Genentech's Activase, also known as tissue plasminogen activator, is approved for use only up to three hours after stroke.

FORBES: Brain Repair

Activase isn't all that effective against occlusive strokes, and risks killing the patient if in fact he is suffering from a hemorrhagic stroke.

FORBES: Repairing The Brain

But Activase isn't very effective against occlusive strokes, and it even risks killing the patient if he in fact suffered a hemorrhagic stroke.

FORBES: Repairing The Brain

For now, treatment of strokes is pretty much limited to Genentech's clot-busting drug, Activase, a tissue plasminogen activator, which is primarily used to treat heart attacks.

FORBES: Repairing The Brain

At least 20 antistroke compounds have entered large human trials in recent years after promising lab results, but only one, Genentech's clot-buster Activase, has made it to the market.

FORBES: Brain Repair

Doctors can break up the clot by using Activase, a drug used by Genentech (nyse: DNA - news - people ), but that drug must be used quickly after the stroke happens.

FORBES: Winning A Battle In The War On Stroke