ERBB2 and adenocarcinoma: Nevertheless, in addition to trastuzumab, the following HER2-targeted agents for advanced metastatic G/GEJ adenocarcinoma are still under investigation: monoclonal antibodies (mAbs) (e.g., pertuzumab, margetuximab, hersintuzumab), antibody–drug conjugates (ADCs) (e.g., T-DM1, DS-8201, Disitamab vedotin), bispecific antibodies (BsAbs) (e.g., ZW25, KN026), tyrosine kinase inhibitors (TKIs), and other novel therapeutic approaches (e.g., CAR-T, BVAC-B).