Improving IL-2 Therapy With MAbs

Combining interleukin-2 with monoclonal antibodies targeted at cytotoxic killer cells offers improved anticancer effects compared with either treatment alone, according to a study published in the Proceedings of the National Academy of Sciences (August 15).

The study researchers, from the Rogosin Institute of the New York Hospital Cornell Medical Center, found that tumor-bearing mice which were treated with both interleukin-2 (Hoffmann-La Roche's Proleukin) and an antibody directed at the CD3 receptor on T-cells showed prolonged survival time and fewer liver metasases than mice who received either therapy alone.

IL-2 stimulates the proliferation of T-cells and boosts their ability to kill tumor cells, while the anti-CD3 antibody appears to enhance T-cells responsiveness to the cytokine. The authors note that current immunotherapy for cancer using IL-2 generally uses nonphysiological and toxic doses of the drug, "so identification of an in vivo stimulant that renders T-cells responsive to physiologic concentrations of IL-2 represents a potential improvement over existing approaches." Current therapy also requires leukapheresis and in vitro activation of cells, which may be done away with using the new regimen.