymphoma kinase (ALK)-negative. This marks the seventh indication application for sac-TMT accepted for review by the NMPA.

This application is based on positive results from the Phase III registrational OptiTROP-Lung06 study evaluating the efficacy and safety of sac-TMT in combination with pembrolizumab compared with pembrolizumab plus chemotherapy as first-line treatment for patients with PD-L1-negative locally advanced or metastatic non-squamous NSCLC. This study directly compared two treatment strategies— "ADC plus immunotherapy" versus "immunotherapy plus chemotherapy".

At a prespecified interim analysis, sac-TMT plus pembrolizumab demonstrated a statistically significant and clinically meaningful improvement in the primary endpoint of progression-free survival (PFS) as assessed by blinded independent central review (BICR) compared with pembrolizumab plus pemetrexed and platinum-based chemotherapy; a positive trend was also observed in the secondary endpoint of overall survival (OS). The safety profile of this combination regimen was consistent with that reported in previous studies, with no new safety signals observed.

The OptiTROP-Lung06 study has been selected as a late-breaking abstract (LBA) at the 2026 European Society for Medical Oncology (ESMO) Congress, and the detailed results had been presented as an oral report during the congress.

Dr. Michael Ge, Chief Executive Officer of Kelun-Biotech, said: "Following the acceptance for review of the new indication application for sac-TMT in combination with pembrolizumab as first-line treatment for PD-L1-positive NSCLC, this combination has demonstrated encouraging progress in the more challenging setting of PD-L1-negative non-squamous NSCLC, highlighting the therapeutic potential of this ADC plus pembrolizumab combination across a broad lung cancer population, and its potential to reshape the current first-line treatment landscape with improved efficacy. We will continue to work with our partners to advance the clinical development and combination strategies of sac-TMT, with the goal of delivering meaningful benefits to cancer patients and improving clinical outcomes."

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 (KL610023) 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 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-tyrosine kinase inhibitor (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 by the NMPA.

Sac-TMT is the world's first TROP2 ADC drug approved for marketing in lung cancer.  Three new indication applications have been accepted for review by the NMPA: 1) sac-TMT in combination with pembrolizumab as first‑line treatment for locally advanced or metastatic NSCLC who have PD-L1 TPS≥1% and are EGFR-negative and ALK-negative; 2) sac‑TMT as first‑line treatment for patients with recurrent or metastatic TNBC who have a PD‑L1 combined positive score (CPS) <10 or have recurred after prior PD‑1/PD‑L1 inhibitor therapy in the early stage, both of the above two applications have been included in the priority review and approval process; 3) sac-TMT in combination with pembrolizumab as first‑line treatment of adult patients with locally advanced or metastatic non‑squamous NSCLC whose tumors have PD‑L1 TPS<1% and are EGFR‑negative and ALK-negative. As of today, the Company has initiated 9 registrational clinical studies in China. MSD has initiated 18 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, 2 projects with 4 indications are 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/.