Prospects for the management of non-Hodgkin's lymphomas with monoclonal antibodies and immunoconjugates.

PURPOSE

To review the role of monoclonal antibody constructs in the treatment of B-cell malignancies.

PATIENTS AND METHODS

The efficacy and tolerability of unmodified monoclonal antibodies, immunotoxins, and radioimmunoconjugates have been investigated in patients with hematologic B-cell malignancies. Response rates, durability of responses, and tolerability were the principal measures of treatment outcome.

RESULTS

Investigators from several institutions have documented response rates ranging from 25% to 95% in lymphoma patients suffering relapses who were treated with antibody constructs targeting the CD19, CD20, CD22, DR, or idiotypic immunoglobulin epitopes on malignant B-cell lymphomas. Chimeric anti-CD20 antibodies and 131I-labeled anti-CD20 antibodies appear particularly promising, producing response rates of 50% to 95%. Complete remissions (CRs) appear to be more frequent and durable with radiolabeled anti-CD20 antibodies (33% to 85% CR rate) than with unmodified chimeric anti-CD20 antibodies (6% to 10% CR rate), although a randomized comparison has not yet been made.

CONCLUSION

Monoclonal antibodies provide promising new reagents for the treatment of patients with B-cell non-Hodgkin's lymphomas. Impressive response rates have been achieved in clinical trials using unmodified monoclonal antibodies, immunotoxins, and radioimmunoconjugates, although the durability of responses is still under scrutiny. Durability may be improved when the antibodies are used in conjunction with chemotherapy or stem cell transplantation.