Immune stimulants may help cancer patients, study shows

This investigation is the first to indicate that the drug trastuzumab (marketed by Genentech as Herceptin) may work better when it is followed by injections of interleukin (IL) 2 or IL-12. Both substances trigger the activity of immune cells known as natural killer (NK) cells.

The drug trastuzumab consists of an antibody that targets the protein HER2, which is present on cancer cells of many breast tumors. NK cells are the body’s first line of defense against many infections, and they also attack tumor cells. NK cells rush into action when they encounter bacteria or other foreign agents in the body that are coated with antibodies, large proteins released by immune cells in response to the presence of foreign material in the body.

The investigators found that the combination of antibody-coated cells and IL-2 or IL-12 causes the NK cells to release substances that attract more potent immune cells, mainly killer T cells, thereby trigging a larger and more effective immune response against the tumor.

“The findings suggest that using trastuzumab and the IL-12 together makes the body think an infection is underway, and this activates cells of the immune system to eliminate tumor cells in the same way they would eliminate an infection,” explained Julie Roda, a graduate research associate at Ohio State University. “Trastuzumab was not designed to mimic an infectious condition, but we think that’s exactly what is happening”.

The researchers used both cell culture techniques and analyzed plasma samples from 15 cancer patients to reach their findings. They conclude that although further research is needed, the preliminary results suggest that using immune-stimulating agents may benefit patients receiving antibody drugs like trastuzumab.