Disclaimer: This information is intended to help you understand your treatment. Always discuss your health and treatment plan with your doctor or nurse, who can answer your specific questions.
At a Glance: Quick Facts about Trastuzumab Deruxtecan
- Generic Name: fam-trastuzumab deruxtecan-nxki
- Brand Name(s): The original formulation of fam-trastuzumab deruxtecan-nxki is Enhertu®. As of 2025, the drug is patented and no biosimilar is available.
- Type of Drug: Antibody-Drug Conjugate (a type of targeted therapy)
- How It’s Given: As an infusion into a vein (intravenous or IV)
- Common Cancers Treated: Certain types of HER2-positive or HER2-low breast cancer, lung cancer, stomach cancer, and other solid tumors. Your doctor will have tested your cancer to see if this drug is right for you.
1. About Trastuzumab Deruxtecan
- What It Is and What It’s Used For:Trastuzumab deruxtecan is a targeted cancer therapy. Think of it as a “smart bomb” designed to deliver a powerful cancer-killing medicine directly to cancer cells while limiting damage to healthy cells. It is used to treat certain advanced cancers that have a protein called HER2 on their surface. It is typically used when the cancer has spread (metastasized) or cannot be removed by surgery, and after other cancer treatments have been tried.
- How It Works:This drug has two main parts. The first part, trastuzumab, is an antibody that searches for and attaches to the HER2 protein on cancer cells. Once attached, the drug is taken inside the cancer cell. There, the second part, a chemotherapy drug called deruxtecan, is released. This chemotherapy damages the cancer cell’s DNA, causing it to die.
2. How You Will Receive This Drug
- Your Dosing Schedule:Trastuzumab deruxtecan is typically given once every three weeks (a 21-day cycle). Your doctor will determine the right number of cycles for you based on how your cancer responds and how you tolerate the treatment.
- How It’s Given:You will receive this medicine at a hospital or clinic. A nurse will place a small tube (an IV catheter) into a vein in your arm. The medicine is then given as a slow infusion.
- Your first infusion will be given slowly over about 90 minutes to ensure you don’t have a reaction.
- If you tolerate the first dose well, your future infusions may be shorter, around 30 minutes.
- You will be given other medications before the infusion to help prevent nausea and allergic reactions.
- Important Instructions:You do not need to do anything special to prepare for your infusion, but it is a good idea to be well-hydrated and have a light meal beforehand.
3. Possible Side Effects
This drug can cause side effects, some of which are serious. Your healthcare team will monitor you closely. It’s very important to report any new or worsening symptoms to them right away.
- Most Common Side Effects:
- Nausea and Vomiting: Your doctor will prescribe anti-nausea medicine. Take it as directed, even if you don’t feel sick.
- Fatigue: Feeling very tired is common. Plan for rest periods and don’t be afraid to ask for help with daily activities.
- Low Blood Counts: The drug can lower your white blood cells (increasing infection risk), red blood cells (causing anemia, tiredness, and shortness of breath), and platelets (increasing bruising or bleeding risk).
- Hair Loss: Hair may thin or you may lose it completely. This is usually temporary and grows back after treatment ends.
- Diarrhea or Constipation: Your doctor can recommend medicine to help manage these.
- Sore Mouth: You may develop sores in your mouth. Use a soft toothbrush and alert your nurse if this happens.
- Less Common but SERIOUS Side Effects:This drug has a boxed warning (the most serious type of warning from drug safety agencies) for two major risks:
- Lung Problems (Interstitial Lung Disease/Pneumonitis): This is a serious inflammation of the lungs that can be life-threatening.
- Heart Problems: The drug can weaken your heart’s ability to pump blood (a condition called cardiomyopathy). Your doctor will check your heart function before and during treatment.
- When to Contact Your Doctor Immediately:Call your doctor or go to an emergency room right away if you experience any of the following:
- Signs of Lung Problems: New or worsening cough, trouble breathing, shortness of breath, or fever.
- Signs of Heart Problems: New or worsening shortness of breath, coughing, swelling in your ankles or legs, feeling tired, irregular heartbeat, or sudden weight gain.
- Signs of Infection: Fever over 38°C (100.4°F), chills, sore throat, or pain when urinating.
- Unusual Bleeding or Bruising: Including nosebleeds, bleeding gums, or blood in your stool or urine.
4. Important Information to Discuss with Your Doctor
- Before You Start Treatment:It is crucial that you tell your doctor your full medical history. Be sure to mention if you:
- Have any lung or breathing problems.
- Have any heart conditions, including heart failure.
- Have liver or kidney problems.
- Are pregnant, planning to become pregnant, or are breastfeeding. This drug can cause serious harm to an unborn baby.
- Pregnancy and Contraception:
- Women: You must not become pregnant while on this treatment. You will need to use effective birth control during treatment and for at least 7 months after your final dose.
- Men: You must use effective birth control with a female partner during treatment and for at least 4 months after your final dose.
- Drug and Food Interactions:There are no widespread, major interactions known with this drug, but it is always best to be safe. Tell your doctor and pharmacist about everything you take, including prescription drugs, over-the-counter medicines, vitamins, and herbal supplements.
5. Practical Tips While Taking Trastuzumab Deruxtecan
- What to Do If You Miss a Dose:If you miss your scheduled appointment for an infusion, call your doctor’s office as soon as possible to reschedule. Do not wait for your next planned cycle.
- Storage:This medication is handled and stored by your healthcare team at the clinic or hospital.
- Follow-Up and Monitoring:You will have regular appointments with your doctor. Expect to have frequent blood tests to check your blood counts and to monitor your liver function. Your doctor will also schedule tests to check your heart (like an echocardiogram) before you start and during your treatment.
6. Questions to Ask Your Healthcare Team
Don’t hesitate to ask questions. It helps you to be an active partner in your care.
- What is the main goal of this treatment for my cancer?
- Which side effects should I be most concerned about, and who do I call if they happen?
- What is the number to call if I have a problem at night or on the weekend?
- How will we know if the treatment is working?
- Are there any activities I should avoid while on this treatment?