A team of Canadian scientists and clinicians, led by Dr. Michael Hill of the Calgary Stroke Program at Foothills Medical Centre and University of Calgary's Hotchkiss Brain Institute (HBI), have demonstrated that a neuroprotectant drug, developed by Dr. Michael Tymianski at the Krembil Neuroscience Centre, located at the Toronto Western Hospital, protects the human brain against the damaging effects of stroke.
The study, "Safety and efficacy of NA-1 for neuroprotection in iatrogenic stroke after endovascular aneurysm repair: a randomized controlled trial," published online today in The Lancet Neurology, was conducted concurrently with a laboratory study published in Science Translational Medicine, that predicted the benefits of the stroke drug.
This landmark clinical trial was a randomized, double blinded, multi-centre trial that was conducted in Canada and the USA. The study evaluated the effectiveness of NA-1[Tat-NR2B9c] when it was administered after the onset of small strokes that are incurred by patients who undergo neurointerventional procedures to repair brain aneurysms. This type of small ischemic stroke occurs in over 90% of aneurysm patients after such a procedure, but usually does not cause overt neurological disability.
In the clinical trial, patients were randomized to receive either Tat-NR2B9c or placebo. Those treated with Tat-NR2B9c showed a reduction in the amount of brain damage sustained as a result of the aneurysm repair procedure. Also, in patients who had ruptured brain aneurysm, which comprise a population of patients at very high risk of neurological damage, those treated with Tat-NR2B9c all had good neurological outcomes, whereas only 68% of those treated with placebo had good outcomes.
"The results of this clinical trial represent a major leap forward for stroke research," said Dr. Hill. "There have been over 1,000 attempts to develop such drugs, which have failed to make the leap between success in the lab and in humans."
"This clinical trial is, to our knowledge, the first time that a drug aimed at increasing the resistance of the brain to stroke, has been shown to reduce stroke damage in humans. No efforts should be spared to develop it further," said Dr. Michael Tymianski, who oversaw the development of Tat-NR2B9c from its invention in his lab, through to clinical trials.
Currently, t-PA is the only widely approved acute stroke therapy. It works by unblocking the arteries to the brain, however, this treatment is only beneficial for a portion of stroke victims. It also has serious potential for side-effects, including bleeding in the brain.
"Through our lab research and clinical trial, we now have a better method of predicting whether a stroke drug may be effective in humans and we now have the evidence that there is a neuroprotectant that can prevent damage in the brain caused by reduced blood flow," said Dr. Tymianski, inventor of NA-1 and one of the study's authors. "The benefits of this can be explored not only for stroke, but for other conditions such as vascular dementia."
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UCalgary Faculty of Medicine
Dr. Michael Hill is a stroke neurologist and the Director of the Foothills Medical Centre Stroke Unit for the Calgary Stroke Program. The Calgary Stroke program is a collaboration between the University of Calgary and Alberta Health Services and is one of North America's leading programs for stroke treatment and research. Dr. Hill is a member of the Hotchkiss Brain Institute and a Professor in the Department of Clinical Neurosciences in the Faculty of Medicine at the University of Calgary. He currently holds a Heart and Stroke Foundation Professorship in Stroke Research, and serves as the Associate Dean, Clinical Research in the Faculty of Medicine.
About the University of Calgary
The University of Calgary is a leading Canadian university located in the nation's most enterprising city. The university has a clear strategic direction - "Eyes High" - to become one of Canada's top five research universities by 2016, grounded in innovative learning and teaching and fully integrated with the community of Calgary. For more information, visit ucalgary.ca.
About the Hotchkiss Brain Institute
The Hotchkiss Brain Institute at the University of Calgary brings together over 100 clinician-scientists, researchers, and physicians who are dedicated to advancing neurological and mental health research and education. The research priorities of the Hotchkiss Brain Institute balance translational and foundational research in the areas of: stroke and vascular dementia through the study of the cerebral circulation; multiple sclerosis and spinal cord and nerve injury through the study of axon biology and regeneration; depression and psychosis through the study of neural systems and behaviour. More information on the Hotchkiss Brain Institute can be found at www.hbi.ucalgary.ca.
About Alberta Health Services
Alberta Health Services is the provincial health authority responsible for planning and delivering health supports and services for more than 3.8 million adults and children living in Alberta. Its mission is to provide a patient-focused, quality health system that is accessible and sustainable for all Albertans.
Krembil Neuroscience Centre
Toronto Western Hospital
Dr. Michael Tymianski holds a Tier 1 Canada Research Chair in Translational Stroke Research. He is a neurosurgeon at Toronto Western Hospital, the Medical Director of the Neurovascular Therapeutics Program and Head of the Division of Neurosurgery at the University Health Network. He is also a Professor in the Department of Surgery and a member of the Institute of Medical Science at the University of Toronto.
About Krembil Neuroscience Centre
The Krembil Neuroscience Centre (KNC), located at Toronto Western Hospital, is home to one of the largest combined clinical and research neurological facilities in North America. Since opening in 2001, KNC has been recognized as a world leader through its research achievements, education and exemplary patient care. The centre focuses on the advancement, detection and treatment of neurological diseases and specializes in movement disorders, dementias, stroke, spinal cord injury, blinding eye diseases, epilepsy and cancer-related conditions.
For more information please visit www.krembil.com