Margenza (margetuximab): What to Expect, Side Effects, and More
Margenza (chemical name: margetuximab-cmkb) is a medicine that targets HER2-positive cancer cells. It is used in combination with chemotherapy.
You may be prescribed Mergenza if you have been diagnosed with metastatic HER2-positive breast cancer and have been treated previously with two or more anti-HER2 regimens, such as Herceptin (trastuzumab), Perjeta (pertuzumab), Kadcyla (trastuzumab-DM1), or Enhertu (trastuzumab-deruxtecan), at least one of which was for metastatic disease. (Metastatic disease is the term used to describe breast cancer that has spread to other areas of the body.)
See Margenza prescribing information.
How Margenza works
Cancer cells grow in an uncontrolled fashion. Margenza works on the surface of the cancer cell by blocking the chemical signals that can stimulate this uncontrolled growth.
Genes are like instruction manuals that tell each cell of your body how to grow, what kind of cell to become, and how to behave.
Breast cancer cells that are HER2-positive make too many copies of a gene known as HER2. This gene makes a protein called a HER2 receptor. HER2 receptors are like ears, or antennae, on the surface of all cells. These HER2 receptors receive signals that stimulate the cell to grow and multiply. Breast cancer cells with too many HER2 receptors can pick up too many growth signals. This causes the cells to rapidly grow and multiply.
Margenza works by binding to the HER2 receptors on the surface of breast cancer cells and blocking them from receiving growth signals. By blocking these signals, Margenza can slow or stop the growth of breast cancer. Margenza also helps immune cells to bind to HER2-positive breast cancer cells, allowing the immune cells to destroy the cancer cells.
What to expect during Margenza treatment
Margenza is given intravenously through an IV or a port. The first dose of Margenza — typically 15 mg per kilogram of body weight — takes two hours; doses after that take at least 30 minutes. You’ll be treated with Margenza every three weeks.
Margenza is given in combination with chemotherapy. On days that you receive both Margenza and chemotherapy, you can receive Margenza immediately after the chemotherapy infusion is complete.
Margenza side effects
Like any cancer medicine, Margenza can cause side effects, some of them severe.
The most common side effects of Margenza and chemotherapy are:
pain in the bones, joints, and muscles
Margenza also may cause serious side effects, such as:
Heart problems, including decreased ability for your heart to pump blood. Symptoms to watch for include swelling of the ankles or legs, shortness of breath, irregular heart beat, cough, or weight gain of more than 5 pounds in less than 24 hours. Contact your doctor immediately if you have any of these symptoms.
Your risk of heart problems is higher if you are treated with an anthracycline chemotherapy medicine less than 4 months after stopping Margenza. Examples of anthracycline chemotherapy include Adriamycin (chemical name: doxorubicin), Doxil (chemical name: liposomal doxorubicin), and Ellence (chemical name: epirubicin).
Before starting Margenza therapy, you should have an echocardiogram or a MUGA (multigated blood-pool imaging) scan to check how well your heart is functioning. Your doctor will continue to monitor your heart function while you are receiving Margenza and may recommend continued monitoring even after you complete treatment.
Infusion-related reactions, including:
fever
chills
joint pain
pain at the infusion site
cough
dizziness
fatigue
nausea
vomiting
headache
sweating
racing heartbeat
low blood pressure
itching
rash
hives
difficulty breathing
The team at your infusion center will monitor you for any signs of an allergic reaction while you’re receiving Margenza and after the infusion is completed. Contact your doctor immediately if you develop any of the symptoms above after you leave the infusion center.
You should not take Margenza if you’re pregnant or breastfeeding. If there’s any chance you might become pregnant, you must use effective birth control while you’re taking Margenza and for at least 4 months after your last dose.
Paying for Margenza
The cost of Margenza may vary. The price you’ll pay depends on the drug manufacturer, your health insurance provider and plan, where you live, and the pharmacy you use. You may also be charged for the office visits required for Margenza infusions.
Note: Your insurance company may require you to get prior authorization before covering Margenza.
Learn more about financial assistance and medicine cost-lowering tips.
Margenza (chemical name: margetuximab-cmkb) prescribing information. MacroGenics. Rockville, MD. 2020. Available at: https://www.margenza.com/pdf/prescribing-information.pdf. (PDF)
— Last updated on December 3, 2024 at 9:31 PM
