Up until the mid-1950s polio was epidemic across many countries with an estimated 500,000 people paralysed or killed each year. Two vaccines were developed (one by Jonas Salk launched in 1957, the other by Albert Sabin in 1962), which lead to a dramatic decline in cases, and eventually eradication in many high-income countries. Following this the World Health Organization, UNICEF and the Rotary Foundation began an eradication campaign in 1988, and as a result there were only 22 reported polio cases worldwide in 2017. However, recent research has suggested that polio may be able to help patients with grade IV malignant gliomas. Such patients have low survival rates – less than 20 months following diagnosis, and less than 12 months for recurrent gliomas. Current therapies are ineffective, inconsistent in improving survival and have many toxic effects. The trial was conducted using PVSRIPO, a modified live attenuated poliovirus type 1 vaccine. This is able to recognise CD155, a poliovirus receptor that is widely expressed in tumour cells. In total 61 patients were given a dose of PVSRIPO and followed up. Although 19% of patients had moderate-severe (grade 3 or higher) adverse events attributed to PVSRIPO, the overall survival of patients reached a plateau of 21% (95% CI 11-33) at 24 months, which was sustained at 36 months. This was higher than the rate among historical controls.
- Desjardins A, Gromeier M, Herndon JE, et al. Recurrent Glioblastoma Treated with Recombinant Poliovirus. New Engl J Med. 2018.