Medium Vessel Occlusion

Study purpose: A multicenter, prospective, randomized, open-label, blinded-endpoint (PROBE) phase III trial is planned to evaluate the efficacy and safety of intra-arterial thrombolysis (IAT) in patients with acute ischemic stroke caused by medium vessel occlusion (MeVO), compared with best medical management alone. Eligible participants (aged 18-80 years, baseline NIHSS score 6-25 or 3-5 with disabling deficits, confirmed MeVO within 24 hours of symptom onset) will be randomly assigned 1:1 to the intra-arterial thrombolysis plus best medical management group or the best medical management alone group. Primary endpoint: proportion of patients with favorable functional outcome (modified Rankin Scale score 0-2) at 90±7 days post-randomization. Secondary endpoints: 1. Recanalization rate (meTICI ≥ 2b) at 24±12 hours post-randomization; 2. Early neurological improvement (NIHSS score change from baseline) at 7±1 days or discharge; 3. Overall distribution of mRS scores at 90±7 days (shift analysis); 4. Excellent functional outcome (mRS score 0-1) at 90±7 days; 5. Health-related quality of life (EQ-5D-5L) at 90±7 days; 6. Functional independence (Barthel Index score 95-100) at 90±7 days; 7. Symptomatic intracranial hemorrhage (sICH) per Heidelberg criteria within 48 hours; 8. Early neurological deterioration (NIHSS increase ≥ 4 points or any single item increase ≥ 2 points) within 7 days; 9. Any intracranial hemorrhage within 48 hours; 10. Procedure-related complications; 11. All-cause mortality within 90±7 days.

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).

Acute ischemic stroke (AIS) due to medium vessel occlusion (MeVO) or severe stenosis poses a significant clinical challenge. Recent large randomized controlled trials, DISTAL and ESCAPE-MeVO, demonstrated no significant benefit of endovascular therapy in patients with MeVO. Although intra-arterial thrombolysis has shown promise in clinical experience, robust evidence supporting its efficacy in MeVO or severe stenosis-related AIS is still absent. To fill this gap, the RESCUE MeVO trial has been designed as a multicenter, prospective, randomized, open-label, blinded end-point (PROBE) study to evaluate the efficacy and safety of intra-arterial thrombolysis in patients with AIS caused by MeVO or severe stenosis.

Medium vessel occlusion (MeVO) accounts for 20-45% of acute ischemic stroke (AIS). Although patients with MeVO often present with relatively low NIHSS scores, up to one-third remain functionally dependent at follow-up despite receiving standard medical therapy, including intravenous thrombolysis. Recent randomized trials (DISTAL, ESCAPE-MeVO, DISCOUNT) have not demonstrated clinical benefit of endovascular treatment (EVT) for MeVO and have suggested higher risks of symptomatic intracranial hemorrhage and mortality, underscoring the need for safer and more targeted reperfusion strategies. Intra-arterial thrombolysis (IAT) enables localized, high-concentration thrombolytic delivery with minimal mechanical manipulation, which may be advantageous for medium and distal vessels. Recombinant human TNK tissue-type plasminogen activator (rhTNK-tPA), a genetically engineered third-generation thrombolytic agent, has shown favorable pharmacologic properties and clinical safety in AIS, including in intra-arterial use following EVT. However, prospective evidence supporting its direct therapeutic role in MeVO-related AIS remains lacking. This multicenter, prospective, open-label randomized controlled trial with blinded endpoint assessment is designed to evaluate the efficacy and safety of intra-arterial rhTNK-tPA thrombolysis in improving functional outcome in MeVO within 24 hours of symptom onset.