Use of isotopic immunoglobulin in therapy.

Antibodies raised in heterologous species against tumor-associated antigens such as ferritin and carcinoembryonic antigen may be utilized in diagnostic scanning and in cancer therapy. The radiolabeled (131I) antibodies have a mean effective half-life of 3 days. The tumor-bearing regions retain activity which was associated with objective evidence of remission in primary hepatic cancers. Major organ toxicity was not apparent in eight of nine patients treated with radioactive antibody. Objective evidence of clinical remission was documented by computer-assisted axial tomography scan remission in sequential studies that determine residual tumor in the same planar cuts. Future possible improvements in radioimmunoglobulin are discussed in light of the clinical findings.