Lapatinib (Tyverb)

Lapatinib is also known by its brand name Tyverb. In North America it is called Tykerb. It is a treatment for advanced breast cancer. You may have it with the chemotherapy drug capecitabine. It is also sometimes used with hormone therapies called aromatase inhibitors. Researchers are looking at using it to treat other types of cancer.

Lapatinib is a type of biological therapy called a protein tyrosine kinase inhibitor (TKI). Tyrosine kinases are proteins which stimulate cancer cells to grow. Lapatinib stops (inhibits) two of these proteins from working

• ErbB1 (epidermal growth factor receptor – EGFR)
• ErbB2 (HER2)

Lapatinib comes as tablets. You take them once a day with a glass of water, either an hour before or an hour after food. You should not eat grapefruit or drink grapefruit juice when you are taking lapatinib because it can interact with the drug.

It is very important that you take tablets according to the instructions your doctor or pharmacist gave you. Whether you have a full or empty stomach, for example, can affect how much of a drug gets into your bloodstream. You should take the right dose, not more or less. And never stop taking a cancer drug without talking to your specialist first.

The side effects of lapatinib are listed below. Remember most people don’t have all of them and the effects can be mild.

More than 10 in every 100 people have one or more of these.

• Diarrhoea affects more than 3 out of 10 people (30%) – drink plenty of fluids and tell your doctor or nurse if you have diarrhoea as you may need treatment
• Skin changes – about 3 out of 10 people (30%) have a rash or red, dry, itchy skin
• Fatigue (tiredness) affects 1 out of 4 people (25%) during and after treatment – most people find their energy levels are back to normal a few months after treatment ends
• Some people develop soreness, redness and peeling on the palms of the hands and soles of the feet (palmar-plantar syndrome), which may cause tingling, numbness, pain and dryness
• Loss of appetite
• Indigestion
• Muscle and joint pain or back pain – this can usually be helped with mild painkillers
• Loss of fertility – we don’t know exactly how this drug may affect fertility so talk to your doctor before starting treatment if having a baby is important to you
• Lapatinib could harm a baby developing in the womb so talk to your doctor about contraception before having treatment if there is any chance that you could become pregnant

Between 1 and 10 in every 100 people have one or more of these.

• Feeling sick and being sick happen in just over 1 in 10 people (10%) but this is usually well controlled with anti sickness drugs
• Some people have an allergic reaction while having lapatinib treatment, usually at the first or second treatment – let your treatment team know immediately if you have any skin rashes, itching, feeling hot, shivering, going red in the face, feeling dizzy, headaches, shortness of breath, anxiety or a sudden need to pass urine
• Brittle, chipped and ridged nails – some people have infection around the nail

Fewer than 1 in 100 people have these.

• Heart problems including chest pain – you must contact your doctor as soon as possible if you have any pain. If you have a history of heart problems you may not be able to have lapatinib
• Mild effect on the liver – this is unlikely to cause symptoms, and your liver will almost certainly go back to normal after the treatment ends, but you will have regular blood tests to check how your liver is working
• Shortness of breath due to inflammation of the lungs – tell your doctor if you feel breathless

You won't get all of these side effects and any that you have may be mild. A side effect may get worse through your course of treatment. Or you may have more side effects as the course goes on. This depends on

• How many times you've had a drug before
• Your general health
• How much of the drug you have (the dose)
• Other drugs you are having

Talk to your doctor, pharmacist or nurse about all your side effects so they can help you manage them. Your nurse will give you a contact number. You can ring them if you have any questions or problems. They can give you advice or reassure you. If in doubt, call them.

Tell your doctor about any other medicines you are taking, including vitamins, herbal supplements and other over the counter remedies – some drugs can react together and many drugs can affect how well lapatinib works.

You should not have immunisations with live vaccines while you are having this treatment or for at least 6 months afterwards. In the UK, these include rubella, mumps, measles (usually given together as MMR), BCG and yellow fever. You can have other vaccines, but they may not give you as much protection as usual until your immune system has fully recovered.

It is safe for you to be in contact with other people who've had live vaccines as injections. There can be problems with oral vaccines, but not many people in the UK have oral vaccines now. So there is usually no problem in being with any baby or child who has recently had any vaccination in the UK. You might need to make sure that you aren't in contact with anyone who has had oral polio, cholera or typhoid vaccination recently, particularly if you live abroad.