By Fineline Cube 
China-based BeOne Medicines Ltd. (NASDAQ: ONC, HKG: 6160, SHA: 688235) announced the official commercial availability and clinical deployment of its internally developed bispecific HER2 inhibitor Ziihera (zanidatamab) across multiple medical institutions in China.
Regulatory Approvals
Ziihera received conditional approval from the National Medical Products Administration (NMPA) on May 27, 2025, for the treatment of HER2-high (IHC 3+) unresectable locally advanced or metastatic biliary tract cancer (BTC) in patients previously treated with systemic therapy. The drug was initially approved by the FDA in November 2024 and received a positive opinion from the EMA’s CHMP in April 2025 for HER2-positive (IHC 3+) unresectable or metastatic BTC in adults.
Drug Mechanism
Ziihera is China’s first and only bispecific antibody approved for HER2-high BTC. It uniquely targets two non-overlapping HER2 epitopes (ECD2 and ECD4), enhancing anti-HER2 activity through complement-dependent cytotoxicity (CDC), antibody-dependent cellular cytotoxicity (ADCC), and antibody-dependent cellular phagocytosis (ADCP). These mechanisms collectively drive potent tumor growth inhibition and cell death in preclinical and clinical studies.-Fineline Info & Tech