In a major breakthrough, Stanford researchers found that activating T cells in tumors of mice could eliminate even remote metastases, paving the way for a clinical trial on humans with lymphoma.
Researchers Ronald Levy and Idit Sagiv-Barfi at the Stanford University School of Medicine injected minute amounts of two immune-stimulating agents into solid tumors in mice that has turned positive and most effective in the treatment of several types of cancer in mice.
"When we use these two agents together, we see the elimination of tumors all over the body," said Ronald Levy, professor of oncology. "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."
Since one of these two agents was already approved for use in humans, the other has been tested in several unrelated clinical trials conducted since January in patients with lymphoma.
Injecting one tumor site with the two agents caused the regression of both the treated and the untreated tumor, resulting in 87 of 90 mice cured of the cancer. When the cancer recurred in three of the mice during the experiment, a second treatment again regressed them.
"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," Levy said.
Levy, a pioneer in the field of cancer immunotherapy, who led to the development of rituximab, one of the first monoclonal antibodies approved for use as an anti-cancer treatment in humans, said: "Our approach uses a one-time application of very small amounts of two agents to stimulate the immune cells only within the tumor itself. In the mice, we saw amazing, bodywide effects, including the elimination of tumors all over the animal."
The findings of the study have been published in the journal Science Translational Medicine.