Key takeaways
- Enhertu is a targeted cancer therapy that’s used to treat different types of breast, lung, and stomach cancer in adults. It’s given as an IV infusion once every 3 weeks.
- Common side effects of Enhertu include nausea, vomiting, diarrhea, constipation, tiredness, and hair loss. Enhertu also has serious FDA warnings for the risks of lung disease and pregnancy complications.
- The price of Enhertu can depend on several factors, including your insurance coverage and whether you qualify for any coupons or savings programs.
Enhertu (fam-trastuzumab deruxtecan-nxki) treats some cancers that have high levels 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
- HER2-positive gastric or gastroesophageal junction adenocarcinoma (a kind of stomach cancer)
Enhertu also has accelerated approval to treat some types of cancer in people who have already had systemic (whole-body) therapy, like chemotherapy. Specifically, it has accelerated approval to treat:
- non-small cell lung cancer (NSCLC) that has certain changes in the HER2 gene
- HER2-positive solid tumors (masses of cancerous tissue), when other treatments aren’t an option
Enhertu is used in certain situations when these cancers can’t be removed with surgery or have spread to other parts of the body.
What is accelerated approval?
If additional trials don’t show a drug to be safe and effective for a specific condition, the FDA will remove its accelerated approval status.
Enhertu is a combination of chemotherapy and targeted therapy.
Targeted therapies are designed to attack cancer cells without harming healthy cells. In contrast, chemotherapy drugs typically kill all rapidly dividing cells. While this includes cancer cells, it may also harm healthy cells.
How it works (mechanism of action)
Enhertu works by attaching directly to HER2 proteins on cancer cells, then releasing targeted chemotherapy into the affected cells.
In clinical studies, Enhertu was shown to delay cancer progression longer than chemotherapy did.
Like most drugs, Enhertu may cause mild or serious side effects. The table below describes some of the more common side effects that Enhertu may cause. These lists don’t include all possible side effects.
| Mild side effects | Serious side effects |
|---|---|
| • nausea and vomiting • constipation • diarrhea • fatigue (low energy) • reduced appetite • muscle pain or bone pain • hair loss • headache • mouth sores • upper respiratory infection, such as the common cold • mild allergic reaction | • 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 neutrophils (a type of white blood cell), which may raise your risk of infection • low level of red blood cells • low level of platelets (cells that help with blood clotting) • interstitial lung disease (ILD) • lung inflammation • serious allergic reaction |
Side effects may vary depending on the condition you’re receiving Enhertu infusions to treat. Your doctor or pharmacist can tell you more about the potential side effects of Enhertu and suggest ways to help manage them.
Note: Enhertu has boxed warnings for the risks of severe lung problems and pregnancy complications. A boxed warning is the most serious kind of warning from the FDA. For details, see “What should be considered before starting Enhertu?” below.
Like prescription drugs in general, the cost of Enhertu can vary depending on many factors. These include what your health insurance plan covers (if you have one) and where you receive your infusions.
If you have questions about how to pay for your prescription, talk with your doctor. In addition, you may be eligible for cost savings through a program called ENHERTU4U.
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, then give you the drug as an IV infusion.
You’ll receive doses of Enhertu in a hospital or infusion center once every 3 weeks.
Before each infusion, you’ll receive medication to help prevent nausea and vomiting (two side effects of the drug).
Your first infusion will likely take 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 during your first infusion, your next infusion may only take 30 minutes.
No, Enhertu and Herceptin (trastuzumab) are not the same drug. Both drugs are targeted cancer therapies, but they work in different ways.
Herceptin is an antibody that tells the immune system to attack HER2-positive cancer cells, which stops the cancer cells from growing. It’s often prescribed in combination with a separate chemotherapy drug.
Enhertu also contains trastuzumab, but it’s chemically linked to a chemotherapy drug. This allows it to deliver the chemotherapy directly to the cancer cells without harming healthy cells. Because it already contains a chemotherapy drug, it’s typically prescribed on its own.
To find out more about how Enhertu compares with Herceptin, talk with your doctor. They can recommend the treatment option that is best for you.
Below is important information you should consider before receiving Enhertu.
Boxed warnings
Enhertu has boxed warnings. These are serious warnings from the Food and Drug Administration (FDA) about drug effects that may be dangerous.
Boxed warnings for Enhertu include:
Risk of pregnancy complications: Enhertu is not safe to receive during pregnancy or while breastfeeding. In studies, people who received Enhertu during pregnancy had higher risks of complications, including birth defects and pregnancy loss. Because of this, doctors recommend using birth control during treatment with Enhertu and for 7 months after your last dose. If you become pregnant during treatment, talk with your doctor right away.
Risk of serious lung conditions: In rare cases, Enhertu may cause serious lung conditions that involve inflammation and scarring. These conditions can be life threatening. Contact your doctor right away if you experience shortness of breath, wheezing, chest tightness, cough, or fever.
If you develop a serious lung condition during treatment, 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.
Other warnings
Before starting treatment with Enhertu, talk with your doctor about your health history. Enhertu may not be right for you if you have certain medical conditions or other health factors. Let your doctor know if any of the following apply to you:
- active or recurring infections
- history of heart problems, such as heart failure
- existing lung or breathing problems
- liver or kidney problems
- pregnancy or breastfeeding
- previous allergic reaction to Enhertu or any of its ingredients
Enhertu is a targeted cancer therapy for certain HER2-positive cancers. It works by attaching to HER2 proteins on cancer cells and delivering chemotherapy directly to the tumor.
Enhertu is given as an IV infusion every 3 weeks. Frequently reported side effects include nausea, vomiting, fatigue, hair loss, and low white blood cell counts.
For more details about Enhertu and whether it may be right for you, talk with your doctor.
Disclaimer: While Healthline strives for factual, comprehensive, and current information, this article is not a substitute for a licensed healthcare professional’s expertise. Always consult a doctor before taking or discontinuing any medication. Drug information is subject to change and may not cover all uses, directions, precautions, warnings, interactions, reactions, or adverse effects. The lack of a warning does not guarantee a drug’s safety, effectiveness, or appropriateness for all patients or specific uses. Learn more about our approach to content integrity.