The purpose of this study is to assess the efficacy of AX200 (filgrastim) in the treatment of acute ischemic stroke and to assess the safety and tolerability of AX200.

Major Inclusion Criteria:

• diagnosis of acute ischemic stroke with an onset within 9 hours prior to start of study agent administration
• ischemic stroke in the MCA territory confirmed by MRI (diffusion)
• age ≥18 years and ≤85 years
• lesion size on DWI ≥15 ccm
• written informed consent

Major Exclusion Criteria:

• prior to current stroke: inability to walk or to lead an independent life
• life expectancy less or equal 6 months
• stupor or coma
• lacunar infarct
• any evidence of ICH
• malignant hypertension
• presence of history of active malignancies
• platelet count <100/nl at randomization
• leukocyte count >20/nl at randomization
• congenital neutropenia
• pregnant or lactating women