Immune changes in patients with colorectal cancer treated by adjuvant therapy with monoclonal antibody 17-1A: a pilot study.

We investigated the efficacy of Mo17-1A to improve important immunological parameters in vivo and in vitro in colorectal cancer (CRC) patients receiving no second-line treatment. Eighteen CRC patients stage Dukes' C were treated postoperatively with 5 doses of Mo17-1A. Peripheral blood mononuclear cells (PBMC) were analyzed for proliferative responses and cytolytic activity. Serum levels of cytokines were determined during treatment. Enhancement in the proliferative activity of patients' T cells, improvement in their lymphocytes' killing ability of natural killer (NK) and lymphokine-activated killer (LAK) sensitive tumor targets, and an in vivo increase in serum levels of interleukin (IL)-2, IL-12, IL-15, interferon (IFN)-gamma and granulocyte-macrophage colony-stimulating factor (GM-CSF) were noted. We conclude that treatment of CRC patients with Mo17-1A partially restores deficient cellular immune responses and the secretion of cytokines with immuno-enhancing properties. The development of novel immunotherapeutic protocols using combinations of Mo17-1A with stimuli that enhance the lytic capacity of effector cells (e.g. cytokines), may improve clinical responses in these types of patients.