Monoclonal Antibodies for the Treatment of Hematologic Malignancies: Schedule and Maintenance Therapy

In the last decade rituximab, alemtuzumab, and gemtuzumab ozogamicin (GO) have been used to treat patients with hematologic malignancies. Their efficacy and safety are now well established. Since their preclinical development, many studies have been performed to optimize dose and schedule. Rituximab is usually given at 375 mg/m², a dose that shows activity and little toxicity. It is normally administered as single agent or in combination with chemotherapy to induce remission in B-cell neoplasias. Moreover, given its low toxicity and long half-life, rituximab also can be used as maintenance therapy. Alemtuzumab is administered with a schedule of 30 mg, three times per week, after an initial dose escalation in the first week, showing activity against chronic lymphocytic leukemia (B-CLL) and some T-cell neoplasias. GO is administered at a dose of 9 mg/m² at 2-week intervals for two doses; it is the first monoclonal antibody approved for the treatment of relapsed or refractory CD33⁺ acute myeloid leukemia (AML).