A Phase III, prospective, double-blind, randomized, placebo-controlled trial of thrombolysis in imaging-eligible, late-window patients to assess the efficacy and safety of tenecteplase (TIMELESS): Rationale and design.

RATIONALE: While thrombolysis is standard of care for patients with acute ischemic stroke (AIS) within 4.5 h of symptom onset, the benefit of tenecteplase beyond this time window is less certain. AIM: The TIMELESS trial (NCT03785678) aims to determine if treatment with tenecteplase increases the proportion of good clinical outcomes among patients with stroke due to a large vessel occlusion who present beyond 4.5 h after symptom onset. SAMPLE SIZE ESTIMATES: A total of 456 patients will provide ⩾90% power to detect differences in the distribution of modified Rankin Scale scores at Day 90 at the two-sided 0.049 significance level. METHODS AND DESIGN: TIMELESS is a Phase III, double-blind, randomized, placebo-controlled trial of tenecteplase with or without endovascular thrombectomy in patients with AIS and evidence of salvageable tissue via imaging who present within the 4.5- to 24-h time window with an internal carotid artery (ICA) or middle cerebral artery (MCA) (M1/M2) occlusion. STUDY OUTCOMES: The primary efficacy objective of tenecteplase compared with placebo will be evaluated with ordinal modified Rankin Scale scores at Day 90. Safety will be evaluated via incidence of symptomatic intracranial hemorrhage, incidence and severity of adverse events, and mortality rate. DISCUSSION: Results from TIMELESS will contribute to understanding of the safety and efficacy of tenecteplase administered 4.5-24 h following symptom onset for patients with an ICA or MCA occlusion.

Choosing the Correct "-ase" in Acute Ischemic Stroke: Alteplase, Tenecteplase, and Reteplase.

Alteplase is a tissue plasminogen activator approved for treating acute ischemic stroke (AIS), acute myocardial infarction (AMI), and acute massive pulmonary embolism. Two additional tissue plasminogen activators, tenecteplase and reteplase, are also approved for AMI treatment. However, neither tenecteplase nor reteplase is approved for AIS treatment. The U.S. Food and Drug Administration has received reports of accidental administration of tenecteplase or reteplase instead of alteplase in patients with AIS, which can lead to potential overdose. Primary factors contributing to medication errors include use of the abbreviations "TPA," "tPA," or "TNK" in written or verbal orders and use of these agents in similar settings. Steps to reduce the likelihood of accidental substitution include use of full brand or generic names and inclusion of the indication in written and verbal orders, addition of alerts in automated dispensing machines and ordering systems, and use of stroke boxes containing alteplase and materials for administration.

Making a case for the right '-ase' in acute ischemic stroke: alteplase, tenecteplase, and reteplase.

INTRODUCTION: Alteplase, reteplase, and tenecteplase are tissue plasminogen activators (TPA) approved for the management of acute myocardial infarction. Only alteplase is also approved for the treatment of acute ischemic stroke (AIS). The US Food and Drug Administration has received reports of accidental administration of tenecteplase or reteplase instead of alteplase in patients with AIS, which can result in failure to treat patients with the intended agent and lead to potential overdose. AREAS COVERED: This review compares the molecular and clinical features of alteplase, reteplase, and tenecteplase (TNK), identifies factors contributing to medication errors among these agents, and provides steps to reduce medication errors. EXPERT OPINION: Primary factors contributing to medication errors among tissue plasminogen activators include the use of the abbreviations 'TPA,' 'tPA,' or 'TNK' in written or verbal orders and use of these agents in similar settings (e.g. emergency departments and critical care areas). Steps to reduce the likelihood of accidental substitution of tenecteplase or reteplase for alteplase in patients with AIS include the use of full brand or generic names and inclusion of the indication in written and verbal orders, the addition of alerts in automated dispensing machines and ordering systems and use of stroke boxes containing alteplase and materials for administration.