The goal of this study is to evaluate the safety and efficacy of JX10 versus placebo in participants with Acute Ischemic Stroke (AIS) who present for care within 4.5 to 24 hours.

The main question the study aims to answer are:

1. JX10 improves functional outcomes as measured by the modified Rankin Scale score when compared with placebo following AIS.
2. Risk of symptomatic intracranial hemorrhage of JX10 in participants with AIS.

During Part 1, participants will be randomized to JX 10 (1mg/kg, 3 mg/kg) or placebo. During Part 2, participants will receive JX10 (optimal dose chosen from Part 1) or placebo.

Inclusion Criteria:

1. Age ≥ 18 and ≤ 90 years old.
2. Acute ischemic stroke with compatible clinical presentation and symptomatic high grade or complete occlusion of the intracranial internal carotid, M1, M2 or distal branches of the middle cerebral artery (MCA), anterior cerebral artery (ACA), or posterior cerebral artery (PCA).
3. Radiographic evidence of salvageable tissue.
4. Pre-treatment score of NIHSS ≥ 5.

Exclusion Criteria:

1. Radiographic findings pre-randomization of any of the following:

   1. Large core infarction, or
   2. Occlusion in more than 1 vascular territory, or
   3. Significant mass effect or clinically significant cerebral edema, or
   4. Evidence of acute intracranial or extracranial hemorrhage, intracranial tumor (except small meningioma), neoplasm, or arteriovenous malformation), or
   5. Clinical history, past imaging, or clinical judgement suggests that the intracranial occlusion is chronic.

2. Medical history or active clinically significant bleeding, lesions, or conditions (at the investigator's judgement) considered to be of significant risk for major bleeding.

3. Severe, uncontrolled hypertension (systolic blood pressure ≥ 185 mmHg or diastolic blood pressure ≥ 110 mmHg) that cannot be controlled with antihypertensive therapy.

4. Known bleeding diathesis (hereditary or acquired) or any significant coagulopathy. Specifically, platelet count < 100,000/μL, international normalized ratio > 1.7, aPTT > 40 seconds, or prothrombin time > 15 seconds.

5. Major trauma, surgery, or invasive procedures.

6. Pre-existing medical, neurological, or psychiatric disease that would confound the neurological or functional evaluations of this study.

7. Pre-treatment blood glucose > 400 mg/dL (22.20 mmol/L) or Pre-treatment blood glucose < 50 mg/dL (2.78 mmol/L) unless it is corrected prior to study treatment administration. Participants with subsequently normalized blood glucose levels may be considered for inclusion, per Investigator judgement.