The primary purpose of this study is to determine if a single dose of nerinetide can reduce global disability in people who have had a stroke and are selected for endovascular therapy without the use of a tissue plasminogen activator (alteplase, tenecteplase, or equivalent).

This study is a Phase 3, randomized, multicentre, blinded, placebo-controlled, parallel group, single-dose with a single interim analysis. Because AIS (acute ischemic stroke) is a medical emergency, the trial is designed to enable the administration of standard-of-care treatments without delay in order to save the life of the person concerned, restore good health or alleviate suffering.

Participants harboring an acute ischemic stroke who are selected for endovascular revascularization without intravenous or intra-arterial thrombolytic therapy will be given a single, 2.6 mg/kg (up to a maximum dose of 270 mg) intravenous dose of nerinetide or placebo. Outcomes of the main trial will be evaluated throughout a 90 day observation period.

Participants will be followed at 1-Year for the analytic sub-trial for further outcome assessment by telemedicine or telephone interview conducted by individuals blinded to the outcome of the main trial. This sub-trial will be conducted to explore the independent functioning and quality of life at 1-Year.

Inclusion Criteria:

1. Acute ischemic stroke (AIS) selected for emergency endovascular treatment.

2. Age 18 years or greater.

3. Onset (last-known-well) time to randomization time within 12 hours.

4. Disabling stroke defined as a baseline National Institutes of Health Stroke Score (NIHSS):

   1. NIHSS > 5 for internal carotid artery (ICA) and M1-middle cerebral artery (MCA) occlusion; or
   2. NIHSS > 10 for M2-MCA occlusion.

5. Confirmed symptomatic intracranial occlusion at one or more of the following locations: Intracranial carotid I/T/L, M1 or M2 segment MCA. Tandem extracranial carotid and intracranial occlusions are permitted.

6. Pre-stroke (24 hours prior to stroke onset) independent functional status in activities of daily living with modified Barthel Index (BI) ≥ 95. Patient must be living without requiring nursing care.

7. Qualifying imaging performed less than 2 hours prior to randomization.

8. Consent process completed as per national laws and regulation and the applicable ethics committee requirements.

Exclusion Criteria:

1. Treated with a tissue plasminogen activator (e.g., alteplase or tenecteplase) within 24 hours before randomization.
2. Determination by the treating physician, based on current treatment guidelines and medical evidence, that treatment with a plasminogen activator is indicated.
3. Large core of established infarction defined as ASPECTS 0-4.
4. Absent or poor collateral circulation on qualifying imaging (e.g. collateral score of 0 or 1).
5. Any intracranial hemorrhage on the qualifying imaging.
6. Planned use of an endovascular device not having approval or clearance by the relevant regulatory authority.
7. Endovascular thrombectomy procedure is completed as defined by the presence of TICI 2c/3 reperfusion or completion of groin / arterial closure.
8. Clinical history, past imaging or clinical judgment suggesting that the intracranial occlusion is chronic or there is suspected intracranial dissection such that there is a predicted lack of success with endovascular intervention.
9. Estimated or known weight > 120 kg (264 lbs).
10. Pregnancy/Lactation; female, with positive urine or serum beta human chorionic gonadotropin (β-hCG) test, or breastfeeding.
11. Known prior receipt of nerinetide for any reason, including prior enrolment in this ESCAPE-NEXT trial.
12. Severe known renal impairment defined as requiring renal replacement therapy (hemo- or peritoneal dialysis).
13. Severe or fatal comorbid illness that will prevent improvement or follow up.
14. Inability to complete follow-up treatment to Day 90.
15. Participation in another clinical trial investigating a drug, medical device, or a medical procedure in the 30 days preceding trial inclusion.