Intravenous rhPro-UK Before Stroke Thrombectomy in the Extended Time Window (BRIDGE-PUK EXTEND)

This randomized, double-blind, placebo-controlled phase III clinical trial aims to evaluate the efficacy and safety of intravenous recombinant human Prourokinase (rhPro-UK) in acute ischemic stroke patients with large vessel occlusion presenting 4.5-24 hours after last known well. The study will address two primary questions: 1) Whether rhPro-UK enhances pre-thrombectomy reperfusion rates and improves 90-day functional outcomes compared to placebo; 2) Whether rhPro-UK increases the risk of symptomatic intracranial hemorrhage and mortality. Participants will be randomized to receive an intravenous bolus of rhPro-UK or matching placebo, with a total dose of 35mg (15mg administered as an intravenous push within 5 minutes, and the remaining 20mg continuously infused intravenously over 30 minutes). Key assessments include repeat neuroimaging (CT/CTA or MRI/MRA) at 24 hours post-treatment to evaluate reperfusion, NIH Stroke Scale score at day 5-7, and modified Rankin Scale score assessment at 90 days. Safety monitoring will focus on hemorrhagic transformation and mortality events throughout the study period.