PVSRIPO
{{Virusbox
| parent = Enterovirus
| species = Enterovirus C
| strain = PVSRIPO
}}
PVSRIPO, or PVS-RIPO, is the name of a modified polio virus that has recently shown promise for treating cancer. It is the focus of clinical trials being conducted at Duke University.{{cite journal|last1=Brown|first1=Michael C.|last2=Dobrikova|first2=Elena Y.|last3=Dobrikov|first3=Mikhail I. |last4=Walton|first4=Ross W. |last5=Gemberling|first5=Sarah L. |last6=Nair|first6=Smita K. |last7=Desjardins |first7=Annick |last8=Sampson |first8=John H. |last9=Friedman |first9=Henry S. |last10=Friedman |first10=Allan H. |last11=Tyler |first11= Douglas S. |last12=Bigner |first12=Darell D. |last13=Gromeier|first13=Matthias|authorlink8=Matthias Gromeier |title=Oncolytic polio virotherapy of cancer|journal=Cancer |date=1 November 2014 |volume=120 |issue=21 |pages=3277–3286 |doi=10.1002/cncr.28862 |pmid=24939611 |pmc=4205207}}
PVS-RIPO consists of a genetically modified nonpathogenic version of the oral poliovirus Sabin type 1. The internal ribosome entry site (IRES) on the poliovirus was replaced with the IRES from human rhinovirus type 2 (HRV2), to avoid neurovirulence. Once administered, the virus enters and begins replicating within cells that express CD155/Necl5, which is an onco-fetal cell adhesion molecule that is common across solid tumors.{{cite web |url=http://global.onclive.com/web-exclusives/oncolytic-poliovirus-receives-breakthrough-designation-for-glioblastoma |title=Oncolytic Poliovirus Receives Breakthrough Designation for Glioblastoma |date=May 2016 |access-date=2016-05-25 |archive-url=https://web.archive.org/web/20160520034902/http://global.onclive.com/web-exclusives/oncolytic-poliovirus-receives-breakthrough-designation-for-glioblastoma |archive-date=2016-05-20 |url-status=dead }}
A website at Duke University describes many of properties of PVSRIPO, and historical background about using viruses to oppose cancer.{{cite web|title=Targeting Cancer with Genetically Engineered Poliovirus (PVS-RIPO)|url=http://www.cancer.duke.edu/btc/modules/Research3/index.php?id=41|website=The Preston Robert Tisch Brain Tumor Center|access-date=2015-03-31|archive-url=https://web.archive.org/web/20150401063859/http://www.cancer.duke.edu/btc/modules/Research3/index.php?id=41|archive-date=2015-04-01|url-status=dead}} According to that website,
{{blockquote|
The FDA approved clinical trials with PVS-RIPO in brain tumor patients recently. Since May 2012, five brain tumor patients have been treated. Remarkably, there have been no toxic side effects with PVS-RIPO whatsoever, even at the highest possible dose (10 billion infectious virus particles).
}}
The potential value of PVSRIPO was the focus of a 2015 story on 60 Minutes.{{cite news|title=Using polio to kill cancer: A producers' notebook|url=http://www.cbsnews.com/news/using-polio-to-kill-cancer-60-minutes/|accessdate=31 March 2015|work=60 Minutes Overtime|agency=CBS News|date=29 March 2015}}
In May 2016, the US Food and Drug Administration granted it breakthrough therapy designation for glioblastoma.