What are pertuzumab (Perjeta®) and trastuzumab?

Pertuzumab (Perjeta®) and trastuzumab are only used to treat breast cancers that have too much of a protein (receptor) called HER2 on the surface of their cells. This is called HER2-positive breast cancer.

If you have HER2-positive early breast cancer that has spread to the lymph nodes or has a higher risk of coming back, you may have these drugs along with chemotherapy.

It is best to read this information with our general information about breast cancer.

Pertuzumab and trastuzumab belong to a group of targeted therapy drugs known as monoclonal antibodies.

Your doctor will talk to you about this treatment and its possible side effects before you agree (consent) to have treatment.

How pertuzumab and trastuzumab are given

You will have this treatment at a day unit as an outpatient.

During treatment, you will usually see a cancer doctor, a chemotherapy nurse or a specialist nurse, and a specialist pharmacist. This is who we mean when we mention doctor, nurse or pharmacist in this information.

Before or on the day of treatment a nurse or person trained to take blood (phlebotomist) will take a blood sample from you. This is to check that your blood cells are at a safe level to have treatment. If you are not having chemotherapy, you may not need your blood checked before every treatment.

You will see a doctor or nurse before you have treatment. They will ask you how you have been feeling. If your blood results are okay on the day of your treatment, the pharmacist will prepare your treatment. Your nurse will tell you when your treatment is likely to be ready.

Your nurse will give you the treatment as a drip into a vein (intravenous infusion). The nurse will put:

  • a short thin tube into a vein in your arm or hand (cannula)
  • a fine tube under the skin of your chest and into a vein close by (central line)
  • a fine tube that is put into a vein in your arm and through into a vein in your chest (PICC line).

Your course of treatment

You usually have a course of several cycles of treatment for a year. Each cycle takes 21 days (3 weeks).

You have pertuzumab and trastuzumab once every 3 weeks for 1 year. To begin with you have them with chemotherapy which you have over a few months.

Pertuzumab is usually given first over 1 hour. Some people may have a reaction the first time they have the drug. The nurse will monitor you during treatment and for an hour after you have pertuzumab. If you do not have a reaction, future treatments are given over a shorter time.

The first treatment of trastuzumab is also given slowly. You stay in hospital for a few hours after your first treatment. This is so the nurse can monitor you. Sometimes you can have trastuzumab as an injection under the skin.

Some hospitals give the first dose of trastuzumab the day after you have pertuzumab. Your nurse gives you your chemotherapy after you have had  your pertuzumab and trastuzumab.

Your nurse, pharmacist or doctor will discuss your treatment plan with you.

About side effects

We explain the most common side effects of this treatment here. We also include some less common side effects.

You may get some of the side effects we mention, but you are unlikely to get all of them. If you are also having treatment with other cancer drugs, you may have some side effects that we have not listed here. Always tell your doctor, nurse or pharmacist about any side effects you have.

Your doctor can give you drugs to help control some side effects. It is important to take them exactly as your nurse or pharmacist explains. This means they will be more likely to work for you. Your nurse will give you advice about managing your side effects. After your treatment is over, most side effects start to improve.

Serious and life-threatening side effects

Some cancer treatments can cause severe side effects. Rarely, these may be life-threatening. Your cancer doctor or nurse can explain the risk of these side effects to you.

Contact the hospital

Your nurse will give you telephone numbers for the hospital. If you feel unwell or need advice, you can call them at any time of the day or night. Save these numbers in your phone or keep them somewhere safe.

More information

We cannot list every side effect for this treatment. There are some rare side effects that are not listed. You can visit the electronic Medicines Compendium (eMC) for more detailed information.

Side effects while treatment is being given

Some people may have side effects while they are being given the treatment or shortly after they have it:

Allergic reaction

Some people have an allergic reaction while having this treatment. Before treatment, you will be given medicines to help prevent or reduce any reaction.

Signs of a reaction can include:

  • feeling hot or flushed
  • a skin rash
  • itching
  • shivering
  • feeling dizzy
  • a headache
  • feeling breathless
  • swelling of your face or lips
  • pain in your back, tummy or chest.

Your nurse will check you for signs of a reaction during your treatment. If you feel unwell or have any of these signs, tell them straight away. If you do have a reaction, it can be treated quickly.

Sometimes a reaction can happen a few hours after treatment. If you develop any signs or feel unwell after you get home, contact the hospital straight away.

Flu-like symptoms

Trastuzumab may cause temporary flu-like symptoms while it is being given. These may include:

  • a headache
  • a high temperature (fever) and chills
  • feeling sick (nausea) or being sick (vomiting).

These symptoms can be controlled or reduced with medicines, which your doctor can prescribe. If you experience flu-like symptoms, you generally get better within a few hours of having trastuzumab.

Common side effects of pertuzumab and trastuzumab

Risk of infection

This treatment can reduce the number of white blood cells in your blood. These cells fight infection.

If the number of white blood cells is low, you are more likely to get an infection. A low white blood cell count is called neutropenia.

If you have an infection, it is important to treat it as soon as possible. Contact the hospital straight away on the 24-hour contact number you have if:

  • your temperature goes over 37.5°C (99.5°F)
  • you suddenly feel unwell, even with a normal temperature
  • you have symptoms of an infection.

Symptoms of an infection include:

  • feeling shivery
  • a sore throat
  • a cough
  • diarrhoea
  • needing to pass urine often.

It is important to follow any specific advice your cancer treatment team gives you.

The number of white blood cells will usually return to normal before your next treatment. You will have a blood test before having more treatment. If your white blood cell count is low, your doctor may delay your treatment for a short time.

Bruising and bleeding

This treatment can reduce the number of platelets in your blood. Platelets are cells that help the blood to clot. 

Tell your doctor if you have any bruising or bleeding that you cannot explain. This includes:

  • nosebleeds
  • bleeding gums
  • tiny red or purple spots on the skin that may look like a rash.

Some people may need a drip to give them extra platelets. This is called a platelet transfusion.

Anaemia (low number of red blood cells)

This treatment can reduce the number of red blood cells in your blood. These cells carry oxygen around the body. If the number of red blood cells is low, you may be tired and breathless. Tell your doctor or nurse if you feel like this. If you are very anaemic, you may need a drip to give you extra red blood cells. This is called a blood transfusion.

Effects on the heart

This treatment can affect the way the heart works. You may have tests to see how well your heart is working. These may be done before, during, and sometimes after treatment. If the treatment is causing heart problems, your doctor can change the type of treatment you are having.

Contact a doctor straight away if you:

  • have pain or tightness in your chest 
  • feel breathless or dizzy
  • feel your heart is beating too fast or too slowly.

Other symptoms of heart problems can include breathlessness, feeling very tired and swollen ankles and legs. Different conditions can cause these symptoms, but it is important to get them checked by a doctor.

Diarrhoea

Pertuzumab may cause severe diarrhoea. If you have diarrhoea, contact the hospital for advice. They may give you anti-diarrhoea drugs to take. Try to drink at least 2 litres (3½ pints) of fluids every day. It can help to avoid alcohol, caffeine, milk products, high-fat foods and high-fibre foods.

Feeling sick

If you feel sick this is usually mild. Tell your nurse or doctor if this happens. They can give you anti-sickness drugs to help prevent sickness. Take the drugs exactly as your nurse or pharmacist tells you.

Loss of appetite

This treatment can affect your appetite. Do not worry if you do not eat much for a day or two. But if your appetite does not come back after a few days, tell your nurse or dietitian. They will give you advice. They may give you food or drink supplements.

Sore mouth

You may get a sore mouth or mouth ulcers. This can make you more likely to get a mouth infection. Use a soft toothbrush to clean your teeth or dentures in the morning, at night and after meals.

If your mouth is sore:

  • tell your nurse or doctor – they can give you a mouthwash or medicines to help
  • try to drink plenty of fluids
  • avoid alcohol, tobacco, and foods that irritate your mouth.

It is more common to have a sore mouth when you are having these drugs with chemotherapy. It will usually improve once you finish the chemotherapy.

Changes to your taste

You may get a bitter or metal taste in your mouth. Sucking sugar-free sweets may help with this. Some foods may taste different or have no taste. Try different foods to find out what tastes best to you. Taste changes usually get better after treatment finishes. Your nurse can give you more advice.

Skin changes

This treatment may affect your skin. Your doctor or nurse can tell you what to expect. If your skin feels dry, try using an unperfumed moisturising cream every day. It can cause a rash, which may be itchy.

Always tell your doctor or nurse about any skin changes. They can give you advice and may prescribe creams or medicines to help. Any changes to your skin are usually temporary and improve when treatment finishes.

Feeling tired

Feeling tired is a common side effect. It is often worse towards the end of treatment and for some weeks after it has finished. Try to pace yourself and plan your day so you have time to rest. Gentle exercise, like short walks, can give you more energy. If you feel sleepy, do not drive or operate machinery.

Effects on the lungs

This treatment can cause changes to the lungs. Tell your doctor if you develop:

  • a cough
  • wheezing
  • a fever (high temperature)
  • breathlessness.

You should also tell them if any existing breathing problems get worse. You may have tests to check your lungs.

Headaches

This treatment may cause headaches. If this happens, tell your doctor or nurse. They can give you painkillers.

Numb or tingling hands or feet (peripheral neuropathy)

This treatment affects the nerves. This can make your hands or feet feel:

  • numb
  • tingly
  • painful.

You may find it hard to fasten buttons or do other fiddly tasks.

Tell your doctor if you have these symptoms. They sometimes need to lower the dose of the drug. They may also delay treatment for a short time. The symptoms usually improve slowly after treatment finishes, but for some people they may never go away. Talk to your doctor if you are worried about this.

Peripheral neuropathy is more common when you are having the drugs with chemotherapy. It may start to improve once you finish the chemotherapy.

Muscle or joint pain

You may have pain in your muscles and stiffness in your joints. Tell your doctor or nurse if this happens. They can prescribe painkillers and give you advice. Tell them if the pain does not get better. Having warm baths and taking regular rests may help.

Watery, sore eyes

Your eyes may become watery. Sometimes they may become sore and inflamed (conjunctivitis). Your doctor can prescribe eye drops if you need them.

Blocked or runny nose, or nose bleeds

These side effects are not usually serious but tell your doctor or nurse if you have any of them. They may be able to help if you find them difficult to cope with.

Other information

Blood clot risk

Cancer and some cancer treatments can increase the risk of a blood clot. Symptoms of a blood clot include:

  • pain, redness or swelling in a leg or arm
  • breathlessness
  • chest pain.

If you have any of these symptoms, contact a doctor straight away.

A blood clot is serious, but can be treated with drugs that thin the blood. Your doctor or nurse can give you more information.

Other medicines

Some medicines can affect how this treatment works or be harmful when you are having it. Always tell your cancer doctor about any drugs you are taking or planning to take, such as:

  • medicines you have been prescribed
  • medicines you buy in a shop or chemist
  • vitamins, herbal drugs and complementary therapies.

Tell other doctors, pharmacists or dentists who prescribe or give you medicines that you are having this cancer treatment.

You can visit the electronic Medicines Compendium (eMC) for more detailed information about your treatment.

Contraception

Your doctor will advise you not to get pregnant or make someone pregnant while having this treatment. The drugs may harm a developing baby. It is important to use contraception during your treatment and for a while after treatment finishes. Your doctor, nurse or pharmacist can tell you more about this.

Vaccinations

Your doctor or nurse may talk to you about vaccinations. These help reduce your risk of getting infections.

Doctors usually recommend that you have a flu jab, which is an inactivated vaccination. People with weak immune systems can have this type of vaccination.

If your immune system is weak, you need to avoid live vaccinations such as shingles. Your cancer doctor or GP can tell you more about live vaccinations.

Breastfeeding

Women are advised not to breastfeed while having this treatment. This is because the drugs could be passed to the baby through breast milk.

Fertility

Some cancer drugs can affect whether you can get pregnant or make someone pregnant. If you are worried about this, it is important to talk with your doctor before you start treatment.

Medical and dental treatment

If you need medical treatment for any reason other than cancer, always tell the doctors and nurses that you are having cancer treatment. Give them the contact details for your cancer doctor so they can ask for advice.

If you think you need dental treatment, talk to your cancer doctor or nurse. Always tell your dentist you are having cancer treatment.

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