Enhertu (fam-trastuzumab deruxtecan-nxki) is a brand-name drug prescribed for certain cancers. Enhertu comes as an intravenous (IV) infusion given by a healthcare professional. The dosage can vary depending on the cancer Enhertu is prescribed to treat.
Enhertu is specifically approved to treat the following conditions in certain adults:
- HER2-positive or HER2-low breast cancer that can’t be surgically removed or has spread to other areas of the body
- non-small cell lung cancer that’s HER2-mutant (has mutations in the HER2 gene) and either can’t be surgically removed or has spread to other areas of the body*
- HER2-positive stomach or gastroesophageal cancer that has spread to other areas of the body
- HER2-positive solid tumors that can’t be surgically removed or have spread to other areas of the body*
Enhertu is an antibody-drug conjugate. This means it contains two active ingredients: fam-trastuzumab, which is an HER2 antibody, and deruxtecan-nxki, which is a topoisomerase I inhibitor (a type of chemotherapy). Enhertu is not available in a generic version.
Keep reading for specific information about the dosage of Enhertu, including its strength and how the medication is given. For a look at other aspects of Enhertu, including specifics about the cancers it treats, see this Enhertu overview.
Note: This article describes typical dosages for Enhertu provided by the drug’s manufacturer. However, your doctor will prescribe the Enhertu dosage that’s right for you.
* For this use, Enhertu received
The following chart summarizes Enhertu’s typical dosages for the types of cancer it treats. Your doctor will determine the dosage that’s best for you. Dosages are given in milligrams per kilogram of body weight (mg/kg) and strength is given in milligrams (mg). Note that 1 kg is about 2.2 pounds (lb).
| Condition | Form | Dosage | Strength | Frequency |
|---|---|---|---|---|
| breast cancer | intravenous (IV) infusion | 5.4 mg/kg | 100 mg | every 3 weeks |
| non-small cell lung cancer | IV infusion | 5.4 mg/kg | 100 mg | every 3 weeks |
| stomach cancer or gastroesophageal cancer | IV infusion | 6.4 mg/kg | 100 mg | every 3 weeks |
| solid tumors | IV infusion | 5.4 mg/kg | 100 mg | every 3 weeks |
Keep reading for more information about Enhertu’s dosage.
Enhertu form
Enhertu comes as a powder that’s mixed into a solution. A healthcare professional will use the solution to give you an IV infusion at your doctor’s office or clinic.
Enhertu strength (100 mg)
Enhertu comes in one strength: 100 milligrams (mg).
Typical dosages
Your doctor will recommend the best dosage for you. They may adjust it over time to reach the amount that’s right for you. Your doctor will ultimately prescribe the smallest dosage that provides the desired effect.
Before you receive an Enhertu infusion, you might be given premedications. These are medications you take before Enhertu to help prevent side effects such as nausea and vomiting.
If you have more questions about Enhertu dosing, such as the maximum dose or the best dosage for you, talk with your doctor.
The following information describes dosages that are commonly used or recommended. Your doctor will determine the best dosage to fit your needs.
Dosage for stomach cancer or gastroesophageal cancer
The dosage of Enhertu for stomach cancer or gastroesophageal cancer is based on your body weight. The recommended dosage of Enhertu is 6.4 mg per kilogram of body weight (mg/kg). For reference, 1 kg is about 2.2 pounds (lb).
For example, if you weigh 70 kg (about 154 lb), your dose would be 448 mg. You’ll receive this dose of Enhertu once every 3 weeks.
Dosage for breast cancer, lung cancer, or solid tumors
To treat breast cancer, non-small cell lung cancer, or solid tumors, your dosage of Enhertu is based on your body weight. The recommended dosage is 5.4 mg/kg.
Long-term treatment
Enhertu is meant to be a long-term treatment. If you and your doctor determine that Enhertu is safe and effective for you, you’ll likely take it long term. If you develop serious side effects from Enhertu or if your cancer progresses, your doctor may recommend that you stop receiving Enhertu.
The Enhertu dosage your doctor prescribes will depend on several factors. These include:
- the type of cancer you have
- your weight
- if you develop side effects with Enhertu treatment
Other medical conditions you have can also affect your Enhertu dosage.
Dosage adjustments
In some cases, your doctor may recommend adjusting your dosage of Enhertu if you’re experiencing side effects during your treatment. These side effects can include:
- lung problems
- neutropenia (low white blood cell levels)
- febrile neutropenia (fever with low white blood cell levels)
- low platelet level (platelets are cells that help blood clot)
- heart problems
In these cases, your doctor may recommend a dose reduction to try to decrease the risk of side effects occurring. If you have severe side effects, your doctor may recommend that you stop treatment with Enhertu and try a different medication.
Enhertu comes as a powder that’s mixed into a solution. A healthcare professional administers the solution as an IV infusion at your doctor’s office or clinic. (An IV infusion is an injection given over a period of time.)
You’ll get your first dose of Enhertu over 90 minutes to be sure that you don’t have any side effects from the drug. Then, after your first dose, your Enhertu infusions will take 30 minutes. If you develop side effects during your treatment with Enhertu, your infusion may be slowed down and may take longer.
If you have questions about how Enhertu is given, talk with your doctor.
If you miss a dose of Enhertu, reschedule your appointment to get your dose as soon as possible. Then, your dosing schedule will be adjusted so that you’re continuing to receive doses every 3 weeks. Do not skip a dose of Enhertu.
To help make sure that you don’t miss an appointment for your dose of Enhertu, try using a medication reminder. This can include setting an alarm or putting a note where you’ll see it, such as on your bathroom mirror or bedside table. You could also download a reminder app on your phone.
Disclaimer: Medical News Today 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.