Researchers at Duke University used a modified form of the poliovirus to treat patients with a deadly form of brain cancer with mild success, giving hope for a potential cure down the road.

The study was published in The New England Journal of Medicine and involved patients with grade IV malignant glioma, also known as glioblastoma. That's the same type of brain cancer that killed former Sen. Ted Kennedy and Beau Biden, the son of former Vice President Joe Biden.

More recently, Sen. John McCain, R-Ariz., is also suffering from the aggressive cancer and did not receive a positive prognosis.

According to the study's results, however, 21 percent of patients given the experimental poliovirus treatment survived for either 24 months or 36 months. Some patients even lived more than 69 months after treatment began.

"Of the 35 patients with recurrent WHO grade IV malignant glioma who were treated more than 24 months before March 20, 2018, a total of 8 patients remained alive as of that cutoff date," the study's authors concluded. "Two patients were alive more than 69 months after the PVSRIPO infusion. Further investigations are warranted."

According to the study, patients diagnosed with grade IV malignant glioma generally do not survive for more than 20 months. The researchers dealt with 61 patients during a five-year period that ended in May 2017.

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