Radiolabeled antibody therapy of B-cell lymphomas

Patients with relapsed B-cell lymphomas are currently incurable with conventional doses of chemotherapy or radiotherapy. In recent years, new treatment options have become available for these patients, including the use of chimeric mouse-human anti-CD20 antibodies and radiolabeled anti-CD20 antibodies. The nonradioactive rituximab (Rituxan; IDEC Pharmaceuticals, San Diego, CA, and Genentech, Inc, San Francisco, CA) antibody induces remissions in 60% of patients with relapsed follicular lymphomas, including 5% to 10% complete remissions. Anti-CD20 antibodies radiolabeled with iodine 131 and yttrium 90 given at nonmyeloablative doses yield remissions in 75% to 80% of cases, including 35% to 40% complete remissions. High-dose (131)I-anti-B1 antibody with stem cell transplantation generates objective responses in 85% to 90% of cases, including 75% to 80% complete remissions. Although more patients need to be evaluated with a longer follow-up period, radioimmunotherapy appears to be an effective and well-tolerated addition to the oncologists' armamentarium for relapsed lymphomas.