Scientists report that the poliovirus could help some patients fight a deadly form of brain cancer.
Experimental treatment appears to have extended the life of a small group of patients with a type of brain tumor, glioblastoma, from Duke University, published Tuesday, in The New England Journal of Medicine ,
"I have been doing this for 50 years and have never seen such results." Darell Bigner, Emeritus Director of the Preston Robert Tisch Brain Tumor Center at the Duke Cancer Institute, who is involved in the development of the treatment, said NPR:
Glioblastoma is the most common and aggressive cancer tumor in adults. It is the cancer that killed ex-vice president Joe Biden's son Beau. Senator John McCain was diagnosed. The prospects for patients with this cancer are often bleak.
To develop the new experimental treatment, scientists used a genetically modified version of the poliovirus because the virus can inhabit the cells of the nervous system.
One of the genes of the virus has been removed to prevent it causing polio, which can lead to devastating paralysis, and replaced it with a gene from a harmless cold.
Researchers then infused the altered virus directly into brain tumors. The modified virus retains the ability to infect and kill brain tumor cells and also appears to activate the patient's immune system cells to fight the tumors. This is particularly important as glioblastoma patients often have a malfunctioning immune system from cancer treatments such as radiation, ABC News reported.
This treatment was associated with some risks. Some patients had side effects such as seizures, headaches and speech problems. In some cases, there may be inflammation in the brain.
According to the results of the clinical study, 21 percent of the 61 patients with relapsed glioblastoma who received the experimental therapy survive the current standard therapy for three years or more, compared to only 4 percent of those receiving chemotherapy, CNN reported.
The scientists were surprised by the results. "You just do not see that percentage of long-term survivors with this disease," said Bigner NPR. "Those who have survived for more than two years are in remission, and we expect them to continue to be long-term survivors."