This study is a Phase 3, randomized, multicentre, blinded, placebo-controlled, parallel group, single-dose design. Subjects harboring an acute ischemic stroke and who are selected for endovascular revascularization in accordance with local institutional practices and who harbor a small established infarct core and with good collateral circulation will be given a single, 2.6 mg/kg intravenous dose of NA-1 or placebo as soon as they are deemed to have met the enrollment criteria and started within 30 minutes of randomization. The randomization will be by stochastic minimization to balance baseline factors.