CML Treatment Response — RACP Adult Medicine MCQ

Instant feedback + full explanation. One question, done properly.

ModerateHaematologyCML Treatment ResponseRACP Adult Medicine

A 60-year-old man with known chronic myeloid leukaemia (CML) in chronic phase has been on imatinib 400 mg daily for 12 months. His BCR-ABL1 transcript level at 12 months is 15% (IS). According to ELN criteria, this represents which response category?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: D — Failure

ELN 2020 criteria define failure at 12 months as BCR-ABL1 >1% (IS). At 15%, this clearly represents treatment failure. The expected milestones are: 3 months – BCR-ABL1 ≤10% (IS); 6 months – BCR-ABL1 <1%; 12 months – BCR-ABL1 ≤0.1% (major molecular response). Treatment failure requires switching to a second-generation TKI (dasatinib, nilotinib, or bosutinib) and consideration of ABL1 kinase domain mutation testing.

Reference: eTG – 2025 – Haematology; ELN – 2020 – CML Management Recommendations