margetuximab

High Alert

Metastatic HER2-positive breast cancer in patients who have previously received ≥2 anti-HER2 regimens, at least one of which was for metastatic disease (in combination with chemotherapy).

Contraind./Precautions ⬆ ⬇

Contraindicated in:

OB: Pregnancy.

Use Cautiously in:

HF or history of MI or unstable angina within past 6 mo;
Lactation: Safety not established in breastfeeding;
Rep: Women of reproductive potential;
Pedi: Safety and effectiveness not established in children;
Geri: Older adults may have ↑ risk of cardiotoxicity.

Adv. Reactions/Side Effects ⬆ ⬇

CV: HF, hypertension, syncope

Derm: alopecia, palmar-plantar erythrodysesthesia, rash

GI: ↑lipase, abdominal pain, constipation, diarrhea, ↑liver enzymes, nausea, stomatitis, vomiting

GU: ↑serum creatinine

Hemat: ↑activated partial thromboplastin time (aPTT), ↑international normalized ratio (INR), anemia, leukopenia, lymphocytopenia, NEUTROPENIA

Metab: ↓appetite, weight loss

MS: arthralgia, myalgia

Neuro: dizziness, fatigue, headache, peripheral neuropathy, insomnia

Resp: cough, dyspnea, dysgeusia

Misc: fever, infusion reactions

Interactions ⬆ ⬇

Drug-drug:

Concurrent anthracycline (daunorubicin, doxorubicin, or idarubicin) therapy may ↑ risk of cardiotoxicity; avoid anthracycline therapy for ≥4 mo after discontinuing margetuximab.

Availability ⬆ ⬇

Solution for injection: 25 mg/mL

Route/Dosage ⬆ ⬇

IV (Adults ): 15 mg/kg every 3 wk (on days when administered with chemotherapy, give margetuximab immediately after chemotherapy). Continue until disease progression or unacceptable toxicity.

US Brand Names ⬆ ⬇

Action ⬆ ⬇

A monoclonal antibody that binds to HER2 sites in breast cancer tissue and inhibits proliferation of cells that overexpress HER2 protein.

Therapeutic effects:

Improved progression-free survival.

Classifications ⬆ ⬇

Therapeutic Classification: antineoplastics

Pharmacologic Classification: monoclonal antibodies

Pharmacokinetics ⬆ ⬇

Absorption: IV administration results in complete bioavailability.

Distribution: Not widely distributed to extravascular tissues.

Metabolism/Excretion: Metabolized into small peptides by catabolic pathways.

Half-Life: 19.2 days.

Time/Action Profile ⬆ ⬇

(plasma concentrations)

ROUTE	ONSET	PEAK	DURATION
IV	unknown	unknown	unknown

Patient/Family Teaching ⬆ ⬇

Explain purpose and side effects of medication to patient. Advise patient to read Patient Information before starting therapy. If a dose is missed, administer the scheduled dose as soon as possible and adjust the administration schedule to maintain a 3-wk interval between doses.
Advise patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to consult health care professional before taking other medications.
Advise patient to notify health care professional if cough or shortness of breath that is new or worse, swelling of the ankles or legs, a heartbeat that does not feel normal, weight gain of >5 pounds in 24 hr, dizziness, or passing out occurs.
Advise patient to notify health care professional if signs of infection develop (fever, chills, sore throat).
Rep: May cause fetal harm. Advise women of reproductive potential to notify health care professional if pregnancy is planned or expected or if breastfeeding. Patients who may become pregnant should use effective contraception during treatment and for 4 mo after the last dose.

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Indications ⬇