This information is about a drug called dasatinib, which is also known as Sprycel®. Dasatinib may be used to treat people with chronic myeloid leukaemia (CML), who are no longer being helped by imatinib (Glivec®). It can also be used to treat adults with Philadelphia chromosome positive (Ph+) acute lymphoblastic leukaemia (ALL).

Although dasatinib is licensed and can be prescribed in the UK, it has not yet been assessed by the National Institute for Health and Clinical Excellence (NICE). NICE gives advice on which new drugs or treatments should be available on the NHS. As a result, dasatinib may not be widely available on the NHS.

For more information see our section on what you can do if a treatment isn't available.

You may be given dasatinib as part of a clinical trial. Dasatinib has been approved by the Scottish Medicines Consortium (an organisation similar to NICE) for some people with CML.

Dasatinib works by blocking (inhibiting) signals within cancer cells that cause the cell to grow and divide.

The growth of cells in our bodies is controlled by signals that switch on and off within the cells. When the signals for growth are switched on the cells are triggered to grow and multiply. People with chronic myeloid leukaemia have an abnormal signaling protein inside their leukaemia cells. This abnormal protein sends out grow-and-divide signals to the cells at all times and never switches off.

Dasatinib finds the faulty protein and locks onto it. This prevents the protein from stimulating the cells to grow. Dasatinib is known as a signal transduction inhibitor, because it blocks the 'grow' signal. The chemical it blocks is called tyrosine kinase, so dasatinib is also known as a tyrosine kinase inhibitor.

Dasatinib is normally taken once or twice daily as directed by your doctor. It is available as 20mg, 50mg and 70mg tablets or capsules. The tablets should be taken with a large glass of water with or without a meal. They should not be crushed or broken. You will usually take dasatinib for as long as it is helping you.

Each person's reaction to dasatinib is different. Some people have very few side effects, while others may experience more. If you notice any effects which you think may be due to the drug, but which aren’t mentioned here, please discuss them with your doctor.

The side effects of dasatinib are generally mild or moderate and usually stop once treatment is ended. However, sometimes, more serious problems can occur. Side effects are most common during the first two months of treatment and may begin to gradually disappear after this. However, late side effects can occur. Check with your doctor if any side effects continue or are troublesome.

Lowered resistance to infection Dasatinib can reduce the numbers of white blood cells made in the bone marrow. This makes you more prone to infection. Your blood cell numbers (blood count) will be monitored while you are taking dasatinib. If the blood count is too low, your doctor may ask you to stop taking dasatinib or reduce the dose for a time.

Contact your doctor or the hospital immediately if:

• Your temperature goes above 38ºC (100.5ºF)
• You suddenly feel unwell (even with a normal temperature)
• You notice any signs that you may have an infection.

Bruising or bleeding Dasatinib can reduce the numbers of platelets (which help the blood to clot) in your blood. Having low numbers of platelets increases your chance of bleeding. This can affect people in different ways. For example, your gums may bleed, or you may bruise more easily or notice blood in your urine or stools. If you notice any unusual bleeding contact your doctor immediately. You may need to have a transfusion of platelets if the levels in your blood are low.

Anaemia (low number of red blood cells) You may become anaemic while having treatment with dasatinib. This may make you feel tired and breathless. You may need to have a transfusion of blood if the number of red blood cells becomes too low.

Fluid retention This can affect different parts of your body. Most commonly it causes swelling of the ankles or swelling around the eyes. Drugs which make you pass more urine, called diuretics, can help to get rid of some of the fluid. A short course of steroids may also be helpful. However, fluid retention often settles without treatment.

Sometimes fluid may collect in the lining of the lungs, (pleural effusion) or rarely in the abdominal space (ascites) or in the sac around the heart (pericardial effusion).

If you develop a cough, chest pain, are feeling more breathless than usual or if you gain weight suddenly let your doctor know straight away.

Diarrhoea You may have frequent or loose bowel movements. Tell your doctor if this is severe or if it continues. It's important to drink plenty of fluids if you have diarrhoea.

Feeling sick (nausea) This is quite common but is usually easy to control. Your doctor can prescribe effective anti-sickness (anti-emetic) drugs to prevent or greatly reduce nausea. It may also be helped by taking your tablet with food.

Headaches These are common. Let your doctor know if you get headaches as painkillers can be given to help.

Muscle and bone pain Some people have muscle, joint or bone pain while on treatment. Your doctor can prescribe painkillers if you are affected by muscle and bone pain.

Skin changes Rashes, dryness, itching, increased sweating or greater sensitivity to sunlight are quite common. These side effects are usually mild. Speak to your doctor or nurse if you have any of these skin changes. They can advise you about creams or lotions to use, or prescribe medicines to relieve itching.

Tiredness and feeling weak This is common but is usually mild. It's important to allow yourself plenty of time to rest.

Abdominal (tummy) pain Some people have pain or discomfort in their tummy when taking dasatinib.

Effects on the eyes Your eyes may become dry, or you may notice changes to how well you can see, such as blurred vision. In some people this may affect their ability to drive safely. Tell your doctor if you notice any of these changes.

Loss of appetite If you don't feel like eating it may be helpful to speak to a dietitian at the hospital.

Dizziness Some people have episodes of dizziness or feel lightheaded at times. If you have this tell your doctor. It may affect your ability to drive.

Changes in sensation in hands and feet Occasionally dasatinib can cause tingling or numbness in the hands or feet. This may cause you difficulty with tasks such as doing up small buttons. Let your doctor know if you are affected.

Sore mouth and ulcers Your mouth may become sore, or you may notice small ulcers during this treatment. Drinking plenty of fluids and cleaning your teeth regularly can help. Tell your nurse or doctor if you have mouth problems. They may prescribe mouthwashes and medicines to prevent or clear any mouth infection.

Constipation It usually helps to drink plenty of fluids, eat a high fibre diet and take gentle exercise. Sometimes you may need to take medicines to stimulate your bowel. Your doctor can prescribe these.

Changes to heart rhythm A small number of people may notice a change in their heart rhythm. Heart beats may become less regular or the heart my feel as if it is beating too fast. If you notice any changes in your heart rhythm let your doctor know immediately.

Other medicines Some medicines can interact with dasatinib and may make it less effective or increase side effects. Always tell your doctor about any other medicine you are taking, including those bought over the counter and herbal medicines.

Contraception It is not advisable to become pregnant or father a child while taking this treatment. It is important to use effective contraception while taking this drug, and for at least a few months afterwards.

Fertility More research needs to be done to find out how dasatinib may affect fertility.

Breast feeding Dasatinib may be passed on in breast milk. Breast feeding, therefore, should be stopped before starting treatment.

Things to remember about dasatinib tablets:

• It is important to take your tablets at the right times. You must take them as directed by your doctor.
• Store the tablets at room temperature.
• Keep them in a safe place where children cannot reach them, as dasatinib could harm them.
• If your doctor decides to stop the treatment, return any tablets you have to the pharmacist. Do not flush them down the toilet or throw them away.
• If you forget to take a tablet don’t take a double dose. Tell your doctor and keep to your regular dose schedule.

If you have any questions about these or any other side effects talk to your doctor or nurse. It is important to let them know if you are having any symptoms or side effects that may be related to any treatment you are having

This section has been compiled using information from a number of reliable sources including:

• Martindale: The Complete Drug Reference (35th edition) Eds Sweetman et al. Pharmaceutical Press, 2006.
• British National Formulary (55th edition). British Medical Association and Royal Pharmaceutical Society of Great Britain, March 2008.

For further references, please see the general bibliography.