Zanidatamab in HER2-Positive Biliary Tract Cancer: A First Narrative Literature Review

Abstract

Biliary Tract Cancers (BTCs) are uncommon but aggressive tumors with limited therapeutic options and generally poor survival outcomes. Advances in molecular profiling have identified HER2 amplification and overexpression as potential therapeutic targets in a subset of these patients. Zanidatamab, a new monoclonal antibody that targets HER2, received Food and Drug Administration (FDA) approval in 2024 for patients with previously treated HER2-positive BTC, representing a significant development in targeted cancer therapy. The drug, marketed as ZIIHERA® (zanidatamab-hrii), is indicated for adults with unresectable or metastatic HER2-positive (IHC 3+) Biliary Tree Cancers (BTCs), confirmed via an FDA-approved diagnostic test. Zanidatamab is being developed by Jazz Pharmaceuticals and BeiGene Ltd under license from Zymeworks Inc., the original creator of the molecule, for treating HER2-expressing solid tumors. This review summarizes the pharmacodynamic and pharmacokinetic properties of Zanidatamab, evaluates its clinical efficacy and safety based on emerging clinical trial data and discusses its potential role in the evolving treatment landscape of BTC.