Modulation of cancer patients' immune responses by administration of anti-idiotypic antibodies.

Abstract

Thirty patients with Dukes stage D colon carcinoma who had undergone operative removal of the primary tumor and had growing hepatic metastases each received four intradermal injections of 0.5-4 mg of alum-precipitated goat anti-idiotypic antibodies (anti-Id). The anti-Id had been produced against murine monoclonal antibody (mAb) CO17-1A, which defines a human colon carcinoma associated antigen. All patients elaborated anti-anti-Id that shared idiotopes with mAb CO17-1A, bound to tumor cells and isolated tumor antigen, and competed with the mAb for binding to tumor cells. The clinical response was monitored by ultrasonography, CT, radionuclide scanning, and serum marker assays. Six patients had partial tumor responses; five of these had received additional booster anti-Id injections along with chemotherapy. Seven patients had stabilized tumor; six had received additional anti-Id, with chemotherapy also in four. Conclusions about the clinical role of such immunization await further study, but in demonstrating a specific response to anti-Id, our results support the use of this approach in human immunotherapy against tumors or pathogens.