Chronic myeloid leukaemia (CML) treatment and side effects

You might also want to read our general information about how blood cancer treatment is planned and managing your treatment.

We also have some important information on staying safe if you’ve got blood cancer, covering things like risk of infection and vaccinations.

The aim of treatment for CML is to reduce the number of leukaemia cells in your body to low enough levels for you to have a normal life expectancy. The most common treatment for CML is a targeted therapy drug called a tyrosine kinase inhibitor (TKI), which is taken daily in tablet form (orally).

If your white blood cell count is high and/or you have a lot of symptoms and feel unwell when doctors first suspect you have CML, your doctor may give you a mild chemotherapy tablet, known as hydroxycarbamide.

This will lower the number of blood cells in your bloodstream and control your symptoms until your diagnosis is confirmed.

If you’re given hydroxycarbamide, you’ll usually also be given another tablet called allopurinol. This is to prevent gout (which happens when uric acid builds up in the blood), which can be a side effect of hydroxycarbamide.

If you're diagnosed with blast phase CML, your doctor may then recommend stronger chemotherapy.

If your white blood cell count is very high, and particularly if you have certain symptoms such as blurred vision, your doctors might advise removing some white blood cells from your bloodstream in a process called leukapheresis.

In this procedure, a plastic tube will be inserted into each arm. Your blood will drain from one tube into a machine (centrifuge) which will be spinning at high speed. The spinning separates the blood into white blood cells, red blood cells and plasma.

The white blood cells are removed and either thrown away or, with your agreement, could be used for research. The red blood cells and plasma are then returned to your body through the tube in your other arm.

At any one time no more than a cupful of blood will be in the centrifuge and the procedure is very safe. As the procedure can take two to three hours to lower your white blood cell count in this way, you may want to bring something to keep you entertained, like a book or tablet. The leukapheresis will be done by a specially trained nurse, who will talk you through the procedure.

Once your diagnosis is confirmed, your doctors will usually prescribe a targeted therapy drug called a tyrosine kinase inhibitor (TKI).

It’s important that you take your TKI exactly as directed by your doctor. Evidence shows that if you do, you’ll have a better response to the treatment. Your healthcare team can help you with this.

At the moment, most people with chronic-phase CML are advised to take their TKI for life. However, growing research suggests that it’s safe for some people who are doing well on TKIs (and who have been taking them for five years or more with a deep molecular response for at least two years) to reduce their dose or potentially stop taking them altogether, as long as they continue to be closely monitored by their doctor.

This won’t be suitable for everyone, so it’s very important that you don’t stop taking your TKI unless your doctor tells you to. Otherwise, the number of leukaemia cells in your blood could increase and you’ll be at greater risk of progressing to the accelerated or blast phases. If you have any questions about your treatment plan, your healthcare team will be able to talk you through it.

If TKIs don't work for you, or if you're diagnosed with blast phase CML and treatment gets you back to the chronic phase, your doctor may recommend a stem cell transplant.

If you’d like to find out more about clinical trials for CML, speak to your healthcare team. You can also visit the NHS website Be Part of Research.