Trial shows virus hits cancer, spares normal cells
Mid-stage trial in liver cancer patients under way
Another big step in ‘customizing’ viruses to target tumors
Reovirus attacking a cancer cell
By Deena Beasley
Aug 3, 2011 (Reuters) – Researchers have shown for the first time that a single intravenous infusion of a genetically engineered virus can home in on cancer, killing tumor cells in patients without harming healthy tissue.
Scientists have been intrigued for decades with the idea of using viruses to alert the immune system to seek and destroy cancerous cells. That interest has taken off in recent years as advances in genetic engineering allow them to customize viruses that target tumors.
The field received a boost in January when biotech giant Amgen Inc (AMGN.O) agreed to pay up to $1 billion for BioVex, the developer of experimental cancer-fighting virus OncoVex. But the only “oncolytic virus” so far approved by a regulatory agency is for treatment of head and neck cancer in China.
In a study published in the journal Nature on Wednesday, scientists at institutions including the University of Ottawa and privately held biotech company Jennerex Inc, said a small, early-stage trial of experimental viral therapy JX-594 found that it consistently infected tumors with only minimal and temporary side effects.
The experimental virus will next be tested in a mid-stage trial of patients with liver cancer.
“With chemotherapy you get drastic side effects,” said Dr. John Bell, chief scientific officer at Jennerex and senior scientist at the Ottawa Hospital Research Institute. “Patients on this treatment only had 24-hour flu symptoms, and nothing after that.”
The trial, which involved 23 patients with various types of advanced cancer, was designed to assess the safety of JX-594. It also found that six of the eight patients given the two highest doses saw their tumors stabilize or shrink.
He said earlier trials of JX-594 showed really strong activity in liver cancer. Since some kinds of liver cancer are caused by viruses — like hepatitis B — the theory is that those tumor cells may be more susceptible to a second virus.
JX-594 is derived from a strain of the virus (reovirus) once commonly used to vaccinate children against smallpox.
“We know it is pretty safe,” Dr. Bell said, noting that genetic information needed for the virus to mutate has been deleted from JX-594.
He also said that because the Jennerex virus can be given intravenously, spreading throughout the body, it may hold promise for limiting the ability of cancer cells to metastasize and spread.
Other viral cancer therapies are also progressing in clinical trials, but they either require direct injection into the tumor or accompany chemotherapy.
“We are all competing against standard of care,” said Matt Coffey, chief operating officer at Oncolytics Biotech.
Jennerex is primarily funded by investors from Canada and South Korea. European rights to JX-594 have been licensed to Transgene (TRNG.PA)
More links on this subject:
Harmless Virus Could Be an Answer to Cancer:
The answer to cancer could be a virus By Jennifer Young:
Cancer-Killing Virus May Be The Answer For Patients With KRAS Mutated Tumors:
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