Overview

The ANGEL-MeVO-TNK is a multicentered, prospective, randomized, open label, blinded endpoint (PROBE) phase III trial. A total of 488 AIS patients (age ≥18 years) with acute MeVO-AIS (occlusion of the M2/M3, the A1/A2/A3, the P1/P2/P3, and with baseline NIHSS score \>5 or disabling stroke with NIHSS score 3-5 \[such as neurological deficits in motor strength, language, vision, etc\]), will be enrolled. Patients fulfilling all the inclusion criteria and none of the exclusion criteria will be randomized 1:1 into the IA TNK group or the control group after offering informed content.

• The IA TNK group：1) If the patient has not received IVT, IA TNK will be administered as a slow, continuous infusion for super-selective contact thrombolysis in a stepwise manner: an initial dose of 0.0625 mg/kg with a duration of 15 minutes. A repeat angiographic assessment will then be performed; if recanalization is not achieved, an additional dose of 0.0625 mg/kg will be administered over a further 15 minutes (maximum dose 12.5 mg) .

2\) If the patient has received IVT, intra-arterial TNK will be administered as a slow infusion for super-selective contact thrombolysis at a dose of 0.0625 mg/kg (maximum dose 6.25 mg) with a duration of 15 minutes. * The control group will be given standard medical management.

The study consists of four visits including the day of randomization, 48±12 hours after randomization, and 90±7 days after randomization. Demographic information, symptoms and signs, laboratory test, neuro-imaging assessment neurological function rating scale will be recorded during the program.

The primary outcome is the modified Rankin Scale (mRS) score of 0 to 1 at 90±7 days after onset. The primary safety outcome is the incidence of sICH within 48±12 hours after randomization (ECASS III).

Eligibility

Inclusion Criteria:

Clinical Inclusion Criteria:

1. Age ≥18 years;
2. Pre-stroke mRS 0-1;
3. Within 24 h from symptom onset;
4. Baseline National Institutes of Health Stroke Scale (NIHSS) score \>5 or baseline NIHSS 3-5 with disabling deficit (e.g., loss of hand function, aphasia, hemianopia);
5. Informed consent obtained from patients or their legal representatives.

Imaging Inclusion Criteria:

1. Baseline CTA/MRA/DSA diagnosed isolated MeVO, referring to the M2/M3 segment of the MCA, the A1/A2/A3 segment of the ACA, the P1/P2/P3 segment of the PCA;
2. NCCT or MRI DWI imaging showing that the territory of the ischemic infarct volume is less than 50% of the estimated territory supplied by the occluded artery.

Exclusion Criteria:

1. Acute intracranial hemorrhage;
2. ASPECT ≤5;
3. MeVO secondary to spontaneous fragmentation and distal migration of thrombus from an acute large vessel occlusion, or occurring after intravenous thrombolysis (IVT), intra-arterial thrombolysis, or endovascular thrombectomy;
4. Contraindication to TNK;
5. Known severe allergy to contrast agents (excluding mild rash-type allergic reactions);
6. Use of heparin or novel oral anticoagulants within the previous 48 hours with an INR ≥ 1.7;
7. A history of major bleeding within the past 6 months or the presence of conditions such as active gastrointestinal ulcer, aortic dissection, platelet count \< 100 × 10⁹/L, etc.;
8. Radiologically confirmed vascular malformations, arterial dissection, intracranial aneurysm (diameter≥3 mm), tumors (except small meningiomas), cerebral vasculitis, cerebral amyloid angiopathy, or other major non-ischemic intracranial diseases (e.g., multiple sclerosis);
9. Acute renal failure, current dialysis, or estimated glomerular filtration rate (eGFR)\<30ml/min/1.72m2, and/or serum creatinine\>220mmol/L (2.5mg/dl);
10. History of severe liver disease, or aspartate aminotransferase (AST) and/or alanine aminotransferase (ALT) and/or glutamyl transferase (GGT) ≥3×upper limit of normal value (ULN) and/or total bilirubin (TBIL) ≥2×ULN;
11. Severe non-cardiovascular comorbidity with an expected life expectancy of less than 3 months (e.g., malignant tumors);
12. Known pregnancy or breastfeeding, or a positive pregnancy test prior to randomization;
13. Current participation in another drug or device clinical trial;
14. Any other condition deemed by the investigator to make the patient unsuitable for participation in the study or to pose a significant risk to the patient (e.g., inability to understand and/or comply with study procedures and/or follow-up due to psychiatric illness, cognitive impairment, or emotional disorders).