Treatment of patients with metastasizing colo-rectal carcinoma with mouse monoclonal antibodies (Moab 17-1A): a progress report.

Eight patients with metastasizing colo-rectal carcinoma have been treated with Moab 17-1A. Before infusion the antibodies were incubated in vitro with isolated autologous blood mononuclear cells (AMC) enriched for monocytes/macrophages. Treatment was given in repeated courses (2-4 times) up to a maximum amount of 1000 mg Moab 17-1A. Two patients had an objective tumor reduction. In further four patients a period of stable disease varying between 3-6 months on was observed. Therapy was well tolerated. Out of 24 treatment courses only on one occasion an anaphylactoid reaction occurred at the third infusion. All patients developed anti-mouse antibodies of IgG and IgM class with increasing levels during the course of therapy. Repeated tumor biopsies and immunohistochemical analyses showed no antigenic modulation, a weak staining for mouse IgG, no deposits of complement components but no obvious increases in the number of cells infiltrating the tumors 24 h after infusion of antibody-armed AMC.