Commonly retailed under the trade name Herceptin, Trastuzumab is a Monoclonal Antibody used in the treatment of Breast Cancer cases where a patient has been confirmed to be HER2 receptor positive. It is sometimes used independently, and sometimes in combination with other chemotherapy drugs.
Recently, the FDA has approved two low-cost biosimilar molecules for Trastuzumab, to be sold by the companies Mylan and Biocon. While this ushers in a new era of hope for targeted therapies in the treatment of Breast Cancer, we also need to understand what Trastuzumab is, and what makes it so effective for cancer care.
What Is Trastuzumab?
Trastuzumab is a targeted therapy used in the treatment of Breast Cancer. It belongs to a class of drugs known as Monoclonal Antibodies.
mAbs (or Monoclonal Antibodies)
Monoclonal Antibodies (abbreviated as mAb/moAb) are essentially antibodies that are engineered by cloning one unique immune cell into many identical immune cells.
Ever since scientists discovered how to generate monoclonal antibodies, they have targeted the creation of "fully" human products to reduce the side effects of humanised or chimeric antibodies.
As of November 2016, nineteen "fully" human monoclonal antibody therapeutics have been available in the market.
Uses Of Trastuzumab
Trastuzumab has been currently been approved for the following medical applications:
- In the treatment of HER-2 receptor positive Breast Cancer cases, when the cancer has been detected at an early stage. The drug can be administered for both locally advanced and metastatic disease conditions.
- In the treatment of HER-2 receptor positive, Metastatic Stomach Cancer cases (As an add-on to Chemotherapy treatment).
Known Side Effects Of Trastuzumab
Confirmed side effects of Trastuzumab (Herceptin) include:
- Infusion related symptoms such as fever, chills, flushing, fatigue, headache, hypotension, etc
- Cardiotoxicity in the form of shortness of breath, peripheral oedema, decreased ventricular function, etc
- Immunosuppression/Myelosuppression - Caused by a decrease in the overall WBC count; May lead to infections
- Lung Toxicity in the form of increased coughing, difficulty in breathing, sinusitis, pleural effusion, etc
- Complications - Trastuzumab may lead to an increased risk of cardiac toxicity when paired with Anthracyclines Chemotherapy.
Availability Of Trastuzumab
In its current trade formats, Trastuzumab (Herceptin) is available in the following volumes:
- Single Dosage Vial (150 mg)
- Multi Dosage Vial (420 mg)
Low Cost Alternative For Trastuzumab
Aside from this, as pointed out above, the US Food & Drug Administration Authority has approved two Biosimilar Molecules for Trastuzumab to be sold by the companies Mylan and Biocon respectively.
Administration & Dosage Of Trastuzumab
• It is administered intravenously.
• The common regimen is loading dose of 4mg/kg given over 90min followed by maintenance dose of 2mg/kg over 30min on weekly basis.
Usage Precautions For Trastuzumab
Despite the obvious evolutionary aspect of targeted therapies, Trastuzumab is still a relatively new medication, and appropriate care should be taken to ensure that it does not create conflicts/complications when used on patients with known, pre-existing conditions. More specifically,
- Caution must be exercised when Trastuzumab is used for patients with pre-existing Cardiac Dysfunction.
- Usage should be scrutinized and reviewed with relevant doctors when treating pregnant women/breastfeeding mothers.
- Click here to read more on HER-2 Receptors and how they affect the treatment for women who have recently been diagnosed with Breast Cancer.
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