NCT05105633

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

Extending the Time Window for Tenecteplase by Effective RecanalizatioN of bAsilar Artery occLusion in Patients With POSTerior Circulation Stroke (POST-ETERNAL)

• Status: Recruiting
• Phase: Phase 2 / Phase 3
• Study type: Interventional
• Enrollment: 688 (estimated)
• Sponsor: University of Melbourne · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

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).

Detailed description

The study is a Multi-Arm Multi-Stage (MAMS), multiregional, multicentre, prospective, randomised, open-label, blinded endpoint (PROBE), controlled seamless phase 2b/3 trial (2 arm with 1:1 randomisation) with adaptive sample size recalculation in patients with stroke due to basilar artery occlusion. Stage 1 will use the surrogate outcome of recanalization without symptomatic intracerebral hemorrhage (sICH) to establish whether proceeding to Stage 2 is warranted. If results in the first n= 202 patients meet success criteria, the trial will seamlessly convert to a phase 3 design using modified Rankin scale 0-1 at 3 months as the primary outcome (minimum n=320 with interim sample size re-estimation at n=240, maximum sample n=688) using the Mehta and Pocock conditional power method. Each regionally-based stratum will be pooled in the final analysis and analysed as a stratification by geographic region. Randomisation of patients within each stratum will be stratified by the investigator's intention to treat with mechanical thrombectomy (or not) and the investigator's intention to treat with alteplase intravenous thrombolysis should the patient be randomised to the control group (or not). Covariate adjusted minimum sufficient balance randomisation will then be applied to control for age, NIHSS and time from onset-to-randomisation (dichotomized as 0-6 hours vs 6-24 hours). The primary objective of the study is to test the hypothesis that the thrombolytic tenecteplase (TNK, 0.25mg/kg) ± mechanical thrombectomy administered within 24 hours after symptoms onset, is superior to current best practice (alteplase, rtPA, 0.9mg/kg or standard care/no lysis ± mechanical thrombectomy) in achieving excellent functional outcome (mRS 0-1) or return to the premorbid modified Rankin Scale at 90 days in patients with acute ischemic stroke due to basilar artery occlusion. Estimated study duration is 5 years. Patients will participate in the trial for 12 months.

Conditions

• Basilar Artery Occlusion

Interventions

Type	Name	Description
DRUG	Tenecteplase	Genetically modified tissue plasminogen activator at a dose of 0.25mg/kg given as an intravenous bolus over 5-10 seconds.
DRUG	Standard Care (which may include intravenous Alteplase)	Patients will receive standard care which may include intravenous alteplase at the standard licensed dose of 0.9 mg/kg up to a maximum of 90mg, 10% as a bolus and the remainder as an infusion over 1 hour.

Timeline

• Start date: 2021-11-29
• Primary completion: 2026-08-01
• Completion: 2026-12-01
• First posted: 2021-11-03
• Last updated: 2023-12-06

Locations

13 sites across 1 country: Australia