An innovative poliovirus therapy developed at the Duke Cancer Institute, at Duke University, shows significantly improved rates of survival for patients with recurrent glioblastoma — an aggressive cancer that can occur in the brain or spinal cord.
Sixty-one patients received the genetically modified poliovirus treatment between May 2012 through May 2017. Twenty-one percent of the patients were alive after three years, sharply higher than a survival rate of just 4 percent for those receiving standard treatment.
“I’ve been doing research on brain tumors for 50 years, and I’ve never seen clinical trial results this good,” says Dr. Darell Bigner, the director emeritus of the The Preston Robert Tisch Brain Tumor Center at the Duke Cancer Institute in North Carolina.
The recent trials are attributed to research that began 25 years ago in the lab of Dr. Matthias Gromeier, a professor of neurosurgery at Duke Medical Center.
Gromeier and his team discovered that the poliovirus receptor, CD155, is almost universally expressed on cancer cells — a finding that means tumor cells from most cancers can be infected with the poliovirus, damaging the cells and possibly destroying them. Gromeier engineered the virus so it can only reproduce in cancer cells, ensuring the therapy can’t cause polio’s paralysis or death.
“One of the attractions of the poliovirus receptor is that it appears on virtually any solid cancer — prostate, liver, pancreas, lung — and the mechanisms we believe that work apply to all these tumors,” Gromeier says. Duke is already working on testing the treatment on other cancers.
Patients see positive results
Last August, 33-year-old Michael Niewinski flew to Durham, North Carolina, to receive the poliovirus treatment. Niewinski was diagnosed with a Grade II brain tumor in 2011, but six years later his tumor progressed to a Grade IV glioblastoma.
The diagnosis, though grim, made him eligible for the Duke clinical trial.
“A lot of people have asked me, ‘How did you feel knowing this might save your life?’ But I already knew it was going to save my life. I never thought for a second that I was dying,” says Niewinski.
Five months after the treatment, brain scans showed tumor shrinkage, and a recent scan indicates further improvement. Niewinski is optimistic about the results.
“The fight against cancer is no joke,” says Niewinski. “I’ve had so much great help during this process, and I feel like maybe this is my opportunity to give back.”
The poliovirus treatment used to treat Niewinski received “breakthrough therapy designation” from the U.S. Food and Drug Administration, which expedites the process to approve the experimental drug for widespread clinical use.
Bigner is in negotiations with the FDA and believes the approval process could be “as short as two years.”
Next steps
The Duke University researchers will treat triple-negative breast cancer and melanoma in an upcoming trial. This trial will also begin using a new class of agents called “checkpoint inhibitors,” which overcome one of cancer’s main defenses against an immune system attack.
“We are combining checkpoint inhibitors with the virus in one of our next trials,” says Bigner. “Our hope is that it will increase the [survival] percentage up to as much as 50 percent.”
“Every clinical trial is just a step toward the next one, and the next approach,” says Gromeier. “For the past 20 years, we have worked on this in the lab, and the lab science actually correlates with what we see in the patient — I’m excited about this.”
