Leukemia pill may improve stroke treatment: study

By Julie Steenhuysen

CHICAGO (Reuters) - A highly effective leukemia pill may reduce complications and boost the effectiveness of a treatment for the most common type of stroke, an international team of researchers said on Sunday.

Studies in mice showed giving Gleevec or imatinib, a drug made by Novartis AG, significantly reduced bleeding in the brain associated with the clot-busting drug known as tissue plasminogen activator or tPA.

It also appeared to extend the time window in which the drug could be given, they said.

"You potentially could reduce the amount of side effects associated with tPA and increase the population that could receive it," said Daniel Lawrence of the University of Michigan Medical School, whose findings appear in the journal Nature Medicine.

Lawrence worked with researchers from the Karolinska Institutet in Stockholm, Sweden, which plan to start testing the drug combination in humans in the next few months.

The clot-buster tPA is used to dissolve blood clots in ischemic stroke, a type of stroke triggered when a blood clot impedes blood flow to the brain. These strokes account for 80 percent of the 15 million strokes that occur each year worldwide, according to the World Health Organization.

When given within the first three hours of a stroke, tPA can chew up the clot and significantly reduce death and disability. But tPA has two major drawbacks: it can cause blood to leak into the brain and it must be used within three hours after the start of the stroke.

And because the drug causes bleeding, it can not be used in a more rare type of stroke known an intracerebral hemorrhage, which is caused when a blood vessel in the head ruptures.