According to an announcement from SKB BIO-B (06990), the antibody-drug conjugate (ADC) targeting human epidermal growth factor receptor 2 (HER2), known as bodotuzumab (formerly A166), has had its new drug application (NDA) accepted by the China National Medical Products Administration (NMPA) Drug Evaluation Center (CDE) for the treatment of adult patients with HER2-positive unresectable or metastatic breast cancer who have received at least one previous anti-HER2 treatment.

This application is based on a multicenter, randomized, open-label, controlled, Phase III KL166-III-06 clinical study that evaluates the efficacy and safety of bodotuzumab monotherapy compared to emtansine (T-DM1) in HER2-positive unresectable or metastatic breast cancer patients who have previously received trastuzumab and taxane treatment. In a pre-specified interim analysis, bodotuzumab monotherapy showed significant statistical and clinical improvement in progression-free survival (PFS) compared to T-DM1 as assessed by blinded independent central review (BICR) of the primary endpoint.

Bodotuzumab is an innovative HER2 ADC developed by the company, which couples a novel MMAF derivative (highly cytotoxic microtubule inhibitor Duo-5) with a HER2 monoclonal antibody via a stable enzyme-cleavable linker, with a drug-antibody ratio (DAR) of 2. Bodotuzumab specifically binds to HER2 on the surface of tumor cells and is internalized by them, releasing the toxic molecule Duo-5 within the cells, which induces cell cycle arrest at the G2/M phase, leading to tumor cell apoptosis. After targeting and binding to HER2, bodotuzumab can also inhibit the HER2-mediated signaling pathways; it exhibits antibody-dependent cell-mediated cytotoxicity (ADCC) activity.