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Kadcyla

ado-trastuzumab emtansine
Used for Breast Cancer
Used for Breast Cancer

Kadcyla (ado-trastuzumab emtansine) is used to treat people with HER2-positive breast cancer who’ve previously received cancer therapy. It can be used for early breast cancer after surgery and for breast cancer that’s spread to other parts of the body (metastatic). Kadcyla is a targeted anticancer medication known as an antibody-drug conjugate (ADC). It’s given by a healthcare professional as an infusion through the vein once every 3 weeks. This medication commonly causes side effects like nausea, fatigue, headache, and muscle or joint pain.

Reviewed by:
reviewer
Julia Lee, PharmD, BCOP
reviewer
Cydnee Ng, PharmD
Last reviewed on October 8, 2024
BasicsSide effectsPros & consPharmacist tipsFAQsWarningsDosageInteractionsAlternativesLatest newsReferencesPricesMedicare
basics-icon

What is Kadcyla?

What is Kadcyla used for?

How Kadcyla works

Kadcyla is a type of targeted therapy called an antibody-drug conjugate (ADC). It’s made up of a few parts that work together to find and kill breast cancer cells.

  1. Ado-trastuzumab, or trastuzumab, is a monoclonal antibody. It finds and attaches to a specific protein on the surface of cells called HER2. Kadcyla uses trastuzumab to find cancer cells with large amounts of HER2 on them.

  2. Once Kadcyla reaches and enters into the cancer cell, the medication breaks apart so the chemotherapy part called DM1 can work. DM1 is a microtubule inhibitor. It blocks cells from using their microtubules, an important component of cells for normal structure and functioning. By blocking cells from using their microtubules, Kadcyla prevents the cancer cell from growing and eventually kills it.

Are you looking for information on Herceptin (trastuzumab) or Enhertu (fam-trastuzumab deruxtecan-nxki) instead?

Drug Facts

Common BrandsKadcyla
Drug ClassAntibody-drug conjugate
Controlled Substance ClassificationNot a controlled medication
Generic StatusNo lower-cost generic available
AvailabilityPrescription only
basics-icon

What are the side effects of Kadcyla?

The following side effects may get better over time as your body gets used to the medication. Let your healthcare provider know immediately if you continue to experience these symptoms or if they worsen over time.

Common Side Effects

  • Low platelet counts (up to 83%)
  • Low white blood cell counts (60%)
  • Elevated liver enzymes (29%)
  • Nausea (40%)
  • Fatigue (36%)
  • Muscle, bone, or joint pain (36%)
  • Low potassium levels (33%)
  • Bleeding (32%)
  • Headache (28%)
  • Constipation (27%)

Other Side Effects

Note: Side effects and percentages are reported from studies of people with metastatic HER2-positive breast cancer.

Serious Side Effects

Contact your healthcare provider immediately if you experience any of the following.
  • Liver injury: pain in the right side of the stomach, yellowing of the eyes or skin, dark or brown urine
  • Heart problems: chest pain, racing heartbeat, shortness of breath that usually worsens with activity or when lying flat, fatigue, swelling in your legs or feet, sudden weight gain (more than 5 lbs in 24 hours)
  • Lung damage: cough, shortness of breath, fever
  • Infusion-related reaction: trouble breathing, wheezing, dizziness, fever, chills, flushing, chest pain
  • Allergic reaction: hives, trouble breathing, swelling of the mouth or lips
  • Severe bleeding or severely low platelet counts: sudden or painful headache, changes in vision, coughing or spitting up blood

Source: DailyMed

The following side effects have also been reported

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur:

More common

Black, tarry stools

bladder pain

bleeding gums

bloating or swelling of the face, arms, hands, lower legs, or feet

bloody or cloudy urine

blurred vision

burning, numbness, tingling, or painful sensations

chills

cough

decreased urine

difficult or labored breathing

difficult, burning, or painful urination

dizziness

dry mouth

fever

frequent urge to urinate

headache

increased thirst

irregular heartbeat

loss of appetite

lower back or side pain

mood changes

muscle pain or cramps

nausea

nervousness

nosebleeds

numbness or tingling in the hands, feet, or lips

pale skin

pinpoint red spots on the skin

pounding in the ears

rapid weight gain

seizures

slow or fast heartbeat

sore throat

stomach pain

tightness in the chest

troubled breathing with exertion

ulcers, sores, or white spots in the mouth

unsteadiness or awkwardness

unusual bleeding or bruising

unusual tiredness or weakness

unusual weight gain or loss

vomiting

weakness in the arms, hands, legs, or feet

Less common

Chest pain

dilated neck veins

extreme tiredness or weakness

general feeling of discomfort or illness

irregular breathing

skin rash

thickening of bronchial secretions

Rare

Dark urine

general feeling of tiredness or weakness

light-colored stools

stomach bloating

vomiting blood

yellow eyes or skin

Incidence not known

Agitation

confusion

decreased awareness or responsiveness

depression

hostility

irritability

itching

joint pain, stiffness, or swelling

loss of consciousness

muscle twitching

severe sleepiness

stomach tenderness or cramps

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

Belching

change in taste

constipation

diarrhea

difficulty with moving

heartburn

indigestion

lack or loss of strength

loss of taste

muscle stiffness

stomach discomfort or upset

swelling or inflammation of the mouth

trouble sleeping

Less common

Burning, dry, or itching eyes

discharge or excessive tearing

redness, pain, or swelling of the eye, eyelid, or inner lining of the eyelid

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

pros-and-cons

Pros and cons of Kadcyla

thumbs-up

Pros

Given as an infusion once every 3 weeks, over either 30 or 90 minutes

Given just by itself (not taken alongside other cancer treatments)

Recommended option for HER2-positive early breast cancer that has some cancerous tissue remaining after initial treatment

An option for metastatic HER2-positive breast cancer when other treatments haven’t worked well

thumbs-down

Cons

Must stay at the center for some time after each infusion to make sure you’re tolerating the medication well

Can cause nausea; fatigue; and muscle, bone, or joint pain

Not safe to take during pregnancy or while breastfeeding

pharmacist-tips

Pharmacist tips for Kadcyla

pharmacist

  • Plan plenty of time for your Kadcyla infusion appointments. Your first infusion will take about 90 minutes. Afterwards, you’ll need to stay at the center for at least 90 more minutes so your care team can check for any reactions to the medication. If the first infusion goes smoothly, your next infusions will take 30 minutes, and then you’ll stay at the center for at least 30 more minutes for monitoring.

    • It can help to bring a blanket, a book, and other things to help pass the time and make you feel more comfortable during your each of your Kadcyla infusion visits.

      • Be sure to look out for infusion-related reactions, even though they aren’t very common. Your care team will also watch for these reactions during and after your Kadcyla infusion. Tell your care team right away if you notice any sign of an infusion reaction, such as throat tightness, trouble breathing, fever, chills, flushing, dizziness, or chest pain. Your care team can help manage these symptoms.

        • Call your care team if you notice any redness, pain, swelling, or blistering near your IV site. Kadcyla might irritate the area where you have the IV placed, especially if some medication leaks out of the vein to the tissue around it. Your care team might recommend a warm or cold compress or medications to help relieve the irritation. Your infusion might get paused if this happens while you’re receiving Kadcyla.

          • Make sure to get any blood tests or imaging done in a timely manner as instructed by your care team so they can check that Kadcyla is safe for you. For example, it’s important to have heart imaging done because the medication can affect how well your heart pumps blood and lead to symptoms of heart failure (e.g., shortness of breath, chest pain, swelling, sudden weight gain).

            • Talk with your care team first before starting any new medications, supplements, or herbal products to check that they’re safe to take with Kadcyla. Drug interactions with Kadcyla can make your cancer medication work less well or put you at risk for side effects. For example, taking the antibiotic clarithromycin with Kadcyla can raise your risk for side effects from the cancer medication (like liver injury or nerve pain).

              • Kadcyla can harm an unborn baby if it’s given during pregnancy. If you or your partner can get pregnant and is sexually active, use birth control during treatment. Continue using birth control for 4 months after the last dose if you’re male and for 7 months after stopping treatment if you’re female. Tell your oncologist right away if you or your partner becomes pregnant. Also report the pregnancy to Genentech (the manufacturer) by calling 1-888-835-2555 to help them track medication safety.

                • Avoid breastfeeding while you’re getting treated with Kadcyla and for 7 months after your last dose. Based on how the medication works, it’s possible for Kadcyla to cause serious side effects to your breastfed baby. Speak with a healthcare professional about other options to feed your baby.

                  faqs

                  Frequently asked questions about Kadcyla

                  Is Kadcyla chemotherapy?
                  No. Kadcyla is a type of targeted therapy, not chemotherapy. In the body, Kadcyla finds and kills breast cancer cells that have a high amount of a specific protein called HER2. This cancer medication works in a more specific way than traditional chemotherapy. Traditional chemotherapy works against all rapidly growing cells, not just cancer cells.
                  What’s the difference between Herceptin, Kadcyla, and Enhertu?
                  Kadcyla, Enhertu, and Herceptin can all help treat HER2-positive breast cancer. They all include the antibody trastuzumab, which helps the medication get to cancer cells with the protein HER2 on them. But you can’t substitute one for the other. This is because Kadcyla and Enhertu have an additional component to them; they’re each attached to a different chemical that helps kill the cancer cells. Your oncologist will examine your cancer and your treatment history to create a treatment plan for you. Talk with your oncologist about which cancer treatment they’d recommend for your particular situation.
                  How do I know if Kadcyla is an option for me?
                  Ask your oncologist whether Kadcyla is an option for you. Kadcyla is approved for treating certain HER2-positive breast cancers. This is because it works by targeting a specific protein called HER2 on cancer cells. Your oncology care team will take a small sample of your tumor (biopsy) to check whether your cancer has the HER2 protein. Kadcyla might be a treatment option for you if your tumor has high amounts of HER2.
                  Does Kadcyla cause hair loss?
                  Kadcyla doesn’t commonly cause hair loss. In studies, fewer than 5% of people taking Kadcyla experienced hair loss. Talk with your treatment team if you’re concerned about hair loss. They can offer tips for hair care or other strategies to manage hair loss (e.g., wigs, scarves, hats).
                  What can I do to help with any numbness and tingling in the hands and feet that I might have as a side effect from Kadcyla?
                  Talk with your oncology treatment team if you feel uncomfortable pain, numbness, and tingling in the hands and feet while you’re getting treated with Kadcyla. It’s especially important to let them know about these side effects if they start to disrupt your daily activities. Your treatment team can provide recommendations on how to manage this side effect. These recommendations can include prescribing medications to help with nerve pain or giving you a break from treatment.
                  How long does Kadcyla stay in your system?
                  It takes about 20 days for most of Kadcyla to leave your body after a single infusion. This time frame is estimated based on the medication’s half-life, which is a measure of the time it takes for the body to get rid of the medication from its system. Kadcyla is given once every 3 weeks because the medication from a single infusion can stay in your system and continue working for several days.
                  Can you drink alcohol while you’re taking Kadcyla?
                  Talk with your oncologist about your drinking habits. In general, it’s best to avoid regularly drinking alcohol while you’re taking Kadcyla because it might make your cancer treatment work less well. In addition, alcohol generally raises the risk for breast cancer. It can also raise the risk for other types of cancers.
                  How do you know if Kadcyla is working?
                  During treatment, you might not feel whether Kadcyla is working or not. So to check whether it's working to keep your cancer from growing or coming back, you’ll typically need certain scans, like CT or MRI scans, done every so often. Your care team will look for signs of tumor growth, new tumors, or new areas of cancer (metastasis) on your scans. Also at each visit, your care team will ask about any new or worsening symptoms. Share with them about any lumps or bumps or other troublesome symptoms. Your care team can see whether those symptoms could be side effects from treatment, signs of worsening cancer, or something unrelated to your cancer. Then, they can recommend tips to help manage your symptoms or make updates to your treatment plan if needed.
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                  warings-icon

                  What are the risks and warnings for Kadcyla?

                  Kadcyla can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.

                  risk-warning

                  Liver injury

                  • Risk factors: Liver problems | Taking other medications that can harm the liver

                    Kadcyla can potentially harm your liver. In very rare situations, it’s possible for this liver damage to be serious or even fatal.

                    You might not feel any symptoms when your liver is having problems, but your oncology care team can see signs of liver damage from your blood test results. This is why you’ll need to get blood tests done to check your liver before each Kadcyla infusion. Tell your treatment team if you have more noticeable symptoms of liver damage, like pain on the right side of the stomach, yellowing of the eyes or skin, or dark urine.

                    If your oncologist suspects that you have liver damage, you might need to take a break from Kadcyla. Once your liver test results return to normal, you might be able to restart the medication at a lower dose.

                    risk-warning

                    Problems with heart function

                    Kadcyla can raise the risk of developing new or worsened left-sided heart failure. It can affect how well your heart pumps blood through your body. Make sure your oncology care team knows about your health conditions, especially any heart problems you've had.

                    Your oncologist will check your heart function through imaging using an echocardiogram (echo) or a MUGA scan. You’ll need to get imaging done before you start Kadcyla and also periodically during treatment. Tell your care team if you have any signs or symptoms of heart failure, including shortness of breath, dry cough, irregular heartbeats, chest pain, or sudden weight gain, while you’re taking this medication.

                    risk-warning

                    Harm to an unborn baby

                    Kadcyla can harm an unborn baby if it’s given during pregnancy. If you’re able to have children, your oncologist will ask you to do a pregnancy test before you start Kadcyla to make sure it’s safe to take the medication.

                    If you or your partner can become pregnant and you’re sexually active, use birth control while you’re taking Kadcyla. For females, continue to use birth control for another 7 months after you stop the medication. And for males, keep using birth control, such as condoms during sex, after your last dose. Let your oncology care team know right away if you or your partner becomes pregnant while you’re taking Kadcyla.

                    risk-warning

                    Lung damage

                    • Risk factors: Shortness of breath when you’re at rest

                      Although rare, some people who’ve taken Kadcyla had serious and sometimes fatal lung problems, including inflammation of the lungs and fluid buildup in the lungs. Tell your oncology care team if you have difficulty breathing, cough, or fatigue during your treatment.

                      risk-warning

                      Infusion-related reactions or allergic reactions

                      • Risk factors: Getting your first Kadcyla infusion

                        It’s possible to feel unwell during your Kadcyla infusion. These symptoms are called infusion reactions and can include fever, chills, trouble breathing, fast heartbeat, or feeling flushed, dizzy, or lightheaded. Infusion-related reactions are usually mild and tolerable, but they can be serious in rare cases.

                        Tell your treatment team right away if you experience any throat tightness, trouble breathing, fast heartbeat, fever, chills, hives, flushing, dizziness, or chest pain. They’ll pause the infusion and manage your symptoms. Depending on how severe the reaction is, your care team will decide whether to continue the infusion at a slower speed once you’re feeling better or have you take a break from treatment. In general, your symptoms should get better over the course of several hours to a day.

                        risk-warning

                        Risk for severe bleeding

                        • Risk factors: Taking blood thinners or antiplatelets | Low platelets

                          During clinical studies, some people experienced bleeding while they were taking Kadcyla. The bleeding can happen anywhere in the body and, though rarely, can even be fatal. You might be at risk if you have a low platelet count or if you’re taking other medications that can cause bleeds.

                          Contact your healthcare team if you have bleeding that’s hard to stop. Also call your care team if you notice symptoms of bleeding on the inside of your body, such as feeling lightheaded, having black or bloody stools, coughing up blood, or vomiting up coffee ground-like bits. Your treatment will probably get paused if you have serious bleeding.

                          risk-warning

                          Low platelet counts (thrombocytopenia)

                          Kadcyla can cause your body to make fewer platelets, the blood cells that help your blood clot to stop bleeding. Having low amounts of platelets can put you at risk for bleeding. This can be anything from easy bruising and easily getting nose bleeds or gum bleeds to more life-threatening situations.

                          You’ll have your blood drawn before each Kadcyla infusion to make sure that the medication is safe to take. If your platelet levels are too low, your team will adjust your treatment schedule. They might also lower your Kadcyla dose.

                          risk-warning

                          Nerve problems (neuropathy)

                          Kadcyla can sometimes cause discomfort, pain, numbness, and tingling in the hands and feet (peripheral neuropathy). Usually, these symptoms are mild. But let your treatment team know if they’re disrupting your daily activities.

                          Your treatment team can recommend medications to help with these nerve problems. Your oncologist might also lower the Kadcyla dose or give you a longer break between infusions to help relieve your side effects. And if you continue to experience nerve problems with Kadcyla, your oncologist might consider switching you to a different medication.

                          dosage

                          Kadcyla dosage forms

                          Typical dosing for Kadcyla

                          Your treatment team will calculate your specific Kadcyla dose based on your weight (kg). The recommended dose is 3.6 mg/kg as an infusion through the vein once every 3 weeks.

                          interactions

                          Interactions between Kadcyla and other drugs

                          Kadcyla may interact with certain medications or supplements. Always let your doctor and pharmacist know about any other medications or supplements (including prescribed and over-the-counter medications, vitamins, and dietary or herbal supplements) that you are currently taking. The list below does not include all possible drug interactions with Kadcyla. Please note that only the generic name of each medication is listed below.

                          Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are receiving this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

                          Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

                          alternatives

                          What are alternatives to Kadcyla?

                          There are a number of medications that your doctor can prescribe in place of Kadcyla. Compare a few possible alternatives below.
                          Kadcyla
                          Used for:
                          View Prices
                          Enhertu
                          Used for:
                          View Prices
                          Herceptin (trastuzumab)
                          Used for:

                          • HER2-positive, breast cancers - IV and SQ injections

                          • HER2-positive, metastatic stomach cancer - IV injection only

                          View Prices

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                          References

                          Best studies we found

                          American Cancer Society. (2019). How chemotherapy drugs work.

                          American Cancer Society. (2021). How targeted therapies are used to treat cancer.

                          American Cancer Society. (2021). Imaging tests to look for breast cancer spread.

                          View All References (20)

                          American Cancer Society. (2022). Breast cancer HER2 status.

                          American Cancer Society. (2024). Hair loss (alopecia).

                          American Cancer Society. (2024). Infusion or immune reactions.

                          American Cancer Society. (2024). Peripheral neuropathy.

                          American Cancer Society. (2024). Thrombocytopenia (low platelet count).

                          American Heart Association. (2023). Ejection fraction heart failure measurement.

                          American Heart Association. (2023). Radionuclide angiography (MUGA scan).

                          Barok, M., et al. (2014). Trastuzumab emtansine: Mechanisms of action and drug resistance. Breast Cancer Research.

                          Genentech, Inc. (2024). Kadcyla- ado-trastuzumab emtansine injection, powder, lyophilized, for solution [package insert]. DailyMed.

                          Genentech USA, Inc. (n.d.). Treatment schedule for KADCYLA.

                          Genentech USA, Inc. (n.d.). Understanding possible side effects with KADCYLA.

                          MedlinePlus. (2024). Platelet tests.

                          Nabholtz, J., et al. (2005). The role of taxanes in the treatment of breast cancer. Expert Opinion on Pharmacotherapy.

                          National Cancer Institute. (n.d.). Extravasation.

                          National Cancer Institute. (n.d.). HER2.

                          National Cancer Institute. (2024). Trastuzumab.

                          National Comprehensive Cancer Network. (2024). Invasive breast cancer.

                          National Comprehensive Cancer Network. (2024). Metastatic breast cancer.

                          Pérez Fidalgo, J. A., et al. (2012). Management of chemotherapy extravasation: ESMO–EONS Clinical Practice Guidelines. Annals of Oncology.

                          Phillips, C. (2023). Drinking alcohol, often heavily, common among people with cancer and long-term survivors. National Cancer Institute.

                          GoodRx Health has strict sourcing policies and relies on primary sources such as medical organizations, governmental agencies, academic institutions, and peer-reviewed scientific journals. Learn more about how we ensure our content is accurate, thorough, and unbiased by reading our editorial guidelines.
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