Key takeaways
- Enhertu is administered via IV infusion by a healthcare professional. It’s used either as a standalone treatment or in combination with pertuzumab (Perjeta) for certain breast cancers.
- The typical dosage is based on body weight, measured in milligrams per kilogram (mg/kg). Most conditions require a dose of 5.4 mg/kg once every 3 weeks, though stomach cancer requires a higher dose of 6.4 mg/kg.
- Dosage adjustments may be necessary based on side effects. If you miss a dose, you should reschedule your appointment as soon as possible.
Enhertu (fam-trastuzumab deruxtecan-nxki) is a brand-name drug prescribed to treat the following conditions in certain adults:
- HER2-positive breast cancer: This includes first-line treatment (in combination with pertuzumab) or as a standalone treatment for cancer that cannot be surgically removed or has spread to other areas.
- HER2-low or HER2-ultralow breast cancer: Specifically for hormone receptor (HR)-positive cancer that has spread or cannot be surgically removed and has progressed after endocrine therapy or prior chemotherapy.
- Non-small cell lung cancer (NSCLC): For tumors that are HER2-mutant and cannot be surgically removed or have spread.*
- HER2-positive stomach or gastroesophageal cancer: For cancer that has spread to other areas of the body.
- HER2-positive solid tumors: For tumors (IHC 3+) that cannot be surgically removed or have spread, where no other satisfactory treatment options exist.*
Enhertu is an antibody-drug conjugate. It contains two active ingredients: fam-trastuzumab (a HER2 antibody) and deruxtecan-nxki (a topoisomerase I inhibitor chemotherapy). Enhertu is not available in a generic version.
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. Strength is given in milligrams (mg), and doses are given in mg per kilogram of body weight (mg/kg). Note that 1 kg is about 2.2 pounds (lb).
| Condition | Form | Dose | Strength | Frequency |
|---|---|---|---|---|
| breast cancer (HER2+, low, or ultralow) | 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 (IHC 3+) | IV infusion | 5.4 mg/kg | 100 mg | every 3 weeks |
Note: For first-line HER2-positive metastatic breast cancer, Enhertu is given in combination with pertuzumab. In this case, you will receive Enhertu (5.4 mg/kg) followed by pertuzumab.
Enhertu strength
Enhertu comes in one strength of 100 milligrams (mg).
Enhertu form and how it’s given
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 into a vein over a period of time.)
- First dose: Given over 90 minutes to monitor for reactions.
- Follow-up doses: If the first dose is well tolerated, subsequent infusions usually take 30 minutes.
- Premedication: Your doctor may give you medications before the infusion to help prevent nausea and vomiting.
Typical dosages by condition
Typical dosages of Enhertu vary based on the condition the drug is being used to treat.
Breast cancer, lung cancer, and solid tumors
For most indications (including HER2-positive, HER2-low, and HER2-ultralow breast cancer), the recommended dosage is 5.4 mg/kg every 3 weeks.
If you are receiving Enhertu as a first-line treatment for HER2-positive metastatic breast cancer, it will be administered alongside pertuzumab.
Stomach or gastroesophageal cancer
The dosage for these cancers is higher, at 6.4 mg/kg every 3 weeks.
Long-term treatment
Enhertu is typically a long-term treatment. You will continue receiving it as long as the medication is safe and the cancer does not progress.
If you develop serious side effects from Enhertu (such as severe lung or heart problems), your doctor may reduce your dose, pause your treatment, or stop it entirely.
Your prescribed dosage depends on your weight, the specific cancer type, and how your body responds to the drug. Your doctor may reduce your dose if you experience certain side effects, including:
- heart problems (low ejection fraction)
- lung problems (interstitial lung disease or pneumonitis)
- low white blood cell levels (neutropenia)
- low platelet levels (thrombocytopenia)
If you miss an appointment, call your doctor right away to reschedule. Do not skip a dose. Your doctor will adjust your schedule to ensure you continue receiving a dose every 3 weeks from the date of your last infusion. Using a medication reminder or calendar alert can help you stay on track with your appointments.
Disclaimer: While Medical News Today strives for factual, comprehensive, and current drug 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.