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

A Phase II/III, Multicenter, Randomized, Double-Blind, Placebo-Controlled Clinical Trial to Evaluate the Safety and Efficacy of SIM0811 Injection in Patients With Acute Ischemic Stroke

The study will evaluate the efficacy and safety of SIM0811 in participants with acute ischemic stroke who are present within 4.5 to 24 hours since last known well. The main questions it aims to answer are:

1. Does SIM0811 improve overall functional outcome, measured by the ability to perform daily activities independently without help 90 days after treatment?
2. What medical problems do participants have when taking SIM0811? Researchers will compare different doses of SIM0811 to a placebo (a look-alike substance that contains no drug) to see if SIM0811 works to treat acute ischemic stroke.

Participants will:

1. Receive SIM0811 or a placebo .
2. Receive standard medical care for stroke. On the first day, all participants will also take an aspirin pill or an aspirin placebo to keep the treatment assignment a secret.
3. Stay in the hospital for a few days to undergo medical tests, including CT or MRI scans and blood draws.
4. Return to the clinic for follow-up visits for up to 90 days to check their recovery and overall health.

Study Overview

• Status: Not yet recruiting
• Conditions: Acute Ischemic Stroke AIS
• Intervention / Treatment: Drug: SIM0811 Dose Level A (Phase II); Drug: SIM0811 Dose Level B (Phase II); Drug: SIM0811 Dose Level C (Phase II); Drug: Placebo(Phase II); Drug: SIM0811（Phase III）; Drug: Placebo(Phase III)

• Study Type: Interventional
• Enrollment (Estimated): 1092
• Phase: Phase 2; Phase 3

Contacts and Locations

• Study Contact: Name: zhibiao song; Phone Number: 86-13641133681; Email: songzhibiao@simcere.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

6

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: SIM0811 2 Dose Level A (Phase II); Participants receive SIM0811 Dose Level A.	Drug: SIM0811 Dose Level A (Phase II); Participants receive SIM0811 Dose Level A.
Experimental: SIM0811 Dose Level B (Phase II); Participants receive SIM0811 Dose Level B.	Drug: SIM0811 Dose Level B (Phase II); Participants receive SIM0811 Dose Level B.
Experimental: SIM0811Dose Level C (Phase II); Participants receive SIM0811 Dose Level C.	Drug: SIM0811 Dose Level C (Phase II); Participants receive SIM0811 Dose Level C.
Placebo Comparator: Placebo（Phase II）; Participants receive SIM0811 placebo.	Drug: Placebo(Phase II); Participants receive SIM0811 placebo
Experimental: SIM0811(Phase III); Participants receive the selected target dose of SIM0811.	Drug: SIM0811（Phase III）; Participants receive the selected target dose of SIM0811
Placebo Comparator: Placebo (Phase III); Participants receive SIM0811 placebo.	Drug: Placebo(Phase III); Participants receive SIM0811 placebo.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Proportion of patients achieving a modified Rankin Scale (mRS) score of 0-1 at Day 90	Day 90

Secondary Outcome Measures

Outcome Measure	Time Frame
mRS distribution at Day 30 and 90;	Day30 Day 90
Proportions of symptomatic intracranial hemorrhage within 36 h, intracranial hemorrhage, and major extracranial hemorrhage 90-day mortality	Day 0-Day 90
Number of Participants With Any Adverse Event (AE)	Day 0-Day 90
Number of Participants With Treatment-Related Adverse Events (TRAEs)	Day 0-Day 90
Number of Participants With Serious Adverse Events (SAEs)	Day 0-Day 90
Number of Participants With Clinically Significant Abnormal Laboratory Values	Day 0-Day 90
Number of Participants With Clinically Significant Abnormal Vital Signs	Day 0-Day 90
Number of Participants With Clinically Significant Abnormal Physical Examination Findings	Day 0-Day 90

Collaborators and Investigators

• Sponsor: Jiangsu Simcere Pharmaceutical Co., Ltd.
• Investigators: Principal Investigator: yongjun Wang, professor, Beijing Tiantan Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): November 30, 2026
• Primary Completion (Estimated): June 30, 2029
• Study Completion (Estimated): June 30, 2029

Study Registration Dates

• First Submitted: October 23, 2026
• First Submitted That Met QC Criteria: October 23, 2026
• First Posted (Actual): October 29, 2026

Study Record Updates

• Last Update Posted (Actual): November 6, 2026
• Last Update Submitted That Met QC Criteria: November 5, 2026
• Last Verified: November 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Health Care Quality, Access, and Evaluation; Investigative Techniques; Epidemiologic Methods; Health Care Evaluation Mechanisms; Quality of Health Care; Public Health; Environment and Public Health; Epidemiologic Study Characteristics; Clinical Trials as Topic; Clinical Studies as Topic; Clinical Trials, Phase II as Topic
• Other Study ID Numbers: SIM0811-201

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No