A genetically modified poliovirus therapy has demonstrated significantly improved long-term survival in patients with recurrent glioblastoma.
The phase 1 dose-finding and toxicity study enrolled 61 adult patients with histopathologically-confirmed recurrent supratentorial World Health Organization (WHO) grade IV malignant glioma, with measurable disease (contrast-enhancing tumour of ≥1cm and ≤5.5cm in greatest dimension). Participants received varying doses of convection-enhanced, intratumoral delivery of the recombinant nonpathogenic polio-rhinovirus chimera (PVSRIPO), first in a dose-escalation phase and then in a dose-expansion phase.
PVSRIPO recognises the poliovirus receptor CD155, which is widely expressed in neoplastic cells of solid tumours and in major components of the tumour microenvironment.
Overall survival among the patients who received PVSRIPO reached a plateau of 21 per cent (95% CI 11-33) at 24 months, which was sustained at 36 months. In the dose-expansion phase, 19 per cent of participants were recorded as having had a PVSRIPO-related adverse event of grade 3 or higher.
The phase 1 trial results were presented at the 22nd International Conference on Brain Tumor Research and Therapy in Norway earlier this week and were simultaneously published in the New England Journal of Medicine.