A Study of the Efficacy and Safety of Alteplase in Participants With Mild Stroke

PRISMS is a double-blind, multicenter, randomized, Phase IIIb study to evaluate the efficacy and safety of intravenous (IV) alteplase in participants with mild acute ischemic strokes that do not appear to be clearly disabling. Participants will be randomized in a 1:1 ratio to receive within 3 hours of last known well time either 1) one dose of IV alteplase and one dose of oral aspirin placebo or 2) one dose of IV alteplase placebo and one dose of oral aspirin 325 milligrams (mg).