This trial aims to evaluate the effectiveness and safety of Y-3 for injection in the treatment of patients with acute ischemic stroke within 48 hours of onset

A multi-center, randomized, double-blind, parallel, placebo-controlled trial design was adopted, and subjects were randomly assigned to Y-3 for injection group and placebo group in a 1:1 ratio. randomization stratification factors include: onset time (≤12 hours, >12 hours) and research site.

Treatment was continued for 10 days (10 times), and follow-up was conducted until the 90th day from the first dose.

The trial is divided into three phases: screening/baseline phase, treatment phase, and follow-up phase.

Screening/baseline period: After the subjects sign the informed consent form, they enter the screening/baseline period for screening examination.

Treatment period: Qualified subjects are randomly divided into groups in a 1:1 ratio and receive continuous treatment for 10 days (10 times) with Y-3 for injection and placebo respectively. During the treatment period, relevant examinations and evaluations required by the protocol will be carried out; PK blood samples from subjects were collected for population pharmacokinetic analysis.

Follow-up period: Subjects who have completed treatment will enter the follow-up period until the 90th day of treatment.

Inclusion Criteria:

1. Age ≥ 18 years and < 81 years, male or female;
2. After onset of disease, ischemic stroke meeting the following characteristics: 7≤ NIHSS(National Institutes of Stroke score)≤20 , and the sum of the scores of the item 5 upper limb and item 6 lower limb ≥ 2 points. If patients received thrombolytic therapy, they would be screened and assessed by NIHSS score after thrombolysis;
3. Within 48 hours (inclusive) of onset;
4. Patients who were diagnosed as ischemic stroke according to Key Points in Diagnosis of Various Major Cerebrovascular Diseases 2019 in China and recovered well after the first or last onset of disease (mRS score ≤ 1 point before this episode);
5. The patient or his/her legal representative voluntarily signed informed consent form approved by the Ethics Committee.

Exclusion Criteria:

1. Intracranial hemorrhagic disease by cranial imaging: hemorrhagic stroke, epidural hematoma, intracranial hematoma, ventricular hemorrhage, subarachnoid hemorrhage, etc.; if it was only oozing, the investigator could determine whether it was suitable for enrollment;
2. Severe disturbance of consciousness: NIHSS score > 1 on item 1a level of consciousness;
3. Transient ischemic attack (TIA);
4. Systolic blood pressure ≥ 220 mmHg or diastolic blood pressure ≥ 120 mmHg after blood pressure control;
5. Previous diagnosis of severe mental disorders and severe dementia;
6. Previously diagnosed with depression or anxiety;
7. Receiving antidepressant or anxiolytic therapy;
8. Have been diagnosed with severe active liver diseases, such as acute hepatitis, chronic active hepatitis, cirrhosis, etc.; or alanine aminotransferase or aspartate aminotransferase > 2.0 × upper limit of normal;
9. Have been diagnosed with severe active renal disease, renal dysfunction; or serum creatinine > 1.5 × upper limit of normal;
10. After this episode, drugs with brain cell protective effect clarified in the package insert have been applied, such as commercially available edaravone,concentrated solution of edaravone and dextranol for injection, nimodipine, ganglioside, citicoline, piracetam, oxiracetam, butylphenyl peptide, human urinary kininogenase (urinary kallidinogenase), cinepazide, rat nerve growth factor, cerebrolysin (brain protein hydrolysate), deproteinized calf serum injection, deproteinized calf blood extract injection, etc.;
11. Thrombectomy or interventional therapy has been applied or planned after this episode;
12. Previous diagnosis of concurrent malignancy and ongoing anti-tumor therapy;
13. Previous diagnosis of severe systemic disease with expected survival times < 90 days;
14. The patient is pregnant, lactating and the patient/patient's partner may become pregnant and plans to become pregnant during the trial;
15. Previously known hypersensitivity to the product or any of its excipients (15-hydroxystearate polyethylene glycol, propylene glycol, mannitol, potassium dihydrogen phosphate, dipotassium hydrogen phosphate trihydrate);
16. History of major surgery within 4 weeks prior to enrollment that impacts neurological score assessed by the investigator or impacts 90-day survival;
17. Participation in another clinical study within 30 days prior to randomization or ongoing participation in another clinical study;
18. Investigator considered inappropriate for participation in this clinical study.