Margetuximab-cmkb Injection
Margetuximab-cmkb is a HER2-targeted antibody used in combination with chemotherapy to treat metastatic HER2-positive breast cancer in adults who have already tried at least two prior HER2-directed 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 →
⚠️ FDA Boxed Warning — the FDA’s strongest safety alert ▾
Margenza carries two serious warnings that the FDA requires to be highlighted:Heart problems: Margenza can weaken the heart's pumping ability. Your doctor will check your heart before and regularly during treatment. If your heart function drops too much, Margenza must be paused or stopped.Harm to unborn babies: Taking Margenza during pregnancy — or becoming pregnant within 4 months before starting treatment — can seriously harm or kill a developing baby. Women who can become pregnant must use effective birth control during treatment and for 4 months after the last dose. Tell your doctor immediately if you become pregnant.
📖 Margetuximab-cmkb Injection: Patient Information Guide
A plain-language walkthrough of Margetuximab-cmkb Injection — what it treats, how it works, how it’s taken, side effects, warnings and interactions. Tap any section to expand it.
🎯What it's used for▾
Margetuximab-cmkb (brand name Margenza) is a HER2-targeted antibody indicated for a specific group of adults with advanced breast cancer.
- Margenza injection is approved, in combination with chemotherapy, for adult patients with metastatic HER2-positive breast cancer who have already received two or more anti-HER2 treatment regimens, at least one of which was used for metastatic disease.
⚙️How it works▾
Margetuximab-cmkb is an antibody designed to lock onto the HER2 protein — a receptor found in high amounts on some breast cancer cells. When it binds to HER2, it slows cancer cell growth and reduces the amount of HER2 protein the tumor releases. Its Fc region (the "tail" of the antibody) has been specially engineered to bind more strongly to an activating immune receptor and less to an inhibiting one. This means immune cells — particularly natural killer (NK) cells — are more strongly recruited to recognize and destroy HER2-positive cancer cells, a process called antibody-dependent cellular cytotoxicity (ADCC).
💊How it's taken▾
Margenza is given as an intravenous (IV) infusion in a clinical setting by trained healthcare professionals — it is not something you take at home. It is administered once every 3 weeks. The first infusion takes about 2 hours; if tolerated well, later infusions can be given over as little as 30 minutes. On days when chemotherapy is also scheduled, Margenza may be given immediately after chemotherapy is complete.
- If you miss a dose, your care team will reschedule it and adjust the timing to keep the 3-week interval between doses.
- Your doctor will determine how long you continue treatment based on how well it is working and how well you tolerate it.
🤒Side effects — in detail▾
The most commonly reported side effects with Margenza (occurring in more than 10% of patients) include:
- Fatigue or weakness
- Nausea, diarrhea, vomiting, or constipation
- Headache
- Fever
- Hair loss
- Infusion-related reactions (chills, fever, rash, dizziness, shortness of breath — usually during or just after the first infusion)
- Peripheral neuropathy (tingling, numbness, or pain in hands or feet)
- Decreased appetite
- Joint or muscle pain
- Cough or shortness of breath
More serious reactions — including significant heart function decline, severe infusion reactions, and low white blood cell counts (which can increase infection risk) — require prompt medical attention. Contact your care team immediately if you develop chest symptoms, severe difficulty breathing, or signs of infection.
⚠️Warnings & precautions▾
- Heart function decline (left ventricular dysfunction): Margenza can weaken the heart's pumping ability. Heart function must be tested before starting and every 3 months during treatment. Margenza has not been studied in patients with a history of recent heart attack, unstable angina, or moderate-to-severe heart failure.
- Embryo-fetal toxicity: Margenza can cause serious harm to an unborn baby, including kidney abnormalities and potentially fatal outcomes. Pregnancy must be confirmed negative before starting treatment. Effective contraception is required during treatment and for 4 months after the last dose.
- Infusion-related reactions: Reactions are most common during the first infusion. Symptoms can include fever, chills, rash, low blood pressure, and breathing difficulty. Severe reactions require permanent discontinuation of Margenza.
- Anthracycline interaction risk: Using certain chemotherapy drugs called anthracyclines within 4 months of stopping Margenza may raise the risk of heart damage.
- Older adults: Patients age 65 and older had higher rates of serious side effects, including heart-related effects, compared to younger patients.
🔀What it interacts with▾
There is one key drug interaction to be aware of with Margenza:
- Anthracycline chemotherapy (e.g., doxorubicin): Receiving anthracyclines within 4 months of stopping Margenza may increase the risk of heart damage, because Margenza stays in the body for several months after the last dose. Avoid this combination if possible; if unavoidable, heart function should be closely monitored.
This is not a complete list of interactions. Always talk with your doctor or pharmacist before starting, stopping, or changing any medication.
📋Before taking it▾
- Heart history: Tell your doctor if you have a low heart pumping function (LVEF below 50%), a recent heart attack or unstable angina within 6 months, or moderate-to-severe heart failure — Margenza has not been studied in these patients.
- Pregnancy: A pregnancy test is required before starting Margenza. Do not use Margenza during pregnancy — it can seriously harm the fetus. Use effective contraception during treatment and for 4 months after the last dose.
- Breastfeeding: It is unknown whether Margenza passes into breast milk. Discuss the risks with your doctor, factoring in the 4-month washout period after stopping treatment.
- Children: Margenza has not been studied in pediatric patients and is not approved for use in children.
- Older adults (age 65+): Higher rates of serious and heart-related side effects have been observed — closer monitoring is important.
- Severe kidney or liver impairment: The effect of severe kidney disease, end-stage renal disease, or moderate-to-severe liver impairment on how the body processes Margenza is unknown — tell your doctor about any kidney or liver conditions.
📡Pharmacodynamics — effects in the body▾
The full relationship between Margenza blood levels and its effects on safety or effectiveness has not been completely established. In laboratory studies, the engineered Fc region of margetuximab-cmkb increased the activation of natural killer (NK) immune cells and enhanced antibody-dependent cellular cytotoxicity (ADCC) compared to standard antibodies — meaning the immune system's cancer-fighting response appears to be amplified. However, how these lab findings translate to clinical outcomes in individual patients is still being studied.
🔬Pharmacokinetics — how your body processes it▾
Margenza is given intravenously and reaches steady-state levels in the blood after about 2 months of regular dosing. It has a long half-life of approximately 19 days, meaning it takes several weeks to be cleared from the body after treatment is stopped — concentrations fall to about 3% of their steady-state level around 4 months after the last dose. The drug is broken down through normal protein metabolism pathways (into small peptides) and does not appear to be significantly affected by age, sex, race, or mild-to-moderate kidney or liver impairment. The impact of severe kidney disease or moderate-to-severe liver disease on drug levels is not known.
📦How to store it▾
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 Margetuximab-cmkb Injection’s FDA-approved label information, summarized in plain language with AI, and reviewed by our pharmacy team before publication. Every point is grounded in that labeling — nothing is invented. How we use AI →
🩺 Pharmacist Counseling Corner
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 exactly is Margenza and why has my doctor prescribed it? ▾
What should I expect during my infusion appointments? ▾
Why does my doctor keep checking my heart during treatment? ▾
Is it safe to get pregnant or try to conceive while on Margenza? ▾
Can I take other cancer medications along with Margenza? ▾
Are the side effects worse for older patients? ▾
Is Margetuximab-cmkb Injection available over the counter? ▾
When was Margetuximab-cmkb Injection first available? ▾
Who makes Margetuximab-cmkb Injection? ▾
💬 Answers drafted from Margetuximab-cmkb Injection’s FDA-approved label information, summarized in plain language with AI, and reviewed by our pharmacy team before publication. Grounded in that labeling — nothing is made up. How we use AI →
🧰 Keep exploring
💊 How Margetuximab-cmkb Injection 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.
Injection
How this form is used
- Margenza injection is used in combination with chemotherapy to treat adults with metastatic HER2-positive breast cancer who have had two or more prior anti-HER2 treatment regimens, with at least one for metastatic disease
- Margenza is given as an intravenous infusion by a healthcare professional — never as a push or bolus injection
- Margenza's first infusion is given over 120 minutes; subsequent infusions may be shortened to a minimum of 30 minutes if earlier infusions were well tolerated
- Margenza is given once every 3 weeks (21-day cycle); on days when chemotherapy is also scheduled, Margenza may be given immediately after chemotherapy
- Margenza must not be mixed with other drugs in the same infusion line
📊 Margetuximab-cmkb Injection across the U.S. market
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.
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 × 3 listings | BLA | View NDC → |
| 25 mg/mL | Intravenous | TerSera Therapeutics LLC | BLA | View label ↗ |
Showing 4 of 4 products — FDA National Drug Code Directory. See every product, package size and price: browse all 4 Margetuximab-cmkb Injection NDCs →
📈 What people report — real-world data (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.
🏛️ The road to your pharmacy
How Margetuximab-cmkb Injection went from FDA review to the pharmacy shelf — the key milestones in its regulatory journey.
Source: Drugs@FDA.
🚨 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.
Source: openFDA drug enforcement (recall) reports.
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.
📦 Supply & 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.
🏷️ Sold under these brand names
🏭 Manufacturers & labelers
RxNorm drug class
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.
🔬 Where this comes from
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 we combine label and product data
HelloPharmacist combines public FDA and NLM records; we don’t author the underlying clinical facts. We identified 2 FDA-filed SPL label sets within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. The representative label is the starting point for the displayed reference monograph; the 12 largest stored in-scope SPL records, which may include that representative, are compared section by section, and the longest available version of each section is retained. Forms, routes, brands, labelers, product-listed strengths, and product-record counts are aggregated separately from ingredient-matched FDA NDC Directory records; package records listed above are associated with the linked SPL; and the normalized concept hierarchy comes from NLM RxNorm.
Where a section is identified as AI-written, its plain-language text is generated from bounded label evidence. New draft drug pages remain in the admin review queue before first publication. TerSera Therapeutics LLC is the representative DailyMed label linked for verification and dates; it is not the sole source used for the page.
This is general education, not medical advice — always consult your doctor or pharmacist about your medications and any medical condition. For the exact wording of the linked representative label, view that label on DailyMed; some displayed composite sections may come from other in-scope SPL labels. Learn how we use AI and our data sources & update cadence.