Imatinib Mesylate After a Donor Stem Cell Transplant in Treating Patients With Philadelphia Chromosome-Positive Leukemia

You may be eligible if

• DISEASE CHARACTERISTICS:
• Diagnosis of 1 of the following:
• * Acute lymphoblastic leukemia or chronic myeloid leukemia (CML) characterized by p\^190 and/or p\^210 bcr/abl gene rearrangement
• * Accelerated or blastic phase CML
• * CML in second or greater chronic phase
• No imatinib mesylate-resistant leukemia
• Planned allogeneic hematopoietic stem cell transplantation
• * Availability of an appropriately matched related or unrelated donor
• * Autologous or nonmyeloablative transplantation is not allowed
• None of the following within 4 days after the date of neutrophil engraftment\*:
• * More than 5% marrow blasts
• * Circulating peripheral blood leukemic blasts
• * Aberrant antigen expression on marrow myeloblasts ≥ 1% by multidimensional flow cytometric assay
• * Presence of bcr/abl in \> 5% of marrow interphase nuclei by fluorescent in situ hybridization
• * More than 1 of 20 Philadelphia chromosome-positive marrow metaphases
• * CNS involvement by leukemia NOTE: \*The date of neutrophil engraftment is defined as the second consecutive day at which the peripheral blood absolute neutrophil count exceeds 500/mm3
• PATIENT CHARACTERISTICS:
• Performance status
• Not specified
• Life expectancy
• At least 2 months
• Hematopoietic
• See Disease Characteristics
• Absolute neutrophil count ≥ 1,200/mm\^3 (use of filgrastim \[G-CSF\] allowed)
• Hepatic
• Not specified
• Renal
• Not specified
• Other
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception
• No known imatinib mesylate hypersensitivity
• No other disease that severely limits life expectancy
• PRIOR CONCURRENT THERAPY:
• Biologic therapy
• See Disease Characteristics