Cancer Survival Boosted by Tetanus Shot With Vaccine

A common tetanus booster shot given to patients with a deadly form of brain cancer shortly before an experimental cancer vaccine prolonged their survival, a small study found.

Duke University researchers who led the study say the regimen could mark a new way to stimulate the body’s immune system to attack tumors, a growing area of interest in cancer treatment. The scientific journal Nature published the study results online Wednesday.

“We’ve discovered a way to enhance cancer vaccines which dramatically improves their efficacy” without significant side effects, said John Sampson, chief of neurosurgery at Duke and lead author of the study. He cautioned the study was small—12 patients—and the regimen needs to be validated in further testing, which is being planned.

Duke is in the process of licensing the vaccine technology to a startup company, Annias Immunotherapeutics Inc.

Dr. Sampson and colleagues studied patients with glioblastoma, a fast-growing type of malignant brain tumor. Surgeons typically can remove part of the tumor, which is often followed by radiation and chemotherapy. But such treatments typically can’t eradicate all of the cancer, and most patients die within about 15 months of diagnosis, Dr. Sampson said.

Prior research found that most glioblastomas harbor a strain of cytomegalovirus, or CMV, a common virus not found in healthy brain tissue. The Duke researchers developed a therapeutic vaccine made by extracting white blood cells from a patient and using them to grow dendritic cells, which help initiate the body’s immune response to attack tumors. Researchers load the dendritic cells with a viral protein particle that helps the immune system home in on the CMV in the brain tumor, and then inject them back into patients.

Because other attempts to develop cancer vaccines had produced limited efficacy, the Duke researchers tested whether first administering a tetanus-diphtheria shot would enhance the cancer vaccine’s effects. The tetanus shots, which are normally given to protect against bacterial infections, were given to six of the patients, while the other six received a placebo. All 12 patients received the dendritic-cell vaccine a day after getting the tetanus shot or placebo.

The median overall survival of the six patients who received only the vaccine was 18.5 months from the time of diagnosis. The six patients who received the tetanus booster lived longer on average. The first three who died lived from 20 to 26 months after diagnosis. Two others lived for nearly five and six years, respectively. A sixth patient is still alive more than eight years after diagnosis, according to Duke.

Researchers say they think the tetanus booster bolstered the immune system’s attack on the tumor by helping more dendritic cells from the cancer vaccine migrate to the lymph nodes, activating an immune response.

The tetanus shot “operated like a tornado warning siren,” said Kristen Batich, a Duke graduate student and neurosurgeon candidate who co-wrote the study. “It was a great opportunity to use tetanus to sort of awaken the immune system.”

The researchers said there were no significant treatment-related side effects.

The study was funded by the U.S. National Institutes of Health and brain-tumor research associations.

Write to Peter Loftus at peter.loftus@wsj.com