For a newly diagnosed adult acute myeloid leukemia (AML) patient with no significant comorbidities, how many cycles of induction therapy with daunorubicin and cytarabine should be given prior to checking for complete remission?

Induction Therapy for Newly Diagnosed AML: Number of Cycles Before Assessing Complete Remission

One cycle of induction therapy with daunorubicin and cytarabine (7+3 regimen) should be given before checking for complete remission, with bone marrow assessment performed 14-21 days after starting induction. 1, 2

Timing of Response Assessment

• Perform bone marrow assessment between day 14 and day 21 after starting the first induction cycle to evaluate early response and determine if a second induction cycle is needed. 1

• Definitive assessment for complete remission should occur at count recovery (typically 4-6 weeks after starting induction), not before, as premature assessment can be misleading due to ongoing differentiation of leukemic cells. 1, 2

• The FDA-approved daunorubicin label specifies that "evaluation of the bone marrow following recovery from the previous course of induction therapy determines whether a further course of induction treatment is required," supporting assessment after each cycle rather than waiting for multiple cycles. 3

Decision Algorithm After First Induction

If day 14-21 bone marrow shows ≥5% blasts (blast persistence):

• Administer a second induction cycle immediately, which may consist of either the identical 7+3 regimen or an intermediate-dose cytarabine-containing regimen such as FLAG-Ida. 1

If day 14-21 bone marrow shows <5% blasts:

• Wait for count recovery and reassess for complete remission (CR/CRi). 1
• If CR/CRi is achieved after one cycle, proceed directly to consolidation therapy. 1

If no CR/CRi after two induction cycles:

• The patient is defined as having primary refractory disease and should be considered for salvage therapy or clinical trials. 1

Supporting Evidence and Rationale

The ESMO guidelines explicitly state that "as soon as patients achieve CR/CRi after 1 or 2 induction cycles, they should proceed to consolidation treatment," indicating that response assessment occurs after each cycle, not after a predetermined number of cycles. 1

The recent DaunoDouble trial (2025) demonstrated that among 389 patients with good early response (defined as <5% marrow blasts on day 15), those receiving only one induction cycle had comparable outcomes to those receiving two cycles, with 3-year overall survival of 76% versus 75% respectively. 4 This supports the practice of assessing response after the first cycle and proceeding to consolidation if adequate response is achieved.

Common Pitfalls to Avoid

• Do not wait for multiple cycles before assessing response - this delays appropriate therapy adjustments and may worsen outcomes in non-responders. 1

• Do not perform "nadir" bone marrow assessment at day 10-14 as the sole determinant of response, as this can be misleading; the day 14-21 assessment is specifically to guide the need for a second induction cycle, not to declare CR. 1

• Do not assess molecular remission before 4-5 weeks after induction - patients often remain molecularly positive even when morphologic remission is present. 1

• Ensure adequate count recovery before declaring CR - assessment should occur when neutrophils and platelets have recovered sufficiently to meet CR criteria (absolute neutrophil count ≥1000/μL, platelets ≥100,000/μL). 1