Experimental vaccine increases survival to 50% in four people with fatal brain cancer | The science

Four people with extremely aggressive brain cancer lived 50% longer than expected thanks to a personalized experimental vaccine, according to results published this Wednesday by Spanish biochemist Hector Mendez and his colleagues at the University of Florida in Gainesville. The patients, now deceased, were suffering from end-stage glioblastoma, the most common malignant brain tumor, when they voluntarily participated in the clinical trial. “It’s very promising,” says Mendes, who was born in Salamanca 42 years ago and settled in the United States.

The human body’s defenses often do not recognize cancer cells as a threat. The Florida team uses a complex strategy. Researchers inject millionth-of-a-millimeter lipid particles into a vein, with genetic information obtained directly from each patient’s tumor. This messenger RNA recipe, like the Pfizer and Moderna Covid vaccine recipe, trains the immune system to think that tumor cells are dangerous viruses and destroy them.

Mendez explains that patients who received the standard treatment used as the reference had a six-month survival rate. However, one of those vaccinated lived to nine months, a 50% increase. Another participant lived eight months, 33% longer. In two other patients, the results were positive, but not as positive, says the Spanish biochemist. The team, led by American oncologist Elias Sayur, now wants to start a larger study involving 24 patients to confirm the safety of the vaccine and refine the dose. The next step will be another study of about 25 children with glioblastoma.

“It seems to improve survival in humans, and we have not yet found any type of chronic toxicity,” says Mendes, who trained at the University of Salamanca and the Cajal Institute in Madrid. Previous animal experiments have also been promising. A dozen dogs with fatal brain cancer lived an average of nearly five months after receiving the vaccine, longer than the usual survival rate of one or two months. The new results will be published this Wednesday in a specialized journal cell.

Oncologist Laura Angelac she applauds the new job but is cautious. “This is a very innovative strategy and the preclinical data is very interesting, but we still have very little patient data to confirm that this is a safe and effective treatment,” emphasizes the expert from the Hospital Clínic in Barcelona. .

Two more experimental RNA vaccines are in advanced human trials. Oncologist Vinod Balachandran is leading a pancreatic cancer vaccine trial at Memorial Sloan-Kettering Cancer Center in New York. And pharmaceutical companies Moderna and Merck have also seen promising results with an RNA melanoma vaccine. All of them are therapeutic vaccines for the treatment of already established cancer. English oncologist Sarah Blagden from the University of Oxford is leading a project to develop a preventive vaccine against lung cancer based on harmless chimpanzee cold viruses. The technology is similar to that of the AstraZeneca Covid vaccine.

Angelats reminds that glioblastomas are “cold tumors” because there are almost no inflammatory or immune cells around the cancer cells. Immunotherapy, which involves stimulating one’s own defenses against cancer, is much less effective for cold tumors. The oncologist emphasizes that if the experimental vaccine against glioblastoma finally works, the same strategy could be applied against other cold tumors, such as colon cancer. “There is still a lot left to do, but this is promising data,” he says.

Immunologist Luis Alvarez Vallina also praises the new work. “I find this very interesting, this is another step towards the advent of RNA vaccines, which will be very important against cancer. This is a significant contribution, despite its limitations,” says the scientist, director of clinical research for cancer immunotherapy at the 12 October Hospital and National Cancer Research Center in Madrid.

Alvarez Vallina points out that the lipid nanoparticles used by the American team are larger than usual and have a multi-layered onion-like structure, which enhances their preventive effect on the immune system. The immunologist predicts a future with combination strategies, such as vaccination combined with other immunotherapies such as immune checkpoint inhibitors. “The scenario will be very flexible, depending on the characteristics of each patient and their clinical situation, but I believe that vaccines will become an important element of the arsenal,” he says.

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