Evaluating QTc, PK, Safety of Gemtuzumab Ozogamicin (GO) in Patients With CD33+ R/R AML

This is a single-arm, open-label, Phase 4 study evaluating the effect of GO on the QTc, pharmacokinetics, safety, and immunogenicity of GO as a single-agent monotherapy in adult and pediatric patients with relapsed or refractory CD33-positive AML. Approximately 50 adult (age >=18 years) and 6 pediatric (12 years =< age =< 17 years) patients who satisfy the study eligibility criteria will be enrolled. Enrolled patients will receive GO 3 mg/m2 up to 2 cycles on Days 1, 4, and 7 at each cycle. The impact of GO on VOD/SOS in the context of previous and subsequent HSCT will also be assessed. Patients enrolled in the study will receive three doses of GO 3 mg/m2 (up to one vial) as a 2-hour intravenous infusion on Cycle 1 Days 1, 4, and 7. A second cycle of GO 3mg/m² (up to one vial) on Cycle 2 Days 1, 4, and 7 will be allowed at the investigator's discretion for patients who meet the following criteria after Cycle 1: Bone marrow with a decrease of blast percentage to at least 25% or a decrease of pretreatment blast percentage by at least 50%; and Blood count with neutrophils >=1,000/µL, and platelets >=50,000/µL, except in patients with the bone marrow blasts >=5%, the decrease in neutrophils and platelets thought to be due to the underlying leukemia. After GO treatment, subsequent anticancer therapy such as consolidation or conditioning regimen and/or HSCT could be considered at the investigator's discretion. A minimum interval of 2 months is recommended between the last dose of GO and HSCT.