Stanford researchers have developed a synthetic, tumor-targeting molecule that promotes immune activation and tumor regression in laboratory mice after it’s injected into their bloodstreams.
November 12, 2021 - By Krista Conger
An immunotherapy molecule administered intravenously to mice was shown to target tumors.
Activating the immune system at the site of a tumor can recruit and stimulate immune cells to destroy tumor cells. One strategy involves injecting immune-stimulating molecules directly into the tumor, but this method can be challenging for cancers that are not easily accessible.
Now, Stanford researchers have developed a new synthetic molecule that combines a tumor-targeting agent with another molecule that triggers immune activation. This tumor-targeted immunotherapy can be administered intravenously and makes its way to one or multiple tumor sites in the body, where it recruits immune cells to fight the cancer.
Three doses of this new immunotherapy prolonged the survival of six of nine laboratory mice with an aggressive triple negative breast cancer. Of the six, three appeared cured of their cancer over the duration of the monthslong study. A single dose of this molecule induced complete tumor regression in five of 10 mice. The synthetic molecule showed similar results in a mouse model of pancreatic cancer.
“We essentially cured some animals with just a few injections,” said Jennifer Cochran, PhD, the Shriram Chair of the Department of Bioengineering. “It was pretty astonishing. When we looked within the tumors, we saw they went from a highly immunosuppressive microenvironment to one full of activated B and T cells — similar to what happens when the immune-stimulating molecule is injected directly into the tumor. So, we’re achieving intra-tumoral injection results but with an IV delivery.”
A paper describing the study published online Nov. 12 in Cell Chemical Biology. Cochran shares senior authorship with Carolyn Bertozzi, PhD, the Baker Family Director of Stanford ChEM-H, Anne T. and Robert M. Bass Professor in the School of Humanities and Sciences and professor of chemistry; and Ronald Levy, MD, the Robert K. and Helen K. Summy Professor in the School of Medicine. The lead authors are graduate student Caitlyn Miller and instructor of medicine Idit Sagiv-Barfi, PhD.