Glioblastoma is among the most dire diagnoses, with a median survival of around 15 months. The current standard of care involves surgery, radiation, and chemotherapy. The results of the study mirror those of a trial in 10 pet dogs that had developed brain tumors—whose owners agreed to their participation after running out of treatment options—and a preclinical study in mice, the U.S. university said in a statement. “The discovery will now be tested in a Phase 1 pediatric clinical trial for brain cancer,” it added. Published Wednesday in the U.S. journal Cell, it could provide a new way to use the immune system to fight treatment-resistant cancers because, while it uses mRNA and lipid nanoparticle technology—like the COVID-19 vaccines—it uses “a patient’s own tumor cells to create a personalized vaccine” and has “a newly engineered and complex delivery mechanism.” “Instead of injecting single particles, we are injecting clusters… these alert the immune system in a much more profound way than the particles alone,” said Elias Sayour, a pediatric oncologist at UF Health and the new vaccine’s inventor who led the study, in the statement. It is administered intravenously, like other immunotherapies, which attempt to “teach” the immune system to recognize a tumor as foreign. Sayour said that “one of the most striking findings was how quickly” the new vaccine “stimulated a robust immune response to reject the tumor.” Within “less than 48 hours,” he said, the immune response had ramped up and become “very active.” “What that tells us is that we were able to activate the very early part of the immune system against these cancers very quickly, and that is critical to unlocking the downstream effects of the immune response.” The new publication is the culmination of “promising results” Sayour’s team has seen over seven years of research. With approval from the U.S. Food and Drug Administration (FDA), the researchers have now launched this small clinical trial, designed to ensure the safety and feasibility of testing before moving to a larger trial. “Demonstrating that making an mRNA vaccine against aggressive malignancies like this generates similar and robust responses in mice, dogs… and human patients with brain cancer is a really important finding, because we often don’t know to what extent preclinical studies in animals will translate to similar responses in patients,” said Duane Mitchell, director of UF’s Clinical and Translational Science Institute and the university’s Brain Tumor Immunotherapy Program, who co-authored the paper. “And while mRNA vaccines and therapeutics have certainly been a ‘hot topic’ since the COVID pandemic, this is a novel and unique way of delivering mRNA to generate these really significant and rapid immune responses,” he added. The scientists note that while it is too early to assess the vaccine’s clinical benefit, patients have either lived disease-free for longer than expected or survived longer than predicted. The 10 pet dogs lived a median of 139 days, compared to a typical median survival of 30 to 60 days for dogs with the disease. The next step, with support from the FDA and the CureSearch for Children’s Cancer foundation, is a larger Phase 1 clinical trial, involving up to 24 adult and pediatric patients, to validate the findings. Once the “optimal safe dose” has been confirmed, a Phase 2 trial will follow, involving around 25 children, Sayour said. Despite the promising results, the authors warn that there is still much uncertainty about how best to harness the immune system while minimizing the potential for adverse side effects. Read Also: COVID-19. Agency recommends updating vaccines against JN.1 variant (Portuguese version)