Administering brain tumour patients genetically modified poliovirus therapy can boost their three-year survival rate by 21 per cent, show results of a clinical trial.

Comparatively, the previously available standard treatment could save just 4 per cent of patients with glioblastoma -- a malignant tumour affecting the brain or spine, the researchers said. "Glioblastoma remains a lethal and devastating disease, despite advances in surgical and radiation therapies, as well as new chemotherapy and targeted agents," said Darell D. Bigner, from the Duke University in North Carolina, US.

"With the survival rates in this early phase of the poliovirus therapy, we are encouraged and eager to continue with the additional studies that are already underway or planned," Bigner added. The poliovirus therapy had in 2016 obtained "breakthrough therapy" designation from the US Food and Drug Administration. The therapy, described in the journal Science Translational Medicine, includes a genetically modified form of the poliovirus vaccine, which is infused directly into the brain tumour via a surgically implanted catheter and preferentially zeroes in on tumour cells, igniting a targeted immune response.

For the phase 1 trial, launched in 2012, the team included a small group of pateints who were followed-up for 27.6 months. For all the poliovirus patients, the median overall survival was 12.5 months, compared to 11.3 months for the historical control group. At three years, the gap widened further, with a survival rate of 21 per cent for poliovirus patients, compared to 4 per cent in the control group. The researchers are further planning to combine the poliovirus with other approved therapies to improve survival.