A novel cancer vaccine is moving to Phase 1 human trials in the United States after promising results from animal studies showed encouraging efficacy and a robust safety profile. A new study describes the vaccine as producing complete responses in 90 percent of animals when combined with a second immunotherapy drug.
Perhaps the biggest breakthrough in cancer therapy over the past couple of decades has been the development of immune checkpoint inhibitors. These treatments focus on blocking the mechanisms cancer cells use to evade attack from immune cells.
One such mechanism cancer cells can often cleverly highjack to avoid attack from the body’s immune system involves PD-1, a checkpoint protein expressed on the surface of killer immune cells. When PD-1 binds with PD-L1, another checkpoint protein found on healthy cells as well as some cancer cells, it essentially serves as a way to tell killer immune cells, nothing to see here and to move on.
PD-1 inhibitors are a relatively new class of drugs that allow killer immune cells to more effectively detect and kill cancer cells. Several first-generation anti-PD-1 monoclonal antibodies have been approved to treat various cancers in recent years. This new therapy, called PD1-Vaxx, is designed to trigger a broader polyclonal antibody response, with hopefully better efficacy than the first generation of checkpoint inhibitors.