Trastuzumab emtansine is a type of targeted cancer drug. It is a treatment for breast cancer that has spread around the body or come back. It is also known by its brand name Kadcyla.
Trastuzumab emtansine is a combination of the drug trastuzumab (also know by its brand name Herceptin) and a drug called emtansine.
Trastuzumab emtansine is pronounced trast-oo-zoo-mab em-tan-seen.
How trastuzumab emtansine works
Trastuzumab is a type of targeted cancer drug (biological therapy) called monoclonal antibody. Emtansine is a cancer drug that becomes active once Kadcyla enters the cancer cell.
Some breast cancers have too much of a protein called human epidermal growth factor receptor 2 (HER2) on the surface of their cells. These are called HER2 positive cancers. HER2 makes the cells grow and divide. Trastuzumab attaches to the HER2 receptor. When this happens it allows the emtansine to go into the cancer cell. Inside the cell emtansine becomes active and kills the cancer cell.
How you have trastuzumab emtansine
You have trastuzumab emtansine as a drip into your bloodstream (intravenously).
Into your bloodstream
You have treatment through a thin short tube (a cannula) that goes into a vein in your arm each time you have treatment.
Or you might have treatment through a long line: a central line, a PICC line or a portacath. These are long plastic tubes that give the drug into a large vein in your chest. The tube stays in place throughout the course of treatment.
When you have trastuzumab emtansine
You have trastuzumab emtansine every 3 weeks. You have the first treatment over 90 minutes. You might have the next treatments over 30 minutes if the first one went well.
You continue to have treatment as long as it helps and the side effects aren't too bad.
You have blood tests before and during your treatment. They check your levels of blood cells and other substances in the blood. They also check how well your liver and kidneys are working.
We haven't listed all the side effects. It is very unlikely that you will have all of these side effects, but you might have some of them at the same time.
How often and how severe the side effects are can vary from person to person. They also depend on what other treatment you are having. For example, your side effects could be worse if you are also having other drugs or radiotherapy.
When to contact your team
Your doctor or nurse will go through the possible side effects. They will monitor you closely during treatment and check how you are at your appointments. Contact your advice line as soon as possible if:
- you have severe side effects
- your side effects aren’t getting any better
- your side effects are getting worse
Early treatment can help manage side effects better.
Common side effects
These side effects happen in more than 10 in 100 people (10%). You might have one or more of them. They include:
You might have liver changes that are usually mild and unlikely to cause symptoms. They usually go back to normal when treatment finishes. You have regular blood tests to check for any changes in the way your liver is working.
Bruising, bleeding gums or nose bleeds
This is due to a drop in the number of platelets in your blood. These blood cells help the blood to clot when we cut ourselves. You may have nosebleeds or bleeding gums after brushing your teeth. Or you may have lots of tiny red spots or bruises on your arms or legs (known as petechia).
Numbness or tingling in fingers or toes
Numbness or tingling in fingers or toes is often temporary and can improve after you finish treatment. Talk to the team looking after you when you first notice this.
Breathlessness and looking pale
You might be breathless and look pale due to a drop in red blood cells. This is called anaemia.
Feeling or being sick
Feeling or being sick is usually well controlled with anti sickness medicines. Avoiding fatty or fried foods, eating small meals and snacks, drinking plenty of water, and relaxation techniques, can all help.
It is important to take anti sickness medicines as prescribed even if you don’t feel sick. It is easier to prevent sickness rather than treating it once it has started.
Diarrhoea or constipation
Tell your doctor or nurse if you have diarrhoea or constipation. They can give you medicine to help.
A dry mouth is also called xerostomia (pronounced zero-stow-mee-a). Talk to your nurse or doctor if you have this. They can give you artificial saliva to help with a dry mouth. It can also help to drink plenty of fluids.
Urinary tract infections (UTIs)
Tell your doctor or nurse if you think you might have a urinary tract infection. You might find it difficult to pass urine, want to go with some urgency or are going more often. There may be pain or burning when you go. You may see blood in your urine, or your urine might smell bad or look cloudy.
It can help to change a few things about how you try to sleep. Try to go to bed and get up at the same time each day and spend some time relaxing before you go to bed. Some light exercise each day may also help.
Tell your doctor or nurse if you keep getting headaches. They can give you painkillers to help.
Tummy (abdominal) cramps
Tell your treatment team if you have this. They can check the cause and give you medicine to help.
Cough and difficulty breathing
It is important to tell your doctor or nurse if you have a cough. This could be due to an infection, such as pneumonia. Or it could be caused by changes to the lung tissue, making it less flexible.
Mouth sores and ulcers can be painful. Keep your mouth and teeth clean; drink plenty of fluids; avoid acidic foods such as oranges, lemons and grapefruits; chew gum to keep the mouth moist and tell your doctor or nurse if you have ulcers.
Joint or muscle pain
You might feel some pain from your muscles and joints. Speak to your doctor or nurse about what painkillers you can take to help with this.
Tiredness and weakness
You might feel very tired and as though you lack energy.
Various things can help you to reduce tiredness and cope with it, for example exercise. Some research has shown that taking gentle exercise can give you more energy. It is important to balance exercise with resting.
High temperature (fever)
If you get a high temperature, let your treatment team know straight away. Ask them if you can take paracetamol to help lower your temperature.
Occasional side effects
These side effects happen in between 1 and 10 out of every 100 people (1 to 10%). You might have one or more of them. They include:
- allergic reaction which can cause flushing of the skin, shivering, seizures (fits), fever, difficulty breathing, low blood pressure and a fast heartbeat during the infusion or up to 24 hours after
- heart problems which can include shortness of breath, swollen arms or ankles, chest pain and changes to heartbeat
- increased risk of getting an infection due to a drop in the levels of white blood cells - symptoms include a change in temperature, aching muscles, headaches, feeling cold and shivery and generally unwell
- low levels of potassium in blood
- feeling dizzy
- changes to taste
- difficulty in remembering
- eye problems such as dry eyes, watery eyes, blurred vision, redness of the eye or an infection
- high blood pressure
- indigestion which can cause bloating, feeling sick, discomfort and burping
- swelling in the arms and legs due to a build up of fluid
- hair loss
- skin problems such as a rash, itchy skin and hives
- nail changes
- the palms of your hands and soles of your feet might become sore and red and the skin might peel - this is known as palmar-plantar syndrome and can cause tingling, numbness, pain and dryness
Rare side effects
These side effects happen in fewer than 1 in 100 people (1%). You might have one or more of them. They include:
- breathing problems due to inflammation of the lungs (pneumonitis) - let your doctor or nurse know straight away if you suddenly become breathless or develop a cough
- severe liver problems which can cause your skin and the whites of your eyes to go yellow (jaundice). You may also have bloating, swelling of your tummy (abdomen) and bleeding
- inflammation around the drip side which can cause redness, pain, swelling or leaking
Coping with side effects
We have more information about side effects and tips on how to cope with them.
What else do I need to know?
Other medicines, foods and drinks
Cancer drugs can interact with some other medicines and herbal products. Tell your doctor or pharmacist about any medicines you are taking. This includes vitamins, herbal supplements and over the counter remedies.
Loss of fertility
It is not known whether this treatment affects fertility in people. Talk to your doctor before starting treatment if you think you may want to have a baby in the future.
Contraception and pregnancy
This treatment might harm a baby developing in the womb. It is important not to become pregnant or father a child while you're having treatment and for a few months afterwards. Talk to your doctor or nurse about effective contraception before starting treatment.
You should continue to take your contraception for at least 7 months after your last dose of trastuzumab emtansine. Talk to your doctor before stopping your contraception.
Don’t breastfeed during this treatment and for 7 months afterwards. The drug may come through in the breast milk.
Treatment for other conditions
Always tell other doctors, nurses, pharmacists or dentists that you’re having this treatment if you need treatment for anything else, including teeth problems.
Don’t have immunisations with live vaccines while you’re having treatment and for up to 12 months afterwards. The length of time depends on the treatment you are having. Ask your doctor or pharmacist how long you should avoid live vaccinations.
In the UK, live vaccines include rubella, mumps, measles, BCG, yellow fever and the shingles vaccine (Zostavax).
- have other vaccines, but they might not give you as much protection as usual
- have the flu vaccine (as an injection)
Contact with others who have had immunisations
You can be in contact with other people who have had live vaccines as injections. Avoid close contact with people who have recently had live vaccines taken by mouth (oral vaccines) such as the oral typhoid vaccine.
If your immune system is severely weakened, you should avoid contact with children who have had the flu vaccine as a nasal spray. This is for 2 weeks following their vaccination.
Babies have the live rotavirus vaccine. The virus is in the baby’s poo for about 2 weeks and could make you ill if your immunity is low. Get someone else to change their nappies during this time if you can. If this isn't possible, wash your hands well after changing their nappy.
More information about this treatment
For further information about this treatment go to the electronic Medicines Compendium (eMC) website.
You can report any side effect you have to the Medicines Health and Regulatory Authority (MHRA) as part of their Yellow Card Scheme.