Herzuma is a prescription medication used to treat adults with certain types of breast cancers and stomach cancer in which human epithelial growth factor receptor (HER2) is overexpressed. 

Herzuma, a monoclonal antibody, belongs to a group of drugs called HER2/neu receptor antagonists. HER2 is found in large amounts on the surface of some cancer cells where it promotes their growth. When Herzuma binds to HER2 it stops the growth of such cells and causes them to die.

This medication is available in an injectable form to be given directly into a vein (IV) by a healthcare professional. For early breast cancer, metastatic breast cancer and metastatic gastric cancer, Herzuma is given every 3 weeks. Herzuma may also be given once a week for metastatic breast cancer.

Common side effects of Herzuma include fever, chills, headache, diarrhea, nausea, chills, congestive heart failure, insomnia, cough, and rash.

Herzuma is a prescription medication used alone or with other medications to treat

• early breast cancer, with high levels of a protein called HER2

• metastatic breast cancer (breast cancer that has spread beyond the original tumor) with high levels of HER2

• metastatic gastric (stomach) cancer with high levels of HER2

This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.

Serious side effects have been reported with Herzuma. See the “Herzuma Precautions” section.

Breast Cancer that Has Not Spread

• Most common adverse reactions (≥ 5%) are headache, diarrhea, nausea, and chills. 

Metastatic Breast Cancer

• Most common adverse reactions (≥ 10%) are fever, chills, headache, infection, congestive heart failure, insomnia, cough, and rash. 

This is not a complete list of Herzuma side effects. Ask your doctor or pharmacist for more information. 

Tell your doctor if you have any side effects that bother you or that do not go away. 

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Tell your doctor about all the medicines you take, including prescription and non-prescription medicines, vitamins, and herbal supplements. Especially tell your doctor if you take:

• Anthracycline medications such as:
  • doxorubicin (brand names: Adriamycin, Doxil, others)
  • epirubicin (brand name: Ellence)
  • daunorubicin (brand names: Cerubidine, DaunoXome, others)
  • mitoxantrone (brand name: Novantrone)
  • idarubicin (brand name: Idamycin)

This is not a complete list of Herzuma drug interactions. Ask your doctor or pharmacist for more information.

Serious side effects have been reported with Herzuma including the following: 

• Heart problems. These are conditions where the heart cannot function properly and can lead to abnormal heart rhythms, elevated blood pressure, a decreased ability to pump blood or weakening of the heart, or cardiac death. Tell your healthcare provider right away if you have some or all of the following symptoms:

  • Shortness of breath, particularly with exertion/exercise
  • Heart palpitations
  • High blood pressure
  • Chest pain
  • Sudden swelling in the feet, ankles, and legs
• Infusion reactions. Infusion reactions can occur with this medication. Tell your doctor or get medical help right away if you get any of these symptoms during or after an infusion this medication:
  • hives (red itchy welts) or rash
  • itching
  • swelling of your lips, tongue, throat or face
  • sudden cough
  • weakness
  • dizziness or feel faint
  • palpitations (feel like your heart is racing or fluttering)
  • chest pain

• Harm to unborn baby. In rare cases, a reduction in the amount of amniotic fluid that surrounds the developing baby was observed in pregnant women who received Herzuma. Ask your doctor for advice if you are pregnant or may become pregnant while taking this medication.

• Lung problems. Complications with the lungs and airways can occur with this medication. Tell your doctor or get medical help right away if you get any of these symptoms during or after an infusion this medication:

  • breathlessness during exercise
  • fatigue
  • dry cough
  • shortness of breath
  • discomfort or worsening symptoms when lying on your back

• Worsening of low white blood cell count (neutropenia). A low white blood cell count can cause you to get infections, which may be serious. Serious illness or death can happen if an infection is not treated right away when white blood cell counts are very low. Tell your doctor right away if you have any of the following signs or symptoms of an infection:

  • fever
  • shortness of breath
  • pain or burning on urination
  • chills
  • cough

Do not take Herzuma if you are allergic to Herzuma or to any of this medication’s ingredients.

Medications can interact with certain foods. In some cases, this may be harmful and your doctor may advise you to avoid certain foods. In the case of Herzuma, there are no specific foods that you must exclude from your diet when receiving this medication.

Before taking Herzuma, tell your doctor about all of your medical conditions. Especially tell your doctor if you:

• are allergic to Herzuma or to any of its ingredients

• have heart or lung problems

• you have ever had or are currently using a medicine called doxorubicin or epirubicin (medicines used to treat cancer) or any other anthracycline medication as these drugs can damage heart muscle and increase the risk of heart problems with Herzuma

• have signs of infection like fever, chills, bad sore throat, ear or sinus pain, or wounds that will not heal 

• are pregnant or plan to become pregnant

• are breastfeeding or plan to breastfeed

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

Tell your doctor if you are pregnant or plan to become pregnant.

Post-marketing studies show that products similar to Herzuma, when administered to a pregnant woman, can cause the reduction of amniotic fluid which can harm the unborn baby when and lead to serious birth defects or death. Use effective contraception during treatment with Herzuma and for at least 7 months after treatment has ended.

Tell your doctor if you are breastfeeding or plan to breastfeed.

It is not known if Herzuma crosses into human milk. Because many medications can cross into human milk and because of the possibility for serious adverse reactions in nursing infants with use of this medication, a choice should be made whether to stop nursing or stop the use of this medication. Your doctor and you will decide if the benefits outweigh the risk of using Herzuma.

Do not breastfeed your baby during Herzuma therapy and for 7 months after the last dose of Herzuma.

• Take Herzuma exactly as prescribed.
• This medication is available in an injectable form to be given directly into a vein by a healthcare professional.
• The first dose of Herzuma is given over 90 minutes.
• If the first dose is well tolerated the next doses may be given over 30 minutes.
• Herzuma is given every 3 weeks. It may also be given once a week for breast cancer that has spread to other parts of the body (metastatic).
• Work with your healthcare provider to ensure that doses are regularly scheduled. 
• Do not miss doses or stop using this medication.
• Herzuma is removed from the body after approximately 7 months. Your doctor will continue to monitor your heart function after treatment has stopped.

Take this medication exactly as prescribed by your doctor. Follow the directions on your prescription label carefully.

The dose your doctor recommends may be based on the following:

• the condition being treated
• other medical conditions you have
• other medications you are taking
• how you respond to this medication
• your weight

The recommended dose/dose range of Herzuma is based on weight and is given with other anti-cancer medications. Your doctor will work with you to establish a proper dose and regimen for the treatment period with this medication.

If Herzuma is administered by a healthcare provider in a medical setting, it is unlikely that an overdose will occur. However, if overdose is suspected, seek emergency medical attention.

Herzuma vials should be stored in the refrigerator at 2°C to 8°C (36°F to 46°F) until time of reconstitution.

WARNING: CARDIOMYOPATHY, INFUSION REACTIONS, EMBRYO-FETAL TOXICITY, AND PULMONARY TOXICITY

Cardiomyopathy

Administration of trastuzumab products can result in sub-clinical and clinical cardiac failure. The incidence and severity was highest in patients receiving trastuzumab with anthracycline-containing chemotherapy regimens.

Evaluate left ventricular function in all patients prior to and during treatment with Herzuma. Discontinue Herzuma treatment in patients receiving adjuvant therapy and withhold Herzuma in patients with metastatic disease for clinically significant decrease in left ventricular function.

Infusion Reactions; Pulmonary Toxicity

Administration of trastuzumab products can result in serious and fatal infusion reactions and pulmonary toxicity. Symptoms usually occur during or within 24 hours of administration. Interrupt Herzuma infusion for dyspnea or clinically significant hypotension. Monitor patients until symptoms completely resolve. Discontinue Herzuma for anaphylaxis, angioedema, interstitial pneumonitis, or acute respiratory distress syndrome.

Embryo Fetal Toxicity

Exposure to trastuzumab products during pregnancy can result in oligohydramnios and oligohydramnios sequence manifesting as pulmonary hypoplasia, skeletal abnormalities, and neonatal death. Advise patients of these risks and the need for effective contraception.