Sichuan Kelun Pharmaceutical Co., Ltd. announced that its subsidiary's core product sacituzumab tirumotecan (sac-TMT) has been approved by the National Medical Products Administration for the second indication (for the treatment of EGFR mutated non-small cell lung cancer).

Securities code: 002422 Securities abbreviation: Kelun Pharmaceutical Announcement number: 2025-016

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. (hereinafter referred to as the "Company") recently learned that the company's controlled subsidiary Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. (hereinafter referred to as "Kelun-Biotech")'s antibody drug conjugate (ADC) sacituzumab tirumotecan (sac-TMT, formerly known as SKB264/MK-2870) (Jiatelai®) targeting human trophoblast surface antigen 2 (TROP2) has been approved by the National Medical Products Administration. (NMPA) approved a second indication for the treatment of adult patients with EGFR gene mutation-positive locally advanced or metastatic non-squamous non-small cell lung cancer (NSCLC) that has progressed after treatment with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) and platinum-containing chemotherapy. This is the world's first TROP2 ADC drug approved for marketing in lung cancer indications. Compared with the current standard treatment, sacituzumab tirumotecan (sac-TMT) significantly prolonged the overall survival benefit in these patients.

The approval is based on a multicenter, randomized, controlled pivotal clinical study (OptiTROP-Lung03) evaluating the efficacy and safety of sacituzumab tirumotecan (sac-TMT) monotherapy 5 mg/kg intravenously every two weeks (Q2W) compared with docetaxel for the treatment of patients with locally advanced or metastatic EGFR-mutated NSCLC after failure of EGFR-TKI and platinum-containing chemotherapy (sequential or combined). Results of a prespecified interim analysis showed that sacituzumab tirumotecan (sac-TMT) monotherapy had statistically significant and clinically meaningful improvements in objective response rate (ORR), progression-free survival (PFS), and overall survival (OS) compared with docetaxel.

1. 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 NSCLC, breast cancer (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, and is subsequently endocytosed by tumor cells and releases 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.

Since KL610023 is cell membrane permeable, it can achieve the bystander effect, killing neighboring tumor cells.

Previously, the NMPA has approved sacituzumab tirumotecan (sac-TMT) for the treatment of unresectable locally advanced or metastatic triple-negative breast cancer that has received at least 2 prior systemic therapies (at least 1 of which is for advanced or metastatic stages); and has accepted a supplemental new drug application (sNDA) for sacituzumab tirumotecan (sac-TMT) monotherapy for patients with EGFR-mutant NSCLC who have failed EGFR-TKI treatment.

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).

2. Risk warning: The commercialization of innovative drugs has 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. March 11, 2025