A Phase II/III Clinical Study of SIM0811 in the Treatment of Acute Ischemic Stroke

Inclusion Criteria:

1. Age ≥ 18 years.
2. Time from last known well: 4.5 to 24 hours.
3. Acute ischemic stroke in a supratentorial territory, with corresponding clinical manifestations, and symptomatic high-grade stenosis or complete occlusion of the culprit vessel, involving the middle cerebral artery (MCA) M1, M2, or distal branches, the anterior cerebral artery (ACA), or the posterior cerebral artery (PCA).
4. NIHSS score of 6-25 for the current stroke.
5. Pre-stroke mRS ≤ 1.
6. Female participants of childbearing potential and male participants whose partners are of childbearing potential must agree to use a highly effective contraceptive method from the time of informed consent signature until 6 months after the last dose of investigational product, and to refrain from donating sperm/ova.
7. A written informed consent form approved by the Ethics Review Committee/Institutional Review Board (IRB), voluntarily signed by the patient or their legally authorized representative

Exclusion Criteria:

1. Planned to undergo endovascular treatment or planned to receive thrombolytic drug therapy
2. NIHSS consciousness score 1a > 2
3. .Head, neck, or aortic dissection
4. History of intracranial hemorrhage
5. Ischemic stroke, severe traumatic brain injury, or intracranial/spinal surgery within 3 months; internal bleeding within 3 weeks; major surgical operation or trauma within 2 weeks; arterial puncture at a non-compressible site within the past week; active internal bleeding
6. Uncontrolled hypertension (systolic blood pressure ≥ 180 mmHg or diastolic blood pressure ≥ 100 mmHg)
7. Known bleeding tendency (hereditary or acquired) or any severe coagulation disorder. Specifically: platelet count < 100,000/μL, international normalized ratio (INR) > 1.7, aPTT > 40 seconds, or prothrombin time > 15 seconds
8. Therapeutic-dose heparin or low molecular weight heparin within 24 hours
9. Use of oral anticoagulants within 48 hours, including vitamin K antagonists, thrombin inhibitors, or factor Xa inhibitors, or other investigational anticoagulant drugs
10. Use of platelet glycoprotein IIb/IIIa receptor inhibitors within 48 hours
11. Uncorrected blood glucose level > 22.22 mmol/L or < 2.78 mmol/L during screening (participants whose blood glucose level is subsequently corrected may be considered for enrollment upon investigator assessment)
12. Severe neurological or psychiatric disorders that affect study follow-up or neurological function assessment
13. Clinically significant severe renal impairment, or estimated glomerular filtration rate (eGFR) < 30 mL/min/1.73 m²
14. Severe hepatic impairment, such as aspartate aminotransferase (AST) and/or alanine aminotransferase (ALT) and/or total bilirubin (TBIL) ≥ 2 × ULN, or known pre-existing congenital disorder of bilirubin metabolism
15. Within 3 months: acute ST-elevation myocardial infarction (MI), and/or acute decompensated heart failure, and/or QTc > 520 ms, and/or hospitalization due to acute coronary syndrome, MI, or cardiac arrest, or non-elective coronary intervention; or New York Heart Association (NYHA) heart failure Class III/IV; or known ventricular tachycardia
16. History of hemolytic anemia of any cause, currently under treatment or not meeting the criteria for cure
17. Known allergy or intolerance to SIM0811 or its formulation excipients, or to aspirin
18. Women who are pregnant or breastfeeding, or women with a positive pregnancy test
19. Participation in other drug or device clinical studies within 3 months prior to screening
20. End-stage disease with expected survival of less than 1 year
21. Any other condition that, in the opinion of the investigator, makes the subject unsuitable for participation in this trial