A phase I study has shown that a small group of patients with recurrent glioblastoma who received treatment with a modified form of poliovirus showed survival improvement over historical controls. The findings, which were not peer reviewed, were presented at the 2016 American Society of Clinical Oncology annual meeting.

The researchers reported the results of the first 15 patients in the phase I study. The initial findings showed a two-month survival advantage when compared to similar, non-study patients treated at the same institution. It also demonstrated higher survival at 24 and 36 months’ follow-up.

The 15 patients were participating in a dose-escalation trial. Five different doses at increasingly higher levels were tested: one patient at dose level one, seven at dose level two, one at level three, two at level four, and four at level five. The researchers compared the patients to 124 patients at their institution who did not receive the poliovirus therapy but were closely matched for demographic and treatment variables.

Nearly four years later, the median survival of patients receiving poliovirus therapy was 12.6 months, compared to 10.5 months for non-study patients. Approximately 20% of the poliovirus recipients were alive at 24 months compared to 13.7% of the non-study patients.

The poliovirus is modified to eliminate harmful effects and is attracted to certain receptors in cancer cells. The virus works by infecting the tumor cells and igniting an additional immune response to trigger the body to fight the cancer.

In May, the U.S. Food and Drug Administration granted it breakthrough therapy designation to speed research.