In addition, ongoing studies are investigating alternative HER2-targeted strategies for HER2-overexpressing CCA, including the combination of trastuzumab and the HER2-directed tyrosine kinase inhibitor tucatinib (NCT04579380), as well as novel antibody–drug conjugates such as A166 (NCT03602079) and zanidatamab zovodotin (NCT03821233). Here, ERBB2 is linked to cholangiocarcinoma.