New drug application (NDA) for the core product sacituzumab tirumotecan (sac-TMT, formerly SKB264/MK-2870) based on the positive results from the pivotal OptiTROP-Lung03 study has been accepted by the Center for Drug Evaluation (CDE) of the National Medical Products Administration (NMPA) of China, Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. ("Kelun-Biotech", 6990.HK)

OptiTROP-Lung03 is a multi-center, randomized, pivotal clinical study that evaluates sac-TMT monotherapy 5mg/kg every other week (Q2W) as an intravenous injection versus docetaxel for the treatment of patients with locally advanced or metastatic epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) who failed after treatment with EGFR-tyrosine kinase inhibitor (TKI) therapy and platinum-based chemotherapy. At a pre-specified analysis, sac-TMT monotherapy demonstrated a statistically significant and clinically meaningful improvement in objective response rate (ORR) and progression-free survival (PFS) compared with docetaxel.

Lung cancer mainly includes non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC), of which NSCLC is the most common pathological type, accounting for about 80%-85% of all lung cancers. The molecular typing of NSCLC patients in China is different from that of Western populations, and EGFR mutation is a common variant gene type, accounting for about 40%-50% of lung adenocarcinoma patients in China ^[1]. According to the 2024 CSCO guidelines, EGFR-TKIs are the preferred treatment for stage IV EGFR-mutant NSCLC ^[2]; platinum-containing chemotherapy is the main first-line chemotherapy regimen after resistance to EGFR-TKIs; and existing treatment regimens are ineffective in those who have failed EGFR-TKIs and platinum-containing chemotherapy. Single-agent chemotherapy is the current standard of care for this population, and docetaxel is the most commonly used single-agent chemotherapy, with an ORR of 3.2%-10.8%, a median PFS of only about 2 months, and a median OS of about 6-8 months ^[3,4,5,6,7]. For patients with locally advanced or metastatic EGFR-mutated NSCLC who have failed treatment with EGFR-TKIs and who have failed platinum-containing chemotherapy, the existing treatment regimens are less efficacious, there is a large unmet clinical need, and new drugs are urgently needed to improve patient survival.

Kelun-Biotech has filed the Application for sac-TMT for injection for the treatment of patients with locally advanced or metastatic EGFR-mutant NSCLC who failed after treatment with an EGFR-TKI and platinum-based chemotherapy.

The Application is the second NDA for sac-TMT that has been accepted by the NMPA. On August 14, 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, an NDA 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) was accepted by the NMPA.

Dr. Junyou Ge, CEO of Kelun-Biotech, said, "It is a great honor to have the second NDA of SKB264 accepted. Kelun-Biotech has always adhered to an innovation-driven development strategy, actively exploring cutting-edge technologies and new approaches to the treatment of major diseases. In response to unmet medical needs, we are committed to the original innovation of new drugs with differentiated advantages and international potential. By enhancing our end-to-end innovative drug development capabilities, we continuously improve the efficiency and success rate of drug research and development, and make every effort to move forward our clinical research progress. We are dedicated to continuously exploring and rapidly validating the clinical value of core projects. The company will always be guided by a caring heart, striving for excellence, and contributing to the great global oncology health cause."