Gemtuzumab ozogamicin for the treatment of acute promyelocytic leukemia: Mechanisms of action and resistance, safety and efficacy

Acute promyelocytic leukemia (APL) is characterized by peculiar biological features and high sensitivity to therapeutic agents such as anthracyclines, all-trans retinoic acid (ATRA) and arsenic trioxide (ATO). Because cure rates of up to 80 - 90% have been reported using various combinations of the above agents, future strategies will probably aim at reducing therapy-related toxicity while maintaining therapeutic efficacy. Gemtuzumab ozogamicin (GO) is a calicheamicin-conjugated mAb directed against CD33, a surface antigen highly expressed on APL blasts. GO has been shown to be effective in this disease and better tolerated than conventional chemotherapy.