Researchers use virus to fight cancer

Treatment blows up leukemia cells ‘like popcorn,’ scientist says

OTTAWA — Cancer researchers around the world are excited about a virus-based treatment developed in Ottawa that blows up leukemia cells “like popcorn.”

Results of the treatment, which boasts a 60-per-cent cure rate in mice, are so promising and safe it could go to clinical trials in humans in as little as two years.

The treatment is an engineered virus micro-particle that attacks leukemia cells. Within a day of an injection, the membranes of the cancer cells are compromised.

The cell membranes deteriorate and the cells blow up “like popcorn,” says hematologist Dr. David Conrad, the senior co-author of the study.

Three doses cured 60 per cent of the mice, and 80 per cent of the experimental population had long-term survival.

This is a “paradigm shift” in the understanding of using virus-based therapies to treat acute leukemia, the researchers said in Blood Cancer Journal, which is associated with the prestigious science journal Nature.

The news generated a lot of buzz at a recent international cancer conference in Quebec City, says Conrad, who’s part of a research team with members from the Ottawa Hospital Research Institute, the Ottawa Hospital and the University of Ottawa.

“When the immune system sees these cells, it gets rid of the debris. It forms an immune response. If new cancer cells grow, the immune system recognizes them and kills them,” Conrad says.

“There’s a lot of interest because it’s not just potent, it’s safe.”

For about a decade, Ottawa Hospital Research Institute scientists including Dr. John Bell, who was the other senior researcher in this study, have been investigating viruses as cancer therapeutics.

But there’s an added wrinkle to using viruses to attack leukemia.

Conrad said he believes it will be possible to increase the cure rate in mice and to move on to human clinical trials within the next few years.

Because the virus particles don’t replicate, the route to getting approval for a therapy will be less onerous, he says.