Fam-Trastuzumab Deruxtecan-Nxki: uses, dosing, side effects & brands
Fam-Trastuzumab Deruxtecan-Nxki is a medicine sold in the U.S. under one brand, for breast neoplasms and gastrointestinal neoplasms. Below: what the FDA label says, every product that contains it, what the pills look like, and its recall record.
Key facts
- Treats
- Breast Neoplasms and Gastrointestinal Neoplasms
- Available as
- Injectable
- Sold as
- Enhertu
- Prescription?
- Prescription only
- Generic available?
- Not in our catalog
- Boxed warning
- Boxed warning
How fam-trastuzumab deruxtecan-nxki is dosed
From the FDA label for Enhertu (application BLA761139). Other fam-trastuzumab deruxtecan-nxki products — different forms, different strengths — are dosed differently. Follow the label for the one you were prescribed.
Do not substitute ENHERTU for or with trastuzumab or ado-trastuzumab emtansine. ( 2.2 , 2.4 ) For intravenous infusion only . Do not administer as an intravenous push or bolus. DO NOT use Sodium Chloride Injection, USP. ( 2.4 ) Premedicate for prevention of chemotherapy-induced nausea and vomiting. ( 2.2 ) HER2-Positive Early Breast Cancer Neoadjuvant: ENHERTU 5.4 mg/kg every 3 weeks for 4 cycles, followed by THP regimen for 4 cycles. ( 2.2 , 2.3 ) Post Neoadjuvant: ENHERTU 5.4 mg/kg every 3 weeks for 14 cycles unless disease recurrence or unacceptable toxicity. ( 2.2 , 2.3 ) HER2-Positive, HER2-Low, or HER2-Ultralow Breast Cancer, HER2-Mutant NSCLC, and HER2-Positive (IHC 3+) Solid Tumors: ENHERTU 5.4 mg/kg every 3 weeks until disease progression or unacceptable toxicity. ( 2.2 , 2.3 ) HER2-Positive First-line Metastatic Breast Cancer: ENHERTU 5.4 mg/kg every 3 weeks in combination with pertuzumab until disease progression or unacceptable toxicity. Cycle 1, Day 1: ENHERTU 5.4 mg/kg followed by pertuzumab 840 mg. ( 2.2 , 2.3 ) Subsequent cycles, Day 1: ENHERTU 5.4 mg/kg followed by pertuzumab 420 mg. ( 2.2 , 2.3 ) HER2-Positive Gastric Cancer: 6.4 mg/kg every 3 weeks until disease progression or unacceptable toxicity. ( 2.2 , 2.3 ) Management of adverse reactions (ILD, neutropenia, thrombocytopenia, or left ventricular dysfunction) may require temporary interruption, dose…
Fam-Trastuzumab Deruxtecan-Nxki side effects
The following clinically significant adverse reactions are described elsewhere in the labeling: Interstitial Lung Disease/Pneumonitis [see Warnings and Precautions (5.1) ] Neutropenia [see Warnings and Precautions (5.2) ] Left Ventricular Dysfunction [see Warnings and Precautions (5.3) ] The most common adverse reactions (≥20%), including laboratory abnormalities, in patients with: HER2-Positive, HER2-Low, and HER2-Ultralow Breast Cancer, HER2-Mutant NSCLC, and HER2-Positive (including IHC 3+) Solid Tumors are decreased white blood cell count, nausea, decreased hemoglobin, decreased neutrophil count, decreased lymphocyte count, fatigue, decreased platelet count, increased aspartate aminotransferase, increased alanine aminotransferase, increased blood alkaline phosphatase, vomiting, alopecia, constipation, decreased blood potassium, decreased appetite, diarrhea, and musculoskeletal pain. ( 6.1 ) HER2-Positive Early Breast Cancer are decreased hemoglobin, increased alanine aminotransferase, increased aspartate aminotransferase, decreased white blood cell count, nausea, peripheral neuropathy, diarrhea, decreased neutrophil count, alopecia, fatigue, decreased lymphocyte count, rash, musculoskeletal pain, decreased blood potassium, constipation, vomiting, stomatitis, and decreased appetite. ( 6.1 ) HER2-Positive Metastatic Breast Cancer in Combination with Pertuzumab are decreased…
Who shouldn’t take fam-trastuzumab deruxtecan-nxki
None . None. ( 4 )
Every fam-trastuzumab deruxtecan-nxki product we track (1)
Same active ingredient — different manufacturer, form, price and FDA recall record. That last one is what our independent score measures.
Only one: Enhertu.
What people report to the FDA about fam-trastuzumab deruxtecan-nxki
The FDA Adverse Event Reporting System (FAERS) collects reports from patients and clinicians. It holds 369 reports naming fam-trastuzumab deruxtecan-nxki, and the FDA flagged 92% of those reports as serious. The effects reported most often — leaving out reports about overdose, misuse or the condition being treated, which dominate the raw list for common medicines:
- metastases to central nervous system59 reports
- diarrhoea37 reports
- pneumonia36 reports
- nausea33 reports
- febrile neutropenia29 reports
- neutropenia29 reports
- vomiting24 reports
- covid-1923 reports
Read these as a signal, not a rate. A report does not mean fam-trastuzumab deruxtecan-nxki caused the effect — anyone can file one, and many describe people taking several medicines for several conditions. Crucially there is no denominator: FAERS does not record how many people took the drug, so these counts cannot be turned into “X% of patients” — a bigger number often just means a more widely used or more talked-about drug. Duplicates exist, and publicity drives reporting. For what is actually established, read the FDA label section above.
Source: openFDA drug/event (FAERS), retrieved July 25, 2026.
Related calculators
Frequently asked questions
What is fam-trastuzumab deruxtecan-nxki?
Fam-trastuzumab deruxtecan-nxki is a HER2-directed antibody and topoisomerase inhibitor conjugate.
Can you take fam-trastuzumab deruxtecan-nxki with other medicines?
It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run fam-trastuzumab deruxtecan-nxki against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.
What forms does fam-trastuzumab deruxtecan-nxki come in?
Across the brands we track, fam-trastuzumab deruxtecan-nxki is currently marketed as injectable, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.
Is there a generic fam-trastuzumab deruxtecan-nxki?
We do not currently list a generic-labelled fam-trastuzumab deruxtecan-nxki product. That does not always mean none exists — it means none appears under a generic name in the FDA data we track. Ask your pharmacist.
Cite this page
- APA
- pharmaranks. (2026, July 24). Fam-Trastuzumab Deruxtecan-Nxki: uses, dosing, side effects & brands. https://pharmaranks.com/drugs/fam-trastuzumab-deruxtecan-nxki
- MLA
- “Fam-Trastuzumab Deruxtecan-Nxki: uses, dosing, side effects & brands.” pharmaranks, 24 July 2026, https://pharmaranks.com/drugs/fam-trastuzumab-deruxtecan-nxki.
We summarise public FDA and NIH sources — for a clinical claim, cite the primary source we link to as well.
Sources: FDA openFDA drug label, National Drug Code Directory, and Enforcement (recall) database. This page reproduces public FDA data and is not medical advice. Dosing is set by your prescriber.
Read the full FDA label for fam-trastuzumab deruxtecan-nxki on DailyMed (NIH) ↗ — including its boxed warning in full.