Indications - Adjuvant Breast Cancer: Trastuzumab is indicated for adjuvant treatment of HER2 overexpressing node positive or node negative (ER/PR negative or with one high risk feature) 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-approved companion diagnostic for Trastuzumab Metastatic Breast Cancer: Trastuzumab is indicated: In combination with paclitaxel for first-line treatment of HER2-overexpressing metastatic breast cancer As a single agent for treatment of HER2-overexpressing breast cancer in patients who have received one or more chemotherapy regimens for metastatic disease. Select patients for therapy based on an FDA-approved companion diagnostic for Trastuzumab Metastatic Gastric Cancer: Trastuzumab is indicated, in combination with cisplatin and capecitabine or 5-fluorouracil, for the treatment of patients with HER2-overexpressing metastatic gastric or gastroesophageal junction adenocarcinoma who have not received prior treatment for metastatic disease. Select patients for therapy based on an FDA-approved companion diagnostic for Trastuzumab
Dosage & Administration - Early breast cancer: For treatment after chemotherapy, radiotherapy or surgery. Initially, 4 mg/kg via infusion over 90 min followed by 2 mg/kg via infusion over 30 min wkly for 1 yr or until disease recurrence, whichever occurs 1st. Alternatively, initial dose of 8 mg/kg via infusion over 90 min followed by 6 mg/kg via infusion over 30-90 min at 3-wkly interval for 1 yr or until disease recurrence, whichever occurs 1st. Metastatic breast cancer: As monotherapy or combination therapy (with an aromatase inhibitor or taxane): Initially, 4 mg/kg via infusion over 90 min followed by 2 mg/kg via infusion over 30 min at wkly interval until progression of disease. As trastuzumab emtansine: 3.6 mg/kg as infusion 3 wkly (21-day cycle). Admin initial dose for 90 min. Subsequent doses may be administered as 30 min infusions. Gastric cancer: For metastatic: Initially, 8 mg/kg via infusion over 90 min followed by 6 mg/kg via infusion over 30-90 min at 3-wkly interval until progression of disease.
Side Effects - Fever, headache, fatigue, nausea, vomiting, diarrhoea, infections, increased cough, dyspnoea, rash, neutropenia, anaemia, and myalgia; cardiac dysfunction, CHF.
Contraindications - Severe dyspnoea at rest.
Others - Pregnancy & Lactation Pregnancy Category D. There is positive evidence of human foetal risk, but the benefits from use in pregnant women may be acceptable despite the risk (e.g., if the drug is needed in a life-threatening situation or for a serious disease for which safer drugs cannot be used or are ineffective).