PVSRIPO | |
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Virus classification | |
(unranked): | Virus |
Realm: | Riboviria |
Kingdom: | Orthornavirae |
Phylum: | Pisuviricota |
Class: | Pisoniviricetes |
Order: | Picornavirales |
Family: | Picornaviridae |
Genus: | Enterovirus |
Species: | |
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. [1]
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. [2]
A website at Duke University describes many of properties of PVSRIPO, and historical background about using viruses to oppose cancer. [3] According to that website,
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 . [4]
In May 2016, the US Food and Drug Administration granted it breakthrough therapy designation for glioblastoma. [2]
Gene therapy is a medical field which focuses on the genetic modification of cells to produce a therapeutic effect or the treatment of disease by repairing or reconstructing defective genetic material. The first attempt at modifying human DNA was performed in 1980, by Martin Cline, but the first successful nuclear gene transfer in humans, approved by the National Institutes of Health, was performed in May 1989. The first therapeutic use of gene transfer as well as the first direct insertion of human DNA into the nuclear genome was performed by French Anderson in a trial starting in September 1990. It is thought to be able to cure many genetic disorders or treat them over time.
A brain tumor occurs when abnormal cells form within the brain. There are two main types of tumors: malignant tumors and benign (non-cancerous) tumors. These can be further classified as primary tumors, which start within the brain, and secondary tumors, which most commonly have spread from tumors located outside the brain, known as brain metastasis tumors. All types of brain tumors may produce symptoms that vary depending on the size of the tumor and the part of the brain that is involved. Where symptoms exist, they may include headaches, seizures, problems with vision, vomiting and mental changes. Other symptoms may include difficulty walking, speaking, with sensations, or unconsciousness.
Glioblastoma, previously known as glioblastoma multiforme (GBM), is one of the most aggressive types of cancer that begin within the brain. Initially, signs and symptoms of glioblastoma are nonspecific. They may include headaches, personality changes, nausea, and symptoms similar to those of a stroke. Symptoms often worsen rapidly and may progress to unconsciousness.
Cancer immunotherapy is the stimulation of the immune system to treat cancer, improving on the immune system's natural ability to fight the disease. It is an application of the fundamental research of cancer immunology and a growing subspeciality of oncology.
An oncolytic virus is a virus that preferentially infects and kills cancer cells. As the infected cancer cells are destroyed by oncolysis, they release new infectious virus particles or virions to help destroy the remaining tumour. Oncolytic viruses are thought not only to cause direct destruction of the tumour cells, but also to stimulate host anti-tumour immune system responses. Oncolytic viruses also have the ability to affect the tumor micro-environment in multiples ways.
Virotherapy is a treatment using biotechnology to convert viruses into therapeutic agents by reprogramming viruses to treat diseases. There are three main branches of virotherapy: anti-cancer oncolytic viruses, viral vectors for gene therapy and viral immunotherapy. These branches use three different types of treatment methods: gene overexpression, gene knockout, and suicide gene delivery. Gene overexpression adds genetic sequences that compensate for low to zero levels of needed gene expression. Gene knockout uses RNA methods to silence or reduce expression of disease-causing genes. Suicide gene delivery introduces genetic sequences that induce an apoptotic response in cells, usually to kill cancerous growths. In a slightly different context, virotherapy can also refer more broadly to the use of viruses to treat certain medical conditions by killing pathogens.
The Semliki Forest virus is an alphavirus found in central, eastern, and southern Africa. It was first isolated from mosquitoes in the Semliki Forest, Uganda by the Uganda Virus Research Institute in 1942 and described by Smithburn and Haddow. It is known to cause disease in animals including humans.
Senecavirus is a genus of viruses in the order Picornavirales, in the family Picornaviridae. Pig and maybe also cow serve as natural hosts. There is only one species in this genus: Senecavirus A. Senecavirus is a replication-competent oncolytic picornavirus. It has selective tropism for cancers with neuroendocrine features including small cell lung cancer (SCLC) and several pediatric solid tumors including retinoblastoma, neuroblastoma, and medulloblastoma. A Phase I clinical trial of Senecavirus in adults with neuroendocrine tumors showed that senecavirus is apparently safe to administer at doses up to 1E11 vp/kg. It has potential antineoplastic activity.
Oncolytics Biotech Inc. is a Canadian company headquartered in Calgary, Alberta, that is developing an intravenously delivered immuno-oncolytic virus called pelareorep for the treatment of solid tumors and hematological malignancies. Pelareorep is a non-pathogenic, proprietary isolate of the unmodified reovirus that: induces selective tumor lysis and promotes an inflamed tumor phenotype through innate and adaptive immune responses.
Pelareorep is a proprietary isolate of the unmodified human reovirus being developed as a systemically administered immuno-oncological viral agent for the treatment of solid tumors and hematological malignancies. Pelareorep is an oncolytic virus, which means that it preferentially lyses cancer cells. Pelareorep also promotes an inflamed tumor phenotype through innate and adaptive immune responses. Preliminary clinical trials indicate that it may have anti-cancer effects across a variety of cancer types when administered alone and in combination with other cancer therapies.
JX-594 is an oncolytic virus is designed to target and destroy cancer cells. It is also known as Pexa-Vec, INN pexastimogene devacirepvec) and was constructed in Dr. Edmund Lattime's lab at Thomas Jefferson University, tested in clinical trials on melanoma patients, and licensed and further developed by SillaJen.
Talimogene laherparepvec, sold under the brand name Imlygic, is a biopharmaceutical medication used to treat melanoma that cannot be operated on; it is injected directly into a subset of lesions which generates a systemic immune response against the recipient's cancer. The final four year analysis from the pivotal phase 3 study upon which TVEC was approved by the FDA showed a 31.5% response rate with a 16.9% complete response (CR) rate. There was also a substantial and statistically significant survival benefit in patients with earlier metastatic disease and in patients who hadn't received prior systemic treatment for melanoma. The earlier stage group had a reduction in the risk of death of approximately 50% with one in four patients appearing to have met, or be close to be reaching, the medical definition of cure. Real world use of talimogene laherparepvec have shown response rates of up to 88.5% with CR rates of up to 61.5%.
Many variants of herpes simplex virus have been considered for viral therapy of cancer; the early development of these was thoroughly reviewed in the journal Cancer Gene Therapy in 2002. This page describes the most notable variants—those tested in clinical trials: G207, HSV1716, NV1020 and Talimogene laherparepvec. These attenuated versions are constructed by deleting viral genes required for infecting or replicating inside normal cells but not cancer cells, such as ICP34.5, ICP6/UL39, and ICP47.
Dr. Matthias Gromeier is a Professor in the Department of Neurosurgery at Duke University Medical Center, who has developed a way to re-engineer a poliovirus to inspire the human immune system to kill cancer cells in a specific set of cancers. The re-engineered virus, called PVSRIPO, cannot replicate itself in normal cells, but can replicate itself in cancer cells that have an overabundance of the protein marker that the poliovirus targets.
John Howard Sampson, M.D., Ph.D, M.B.A, M.H.S.c, is the former chief of the department of neurosurgery at Duke University where he serves as a professor of surgery, biomedical engineering, immunology, and pathology.
GL-ONC1 is an investigational therapeutic product consisting of the clinical grade formulation of the laboratory strain GLV-1h68, an oncolytic virus developed by Genelux Corporation. GL-ONC1 is currently under evaluation in Phase I/II human clinical trials in the United States and Europe.
Genelux Corporation is a privately held, biopharmaceutical clinical stage company that was founded in 2001. The main focus of Genelux is oncolytic immunotherapy based on attenuated, genetically engineered oncolytic viruses as therapeutic agent.
Peter Edward Fecci is an American neurosurgeon, professor and researcher. He is an Associate Professor of Neurosurgery, Pathology and Immunology at Duke University School of Medicine. He also serves as Director of the Duke Center for Brain and Spine Metastasis, Director of the Brain Tumor Immunotherapy Program, Residency Program Director, and Associate Deputy Director of the Preston Robert Tisch Brain Tumor Center at Duke.
Duane A. Mitchell, M.D., Ph.D. is an American physician-scientist and university professor. He is currently employed at the University of Florida College of Medicine, in Gainesville, Florida as the Assistant Vice President for Research, Associate Dean for Translational Science and Clinical Research, and Director of the University of Florida (UF) Clinical and Translational Science Institute. He is the Phyllis Kottler Friedman Professor in the Lillian S. Wells Department of Neurosurgery. and Co-Director of the Preston A. Wells, Jr. Center for Brain Tumor Therapy. Dr. Mitchell is also the Founder, President, and Chairman of iOncologi, Inc., a biotechnology company in Gainesville, FL specializing in immuno-oncology.
Transgene S.A. is a French biotechnology company founded in 1979. It is based in Illkirch-Graffenstaden, near Strasbourg, and develops and manufactures immunotherapies for the treatment of cancer.