STANFORD, Calif. - Researchers at Stanford University School of Medicine in California have developed a breakthrough cancer treatment that eliminates tumors in mice, a newly released study found.
The cancer vaccine, which was tested on laboratory mice injected with various forms of cancer throughout their bodies, is currently in a clinical trial for patients receiving treatment for lymphoma. One of the two agents that make up the vaccine is currently approved for use in humans, according to researchers.
Of the 90 total laboratory mice that were tested, 87 were cured of the cancer. Although the cancer recurred in three of the mice, the tumors regressed after a second treatment, according to researchers.The treatment worked best in mice that were transplanted with mouse lymphoma tumors. Researchers also saw similar results in mice bearing breast, colon and melanoma tumors.
“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,” said Dr. Ronald Levy, professor of oncology.
To eliminate the tumors, researchers used an immunotherapy approach by activating T cells in cancerous tumors. The role of T cells in the human body is to act like soldiers, searching out to destroy harmful invaders, like cancer.
Injecting minute amounts of two immune-stimulating agents directly into solid tumors in mice proved to eliminate all traces of cancer in the mice, according to the study. This approach also worked for many different types of cancers, including those that arise spontaneously, researchers found. Treating the first tumor that arose often prevented the occurrence of future tumors and significantly increased the animals’ life span.
What’s even more encouraging is researchers believe that the local application of very small amounts of the agents could serve as both a rapid--and relatively inexpensive--cancer therapy.
Similarly, recently approved cancer treatments, like CAR T-cell therapy--while proven to be successful--comes with difficult-to-handle side effects as well as an extremely high cost. The breakthrough treatment is also unlikely to cause the adverse side effects often seen with bodywide immune stimulation, according to researchers.
“When we use these two agents together, we see the elimination of tumors all over the body,” said Levy. “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’s immunotherapy method works to reactivate the cancer-specific T cells by injecting microgram (one-millionth of a gram) amounts of two agents directly into the site of the tumor. Some of these tumor-specific, activated T cells then leave the original tumor to find and destroy other identical tumors throughout the body.
A current clinical trial underway is expected to recruit about 15 patients with low-grade lymphoma. If successful, Levy believes the treatment could be useful for many tumor types in humans.
Eventually, Levy said he envisions a future in which clinicians inject the two agents into solid tumors in humans prior to surgical removal of the cancer, which, Levy hopes, would prevent any recurrence of any cancerous tumor in the body.