Researchers at the Stanford University School of Medicine recently announced the results of a study in which they were able to eliminate all traces of cancer in laboratory mice by injecting tiny amounts of “two immune-stimulating agents” into their tumors. Furthermore, the injection appears to be effective in treating numerous types of cancer throughout the body. Lead researcher Dr. Idit Sagiv-Barfi and her colleague, Dr. Ronald Levy, believe their findings could lead to fast, inexpensive cancer treatments without the harmful side effects that often occur with other types of immune therapy.
Their findings were published on January 31st in Science Translational Medicine.
Using the body’s own immune system as a cure for cancer has long been the “Holy Grail” for oncology researchers. There have been a few problems with this approach, however. One of these is the fact that cancer cells are not foreign pathogens. Rather, they are native cells that begin to grow in an uncontrolled manner and refuse to die like normal cells. Because of this, the body’s immune system does not normally “see” cancer cells.
That said, there are molecules on the surface of malignant tumors that the body’s defenses do recognize, including certain proteins and carbohydrates. Currently, there are a number of specialized antibody therapies approved by the FDA used to treat specific forms of the disease. These include Campath (used to treat lymphatic cancers), Tecentriq (bladder cancer), Yervoy (melanoma) and Opdivo (cancers of the lung, kidneys and colon). Unfortunately, these drugs also cause serious – and in some cases, potentially fatal – side effects, ranging from hypotension and respiratory distress to life-threatening inflammation.
Sagiv-Barfi and Levy have found that their approach works for a wide range of cancers, and believe it will not cause the same adverse side effects that patients experience with current immunotherapies. Levy reports that the two agents used in their experiments resulted in the elimination of tumors throughout the test subjects’ bodies. He explains, “[Our] 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.”
Part of the vaccination, delivered locally, consists of the molecule from a protein known as a toll-like receptor (TLR ligand), which plays an important role in helping antibodies to recognize microbial pathogens. The other component, already approved for use in human patients, is called an anti-OX40 monoclonal antibody. This agent affects the OX40 receptor found on T-cells.
Levy, who has been doing some ground-breaking research in cancer immunotherapy, expresses optimism over the results of the recent study. Out of 90 test mice, 87 were completely cured of their cancer. Three of the mice experiencing recurrences, but these tumors again went into regression after a second treatment. He says, “I don’t think there’s a limit to the type of tumor we could potentially treat, as long as it has been infiltrated by the immune system.”