Adult case series of extramedullary relapsing acute myeloid leukemia (AML) after allogeneic stem cell transplantation in whom a rapid response and a reasonably long remission could be achieved with gemtuzumab ozogamycin (GO)

Gemtuzumab Ozogamycin (GO) is a drug conjugated monoclonal antibody which targets CD33 an antigen highly expressed on the surface of AML blasts. GO is approved for the treatment of both newly-diagnosed and relapsed AML. Despite growing evidence regarding its efficacy and safety among AML patients there is limited data about the use of GO in isolated extra-medullary relapsed AML. Extramedullary AML remains as an unmet clinical need regarding the poor prognosis and lack of a standard therapeutic approach. Our cases demonstrated a rapid and long lasting response with a favorable toxicity profile, in patients who were treated with GO as a single agent after an isolated extramedullary relapsing disease.