A new cancer therapy is currently under clinical trials at Duke's Preston Robert Tisch Brain Tumor Center.
This new approach involves injecting a brain tumor with modified poliovirus, which invades and kills cancerous brain cells while being harmless to normal brain cells. Nine patients have been successfully treated so far in phase one of the trial, which aims to determine a safe and effective dosage at which to treat patients, said Dr. Annick Desjardins, associate professor of neurology and principal investigator of the study.
Dr. Matthias Gromeier, associate professor in the department of neurosurgery, began preclinical development of the modified poliovirus in 2002.
More than 15 years of research went into the poliovirus therapy prior to starting clinical trials, which is not unusual, Gromeier said.
“The absolutely essential prerequisite on the research side was a large monkey neurovirulence study,” he said, which tested the treatment on monkeys to establish the safety of the approach.
Additional research was also done to determine how the poliovirus interacted with cancer cells.
Another vital component before trials could begin was a modified poliovirus that infected cancer cells while having no effect on normal cells, which was developed by the National Institute of Health, Gromeier said.
The first patient, Stephanie Lipscomb, found out she had stage four gioblastoma, the most lethal and common form of brain cancer, as a nursing student at age 20. Although chemotherapy was unsuccessful in eradicating the tumor entirely, the experimental poliovirus therapy was able to reduce the tumor to the size of a pea, Desjardins said.
"She has a normal life as a nursing student," Desjardins said of Lipscomb. "Looking at her, no one could imagine that she had been diagnosed with a terminal brain cancer. We cannot say that she is cured, but she is in remission for sure.”
Currently, side effects of the poliovirus therapy are minimal, Gromeier said.
“Thus far, the main side effects we have observed are due to the infusion of fluid into the brain of the patients when we administer the poliovirus," he said. "Because of that, they have increased brain swelling, which can trigger short-lived spells of brain dysfunction, like seizures, weakness, speech difficulties."
Gromeier noted that the side effects, including brain swelling, normally resolve very rapidly with the utilization of steroids.
Dr. Henry Friedman, deputy director at the Brain Tumor Center, said he is optimistic about the potential of the poliovirus therapy for other types of cancers, such as prostate cancer, melanoma and breast cancer.
Although the new therapy is not a cure, it will drastically improve the life expectancy and quality of life of these patients, he noted.