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.
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.
Investigation priorities
Identify a compatible myeloid pattern and demonstrate the defining fusion promptly.
Management branches
Persistent myeloid leukocytosis, basophilia or splenomegaly suggests a clonal myeloproliferative disorder.
- Send FBC, expert film, blood BCR::ABL1 testing, lysis and organ baseline and assess leucostasis symptoms.
- Perform marrow morphology, trephine and conventional karyotype and record transcript type and quantitative baseline.
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.
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.