Extending the Time Window for Tenecteplase by Recanalization of Basilar Artery Occlusion in Posterior Circulation Stroke

Patients presenting to the emergency department with an acute ischemic stroke due to basilar artery occlusion within 24 hours of stroke onset will be assessed to determine their eligibility for randomization into the trial. If the patient gives informed consent they will be randomised 50:50 using a central computerised allocation process to either standard of care (no intravenous thrombolytic treatment or intravenous alteplase 0.9mg/kg) or tenecteplase 0.25mg/kg before undergoing mechanical thrombectomy as required at treating clinician's discretion. The trial is Multi-arm, Multi-stage, prospective, randomised, open-label, blinded endpoint (PROBE) design with seamless phase 2b/3 transition if the intermediate endpoint (recanalization without symptomatic intracerebral hemorrhage) is met in analysis of the first 202 patients. Adaptive sample size re-estimation (Mehta and Pocock) will be performed when 240 patients have completed 3 month follow-up (minimum sample size 320, maximum sample size 688).