By Emily Ng
New clinical trials led by University of Calgary researchers find promising results in clinical trials using a drug that may reduce brain damage caused by strokes.
The findings state that NA-1, a neuroprotectant drug, will help protect the human brain from damage caused by strokes.
The research, Evaluating Neuroprotection in Aneurysm Coiling Therapy, was led by U of C clinical neuroscience professor Michael Hill and his team at the Hotchkiss Brain Institute at the Foothills Medical Centre.
ALS, epilepsy, strokes and head trauma can cause excitotoxicity, which triggers brain cell death. Neuroprotectant drugs such as NA-1 inhibit excitotoxcity.
There have been thousands of neuroprotectant drugs tested without success in human subjects.
“[Neuroprotectants] have been discovered in labs and tested in cell culture and tested in rats. They have shown a lot of promise, but none have ever been shown to work in people,” said Hill.
NA-1 was developed at the Toronto Western Hospital’s Krembil Neuroscience Centre in the ’90s by researcher Michael Tymianski. Initial testing was performed on primates with positive results.
In order to test the effectiveness of NA-1 in humans, Hill and his collaborators tested patients with procedurally induced strokes as intermediary human models.
Patients suffering from brain aneurysms may receive a procedure called endovascular coiling. This involves inserting a catheter leading up to the patient’s brain to the location of the aneurysm and packing the area with coils to stop blood flow.
Endovascular coiling has minimal side effects. However, roughly 90 per cent of all patients who underwent the procedure have had one or more small strokes, according to MRI scans.
“[These small strokes] may not cause the patient any trouble, but they are there,” said Hill. “So we thought this is a perfect model for us to test NA-1 because it’s a controlled circumstance. We know when the strokes occur during the procedure and we have a way of identifying them with MRI.”
The trials began in 2008 and had 185 participants from 11 Canadian hospitals and three American hospitals. Patients were randomly chosen to be given either placebo or NA-1 intravenously.
Results showed that patients administered NA-1 had a 50 per cent decrease in the number of recurring strokes.
“This is one of the first demonstrations in humans that you can give a drug like NA-1 and reduce damage due to stroke,” said Hill.
Hill said that the next step in developing NA-1 is the administration of the drug to patients suffering from non-procedurally induced strokes.
“The patients we were dealing with are highly selected. They have a very specific type of minor stroke, which is a procedurally induced minor stroke. This is not a major issue clinically,” said Hill. “What matters are the strokes where people are disabled. That is our biggest challenge right now. How do we move this therapy into a situation where we can treat patients who have clinical strokes.”
Hill said there was a major collaborative effort across Canada to complete the trials with several participating hospitals and research centres.
“It really was a collaboration across the country,” said Hill. “We had a lot of support from a lot of local people to make this happen.”