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ANTINEOPLASTIC AND IMMUNOMODULATING AGENTS › ANTINEOPLASTIC AGENTS › MONOCLONAL ANTIBODIES AND ANTIBODY DRUG CONJUGATES › HER2 (Human Epidermal Growth Factor Receptor 2) inhibitors
trastuzumab
L01FD01
Forms & Strengths
- Intravenous infusion: 150 mg single-dose vial
- Intravenous infusion: 420 mg multi-dose vial
- Subcutaneous injection: 600 mg/5 mL solution in a single-dose vial
Adult Dosing
- HER2-overexpressing breast cancer (IV): Initial loading dose of 4 mg/kg over 90 minutes, followed by 2 mg/kg over 30 minutes weekly, or 8 mg/kg loading followed by 6 mg/kg every 3 weeks
- HER2-overexpressing breast cancer (SC): 600 mg fixed dose administered subcutaneously over approximately 2 to 5 minutes every 3 weeks
- HER2-overexpressing metastatic gastric cancer (IV): Initial loading dose of 8 mg/kg over 90 minutes, followed by 6 mg/kg over 30 to 90 minutes every 3 weeks
Pediatric Dosing
- Safety and efficacy in pediatric patients have not been established
Indications
- Adjuvant treatment of HER2-overexpressing node-positive or node-negative (ER/PR negative or with high risk factors) breast cancer
- First-line treatment of HER2-overexpressing metastatic breast cancer
- Treatment of HER2-overexpressing metastatic gastric or gastroesophageal junction adenocarcinoma in combination with a platinum-based chemotherapy
Mechanism of Action
- Recombinant humanized monoclonal antibody that selectively binds to the extracellular domain of the human epidermal growth factor receptor 2 (HER2)
- Mediates antibody-dependent cellular cytotoxicity (ADCC)
- Inhibits ligand-independent cell signaling and prevents the proteolytic cleavage of the extracellular domain, thereby inhibiting proliferation of human tumor cells that overexpress HER2
Contraindications
- Known hypersensitivity to trastuzumab, hamster proteins, or any excipients
Adverse Reactions
- Cardiotoxicity (including left ventricular dysfunction and congestive heart failure)
- Infusion-related reactions (fever, chills, dyspnea, hypotension, wheezing)
- Neutropenia, leukopenia, and anemia
- Diarrhea, nausea, vomiting, abdominal pain, and fatigue
- Pulmonary toxicity (pneumonitis, interstitial pneumonia, acute respiratory distress syndrome)
Drug Interactions
- Anthracyclines (e.g., doxorubicin, epirubicin): Increased risk of severe cardiotoxicity and heart failure
- Paclitaxel: May increase trastuzumab serum concentrations
- CYP450 substrates: Trastuzumab does not appear to significantly inhibit or induce CYP450 enzymes
Curated Content: Needs Vetting Before Put to Clinical Use