Core product Trastuzumab botidotin approved for marketing by the NMPA for 2L+ HER2+ breast cancer

CAR-T Digest - August 2020

17 October 2025: Core product Trastuzumab botidotin approved for marketing by the NMPA for 2L+ HER2+ breast cancer

Sichuan Kelun-Biotech’s core product trastuzumab botidotin (A166) received marketing approval from China’s NMPA for the treatment of adults with unresectable or metastatic HER2-positive breast cancer who have received one or more prior anti-HER2 therapies
The approval was supported by the Phase 3 KL166-III-06 trial, where trastuzumab botidotin showed a statistically significant and clinically meaningful improvement in progression-free survival versus T-DM1, with a favorable overall survival trend
The pivotal study results was presented as an oral late-breaking abstract (LBA24) at the 2025 ESMO Congress in Berlin, underscoring the global recognition of the data
Trastuzumab botidotin is an innovative HER2-directed ADC that combines a monomethyl auristatin F (MMAF) derivative payload (Duo-5) with a HER2 monoclonal antibody via a stable, enzyme-cleavable linker (DAR 2), offering a differentiated mechanism of action
The company is also advancing a Phase 2 trial to explore trastuzumab botidotin in HER2+ breast cancer patients previously treated with a topoisomerase inhibitor ADC, expanding its potential role in later-line settings