From the Ebola and Zika viruses to the common flu and influenza – which alone is responsible for half a million deaths per year – viruses have always been a major threat to our health.
But now the pharmaceutical industry is investing a huge amount of research into utilizing these infectious agents as medical agents against another deadly killer: cancer.
Known as oncolytic viruses, they can be engineered to attack and replicate in cancerous cells and not harm the healthy cells of the body, which means fewer side effects.
Scientists can modify viruses to target specific surface antigens on cancerous cells or to infect both normal and malignant cells, but only replicate in tumor cells.
When a virus does attack and proliferate in a cancerous cell, it causes it to burst open, exposing the virus to more of the cancerous cells and killing the tumor.
Because the mutations that cause a cancer to form also leave it susceptible to attack from a viral infection, oncolytic viruses can take advantage of the weakened immune response of a cancerous cell.
This is a two-pronged attack, as the damaged cancerous cells now initiate a broader immune response from the body, as our own immune response attacks other cancerous cells.
Groundbreaking approach to cancer treatment
In 2015, the FDA approved the first oncolytic virus therapy, Amgen’s Imlygic, for the treatment of inoperable melanoma lesions in the skin and lymph nodes.
The live oncolytic herpes virus is injected directly into the tumor and causes the cells to rupture and die.
It is also hoped that this therapy will yield a lasting effect, reducing the risk of relapse and proving hugely important in treating cancers that have spread into the blood or lymph nodes, which are typically hard to treat.
Research is still being carried out on this pioneering treatment, which could greatly improve cancer patients’ quality of life.