Study 1 Overview (Menon et al)
Objective: To determine whether a 0.25 mg/kg dose of intravenous tenecteplase is noninferior to intravenous alteplase 0.9 mg/kg for patients with acute ischemic stroke eligible for thrombolytic therapy.
Design: Multicenter, parallel-group, open-label randomized controlled trial.
Setting and participants: The trial was conducted at 22 primary and comprehensive stroke centers across Canada. A primary stroke center was defined as a hospital capable of offering intravenous thrombolysis to patients with acute ischemic stroke, while a comprehensive stroke center was able to offer thrombectomy services in addition. The involved centers also participated in Canadian quality improvement registries (either Quality Improvement and Clinical Research [QuiCR] or Optimizing Patient Treatment in Major Ischemic Stroke with EVT [OPTIMISE]) that track patient outcomes. Patients were eligible for inclusion if they were aged 18 years or older, had a diagnosis of acute ischemic stroke, presented within 4.5 hours of symptom onset, and were eligible for thrombolysis according to Canadian guidelines.
Patients were randomized in a 1:1 fashion to either intravenous tenecteplase (0.25 mg/kg single dose, maximum of 25 mg) or intravenous alteplase (0.9 mg/kg total dose to a maximum of 90 mg, delivered as a bolus followed by a continuous infusion). A total of 1600 patients were enrolled, with 816 randomly assigned to the tenecteplase arm and 784 to the alteplase arm; 1577 patients were included in the intention-to-treat (ITT) analysis (n = 806 tenecteplase; n = 771 alteplase). The median age of enrollees was 74 years, and 52.1% of the ITT population were men.
Main outcome measures: In the ITT population, the primary outcome measure was a modified Rankin score (mRS) of 0 or 1 at 90 to 120 days post treatment. Safety outcomes included symptomatic intracerebral hemorrhage, orolingual angioedema, extracranial bleeding that required blood transfusion (all within 24 hours of thrombolytic administration), and all-cause mortality at 90 days. The noninferiority threshold for intravenous tenecteplase was set as the lower 95% CI of the difference between the tenecteplase and alteplase groups in the proportion of patients who met the primary outcome exceeding –5%.
Main results: The primary outcome of mRS of either 0 or 1 at 90 to 120 days of treatment occurred in 296 (36.9%) of the 802 patients assigned to tenecteplase and 266 (34.8%) of the 765 patients assigned to alteplase (unadjusted risk difference, 2.1%; 95% CI, –2.6 to 6.9). The prespecified noninferiority threshold was met. There were no significant differences between the groups in rates of intracerebral hemorrhage at 24 hours or 90-day all-cause mortality.
Conclusion: Intravenous tenecteplase is a reasonable alternative to alteplase for patients eligible for thrombolytic therapy.
Study 2 Overview (Wang et al)
Objective: To determine whether tenecteplase (dose 0.25 mg/kg) is noninferior to alteplase in patients with acute ischemic stroke who are within 4.5 hours of symptom onset and eligible for thrombolytic therapy but either refused or were ineligible for endovascular thrombectomy.
Design: Multicenter, prospective, open-label, randomized, controlled noninferiority trial.
Setting and participants: This trial was conducted at 53 centers across China and included patients 18 years of age or older who were within 4.5 hours of symptom onset and were thrombolytic eligible, had a mRS ≤ 1 at enrollment, and had a National Institutes of Health Stroke Scale score between 5 and 25. Eligible participants were randomized 1:1 to either tenecteplase 0.25 mg/kg (maximum dose 25 mg) or alteplase 0.9 mg/kg (maximum dose 90 mg, administered as a bolus followed by infusion). During the enrollment period (June 12, 2021, to May 29, 2022), a total of 1430 participants were enrolled, and, of those, 716 were randomly assigned to tenecteplase and 714 to alteplase. Six patients assigned to tenecteplase and 7 assigned to alteplase did not receive drugs. At 90 days, 5 in the tenecteplase group and 11 in the alteplase group were lost to follow up.
Main outcome measures: The primary efficacy outcome was a mRS of 0 or 1 at 90 days. The primary safety outcome was intracranial hemorrhage within 36 hours. Safety outcomes included parenchymal hematoma 2, as defined by the European Cooperative Acute Stroke Study III; any intracranial or significant hemorrhage, as defined by the Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries criteria; and death from all causes at 90 days. Noninferiority for tenecteplase would be declared if the lower 97.5% 1-sided CI for the relative risk (RR) for the primary outcome did not cross 0.937.
Main results: In the modified ITT population, the primary outcome occurred in 439 (62%) of the tenecteplase group and 405 (68%) of the alteplase group (RR, 1.07; 95% CI, 0.98-1.16). This met the prespecified margin for noninferiority. Intracranial hemorrhage within 36 hours was experienced by 15 (2%) patients in the tenecteplase group and 13 (2%) in the alteplase group (RR, 1.18; 95% CI, 0.56-2.50). Death at 90 days occurred in 46 (7%) patients in the tenecteplase group and 35 (5%) in the alteplase group (RR, 1.31; 95% CI, 0.86-2.01).
Conclusion: Tenecteplase was noninferior to alteplase in patients with acute ischemic stroke who met criteria for thrombolysis and either refused or were ineligible for endovascular thrombectomy.