Stanford University researchers have reported 97 percent laboratory success eliminating metastasized tumors in mice by injecting vaccines directly into tumors to activate T cells.
Ronald Levy and Idit Sagiv-Barfi have led a team at the Stanford University School of Medicine to develop what they believe could be a possibly wide-ranging cancer treatment that involves injecting microgram (one-millionth of a gram) amounts of two immune-stimulating agents directly into solid tumors.
The discovery was published in Science Translational Medicine on Jan. 31.
The researchers did not disclose the two-part cocktail being injected into tumors, but they did acknowledge that one agent has already been approved for human use, and the other agent has been approved for human testing in several unrelated clinical trials.
The procedure has been shown to be effective against a wide spectrum of cancers, including what researchers referred to as “distant, untreated metastases cancers” that arose spontaneously during laboratory animal tests.
Researchers believe the direct injections of very small amounts of the cocktail of two agents could serve as a rapid and relatively inexpensive cancer therapy, with a very low likeliness of causing the type of human immune reaction that causes patient side-effects.
The success rate in animals was so high that human lymphoma patients have already been recruited to participate in a Stage 1 human clinical trial that began in month.
Ronald Levy, MD, professor of oncology, who holds the Robert K. and Helen K. Summy Professorship in the School of Medicine, is the senior author of the study. He is a pioneer in the field of cancer immunotherapy, trying to stimulate immune systems to more effectively attack cancer cells. Levy led the effort to development rituximab, one of the first monoclonal antibodies to receive FDA approval for human anticancer therapies.
Cancers often exist in a type of limbo with regard to the immune system. Immune cells like T cells recognize the abnormal proteins that attach to cancer cells, and they infiltrate to attack the tumor. However, as the tumor grows, it often devises defensive responses to suppress the activity of the T cells.
But once Stanford researchers used their technique to activate tumor-specific T cells in the original tumors, T-cells were also released and traveled through the animal subjects to find and destroy identical tumors throughout the mice.
According to Dr. Levy: “When we use these two agents together, we see the elimination of tumors all over the body.” He added “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.”