Intravenous Tenecteplase Prior to Endovascular Treatment for Ischemic Stroke at 4.5 to 24 Hours

Importance: Whether intravenous tenecteplase prior to endovascular treatment (EVT) for ischemic stroke reduces disability in the late time window is unclear. Objective: To investigate the adverse events and efficacy of tenecteplase prior to EVT in patients 4.5 to 24 hours after ischemic stroke onset due to proximal middle cerebral artery (MCA) occlusion. Design, Setting, and Participants: Multicenter, phase 3, randomized, open-label, blinded end point, superiority trial conducted at 40 centers in China. Adult (≥18 years) patients with acute ischemic stroke 4.5 to 24 hours after last known to be well due to MCA-M1 or proximal M2 occlusion with salvageable brain tissue (ischemic core volume <70 mL, mismatch ratio ≥1.8, and mismatch volume ≥15 mL) identified on computed tomography-perfusion or magnetic resonance-perfusion-diffusion imaging were enrolled from January 25, 2024, through July 21, 2025, and followed up for 90 days. Final follow-up occurred on October 14, 2025. Interventions: Eligible patients were randomly assigned in a 1:1 ratio to receive intravenous tenecteplase (0.25 mg/kg; maximum dose, 25 mg) before EVT (n = 199) or EVT alone (n = 192). Main Outcomes and Measures: The primary outcome was functional independence, defined as a score of 0 to 2 on the modified Rankin Scale (range, 0-6, with higher scores indicating greater disability) at 90 days. Adverse events outcomes included symptomatic intracranial hemorrhage and death. Results: All of the 391 patients enrolled (median age, 68 years [IQR, 59-75]; 155 [39.6%] females) completed the trial. Functional independence at 90 days occurred in 88 patients (44.2%) in the tenecteplase before EVT group and 83 patients (43.2%) in the EVT alone group (adjusted relative rate, 1.01 [95% CI, 0.83-1.24]; P = .89; risk difference, 0.99% [95% CI, -8.84% to 10.83%]). Mortality within 90 days was 12.7% (25/197) in the tenecteplase before EVT group and 14.2% (27/190) in the EVT alone group. Symptomatic intracranial hemorrhage within 36 hours was 5.1% (10/197) and 2.6% (5/190), respectively. Conclusions and Relevance: In patients presenting to EVT-capable centers 4.5 to 24 hours after stroke onset with proximal MCA occlusion, intravenous tenecteplase before EVT did not improve clinical outcomes vs EVT alone. Trial Registration: ClinicalTrials.gov Identifier: NCT06221371.