Trade Name: Herceptin
A biosimilar is a biologic medical product that is almost an identical copy of an original medication that is manufactured by a different pharmaceutical company.
Trastuzumab is a monoclonal antibody. (For more detail, see "How Trastuzumab Works"
What Trastuzumab Is Used For:
- Trastuzumab is used to treat metastatic (spread) breast cancer. It is effective
against tumors that overexpress the HER2/neu protein.
- As part of chemotherapy regimen for
adjuvant treatment of lymph-node positive, HER2/neu protein positive
- Treatment of gastric (stomach) cancer.
- It is not known whether or not trastuzumab may be effective in other cancers that
may also have this HER-2/neu protein, including ovarian, colon, endometrial,
lung, bladder, prostate, and salivary gland tumors.
Note: If a drug has been approved for one use, physicians may elect to use
this same drug for other problems if they believe it may be helpful.
How Trastuzumab Is Given:
- Trastuzumab is given through an infusion into vein (intravenous, IV). The
first dose is given over 90 minutes. If well-tolerated subsequent maintenance
doses may be given over 30 minutes.
- The amount of Trastuzumab that you will receive depends on many factors, including
your height and weight, your general health or other health problems, and the type
of cancer or condition being treated. Your doctor will determine your dose
Important things to remember about the side effects of Trastuzumab:
- Most people do not experience all of the side effects listed.
- Side effects are often predictable in terms of their onset and duration.
- Side effects are almost always reversible and will go away after treatment is complete.
- There are many options to help minimize or prevent side effects.
- There is no relationship between the presence or severity of side effects and the
effectiveness of the medication.
- The side effects of Trastuzumab and their severity depend on whether the drug is
given in combination with other medications. In other words, Trastuzumab given
in combination with other chemotherapy drugs may produce more severe side effects.
The following side effects are common (occurring in greater than 30%) for patients
taking Trastuzumab. The frequency of side effects reported is based on single
- During the first infusion of this Trastuzumab, you may develop chills or a fever. Your health care provider might prescribe medicine
to prevent or treat these symptoms.
These side effects are less common side effects (occurring in about 10-29%) of patients
receiving Trastuzumab. The frequency of side effects reported is based on
single agent Trastuzumab:
- Abdominal pain
- Back pain
- Flu-like symptoms
- Shortness of breath
- Rhinitis or pharyngitis (see cold symptoms)
- Insomnia (see sleep problems)
- Rash (see skin reactions)
- Swelling (usually of the feet, ankles or hands)
Infrequently, serious hypersensitivity reactions (anaphylaxis) (see allergic reactions),
have been associated with Trastuzumab. Most of these events occur within 24 hours
of infusion. However, delayed reactions have occurred. Trastuzumab should be used
with caution in people with lung problems. If a person experiences severe
hypersensitivity reaction, Trastuzumab may be discontinued.
A serious but uncommon side effect of Trastuzumab can be interference with the pumping
action of the heart. The incidence of heart problems (heart failure) increase in
people with heart disease or other risk factors such as radiation to the chest,
advancing age, and use of other heart-toxic drugs (such as doxorubicin and cyclophosphamide).
Your doctor may check your heart function before you may take any Trastuzumab and
will monitor your heart closely during your treatment. Trastuzumab may be
discontinued if symptoms of heart failure appear.
Not all side effects are listed above. Some that are rare (occurring in less than
10% of patients) are not listed here. However, you should always inform your
health care provider if you experience any unusual symptoms.
When to contact your doctor or health care provider:
Seek emergency help immediately and notify your health care provider, it you experience
the following symptoms:
- Shortness of breath, wheezing, difficulty breathing, closing up of the throat, swelling
of facial features, hives (possible allergic reaction).
Contact your health care provider immediately, day or night, if you should experience
any of the following symptoms:
- Shortness of breath or chest pain
The following symptoms require medical attention, but are not an emergency.
Contact your health care provider within 24 hours of noticing any of the following:
- Nausea (interferes with ability to eat and unrelieved with prescribed medication)
- Vomiting (vomiting more than 4-5 times in a 24 hour period)
- Diarrhea (4-6 episodes in a 24-hour period)
- Swelling of the feet or ankles. Sudden weight gain
- Signs of infection such as redness or swelling, pain on swallowing, coughing up
mucous, or painful urination.
- Pain that is unrelieved by prescribed medication
Always inform your health care provider if you experience any unusual symptoms.
- Before starting Trastuzumab treatment, make sure you tell your doctor about any
other medications you are taking (including prescription, over-the-counter, vitamins,
herbal remedies, etc.).
- Inform your health care professional if you are pregnant or may be pregnant prior
to starting this treatment. Pregnancy category B (there is no evidence of
risk in humans based on negative animal studies. Use in pregnancy only if
- For both men and women: It is not recommended to conceive a child (get pregnant)
while taking Trastuzumab. Barrier methods of contraception, such as condoms, are
recommended. Discuss with your doctor when you may safely become pregnant or conceive
a child after therapy.
- Do not breast feed while taking this Trastuzumab.
- Drink at least two to three quarts of fluid every 24 hours, unless you are instructed
- Trastuzumab causes little nausea. But if you should experience nausea, take
anti-nausea medications as prescribed by your doctor, and eat small frequent meals.
Sucking on lozenges and chewing gum may also help.
- You may experience drowsiness or dizziness; avoid driving or engaging in tasks that
require alertness until your response to the drug is known.
- For flu-like symptoms, keep warm with blankets and drink plenty of liquids.
There are medications that can help reduce the discomfort caused by chills.
- Acetaminophen or ibuprophen may help relieve discomfort from fever, headache and/or
generalized aches and pains. However, be sure to talk with your doctor before
- In general, drinking alcoholic beverages should be kept to a minimum or avoided
completely. You should discuss this with your doctor.
- Get plenty of rest.
- Maintain good nutrition.
- If you experience symptoms or side effects, be sure to discuss them with your health
care team. They can prescribe medications and/or offer other suggestions that
are effective in managing such problems.
Monitoring and Testing:
You will be checked regularly by your health care professional while you are taking
Trastuzumab, to monitor side effects and check your response to therapy. Periodic
blood work to monitor your complete blood count (CBC) as well as the function of
other organs (such as your kidneys and liver) may also be ordered by your doctor.
Your doctor will monitor your heart while you are taking Trastuzumab.
How Trastuzumab Works:
Monoclonal antibodies are a relatively new type of "targeted" cancer therapy.
Antibodies are part of the immune system. Normally, the body creates antibodies
in response to an antigen (such as a protein in a germ) entering the body.
The antibodies attach to the antigen in order to mark it for destruction by the
body's immune system. In the laboratory, scientists analyze specific antigens
on the surface of cancer cells (target) to determine a protein to match the antigen.
Then, using animal and human proteins, scientists work to create a special antibody
that will attach to the target antigen. Antibodies will attach to matching
antigens like a key fits a lock. This technology allows treatment to target
specific cells, causing less toxicity to healthy cells. Monoclonal antibody
therapy can be done only for cancers in which antigens (and the respective antibodies)
have been identified.
Trastuzumab works by targeting the HER2/neu receptor on cancer cells. The
HER2 gene produces a protein receptor on the cell surface that signals normal cell
growth by telling the cell to divide and multiply. Some cancerous breast tissue
has too much HER2 (HER2/neu overexpression), triggering the cells to divide and
multiply very rapidly. Trastuzumab attaches to the HER2 receptors to prevent
cells from multiplying, preventing further cancer growth and slowing cancer progression.
It may also work by stimulating an immune mechanism.
Note: We strongly encourage you to talk with your health care professional
about your specific medical condition and treatments. The information contained
in this website is meant to be helpful and educational, but is not a substitute
for medical advice.