Chronic myeloid leukaemia (CML) is one of the cancers where tablets have changed the outlook most. Most people take a tyrosine kinase inhibitor (TKI) such as imatinib, dasatinib or nilotinib, often for many years6. This guide compares the main options, explains the checks you will have, and answers a common question: can you ever stop?
CML in brief
In CML, two genes (BCR and ABL1) join together to make an abnormal gene, called BCR::ABL1, on what is known as the Philadelphia chromosome. This gene drives the bone marrow to make too many white blood cells1. TKIs block the signal from this gene. For more on how this works, see our guide to how imatinib works.
The first-choice tablets
Imatinib, dasatinib and nilotinib are all licensed in the US for newly diagnosed CML in the chronic phase234. Bosutinib and asciminib are also used15. European guidelines describe how doctors choose a first-line drug and its starting dose for each person6.
| Imatinib (Gleevec) | Dasatinib (Sprycel) | Nilotinib (Tasigna) | |
|---|---|---|---|
| Usual dose in chronic phase | 400 mg once a day2 | 100 mg once a day3 | 300 mg twice a day4 |
| Food | With a meal and a large glass of water2 | With or without food3 | Empty stomach: no food 2 hours before and 1 hour after4 |
| Side effects to watch | Swelling and fluid retention2 | Fluid around the lungs (pleural effusion)3 | Heart rhythm (QT) and blood vessel problems4 |
Side effects compared
- Imatinib: the most common side effects are diarrhoea, tiredness, nausea, swelling, rash, vomiting and stomach pain. Swelling is common and fluid retention can occasionally be serious, so weigh yourself regularly and report sudden weight gain. Swelling is more likely at higher doses and over the age of 652.
- Dasatinib: common side effects include low blood counts, fluid retention, diarrhoea, headache, rash, bleeding, breathlessness, tiredness, nausea and muscle pain. Fluid can build up around the lungs, and dasatinib can raise the pressure in the lungs’ blood vessels (pulmonary arterial hypertension), so report breathlessness or a cough3.
- Nilotinib: it can change the heart’s rhythm (QT prolongation), and sudden deaths have been reported. You need heart tracings (ECGs) before starting, after 7 days and regularly after that, and low potassium or magnesium must be corrected. It has also been linked with blocked blood vessels, pancreas inflammation and liver problems, so heart risk factors and blood tests are checked regularly4.
When side effects are a problem, European guidelines favour lowering the dose before switching to another drug6. Never change your dose without your specialist.
Taking them: the practical differences
- Nilotinib’s fasting rule matters because food changes how much is absorbed: no food for 2 hours before and 1 hour after each dose, twice a day, about 12 hours apart. If you cannot swallow the capsules, the contents can be mixed with a teaspoon of apple purée and taken straight away4.
- Acid medicines. Dasatinib should not be taken with omeprazole-type medicines (PPIs) or H2 blockers, or at the same time as antacids3. With nilotinib, short-acting antacids or H2 blockers are suggested instead of PPIs4.
- Grapefruit should be avoided with all three234.
- Missed dose of imatinib: take the next dose at the usual time; never two at once2.
For more practical tips, see our guide to taking cancer tablets at home.
Monitoring: the BCR::ABL1 blood test
The main way to check how well treatment is working is a blood test that measures the amount of the BCR::ABL1 gene4. As an example of how closely this is followed, the nilotinib label sets out regular blood counts every 2 weeks for the first 2 months and then monthly4. Your specialist will compare your results with expected milestones. European guidelines now take more account of each person’s circumstances when deciding whether to switch drugs because a milestone was missed6.
If treatment stops working
If the leukaemia stops responding or comes back, the options include a different TKI, such as ponatinib or asciminib1, and a stem cell transplant for some people16. Gene tests can guide the choice: asciminib, for example, is licensed for CML with a specific change called T315I5. Dasatinib and nilotinib are also licensed for CML that has not responded to, or could not be tolerated on, imatinib34. See our guide to when a cancer medicine stops working.
Can you ever stop? Treatment-free remission
For most people, CML treatment continues for many years6. But some people whose leukaemia has become almost undetectable for a long time can try stopping under close specialist supervision. This is called treatment-free remission, and European guidelines cover it6.
The nilotinib label gives a clear example of how strict the conditions are. Stopping can be considered in people who have4:
- taken nilotinib for at least 3 years
- kept a very deep response on the BCR::ABL1 test for at least a year
- the common types of the BCR::ABL1 gene, which the test can measure accurately
- never had the more advanced phases of CML, and no earlier failed attempt to stop
After stopping, the blood test is repeated monthly for the first year, every 6 weeks in the second year and every 12 weeks after that. If the response is lost, treatment is restarted within 4 weeks4. Never stop your tablets on your own: stopping is only safe with this level of testing.
Withdrawal symptoms after stopping
Some people get aches after stopping a TKI. In people who stopped nilotinib, muscle, joint and bone pain was more common in the first year and usually became less common in the second4. This is sometimes called TKI withdrawal syndrome. Tell your team if it happens.
Generic versions and cost
Generic imatinib, dasatinib and nilotinib contain the same active ingredients as the original brands. Our generic Gleevec, generic Sprycel and generic Tasigna pages explain the options, and our guide to what Gleevec costs compares prices. We stock products including Imatib 400 mg and Sprycel 50 mg; see also our dasatinib, nilotinib, asciminib and ponatinib pages and our blood cancer medicines. All need a prescription.
Frequently asked questions
Can imatinib be stopped?
Some people with a very deep response that has lasted a long time can try stopping a TKI such as imatinib, under close specialist supervision with frequent blood tests. Most people stay on treatment for many years. Never stop on your own.
How long do you take imatinib?
Usually for many years, often long term, as long as it keeps CML under control and the side effects are manageable.
Is dasatinib better than imatinib?
Neither is simply better for everyone. They have different side effects and practical rules, and your specialist will choose based on your health, other conditions and other medicines.
What is imatinib withdrawal syndrome?
Some people get muscle, joint or bone aches after stopping a TKI. In studies of people who stopped nilotinib, these were more common in the first year and became less common in the second.
What happens if I miss a dose of imatinib?
Take your next dose at the usual time. Do not take two doses together.
Sources & references
- National Cancer Institute. Chronic Myeloid Leukemia Treatment (PDQ), Patient Version. Updated 9 April 2025.
- US National Library of Medicine, DailyMed. Gleevec (imatinib) prescribing information.
- US National Library of Medicine, DailyMed. Sprycel (dasatinib) prescribing information.
- US National Library of Medicine, DailyMed. Tasigna (nilotinib) prescribing information.
- US National Library of Medicine, DailyMed. Scemblix (asciminib) prescribing information.
- Apperley JF, et al. 2025 European LeukemiaNet recommendations for the management of chronic myeloid leukemia. Leukemia. 2025;39(8):1797-1813.
Related reading
This content is for informational purposes only and is not medical advice. Never stop or change CML treatment without your specialist. Used as prescribed by a licensed medical professional.
Reeta Malti is a licensed clinical pharmacist with 8 years of experience. She holds a B.Pharm and M.Pharm from Pt. Ravishankar Shukla University. At OnlineMeds, she reviews medicine and health content to help ensure it is accurate, evidence-based, and easy to understand.