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.