ENHERTU 100MG INJECTION

🧬💉🎗️ Trastuzumab Deruxtecan 100mg: Targeted Antibody-Drug Conjugate for HER2-Positive Cancers

Trastuzumab Deruxtecan 100mg (brand name: Enhertu) is an advanced antibody-drug conjugate (ADC) designed for the treatment of HER2-positive cancers, especially breast cancer, gastric cancer, and non-small cell lung cancer (NSCLC). This breakthrough medication combines the precision of trastuzumab (a monoclonal antibody targeting HER2 receptors) with a potent chemotherapy agent (deruxtecan) to deliver cytotoxic effects directly to cancer cells, minimizing damage to healthy tissue.

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🔬 Mechanism of Action

Trastuzumab Deruxtecan is composed of:

• Trastuzumab: a HER2-targeted monoclonal antibody that binds to the HER2 receptor, overexpressed in certain tumors.

• Deruxtecan (DXd): a topoisomerase I inhibitor linked to trastuzumab via a cleavable linker.

How it works:

1. Binding: The antibody component targets and binds to HER2-positive cancer cells.

2. Internalization: The ADC is internalized into the cell.

3. Release: Inside the cancer cell, enzymes cleave the linker, releasing deruxtecan.

4. Cytotoxic action: Deruxtecan interferes with DNA replication, leading to cell cycle arrest and apoptosis (cell death).

Additionally, the bystander effect enables deruxtecan to diffuse into neighboring tumor cells—even those with low HER2 expression—enhancing its therapeutic reach.

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📌 Indications and Uses

Approved for use in:

• HER2-positive metastatic breast cancer after prior anti-HER2 therapies

• HER2-low breast cancer (newly defined subtype)

• Unresectable or metastatic HER2-positive gastric or gastroesophageal junction adenocarcinoma

• HER2-mutated non-small cell lung cancer (NSCLC)

It is used when prior standard therapies (e.g., trastuzumab, pertuzumab, taxanes) have failed or are not tolerated.

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💊 Dosage and Administration

• Recommended dose: 5.4 mg/kg IV infusion every 3 weeks (21-day cycle)

• Administered as an intravenous infusion over 90 minutes (first dose), then 30 minutes if tolerated

• Pre-medications (antiemetics) may be given to reduce nausea/vomiting

Dose modifications or delays may be required based on toxicity or side effects.

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⚠️ Precautions and Warnings

1. Interstitial Lung Disease (ILD) / Pneumonitis:

   • Serious and potentially fatal

   • Monitor for new or worsening cough, dyspnea, or fever

   • Immediate discontinuation if Grade 2 or higher ILD is suspected

2. Neutropenia and anemia

3. Cardiotoxicity: Monitor left ventricular ejection fraction (LVEF)

4. Nausea/Vomiting: Prophylactic antiemetics recommended

5. Embryo-fetal toxicity: Avoid during pregnancy and breastfeeding

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🤒 Side Effects

Common:

• Nausea

• Fatigue

• Hair loss

• Vomiting

• Constipation

• Low white blood cells (neutropenia)

Serious:

• Interstitial lung disease (ILD)

• Decreased heart function

• Infusion-related reactions

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🔄 Drug Interactions

• No major cytochrome P450 interactions noted

• Avoid use with other pulmonary-toxic or myelosuppressive agents unless necessary

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🧊 Storage Instructions

• Store vial at 2°C to 8°C (refrigerated)

• Do not freeze or shake

• Reconstituted solution must be used within specified time frame under sterile conditions

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📝 Conclusion

Trastuzumab Deruxtecan 100mg is a revolutionary targeted therapy combining precision oncology with potent chemotherapy. It offers significant clinical benefits in patients with HER2-positive and HER2-low cancers, especially those who have exhausted conventional treatments. While it requires close monitoring for lung and heart-related side effects, its high efficacy and durable response rates make it a critical component in modern oncologic care.

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Always follow your doctor’s advice, dosage instructions, and never self-medicate.