Product Introduction:
Vivitra is a lyophilized powder formulation of Trastuzumab, a humanized monoclonal antibody developed for intravenous administration. It is indicated for HER2-overexpressing cancers and is often used in combination with chemotherapy or as a maintenance agent. This biosimilar offers a more accessible alternative to branded Trastuzumab (Herceptin), while maintaining equivalent efficacy and safety.
Uses (Indications):
Vivitra (Trastuzumab) is used in the treatment of:
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HER2-positive metastatic breast cancer – as monotherapy or with chemotherapy
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Adjuvant treatment of HER2-positive early breast cancer
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HER2-positive metastatic gastric or gastroesophageal junction adenocarcinoma
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Neoadjuvant (pre-surgery) treatment in breast cancer
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Maintenance therapy after initial response
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HER2-positive recurrence prevention in high-risk early breast cancer
Storage Instructions:
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Store the vial at 2°C to 8°C (refrigerated)
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Do not freeze
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Protect from light and moisture
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After reconstitution, the solution should be used within 28 days if refrigerated
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Always follow cytotoxic handling protocols during preparation and disposal
How It Works (Mechanism of Action):
Trastuzumab binds with high affinity and specificity to the extracellular domain (subdomain IV) of the HER2 receptor, which is overexpressed in certain cancers. It acts by:
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Inhibiting HER2-mediated signaling pathways (MAPK and PI3K/AKT) that promote tumor cell growth
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Mediating antibody-dependent cellular cytotoxicity (ADCC)
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Promoting cell cycle arrest and apoptosis in HER2-overexpressing cells
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Enhancing the effect of chemotherapeutic agents such as paclitaxel, docetaxel, and cisplatin
Side Effects:
Common Side Effects:
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Fever, chills
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Fatigue
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Diarrhea or nausea
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Headache
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Pain at infusion site
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Upper respiratory symptoms (cough, sore throat)
Serious Side Effects:
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Cardiotoxicity – especially in patients with prior anthracycline use or pre-existing heart disease
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Infusion-related reactions – including fever, hypotension, dyspnea, and bronchospasm
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Pulmonary toxicity – interstitial pneumonitis or ARDS
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Anaphylaxis and hypersensitivity
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Neutropenia and severe infections
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Hepatotoxicity (rare)
Dosage (Typical Recommended Dose):
For Metastatic Breast Cancer (IV route):
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Loading dose: 4 mg/kg IV infusion over 90 minutes
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Maintenance dose: 2 mg/kg IV weekly over 30 minutes
For Adjuvant Treatment (IV route):
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Loading dose: 8 mg/kg over 90 minutes
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Maintenance dose: 6 mg/kg every 3 weeks over 30–90 minutes
For Gastric Cancer:
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Loading dose: 8 mg/kg
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Maintenance dose: 6 mg/kg every 3 weeks
Note: Dosing depends on body weight and treatment protocol (weekly or 3-weekly).
Method of Administration:
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Administered intravenously via infusion pump
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First dose over 90 minutes; subsequent doses may be shortened to 30 minutes if well tolerated
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Premedication may be required for infusion reactions (e.g., paracetamol, antihistamines)
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Must be administered by trained oncology personnel
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Do not give as IV push or bolus
Precautions:
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Baseline and periodic cardiac evaluation (ECHO or MUGA scan) is mandatory
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Use with caution in patients with existing heart conditions or prior anthracycline exposure
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Not recommended during pregnancy or breastfeeding – may cause fetal harm
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Patients must use effective contraception during treatment and for 7 months after the last dose
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Monitor for signs of infusion reaction, pulmonary symptoms, or liver abnormalities
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Discontinue in cases of severe allergic reactions or significant cardiac dysfunction
Drug Interactions:
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Anthracyclines (e.g., doxorubicin, epirubicin) – significantly increased risk of cardiotoxicity
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Cyclophosphamide – increased bone marrow suppression
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Live vaccines – avoid due to immunosuppression
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Paclitaxel and docetaxel – often co-administered; monitor for cumulative toxicity
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Use caution with NSAIDs or nephrotoxic drugs in renally compromised patients
Allergies (Warnings for Allergic Reactions):
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Hypersensitivity may occur, especially during the first infusion
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Symptoms include rash, fever, hypotension, chest tightness, and dyspnea
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Severe cases can lead to anaphylaxis or respiratory distress syndrome
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Emergency equipment and medications (e.g., epinephrine, corticosteroids) should be readily available
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Discontinue if Grade 3 or 4 infusion reaction occurs
Overdose Information:
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No specific antidote exists
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Overdose may lead to severe cardiac dysfunction or respiratory compromise
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Provide symptomatic and supportive care, including cardiac monitoring and fluid management
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Hospitalization may be required in severe cases
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Monitor cardiac function continuously
Missed Dose Instructions:
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If a scheduled dose is missed, it should be administered as soon as possible
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Do not double the dose
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Adjust future schedule to maintain consistent intervals (weekly or every 3 weeks)
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Consult the oncologist for a revised dosing plan
Additional Notes:
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Vivitra is a biosimilar and meets international standards for efficacy, safety, and quality
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Patients should receive patient education on signs of cardiac dysfunction and infusion reactions
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May be used for up to 1 year in adjuvant breast cancer settings
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Regular monitoring of LVEF (left ventricular ejection fraction) is critical during therapy
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Trastuzumab has revolutionized treatment outcomes in HER2+ cancers, offering improved survival rates
