New developments in antibody therapy for acute myeloid leukemia.

In the past three decades, improvements in the treatment of acute myeloid leukemia (AML) have increased survival in patients younger than 55 years without significant survival impact in older individuals. Unfortunately, many patients, regardless of age at diagnosis, will eventually die from their disease. Advances in the development of targeted therapies have proven beneficial in chronic myeloid leukemia and lymphoma. Gemtuzumab ozogamicin (GO; Mylotarg, Wyeth-Ayerst, St Davids, PA), a monoclonal antibody conjugated to calicheamicin, targets the CD33 antigen found on the surface of more than 80% of AML leukemic blasts. GO is approved for relapsed disease in patients older than 60 years, but is being evaluated in combination with chemotherapy, in the setting of hematopoietic stem cell transplant, and in high-risk myelodysplasia.