Margetuximab-cmkb Injection
Margetuximab-cmkb Injection (Margenza) is an intravenous HER2-targeted antibody medicine used with chemotherapy to treat adults with metastatic HER2-positive breast cancer after earlier treatments.
🧬 Where this information comes from Click to expand
The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 2 clinical label sets within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →
Margenza (margetuximab) is an IV antibody used with chemotherapy for metastatic HER2-positive breast cancer. It latches onto the HER2 protein to slow cancer cell growth and helps the immune system attack those cells, and since about 2020 it has been a specialist option for people who have already had two or more anti-HER2 treatments. Side effects blur with the chemotherapy's, mainly tiredness, nausea, diarrhea and tingling hands or feet, and infusion reactions are most likely with the first dose. The boxed warning covers weakened heart pumping (left ventricular dysfunction) and harm to an unborn baby, so expect heart checks before and during treatment, use effective contraception, and report new breathlessness or swelling promptly.
Clinical pearls
- Avoid anthracycline chemotherapy (the doxorubicin family) for 4 months after stopping Margenza, because the combination raises heart risk.
- Contraception must continue for 4 months after the last dose, since the drug stays in the body that long.
- Report any fever right away, because low white blood cell counts with fever were among the serious reactions seen.
- Adults 65 and older had more serious side effects, including heart problems, so heart symptoms deserve extra attention.
⚠️ FDA Boxed Warning — the FDA’s strongest safety alert ▾
Margenza can weaken the heart's pumping ability (left ventricular dysfunction) and can harm an unborn baby.
Your heart function should be checked before and during treatment. Treatment is stopped if there is a confirmed, clinically significant drop in heart function. Watch for new shortness of breath, swelling or unusual tiredness.
If you are pregnant or could become pregnant, talk with your doctor about the risk. Effective contraception is needed.
Patient information guide A plain-language walkthrough of Margetuximab-cmkb Injection, written from its FDA label.
What Margetuximab-cmkb Injection is used for
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Margetuximab-cmkb Injection is used for one cancer indication.
- Margenza, given by IV infusion with chemotherapy, treats adults with metastatic HER2-positive breast cancer who have had two or more prior anti-HER2 regimens, at least one for metastatic disease.
How Margetuximab-cmkb Injection works
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Margetuximab-cmkb binds to HER2 on the surface of tumor cells. This slows cancer cell growth and reduces shedding of part of the HER2 protein.
It also helps immune cells recognize and attack the cancer cells. In lab studies its modified design boosted this immune response.
Margetuximab-cmkb Injection dosage
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Margenza is given only by IV infusion in a healthcare setting.
- It is given every 3 weeks with chemotherapy.
- The first infusion takes longer than later ones.
- It continues until the disease progresses or side effects are unacceptable.
- If you miss a dose, it is given as soon as possible, and the schedule is adjusted to keep 3 weeks between doses.
Dosing details from the FDA-approved label
From the Margetuximab-cmkb Injection prescribing information (“Dosage and Administration”). Doses are set by your prescriber for your product, condition, kidney function and age — never change a dose on your own.
- Recommended dose and schedule (used in combination with chemotherapy)
- 15 mg/kg administered as an intravenous infusion every 3 weeks (21-day cycle) until disease progression or unacceptable toxicity
- Infuse over 120 minutes for the initial dose, then over a minimum of 30 minutes every 3 weeks for all subsequent doses
- On days when both MARGENZA and chemotherapy are administered, MARGENZA may be given immediately after chemotherapy completion
- Missed dose
- Administer the scheduled dose as soon as possible
- Adjust the administration schedule to maintain a 3-week interval between doses
- Left ventricular dysfunction
- Withhold MARGENZA dosing for at least 4 weeks for ≥ 16% absolute decrease in LVEF from pretreatment values, or LVEF below institutional limits of normal (or 50% if no limits are available) and ≥ 10% absolute decrease in LVEF from pretreatment values
- May resume if within 8 weeks LVEF returns to normal limits and absolute decrease from baseline is ≤ 15%
- Perm
- Assess LVEF before starting MARGENZA and regularly during treatment
- Infusion-related reactions
- Decrease the rate of infusion for mild or moderate IRRs
- Interrupt the infusion for dyspnea or clinically significant hypotension
- Permanently discontinue in patients with severe or life-threatening IRRs
Read the label’s full dosing text
2 DOSAGE AND ADMINISTRATION For intravenous infusion only. ( 2.1 ) Administer MARGENZA as an intravenous infusion at 15 mg/kg over 120 minutes for the initial dose, then over a minimum of 30 minutes every 3 weeks for all subsequent doses. ( 2.1 ) On days when both MARGENZA and chemotherapy are to be administered, MARGENZA may be administered immediately after chemotherapy completion. ( 2.1 ) 2.1 Recommended Doses and Schedules The recommended dose of MARGENZA is 15 mg/kg, administered as an intravenous infusion every 3 weeks (21-day cycle) until disease progression or unacceptable toxicity. Administer MARGENZA as an intravenous infusion at 15 mg/kg over 120 minutes for the initial dose, then over a minimum of 30 minutes every 3 weeks for all subsequent doses. On days when both MARGENZA and chemotherapy are to be administered, MARGENZA may be administered immediately after chemotherapy completion. Refer to the respective Prescribing Information for each therapeutic agent administered in combination with MARGENZA for the recommended dosage information, as appropriate. 2.2 Dose Modification or Important Dosing Considerations If a patient misses a dose of MARGENZA, administer the scheduled dose as soon as possible. Adjust the administration schedule to maintain a 3-week interval between doses. Left Ventricular Dysfunction [see Warnings and Precautions (5.1) ] Assess left ventricular ejection fraction (LVEF) before starting MARGENZA and regularly during treatment. Withhold MARGENZA dosing for at least 4 weeks for any of the following: ≥ 16% absolute decrease in LVEF from pretreatment values LVEF below institutional limits of normal (or 50% if no limits are available) and ≥ 10% absolute decrease in LVEF from pretreatment values. MARGENZA dosing may be resumed if, within 8 weeks, LVEF returns to normal limits and absolute decrease from baseline is ≤ 15%. Permanently discontinue MARGENZA if LVEF decline persists for greater than 8 weeks, or if dosing is interrupted on greater than 3 occasions for LVEF decline. Infusion-Related Reactions [see Warnings and Precautions (5.3) ] Decrease the rate of infusion for mild or moderate infusion-related reactions (IRRs). Interrupt the infusion for dyspnea or clinically significant hypotension. Permanently discontinue MARGENZA dosing in patients with severe or life-threatening IRRs .
Excerpted — the section continues on the label. Read the full Dosage and Administration section on DailyMed →
Margetuximab-cmkb Injection side effects
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The most common side effects with chemotherapy include:
Common side effects
- Tiredness or weakness
- Nausea, vomiting, diarrhea or constipation
- Headache
- Fever
- Hair loss
- Stomach pain
- Numbness or tingling in hands or feet (peripheral neuropathy)
- Infusion-related reactions
- Nerve tingling or numbness
- Joint or muscle pain, cough, decreased appetite, shortness of breath, arm or leg pain
- Infusion-related reactions and hand-foot skin reaction
When to get medical help
- Call your care team about shortness of breath, swelling or other new heart symptoms. Margenza can reduce how well the heart pumps.
- Tell staff right away during or after an infusion if you have fever, chills, dizziness, trouble breathing, rash, itching or a racing heartbeat.
- Tell your doctor right away if you are or may be pregnant.
- Report fever or signs of infection. Low white blood cell counts with fever (febrile neutropenia) were among the serious reactions seen.
Serious effects include heart function decline, severe infusion reactions and low white blood cell counts with fever. Report these promptly.
Margetuximab-cmkb Injection warnings and precautions
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- Heart problems: Margenza can lower heart pumping function. Heart tests are done before treatment and about every 3 months. Dosing is held or stopped if function drops.
- Pregnancy harm: It can cause fetal harm, including low amniotic fluid (oligohydramnios) with other HER2 antibodies.
- Infusion reactions: These are most likely with the first dose and usually resolve within 24 hours. Severe ones lead to permanent discontinuation.
Margetuximab-cmkb Injection interactions
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One interaction is highlighted on the label.
- Anthracycline chemotherapy: may raise the risk of heart problems if used within 4 months after stopping Margenza, so it is avoided or the heart is monitored closely.
- Margenza should not be mixed with other drugs or run through the same IV line.
Interactions listed in the FDA-approved label
From the Margetuximab-cmkb Injection prescribing information (“Drug Interactions”): what the manufacturer studied or reported to the FDA.
- Anthracyclines: Patients who receive anthracyclines less than 4 months after stopping MARGENZA may be at increased risk of cardiac dysfunction; this interaction has not been studied with MARGENZA, but clinical data from other HER2-directed antibodies warrants consideration. Avoid anthracycline-based therapy for up to 4 months after stopping MARGENZA. If concomitant use is unavoidable, closely monitor patient's cardiac function.
Read the label’s full interactions text
7 DRUG INTERACTIONS Anthracyclines Patients who receive anthracyclines less than 4 months after stopping MARGENZA [see Clinical Pharmacology (12.3) ] may be at increased risk of cardiac dysfunction. While this interaction has not been studied with MARGENZA, clinical data from other HER2-directed antibodies warrants consideration. Avoid anthracycline-based therapy for up to 4 months after stopping MARGENZA. If concomitant use is unavoidable, closely monitor patient's cardiac function.
Not a complete list. The label covers the interactions the manufacturer studied or reported, and our own interaction database does not cover every medicine either. Bring your full medication list, including vitamins and herbal products, to your pharmacist.
Before taking Margetuximab-cmkb Injection
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- Heart disease: tell your doctor about low heart function, recent heart attack, unstable angina or heart failure.
- Pregnancy: a test is needed first, and contraception is advised during treatment and for 4 months after.
- Breastfeeding: discuss with your doctor, since the drug stays in the body for about 4 months.
- Children: not established as safe or effective.
- Older adults: higher rates of serious and heart-related side effects were seen in those 65 and older.
What Margetuximab-cmkb Injection does in the body
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How the strength of the effect relates to dose and timing has not been fully characterized for either safety or effectiveness.
How your body processes Margetuximab-cmkb Injection
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Margetuximab-cmkb reaches steady state in about 2 months. It is expected to be broken down into small peptides. Its half-life is about 19 days. About 4 months after stopping, levels fall to roughly 3% of steady-state trough levels. Age, sex, race and mild to moderate kidney impairment did not cause clinically significant differences. The effects of severe kidney problems or moderate to severe liver problems are unknown.
How to store Margetuximab-cmkb Injection
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Store vials refrigerated at 2°C to 8°C (36°F to 46°F) in original carton to protect from light until time of use. Do not freeze.
Written from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →
Margetuximab-cmkb Injection: pharmacist answers to common questions
Quick, plain-English answers to the questions patients ask most about Margetuximab-cmkb Injection — the kind of thing our pharmacy team would talk through with you at the counter.
What is Margenza for?
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How will I get it?
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What side effects should I expect?
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Does it affect my heart?
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Can I take it if I might get pregnant?
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Are there other cancer drugs I should be careful with?
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Is Margetuximab-cmkb Injection available over the counter?
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When was Margetuximab-cmkb Injection first available?
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Who makes Margetuximab-cmkb Injection?
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Answers drafted from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →
More about Margetuximab-cmkb Injection on HelloPharmacist
Margetuximab-cmkb Injection forms and strengths (how it comes)
Margetuximab-cmkb Injection is available in 1 form. Different forms and brands can have different approved uses, doses, schedules, and directions. Follow the instructions for your exact product, and do not switch forms without guidance from your prescriber or pharmacist.
Need a version that does not list lactose, a gluten source, a dye or gelatin? Inactive ingredients differ by manufacturer: see Margetuximab-cmkb Injection inactive ingredients by manufacturer.
Injection
How this form is used
- Margenza is used with chemotherapy for adults with metastatic HER2-positive breast cancer who have had two or more prior anti-HER2 regimens.
- Margenza is given only as an intravenous infusion, never as an IV push or bolus.
- Margenza is given every 3 weeks; the first infusion runs longer than later ones.
- Margenza is diluted before use and given through a filtered IV line without other drugs.
Margetuximab-cmkb Injection on the U.S. market: products, makers and brands
How Margetuximab-cmkb Injection appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.
2 companies list 2 Margetuximab-cmkb Injection product records with the FDA, mostly as injection; the earliest marketing or approval year on record is 2020. Brand names on the directory include Margenza; the rest are generics.
Share of FDA-listed product records by manufacturer — FDA National Drug Code Directory. Record counts are not sales or prescription volume.
Compare Margetuximab-cmkb Injection products
A representative set of FDA-listed product records for Margetuximab-cmkb Injection — across manufacturers, strengths, and dosage forms, grouped by form with each product’s manufacturer and how the FDA approved it. The same medicine may be made and packaged by different companies, so a single drug can have many directory entries. (It’s also why a refill can look different — a new shape, color, or box — even though it contains the same medication.)
| Strength | Route | Manufacturer / Labeler | Category ⓘ | Details |
|---|---|---|---|---|
| 💊Injection | ||||
| 25 mg/mL | Intravenous | MacroGenics, Inc | BLA | View NDC → |
| 25 mg/mL | Intravenous | TerSera Therapeutics LLC | BLA | View label ↗ |
Showing 2 of 2 products — FDA National Drug Code Directory. See every product, package size and price: browse all 2 Margetuximab-cmkb Injection NDCs →
Margetuximab-cmkb Injection side effects reported to the FDA (FAERS)
After a medicine reaches the market, patients, doctors and drugmakers can send the FDA reports of problems they think may be linked to it. Here’s what’s been reported for Margetuximab-cmkb Injection — a signal of what to watch for, not proof the drug caused it.
Source: openFDA, from the FDA Adverse Event Reporting System (FAERS). These are voluntary reports — they don’t prove the drug caused the effect, and counts reflect how often something was reported, not how often it actually happens. Reports also often name the very problem the medicine is taken for — a common reason to file one is that the drug didn’t help — so for a pain reliever you may see “pain” high on the list; that points to why the report was filed, not to the drug causing the symptom. This counts every report that lists Margetuximab-cmkb Injection in any role, so the total runs higher than the FDA’s official dashboard, which counts only cases where the drug is the suspect. For the authoritative figures, see the FDA FAERS Public Dashboard. Always talk to your pharmacist or doctor.
Margetuximab-cmkb Injection FDA approval history
How Margetuximab-cmkb Injection went from FDA review to the pharmacy shelf — the key milestones in its regulatory journey.
Source: Drugs@FDA.
Margetuximab-cmkb Injection recall history
A recall is when a specific batch of a medicine is pulled from the market — usually a manufacturing issue, not a problem with the drug itself. Class I is most serious, Class III least.
The FDA’s enforcement reports list no Margetuximab-cmkb recalls since July 2021.
✅No Margetuximab-cmkb recalls on record since July 2021Source: FDA enforcement (recall) reports, via openFDA; our copy was last updated Sep 24, 2026.
RxNorm Concept Web — From Ingredient to Every Form and Strength
This page starts with one ingredient concept (IN). The branches below show its dose-form concepts (SCDF), then the available clinical drug and strength concepts (SCD). Combination products remain separate concepts with their own pages.
RxCUI 2473851 1 dose form · 1 strength
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Dose form (SCDF) Injection RxCUI 2474027In current FDA listingsClinical drug / strength (SCD) 10 ML margetuximab-cmkb 25 MG/MLRxCUI 2474028
Look up RxCUI 2473851 in the RxCUI Atlas →
RxNorm is the U.S. National Library of Medicine’s normalized drug vocabulary. Its concept hierarchy can include forms that are not currently marketed; the status on each branch compares that concept with current FDA listings. RxCUIs identify vocabulary concepts, not individual packages or manufacturers.
Margetuximab-cmkb Injection supply and shortage status
Whether Margetuximab-cmkb Injection is in short supply in the U.S. right now, plus any shortage history the FDA has on record. A shortage usually reflects a manufacturing or demand issue — not a safety problem with the drug.
Source: openFDA, from the FDA Drug Shortages database.
Margetuximab-cmkb Injection brand names
Margetuximab-cmkb Injection is sold under one brand name in the FDA directory — Margenza. A brand and its generic contain the same active ingredient; the brand name belongs to one company's product.
Who makes Margetuximab-cmkb Injection: manufacturers and labelers
2 companies list Margetuximab-cmkb Injection products with the FDA. By number of product records, the largest are MacroGenics, Inc, TerSera Therapeutics LLC. Labelers include manufacturers and repackagers; the product in your bottle depends on which one your pharmacy stocks.
Margetuximab-cmkb Injection drug class (RxNorm)
Margetuximab-cmkb Injection belongs to the HER2/neu Receptor Antagonist class.
Classified by RxNorm RxClass — the U.S. National Library of Medicine's standardized drug-classification service (Established Pharmacologic Class from the FDA, the ATC drug family from the WHO, and mechanism of action). Reference only, not medical advice.
Sources for this Margetuximab-cmkb Injection page
Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.
How this page is built
HelloPharmacist combines public FDA and NLM records and does not author the underlying clinical facts. The plain-language sections are written with AI from the FDA-approved label text and reviewed by our pharmacy team before publication. TerSera Therapeutics LLC is the representative DailyMed label linked for verification and dates. This is general education, not medical advice: always talk to your doctor or pharmacist about your own medicines. How we build and review drug pages →