Effects of monoclonal antibody immunotherapy on patients with gastrointestinal adenocarcinoma.

Twenty patients with metastasis of gastrointestinal malignancies were treated with an anti-colorectal cancer mouse monoclonal antibody 1083-17-1A of the IgG2a class between December 1980 and January 1983. With two exceptions, all patients received a single injection of monoclonal antibody in a dose range of 15-1,000 mg/patient. No untoward immediate or delayed reaction to the initial injection was observed in any of the patients. Mouse immunoglobulin circulated in the patients' blood for 2-50 days, depending on the dose of monoclonal antibody injected, and was detected in tumor tissue within 1 week of its administration. Eight of nine patients who received doses of 366-1,000 mg monoclonal antibody did not develop anti-mouse antibodies, while eight of nine who received less than 200 mg developed anti-mouse immunoglobulin antibody. Three of this heterogeneous group of patients have no detectable disease now--10, 13, and 22 months since immunotherapy.