Dual Stem Cell Treatment Targets Melanoma Brain Metastases in Mice

Source: Genetic Engineering & Biotechnology News, June 2023

Overall survival for patients with melanoma that has spread to the brain is only four to six months. Immunotherapies, which harness the power of the immune system to attack cancer cells, have garnered excitement in recent years for their potential to revolutionize the treatment of metastatic melanomas, but results from early clinical studies indicate that the prognosis for most patients with brain metastatic disease remains poor.

Scientists from Brigham and Women’s Hospital, a founding member of the Mass General Brigham healthcare system, have integrated multiple therapeutic approaches to more effectively target melanoma in the brain. They developed an allogeneic twin stem cell (TSC) system composed of two tumor-targeting stem cell (SC) populations which they found successfully activated immune responses in metastatic melanoma mouse models that mimic human disease, to suppress tumor growth and prolong survival. The dual stem cell treatment comprised one set of stem cells engineered with a cancer cell-killing virus and another stem cell set engineered to produce immunomodulating proteins that ease the way for the virus to enter cells. The treatment boosted immune cell responses against humanized mouse models of brain metastatic melanoma and was more effective at treating the melanoma than oncolytic virus therapy alone.

“We know that in advanced cancer patients with brain metastases, systemic drugs, given intravenously and orally, do not effectively target brain metastases,” said corresponding author Khalid Shah, MS, PhD, director of the Center for Stem Cell and Translational Immunotherapy (CSTI) and the vice chair of research in the Department of Neurosurgery at the Brigham and faculty at Harvard Medical School and Harvard Stem Cell Institute (HSCI). “We have now developed a new immuno-therapeutic approach that is sustainable and delivered locally to the tumor. We believe that locally delivered immunotherapies represent the future of how we will be treating metastases to the brain.”