Drug's ability to reverse acute ischemic stroke

Ischemic stroke patients who arrive at the hospital too late to receive currently available treatment options might someday have a new treatment option. Northwestern Memorial Hospital is the only site in Chicago to participate in a phase III trial of abciximab (ReoPro - Centocor/Eli Lilly and Company), which seeks to determine the drug's ability to improve neurological function and minimize disability in patients who present with an acute ischemic stroke.

"tPA is the only FDA-approved treatment for ischemic stroke within three hours of onset, but most patients can't be treated with it because they arrive in the emergency department more than three hours after their stroke occurred," explains Richard Bernstein, M.D., Ph.D., a stroke neurologist at Northwestern Memorial Hospital and assistant professor of neurology at the Northwestern University's Feinberg School of Medicine. "Preliminary results with abciximab suggest we may be able to use it to extend this time window to six hours and possibly use it to treat the many patients who wake up from sleep with a stroke. Currently, there is no approved acute treatment for these patients and abciximab may represent a new approach."

Abciximab prevents blood platelets from forming clots, and also helps diminish clots that have already formed. Since ischemic stroke results from clots that block arteries supplying blood to the brain, it makes sense to test this agent in stroke. The research study currently underway, called AbESTT-II, is a randomized, double blind, placebo controlled trial of abciximab in acute stroke. It is sponsored by Eli Lilly and Centocor, and seeks to enroll 1,800 participants worldwide.

Unlike other investigational treatments to open blocked arteries in stroke beyond three hours, abciximab can be given into a vein in the arm and requires no additional invasive procedures. "Abciximab has been used for years by cardiologists to help keep diseased coronary arteries open," explains Dr. Bernstein. "If this treatment proves safe and effective in acute stroke, it could be used in any emergency room throughout the country. This could fundamentally change the way we treat this common and devastating disease."

Participants are potentially eligible for this trial if they can receive study drug or placebo within 6 hours of stroke onset, or if they wake up from sleep with a stroke and can receive study drug or placebo within three hours of waking up.

An acute stroke occurs when a blood vessel becomes blocked in the brain. This blockage prevents oxygen and nutrients in the blood from getting to part of the brain, resulting in the death of that part of the brain. Blood clots are formed when cells called platelets bind to each other and to other blood components. Since permanent damage can be done to the brain the longer it does not get blood and oxygen, it is important to restore blood flow as quickly as possible.

Stroke is the third leading cause of death worldwide, resulting in approximately five million deaths every year. It is the leading cause of adult long-term disability. About 85 percent of all strokes are termed ischemic, meaning they are caused by a blood clot or plaque that blocks a blood vessel in the brain.