Using a process called in situ vaccination, in which the host’s immune system is recruited to attack cancer cells, researchers were able to clear injected tumors—and nearby metastases—in mice, according to a study published yesterday (January 31) in Science Translational Medicine.
Scientists at Stanford University injected a pair of molecules—an antibody against a protein on the surface of T cells, known as OX40, and a short piece of DNA called a CpG oligodeoxynucleotide—into various types of solid tumors, including melanoma and breast and colon cancers, in mice. “When we use these two agents together, we see the elimination of tumors all over the body,” Ronald Levy, an oncologist at Stanford University, says in a statement. “This approach bypasses the need to identify tumor-specific immune targets and doesn't require wholesale activation of the immune system or customization of a patient's immune cells.”
Levy and his team also tested the approach on a mouse strain prone to a highly invasive form of breast cancer that often metastasizes, and found that the treatment reduced the size of the injected tumor and nearby cancerous growths. It was also able to prevent further tumor development.
“The data is very impressive, particularly for the uninjected tumors,” Drew Pardoll, a cancer immunologist at the Bloomberg~Kimmel Institute for Cancer Immunotherapy who did not take part in the study, tells Science.
“This early research in mice suggests that this could be an effective way of engaging the immune system to tackle cancer,” Catherine Pickworth of Cancer Research UK tells The Telegraph. “These types of treatments are exciting but can be complicated—one of the biggest challenges of immunotherapies is predicting how they will work with patients’ immune systems, and understanding what the side effects could be.”
Levy and colleagues are now launching a clinical trial to test the injection in patients with lymphoma.