What is the treatment for Acute Myeloid Leukemia (AML) blast crisis?

Treatment of AML Blast Crisis

The standard treatment for AML blast crisis should include induction chemotherapy with an anthracycline and cytarabine using the well-established "3+7" regimen, followed by consolidation therapy and consideration for allogeneic stem cell transplantation based on risk stratification. 1

Initial Management

• Emergency measures:

  • For patients with excessive leukocytosis and leukostasis symptoms: Emergency leukapheresis coordinated with chemotherapy initiation 1
  • Monitor for tumor lysis syndrome; consider rasburicase for hyperuricemia prevention 1
  • Insert central venous line (under platelet transfusion if needed) 1

• Pre-treatment evaluation:

  • Complete diagnostic workup including cytogenetics and molecular testing
  • HLA typing for potential transplant candidates 1
  • Cardiac assessment with echocardiography 1
  • CT scans of chest and abdomen to identify infectious foci 1
  • Coagulation studies before central line placement 1

Induction Therapy

• Standard "3+7" regimen:

  • Cytarabine 100-200 mg/m² continuous IV infusion for 7 days 1, 2
  • Anthracycline (typically daunorubicin) for 3 days 1, 3
  • Response evaluation with bone marrow examination 14-21 days after induction 1

• Considerations for specific molecular subtypes:

  • For FLT3-mutated AML: Add midostaurin to standard chemotherapy 4
  • For CD33+ AML: Consider adding gemtuzumab ozogamicin 4

Consolidation Therapy

• Risk-stratified approach:

  • Good-risk patients: High-dose cytarabine (3 g/m² q12h on days 1,3, and 5) for 3-4 cycles 1
  • Intermediate/poor-risk patients: Allogeneic stem cell transplantation if eligible 1
  • For patients without suitable donor: Consider autologous stem cell transplantation or high-dose cytarabine 1

• Transplantation considerations:

  • Early HLA typing of patient and family members 1
  • For poor-risk karyotype: Early matched unrelated donor search 1
  • Reduced-intensity conditioning regimens for patients >50 years 1

Management of Refractory/Relapsed Disease

• Salvage options:
  • Allogeneic stem cell transplantation for eligible patients 1
  • For FLT3-mutated AML: Consider gilteritinib 4
  • Clinical trials with novel agents or combinations 4

Special Considerations

• Age and comorbidities:

  • Patients ≥60-65 years have higher risk of treatment complications 1
  • Assess pre-existing conditions (diabetes, heart disease, COPD) 1
  • Consider reduced-intensity approaches for older/unfit patients 4

• Common pitfalls to avoid:

  1. Delaying treatment unnecessarily in patients with hyperleukocytosis
  2. Undertreatment of fit elderly patients or overtreatment of unfit patients
  3. Neglecting molecular testing that could guide targeted therapy
  4. Failing to monitor for anthracycline-induced cardiotoxicity (especially at cumulative doses >300 mg/m²) 4

Response Assessment

• Complete remission criteria: 4
  • Neutrophils >1,000/μL
  • Platelets >100,000/μL
  • <5% blasts in bone marrow
  • No extramedullary disease
  • Transfusion independence

While historical outcomes for blast crisis have been poor 5, modern intensive chemotherapy approaches with targeted agents and transplantation offer the best chance for long-term remission 6. The treatment landscape continues to evolve with newer agents and combinations showing promise beyond the standard "3+7" regimen 7.