mRNA vaccine provokes strong immune response against brain tumor

Glioblastoma is among the most terrible diagnoses, with an average survival rate of around 15 months. The current standard of care involves surgery, radiation and chemotherapy.

The results of the study reproduce those obtained in a test with 10 dogs that had developed brain tumors, whose owners approved their participation as there were no other treatment options, as well as those of a pre-clinical study with rats, indicates the university in the United States in a statement.

“The discovery will now be tested in a Phase 1 pediatric clinical trial for brain cancer.”he added.

Published this Wednesday in the North American scientific journal Cell, this could be a new way of using the immune system to combat treatment-resistant cancers, because, although it uses mRNA technology and lipid nanoparticles (like the vaccines against Covid- 19), uses “the patient’s tumor cells to create a personalized vaccine” and has “a newly designed and complex delivery mechanism.”

“Instead of injecting single particles, we inject clusters, (…) these alert the immune system in a much more profound way than single particles,” said Elias Sayour, a pediatric oncologist at UF Health and pioneer of the new vaccine, which supervised the study, cited in the statement.

This, like other immunotherapies, tries to “educate” the immune system to consider the tumor as foreign and is administered intravenously.

Elias Sayour added that “one of the most impressive discoveries was how quickly” the new vaccine “stimulated a vigorous immune system response to reject the tumor.”

According to the researcher, “in less than 48 hours” the immune response increased and became “very active”.

“What this tells us is that we were able to very quickly activate the initial part of the immune system against these cancers and that is fundamental to unlocking the later effects of the immune response.”

The new publication is the culmination of “promising results” obtained by Sayour’s team over seven years of studies.

With approval from the Food and Drug Administration (FDA), researchers have now carried out this small clinical trial, designed to ensure the safety and feasibility of the tests before carrying out a larger trial. .

“The demonstration that making an mRNA vaccine against malignant tumors like this generates similar and strong responses in mice, dogs (…) and human patients with brain cancers is a really important discovery, because we often don’t know to what extent preclinical animal studies will translate into similar responses in patients,” said Duane Mitchell, director of the UF Clinical and Translational Science Institute and the Brain Tumor Immunotherapy Program at the same university, and co-author of the paper.

“And while mRNA vaccines and therapeutics have certainly been on the agenda since the Covid pandemic, this is a new and unique way of delivering mRNA to generate these really significant and rapid immune responses,” he added.

Scientists point out that, although it is premature to assess the clinical effects of the vaccine, patients lived without the disease for longer than expected or survived longer than expected.

The 10 pet dogs lived an average of 139 days, compared to an average survival of 30 to 60 days typical for dogs with the disease.

The next step, with support from the FDA and the CureSearch for Children’s Cancer foundation, is an expanded Phase 1 clinical trial, with up to 24 patients among adults and children, to validate the results.

Once the “optimal and safe dose” is confirmed, it will move to Phase 2, with the participation of around 25 children, said Sayour.

Despite the promising results, the authors warn of continued uncertainty about how best to harness the immune system while minimizing the potential for adverse side effects.