Enhertu (fam-trastuzumab deruxtecan-nxki*) is a prescription drug that’s used to treat certain kinds of cancer, including breast cancer. Enhertu is given by intravenous (IV) infusion (an injection into a vein given over a period of time).
Enhertu treats certain cancers that have an unusually high level of a protein called human epidermal growth factor receptor 2 (HER2). Specifically, Enhertu is used to treat the following kinds of cancer in adults:
- HER2-positive breast cancer
- HER2-low breast cancer
- non-small cell lung cancer that has certain changes in the HER2 gene
- HER2-positive gastric or gastroesophageal junction adenocarcinoma (a kind of stomach cancer)
Enhertu is used in certain situations when these cancers can’t be removed with surgery or have spread to other parts of the body.
To learn more about Enhertu’s uses, see the “What is Enhertu used for?” section below.
* The reason “-nxki” appears at the end of the drug’s name is to show that the drug is distinct from similar medications that may be created in the future.
Enhertu contains the active ingredient fam-trastuzumab deruxtecan-nxki. (An active ingredient is what makes a drug work.)
Enhertu is a targeted cancer therapy. This means it can attack cancer cells without harming healthy cells.
Enhertu is a
You’ll receive Enhertu infusions in a hospital or infusion center.
Like most drugs, Enhertu may cause mild or serious side effects. The lists below describe some of the more common side effects that Enhertu may cause. These lists don’t include all possible side effects.
Keep in mind that side effects of a drug can depend on:
- your age
- other health conditions you have
- other medications you take
Your doctor or pharmacist can tell you more about the potential side effects of Enhertu. They can also suggest ways to help reduce side effects.
Mild side effects
Here’s a list of some of the mild side effects that Enhertu can cause. To learn about other mild side effects, talk with your doctor or pharmacist, or read Enhertu’s prescribing information.
Mild side effects of Enhertu that have been reported include:
- nausea and vomiting
- fatigue (low energy)
- reduced appetite
- muscle pain or bone pain
- hair loss
- mouth sores
- upper respiratory infection, such as the common cold
- mild allergic reaction*
Mild side effects of many drugs may go away within a few days to a couple of weeks. But if they become bothersome, talk with your doctor or pharmacist.
* To learn more about this side effect, see the “Allergic reaction” section below.
Serious side effects
Serious side effects from Enhertu can occur, but they aren’t common. If you have serious side effects from Enhertu, call your doctor right away. But if you think you’re having a medical emergency, you should call 911 or your local emergency number.
Serious side effects of Enhertu that have been reported include:
- low potassium level
- elevated liver enzymes, which may be a sign of liver damage
- weakening of the left side of the heart, which makes it harder for the heart to pump blood
- low levels of certain white blood cells, which may raise your risk of infection
- low level of red blood cells
- low level of platelets (cells that help with blood clotting)
boxed warnings: risk of fetal harm and serious lung conditions*
- severe allergic reaction†
* For more information, see the “What should be considered before taking Enhertu?” section.
† To learn more about this side effect, see the “Allergic reaction” section below.
Some people may have an allergic reaction to Enhertu.
Symptoms of a mild allergic reaction can include:
A more severe allergic reaction is rare but possible. Symptoms of a severe allergic reaction can include swelling under your skin, usually in your eyelids, lips, hands, or feet. They can also include swelling of your tongue, mouth, or throat, which can cause trouble breathing.
Call your doctor right away if you have an allergic reaction to Enhertu. But if you think you’re having a medical emergency, call 911 or your local emergency number.
Enhertu is used to treat certain types of cancer that have an unusually high level of a protein called human epidermal growth factor receptor 2 (HER2). A high level of the HER2 protein helps cancer cells grow and spread. Your doctor will test your cancer before you start treatment to determine whether Enhertu may be a good option for you.
Enhertu is used to treat the following kinds of cancer in adults:
- HER2-positive breast cancer. Enhertu is used for cancer that can’t be removed with surgery or that is metastatic (has spread to other parts of the body). It’s used in people who’ve had anti-HER2 treatment before.
- HER2-low breast cancer. With this type of cancer, the HER2 level is higher than usual but not high enough to be classified as HER2-positive. Enhertu is used for cancer that can’t be removed with surgery or that’s metastatic. It’s used in people who’ve had chemotherapy (traditional drugs used to treat cancer) before.
- Non-small cell lung cancer that has certain changes in the HER2 gene.* Enhertu is used for cancer that can’t be removed with surgery or that’s metastatic. It’s used in people who’ve tried chemotherapy or other drugs before.
- HER2-positive gastric or gastroesophageal junction adenocarcinoma (a type of stomach cancer). Enhertu is used for cancer that’s locally advanced (spread into nearby tissues) or that’s metastatic. It’s used in people who’ve received trastuzumab (Herceptin) before.
Enhertu is a targeted cancer therapy. This means it can attack cancer cells without harming healthy cells. Enhertu attaches to HER2 proteins on the cancer cells and delivers a chemotherapy drug directly into the cancer cells.
* For this use, Enhertu received
Find answers to some commonly asked questions about Enhertu.
How does Enhertu compare with other similar drugs, such as Kadcyla or Herceptin?
Enhertu, ado-trastuzumab emtansine(Kadcyla), and trastuzumab (Herceptin) are all targeted cancer therapies. They treat certain cancers that have a higher than usual level of a protein called human epidermal growth factor receptor 2 (HER2). Specifically, they’re all used to treat certain kinds of HER2-positive breast cancer.
All three drugs are given by intravenous (IV) infusion (an injection into a vein given over a period of time). The drugs have some similar side effects and others that vary.
To find out more about how Enhertu compares with other drugs, talk with your doctor. They can recommend the treatment option that’s best for you.
Can Enhertu be used for lung cancer or gastric cancer?
Yes, Enhertu can be used to treat certain types of lung cancer and gastric (stomach) cancer. To learn more about the kinds of cancer that Enhertu treats, see the “What is Enhertu used for?” section above.
How does Enhertu work?
Enhertu is a targeted cancer therapy. This means it can attack cancer cells without harming healthy cells.
Enhertu treats certain cancers that have a higher than usual level of a protein called human epidermal growth factor receptor 2 (HER2). A high level of this protein helps cancer cells grow and spread. Enhertu works by targeting the HER2 protein.
Enhertu contains an anti-HER2 antibody attached to a chemotherapy drug. (Chemotherapy drugs are traditional drugs used to treat cancer.) The antibody attaches to the HER2 proteins on the cancer cells. This delivers the chemotherapy drug directly into the cancer cells. Chemotherapy kills the cancer cells.
Costs of prescription drugs can vary depending on many factors. These include what your health insurance plan covers (if you have one) and which pharmacy you use.
If you have questions about how to pay for your prescription, talk with your doctor or pharmacist. A program called ENHERTU4U may also be available.
You can also check out this article to learn more about saving money on prescriptions.
This section describes commonly used dosages of Enhertu, but your doctor will determine the dosage that’s right for you.
Form and strength
Enhertu comes as a powder in a single-dose vial. Each vial contains 100 milligrams (mg) of Enhertu. A healthcare professional will mix the powder with liquid to make a liquid solution.
Enhertu is given as an intravenous (IV) infusion (an injection into your vein given over a period of time).
You’ll receive doses of Enhertu in a hospital or infusion center.
You’ll typically receive an infusion of Enhertu once every 3 weeks.
To learn more about Enhertu’s dosage, see this article.
Questions about Enhertu’s dosing
Below are some common questions about Enhertu’s dosing.
- What if I miss a dose of Enhertu? If you miss an appointment to have an infusion of Enhertu, call your doctor’s office right away to reschedule. You should receive the missed infusion as soon as possible.
- Will I need to receive Enhertu long term? Yes, your Enhertu treatment will likely be long term. You’ll usually keep receiving Enhertu infusions unless you have bothersome side effects or the drug stops working for you.
- How long does Enhertu take to work? Enhertu starts working as soon as you have your first infusion. But because of how the drug works, you likely won’t feel it working in your body. Your doctor will order tests during your treatment to check that Enhertu is working for you. If you have questions about what to expect from your treatment, talk with your doctor.
Your doctor will explain how Enhertu will be given to you. They’ll also explain how much you’ll be given and how often.
You’ll receive Enhertu as an intravenous (IV) infusion, usually once every 3 weeks. (An IV infusion is an injection into a vein given over a period of time.)
You’ll receive Enhertu infusions in a hospital or infusion center. A healthcare professional will administer the infusion. Before each infusion, you’ll receive medication to help prevent nausea and vomiting (two side effects of the drug).
Your first infusion will likely be given over 90 minutes. But if you have side effects during the infusion, your doctor may slow down or pause your infusion until the side effects go away. If you don’t have bothersome side effects with your first infusion, your next infusions may be given over a period of 30 minutes.
There currently aren’t any medications or supplements known to interact with Enhertu. But this doesn’t mean drug interactions with Enhertu won’t be recognized in the future. For example, new medications may be approved that interact with Enhertu.
For this reason, you should still tell your doctor and pharmacist about any medications you take besides Enhertu. This way, they can check for any new interactions during your treatment.
Boxed warnings for Enhertu include:
Risk of fetal harm. Receiving Enhertu while pregnant can cause harm to a fetus. To learn more, see the “Pregnancy and breastfeeding” section below.
Risk of serious lung conditions. In rare cases, Enhertu may cause serious lung conditions that involve inflammation (swelling) and scarring in the lungs. These conditions can be life threatening.
Your doctor will monitor you for serious lung conditions during your Enhertu treatment. If you experience shortness of breath, wheezing, chest tightness, cough, or fever, contact your doctor right away.
If you have a serious lung condition, your doctor may prescribe a corticosteroid to treat it. They may also lower your Enhertu dose. In some cases, your doctor may pause or permanently stop your Enhertu treatment.
If you have questions about these warnings, talk with your doctor.
Enhertu can sometimes cause harmful effects in people who have certain conditions. This is known as a drug-condition interaction. Other factors may also affect whether Enhertu is a good treatment option for you.
Talk with your doctor about your health history before you take Enhertu. Factors to consider include those described below.
Infection. Enhertu can lower your levels of certain white blood cells. These cells help your body fight infections. If you already have an infection, receiving Enhertu can make it harder for your body to fight it. Your doctor may prescribe medication to treat any infections you have before you begin Enhertu treatment.
Heart problems. Enhertu may weaken the left side of your heart, which makes it harder for your heart to pump blood. If you already have a heart problem, such as heart failure, Enhertu could make it worse. Talk with your doctor about whether Enhertu is safe for you. If you do receive Enhertu, your doctor will monitor your heart health during your treatment.
Lung or breathing problems. Enhertu can cause serious lung conditions* in some people. If you already have a lung or breathing problem, talk with your doctor before starting Enhertu treatment. If you do receive Enhertu, contact your doctor right away if your symptoms get worse during your treatment.
Liver or kidney problems. If you have liver or kidney problems, you may have a higher risk of certain side effects with Enhertu. These include serious lung conditions.* Talk with your doctor about whether this medication is safe for you.
Allergic reaction. If you’ve had an allergic reaction to Enhertu or any of its ingredients, your doctor will likely not prescribe Enhertu. Ask them what other medications are better options for you.
Enhertu and alcohol
There is no known interaction between Enhertu and alcohol. But drinking alcohol during your Enhertu treatment may raise your risk of having certain side effects, or it could make the side effects worse.
Examples of these side effects include headache, nausea, vomiting, and diarrhea.
If you drink alcohol, talk with your doctor about how much may be safe to drink while you’re receiving Enhertu.
Pregnancy and breastfeeding
Enhertu is not safe to receive during pregnancy or while breastfeeding. See below for details.
Risk of fetal harm
Enhertu has a
If received during pregnancy, Enhertu could harm the fetus or cause pregnancy loss. Due to this risk, your doctor will not prescribe Enhertu if you’re pregnant. If you’re pregnant or planning a pregnancy, talk with your doctor about your treatment options.
If you or your partner could become pregnant, you should use birth control to help prevent pregnancy during your Enhertu treatment.
- Females* who can become pregnant should use birth control during Enhertu treatment and for 7 months after their last dose.
- Males* with a partner who can become pregnant should use birth control during their Enhertu treatment and for 4 months after their last dose.
If you or your partner become pregnant while you’re receiving treatment with Enhertu, contact your doctor right away.
* In this article, we use the terms “male” and “female” to refer to someone’s sex assigned at birth. For information about the difference between sex and gender, see this article.
You should not breastfeed during Enhertu treatment and for 7 months after your last dose.
It’s not known whether Enhertu can pass into breast milk. But if it does, it could cause serious side effects in a child who’s breastfed.
If you’re currently breastfeeding or planning to breastfeed, talk with your doctor about your options.
If you have questions about taking Enhertu, talk with your doctor or pharmacist. Questions you may want to ask include:
- How effective is Enhertu? Can it cure my cancer?
- Will I need to have any other treatments with Enhertu?
- Will Enhertu affect my fertility?
To learn more about Enhertu, see these articles:
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Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.