Tenecteplase versus alteplase for large vessel occlusion recanalization (T-FLAVOR): Trial protocol.

Background: Tenecteplase has higher fibrin specificity with a longer half-life and the potential to achieve higher rates of recanalization than alteplase. A critical limitation of tenecteplase is no commercial use in Japan and no experience with its administration to Japanese patients.

Hypothesis: Tenecteplase is superior to alteplase in achieving recanalization on the initial angiogram when administered ≤4.5-hour of stroke onset in patients planned for mechanical thrombectomy (MT) in Japan where alteplase at the unique dose of 0.6mg/kg is officially used.

Methods: The Tenecteplase versus alteplase For LArge Vessel Occlusion Recanalization (T-FLAVOR) trial is an investigator-initiated, phase II, multicenter, prospective, randomized, open-label, masked-endpoint, superiority study. Eligibility criteria include acute ischemic stroke with pre-stroke modified Rankin Scale score ≤3 and large vessel occlusion (internal carotid artery, middle cerebral artery, or basilar artery) eligible for intravenous thrombolysis ≤4.5-hour and MT ≤6-hour of stroke onset. After completing the safety confirmation phase involving three patients who received non-masked tenecteplase (0.25 mg/kg), 220 patients will be randomized to two groups (1:1), intravenous alteplase (0.6mg/kg = 110) or tenecteplase (0.25mg/kg, = 110), prior to MT.

Outcomes: In the safety confirmation phase, the primary outcome is symptomatic intracranial hemorrhage (sICH) ≤24-36-hour. In the randomized, comparative phase, the primary efficacy outcome is substantial angiographic reperfusion (mTICI grade 2b/2c/3) or absence of retrievable thrombus on the initial angiogram. The primary safety outcome is sICH ≤24-36-hour and 90-day mortality.

Discussion: T-FLAVOR may help determine if tenecteplase should be recommended as a routine clinical strategy before MT for Japanese stroke patients.

Trial Registration: jRCTs051210055.