Dasatinib

Dasatinib is pronounced das-at-in-nib and is also known by its brand name Sprycel. It is a type of biological therapy called a protein tyrosine kinase inhibitor (TKI). Tyrosine kinases are proteins that act as chemical messengers to stimulate cancer cells to grow.

Dasatinib blocks and interferes with how cells make a number of protein kinases and is called a multi kinase inhibitor. It works by blocking the signals that tell the cells to grow.

Dasatinib is a treatment for

• Chronic myeloid leukaemia - it is licensed for people who have already had other treatments including imatinib
• Acute myeloid leukaemia which is Philadelphia chromosome positive when other treatments are no longer working
• Acute lymphoblastic leukaemia which is Philadelphia chromosome positive when other treatments are no longer working

It is also being used in clinical trials for melanoma.

Dasatinib is a tablet that you swallow whole with a glass of water. You can take it with or without food. Dasatinib can interact with some other drugs and herbal remedies. Tell your doctor if you are taking any other medicines.

You have dasatinib either once or twice a day. You usually carry on taking it for as long as it works, unless the side effects get too bad.

If you are taking any medicines for indigestion (antacids), take them either 2 hours before or 2 hours after the dasatinib as they stop the stomach absorbing dasatinib. You should not take any other medicines that affect the production of stomach acid.

It is very important that you take tablets according to the instructions your doctor or pharmacist gave you. You should take the right dose, not more or less. And never stop taking a cancer drug without talking to your specialist first.

The side effects associated with dasatinib are listed below. Remember that you may only have a few of them.

More than 10 in every 100 people have one or more of the side effects listed below.

Temporary drop in the number of blood cells made by the bone marrow, causing

• Increased risk of getting an infection from a drop in white blood cells - it is harder to fight infections and you can become very ill. You may have headaches, aching muscles, a cough, sore throat, pain passing urine or feel cold and shivery. 
• Tiredness and breathlessness due to a drop in red blood cells (anaemia) - you may need a blood transfusion
• Bruising more easily due to a drop in platelets - you may have nosebleeds, bleeding gums after brushing your teeth, or lots of tiny red spots or bruises on your arms or legs (known as petechia).

Some of these side effects can be life threatening, particularly infections.  You should contact your doctor if you have any of these side effects.  Your doctor will check your blood counts regularly to see how well your bone marrow is working

Other common side effects include

• Diarrhoea affects 3 out of 10 people (30%) - drink plenty of fluids and tell your doctor if it becomes severe or lasts for more than 3 days
• Headaches affect 1 in 4 people (25%)
• Fluid around the lungs (pleural effusion) affects 1 in 4 people (25%) and can be a serious problem - if you are breathless or have a cough contact your doctor as soon as possible
• Skin changes occur in just over 1 out 5 people (20%) and you may have a rash or red, dry, itchy skin - this can be difficult to cope with so tell your doctor or nurse
• Fluid build up in the body affects 1 out 5 people (20%) - you may need to take tablets to reduce the amount of fluid. It can build up anywhere including your legs, face and around your organs
• Tiredness (fatigue) affects just over 1 out of 5 people (20%) during and after treatment - most people find their energy levels are back to normal within 6 months to a year
• Feeling and being sick affects just over 1 in 5 (20%) people, but is usually well controlled with anti sickness drugs
• Bone and muscle pain occurs in 1 out of 10 people (10%)
• Loss of fertility - we don’t know exactly how this drug may affect fertility so talk to your doctor before starting treatment if this is important to you
• We don’t know whether dasatinib can harm a developing baby - do talk to your doctor about contraception before having treatment if there is any chance you or your partner could become pregnant

Between 1 and 10 in every 100 people have one or more of these.

• Numbness or tingling in fingers and toes can cause difficulty with fiddly things such as doing up buttons - this starts within a few days or weeks and usually goes within a few months of finishing treatment
• Indigestion occurs in less than 1 in 10 people (10%)
• Loss of appetite
• Aching joints
• A sore mouth
• Hair thinning
• Dizziness
• Eye problems - these include blurred vision, dry eyes and infections

A few people may have heart problems including chest pain. You must contact your doctor as soon as possible if you have any pain.

Not everyone will get these side effects. You may have none or several. A side effect may get worse through your course of treatment. Or you may have more side effects as the course goes on. This depends on

• How many times you've had a drug before
• Your general health
• How much of the drug you have (the dose)
• Other drugs you are taking

Talk to your doctor, pharmacist or nurse about all your side effects so they can help you manage them.

Tell your doctor about any other medicines you are taking, including vitamins, herbal supplements and other over the counter remedies - some drugs can react together.

You should not have immunisations with live vaccines while you are having chemotherapy or for at least 6 months afterwards. In the UK, these include rubella, mumps, measles (usually given together as MMR), BCG and yellow fever. You can have other vaccines, but they may not give you as much protection as usual until your immune system has fully recovered from your chemotherapy.

It is safe for you to be in contact with other people who've had live vaccines as injections. There can be problems with oral vaccines, but not many people in the UK have oral vaccines now. So there is usually no problem in being with any baby or child who has recently had any vaccination in the UK. You might need to make sure that you aren't in contact with anyone who has had oral polio, cholera, or typhoid vaccination recently, particularly if you live abroad.