A targeted antibody for HER2-positive breast and stomach cancers.
Herceptin is a HER2/neu receptor antagonist indicated in adults for: The treatment of HER2-overexpressing breast cancer. ( 1.1 , 1.2 ) The treatment of HER2-overexpressing metastatic gastric or gastroesophageal junction adenocarcinoma. ( 1.3 ) Select patients for therapy based on an FDA-authorized companion diagnostic for Herceptin ( 1 , 2.2 ). 1.1 Adjuvant Breast Cancer Herceptin is indicated in adults for adjuvant treatment of HER2 overexpressing node positive or node negative (ER/PR negative or with one high risk feature [see Clinical Studies (14.1) ] ) breast cancer as part of a treatment regimen consisting of doxorubicin, cyclophosphamide, and either paclitaxel or docetaxel as part of a treatment regimen with docetaxel and carboplatin as a single agent following multi-modality anthracycline based therapy. Select patients for therapy based on an FDA-authorized companion diagnostic f…
12.1 Mechanism of Action The HER2 (or c-erbB2) proto-oncogene encodes a transmembrane receptor protein of 185 kDa, which is structurally related to the epidermal growth factor receptor. Herceptin has been shown, in both in vitro assays and in animals, to inhibit the proliferation of human tumor cells that overexpress HER2. Herceptin is a mediator of antibody-dependent cellular cytotoxicity (ADCC). In vitro , Herceptin-mediated ADCC has been shown to be preferentially exerted on HER2 overexpressing cancer cells compared with cancer cells that do not overexpress HER2.
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Plain-English summaries and drug-class explainers are written and reviewed by the Priya Life Science editorial team, led by Sreepriya Prasannan (MSc Digital Transformation of Life Sciences (Innopharma Education / Griffith College); MSc & BSc Botany). Data is retrieved automatically from the sources above and cross-checked with AI-assisted verification (Anthropic's Claude) — brand and generic names are matched against the exact FDA product record so that a combination product or a different formulation cannot be mistaken for the drug on this page. An editor reviews the result before publication. We describe this in full in our editorial standards and corrections policy. The FDA data on this page was last retrieved on 6 Aug 2026.