Immunochemotherapy and AlloSCT in Patients With High Risk CD33+ AML/MDS

Gemtuzumab ozogamicin in combination with busulfan and cyclophosphamide (immunochemotherapy) conditioning followed by allogeneic stem cell transplantation + anti-thymocyte globulin (unrelated donors only) in patients with high risk CD33+AML or MDS meeting eligibility criteria.

Inclusion criteria

• Disease Status:

• History of AML Induction/Reinduction Failure
• AML 1st Complete Remission (CR) with poor cytogenetics
• AML 2nd CR with minimal residual disease (MRD)
• AML 3rd CR
• AML in refractory relapse but ≤25% bone marrow leukemia blasts
• MDS with >6% bone marrow blasts at diagnosis
• Secondary MDS with ≤5% bone marrow myeloblasts at diagnosis

Disease Immunophenotype:

• Disease must express a minimum of >/= 10% CD33+ for patients with AML

Organ Function:

• Adequate renal function, adequate liver function, adequate cardiac function, adequate pulmonary function Age: ≤25 years of age Donor: matched family donor, unrelated cord blood donor, unrelated adult donor

Exclusion criteria

• Patients with active central nervous system (CNS) AML/MDS disease at time of conditioning therapy
• Female patients who are pregnant
• Karnofsky <50% or Lansky <50% if 10 years or less
• Age >25 years
• Has received gemtuzumab in the previous 30 days or has not recovered from prior gemtuzumab therapy.