Use of gemtuzumab ozogamicin in the treatment of pediatric relapsed/ refractory Acute Myeloid Leukemia.

Gemtuzumab ozogamicin (GO, MylotargTM) is an antibody-targeted chemotherapy agent that has been studied in acute myeloid leukemia (AML) at first relapse in adults. There is limited experience in pediatric patients. We report six patients with refractory/relapsed CD33+AML who were treated with GO on compassionate-use basis. One patient attained remission. One patient is still alive following hematopoietic stem cell transplantation (HSCT), and one patient died in remission. Two patients were refractory and three patients had a response with <5% blasts in the bone marrow. Fever and chills, hypotension and hypoxia were observed as side effects. Three patients developed veno-occlusive disease (VOD) of the liver. Two of these three patients had persistence of VOD at the time of their deaths. One patient treated postSCT had bone marrow response without VOD. GO should be used cautiously in chemotherapy-refractory AML pediatric patients due to the high incidence of VOD.