Transtuzumab is approved for the treatment of early-stage breast cancer that is Human Epidermal growth factor Receptor 2-positive (HER2+) and has spread into the lymph nodes, or is HER2+ and has not spread into the lymph nodes. If it has not spread into the lymph nodes, the cancer needs to be estrogen receptor/progesterone receptor (ER/PR)-negative or have one high risk feature.
Trastuzumab is approved to be used alone or with other drugs to treat:
Adenocarcinoma of the stomach or gastroesophageal junction. It is used for HER2 positive (HER2+) disease that has metastasized (spread to other parts of the body) in patients who have not already been treated for metastatic cancer.
Breast cancer that is HER2+. It is used in patients whose disease has not gotten better with other chemotherapy.
Trastuzumab usually is administered intravenously with an initial dose of 4 mg per kilogram of body weight followed by a weekly dose of 2 mg per kilogram of body weight.