Cytosine Arabinoside and Mitoxantrone for Patients With Juvenile Myelomonocytic Leukemia Receiving Repeat Stem Cell Transplantation

OBJECTIVES: Primary * To determine the incidence of 1-year disease-free survival in patients with juvenile myelomonocytic leukemia and who is undergoing a repeat stem cell transplantation. Secondary * To evaluate the incidence of regimen-related toxicity. * To evaluate the incidence of acute and chronic graft-versus-host-disease. * To evaluate the incidence of relapse. OUTLINE: * Preparative cytoreductive therapy: Patients receive high-dose cytarabine IV over 2 hours on days -9 to -4 and mitoxantrone hydrochloride IV over 30 minutes on days -9 to -7. * Allogeneic hematopoietic stem cell transplantation (HSCT): Patients undergo HSCT on day 0. Patients undergoing umbilical cord blood transplantation receive methylprednisolone (as graft failure prophylaxis) IV twice daily on days 5 to 19 followed by a taper every other day thereafter until day 25. * Graft-versus-host-disease (GVHD) prophylaxis: Patients receive cyclosporine IV over 2 hours every 8-12 hours or orally twice daily beginning on day -3 and continuing until day 50, followed by a taper to day 90, in the absence of GVHD. Patients undergoing nongenotypically identical bone marrow transplantation also receive methotrexate IV on day 1 beginning 24 hours after completion of stem cell infusion and on days 3, 6, and 11. * Post-transplantation isotretinoin therapy: Patients receive oral isotretinoin once daily beginning on day 60 and continuing until 1 year after HSCT. Patients undergo bone marrow sample collection on day 21, day 60, day 100, at 6 months, and at 1 year for chimerism studies. Patients also undergo blood sample collection periodically to monitor peripheral blood counts for immune reconstitution. After completion of study treatment, patients are followed on day 21, day 100, at 6 months, and at 1 year.