Fam-trastuzumab deruxtecan-nxki (Enhertu)

How is this drug name pronounced?

Fam-trastuzumab deruxtecan: fam-tras-TOO-zoo-mab DEH-rux-TEE-kan

Enhertu: en-HER-too

What cancer(s) does this drug treat?

Enhertu is approved for:

Advanced breast cancer

  • Patients with advanced breast cancer that tests positive for the HER2 molecule and either cannot be removed by surgery or has spread to other parts of the body, and who have previously received two or more anti-HER2-based treatments for their advanced disease.

Limitations of use:

Age: The safety and efficacy of Enhertu in patients under 18 years of age have not been established.
Fertility/Pregnancy/Breastfeeding: Enhertu may impair fertility in men. Enhertu can result in the death of the fetus and can cause birth defects. Women should not start Enhertu treatment when pregnant and should use effective contraception to prevent pregnancy during treatment with Enhertu and for at least seven months after the last dose of Enhertu. Men should use effective contraception during treatment with Enhertu and for at least four months after the last dose of Enhertu. Enhertu may cause serious adverse reactions to the breastfed child. Women are advised not to breastfeed during treatment with Enhertu and for at least seven months after the last dose of Enhertu.

What type of immunotherapy is this?

Antibody therapy

  • Antibody-drug conjugate

How does this drug work?

  • Target: HER2

Enhertu is a medicine that consists of two parts that are connected: an antibody called trastuzumab that attaches to a molecule called HER2 on the surface of cancer cells, and a chemotherapy drug called DXd. HER2 is a protein present on the surface of different types of healthy cells, and it plays a role in regulating the multiplication and survival of cells. HER2 is also found in higher quantities on the surface of some breast cancer cells.

By targeting HER2, Enhertu is designed to minimize harm to normal, healthy cells and to bring the chemotherapy directly to the cancer cells. When Enhertu binds to HER2, it can enter the cell it is bound to. Inside the cell, the chemotherapy part of Enhertu, known as DXd, is released. DXd travels to the nucleus of the cell, where it causes DNA damage, and leads to cell death. Free DXd can then also enter surrounding cancer cells that may have lower amounts of HER2 on their surface and may not be directly targeted by Enhertu.

Illustration showing how Enhertu works

How is this drug given to the patient?

Enhertu is administered via a tube into a vein (intravenous infusion, or I.V.) every 3 weeks. The first infusion is administered over 90 minutes. If the first infusion is well tolerated, subsequent infusions are administered over 30 minutes.

What are the observed clinical results?

It is important to keep in mind that each patient’s actual outcome is individual and may be different from the results found in the clinical studies. 

Advanced breast cancer

In a clinical trial, 184 patients with advanced breast cancer that could not be removed by surgery and/or had spread to other parts of the body, and that tested positive for the HER2 molecule, who had previously received two or more anti-HER2-based treatments, were treated with Enhertu. At a median follow-up of 11 months, 60% of patients responded to treatment, including 4% whose tumors went away completely and 56% who saw their tumors shrink. Patients continued to respond for a median of 15 months.

What are the side effects?

The most common side effects of Enhertu include tiredness, nausea, vomiting, constipation, diarrhea, decreased appetite, cough, hair loss, low red blood cell count, low white blood cell count, and low platelet count.

Enhertu can cause side effects that can become serious or life-threatening, and may lead to death. Some of the serious side effects related to Enhertu include severe problems with the lungs and heart, and severe low white blood cell count (which can increase the risk of infection).

Patients should report any symptoms to their healthcare provider, who can then initiate actions to limit or reverse the side effects. For a more complete list of possible side effects, see the full prescribing information.

Additional information


Daiichi-Sankyo and AstraZeneca



Other references

Understanding Cancer Immunotherapy Research