HS234

HS234 is a recombinant humanized anti-HER2 monoclonal antibody-drug conjugate (ADC) developed by Zhejiang Hisun Pharmaceutical. It is designed as a biosimilar candidate for trastuzumab emtansine (Kadcyla). The molecule consists of the HER2-targeting antibody trastuzumab covalently linked to the cytotoxic maytansinoid DM1 (a microtubule inhibitor) via a non-cleavable thioether linker (MCC). HS234 specifically targets cells overexpressing the Human Epidermal Growth Factor Receptor 2 (HER2), which is a key driver in certain aggressive forms of breast cancer. Upon binding to the extracellular domain of HER2, the ADC is internalized through receptor-mediated endocytosis and subsequently degraded in lysosomes, releasing active DM1 metabolites. These metabolites bind to tubulin, disrupting microtubule assembly and leading to cell cycle arrest and apoptosis. HS234 is currently being evaluated in Phase 3 clinical trials in China for the treatment of HER2-positive metastatic breast cancer.

Other names

Trastuzumab emtansine biosimilarRecombinant humanized anti-HER2 monoclonal antibody-DM1 conjugate