The result of a pre-planned interim futility analysis

The purpose of this trial is to determine if intravenous administration of the metal ion trapping agent DP-b99 up to 9 hours following acute ischemic stroke onset, and then for 3 additional days (4 consecutive days in total) is effective in improving long term outcome. Patients will be followed up for 3 months after the stroke.

This will be a randomized, double-blind, placebo-controlled, multicenter, multi-national, parallel-arm, pivotal study comparing a placebo group to a DP-b99 group treated with intravenous 1.0 mg/kg/d for 4 consecutive days, in acute ischemic stroke patients with an entry National Institutes of Health Stroke Scale (NIHSS) score of 10-16 and a clinical syndrome that includes at least 1 of the following: language dysfunction, visual field defect or Extinction and Inattention (formerly Neglect) (as reflected by at least 1 point on any of the corresponding items of the NIHSS: 9, 3 or 11). An interim analysis for futility will be performed after Day 90 (or last available observation) primary endpoint data have been collected on about 45% of subjects planned to be enrolled. Clinical trial material (CTM) will be administered within 9 hours after the onset of acute ischemic stroke symptoms. Subjects will be randomized at a ratio of 1:1 to receive either DP-b99 or placebo. A data and safety monitoring board (DSMB) will assess the accumulating safety data periodically and will oversee the interim futility analysis.

Inclusion criteria:

1. M or F age 18 - 85, inclusive

2. Suffered an acute, likely hemispheric, ischemic stroke, defined as acute, focal, neurological deficit(s), secondary to a presumed vascular event, which must include at least one of the following components (as reflected by at least 1 point on any of the corresponding items of the NIHSS: 3, 9 or 11):

   • Visual
   • Best Language
   • Extinction and Inattention (formerly Neglect)

3. Suffered the onset of an acute ischemic stroke that can be evaluated and treatment initiated within 9 hours after the onset of acute ischemic stroke symptoms.

4. Screening NIHSS score of 10 to 16, inclusive

5. Readily accessible peripheral venous access for clinical trial material (CTM) administration and blood sampling

6. Ability to understand the requirements of the study and be willing to provide written informed consent as evidenced by signature on an informed consent document approved by an institutional review board or independent ethics committee, and agree to abide by the study restrictions and return for the required assessments.

7. Provided written authorization for use and disclosure of protected health information in accordance with the Health Insurance Portability and Accountability Act in the United States and the Personal Information Protection and Electronic Documents Act in Canada

Exclusion Criteria:

1. An intracerebral or subarachnoid hemorrhage per screening/baseline computerized tomography scan or susceptibility-weighted magnetic resonance imaging

2. A candidate for either:

   1. thrombolytic therapy, or have been treated with thrombolytic therapy for the current stroke
   2. mechanical thromboembolectomy, or have been treated with mechanical thromboembolectomy for the current stroke

3. Delirious, comatose or stuporous or demented, or having a mental impairment that in the investigator's opinion renders the subject incapable to participate in the study

4. Have seizure(s) anytime from stroke onset to screening/baseline NIHSS evaluation

5. Neurological or non-neurological comorbidities that in the investigator's opinion may lead, independent of the current stroke, to further deterioration in the subject's neurological status during the trial period, or may render the study's neurological assessments inconclusive for the purpose of evaluating solely the stroke's effects

6. Likely to undergo a procedure involving cardiopulmonary bypass during the study period

7. Suffered a myocardial infarction in the last 90 days

8. Any medical condition that in the investigator's opinion may threaten the subject's ability to complete the study (e.g., concurrent significant or life-threatening diseases, such as malignancies or end stage organ failure)

9. Rapid spontaneous improvement of neurological signs during screening/baseline assessments

10. Premorbid neurological deficits and functional limitations assessed by a pre-stroke Modified Rankin Scale score of > 1

11. Suffered a stroke within 90 days of the screening/baseline assessments that is either diagnostically confirmed or assumed to be in the same cerebral territory as is the current acute stroke

12. Either severe hypertension or hypotension, as measured by at least 2 consecutive supine measurements taken 10 minutes apart prior to randomization.

13. Significant current renal or hepatic disease(s): a serum creatinine concentration of >2.5 mg/dL; alanine aminotransferase, aspartate aminotransferase, or gamma-glutamyl transferase values that are three times greater than the upper limit of normal.

14. Have a platelet count of <100,000/mm3 or, for patients on oral anticoagulants at study entry, INR of >4

15. Female of childbearing potential who is not willing to use adequate and effective birth control measures for the duration of the trial. Effective birth control measures include hormonal contraception, a barrier method such as a diaphragm, intrauterine device and/or condom with spermicide

16. Positive urine pregnancy test at screening/baseline or be a lactating female

17. Currently dependent on, or abusing, alcohol or one or more of the following: sympathomimetic amines, cannabis, cocaine, hallucinogens, inhalants, opioids, phencyclidine, sedatives and hypnotics

18. Received an investigational drug or product or participated in an investigational drug study within a period of 30 days prior to receiving study medication or have previously participated in a clinical trial involving DP-b99

19. Severe anemia as measured by a hemoglobin value of < 7 g/dl.

20. In a dependent relationship with the physician or the study sponsor.

21. Known hypersensitivity to any component of the investigational product.