Combined Tretinoin and Arsenic Trioxide for Patients With Newly Diagnosed Acute Promyelocytic Leukemia Followed by Risk-Adapted Postremission Therapy

Induction will consist of tretinoin 45 mg/m2 po daily (rounded up to the nearest 10mg) in two divided doses (25 mg/m2 in patients \<20 years of age) for 35 days and ATO 0.15 mg/kg IV daily for 35 doses given 5-7 days per week. The drugs will then be discontinued, and the patient will be followed until a clinical complete remission is achieved. Idarubicin 12 mg/m2 IV for 4 doses will be added during induction on day 2 if the presenting WBC is \>10,000/μl, or if the WBC increases to 5,000/μl on day 5, 10,000/μl on day 10, or 15,000/μl on day 15, because of the increased risk of the APL differentiation syndrome and relapse in these patients. Dexamethasone 10 mg twice daily with be given on days 1-14 of induction as prophylaxis for the APL differentiation syndrome. All patients will then receive four courses of consolidation with tretinoin 45 mg/m2 po daily (rounded up to the nearest 10mg) (25 mg/m2 in patients \<20 years of age) for 15 days and ATO 0.15 mg/kg IV for 25 doses. Patients with high-risk disease or who received Idarubicin during Induction may receive intrathecal cytarabine as CNS prophylaxis given by the treating physician during consolidation, at the discretion of the site PI. High-risk patients will also receive maintenance therapy with additional courses of tretinoin and ATO every 3 months for 2 years. Each maintenance course will consist of tretinoin 45 mg/m2 po daily (25 mg/m2 in patients \<20 years of age) for 15 days and ATO 0.15 mg/kg IV for 10 doses. Disease status will be monitored with serial analyses of peripheral blood samples using RT-PCR for PML-RARα mRNA. Patients will be followed until relapse, death, loss to follow-up, or removal from study. Induction therapy can be given as an inpatient or outpatient. Consolidation and maintenance treatments will be given as an outpatient. Consolidation may also be given at the patient's local institution. Intrathecal cytarabine treatments will be administered as an outpatient.