The Good Virus - Reovirus' New Role as Cancer Fighter
viruses are undergoing an "extreme makeover" after a long-standing reputation as bothersome and in many cases, lethal to the human body. A virus named the Respiratory Enteric Orphan virus, or reovirus, has been discovered to have the ability to grow in and kill a broad range of cancer cells without growing in or damaging normal, non-cancerous cells.
Oncolytics Biotech's REOLYSIN(R), an experimental, reovirus-based cancer therapy, is able to freely replicate in and kill the host tumor cell. When the cancer cell dies, thousands of progeny viruses are freed, which proceed to infect and kill adjacent cancer cells. This process is believed to continue until all adjacent cancer cells have been infected with the reovirus, according to Brad Thompson, CEO of Oncolytics Biotech. The reovirus cannot grow in healthy cells, therefore normal cells remain healthy.
"REOLYSIN targets these tumors directly and has been shown to be effective in various trials," says Thompson. Oncolytics has successfully completed two human clinical studies in Canada, and is currently conducting two additional trials: a Phase I intravenous administration trial with the reovirus at the Royal Marsden Hospital in the United Kingdom, and a direct injection brain tumor trial in Canada. Plans are underway for additional trials both in the U.K. and in the U.S.
The science behind the new therapy was discovered at the University of Calgary back in 1998 when researchers were studying how certain viruses grow and multiply. They determined that the reovirus needed an "activated Ras Pathway" in order to be able to grow in and subsequently kill the cancer cell. The Ras Pathway is instrumental in transferring growth signals to the nucleus of a cell, telling the cell when and how to grow-much like an "on-off" switch. An activated Ras Pathway, which has lost its ability to "turn off," leads to uncontrolled cell growth. An activated Ras Pathway is found in approximately two-thirds of all human cancers.
As the population ages, cancer is expected to surpass cardiovascular disease as the leading cause of death. In fact, half of all men and one-third of all women will develop some form of cancer during their lifetimes. The American Cancer Society estimates that there are currently 8.9 million people in the United States with a history of cancer.
Other news from the department research and development
