This is a randomized, double-blind, placebo-controlled, single-dose study investigating the safety and efficacy of NA-1 in patients with subarachnoid hemorrhage (SAH) undergoing endovascular repair of ruptured intracranial aneurysms. Up to 300 male and female patients with SAH undergoing endovascular repair of a ruptured intracranial aneurysm will be dosed with 2.60 mg/kg of NA-1 or placebo as a 10 minute intravenous infusion after completion of the endovascular procedure on Day 1 of the study period. Subjects will undergo interim procedures at Day 2-4, Day 30-45, and end-of-study procedures on Day 90.

Inclusion Criteria:

• 1. A diagnosis of a ruptured brain aneurysm deemed suitable for repair by neuroendovascular techniques involving intraluminal occlusion by detachable platinum coils, or any neuroendovascular technique such as balloon-assisted coiling, stenting, or flowed diversion.

• 2. Patient should be Grade II-IV on the WFNS grading scale for SAH.

• 3. Male or female with a minimum age of 18 years on the day of enrolment.

• 4. Female subjects of childbearing potential: Negative pregnancy test.

• 5. Non-surgically sterile males or males with partners of childbearing potential must be willing to use condoms with spermicide for 3 months after completion of dosing.

• 6. Body weight less than or equal to 180 kg.

• 7. Vital signs on admission:

  • Blood pressure between 80-180 mm Hg systolic/50-100 mm Hg diastolic;
  • Body temperature ≤ 38.5C.

• 8. Informed consent and availability of the subject for the entire study period and willingness of the subject to adhere to protocol requirements.

Exclusion Criteria:

• 1. Prior SAH within 6 months of presentation.
• 2. Dissecting or mycotic brain aneurysm.
• 3. Planned endovascular vessel sacrifice as the primary modality for aneurysm treatment.
• 4. Known history of life-threatening allergic reaction to any medication.
• 5. Chronic renal disease defined as a baseline serum creatinine > 150 µmol/L.
• 6. Women who are pregnant, or have a positive urine or blood (β-hCG) pregnancy test.
• 7. Women who are breastfeeding.
• 8. Any clinically significant psychiatric or psychological disease, which would preclude the patient from completing the protocol.
• 9. Pre-morbid (estimated) modified Rankin scale score of >1.
• 10. Previous major stroke.
• 11. Patients with known HIV infection.
• 12. Participation in a clinical trial with an investigational drug within 30 days preceding this study.
• 13. Previous participation in the ENACT trial (e.g, to treat a prior aneurysm), participation in another trial involving NA-1 or prior receipt of NA-1.
• 14. Any other medical condition that the site investigator deems would put the patient at excessive risk of participation in the study or an expected life expectancy less than 1 year or that would result in inability to collect clinical outcomes at 90 days.