CHEO researcher to test virus in fight against brain cancer
A CHEO scientist has received a $2.2-million research grant to manufacture a cancer-fighting virus that could give doctors a new weapon to deploy against the aggressive form of brain cancer that now afflicts Gord Downie, lead singer of The Tragically Hip.
Dr. David Stojdl, a senior scientist at the Children’s Hospital of Eastern Ontario Research Institute, will use the grant to prepare the Farmington virus for use in a Phase I clinical trial.
The trial will be the first to test a modified version of Farmington in patients with glioblastoma, a fastgrowing cancer that originates in the brain. It is the most common form of brain cancer among adults.
Stojdl, a professor at the University of Ottawa, has been working for years to take Farmington out of the lab, where it has shown great promise, and into human trials.
“We’re incredibly excited and humbled by the opportunity,” he said. “But to be honest, it’s now a bit scary because we have to get the job done.”
Almost 3,000 Canadians are diagnosed with brain cancer each year.
Brain tumours are some of the most difficult cancers to treat: The average adult diagnosed with glioblastoma survives about a year, according to the Ontario Institute for Cancer Research. Treatment usually consists of surgery, chemotherapy and radiation, but glioblastomas can be located in sensitive areas of the brain, and often have fast-growing cells that are hard to completely eliminate.
Treatment is also complicated by the fact that many drugs cannot cross the blood-brain barrier to act on a tumour, and by the need to strictly control inflammation since the brain has little room to swell. Each patient’s brain tumour is also genetically distinct.
There are currently no effective long-term treatments.
“We know there’s a need for something drastically better,” said Stojdl, “and we think this particular technology — Farmington — checks many of the boxes in terms of what we’ve been searching for.”
Farmington was first isolated from a wild bird captured in central Connecticut in 1969 as scientists were searching for evidence of another virus — one tied to encephalitis outbreaks.
Stojdl came to focus on Farmington as he searched for the best viruses to use in the fight against cancer. Farmington held intriguing possibilities because it existed in the brains of healthy birds.
“For us, that was an exciting proposition,” he said. “We were really looking for viruses that were able to exist in the brain but do so in a safe way: We wanted something that would not damage normal brain cells.”
Since brain tissue is sensitive and not easily regenerated, Stojdl wanted a virus that would only infect and destroy cancer cells while leaving the rest of the central nervous system intact. Farmington fit the bill.
Viruses are highly evolved infectious agents that can colonize and destroy human cells. Those properties, scientists believe, make them ideally suited to attacking malignant tumour cells, which have genetic mutations that make them particularly susceptible to viruses.
Stojdl has custom-designed the Farmington virus to seek out and destroy brain-cancer cells, while at the same time triggering a broad immune response against the same type of tumour. Researchers hope the virus will also act as a vaccine and offer patients long-lasting protection against a relapse.
The clinical trial to test the safety and effectiveness of the Farmington virus will be based at Toronto’s St. Michael’s Hospital; it’s expected to launch in about 18 months.
The clinical trial funding was part of a $24-million announcement made this week by the Ontario Institute for Cancer Research. As part of that announcement, a team co-directed by Dr. John Bell, a senior scientist at The Ottawa Hospital, received $4 million to explore and test new, virus-based cancer treatment strategies. aduffy@postmedia.com