Key points
- Imatinib is a targeted tablet that blocks the faulty protein made by the “Philadelphia chromosome”; it also blocks another protein called KIT [1].
- In chronic myeloid leukaemia (CML), imatinib was far more effective than older treatments [2], and more than 8 in 10 patients were alive after 10 years [3].
- It is also used for advanced gastrointestinal stromal tumour (GIST) and after GIST surgery; in high-risk patients, 3 years of tablets after surgery was better than 1 year [1, 4].
- The most common side effects: swelling, nausea, muscle cramps and pain, diarrhoea and skin rash [1].
- Take the tablet with food and a large glass of water, and do not eat grapefruit [1]. Take it every day without missing doses (why?).
What is this drug and how does it work?
For physicians
Imatinib (brand name Gleevec / Glivec) is a protein tyrosine kinase inhibitor [1]. In CML, a chromosomal translocation known as the Philadelphia chromosome produces the abnormal, constitutively active BCR-ABL enzyme that drives leukaemia cell proliferation. Imatinib inhibits this enzyme and, in BCR-ABL-positive cells, stops proliferation and induces apoptosis [1].
Imatinib also inhibits the receptor tyrosine kinases for platelet-derived growth factor (PDGFR) and stem cell factor (c-KIT); this is why it works in GIST, which usually carries an activating KIT mutation, and in some blood disorders with PDGFR gene rearrangements [1]. Imatinib was first approved in the United States in 2001 [1].
Which cancers is it used for?
Your doctor may prescribe this drug for:
- Philadelphia-positive chronic myeloid leukaemia (CML) in chronic phase [1, 2, 3]
- CML in accelerated phase or blast crisis, or in chronic phase after failure of interferon alfa [1]
- Philadelphia-positive acute lymphoblastic leukaemia (Ph+ ALL) [1]
- KIT (CD117)-positive gastrointestinal stromal tumour (GIST) [1, 5]
- KIT (CD117)-positive GIST after complete surgery [1, 4, 6]
- Myelodysplastic/myeloproliferative syndromes with PDGFR gene rearrangements [1]
- Aggressive systemic mastocytosis [1]
- Hypereosinophilic syndrome and/or chronic eosinophilic leukaemia [1]
- Dermatofibrosarcoma protuberans (DFSP) [1]
Whether it suits you depends on the type and stage of your cancer and your test results. Details of each use are in the section for doctors.
For physicians
| Cancer | Setting | Key evidence |
|---|---|---|
| Philadelphia-positive CML in chronic phase | Newly diagnosed, in adults and children | IRIS (1106 patients): complete cytogenetic response 74.7% vs 6.5% and 84-month progression-free survival 81.2% vs 60.6% [1, 2]; 10-year overall survival 83.3% [3] |
| CML in accelerated phase or blast crisis, or chronic phase after interferon alfa failure | Treatment of advanced disease or after interferon failure | FDA-approved use [1] |
| Philadelphia-positive acute lymphoblastic leukaemia (Ph+ ALL) | Adults with relapsed or refractory disease | Phase 2 study (43 patients at 600 mg): complete haematological response 19% [1] |
| Philadelphia-positive acute lymphoblastic leukaemia (Ph+ ALL) | Newly diagnosed children, with chemotherapy | FDA-approved use based on a Children's Oncology Group study [1] |
| KIT (CD117)-positive gastrointestinal stromal tumour (GIST) | Unresectable and/or metastatic | Two phase 3 trials (1640 patients): median progression-free survival 18.9 months at 400 mg and 23.2 months at 800 mg, with no difference in overall survival (49.0 vs 48.7 months) [1]; pivotal phase 2 study [5] |
| KIT (CD117)-positive GIST after complete resection | Adjuvant treatment in adults | Double-blind placebo-controlled trial (713 patients, 12 months of treatment): HR for recurrence-free survival 0.398 at the interim analysis [1, 6]; 3 years vs 1 year in high-risk patients (397 patients): HR for recurrence-free survival 0.46 and for overall survival 0.45 [1, 4] |
| Myelodysplastic/myeloproliferative syndromes with PDGFR gene rearrangements | Adults | FDA-approved use [1] |
| Aggressive systemic mastocytosis | Adults without the c-Kit D816V mutation or with unknown mutation status | FDA-approved use [1] |
| Hypereosinophilic syndrome and/or chronic eosinophilic leukaemia | Adults (with or without the FIP1L1-PDGFRα fusion) | FDA-approved use [1] |
| Dermatofibrosarcoma protuberans (DFSP) | Adults with unresectable, recurrent and/or metastatic disease | FDA-approved use [1] |
HR: hazard ratio; a value below 1 means a lower risk of the event.
How it is taken and dosing
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Treatment regimens and doses: index10 regimens
Imatinib is a tablet and should be taken with food and a large glass of water to reduce stomach irritation [1]. Doses of 400 or 600 mg are taken once a day, and the 800 mg dose as 400 mg twice a day [1]. If you cannot swallow the tablet, you can dissolve it in a glass of water or apple juice (about 50 mL for a 100 mg tablet and 200 mL for a 400 mg tablet), stir and drink it straight away [1]. Do not crush the tablets, and avoid skin contact with crushed tablets [1].
If you miss a dose, take the next one at the usual time and never take two doses together [1]. Treatment continues as long as the disease does not progress and side effects are tolerable [1]; do not change the dose yourself or stop the drug without your doctor's advice [1].
- Administration: use the 400 mg tablet for doses of 800 mg and above [1].
- Haematological dose modification (neutrophils below 1000 and/or platelets below 50,000 per µL): chronic-phase CML, GIST, MDS/MPD, ASM and HES/CEL at 400 mg: hold until neutrophils are 1500 or more and platelets 75,000 or more, then 400 mg; on recurrence, 300 mg. DFSP (800): same thresholds, resume at 600 and on recurrence 400 mg. ASM or HES/CEL at 100 mg: resume at the same dose. Accelerated-phase/blast-crisis CML and Ph+ ALL (600): if neutrophils are below 500 and/or platelets below 10,000 and the cytopenia is unrelated to leukaemia (marrow aspirate or biopsy): reduce to 400; if it persists for 2 weeks, 300; if it persists for 4 weeks, hold until neutrophils are 1000 or more and platelets 20,000 or more, then 300 mg. Children (340 mg/m²): hold until recovery, resume at the same dose and on recurrence 260 mg/m² [1].
- Hepatic and non-haematological toxicity: bilirubin above 3 times or transaminases above 5 times the upper limit of normal: hold until bilirubin is below 1.5 times and transaminases below 2.5 times, then a lower dose (400 to 300, 600 to 400, 800 to 600 mg; children 340 to 260 mg/m²). Other severe non-haematological reactions (such as severe fluid retention): hold until resolved [1].
- Liver and kidney: mild and moderate hepatic impairment: no adjustment; severe hepatic impairment: reduce the dose by 25%. Moderate renal impairment (creatinine clearance 20 to 39 mL/min): reduce the starting dose by 50% (increase if tolerated), and doses above 400 mg are not recommended; mild impairment (40 to 59): doses above 600 mg are not recommended; severe impairment: with caution (100 mg daily was tolerated in two patients) [1].
- Interactions: if a strong CYP3A4 inducer is unavoidable, increase the imatinib dose by at least 50% and monitor the response closely. The list of interacting drugs (strong CYP3A4 inducers and inhibitors, grapefruit, CYP3A4 substrates) and switching warfarin to heparin are in the section Interactions, pregnancy and precautions [1].
- Monitoring: CBC weekly in the first month, every 2 weeks in the second month and then periodically (e.g., every 2 to 3 months); liver tests before starting and monthly; renal function before starting and during treatment; regular weighing and signs of fluid retention; monitoring of patients with heart disease or risk factors for heart failure; TSH in thyroidectomised patients on levothyroxine; risk of tumour lysis syndrome with high tumour burden [1].
- Response monitoring in CML: according to ELN 2020, response is measured by molecular BCR-ABL1 testing; an optimal response means BCR-ABL1 at most 10% at 3 months, at most 1% at 6 months and at most 0.1% (major molecular response) at 12 months [7].
For physicians
Standard dosing: CML and Ph+ ALL (FDA label)
Philadelphia-positive CML, chronic phase (adults)
Newly diagnosed or after interferon failureCycle length: Continuous
Newly diagnosed or after interferon failure [1]
Before prescribing: Prescribing notes: dose modification, interactions and monitoring| Drug | Dose | Route | Schedule |
|---|---|---|---|
| Continuous | |||
| Imatinib | 400 mg | Oral, with food and a large glass of water | Once daily |
Increase to 600 mg in the absence of severe adverse reactions and severe neutropenia or thrombocytopenia unrelated to leukaemia, in case of: disease progression, no satisfactory haematological response after at least 3 months, no cytogenetic response after 6 to 12 months, or loss of a previous response [1].
Philadelphia-positive CML, accelerated phase or blast crisis (adults)
Advanced diseaseCycle length: Continuous
Advanced disease [1]
Before prescribing: Prescribing notes: dose modification, interactions and monitoring| Drug | Dose | Route | Schedule |
|---|---|---|---|
| Continuous | |||
| Imatinib | 600 mg | Oral, with food and a large glass of water | Once daily |
With the same criteria, increase to 800 mg daily (400 mg twice daily) [1].
Newly diagnosed chronic-phase CML and newly diagnosed Ph+ ALL (children)
In Ph+ ALL with chemotherapyCycle length: Continuous
In Ph+ ALL with chemotherapy [1]
Before prescribing: Prescribing notes: dose modification, interactions and monitoring| Drug | Dose | Route | Schedule |
|---|---|---|---|
| Continuous | |||
| Imatinib | 340 mg/m² daily (maximum 600 mg) | Oral, with food and a large glass of water | Once daily; in CML it may be split into morning and evening doses |
There is no experience in children under 1 year. Monitor children's growth [1].
Relapsed or refractory Ph+ ALL (adults)
MonotherapyCycle length: Continuous
Monotherapy [1]
Before prescribing: Prescribing notes: dose modification, interactions and monitoring| Drug | Dose | Route | Schedule |
|---|---|---|---|
| Continuous | |||
| Imatinib | 600 mg | Oral, with food and a large glass of water | Once daily |
Doses follow the trial protocol, guideline or official drug label (source given in the notes of each regimen). Before prescribing, check blood counts, renal and hepatic function, drug interactions and the patient’s condition, and adjust the dose according to the drug label.
Standard dosing: GIST, DFSP and other uses (FDA label)
Unresectable and/or metastatic GIST (KIT-positive)
AdultsCycle length: Continuous
Adults [1]
Before prescribing: Prescribing notes: dose modification, interactions and monitoring| Drug | Dose | Route | Schedule |
|---|---|---|---|
| Continuous | |||
| Imatinib | 400 mg | Oral, with food and a large glass of water | Once daily |
With progression at a lower dose and no severe adverse reactions, increase to 800 mg daily (400 mg twice daily) [1].
Adjuvant GIST (after complete resection)
KIT-positive; adultsCycle length: Continuous
KIT-positive; adults [1]
Before prescribing: Prescribing notes: dose modification, interactions and monitoring| Drug | Dose | Route | Schedule |
|---|---|---|---|
| Continuous | |||
| Imatinib | 400 mg | Oral, with food and a large glass of water | Once daily |
In the high-risk population of the second trial, 3 years of treatment is recommended; the optimal duration is not known [1, 4].
Evidence: One vs Three Years of Adjuvant Imatinib for Operable Gastrointestinal Stromal Tumor (2012)
MDS/MPD with PDGFR gene rearrangement
Adults; determine PDGFRB rearrangement status before startingCycle length: Continuous
Adults; determine PDGFRB rearrangement status before starting [1]
Before prescribing: Prescribing notes: dose modification, interactions and monitoring| Drug | Dose | Route | Schedule |
|---|---|---|---|
| Continuous | |||
| Imatinib | 400 mg | Oral, with food and a large glass of water | Once daily |
Aggressive systemic mastocytosis (ASM)
Without the c-Kit D816V mutation (determine mutation status before starting)Cycle length: Continuous
Without the c-Kit D816V mutation (determine mutation status before starting) [1]
Before prescribing: Prescribing notes: dose modification, interactions and monitoring| Drug | Dose | Route | Schedule |
|---|---|---|---|
| Continuous | |||
| Imatinib | 400 mg | Oral, with food and a large glass of water | Once daily |
If mutation status is unknown, 400 mg may be considered in patients not responding adequately to other therapies. ASM with eosinophilia and FIP1L1-PDGFRα: start at 100 mg daily, increasing to 400 mg if the response is insufficient and there are no adverse reactions [1].
Hypereosinophilic syndrome / chronic eosinophilic leukaemia (HES/CEL)
AdultsCycle length: Continuous
Adults [1]
Before prescribing: Prescribing notes: dose modification, interactions and monitoring| Drug | Dose | Route | Schedule |
|---|---|---|---|
| Continuous | |||
| Imatinib | 400 mg | Oral, with food and a large glass of water | Once daily |
With the FIP1L1-PDGFRα fusion: start at 100 mg daily, increasing to 400 mg if the response is insufficient and there are no adverse reactions. Consider echocardiography and serum troponin [1].
Dermatofibrosarcoma protuberans (DFSP)
Unresectable, recurrent and/or metastatic; adultsCycle length: Continuous
Unresectable, recurrent and/or metastatic; adults [1]
Before prescribing: Prescribing notes: dose modification, interactions and monitoring| Drug | Dose | Route | Schedule |
|---|---|---|---|
| Continuous | |||
| Imatinib | 800 mg daily | Oral, with food and a large glass of water | 400 mg twice daily |
Before prescribing, check each dose against the drug label, laboratory tests and the patient’s condition.
Side effects
The most common side effects:
For physicians
The frequencies below come from the IRIS trial (551 patients with newly diagnosed chronic-phase CML who received imatinib) in the FDA label and include all adverse events regardless of relationship to the drug [1]. Oedema is seen mostly around the eyes or in the lower legs and is usually managed with diuretics, supportive measures or dose reduction [1].
| Adverse event | Frequency (all grades) | Grade 3 or 4 |
|---|---|---|
| Fluid retention (mostly superficial oedema) | 61.7% | 2.5% [1] |
| Nausea | 49.5% | 1.3% [1] |
| Muscle cramps | 49.2% | 2.2% [1] |
| Musculoskeletal pain | 47.0% | 5.4% [1] |
| Diarrhoea | 45.4% | 3.3% [1] |
| Rash | 40.1% | 2.9% [1] |
| Fatigue | 38.8% | 1.8% [1] |
| Headache | 37.0% | 0.5% [1] |
| Abdominal pain | 36.5% | 4.2% [1] |
| Arthralgia | 31.4% | 2.5% [1] |
| Haemorrhage (any) | 28.9% | 1.8% [1] |
| Vomiting | 22.5% | 2.0% [1] |
Source: FDA label, Table 2 [1]. Weight gain was reported in 15.6% (grade 3 or 4: 2.0%) [1]. In IRIS only 2.4% of patients stopped treatment because of drug-related adverse events [1].
Serious side effects
These are less common but serious; tell your team early if you notice any sign of them:
- Fluid build-up in the body: rapid weight gain, shortness of breath or a swollen abdomen; weigh yourself regularly [1].
- Low blood counts: fever, bruising or severe tiredness [1].
- Heart problems: shortness of breath or swollen legs, mostly in older people [1].
- Liver damage: yellow skin or eyes, dark urine [1].
- Bleeding or severe abdominal pain, and severe skin reactions [1].
- Harm to an unborn baby and slower growth in children [1].
For physicians
The FDA label has no boxed warning but lists these warnings and precautions [1]:
- Severe fluid retention: such as pleural or pericardial effusion, pulmonary oedema and ascites; in newly diagnosed CML, severe superficial oedema in 1.5% and other severe cases in 1.3%, and in GIST severe fluid retention in 9 to 13.1% of patients. The risk is higher with higher doses and age over 65 [1].
- Cytopenias: anaemia, neutropenia and thrombocytopenia, especially in advanced phases of CML [1].
- Congestive heart failure and left ventricular dysfunction: mostly in older patients and those with prior heart disease [1].
- Hepatotoxicity: sometimes severe; cases of fatal liver failure and liver transplantation have been reported [1].
- Haemorrhage: grade 3 or 4 bleeding occurred in 1.8% in newly diagnosed CML and in 12.9% of patients in the phase 3 GIST trials [1].
- Gastrointestinal perforation (rare, sometimes fatal) [1].
- Cardiogenic shock on starting treatment in patients with high eosinophils (HES, MDS/MPD and ASM) [1].
- Bullous skin reactions such as erythema multiforme and Stevens-Johnson syndrome [1].
- Hypothyroidism in thyroidectomised patients taking levothyroxine [1].
- Tumour lysis syndrome, reduced renal function, growth retardation in children and embryo-fetal toxicity [1].
When should I call my doctor?
Contact your treatment team straight away if you have [1]:
- Rapid, unexpected weight gain, severe swelling or shortness of breath (a possible sign of fluid retention)
- Yellow skin or eyes, severe loss of appetite, or unusual bleeding and bruising
- Fever, chills or signs of infection
- Black or bloody stools, vomiting blood or sudden severe abdominal pain
- A severe skin rash with blisters
- A possible or confirmed pregnancy
Interactions, pregnancy and precautions
- Other medicines: the steroid dexamethasone, epilepsy medicines (phenytoin, carbamazepine, phenobarbital) and the tuberculosis drug rifampicin lower the level of imatinib and are best not taken with it [1]. The herb St John's wort also lowers imatinib levels in the blood [1]. Antifungal drugs (ketoconazole, itraconazole) and the antibiotic clarithromycin raise it [1].
- Grapefruit: grapefruit juice may raise imatinib levels; avoid it [1].
- Imatinib also raises the level of some other medicines, such as some cholesterol tablets (simvastatin), some blood pressure medicines (amlodipine and similar drugs) and some sedatives [1].
- Anticoagulants: patients who need an anticoagulant should receive low-molecular-weight heparin or standard heparin instead of warfarin [1].
- If you take or plan to take an iron supplement, tell your doctor [1]. Imatinib may delay the elimination of high-dose methotrexate [1].
- Pregnancy: a pregnancy test is done before starting. Women who could become pregnant should use highly effective contraception during treatment and for 14 days after stopping it [1].
- Breastfeeding: imatinib passes into breast milk; do not breastfeed during treatment and for 1 month after the last dose [1].
- Driving: it may cause dizziness, blurred vision or sleepiness; take care when driving or using machines [1].
- Children: the growth of children taking imatinib should be monitored closely [1].
Frequently asked questions
Do I have to take imatinib for the rest of my life?
According to the label, treatment continues as long as the disease does not progress and side effects are tolerable [1]. In CML, the ELN 2020 guideline allows a trial of stopping the drug for “treatment-free remission” only in particular conditions, including more than 5 years of treatment, more than 2 years of deep molecular response and access to frequent, good-quality PCR monitoring after stopping [7]. This decision should only be made with a specialist.
Is swelling around the eyes and legs normal?
What if I cannot swallow the tablet?
The tablet can be dissolved in water or apple juice (about 50 mL for a 100 mg tablet and 200 mL for a 400 mg tablet), stirred and drunk straight away once fully dissolved [1].
Are newer drugs better than imatinib?
The ELN 2020 guideline considers imatinib, dasatinib, nilotinib and bosutinib all options for first-line treatment of chronic-phase CML and recommends choosing by comorbidities, likely side effects and the patient's risk score [7]. In a large study, in the group compared with imatinib, after about a year asciminib brought the disease down to a very low level in more patients than imatinib did [8]. A difference in response does not necessarily mean a difference in survival; discuss the choice of drug with your doctor.
Key studies
Show detailsHide
Key studies
3 itemsLong-Term Outcomes of Imatinib Treatment for Chronic Myeloid Leukemia
European LeukemiaNet 2020 recommendations for treating chronic myeloid leukemia
Asciminib in Newly Diagnosed Chronic Myeloid Leukemia
Related cancer types
References
8 referencesShow all references, 7 with a study cardClose the reference list
Numbers in the text, such as [1], refer to these sources. Sources with a “Study card” button are summarised in the site’s evidence library.
- 1GLEEVEC (imatinib mesylate) tablets — Prescribing InformationSource Back to text: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124
- 2Imatinib Compared with Interferon and Low-Dose Cytarabine for Newly Diagnosed Chronic-Phase Chronic Myeloid Leukemia
- 3Long-Term Outcomes of Imatinib Treatment for Chronic Myeloid Leukemia
- 4
- 5Efficacy and Safety of Imatinib Mesylate in Advanced Gastrointestinal Stromal Tumors
- 6Adjuvant imatinib mesylate after resection of localised, primary gastrointestinal stromal tumour: a randomised, double-blind, placebo-controlled trial
- 7
- 8Asciminib in Newly Diagnosed Chronic Myeloid Leukemia
This page is based on reputable scientific sources and was last updated on 27 October 2026. The content of this website is for educational and informational purposes only and does not replace consultation, diagnosis or treatment by a specialist physician. Consult your treating physician about any treatment decision.
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