Skip to textbook content
Doctor’s PassportTextbook
TopicsAll topics

Loading topic navigation…

Textbook navigation
TopicsAll topics

Loading topic navigation…
Educational draft · awaiting clinical reviewUse Rapid for revision, not patient-care decisions. Check current national and local guidance and the BNF or BNFC before acting.

Chronic myeloid leukaemia

Haematology and transfusion · UK scope · Sources checked 27 Aug 2026 · Clinical review pending

RapidFull
!
Blast phase or symptomatic hyperleukocytosis

Fever, bleeding, rapidly worsening cytopenias, new blasts, chloroma, severe splenic pain or respiratory, retinal, neurological or priapic symptoms can represent blast-phase progression or leucostasis.

Action: Use ABCDE assessment, obtain urgent FBC and film, coagulation, lysis chemistry, marrow, cytogenetics and BCR::ABL1 kinase-domain material, treat sepsis and lysis, cytoreduce symptomatic hyperleukocytosis and refer immediately for lineage-directed acute-leukaemia therapy plus an active TKI and allogeneic transplant assessment.

Synopsis

Confirm BCR::ABL1-positive chronic myeloid leukaemia, choose a tyrosine kinase inhibitor from disease and comorbidity, interpret molecular milestones and manage resistance, pregnancy, progression and treatment-free remission safely.

  • Suspect CML from persistent neutrophilia with left shift, basophilia, thrombocytosis and splenomegaly; confirm BCR::ABL1 rather than diagnosing from count pattern alone.
  • First-line confirmation uses peripheral-blood BCR::ABL1 FISH or RT-PCR, while baseline marrow morphology and conventional karyotype establish phase and additional chromosomal abnormalities.
  • Record the exact BCR::ABL1 transcript type and baseline International Scale result so subsequent quantitative RT-PCR uses a valid marker.
  • Imatinib, dasatinib and nilotinib are NICE-supported first-line options for untreated adult chronic-phase Philadelphia-positive CML; choose from molecular goal and comorbidity, not potency alone.
  • Monitor BCR::ABL1 on the International Scale at least every 3 months until major molecular response is achieved and confirmed; stable deep responders can later move to 4–6-month intervals.
  • Favourable molecular landmarks are BCR::ABL1 at or below 10% at 3 months, 1% at 6 months and 0.1% at 12 months, but confirm trends and check adherence before switching on one result.
  • Rising transcript or milestone failure requires dose and interaction review, marrow cytogenetics and BCR::ABL1 kinase-domain mutation testing before selecting the next TKI.
  • Treatment-free remission is a monitored specialist strategy for selected chronic-phase patients with prolonged TKI exposure and sustained deep molecular response; restart promptly if major molecular response is lost.
  • Pregnancy or conception requires a pre-agreed specialist TKI interruption and monitoring plan.

Key red flags

New cytopenias, rising blasts or basophils, rapidly enlarging spleen, constitutional decline or extramedullary mass suggests accelerated biology or blast phase rather than simple TKI intolerance.

Dyspnoea, hypoxaemia, confusion, retinal haemorrhage or priapism with extreme leukocytosis requires emergency leucostasis assessment and cytoreduction.

A rising BCR::ABL1 trend, loss of major molecular response or loss of complete haematological response requires adherence, interaction and resistance assessment rather than waiting for the next routine sample.

Chest pain, focal neurology, limb ischaemia, pleural effusion or pulmonary hypertension may reflect TKI-specific serious toxicity and should change treatment promptly.

Investigation priorities

01
First-line: FBC, film and blood BCR::ABL1First stepFirst line

Identify a compatible myeloid pattern and demonstrate the defining fusion promptly.

Management branches

Suspected CMLConfirm fusion and establish phase

Persistent myeloid leukocytosis, basophilia or splenomegaly suggests a clonal myeloproliferative disorder.

  1. Send FBC, expert film, blood BCR::ABL1 testing, lysis and organ baseline and assess leucostasis symptoms.
  2. Perform marrow morphology, trephine and conventional karyotype and record transcript type and quantitative baseline.
  3. Classify phase and ELTS risk and select a first-line TKI using comorbidity, reproductive goals and treatment aim.

Key medicines

ImatinibGive 400 mg orally once daily with a meal and a large glass of water for chronic-phase CML; the SmPC dose is 600 mg once daily for accelerated phase or blast crisis, integrated with specialist phase-directed therapy.Monitor FBC, liver, renal function, oedema, weight, cramps and gastrointestinal effects; review CYP3A interactions and dose interruption criteria. Avoid during pregnancy unless specialist life-saving benefit outweighs risk, use effective contraception and stop breastfeeding.
DasatinibGive 100 mg orally once daily for chronic-phase CML; use 140 mg once daily for accelerated or blast phase when selected, with dose interruption or reduction according to cytopenia and toxicity.Avoid or use cautiously with pleural effusion, pulmonary arterial hypertension or major bleeding risk. Do not combine with proton-pump inhibitors or H2 antagonists without specialist review, assess CYP3A interactions and avoid pregnancy and breastfeeding.
Open full textbook →Answer 2 questions
Sources and review status6 sources · checked 27 Aug 2026 · clinical review pending+
Sources

Sources and review status

National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 27 Aug 2026; clinical approval remains outstanding.

  • British Society for Haematology CML guidelineUK diagnosis, TKI management, monitoring, pregnancy and treatment-free remission framework.
  • NICE TA426 untreated CML recommendationsNHS first-line imatinib, dasatinib and nilotinib options.
  • European LeukemiaNet 2025 CML recommendationsCurrent international molecular milestones and monitoring used because UK BSH guidance predates the 2025 update.
  • Imatinib Summary of Product CharacteristicsChronic- and advanced-phase doses, administration and safety modifiers.
  • Dasatinib Summary of Product CharacteristicsChronic- and advanced-phase doses and pulmonary, interaction and reproductive cautions.
  • Nilotinib Summary of Product CharacteristicsFasting dose, QT, metabolic, vascular and reproductive safety.

Editorial contact: Doctor’s Passport editorial team. Source-check date is separate from clinical approval. Report a content problem · Content changes

Authoring stateRapid draft
Clinical stateAwaiting review
JurisdictionUnited Kingdom