How long does chemotherapy take to work for acute lymphoblastic leukaemia?

Treatment usually begins with an intensive phase intended to reduce leukaemia cells in the blood and bone marrow. Doctors use blood counts, physical findings, and bone marrow tests to see how the leukaemia is responding. A deeper response may be assessed with tests for very small amounts of remaining disease, sometimes called measurable residual disease.

The result of an early assessment can affect the next medicines, dose intensity, and length of treatment. Further phases are often needed even when the first tests show a good response, because treatment also aims to clear cells that cannot be seen on routine examination.

Keep a written record of treatment dates, medicines, test results, and questions. Take medicines exactly as prescribed and report new symptoms to the leukaemia team. Avoid changing supplements or stopping treatment without advice, since interactions and interruptions can affect the plan.

Your team can explain the next milestone and what result would change your care. General information is available in the [Chemotherapy](/treatments/systemic-therapy/chemotherapy/) guide.

Call the treatment team urgently for fever or chills, breathlessness, new bleeding, black stools, severe weakness, confusion, or a sudden rash. Chemotherapy can lower blood-cell counts and weaken infection defences. Do not wait for the next scheduled blood test if you feel acutely unwell.

Ask: When will my first response assessment happen? Which tests will be used? What does a measurable residual disease result mean for me? How many treatment phases are planned? Which symptoms require a same-day call?