Trastuzumab
Indications
Trastuzumab is used for:
Breast cancer, Gastric cancer
Adult Dose
Intravenous
Breast Cancer
Adjuvant treatment
Indicated for adjuvant treatment of HER-2 overexpressing breast cancer
Administer during and following paclitaxel, docetaxel, or docetaxel/carboplatin
4 mg/kg IV over 90 minutes, THEN
2 mg/kg IV over 30 minutes qWeek during chemotherapy for the first 12 weeks (paclitaxel or docetaxel) or 18 weeks (docetaxel/carboplatin)
One week following the last weekly dose administer at 6 mg/kg as an IV infusion over 30?90 min every three weeks
As single agent within three wk following completion of multi-modality, anthracycline based chemotherapy regimens: Initial dose at 8 mg/kg as an IV infusion over 90 min; subsequent doses at 6 mg/kg as an IV infusion over 30?90 min every three wks
Extending adjuvant treatment beyond one year not recommended
Metastatic breast cancer
Treat as a single agent or in combination with paclitaxel
4 mg/kg IV over 90 minutes, THEN
2 mg/kg IV over 30 minutes qWeek
Gastric Cancer
Indicated for treatment of HER2-overexpressing metastatic gastric or gastroesophageal junction adenocarcinoma
Administered in combination with cisplatin and capecitabine or 5-fluorouracil who have not received prior treatment for metastatic disease
First cycle: 8 mg/kg IV; infuse IV over 90 min
Subsequent cycles: 6 mg/kg IV q3wk; infuse IV over 30-90 min
Continue q3week cycles until disease progression
Child Dose
Safety and efficacy not established
Renal Dose
Administration
IV Administration
Not for IV push or bolus administration
Administer initial IV infusion over 90 min
Subsequent weekly IV infusions may be administered over 30 min if prior infusions are well tolerated
Contra Indications
Lactation (start only 6 mth after last dose of drug). Do not admin by rapid IV or bolus inj.
Precautions
Patient w/ pre-existing CV and pulmonary disease; extensive pulmonary tumour involvement. Pregnancy and lactation. Monitoring Parameters Monitor cardiac function prior and during treatment.
Lactation: not known if excreted in breast milk, discontinue nursing during treatment and for 6 months after last dose
Pregnancy-Lactation
Interactions
Increased risk of severe cardiotoxicity with anthracyclines. Increased risk of leukopenia and anaemia in combination chemotherapy (e.g. paclitaxel). Paclitaxel may decrease the clearance of trastuzumab. Increased risk of bleeding with warfarin.
Adverse Effects
Side effects of Trastuzumab :
>10%
Pain (47%),Asthenia (42%),Fever (36%),Nausea (33%),Chills (32%),Cough (26%),Headache (26%),Diarrhea (25%),Vomiting (23%),Abdominal pain (22%),Back pain (22%),Dyspnea (22%),Infection (20%),Rash (18%),Anorexia (14%),Insomnia (14%),Dizziness (13%)
1-10%
Flu-like syndrome (10%),Peripheral edema (10%),CHF (7%),Depression (6%),Tachycardia (5%),UTI (5%),Anemia (4%),Hypersensitivity (3%),Leukopenia (3%)
Potentially Fatal: Severe hypersensitivity (anaphylaxis) and infusion reactions; pulmonary events e.g. acute respiratory distress syndrome; cardiotoxicity. Neutropenia (especially when given with chemotherapy).
Mechanism of Action
Trastuzumab, a monoclonal antibody, has action directed against a cell surface protein produced by human epidermal growth factor receptor 2 (HER2). It inhibits proliferation of tumour cells that overexpress HER2 e.g. in 1/3 of breast cancer.