Enhertu

Trastuzumab deruxtecan is used to treat certain types of breast cancer. This medication is used to treat tumors that produce more than the normal amount of a certain substance called HER2 protein.

This medication is called a monoclonal antibody and topoisomerase inhibitor conjugate. Trastuzumab deruxtecan works by attaching to the HER2 cancer cells and blocking them from dividing and growing.

Read the Medication Guide provided by your pharmacist before you start using trastuzumab deruxtecan and each time you get a refill. If you have any questions, ask your doctor or pharmacist.

This medication is given by slow injection into a vein by a health care professional. It is given as directed by your doctor, usually once every 3 weeks. Your first infusion will be given over at least 90 minutes.

The dosage, the speed of your injection, and the length of time you receive trastuzumab deruxtecan are based on your body weight, medical condition, and response to treatment.

To get the most benefit from this medication, do not miss any doses. To help you remember, mark the days on the calendar when you need to receive the medication.

See also Warning section.

Diarrhea, dizziness, stomach/abdominal pain, constipation, nausea, vomiting, mouth sores, dry mouth, loss of appetite, tiredness, hair loss, nose bleeds, or headache may occur. Nausea and vomiting can be severe. In some cases, your doctor may prescribe medication to prevent or relieve nausea and vomiting. Eating several small meals, not eating before treatment, or limiting activity may help lessen some of these effects. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor right away if you have any serious side effects, including: unusual tiredness, pale skin, easy bruising/bleeding.

Trastuzumab deruxtecan may lead to serious heart problems, including heart failure. Past use of certain other anti-cancer drugs (including anthracyclines such as doxorubicin) may increase your risk of heart problems. Tell your doctor right away if you have any symptoms of heart failure, including shortness of breath, swelling ankles/feet, unusual tiredness, unusual/sudden weight gain.

This medication may lower your ability to fight infections. This may make you more likely to get a serious (rarely fatal) infection or make any infection you have worse. Tell your doctor right away if you have any signs of infection (such as sore throat that doesn't go away, fever, chills, cough).

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

See also Warning section.

Before using trastuzumab deruxtecan, tell your doctor or pharmacist if you are allergic to it; or to any trastuzumab emtansine, trastuzumab, or trastuzumab-hyaluronidase products; or if you have any other allergies. This product may contain inactive ingredients which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: current infection, heart disease, lung problems.

Trastuzumab deruxtecan can make you more likely to get infections or may worsen any current infections. Avoid contact with people who have infections that may spread to others (such as chickenpox, measles, flu). Consult your doctor if you have been exposed to an infection or for more details.

Do not have immunizations/vaccinations without the consent of your doctor. Avoid contact with people who have recently received live vaccines (such as flu vaccine inhaled through the nose).

To lower the chance of getting cut, bruised, or injured, use caution with sharp objects like razors and nail cutters, and avoid activities such as contact sports.

This drug may make you dizzy. Alcohol or marijuana (cannabis) can make you more dizzy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

Tell your doctor if you are pregnant or plan to become pregnant. You should not become pregnant while using trastuzumab deruxtecan. Trastuzumab deruxtecan may harm an unborn baby. A pregnancy test should also be done before starting treatment. Women should ask about reliable forms of birth control while using this medication and for 7 months after stopping treatment. Men with female partners should ask about reliable forms of birth control while using this medication and for 4 months after stopping treatment. If you or your partner becomes pregnant, talk to your doctor right away about the risks and benefits of this medication.

It is unknown if this drug passes into breast milk. Because of the possible risk to the infant, breast-feeding is not recommended while using this drug and for 7 months after the last dose. Consult your doctor before breast-feeding.

Not applicable. This medication is given in a clinic or hospital and will not be stored at home.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

If you will be using an anthracycline (such as doxorubicin) after stopping trastuzumab deruxtecan, if possible, wait at least 7 months.

Trastuzumab deruxtecan is very similar to trastuzumab, trastuzumab emtansine, and trastuzumab-hyaluronidase. Do not use a trastuzumab, trastuzumab emtansine, or trastuzumab-hyaluronidase product while using trastuzumab deruxtecan.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center.

It is important to get each dose of this medication as scheduled. If you miss a dose, ask your doctor or pharmacist right away for a new dosing schedule.

Lab and/or medical tests (such as heart exams, complete blood counts) should be done before you start using this medication and while you are using it. Keep all medical and lab appointments. Consult your doctor for more details.