Monoclonal antibody therapies for lymphomas

Important advances in molecular biology and chelation chemistry have led to new and improved monoclonal antibody reagents. Rituximab (IDEC-C2B8) was approved by the United States Food and Drug Administration for relapsed CD20-positive lymphomas, and denileukin diftitox was approved (DAB389IL-2) for CTCL. Ibritumomab tiuxetan and iodine 131 anti-B1 have excellent activity and acceptable toxicity and likely higher responses than rituximab. These questions should be answered in phase III trials, and preliminary results from the rituximab versus ibritumomab tiuxetan trial suggest higher responses to the latter. Data on radiolabeled Lym-1, T101, LL2, and anti-Tac also look promising. The therapeutic role of immunotoxins has yet to be determined, but encouraging data with DAB389IL-2 and LMB-2 have been reported. Antibody conjugates with drugs, prodrugs, nonprotein toxins, and other agents are also under investigation. Bispecific antibodies for lymphoma may also have a future role in lymphoma therapy. It is anticipated that many of the major advances in lymphoma therapy will be antibody based.