News Release

Toronto researcher's discovery points to a new treatment avenue for acute myeloid leukemia

Peer-Reviewed Publication

University Health Network

Toronto, July 6, 2009-- Dr. John Dick, Senior Scientist at the Ontario Cancer Institute, the research arm of Princess Margaret Hospital, co-led a multinational team that has developed the first leukemia therapy that targets a protein, CD123, on the surface of cancer stem cells that drive acute myeloid leukemia (AML), which is an aggressive disease with a poor outcome.

Dr. Richard Lock is leading the clinical trial in Australia that expands on research suggesting that antibodies targeting cancer stem cells significantly reduced the growth of human AML cells that had been transplanted into immune-deficient mice, a laboratory model that mimics the human disease, establishing the therapeutic potential of this type of therapy.

Dr. Tom Hudson, President and Scientific Director of the Ontario Institute for Cancer Research (OICR) congratulated Dr. Dick, who is the Program Leader of OICR's Cancer Stem Cell Program. Dr. Hudson said, "John Dick has made remarkable progress in the understanding of what initiates and sustains cancer. Together with his collaborators Dr. Dick has developed the first anti-cancer monoclonal antibody therapy that specifically targets cancer stem cells. This discovery offers hope for the development of treatments that target the cancer stem cells of other types of tumours as well."

"This is precisely the role we envisioned for the Ontario Institute for Cancer Research when the McGuinty government created it back in 2005," said Minister of Research and Innovation John Milloy. "Bringing together this province's considerable strengths around cancer prevention, detection, diagnosis and treatment is helping Ontario lead the fight against this terrible disease."

The research on AML builds on the discovery by Dr. Dick that there is a population of cells within cancer, termed cancer stem cells, which are responsible for sustaining cancer growth. Their earlier research had shown that cancer stem cells are often resistant to standard chemotherapy and since they survive such therapy, they can eventually cause a recurrence of the disease.

The antibody targets the CD123 protein (IL-3 receptor α chain) on the cancer stem cells that drive cancer growth. The antibody does not appear to affect normal blood cells. On the basis of this experimental work, a Phase I clinical trial has been initiated to test safety and effectiveness in patients.

"The cancer stem cell hypothesis is one of the most exciting ideas in cancer biology, with the potential to truly transform cancer therapy. A major question has been whether agents could be developed that specifically target these cells without affecting normal stem cells," said Dr. Benjamin Neel, Director of the Ontario Cancer Institute. "The work of Drs. Dick and Lock provides the first evidence that such therapies may be possible."

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The research paper Monoclonal Antibody-Mediated Targeting of CD123, IL-3 Receptor α Chain, Eliminates Human Acute Myeloid Leukemic Stem Cells was published in Cell Stem Cell July 2, 2009.

OICR is a new research institute, moving Ontario to the forefront of discovery and innovation. It is dedicated to research in prevention, early detection, diagnosis, treatment and control of cancer. OICR is a not-for-profit corporation funded by the Government of Ontario through the Ministry of Research and Innovation. For more information, please visit the website at www.oicr.on.ca.

University Health Network consists of Toronto General, Toronto Western and Princess Margaret Hospitals. The scope of research and complexity of cases at University Health Network has made it a national and international source for discovery, education and patient care. It has the largest hospital-based research program in Canada, with major research in oncology, cardiology, transplantation, neurosciences, surgical innovation, infectious diseases, and genomic medicine. University Health Network is a research hospital affiliated with the University of Toronto. For more information, please visit www.uhn.ca.

For more information, please contact:
Rhea Cohen
Director of Communications
Ontario Institute for Cancer Research
Telephone: 416-673-6642
Mobile: 416-671-2846
Email: rhea.cohen@oicr.on.ca

Nicole Bodnar
Public Affairs & Communications
Princess Margaret Hospital, University Health Network
Telephone: 416-946-2846
Email: nicole.bodnar@uhn.on.ca


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