Antibody Therapy for Acute Myeloid Leukemia

Due to the high rate of relapse in younger patients and the overall poor outcome in older patients, novel therapies are needed for the treatment of acute myeloid leukemia (AML). Monoclonal antibodies have become an important treatment modality in cancer therapy. Gemtuzumab ozogamicin (GO), an anti-CD33 immunoconjugate, was approved by the US Food and Drug Administration (FDA) for the treatment of elderly patients with relapsed AML who are not candidates for standard chemotherapy. Single-agent GO and combinations with standard chemotherapeutics have been explored extensively in this disease. Hepatotoxicity and delayed myelosuppression have been dose-limiting. Its toxicity profile is reduced with decreased doses of GO and even by administering only a single infusion. In patients with acute promyelocytic leukemia (APL), the addition of GO can produce molecular remissions and is well tolerated. Targeted immunotherapy with GO for treatment of AML has produced remissions. In order to reduce toxicity and improve efficacy, its optimal dose and schedule and pairing with other standard chemotherapeutic agents need to be defined better in large clinical trials.