AcT Trial: Protocol for a Pragmatic Registry-Linked Randomized Clinical Trial

Intravenous thrombolysis with alteplase is widely used in patients with acute ischemic stroke presenting early after symptom onset. Recent phase II trials have suggested that intravenous tenecteplase may be safer and associated with higher early reperfusion rates as compared with alteplase. This study investigates whether intravenous tenecteplase is noninferior to intravenous alteplase for the treatment of acute ischemic stroke.

This is a pragmatic, registry-linked, prospective, randomized (1:1) controlled, open-label parallel group clinical trial (AcT [Alteplase Compared to Tenecteplase in Patients With Acute Ischemic Stroke]) with blinded end point assessment of 1600 patients to test if intravenous tenecteplase (0.25 mg/kg body weight, maximum dose 25 mg) is noninferior to intravenous alteplase (0.9 mg/kg body weight; maximum dose, 90 mg) in patients with acute ischemic stroke eligible for intravenous thrombolysis in clinical routine. Patients are recruited from comprehensive and primary stroke centers and enrolled using deferral of consent. The proposed sample has at least 90% power with a noninferiority margin of 5%, assuming incidence of the 90-day modified Rankin Scale score of 0 to 1 is 38% in the tenecteplase and 35% in the alteplase groups, and a loss to follow-up rate <5%.

The blinded primary end point is the proportion of subjects achieving a 90-day modified Rankin Scale score of 0 to 1. Key safety outcomes include 24-hour symptomatic intracerebral hemorrhage and 90-day all-cause mortality. All serious adverse events within a 24-hour period will be reported and coded using the Medical Dictionary for Regulatory Activities. Outcomes are collected either centrally (primary, key secondary, and safety end points) or through ongoing Canadian stroke registries. The primary analysis is a simple unadjusted comparison of proportions.

Results from the trial will provide real-world evidence of the effectiveness of intravenous tenecteplase versus alteplase in patients with acute ischemic stroke presenting early after stroke onset.