A Canadian effort to develop a drug to limit the brain damage caused by strokes has made an important step forward.
Scientists involved in the project reported this week that in a trial conducted on patients undergoing repair of brain aneurysms, the drug, called NA-1, reduced the number of post-procedure strokes by about half.
This is rare good news in the quest to develop a neuro-protective drug, a field where over 1,000 compounds have been tested, and all failed.
The researchers themselves have founded a biotechnology company - NoNO Inc. - to finance the work, because the pharmaceutical industry has essentially left the field. NoNO means "no nitric oxide," the free radical produced during a stroke that damages brain tissues.
"Stroke has been such a wasteland for them that no one's willing to invest," said Dr. Michael Hill, a stroke neurologist with the University of Calgary's Hotchkiss Brain Institute.
Hill is first author on the scientific paper outlining the findings, published in the journal Lancet Neurology. The paper reports the results of a Phase II trial, but Phase II trials are small; this one only included 185 subjects. To persuade Health sa国际传媒 or the drug regulators of other countries that this drug should be brought to market, a larger, Phase III trial will have to be conducted.
That's already in the planning stages, said Dr. Michael Tymianski, a neurosurgeon at Toronto Western Hospital and president of NoNO Inc. Tymianski was the senior author on this study.
In the study, people who had to undergo surgery to repair a brain aneurysm were randomly assigned to get NA-1 or a shot of salt water. Subjects got the injection at the end of their surgery. Timeliness is a problem in stroke care. There is an existing treatment regime - clot-busting drugs - but they can only be given after it's been determined that a stroke is an ischemic one (caused by a clot) and not the result of a bleed in the brain.
Clot busters must be given within 4.5 hours of a stroke to have any effect. But few people make it to the hospital and through the testing needed to determine the cause of the stroke in time to benefit.
Hill said about 90 per cent of people who undergo brain-aneurysm repair will experience small strokes caused by blood clots in the hours after the procedure.
People who got NA-1 had about half as many small strokes as those who got the saline shot. And in cases where the surgery was done to repair a brain aneurysm that had already burst, people who got the drug did substantially better than those who did not.
Hill said the next level of testing will look at whether people who receive the drug retain more function and sustain less memory loss.
