Cancer drugs A to Z list
Encorafenib and cetuximab are . Targeted cancer drugs work by ‘targeting’ the differences that help a cancer cell to survive and grow.
Encorafenib is also known as Braftovi. Cetuximab is also known as Erbitux. You pronounce encorafenib as en-ko-raf-e-nib. Cetuximab is pronounced se-tux-i-mab.
You have these drugs if has stopped working and you have both a:
BRAF change () called BRAF V600E
normal RAS gene (also called RAS wild type)
You have tests on your bowel cancer cells to check for these gene changes.
Get more information on advanced bowel cancer
Encorafenib is a type of cancer growth blocker. It works by targeting certain proteins that help cancer cells grow. By blocking these proteins, it stops or slows down the growth of cancer cells.
Go to information about cancer growth blockers
Cetuximab is a type of monoclonal antibody. Monoclonal antibodies (mAbs) are made in the laboratory. They seek out cancer cells by targeting particular proteins on their cell surface.
Find out more about monoclonal antibodies
You have cetuximab as a drip into your bloodstream. You take encorafenib as capsules.
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.
You swallow the capsules whole with a glass of water. You can take them with or without food.
For people who are unable to swallow, encorafenib capsules can be opened and mixed in a small quantity (about 20 ml) of apple sauce and taken immediately.
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 miss a dose.
You have encorafenib and cetuximab as cycles of treatment. This means that you have the drugs and then a rest to allow your body to recover. Each cycle of treatment lasts 28 days (4 weeks).
You take encorafenib capsules once a day, continuously for the 28 days of your cycle. You have cetuximab as a drip into your bloodstream on day 1 and day 15.
You have cetuximab over about 2 hours the first time you have it. If you don’t have any problems, the following treatments take around an hour.
You usually take encorafenib and cetuximab for as long as it is working and you are not experiencing too many side effects.
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.
Before treatment starts you may have a blood test to check for viruses such as hepatitis B, hepatitis C, and This is called a viral screen.
It’s important for your doctor to know if you have had any of these viruses. This is because this treatment can weaken your and can cause the virus to become active again (reactivation).
You have an before and regularly during this treatment to check for how well your heart is working.
Go to information about having and ECG
Side effects can vary from person to person. They also depend on what other treatment you are having.
Your doctor, nurse, or pharmacist 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
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.
These side effects happen in more than 10 in 100 people (more than 10%). You might have one or more of them. They include:
Tell your healthcare team straightaway if you get a high temperature. Ask them if you can take paracetamol to help lower your temperature.
A reaction may happen while you have cetuximab or at a later time. Symptoms can include dizziness, difficulty breathing, fever, chills, feeling faint, chest pain and an itchy raised red rash (hives). This can be life threatening, but this happens less often.
Your nurse will give you medicines beforehand to try to prevent a reaction.
Cetuximab can cause low levels of magnesium in the body. This can cause muscular weakness, spasms and tremors. Your doctor will do regular blood tests to check for this. You might have magnesium if your levels become too low. Let your healthcare team know if you are having any of these symptoms.
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.
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.
You might lose your appetite for various reasons while having cancer treatment. Sickness, taste changes or tiredness can put you off food and drinks.
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 healthcare team if you keep getting headaches. They can give you painkillers to help.
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.
You might bleed from different areas of the body. This can be serious.
Symptoms of bleeding can include a severe headache - its often described as a thunderclap. Feeling or being sick, confused, dizziness, changes to your speech or eyesight, weakness or numbness on one side of the body.
You might vomit or cough up blood. You might pass blood when you pee or poo. You might bleed in between your periods (menstrual cycle) and it might be heavier than usual.
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 , 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.
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.
Also tell your doctor about any changes to your bowel habits.
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.
You might feel some pain in your tummy (abdomen), arms, legs, muscles, joints or back. Speak to your doctor or nurse about what painkillers you can take to help with this.
Skin changes can include new moles and non cancerous skin tumours. These are also called skin papilloma’s.
You might develop an acne like rash, itchy dry, cracked or irritated skin. Your skin tone may change to become lighter or darker. Your skin might feel thicker or peel.
In some people the skin on your hands and feet may get sore, blister or peel. You may also have tingling, numbness, pain and dryness. This is called hand-foot syndrome or palmar plantar syndrome.
You are at an increased risk of developing skin cancer. This is a less common side effect. Your doctor will check your skin regularly throughout your treatment.
Rarely some people can get a severe skin reaction that may start as tender red patches which leads to peeling or blistering of the skin. You might also feel feverish, and your eyes may be more sensitive to light. This is serious and could be life threatening.
Mouth sores and ulcers can be painful. Keep your mouth and teeth clean, drink plenty of fluids, avoid acidic foods such as oranges and lemons, chew gum to keep the mouth moist and tell your doctor or nurse if you have ulcers.
Let your doctor or nurse know if you have any weakness or you experience any twitching, jerking or cramping in your muscles during or after having this treatment.
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.
Taste changes might make you go off certain foods and drinks. You may also find that some foods taste different from usual or that you prefer to eat spicier foods. Your taste gradually returns to normal a few weeks after your treatment finishes.
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:
feeling dizzy
a fast heartbeat
changes to how your kidneys work, including your kidneys may stop working – symptoms might include not passing enough pee, breathlessness, feeling tired and weak, confused, feeling sick, and you might have swelling on your legs, ankles and feet. You have regular blood tests to check this
eyesight changes, you might get an eye infection (conjunctivitis) that can make your eyes feel gritty, itchy, sticky from pus, watery and look red. Rarely you might get of the middle of the eyes, eyelids or the clear dome shaped surface of the eye (cornea). Let your team know if you have any eye problems
a lack of water in the body (dehydration)
low levels of calcium in the blood
problems with your . Blood tests might show you have pancreatic changes. Rarely this treatment can cause inflammation of the pancreas. Symptoms can include severe tummy pain, feeling or being sick, a high temperature or diarrhoea
These side effects happen in fewer than 1 in 100 people (fewer than 1%). You might have one or more of them. They include:
blood clots that can be life threatening; signs are pain, redness and swelling where the clot is. Feeling breathless can be a sign of a blood clot in the lung. Contact your advice line or doctor straight away if you have any of these symptoms
inflammation, stiffening and scarring of the lung tissue (interstitial lung disease). Some of the symptoms include shortness of breath when you’re resting. Or it may get worse with movement or activity. You might have a dry cough and feel very tired and weak
We have more information about side effects and tips on how to cope with them.
Read more about how to cope with side effects
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.
It is not known whether this treatment affects in people. Talk to your doctor before starting treatment if you think you may want to have a baby in the future.
Men might be able to store sperm before starting treatment. And women might be able to store eggs or ovarian tissue. But these services are not available in every hospital, so you would need to ask your doctor about this.
It is not known whether these drugs come through into the breast milk. Doctors usually advise that you don’t breastfeed during this treatment and for 2 months after your last treatment.
This drug may harm a baby developing in the womb. It is important not to become pregnant or get someone pregnant while you are having treatment with this drug and for at least a month afterwards.
If you are taking hormonal contraceptives like the pill, you should also use another barrier method such as a condom for at least a month. This is because encorafenib affects how well hormonal contraceptives work.
Talk to your doctor or nurse about effective contraception before starting treatment. Let them know straight away if you or your partner become pregnant while having treatment.
If you are having tests or treatment for anything else, always mention your cancer treatment. For example, if you are visiting your dentist.
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.
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 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
For further information about this treatment and possible side effects go to the electronic Medicines Compendium (eMC) website. You can find the patient information leaflet on this website.
You can report any side effect you have to the Medicines and Healthcare products Regulatory Agency (MHRA) as part of their Yellow Card Scheme.
Last reviewed: 23 Jan 2026
Next review due: 23 Jan 2029
Bowel cancer means cancer that starts in the colon (large bowel) or back passage (rectum). It is also known as colorectal cancer.
Cancer drugs have side effects and these can vary from person to person. But there are things that you can do to help you cope.
Coping with cancer can be difficult. There is help and support available. Find out about the emotional, physical and practical effects of cancer and how to manage them.
Targeted cancer drugs work by ‘targeting’ the differences that help a cancer cell to survive and grow. They are one of the main treatments for some cancers.
About Cancer generously supported by Dangoor Education since 2010. Learn more about Dangoor Education
Search our clinical trials database for all cancer trials and studies recruiting in the UK.
Connect with other people affected by cancer and share your experiences.
Questions about cancer? Call freephone 0808 800 40 40 from 9 to 5 - Monday to Friday. Alternatively, you can email us.
