Tumor-Melting Virus vs. Prostate Cancer
Reovirus Is Harmless -- Except to Many Kinds of Cancers
WebMD News Archive
One way of overcoming this problem is by using reovirus together with
chemotherapy. Chemo kills cancer cells, but also dampens antiviral immune
responses. A recent human study shows this strategy can benefit patients with
advanced head and neck cancer.
Another way to overcome the problem is to harness anti-reovirus immune
responses to attack cancer cells.
"The virus only sticks to tumor cells, so it sort of directs the immune
response to the tumor area," Morris says. "We have actually taken reovirus and
injected it in combination with tumor antigens, so the immune system kills
tumors pasted with the virus."
There's still a lot of work to do before reovirus in general, or Reolysin in
particular, becomes an approved cancer treatment, says cancer expert Rameen
Beroukhim, MD, PhD. Beroukhim was not involved in the Morris study.
"There is a long way between this interesting study and showing that
reovirus is going to be beneficial to patients," Beroukhim says. "But the hope
is that this treatment could be tweaked in some way to have a systemic
Morris is the first to acknowledge that there's a lot more work to do. One
major issue, he says, is that not every patient's cancer is susceptible to
"In the majority of cancers, if you take specimens from different patients,
not all cancers are killed. Maybe seven or eight of 10 patients' cancers are
sensitive. So we need to find out what makes a cancer cell susceptible to
reovirus," he says.
The Morris study was partially funded by Oncolytics Biotech, and the company
funds his laboratory. But Morris says he has not been compensated by any
companies in the oncology-virus field for the last five years. Although he is a
patent holder on some indications for reovirus, he has signed away rights to
Morris and colleagues report their findings in the March 15 issue of