pertuzumab + trastuzumab: clinical use

Prescribing considerations

• Confirm HER2-positive tumour status using a validated test in an appropriate laboratory.
• Initiate under an experienced anticancer prescriber with anaphylaxis management and resuscitation facilities available.
• Assess cardiac history, previous anthracycline exposure and chest radiotherapy before treatment.
• Patients with dyspnoea at rest from advanced malignancy or comorbidity should not receive the product because pulmonary risk may be increased.
• Limited evidence is available in severe renal impairment, hepatic impairment and adults older than 75 years.

Contraindications and cautions

• Hypersensitivity to pertuzumab, trastuzumab or any excipient.
• Use particular caution with impaired cardiac function, previous heart failure, uncontrolled hypertension, recent myocardial infarction or clinically important arrhythmia.
• Permanently discontinue for severe anaphylaxis, bronchospasm or acute respiratory distress syndrome.

Monitoring

• Measure left ventricular ejection fraction before treatment and regularly during treatment; reassess promptly if heart-failure symptoms occur.
• Observe during and after injection for systemic injection reactions and hypersensitivity.
• Monitor for infection, febrile neutropenia and chemotherapy-related cytopenias.
• Assess diarrhoea early and monitor hydration and electrolytes when severe or prolonged.
• Investigate new respiratory symptoms for pneumonitis or interstitial lung disease.
• Record the product name and batch number for biological traceability.

Clinical pharmacology

Pertuzumab and trastuzumab are humanised IgG1 antibodies binding distinct extracellular HER2 subdomains. They inhibit complementary HER2 signalling pathways and mediate antibody-dependent cellular cytotoxicity. Antibodies are cleared mainly through catabolism.

Formulation and product differences

• Ready-to-use, preservative-free solution for subcutaneous injection only; it must not be diluted, mixed, shaken or administered intravenously.
• The 600 mg/600 mg vial contains 10 mL and has an orange cap.
• The 1200 mg/600 mg vial contains 15 mL and has a cool-green cap.
• The formulation includes vorhyaluronidase alfa to aid subcutaneous dispersion and absorption.

Injection

Route: Parenteral

Strengths: 600 mg + 600 mg, 1200 mg + 600 mg