NXY-059 given within 6 h of acute ischemic stroke significantly reduced disability measured across the entire mRS at 90 days (in 1699 intent to treat patients: CMH test p=0.038; odds ratio 1.20, p=0.04). NXY-059 was well tolerated with no safety issue identified--mortality, serious and non-serious adverse event rates were each similar between the two groups. Measures of neurological function and of activities of daily living were not significantly improved but showed supportive trends in secondary analyses, suggesting a benefit in all patients, irrespective of factors such as time to treatment, stroke severity or thrombolysis use. There was no interaction between the benefit of NXY-059 on outcome and time to treatment (p=0.92), stroke severity (p=0.72) or use of thrombolysis (p=0.93). When given in combination with rt-PA, NXY-059 reduced the risk of any hemorrhagic transformation from 27.3% to 15.4% (p<0.005 post hoc) and of symptomatic intracranial hemorrhage from 6.4% to 2.5% (p<0.05 post hoc).