Trastuzumab emtansine (Kadcyla)

Trastuzumab emtansine is a type of targeted cancer drug. It is also known as Kadcyla. 

You pronounce it as tras-too-zoo-mab em-tan-seen.

Trastuzumab emtansine is a combination of the drug trastuzumab (also known as Herceptin) and a chemotherapy drug called emtansine. 

It is a treatment for HER2 positive breast cancer. You might be offered it if you have: 

• early HER2 positive breast cancer and there is still some cancer in the breast or lymph nodes after having surgery, taxane chemotherapy and trastuzumab or pertuzumab
• HER2 positive breast cancer that has spread or come back (advanced) after previous treatment with chemotherapy or trastuzumab

How does trastuzumab emtansine work?

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 is a type of targeted cancer drug called a monoclonal antibody. Trastuzumab attaches to the HER2 receptor. When it attaches to the HER2, it allows the emtansine to go into the cancer cell. Inside the cell emtansine becomes active and kills the cancer cell.

How do you have trastuzumab emtansine?

You have trastuzumab emtansine as a drip into your bloodstream (intravenously).

You might have treatment through a long plastic tube that goes into a large vein in your chest. The tube stays in place throughout the course of treatment. This can be a:

• central line
• PICC line
• portacath

You might have treatment through a thin short tube (a cannula) that goes into a vein in your arm. You have a new cannula each time you have treatment.

How often do you have trastuzumab emtansine?

You have trastuzumab emtansine as cycles of treatment. This means that you have the drug and then a rest to allow your body to recover.

You have trastuzumab emtansine every 3 weeks.

You have the first treatment over 90 minutes. You usually have your first treatment as an inpatient to monitor you for any reactions to the drug. If the first one went well you might have the next treatments over 30 minutes. 

If you're having trastuzumab emtansine after surgery for early breast cancer you might have up to 14 cycles.

For breast cancer that has come back or spread around the body, you continue to have treatment for as long as it helps and the side effects aren't too bad.

If you're having radiotherapy as well as trastuzumab emtansine your treatment is usually spaced to reduce the risk of having radiation related side effects. Your healthcare team will go through this with you. 

Tests

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.

You usually have heart tests such as an echocardiogram (ECHO) or a multigated acquisition (MUGA) scan to build up a picture of how well your heart if working. You usually have one of these before starting treatment and every 3 months during treatment. 

What are the side effects of trastuzumab emtansine?

Side effects can vary from person to person. They also depend on what other treatment you are having. 

When to contact your team

Your doctor, pharmacist 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. 

We haven't listed all the side effects here. Talk to your healthcare team if you have any new symptoms that you think might be a side effect of your treatment.

Remember it is very unlikely that you will have all of these side effects, but you might have some of them at the same time.

Common side effects

These side effects happen in more than 10 in 100 people (more than 10%). You might have one or more of them. They include:

Liver changes

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. This is known as petechiae.

Numbness or tingling in fingers or toes

Numbness or tingling in fingers or toes is often temporary and can improve after you finish treatment. Tell your healthcare team if you're finding it difficult to walk or complete fiddly tasks such as doing up buttons. 

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. It might help to avoid fatty or fried foods, eat small meals and snacks and take regular sips of water. Relaxation techniques might also 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 treat it once it has started.

Diarrhoea

Contact your advice line if you have diarrhoea. For example, in one day you have 2 or more loose bowel movements than usual. If you have a stoma , you might have more output than normal. Your doctor may give you anti diarrhoea medicine to take home with you after treatment.

Try to eat small meals and snacks regularly. It’s best to try to have a healthy balanced diet if you can. You don’t necessarily need to stop eating foods that contain fibre. But if your diet is normally very high in fibre, it might help to cut back on high fibre foods such as beans, nuts, seeds, dried fruit, bran and raw vegetables. 

Drink plenty to try and replace the fluid lost. Aim for 8 to 10 glasses per day.

Constipation 

Constipation is easier to sort out if you treat it early. Drink plenty and eat as much fresh fruit and vegetables as you can. Try to take gentle exercise, such as walking. Tell your healthcare team if you think you are constipated. They can give you a laxative if needed.

Dry mouth

A dry mouth is also called xerostomia (pronounced zero-stow-mee-a). Talk to your healthcare team 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.

Difficulty sleeping

If you have difficulty sleeping, 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. 

Headaches

Tell your healthcare team 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.

Sore mouth

Mouth sores and ulcers can be painful. It helps to keep your mouth and teeth clean, drink plenty of fluids and avoid acidic foods such as lemons. Chewing gum can help to keep your mouth moist. 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)

Tell your healthcare team straightaway if you get a high temperature. 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 (between 1 and 10%). You might have one or more of them. They include:

• 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

• 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

• low levels of potassium in blood

• feeling dizzy

• changes to taste

• problems with your memory

• 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

• feeling shivery (chills)

• thinning of your hair

• 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

This side effects happens in fewer than 1 in 100 people (fewer than 1%). You might have one or more of them. They include: