Chemotherapy Followed by Peripheral Stem Cell Transplantation And Biological Therapy in Treating Patients With Chronic Myelogenous Leukemia

RATIONALE: Drugs used in chemotherapy use different ways to stop tumor cells from dividing so they stop growing or die. Biological therapies use different ways to stimulate the immune system and stop cancer cells from growing. Peripheral stem cell transplantation may be able to replace immune cells that were destroyed by chemotherapy. PURPOSE: Phase II trial to study the effectiveness of chemotherapy followed by peripheral stem cell transplantation and biological therapy in treating patients who have chronic myelogenous leukemia.

OBJECTIVES: I. Determine the toxicity of high-dose busulfan followed by interleukin-2 (IL-2) and sargramostim (GM-CSF) activated autologous/syngeneic peripheral blood stem cell (PBSC) transplantation, sequential IL-2 and GM-CSF therapy, and interferon alfa in patients with chronic myelogenous leukemia. II. Determine engraftment potential of IL-2/GM-CSF activated PBSC followed by sequential IL-2/GM-CSF therapy in this patient population. III. Assess the time to cytogenetic and/or morphologic relapse, overall event-free survival, and overall survival in these patients treated with this regimen. OUTLINE: Autologous peripheral blood stem cells (PBSC) are harvested and activated with interleukin-2 (IL-2) and sargramostim (GM-CSF) on another protocol. Patients receive oral busulfan every 6 hours on days -6 to -3 for a total of 16 doses. IL-2 and GM-CSF-activated PBSC are reinfused on day 0. Beginning 4 hours after PBSC infusion, patients receive IL-2 IV continuously for 5 days followed by 2 days of rest for 4 weeks. In addition, GM-CSF is administered subcutaneously (SC) every Monday, Wednesday, and Friday for 4 weeks. Upon hematologic recovery, but no earlier than 2 weeks after IL-2 and GM-CSF, patients receive interferon alfa SC 3 times weekly until clear evidence of disease progression. Patients are followed every 6 months for 3 years and then annually thereafter. PROJECTED ACCRUAL: A total of 25 patients will be accrued for this study within 2-3 years.