Combination Chemotherapy With or Without PSC 833, Peripheral Stem Cell Transplantation, and/or Interleukin-2 in Treating Patients With Acute Myeloid Leukemia

PRIMARY OBJECTIVES:

I. To determine whether the addition of PSC-833 (valspodar) to induction chemotherapy improves disease-free survival and overall survival for patients with acute myeloid leukemia (AML) < 60 years.

II. To determine whether post-consolidation immunotherapy with low-dose continuous/intermittent high-dose bolus subcutaneous recombinant interleukin-2 (rIL-2) (aldesleukin) improves disease-free survival and overall survival in patients with AML < 60 years in first complete remission (CR).

SECONDARY OBJECTIVES:

I. To continue to evaluate the effectiveness of three courses of high-dose ARA-C (HiDAC) (cytarabine) as curative consolidation chemotherapy in patients with core binding factor (CBF) leukemias.

II. To continue to establish the use of intensive post-remission chemotherapy with PSCT or a novel intensification sequence consisting of HiDAC/high-dose etoposide/G-CSF (filgrastim) followed by two cycles of HiDAC in patients in CR with unfavorable cytogenetics.

III. To correlate the rate of relapse and toxicity with busulfan pharmacokinetics when busulfan and etoposide are used prior to autologous stem cell transplantation for AML patients in first CR.

OUTLINE: This is a randomized, multicenter study.

INDUCTION THERAPY: Patients are randomized to 1 of 2 treatment arms.

ARM I: Patients receive cytarabine IV continuously on days 1-7 and daunorubicin IV over 5-10 minutes followed by etoposide IV over 2 hours on days 1-3. Patients with 20% or greater bone marrow cellularity and greater than 5% leukemia blasts at the end of the first course receive a second course of cytarabine IV continuously on days 1-5 and daunorubicin IV over 5-10 minutes followed by etoposide IV over 2 hours on days 1 and 2.

ARM II: Patients receive PSC 833 IV continuously on days 1-3 and cytarabine, daunorubicin, and etoposide as in arm I. Patients with 20% or greater bone marrow cellularity and greater than 5% leukemia blasts at the end of the first course receive a second course of PSC 833 IV continuously on days 1 and 2 and cytarabine, daunorubicin, and etoposide as in arm I.

INTENSIFICATION THERAPY: Patients in complete remission receive intensification therapy. Therapy begins no earlier than 2 weeks and no later than 4 weeks after complete remission is attained. Patients are stratified according to cytogenetics (favorable [t(8;21)(q22;q22) or inv(16)(p13;q22) or t(16;16)(p13;q22)] vs unfavorable [all other karyotypes]).

FAVORABLE: Patients receive high-dose cytarabine (HiDAC) IV over 3 hours every 12 hours on days 1, 3, and 5. Treatment repeats no earlier than 28 days after the prior course and no later than 14 days after hematopoietic recovery for two more courses.

UNFAVORABLE: Patients are further divided into two groups based on ability to receive peripheral blood stem cell transplantation (PBSCT) (yes vs no).

PBSCT GROUP: Patients receive etoposide IV continuously and HiDAC IV over 2 hours every 12 hours on days 1-4. Patients also receive filgrastim (G-CSF) subcutaneously (SC) daily beginning on day 14 and continuing until peripheral blood stem cell (PBSC) collection is completed. Patients who are not able to undergo PBSCT after HiDAC/etoposide continue treatment in the non-PBSCT group. At least 4 weeks after HiDAC/etoposide recovery, patients receive oral busulfan every 6 hours on days -7 to -4 and etoposide IV over 4 hours on day -3 prior to PBSCT. Patients receive autologous PBSC infusion on day 0. Patients also receive G-CSF SC beginning on day 0 and continuing until hematopoietic recovery.

NON-PBSCT GROUP: Patients receive etoposide, HiDAC, and G-CSF as in the PBSCT group. After hematopoietic recovery, patients then receive HiDAC IV over 3 hours every 12 hours on days 1, 3, and 5. Treatment repeats no earlier than 28 days after prior course and no later than 14 days after hematopoietic recovery for one more course.

IMMUNOTHERAPY: Patients are again randomized to 1 of 2 treatment arms.

ARM I: Patients begin therapy no later than 120 days after the first day of the last course of HiDAC treatment OR day 0 of PBSCT. Patients receive low-dose interleukin-2 (IL-2) SC on days 1-14, 19-28, 33-42, 47-56, 61-70, and 75-90. In addition, patients receive high-dose IL-2 SC on days 15-17, 29-31, 43-45, 57-59, and 71-73.

ARM II: Patients are observed and receive no further therapy.

Patients are followed at 1 month, every 2 months for 2 years, every 6 months for 2 years, and then annually for 6 years.

PROJECTED ACCRUAL: A total of 720 patients will be accrued for this study within 4 years.

Inclusion criteria

• Unequivocal histologic diagnosis of AML (> 20% blasts in the bone marrow based on the World Health Organization [WHO] and/or French-American-British Cooperative group [FAB] classifications), excluding M3 (acute promyelocytic leukemia); patients with antecedent myelodysplasia are eligible for treatment on this trial only if there was no bone marrow biopsy showing myelodysplastic syndrome (MDS) > 3 months prior to enrollment; patients with therapy-related MDS or therapy-related AML or a chronic myeloproliferative disorder are not eligible
• No prior treatment for leukemia or myelodysplasia with four permissible exceptions:

• Emergency leukapheresis
• Emergency treatment for hyperleukocytosis with hydroxyurea
• Cranial radiation therapy (RT) for central nervous system (CNS) leukostasis (one dose only)
• Growth factor/cytokine support