Enhertu
Enhertu (fam-trastuzumab deruxtecan-nxki) is used to treat adults with certain cancers that have a protein called HER2 on tumor cells. These cancers include breast cancer, non-small cell lung cancer (NSCLC), stomach cancer, esophageal cancer, and other solid tumors. Enhertu is a type of targeted anticancer medication called an antibody-drug conjugate (ADC). This medication is given as an infusion through the vein (IV) every 3 weeks. Common side effects include nausea, tiredness, and hair loss.
What is Enhertu?
What is Enhertu used for?
Advanced or metastatic HER2-positive or HER2-low breast cancer, after previous anti-HER2 treatment has stopped working
Advanced or metastatic non-small cell lung cancer with HER2 mutations, after previous treatment
Advanced or metastatic HER2-positive stomach cancer, after previous treatment with Herceptin (trastuzumab)
Advanced or metastatic HER2-positive esophageal cancer, after previous treatment with Herceptin (trastuzumab)
Advanced or metastatic HER2-positive solid tumors, after previous treatment
How Enhertu works
Enhertu is a targeted therapy called an antibody-drug conjugate (ADC). It's made up of a few parts that work together to find and kill cancer or tumor cells in the body.
Fam-trastuzumab or trastuzumab is a monoclonal antibody. It targets a protein that’s found on cancer cells called HER2. This means that the antibody guides Enhertu specifically to the cancer cells with the HER2 protein on it.
Once Enhertu reaches and enters the cancer cell, the chemotherapy part of the medication (called deruxtecan or DXd) works as a topoisomerase inhibitor. DXd damages the DNA in the cancer cell, which kills the cancer cell. This helps stop the cancer from growing or spreading as easily.
Drug Facts
What are the side effects of Enhertu?
Common Side Effects
- Nausea (73%)
- Low blood cell counts (up to 70%)
- Feeling very tired (56%)
- Elevated liver enzyme levels (up to 47%)
- Vomiting (40%)
- Hair loss (34%)
- Constipation (33%)
- Low appetite (32%)
- Low potassium levels (31%)
- Diarrhea (29%)
- Muscle, bone, or joint pain (24%)
- Stomach pain (20%)
Serious Side Effects
- Lung damage: cough, having trouble catching your breath, wheezing, fever
- Low white blood cells and a risk for infection: fever, chills, feeling generally unwell
- Lower heart function: cough, fatigue, having trouble catching your breath, dizziness, swelling in the legs, sudden weight gain, irregular heartbeat
Source: DailyMed
The following side effects have also been reported
Side effects that you should report to your care team as soon as possible:
- Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat
- Dry cough, shortness of breath or trouble breathing
- Infection—fever, chills, cough, sore throat, wounds that don't heal, pain or trouble when passing urine, general feeling of discomfort or being unwell
- Heart failure—shortness of breath, swelling of the ankles, feet, or hands, sudden weight gain, unusual weakness or fatigue
- Unusual bruising or bleeding
Side effects that usually do not require medical attention (report these to your care team if they continue or are bothersome):
Pros and cons of Enhertu
Pros
Given just by itself (not taken alongside other cancer treatments)
Given once every 3 weeks
A possible option after previous treatments haven’t worked
Cons
Given as an infusion through the vein (IV)
Can cause nausea, vomiting, and hair loss
Not safe during pregnancy
Pharmacist tips for Enhertu
Be sure to keep track of when your Enhertu infusions are. This medication is given once every 3 weeks (on day 1 of every 21-day treatment cycle). Jot the dates and times of your infusion appointments in your calendar to help you remember.
Since Enhertu often causes nausea and vomiting, your oncology team will give you medications to take before each infusion to prevent this side effect. Your oncologist will also probably prescribe anti-nausea medications that you can take as needed.
Your first Enhertu infusion will take about an hour and a half. This helps your care team gauge whether you’re able to tolerate the medication. If the first infusion goes smoothly, the rest of your infusions can be faster and take a shorter period of time (30 minutes).
It’s a good idea to budget a few hours for each of your Enhertu infusion appointments. There might be other things, like lab draws, that you need to do when you’re at the infusion center or clinic.
Get heart imaging done when your oncologist tells you to while you're getting treated with Enhertu. Your care team needs to check for any changes in heart function that the medication might cause and for the risk for heart failure. Tell your care team right away if you have any new or worsening shortness of breath, cough, swelling of your legs or feet, sudden weight gain, or dizziness. These can be symptoms of heart failure.
If you or your partner can get pregnant, use effective birth control during treatment with Enhertu. Continue using birth control for 7 months after your last dose if you’re female and for 4 months after your last dose if you’re male. Enhertu can harm an unborn baby if it’s taken during pregnancy.
It’s recommended that you don’t breastfeed while you’re taking Enhertu and for 7 months after your last dose. There’s a potential risk for the medication to harm a breastfed baby.
Talk with your care team before you start taking Enhertu if you’re planning on fathering a child. This medication might affect fertility, so it’s best to discuss with your care team about family planning.
Frequently asked questions about Enhertu
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What are the risks and warnings for Enhertu?
Enhertu 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.
Harm to an unborn baby
Enhertu 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 Enhertu to make sure you’re not pregnant and to lower the risk of harm.
If you or your partner can become pregnant, use birth control while you’re taking Enhertu. For females, continue to use birth control for another 7 months after your last dose of treatment. And for males, keep using birth control until 4 months after you stop Enhertu. Contact your healthcare team right away if you or your partner becomes pregnant.
Lung damage
Risk factors: History of kidney problems
Although rare, people who’ve taken Enhertu have had serious and sometimes life-threatening lung problems, including inflammation of the lungs and fluid buildup in the lungs. During clinical studies, these problems usually started within the first 6 months of Enhertu treatment.
Let your care team know if you have any trouble breathing, cough, fever, or fatigue during your treatment with Enhertu. You’ll probably need to get scans done so your care team can check on your lungs. You might need to take supportive medications, like corticosteroids, to lower the inflammation in the lungs. And depending on how serious your lung problem is, you’ll need to take a break from treatment until you get better or stop treatment altogether.
Low white blood cell counts (neutropenia)
It’s common to have low white blood cell counts while you’re taking Enhertu. In clinical studies, a drop in white blood cell counts usually first occurred within the first month of Enhertu treatment. White blood cells are important for fighting infection. So when these levels are low, it puts you at risk for infection.
Before each Enhertu infusion, your care team will check your blood counts to make sure the medication is safe for you to take. Let your care team know as soon as possible if you have fevers or chills or feeling unwell while you’re taking Enhertu. You’ll have your blood checked then as well. Depending on how low your white blood cell counts are, you might need to take a break from treatment or stop the medication altogether.
Problems with heart function
Although rare, Enhertu can cause new or worsening left-sided heart failure. It can affect how well your heart pumps blood through your body. Make sure your oncology care team has your full medical history, especially if you’ve had any heart problems in the past.
Your oncology care team will check your heart function before you start treatment and while you’re taking Enhertu. They’ll send you to get an echocardiogram (echo) or a MUGA scan, which is imaging of your heart. Let your care team know if you have any signs or symptoms of heart failure, including shortness of breath, dry cough, irregular heartbeats, chest pain, or sudden weight gain.
Enhertu dosage forms
Typical dosing for Enhertu
In general, Enhertu is given by a healthcare professional as an infusion through the vein (IV).
Your Enhertu dose depends on your cancer. Your oncologist will calculate your specific dose based on your weight.
Breast cancer, NSCLC, or solid tumors: The typical dose is 5.4 mg/kg of weight IV once every 3 weeks (on day 1 of each 21-day treatment cycle).
Stomach or esophageal cancer: The typical dose is 6.4 mg/kg of weight IV once every 3 weeks (on day 1 of each 21-day treatment cycle).
Your care team might lower your dose if you have serious side effects during treatment.
What is the latest news about Enhertu?
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References
Best studies we foundAmerican Cancer Society. (2019). How chemotherapy drugs work.
American Cancer Society. (2021). How targeted therapies are used to treat cancer.
American Cancer Society. (2023). How is a biopsy done?
American Cancer Society. (2024). Hair loss (alopecia).
American Cancer Society. (2024). Neutropenia (low white blood cell counts).
American Heart Association. (2023). Radionuclide angiography (MUGA scan).
Ciruelos, E., et al. (2024). Safety profile of trastuzumab deruxtecan in advanced breast cancer: Expert opinion on adverse event management. Clinical & Translational Oncology.
Curigliano, G., et al. (2023). Patient-reported outcomes and hospitalization data in patients with HER2-positive metastatic breast cancer receiving trastuzumab deruxtecan or trastuzumab emtansine in the phase III DESTINY-Breast03 study. Annals of Oncology.
Daiichi Sankyo Inc. (2024). Enhertu- fam-trastuzumab deruxtecan-nxki injection, powder, lyophilized, for solution [package insert]. DailyMed.
Jaber, N. (2022). Enhertu marks first targeted therapy for HER2-mutant lung cancer. National Cancer Institute.
National Cancer Institute. (n.d.). HER2.
National Cancer Institute. (n.d.). Topoisomerase inhibitor.
National Cancer Institute. (2024). Nausea and vomiting and cancer treatment.
National Comprehensive Cancer Network. (2023). Stomach cancer.
National Comprehensive Cancer Network. (2024). Esophageal cancer.
National Comprehensive Cancer Network. (2024). Metastatic non-small cell lung cancer.
Phillips, C. (2024). FDA approves trastuzumab deruxtecan for any HER2-positive solid cancer. National Cancer Institute.
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