CHENGDU,China,Oct. 31,2024 -- The new drug application (NDA) (the "Application") based on the positive results from the pivotalphase III OptiTROP-Lung04 study of sacituzumab tirumotecan (sac-TMT,formerly SKB264/MK-2870) developed by SichuanKelun-Biotech Biopharmaceutical Co.,Ltd. (the "Company") was accepted by the Center for Drug Evaluation (CDE) of the National Medical Products Administration (NMPA) of China in adult patients with epidermal growth factor receptor (EGFR)-mutant locally advanced or metastatic non-small cell lung cancer (NSCLC) who progressed after treatment with EGFR-tyrosine kinase inhibitor (TKI) therapy.

OptiTROP-Lung04 is a multi-center,randomized,registrational phase III clinical study that evaluates the efficacy and safety results of sac-TMT monotherapy versus pemetrexed plus platinum chemotherapy for the treatment of patients with EGFR-mutant locally advanced or metastatic NSCLC who progressed after treatment with EGFR- TKI therapy. At a pre-specified interim analysis,sac-TMT monotherapy demonstrated a statistically significant and clinically meaningful improvement in the primary endpoint of progression-free survival (PFS) as assessed by the blinded independent review committee (BIRC) compared with pemetrexed plus platinum chemotherapy. Sac-TMT also showed a manageable safety profile,with no unexpected safety signals identified.

The Application is the third NDA for sac-TMT that has been accepted by the NMPA. On October 25,2024,it was announced on the official website of the CDE that the Application was planned to be included in the priority review and approval process of the CDE.

Previously,two NDAs for sac-TMT in patients with 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) and for sac-TMT monotherapy in adult patients with locally advanced or metastatic EGFR-mutant NSCLC who experience progression following treatment with an EGFR-TKI and platinum-based chemotherapy,respectively,were accepted by the NMPA.

Sac-TMT,a core product of the Company,is a novel human trophoblast cell-surface antigen 2 (TROP2) antibody-drug conjugate (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 (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,Macao,and Taiwan).

Dr. Micheal Ge,CEO of Kelun-Biotech,said,"sac-TMT (sacituzumab govitecan) has received its third NDA. In response to unmet clinical needs,the company has always adhered to the spirit of hard work inherent in Kelun,focusing on original innovation and doing practical work to develop new drugs with differentiated advantages and international potential. We believe that sac-TMT will shine in the field of oncology and contribute Chinese strength to the global health cause."

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 innovative projects in major disease areas such as solid tumors,including over 10 projects in the clinical stage and 4 projects in the NDA stage with several global trials being conducted simultaneously in multiple countries,including China,Europe,and the United States. The company has established one of the world's leading proprietary ADC platforms,OptiDC™,and has 5 ADC projects in the clinical stage (2 of which are in the NDA stage) and several projects in the preclinical stage. For more information,please visit https://kelun-biotech.com/.