Antibody-targeted chemotherapy for the treatment of relapsed acute myeloid leukemia.

A promising new development in cancer treatment is antibody-targeted chemotherapy (ATC), a strategy that allows antineoplastic drugs to be delivered to malignant cells but not most normal ones, possibly resulting in fewer side effects. A new drug, gemtuzumab ozogamicin (Mylotarg), employs the ATC strategy and has been approved by the Food and Drug Administration for the treatment of CD33+ acute myeloid leukemia (AML) in patients who are 60 years of age and older, are in their first relapse, and are not considered candidates for cytotoxic chemotherapy. AML is the second most frequent type of leukemia in adults and is associated with a poor prognosis. If untreated, death usually occurs within a few months of diagnosis.