Herzuma (Trastuzumab-Pkrb) for Breast Cancer

Herzuma (trastuzumab-pkrb) is a prescription medication approved by the U.S. Food and Drug Administration (FDA) to treat adults with HER2-overexpressing breast cancer.

How Herzuma Works and How It’s Taken

Herzuma is a type of targeted therapy called a HER2 receptor antagonist. HER2 stands for human epidermal growth factor receptor 2 and is a protein found in high amounts on some cancer cells. Herzuma attaches to HER2 and may help slow the growth of cancer cells that overexpress this protein.

Herzuma may also help the body’s immune system attack HER2-overexpressing cancer cells.

Herzuma is a biosimilar of Herceptin. This means it is made from living cells and is designed to work like the original medicine. The FDA requires biosimilars to have no meaningful differences in safety or how well they work.

Doctors may prescribe Herzuma for certain adults with HER2-overexpressing early-stage or metastatic breast cancer (cancer that has spread to another part of the body). Depending on the type and stage of breast cancer, it may be used:

As part of a treatment plan for early-stage breast cancer with chemotherapy that includes doxorubicin, cyclophosphamide, and either paclitaxel or docetaxel.
With docetaxel and carboplatin for certain adults with early-stage breast cancer.
By itself after anthracycline-based chemotherapy for certain adults with early-stage breast cancer.
With paclitaxel as the first treatment for HER2-overexpressing metastatic breast cancer.
By itself for HER2-overexpressing metastatic breast cancer after one or more chemotherapy treatments.

The cancer must show HER2 protein overexpression or HER2 gene amplification using an FDA-approved test.

Herzuma is given as an intravenous (IV) infusion. Depending on the treatment plan, it may be given once a week or once every three weeks.

For early-stage breast cancer, treatment is usually given for a total of 52 weeks. Treatment beyond one year is not recommended. For metastatic breast cancer, treatment continues until the cancer gets worse or side effects become unacceptable.

Typical Dosing for Breast Cancer

Early-stage breast cancer

When Herzuma is given during chemotherapy with paclitaxel or docetaxel:

The starting dose is 4 milligrams per kilogram, given as an IV infusion over 90 minutes.
After that, 2 milligrams per kilogram is given once a week during chemotherapy.
One week after the last weekly dose, 6 milligrams per kilogram is given every three weeks.

When Herzuma is used by itself after anthracycline-based chemotherapy:

The starting dose is 8 milligrams per kilogram, given as an IV infusion over 90 minutes.
After that, 6 milligrams per kilogram is given every three weeks.
Treatment continues for a total of 52 weeks.

Metastatic breast cancer

For HER2-overexpressing breast cancer that has spread:

The starting dose is 4 milligrams per kilogram, given as an IV infusion over 90 minutes.
After that, 2 milligrams per kilogram is given once a week as an IV infusion.
Treatment continues until the cancer gets worse.

Doctors may slow the infusion rate, interrupt or withhold treatment, or stop treatment for certain serious side effects or if side effects become too difficult to manage.

This information is based on the prescribing information, but your healthcare provider may tailor your treatment plan. Always follow their guidance.

Herzuma Side Effects

In trastuzumab clinical trials, common side effects differed between adjuvant and metastatic breast cancer. The adjuvant list below includes reactions reported in at least 5 percent of people in HERA, and the metastatic list includes reactions reported in at least 5 percent of people in at least one trastuzumab-containing arm of H0648g or H0649g.

For adjuvant breast cancer, these side effects include:

Headache
Diarrhea
Nausea
Chills
Nasopharyngitis (common cold-like symptoms)
Arthralgia (joint pain)
Pyrexia (fever)
Peripheral edema (swelling in the arms, legs, hands, or feet)
Cough
Back pain

For metastatic breast cancer, these side effects include:

Fever
Chills
Headache
Infection
Cough
Rash
Insomnia (trouble sleeping)
Congestive heart failure
Nausea
Diarrhea
Vomiting
Fatigue or weakness
Pain
Dyspnea (shortness of breath)
Dizziness
Rhinitis (runny nose)
Pharyngitis (sore throat)
Peripheral edema
Anorexia (loss of appetite)

Serious Side Effects and Warnings

Herzuma can cause serious side effects that may require immediate medical attention. These include:

Cardiomyopathy — Herzuma can cause heart problems, including weakened heart function, heart failure, abnormal heart rhythm, high blood pressure, and cardiac death.
Infusion reactions — These can be severe or life-threatening and may happen during or within 24 hours after treatment.
Pulmonary toxicity — Serious lung problems can include interstitial pneumonitis, pulmonary infiltrates, pleural effusions, noncardiogenic pulmonary edema, pulmonary insufficiency and hypoxia, acute respiratory distress syndrome, and pulmonary fibrosis.
Embryo-fetal toxicity — Exposure during pregnancy can cause low amniotic fluid, lung problems, skeletal abnormalities, and neonatal death.
Exacerbation of chemotherapy-induced neutropenia — Severe low white blood cell counts can increase the risk of serious infection.

Get medical help right away if you think you are having a serious reaction.

How To Save on Herzuma

The Herzuma Cost Support Program is available through the Herzuma website. Eligible individuals with commercial insurance may pay as little as $0. The program is not available to people eligible for Medicare, Medicaid, or other government insurance coverage.

The program is part of Teva Total Support, which offers help with insurance and enrollment navigation, as well as financial assistance support. To learn more or enroll, call 844-355-1499.

What To Know Before Taking Herzuma

Before starting Herzuma, your doctor will check:

Your heart function, including left ventricular ejection fraction (LVEF, a measure of how well your heart pumps blood)
Whether your tumor has HER2 protein overexpression or HER2 gene amplification
Your pregnancy status if you can become pregnant

Tell your doctor about all medicines you take, including prescription drugs, over-the-counter medicines, vitamins, and herbal supplements.

Herzuma is also FDA-approved to treat adults with HER2-overexpressing metastatic gastric cancer or gastroesophageal junction adenocarcinoma.

If you miss a Herzuma dose by one week or less, you should receive the missed dose as soon as possible. Do not wait until your next scheduled treatment.

If you miss a dose by more than one week, your healthcare provider may give you a higher starting dose before you return to your regular dosing schedule. Talk with your doctor if you miss an appointment for a Herzuma infusion.

Herzuma can harm your baby if you are pregnant. Your doctor should check your pregnancy status before you start treatment.

Females who can become pregnant should use effective birth control during treatment and for seven months after their last dose of Herzuma.

It is not known whether Herzuma passes into human breast milk. Talk with your healthcare provider about breastfeeding and the seven-month washout period (the time it takes most of the medicine to leave the body) after treatment.

Community FAQs

These answers are fact-checked by our editorial staff.

How effective is Herzuma?

Herzuma is a biosimilar of Herceptin. In studies of HER2-overexpressing early-stage breast cancer, people who received trastuzumab were more likely to live without their cancer coming back. Some people were also more likely to live longer.

Two large studies found that trastuzumab improved disease-free survival and overall survival. Disease-free survival means living without the cancer coming back or getting worse. Overall survival means living longer.

Trastuzumab improved disease-free survival, with a hazard ratio of 0.48. A hazard ratio below 1 means the treatment group had fewer cancer-related events over time than the comparison group.

Trastuzumab also improved overall survival, with a hazard ratio of 0.64. A hazard ratio below 1 means people receiving trastuzumab were less likely to die during the study period than those who did not receive trastuzumab.

After a median follow-up of 8.3 years, people who received trastuzumab were more likely to live longer than people who did not receive trastuzumab.

In another study, one year of trastuzumab improved disease-free survival compared with observation alone, with a hazard ratio of 0.54. This means people receiving trastuzumab were less likely to have their cancer come back or get worse during the study period.

In metastatic breast cancer, people who received trastuzumab plus chemotherapy lived longer than people who received chemotherapy alone. Median survival was 25.1 months with trastuzumab plus chemotherapy compared with 20.3 months with chemotherapy alone.

How often is Herzuma taken for breast cancer?

For early-stage breast cancer, Herzuma may be given once a week during certain chemotherapy regimens and then every three weeks afterward, for a total of 52 weeks of treatment. It may also be given every three weeks by itself after completion of certain chemotherapy treatments. Treatment beyond one year is not recommended.

For metastatic breast cancer, Herzuma is usually given once a week until the cancer gets worse.

What medications should be avoided while taking Herzuma?

The Herzuma prescribing information does not list any medicines that must be completely avoided during treatment.

However, some chemotherapy medicines called anthracyclines, such as doxorubicin, may increase the risk of heart problems when used after Herzuma treatment. Because Herzuma can stay in the body for several months after treatment ends, anthracycline-based therapy should be avoided for up to seven months after the last dose when possible.

Tell your healthcare provider about all prescription medicines, over-the-counter medicines, vitamins, and herbal supplements you take before starting Herzuma.