In a first-in-human trial involving four adults with glioblastoma, the most aggressive and lethal brain cancer, an mRNA vaccine quickly reprogrammed the immune system to attack the tumor, researchers reported in Cell.
The mRNA technology is similar to what was used in mRNA COVID-19 vaccines, with two important differences, researchers said. The patient’s own tumor cells are used to create a personalized vaccine, and the delivery mechanism inside the vaccine has been re-engineered.
Instead of injecting single tiny lipid particles used to encapsulate the mRNA, the vaccine injects clusters of particles that wrap around each other.
“In the context of cancer… these clusters alert the immune system in a much more profound way than single particles would,” senior author Dr. Elias Sayour of the University of Florida said in a statement.
In each of the four volunteers, RNA was extracted from the surgically removed tumor and then messenger RNA (mRNA) — the blueprint of what is inside the cell — was copied and wrapped in lipid nanoparticles to make the tumor cells look like a dangerous virus that would promote an immune response when reinjected into the bloodstream.
In less than 48 hours, the tumors shifted from so-called cold tumors with a silenced immune response, to hot or “a very active immune response,” Sayour said, adding that the speed of the transformation “was very surprising.”
“What that told us is we were able to activate the early part of the immune system very rapidly against these cancers, and that’s critical to unlock the later effects of the immune response.”
While too little time has elapsed to assess the true clinical effects of the vaccine, the patients either lived disease-free longer than expected or survived longer than expected, the researchers reported
The vaccine will next be tested in a small early trial in adults and children with brain cancer, they said.
This newsletter was edited by Bill Berkrot; additional reporting by Shawana Alleyne-Morris.
