Improving neurological outcome for acute basilar artery occlusion with sufficient recanalization after thrombectomy by intraarterial tenecteplase (INSIST-IT): Rationale and design

Background: The potential benefit of intraarterial tenecteplase in acute basilar artery occlusion (BAO) patients with successful reperfusion following endovascular treatment (EVT) has not been studied. Aims: To explore the efficacy and safety of intraarterial tenecteplase in acute BAO patients with successful reperfusion after EVT. Sample size estimates: A maximum of 228 patients are required to test the superiority hypothesis with 80% power according to a two-side 0.05 level of significance, stratified by center. Design: We will conduct a prospective, randomized, adaptive-enrichment, open-label, blinded-end point, multicenter trial. Eligible BAO patients with successful recanalization after EVT [modified Thrombolysis in Cerebral Infarction (mTICI) 2b-3] will be randomly assigned into the experimental and control group with a 1:1 ratio. Patients in the experimental group will receive intraarterial tenecteplase (0.2-0.3 mg/min for 20-30 min), while patients in the control group will receive routine treatment according to the usual practice of each center. Patients in both groups will receive standard guideline-based medical treatment. Outcome: The primary efficacy endpoint is a favorable functional outcome, defined as the modified Rankin Scale 0-3 at 90 days after randomization. The primary safety endpoint is symptomatic intracerebral hemorrhage, defined as National Institutes of Health Stroke Scale score increase > 4 caused by intracranial hemorrhage within 48 h after randomization. Subgroup analysis of the primary outcome will be performed by age, gender, baseline NIHSS score, baseline pc-ASPECTS, intravenous thrombolysis, time from estimated symptom onset to treatment, mTICI, blood glucose, and stroke etiology. Conclusions: The results of this study will provide evidence of whether adjunct use of intraarterial tenecteplase after successful reperfusion with EVT is associated with better outcomes for acute BAO patients.