modified poliovirus under investigation for the treatment of malignant
glioma appears to attack the cancer directly as well as by
stimulating the immune system
- The oncolytic
virus PVSRIPO, an engineered hybrid of poliovirus and rhinovirus, is being
investigated for its anticancer effects in malignant glioma
- It appears to act
in two ways - by directly killing tumor cells and by activation
of the immune system to fight the cancer
. The research that revealed the dual effect of
the oncolytic virus was published in Science
The modified virus
called PVSRIPO, an engineered hybrid of poliovirus and rhinovirus, appears to
act in two ways:
- It directly kills the tumor cells. Once injected into the body, the virus attaches to the
CD155 protein, also called the poliovirus receptor, which is abundant on
cancer cells. It directly kills most cells and releases tumor antigens in
the body. The exposed antigen can stimulate an immune response, that is,
it can activate neutrophils (a type of white blood cells) which then
attack the cancer.
modified vaccine has been in clinical trials for the treatment of recurrent
World Health Organization grade IV malignant glioma
- It stimulates the body's immune response to fight the
cancer. It enters immune cells called
dendritic cells and macrophages. It does not damage these cells but these
cells in turn stimulate the immune cells called T-cells, which recognize,
infiltrate and attack the cancer cells. The long-lasting immune response
produced in this manner can possibly prevent the regrowth of the cancer.
. This cancer is
considered to be of high grade.
‘The oncolytic virus PVSRIPO, an engineered hybrid of poliovirus and rhinovirus, appears to exhibit dual action against glioma cancer cells.’
treatment has recently received a breakthrough therapy designation from the US
Food and Drug Administration
. Such a designation ensures the expedition of
the development process for a drug that has shown substantial clinical improvement
over an existing treatment in a serious or life-threatening disease. Further research could see a
new treatment that could be used as an adjuvant along with other treatments for
the life-threatening cancer.
A glioma is a cancer
that arises from the glial or the supporting cells of the brain or spinal cord.
Gliomas are of three types, astrocytomas, oligodendrogliomas, and ependymomas.
While some gliomas can be benign, around 80% are malignant. They are diagnosed
on brain scans and biopsy of the growth. They are usually surgically treated, with
radiotherapy and chemotherapy used to kill the cancer cells that remain after
Cancer treatment has
seen several additions to the conventional surgery, radiotherapy and
chemotherapy in the recent years. Oncolytic viruses
selectively break down cancer cells, are among the new treatments that have
spurred great interest. T-VEC
(talimogene laherparepvec (T-VEC) was the first oncolytic virus approved in the
United States for the treatment of metastatic melanoma, a deadly skin cancer
arising from the pigment cells called melanocytes.
- Brown MC et al. Cancer immunotherapy with recombinant poliovirus induces IFN-dominant activation of dendritic cells and tumor antigen-specific CTLs. Science Translational Medicine (2017): Vol. 9, Issue 408, eaan4220 DOI: 10.1126/scitranslmed.aan4220
- Biological Therapies for Cancer - (https://www.cancer.gov/about-cancer/treatment/types/immunotherapy/bio-therapies-fact-sheet#q7)