Intravenous rhTNK-tPA Before Stroke Thrombectomy in the Extended Time Window

This randomized, double-blind, placebo-controlled phase III clinical trial aims to evaluate the efficacy and safety of intravenous recombinant human tenecteplase (rhTNK-tPA) 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 rhTNK-tPA enhances pre-thrombectomy reperfusion rates and improves 90-day functional outcomes compared to placebo; 2) Whether rhTNK-tPA increases the risk of symptomatic intracranial hemorrhage and mortality. Participants will be randomized to receive either a single bolus of rhTNK-tPA (0.25 mg/kg, max 25 mg) or matching placebo administered intravenously over 5 seconds. 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.