Ado-trastuzumab Emtansine Injection
Ado-trastuzumab emtansine (Kadcyla) is an intravenous HER2-targeted cancer medicine used to treat HER2-positive metastatic breast cancer and HER2-positive early breast cancer with residual disease after surgery.
🧬 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 1 clinical label set 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 →
Kadcyla is a targeted IV cancer medicine that joins trastuzumab, which finds HER2 on cancer cells, to a chemotherapy drug (DM1) that disrupts the scaffolding those cells need to divide, used for HER2-positive breast cancer that has spread or that remains after pre-surgery treatment; a specialist drug since about 2013, it has no generic. It is usually gentler than traditional chemotherapy, but tiredness, nausea, muscle aches, headache and nosebleeds are common. The one thing to watch is its boxed warning for serious, sometimes fatal liver damage, weakened heart pumping and harm to an unborn baby, so expect liver tests before every dose and heart checks throughout.
Clinical pearls
- Kadcyla cannot be swapped for plain trastuzumab despite the shared name, so confirming the bag before an infusion is reasonable.
- Tell every prescriber you get Kadcyla, since some antibiotics and antifungals like clarithromycin or voriconazole can raise DM1 levels and toxicity.
- Platelets are checked before each dose because they can fall, and blood thinners or antiplatelet drugs add to the bleeding risk.
- Contraception lasts 7 months past the last dose for women and 4 months for men with partners who could conceive.
⚠️ FDA Boxed Warning — the FDA’s strongest safety alert ▾
Kadcyla has a boxed warning, the FDA's strongest warning, for three serious risks.
- Liver damage: serious liver problems, including liver failure and death, have occurred. Blood tests of liver function are done before treatment and before each dose.
- Heart problems: Kadcyla can lower the heart's pumping ability (left ventricular ejection fraction). Your heart function is checked before and during treatment, and treatment is held if it drops significantly.
- Harm to an unborn baby: exposure during pregnancy can cause fetal harm, so effective contraception is needed.
Report signs of liver trouble, new breathlessness or swelling, or any possible pregnancy to your care team promptly.
Patient information guide A plain-language walkthrough of Ado-trastuzumab Emtansine Injection, written from its FDA label.
What Ado-trastuzumab Emtansine Injection is used for
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Kadcyla (ado-trastuzumab emtansine) is used alone to treat HER2-positive breast cancer in these settings:
- Kadcyla for metastatic breast cancer in people previously treated with trastuzumab and a taxane, who had prior therapy for metastatic disease or recurrence during or within six months of adjuvant therapy.
- Kadcyla for adjuvant treatment of early breast cancer with residual invasive disease after neoadjuvant taxane and trastuzumab-based treatment.
How Ado-trastuzumab Emtansine Injection works
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Kadcyla links the antibody trastuzumab to a cell-killing drug called DM1. The antibody attaches to HER2 on cancer cells, and the cell takes the drug inside. DM1 then binds to tubulin and disrupts the cell's microtubules, causing the cell to stop dividing and die.
Lab studies also show it blocks HER2 signaling and helps the immune system attack HER2-heavy breast cancer cells.
Ado-trastuzumab Emtansine Injection dosage
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Kadcyla is given as an intravenous infusion only, usually every 3 weeks. Your team sets the dose based on your body weight and adjusts it for side effects.
- The first infusion is slower, with observation for at least 90 minutes afterward. Later ones can be shorter if you did well, with at least 30 minutes of observation.
- Metastatic disease: treatment continues until the cancer progresses or side effects become unmanageable.
- Early breast cancer: a total of 14 cycles unless the cancer returns or side effects are unmanageable.
- If a dose is delayed or missed, it is given as soon as possible rather than waiting for the next cycle.
Dosing details from the FDA-approved label
From the Ado-trastuzumab Emtansine 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.
- Metastatic Breast Cancer (MBC)
- 3.6 mg/kg given as an intravenous infusion every 3 weeks (21-day cycle) until disease progression or unmanageable toxicity
- First infusion over 90 minutes
- Subsequent infusions over 30 minutes if prior infusions were well tolerated
- Maximum: Do not administer at doses greater than 3.6 mg/kg
- Dose reductions: first 3 mg/kg, second 2.4 mg/kg; further reduction requires discontinuation; do not re-escalate after a dose reduction
- Early Breast Cancer (EBC)
- 3.6 mg/kg given as an intravenous infusion every 3 weeks (21-day cycle) for a total of 14 cycles unless there is disease recurrence or unmanageable toxicity
- First infusion over 90 minutes
- Subsequent infusions over 30 minutes if prior infusions were well tolerated
- Maximum: Do not administer at doses greater than 3.6 mg/kg
- Dose reductions: first 3 mg/kg, second 2.4 mg/kg; further reduction requires discontinuation; do not re-escalate after a dose reduction
Read the label’s full dosing text
2 DOSAGE AND ADMINISTRATION Do not substitute KADCYLA for or with trastuzumab. HER2 Testing: Perform using FDA-authorized tests by laboratories with demonstrated proficiency. ( 2.1 ) For intravenous infusion only . Do not administer as an intravenous push or bolus. Do not use Dextrose (5%) solution. ( 2.4 ) The recommended dose of KADCYLA is 3.6 mg/kg given as an intravenous infusion every 3 weeks (21-day cycle) until disease progression or unacceptable toxicity, or a total of 14 cycles for patients with EBC. Do not administer KADCYLA at doses greater than 3.6 mg/kg. ( 2.2 ) Management of adverse reactions (infusion-related reactions, hepatotoxicity, left ventricular cardiac dysfunction, thrombocytopenia, pulmonary toxicity or peripheral neuropathy) may require temporary interruption, dose reduction, or treatment discontinuation of KADCYLA. ( 2.3 ) 2.1 Patient Selection Select patients based on HER2 protein overexpression or HER2 gene amplification in tumor specimens [see Indications and Usage (1) , Clinical Studies (14) ]. Assessment of HER2 protein overexpression and/or HER2 gene amplification should be performed using FDA-authorized tests specific for breast cancers by laboratories with demonstrated proficiency. Information on the FDA-authorized tests for the detection of HER2 protein overexpression and HER2 gene amplification is available at: http://www.fda.gov/CompanionDiagnostics. Improper assay performance, including use of sub-optimally fixed tissue, failure to utilize specified reagents, deviation from specific assay instructions, and failure to include appropriate controls for assay validation, can lead to unreliable results. 2.2 Recommended Doses and Schedules Do not substitute trastuzumab for or with KADCYLA. The recommended dose of KADCYLA is 3.6 mg/kg given as an intravenous infusion every 3 weeks (21-day cycle). Do not administer KADCYLA at doses greater than 3.6 mg/kg . Closely monitor the infusion site for possible subcutaneous infiltration during drug administration [see Warnings and Precautions (5.9) ] . First infusion: Administer infusion over 90 minutes. Observe patients during the infusion and for at least 90 minutes following the initial dose for fever, chills, or other infusion-related reactions [see Warnings and Precautions (5.5) ] . Subsequent infusions: Administer over 30 minutes if prior infusions were well tolerated.
Excerpted — the section continues on the label. Read the full Dosage and Administration section on DailyMed →
Ado-trastuzumab Emtansine Injection side effects
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The most common side effects in clinical trials were:
Common side effects
- Tiredness (fatigue)
- Nausea
- Muscle and bone pain
- Bleeding, including nosebleeds
- Low platelet count (thrombocytopenia)
- Headache
- Raised liver enzymes (transaminases)
- Constipation
- Peripheral neuropathy and joint pain (more in early breast cancer)
When to get medical help
- Call your care team right away for yellowing of skin or eyes, or other signs of liver problems; liver failure and death have occurred.
- Report new shortness of breath, cough, or swelling that could signal heart problems or heart failure.
- Tell your team immediately about new or worsening cough or trouble breathing, which can signal lung inflammation (interstitial lung disease or pneumonitis).
- Report fever, chills, flushing, wheezing, trouble breathing, or a racing heart during or after an infusion.
- Seek help for serious or unusual bleeding; fatal bleeding has occurred.
- Report worsening numbness, tingling, or weakness in hands or feet.
- Report pain, redness, or swelling at the infusion site, which may signal leakage of the drug into surrounding tissue.
- Tell your doctor right away if you become pregnant or think you might be.
Call your team about liver, heart, lung, bleeding, nerve, infusion-reaction, or infusion-site symptoms.
Ado-trastuzumab Emtansine Injection warnings and precautions
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- Liver toxicity: includes liver failure, death, and a rare liver condition called nodular regenerative hyperplasia. Liver tests are done before every dose.
- Heart problems: can reduce heart pumping function. Heart function is checked before and regularly during treatment.
- Harm to an unborn baby: pregnancy must be avoided.
- Lung inflammation: treatment is permanently stopped if interstitial lung disease or pneumonitis is diagnosed.
- Infusion and allergic reactions: you are watched closely, especially for the first infusion.
- Bleeding: some cases were fatal, including in people with no known risk factors.
- Low platelets: counts are checked before each dose.
- Nerve damage: dosing is paused for severe neuropathy.
- Extravasation: the infusion site is monitored for leakage.
Ado-trastuzumab Emtansine Injection interactions
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No formal interaction studies were done, but some combinations call for caution.
- Strong CYP3A4 inhibitors (such as ketoconazole, itraconazole, clarithromycin, ritonavir, voriconazole): can raise DM1 levels and toxicity, so they should be avoided. If unavoidable, your team may delay Kadcyla or monitor you closely.
- Blood thinners and antiplatelet drugs: may add to bleeding risk, so extra monitoring is considered.
- Trastuzumab: Kadcyla cannot be substituted for or with it.
Interactions listed in the FDA-approved label
From the Ado-trastuzumab Emtansine Injection prescribing information (“Drug Interactions”): what the manufacturer studied or reported to the FDA.
- Strong CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, clarithromycin, atazanavir, indinavir, nefazodone, nelfinavir, ritonavir, saquinavir, telithromycin, and voriconazole): DM1, the cytotoxic component of KADCYLA, is metabolized mainly by CYP3A4, so there is potential for an increase in DM1 exposure and toxicity. Avoid concomitant use and consider an alternate medication with no or minimal potential to inhibit CYP3A4. If unavoidable, consider delaying KADCYLA treatment until the inhibitors have cleared from the circulation (approximately 3 elimination half-lives of the inhibitors) when possible. If coadministered and treatment cannot be delayed, closely monitor patie
Read the label’s full interactions text
7 DRUG INTERACTIONS No formal drug-drug interaction studies with KADCYLA have been conducted. In vitro studies indicate that DM1, the cytotoxic component of KADCYLA, is metabolized mainly by CYP3A4 and to a lesser extent by CYP3A5. Concomitant use of strong CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, clarithromycin, atazanavir, indinavir, nefazodone, nelfinavir, ritonavir, saquinavir, telithromycin, and voriconazole) with KADCYLA should be avoided due to the potential for an increase in DM1 exposure and toxicity. Consider an alternate medication with no or minimal potential to inhibit CYP3A4. If concomitant use of strong CYP3A4 inhibitors is unavoidable, consider delaying KADCYLA treatment until the strong CYP3A4 inhibitors have cleared from the circulation (approximately 3 elimination half-lives of the inhibitors) when possible. If a strong CYP3A4 inhibitor is coadministered and KADCYLA treatment cannot be delayed, patients should be closely monitored for adverse reactions.
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 Ado-trastuzumab Emtansine Injection
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- Pregnancy: can cause fetal harm. Pregnancy status is verified first. Use effective contraception during treatment and for 7 months after (women) or 4 months after (men with partners who could become pregnant).
- Breastfeeding: not advised during treatment and for 7 months after the last dose.
- Fertility: may be impaired in women and men.
- Children: safety and effectiveness have not been established.
- Older adults: no overall safety differences were seen in people 65 and older. Too few people 75 and older were studied.
- Kidney problems: no dose adjustment for mild or moderate impairment. No recommendation for severe impairment due to limited data.
- Liver problems: no starting dose change for mild or moderate impairment, but close monitoring is needed. Not studied in severe impairment.
- Heart and platelet issues: not well studied with low heart function (LVEF under 50%) or platelets under 100,000/mm3.
Ado-trastuzumab Emtansine Injection overdose
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There is no known antidote for Kadcyla overdose. In trials, an overdose of about twice the recommended dose caused low platelets that resolved in 4 days, and one patient who received a much higher dose died about 3 weeks later, though a cause was not established. Because Kadcyla is given by health professionals, tell them right away if you think an error occurred.
What Ado-trastuzumab Emtansine Injection does in the body
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Kadcyla blocks HER2 signaling and kills HER2-overexpressing breast cancer cells in lab studies. In a study of 51 patients with metastatic breast cancer, repeated doses did not cause large changes in the QT interval (a heart rhythm measurement).
How your body processes Ado-trastuzumab Emtansine Injection
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After an IV infusion, peak levels occur near the end of the infusion. The antibody-drug conjugate has a half-life of about 4 days and does not build up with every-3-week dosing. DM1 is broken down mainly by the liver enzyme CYP3A4/5, and the liver is a main route for clearing it. Age, race, and mild to moderate kidney problems did not have a meaningful effect on how the drug behaves in the body.
How to store Ado-trastuzumab Emtansine Injection
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Store vials in a refrigerator at 2°C to 8°C (36°F to 46°F) until time of reconstitution. Do not freeze or shake.
Written from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →
Supplements & herbs that interact with Ado-trastuzumab Emtansine Injection
121 supplements and herbal products have documented interactions with Ado-trastuzumab Emtansine Injection in the licensed clinical database we use. Most are manageable — but your pharmacist should know about everything you take, including vitamins and herbals.
- Major · 2
- Moderate · 87
- Minor · 32
Educational information from a licensed clinical database (Natural Medicines) — see our data sources & update cadence. Not medical advice: an interaction being documented does not mean it will happen to you; do not start or stop medications or supplements without professional guidance.
Ado-trastuzumab Emtansine Injection: pharmacist answers to common questions
Quick, plain-English answers to the questions patients ask most about Ado-trastuzumab Emtansine Injection — the kind of thing our pharmacy team would talk through with you at the counter.
What is Kadcyla used for?
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How will I get it?
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What side effects should I expect?
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When should I call my care team?
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Can I take other medicines with it?
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What about pregnancy and breastfeeding?
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Is Ado-trastuzumab Emtansine Injection available over the counter?
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When was Ado-trastuzumab Emtansine Injection first available?
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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 Ado-trastuzumab Emtansine Injection on HelloPharmacist
Ado-trastuzumab Emtansine Injection forms and strengths (how it comes)
Ado-trastuzumab Emtansine 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
- Kadcyla is used alone for HER2-positive metastatic breast cancer after prior trastuzumab and a taxane.
- Kadcyla is used alone as adjuvant treatment of HER2-positive early breast cancer with residual invasive disease after neoadjuvant taxane and trastuzumab-based treatment.
- Kadcyla is given only as an intravenous infusion, never as an IV push or bolus.
- Kadcyla is usually given every 3 weeks, with a longer first infusion and observation afterward.
- Kadcyla is not interchangeable with trastuzumab and should not be substituted for it.
- For early breast cancer, Kadcyla is given for a total of 14 cycles unless the cancer returns or side effects are unmanageable.
Ado-trastuzumab Emtansine Injection on the U.S. market: products, makers and brands
How Ado-trastuzumab Emtansine 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.
1 company lists 2 Ado-trastuzumab Emtansine Injection product records with the FDA, mostly as injection; the earliest marketing or approval year on record is 2013. Brand names on the directory include Kadcyla; the rest are generics.
How widely Ado-trastuzumab Emtansine Injection is used (Medicaid data)
A general measure of how commonly Ado-trastuzumab Emtansine Injection is prescribed, based on Medicaid — one of the largest public drug programs. The figure below is prescriptions filled in Q1–Q4 2025, summed across every form and brand of the drug.
Think of this as a proxy for how widely Ado-trastuzumab Emtansine Injection is used, drawn from freely available public data. Medicaid is just one program — these numbers don’t include Medicare, other government coverage, or commercial and cash-pay prescriptions, so real-world use is higher than what’s shown here.
How commonly is Ado-trastuzumab Emtansine Injection prescribed? Of the 1,601 medications we measure, Ado-trastuzumab Emtansine Injection ranks #1,006 by Medicaid prescriptions — more than 37% of them.
Utilization by Ado-trastuzumab Emtansine Injection product
Pick a product to see its own Medicaid numbers. Each chip is one clinical product — a specific strength & dosage form as defined by RxNorm — with brand-name and generic versions combined.
Other Ado-trastuzumab Emtansine Injection products — combination packs and listings not yet matched to a specific clinical product (kept visible so every prescription is accounted for)
Summed across the 2 of 2 listed NDC products with Medicaid activity.
Shares are of the Medicaid prescriptions shown here. Product grouping follows RxNorm (the National Library of Medicine’s drug terminology), so “one product” means one strength & dosage form regardless of manufacturer. Dollar figures are gross Medicaid reimbursement before mandatory rebates — rebates (often large, especially for brand-name drugs) are confidential, so actual net cost to Medicaid is lower than shown.
Source: Medicaid State Drug Utilization Data (CMS), aggregated by generic ingredient — summed across every NDC (all brands, strengths, salt forms and dosage forms) of Ado-trastuzumab Emtansine Injection, and across all states and both fee-for-service and managed-care claims. A general popularity signal; it excludes Medicare, commercial insurance and cash prescriptions, so it is not total U.S. use. Based on the 2 of 2 listed Ado-trastuzumab Emtansine Injection NDCs with Medicaid activity.
Compare Ado-trastuzumab Emtansine Injection products
A representative set of FDA-listed product records for Ado-trastuzumab Emtansine 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 | ||||
| 20 mg/mL | Intravenous | Genentech, Inc. × 2 listings | BLA | View NDC → |
Showing 2 of 2 products — FDA National Drug Code Directory. See every product, package size and price: browse all 2 Ado-trastuzumab Emtansine Injection NDCs →
Ado-trastuzumab Emtansine 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 Ado-trastuzumab Emtansine 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 Ado-trastuzumab Emtansine 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.
Ado-trastuzumab Emtansine Injection FDA approval history
How Ado-trastuzumab Emtansine Injection went from FDA review to the pharmacy shelf — the key milestones in its regulatory journey.
Source: Drugs@FDA.
Ado-trastuzumab Emtansine 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 Ado-trastuzumab Emtansine recalls since July 2021.
✅No Ado-trastuzumab Emtansine recalls on record since July 2021Source: FDA enforcement (recall) reports, via openFDA; our copy was last updated Sep 24, 2026.
Ado-trastuzumab Emtansine Injection supply and shortage status
Whether Ado-trastuzumab Emtansine 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.
Ado-trastuzumab Emtansine Injection brand names
Ado-trastuzumab Emtansine Injection is sold under one brand name in the FDA directory — Kadcyla. A brand and its generic contain the same active ingredient; the brand name belongs to one company's product.
Who makes Ado-trastuzumab Emtansine Injection: manufacturers and labelers
One company lists Ado-trastuzumab Emtansine Injection products with the FDA. By number of product records, the largest are Genentech, Inc.. Labelers include manufacturers and repackagers; the product in your bottle depends on which one your pharmacy stocks.
Ado-trastuzumab Emtansine Injection drug class (RxNorm)
Ado-trastuzumab Emtansine 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 Ado-trastuzumab Emtansine 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. Genentech, Inc. 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 →