Poliovirus against glioblastoma

The modified virus stopped the development of a brain tumor

Natalia Pelezneva, Naked Science

Researchers from Duke University managed to significantly prolong the life of patients with the most aggressive form of brain tumor — glioblastoma. To do this, they used a genetically modified poliovirus. The work was published in the New England Journal of Medicine (Desjardins et al., Recurrent Glioblastoma Treated with Recombinant Poliovirus).

Glioblastoma is not only the most aggressive, but also one of the most common brain tumors, up to 52% of primary neoplasms in the brain belong to this type. In the fight against the disease, chemotherapy, radiation therapy and surgical treatment are used, while patients rarely live longer than 15-20 months after the diagnosis is announced. Recurrent ("returning") tumors that reappear after the end of therapy are especially dangerous – in this case, patients rarely live longer than a year.

Poliomyelitis – spinal paralysis – occurs when a poliovirus that has entered the body binds to the CD155 protein (poliovirus receptor) on the cell surface. It is known that CD155 overexpression can occur in tumor tissues: an excessive amount of this protein appears on the surface of cancer cells.

The researchers created a non-pathogenic modification of the poliovirus, which was called PVSRIPO. The drug was injected directly into the tumor using a thin tube. The modified virus effectively recognizes CD155 and promotes necrosis of malignant cells, but does not affect healthy ones. Also, the introduction of PVSRIPO stimulates the activity of the immune system, forcing its cells to fight the tumor.

61 patients with recurrent glioblastoma participated in the study of the new treatment method. 21% of patients who underwent such therapy were able to live for more than three years. In the control group of 104 people with the same disease who were treated with standard methods, such a life expectancy was recorded in only 4%. Two patients who received PVSRIPO remain alive six years after the first administration of the drug. Both patients had a relapse of the tumor, and repeated administration of the modified virus also proved effective.

Tumor reduction after therapy (bottom row, from left to right: one, two and five years after PVSRIPO administration). A drawing from an article in NEJM.

In the future, scientists plan to combine PVSRIPO with other treatments that enhance the immune response to make the technique more effective.

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