- The NeoVax treatment is surprisingly effective in treating cancer cells.
- Its effectiveness lasts at least for four years.
A vaccine effective for several years against melanoma: this is the discovery made by researchers from the Dana-Farber Cancer Institute, Brigham and Women’s Hospital, MIT and Harvard (United States). The vaccine, called NeoVax, targets specific proteins on the tumor cells of each patient. Four years later, the immune response triggered by the vaccine remains robust and effective in keeping cancer cells under control. The results were published in the journal Nature medicine January 21, 2021.
For this study, eight people underwent surgery for advanced melanoma that could potentially recur. In a phase 1 clinical trial, they were treated with NeoVax 18 weeks after the operation. The vaccine, made up of epitopes – fragments of proteins that come out of the surface of cells and serve as signals to the immune system – works to increase the efficiency of T lymphocytes. NeoVax epitopes come from abnormal proteins of tumor cells, their role is to warn the body that a cell is cancerous and that it must be destroyed. Since neoantigens are only found on tumor cells, the triggered immune response spares normal cells.
Four years after treatment with NeoVax, all eight patients were alive and six of them showed no signs of active disease. Looking at patients’ T cells, the researchers found that not only did cells “remember” their original target epitopes, they also expanded their repertoire to recognize other melanoma-related epitopes.
An effective vaccine over time
“These results demonstrate that a personal neoantigen vaccine can stimulate a long-lasting immune response in patients with melanoma“said Catherine Wu, the co-director of the study. We found evidence that the initial and targeted immune response has broadened over the years to provide patients with continued protection against disease.”
In two patients, whose cancer had spread to the lungs, the researchers found signs that the T cells had entered the tumor tissue, where they could more actively fight the melanoma cells.
“We have found evidence of everything we look for in a strong and sustained immune responsesays Patrick Ott, who co-led the study with Catherine Wu. T cells continued to specifically target melanoma cells and retained a memory of the epitopes to which they initially responded. T cells have been activated to kill tumor cells and, critically, have branched out to target melanoma epitopes not included in the original vaccine. ”