Margetuximab

Margetuximab is a prescription medication used in combination with chemotherapy for metastatic human epidermal growth factor receptor 2-positive (HER2+) breast cancer in patients who have received ≥2 anti-HER2 regimens, at least 1 of which was for metastatic disease.

• Margetuximab is available under the following different brand names: Margenza, margetuximab-cmkb

Common side effects of margetuximab include:

• fatigue
• weakness
• nausea
• diarrhea
• vomiting
• constipation
• headache
• fever
• hair loss
• abdominal pain
• numbness and tingling in extremities, cough
• decreased appetite
• shortness of breath
• infusion-related reactions
• hand-foot syndrome (palmar-plantar erythrodysesthesia)
• extremity pain

Serious side effects of margetuximab include:

• arm or leg pain
• burning
• numbness
• tingling, or painful sensations
• constipation
• decreased appetite
• diarrhea
• hair loss, thinning of hair
• stomach pain
• unsteadiness or awkwardness
• weakness in the arms, hands, legs, or feet

Rare side effects of margetuximab include:

• none

Seek medical care or call 911 at once if you have the following serious side effects:

• Severe headache, confusion, slurred speech, arm or leg weakness, trouble walking, coordination loss, unsteady, very stiff muscles, high fever, profuse sweating, or tremors;
• Serious eye symptoms such as sudden vision loss, blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights;
• Serious heart symptoms include fast, irregular, or pounding heartbeats; fluttering in the chest; shortness of breath; sudden dizziness, lightheadedness, or passing out.

This is not a complete list of side effects and other serious side effects or health problems that may occur because of the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.

Adult dosage

Injection, solution concentrate

• 250 mg/10mL (25 mg/mL) single-dose vial

Breast cancer

Adult dosage

• 15 mg/kg IV every 3 weeks
• Continue until disease progression or unacceptable toxicity
• Refer to the prescribing information for each therapeutic agent administered in combination therapy for dosing information

Dosage Considerations – Should be Given as Follows:

• See “Dosages”

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, healthcare provider, or pharmacist first.

• Margetuximab has no noted severe interactions with any other drugs
• Margetuximab has no noted serious interactions with any other drugs
• Margetuximab has no noted moderate interactions with any other drugs
• Margetuximab has no noted minor interactions with any other drugs

This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drug interactions. Therefore, before using this product, tell your doctor or pharmacist about all the products you use. Keep a list of all your medications with you and share this information with your doctor and pharmacist. Check with your healthcare professional or doctor for additional medical advice, health questions, or concerns.

Contraindications

• None

Effects of drug abuse

• None

Short-Term Effects

• See “What Are Side Effects Associated with Using Margetuximab?”

Long-Term Effects

• See “What Are Side Effects Associated with Using Margetuximab?”

Cautions

• May cause fetal harm when administered to pregnant women.
• Left ventricular dysfunction
  • Left ventricular dysfunction may occur.
  • Not studied in patients with pretreatment LVEF below 50%, history of myocardial infarction or unstable angina within 6 months, or congestive heart failure NYHA class II-IV
  • Conduct thorough cardiac assessment (eg, history, physical examination, determination of LVEF by ECG or multiple gated acquisitions (MUGA) scans
  • Measure baseline LVEF within 4 weeks before initiation; then every 3 months during and upon completion
  • Repeat LVEF at 4-week intervals if therapy is withheld for significant left ventricular dysfunction
• Infusion-related reactions
  • Infusion-related reactions (IRR) were reported
  • Symptoms may include fever, chills, arthralgia, cough, dizziness, fatigue, nausea, vomiting, headache, diaphoresis, tachycardia, hypotension, pruritus, rash, urticaria, and dyspnea
  • Monitor for IRRs during administration and as clinically indicated after completing an infusion
  • Have medications and emergency equipment available immediately to treat IRRs
• Drug interaction overview
• Anthracyclines
  • Avoid anthracycline-based therapy for up to 4 months after discontinuing margetuximab
  • Patients treated with anthracyclines under 4 months after discontinuing therapy may be at increased risk of cardiac dysfunction
  • Interaction has not been studied with margetuximab
  • Clinical data from other HER2-directed antibodies warrant consideration
  • If use is unavoidable, closely monitor cardiac function

Pregnancy and Lactation

• Based on findings in animals and mechanism of action, fetal harm may occur when administered to pregnant women
• No data available on use in pregnant women to inform of the drug-associated risks
• In postmarketing reports, the use of a HER2-directed antibody during pregnancy resulted in cases of oligohydramnios and oligohydramnios sequence manifesting as pulmonary hypoplasia, skeletal abnormalities, and neonatal death
• Verify the pregnancy status of women of reproductive potential before initiation
• Fetal/neonatal adverse reactions
  • Monitor treated women during pregnancy or within 4 months before conception for oligohydramnios
  • If oligohydramnios occurs, perform fetal testing appropriate for gestational age and consistent with community standards of care
• Contraception
  • Women of reproductive potential: Use effective contraception during treatment and for 4 months following the final dose
• Lactation
  • No information is available on drug presence in human milk, its effects on breastfed children, or on milk production
  • Published data suggest human IgG is present in human milk but does not enter neonatal or infant circulation in substantial amounts
  • Consider a drug washout period of 4 months when weighing the risks versus benefits