Immune function of patients with gastrointestinal carcinoma after treatment with multiple infusions of monoclonal antibody 17.1A.

Ten patients with metastatic adenocarcinomas of the colon or pancreas were treated with multiple injections of monoclonal antibody 17.1A. For each injection, antibody concentration in the patients' sera plateaued during the entire treatment course, and then decreased, with faster antibody clearance in patients given previous injections of mouse monoclonal antibodies for immunoscintigraphy. Six of the ten patients were able to generate anti-mouse antibodies, detectable 7 days after the initial infusion. Peripheral blood mononuclear cells from patients showed only low level ability to mediate spontaneous and antibody-dependent cytotoxicity in vitro, both before monoclonal antibody treatment and during the entire treatment period. Undiluted sera from these patients were unable to generate antibody-dependent cytotoxicity activity in vitro at any time during the observation period.