Neratinib (Nerlynx)

Neratinib is a type of targeted cancer drug. It is pronounced ne-rat-ti-nib. It is also known as Nerlynx.

It is a treatment for early stage breast cancer that is ​hormone receptor positive​ and human epidermal growth factor receptor 2 positive (​HER2 positive​ ).

You have tests on your breast cancer cells to check for these.

Find out more about breast cancer treatment

How do you take neratinib?

You have neratinib as tablets. You take the tablets with food and swallow them whole with water. You should not crush, chew or break them.

Taking your tablets

Speak to your pharmacist if you have problems swallowing the tablets.

Whether you have a full or an empty stomach can affect how much of a drug gets into your bloodstream.

You should take the right dose, no more or less.

Talk to your healthcare team before you stop taking a cancer drug or if you miss a dose.

You might also have an assessment of your heart before and during your treatment .

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:

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.

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.

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.

Skin rash

A rash can also be itchy. Less commonly your skin might get dry, cracked and split. Tell your doctor or nurse if you have a skin rash. They can prescribe medicine to stop the itching and soothe your skin.

Loss of appetite

You might lose your appetite for various reasons while having cancer treatment. Sickness, taste changes or tiredness can put you off food and drinks.

Tummy (abdominal) pain

Tell your doctor or nurse if you have this. They can check for the cause of the pain and give you medicine to help. 

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.

Muscle spasms

Let your doctor or nurse know if you have muscle spasms during or after having treatment.

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:

• infection of your water works (urinary tract infection) – you might have a stinging or burning sensation when you wee, you might go very often or need to go very urgently

• lack of fluid in your body (dehydration)

• feeling weak, faint or unsteady

• nosebleeds

• bloating of your tummy

• dry mouth

• heartburn or indigestion

• liver changes - these are usually picked up on blood tests so you have regular blood tests to check this

• nail changes - they may break easily, the colour might change or you might develop an infection

• weight loss

• high levels of a waste product (creatinine) in your blood – you have regular blood tests to check for this

Rare side effects

This side effect happens in fewer than 1 in 100 people (less than 1%). 

• Your kidneys stop working properly (you have regular blood tests to check for this) – symptoms might include feeling or being sick, weeing less than usual, blood in your wee, tiredness, confusion, swelling (fluid build up) in your ankles, feet and hands

What else do I need to know?

Other medicines, foods and drinks

Cancer drugs can interact with medicines, herbal products, and some food and drinks. We are unable to list all the possible interactions that may happen. An example is grapefruit or grapefruit juice which can increase the side effects of certain drugs.

Tell your healthcare team about any medicines you are taking. This includes vitamins, herbal supplements and over the counter remedies. Also let them know about any other medical conditions or allergies you may have.

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

It is unknown whether treatment may or may not harm a baby developing in the womb. It is important not to become pregnant or get someone pregnant while you are having treatment.

Neratinib might stop hormonal contraceptives from working properly. Women should use a barrier method of contraception during treatment and for at least 1 month after finishing treatment. You should do this even if you are using another type of contraception.

Men should use a barrier method of contraception, such as a condom during treatment and for at least 3 months after finishing treatment.

Talk to your healthcare team about contraception you can use during treatment.

Breastfeeding

It is not known whether this drug comes through into the breast milk. Doctors usually advise that you don’t breastfeed during this treatment.

Treatment for other conditions

If you are having tests or treatment for anything else, always mention your cancer treatment. For example, if you are visiting your dentist.

Driving or operating machinery

This drug can cause tiredness and dizziness. Don’t drive or operate heavy machinery if you have these symptoms.

Immunisations

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, and yellow fever.

You can usually have:

• other vaccines, but they might not give you as much protection as usual

• the flu vaccine (as an injection)

• the coronavirus (COVID-19) vaccine

Talk to your doctor or pharmacist about the best time to have a vaccine in relation to your cancer treatment.

Contact with others who have had immunisations 

You can be in contact with other people who have had live vaccines as injections. If someone has had a live vaccine by mouth or nasal spray there may be a small risk the vaccine virus can be passed onto you if your ​immune system​ is weakened.

Your healthcare team will let you know if you need to take any precautions if you are in close contact with someone who has had a live vaccine.

Read more about immunisations and cancer treatment