Herceptin: A Targeted Biologic Therapy for Breast Cancer

Learn How Herceptin Works Against Breast Cancer

A bottle of the Herceptin drug.
A bottle of the Herceptin drug. Jeff J Mitchell/Getty Images

Herceptin, also known by its generic name trastuzumab, is a chemotherapy infusion medication approved to treat adjuvant breast cancer and metastatic breast cancer. It is essentially a protein that targets and binds to the HER2 protein (human epidermal growth factor receptor2). About 1 in 4 people with breast cancer have HER2-positive breast cancer, or protein human epidermal growth factor receptor2.

HER2 is an aggressive breast cancer that grows quickly and spreads rapidly.

Adjuvant Breast Cancer and Herceptin

Herceptin treats early-stage breast cancer that is HER2-positive and may or may not have yet spread to the lymph nodes. For adjuvant breast cancer, Herceptin is used as part of a treatment course during chemotherapy.

Metastatic Breast Cancer and Herceptin

Herceptin is approved to treat metastatic breast cancer in two ways. It can be used in combination with chemotherapy medication paclitaxel or it can be used alone for patients who have already received chemotherapy for their metastatic breast cancer.

How Herceptin Works

Herceptin is part of a class of drugs that are called biologic therapies. This drug works by hunting down only those cancer cells that have HER2/neu receptors on their outer surface. The HER2 gene makes a protein receptor on the surface of a tumor cell. This receptor signals the cell to divide and multiply.

When there is too much HER2 in breast cancer tissue, cell division goes out of control, growing much too quickly. Herceptin attaches to the HER2 receptors and blocks the growth signal, preventing more cell division and slowing the progress of cancer.

It is a pale white or yellow fluid that is typically administered through chemotherapy.

How Herceptin is Administered

Herceptin is administered through a chemotherapy infusion. Your first dose will be given slowly in a 90-minute session to see how well you tolerate the drug and to watch for allergic reactions. If you do well with Herceptin, your following infusions can be given in 30-minute sessions.

Side Effects of Herceptin

Some patients receiving Herceptin for breast cancer had the following side effects:

  • Fever
  • Feeling sick to your stomach (nausea)
  • Throwing up (vomiting)
  • Infusion reactions
  • Diarrhea
  • Infections
  • Increased cough
  • Headache
  • Feeling tired
  • Shortness of breath
  • Rash
  • Low white and red blood cell counts
  • Muscle pain

Some patients receiving Herceptin for metastatic stomach cancer had the following side effects:

  • Low white blood cell counts
  • Diarrhea
  • Feeling tired
  • Low red blood cell counts
  • Swelling of the mouth lining
  • Weight loss
  • Upper respiratory tract infections
  • Fever
  • Low platelet counts
  • Swelling of the mucous membranes
  • Swelling of the nose and throat
  • Change in taste

These symptoms usually appear within 24 hours of receiving Herceptin.

If you have an allergic reaction to Herceptin, call your doctor right away. Allergic symptoms include extreme shortness of breath, wheezing, swelling of throat or lips and hives.

Urgent symptoms include shortness of breath and chest pain.

Possible Risks of Using Herceptin

Herceptin can cause heart problems and congestive heart failure. Your doctor may recommend a test to check your left ventricular function before starting Herceptin treatment. The risk of heart problems increases if you are being treated with Adriamycin and Cytoxan as well as Herceptin.

Do Not Take Herception If:

  • You are allergic to Herceptin
  • You are pregnant or breastfeeding

Recommendations During Treatment:

Most oncologists recommend that you avoid the use of alcohol, tobacco, or caffeine during treatment with Herceptin.

Caffeine causes drying of your tissues, which only adds to the drying effects already caused by your chemo drugs. Tell your health care team if you are using tobacco, alcohol or recreational drugs, and ask for help in quitting the use of these drugs. Use contraception while in treatment with Herceptin, because this drug may cause harm to the baby if you conceive. If you are already pregnant, be sure to tell your doctor.

Self-Care Tips While Taking Herceptin:

  • Stay well-hydrated by drinking two or three quarts of fluids every 24 hours
  • If needed, take your anti-nausea medications as directed
  • Some patients experience dizziness and drowsiness, so take it easy until these symptoms subside
  • If you have flu-like symptoms, pile on the blankets and drink lots of fluids (sports drinks can help)
  • Aches and pains can be relieved with acetaminophen or ibuprofen, but check with your doctor first
  • Rest as much as you can
  • Eat a good, nutritious diet


FDA. Drug Information. Trastuzumab Product Label Details. Updated: September 2013.​​

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