Product Introduction:
Hermab is an anti-HER2 monoclonal antibody therapy used in HER2-positive cancers. It is available in 150 mg single-use and 440 mg multi-dose vials and is manufactured by Reliance Life Sciences. It is typically administered via intravenous infusion.
Uses (Indications):
Trastuzumab is specifically designed for patients with tumors that overexpress HER2. Major indications include:
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HER2-Positive Metastatic Breast Cancer – alone or in combination with paclitaxel or docetaxel
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HER2-Positive Early Breast Cancer – adjuvant setting with chemotherapy (e.g., AC-T or TCH regimens)
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Neoadjuvant Therapy – before surgery in HER2-positive locally advanced breast cancer
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HER2-Positive Metastatic Gastric or Gastroesophageal Junction Adenocarcinoma – in combination with cisplatin and 5-FU/capecitabine
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HER2-positive recurrent breast cancer – as monotherapy or maintenance
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Investigational uses in endometrial, ovarian, and bladder cancers with HER2 overexpression
Storage Instructions:
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Store vials at 2°C to 8°C in the refrigerator
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Do not freeze the reconstituted or unreconstituted product
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Protect from light and moisture
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After reconstitution, 150 mg vial must be used immediately; 440 mg vial (with bacteriostatic water) can be stored for up to 28 days at 2°C–8°C
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Discard if solution is cloudy or discolored
How It Works (Mechanism of Action):
Trastuzumab is a recombinant humanized monoclonal antibody that binds to the extracellular domain of the HER2/neu receptor.
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HER2 is overexpressed in 20–30% of breast cancers and associated with poor prognosis
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Trastuzumab inhibits dimerization of HER2 receptors, blocking downstream signaling pathways (MAPK, PI3K)
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It also triggers antibody-dependent cellular cytotoxicity (ADCC), recruiting immune cells to destroy HER2-expressing cancer cells
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The result is reduced cell proliferation and increased apoptosis
Side Effects:
Common Side Effects:
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Fever, chills, and flu-like symptoms (especially first infusion)
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Nausea and vomiting
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Headache
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Fatigue
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Diarrhea
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Skin rash
Severe Side Effects:
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Cardiotoxicity – heart failure, decreased left ventricular ejection fraction (LVEF)
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Infusion-related reactions – bronchospasm, hypotension, anaphylaxis
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Pulmonary toxicity – interstitial lung disease, pneumonitis
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Neutropenia and increased infection risk (with combination therapy)
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Liver enzyme elevation and hepatotoxicity
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Serious allergic reactions – rare but possible
Dosage (Typical Recommended Dose):
For Breast Cancer (IV infusion):
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Loading dose: 8 mg/kg IV over 90 minutes
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Maintenance dose: 6 mg/kg every 3 weeks over 30–90 minutes
For Gastric Cancer (IV infusion):
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Loading dose: 8 mg/kg on day 1
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Maintenance dose: 6 mg/kg every 3 weeks until disease progression or toxicity
Note: Dose should be adjusted for body weight and cardiac function should be assessed before and during therapy.
Method of Administration:
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Reconstitute lyophilized powder with sterile water or bacteriostatic water (depending on vial size)
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Further dilute with 250 mL of normal saline (0.9%) for IV infusion
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Do not use dextrose-containing solutions
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Administer first dose over 90 minutes, subsequent doses can be given over 30 minutes
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Monitor vitals closely during the first infusion
Precautions:
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Baseline and periodic echocardiograms (LVEF) are required to monitor cardiac function
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Not recommended for patients with pre-existing heart failure or recent MI
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Avoid in pregnancy – known to cause oligohydramnios and fetal harm (Pregnancy Category D)
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Use effective contraception during and for at least 7 months after last dose
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Caution in patients with pulmonary conditions – risk of interstitial pneumonitis
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Discontinue immediately if patient develops severe infusion reactions or significant cardiac dysfunction
Drug Interactions:
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Anthracyclines (e.g., Doxorubicin) – increases risk of cardiotoxicity; avoid concurrent use
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Cyclophosphamide and platinum agents – additive myelosuppression
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Paclitaxel/Docetaxel – commonly used in combination, monitor for additive toxicities
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Live vaccines – avoid during treatment
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CYP450 interactions are minimal, as Trastuzumab is a biologic
Allergies (Warnings for Allergic Reactions):
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Contraindicated in patients with known hypersensitivity to Trastuzumab or murine proteins
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Hypersensitivity symptoms may include fever, chills, rash, hypotension, or angioedema
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Emergency resuscitation equipment should be readily available during infusion
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Patients should be pre-medicated if prior reactions occurred
Overdose Information:
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No specific antidote for Trastuzumab overdose
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Symptoms may include cardiac dysfunction or severe infusion reactions
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Supportive management includes monitoring cardiac status, fluid/electrolyte management, and symptomatic care
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Hospitalization may be required in severe cases
Missed Dose Instructions:
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If a scheduled dose is missed, administer as soon as possible
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Do not double the next dose
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If the interval between doses is >1 week, resume with loading dose (8 mg/kg)
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Always consult the treating oncologist before resuming therapy
Additional Notes:
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Trastuzumab is a HER2-targeted biologic, not a traditional chemotherapy drug
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Regular monitoring of HER2 status (via IHC or FISH) is essential before initiating therapy
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Cardiac monitoring is mandatory due to potential for reversible or irreversible heart failure
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Trastuzumab has revolutionized survival outcomes in HER2-positive breast cancer
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Hermab by Reliance Life Sciences is a cost-effective Indian biosimilar, widely used in oncology centers
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Do not interchange IV and SC formulations without consulting the oncologist
