• Effects of anti-CD45 on normal hematopoiesis and on complement levels [ Designated as safety issue: No ]
• Effects of anti-CD45 on leukemic blast cells [ Designated as safety issue: No ]

RATIONALE: Giving anti-CD45 monoclonal antibody, alemtuzumab, chemotherapy, and radiation therapy before a donor peripheral blood stem cell transplant or bone marrow stem cell transplant helps stop the growth of cancer cells and stops the patient's immune system from rejecting the donor's stem cells. Donated stem cells may replace the patient's immune cells and help destroy any remaining cancer cells (graft-versus-tumor effect).

PURPOSE: This phase I trial is studying the side effects of giving anti-CD45 monoclonal antibody together with cytarabine, cyclophosphamide, and total-body irradiation with or without alemtuzumab followed by a donor stem cell transplant and to see how well it works in treating patients with relapsed or resistant leukemia or other hematologic cancer.

OBJECTIVES:

Primary

• To evaluate the toxicity and the anti-tumor activity of anti-CD45 monoclonal antibody in patients with relapsed or resistant leukemia or other hematologic malignancy undergoing allogeneic stem cell transplantation.

Secondary

• To describe the effects of anti-CD45 on normal hematopoiesis and on complement levels.
• To describe the effects of anti-CD45 on leukemic blast cells.

OUTLINE:

• Preparative regimen: Patients receive treatment based on their relationship to the stem cell donor (related or unrelated).

  • HLA-identical or 5/6 matched related donors: Patients receive anti-CD45 monoclonal antibody IV on days -5 to -2, cytarabine IV twice daily on days -7 to -5, cyclophosphamide IV on days -7 and -6. Patients also undergo total body irradiation twice daily on days -4 to -1.
  • HLA-identical or 5/6 matched unrelated donors: Patients receive anti-CD45 monoclonal antibody, cytarabine, and cyclophosphamide and undergo total-body irradiation therapy as above. Patients also receive alemtuzumab IV on days -8 to -6.
• Allogeneic stem cell transplantation: All patients undergo peripheral blood or bone marrow stem cell infusion on day 0.
• Graft-versus-host disease prophylaxis: Patients receive tacrolimus IV beginning on day -2 and continuing as per the treating physician.

• Leukemia
• Myelodysplastic Syndromes

• Biological: alemtuzumab
• Biological: anti-CD45 monoclonal antibody
• Drug: cyclophosphamide
• Drug: cytarabine
• Radiation: total-body irradiation

• Experimental: (For HLA-identical or 5/6 matched related donors): Patients receive anti-CD45 monoclonal antibody IV on days -5 to -2, cytarabine IV twice daily on days -7 to -5, cyclophosphamide IV on days -7 and -6. Patients also undergo total body irradiation twice daily on days -4 to -1.
• Experimental: (For HLA-identical or 5/6 matched unrelated donors): Patients receive anti-CD45 monoclonal antibody, cytarabine, and cyclophosphamide and undergo total-body irradiation therapy as for patients with related donors. Patients also receive alemtuzumab IV on days -8 to -6.

DISEASE CHARACTERISTICS:

• Confirmed diagnosis of advanced leukemia or other hematologic malignancy, including acute myeloid leukemia, acute lymphoblastic leukemia, chronic myelogenous leukemia (CML), or myelodysplastic disease

  • Advanced features include any of the following:

    • Induction failure, prolonged induction beyond 6 weeks
    • Incomplete response to salvage therapy
    • CML in blast crisis or acute leukemia in chemotherapy resistant relapse
    • Secondary leukemia or secondary myelodysplastic disease
• CD45 present on leukemic blasts at a level of > 95% as documented by flow cytometry
• HLA identical sibling donor or 5/6 matched related donor OR fully matched or 5/6 matched unrelated donor available
• No T-cell lymphoblastic lymphoma

PATIENT CHARACTERISTICS:

• Lansky performance status (PS) 70-100%% or Karnofsky PS 70-100%
• Life expectancy > 6 weeks (not limited by diseases other than leukemia)
• No symptomatic cardiac disease, or evidence of significant cardiac disease by echocardiogram (i.e., shortening fraction < 25%)
• No liver disease that on evaluation by the Principal Investigator precludes ablative radio/chemotherapy or successful transplantation
• Creatinine ≤ 2 times upper limit of normal
• No known allergy to rat serum products
• No severe infection that on evaluation by the Principal Investigator precludes ablative radio/chemotherapy or successful transplantation
• No severe personality disorder or mental illness
• No documented HIV positivity
• Not pregnant or lactating

PRIOR CONCURRENT THERAPY:

• Not specified