Encorafenib (Braftovi) and Binimetinib (Mektovi)

Encorafenib and binimetinib are types of targeted cancer drugs. They are a treatment for melanoma skin cancer that either:

  • can’t be removed with surgery
  • has spread to other areas of the body (advanced or metastatic melanoma)

You can only have these drugs if you have a change (mutation) in the BRAF gene. You have tests on the melanoma cells to check for this gene change.

How encorafenib and binimetinib works

Encorafenib and binimetinib are types of cancer growth blockers. They work by targeting certain proteins that help cancer cells grow. By blocking these proteins, this combination of drugs stops or slows down the growth of cancer cells.

How you have encorafenib and binimetinib

You take encorafenib as capsules and binimetinib as tablets.

You swallow the capsules and tablets whole with a glass of water. You can take them with or without food.

Taking your tablets or capsules

You must take tablets and capsules according to the instructions your doctor or pharmacist gives you.

You should take the right dose, not more or less.

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

When you have encorafenib and binimetinib

Usually you take encorafenib once a day. You take binimetinib twice a day, about 12 hours apart.

You continue taking encorafenib and binimetinib for as long as the treatment is working 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.

You might have other tests or scans during this treatment to check for possible side effects.

Side effects

How often and how severe the side effects are can vary from person to person. They also depend on what other treatments you're having. 

When to contact your team

Your doctor, nurse or pharmacist will go through the possible side effects. They will monitor you 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. 

Contact your advice line immediately if you have signs of infection, including a temperature above 37.5C or below 36C.

We haven't listed all the side effects here. 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 effect

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

High temperature (fever)

If you get a high temperature, let your healthcare team know straight away. Ask them if you can take paracetamol to help lower your temperature.


You might be breathless and look pale due to a drop in red blood cells. This is called anaemia.

Numbness of fingers and 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. 

Headaches and dizziness

Let your doctor or nurse know if you have headaches. They can give you painkillers. Don’t drive or operate machinery if you feel dizzy.

Eye problems

This can include blurred vision, redness, irritation, pain, loss of vision, or spots before your eyes. Some people have floaters which might appear as moving shapes, shadows or halo’s (blurred outline around objects).  

Eye problems usually get better after you stop taking these drugs.

Let your doctor or nurse know straight away if you have any eye problems.

Bleeding problems

You might bleed from different areas of the body. This includes vomiting or coughing up blood and passing blood in your wee (urine) or poo.

This can be serious. Contact your advice line if you have any bleeding.

High blood pressure

Tell your doctor or nurse if you have headaches, nosebleeds, blurred or double vision or shortness of breath. Your nurse will check your blood pressure regularly.

Tummy (abdominal) pain

Tell your doctor or nurse if you have this. They may give you medicine to help.

Diarrhoea or constipation

Tell your healthcare team if you have diarrhoea or constipation. They can give you medicine to help. 

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.

Skin problems

Skin problems can include a rash, dry skin, itching, and reddening of the skin. Your skin might feel thicker or look crusty, scaly or bumpy.

Your skin might also be more sensitive to the sun and at risk of severe sunburn. It's a good idea to wear sunscreen.

Your doctor will check your skin regularly throughout your treatment.

Let your doctor or nurse know if you’re worried about an area of skin. They might be able to give you something to help.

Hair loss or thinning

Your hair may thin, you might lose hair in certain areas (patches) or it may go completely. It usually grows back when you finish treatment. 

Other areas of hair that might be affected include your eyelashes, eyebrows, underarm, leg and sometimes pubic hair.

Arm, leg, joint, back or muscle pain

You might feel some pain from your arms, legs, muscles or joints. Speak to your doctor or nurse about what painkillers you can take to help with this.

Muscle weakness, spasms and pain

Let your doctor or nurse know if you have any weakness, spasms or pain in your muscles during or after having treatment. 

Your blood tests might show that you have high levels of an enzyme in your blood called creatinine kinase (CK). This is mainly found in the heart, brain or skeletal muscles.

Your doctor might do a blood test to check why you might have chest pain, muscle aches or pains, muscle tenderness or weakness or dark reddish – brown urine.

Fluid build up in your hands and legs

You may have swelling of your hands and legs due to a build up of fluid (oedema). 


Tiredness and weakness (fatigue) can happen during and after treatment. Doing gentle exercises each day can keep your energy up. Don't push yourself, rest when you start to feel tired and ask others for help.

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 levels of chemicals produced by the liver.

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:

  • another type of skin cancer called squamous cell carcinoma (SCC) or basal cell carcinoma (BCC)
  • non cancerous skin growths (skin papilloma)
  • an allergic reaction that can cause a rash, shortness of breath, redness or swelling of the face and dizziness
  • taste changes
  • problems with your heart not pumping properly – you have regular tests to check this
  • blood clots - these can be life threatening. Signs are pain, swelling and redness where the clot is. Feeling breathless can be a sign of a blood clot on the lung. Contact your advice line or doctor straight away if you have any of these symptoms
  • inflammation of your bowel (colitis) – you might have diarrhoea, pain or cramping in your tummy, pass blood in your poo (stool), and lose weight
  • the skin on your hands and feet may get sore, red, blister or peel
  • changes to how well your kidneys work – rarely your kidneys may stop working. You have regular bloods tests to check this
  • changes to how your pancreas is working – you have regular blood tests to check this

Rare side effects

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

  • weakness or unable to move your face muscles – you may slur your words, dribble or not be able to eat or drink properly
  • inflammation of the pancreas (pancreatitis) – you might get severe tummy pain
Let your doctor or nurse know (or go to A&E) if you have any of these side effects.

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 drink

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.

Grapefruit and grapefruit juice

You should not eat grapefruit or drink grapefruit juice when you are taking encorafenib because it can react with the drug and make side effects worse.

Lactose intolerance

Binimetinib contains lactose (milk sugar). Contact your doctor before taking this medicine if you have an intolerance to lactose.

Driving and use of machinery

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


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.


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

Pregnancy and contraception

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 month afterwards. Talk to your doctor or nurse about effective contraception before starting treatment.

If you are taking hormonal contraceptives like the pill, you should also use another barrier method such as a condom. This is because encorafenib affects how well hormonal contraceptives work.

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 one of the shingles vaccines called Zostavax.

You can 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 it in relation to your cancer treatment

Members of your household who are aged 5 years or over are also able to have the COVID-19 vaccine. This is to help lower your risk of getting COVID-19 while having cancer treatment and until your immune system Open a glossary item recovers from treatment.

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. Sometimes people who have had the live shingles vaccine can get a shingles type rash. If this happens they should keep the area covered.

If your immune system is severely weakened, you should avoid contact with children who have had the flu vaccine as a nasal spray as this is a live vaccine. 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.

This page is due for review. We will update this as soon as possible.

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