Chinese biopharmaceutical company Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. (HKG: 6990), a subsidiary of Kelun Pharmaceutical (SHE: 002422), said on Monday that its TROP2-directed antibody-drug conjugate sacituzumab tirumotecan, used in combination with Merck & Co., Inc.'s (NYSE: MRK) pembrolizumab, has received Breakthrough Therapy Designation from China's National Medical Products Administration.

The designation covers first-line treatment of patients with locally advanced or metastatic non-small cell lung cancer who are PD-L1 positive and EGFR- and ALK-negative.

The decision follows Phase III OptiTROP-Lung05 data showing a statistically significant improvement in progression-free survival for the combination, with a positive trend in overall survival.

Sacituzumab tirumotecan has now received five Breakthrough Therapy Designations in China across lung and breast cancer indications since 2022. The drug is already approved and marketed in China for three indications, two of which are included in the National Reimbursement Drug List.

Outside Greater China, Kelun-Biotech has licensed exclusive development and commercialisation rights for sacituzumab tirumotecan to Merck & Co., Inc., which is running multiple global Phase III trials.