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

Overview

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.

This multicenter, phase III trial employs a randomized, double-blind, placebo-controlled design to investigate the therapeutic window extension for rhTNK-tPA in large vessel occlusion stroke. Eligible participants are adults with large vessel occlusion confirmed by vascular imaging (CTA/MRA), and salvageable brain tissue demonstrated by perfusion imaging (CTP/MRP) mismatch. Exclusion criteria include contraindications to thrombolysis, and large core infarction (\>70 mL on CTP). Patients will be randomized 1:1 to receive either weight-adjusted rhTNK-tPA (0.25 mg/kg) or placebo. All participants will undergo endovascular thrombectomy. The primary outcome is functional independence (mRS 0-2) at 90 days. Secondary outcomes include substantial reperfusion at initial angiogram, first-pass reperfusion, final infarct volume on day 1.5 MRI/CT, etc. Safety outcomes include symptomatic intracranial hemorrhage per Heidelberg Bleeding Classification criteria within 36 hours, and 90-day mortality. Safety monitoring includes independent adjudication of hemorrhagic events and all-cause mortality. A sample size of 820 participants provides 80% power to detect a 10% absolute difference in functional independence (α=0.05). The trial incorporates centralized blinded outcome assessment and intention-to-treat analysis, with data oversight by an independent clinical events committee and data safety monitoring board.