This study will examine if DP-b99 can improve neurological function (for example strength and coordination) in the 3 months after an acute stroke

The study will include a Screening/Baseline Period, a Treatment Period, and a Post-treatment Follow-up Period. During the Screening Period, subjects will be selected for the study on the basis of inclusion and exclusion criteria (see below). A screening computed tomography scan to exclude brain bleeding will be performed. The patient's informed consent will be obtained. The patient will be randomly allocated to DP-b99 or placebo. Immediately after this randomization and baseline assessments (lab tests and ECG), subjects will be given a 2-hour intra-venous infusion of DP-b99 or placebo. Additional 3 such infusions will then be given daily to a total of 4 consecutive treatment days, which make up the "Treatment Period". Throughout the 4-day Treatment Period the treatment's safety and the National Institutes of Health Stroke Scale (NIHSS) score will be evaluated daily. (The NIHSS assesses certain abilities of the patient, e.g. strength, speech, vision and coordination). If their condition requires, patients may have to stay in hospital more than these 4 days, regardless of their participation in the study.Subjects will be further assessed for NIHSS score changes and safety (lab tests and ECG) during the Post-treatment Follow-up Period, with data collected 30 and 90 days after the stroke. Other outcome scales (Barthel Index and Modified Rankin Scale) will be also used in the Day 30 and Day 90 visits

Patients that may enter the study:

• Patients with ischemic stroke, (that is, stroke that results from a blockage of blood flow to part of the brain), which is accompanied by language dysfunction (e.g. inability to understand speech), visual field defect or inattention to one side of the body or the space around the patient.
• Patients in whom the study treatment can start no less than 1 and not more than 9 hours after the stroke's onset
• Patients with moderate-severe degree of neurological deficit in the 9 hours after stroke onset (defined as NIHSS score of 7 to 20
• Patients that can understand the requirements of the study and are willing to provide written informed consent (If the subject is incapacitated, informed consent will be sought from a legally acceptable representative.)

Patients that cannot participate:

• Patients with a brain (intracerebral or subarachnoid) hemorrhage per screening computed tomography scan candidates for thrombolytic therapy for the current stroke patients having a mental impairment that renders them incapable to understand the study's requirements patients with other diseases that in the investigator's opinion may lead, independently of the current stroke, to further deterioration in the subject's neurological status during the trial period, or may confuse the evaluation of the present stroke
• Patients likely to undergo a procedure involving cardiopulmonary bypass during the study period
• Patients with medical conditions that may not enable them to complete the study (e.g life-threatening diseases,)
• Patients whose condition improves already during the screening period
• Patients who already have functional limitations before the present study (retrospective Modified Rankin Scale score of >3)
• Patients who suffered a stroke within the past 90 days that seems to have been in the same brain region as the current acute stroke
• Patients with severe hypertension (systolic BP >210 mm Hg or diastolic BP >120 mm Hg) or hypotension (systolic BP <90 mm Hg), Patients with significant history of renal or liver disease(s) (serum creatinine of > 2.0 mg/dL; alanine aminotransferase, aspartate aminotransferase, or gamma-glutamyl transferase values of > threefold the upper normal limit)
• Patients with a platelet count of <100,000/mm3
• Female patients of childbearing potential who are not using adequate and effective birth control measures or who are pregnant or lactating (the screening evaluation of female subjects of childbearing potential will include a serum pregnancy test.)
• Patients who are users of addictive agents, or alcoholics
• Patients who have received an investigational drug within the 90 days before the present stroke or such that are past recipients of DP-b99