'firing on all cylinders'

When Treating Blood Cancers

Dr. Christopher Paige, Senior Scientist, spent close to two decades as University Health Network's Head of Research. He's been instrumental in advancing the area of immunotherapy and the treatment of leukemia.

Research has shown that white blood cells can talk to each other by exchanging signals and Dr. Paige has been studying how to distinguish the signals that activate the immune system compared to others that suppress it.

With this information, his team engineered a virus to have the same genetic blueprint as a protein called IL-12, which stimulated T-cells to fight the cancer. They developed an approach where they removed leukemia cells from the patient, inserted the virus into the DNA of the cells and then re-injected the cells into the patient.

“If you can stimulate the immune system, get it over a certain threshold, the immune system knows what to do. It will kill all of the other leukemia cells,” says Dr. Paige.

The result of this discovery led the team to begin a Phase 1 clinical trial to test a new therapy for leukemia.

“There have been incredible advances in immunotherapy, as well as targeted radiation medicine, image-guided surgery, new drug development and other areas all leading to new therapies that are more effective than anything we've seen before,” says Dr. Paige. “Princess Margaret Cancer Centre is really firing on all cylinders in all of these areas.”

Much progress has also been made in the treatment of one type of blood cancer known as acute myeloid leukemia (AML) in the past 10 years. One of the more common subtypes of AML has a mutation in the gene involved in regulating cell growth.

Dr. Tak Mak, world-renowned Senior Scientist, and his collaborators discovered a small molecule drug that could block the activity of the mutated gene, which can result in the leukemia going into remission.

As a result, the drug, called Enasidenib, has been fast-tracked by the U.S. Food and Drug Administration (FDA) to be made available to patients with this type of mutation in AML, as well as certain subsets of brain tumours and lymphomas.

“It's a pill. It doesn't require being in hospital for weeks or months at a time and it doesn't cause the same side effects as the usual chemotherapy for AML. In particular, it doesn't cause the damage to normal tissue that leads to infections that really compromise the outcome of patients with AML with our current therapies,” says Dr. Mark Minden, Clinician Scientist at The Princess Margaret who specializes in acute leukemia.