Asciminib (Scemblix®)

Asciminib (Scemblix®) belongs to a group of targeted therapy drugs called tyrosine kinase inhibitors (TKIs). It is used to treat chronic myeloid leukaemia (CML).

It is used when the leukaemia cells have a genetic change called the Philadelphia chromosome (Philadelphia chromosome positive). Your doctor can test your blood or bone marrow to look for the Philadelphia chromosome.

It may sometimes be used to treat other cancers. It is best to read the information about this drug with our general information about targeted therapy drugs and the type of cancer you have.

Your cancer doctor, nurse or pharmacist will talk to you about this treatment and its possible side effects before you agree (consent) to have treatment.

More information about this treatment

This information is correct at time of publishing. But sometimes the types of cancer this treatment is used for, or treatment side effects, may change between revision dates.

You can talk to your cancer team if you want more detailed information about this treatment. Or visit the electronic Medicines Compendium (eMC) website, which has patient information leaflets (PIL) for individual drugs.

How asciminib is given

Asciminib comes as tablets you take at home. During treatment, you usually see a:

  • blood cancer doctor (haematologist)
  • cancer nurse or specialist nurse
  • specialist pharmacist.

This is who we mean when we mention doctor, nurse or pharmacist in this information.

During treatment, a nurse or person trained to take blood (phlebotomist) will take regular blood samples from you. This is to check that it is safe for you to keep taking your treatment.

You will speak to a doctor, nurse or pharmacist regularly during treatment. They will ask how you have been feeling and check your blood results are okay.

Your course of treatment

You usually take asciminib for as long as it is working for you and any side effects can be managed. Do not stop taking it without talking to your doctor.

Taking asciminib tablets

The nurse or pharmacist will give you the tablets to take home. Always take them exactly as explained. This is important to make sure they work as well as possible for you. You may be given tablets of different strengths.

You take asciminib once or twice a day. Your doctor, nurse or pharmacist will explain how, and when, to take the tablets. Try to take them at the same time every day. 

You should not take asciminib with food. Take the tablets at least 2 hours after eating, then wait at least 1 hour before eating again. Swallow them whole with a glass of water. Do not break, chew or crush them. Take them at the same time every day.

If you forget to take your tablets, do not take a double dose to make up for the missed dose.

  • If you take your tablets once a day and you forget to take a dose, take them as soon as you remember. But if you are more than 12 hours late taking a dose, skip the dose and take your next dose at the usual time. 
  • If you take your tablets twice a day and you forget to take a dose, take them as soon as you remember. But if you are more than 6 hours late taking a dose, skip the dose and take your next dose at the usual time. 
  • If you are sick just after taking the tablets, do not take another dose. Take the next dose at the usual time.

Other things to remember about your tablets:

  • Wash your hands after taking your them.
  • Other people should avoid direct contact with them.
  • Keep them in the original package and at room temperature, away from moisture, heat and direct sunlight.
  • Keep them safe, somewhere children cannot see or reach them. 
  • If your treatment is stopped, return any unused tablets to the pharmacist.

Lactose

This treatment may contain lactose. If you have a lactose allergy or intolerance, ask your doctor, nurse or pharmacist for more information.

About side effects

We explain the most common side effects of this treatment here. We also include some that are less common. 

You may get some of the side effects we mention, but you are unlikely to get all of them. And you may have some side effects, including rarer ones, that we have not listed here. 

Other cancer treatments may cause different side effects. If you are also having other cancer treatment, you may have other side effects.

Always tell your doctor, nurse or pharmacist about any side effects you have. They can give you: 

  • drugs to help control some side effects 
  • advice about managing side effects. 

It is important to take any drugs exactly as explained. This means they will be more likely to work for you.

Serious and life-threatening side effects

Some cancer treatments can cause serious side effects. Sometimes, these may be life-threatening. Your doctor, nurse or pharmacist can explain the risk of these side effects to you.

Contact the hospital

Your doctor, nurse or pharmacist will give you 24-hour contact numbers for the hospital. If you feel unwell or need advice, you can call at any time of the day or night. Save these numbers in your phone or keep them somewhere safe.

Common side effects

Risk of infection

This treatment can reduce the number of white blood cells in your blood. These cells fight infection. If your white blood cell count is low, you may be more likely to get an infection. A low white blood cell count is called neutropenia.

An infection can be very serious when the number of white blood cells is low. It is important to get any infection treated as soon as possible. If you have any of the following symptoms, contact the hospital straight away on the 24-hour number:

  • a temperature above 37.5°C 
  • a temperature below 36°C
  • you feel unwell, even with a normal temperature
  • you have symptoms of an infection.

Symptoms of an infection include:

  • feeling shivery and shaking
  • a sore throat
  • a cough
  • breathlessness
  • diarrhoea
  • needing to pass urine (pee) often, or discomfort when you pass urine.

It is important to follow any specific advice your cancer treatment team gives you.

You will have regular blood tests during treatment. If your white blood cell count is low, your doctor may stop your treatment for a short time, until your cell count increases. Sometimes they will reduce the dose of your treatment.

Bruising and bleeding

This treatment can reduce the number of platelets in your blood. Platelets are cells that help the blood to clot.

If the number of platelets is low, you may bruise or bleed easily. You may have:

  • nosebleeds
  • bleeding gums
  • heavy periods
  • blood in your urine (pee) or stools (poo)
  • tiny red, brown or purple spots that may look like a rash – these spots can be harder to see if you have black or brown skin. 

If you have any unexplained bruising or bleeding, contact the hospital straight away on the 24-hour number. You may need a drip to give you extra platelets. This is called a platelet transfusion.

Anaemia (low number of red blood cells)

This treatment can reduce the number of red blood cells in your blood. Red blood cells carry oxygen around the body. If the number of red blood cells is low, this is called anaemia. You may feel:

  • very low in energy
  • breathless 
  • dizzy and light-headed. 

If you have these symptoms, contact the hospital straight away on the 24-hour number. You may need treatment for anaemia. If you are very anaemic, you may need a drip to give you extra red blood cells. This is called a blood transfusion.

Tummy pain

You may get mild pain in your tummy (abdomen) or have indigestion. Your doctor, nurse or pharmacist can give you drugs to help improve these symptoms.

Sometimes tummy pain can be a sign of a more serious problem called pancreatitis. Tell your doctor, nurse or pharmacist if the pain gets worse or does not get better.

Effects on the pancreas

This treatment can cause inflammation of the pancreas (pancreatitis). You will have regular blood tests to check your pancreas.

Contact the hospital straight away on the 24-hour telephone number you have been given if you have any of these symptoms:

  • severe pain in the centre of your tummy area (upper abdomen)
  • tenderness or swelling of the tummy
  • fast heartbeat (tachycardia)
  • rapid breathing
  • a temperature of 37.5°C or more (fever)
  • yellow skin or eyes
  • feeling sick (nausea) or being sick (vomiting)
  • indigestion.

Effects on the liver

This treatment may affect how your liver works. You will have regular blood tests to check how well your liver is working. 

Diarrhoea

This treatment may cause diarrhoea. Diarrhoea means passing more stools (poo) than is normal for you, or having watery or loose stools. You may also have stomach cramps. If you have a stoma, it may be more active than usual. 

If you are passing loose stools 3 or more times a day and this is not normal for you, contact the hospital as soon as possible on the 24-hour number. Follow the advice they give you about:

  • taking anti-diarrhoea medicines 
  • drinking enough fluids to keep you hydrated and to replace lost salts and minerals
  • any changes to your diet that might help. 

They might also ask you for a specimen of your stool to check for infection.

Feeling sick

You may feel sick with this treatment. Your doctor, nurse or pharmacist may prescribe you anti-sickness drugs to help prevent or control sickness. Take the drugs exactly as they tell you to. If you feel sick, take small sips of fluid often and eat small amounts regularly. It is important to drink enough fluids.

If you continue to feel sick, or if you are sick (vomit) 1 to 2 times in 24 hours, contact the hospital on the 24-hour number as soon as possible. They will give you advice. 

Headaches and dizziness

This treatment may cause headaches and dizziness. If you have these symptoms, tell your doctor, nurse or pharmacist. They may give you medicines to help.

Muscle or joint pain (general)

You may get pain in your muscles or joints during treatment. If this happens, tell your doctor, nurse or pharmacist. They can give you painkillers and advice. They can also tell you if any of the painkillers you usually take are suitable.

Tell them if the pain does not get better. Having warm baths and resting regularly may help.

Feeling tired (fatigue)

Feeling tired is a common side effect of this treatment. Try to pace yourself and plan your day so you have time to rest. Gentle exercise, like short walks, can help you feel less tired. If you feel sleepy, do not drive or operate machinery.

Loss of appetite

This treatment can affect your appetite. Don’t worry if you do not eat much for 1 or 2 days. But if your appetite does not come back after a few days, or if you are losing weight, tell your doctor, nurse or pharmacist. They can give you advice. They may give you food or drink supplements. Or they may suggest changes to your diet or eating habits to help.

Skin changes

This treatment may affect your skin. It might feel dry. You may develop a rash, which may be itchy. Always tell your doctor, nurse or pharmacist about any skin changes. They can give you advice or prescribe creams or medicines to help.

If your skin feels dry, try using soap-free cleansers and unperfumed moisturising cream every day.

Effects on the lungs

This treatment can cause changes to the lungs. It can sometimes cause fluid to build up in the lining of the lungs. This is called pleural effusion. Tell your doctor if you develop:  

  • a cough that does not go away
  • wheezing 
  • breathlessness. 

You should also tell them if any existing breathing problems get worse. You may have tests to check your lungs. 

Fluid build-up

This treatment can cause a build-up of fluid in the body. This will slowly get better after treatment ends. Contact the hospital on the 24-hour number if you:

  • are gaining weight 
  • have swelling in your face, legs or ankles.

They can give you advice and treatment to help.

Raised cholesterol level

This treatment can raise the level of cholesterol. This is a fatty substance in the blood. You may have a blood test to check the level of cholesterol. Your doctor may refer you to a dietitian for advice on diet, or prescribe medicines to control your cholesterol levels.

Less common side effects

Effects on the heart

This treatment can affect how the heart works. You may have tests to check how well your heart is working. These may be done before, during and after treatment.

If the treatment is causing heart problems, your doctor may change the type of treatment you are having.

Contact the hospital straight away on the 24-hour number if you have any of these symptoms during or after treatment:

  • breathlessness
  • dizziness
  • changes to your heartbeat
  • swollen feet and ankles.

Other conditions can cause these symptoms, but it is important to get them checked by a doctor. 

Always call 999 if you have:

  • chest pain, pressure, heaviness, tightness or squeezing across the chest
  • difficulty breathing.

High blood pressure

This treatment can cause high blood pressure. Your nurse will regularly check your blood pressure during treatment. Let them know if you have any headaches.

Eye problems

This treatment may make your eyes feel dry. Tell your doctor, nurse or pharmacist if you have this so they can suggest things to help.

This treatment can also cause blurry vision. Always tell your doctor, nurse or pharmacist if you notice changes to your eyesight. Do not drive if you notice this.

Allergic reaction

Some people have an allergic reaction while having this treatment. Sometimes a reaction happens a few hours after taking your tablets. Signs of a reaction can include:

  • feeling hot or flushed
  • shivering
  • itching
  • a skin rash
  • feeling dizzy or sick
  • a headache
  • feeling breathless or wheezy
  • swelling of your face or mouth
  • pain in your back, tummy or chest.

If you feel unwell or have any of these signs, contact the hospital on the 24-hour number straight away. If you have a reaction, it can be treated quickly.

Other important information

Blood clot risk

Cancer and some cancer treatments can increase the risk of a blood clot. Contact the hospital straight away on the 24-hour number if you have any of these symptoms during or after treatment:

  • throbbing pain or swelling in a leg or arm
  • reddening of the skin in the area – if you have black or brown skin, this can be harder to notice, but the skin might become darker
  • suddenly feeling breathless or coughing.

Always call 999 if you have:

  • chest pain
  • difficulty breathing.

A blood clot is serious, but it can be treated with drugs called anticoagulants. These thin the blood. Your doctor, nurse or pharmacist can give you more information about preventing and treating blood clots.

Other medicines

Some medicines can affect how this treatment works or be harmful while you are having it. Always tell your cancer doctor, nurse or pharmacist about any drugs you are taking or planning to take, such as: 

Vaccinations

Doctors usually recommend that people with cancer have vaccinations for flu and for coronavirus (covid). These help reduce your risk of serious illness from these infections. Most people can have these vaccines, including people with weak immune systems.

If your immune system is weak, you should not have live vaccinations. Live vaccines can make you unwell because they contain a very weak version of the illness they will protect you against. Live vaccines include Zostavax®, which is a shingles vaccine, and the yellow fever vaccine.

It is important to ask your doctor, nurse or pharmacist for advice about having vaccinations. They can explain what vaccines are right for you and when it is best to have them.

Hepatitis B reactivation

If you have had a liver infection called hepatitis B in the past, this treatment can make it active again. Your doctor or nurse will talk to you about this. They will test you for hepatitis B.

Contraception

Your doctor, nurse or pharmacist will advise you not to get pregnant or make someone pregnant while having this treatment and for some time afterwards. The drugs may harm a developing baby. It is important to use contraception to prevent pregnancy. Follow their advice about:

  • what types of contraception to use 
  • how long after treatment you should continue to use contraception. 

Breastfeeding

You are advised not to breastfeed while having this treatment, or for some time after treatment ends. This is because the drugs could be passed to the baby through breast milk. 

Your doctor, nurse or pharmacist can give you more information.

Fertility

Some cancer drugs can affect whether you can get pregnant or make someone pregnant. If you are worried about this, it is important to talk with your doctor before you start treatment.

Medical and dental treatment

If you need medical treatment for any reason other than cancer, always tell the healthcare professional that you are having cancer treatment. Give them the contact details for your cancer doctor or cancer team so they can ask for advice.

If you have appointments with a dentist, always tell them you are having cancer treatment. Talk to your cancer team before you have any dental treatment.

Date reviewed

Reviewed: 01 June 2024
|
Next review: 01 June 2026
Trusted Information Creator - Patient Information Forum
Trusted Information Creator - Patient Information Forum

Our cancer information meets the PIF TICK quality mark.

This means it is easy to use, up-to-date and based on the latest evidence. Learn more about how we produce our information.